HfB2-doped ZrB2-30 vol.% SiC composites: Oxidation resistance behavior

Abstract

In order to investigate the HfB2 on microstructure and oxidation resistance of ZrB2-30 vol% SiC, ZrB2-30 vol% SiC composites with different amount of HfB2 (4, 8 and 12 vol%) were SPSed. Microstructural evaluations were done by scanning electron microscopic (SEM). In order to investigate the oxidation resistance, the samples were placed in box furnace at the temperature of 1400 C for different times. The samples were weighted before and after the oxidation and the 𝛥w was applied as criterion of oxidation. Thickness of SiO2 layer and Si depleted layer were also used as oxidation criterion. The results showed that HfB2 addition, caused to decrease 𝛥w and better oxidation resistance.