Verification of Strip Drawing Analysis Using New Sapphire Dies

Abstract

In this paper a simple analysis of strip drawing, including the influence of back tension on drawing force, is developed and verified by experiments using new sapphire dies and traditional carbide dies. The simple analysis provides a good estimate of forces and pressures acting on the dies and would be considered as a quick alternate to the solutions based on the more expensive finite element methods. It is found from experiments that friction is less for sapphire compared with carbide [1]. Although sapphire is an attractive die material because it fulfills certain wear requirements and has low friction, it is a brittle material. In order to withstand cold metal drawing, it should be supported by a high-strength steel holder. Such design considerations are also presented to facilitate the use of sapphire dies in practical applications.