Boron nitride-aluminum nitride ceramic composites fabricated by transient plastic phase processing

BN-AIN ceramic composites have been successfully fabricated by a novel process referred to as transient plastic phase processing (TPPP), The process used BN as both the reactant phase and the matrix and Al as the transient plastic phase. The products AIN and AIB(12) were regarded as the reinforcing phases. With the addition of Al powder in BN, both the mechanical and thermal properties were improved. Relatively high green density (2.03 g/cm(3), 82.0% of theoretical density (TD)) and as-sintered density (2.18 g/cm(3), 92,6%TD), high bending strength (106 MPa), and high thermal conductivity (72 W/(m.K)) were attained for one kind of BN-AIN composite. A low thermal expansion coefficient of 2.0 x 10(-6)/K was also achieved.