In-Situ Si/Al Composite Produced by Semisolid Metal Processing

Abstract

Hypereutectic aluminium-silicon alloy can be considered as an in-situ composite with primary silicon acting as the reinforcing phase. In this paper, we use semisolid metal processing technique to produce such in-situ Si/Al composite. Hypereutectic Al–Si alloy, AlSi17Cu5Mg0.55, was cast into a permanent mould with controlled solidification conditions. In the resulted composite, primary Si particles were observed to co-exist with primary α-Al particles, uniformly dispersing in Al–Si eutectic matrix. The structure of the Si particle can be controlled by AlP refinement and thermal refinement, and the α-Al particle can be controlled by semisolid partial remelting.

Keywords:

• AlP refinement
• Aluminium-silicon alloy
• Hypereutectic aluminium alloy
• In-situ aluminium-based composite
• Semisolid metal processing

ACKNOWLEDGMENTS

The author would like to acknowledge the financial support of the Australia Research Council and the Australian Government's Department of Education, Science and Training.