Graphite cluster/copper-based powder metallurgy composite for pantograph slider with well-behaved mechanical and wear performance

Copper based composites with high graphite contents for pantograph sliders have been manufactured via an inexpensive powder metallurgy method. Large size cluster graphite is added into the matrix as solid lubricant to optimize the mechanical and wear performance of the composites. The mechanical performance and microstructure of graphite cluster/ copper-based (GC/Cu) composites are investigated. The highest graphite content in GC/Cu composites can reach up to 5wt%. The graphite cluster/copper-based composites show an outstanding mechanical performance, in which the impact toughness can reach 4.8J/cm2 with 5wt% graphite cluster. The matrix is constituted with single α-phase Cu10Sn3with second phase particles CuNi2Sn. Moreover, friction and wear behavior with or without electric currency have been explored systematically, which indicates that the friction coefficient with 5wt% graphite composites reached a minimum of 0.184at a load of 25N. It also exhibits the excellent friction performance under the effect of electric current. The smallest wear rate of 4.2×10−3 mg/m occurs in the sample with 2wt% graphite at 30 A. Meanwhile, the interaction between pantographs and contact wire has been investigated based on elemental analysis and surface morphology. Oxidation and material transfer is found on the worn surface. [Display omitted] •The graphite cluster/copper composites were manufactured via an inexpensive powder metallurgy method.•Large size graphite clusters were added into the composite instead of ordinary flakey graphite.•Excellent physical and mechanical properties were obtained.•The composite shew excellent friction and wear behaviors with or without electric currency.