Effect of laser texturing on the antiwear properties of micro-arc oxidation coating formed on Ti-6Al-4V

In this study, the advantages of laser texturing and micro-arc oxidation were combined to prepare an antiwear coating with a graded structure to improve the antiwear properties of titanium alloys. The morphology, structure, and composition of the coating were characterized by 3D surface profiler, SEM, EDS, and XRD, respectively. The antiwear properties and wear reduction effect of the composite coating were analyzed by using friction coefficient, wear rate, and wear scars. The results indicated that the micro-arc oxide coating consisted mainly of anatase and rutile, and higher proportions of rutile were detected in the laser texture composite micro-arc oxide (LT/MAO) coatings. The main elements of the micro-arc oxidation coating were Si, Ti, and O. Laser texturing can significantly reduce wear rates and improve the antiwear properties of the micro-arc oxidation coating. Compared with the untextured micro-arc oxidation coating, the wear rate and average friction coefficient of the LT/MAO coating were reduced by 26 % and 28 %, which were 0.262 × 10−6 mm3·N−1·m−1 and 0.23, respectively. Meanwhile, the LT/MAO coating exhibits longer life under extended wear. In the later stages of wear, the coating debris from the inner edge of the microgroove floated to the upper surface forming secondary lubrication and extending the protective effect of the micro-arc oxidation coating on the substrate.