Experimental Appraisal of Efficiency of Predictive Approaches for Forces and Work in Extruding Hollow Components from Ferrous and Non-Ferrous Materials

In the present study a brief review is presented made of previous investigations which looked at the current practices in a contained tube extrusion process i.e. Hooker extrusion process. This is followed by the results of a systematic study of press forces (and hence press power) and press work, when extruding S1010 cold rolled steel and 1200 aluminium billet work materials using specially designed tool sets tested in uncoated and coated conditions. The aim was to study the accuracy of reported predictive equations for force and work predictions, and to examine both the pattern and quantities of the experimental forces and work for uncoated and tin coated tools. Results showed that the force and work trends were not influenced qualitatively by the tool substrate material or tool surface coatings. The best predictions for forces and work were for the steel billet materials and the uncoated tools. In the coated conditions the tools reduced, on average, the total press force by ~15% and the total press work by ~14.5%, and therefore they were economically efficient. Moreover, the products made by the coated tools exhibited better quality than items produced by uncoated tools.