活塞销材料20CrMo上沉积CrN 涂层的摩擦性能研

The CrN coatings were deposited on the highly intensified diesel engine piston pin material(20CrMo). The differences in tribological properties of the 20CrMo against the Si₃N₄ and the CrN coating against the Si₃N₄ were investigated through-ball-on-disk testing. Under the dry friction condition, the friction coefficient and wear rate of two tribopairs were tested at room temperature, 300, 500, 700 and 900℃, respectively. The effects of different speeds and loads on the friction performance of two tribopairs were investigated under the PAO6 oil lubrication. Also, the friction performances were compared under the PAO6 oil and the engine oil 5W40 lubrication. The results demonstrates that the high temperature wear mechanism changes through the CrN coating deposition on the 20CrMo substrate and the wear resistance is significantly enhanced. Under the PAO6 oil lubrication, the CrN coating reduces the effect of load on the friction coefficient compared with the 20CrMo substrate, whereas the 5W40 oil lubrication, as well as the application of CrN coating, significantly improves the tribological properties under the high speed and heavy load conditions.