退火工艺对冷轧态CoCrNi中熵合金组织与性能的影响  

Effect of Annealing on Microstructure and Properties of Cold Rolled CoCrNi Medium-Entropy Alloy

作　　者：李双元 王宏 彭渝丽[1] 王军 武上焜 LI Shuangyuan;WANG Hong;PENG Yuli;WANG Jun;WU Shangkun(School of Materials and Chemical Engineering,Xi’an Technological University,Xi’an 710021,China)

机构地区：[1]西安工业大学材料与化工学院

出　　处：《西安工业大学学报》2020年第1期95-101,共7页Journal of Xi’an Technological University

基　　金：国家自然科学基金（51671150）;陕西省教育厅重点实验室基金（17JS054）;陕西省自然科学基础研究计划项目（2017JM5057）

摘　　要：为研究冷轧态的CoCrNi中熵合金组织与性能的演变,采用真空电弧熔炼法制备CoCrNi中熵合金并进行双辊冷轧轧制,采用不同的热处理工艺,对冷轧后的试样进行退火处理。利用扫描电子显微镜和X射线衍射仪分析其组织与结构的变化;通过显微硬度测试和拉伸试验研究其性能变化。研究结果表明:CoCrNi中熵合金冷轧后退火处理,没有新相的产生,依然是单一FCC结构;在退火过程中发生了再结晶现象,当退火温度为900℃时,由于温度较低,再结晶发生缓慢,随退火时间延长,显微硬度从456 HV降至215 HV,屈服强度从1570 MPa降至400 MPa,塑性从5%提高至69%,组织逐渐转变为再结晶后的等轴晶;当退火温度提高至1000℃时,能快速完成再结晶,退火10 min时,显微硬度为219 HV,屈服强度和塑性分别为315 MPa和71%,随退火时间延长,组织与性能变化均无明显变化;当退火温度继续提高至1100℃时,由于退火温度较高,再结晶迅速完成,退火10 min时,显微硬度为199 HV,屈服强度和塑性分别为351 MPa和77%,随退火时间和温度的增加,发生晶粒长大,影响材料性能。In order to study the effect of annealing process(above the recrystallization temperature)on the structure and properties of cold rolled CoCrNi medium entropy alloy,the vacuum arc melting method was used to prepare CoCrNi medium entropy alloy for twin roll cold rolling,and different heat treatment processes were adopted to anneal the cold rolled samples.The changes in their microstructure were analyzed by scanning electron microscopy and X ray diffraction,and the changes of their properties were studied through microhardness test and tensile test.The results are as follows.In the annealing treatment of the cold rolled CoCrNi medium entropy alloy,no phase transition emerged,and it remained a single FCC structure.Recrystallization occurred during annealing process.When the annealing temperature was at 900℃,the recrystallization occurred slowly due to the lower annealing temperature.With annealing time was prolonged,the microhardness decreased from 456 HV fall to 215 HV,the yield strength fell from 1570 MPa to 400 MPa,and the plasticity increased from 5%to 69%.The structure gradually transformed into equiaxed crystals after recrystallization.When the annealing temperature rose to 1000℃,the recrystallization was completed quickly.When the sample was annealed for 10 mins,its microhardness was about 219 HV,its yield strength and plasticity were 315 MPa and 71%respectively.With the annealing prolonged,there were no obvious changes in its structure and properties.When the annealing temperature continued to rise to 1100℃,because of the higher temperature,the recrystallization was completed rapidly.After 10 mins annealing,the microhardness was about 199 HV,and the yield strength and the plasticity were 351 MPa and 77%respectively.With the annealing time and temperature increasing further,the grain became larger,affecting the properties of the materials.

关 键 词：中熵合金 冷轧 退火处理 显微组织 力学性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]