Simulation of Welding Conditions in Porthole die Extrusion

Abstract

In aluminum extrusion with porthole dies, the welding of material seams represents a major manufacturing problem inasmuch it affects the integrity of the final product. The way the problem is treated is yet not consistent in literature, and different quality parameters for welding are still used in practice.

In this work a new parameter for evaluating the welding quality is proposed. Its effectiveness is tested in comparison with other parameters by means of a parametric FEM analysis in which the distribution of pressure and velocity along the welding line is considered. The investigated geometry is a simple two-seams plane-strain die. Many die shapes have been considered, by varying the position and the shape of the leg, in order to understand the sensitivity of the parameters in a wide range of operative conditions. The solutions are also significant for evaluating process load, productivity and die-stresses.