Porosity and particle size effects on the gas flow characteristics of porous metals

Several models have been proposed in the past which relate the gas flow characteristics of a porous material to the pore microstructure. Such approaches require metallographic measurements to predict the permeability or inertial flow coefficients. The present study approaches the problem through the dominant adjustable extrinsic processing variables. Specifically, porosity and mean particle size are used to predict the gas flow coefficients for porous 316L stainless steel. Although such an approach proves successful, it is established that traditional processing variables (compaction pressure, sintering temperature and sintering time) have a significant influence on pore shape and therefore on gas flow. Such factors must be included in any comprehensive future predictive models of gas flow through porous metals.