LAUSR

Highly porous Si3N4 ceramics with bimodal pore structure were prepared by the extrusion processing with petroleum coke of 30 μm as pore-maker. The microstructure, mechanical strength and gas permeability were investigated. The microstructure with petroleum coke contained not only numerous fine pores by interlocking the high aspect ratio β-Si3N4 grains, but also some large pores of 15-25 μm left by the burnout of petroleum coke. The resultant samples obtained an improved gas permeability of 1.2×10-12 m2, which is approximately two times that of samples without petroleum coke addition. Furthermore, the mechanical strength is still superior even at a porosity of 67% in comparison with the other porous ceramics used in the current diesel particulate filter. This article is protected by copyright. All rights reserved.