Effects of Red Mud Reinforcement on Hardness, Wear Behaviour of Cast Al-6Si-0.45 Mg Alloy

Abstract

An Investigation was carried out to study the effect of red mud reinforcement in Al-6Si-0.45Mg alloy (A356) for improving hardness, wear rate and co-efficient friction. The red mud 53 micron size particles collected from MALCO, Mettur, Tamil Nadu, India, was preheated in a furnace to 500o C and mixed with molten Al-6Si-0.45Mg alloy to make the composite specimens. Al-6Si-0.45Mg alloy-red mud composite specimens were manufactured by stir casting technique using Al-6Si-0.45Mg alloy as matrix and reinforced with 5%, 10%, 15% and 20% volume percentages red mud as the reinforcement. The Al-6Si-0.45Mg alloy–red mud composite specimens were T6 heat treated to improve the mechanical properties. The artificial aging time and aging duration were varied to study their effect on mechanical properties of the composites. Then the specimens hardness, wear rate and coefficient of friction were tested as per ASTM standards. It was found that the hardness increased when the red mud content was increased in the base alloy at all the heat treatment conditions. The peak age timing which gives highest hardness was found to decrease with increased red mud content. The wear rate was decreased when the hardness was increased. The effect of solution treatment and artificial aging on the microstructure was also studied by microscopy.