TC18钛合金热压参数对流动应力与显微组织的影响

通过在700~950℃和应变速率0.001~50s-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。

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

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℃.