Investigation of the Effect of Laser Cutting Parameters on Surface and Kerf Quality of Thick Ti–6Al–4V Alloy Sheets

Abstract

Titanium alloys, especially Ti–6Al–4 V alloy, are significant materials because of their superior mechanical and chemical properties. They are used in most high-strength and elevated temperature applications, such as aircraft, ships, biomedicine, and marine applications. Recently, laser machines were used to cut a variety of sheet metals. It is critical to comprehend how laser cutting parameters influence surface and kerf quality. In this work, a 4 mm-thick Ti–6Al–4 V sheet was cut. Laser beam power, cutting velocity, and assist gas pressure were used as cutting parameters, while surface roughness, kerf width, taper angle, and dross height were measured to determine which parameter has the greatest influence on the cutting quality. It was found that laser power of 3 kW, cutting velocity of 2000 mm/min, and assist gas pressure of 8 bar were the optimized parameters to achieve the minimum surface roughness value of 2.34 ± 0.12 µm and the minimum dross value of 0.270 mm due to the high velocity. The minimum value of kerf width was found to be 0.774 ± 0.016 mm at upper surface and 0.408 ± 0.039 mm at lower surface of cut at cutting conditions of Pu = 2.5 kW, V = 1500 mm/min, and assist gas pressure of 10 bar. The minimum value of kerf taper was found to be 1.89 ± 0.61° at cutting conditions of Pu = 2 kW, V = 1500 mm/min, and assist gas pressure of 8 bar.