烧成温度对反应烧结碳化硅蜂窝陶瓷的性能调控

Sintering Temperature Adjusted Performance of Reaction Sintered SiC Honeycomb Ceramics

以α-SiC粉、炭黑及鳞片石墨为主要原料,采用挤出成型法并结合反应烧结工艺制备得到碳化硅蜂窝陶瓷,探究得到烧成温度对材料物相组成、微观形貌、孔径分布及主要物理性能的影响规律及调控机制。研究表明:经高温烧成后,蜂窝陶瓷材料的主物相均为α-SiC、β-SiC和Si。随烧成温度增大,碳化硅晶粒发育良好,材料中残余硅含量增加,导致其孔径分布变大且更加集中,同时,其显气孔率及比孔容减小,而体积密度和常温耐压强度得到提升。当烧成温度为1500℃时,材料更适用于柴油车尾气净化用蜂窝陶瓷,其显气孔率、常温耐压强度及中位孔径分别为(45.2±0.3)%、(14.11±0.14) MPa和15.24μm。

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.