Ti-25V-15Cr-2Al-0.2C合金的组织、性能及其变形机制

Microstructure, tensile properties and deformation mechanisms of Ti-25V-15Cr-2Al-0.2C alloy

对Ti 25V 15Cr 2Al 0.2C阻燃β钛合金的微观组织、拉伸性能和变形机制进行了研究。结果表明:(Ti,V)C和α相是β基体上的2种主要析出相;高温长期热暴露(540℃,100h)后的合金晶界上形成连续的α膜,其塑性因此急剧下降;β基体在热暴露过程中发生微弱的短程有序化(SRO)转变,这在一定程度上破坏了合金的热稳定塑性;该合金室温变形以普通位错滑移为主要形变机制,热暴露后的变形结构中出现少量平面滑移带,位错的交滑移和攀移是合金540℃高温变形的重要形变机制。

The microstructure, tensile properties and deformation mechanisms of nonburning β titanium alloy Ti25V15Cr2Al0.2C (mass fraction, %) were investigated. The results show that, (Ti, V)C and α are two main precipitation phases in the β matrix of the alloy; after longterm exposure (540 ℃, 100 h), the ductility of the alloy is decreased drastically, mainly due to a continuous α film formed at β grain boundaries; a low degree of short range ordering (SRO) of the β matrix occurs during longterm exposure at 540 ℃, which impairs the thermal stability of the alloy to a certain degree; the ordinary dislocation slip is the main mode of room plastic deformation of the alloy; a small number of planar slip bands appear in the deformation structure of the alloy after longterm exposure; dislocation crossslip and climb are the important deformation modes of the alloy at 540 ℃.