Fabrication and microstructure of BN matrix composites with electrical conductivity

Abstract

BN ceramic is an advanced engineering ceramics with excellent thermal shock resistance, good workability and excellent dielectricity. TiB₂ ceramic has excellent electric conductivity, high melting points, and corrosion resistance to molten metal. Therefore, the composite consisting of BN and TiB₂ ceramics is expected to have a combination of above-mentioned properties, thereby can be used as self- heating crucible. In this paper, hot pressing technology was used to fabricate the high performance BN-TiB₂ composite materials. microstructure and electric conducting mechanism were studied, and the relationship between the microstructure and physical property was discussed. The results show that the microstructure of composites has a great influence on the physical property of composites. The BN-TiB₂ composites with excellent mechanical strength and stable resistivity can be obtained by optimizing the processing parameter and controlling the microstructure of composites.

Keywords

BN-TiB₂ composites / hot pressing sintering / microstructure / physical property / electric conduct mechanism

References

[1] US patent. No. 3544486, Refractory Bodies Containing Aluminum Nitride, Born Nitride and Titanium Boride. 1970

[2] Guojun Zhang. Reaction Sintering of TiB₂-BN Composites. China Ceramic, 1994, 3: 8-8.

[3] Weimin Wang. Self-propagating High-temperature Synthesis of TiB₂. J. of Wuhan Univ. of Tech.-Mater. Sci. Ed., 1995, 10(2): 34-34.