An experimental study on consolidation of aluminium based metal matrix composites by two-step sintering and spark plasma sintering

Powder Metallurgy is the process of Mixing, Blending, Compaction, and Sintering of powders. Three powders namely Aluminium (Metal Matrix Element), Nickel and Silicon Carbide [90%, 7% and 3% by mass, respectively] were mixed thoroughly and blended with the help of Zirconium balls in the ratio of 2:1 in the ball mill cylindrical drum. One specimen was prepared using a Green Compaction by Universal Testing Machine (UTM) under a load of 280kN followed by Two Step Sintering. In the two-step sintering process, the compacted specimen was heated initially up to 300°C and dwelled for 3 hours, and then the temperature was increased to 462°C and maintained for 2 hours. Another specimen was consolidated through the Spark Plasma Sintering and processed at a temperature of 450°C under the load of 50Mpa. Both specimens were examined to study Microstructure, Density, and Hardness. The comparison results show that the Spark Plasma Sintering technique was better than the two-step sintering technique to improve the hardness and density values.