热变形参数对TC21钛合金微观组织的影响

Effects of hot forming parameters on the microstructures of TC21 titanium alloy

通过在Gleeble-1500D型热模拟试验机上进行的等温恒应变速率压缩试验和金相及透射分析,研究了变形温度和应变速率对TC21钛合金热变形后微观组织的影响.结果表明:变形温度和应变速率对TC21钛合金的变形组织有着显著的影响.在两相区,随着变形温度的升高,组织中初生α相含量减少,β相含量增加;在应变速率为0.01 s-1、变形温度为860和890℃时,初生α相发生了再结晶.随着应变速率的增加,马氏体条变窄,当应变速率较低时(0.01 s-1),组织中观察了再结晶晶粒.

The effects of temperature and strain rate on microstructure of TC21 titanium alloy after hot deformation have been investigated through isothermal constant strain rate compression tests on the Gleeble - 1500D Thermal Simulator as well as metallurgical and transmission analyses. The results show that the deformation temperature and strain rate have significant influence on microstructure of TC21 titanium alloy. In two phased region, the volume fraction of ct phase decreases with the increasing of temperature, but that of β phase increases. The recrystallization of ct phase occurs when the strain rate is 0.01 s -1 and the deformation temperature is 860 ℃ and 890 ℃. The martensite lath becomes narrow with the increasing of strain rate.