As the surface friction between feeding rolls and metal sheet generates the feeding power
of ECAR, the generated feeding power is low, and the friction between the metal sheet and ECAR die
should be minimized. However, for obtaining a large shear deformation by ECAR, the metal sheet
should be tightly contacted with the wall of ECAR die. In this condition, the thickness of the metal
sheet is continuously increased during ECAR. A new ECAR apparatus is developed for maximizing
the shear deformation and obtaining sheet thickness uniformity, and succeeding continuous ECAR
with such a limited feeding power. By controlling the outlet gap of the ECAR die with elastic unit, the
thickness of the metal sheet is kept uniform. Detailed thickness control mechanism during the new
ECAR process is analyzed. A sheet of Al 6063 alloy that is 1-pass deformed with the new ECAR
apparatus shows below ±0.037 mm of thickness variation and 0.61 of shear strain.
Axial-Shear Strain Imaging for Differentiating Benign and Malignant Breast Masses