Surface modification and mechanical property studies of Ti6Al4V alloy using high power diode laser in nitrogen atmosphere

Ti6A14V alloy was surface modified by Laser surface nitridation with a high power diode laser (HDPL) in a nitrogen atmosphere in an acrylic chamber. In this report, a complete study of structure and mechanical properties of two scanning speeds (5, 10 mm/sec) presented, by keeping the power (3 kW) and nitrogen gas flow (75 1/min) as constant after a complete study of various powers and nitrogen gas flow. A complete conversion of Ti6A14V alloy to TiN on the surface was observed by X-ray diffraction in the case of slow scanning speed (5 mm/sec), whereas unreacted Ti was observed in the fast scanning speed (10 mm/sec). The surface roughness of slow scanning speed (5 mm/sec) was larger than the fast scanning speed (10 mm/sec). Nanoindentation hardness of slow scanning speed and fast scanning speed were 18 GPa and 16 GPa, respectively. Friction coefficient of unmodified Ti6A14V alloy was measured as 0.7, whereas slow and fast scanning speed was 0.42 and 0.62, respectively.