Coarse-grained Cu sheets were subjected to tension–rolling and rolling–tension strain path sequences. In both cases, 2 different types of strain path change were studied: the tensile and rolling directions were parallel and normal to each other. Transmission electron microscopic observations of deformed samples showed the typical dislocation structures for the pre-straining paths in tension and rolling. Special micro-band features, not observed during pre-strain, were found during the second strain path, whatever the sequence and type of strain path change. The microstructure observed during reloading was explained in terms of the sequence and type of strain path change, parallel or normal. The frequency of appearance of micro-bands was explained in terms of the activity of new slip systems. That is, those not active along the pre-strain path and connected with the number of active slip systems after reloading. The present results, for coarse-grained multicrystalline Cu sheets, were compared with those for fine- and medium-grained Cu.

Strain Path Change Effect on Dislocation Microstructure of Multicrystalline Copper Sheets. N.A.Sakharova, J.V.Fernandes: Materials Chemistry and Physics, 2006, 98[1], 44-50