Analysis and modelling by finite element method of the equal channel angular extrusion pressure

Equal channel angular extrusion (ECAE) is a process used to impart severe plastic deformation within the material billet. This has a great deal of interest because of the improvement achieved in the mechanical properties of the material to be processed. In this study, a finite element method (FEM) analysis has been used in order to find out how the geometrical parameters of the ECAE dies and the part affect the punch force. This is important in order to predict the force required to perform the process accurately. By solving several finite element models with different geometries, a mathematical model for the extrusion pressure was obtained, and it has been possible to study the influence of the geometry on the processing force. From this, a better die design can be made. FEM modelling has been validated by comparison with experimental results. This comparison has shown a good agreement between both of them (a difference lower than 8 per cent). Moreover, the error obtained with an analytical analysis based on the upper bound method has been determined by comparison of analytical and FEM results. This has shown that the difference between analytical and FEM results was less than 9 per cent.