INFLUENCE OF POWDER PARTICLE SIZE DISTRIBUTION ON RHEOLOGICAL PROPERTIES OF 316L POWDER INJECTION MOULDING FEEDSTOCKS

摘要

In this communication we present the study of the influence of particle size distribution on the rheological properties of 316L stainless steel feedstocks. Two kinds of gas-atomized powders were employed with d_(90) of 8 and 26 microns of particle size, respectively. Five feedstocks were prepared at powder loadings of 50, 55, 60 and 65 vol %, employing the pure powders and their own mixtures in ratios 25/75, 50/50 and 75/25. The binder was composed by 50 vol % of high density polyethylene and 50 vol % of paraffin wax. Feedstocks were prepared in a torque rheometer with a pair of roller rotor blades. Rheological measurements were performed in a capillary rheometer. The effects of the powder loading and different particle size distributions on the rheological properties of feedstocks were investigated. Different rheological parameters, like melt viscosity, power flow index and activation energy were determined. A relationship between powder characteristic and rheological behaviour was established.