Multimaterial powder bed fusion techniques: laser-based powder deposition approaches and interface properties

Purpose This study aims to provide the latest powder deposition approaches in multimaterial laser powder bed fusion (LPBF) and to discuss the produced interface properties based on effects caused by the intrinsic material compatibility, process parameters, powder characteristics, melt pool dynamics, and thermal models. It reviews the current metallurgical challenges at the diffusion zone of the pairs, including the formation of brittle intermetallic phases and other microstructural and thermodynamical challenges to provide better solutions to tackle these problems. Design/methodology/approach This review paper used a systematic approach to search for and investigate notable works and peer-reviewed publications concerning multimaterial LPBF. Findings The key results explain how the interface type and dynamic process parameter optimization for different layers at the interface, near the interface, and within single materials affect the avoidance of energy-related defects. Understanding the differences in intrinsic material properties such as thermal conductivity, thermal expansion, and melting point, allows us to initially select the most appropriate interface type. The effects of process parameters and powder characteristics are discussed. Common challenges, including microstructural defects, melt-pool-induced defects, and unwanted brittle intermetallic phases, can be solved by nonequilibrium phase diagram simulations, proper interface-type selection, better alloy design, and the use of interlayers at the interface. Originality/value By outlining the powder deposition approaches and their interface properties and challenges in multimaterial LPBF, this study provides deeper metallurgical aspects shared among material pairs. This helps researchers in troubleshooting common interface challenges based on the guidelines suggested in this paper.