Numerical simulations on LBW of thin sheets of Ti-6Al-4V alloy using the Taguchi method to determine ideal processing parameters

This paper deals with pulsed mode laser beam welding (LBW) on 2 mm thick Ti-6Al-4V alloy sheets. ANSYS Fluent 16.0 version is utilized to develop a generic model with Vc++ code. The model is validated with test results. The optimal LBW parameters are obtained by maximizing the depth of penetration (DP) and minimizing the weld bead width (BW). To minimise the number of numerical simulations, Taguchi approach is adopted. The LBW parameters considered are pulse frequency, pulse width and welding speed, the absorbed power is kept as constant. The performance indicators are width of fusion zone, depth of penetration, heat affected zone and maximum temperature. The optimal LBW parameters are found to be dependent on the process indicators. A simple reliable modified Taguchi approach is followed to get a set of optimal LBW parameters for maximum DP and minimum BW.