Heat treatment optimization of Hastelloy X superalloy produced by Direct Metal Laser Sintering

Direct Metal Laser Sintering (DMLS) is a free-form manufacturing process that enables the production of components with a very complex shape in a single step, without using a mold, thus decreasing the production costs and time. In this work, a Ni-based superalloy, known as Hastelloy X, has been developed by DMLS. The microstructure and hardness of the -Hastelloy X produced are very different with respect to the traditional manufacturing, therefore it is necessary to specifically study the heat treatment. The change of microstructure after heat treatment has been studied with optical microscopy and scanning electron microscopy, whilst the phases present by X-ray diffraction analysis. It has been observed that the heat treatment modifies the grain size and also causes the precipitation of carbides, thus impacting on the hardness.