DONG Bo, DENG Chengji, YU Chao, CHEN Yufeng, DING Jun, LIU Hao, ZHU Hongxi

(The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology,
Wuhan 430081, Hubei, China)

Abstract: SiC honeycomb ceramics were prepared using α-SiC powders, carbon black and flake graphite as raw materials by extrusion molding, combined with the reaction sintering process. The effects of sintering temperature on phase composition, microstructure, pore size distribution, and main physical properties of the materials were studied. The main phases of the honeycomb ceramic materials were α-SiC, β-SiC, and Si after firing at high temperatures. With increasing sintering temperature, the SiC grains developed well, and the mass content of residual silicon increased, resulting in a more extensive and concentrated pore size distribution. At the same time, the apparent porosity and specific pore volume decreased while the bulk density and cold crush strength were increased. When the sintering temperature was 1500 ℃, the material was more suitable for honeycomb ceramics for diesel vehicle exhaust purification. In addition, the apparent porosity, cold crush strength and median pore diameter were (45.2±0.3)%, (14.11±0.14) MPa and 15.24 μm, respectively.

Key words: SiC honeycomb ceramics; sintering temperature; reaction sintering; pore characteristics; mechanical properties