Tribological performance of Cu-Gr-B4C hybrid composites prepared by powder metallurgy route

This research studies the tribological capabilities of copper-based self-lubricating hybrid composites with different weights of graphite (Gr) and B4C reinforcements developed by the P/M technique. The developed materials (such as Cu-0Gr-0B(4)C-0Cr, Cu-1.5Gr-1.5B(4)C-2Cr, Cu-3Gr-3B(4)C-2Cr, and Cu-4.5Gr-4.5B(4)C-2Cr) were characterised and investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), and pin-on-disc tribometer. The composite's microstructure revealed that the reinforcing particles were dispersed uniformly across its matrix. The dry sliding wear test was accomplished at the normal load (10 N to 30 N) and sliding speeds (1 m/s and 2 m/s) for a sliding distance of 2 km. It was found that the wear rate and coefficient of friction of developed composites decrease as the reinforcing weight increases due to the lubricating action of graphite and B4C. Cu-3Gr-3B(4)C-2Cr displayed the highest hardness among all developed materials. However, Cu-4.5Gr-4.5B(4)C-2Cr exhibited the least wear. Worn surfaces were also investigated to reveal the wear mechanism involved.