Wire arc additive manufacturing of dissimilar alloys: Processing strategies and interfacial phenomena

Dissimilar alloys additive manufacturing enables the tailored creation of heterogeneous microstructures with exceptional mechanical properties, significantly expanding the application boundaries of metallic materials and accelerating the convergence of materials science with advanced manufacturing technologies. However, the thermophysical property mismatch between dissimilar materials frequently induces intermetallic compounds (IMCs) formation at component interfaces, leading to cracking and structural failure. This review focuses on deposition architecture strategies in wire arc additive manufacturing (WAAM) of dissimilar alloys, providing an in-depth analysis of how precise microstructure regulation affects the type, size, and distribution of interfacial IMCs. Few systematic reviews on the complex interrelationships between the interfacial microstructural characteristics and mechanical properties of dissimilar alloys WAAM components exist. To address this, a comprehensive analysis of WAAM process parameters was carried out, deposition optimization strategies were explored, and the correlations between microstructure and properties across diverse dissimilar alloys systems were investigated. Furthermore, this work synthesizes recent breakthroughs in fabrication forming control and microstructure optimization for WAAM processed dissimilar alloys while prospectively discussing emerging opportunities and technical challenges to guide future research in this field.