Experimental and numerical study of temperature field and molten pool dimensions in dissimilar thickness laser welding of Ti6Al4V alloy

Laser study is an important consideration in the present century with advances in laser technology. Titanium alloys are of great importance to the defense industry, aerospace and other industries due to its properties, including strength to weight. In this research, experimental and numerical study are investigated for laser welding on sheets of Ti6Al4V alloy with different thicknesses. Analysis of the temperature distribution around the molten pool and dimensions of the depth and width of the molten pool are performed by changing the parameters of laser such as focal length, speed of laser welding and power. The results show that the heat affected zone (HAZ) and molten pool is diverted to the thinner sheet. Also, by decreasing the focal length, the temperature of the workpiece and the dimensions of depth and width of the molten pool are increased. In addition, with enhancing the laser speed, the laser beam contact time with the workpiece surface reduces and the temperature decreases, resulting in a decrease in the dimensions of the depth and width of the molten pool. Eventually, as the power increases, the dimension of the melt pool increase and at both 180 W and 240 W powers, the thinner sheet experiences higher temperatures compared to the thicker sheet. In this study, the results of numerical simulation are matched with the experimental results and can be applied to obtain the temperature and geometry of the melt pool in other cases to reduce the cost and time.