2026,Volume 55, Issue 12

>ARTICLE

• Influence of Ce Addition on Microstructure and Mechanical Properties of Al-Cu-Mn-Mg Alloy

  Yu Wentao, Zhang Han, Zhang Weixia, Lv Yadong, Yang Haiyan, Xue Yanqing, Hao Qitang

  2026,55(12):2993-3002 DOI: 10.12442/j.issn.1002-185X.20250625

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  Abstract:This study systematically investigated the influence of cerium (Ce) addition on the microstructure and mechanical properties of Al-Cu-Mn-Mg alloys through multi-scale characterization techniques, including OM, SEM, TEM, and XRD. The results reveal that the addition of Ce leads to the formation of two distinct Ce-containing intermetallic compounds. One is the primary Al₂₀Ti₂Ce phase formed during solidification, which induces grain coarsening by consuming the effective grain-refining element Ti in the melt. The other Ce-containing phase is Al₁₆Cu₄Mn₂Ce, which forms through a eutectic reaction at the final stage of the solidification process. Unlike Al₂Cu, this phase is unstable at high temperatures and undergoes transformation into Al₂₄Ce₃Cu₈Mn and Al₂₀Cu₂Mn₃ during heat treatment. Consequently, Cu and Mn from Al₁₆Cu₄Mn₂Ce phase cannot dissolve into the Al matrix, resulting in a reduction in supersaturation degree. Furthermore, the minor addition of Ce retards the phase transformation from θ′′ to θ′ in the Al matrix. Thus, with the identical heat treatment, the primary strengthening phase is θ′′ phase in the Ce-containing alloy, whereas the strengthening phase is θ′ phase in the alloy without Ce addition. These changes in the microstructure and phase composition directly influence the mechanical properties of alloys: with Ce content increasing from 0wt% to 0.3wt%, the ultimate tensile strength and yield strength are decreased by 95.0 and 45.5 MPa, respectively, and the elongation is reduced by about 50%, compared with those counterparts of the alloy without Ce addition.

• Influences of Nb on Impurity C Distribution in Surface and Oxide Film of Zirconium Alloys

  Huang Jiao, Chen Jidan, Yao Meiyi, Fan Lifeng, Ma Wen

  2026,55(12):3003-3010 DOI: 10.12442/j.issn.1002-185X.20250635

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  Abstract:Zr-0.75Sn-0.35Fe-0.15Cr-xNb alloys were investigated, and static autoclave tests were conducted in deionized water at 360 ℃ and 18.6 MPa for 580 d. Secondary ion mass spectrometry was employed to characterize the concentration gradient distribution of carbon from the oxide film surface to the oxide/matrix interface, and X-ray photoelectron spectroscope was used to analyze the valence states of carbon on the substrate surface. The experimental results show that the C concentration in the oxide film on the rolling surface (S_N) of the Zr-0.75Sn-0.35Fe-0.15Cr alloy was significantly higher than that on the surface perpendicular to the transversal direction (S_T). Adding 0.15wt% Nb can considerably decrease the C concentration in the oxide film and reduce the difference in carbon concentration distribution among oxide films on different surfaces. The C/Zr ratio on the S_N surface of the Nb-free alloy increases more obviously with the rise of temperature, suggesting a potential competitive relationship between Nb and Zr in C binding. In conjunction with experimental observations of corrosion anisotropy of the Zr-0.75Sn-0.35Fe-0.15Cr alloy, this study explored the relationship between C and anisotropic corrosion from the perspective of the effects of Nb on impurity C distribution.

• Effect of Hot Rolling on Microstructure and Mechanical Properties of N08120 Ni-Based Superalloy

  Chen Zhixiang, Jia Zhi, Wang Yanjiang, Ren Bin, Zhao Zhixin, Su Peilong

  2026,55(12):3011-3021 DOI: 10.12442/j.issn.1002-185X.20250645

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  Abstract:The microstructure evolution and mechanical properties of the N08120 superalloy rolled at 780 ℃ and deformed through the cumulative reduction of 40%, 60%, and 80% with the single pass reduction of 10% were investigated. The experimental results show that MC and M₂₃C₆ carbides precipitate at grain boundaries and within the grains during deformation. These finely dispersed carbides effectively hinder dislocation motion, thereby enhancing the strength of the material. Dynamic recovery is identified as the predominant softening mechanism during hot rolling, where dislocations progressively reorganize into dislocation cell structures through slip and recombination. Owing to the strong pinning effect of grain boundaries on dislocations and their high interfacial energy, dislocations preferentially accumulate near grain boundaries, inducing localized recrystallization and the formation of fine recrystallized grains. With increasing deformation amount, the alloy texture transitions progressively from Rotated Goss {110}<110> to Rotated Cube {110}<112> and finally to the Copper {112}<111> type. After 40% deformation, work hardening is significant, with the yield strength increasing from 322 MPa to 867 MPa and the microhardness rising from 196 HV_0.5 to 337 HV_0.5. Beyond 40% deformation, both yield strength and microhardness tend to stabilize. This is mainly attributed to the evolution of carbides, dislocation density, substructure, and recrystallization in N08120 superalloy during hot rolling.

• Achieving High-Quality Al/Cu T-Lap FSW Joints Using Pre-set Wires and an Eccentric Progressive Pin

  Liu Shixi, Chen Furong, Ru Lili, Cao Silong

  2026,55(12):3022-3036 DOI: 10.12442/j.issn.1002-185X.20260048

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  Abstract:In Al/Cu friction stir welding (FSW) T-lap joints, the hook-shaped structure present in the nugget zone (NZ) serves as a crack initiation site, which severely compromises the performance of the joints. In this study, FSW of 6061 aluminum alloy and pure copper in a T-lap configuration was performed employing an eccentric progressive pin. Two types of welding wires with different chemical composition were pre-set at the corner die, and the applicability of three tools for T-lap joints was examined. The research was intended to improve the bonding quality between the hook-shaped structure and the base material to obtain high-quality welded joints. Two optimal welding tools were selected. The influences of these tools on the grain morphology at the Al/Cu interface and the morphology of intermetallic compounds (IMCs) were analyzed, and the mechanical properties of the joints along the skin and stringer directions were evaluated. The results reveal that the tool with a small eccentric pin reduces the thickness of the interfacial IMC layer, simultaneously thinning the tip of the Cu hook and enlarging the volume of the NZ, and achieving metallurgical bonding between the periphery of the Cu hook and the matrix, thus improving the welding quality. For the M800Al welding tool equipped with a small eccentric pin and three cutting surfaces, its periodic shearing action facilitates the formation of a vortex-like interlocking interface. Meanwhile, more fragments scraped from the Cu hook are distributed throughout the NZ. This phenomenon not only refines the grain structure but also promotes discontinuous dynamic recrystallization and geometric dynamic recrystallization. The ultimate tensile strength of the M800Al joint along the stringer direction reaches 176 MPa, marking a 23.9% increment compared with that of the joint produced using a non-eccentric tool. This work provides a feasible solution for improving the performance of FSW T-lap joints of dissimilar metals.

• Synergistic Enhancement of Corrosion Resistance and Electrical Conductivity of TaTiN Coating for Ti Bipolar Plates

  Gu Guosong, Lv Yuanjiang, Gao Jianping, Sun Wenqian, Luo Qiaomei, Tan Zhiying, Chang Gengrong, Liu Mingxia, Meng Yu, Bao Hongwei, Ma Fei

  2026,55(12):3037-3052 DOI: 10.12442/j.issn.1002-185X.20260059

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  Abstract:Coatings with strong corrosion resistance and high electrical conductivity on bipolar plates are urgently required for large-scale applications of proton exchange membrane water electrolysis (PEMWE). High-performance TaTiN coatings were fabricated via magnetron sputtering. Results show that TaTiN coatings with preferred (111) planes and refined grains show higher corrosion resistance and better electrical conductivity. On the one hand, the closely-packed (111) plane favors a dense texture; moreover, grain refinement can smooth the surface and facilitate the formation of a continuous, compact passive layer, thereby improving corrosion resistance. On the other hand, the small lattice mismatch between TaTiN (111) and Ti (0001) enhances interfacial bonding and thus electrical conductivity across the interface, resulting in lower interfacial contact resistance (ICR). The optimized TaTiN coating shows a low corrosion current density of 6.56×10^-7 A·cm^-2 and an ICR of 9.11 mΩ·cm², indicating the strong potential of TaTiN coatings to protect metallic bipolar plates in PEMWE systems.

• Effect of Scratching Speed on Nano-scratched Performance of γ-TiAl Alloy Under Water Lubrication

  Zhou Baocheng, Huang Qianqian, Liu Shiwei, Cao Hui, Rui Zhiyuan, Feng Ruicheng

  2026,55(12):3053-3066 DOI: 10.12442/j.issn.1002-185X.20250648

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  Abstract:γ-TiAl alloys feature superior high-temperature performance and low-density properties. However, the inherent brittleness of γ-TiAl alloys poses significant challenges to precision machining. As a highly promising machining approach, water lubrication enables temperature reduction and mitigates frictional heat accumulation, tool wear, and crack-associated defects. This work investigated the effects of nano-scratching speed on scratching force, temperature evolution, plastic deformation, and surface quality of single-crystal γ-TiAl alloy under water lubrication. The results show that the coupling effect between scratching speed and water lubrication governs the machinability and surface quality of single-crystal γ-TiAl alloys. An increase in scratching speed substantially elevates scratching force and frictional heat, which further induces local temperature rise and stress concentration. In comparison, a 1-nm-thick water lubrication layer yields minor temperature fluctuation of the substrate and delivers favorable cooling capacity. At a scratching speed of 400 m/s, water lubrication alleviates surface plastic deformation and damage, promotes chip accumulation, and reduces surface roughness. Experimental observations further confirm that scratching speed exerts a pronounced effect on surface quality.

