Tribological performance of heavy-duty functionally gradient friction material (Cu-Sn-Fe-Cg-SiC-Al2O3) synthesized by PM route

Copper-based sintered materials with ceramic reinforcements and solid lubricants are identified as potential brake pad materials for heavy-duty applications (wind turbine), because of their prime thermal and tribological properties. However, the presence of ceramic reinforcement reduces the joint strength between the brake pad and the substrate material. The reduction in joint strength may lead to catastrophic failure of the braking system in the wind turbines when brakes are applied suddenly. This study attempts to synthesize functionally gradient material (FGM), which has a gradient composition of the ceramic particles along the traverse section. FGM was synthesized layer by layer deposition of Cu, Fe, Sn, Cg, SiC, Al2O3 powders with gradient composition. Microstructure, phases, and microhardness of the specimen were analyzed. Tribological studies were performed to assess the wear rate and friction coefficient of the FGM at various loads. The surface morphology of the worn surface was characterized using field emission scanning electron microscope. The study investigated the wear mechanism of the FGM at various loads.