TiN formation on Ti target by laser ablation method under different N2 gas pressure and laser scanning cycles: A wettability study

Titanium (Ti) and its alloys have vast applications in industry. However, surface modification technology should be performed to maintain Ti properties for its use in a variety of applications. Titanium nitride (TiN) is often used as a coating to improve surface properties due to its special characteristics. In this research, the laser ablation method is applied on Ti target in N2 atmosphere to make TiN structure using a fiber laser. The different N2 gas pressures and the number of laser scanning cycle effect was investigated on the formation of TiN structure. Different techniques were utilized to scrutinize samples. It was concluded that increasing the laser scanning cycle has a greater effect on the amount and quality of TiN structure compared to the change of N2 gas pressure. The aging effect on ablated surface wettability of samples was assessed by water contact angle (WCA) measurement. The samples illustrated superhydrophilic behavior immediately after laser processing and became hydrophobic over time. Due to the fact that the surface morphology didn't change with the aging effect, the wettability changing is due to the surface chemical composition by the oxidation process and adsorption of the airborne organic compounds of TiN surface by the effect of the long-term storage of ablated sample in the air that was studied by the X-ray photoelectron spectroscopy (XPS).