Solid solution and densification behavior of zirconium oxycarbide (ZrCxOy) ceramics via doping ZrO2 and Zr in ZrC

Abstract zirconium oxycarbide (ZrC x O y ) ceramics were hot pressed using ZrC-5ZrO 2 and ZrC-5ZrO 2 -5Zr (number in mol%) mixtures as starting powders, and the solid solution and densification processes were investigated. When 5 mol% ZrO 2 were added to ZrC matrix, ZrC x O y and CO were formed during the reaction between ZrC and ZrO 2 occurred above 1600 °C. And the sintered ZrC x O y ceramic had numerous pores. However, the co-doping of ZrO 2 and Zr could reduce the reaction temperatures and CO amounts in ZrC-5ZrO 2 -5Zr system, resulting in a near fully dense ZrC x O y ceramic. The chemical composition of obtained ZrC x O y ceramics were also calculated according to oxygen content and reaction processes.