Wear behaviour of La₂O₃/Cu composite under extreme electrical contacts and mechanical load

Abstract

In the present study, wear behaviour of lanthanum oxide strengthened copper alloy (La₂O₃/Cu) was investigated under extreme conditions of strong currents, heavy loads and high speeds. The results showed that the wear rate of La₂O₃/Cu was positively correlated with current and inversely related to load. Microstructure and phase composition of wear surface were analysed using optical microscope, scanning electron microscope, energy dispersive spectrometer and X-ray diffractometer. Obvious damage on the wear surface and a micro-sized affected zone on the surface of the matrix was observed, which were attributed to arc erosion wear as well as the interaction effect of the extreme conditions. The affected zone was divided into a deposition layer, softened layer and strengthened layer. La₂O₃ nanoparticles acting as effective nuclei of heterogeneous nucleation during the crystallisation process impelled the formation of the strengthened layer.

Keywords:

• La₂O₃/Cu composite
• Wear behaviour
• Strong current
• Arc erosion wear
• Wear rate