Achieving nearly zero earing defects on cylindrical drawn cups with the zoning lubricant technique

Abstract

Earing has been a major issue in the deep-drawing process, especially for cylindrical cups. The additional work required to fabricate the cylindrical cup according to its specifications is frequently caused by these defects. Only a few methods have been developed to eliminate these defects, despite knowing the origin of these defects to be the material's anisotropic mechanical property (R-value). In this study, we proposed a zoning lubricant technique to achieve practically zero earing defects by applying a varied friction coefficient in relation to the R-value. This technique was examined based on experimental work and the finite-element method (FEM). The deep-drawing process for achieving practically zero earing defects was evident based on the FEM simulation findings. This resulted in practically no earing defects being discovered, and earing defects were avoided as a result of these characteristics. However, to accomplish almost zero earing defects, the proper design of zoning lubricant uses connected to the R-value should be properly considered. According to these findings, a smaller friction coefficient should be placed along the plane and at 90° to the rolling direction, whereas a larger friction coefficient should be positioned at 45° to the rolling direction. Furthermore, it was initially discovered in the current investigation that the use of zoning lubricant could successfully execute the procedure with nearly zero earing defects.