变形态Ti40合金高温变形行为

在GLEEBLE热模拟试验机上对变形态Ti40合金进行热压缩实验,采用基于Prasad准则的加工图技术,研究变形态Ti40合金在变形温度950℃～1100℃、应变速率0.001s-1～1.0s-1范围内的微观变形机制和流变失稳现象,并优化该合金的高温变形参数。结果表明,失稳区出现在低温、高应变速率区,当变形温度为950℃～1010℃、应变速率0.13s-1～1.0s-1时,失稳区会出现局部流动,在实际热加工时应尽量避开这一参数范围;变形温度950℃～1100℃、应变速率0.001s-1～0.01s-1为较佳的变形参数范围,其变形机制以动态再结晶为主,伴随动态回复,最佳的变形参数位于温度1050℃、应变速率0.001s-1附近,该区域发生了完全动态再结晶;除失稳区和较佳变形区以外的区域,变形机制以动态回复为主,伴随动态再结晶,是可加工的区域。

Study on high temperature deformation behavior of wrought Ti40 alloy

Hot compression tests of wrought Ti40 alloy were conducted on the GLEEBLE hot working simulator.Micro-deformation mechanism and the manifestation of flow instability were investigated by means of processing map technology based on Prasad criterion at temperature 950℃~1100℃ and strain rate 0.001s-1~1.0s-1,and deformation parameters were optimized.The results show that the area of flow instability appears at low temperature and high strain rate.At temperature 950℃~1010℃ and strain rate 0.13s-1~1.0s-1,localized flowing may appear at the area of flow instability which should be avoided in practical hot working.Temperature 950℃~1100℃ and strain rate 0.001s-1~0.01s-1 are better range,in which the deformation mechanisms are mainly dynamic recrystallization accompanied with dynamic recovery.The optimum parameters are near 1050℃ and 0.001s-1 accompanying complete dynamic recrystallization.The deformation mechanisms of the regions beside those described above,are mainly dynamic recovery accompanied with dynamic recrystallization,and which can be selected for processing.