Improving the Tribological Behavior of Graphite/Cu Matrix Self-Lubricating Composite Contact Strip by Electroplating Zn on Graphite

摘要

A novel Zn-coated graphite/Cu matrix self-lubricating composite contact strip (ZGCCS) was prepared by electroplating, pressing plus roasting and its tribological behaviors against the copper disk were studied under the simulated actual conditions, in comparison with the common graphite/Cu matrix self-lubricating composite (GCCS). The wear rate of both the ZGCCS and the GCCS increased with the increment of the current density and the sliding velocity. However, the ZGCCS exhibited wear resistance superior to the GCCS, indicating the electroplating Zn on graphite played an important role in improving the wear resistance and the wear rate of the former was only one-third of the latter at the sliding velocity of 41.7 m/s and with the current density of 285A/cm2. Arc erosion wear, oxidative wear, and adhesive wear were the dominant mechanisms during the electrical sliding process. The arc erosion of the composite contact strip was remarkably reduced by the electroplating of Zn on graphite since the Zn-coated graphite particles were homogeneously distributed in the Cu matrix.