Development of functionally gradient Cu-Fe based sintered brake pad materials

Abstract

The world is seeking a sustainable co-existence with nature to preserve the balance of our ecosystem. This has opened a wider market for green and renewable forms of energy to realize the energy requirements of global countries. Among the various renewable energy sources, harnessing the kinetic energy of the wind through a turbine to generate electricity has seen an ardent growth. Wind turbines, in general, function between 2 m/s and 25 m/s wind speed. When the winds cross the cut-out speed (25 m/s) or during the maintenance of wind turbine components, the brakes are implemented. The primary aerodynamic and secondary mechanical brakes comprise the wind turbine braking system. The mechanical brake pads are fixed to the brake caliper. On braking, the brake caliper pushes the brake pads against the brake disc. This recurring action gradually wears the brake material. The presence of ceramic particles in the traditionally used bulk composite pads imparts poor joint properties between the brake pad and caliper. These mandate frequent replacement of the brake pads. The current research work developed a functionally gradient brake pad through the powder metallurgy technique. The microstructure, microhardness, and tribological properties of the fabricated brake pads are tested and analyzed. Microstructural analysis revealed a homogeneous distribution of the reinforcements in the metal matrix. COF was observed to be within the desired range of between 0.3 and 0.4. The brake pad exhibited a combination of adhesive-abrasive-oxidative wear.