THE EFFECT OF STRAIN PER PASS ON THE MICROSTRUCTURE DEVELOPED IN ALUMINUM PROCESSED BY EQUAL CHANNEL ANGULAR EXTRUSION

摘要

The die angle used in equal channel angular extrusion (ECAE) determines both the shear plane orientation and the strain per pass. It is interesting to separate the effect of the shear plane orientation and the strain per pass on microstructural development. By rotating the billet 180°about the extrusion axis between passes (route C), the shear plane is kept unchanged during straining. Then the effect of strain per pass can be studied by using different die angles. In the present study, commercial pure aluminum was deformed by ECAE route C with two different die angles (90°and 120°. The deformed microstructure was characterized by TEM and the boundary misorientations were determined from TEM Kikuchi diffraction.