Build Height Effect on the Inconel 718 Parts Fabricated by Selective Laser Melting

Abstract

Selective laser melting (SLM) is an emerging metal additive manufacturing (AM) technology. It has been employed in many applications including propulsion components which are made of nickel-based superalloys, such as Inconel 718. In this study, the effect of the build height on the mechanical properties and microstructure of SLM-processed Inconel 718 parts was investigated. The samples were cut from the Inconel 718 build part after stress relief. They were prepared for microstructure observations and nanoindentation testing. The results are summarized as following. Young's modulus and hardness obtained from the nanoindentation tests are comparable with or superior to that from traditional manufacturing methods. In addition, there do not appear significant differences in mechanical properties along the build height of the parts, though the columnar grains of the side-surface specimens are narrower at the bottom layers of the part. Moreover, the texture analysis results imply no significant anisotropic characteristics for the mechanical properties between the scanning surface and the side surface of the build parts.