Abstract: Laser powder bed fusion (LPBF) is successfully used in the production of different Ni-based superalloys such as IN718 and IN625 alloys. However, for other Ni-based superalloys characterized by high crack susceptibility such as Hastelloy X, the occurrence of cracks is difficult to avoid, even when a process parameter optimization is applied. This problem was mitigated by controlling the chemical composition and powder size distribution. The used powder in this study met the conventional cast Hastelloy X commercially compositional limits. However, LPBF parts often show directional anisotropy in performance and material properties. Consideration is needed to ensure the parts will have the required performance along the necessary load paths and that these properties are reproducible.
The present study presents insights into the development of heat treatment procedure that remove the residual stresses and achieve isotropic microstructure for desired mechanical properties such as room temperature and elevated temperature tensile properties.
Authors: Alber Sadek and Hyeyun Song
Keywords: Additive manufacturing, Hastelloy X, Heat treatment, Mechanical Properties