Predicting segregation of metal powders

Abstract

Close tolerances in powder quality are necessary for efficient production and control of these tolerances can be achieved only by detailed analysis of materials and processes. The quantification and identification of segregation effects has been a challenge, especially with the powders typically used in PM. An attempt to quantify segregation as a first step towards the predicting segregation behaviour of general powders is reported. Experiments have been undertaken using a lubricated iron alloy powder to analyse rolling segregation, and using am unlubricated powder to determine the effect of height of discharge on segregation. Bulk particulates characterised by small particle sizes, narrow size distributions, free flow, high particle densities and high inter-particle forces require careful experimental procedures to obtain repeatable results.