回火温度对FCC高熵合金Fe_(49.5)Mn_(29.7)Co_(9.9)Cr_(9.9)C_(1)显微组织和力学性能的影响  

Effect of Tempering Temperature on the Microstructure and Mechanical Properties of Fe_(49.5)Mn_(29.7)Co_(9.9)Cr_(9.9)C_(1) HEA

作　　者：李小琳 赵利媛 李雅婷 郝晓晓 王海丰[1] LI Xiaolin;ZHAO Liyuan;LI Yating;HAO Xiaoxiao;WANG Haifeng(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造技术》2022年第10期875-881,共7页Foundry Technology

基　　金：凝固技术国家重点实验室自主课题(2022-TS-10);国家自然科学基金(52004224)。

摘　　要：高熵合金具有很多优于传统钢材的特殊性能,故被广泛研究,但其室温强度较低仍是目前亟需解决的问题之一。本文在FCC高熵合金Fe_(50)Mn_(30)Co_(10)Cr_(10)的基础上加入1%C(原子分数),拟通过析出强化提高高熵合金的屈服强度。研究表明,高熵合金经锻造、轧制及退火后组织中主要包含FCC相和少量HCP相,且在650、800及900℃退火温度时在FCC相中均分布着高密度纳米析出相。根据EDS分析可得析出相为Cr_(23)C_(6),其对晶界起到钉扎效果,可显著提高合金屈服强度。高熵合金在拉伸变形过程中,随着应变的增加HCP相含量及变形孪晶含量增加,即产生TRIP和TWIP效应来提高合金的加工硬化率,从而在提高屈服强度的基础上保证合金具有良好的塑性。High-entropy alloys (HEAs) have been widely investigated due to their special properties,which are superior to those of traditional steels.However,the relatively low yield strength is one of the tough problems that need to be solved.In this paper,1%C(atomic percentage) was added to an Fe_(50)Mn_(30)Co_(10)Cr_(10) FCC high-entropy alloy to increase the yield strength of the alloy by precipitation strengthening.The result shows that the structure of the high-entropy alloy after forging,rolling and annealing is mainly composed of an FCC matrix and a small amount of the HCP phase.High-density nanoprecipitates are distributed in the FCC phase after annealing at 650,800 and 900℃,which are identified as Cr_(23)C_(6) by EDS,playing a pinning effect on the grain boundaries and thus increasing the yield strength of the alloy.In the process of tensile deformation of the high-entropy alloy,the content of the HCP phase and deformation twins increase with increasing tensile strain.In general,TRIP and TWIP effects can improve the work hardening rate of the alloy and ensure that the alloy has a high yield strength and good plasticity.

关 键 词：加工工艺 高熵合金 TWIP效应 TRIP效应 力学性能 

分 类 号：TG113.25[金属学及工艺—物理冶金]