Oxidation Behavior of SiC Platelet‐Reinforced ZrB 2 Ceramic Matrix Composites

Zirconium diboride (ZrB 2 ) ceramic matrix composites reinforced by silicon carbide platelets (SiC pl ) were prepared by hot pressing. Five groups of specimens were prepared, in which the contents of SiC platelets were 0, 5, 10, 15 and 20 vol%, respectively. The oxidation behaviors of specimens at different temperatures from 800° to 1600°C for 1 h and at 1200°C for different times from 0.5 to 4 h were investigated. With the increase of SiC pl content, the mass gain exhibited a decreasing trend. Oxidation thermodynamics and kinetics of the SiC pl /ZrB 2 composites were discussed. A characteristic structure of hollow quadrangular prismy ZrO 2 crystal emerged on the sample surface after oxidation was found and the possible formation mechanism was also presented. The surface element analysis indicated that the main products of oxidation were m ‐ZrO 2 , SiO 2 , and borosilicate (aluminosilicate).