AXISYMMETRICAL LASER-WELDING OF CERAMICS - COMPARISON OF EXPERIMENTALAND FINITE-ELEMENT RESULTS

In this paper, we compare experimental data for a laser spot weld on a ceramic to the solution from an adaptive finite element model of the system. Our focus is on validating the finite element model, which nec essarily includes numerous simplifications. We assume an axisymmetric geometry and flow profile, with flat free surface. Buoyancy and surfac e tension drive the liquid motion in the molten ceramic pool beneath t he laser, which is calculated using the axisymmetric forms of the cont inuity, momentum and energy equations. Latent heat, temperature-depend ent material properties and radiation effects are all included in the formulation. These equations are solved with standard finite element t echniques utilizing mesh relocation with a movement indicator based on solution gradients. Comparision with experimental data indicates that the numerical techniques used successfully predicted the depth and di ameter of the actual ceramic weld pool. (C) 1998 Elsevier Science Ltd. All rights reserved.