Preparation And Tribological Behavior Of C/C-Ni-Cu Composite

The pantograph slide is device for current transmission and conversion on electric locomotives.Its performance not only affects the electric condition in the train operation,but also plays a role in ensuring the stable and safe running of electric locomotives.Pantograph skateboard materials need to have good impact resistance and environmental stability.The materials of pantograph slide are put forward by the continuous improvement of high-speed railway speed,which can improve the electrical conductivity of the skateboard materials while providing security.However,the pantograph slide materials mainly rely on imports at presrent,which is not conducive to independent development of high-speed rail.It is a difficult problem for the high-speed railway that development new pantograph slide materials.In this paper,C/C-Ni-Cu composites have been designed for slide material and research the microstructure,mechanical properties,electrical properties,tribological properties of composites which prepared by a molten copper infiltration and a hydrothermal co-deposition,respectively.This research can provided a reference for the application of C/C-Ni-Cu composite material in pantograph slide.(1)The effects of heat-treatment temperatures on the physical phase,microstructure,graphitization degree,mechanical properties and electrical properties of the C/C-Ni composites were studied.The results show that the C/C-Ni composites with Ni particles of 10-20 ?m can be obtained by the hydrothermal deposition method.The graphitization degree of the matrix carbon increased with the increase of the heat-treatment temperature.The ID/IG value of C/C-Ni composite can rearch 1.18 after 1400? treatment,the maximum bending strength can rearch 66.2 MPa and the electric resistivity is only 23.6??·m.(2)The C/C-Ni composites with different Ni contents were prepared by hydrothermal co-deposition.The influences of Ni contents on the microstructure,graphitization degree and conductivity of C/C composites were studied.The electric resistivity decreased,the density and graphitization degree increased significantly with the increased of Ni content.At the same time,the molten Cu infiltration behavior of C/C-Ni composites with different Ni contents was analyzed.The C/C-15Ni composite has the highest copper infiltration amount.Its density can increase from 1.43 g·cm-3 to 2.83 g·cm-3 after copper infiltration.The C/C-15Ni-Cu composite has good properties.Its bending strength can reaches 107.7 MPa.Its friction coefficient is only 0.179 and 0.189 under 5 N and 10 N loading,respectively.(3)The C/C-Ni-Cu composites were prepared by using a hydrothermal co-deposition method.The influences of different Ni/Cu ratios on the microstructure,mechanical properties,electrical properties and tribological properties were studied.The composite has better mechanical properties and electrical properties when the ratio of Ni/Cu is 3:5,the maximum bending strength is 92.4 MPa and resistivity is 10.86 ??·m.The friction coefficient of the C/C-6Ni-Cu composite is 0.223 and 0.294 under 5 N and 10 N loading,and the wear rate is just 0.43 g·m-3.