>REVIEW

• Ruthenium-Nickel Atomic Cluster Supported on Carbon Black for Improving Hydrogen Evolution Reaction Electrocatalysis Performance in Acidic Solution

  Zhao Panchao, Li Anjin, Chen Xiangping, Pi Hemu, Zhang Busheng, Lei Chi, Dong Ganggang, Zhang Guojun, Cao Qigao

  2026,55(12):3067-3075 DOI: 10.12442/j.issn.1002-185X.20260039

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  Abstract:Research on high-performance and low-cost hydrogen evolution reaction (HER) catalysts is of great significance for the large-scale development and practical application of hydrogen energy. Using cheaper metals instead of platinum (Pt) to reduce catalyst costs while ensuring HER performance is a current challenge. In this work, we used a facile and controllable method, the spray-drying technique combined with thermal decomposition reduction, to synthesize the catalyst of ruthenium-nickel atomic cluster supported on carbon black (RuNi-ac/C) at a reduction temperature of 300 ℃ in H₂. The results show that as-synthesized RuNi atomic clusters are uniformly distributed on the carbon black, with the particle size distribution ranging from 0.5 nm to 2.5 nm. Electrochemical tests indicate that the HER overpotential of RuNi-ac/C is only 37 mV at a current density of 10 mA·cm^-2 in 0.5 mol/L H₂SO₄ electrolyte. The overpotential is increased by only 2 mV after 4000 cyclic voltammetry cycles in the stability test, demonstrating excellent electrochemical stability. Compared with synthesized Ru/C-300 ℃, Ni/C-400 ℃, and RuNi/C (200, 400, and 500 ℃) catalysts, the RuNi-ac/C has the best HER performance. Furthermore, the RuNi-ac/C has better HRE activity as well as lower cost compared with the commercial Johnson Matthey Pt/C catalyst, providing a new idea for the industrial application of low-cost and high-efficiency HER catalysts.

• Synergistic Enhancement in Strength and Electrical Con-ductivity of Cu-Ti Alloys: Composition Design, Microstructure, and Processing

  Zheng Zheshuai, Xu Guanghua, Jin Yiguang, Li Wei, Zhou Yu, Xie Pan, Zhang Xiaomin, Yue Quanzhao, Gu Yuefeng, Zhao Xinbao, Xia Wanshun

  2026,55(12):3076-3096 DOI: 10.12442/j.issn.1002-185X.20250649

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  Abstract:Cu-Ti alloys, owing to their excellent mechanical strength, have been widely applied in aerospace, electrical engineering, and rail transit. However, issues including relatively low electrical conductivity (EC), Ti element segregation, oxidation, and discontinuous precipitation have constrained the enhancement of their comprehensive performance and engineering applications. This research reviewed recent progress on the evolution of microstructure and performance regulation of Cu-Ti alloys, with a focus on the analysis of the formation mechanism of precipitates and their influence on the mechanical properties and EC of the alloys. The composition design strategies, advanced preparation technologies, and thermo-mechanical treatment were also summarized. On this basis, it is proposed that constructing a heterogeneous structure with multiscale and multiphase strengthening is a feasible technical path to further improve the yield strength, ultimate tensile strength, and EC of Cu-Ti alloys through improvements in composition design, hot treatment process, and microstructure control. This work is expected to develop copper alloys with good processability, high strength, and high EC to meet the rapid development of high-end manufacturing fields such as electrical engineering and aerospace.

>Materials Science

• Crack Propagation Performance of FGH4113A Powder Metallurgy Superalloy

  Zhang Gaoxiang, Long Anping, Yin Chao, Xiong Jiangying, Xiao Lei, Liu Yong

  2026,55(12):3097-3106 DOI: 10.12442/j.issn.1002-185X.20250432

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  Abstract:The crack propagation performance of the independently-developed 3rd-generation powder metallurgy superalloy FGH4113A was studied, including the effects of preparation process, temperature, and frequency on crack propagation performance, and a comparison was made with similar superalloys. The preparation process involved a combination of hot isostatic pressing, hot extrusion, isothermal forging (ITF), and heat treatment. Test temperatures included room temperature, 650 ℃, and 700 ℃, with test frequencies of 0.33 and 20 Hz. The effects of process, temperature, and frequency on the high-temperature crack propagation performance of the alloy were analyzed. The crack propagation performance of similar alloys with grades such as FGH95, FGH96, FGH97, FGH98, ME3, and LSHR was compared. The results show that prior particle boundary (PPB) and coarse primary γ′ phase around the grain boundary are unfavorable factors for the crack growth performance of the alloy, and increasing the grain size is beneficial to reducing the crack propagation rate. Extrusion and forging process can effectively eliminate PPB, thereby enhancing the crack propagation resistance of the alloy. The crack propagation rate at room temperature is much lower than that at 650 and 700 ℃, and the crack propagation rate at test frequency of 0.33 Hz is significantly higher than that at 20 Hz. Increasing the temperature and decreasing the test frequency will increase the crack propagation rate of the alloy. In the stable crack propagation stage, the FGH4113A alloy in ITF state exceeds FGH98, LSHR, and ME3 alloys, and reaches the advanced level of the 3rd-generation powder metallurgy superalloy.

• Effect of Precisely-Controlled Cooling Heat Treatment on High-Temperature Ductility of Powder Metallurgy Superalloy FGH4113A for Turbine Disks

  Cheng Junyi, Zhao Chunling, Liu Zhaofeng, Ma Xiangdong, Xiao Lei, Guo Jianzheng, Feng Ganjiang

  2026,55(12):3107-3116 DOI: 10.12442/j.issn.1002-185X.20250430

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  Abstract:This study investigated the powder metallurgy superalloy FGH4113A, focusing on the design and implementation of precisely controlled cooling during the solid solution state. The effect of cooling path on microstructural evolution and tensile properties at 800 ℃ was examined. The results show that the cooling path significantly affects the strength-ductility synergy. At a conventional continuous cooling rate of 150 ℃/min, the alloy exhibits a yield strength of 920±7 MPa, an ultimate tensile strength of 1079±9 MPa, and an elongation of 13.4%±2.9%. In contrast, a two-stage cooling process (CP2), combining an initial slow cooling (44–75 ℃/min) with a subsequent fast cooling (459–594 ℃/min), enhances the yield strength and ultimate tensile strength to 978±7 and 1112±5 MPa, respectively, while also improving the elongation to 14.6%±1.1%. Further optimization of the process parameters to an initial cooling rate of 48–65 ℃/min followed by a second-stage rate of 275–326 ℃/min (CP3) achieves an elongation of 18.5%±0.8% while maintaining high strength levels (yield strength of 975±10 MPa and ultimate tensile strength of 1108±6 MPa). Microstructural characterization shows that the staged cooling strategy effectively produces grain structures with low orientation spread and low dislocation density by promoting dislocation recovery via slow cooling at high temperature and then freezing the low-defect structures through fast cooling at medium temperature. Furthermore, analysis of γ'' precipitation behavior indicates that the primary cooling rate governs the size of secondary γ'' phase, the secondary cooling rate influences the size of tertiary γ'' phase, and the cooling transition temperature regulates the volume fraction of tertiary γ'' phase. Through this multiscale cooperative distribution of γ'' phases, moderately-sized secondary γ'' phase enhances strain hardening capacity by promoting the Orowan bypassing mechanism, while the finely-dispersed tertiary γ'' phase compensates for the strength loss associated with coarsened secondary γ'' phase through shearing mechanism. This work demonstrates that precisely controlled staged cooling is an effective pathway for synergistically optimizing the strength and ductility of FGH4113A superalloy at 800 ℃ without altering its chemical composition, providing both a theoretical basis and practical guidance for the heat treatment design of this alloy.

• Effect of Bonding Temperature on Interfacial Microstructure and Properties of Zr/Ta Diffusion Bonded Joints

  Zhao Zicheng, Gao Yu, Liu Zhongliang, Hu Xiwen, Li Qianru, Niu Shiyu, Yang Zhenwen, Wang Ying

  2026,55(12):3117-3124 DOI: 10.12442/j.issn.1002-185X.20250471

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  Abstract:Zirconium alloys have garnered significant attention and widespread application in the nuclear industry due to their exceptional corrosion resistance and low thermal neutron absorption cross-section, particularly in dissolver equipment for highly corrosive environments. This study investigated the diffusion bonding interface microstructure between Zr-3 alloy and refractory metal tantalum as well as their mechanical properties. The effect of diffusion bonding temperature on the shear strength of zirconium/tantalum joints was examined. Additionally, the interface structure and fracture surface morphology of the joints were analyzed, and a preliminary study on the corrosion resistance of the joint was conducted. Results show that the typical interface structure of the joint is Zr/α-Zr+β-(Zr,Ta) solid solution/Ta, with the thickness of the diffusion layer increasing gradually as the bonding temperature rises. The shear strength of the joint initially increases and subsequently decreases with rising temperature. Under the bonding conditions of 900 °C-30 min-10 MPa, the joint strength reaches its maximum value of 385 MPa, with the fracture surface exhibiting mixed fracture characteristics. Furthermore, the zirconium/tantalum diffusion bonding joint demonstrates excellent corrosion resistance.

