Wear- Corrosion of Calcium Phosphateano-TiO_2 Composite Coatings Electrodeposited on Ti-6AI-4V Alloy in Hanks' solution

摘要

The structure and mechanical properties of the electroplated calcium phosphateano-TiO_2 composite coatings on Ti-6AI-4V alloy were evaluated as well as their effect on the corrosion and wear-corrosion resistance of in Hanks' solution. The anodizing process was performed on Ti-6AI-4V alloy surface to enhance the adhesive of these composite coatings on Ti alloy. The anodizing treatment was conducted at 10V and room temperature with different anodizing time of 40min, 50min, 1h, 2h and 3h. The surface morphologies, element compositions and surface roughness of the composite coatings before and after all tests were analyzed by scanning electron microscopy (SEM), X-ray energy dispersive analyzer (EDS) and atomic force microscope (AFM). Electrochemical polarization measurements are performed for analyzing corrosion characteristics, using the block-on-ring surface friction manner to evaluate the wear-corrosion behavior of these composite coatings in Hanks' solution. Experimental results indicated that the hardness of Ti-6AI-4V alloy was increased due to the anodizing treatment, and that could enhanced the adhesive of electroplated calcium phosphate coating in addition to the electroplated calcium phosphateano-TiO_2 composite coatings. The coatings exhibited more uniform, dense and adhesive than that of non- anodized treatment. The nano-TiO_2 particles could be co-deposited on the Ti-6AI-4V alloy and reinforced the calcium phosphate coating, increasing the hardness and refining the structure. Moreover, the corrosion and wear-corrosion resistance of the electroplated calcium phosphateano-TiO_2 composite coatings were improved significantly as a result of the nano-TiO_2 particles added.