Inhibited cold compactibility of rapidly solidified Al-Si alloy powder with large solidification rate

Rapidly solidified powder with refined microstructure is widely used as raw materials for powder metallurgy route. Understanding and controlling the densification behavior of the powder are important to obtain high quality products. In this work, the effect of solidification rate on cold compactibility is investigated via compaction of the rapidly solidified hypereutectic Al-Si alloy powder with different particle sizes. The deformation capacity of the powder with different particle sizes is investigated by linear compaction equations. Furthermore, the microstructure and fracture surface of the compacts are also examined to understand the powder deformation behavior during compaction. The results indicate that the deformation capacity is significantly affected by the microstructure characteristics and the microhardness of Al matrix controlled by solidification rate (or particle size). (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.