Pre-straining effects on the power-law scaling of size-dependent strengthening in Ni single crystals

被引：55

作者：

El-Awady, Jaafar A. ^{[1
]}

Uchic, Michael D. ^{[2
]}

Shade, Paul A. ^{[2
]}

Kim, Sang-Lan ^{[3
]}

Rao, Satish I. ^{[3
]}

Dimiduk, Dennis M. ^{[2
]}

Woodward, Christopher ^{[2
]}

机构：

[1] Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA

[2] USAF, Res Lab, Wright Patterson AFB, OH 45433 USA

[3] UES Inc, Dayton, OH USA

来源：

SCRIPTA MATERIALIA | 2013年 / 68卷 / 3-4期

关键词：

Dislocation density; Size effects; Pre-straining; Nickel microcrystals; Discrete dislocation dynamics; DISLOCATION; COMPRESSION; FLOW;

D O I：

10.1016/j.scriptamat.2012.10.035

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

We report experimental and three-dimensional discrete dislocation dynamics measurements to characterize the effect of high starting dislocation density on size-affected flow. Microcrystals were focused ion beam milled into a pre-strained bulk Ni single crystal to obtain a dense heterogeneous dislocation cell structure. The strength-scaling exponent is shown to decreases considerably with increasing dislocation density. Cutting the pre-existing forest during microcrystal fabrication can lead to alternate pathways for the advancing slipped areas to defeat the forest, resulting in a lower strength than the pre-strained bulk crystal. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：207 / 210

页数：4

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