Heat-treated Nickel Alloys Produced Using Laser Powder Bed Fusion-based Additive Manufacturing Methods: A Review

Laser powder bed fusion (LPBF) is the most widely used metal additive manufacturing process. It is a novel layer-by-layer manufacturing technique based on a geometrical model that provides a suitable alternative for material processing. This mode is widely used in laser and electron beam welding. Nickel (Ni) alloy preparation using the LPBF method has attracted considerable attention in several areas, owing to the high corrosion resistance and good mechanical properties of the prepared alloys. The specific conditions of solidification through the metal fused during the selective laser fusion process and its layer deposition induces microstructural peculiarities, including the formation of a supersaturated solid solution,extreme microstructural refinement, and the generation of residual stress. Consequently, heat treatment and hot isostatic pressing, which are generally applied to conventionally manufactured Ni alloys, may need to be altered to adapt to the metallurgical properties of Ni alloys manufactured using direct metal laser deposition and address particular issues resulting from the process itself. Several studies have been conducted on this topic over the past few years, suggesting different approaches for addressing different alloying systems. This review summarizes the latest scientific findings in the area of thermal treatment for selective laser sintering of additively manufactured Ni alloys.