(1. 西北工业大学 材料科学与工程学院，西安 710012；
2. 西北有色金属研究院 钛合金研究所，西安 710016)
摘 要: 研究几种不同热处理工艺对TC4-DT钛合金厚板显微组织和力学性能的影响。结果表明：TC4-DT合金在两相区固溶处理得到等轴或双态组织，其室温拉伸性能较好，而经过β相区固溶处理得到片层组织具有较好的断裂韧性；通过控制β相区固溶处理时的冷却速度以及第二重热处理时的温度以及冷却速度，可以获得不同的α片层组织，从而改善其断裂韧性。采用(1 010 ℃, 45 min, AC)+(965 ℃, 1.5 h, AC)+(550 ℃, 8 h, AC)多重热处理工艺，可实现合金强度-塑性-韧性的较好匹配，获得优良的综合性能。
关键字: TC4-DT钛合金；板材；多重热处理；显微组织；力学性能
（1. School of Materials Science and Engineering, Northwest Polytechnical University, Xi’an 710012, China;
2. Titanium Alloy Research Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China）
Abstract:The effects of different heat treatments on microstructure and mechanical properties of TC4-DT alloy were discussed. The results show that the sample with equiaxed or duplex microstructure after two phase field heat treatment has better room temperature tensile properties, while the sample with lamellar microstructure after β phase field heat treatment has better fracture toughness. The different thicknesses of α lamellar are obtained by controlling the cooling rates from β phase field solution treatment, temperature and cooling rates of secondary heat treatment, which improves the fracture toughness. The excellent matching of strength, ductility and fracture toughness are obtained after multi heat treatment of (1 010 ℃, 45 min, AC)+(965 ℃, 1.5 h, AC)+(550 ℃, 8 h, AC).
Key words: TC4-DT titanium alloy; plate; multiple heat treatment; microstructure; mechanical properties
