Analysis of interfacial slip in cross-wedge rolling: an experimentally verified finite-element model

Friction and interfacial slip in metal forming processes are very important parameters when considering tool design, tool wear, and finished product integrity. This paper investigates the interfacial slip between the forming tool and workpiece in a relatively new metal forming process, cross-wedge rolling (CWR). After a brief description of CWR is given, a three-dimensional finite-element model (FEM) is introduced which realistically characterizes the interfacial slip that occurs during a flat-wedge CWR process. Finite-element results, which are generated for various workpiece area reductions, are verified using experimental data obtained from a CWR prototype machine that was specially designed and constructed for understanding the deformations encountered in CWR. From the close agreement between the experiment and numerical results, it is shown that all of the important physical phenomena in the nonlinear deformation process of CWR are included in the FEM. The relevance of developing such a model, as applied to automating CWR tool design, is subsequently discussed. (C) 1998 Elsevier Science S.A. All rights reserved.