A New Theoretical Method for Analysis the Material Flow Pattern in Forward Extrusion

Abstract

Material flow pattern in extrusion is an important part of the forming process. Understanding and formulating the material flow helps to determine the optimum shape of the die and important details of the process. In this paper, physical modelling of forward extrusion of non-symmetric L-shape section has been carried out to obtain an experimental understanding of the material flow pattern. A theoretical formulation using the conformal mapping theory has also been presented to predict the material flow pattern. The conformal mapping function was set up to translate the non-circular cross-section region of special-shaped products into unit dish. The results for the material flow pattern for the forward extrusion of L shaped profile from circular billets are presented here. In the physical modelling tests plasticine was used as the model material and different coloured layers of plasticine were used to build up the billet. Experimental and theoretical results were compared and good agreements were observed.