Tribological characterization of functionally gradient composite (Cu–Fe–CeO 2 –Al 2 O 3 –C g ) for wind turbine brake pad

Abstract

Copper-based functionally gradient composite material is developed using powder metallurgy processing technique, as a potential wind turbine brake pad material. The developed composite has a gradient composition of Cu, CeO₂, Al₂O₃, Fe, and C_g to enable joint strength at the interface (brake calliper) and wear resistance at the contact surface (brake disc). The article presents a comprehensive analysis on the microstructure, microhardness, and tribological performance of the developed composite. The wear mechanism is deduced through surface morphology, elemental composition, and phase composition analysis using field emission scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffractometer, and X-ray photoelectron spectroscope. A maximum hardness of 198.2 HV was obtained at the contact surface. Experimental values from tribology tests show that a decreasing trend was obtained with a wear rate of 2.013 × 10⁻⁷ g N-m⁻¹ and a friction coefficient was 0.215.