高压凝固Ti-48Al合金片层组织失稳机理研究

Instability mechanism of lamellar structures of Ti-48Al alloysolidified under high pressure

摘要:

采用高压凝固设备制备了Ti-48Al(at.%)合金,并在真空封装后进行热处理实验,研究热处理对高压凝固Ti-48Al合金的片层组织失稳机理。结果表明,在低于共析转变温度进行热处理时,常压凝固Ti-48Al合金组织中较难发现α₂相颗粒,而高压凝固片层组织界面处已开始析出α₂相颗粒。加热至1280℃进一步确定,相比于常压凝固,高压凝固Ti-48Al合金更易分解,且片层组织中γ相优先分解,长杆状的残余α₂相经历球化长大,本文的研究为进一步研究高压下组织与相转变提供了基础,丰富了高压凝固理论。

Abstract:

Instability mechanism of lamellar structures of Ti-48Al alloy solidified under high pressure was investigated. The results indicate that after 1100 ℃/12 h air cool, α₂ phase particles can hardly be seen in normal pressure solidified Ti-48Al alloy. Howerver, α₂ phase has been found in high pressure solidified Ti-48Al alloy. Incresaing the temperature to 1280 ℃, the high pressure solidified Ti-48Al alloy is easier to decomposite than normal pressure. This research has provided the basis of further studying on the microstructures and phase transformation of high pressure solidified Ti-Al intermetallics and enriched the theory of high pressure solidification.