析出相对Ti60钛合金蠕变和持久性能的影响

研究了固溶态的Si、硅化物以及α2相对Ti60高温钛合金蠕变和持久性能的影响.结果表明,α片层之间析出的硅化物能提高Ti60钛合金的600℃蠕变抗力,且当α片层内部有α2相析出时蠕变抗力提高更明显,但是硅化物的大量析出和大颗粒硅化物的存在却降低了Ti60钛合金的600℃持久性能;α2相的析出同时提高材料的蠕变抗力和持久性能;减少硅化物的析出以提高固溶态的Si对低应力下蠕变抗力的作用不显著,但是能改善高应力下的持久性能.在蠕变和持久实验条件下固溶态的硅和硅化物的不同作用,可通过不同外加应力水平下材料变形机制的差异加以解释.

Effect of precipitates on the high temperature creep and creep rupture properties of Ti60 alloy

The influence of Si in solution, silicide and α2 phase on the high temperature creep and creep rupture properties of Ti–60 titanium alloy was investigated. The results show that silicide precipitated between α plates increases the creep resistance at 600 ^oC, which becomes more pronounced when α2 phase precipitated in the matrix. However, the effect of silicide on the creep rupture property was negative when silicides exist in large size and amount. Precipitation of α2 phase was beneficial both to high temperature creep and creep rupture properties. Increase of silicide in solution by way of lowering the silicide precipitation was more beneficial to creep rupture properties with higher applied stress than to creep properties with lower applied stress. The underlying  mechanism under creep test condition can be rationalized by the different deformation mechanism under different applied stress.