Effect of zirconia addition on laser powder bed fusion of Inconel 718-zirconia composite

This study investigates the integration of zirconia (ZrO2) as a reinforcing agent in the Inconel 718 (IN718) matrix to potentially enhance material hardness and high-temperature oxidation resistance. Employing laser powder bed fusion (LPBF), 3D composite parts of IN718-ZrO2 were systematically fabricated, varying the ZrO2 mass. The primary objectives encompass exploring the impact of ZrO2 on the microstructure, micro-hardness, and high-temperature oxidation of the IN718- ZrO2 composite. The research employed comprehensive testing methodologies, including scanning electron microscopy (SEM), micro-Vickers hardness, XRD, thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). Results elucidated the successful 3D printing of IN718-ZrO2 composites utilizing the LPBF. Notably, defects such as porosity, cracks, lack of fusion, and balling were identified, intensifying with increased ZrO2 content. The composite demonstrated a substantial increase in hardness across all ZrO2 mass variations compared to pure IN718, with 1 wt.% ZrO2 achieving the highest hardness. Furthermore, oxidation resistance exhibited improvement with higher ZrO2 content in the composite. The comprehensive analysis unveils promising opportunities for developing and applying IN718-ZrO2 composites in industries characterized by high-temperature environments and elevated wear conditions. The findings provide valuable insights into optimizing the performance of these composites, thereby contributing to advancements in materials engineering for challenging operational conditions.