• Effect of Trace Element Zr Addition on Microstructure and Mechanical Properties of K492M Superalloy

  Xu Zhiheng, Yang Guangyu, Yang Yiyan, Cheng Huimin, Jie Wanqi

  2026,55(12):3125-3136 DOI: 10.12442/j.issn.1002-185X.20250437

  Abstract(17) HTML(0) PDF(6.25 M)( 17)

  Abstract:The effect of trace element Zr addition on the microstructure and mechanical properties at room temperature and high temperature of K492M superalloy was investigated. The Zr content in the experimental alloys ranged from 0.006wt% to 0.058wt%. The results show that the addition of element Zr does not change the main phase constitution of the as-cast and heat-treated K492M superalloys. The microstructure of the as-cast K492M superalloy mainly consists of γ matrix phase, γ'' precipitated phase, MC carbides, and (γ+γ'') eutectic phase. After heat treatment, the (γ+γ'') eutectic phase is nearly eliminated, accompanied by the precipitation of M₂₃C₆ carbides. The addition of element Zr significantly refines the grain structure of the as-cast and heat-treated K492M superalloys. When the Zr content is 0.016wt%, both the as-cast and heat-treated superalloys exhibit the most significant grain refinement. With the increase of Zr content from 0.006wt% to 0.058wt%, the MC carbides in both as-cast and heat-treated superalloys tend to be refined, while element Zr addition has a minor effect on the volume fraction and size of γ'' phase. The variation of Zr content has little effect on the tensile properties at room temperature and the tensile strength at high temperature (760 ℃) of the heat-treated superalloy, but significantly influences the ductility at 760 ℃ and stress rupture life at 760 ℃/662 MPa. The superalloy with 0.016wt% Zr content demonstrates the highest high-temperature elongation and the stress rupture life, which are 53.8% and 16.8% higher, respectively, compared to the 0Zr alloy.

• Hot Deformation Behavior of Homogenized GH4975 Superalloy

  Chen Shuo, Zhu Xing, Jiang He, Wan Zhipeng, Wu Han, Wang Tao, Dong Jianxin

  2026,55(12):3137-3144 DOI: 10.12442/j.issn.1002-185X.20250493

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  Abstract:Based on the Gleeble thermal compression simulation tester, the hot deformation behavior of the homogenized GH4975 superalloy was investigated at strain rates of 0.1 and 1 s^–1 with deformation temperature ranging from 1140 ℃ to 1200 ℃. EBSD and SEM were used to observe the microstructure evolution of the homogenized alloy to study the dynamic recrystallization (DRX) mechanism of GH4975 superalloy. The results show that the main DRX mechanism of GH4975 superalloy at low temperature is discontinuous dynamic recrystallization (DDRX) at grain boundaries. As the temperature increases, the mechanism gradually transitions to particle stimulated nucleation, where secondary phase particles promote the nucleation of new grains. This evolution is associated with the morphology and distribution of the precipitates. In the GH4975 superalloy, the γ′ phase promotes DRX. As the deformation temperature increases, the γ′ phase partially dissolves back into the matrix, and the sparsely distributed γ′ phase contributes to a well-developed dynamically recrystallized grain structure. Additionally, the surfaces of the (γ+γ′) eutectic phase can serve as nucleation sites for recrystallization, thereby further promoting DRX.

• Microstructure and Mechanical Properties of Ti6Al4V Alloy Fabricated by Laser Directed Energy Deposition

  Zhou Qingjun, Pan Yu, Kuang Fan, Yue Liansheng, Lu Xin

  2026,55(12):3145-3154 DOI: 10.12442/j.issn.1002-185X.20250495

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  Abstract:Solution-aging treatment is a critical approach for optimizing the microstructure and enhancing the mechanical properties of laser directed energy deposition (LDED)-fabricated Ti6Al4V alloys. The results show that as-deposited Ti6Al4V alloys consist of primary β columnar grains with width ranging from 200 μm to 500 μm. The intragranular features include grain-boundary α phase, Widmanst?tten structure at grain boundaries, and basket-weave microstructure. The ultimate tensile strengths in the directions perpendicular and parallel to the printing direction are 1010 and 996 MPa, with corresponding elongations of 8.1% and 11.2%, respectively. After sub-β-transus solution treatment followed by intermediate-temperature aging, the microstructure consists of discontinuous grain-boundary α phase, short rod-like α phase, and transformed β phase (composed of retained β phase and secondary α phase). Solution treatment above the β-transus causes pronounced grain coarsening and coarse Widmanst?tten structure. The treatment of 850 °C/2 h+500 °C/4 h with air cooling (AC) yields the excellent strength-ductility balance at room temperature. The ultimate tensile strengths perpendicular and parallel to the printing directions reach 1033 and 1007 MPa, respectively, with corresponding elongations of 12.1% and 15.8%. The strength-plasticity synergy originates from the multiscale α/β structure formed by sub-β-transus solution combined with intermediate-temperature aging. Specifically, the grain-boundary α phase transforms from a continuous to a discontinuous/spheroidized morphology, thereby weakening the cracking propagation channels along boundaries. The intragranular α phase is moderately coarsened and evolves from acicular to short-rod morphology, which improves deformation compatibility. Meanwhile, the secondary α phase dispersed within the transformed β phase and the residual β phase jointly promote slip transfer and work hardening.

• High-Temperature Compressive Creep Properties and Mechanisms of Ti-43Al-6Nb-1Mo-1Cr Alloy Reinforced with B₄C

  Yu Hongbao, Geng Xueying, Yang Shengcan, Xiao Shulong, Yu Hongyan, Lin Shengyao, Lu Zhao

  2026,55(12):3155-3167 DOI: 10.12442/j.issn.1002-185X.20260009

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  Abstract:The effect of B₄C addition on the high-temperature compressive creep behavior of a β-solidified γ-TiAl-based alloy under the conditions of 250 MPa/800?850 ℃ and 850 ℃/200?250 MPa was investigated. The results show that the reinforcement of the Ti-43Al-6Nb-1Mo-1Cr alloy with B₄C significantly enhances its high-temperature compressive creep property. This improvement is reflected by a reduction in steady-state creep rate of 38.42% and a decrease in creep strain after 50 h of 46.32%. The steady-state creep rate of alloys as a function of stress and temperature follows the Norton-Bailey power-law model. With the addition of B₄C, the stress exponent increases from 1.96 to 4.16, and the creep activation energy rises from 335.02 kJ/mol to 368.52 kJ/mol. This change indicates a transition in dominant deformation mechanism from grain-boundary sliding to dislocation climb. The remarkable enhancement in compressive creep resistance is attributed to multiple strengthening effects. The precipitated rod-like TiB acts as a hard second phase that strengthens the matrix by hindering dislocation motion and pinning grain boundaries. In synergy with C dissolved in the matrix, it also refines the lamellar clusters. The addition of 0.2at% B₄C notably suppresses dynamic recrystallization, thereby delaying degradation of the lamellar structure and mitigating the softening effect induced by recrystallization. Furthermore, Ti₂AlC and Ti₂Al particles precipitate dynamically during high-temperature compressive creep, pinning at the α₂ phase interfaces and within the B2 phase, respectively. These precipitates strengthen the crystal structure and improve the microstructural stability of the alloy.

• Stress Rupture Properties of a Silicon-Enhanced 9Cr Ferritic/Martensitic Steel

  Yang Ning, Hu Xiaofeng, Zheng Yongfeng, Yang Zhirong, Jiang Haichang, Rong Lijian

  2026,55(12):3168-3179 DOI: 10.12442/j.issn.1002-185X.20250429

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  Abstract:The stress rupture properties at 550 ℃ and the microstructure and hardness of the grip and gauge sections from ruptured specimens of a silicon-enhanced 9Cr ferritic/martensitic steel (denoted as H-Si steel) were investigated by SEM, TEM, EBSD and Vickers hardness tester. A comprehensive investigation was conducted, which included the microstructure evolution of H-Si steel under the coupling effect of temperature and stress and its influence on the creep behavior. The results show that H-Si steel exhibits good stress rupture properties and the stress rupture life is 2252 h under the conditions of 550 ℃ and 167 MPa. The fracture modes under experimental stress conditions are all ductile fracture. The grip section of H-Si steel exhibits relatively stable microstructure under different stresses, with a lath width ranging from 380 nm to 440 nm and the hardness being approximately 230 HV. However, the microstructure of the gauge section undergoes obvious degradation due to the stress, with the rapid decrease in dislocation density and the significant widening of laths. Correspondingly, the hardness drops obviously due to significantly decreasing dislocation strengthening and interface strengthening. The hardness of the 167 MPa@2252 h specimen decreases to 193 HV, which induces a lower high-temperature stress rupture property compared to 9Cr-1Mo-V-Nb martensitic steel (P91).

