On the use of non-linear finite element analysis in deformation evaluation and development of design charts for extrusion processes

Extrusion is a complex process involving thermo-mechanical changes and any analysis would thus depend upon a number of parameters. In the literature, different mathematical models for predicting required extrusion pressure have been reported. Most of them are based on experimental results and attempts have been made to present them in empirical or other forms. For equations such as those to be useful for tool and process design and process control, they must be placed in a form such as nomograph, charts and tables so as to be readily applied under different operating conditions. The current paper presents such a chart developed for the extrusion dies of varying extrusion ratios. To develop these charts, non-linear finite element method has been used as modeling and simulation tool. As a test case, the extrusion of round billet to rod is considered for a certain set of reference extrusion parameters. To predict the extrusion pressure for other conditions, a set of correction factors based on numerical results, is presented. Finally, the prediction of the proposed method is compared with the published experimental results.