(1. 北京航空材料研究院 钛合金研究室, 北京100095;
2. Rolls-Royce Plc, P.O.Box 31, Derby DE24 8BJ, UK)
摘 要: 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。
关键字: 阻燃钛合金； 热暴露； 微观组织； 拉伸性能； 变形机制
of Ti-25V-15Cr-2Al-0.2C alloy
（1. Laboratory of Titanium Alloys, Beijing Institute of Aeronautical Materials, Beijing 100095, China;
2. Rolls-Royce Plc, P. O. Box31, Derby DE24 8BJ, UK）
Abstract: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℃, 100h), 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℃.
Key words: non-burning titanium alloy; thermal exposure; microstructure; tensile property; deformation mechanism
