多次重复固溶时效处理对TB15钛合金组织和力学性能的影响

利用光学显微镜、拉伸试验机和扫描电镜等手段研究了多次重复固溶时效处理对TB15钛合金显微组织和力学性能的影响。结果表明,随着固溶时效处理重复次数的增加,TB15钛合金的显微组织发生了较为明显的变化,次生α相合并长大,原始β晶粒晶界增厚;1次固溶时效处理后合金的综合力学性能达到最优,随着固溶时效处理重复次数的增加,合金的强度和断裂韧度均降低,伸长率和断面收缩率也急剧降低,断裂类型从韧性断裂向脆性断裂转变;相同工艺参数的重复固溶时效处理不能实现在不大幅降低强度和断裂韧度的前提下改善该合金的室温塑性。

Effect of multiple repeated solution and aging treatment on microstructure and mechanical properties of TB15 titanium alloy

Effect of multiple repeated solution and aging treatment on microstructure and mechanical properties of TB15 titanium alloy was studied by means of optical microscope, tensile testing machine and scanning electron microscope. The results show that with the increase of the repeating time of solution and aging treatment, the microstructure of the TB15 titanium alloy changes obviously, the secondary α phase merges and grows, and the original β grain boundary thickens. The mechanical properties of the alloy after one time solution and aging treatment is the best, however, with the increase of repeating time, the strength and fracture toughness of the alloy decrease, the elongation and reduction of area also decrease sharply, and the tensile fracture changes from ductile fracture to brittle fracture. In conclusion, multiple repeated solution and aging treatment with the same process parameters cannot improve the room temperature ductility of the alloy without drastically reducing the strength and fracture toughness.