Effect of preparation methods on the incorporation/distribution of ceramic particulates in metal based composite powders

Abstract

In this study, Al-based alloy composite powders were successfully synthesized using ball milling, spray atomization and coinjection and composite melt atomization techniques. The results of the microstructural characterization studies revealed that the penetration of SiC particulates in the metallic powders was size dependent for the powders greater than 100 μm in diameter, synthesized using ball milling technique and for the powders with diameter less than 20 μm synthesized using spray atomization and coinjection technique. For composite melt atomization technique, no such size dependency was observed. The results also indicated that the final distribution of ceramic particulates in the metallic powders was predominantly governed by the processing parameters (as in ball milling technique) and the coupled influence of both the processing parameters and interaction with the solidification front (as in spray atomization and coinjection and composite melt atomization techniques). Finally, the SEM examinations revealed a strong correlationship between the final distribution of the SiC particulates in the bulk material with that observed in the metallic powders.