Effect of single and duplex surface treatments on wear properties of CP-Ti

Wear behaviours of nitrided, anodised and duplex treated commercially pure (CP)-Ti were investigated using a pin on disc tribotester. First, CP-Ti was nitrided and then anodised at different temperatures and times. Phase structure, cross-section and surface hardness of coatings were examined with XRD, SEM and microhardness tester. Formation of TiN and anatase phases were observed after nitriding and anodising respectively. Thickness of the oxide layer along with hardness increased with increasing the anodisation potential and time. A porous structure with circular tube also formed on the surface after anodising. The duplex treatment caused the formation of rutile phase in the oxide layer. It was finally demonstrated that the duplex treatment increased the load bearing capacity due to an increase in the core hardness of CP-Ti which resulted in a reduction of the friction coefficient and wear rate of CP-Ti. © 2011.