Optimal weld bead profiles in the conduction mode LBW of thin Ti–6Al–4V alloy sheets

Abstract

<abstract> <p>Day by day laser welding (LW) is gaining industrial importance. Good quality of weld joints can be realized through this process. Because this process yields low distortion and small weld bead. Aerospace, nuclear, automotive, and biomedical industries are opting for the lightweight and corrosion resistance titanium alloys. This paper deals with the generation of optimal weld bead profiles in the conduction mode laser beam welding (LBW) of thin Ti–6Al–4V alloy sheets. Laser beam diameter, power and welding speed are the 3 LBW parameters, whereas, bead width, depth of penetration, heat affected zone and maximum temperature are the performance indicators (PIs). 3 levels are set for each LBW parameter. Taguchi's L<sub>9</sub> OA (orthogonal array) is selected to minimize the numerical simulations. ANSYS Fluent V16.0 with Vc++ code is used to develop a generic model. %Contribution of each process variable on the PIs is assessed performing ANOVA analysis. The range of PIs is assessed adopting the modified Taguchi approach. A set of optimal LBW parameters are identified considering a multi-objective optimization technique. For these optimal LBW parameters weld bead width is minimum, and the depth of penetration is maximum. Empirical relations for PIs are developed and validated with simulations. Utilizing the Taguchi's design of experiments, empirical relations are developed for the performance indicators in laser beam welding (LBW) simulations performing few trial runs and identified the optimal LBW process parameters.</p> </abstract>

Structural and Behaviour Optimization of Tubular Structures Made of Tailor Welded Blanks by Applying Taguchi and Genetic Algorithms Methods

“…• establishing the dimensional parameters to be monitored; • selection of parameters that influence the studied process; • establishing a range of variation assigning a lower and an upper limit for each of the process parameters; The general conditions of the method to be applied are the following: correct choice of the geometric parameters of the part; proper determination of the influencing factors and their number; adequate solving of the polynomial functions that describe the dependence of the geometric characteristics of the part on the parameters of the forming process; these functions will then be verified by simulation using the finite element analysis; the correctness of the results obtained based on the established functions can offer the possibility of global optimization of the process [20][21][22][23].…”