轧制及退火对FeCoCrNiN_(0.07)高熵合金组织及力学性能的影响  

Effects of Rolling and Annealing on Microstructure and Mechanical Properties of FeCoCrNiN_(0.07)High-entropy Alloy

作　　者：康亮 梁霄鹏[1,2,3] 李慧中[1,2,3] 吴庆波 KANG Liang;LIANG Xiaopeng;LI Huizhong;WU Qingbo(School of Materials Science and Engineering,Central South University,Changsha 410083,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Key Laboratory of Nonferrous Metal Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]中南大学粉末冶金国家重点实验室,湖南长沙410083 [3]中南大学有色金属材料科学与工程教育部重点实验室,湖南长沙410083

出　　处：《热加工工艺》2024年第17期94-97,共4页Hot Working Technology

基　　金：国家自然科学基金资助项目(51671217,51771232,52001334);国家杰出青年科学基金项目(51625404)。

摘　　要：采用粉末冶金热等静压法(HIP)制备了FeCoCrNiN_(0.07)高熵合金,研究了冷轧变形及后续750℃退火对FeCoCr-NiN_(0.07)高熵合金显微组织及力学性能的影响。结果表明;HIP态FeCoCrNiN_(0.07)高熵合金为简单的单相FCC结构,在经过轧制变形及后续750℃退火后无第二相产生。HIP态合金显微组织由大量的等轴晶粒和退火孪晶构成,经过轧制变形后显微组织中产生大量微观剪切带和一些变形孪晶,同时还存在大量的微观应变以及较高的位错密度。冷轧态合金经过750℃退火后发生完全再结晶形成大量细小的等轴再结晶晶粒和退火孪晶。HIP态合金表现出优异的塑性但强度较低,经过轧制后强度显著增大而塑性显著降低,这主要归因于位错强化。冷轧态合金在750℃退火后强度降低伸长率增加获得最佳的综合力学性能,强度的降低归因于再结晶软化作用,而强度优于HIP态归因于细晶强化的作用。FeCoCrNiN_(0.07)high-entropy alloy(HEA)was prepared by the way of powder metallurgy hot isostatic pressing(HIP),and the effects of cold-rolled deformation and subsequent annealing at 750℃on the microstructure and mechanical properties of FeCoCrNiN_(0.07)high-entropy alloy were studied.The results show that the HIPed FeCoCrNiN_(0.07)HEA has a simple single-phase FCC structure.The HIPed alloy has no second phase transformation after cold-rolled deformation and subsequent annealing at 750℃.The microstructure of the HIPed alloy is composed of a large number of equiaxed grains and annealing twins.After cold-rolled deformation,a large number of microscopic shear bands and some deformation twins are produced in the microstructure,and there are also lots of microscopic strains and high dislocation density.The cold-rolled alloy undergoes complete recrystallization after annealing at 750℃,and a large number of small equiaxed recrystallized grains and annealing twins are formed.The HIPed alloy exhibits excellent plasticity but low strength,after cold-rolling,the strength increases significantly but the plasticity is significantly reduced,which is mainly due to the effect of dislocation strengthening.After annealing at 750℃,the strength decreases and the plasticity increases,and the best comprehensive mechanical properties were obtained,the decrease in strength is due to the effect of recrystallization softening,and the higher strength than that of the HIPed state is due to the effect of fine-grain strengthening.

关 键 词：高熵合金 粉末冶金 冷轧变形 热处理 力学性能 

分 类 号：TG156.2[金属学及工艺—热处理]