Micro-Mechanistic Interpretation of Tool/Workpiece Interactions

Aggressive use of microscopy and profilometry can expedite trouble shooting of a wide variety of friction/lubrication/surface quality problems. Recent research at Rensselaer has focused on physical modelling of the sheet stamping operation, in particular the binder-radius and draw bead regions. Friction models are examined in conjunction with workpiece surface quality and binder-radius tooling topography.

The friction coefficient remains stable throughout a wide variety of test conditions. Area-of-contact measurements confirm the model, although appreciable scatter is noted. Profilometry measurements, taken from a variety of tooling finishes, demonstrate that alternative indices may correlate with friction better than the traditionally quoted R_a.