FEM Analysis of Fiber Laser Welding of Titanium and Aluminum

Abstract

In this paper a simple and versatile model for simulating the laser welding process of lightweight metal sheets is presented. The study was aimed to predict, for assigned welding conditions, the seam morphology and to improve the comprehension of the main thermal aspects involved in the process. The programming was developed by using the Ansys parametric design language (APDL). The moving source was modelled by associating an internal heat generation to several specific elements in the weld zone. Both homogeneous and dissimilar joints were assembled in butt configuration. At first the model was used to simulate the homogeneous joining of 2mm thick Ti6Al4V titanium alloy plates. Two different strategy of modeling were used for the observed fused zone geometries (V-shaped or X-shaped bead). Then, the fiber laser offset welding (FLOW) of dissimilar metal joints was assessed by modeling the assembly of 2mm thick AA5754 aluminum alloy and T40 commercially pure titanium sheets. The calibration of the model was conducted by comparing temperature fields in the cross sections and thermal cycles at certain specific distances from the welding centerline. The accuracy of the model was demonstrated by the good agreement between experimental and numerical results.