Effects of SiC whiskers on performances of cBN-SiCp-Al composites sintered by HTHP

In this research, the cBN composites were fabricated with SiCp-Al as ceramic-metal binder and SiC whiskers (SiCw) as reinforcement via high-temperature and high-pressure (HTHP) sintering. The influences of SiCw on the morphology and mechanical behaviors of PcBN-SiCw composites were systematically evaluated. The results manifested that the samples doped SiCw not only obtained the compact microstructure but also presented better mechanical properties. When the content of SiCw equaled to 15 wt%, the highest fracture toughness reached 7.38 MPa m1/2. Additionally, the flexural strength reached an optimum value of 695.85 MPa with 10 wt% SiCw. In comparison to the composites without SiCw, the fracture toughness and flexural strength increased 41.9% and 23.5%, respectively. The improvements could be ascribed to the strengthening and toughing effects of SiCw including the pull out, bridging and crack deflection.