Optimisation of process parameters for minimum volumetric wear rate on AA7075-TiC metal matrix composite

Aluminium matrix material reinforced with particulates constitutes a material matrix composite with low wear rate and substantial hardness, owing to which it has marked its path in many engineering applications. The sub-sequential design and selection of new variants of composites can be done to improve its tribological performance. In the present work, the wear behaviour of aluminium metal matrix composites (AA7075 as matrix material and titanium carbide (TiC) particulates as reinforced material) fabricated through stir casting method was studied. The wear rate was investigated on a pin-on-disc machine and analysis of variance was used to identify the effect of control parameters such as sliding velocity, sliding distance and wt.% of reinforcement on the volumetric wear rate at a fixed load of 20 N. The hardness and wear resistance of the composites were found to be strengthened with the TiC particles reinforced into the AA7075 matrix material. Results show that volumetric wear rate decreases with increasing sliding velocity but increases with increasing sliding distance, irrespective of the wt.% of TiC particles added to composites. Confirmation tests were carried out to verify the experimental results and the worn-out surfaces of selected samples were analysed with scanning electron microscopy.