Electron beam welding combined with temperature field simulation has been carried out on the Ti70 titanium alloy, and the microstructural evolution and mechanical property of welded joint are systematically investigated. Results show that the simulated molten pool is well consistent with the experimental weld morphology. Microstructure analysis demonstrates that the upper part of fusion zone (FZ) consists of columnar crystals. The middle part of FZ is composed of equiaxed grains and β columnar crystals, and the fine martensite α′ presents the interlaced distribution within grains. The heat-affected zone is composed of transformed phase β structure (β_t), martensite α′ and residual α phase. The microhardness in FZ is the highest. The maximum tensile strength of welded joint reaches 754.5 MPa, which is close to that of base metal. There are many equiaxed dimples on the joint fracture surface, and it dominantly presents the characteristic of ductile fracture.

在Ti70钛合金上进行了电子束焊接与温度场模拟相结合的研究，系统地研究了焊接接头的组织演变和力学性能。结果表明，模拟熔池与实验焊缝形态非常吻合。显微组织分析表明，熔合区（FZ）的上部由柱状晶体组成。FZ的中间部分由等轴晶和β柱状晶体组成，细小的马氏体α '呈现出晶粒内的交错分布。热影响区由转化的相的β结构（β_吨），马氏体α '和残留α相。FZ的显微硬度最高。焊接接头的最大抗拉强度达到754.5 MPa，接近于母材。关节骨折面上有许多等轴凹窝，主要表现出韧性断裂的特征。