Friction and wear properties of Al-20Si-5Fe-2Ni-Graphite solid-lubricating composite at elevated temperatures

Tribological behavior of the Al-20Si-5Fe-2Ni alloy and its composite containing 30 wt % copper-coated graphite were investigated at 25-500 °C. The result indicated that the composite showed a significantly decreased wear rate at all test temperatures as compared to the alloy. Owing to the combined effect of solid lubrication and dispersion strengthening provided by the graphite particles and in situ formed Al2Cu intermetallic, the composite can avoid severe adhesive wear up to 500 °C. At 25 °C, the predominant wear mechanism of the composite is abrasive wear, and it transforms to abrasive wear and delamination wear at elevated temperatures.