Deformation twins and stacking faults in an AA5182 Al-Mg alloy processed by high pressure torsion

作者：Liu Manping^*; Roven Hans J; Murashkin Maxim; Valiev Ruslan Z

来源：Materials Science Forum, 2008, 579: 147-154.

DOI：10.4028/0-87849-384-0.147

• Deformation structures
• Deformation twins
• Dislocation
• Dynamics simulations
• Grain interiors
• High pressure torsions
• High resolutions
• MG alloys
• Microtwins
• Nanocrystalline grains
• Nanostructured
• Planar fault energy curves
• Pure metals
• Room temperatures
• Severe plastic deformation
• Severe plastic deformations
• Shockley partials
• Ultra-fine grains

High-resolution transmission electron microscopy investigations revealed different types of deformation structures in a nanostructured commercial Al-Mg alloy processed by high pressure torsion at room temperature. Microtwins and stacking faults were detected within both nanocrystalline grains and ultrafine grains. Full dislocations in the form of dipoles were observed within grains and near the grain boundaries. Two twinning mechanisms previously predicted by molecular-dynamics simulations were directly verified including the heterogeneous twins nucleated by the successive emission of Shockley partials from grain boundaries and homogeneous twins formed in the grain interiors by the dynamic overlapping of stacking faults. Hence, the formation of full dislocations, stacking faults and twins in the present aluminum alloy subjected to severe plastic deformation may be interpreted in terms of molecular-dynamics simulations based on generalized planar fault energy curves for pure metal systems.

• 出版日期2008
• 单位Norwegian University of Science and Technology