In situ hot‐pressed ZrB 2 ‐based composite with polycarbosilane‐derived SiC: Microstructure and mechanical behavior

In this study, a homogenously dispersed finer SiC particles‐containing ZrB 2 composite was prepared using nanosized polycarbosilane ( PCS ) particles‐containing ZrB 2 mixture powder, followed by hot pressing. The microstructure of the resulting composite was characterized by field‐emission scanning electron microscopy and transmission electron microscopy. The composite microstructure comprised finer equiaxed ZrB 2 and SiC grains. The mechanical behavior of the composite was evaluated using four‐point bending test at different temperatures between room temperature ( RT ) and 1600°C. The results show that the composite exhibited only linear deformation behavior prior fracture at or below 1500°C. However, a trace quantity of nonlinear deformation was observed at 1600°C. In addition, the flexural strength of the composite decreased as the temperature increased from RT to 1200°C, then the strength increased as the temperature raised to 1400°C. Subsequently, the flexural strength remained almost the constant between 1400°C and 1600°C, with a strength of ~760  MP a.