Tribological behavior of diamond like carbon film sliding against CoCrMo or Al2O3 in air and water environment

The effect of counterface material (CoCrMo and Al2O3) on the tribological behavior of hydrogen free diamond like carbon (DLC) film in air and water environment was investigated. The results show CoCrMo causes unstable high friction and high DLC wear in air environment owing to the unstable transfer layer rich in metal oxide. Al2O3 induces less DLC wear than CoCrMo in air due to reduced adhesive wear and solid lubrication. In water environment, CoCrMo brings extremely low wear of DLC film due to the high graphitized transfer material adhering on the counterface and water preventing adhesive wear. For Al2O3 counterpart, relatively high DLC wear is produces in water environment because of the high hardness of Al2O3 and insufficient solid lubrication.