Experimental Analysis of Punch Speed Impact on Plastic Behaviour of Extruded Material

Abstract

The knowledge of plastic behaviour of formed material, especially in critical regions of deformed zone and its dependence on different forming parameters, is very important to avoid failures, e.g. cracks in the final product and to increase efficiency of forming process. The visioplasticity method was applied in this paper for analysing the impact of punch speed on strain rate and stress distribution in cold direct extruded alloy. This method provides accurate information about material flow with the help of experimentally determined velocity field displacements. Different values of punch speed were used during direct extrusion experiments. Strain rate distributions and radial stress values in deformed zone were calculated and analysed. The results obtained by visioplasticity method have shown that higher punch speed has significant impact on increasing strain rate and stress values especially in some critical areas of deformed zone.