A COMPARISON OF THE ELECTRICAL PROPERTIES OF YTTRIA-STABILIZED ZIRCONIA PROCESSED USING CONVETIONAL, FAST-FIRE, AND MICROWAVE SINTERING TECHNIQUES

摘要

Microwave sintering is an energy - efficient process for sintering yttria-stabilized zirconia (YSZ). In this work, a comparative study was conducted using three different techniques - microwave, fast - fire, and traditional - to sinter 8 mol% YSZ. YSZ powders were isostatically pressed into pellets and sintered at 1350°C - 1500°C with rates ranging from 3°C/min (traditional) to 6 - 200°C/min (microwave and fast-fire) and dwell times ranging from 0 - 15min. Sintered pellets were characterized using scanning electron microscopy (SEM) to determine microstructure and impedance spectroscopy to determine high-temperature electrical properties. While the dependency of density and grain-size on sintering temperature was different for the three techniques, there were no significant differences in the relationships of density and electrical conductivity to grain size. By correlating the microstructure (grain size/ shape and the grain boundary) and high temperature electrical properties of sintered samples, a better understanding of the microwave sintering process and how this process affects final electrical properties of YSZ was determined.