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.
作者
王红卫
朱春雷
张继
曹睿
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)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2018年第12期151-156,共6页
Journal of Materials Engineering
关键词
TIAL合金
热暴露
温度
室温拉伸塑性
贫铝层
TiAl alloy
thermal exposure
temperature
room temperature tensile ductility
Al depleted layer
