摘要
在Gleeble-1500热模拟机上对7150铝合金进行等温多道次热压缩实验,变形温度为300℃和400℃,变形速率为0.01s-1和0.1s-1,道次真应变均为0.2,道次间保温时间为10s和100s。结果表明:7150铝合金等温多道次变形过程呈现明显动态和静态软化特性;静态软化率在300℃时随着变形道次(或累积应变)的增加基本保持恒定,而在400℃时随着道次的增加迅速增加;随着温度的升高、应变速率的增大和道次间保温时间延长,软化率均明显增大;合金多道次热变形后,主要呈现典型的回复组织而未发生明显的再结晶。结合金相显微组织及软化率分析,对7150铝合金在变形温度400℃、变形速率0.1s-1条件下的多道次变形时出现软化率大于100%的"奇异"静态软化现象进行了探讨。
The isothermal multistage hot compression tests of 7150 aluminum alloy at 300 ℃ and 400 ℃ with strain rate of 0.01 and 0. 1 s-1 were conducted on Gleeble-1500 system. The delay times between passes were 10 and 100 s after achieving a true strain of approximate 0. 2 at each stage. The results showed that clear dynamic and static softening happened during isothermal multistage hot compression. The fractional softening almost stayed at a steady value under various passes （or accumulative strain） at 300 ℃. However, fractional softening increased rapidly with increasing passes at 400 ℃. The fractional softening also in creased with increasing deformation temperature, strain rate and holding times between passes. The optical microstructure of de formed 7150 aluminum alloy after isothermal multistage hot compression presented typical recovery microstructure, but not re- crystallization. The exceptional softening phenomenon （fractional softening 〉100%） at temperature of 400 ℃ and strain rate of 0.1 s-1 was discussed based on microstructure observation and fractional softening analysis as well.
出处
《中国科技论文》
CAS
北大核心
2015年第4期394-398,共5页
China Sciencepaper
基金
高等学校博士学科点专项科研基金资助项目(20130161110007)
湖南省研究生科研创新项目(CX2013B128)
关键词
铝合金
等温多道次热压缩
静态软化
回复
aluminum alloy
isothermal multistage hot compression
static softening
recovery
