Microstructure and properties of C/C-CuNi composites fabricated by carbothermal reduction of hydrothermal co-deposited oxides

Abstract

A novel hydrothermal co-deposition method was proposed to fabricate C/C-CuNi composites as high-speed railway pantograph strip. The bulk density of composites reached 1.83 g/cm3 with 5 cycles of co-deposition. The effect of Ni addition on the microstructure and properties of the composites was investigated. The Ni addition not only improves the graphitic degree of the carbon matrix but also enhances the fiber/matrix interface bonding. The composites presented outstanding properties when the Ni/Cu molar ratio was 0.6. It possesses high flexural strength (92.4 MPa) and low electrical resistivity (10.78 μΩ m). The friction coefficient was stabilized at 0.223 and wear rate was just 0.45 g h−1 under 10 N applied load. The outstanding tribological performance resulted from the micro-spall fatigue wear and the formation of self-lubricating film owing to the Ni addition. The C/C-CuNi composite provides an attractive high-speed railway pantograph strip material, and the hydrothermal co-deposition method is a feasible strategy to improve the interfacial bonding of Cu-based carbon fiber reinforced composites.

Keywords

• Hydrothermal co-deposition
• Pantograph strip
• Microstructural
• Tribological
• Fatigue wear