A model for dislocation behavior during deformation of Al/Al3SC (fcc/L12)metallic multilayers

被引:124
作者
Phillips, MA [1 ]
Clemens, BM [1 ]
Nix, WD [1 ]
机构
[1] Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA
关键词
dislocations; multilayer thin films; nanostructure; modeling; hardness;
D O I
10.1016/S1359-6454(03)00127-7
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
In previously published work, we have reported on the microstructure and indentation hardness of nanoscale Al/Al3Sc multilayers. In this paper, the large increases in hardness that were observed with decreasing aluminum layer thickness are analyzed in detail and several simple dislocation mechanisms are proposed to describe the behavior. Strengthening can be explained by assuming that yielding occurs first by fort-ning dislocation loops in the aluminum layers-the dislocations are constrained by layers of Al3Sc. We show that the anti-phase boundary (APB) energy of the L1(2) Al3Sc structure can be used to quantify the resistance of the interfaces in the multilayer structure to dislocation motion and that the thickness of the Al3Sc layer also plays an important role in determining the strengthening response. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:3157 / 3170
页数:14
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