• Effect of Brazing Temperature on Ni-Based Tungsten-Carbide Coatings Prepared by Vacuum Brazing Using Flexible Metal Cloth as Brazing Filler Metal

  Pu Juan, Li Xinzhu, Long Fei, Shi Xiaohui, Xu Xiangping, Shi Qingqing, Xu Jiuxie

  2026,55(12):3180-3189 DOI: 10.12442/j.issn.1002-185X.20250424

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  Abstract:A flexible Ni-based tungsten-carbide metal cloth, which was prepared by mixing WC powder, NiCrBSi powder and the binder, was coated on the surface of Q235 steel by vacuum brazing. This flexible metal cloth can be arbitrarily cut and folded, enabling the preparation of coatings with controllable thickness on the surfaces of curved and irregularly shaped structural components. The effects of brazing temperature on the microstructure, shear strength, microhardness and wear resistance of the Ni-based WC coatings were explored. The results show that increasing brazing temperature does not change the microstructure composition of the coating. The interface between Ni-based tungsten-carbide coating and steel substrate is mainly composed of Fe solid solution, Ni₃B and Ni₃Si compounds, while the brazing seam zone is mainly composed of Ni solid solution, WC, W₂C, CrB and Cr₇C₃ compounds. With the increase in brazing temperature, the porosity and average pore area of the coatings gradually decrease, while the density gradually increases. Consequently, the microhardness and wear resistance of the coating are enhanced. This is mainly because after the flexible Ni-based tungsten-carbide metal cloth melts, as the brazing temperature increases, the ability of the molten NiCrBSi alloy to encapsulate WC particles and fill the gaps between them is enhanced. This reduces the porosity in the coatings, improves the density, thus endowing the coatings with higher hardness and wear resistance. The bonding strength between Ni-based tungsten-carbide coating and steel substrate increases first and then decreases with the increase in brazing temperature. When the brazing temperature is 1080 ℃, the shear strength of the coating reaches the maximum value of 336.5 MPa. This is because the thickness of the compound layer at coating/substrate interface increases from 4.7 μm to 9.2 μm when the brazing temperature increases to 1080 ℃, and the compound layer with appropriate thickness increases the bonding strength between the coating and the substrate. However, the thickness of the interface compound layer increases to 13.9 μm when the brazing temperature increases to 1140 ℃, and the compound layer with the excessive thickness leads to a decrease in bonding strength of the coating.

• Synergistic Enhancement of AZ91D Magnesium Alloy Surface via Nanocomposite Electrodeposition with Low-Dimensional Materials

  Li Zhi, Duan Huifan, Liu Chongyu, Liu Guangke, Yang Wenqi

  2026,55(12):3190-3203 DOI: 10.12442/j.issn.1002-185X.20250441

  Abstract(21) HTML(0) PDF(6.63 M)( 12)

  Abstract:To enhance the comprehensive performance of magnesium alloy surfaces, Ni-based composite layers added with zero-dimensional material nano-diamond (ND) and one-dimensional material carbon nanotubes (CNTs) were prepared on the surface of AZ91D magnesium alloy by nano-composite electrodeposition technique. The results show that the synergistic effect of the combination of ND and CNTs optimizes the microstructure of the deposited layer and enhances its comprehensive performance. ND, as a heterogeneous nucleation core, promotes the preferred orientation growth of Ni grains along the (111) plane, reduces the surface roughness of Ni-based deposition layers, and enhances their microstructure uniformity and density. The high specific surface area and excellent electrical conductivity of CNTs further optimize the microstructure and properties of the deposited layer. The combination of two carbon-based nanomaterials exhibits an excellent synergistic effect: the grain refinement effect of ND and the electrical conductivity enhancement effect of CNTs complement each other, significantly optimizing the deposited layer in terms of structural density, grain orientation stability, and interfacial bonding strength, further enhancing wear resistance and corrosion resistance. When the addition amounts of ND and CNTs are 12 and 0.15 g/L, respectively, the microstructure of the deposited layer is uniform and dense, the hardness reaches 1212.7 HV, the coefficient of friction decreases to 0.34, the self-corrosion current density decreases to 1.458×10^?7 A·cm^?2 (three orders of magnitude lower than that of the magnesium alloy matrix), and the resistance to Pseudomonas aeruginosa is good. The antibacterial rate is as high as 90%. This study provides a theoretical basis and process reference for the synergistic reinforcement of composite deposition layers on high-performance magnesium alloy surface with low-dimensional materials.

• Effect of Microstructure Characteristics on Impact Toughness of GH4151 Alloy

  Tang Chao, Liu Jie, Luo Junpeng, Zhang Maicang, Xie Xingfei, Qu Jinglong, Zhang Ji

  2026,55(12):3204-3214 DOI: 10.12442/j.issn.1002-185X.20250461

  Abstract(9) HTML(7) PDF(5.18 M)( 16)

  Abstract:The GH4151 alloy samples after different heat treatments were tested using instrumented impact testing, and the effects of microstructural characteristics and grain boundary features on the impact toughness of GH4151 alloy were analyzed through metallographic microscope, scanning electron microscope, transmission electron microscope, and phase diagram calculations. The results show that the percentage of primary γ′ phase decreases with the increase in solid solution temperature, while the average grain size gradually increases and the impact toughness of the solution-treated alloy also gradually increases. The results of phase diagram calculation by JMatPro depict that there is a certain amount of μ phase (a type of TCP phase) at grain boundaries and M₂₃C₆. Analyses of the instrumented impact curves and fracture surfaces reveal that for the alloy subjected to solution treatment only, the elastic deformation work (E_e), plastic deformation work (E_p), and tearing work (E_c) are all relatively large, indicating a good resistance to crack initiation and propagation and a high impact toughness. After solution treatment followed by two-stage aging, both the E_e and E_p become significantly smaller, and the E_c even approaches zero, resulting in a substantial decrease in impact toughness. Compared with the sample subjected to solution treatment only, the significant reduction in impact toughness of sample after two-stage aging is primarily attributed to grain refinement and the synergistic precipitation of grain boundary μ phase and M₂₃C₆ carbides during aging, while showing relatively little correlation with the grain boundary characteristics of the matrix.

• Formation Mechanism of Fluorescent Linear Defects in ZM6 Mg-RE Alloy Castings

  Wang Xiaoming, Song Zhi, Zhang Lunyong, Han Yonghua, Kang Hongyan, Shen Hongxian, Qiu Ziao, Cai Zenghui, Han Chaowei, Zhao Yinhu, Cao Fuyang, Sun Jianfei

  2026,55(12):3215-3221 DOI: 10.12442/j.issn.1002-185X.20250454

  Abstract(10) HTML(10) PDF(2.16 M)( 78)

  Abstract:Rare-earth magnesium alloys, as a new type of high-strength lightweight structural material, have become increasingly widespread in the aerospace industry. However, issues related to casting defects have grown more prominent. Fluorescent linear defects are a typical defect found in this class of alloys. Nevertheless, their formation mechanism remains unclear, and there is a notable lack of precise control methods to mitigate them. This study systematically characterized the composition, morphology, and microstructure of fluorescent linear defects in a sand-cast low-pressure ZM6 (Mg-Nd-Zr) alloy casing component, and revealed the defect evolution mechanism through numerical simulations of the filling flow field. The results show that fluorescent defects are formed by multi-scale and multi-morphology double-layer oxide films. Meanwhile, the oxide film in ZM6 consists of porous MgO as the matrix, containing Nd₂O₃ particles. This film exhibits poor toughness and is prone to fragmentation, resulting in the formation of small-sized oxide inclusions around the oxide film. Combined with the analysis of the casting structure and filling flow field, it is found that the convergence and backflow of the melt during the filling process cause the oxide film on the melt surface to fold and be incorporated, thereby generating double-layer oxide film that can be displayed by fluorescent inspection.

• Tribological Behavior of High-Velocity Oxygen-Fuel-Sprayed NiCrBSi Coatings at Elevated Temperatures

  Du Pengcheng, Yang Rentao, Wu Zhengjiang, Fan Mingzhen, Zhang Yan, Yuan Zhennan, Chen Tongzhou

  2026,55(12):3222-3230 DOI: 10.12442/j.issn.1002-185X.20250615

  Abstract(16) HTML(0) PDF(2.00 M)( 17)

  Abstract:A NiCrBSi coating was fabricated on 304 stainless steel substrate using high-velocity oxygen-fuel (HVOF) spraying. The tribological behavior of the coating was investigated at room temperature (RT), 200 °C, 400 °C, and 600 °C to reveal the effect of elevated temperatures on its wear mechanisms. The effects of temperature on the microstructure and mechanical properties of the coating were analyzed by scanning electron microscope and high-temperature microhardness tester, respectively. The morphology and chemical composition of the wear tracks were characterized using white light interferometer and Raman spectroscope. The results show that the NiCrBSi coating exhibits a distinct crystallization exothermic peak at approximately 505 °C. Above this temperature, the crystallinity and microstructure of the coating are significantly improved. As the temperature increases, both the porosity and microhardness of the coating generally decrease, with a relatively gentle decrease below 505 °C and a sharp drop beyond it. The combined effect of mechanical action between the coating and the counterpart ball and the high-temperature environment induces oxidation during friction, generating oxides such as NiO, Cr₂O₃, and NiCr₂O₄. At temperatures below 505 °C, the high-temperature environment leads to a certain reduction in friction coefficient. With a further increase in temperature, the lubricating effect of the oxides further contributes to the decrease in friction coefficient. Meanwhile, the wear rate of the coating continuously increases with temperature, rising from 2.0×10^-5 mm³/(N·m) at RT to 11.3×10^-5 mm³/(N·m) at 600 °C. At RT, the dominant wear mechanism is fatigue wear. As the temperature increases to 600 °C, the marked decrease in coating microhardness leads to the generation of substantial debris, making abrasive wear the predominant mechanism. In engineering applications, the determination of the amorphous transition temperature of NiCrBSi coatings provides essential data for the design of coating service temperatures and the formulation of heat treatment processes.

