Enhancing Filtration Performance of Sintered Metal Filters Through Pore Structure Modification using Fine Flake-Shaped Particles

Abstract

Sintered metal gas filters commonly suffer from a trade-off between filtration efficiency and gas permeability due to limited control over pore structure. In this study, fine flake-shaped stainless steel 316L powders were introduced into a sintered filter matrix to modify pore geometry without significantly reducing porosity. Microstructural and pore analyses showed that flake addition subdivided interparticle voids, leading to reduced pore size while maintaining high open porosity at low flake contents. Notably, the filter containing 1 wt.% flake-shaped powder exhibited a clear improvement in filtration efficiency without a pronounced increase in pressure drop. At higher flake contents, further gains in filtration efficiency were accompanied by a rapid increase in flow resistance. This work demonstrates that the controlled incorporation of fine flake-shaped powders provides a simple and scalable approach to pore-structure engineering for high-performance metal gas filters.