Experimental device for tribological measurement aspects in deep drawing process

The purpose of this paper is to improve strip drawing test in order to simulate sheet/tool contact conditions during a stamping operation. An original multi-pass strip drawing test in cylinder/sheet/cylinder contact geometry is presented and we emphasize the influence of certain factors rarely taken into account in the experimental simulation. In particular, we present examples where the bulk plastic deformation and the tools average temperature influence the level of friction and the sheet surface asperities flattening. To try to readjust the friction evolutions with the modifications of surface microgeometry, the tribometer is equipped with various measurements of relative sheet/tool displacement, including or not the stiffness machine and the stiffness of the contact. This was made possible by a potentiometric measurement where the tool plays the part of potentiometer and sheet that of the track, coupled to a measurement using a LVDT sensor. (C) 2008 Elsevier B.V All rights reserved.