• Effect of Material Characteristics and Process Parameters on Quality of 93W-4.9Ni-2.1Fe Alloy Billet Manufactured by Binder Jetting

  Xiao Peng, Yang Kai, Li Tengfei, Zhang Qingxia, Liu Anjin

  2026,55(12):3231-3235 DOI: 10.12442/j.issn.1002-185X.20250425

  Abstract(15) HTML(0) PDF(1.32 M)( 13)

  Abstract:Binder jetting is a potential low-cost near-net-shape forming method for large-scale complex-shaped W-Ni-Fe alloy components. Nonetheless, it faces challenges such as billets cracking during curing and debinding. Developing the manufacturing process for high-strength W-Ni-Fe alloy billets is an inevitable requirement. In this study, a series of 93W-4.9Ni-2.1Fe alloy billets were prepared by binder jetting with variables including powder particle size, binder material, binder saturation, and single-layer printing thickness. The compressive strength of the billets was tested, and the effects of material characteristics and process parameters on the quality of 93W-4.9Ni-2.1Fe billets was analyzed. The results show that the compressive strength of binder-jetted 93W-4.9Ni-2.1Fe alloy billets exhibits a negative correlation with powder particle size and single-layer printing thickness, which improves continuously with the increase in higher binder saturation. By employing a water-based alcohol binder, the 93W-4.9Ni-2.1Fe powders with a D₅₀ particle size of 7.65 μm, a binder saturation of 70%, and a single-layer printing thickness of 60 μm, the binder-jetted 93W-4.9Ni-2.1Fe alloy billets achieve a balance between good strength and dimensional accuracy.

• Research Progress on Cr-Coated Zirconium Alloy Cladding of Accident Tolerant Fuel

  Wang Shun, Li Yifeng, Lin Xiaodong, Li Qiang, Yao Meiyi, Zhou Bangxin

  2026,55(12):3236-3248 DOI: 10.12442/j.issn.1002-185X.20250608

  Abstract(10) HTML(9) PDF(2.15 M)( 14)

  Abstract:Accident tolerant fuel (ATF) can further improve the safety and economics of commercial nuclear reactors. At present, Cr-coated zirconium alloy cladding is the most promising candidate for near-term industrial application as an ATF cladding. This paper provides a comprehensive review of Cr-coated zirconium alloy cladding, covering its development status, preparation processes, microstructural characteristics, and service performance. Initially, the worldwide development of Cr coating is introduced. Subsequently, the main preparation processes of Cr coatings, including cold spraying, laser cladding, and physical vapor deposition, are described, and the characteristics and microstructure of different processes are analyzed. Afterwards, the corrosion, irradiation, and mechanical properties of Cr-coated zirconium alloy cladding are summarized, and the corrosion oxidation mechanism, irradiation damage mechanism, and plastic deformation mechanism are deeply analyzed. Finally, the key challenges in current research are identified, and future development directions are proposed.

• Research Progress on Design, Preparation, and Applications of Platinum-Group Metal High-Entropy Alloys

  Wang Yiqing, Tang Ke, Wen Ming, Zhang Qiubo, Liu Hongxi

  2026,55(12):3249-3259 DOI: 10.12442/j.issn.1002-185X.20250450

  Abstract(17) HTML(0) PDF(2.01 M)( 15)

  Abstract:High-entropy alloys (HEAs) are composed of five or more principal elements in equimolar or near-equimolar ratios, and exhibit distinctive properties including high-entropy effects, lattice distortion, sluggish diffusion, and cocktail effects. Platinum-group metal high-entropy alloys (PGM-HEAs) combine outstanding catalytic activity with superior corrosion resistance, and also exhibit notable functional properties in superconductivity and magnetocaloric refrigeration, which have rendered them a significant branch of HEA research. This review surveys the state of the art in PGM-HEAs, proceeding from compositional design through fabrication techniques to functional applications. In terms of compositional design, the review outlines multi-scale design methods based on phase-diagram calculations, first-principles calculations, and machine learning-assisted screening, with emphasis on the application of machine learning in adsorption energy prediction. For bulk PGM-HEAs, major fabrication techniques including vacuum melting, powder metallurgy, and laser additive manufacturing are summarized, followed by an assessment of research progress concerning mechanical properties, superconductivity, shape memory effect, and magnetocaloric performance. For nanostructured PGM-HEAs, both “top-down” and “bottom-up” synthesis strategies are categorized, and their application and mechanisms in electrocatalytic reactions, including fuel cells and water electrolysis for hydrogen production are discussed in detail. Finally, persistent challenges related to high material cost, scalable production, and compositional homogenization are analyzed, while future research directions including low-PGM alloy design, green synthesis methodologies, and multi-scale computational modeling are discussed.

• Overview of Brazing Technique of Graphite to Metals

  Xu Guoxuan, Chen Biwu, Hong Xianzhi, Chen Hui, Li Yuanxing

  2026,55(12):3260-3277 DOI: 10.12442/j.issn.1002-185X.20250459

  Abstract(12) HTML(5) PDF(4.49 M)( 16)

  Abstract:Graphite is widely used in aerospace, nuclear energy, and electronic heat dissipation due to its many excellent properties, and it plays an increasingly important role in modern industry. Achieving reliable connections among graphite, alloys, and metals is of great significance for achieving complementary performance of heterogeneous materials and expanding application fields. However, there are some urgent problems to be solved in the welding process between graphite and dissimilar materials, mainly including poor wetting of the brazing material, control of formation of brittle phases at interface, and alleviation of interface stress. This study reviews the research progress on brazing of graphite, alloys, and metals, and elaborates on the effects of direct and indirect brazing methods on the joint performance of graphite and metals. It focuses on analyzing the solutions to the problem of poor wetting of graphite using various brazing methods, and finally provides prospects for the connection of dissimilar materials.

• Research Status， Application and Prospect of Key Technologies in Inertial Friction Welding for Aero-engines

  Wu Yanquan, Zhou Jun, Zhang Chunbo, Yuan Mingqiang, Liang Wu, Qin Feng, Yang Haifeng, Huang Caiyan

  2026,55(12):3278-3288 DOI: 10.12442/j.issn.1002-185X.20250421

  Abstract(10) HTML(11) PDF(2.65 M)( 11)

  Abstract:Inertial friction welding (IFW), as an advanced solid-state welding process, has been widely applied in the manufacturing of aero-engine rotor components due to its green, efficient, and superior welding quality. This review systematically summarizes the research achievements in recent years regarding the microstructure, mechanical properties, and numerical simulation of IFWed joints of aviation titanium alloys and superalloys. It also summarizes the large-tonnage, high-precision IFW equipment for aerospace and their application in various types of advanced aero-engine rotor components. Future research should focus on addressing key technical challenges in the engineering application of new materials and new structures. This review also presents prospects for future development, highlighting that continuous innovation of IFW technique will provide critical technical support for achieving the high performance, lightweight design, and enhanced reliability of the new generation of aero-engines.

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• Effect of rare earth Y on mechanical properties of near α titanium alloy with different microstructure states

  He Chengwei, He Wenxuan, Yang Ruize, Li Yu, Liu Weifeng, Liu Sheng, Wang Jianqiang, Guo Yifeng, Xu Bin, Sun Mingyue

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260071

  Abstract(91) PDF(1.49 M)(81)

  Abstract:Ti6321 ingots containing 0~0.20 wt.% rare-earth yttrium (Y) were subjected to multi-pass hot rolling, and equiaxed structure (EQ), bimodal structure (BM) and Widmanst?tten structure (WM) were obtained by different annealing processes. The microstructures were characterized using optical microscopy (OM) and scanning electron microscopy (SEM). Tensile and instrumented impact tests were conducted to systematically investigate the effect of Y content on the microstructural evolution and mechanical properties of Ti6321 alloys with different microstructural states.The results show that Y has a significant refinement effect on the three microstructures. With the increase of Y content, the Y₂O₃ second phase with sub-micron to micron size and gradually increasing size is formed in the alloy matrix of the three microstructures, and the distribution characteristics in different microstructures are obviously different. In the EQ and BM conditions, Y?O? particles were mainly distributed within α_p, at α_p/β_t interfaces, and inside β_t regions, whereas in the WM condition, they were predominantly located at lamellar α/β interfaces. At the same time, it is found that there is a deformation incompatibility between Y₂O₃ and Ti6321 matrix during the deformation process. There is a competitive relationship between the damage intensification effect introduced by Y₂O₃ as a potential microcrack source and the multiple strengthening effects introduced by Y element. As a result, the tensile strength of the EQ alloy decreases significantly with increasing Y content, whereas the reduction is less pronounced in the BM condition. In the WM microstructure, the lamellar α phase effectively suppresses crack initiation and propagation associated with Y₂O₃ particles, leading to a tensile strength that first increases and then decreases with increasing Y content.In addition, the addition of Y significantly reduces the impact properties of Ti6321 alloy with BM and WM. The main reason is that Y₂O₃ weakens the energy absorption capacity in the crack propagation stage.

