热处理对BT25Y钛合金组织和性能的影响

Effect of heat treatment process on structure and property of BT25Y titanium alloy

本文研究了不同的固溶温度、固溶后冷却速度以及热暴露对BT25Y钛合金组织和性能的影响。结果表明,BT25Y钛合金于950℃固溶属于α+β两相区固溶,其组织由初生等轴α相和片状α+β相组成,硬度随冷速的增大而增大,但随着热暴露时间的延长,在40小时时硬度达到最大值,而后降低;而990℃固溶属于β区固溶,由β相降温分解的α+β两相组成,硬度较950℃固溶高,也随冷速的增大而增大,但随着热暴露时间的的延长,硬度在30小时时达到最低值,而后持续增大。

The structure and the property of BT25Y titanium alloy by use of different temperatures and cooling rates for the solution treatment as well as thermal exposure were studied. The results show that solution treating at 950℃ is α＋β two - phase region solution treating, the microstructure is constituted by isometric α crystal and layered α＋β crystal, the rigidity reached the highest at 40 hours in thermal exposure; Solution treating at 990℃ is β single phase region solution treating, the microstrueture is constituted by α＋β phases which were decomposed from high temperature β phase, and the rigidity reached the lowest at 30 hours in thermal exposure, and then grows bigger with the time.