Effects of Processing Parameters on Densification of Nano-ZrB2 Ceramic Prepared by Vacuum Hot Pressing

This paper has focused on the processing, densification and microstructural investigations of hot pressed nano-ZrB2 ultrahigh temperature ceramic, without addition of any sintering aids or reinforcement phases. A design of experiment approach, Taguchi methodology, was used for the statistical analyses of hot pressing parameters (temperature, time and pressure) in order to optimize the densification conditions. The mentioned parameters, each parameter with three levels, were studied in relatively low temperatures/pressures conditions, compared to the previous research works. The relative density of the nano-ZrB2 ceramic reached >92% at the optimized hot pressing conditions, the sintering temperature of 1850 °C, the soaking time of 90 min and the external pressure of 16 MPa. The statistical analyses recognized the hot pressing temperature as the most important parameter and the applied external pressure as the less important factor affecting the densification of nano-ZrB2 ceramic.