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 < 0.05). During cooling after the firing simulation the InPd₃–based phase of tetragonal structure precipitated from the Pd–Ag-rich matrix of the face-centered cubic structure. Hardening by cooling at a higher cooling rate after firing was the result of the coherency strains that formed at the interface of the Pd–Ag-rich matrix and the metastable phase based on the InPd₃ phase. . The reduced hardness obtained in the specimen cooled at a lower cooling rate after firing resulted from the loss of coherency strains as the fine metastable phases based on the InPd₃ phase were transformed into the coarser stable phase with decreased (c/a) of 0.88. This finding revealed that controlling the cooling rate during porcelain firing simulation improves the hardness of the Pd–Ag–In–Sn−Ga metal-ceramic alloy without an additional heat treatment of the alloy.

这项研究检查了冷却速率对Pd-Ag-In-Sn-Ga金属陶瓷合金烧成过程中硬度的影响及其对显微组织的影响。实际上，在每个用于瓷结合的烧制步骤之后，将假体冷却至室温，然后进行下一个烧制步骤。已知冷却步骤可使金属下部结构的硬度增加。该研究的目的是确定在每次烧瓷步骤之后控制冷却速率是否会增加Pd-Ag基金属陶瓷合金的硬度。结果表明，与以较低冷却速率冷却的样品相比，以较高冷却速率冷却的样品的硬度在每个焙烧步骤后均增加（p <0.05）。点火模拟后的冷却期间，InPd ₃面心立方结构的富含Pd-Ag的基质中沉淀出四方结构的基相。焙烧后以较高的冷却速率冷却硬化是在富含Pd-Ag的基体和基于InPd ₃相的亚稳相的界面上形成的相干应变的结果。。由于基于InPd ₃相的精细亚稳相转变为具有降低的（c / a）的较粗糙的稳定相，因此，由于相干应变的损失，在烧结后以较低冷却速率冷却的样品中获得的硬度降低。）的0.88。这一发现表明，在模拟烧瓷过程中控制冷却速率可以提高Pd-Ag-In-Sn-Ga金属陶瓷合金的硬度，而无需对该合金进行额外的热处理。