Abstract
Microstructure of electroless plated Ni-Co coating on plasma-sprayed Cr3C2-NiCr coating which was previously applied onto lCrl8Ni9Ti stainless steel was characterized, and its tribological properties during sliding against different materials were evaluated. It was found that the electroless plated Ni-Co coating on the Cr3C2-NiCr coating had lower cobalt content and a finer structure than that deposited directly on lCrl8Ni9Ti stainless steel. All the self-mated as-sprayed Cr3C2-NiCr coating, the self-mated electroless plated Ni-Co coating on the Cr3C2-NiCr coating, the self-mated electroless plated Ni-Co coating on lCrl8Ni9Ti stainless steel and the frictional pair of the electroless plated Ni-Co coating on lCrl8Ni9Ti stainless steel against the Cr3C2-NiCr coating exhibited higher friction and wear coefficients during sliding. The frictional pair of the electroless plated Ni-Co coating on the Cr3C2-NiCr coating against the Cr3C2-NiCr coating displayed excellent tribological properties with a friction coefficient of 0.10 and a wear coefficient less than 10-6 mm3 Nm-1 during dry sliding in air. The electroless plated Ni-Co coating on the Cr3C2-NiCr coating somewhat reduced friction and wear coefficients during sliding against plasma sprayed TiO2 coating. The above results could be attributed to that the electroless plated Ni-Co coating on the Cr3C2-NiCr coating could weaken the adhesive intensity between the suitable counterpart materials during sliding.
