ZrB2–SiC laminated ceramic composites

The oxidation behavior for ZrB2–20 vol% SiC (ZS20) and ZrB2–30 vol% SiC (ZS30) ceramics at 1500 °C was evaluated by weight gain measurements and cross-sectional microstructure analysis. Based on the oxidation results, laminated ZrB2–30 vol% SiC (ZS30)/ZrB2–25 vol% SiC (ZS25)/ZrB2–30 vol% SiC (ZS30) symmetric structure with ZS30 as the outer layer were prepared. The influence of thermal residual stress and the layer thickness ratio of outer and inner layer on the mechanical properties of ZS30/ZS25/ZS30 composites were studied. It was found that higher surface compressive stress resulted in higher flexural strength. The fracture toughness of ZS30/ZS25/ZS30 laminates was found to reach to 10.73 MPa m1/2 at the layer thickness ratio of 0.5, which was almost 2 times that of ZS30 monolithic ceramics.