Effect of cooling rate on hardness and microstructure of Pd–Ag–In–Sn−Ga alloy during porcelain firing simulation

Abstract This study examined the effect of the cooling rate on the hardness and its effect on the microstructure during porcelain firing simulation of a Pd–Ag–In–Sn−Ga metal-ceramic alloy. In practice, after each firing step for porcelain bonding, the prosthesis is cooled to room temperature before proceeding to the next firing step. The cooling step is known to allow the hardness of the metal substructure to increase. The aim of the study was to determine whether controlling the cooling rate after each porcelain-firing step increases the hardness of the Pd–Ag-based metal-ceramic alloy. The results showed that the hardness of specimens cooled at a higher cooling rate increased after each firing step compared to specimens cooled at a lower cooling rate (p