Effect of lead and molybdenum disulfide additives on wear resistance and physical properties of copper–graphite composite

This study investigated the impact of adding lead (Pb) and molybdenum disulfide (MoS₂) to copper–graphite (Cu–Gr) composites used in electric motors. The composites were produced by mechanical alloying (MA). The mixture was then poured and compressed with varying amounts of Pb and MoS₂. Differential thermal analysis was used to determine the sintering temperature of the samples. Further tests were conducted to assess the samples’ wear resistance, density, hardness, and porosity. The effects of the additives of these factors were examined, and the output current of the samples was measured. Scanning electron microscopy was also used to analyze the morphology of the Gr plates coated with Cu, Pb, and MoS₂. The results indicated that adding Pb and MoS₂ increased the density of the sintered samples and their Vickers hardness. Meanwhile, porosity decreased with increased concentrations of Pb and MoS₂. Additionally, MoS₂ was found to improve wear resistance via a pin-on-disk test.