One of the most widely utilised additive manufacturing processes is powder bed fusion, which fabricates complex, custom-designed components directly from powders using a layer-by-layer procedure. This type of additive manufacturing method provides many advantages and benefits over many other additive manufacturing methods, including a comfortable design, the production of final products without the need for any secondary material removal process, and the easy production of complicated parts in a short time with high three-dimensional accuracy and precision. Powder bed fusion has gained widespread use recently for producing high-performance alloys like those based on titanium and nickel. Despite the advantageous characteristics of powder bed fusion-processed products, they still suffer from poor mechanical properties, low density, porosity, and other defects. Accordingly, post-process thermal and heat treatments significantly improve the overall properties. This study aims to provide an overview of how heat treatment procedures can enhance the properties and performance of powder bed fusion-processed Ti- and Ni-based alloys. Accordingly, stress-relieving, quenching/hardening, annealing/recrystallization, and thermo-mechanical heat treatments have been investigated, which can have a significant impact on the structure–property performance of powder bed fusion-processed Ti- and Ni-based alloys. The heat treatment greatly influences the evolution of the microstructure and the production of new phases.
