IN625–CuCrZr multi-material joints by PBF-LB/M: Process–structure–property relationships

3D-printed multi-material components represent a major advancement in additive manufacturing, allowing the combination of dissimilar materials to achieve tailored properties and functionalities. Recent developments in Laser Powder Bed Fusion (PBF-LB/M) with Selective Powder Deposition modules have enabled the creation of multi-material powder beds, paving the way for complex and functionally graded structures. This study explores the interfacial features of IN625–CuCrZr components produced by PBF-LB/M, with emphasis on the effects of interface orientation and deposition sequence on microstructure, mechanical, and thermal properties. Results demonstrate the formation of dense interfaces with continuous metallurgical bonding. The morphology and width of the transition zone vary with both orientation and deposition sequence. EBSD analyses reveal a columnar-to-equiaxed grain transition when moving from IN625 to CuCrZr. Mechanical tests, especially in-situ SEM tensile tests, suggest that joint strength and crack development strongly depend on interface orientation and loading direction. Laser flash analysis highlights enhanced thermal diffusivity in CuCrZr–IN625 joints, exceeding that of monolithic IN625, thus suggesting potential for high-performance applications. These findings clarify deposition-sequence effects on interfacial bonding, intermixing, defects, and performance in IN625/CuCrZr architectures.