MECHANICAL CHARACTERIZATION OF LM25/ COPPER POWDER REINFORCED METALLIC COMPOSITES

Aluminium metal-matrix composites were broadly used where high strength and low weights are desired. To overcome the limitations with metal ceramic composite systems metallic composite systems were developed. These systems serene of two different metals having good solubility and may give a good, uniform and attuned interface, when they are used as matrix and the reinforcement. The limited solubility led to the alloy formation passing solid solution strengthening while the undissolved particles help achieving dispersion strengthening. A356 alloy and pure copper powders has been used as matrix and reinforcements. The composites (5 to 15 wt. % reinforcements) were synthesized through stir casting technique by dispersing pure copper powders of 53 microns. A decrease in reinforcement size was identified with increasing reinforcement content, which improved the surface area to the volume ratio of the resultant particulates. Composites exhibited improved hardness compared to the matrix of the alloy. The specific properties of the ultimate tensile strength, yield strength, young's modulus and ductility have shown improved specific properties compared to the alloy. Similarly, the specific property interms of ductility has been proved better compared to that of alloy.