粉末冶金Mo-Re合金微观组织及高温拉伸性能  

Microstructure and high temperature tensile properties of powder metallurgy Mo−Re alloys

作　　者：林小辉[1] 薛建嵘 高选乔 梁静[1] 张新[1] 李延超[1] 杨毅超 张文[1] LIN Xiaohui;XUE Jianrong;GAO Xuanqiao;LIANG Jing;ZHANG Xin;LI Yanchao;YANG Yichao;ZHANG Wen(Northwest Institute for Non-Ferrous Metal Research,Xi’an 710016,China)

机构地区：[1]西北有色金属研究院,西安710016

出　　处：《粉末冶金技术》2023年第6期516-522,共7页Powder Metallurgy Technology

基　　金：陕西省科技重大专项资助项目(2020zdzx04-02-01);陕西省重点研发计划资助项目(2019ZDLGY05-05)。

摘　　要：采用粉末冶金结合高温压力加工制备了Mo-14Re和Mo-42Re合金棒材,观察与测试了Mo-Re合金的微观组织、相组成、室温及高温拉伸性能,并结合断口形貌分析了合金断裂机制。结果表明,经高温压力加工后,Mo-Re合金晶粒由等轴状转变为拉长的纤维状,相对密度达99.6%以上。Re固溶于Mo中,使Mo-Re合金晶格常数从Mo-14Re的3.1384?减小到Mo-42Re的3.1304?,导致晶格畸变程度增大。当Re质量分数从14%增加到42%,Mo-Re合金的室温及高温强度得到大幅提升。随测试温度升高,合金强度下降,Mo-14Re断后伸长率有所下降,而Mo-42Re断后伸长率呈上升趋势。Mo-14Re室温断口呈木纹状撕裂型断裂,1100~1300℃断口呈韧窝状,在1500℃时塑性变形主要由晶界滑移产生。Mo-42Re室温断口为穿晶断裂,1100~1500℃断口为完全的韧窝状,塑性变形由韧窝产生的非均匀变形提供。Mo−14Re and Mo−42Re alloy bars were prepared by powder metallurgy and hot press working.The microstructure,phase composition,and tensile properties at room and high temperature were observed and tested,and the fracture mechanism of Mo−Re alloys was analyzed,combined with the fracture morphology.The results show that,after the hot press working,the Mo−Re alloy grains change from equiaxed to elongated fibrous,and the relative density of alloy bars is more than 99.6%.The solid solution of Re in Mo reduces the lattice constant of Mo−Re alloy from 3.1384Åof Mo−14Re to 3.1304Åof Mo−42Re,leading to the increase of lattice distortion.The room and high temperature strength of Mo−Re alloys are greatly improved with the increase of Re mass fraction from 14%to 42%.With the increase of test temperature,the strength of Mo−Re alloys decreases,the elongation of Mo−14Re alloys decreases slightly,while that of Mo−42Re increases.The room temperature fracture of Mo−14Re alloys exhibits a wood-grain tearing fracture,the fracture at 1100~1300℃is dimple,and the plastic deformation is mainly caused by grain boundary slip at 1500℃.The room temperature fracture of Mo−42Re alloys shows a transgranular fracture,the fracture at 1100~1500℃is completely dimpled,and the plastic deformation at high temperature is provided by the non-uniform deformation produced by dimple.

关 键 词：Mo-Re合金 微观组织 拉伸性能 断口形貌 

分 类 号：TG135.1[一般工业技术—材料科学与工程] TF125[金属学及工艺—合金]