Inhibition effect of covalent carbon nanosheets on mechanochemical wear of diamond

Abstract

Diamond tools experience severe chemical wear when machining ferrous metals, which hinders their practical applications. In order to improve the wear resistance of diamond cutting tools, in the diamond-graphite strong covalent structure prepared by laser induced solid-phase diffusion, carbon nanosheets (CNS) can be obtained by electrochemical stripping of the graphite layer onto the diamond matrix, which provides a new way to improve the limitations of diamond tools in application. After 14,400 cycles of reciprocating sliding against the GCr15 ball at a normal load of 2–8 N, friction was reduced by 45.9 %–65.6 % with high durability. The oxygen content is reduced by an order of magnitude during this process, suggesting that the CNS can prevent oxidation behavior at the sliding interface. The bare diamond had a relative wear rate of 4.1–15.4 times that of the CNS. It showed competitive inhibition of mechanochemical wear. Our work provides a convenient and green method of preparing in-situ CNS covalently bonded on a diamond surface, extending the way for the prospect of carbon materials.

Keywords

• Electrochemical exfoliation
• Laser-induced graphitisation
• Carbon nanosheets
• Solid lubricant
• Mechanochemical wear