Tribological Performance of Crosshatch Pattern Textured and Heat Treated Dual Engineered Ti6Al4V Surface under Bio-Lubricated Line Contact Configuration

Abstract

This study combines the laser surface texturing technology and heat treatment process to fabricate a dual surface engineered Ti6Al4V consisting of micro-groove crosshatch pattern texture covered with hard TiO2 oxide coating to reduced friction and improve the wear resistance at the bio-lubricated interface. Crosshatch texture with 25 μm width, 5 μm depth at 25% area density were fabricated using nanosecond Nd:YAG laser over Ti6Al4V surface and then heat treated at 600 °C for 48 hours. XRD result showed rutile TiO2 phase formation along with the presence of anatase TiO2, Al2O3 and Ti3O minor phases whereas, the surface hardness was increased to 1538±41 HV. Bio-tribology experiments were carried out for 45 and 90 o oriented micro-groove crosshatch textures, with and without heat treatment, under partially replicating hip implant articulation. Results demonstrated 60% friction reduction corresponding to the 45 o oriented crosshatch texture with heat treatment. Further, the worn-out surface morphology showed reduced wear damage and good wear debris entrapment inside the micro-grooves.