Abstract:The additive manufacturing of titanium/aluminum dissimilar metals can achieve the integration of lightweight and high strength. However, joining these two metals poses significant challenges. In this study, 6061 aluminum alloy was used as the substrate, and TC4 welding wire was employed as the cladding material for the laser additive manufacturing of titanium-aluminum dissimilar metals. With the aim of controlling the interfacial fusion ratio and minimizing intermetallic compound formation to enhance the interface performance, the process parameters were optimized. The optimal parameters were determined through single-factor experiments and nonlinear regression analysis. Under these parameters, the interfacial tensile strength of the aluminum/titanium dissimilar metal structure reaches to 60.67 MPa. The microstructural evolution of the dissimilar metal interface under different additive manufacturing layer numbers was analyzed. The results show that as the number of titanium alloy additive manufacturing layers increases, the brittle acicular compounds at the titanium-aluminum interface gradually diffuse, transform into granular particles and eventually aggregate into a continuous layer. The evolution of interfacial residual stress was analyzed through finite element simulation. The results indicate that the interfacial residual stress initially increases, then decreases, and finally rises sharply, with severe stress concentration observed at both ends of the weld bead.