TC18钛合金热压参数对流动应力与显微组织的影响

Effects of Hot Process Parameters on Flow Stress and Microstructures of TC18 Titanium Alloy

通过在700950℃和应变速率0.00150s-1条件下的热模拟实验,系统研究了TC18钛合金应变速率、变形温度对变形抗力和显微组织的影响。结果表明：提高变形温度或降低应变速率,可显著降低TC18合金变形过程中的真应力,与单相区相比,两相区变形抗力对温度的变化更为敏感。在α＋β区变形时,α相和β相都参与变形,球状初生α沿形变方向略有拉长,β相沿金属流动方向形成纤维组织;β相变点以上温度变形时,β相沿金属流动方向呈纤维状分布,在950℃可以观察到再结晶的等轴β晶粒。

The effect of strain rate and deformation temperature on the deformation resistance and the microstructure of TC18 titanium alloy was studied through heat simulating test at 700-950℃ and strain rate 0.001-50s-1.The results show that,when the deformation temperature increases or the strain rate decreases,the real stress can be reduced obviously.Comparing to deformation in β phase,deformation resistance in α＋β phase is more sensitive to the change of temperatures.When α＋β phase deformed,α and β phases join in deformation at the same time,but deformation degree is different.Preliminary equiaxed alpha phase is elongated slightly and beta phase changes to fiber texture along deformation direction.When β phase deformed,beta phase is fibrous along metal flowing direction,and equiaxed beta grain can be seen when the deformed temperature is above 950℃.