采用选区激光熔化成形制备TC4钛合金, 分析了沉积态和热处理态下TC4钛合金微观组织, 并通过拉伸试验, 测试了热处理态下TC4钛合金抗拉强度和延伸率。结果表明, 沉积态钛合金在快速冷凝下组织几乎全为非平衡相α′, 组织细密。当固溶热处理工艺为960 ℃、2 h、AC(Air cooling)时, 钛合金组织由非平衡相α′全部转换为平衡相α, 组织粗化为板条状, 试样的抗拉强度最高可以达到1 056 MPa, 延伸率达到16.9%, 整个断面有均匀密集分布的等轴韧窝, 属于典型的韧性断裂, TC4钛合金在热处理下获得较佳的强度-塑性匹配。

TC4 titanium alloy was prepared by selective laser melting forming. The microstructure of TC4 titanium alloy in the as-deposited and heat-treated state was analyzed. The tensile strength and elongation of TC4 titanium alloy in heat treated state were tested by tensile test. The results show that the as-deposited titanium alloy has almost all non-equilibrium phase α' under rapid condensation and the structure is fine. When the solution heat treatment process is 960 ℃, 2 h, AC, the titanium alloy structure is converted from the non-equilibrium phase α' to the equilibrium phase α, the structure is coarsened into a strip shape, and the tensile strength of the sample can reach 1 056 MPa. The elongation rate reaches 16.9%, and the entire section has uniform and evenly distributed equiaxed dimples, which are typical ductile fractures. TC4 titanium alloy obtains better strength-plastic matching under heat treatment.