Effect of heat treatment on microstructure and mechanical properties for laser powder bed fusion of nickel-based superalloy: A review

Abstract

Laser powder bed fusion (LPBF) is most widely used method for presenting an innovative manufacturing approach that operates layer by layer. This technique relies on a geometrical model and offers a viable substitute for material processing. The utilization of LPBF for producing nickel alloys has garnered significant interest across various domains due to their exceptional attributes. These attributes include excellent corrosion resistance, favorable mechanical properties, and the quality of the manufactured alloys. The particular solidification conditions arising from the metal fusion in the selective laser fusion process, combined with layer-by-layer deposition, give rise to unique microstructural characteristics. These include the development of supersaturated solid solutions, significant microstructural refinement, and the introduction of residual stresses. As a result, adjustments might be necessary for heat treatment and hot isostatic pressing, practices commonly employed with conventionally manufactured nickel alloys. These adaptations would accommodate the metallurgical nuances specific to Ni alloys produced through direct metal laser deposition, effectively addressing issues arising from the inherent characteristics of the process. This review paper compiles the most recent scientific discoveries concerning thermal treatment applied to additively manufactured nickel alloys using the selective laser sintering process.