Effect of sintering pressure on the texture of hot-press sintered hexagonal boron nitride composite ceramics

Textured hexagonal boron nitride (BN) composite ceramics with mullite as sintered additive were fabricated by hot-press sintering under different pressures. The degrees of texture and the microstructures of these materials were evaluated using X-ray diffraction, pole figures and scanning electron microscopy. The results showed that the hexagonal BN composite ceramics have obvious directional orientation. The preferred orientation of the c-axis of hexagonal BN grains was along the direction of pressure, and the sintering pressure influences texture formation. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.