Wear and Friction Behavior of Plasma Sprayed NiCrMo-NiCrBSi Alloy Anti-Friction Coatings

Abstract

When the internal combustion engine is working， the friction between the piston ring and the cylinder liner will cause energy loss and wear damage to the cylinder block.Aiming at the problem of friction and wear of cylinder liner and piston ring， a composite anti-friction coating composed of NiCrMo-30%NiCrBSi was designed by using composite material theory.The anti-friction coating was prepared with NiCrMo-NiCrBSi mixed powder by atmospheric plasma spraying technology.The cross-sectional structure， hardness and friction and wear behavior of the coating under simulated cylinder liner-piston ring friction and wear conditions were studied.Results showed that composite coatings with good bonding and moderate hardness (564 HV 3 N) could be obtained by spraying mixed powders.Under dry friction and wear conditions， the NiCrMo-NiCrBSi composite coating exhibited excellent comprehensive wear resistance.The wear amount of the coating itself and the abrasive part (pin) was small， and MoO2 could be generated on the surface to reduce the friction coefficient.Under oil-lubricated wear conditions， due to the formation of MoS2 on the surface， the friction coefficient was significantly reduced (about 0.1 after stabilization)， and the wear of the composite coating and the friction pair could be almost negligible.

Keywords

• atmospheric plasma spraying|composite metal coating|friction and wear