Akademik Veri Yönetim Sistemi
OPTICS AND LASER TECHNOLOGY, cilt.192, 2025 (SCI-Expanded)
The many attractive properties of titanium materials enable their use in many industrial areas. However, its weak tribological properties may impose limitations in some applications. Although there are many traditional methods to improve the surface properties of titanium materials, laser surface treatment appears as an attractive method because of its significant advantages. The most important disadvantage mentioned in the laser surface hardening of titanium materials literature is stated as cracks on the surface. By applying exactly the same laser parameters to Ti6Al4V alloys in atmosphere and nitrogen environment, the differences on the surface were tried to be determined by optical, chemical and tribological measurement methods. The variations in coefficient of friction (COF) values following fiber laser surface treatment of Ti6Al4V material in nitrogen and air environments were investigated. When compared to untreated surfaces, significant increases in COF values were seen in both conditions. The COF rose from 0.35 on untreated surfaces to 0.58 on laser-treated surfaces in the air environment. The COF rose from 0.36 on untreated surfaces to 0.55 on laser-treated surfaces in the nitrogen atmosphere. These increases are assumed to be caused by the increased surface hardness of the material as well as the presence of oxide and nitride layers formed on the surface. The surface hardness of the base metal, which was 335 HV, was gradually increased to 953.45 HV and 802.60 HV in air and nitrogen environments, respectively, with changes in laser scanning speed (from 300 mm/s to 100 mm/s) and spot radius (from 100 mu m to 70 mu m). However, considering the surface cracks that will affect the fatigue behavior of the material, there is an upper limit to the laser hardening process. In this study, the crack structures formed in the laser surface hardening process of titanium alloy and the hardness limits that can be reached without crack formation were tried to be determined by optimizing laser parameters.