Hardness tests and pin-on-disk wear tests have been used to correlate the profiles of nitrogen concentration, wear rate, and hardness in ion implanted Ti-6Al-4V samples. This comparison indicates that the wear rate tends to remain low longer than one might expect from looking at nitrogen concentration profiles or hardness profiles.
Finite element simulations of the hardness tests were conducted in order to deduce the change in the yield stress that was caused by the ion implantation. These simulations indicated that the yield stress was increased by approximately a factor of ten over the strength of the bulk Ti-6Al-4V, indicating a yield strength in the implanted layer on the order of 5-8 GPa. A secondary result of the finite element simulations indicated that the shape of the indents for implanted and unimplanted materials exhibited fundamentally different behavior. The unimplanted specimens showed the buildup of material around the edge of the contact surface, producing a berm, while the implanted specimens showed no such buildup.