Enhanced properties of an AA7075 based metal matrix composite prepared using mechanical alloying

Abstract

In this study, firstly, AA7075 metal powder which average particle size 43.9 µm were manufactured by using gas atomization method. Thereafter with mechanical alloying method which powder metallurgy manufacturing methods, 10% B4C particle reinforcements that average particle size of 49.5 µm by participating into AA7075 metal matrix composite powder mixtures were prepared. They were milled for different durations (0-8 hrs) in a high energy planetary ball mill. From these milled powders; 550°C and under pressure 500 MPa, composite materials were produced by the method of hot pressing. In SEM analysis, after 4 hrs with mechanical alloying method, B4C particles which were homogenously distrubuted into the matrix of AA7075 were seen. Powders size increased to 1 hr and then decrease. In order to determine produced composite material's microstructural properties SEM analysis and determine physical and mechanical properties, density test and hardness test was applied. As a result of the experiments, composite density increased to 1 hr and then decrease. The hardness of composite was increased with increasing milling time and the rate of reinforcement.