• Microstructure, properties and cryogenic temperature deformation mechanism of a cryogenic titanium alloy with high-oxygen

  ·Zhengzhuangzhuang, LuZichuan, HeZongzheng, Qiu Xuyangfan, Chang Yuling, Yang Jianhui, Chang Ruohan, Zhang Yalian, Yao Caogen, LiQijun, KangLi

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260097

  Abstract(86) PDF(1.60 M)(79)

  Abstract:In this study, the microstructure, properties and cryogenic temperature deformation behavior of cryogenic titanium alloy bars with different oxygen contents was investigated, and the strengthening-toughning mechanism of cryogenic titanium alloy with high oxygen content has been revealed. After annealled at 750℃, the microstructue is equaxied α_p phase with dispersed β phase. Due to the α/β phase trasformation temperature affected by the oxygen content, the microstructure of extral-low oxygen content alloy with 0.07wt.% is typical Widmanstatten microstructure with grain boundary α phase and lamellar α/β phase, and the media and high oxygen content is typical bimodal structure after annealled at 950℃. The ultimate tensile strength increase with increased oxygen content. The ultimate tensile strength of high oxygen content alloy at 20K is 1686.42MPa, and the corresponding elongation is 10.96%, while the ultimate tensile strength of high oxygen content alloy at 300K is 838MPa, and the corresponding elongation is 19.0%, which is better than the corresponding properties of TA34 alloy reported at GJB 9583. The deformation mechanism investigated finds that the discations strengthening of equaixed α_p phase and β phase bounadry caused by the non-crystallographic orientation relationship of α_p phase and β phase, which is the key factor of strength increase. As for the high oxygen content alloy with 0.16wt.%, the plasticity at 20K is obtained by the dislocations slip of prismatic and pyramidal , and the activation of stack facults and twins, which breakthrough the inhibition of twins deformation by high oxygen content, and the dislocation accumulated at boudaried and interacted in α phase can improve ultimate tensile strength.

• Research Progress in Titanium Alloys for Ships and Marine Engineering

  yangjing, lihan, wang qiming, liu xianghong, sun guangda, zhanmei, zheng zebang, he yonggang, wangtao, du yuxuan, wang kaixuan

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260103

  Abstract(121) PDF(1.04 M)(77)

  Abstract:With the deepening advancement of the China''s Maritime Power Strategy, the titanium alloys, due to their low density, high specific strength and excellent corrosion resistance, have demonstrated excellent weight reduction and corrosion resistance effects in the pressure-resistant shells of deep-sea submersible vessels and seawater pipeline systems, extending the service life of equipment, reducing maintenance costs and overall usage costs, and showing significant application value in the fields of ships and Marine engineering. The paper first elaborates on the core requirements of naval ships and marine engineering for titanium alloys, including large-scale components, high strength and toughness, corrosion resistance, and long-term service performance. Subsequently, focusing on different service environments such as deep-sea submersible pressure hulls, seawater piping systems, and power systems, systematic review is provided on the composition, microstructure, properties, and engineering applications of typical titanium alloys like Ti80 and TC4. Furthermore, emphasis is placed on discussing the current research status of long-term mechanical properties of titanium alloys in deep-sea environments, such as stress corrosion behavior, creep, and fatigue. At present, long-term performance data of titanium alloys in real marine environments are still insufficient, and a unified evaluation system and standard has not yet been established. The paper also highlights the existing shortcomings and technical challenges hindering the large-scale application of titanium alloys in the marine sector, including high manufacturing costs and insufficient material experimental data under deep-sea environments, and the further systematic research is still required to support the high-quality development of China''s marine equipment.

• Preparation of Lithiophilic Li-Rich Alloy Anode with Uniformly Distribution for High-Rate Lithium Metal Batteries

  HU XIN, LI ZHIQIN, XIAO LUHUI, LI XIAYI, WU ZIPING

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260130

  Abstract(89) PDF(1.24 M)(79)

  Abstract:Lithium metal batteries (LMBs) are regarded as one of the most promising energy-storage systems for next-generation, but their practical application is still hindered by severe lithium dendrite growth. The key factors limiting long cycle life and high-rate performance are the scarcity of lithiophilic sites and their nonuniform distribution. Herein, we report a Li-rich lithium alloy formed via a simple molten-lithium alloying reaction, featuring uniformly dispersed Li9Al4 with strong lithiophilicity. This architecture provides abundant and uniformly distributed lithiophilic sites, ensuring homogeneous lithium plating/stripping and suppressing dendrite formation. As a result, the symmetric cells based on the anode deliver stable cycling for over 1200 h with a low overpotential of 56 mV, and the assembled full cells based on the anode maintain a capacity retention of 93.2% even after 400 cycles at 5 C, offering a scalable pathway toward high-rate lithium metal batteries.

• High-Temperature Oxidation Behavior of two Novel Low-Re Single Crystal Superalloys

  Cui Jinyan, Zhang Jianting, Wang Zhishen, Duan Fangmiao, Li Weiming

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260132

  Abstract(78) PDF(1.34 M)(82)

  Abstract:Developing low-cost, high-performance nickel-based single crystal superalloys has become an inevitable trend to fulfill the performance requirements of advanced gas turbine blades. In this study, the cyclic oxidation behavior of two novel low-Re single crystal superalloys, A1 and A2, was systematically compared with that of the commercial DD5 alloy at 1100?°C for 100?h. The oxidation resistance of the target alloys was assessed via the static weight gain method. The oxidation kinetics, evolution of oxidation products, and oxide scale structure were comprehensively analyzed using XRD, SEM, and EDS. The results show that a continuous and dense Al?O? layer with a thickness of approximately 7?μm is formed on the surface of A1 alloy. This alloy exhibits the lowest mass gain (average oxidation rate K''= 0.0081?g/(m2·h)) and the minimal oxide scale spallation (G''= 0.28?g/m2), indicative of its superior oxidation resistance among the three alloys. For the A2 alloy, due to its insufficient Cr content (6.5%), NiO and spinel preferentially form and dominate the oxidation path. This leads to the formation of a loose multilayer mixed oxide scale with a discontinuous inner Al?O? layer, accompanied by severe scale spallation (G''= 15?g/m2), resulting in the poorest oxidation resistance. Although the DD5 alloy has a relatively higher Cr content (7%), the absence of synergistic regulating elements such as Hf, coupled with its high Re content (3%), gives rise to the lack of a continuous inner Al?O? layer and the occurrence of internal nitridation. Accordingly, its oxidation resistance is inferior to that of A1 but superior to that of A2. The synergistic effects of alloying elements during the oxidation processes induce distinct differences in the oxidation mechanisms of the three tested alloys.

• Research on Systematic Determination of Surface Heat Transfer Coefficient of Wrought Superalloys

  lixin, jianghe, wangxiaobo, dongjianxin

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260139

  Abstract(94) PDF(1.23 M)(75)

  Abstract:In order to accurately predict the heating and cooling process of wrought superalloys during the manufacturing process, accurately evaluate thermal stress and control damage, and reduce energy consumption and production costs, it is necessary to perform a systematic study on the surface heat transfer coefficient of various heat transfer conditions of wrought superalloys, and determine a reliable surface heat transfer coefficient for actual process design and simulation calculation. In this paper, 10 typical heat transfer conditions involved in the manufacturing process of GH4169 alloy disc forgings are taken as examples, and the surface heat transfer coefficient of GH4169 alloy is determined by experimental temperature measurement and finite element parameter optimization method. The study found that the surface heat transfer coefficient measured by the direct heating process can comprehensively describe the temperature change of the alloy in different heating processes; the furnace cooling process can be described by the surface heat transfer coefficient measured by the direct heating process; the insulation materials can make the alloy have an extremely low surface heat transfer coefficient and remain stable in a large temperature range; the surface heat transfer coefficient measured by a small laboratory sample can accurately describe the heating and cooling process of industrial large ingots.

• Orientation Dependence and Microtexture Effects on dwell Fatigue Crack Initiation in TA33 Alloy

  Wang Boning, Huang Longchao, Zhao Min, Lei Fan, Zeng Weidong, Wang Kaixuan

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260143

  Abstract(71) PDF(1.48 M)(70)

  Abstract:Near-α TA33 alloy has been successfully employed in integrally bladed disks of advanced aeroengines due to its outstanding high-temperature performance and favorable room-temperature fatigue strength. Nevertheless, accurately understanding fatigue crack initiation at the microscale is still a major challenge in engineering, which mainly stems from the inherent sensitivity of the crack initiation process to the microstructure. Therefore, the fatigue life and dwell fatigue sensitivity of TA33 alloys with different microtexture region (MTR) characteristics were systematically investigated. Results show that MTR significantly aggravates dwell-fatigue sensitivity and gives rise to a larger crack initiation area, which is closely associated with dislocation slip and crack transmission within MTR. After removing MTR, the crack initiation zone in the no-MTR alloy is confined to 2~3 grains, and the area of the crack source region is remarkably reduced. Meanwhile, the dispersed grain orientations and multi-site nucleation decrease the dwell-fatigue sensitivity of the alloy to 2.86. These initiation characteristics are closely related to basal slip in the [0001] orientation domain. Crack initiation occurs not only on basal planes of hard grains with low Schmid factor (SF) but also in the high SF range, both exhibiting a pronounced near-basal orientation dependence.

• Effect of Aging Treatment on Microstructure and Properties of Rare Earth Magnesium Alloy Fabricated by Additive Friction Stir Deposition

  Ji Haocheng, Xu Naiqiang, Xu Shuming, Wang Yuqing, Luo Ting, Yang Xinqi

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260144

  Abstract(88) PDF(1.86 M)(76)

  Abstract:In this study, additive friction stir deposition (AFSD) experiments of Mg-Gd-Y-Zr (GW83K) rare earth magnesium alloy were carried out using a pressure-controlled solid-phase friction extrusion additive manufacturing equipment. The effects of aging treatment on the microstructure and mechanical properties of the deposited layer were systematically investigated. The results indicate that fully dense GW83K rare earth magnesium alloy deposited specimens without macroscopic defects are obtained under the process parameters of a spindle speed of 250 rpm and a traverse speed of 100 mm/min. Compared with the original bar stock, the deposited zone presents an obvious mixed grain structure. The average grain size of the local coarse-grained region on the advancing side of the deposited layer is 17.37±7.29 μm, whereas the average grain size in most regions of the middle part and the retreating side is significantly refined to 5.66±2.58 μm and 4.36±2.32 ?m. After aging treatment at 215 ℃ for 30 h, the as-deposited specimens possess a uniform and fine grain structure. The hardness increases from 85.8 HV to 109.5 HV; the yield strength (YS) and ultimate tensile strength (UTS) reach up to 329.5±11.7 MPa and 384.25±7.5 MPa, respectively, with an elongation of 8.125±0.25%. The tensile fracture surfaces of the specimens exhibit a ductile-brittle mixed fracture characteristic. This study verifies that aging treatment precipitates fine β" strengthening phases on the basis of retaining the fine grains of the deposited layer, which significantly improves the strength-ductility synergy of the GW83K rare earth magnesium alloy fabricated by AFSD.

