Influence of Wear Parameters on Friction and Wear Behaviour of Friction Stir Processed Al/CaCO3 Surface Composite

The influence of CaCO₃ on the friction and wear behaviour of aluminium is the focus of this chapter. Friction stir processing (FSP) has been used to fabricate Al/CaCO₃ surface composite. The microstructure evaluation is carried out using a scanning electron microscope and an optical microscope. Hardness is measured using a Vickers microhardness tester. The impact of CaCO₃ on the friction and wear rate of aluminium is evaluated using a pin-on-disc apparatus under a dry sliding condition at different loads (5 N, 10 N, and 15 N) and sliding speeds (0.5 m/s, 0.75 m/s and 1.0 m/s). The result showed that fine grain refinement is achieved for the friction stir processed Al/CaCO₃ composite, as a result of severe plastic deformation and dynamic recrystallization. The hardness of Al/CaCO₃ composite is increased to 87 HV_0.3 from 63.3 HV_0.3 of the base metal. A significant improvement in the friction and wear rate is achieved for Al/CaCO₃ composites. Images from the scanning electron microscope showed the transition of wear mechanism from severe adhesive wear to mild adhesive wear.