| 摘要 | The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain boundary- related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced strain hardening and tensile ductility. The strongest twin thickness originates from a transition in the yielding mechanism from the slip transfer across twin boundaries to the activity of preexisting easy dislocation sources.; The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain boundary- related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced strain hardening and tensile ductility. The strongest twin thickness originates from a transition in the yielding mechanism from the slip transfer across twin boundaries to the activity of preexisting easy dislocation sources. |
| 部门归属 | [lu, l.; chen, x.; lu, k.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [huang, x.] tech univ denmark, riso natl lab sustainable energy, ctr fundamental res met struct four dimens, dept mat res, dk-4000 roskilde, denmark.;lu, l (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china;llu@imr.ac.cn
; [lu, l.; chen, x.; lu, k.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [huang, x.] tech univ denmark, riso natl lab sustainable energy, ctr fundamental res met struct four dimens, dept mat res, dk-4000 roskilde, denmark.;lu, l (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china;llu@imr.ac.cn
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推荐引用方式
GB/T 7714 |
L. Lu,X. Chen,X. Huang,et al. Revealing the Maximum Strength in Nanotwinned Copper, Revealing the Maximum Strength in Nanotwinned Copper[J]. Science, Science,2009, 2009,323, 323(5914):607-610, 607-610.
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