Fig. 1. Laser shock peening experiment. (a) Schematic of laser shock peening; (b) diagram of laser shock path

Fig. 2. Anodic oxidation experiment. (a) Schematic of the installation; (b) photograph of experimental installation

Fig. 3. Friction and wear test. (a) Test mechanism diagram; (b) photograph of test equipment

Fig. 4. Three-dimensional morphologies of four samples. (a) Ti6Al4V; (b) Ti6Al4V-LSP; (c) Ti6Al4V-TiO_2; (d) Ti6Al4V-LSP-TiO₂

Fig. 5. Surface and cross-section morphologies of nanotubes. (a) Ti6Al4V-TiO_2; (b) Ti6Al4V-LSP-TiO₂

Fig. 6. Contact angle of four sample surfaces. (a) Ti6Al4V; (b) Ti6Al4V-LSP; (c) Ti6Al4V-TiO_2; (d) Ti6Al4V-LSP-TiO₂

Fig. 7. Microstructures of Ti6Al4V-LSP sample. (a) Bright field image; (b) dark field image; (c) nanocrystalline at high resolution; (d) selected area electron diffraction (SAED) image

Fig. 8. Typical measurement curves of adhesion force

Fig. 9. Variations of friction coefficient of four samples with time

Fig. 10. Friction and wear test results. (a) Average friction coefficient; (b) average mass loss

Fig. 11. Wear morphologies of four kinds of samples (areas within the red box are scanned for elements). (a) Ti6Al4V; (b) Ti6Al4V-LSP; (c) Ti6Al4V-TiO_2; (d) Ti6Al4V-LSP-TiO₂

Fig. 12. Schematics of wear process of TiO₂ nanotube sample in simulated body fluid