Preparation and Properties of Boron Nitride Fiber Reinforced SiBON Composites

In this paper, BNf/SiBON composites were prepared by adding short boron nitride fibers and in-situ inorganic solid state reaction. The relationships among hot-pressing sintering temperature, boron nitride fiber content, density and flexural strength of the composites were studied. The phase composition and microstructure of the composites were also analyzed and characterized. The results show that the bending strength of BNf/SiBON increases with the increase of sintering temperature when the fiber content is constant, and decreases with the increase of fiber content when the sintering temperature is constant. XRD diffraction patterns also showed that BN had higher crystallinity and larger grain size when the sintering temperature was 1700°C and the content of BN fiber was 40%. Therefore, the best content of boron nitride fibers is in the range of 20% to 40%, and the hot pressing sintering temperature is about 1700°C. (paper)