Microstructure and Mechanical Properties of Al6061-Graphite Composites Fabricated by Stir-Casting Process

Abstract

In the present study, the experimental results of the mechanical properties of Al6061-Graphite composites presented. The composites containing 6 to 9 wt% of graphite in steps of 3 wt% were prepared using liquid metallurgy route in particular stir casting technique. For each composite, reinforcement particles were preheated to a temperature of 250°C and then dispersed in steps of two into the vortex of molten Al6061 alloy to improve the wettability and distribution. Microstructural characterization was investigated by optical and scanning electron microscopy. Tensile and hardness tests were carried out in order to identify mechanical properties of composites. The results of microstructural study revealed uniform distribution of graphite particles and low porosity in micro composite specimens.The results of this study revealed that as graphite percentage was increased, there was significant increase in ultimate tensile strength, yield strength and ductility, accompanied by a nominal drop in the hardness of the material