(1. 宁夏东方钽业股份有限公司 钛材分公司，石嘴山 753000； 2. 西北工业大学 材料学院，西安 710072)
摘 要: 对Ti-6Al-6V-2Sn钛合金棒材进行锻造、固溶及时效处理，利用光学显微镜、XRD、SEM 及力学性能试验对该合金不同固溶、时效工艺下的显微组织和力学性能进行研究。结果表明：Ti-6Al-6V-2Sn钛合金锻棒的组织为初生等轴α+β转变组织，合金经固溶处理后的组织为初生αp相、马氏体α′、α″相和亚稳β相，强度有所降低，断面收缩率有所上升，说明固溶处理有一定的软化作用，但随着固溶温度升高，强度增加，塑性下降；经固溶处理后的棒材在时效处理过程中，亚稳态组织析出细小弥散的次生αs相，使合金强度明显强化，塑性略有降低，且随着时效温度的升高，强化效果下降，塑性随之提高。经过综合比较，并考虑强塑性的最佳匹配，可以确定本实验中Ti-6Al-6V-2Sn合金固溶时效热处理的优化工艺为(880 ℃, 1 h, WQ)+(580 ℃, 4 h, AC)。
关键字: Ti-6Al-6V-2Sn；固溶处理；时效处理；显微组织；力学性能
（1. Titanium Product Plant, Ningxia Orient Tantalum Industry Co., Ltd., Shizuishan 753000, China; 2. School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The influences of solution and aging treatment process on microstructure and properties of Ti-6Al-6V-2Sn alloy rods were investigated by using optical microscope (OM), XRD, scanning electron microscopy (SEM) and mechanical properties test. The results show that the as-forged microstructures of Ti-6Al-6V-2Sn alloy rods are fine isothermal primary α and transition β phases. After solution treatment, the microstructure is mainly composed of isothermal primary αp, martensite α′, α″ and metastable β phases. The strength decreases, but the reduction of area increases, which indicates that the solution treatment has a softening effect. With the rise of solution temperature, the strength increases subsequently, and the plasticity decreases. And fine dispersion secondary αs phase precipitates from the metastable structures after aging treatment process, the alloy can be strengthened significantly with slightly reduced plasticity. And with the aging temperature increases, the strengthening effect is reduced, and the plasticity increases. Through comprehensive comparison, considering the best match of the strength and plasticity, it can determined that the optimization solution and aging treatment process of Ti-6Al-6V-2Sn alloy in this experiment is (880 ℃, 1 h, WQ)+ (580 ℃, 4 h, AC).
Key words: Ti-6Al-6V-2Sn; solution treatment; aging treatment; microstructure; mechanical property
