Properties of Mg-3Al-1Zn alloy sheets processed by Equal Channel Angular Pressing


A combination of new technologies could help to alleviate the strong textures formed in Mg sheets. Techniques which apply additional shear strain such as differential speed rolling (DSR) and/or equal channel angular pressing (ECAP) can offer a distinct possibility to reduce the grain size of the material and generate unique textures. In this work the microstructure, texture development and mechanical properties of Mg-3Al-1Zn alloy sheets processed by Equal Channel Angular Pressing (ECAP) were investigated. An AZ31 strip produced by twin roll casting was hot rolled at 400 °C using a rolling speed of 10 m/min. ECAP process was employed to deform sheets with dimension of 200 mm × 200 mm × 1.8 mm3. ECAP trials were carried out successfully at different temperatures up to 200 °C. The effect of the ECAP process on the developing microstructure and texture as well as the related mechanical properties will be shown. The sheets experienced a shear deformation by the ECAP show a lower normal anisotropy, r-value, than the conventionally rolled sheet. Moreover, the deep drawability at room temperature is improved by over 50 % after the ECAP process, in comparison of conventionally rolled sheet. The ECAP process is therefore an effective thermo-mechanical process for the improvement of the cold formability of Mg sheets, by means of the microstructure and texture control.
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