• Effects of hole expansion strengthening on microstructure and fatigue properties of titanium alloy Ti-4Al-5Mo-5V-6Cr-1Nb

  Hu shenshuang, Wang haojun, Zhang bin, Zhu yanru, Gao xiaoyin, Chen Huizi, Cui Xia, ouyangdelai

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260146

  Abstract(95) PDF(1.23 M)(77)

  Abstract:To enhance the fatigue performance of the central hole specimen of the aviation titanium alloy Ti-4Al-5Mo-5V-6Cr-1Nb, hole extrusion strengthening experiment was conducted on the center hole of its plate using a slotted mandrel. The effects of hole extrusion strengthening on the microstructure and fatigue performance of the alloy were analyzed, and the anti-fatigue enhancement effect and microscopic mechanism of hole extrusion strengthening revealed. The results showed that the hole extrusion strengthened layer with a gradient distribution of deformation degree consisted of a grain refinement zone near the hole edge and a deformation zone away from the hole edge. The depth of the residual stress layer on the inner side of the hole wall was 2000 μm, and the maximum residual stress was -700 MPa. The depth of the strengthened layer was 100 μm, and the highest hardness value was 380 HV0.1, which was 20% higher than the hardness value of the matrix. The fatigue life and fatigue life dispersion of the alloy was significantly improved after hole extrusion strengthening, with the median life and average life increasing by 2.74 times and 2.53 times, respectively, and the coefficient of variation decreasing from 48.7% to 29.6%. The residual stress field and strengthened layer effectively suppressed the initiation of fatigue cracks on the inner surface of the hole wall, shifting the initiation of fatigue cracks from the surface to the subsurface, resulting in finer striations with a striation spacing decreasing from 1.94 μm to 0.92 μm..

• Investigation of Steady-State Operating Performance of Cr?O?-Doped UO?-Zircaloy Nuclear Fuel

  Yin Chunyu, Wang Yaofeng, Zhang Kun, He Liang, Liu Xinyue, He Yanan, Wu Yingwei, Zhang Jing, Xiao Zhong, Su Guanghui

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260218

  Abstract(66) PDF(1.86 M)(80)

  Abstract:Cr?O?-doped UO? pellets can promote grain growth and may improve fission-gas retention. This study coupled the fuel-performance code BEEs with the grain-scale fission-gas code SCIANTIX. BEEs transfers local temperature, burnup, fission rate, and grain size to SCIANTIX, while fission gas release (FGR) and gas swelling are returned to the rod-scale calculation. For the BR-3 36i8 rod, the coupled model predicted an end-of-life FGR of 28.49%, 15.7% below the measured value of 33.80%, and a void volume of 5.890×10?? m3, 26.8% below the measured value of 8.046×10?? m3. Because only one rod and endpoint measurements were available, this comparison establishes neither statistical significance nor general predictive accuracy. Deterministic sensitivity calculations for grain sizes of 10–50 μm showed lower FGR and gap pressure but higher retained-gas swelling at larger grain sizes under the adopted model settings.

• Research on the Interaction Mechanism between Magnesium Refining Flux and Solid Inclusions

  Kong fanhong, You Guoqiang, Dong Yinglei, Wang Qiang, Yu Bing, Zhao Yong, Lian Xuehua

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260148

  Abstract(100) PDF(985.61 K)(74)

  Abstract:Aiming at the current lack of clarity regarding the interaction mechanism between magnesium refining fluxes and solid inclusions, this study conducted multi-scale characterization on magnesium refining flux, MgO powder, their mixtures, and the furnace bottom slag generated during the refining process. Techniques including DSC/TG thermal analysis, XRF, XRD, SEM, and TEM were employed. The results indicate that, under the conditions of this study: 1) The bonding mechanism between the magnesium refining flux and solid inclusions (such as MgO) is physical bonding rather than chemical bonding; 2) A significant "core-shell encapsulation" characteristic is observed, where the solid inclusion acts as the core and is encapsulated by the flux shell.

• Research progress of microstructural regulation strategies in Al-Si(-Cu) series heat-resistant casting alloys

  Zheng Zongwen, Meng Xiaodong, Li Juntao, Lin Baosen, Hao Yuanliang, Li Yuanyuan, Pan Yuyao, Zhang Rongqiang, Fu Jinlong

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260153

  Abstract(91) PDF(3.55 M)(66)

  Abstract:Al-Si(-Cu) casting alloys are important candidate materials for complex hot-end components such as engine blocks and cylinder heads because they combine castability, gas tightness and precipitation-strengthening potential. Their use at 300~350°C, however, is limited by the coarsening, dissolution or transformation of metastable θ′ and β′ precipitates, together with degradation of eutectic Si and grain-boundary structures. This review summarizes recent progress in microstructural regulation strategies for improving the heat resistance of Al-Si(-Cu) casting alloys. Three routes are highlighted: thermally stable nanoscale dispersoids formed by low-diffusivity transition or rare-earth elements; interfacial segregation engineering to stabilize θ′, Q′ and other metastable precipitates; and rigid interconnected networks composed of grain-boundary intermetallic compounds and eutectic Si. The roles of CALPHAD calculations, machine learning, multiscale simulation and additive-manufacturing-assisted rapid solidification are also discussed. Overall, the development of heat-resistant Al-Si(-Cu) casting alloys is moving from single-phase strengthening toward multiscale cooperative regulation that balances high-temperature strength, casting adaptability, hot-tearing sensitivity and long-term service stability. This review provides guidance for composition design, heat-treatment optimization and microstructural evaluation of Al-Si(-Cu) alloys for engine hot-end applications.

• Molecular Dynamics Study on the Effects of Displacement Cascades on the Mechanical Properties of Molybdenum-Rhenium Single-Crystal Solid Solution Alloys

  Wang Xiaotong, Dong Yibin, Li Weiyi, Li Qingyu, Zhu Mingdong, Dong yuanyuan, Yan Dapeng, Gao Ning

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260159

  Abstract(84) PDF(896.00 K)(89)

  Abstract:Due to their high melting points, excellent high-temperature mechanical properties, and radiation resistance, molybdenum-rhenium (Mo-Re) alloys have been considered as primary candidates for fuel cladding and core structural materials used in advanced nuclear reactors. In this study, molecular dynamics simulations were employed to systematically investigate the effects of displacement cascades on the mechanical properties of Mo-Re single-crystal solid-solution alloys with different Re contents (5% and 14%), using pure Mo single crystals as a benchmark. The results indicate that increasing the Re content could activate more slip systems within the Mo-Re single-crystal solid-solution alloys under tensile stress, thereby effectively enhancing their plasticity. Results further indicated that displacement cascades could significantly degrade both the tensile strength and plasticity of the Mo-Re alloys. The underlying physical mechanism may be from the defects introduced by the cascades, which can induce localized stress concentrations and energy perturbations, resulting in a reduction in the critical stress required to activate slip systems, thereby accelerating material yielding and decreasing the uniform elongation of the single-crystal solid-solution alloys. Therefore, the results of this study elucidate the influence of displacement cascades on the tensile mechanical properties of Mo-Re single-crystal solid-solution alloys, as well as the underlying atomic-scale mechanisms, providing valuable scientific insights for the design and selection of materials for advanced nuclear reactors.

• Study on the Material Removal Mechanism of 4H-SiC in Thermally Assisted Nanometric Cutting

  Geng ruiwen, Tu Jiajun, Tian Zhuxin, Xie Qiming, You Jinjing, Li Lijun, Wu Haihua

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260160

  Abstract(70) PDF(1.71 M)(71)

  Abstract:Owing to its excellent thermal conductivity, high breakdown voltage, and high-temperature stability, 4H-SiC is a promising material for power electronics and high-frequency devices. However, its extreme hardness and low fracture toughness cause severe subsurface damage and rapid tool wear during nanoscale cutting. Thermally assisted machining can improve machinability by promoting plastic deformation and enhancing efficiency; therefore, understanding the temperature-dependent material removal mechanism in nanometric cutting of 4H-SiC is essential. This study employs molecular dynamics simulations to systematically investigate the cutting mechanical behavior, surface morphology, subsurface damage, stress distribution, and dislocation evolution of 4H-SiC under different cutting temperatures (100–1000 K). The results show that the average cutting forces decrease markedly with increasing temperature. At 1000 K, the tangential and normal forces are reduced by 15.4% and 29.3%, respectively, compared with those at room temperature (300 K). Cutting at intermediate temperatures (500–600 K) effectively suppresses subsurface damage, alleviates stress concentration, and reduces dislocation density. However, excessively high temperatures (≥800 K) aggravate damage and broaden the stress distribution due to enhanced dislocation multiplication and tangling. This work reveals the plastic removal mechanism and damage evolution of 4H-SiC under different temperatures, offering a theoretical basis for efficient, low-damage nanometric cutting.

