In situ multi-metal alloying in laser-based additive manufacturing: A concise review

Additive manufacturing (AM) has increasingly been employed for in situ alloying, facilitating the production of multi-metallic components, often referred to as multi-metal AM (MMAM). This approach enables the design of intricate, functional, and highly customized products with superior mechanical performance. Although the advancements in MMAM in-situ alloying have lagged behind those in single-metal AM, notable progress has been achieved in this emerging field. This concise review examines in situ alloying in laser-based AM alloys over the past decade, with a particular focus on titanium (Ti)-based MMAM and other metal systems. It systematically synthesizes current insights, addressing pre-processing preparations (e.g., powder feedstock preparation and modification), in-process adjustments (e.g., alternations in alloy chemistry and parameters optimization), and numerical simulations. These elements collectively exert a profound influence on the microstructural characteristics and mechanical performance of MMAM products.