Fabrication and Characterization of Copper-Red Mud Particulate Composites Prepared by Powder Metallurgy Technique

Copper-red mud powder mixtures containing 0-14 wt% red mud with 75, 53 and 38 μm particle sizes were prepared. Small cylindrical specimens of 9 mm diameter and 10.5 mm length were fabricated at 300 MPa, using single action die compaction at ambient temperature. These compacts were sintered in argon atmosphere at 8500C. The physical, mechanical and electrical properties of green and sintered compacts were determined as a function of particle size of red mud and its weight percent. It was observed that the ejection pressure, green density, and strength decreased, while spring back, green porosity and hardness increased with increasing the weight percent of red mud. It was also observed that ejection pressure, green density, green hardness and strength increased, while spring back and green porosity decreased with decreasing particle size of red mud. Sintering resulted in a decrease in volume and an increase in the density of green compacts. It was found that the sintered density of the compacts decreases with increasing weight percent of red mud. It was also observed that the addition of red mud results in an increase in hardness and a decrease in compressive yield strength and electrical conductivity of sintered compacts under the present experimental conditions. It was further observed that with the decrease in particle size of red mud, the density, hardness, compressive yield strength and electrical conductivity of sintered compacts gradually increase.