• Research Progress in the Processing of Magnesium Alloy Welding Wire

  Guo Junhua, Yang Yang, Dong Xin, Guo Peng, Nie Mengjie, Lu Quanbin

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260165

  Abstract(85) PDF(1.17 M)(68)

  Abstract:Magnesium alloy, as a lightweight core structural material, has great potential for application in aerospace, automotive, electronics, and biomedical fields. However, its engineering applications are constrained by issues such as insufficient plastic forming ability and poor corrosion resistance. Welding is a key means of manufacturing complex components, and the quality of welding wire directly determines the performance of the welded joint. This article provides a systematic review of the current research status of magnesium alloy welding wire, analyzes the mechanism of action and synergistic/antagonistic effects of alloy elements, elucidates the plastic deformation law of magnesium alloy in a dense hexagonal structure, sorts out the technical characteristics and application progress of preparation processes such as hot extrusion drawing, hot drawing, electric pulse, and ultrasonic assistance, and points out the shortcomings. In the future, we should focus on the development of specialized welding wires, advanced processing technologies, and full chain performance optimization, providing reference for the research and engineering application of high-performance magnesium alloy welding wires.

• Research Progress on Composition Design and Co-firing Behavior of Copper Pastes for LTCC Internal Electrodes

  Qin Zhou, Jia Qiang, Wang Yishu, Hu Hu’an, Zou Guisheng, Guo Fu

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260205

  Abstract(120) PDF(1.28 M)(72)

  Abstract:With the development of 5G/6G communications and high-density electronic packaging, low-temperature co-fired ceramic (LTCC) devices require higher performance in high-frequency signal transmission, high-density integration, and reliable service. Internal electrode paste is a key material in LTCC multilayer interconnect structures, and its composition and co-firing behavior directly affect the electrical conductivity and service reliability of the electrodes. Compared with noble-metal electrodes, Cu is emerging as an important direction for LTCC internal electrodes because of its lower cost and stronger resistance to electrochemical migration. However, its susceptibility to oxidation also increases the difficulty of material composition design and co-firing control. Based on the technical background of the transition of LTCC internal electrode materials from Au and Ag to Cu, this paper reviews the progress in the component design of organic vehicles, inorganic binders, and conductive phases in copper pastes for internal electrodes. It focuses on the oxidation resistance, sintering densification, co-firing compatibility, interfacial bonding behavior, and related influencing factors during co-firing, and further summarizes the current research challenges and future development directions.

• Study on microstructure and texture evolution of Ti750s titanium alloy sheet during rolling process

  Yue Xu, Chen Zhiyong, Wang Qingjiang, Gao Wenzhu, Zhang Mingyu

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260213

  Abstract(77) PDF(2.15 M)(75)

  Abstract:In this paper, a new type of high-temperature titanium alloy Ti750s alloy with nearly α is selected as the experimental material. The plate is rolled from 11.5 mm to 1.5 mm by multi-fire rolling. The microstructure and texture evolution process during rolling deformation are studied. The results show that the microstructure of the 11.5 mm plate retains obvious deformation characteristics, the original β grains are seriously elongated, and a large number of flaky α phases are precipitated inside the grains. The plate presents a T-shaped texture in the {0001}//TD direction, with more 60 ° and 90 ° high-angle grain boundaries, and the internal dislocation density is low. After reversing rolling to 5.2 mm, a large number of twisted strip-like α phases appear in the microstructure, which are uniformly tilted to the TD direction, and the T texture disappears, and the B texture in the {0001} // ND direction appears. At this time, the {0001} axis of the α grain is evenly distributed in the pole diagram deviating from the ND about 20 ° direction, and the large angle grain boundary of the sheet is less, and the dislocation density is larger. After the second reversing rolling to 1.5 mm, the microstructure is mainly composed of deformed strip α grains, the grain size is small, and the B-type texture disappears, the T-type texture reappears, and the plate has almost no large angle grain boundary, and the dislocation density is large.

• High-Entropy Alloy Hydrogen Storage Materials: Core Effects, Hydrogen Absorption/Desorption Behavior, and Application Prospects

  liuwanying

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260215

  Abstract(77) PDF(1.51 M)(74)

  Abstract:As a critical clean energy, hydrogen energy development is restricted by backward hydrogen storage technologies. Traditional hydrogen storage materials still suffer from deficiencies in hydrogen storage capacity, hydrogen absorption/desorption rate and structural stability. In recent years, high-entropy alloys (HEAs) have demonstrated promising hydrogen storage performance, yet their hydrogen storage behavior is complex and requires in-depth investigation. This paper discusses the correlation between the four core effects of HEAs (high-entropy effect, lattice distortion effect, sluggish diffusion effect and cocktail effect) and hydrogen storage performance, focuses onreviewing hydrogen storage kinetics and thermodynamics, analyzes microscopic mechanisms and performance regulation strategies, and explores their potential applications. The results show that: ① The high-entropy effect promotes the formation of single-phase solid solutions; the lattice distortion effect expands interstitial space and enhances hydrogen storage capacity; the sluggish diffusion effect improves material stability; the cocktail effect optimizes comprehensive performance. ② Kinetic models such as JMAK and Chou systematically analyze key processes including hydrogen absorption/desorption, diffusion and phase transformation, reveal rate-controlling mechanisms, and quantify activation energy and diffusion coefficient. ③ Based on the Van''t Hoff equation, the enthalpy and entropy changes of hydrogen absorption/desorption are calculated to clarify hydrogen storage equilibrium behavior. With the advantages of high capacity, fast kinetics and long cycle stability, HEAs exhibit good prospects for engineering applications. Future research should focus on composition design, synthesis process improvement and theoretical model construction to promote the research and application of such materials.

• Study on the Static and Dynamic Mechanical Properties of (Fe60Mn20Cr10Ni10)95(AlSiC)5 Medium-Entropy Alloy at Room Temperature

  Guo Yanyi, Kou Shuanghu, Ma Shengguo, Guo Meiqing, Wang Xiaohua

  Available online:September 29, 2026  DOI: 10.12442/j.issn.1002-185X.20260224

  Abstract(76) PDF(1.85 M)(69)

  Abstract:High-entropy alloys (HEAs) have become one of the hot topics in the field of materials science due to their unique alloy design concepts and excellent comprehensive mechanical properties. However, traditional HEAs often contain valuable Co elements and tend to be designed in equal atomic ratios, which greatly increases the alloy costs and limits their industrial applications. Based on this, a cobalt-free (Fe60Mn20Cr10Ni10)95 (AlSiC)5 medium-entropy alloy (MEA) is established. By moderately decreasing Cr and Ni while obviously increasing Fe elements, the alloy cost can be effectively reduced. Relying on the classical thermodynamic criteria and minor additions of Al, Si, and C elements, the solid-solution strengthening can be significantly improved as well as a certain carbide particle strengthening. The results reveal that the current alloy exhibits a simple face-centered-cubic (FCC) crystal structure, with a phase composition consisting of disordered FCC solid solution and ordered M23C6 carbides. Based on the cube-cube orientation relationship and almost coherent interface characteristics of FCC/M23C6, the (Fe60Mn20Cr10Ni10)95 (AlSiC)5 MEA exhibits excellent room-temperature plasticity and work-hardening ability under quasi-static conditions, with a compressive yield strength of about 360±10 MPa and a compressive strain of up to 70%. Moreover, the alloy undergoes a tensile yielding strength of 365±15 MPa, an ultimate tesnsile strength of 715±25 MPa, as well as about 40% fracture to elongation. Upon dynamic loading, the alloy exhibits a positive strain-rate sensitivity, with a dynamic yield strength of approximately 910±35 MPa, which is about 153% higher than that of quasi-static loading. Meanwhile, it still exhibits visible work hardening and even at the strain of about 40%, the alloy still does not undergo significant damage. TEM analysis shows that visible dislocation walls and cells inside the FCC matrix, as well as the interaction between M23C6 and dislocations, lead to an excellent strength-plasticity combination under quasi-static loading. The formation of deformation twins, 9R phase, stacking faults, and Lomer-Cottrell locks provides the alloy with multiple strengthening and toughening mechanisms, thus yielding the potential damage tolerance capacity upon high-speed loading.

• Microstructure optimization and hydrogen barrier mechanism of MAO/ZrO2-Y2O3 composite coatings on zirconium hydride

  Li-wei Chen, Shu-fang Yan, Ying Wang, Cui-xiao Long, Ji-yuan Zhou, Wei-dong Chen

  Available online:September 21, 2026  DOI: 10.12442/j.issn.1002-185X.20260135

  Abstract(70) PDF(1.21 M)(63)

  Abstract:In this study, by combining micro-arc oxidation (MAO) and sol-gel technology, the composite MAO/ZrO?-Y?O? hydrogen barrier coatings were successfully prepared on the surface of ZrH1.8 zirconium hydride matrix. The effects of the content of Y?O? concentration (0-16 mol%) and heat treatment temperature (300-600°C) on the microstructure, phase composition, and hydrogen-blocking properties of the coatings were systematically investigated. The results showed that the composite coatings exhibited optimal performance when the Y?O? content was 12 mol%, the porosity was as low as 2.9%, the tetragonal phase of zirconia (t-ZrO?) content reached 18.32%, the hydrogen permeation reduction factor (PRF) was elevated to 19.3, and the hydrogen-loss temperature was increased to 682°C. The heat treatment at 600°C further optimized the surface integrity and crystallization of the coatings, and led to the increase of the hydrogen loss temperature to 686°C. The hydrogen barrier mechanism of the coatings was attributed to the synergistic effect of physical barrier, chemical trapping of oxygen vacancies and phase stabilization.

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