دراسة سلوك المائع والسلوك الحراري عند لحام قطعتين معدنيتين بالليزر

Abstract

The laser welding process is one of the most widely used processes in industry. The study of the distributions of temperature and fluid velocity in the weld pool plays an important role in determining the size and the shape of the weld. In this thesis, we are interested on the numerical study of welding phenomenon in weld pool resulting from the interaction of laser beam with a magnesium alloy (AZ91). We use the equation of energy, the equations of conservation of movement, the equation of continuity and the equation of phase transition energy; we take into account effect of Marangoni and buoyancy force. For the numerical model, we use the Finite Volumes Method (FVM) and Gauss-Seidel iterative method. We calculate spatial and temporal distributions of temperature and fluid velocity in cylindrical coordinates system (r, θ, z). We study how laser Power and welding speed affect the width and the depth of the weld pool. The results of this numerical model are compared with an experimental study.