Mechanical and Wear Behaviour of Severe Plastic Deformed Al6063-Nano Al2O3 Composites Processed by Constrained Groove Pressing (CGP)

Abstract

Metal matrix composites have been developed to meet the demand for lighter materials with high specific strength, stiffness and wear resistance. Particulate reinforced aluminium matrix composites are attractive materials due to their strength, ductility and toughness. The aluminium matrix is strengthened when it is reinforced with hard ceramic phases. Most of the metal matrix compound undergoes severe plastic deformation (SPD). SPD is a method to obtain fine crystalline structure in different bulk metals and alloys which possess different crystalline structure. The objective of the present work is to synthesize Al-6063 alloy by stir casting method and varying weight percentage of nano Al2O3 in steps of 2, 4, and 6 wt %. The composites are prepared using the process of compressed groove pressing (CGP) with extreme plastic deformation. The composite is characterized for mechanical and wear behaviour. SEM microphotographs confirmed the distribution of nano Al2O3 particles in the Al6063 Matrix alloy. In addition, SEM micrographs of Al6063 alloy with nano Al2O3 after constrained groove pressing shown grain refinement. Improvements in Hardness, UTS, yield strength, bending strength, percentage elongation and wear resistance of the Al-6063 matrix are obtained with the addition of Al2O3 particulates and also the properties are further enhanced with CGP. The developed metal matrix nano composite may be an alternative material for manufacturing of bearings.