Parametric analysis & empirical modeling of laser beam welding of titanium alloys

Laser beam welding (LBW) is extensively employed for joining a wide range of metals and alloys owing to its high processing speed, excellent weld seam quality, deep penetration, reduced heat input per unit volume, narrow heat-affected zone (HAZ), and minimized tendency for cracking. The performance of the weld is strongly governed by the selection of input process parameters, making their optimization essential. However, as the number of process variables increases, maintaining effective control and achieving reliable weld quality becomes increasingly complex. The present research investigates the welding characteristics of the titanium alloy Ti-6Al-4V, which is widely used in aerospace and biomedical applications. Sixteen butt joint experiments were carried out using a Taguchi-based Design of Experiments (DOE) to achieve a systematic and cost-effective approach. Based on trial studies, four key parameters laser power, welding speed, laser focal diameter, and argon gas flow rate were identified as significant input variables. Output responses including total width, HAZ, fusion zone, and penetration depth were measured and analyzed. Two-dimensional and three-dimensional plots were generated to study both main and interaction effects of the input variables. Further, Response Surface Methodology (RSM) and analysis of variance (ANOVA) were applied to develop predictive models, validated by regression coefficients, to optimize the LBW process.