Microstructure characterization and tribological behavior of anodized ti6al4v alloy

Thin oxide layers were obtained in Ti6A14V alloy by anodizing process in phosphoric acid with different currents and anodizing times. The oxide layers were characterised by X-Ray Diffraction, Optical Microscopy and Scanning Electron Microscopy, as well as by surface roughness and porosity measurements. The tribological response of anodized samples under lubricated sliding contact was studied in a pin-on-disc tribometer, in which UHMWPE discs were the counter bodies and Ringer's solution was the lubricant.The results showed that the oxide layers obtained were amorphous with average pore size smaller than 1 mu m and the pore morphology was affected by the anodizing current. The average surface roughness (Ra) varied between 0.02 and 0.10 mu m, and the oxide thickness varied between 0.5 and 0.88 mu m. The treated Ti6A14V - UHMWPE pair showed friction coefficients in the range between 0.03 and 0.07, while a maximum coefficient of 0.02 was measured in the experiments carried out with untreated samples.