Investigation of novel parameters affecting distribution of reinforcement in nano metal matrix composites

Abstract

Introduction of the nano reinforcement clusters in the metal melt degrades the strength of metal matrix composite (MMC) as they can form large clusters. In view of introducing cluster free nano reinforcement into metal melt, the effect of increasing launching particles and type of reinforcement are observed for distribution of reinforcement over each ball milling sample. Ball milling is performed at 300 rpm for 2 hours with 1:1, 3:1 and 5:1 weight percentage of launching particles to nano reinforcement respectively. In this investigation, aluminium is used as launching particle that is prepared to launch two types of reinforcements, simple and hybrid. The former consists of nano Al2O3 and later is a blend of nano Al2O3 with multi walled carbon nano tubes (MWCNT). Observations based on scanning electron micrographs (SEM) and transmission electron micrographs (TEM) reveal that, hybrid reinforcement ratio 3:1 could decrease the cluster size to 25 nm from 800 nm of simple reinforcement ratio 1:1. Hence the launching particle to hybrid reinforcement ratio 3:1 could produce good distribution when introduced to metal melt.