Low-Temperature Sintering of α- and β-SiC Powders with AlB2 Additive
We sintered α (6H)- and β(3C)-SiC powders using an Al-B-C additive. SiC powders were densified to > 98% of the theoretical density from 1950 to 2150oC with 0.67-2.7 mass % AlB2 and 2.0 mass % C. Sintering temperatures are 150-200 oC lower than the conventional. During sintering, 6H polytype in α-SiC powder was partly transformed to 4H. α-SiC powder grew moderately into plate-shaped grains. β-/SiC powder was completely transformed to 6H and subsequently 4H with large grain growth. Low-temperature sintering enabled us to use hot isostatic pressing resulting in pore-free SiC materials.
T. Ohji, T. Sekino and K. Niihara
H. Tanaka, T. Nishimura, N. Hirosaki, Y. Kishi, H. Matsuo, Y. Ichikawa, "Low-Temperature Sintering of α- and β-SiC Powders with AlB2 Additive", Key Engineering Materials, Vols. 317-318, pp. 23-26, 2006