YANG Guangchao, ZHANG Pengfei, ZHANG Lingfeng, WANG Guangxin
(School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471000, Henan, China)
Abstract: Using micro-sized ceramic powders and chopped carbon fibers as raw materials, Csf/SiC-BN-(ZrC, ZrB2) ceramic matrix composites were prepared by using hot pressing technique at 1800 ℃. The effect of ZrC and ZrB2 on interfacial reaction, microstructure and properties of the composites were carefully studied by using XRD, SEM and mechanical property testing. The Csf/SiC-BN-ZrC composite exhibited preferable fracture toughness (8.83 MPa·m1/2) and weak interfacial reaction between the carbon fibers and the ceramic matrix. With the addition of ZrB2, bending strength of the Csf/SiC-BN-ZrC-ZrB2 and Csf/SiC-BN-ZrB2 composites was increased, but the interfacial reaction became more serious and the fracture toughness decreased to 5.92 MPa·m1/2 and 5.59 MPa·m1/2, respectively. In conclusion, the addition of ZrB2 intensified the interfacial reaction, resulting in the degradation of carbon fibers and the reduction in toughness of the composites.
Key words: ceramic matrix composite; hot pressing; carbon fiber; interfacial reaction; ZrC; ZrB2