放电等离子烧结Fe基块体非晶合金中退火诱导的力学强度与耐腐蚀性能提升

Annealing-Induced Enhancement in Mechanical Strength and Corrosion Resistance of Spark-Plasma-Sintered Fe-Based Bulk Metallic Glasses

摘要:

通过放电等离子烧结（SPS）技术制备FeCrMoBC系块体非晶合金，并采用后续热处理优化其性能，探究了退火处理对Fe基块体非晶合金显微组织、力学行为及耐腐蚀性能的影响。结果表明：在优化SPS工艺参数（烧结温度560 ℃、烧结压力550 MPa、保温时间1 min）后，烧结态试样的相对密度达94.40%，抗压缩强度为678 MPa；经550 ℃×20 min热处理后，试样仍保持非晶态结构，力学性能显著提升——抗压缩强度增至884 MPa，同时展现出优异的耐腐蚀性能，其开路电位（E_corr）为-0.318 V、腐蚀电流密度（I_corr）为 2.098×10^-7 A/cm²、极化电阻（R₂）为59 379 Ω·cm²。值得注意的是，经650 ℃×20 min退火处理后，试样因晶相析出与晶粒细化，相对密度达到最大值97.23%，显微硬度也升至峰值758.86 HV。上述结果表明，通过调控显微组织演化，可控热处理可有效改善SPS制备Fe基块体非晶合金的致密化程度与综合性能。

Abstract:

FeCrMoBC bulk metallic glasses (BMGs) were synthesized via spark plasma sintering (SPS) technique, and subsequent heat treatment was applied to optimize their properties. The effects of annealing on the microstructure, mechanical behavior, and corrosion resistance of the Fe-based BMGs were investigated. Results show that under optimized SPS parameters (sintering temperature of 560 °C, consolidation pressure of 550 MPa, and holding time of 1 min), the as-sintered sample achieves a relative density of 94.40% and a compressive strength of 678 MPa. After heat treatment at 550 °C for 20 min, an amorphous matrix with enhanced mechanical properties can be obtained: the compressive strength increases to 884 MPa, accompanied by superior corrosion resistance, which is characterized by corrosion potential (E_corr) of -0.318 V, corrosion current density (I_corr) of 2.098×10^-7 A/cm², and polarization resistance (R₂) of 59 379 Ω·cm². Notably, annealing at 650 °C for 20 min results in a maximum relative density of 97.23% and a peak microhardness of 758.86 HV, which is attributed to the crystalline phase precipitation and grain refinement. These results demonstrate that controlled heat treatment can effectively improve the densification and comprehensive properties of SPS-processed Fe-based BMGs by regulating the microstructure evolution.