Wear behaviour of Inconel 718 alloy fabricated by selective laser melting

In this study, the fabrication of Inconel 718, a nickel-based superalloy, by the Selective Laser Melting (SLM) method and the effects of different heat treatments on the microstructure, hardness, and wear performance are investigated. Solution heat treatment was applied to the samples produced by additive manufacturing in a vacuum oven at different temperatures and times. All samples were air-cooled after solution heat treatment in a vacuum oven. The microstructure of the samples was examined by the optic, SEM(Scanning Electron Microscope), and EDS (Energy Dispersive Spectroscopy) analyses were performed. Wear tests were carried out under dry conditions. The wear rates were calculated and wear channels were examined by SEM and EDS analysis to determine wear mechanisms. In microstructural examinations, melting pools and parabolic arc-shaped microstructure were determined in the sample produced by SLM. It was determined that with the effect of the applied heat treatments, the parabolic arc-shaped microstructure began to disappear and a more homogeneous microstructure was obtained. According to SEM examinations, δ (Delta) and γ (Gamma) phases were determined in all samples and it was determined that the applied heat treatment affected the distribution of the phases. The highest microhardness values were measured in the sample without heat treatment. It was determined that the microhardness and wear resistance values of the samples decreased after solution heat treatment and air cooling in the vacuum oven. Abrasive and oxidative wear mechanisms were determined by SEM and EDS analysis of the wear channels of the samples.