Surface Modification of Ti3Al2.5V Titanium Alloy Using Laser Texturing With Improved Wettability, Corrosion and Bioactivity Behaviour

The present work aims to improve the wettability, corrosion and bioactivity performance of Ti3Al2.5V alloy through laser surface texturing. For experimental investigations, three different texture patterns such as hexagon, concentric circles and an array of lines were fabricated using nanosecond fibre laser with an intrinsic wavelength of 1064 nm. The wettability behaviour of the surface was determined using contact angle goniometer with two different liquid medium: distilled water and simulated body fluid (SBF), and the corrosion behaviour was examined using potentiodynamic polarization and electrochemical impedance spectroscopy method. Laser surface texturing enhanced the hydrophilicity of the specimens with values in the range of 32.94–57.27º for distilled water and 45.12–69º for SBF with both the liquid medium following Wenzel model. The corrosion rate was lowered because of laser treatment (from 1.18 ×10^-1 mm/year for untextured Ti-3Al2.5V to 5.46 ×10^-3 mm/year for hexagon, 2.99 ×10^-3 mm/year for concentric circles and 1.70 mm ×10^-2 /year for lines). The improvement in the corrosion rate of the specimens was because of the refinement in the grain structure due to rapid solidification along with reduction in β / α volume ratio. In vitro bioactivity test revealed that the textured samples depicts enhancement in the deposition rate of calcium and phosphate ions.