Preparation and Wear Behavior of Enamel Coating on Ti-6Al-4V ELI Titanium Alloy

An enamel coating was prepared on the surface of Ti-6Al-4V extra low interstitial (ELI) titanium alloy by using slurry sintering process. The surface three-dimensional morphology, wear track morphology, microhardness and the tribological behavior of alloy with and without enamel coating and adhesion strength between the coating and base alloy were characterized by means of atomic force microscopy (AFM), scanning electron microscopy (SEM), microhardness test, friction and wear testing machine and thermal shock method, respectively. The morphologies of the coating and base alloy before and after wear were comparatively analyzed, and wear mechanism was discussed. The results show that the microstructure of enamel coating was compact and combines well with the base alloy. The thickness of enamel coating was about 30 mu m, and the coating was uniform and smooth. Compared to base alloy, the hardness of enamel coating improved obviously. Under the condition of dry friction and wear, the wear mass loss and wear rate of alloy with enamel coating was little, only one quarter and about 29.6% of that for alloy without enamel coating. The alloy with enamel coating shows excellent wear-resistance. Wear mechanism of Ti-6Al-4V ELI titanium alloy is adhesive and abrasive wear, while the enamel coating shows abrasive wear.