AISI 304 stainless steel was ion implanted with Co, and the tribological property on the surface of the stainless steel
was investigated. The Co ion
implantation was carried out using a
metal vapor vacuum arc (Mevva) broad-beam ion
source with an extraction voltage of 40 kV, implantation doses of 3×10~(17)/cm~2 and 5×10~(17)/cm~2, and ion current
densities of 13, 22 and 32μA/cm~2. The results showed that the near-surface hardness of Co-implanted stainless steel
sample was increased by 50% or more, and it increased with increasing ion current density at first and then declined.
The friction coefficient decreased from 0.74 to 0.20 after Co implantation. The wear rate after Co implantation
reduced by 25% or more as compared to the unimplanted sample. The wear rate initially decreased with increasing
ion current density and then an increase was observed. Within the range of experimental parameters, there exists
a critical ion current density for the Co-implanted stainless steel, at which the wear rate decreased with increasing
retained dose, going through a minimum and then increased. The critical ion current density in this paper is about
22μA/cm~2.