Properties of sintered SiC whisker-reinforced Si3N4 composites

Temperature‐dependent fracture strength of whisker‐reinforced ceramic composites: Modeling and factor analysis

“…This composite was sintered at 1850°C for 6 h under 1 MPa nitrogen pressure . It comprises of polycrystalline Si 3 N 4 matrix and 10 wt.% SiC whiskers.…”

“…Figure indicates that the model predictions are in good agreement with the experimental results below 1200°C. This temperature corresponds to the outset of fracture originated from slow crack growth . It can cause the fracture of the composite when the applied stress is lower than the strength of composite without slow crack growth.…”

“…Therefore, it is necessary to understand the effects of various influencing factors on their fracture strengths, especially at elevated temperatures. In the past, extensive experimental studies regarding the high‐temperature mechanical properties of whisker‐reinforced ceramic composites have been conducted. For example, Garnier et al investigated the effect of whisker surface quality on the high‐temperature fracture strength of SiC whiskers/Al 2 O 3 matrix composites.…”

“…Hua et al measured the flexural strength of SiC w /SiC composites at different temperatures, and the results indicate that the composite strength is significantly influenced by temperature. Olagnon et al studied the flexural strengths of SiC whisker reinforced Si 3 N 4 composites and showed that the composite strength not only depends on temperature, but also the content of whiskers. It can be observed from these experimental studies that there are many factors which may couple with each other and are always difficult to quantitatively separate their effects and contributions to the composite strength at different temperatures only through experimental methods.…”

“…Olagnon et al studied the flexural strengths of SiC whisker reinforced Si 3 N 4 composites and showed that the composite strength not only depends on temperature, but also the content of whiskers. It can be observed from these experimental studies that there are many factors which may couple with each other and are always difficult to quantitatively separate their effects and contributions to the composite strength at different temperatures only through experimental methods. Meanwhile, considering the technical difficulty in conducting high‐temperature tests, it is necessary to study the high‐temperature fracture behaviors of whisker‐reinforced ceramic composites using theoretical methods, especially for each independent factor.…”