The traditional electric porcelain glaze, widely used today, still exhibits significant limitations in core performance indicators such as mechanical strength and thermal shock resistance, making it challenging to fully satisfy the high standards and demanding operating conditions required by modern power equipment for insulation materials. This paper presents conclusions that the addition of zinc oxide to the glaze does not alter its stability but optimizes its performance, enabling the creation of a low expansion glaze. The hardness of both types of glazes increases as the sintering temperature rises; the maximum Vickers hardness for low expansion glazes can be achieved with sintering temperatures at 1200 ℃. The hardness of both glazes initially rises and then falls, peaking at 2 hours as the holding time extends. Increasing the heating rate leads to a decrease in glaze hardness and a significant increase in the thermal expansion coefficient; the lowest thermal expansion coefficient for the glaze occurs at a heating rate of 3 ℃/min. When the sintering temperature is 1200 ℃, the holding time is 2 hours, and the heating rate is 3 ℃/min, the performance of the added ZnO glaze prepared reaches its peak. The Vickers hardness is 548.9HV, and the thermal expansion coefficient is 1.7×10^{^-6}/K, respectively.

Keywords: Electric porcelain, Low expansion glaze, Sintering parameters, Vickers hardness, Thermal expansion coefficient.