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以铸态TC21钛合金为研究对象,在Gleeble3500热模拟试验机上对TC21钛合金在开坯温度1000～1150℃、应变速率0.01～10 s-1的高温变形行为进行了研究。结果表明,铸态TC21钛合金流动应力随应变速率的提高和温度的降低而升高,具有温度和应变速率敏感性;β区变形激活能为196.277 kJ/mol,变形机制以动态回复为主;低应变速率下(ε≤0.1 s-1),流变曲线呈稳态流动特征,拉长的β晶粒晶界呈锯齿状,晶界处发生连续再结晶;高应变速率下(ε≥1 s-1),拉长的β晶粒晶界平直,为典型动态回复;高应变速率且温度相对较低(ε=10 s-1,T≤1150℃)时,流变曲线呈流动软化特征,原因是局部温升效应及局部塑性流动。
The as-cast TC21 titanium alloy was studied on the Gleeble3500 thermal simulator. The deformation behavior of the TC21 titanium alloy at the billet temperature of 1000 ~ 1150 ℃ and the strain rate of 0.01 ~ 10 s-1 was studied. The results show that the flow stress of as-cast TC21 titanium alloy increases with the increase of strain rate and temperature, and has the sensitivity of temperature and strain rate. The deformation activation energy of β zone is 196.277 kJ / mol, and the deformation mechanism is dominated by dynamic recovery. At low strain rate (ε≤0.1 s-1), the rheological curves showed a steady flow. The grain boundaries of elongated β grains were serrated and continuous recrystallization took place at grain boundaries. At high strain rate (ε≥1 s-1). The grain boundaries of the elongated β grains were straight and the typical dynamic response. At high strain rate and relatively low temperature (ε = 10 s-1, T≤1150 ℃), the rheological curves softened Features, due to local temperature effects and local plastic flow.