+Advanced Search

Volume 0,Issue 12,2024 Table of Contents

  • Display Type:
  • Text List
  • Abstract List
  • 1  Effect of Compression Passes on Mechanical Properties and Corrosion Behavior of ZK60 Magnesium Alloy
    Yin Dongsong Liu Zhiyuan Zhang Youyou Mao Yong Han Tianming
    2024, 53(12):3338-3347. DOI: 10.12442/j.issn.1002-185X.20240102
    [Abstract](24) [HTML](9) [PDF 3.43 M](12)
    Abstract:
    The impact of multi-directional compression passes on the microstructure, mechanical properties, and corrosion behavior of ZK60 magnesium alloy was investigated. Results reveal that severe dendrite segregation exists in the as-cast ZK60 magnesium alloy with coarse MgZn phases distributed along the grain boundaries. After 9 passes of compression, the coarse solidified phases at the grain boundary are significantly refined, and back dissolution occurs. Fine recrystallized grains accompanied with the fine diffused nano-phases emerge in the local area around the large grains. The tensile strength of ZK60 magnesium alloy generally exhibits the upward trend with the increase in compression passes, whereas the compression rate shows the downward trend. The compressive strength reaches 433.6 MPa with the compression rate of 21.3% after 9 passes of compression. Multi-directional compression can significantly reduce the degradation rate of ZK60 magnesium alloy in simulated body fluids. Furthermore, it is observed that in the as-cast ZK60 magnesium alloy, micro-segregation can easily lead to severe intragranular local corrosion. However, after multi-directional compression, the tendency to intragranular local corrosion is significantly diminished.
    2  Formation of Sub-grain Structure Induced by Composition Segregation and Stacking Faults in Laser-Deposited Premixed Near-α Titanium Alloy and Ti2AlNb Alloy Powders
    Liu Na Zhao Zhanglong Liu Yuli Feng Kaikai Zha Xiaohui Li Pu Xu Wenxin Yang Haiou Lai Yunjin
    2024, 53(12):3281-3290. DOI: 10.12442/j.issn.1002-185X.20240097
    [Abstract](10) [HTML](5) [PDF 3.51 M](5)
    Abstract:
    Near-α titanium alloy and Ti2AlNb alloy powders premixed with different proportions were prepared on the near-α titanium alloy substrate by laser deposition technique, and the microstructure characteristics were analyzed and discussed. Results show that numerous river-like sub-grain structures are formed inside the equiaxed B2 grains of the laser-deposited premixed titanium alloy powders with the proportion of Ti2AlNb above 40wt%, whereas the needle-like structure within coarse columnar β grains exist with the proportion of Ti2AlNb below 40wt%. It is noteworthy that the decrease in laser power and scanning speed can accelerate the formation of sub-grain structures. Based on the analysis of experimental results, it can be inferred that the formation of sub-grain structure not only is related to the precipitation of O phase due to composition micro-segregation at sub-grain boundaries, but also is inseparable from the stacking faults caused by the internal stress during the laser deposition.
    3  Simulation of Bubble Dynamics and Electrolyte Flow in Rare Earth Electrolysis Cell with Horizontal Electrode
    Liu Hang Yang Chaoyun Zhang Yao Luan Yikun Li Dianzhong
    2024, 53(12):3291-3298. DOI: 10.12442/j.issn.1002-185X.20240023
    [Abstract](10) [HTML](4) [PDF 1.35 M](4)
    Abstract:
    A 2D transient mathematical model was established to separately describe the anode bubble dynamics and the bubble-induced electrolyte motion in the rare earth electrolysis cell with horizontal electrode. Results indicate that with the increase in the anode inclined angle, the maximum bubble thickness is increased gradually. Furthermore, compared with the conventional anode, the inclined and chamfered anodes are conductive to the bubble length reduction and the bubble velocity improvement. Meanwhile, the bubble-induced electrolyte motion in the electrolysis cell can improve the distribution and transport process of oxyfluorides, thereby enhancing the current efficiency. Finally, a novel feeding method based on the electrolyte flow is proposed.
    4  Influence of Microstructure and Stress State on Service Performance of TiN Coatings Deposited by Dual-Stage HIPIMS
    Hao Juan Wang Baichuan Ding Yuhang Yang Chao Jiang Bailing Wang Ziyi Wang Donghong Dong Dan
    2024, 53(12):3299-3305. DOI: 10.12442/j.issn.1002-185X.20240043
    [Abstract](6) [HTML](4) [PDF 1.91 M](9)
    Abstract:
