不同温度热暴露对铸造TiAl合金室温拉伸塑性的影响  

Influence of Thermal Exposure at Different Temperatures on Room Temperature Tensile Ductility of Cast TiAl Alloy

作　　者：王红卫[1] 朱春雷[2] 张继[2] 曹睿[1] WANG Hong-wei;ZHU Chun-lei;ZHANG Ji;CAO Rui(College of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;High Temperature Materials Research Institute,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]兰州理工大学材料科学与工程学院,兰州730050 [2]钢铁研究总院高温材料研究所,北京100081

出　　处：《材料工程》2018年第12期151-156,共6页Journal of Materials Engineering

摘　　要：研究大气环境中600～750℃/300h热暴露对铸造Ti-47.5Al-2.5V-1.0Cr-0.2Zr(原子分数/%)合金室温拉伸塑性的影响。结果表明:600℃热暴露后,试样表面并未观察到表面反应层,平均室温拉伸塑性从2.81%降至2.54%,降低幅度仅为9.6%;650℃热暴露后,试样表面形成了紧邻基体的贫铝层,室温拉伸塑性进一步降低至1.54%的水平,降低幅度达到45%。温度提高到700℃后,贫铝层厚度未明显增加,此时的室温拉伸塑性与650℃热暴露试样相当;750℃热暴露后,贫铝层厚度显著增加,室温拉伸塑性进一步降低,仅为1.12%,降低幅度达到了60%。不同温度热暴露后室温拉伸塑性呈现不同程度降低,归因于贫铝层的出现及厚度呈台阶式增长,与外侧氧化物层的形成及厚度变化无关。The effect of thermal exposure at 600-750℃ for 300h in atmosphere on room temperature tensile ductility of cast Ti-47.5Al-2.5V-1.0Cr-0.2Zr（atom fraction/%） was investigated.The results indicate that no surface layer on the specimen surface is observed after exposure at 600℃,but tensile ductility at room temperature decreases from 2.81% to 2.54%,the reduction is only 9.6%;after exposure at 650℃,a Al depleted layer is formed on the surface of substrate,tensile ductility is further reduced to 1.54%,the reduction reaches 45%. When exposure temperature increases to 700℃,tensile ductility does not continuously decrease due to no significant increase in the thickness of the Al depleted layer;when the exposure temperature increases to 750℃,tensile ductility is further reduced to 1.12% due to remarkable increase in the thickness of Al depleted layer with the reduction of 60%.Tensile ductility at room temperature decreases in different degrees as the exposure temperature increases,which is attributed to emerging and step-increase of the Al depleted layer adjacent to the substrate, and is not related to the formation of outside oxide layer and the changes in thickness.

关 键 词：TIAL合金 热暴露 温度 室温拉伸塑性 贫铝层 

分 类 号：TG146.2[一般工业技术—材料科学与工程]