Analytic treatment of metallic multilayer strength at all length scales: Influence of dislocation sources

被引:20
作者
Fang, Lei [1 ]
Friedman, Lawrence H. [1 ]
机构
[1] Penn State Univ, Dept Engn Sci & Mech, University Pk, PA 16802 USA
关键词
multilayers; mechanical properties; hardness; dislocation source; micromechanical modeling;
D O I
10.1016/j.actamat.2006.10.012
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Metallic multilayers exhibit a very pronounced size effect where the mechanical strength depends on the layer thickness. Traditionally the Hall-Petch relation is used to account for the size effect. However, rigorous application of dislocation pileup theory predicts significant deviation from the Hall-Petch relation due to elastic inhomogeneity, discreteness of dislocations and dislocation source operation. Elastic inhomogeneity leads to anomalous scaling where the scaling exponent deviates from 1/2 of the classical Hall-Petch relation. The discrete dislocation effect is properly accounted for by a piecewise approach that can be applied at all length scales. In this article, a key step in the formulation is taken: the dislocation source characteristics are taken into consideration. Thus, all the three effects are accounted for. Analytic formulas linking yield stress to microscopic interface strength, dislocation source activation stress and other easily obtainable parameters (the Burgers vector, the elastic constants of constituent materials, crystal structure and layer thickness) are provided for all length scales. The model is then applied to Cu/Ni multilayers and the predicted strength is compared with experimental data. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
引用
收藏
页码:1505 / 1514
页数:10
相关论文
共 35 条
[1]   HALL-PETCH RELATIONS FOR MULTILAYERED MATERIALS [J].
ANDERSON, PM ;
LI, C .
NANOSTRUCTURED MATERIALS, 1995, 5 (03) :349-362
[2]   Dislocation-based deformation mechanisms in metallic nanolaminates [J].
Anderson, PM ;
Foecke, T ;
Hazzledine, PM .
MRS BULLETIN, 1999, 24 (02) :27-33
[3]  
Barenblatt G. I., 2003, Scaling
[4]   STRUCTURE AND PROPERTY RELATIONSHIPS IN MICROLAMINATE NI-CU AND FE-CU CONDENSATES [J].
BUNSHAH, RF ;
NIMMAGADDA, R ;
DOERR, HJ ;
MOVCHAN, BA ;
GRECHANUK, NI ;
DABIZHA, EV .
THIN SOLID FILMS, 1980, 72 (02) :261-275
[5]   NANOINDENTATION STUDY OF THE MECHANICAL-PROPERTIES OF COPPER-NICKEL MULTILAYERED THIN-FILMS [J].
CAMMARATA, RC ;
SCHLESINGER, TE ;
KIM, C ;
QADRI, SB ;
EDELSTEIN, AS .
APPLIED PHYSICS LETTERS, 1990, 56 (19) :1862-1864
[6]   MODEL OF SUPERLATTICE YIELD STRESS AND HARDNESS ENHANCEMENTS [J].
CHU, X ;
BARNETT, SA .
JOURNAL OF APPLIED PHYSICS, 1995, 77 (09) :4403-4411
[7]  
DUNDARS J, 1969, MATH THEORY DISLOCAT
[8]   ON DISLOCATION STORAGE AND THE MECHANICAL RESPONSE OF FINE-SCALE MICROSTRUCTURES [J].
EMBURY, JD ;
HIRTH, JP .
ACTA METALLURGICA ET MATERIALIA, 1994, 42 (06) :2051-2056
[9]   Strength of metallic multilayers at all length scales from analytic theory of discrete dislocation pileups [J].
Fang, L ;
Friedman, LH .
PHILOSOPHICAL MAGAZINE, 2005, 85 (28) :3321-3355
[10]   Exponent for Hall-Petch behaviour of ultra-hard multilayers [J].
Friedman, LH .
PHILOSOPHICAL MAGAZINE, 2006, 86 (11) :1443-1481