基于加工图技术的铸态TB6钛合金锻造工艺优化

Optimization of high-temperature alloy forging process of TB6 alloy casting by processing map

在Thermecmaster-Z型热模拟实验机上对铸态TB6钛合金在800－1150℃、0.001－10 s^-1变形参数范围内进行了等温恒应变速率压缩实验,根据实验数据采用基于Murty准则的加工图技术对该合金的锻造工艺进行了优化,并结合显微组织观察研究了该合金的变形机制。结果表明,在低温区的较佳变形参数为800－950℃、0.001－0.01 s^-1,其变形机制为大晶粒超塑性;在高温区的较佳变形参数为1020－1080℃、0.001－0.006 s^-1,其变形机制为动态再结晶。失稳区出现在800－890℃、0.01－10 s^-1的低温区和975－1120℃、3.162－10 s^-1的高温区域,在流变失稳区会出现晶界裂纹。

The isothermal and constant strain rate compression tests of TB6 alloy casting were conducted in the range of 800-1150 ℃ and 0.001-10 s^-1 by Thermecmaster-Z simulator.According to the experimental data,the alloy forging process was optimized by means of processing map technology based on Murty criterion,and micro-deformation mechanisms was investigated combined with microstructure observation.The results show that at low deformation temperature,the feasible deformation conditions are 800-950 ℃,0.001-0.01 s^-1 with the deformation mechanism of large grain superplasticity.The feasible deformation conditions at high deformation temperature are 1020-1080 ℃,0.001-0.0056 s^-1 with the deformation mechanism of dynamic recrystallization.The region of flow instability occurs in the area of low deformation temperature with 800-890 ℃,0.01-10 s^-1 and of high deformation temperature with 975-1120 ℃,3.162-10 s^-1.The grain boundary crack appears in the region of flow instability.