Research Progress on the Plasticity of Laser Wire-Fed Welded Titanium Alloy Joints

Laser wire-fed welding has gained considerable attention for joining titanium alloys due to its high energy density and controllable heat input. This paper systematically reviews the key factors influencing the plasticity of titanium alloy weld joints produced by this process, focusing on the regulation of phase transformations through alloy composition, as well as strategies for grain refinement and defect suppression under welding thermal cycles. The findings indicate that appropriate additions of β-stabilizing elements effectively suppress the precipitation of high-hardness phases while enhancing weld ductility. Conversely, moderate additions of α-stabilizing elements can improve high-temperature performance but may also induce martensitic transformation. Numerical simulation techniques, including finite element analysis (FEA) and phase-field modeling, provide quantitative insights into temperature fields, stress fields, and phase evolution, thereby facilitating process optimization. Looking ahead, the development of composite wires and novel alloy systems, combined with intelligent monitoring and adaptive control strategies, is expected to further enhance the strength, toughness, and overall service reliability of titanium alloy weld joints produced via laser wire-fed welding.