Phase Prediction, Microstructure, and Microhardness of Sintered Nickel-Based Superalloy

In this study, the phase formation, microstructure and microhardness of nickel-based superalloy fabricated using a spark plasma sintering technique were evaluated. The microstructure and microhardness of the nickel-based superalloy were explored at diverse sintering temperatures (600 °C - 1050 °C). The phase formations and volume fraction with respect to temperature were predicted by using CALPHAD-based software. The microstructure, phase constitution, and microhardness were evaluated via scanning electron microscope (SEM), X-ray diffraction (XRD), and Vickers hardness tester. The findings indicated that the spark plasma sintering technique enables the development and growth of the necking of particles, enhancing elemental bonding and alloy densification as the temperature increases. The hardness value increases at increasing temperatures, with a maximum value of 353 HV attained at a temperature of 1050 °C.