Characterisation of Copper-Chrome-Reduced Graphene Oxide Electrical Contact Materials Using Powder Metallurgy Technique

Abstract

Abstract Copper-chrome alloys are known as contact material alloys with a premium capability for circuit interruption, endurance and erosion resistance and high voltage in a vacuum interrupter. In this research, the alloy fabricated by powder metallurgy mixed Cu, Cr and reduced graphene oxide (rGO). rGO was prepared by electrochemical exfoliation in H2SO4 at 11.5v, 0.5pH and dried by exposure to sunlight. rGO was incorporated to characterise the properties. Optical microscopy, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive analysis (EDS) and Raman spectroscopy were used to determine the identification of phases, morphology, chemical composition and crystal structure orientation of the alloy. Optical microscopy images showed the formation of two distinct areas: a bright area containing Cr-particles and a dark area containing Cu-grains. The XRD patterns exhibited peaks of FCC-Cu, BCC-Cr, Cr2O3 and Cr2C. FESEM revealed the presence of the Cr phase and Cu matrix as well as rGO sheets, while EDS indicated the presence of Cu, Cr, C and O. The Raman peak assessed the degree of rGO disorder in the alloy. The hardest specimen (92 Kg/mm3) was sintered Cu-20%Cr-1%rGO. Electrical resistance exhibited a minimum value of 12.21 µΩ for the sintered Cu-20%Cr-2%rGO alloy and 6.23 µΩ for aged specimens; compressive strength had the highest value (425.235 MPa) for the sintered Cu-20Cr-1.5%rGO alloy.