Effect of laser surface texturing (LST) on tribological behavior of double glow plasma surface zirconizing coating on Ti6Al4V alloy

Abstract

In the present work, double glow plasma zirconizing technique combined with laser surface texturing (LST) were applied to improve the wear resistance of Ti6Al4V (TC4) alloy. A zirconium coating (Zr-coating) was firstly synthesized on TC4 alloy by double glow plasma surface zirconizing. Laser surface texturing (LST) was subsequently conducted to produce uniform dimples on the surfaces of Zr-coating and raw TC4 alloy. The dimple texture with a diameter of 300 μm and gradient densities of 5%, 7%, 11% were distributed in a square array on the surfaces of coated and uncoated TC4 alloy disks, respectively. Comparative assessments on the wear resistance of the related Zr-coating and TC4 alloy were carried out using a ball-on-disk wear tester. The results showed that the Zr-coating with a thickness of about ~50 μm, was tightly adhered to the TC4 alloy matrix. The textured specimens with a texture density of 5% revealed the lowest mass loss values in comparison to other samples, and the wear rate decreased by 20% and 26.6% compared with that of the TC4 alloy and Zr-coating without dimple texture on their surfaces. The wear rate value of the four tested samples were finally sorted in the sequence of the duplex treated TC4 < zirconized TC4 < textured TC4 < polished TC4.