Tailoring Tribological Performance of Pure Titanium by a Duplex Treatment of Laser Surface Texturing-Thermal Oxidation

A combined surface treatment of laser surface texturing (LST)-thermal oxidation (TO) technique was performed on pure titanium (TA2) matrix to enhance its wear resistance. The dimple-shaped texture was fabricated by using an optical fiber laser processing equipment, and the dimple-shaped texture with diameter of 300 μm and density of 5%. The thermal oxidation coating (TO-coating) was prepared by TO treatment under 650 °C for 30 h. Microstructure, microhardness, and bonding strength of the TO-TA2 were systematically characterized. Comparative evaluation of anti-wear performance for relevant samples of duplex treatment TA2 (DT-TA2), LST-TA2, TO-TA2, and TA2 matrix were investigated via the dry sliding process. The results revealed that uniform and dense TO coating with a thickness of approximately 11 μm was fabricated on the surface of the TA2 matrix. The attained TO coating consisted of the compound phase of TiO2 shown by XRD detection. The surface hardness and elasticity modulus of the TA2 were improved by TO treatment, and the attained TO coating had a strong bonding strength with the TA2 matrix. In terms of wear rate, the samples were sorted in the following order: DT-TA2 < TO-TA2 < LST-TA2 < TA2. For tribological behavior, the duplex treatment process can significantly reduce the abrasive wear and adhesive wear tendency of the TA2 matrix. Taking advantage of LST and TO treatment, the wear resistance of TA2 sample after duplex treatment was significantly improved. In view of this, the TO coating is expected to provide wear resistance protection for pure titanium components, the presence of dimples reduced the friction coefficient of pure titanium components, and further extended their service life. The results may provide reference data for surface modification of TA2 by the laser surface texturing and thermal oxidation duplex treatment.