Experimental Studies on Wear Resistance & Mechanical Properties of Aluminium Hybrid Composites (LM25/Al2O3/Graphite)

This paper involves the fabrication of hybrid Aluminium matrix composite samples of different compositions using Stir casting technique and testing the prepared hybrid composite test specimens for analysing their wear and mechanical properties. LM25 Al alloy was used as matrix material reinforced with constant 9 wt.% of Al2O3 with particle size of 6-23 μm and different wt. percentages of Graphite (particle size of 24-94 μm) as 3%, 4% and 5% to prepare hybrid composite samples of three different compositions. Mechanical properties, for examples, tensile strength, hardness, compression strength and impact strength were analysed for both base LM25 Al. alloy and composite samples. Wear loss and coefficient of friction of composite samples also were studied using Pin-on-disc apparatus. Microstructure images of the hybrid composite samples were examined to study dispersion of dual reinforcement particles in the matrix material, porosity and shrinkage cavities developed during the casting of the composite samples using Optical Microscope. Results revealed that Tensile strength, Hardness and Wear properties of the hybrid composite sample, having 9 wt.% of Al2O3 and 4 wt.% of Graphite particles, were found to be superior to those of re-cast LM25 Al. alloy. This study is mainly focussed on achieving the improved wear resistance and mechanical properties of the hybrid aluminium matrix composite materials for meeting the desired properties of the products by exploring newer compositions of the dual particles reinforced hybrid composites.