B对NbMoTiVSi_(0.2)难熔高熵合金组织与力学性能的影响  

Effects of Boron on the Microstructure and Mechanical Properties of NbMoTiVSi_(0.2) Refractory High Entropy Alloys

作　　者：徐琴[1,4] 王琪 李娟 曾平 范谭浩 殷亚军 陈瑞润 Xu Qin;Wang Qi;Li Juan;Zeng Ping;Fan Tanhao;Yin Yajun;Chen Ruirun(School of Mechanic and Electrical Engineering,Henan University of Technology;National Key Laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology;State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology;Henan Provincial Engineering Laboratory of Automotive Composite Materials,Henan University of Technology)

机构地区：[1]河南工业大学机电工程学院,郑州450001 [2]河南工业大学汽车复合材料河南省工程实验室,哈尔滨150001 [3]哈尔滨工业大学金属精密热加工国家级重点实验室 [4]华中科技大学材料成形与模具技术国家重点实验室

出　　处：《特种铸造及有色合金》2022年第3期292-296,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(52001114,51825401);华中科技大学材料成形与模具技术国家重点实验室开放基金资助项目(P2020-023);河南省高等学校青年骨干教师培育计划资助项目(2021GGJS064);河南省科技攻关资助项目(192102210011);河南工业大学青年骨干教师培育计划资助项目(21420152)。

摘　　要：制备了不同B含量的(NbMoTiVSi_(0.2))_(100-x)B_(x)难熔高熵合金铸锭,研究了合金的相组成、微观组织和力学性能。结果表明,添加B后,合金的相组成无变化,均由BCC相和硅化物相组成,且在晶界形成由两相组成的共晶组织。随B含量增加,合金的树枝晶和共晶组织得到细化,组织形态由树枝晶向近等轴晶转变。随B含量增加,合金的屈服强度从1766 MPa提高到2076 MPa,极限压缩强度从2091 MPa提高到2270 MPa,断裂应变由16.47%下降到13.33%。细晶强化和固溶强化共同提高了合金的强度,而晶粒细化引起的塑性提高无法抵消固溶强化导致的塑性降低,因此,合金的塑性随B含量的增加而降低。(NbMoTiVSi_(0.2))_(100-x)B_(x) refractory high entropy alloy ingots with different addition of boron were prepared,and the phase constitution,microstructure and mechanical properties of the alloy were investigated.The results indicate that phase constitution of alloys remains stable after boron addition,which consists of BCC and silicide phase,and eutectic structure composed of the both phases are formed on the grain boundaries.The dendrite structure and eutectic structure of alloys are refined with boron content increasing,and the morphologies are converted from dendrite structure to near equiaxed grains.The yield strength of alloys is increased from 1766 MPa to 2076 MPa,the ultimate strength is increased from 2091 MPa to 2270 MPa,and the fracture strain is reduced from 16.47%to 13.33%.The strength of alloy is synergistically improved by grain refinement strengthening and solid solution strengthening,while plasticity improvement induced by grain refinement effect is unable to offset the plasticity decrease caused by the solid solution strengthening effect,therefore the plasticity is decreased with increase of boron.

关 键 词：难熔高熵合金 B 共晶组织 微观组织 力学性能 

分 类 号：TG139[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—合金]