Joining Technology of Dissimilar Materials and Its Application in Complex Structure Manufacturing

Dissimilar material joining technologies play a critical role in enabling lightweight design and functional integration in complex structures and are widely applied in aerospace, equipment manufacturing, and transportation industries. However, significant differences in properties, such as thermal expansion coefficients, melting points, and metallurgical compatibility, pose major challenges. These disparities often result in poor interfacial bonding, the formation of excessive brittle intermetallic compounds, and high residual stresses within joints. This review summarizes major dissimilar material joining techniques, including brazing, diffusion bonding, friction stir welding, high-energy beam welding, and additive manufacturing, along with their applications in the fabrication of complex structures. Key scientific issues associated with these processes, such as interfacial bonding mechanisms, joint strengthening strategies, and structural reliability, are discussed, and future development trends are briefly outlined.