Study of tribological properties of graphite/copper-ferrum matrix self-lubricating composites prepared by induction sintering at elevated temperature

The graphite/copper-ferrum matrix self-lubricating composites with various amounts of graphite additives were prepared by induction heating sintering method combined with the alloying of the copper-ferrum matrix with various metallic elements. As the temperature was increased from room temperature to 500°C, the mechanical properties of the composites were measured using the mechanical tester, while the friction and wear properties were evaluated by MRH-3 friction-wear tester. The worn surface morphologies of the composites were analyzed by means of scanning electron microscopy. It was found that the mechanical and friction/wear properties of the self-lubricating composites were related to the induction frequencies and the contents of the graphite as the solid lubricant. The increased graphite content resulted in reduced mechanical properties and increased friction/wear properties. The composites with proper graphite contents and induction frequencies have the lower the friction coefficients and wear volume loss at room temperature to 500°C. Meanwhile, wear mechanism of composites have been changed from abrasive wear to ploughing wear.