(1. 西北工业大学 材料学院，西安 710012；
2. 西北有色金属研究院 钛合金研究所，西安 710016)
摘 要: 研究Ti-25V-15Cr-0.2Si和Ti-25V-15Cr-2Al-0.2Si两种阻燃钛合金在550 ℃热暴露不同时间后的力学性能，并应用光学显微镜、X射线衍射、透射电镜对合金组织进行分析。结果表明，Al元素使Ti40阻燃钛合金在550 ℃的热稳定性能显著降低；对相的分析表明，Al元素可促进合金中Ti5Si3和a相的形成。在550 ℃热暴露200 h条件下，出现明显的TiCr2有序相。降低组织的稳定性及使合金在热暴露过程中生成过多的第二相是Al元素降低合金热稳定性能的主要原因。
关键字: Ti40阻燃钛合金；热暴露；析出物；力学性能
stability of Ti40 burn-resistant titanium at 550 ℃
（1. School of Materials Science, Northwestern Polytechnical University,
Xi’an 710012,China;
2. Titanium Alloy Research Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China）
Abstract:The mechanical properties of Ti-25V-15Cr-0.2Si and Ti-25V-15Cr-2Al-0.2Si after thermal exposure at 550 ℃ for different times were studied, and their microstructures were analyzed by OM, XRD and TEM. The results show that the thermal stability of the alloy decreases obviously with the addition of Al element during thermal exposure process. The analysis results of microstructures indicate that the addition of Al improves the precipitation of Ti5Si3 and a phase, and after 550 ℃ thermal exposed for 200 h there formed TiCr2 ordered phases in the alloy with the addition of Al element. The decrease of structure stability and much more precipitated phases are the main reasons of the effect of alloying element Al on the thermal stability.
Key words: Ti40 burn-resistant titanium alloy; thermal exposure; precipitated phases; mechanical property
