Controlled Fabrication of Nanoporous Anodic Titania Films on Ti-6Al-4V Alloy for Enhanced Self-Lubricating Properties by Combining Spark Anodization and Electropulse-Assisted Ultrasonic Rolling
- 9 Downloads
We report the fabrication of self-lubricating nanoporous anodic titania films through spark anodization in an aqueous ammonia sulfate electrolyte on a hardened nanocrystalline layer of Ti-6Al-4V rods after electropulse-assisted ultrasonic surface rolling process (EP-USRP). The spark anodization with an optimum anodizing voltage of 130 V produced sponge-like nanoporous anodic titania films with stable crystalline structure of rutile-phase TiO2, and the EP-USRP resulted in a nanocrystalline layer with a higher surface hardening depth (> 220 µm) through severe plastic deformation. The combinatorial technique resulted in excellent tribological properties, with lower friction coefficient of ~ 0.72 (compared to EP-USRP of ~ 0.80), smoother wear scar with less adhesion and less wear loss (maximum depth of 12 nm, 33.3% lower than the EP-USRP sample). These enhancements are attributed to the synergetic effect of the self-lubricating nanoporous anodic titania films formed by spark anodization (which acted as transition layer and prevented direct contact between the counter materials and the substrate) and the hardened nanocrystalline layer formed by EP-USRP (which slowed down the consumption of the anodic powder).
Keywordselectropulse-assisted ultrasonic surface rolling nanocrystalline layer nanoporous anodic titania film spark anodization Ti-6Al-4V tribological properties
The authors wish to acknowledge the financial support from Shenzhen Science and Technology Supporting Plan Project (GJHS20160331183313435), China. The authors also want to thank The Light Metal Educational Foundation, Nagoya University, and Nagoya Institute of Technology for financial supporting on the research.
- 27.E.S. Jr., G.B.D. Souza, F.C. Serbena, H.L. Santos, G.G.D. Lima, E.M. Szesz, C.M. Lepienski, and N.K. Kuromoto, Effect of Anodizing Time on the Mechanical Properties of Porous Titania Coatings Formed by Micro-arc Oxidation, Surf. Coat. Technol., 2016, 309, p 203–211Google Scholar
- 30.S.-Z. Kure-Chu, H. Sakuyama, S. Saito, S. Miura, H. Yashiro, H. Hirahara, H. Segawa, K. Wada, and S. Inoue, Controllable Fabrication of Multi-tiered Nanoporous Anodic TiO2–TiN Composite Films as High-Performance Anode Materials for Lithium-Ion Batteries, Electrochim. Acta, 2016, 212, p 481–491CrossRefGoogle Scholar
- 40.K. Edalati, D. Akama, A. Nishio, S. Lee, Y. Yonenaga, J.M. Cubero-Sesin, and Z. Horita, Influence of Dislocation–Solute Atom Interactions and Stacking Fault Energy on Grain Size of Single-Phase Alloys After Severe Plastic Deformation using High-Pressure Torsion, Acta Mater., 2014, 69, p 68–77CrossRefGoogle Scholar
- 41.C. Ye, A. Telang, A.S. Gill, S. Suslov, Y. Idell, Z. Kai, J.M.K. Wiezorek, Z. Zhou, D. Qian, and S.R. Mannava, Gradient Nanostructure and Residual Stresses Induced by Ultrasonic Nano-crystal Surface Modification in 304 Austenitic Stainless Steel for High Strength and High Ductility, Mater. Sci. Eng., A, 2014, 613(11–12), p 274–288CrossRefGoogle Scholar