| A new conceptual metal forming process termed as the continuous confined strip shearing(C2S2) based on equal channel angular pressing (ECAP), which enables sheet farming in a continuous mode, is introduced. Likewise rolling, the strength of the material could also be controlled through the multi-pass operation using the continuous ECAP. Strengthening mechanisms were investigated for the processes of cold rolling and ECAP, respectively, by observing microstructural evolutions of the Al specimens using TEM. Experimental observations indicated that the hardness was not increased in the cold rolled and the ECAPed 1050 Al sheets, when the shear strain was increased larger than the critical value, i.e., γ$gt;4. When γ$gt;4, subgrains formed as a result of the dynamic recovery were observed in the cold rolled specimens, while ultra fine grains with an average size of ∼1 ㎛ were formed in the Al specimens processed by continuous ECAP as a result of the dynamic recrystallization. |
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