The Impact of Manufacturing Technology on the Thermal and Electrical Properties of Ceramic Powders Intended for Spraying Using the APS Method

Abstract

This article describes the microstructures, chemical and phase compositions, surface morphologies, and internal structures of three ZrO2 x 8Y2O3-type of powders obtained by different manufacturing methods. The first of the analyzed powders was a conventionally prepared form of the material obtained by the spraying method. The second powder was a spherically shaped form of the material obtained from the spray drying process. It displayed a distinctive surface morphology characterized by a rough structure with visible cavities. The particle sizes of these two powders were comparable. The third form of the powder was classified as “nano” and was obtained by a grinding and crushing method. The shapes of individual particles were generally polyhedral with smooth surfaces and no visible porosity. A study of the chemical composition of each form of the powder did not show significant differences, similar to the results obtained from the phase composition study. The results of thermal diffusivity and electrical impedance studies indicated that the electrical and thermal properties of the powders with spherical structures, i.e., sprayed and spray drying, were very similar. The thermal diffusivity and impedance properties of these two powders were greater than those of the ground powder with a finer grain size.