摘要
Deformation twins and stacking faults were observed in nanostructure A1-Mg alloys subjected to high pressure torsion. These observations are surprising because deformation twinnings have never been observed in their coarse-grained counterparts under normal conditions. Experimental evidences are introduced on non-equilibrium grain boundaries, deformation twinnings and partial dislocation emissions from grain boundaries. Some of these features can be explained by the results reported from molecular-dynamics simulations of pure FCC metals. Special emphasis is laid on the recent observations of high density hexagonal and rhombic shaped nanostructures with an average size of 3 nm in the A1-Mg alloys processed by high pressure torsion. A possible formation process of these nanostructures is proposed based on molecular-dynamics simulations.
Deformation twins and stacking faults were observed in nanostructure Al-Mg alloys subjected to high pressure torsion.These observations are surprising because deformation twinnings have never been observed in their coarse-grained counterparts under normal conditions.Experimental evidences are introduced on non-equilibrium grain boundaries,deformation twinnings and partial dislocation emissions from grain boundaries.Some of these features can be explained by the results reported from molecular-dynamics simulations of pure FCC metals.Special emphasis is laid on the recent observations of high density hexagonal and rhombic shaped nanostructures with an average size of 3 nm in the Al-Mg alloys processed by high pressure torsion.A possible formation process of these nanostructures is proposed based on molecular-dynamics simulations.
基金
Project(50971087) supported by the National Natural Science Foundation of China
Project supported by the Research Council of Norway under the Strategic University Program on Light Metals Technology
Projects(67692, 71594) supported by the Hungarian National Science Foundation
