Investigation of Clad Wire Production by Conclad Extrusion with Twin Wheels NMichihiko HoshinoDNihon University, College of Science and Technology, 1-8-14 Surugadai, Kanda, Chiyoda-ku, Tokyo 101-8308, JAPANMhoshino@mech.cst.nihon-u.ac.jp

摘要

Conform continuous extrusion is a unique extrusion process in which the extrusion force originates in the frictional force between the feedstock and wheel. When this extrusion process is applied to conclad extrusions, however, the metal flow is highly complex and hitherto undetermined. In this study, a model experiment and numerical model were developed, to elucidate the material flow. Previous studies have shown that, in conform devices consisting of one wheel with twin grooves, dead metal in the chamber is incorporated into the product and the joining pressure is not strong. To address these problems, a novel experimental device, consisting of twin wheels, was designed, which succeeded in preventing the incorporation of dead metal into the product; however, numerous relevant characteristics and problems have not yet been elucidated. The present study investigated the effect of differing tool geometries in such a device. Based on experimental results using modeling material, it is clear that the feedstock diameter should be determined with consideration of the joining pressure and product yield ratio. Further, scrapers influence the metal flow in front of the abutment, and are clearly important for ensuring smooth metal flow along the path. Finally, based on the numerical simulation results, it is clear that the gap between the wheel groove and abutment is important for preventing the oxide surface of the feedstock from being incorporated into the product; however, as the gap increases, the joining pressure decreases.