低温时效及冷/温变形工艺对TB17钛合金组织的影响

Effect of low-temperature aging and cold/warm deformation on microstructure of TB17 titanium alloy

研究了不同冷/温变形条件下TB17钛合金的组织演变规律与相变行为,以及低温时效对其组织的影响。结果表明:变形顺序对TB17钛合金的相变行为有着较大的影响,先温变形再冷变形时合金发生了明显的形变诱导α相析出及马氏体相变,形变诱导α相析出发生在塑性变形阶段,而先冷变形再温变形时合金仅有形变诱导马氏体相变。在无低温时效的条件下,经初次冷变形产生的形变诱导马氏体在二次温变形时起到协调变形的作用,当350℃×0.5 h低温时效加入到两次变形之间,原本由初次冷变形产生的马氏体逐渐分解,且低温时效过程中并未发生其它明显的相变,但它促进了二次温变形时α相的析出。

The microstructure evolution and phase transformation behavior of TB17 titanium alloy under different cold/warm deformation conditions were studied,and the effect of low temperature aging on its microstructure was also studied.The results show that the deformation sequence has a great effect on the transformation behavior of the TB17 titanium alloy.The deformation-inducedαphase precipitation and martensitic transformation occur during the first warm deformation and then the cold deformation,and the deformation-inducedα-phase precipitation occurs at the plastic deformation stage,but only deformation-induced martensitic transformation occurs during cold deformation and then warm deformation.Under the condition of no low-temperature aging,the deformation-induced martensite induced by primary cold deformation plays the role of coordinated deformation during the secondary warm deformation.When the alloy first deforms by cold deformation and then low-temperature aging at 350℃for 0.5 h and last warm deformation,the martensite produced by the first cold deformation decomposes gradually,and no other obvious transformation occurs during the low temperature aging process,but it promotes the precipitation ofαphase during the secondary warm deformation.