On the compaction of metal powders with particular reference to densification hardening

Abstract

<p>The purpose of this work was to examine the process of isostatic compaction of metal powders and the related phenomenon of densification hardening.</p> <p>The relationships between density, hardness and compacting pressure, for different commercial powders, have been obtained. Data resulting from the experimental study of isostatic compaction was applied to tests conducted on die compacts, enabling the density and pressure distributions to be examined by simple hardness measurements. The compacts were produced in a range of compacting dies, designed especially for this purpose.</p> <p>Results of density determination and metallographic examination of a series atomized aluminum, copper, lead and reduced iron powder compacts are presented. From these results it is concluded that extensive plastic deformation occurs even during the initial stage of compaction.</p> <p>It has been shown that density and hardness are uniform within compacts produced by the isotatic method, while the die compacts showed remarkable variation of hardness and density within the samples. The results indicate the higher efficiency of the isostatic compaction method as compared to the die method.</p> <p>A method for isostatic pressure measuring and recording, utilizing the expansion of the pressure vessel, is described.</p>