Compocasting of an Al-Si-SiC_p Composite Using Powder Injection Method

摘要

In this work Al-7wt%Si-10wt%SiC_p composites were produced by injection of the reinforcement in the form of SiC_p particles or a specially made particulate composite powder of aluminum and SiC_p into the melt of proper composition at a temperature corresponding to 10% solid fraction. This paper presents the results of the investigation on the effects of reinforcement addition form, reinforcement addition temperature, stirring speed and magnesium addition on the incorporation and distribution of the reinforcement particles. The results showed that incorporation of SiC_p particles was considerably improved by their injection in the form of milled Al/SiC_p composite powder. Better particle wetting, improved particle dispersion and reduced particles size were achieved by injection of milled Al/SiC_p composite powder instead of SiC_p powder. Magnesium addition and high temperature injection were necessary for achieving good incorporation. Reinforcement incorporation was improved by increasing the stirring speed up to 500 rpm, after which the incorporation decreased slowly.