Investigation and characterization of Copper-Fly ash-Tungsten hybrid composites synthesized through P/M process

Abstract This research paper describes the enhancement of mechanical, wear and corrosion behaviour of the Copper (Cu) matrix composite by reinforcing Fly ash (FA) and Tungsten (W). The main objective of this study was to reduce the weight and cost of the hybrid composites. The weight percentage of low density material (FA) was kept constant at 6% and samples were prepared by the addition of W in weight percentages of 3, 6 and 9 in the Cu matrix. The characterization of the hybrid composites was studied using a Scanning Electron Microscope (SEM) and Energy-dispersive spectroscopy (EDS). The micrographs revealed the uniform distribution of W and FA in the Cu matrix. From the mechanical characterization, it was identified that there is an increase in microhardness and compressive strength with the addition of W particles. It can be understood that the W particles occupy substitutional type reinforcement and FA particles occupy interstitial type reinforcement in the Cu matrix. The Wear behavior and its mechanism were studied using worn surface SEM micrographs. It was observed that the lowest specific wear rate was recorded for the hybrid composition of Cu-6FA-6W. Electrochemical polarization test and Electrochemical Impedance Spectroscopy (EIS) study revealed that Cu-6FA-9W shows higher corrosion resistance in both 1 N HCl (256.593 × 10⁻⁴ Ω cm²) and seawater media (219.855 × 10⁻⁴ Ω cm²) than pure Cu.