摘要
采用Gleeble-1500热模拟试验机对Ti-2Al-9.2Mo-2Fe合金进行850-1000℃、应变速率0.01-10 s^-1的高温压缩变形试验。结果表明,热压缩后合金的显微组织为拉长的β晶粒和锯齿状的β晶界。低应变速率（0.01 s^-1和0.1 s^-1）时,原始β晶界处形成了大量小角度晶界以及少量的再结晶晶粒组织;高应变速率（1 s^-1和10 s^-1）时,原始β晶界附近形成了大量细小的再结晶晶粒组织。热压缩过程中,合金在屈服之后随应变速率的变化呈现出不同的应变硬化或软化现象。应变速率较高时,合金呈现出明显的应变硬化效应,流变应力出现非常明显的周期性震荡,当应变速率为1 s^-1时,未出现应变软化现象,而应变速率为10 s^-1时,可观察到明显的流变软化阶段;应变速率较低时,高温（950℃和1000℃）压缩条件下,合金在屈服之后立即进入流变稳态阶段,无明显的流变硬化或软化现象。而在低温（850℃和900℃）压缩时,屈服之后出现轻微的流变硬化现象。
Hot compression deformation behavior of Ti-2Al-9. 2Mo-2Fe alloy compressed at 850-1000 ℃ with strain rates 0. 01-10 s^-1was conducted by Gleeble-1500 thermal simulator. The results show that serrated β grain boundaries and elongated β grains can be found in the alloy after hot compressed. At low strain rates（ 0. 01 s^-1and 0. 1 s^-1）,large amount of low angle grain boundaries form along serrated grain boundaries,accompanying with small amounts of recrystallized β grains. But at high strain rates（ 1 s^-1and 10 s^-1）,large amount of recrystallized grains form along original β grain boundaries. During hot compression,the alloy presents different phenomena of strain hardening or softening with the increase of strain rates after yield. When the alloy deformed at high strain rates,a significant rheological hardening can be found,as well as periodic fluctuations. Moreover,with increasing strain,rheological softening is found in the compress with 10 s^-1,but is not found in condition of 1 s^-1. However,when the alloy deformed at 950 ℃ and 1000 ℃ with low strain rates,rheological static stage can be found after yielding without any noticeable hardening or softening. While compressed at 850 ℃ and 900 ℃with the same strain rates,yielding followed by slight rheological hardening is observed.
出处
《金属热处理》
CAS
CSCD
北大核心
2015年第9期88-91,共4页
Heat Treatment of Metals
关键词
Β钛合金
热压缩
组织演变
流变行为
β titanium alloy
hot compression
microstructure evolution
rheological behavior