    TiN coatings were prepared by the novel dual-stage high power impulse magnetron sputtering (HIPIMS) technique under different deposition time conditions, and the effects of microstructure and stress state at different coating growth stages on the mechanical, tribological, and corrosion resistance performance of the coatings were analyzed. Results show that with the prolongation of deposition time from 30 min to 120 min, the surface structure of TiN coating exhibits a round cell structure with tightly doped small and large particles, maintaining the atomic stacking thickening mechanism of deposition-crystallization-growth. When the deposition time increases from 90 min to 120 min, the coating thickness increases from 3884 nm to 4456 nm, and the stress state of coating undergoes the compression-tension transition. When the deposition time is 90 min, TiN coating structure is dense and suffers relatively small compressive stress of -0.54 GPa. The coating has high hardness and elastic modulus, which are 27.5 and 340.2 GPa, respectively. Meanwhile, good tribological properties (average friction coefficient of 0.52, minimum wear rate of 1.68×10-4 g/s) and fine corrosion resistance properties (minimum corrosion current density of 1.0632×10-8 A·cm-2, minimum corrosion rate of 5.5226×10-5 mm·A-1) can also be obtained for the coatings.
    5  Mechanism and Properties of Al2O3-Ru Composite Coatings Prepared by Cathode Plasma Electrolytic Deposition
    Xue Jianchao Jia Bo Wang Yafei Feng Qing Chai Zuoqiang Hao Xiaojun Xue Juanqin
    2024, 53(12):3306-3312. DOI: 10.12442/j.issn.1002-185X.20240067
    [Abstract](5) [HTML](4) [PDF 2.78 M](5)
    Abstract:
    Alumina coatings doped with different precious metals were prepared by cathode plasma electrolytic deposition. Results show that the porosity of precious metal-doped alumina coatings (especially Al2O3-Ru) decreases, and the high-temperature cyclic oxidation resistance and spallation resistance are enhanced. The Al2O3-Ru composite coating shows better effect: its average oxidation rate K and average amount of oxide spallation G are minimum. Meanwhile, Nernst equation was used to explain the simultaneous deposition of precious metal and alumina, and the whole process and mechanism of deposition were analyzed.
    6  Effect of Grain Refinement on Microtexture and Mechan-ical Properties of Inconel 617 Alloy
    Ji Jinjin Jia Zhi Yang Peiyao Wang Yanjiang Kou Shengzhong
    2024, 53(12):3313-3320. DOI: 10.12442/j.issn.1002-185X.20240091
    [Abstract](12) [HTML](12) [PDF 2.64 M](10)
    Abstract:
    The microstructure and mechanical properties of Inconel 617 alloy rolled at room temperature with different deformation degrees (20%, 50%, 70%) were investigated. The grain refinement mechanism and main texture types of Inconel 617 alloy during rolling were analyzed via electron backscatter diffraction and X-ray diffraction, and the microhardness and tensile properties of Inconel 617 alloy with different deformation degrees were tested. Results reveal that the grains of Inconel 617 alloy are refined during the rolling deformation process, and the refinement mechanism is the fragmentation of original grains caused by the increase in dis-location density and strain gradient. The main microtextures of the rolled samples are Goss {011}<001>, Rotated Goss {110}<110>, Brass {011}<211>, and P {011}<112> textures, and their intensity is increased with increase in deformation degree. After rolling deformation, the strength of the Inconel 617 alloy is improved and the ductility is reduced by the combined effect of grain refinement and dislocation strengthening. Comprehensively, the yield strength and elongation of Inconel 617 alloy after 20% deformation are 772.48 MPa and 0.1962, respectively, presenting good synergy effect.
    7  Biocompatibility of Morphology on Laser-Processed Magnesium Alloy Surfaces
    Liu Peng Guo Xuan Gao Dongfang Zhao Yangyang Qiao Yang
    2024, 53(12):3321-3328. DOI: 10.12442/j.issn.1002-185X.20240249
    [Abstract](10) [HTML](5) [PDF 1.71 M](8)
    Abstract:
    The surface of magnesium alloy was laser-processed, and the laser-etched morphology was determined as grooves by observing the surface morphology of sheep rib bone. The wettability of different morphologies was investigated by contact angle test. Through the cell adhesion test, the effects of different morphologies on cell adhesion, growth and migration were investigated. Results show that the wetting angle of the block-shaped surface is smaller than that of the groove-shaped surface, and block-shaped surface has better hydrophilicity. Compared with the smooth surface, the block-shaped surface has better cell adhesion, and the depressions and bumps are full of cells, suggesting that the micropatterns prepared by the laser processing are conducive to the enhancement of biocompatibility.
