The application of equal-channel angular pressing to an aluminum single crystal

An investigation was conducted to examine the nature of the deformed microstructure when an aluminum single crystal of known orientation is subjected to equal-channel angular pressing (ECAP). The experiment was performed using a single crystal that was initially oriented within the entrance channel of the die so that the (111) slip plane was parallel to the theoretical shear plane and the [110] slip direction lay parallel to the direction of shear. The crystal was subjected to a single pass at room temperature and then examined using various microscopic techniques including orientation imaging microscopy and transmission electron microscopy. It is shown that the detailed experimental observations are fully consistent with the expectations from crystallographic considerations except only in the vicinity of the lower die wall where frictional effects are present.