Effect of the Hot Isostatic Pressing (HIP) and heat treatment to nickel-based alloys obtained with Selective Laser Melting (SLM)

More and more efforts are spent for manufacturing low-weldable nickel-based superalloys in contemporary research applied to additive manufacturing. One of the biggest difficulty with these kinds of alloys is reducing the flaws density obtaining a good final microstructure in the as-built state. Nevertheless, the complete densification of the alloys can be reached only after further heat treatments such as the Hot Isostatic Pressing (HIP). The SLM material microstructure is severely different with respect to that obtainable after traditional manufacturing. This will also impact the final mechanical properties as well as the microstructure stability. Very often, designing specifically tailored heat treatments become the most viable solution for enhancing these materials. In this work the effect of the HIP treatment Is discussed and, after performing DSC and TMA thermal analysis, the effects of two heat treatments on two Ni-based alloys are discussed