(1. 西北工業(yè)大學(xué) 材料學(xué)院，西安 710012；
2. 西北有色金屬研究院 鈦合金研究所，西安 710016)
摘 要: 研究Ti-25V-15Cr-0.2Si和Ti-25V-15Cr-2Al-0.2Si兩種阻燃鈦合金在550 ℃熱暴露不同時(shí)間后的力學(xué)性能，并應(yīng)用光學(xué)顯微鏡、X射線衍射、透射電鏡對合金組織進(jìn)行分析。結(jié)果表明，Al元素使Ti40阻燃鈦合金在550 ℃的熱穩(wěn)定性能顯著降低；對相的分析表明，Al元素可促進(jìn)合金中Ti5Si3和a相的形成。在550 ℃熱暴露200 h條件下，出現(xiàn)明顯的TiCr2有序相。降低組織的穩(wěn)定性及使合金在熱暴露過程中生成過多的第二相是Al元素降低合金熱穩(wěn)定性能的主要原因。
關(guān)鍵字: Ti40阻燃鈦合金；熱暴露；析出物；力學(xué)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
