The fatigue and mechanical properties of composite consisting of AA 6061(LM 25) Aluminium alloy reinforced with silicon carbide and graphite particles were investigated with the primary objective of understanding the influence of the particulate reinforcement on the fatigue and mechanical behavior of theLM25Aluminium alloy. The combined silicon carbide and graphite content in the hybrid composite was 2.5wt %. The composite was fabricated by gravity die casting technique in which the reinforcement particles were dispersed in the vortex created in the molten matrix alloy. Statistical design of experiments was applied to carry out fatigue tests on rotating beam fatigue testing machine under stress controlled conditions. Three different stress levels at 0.9Su, 0.7Su and 0.5Su where Su=Ultimate Strength of the Composite were used. For the hybrid Al-SiC-Gr composite, improvements in Young's modulus, ultimate tensile strength (UTS), compressive strength, yield strength and hardness was observed but at the expense of ductility. Fatigue data exhibited large scatter. Monte Carlo Simulation model was developed. The Simulated fatigue data and the experimental data were compared and validated. The Simulated model helps designers to obtain accurate fatigue data without conducting large number of time consuming fatigue experiments.

Key words: Hybrid metal matrix composites, Monte Carlo Simulation, Fatigue