    8  Enhancement in Mechanical Properties of TiAl Alloys by In-Situ Precipitation of Hybrid TiB2-Ti2AlN
    Wang Yupeng Li Siying Ma Tengfei Wang Xiaohong Dong Duo Zhu Dongdong
    2024, 53(12):3329-3337. DOI: 10.12442/j.issn.1002-185X.20240001
    [Abstract](10) [HTML](3) [PDF 3.15 M](8)
    Abstract:
    TiAl alloy was mixed with BN nanoplates and then sintered at 1300 °C through spark plasma sintering technique, and the hybrid TiB2-Ti2AlN/TiAl composites were in-situ prepared. The microstructural evolution and mechanical properties at room temperature of TiAl composites were investigated. Results show that a fully lamellar microstructure can be achieved in the TiAl composites with BN nanoplates of lower content, whereas a transformation to the nearly lamellar microstructure can be observed under higher BN nanoplate content conditions. The microstructure of TiAl composites is significantly refined due to the even distribution of in-situ prepared TiB2-Ti2AlN particles at the lamellar colony boundaries. Notably, a continuous core-shell structure of TiB2-Ti2AlN particles is formed at the lamellar grain boundary after adding 0.5wt% BN nanoplates. The results of compression and friction wear at room temperature show that the hardness and compressive strength of TiAl composites are greatly improved with the increase in BN nanoplate content from 0wt% to 1wt%. Meanwhile, the average coefficient of friction decreases from 0.59 to 0.47, and the wear rate decreases by 29.9%. These remarkable mechanical properties are mainly attributed to the strengthening effects of the in-situ formation of TiB2-Ti2AlN particles, refined microstructure, and core-shell structure.
    9  Preparation of Core-Shell Nanoparticles and Their Applica-tion in Precision Machining
    Wang Youliang Kang Yating Zhang Wenjuan Jiang Zhe Yin Xincheng
    2024, 53(12):3348-3357. DOI: 10.12442/j.issn.1002-185X.20240011
    [Abstract](10) [HTML](4) [PDF 1.26 M](7)
    Abstract:
    Preparation method of magnetic nanoparticles with core-shell structure was introduced, especially focusing on the preparation principle of sol-gel method, microemulsion method, and self-assembly technique. The application of core-shell nanoparticles in precision machining was discussed. The Fe3O4@SiO2 composite particles were prepared by sol-gel method and were applied to the magnetorheological polishing of titanium alloy plates. Results show that core-shell nanoparticles with higher surface quality can be obtained after processing, compared with those after conventional abrasives. After polishing for 20 min, the surface roughness of the workpiece reaches 23 nm and the scratches are effectively reduced. Finally, the preparation and application of core-shell nanoparticles are summarized and prospected to provide a reference for further research on core-shell nanoparticles.
    10  Research Status of Preparation Technique of Aluminum Alloy Semi-solid Slurry
    Xiu Lei Gu Haozhong Lv Anna Hong Ronghui Zhang Zhirong
    2024, 53(12):3358-3372. DOI: 10.12442/j.issn.1002-185X.20240059
    [Abstract](7) [HTML](1) [PDF 3.71 M](6)
    Abstract:
    Semi-solid processing (SSP) technique is an important method for metal casting. Products made by SSP technique have advantages such as small solidification shrinkage, high dimensional accuracy of castings, fast forming speed, high productivity, and good mechanical properties. Aluminum alloy products produced by SSP technique can be heat-treated. The mechanical properties of the products after heat treatment are similar to those of steel, but they have the lighter mass and are widely used in many fields. Semi-solid slurry preparation technique is one of the key techniques in the field of aluminum alloy semi-solid forming, which determines the industrial application of semi-solid forming and also has significant impact on the quality of aluminum alloy semi-solid slurry. Semi-solid slurry preparation technique with the continuous development has become the emerging technique in the field of metal processing. The principles, advantages and disadvantages of various semi-solid slurry preparation techniques for metal materials were reviewed, and the future trends of semi-solid slurry preparation techniques were predicted.

    Current Issue


    ,Vol., Issue

    Table of Contents

    Search by Issue

    Issue

    Most Read

    Most Cited

    Most Downloaded