Abstract
In order to prepare closely packed mixtures for hot isostatic compaction, the flowing properties and blending conditions of gas-atomized steel powders were investigated. Being liable to size-segregation, spherical particles show a marked heterogeneity during the flow in a glass vessel.
A magnetization treatment was tried to make the flowable steel powders attractive to each other, for varying their flow rates. Mixtures of attractive particles could be homogenized, when stirred in a certain range of flow rates.
This enabled to prepare the closely packed mixtures without segregation, having apparent density of up to 75 per cent, whereas the values of untreated powders ranged from 63 to 65 per cent. The high density mixtures were compacted by hot isostatic pressing and the homogeneity of their structures was microscopically confirmed.
