热加工工艺对医用TC20合金显微组织的影响

Effect of Hot Working Technology on Microstructure of Biomedical TC20 Alloy

通过Gleeble-1500热模拟机对TC20合金的热压缩行为进行了研究。变形温度分别为:750、800、850、900℃;变形速率分别为:0.001、0.01、0.1、1.0 s-1;最大变形量为60%。结果表明:流变应力和微观组织受变形温度和应变速率影响显著;流变应力随变形温度的升高和应变速率的降低而降低。随着应变速率的减小,微观组织中α相尺寸增大,所占的比例减少;随着变形温度的升高,初生α相逐渐粗化,并转变为β相,所占比例降低。按照变形行为和微观组织大小,合适的热加工区域温度是750～850℃,应变速率是0.01～0.1s-1。

The hot compression behavior of TC20 alloy was investigated by Gleeble-1500 simulation machine.The deformation temperatures were 750,800,850 and 900℃ ; the strain rates of deformation were 0.001,0.01,0.1 and 1.0s-1; the maximum deformation was 60%. The results show that the flow stress and the microstructure are influenced strikingly by both deforming temperature and strain rate; the flow stress decreases with increasing deforming temperature and decreasing strain rate. As strain rate decreases, the sizes of s-phase increase while the proportion of α-phase decreases; as the deformation temperature increases, β-phase turns into β-phase and is coarsened, while the proportion of β-phase decreases. According to deformationa behavior and the size of microstructure, the suitable hot working zone is in the temperature range of 750-850℃ and strain rate range of 0.01-0. 1s-1.