Porous Si₃N₄ ceramics were prepared by gel casting combined with a reaction bonding route using monodispersed PMMA as the pore former, and Isobam was used as a gel agent. With the PMMA addition varying from 0 to 20 wt.%, the bending strength was degraded from 94.0 to 39.1 MPa owing to the increased porosity and decreased bulk density. The β-Si₃N₄ prismatic grains and round pores introduced by the monodispersed PMMA micro balls would endow the samples with high strength, and the permeability of the resulting samples was increased obviously with the increase of PMMA addition. Flue gas filtration test exhibited that the filtration efficiency of the porous ceramics filter was not degraded with introducing of the PMMA pore former, even though the permeability was increased obviously. The block type of the sample with 20-wt.% PMMA additions during filtration was cake filtration, which indicates that the sample has the characteristic of being reusable after back-blowing in flue gas filtration applications. Porous Si₃N₄ with high strength and permeability fabricated via the reaction bonding route exhibits great potential for low-cost high-performance ceramics filters.

中文翻译：

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以单分散PMMA为造孔剂的多孔反应键合Si3N4的力学性能和气体过滤行为

以单分散PMMA为造孔剂，以Isobam为凝胶剂，采用凝胶浇注结合反应键合路线制备多孔Si ₃ N _4陶瓷。随着 PMMA 添加量从 0 到 20 wt.%，由于孔隙率增加和体积密度降低，弯曲强度从 94.0 降低到 39.1 MPa。β-Si ₃ N ₄单分散PMMA微球引入的棱柱状晶粒和圆形孔隙赋予样品较高的强度，所得样品的渗透率随着PMMA添加量的增加而明显增加。烟气过滤试验表明，多孔陶瓷过滤器的过滤效率并未随着PMMA成孔剂的引入而降低，但渗透率明显提高。过滤过程中添加20% PMMA的样品块型为滤饼过滤，这表明样品在烟气过滤应用中具有反吹后可重复使用的特性。多孔Si ₃ N ₄通过反应键合路线制造的高强度和高渗透性的陶瓷过滤器具有巨大的低成本高性能陶瓷过滤器潜力。