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研究TC4/TA15异质钛合金激光焊焊缝的显微组织和力学性能。结果表明:TC4/TA15异质钛合金激光焊缝熔合区显微组织由针状α相和马氏体α′组成,TC4侧热影响区主要是残余α相和马氏体α′,TA15侧热影响区则出现了大量等轴α相。焊缝显微硬度呈现不对称特征,熔合区最高,TA15母材区最低。随应变速率由1×10~(-4) s~(-1)增加到1×10~(-2) s~(-1),接头屈服强度和抗拉强度均升高,且满足TC4母材>TC4/TC4同质接头>TA15母材>TA15/TA15同质接头>TC4/TA15异质接头,而硬化能力和应变硬化指数则降低。不同应变速率下拉伸TC4/TA15异质接头均在TA15母材断裂,断口呈现韧性断裂特征。
Study TC4 / TA15 heterogeneous titanium alloy laser welding microstructure and mechanical properties. The results show that the microstructure of fusion zone of TC4 / TA15 heterogeneous titanium alloy is composed of acicular α phase and martensite α ’, and the TC4 heat affected zone is mainly residual α phase and martensite α’, TA15 side There are a large number of equiaxed α phases in the HAZ. The weld microhardness showed asymmetric characteristics, the highest fusion zone, the lowest TA15 base material area. With the strain rate increasing from 1 × 10 ~ (-4) s ~ (-1) to 1 × 10 ~ (-2) s ~ (-1), the yield strength and tensile strength of the joint all increased, TC4 / TC4 homogeneous connector> TA15 base material> TA15 / TA15 homogeneous connector> TC4 / TA15 heterogeneous connector, while the hardening ability and strain hardening index decreased. At different strain rates, TC4 / TA15 heterogeneous joints were broken in TA15 base metal and the fracture showed ductile fracture.