STRESS-DRIVEN ROTATIONS OF DEFORMATION-DISTORTED GRAIN BOUNDARIES IN NANOCRYSTALLINE AND ULTRAFINE-GRAINED MATERIALS

被引：0

作者：

Bobylev, S. V. ^{[1
,2
,3
]}

Ovid'ko, I. A. ^{[1
,2
,3
]}

机构：

[1] St Petersburg State Univ, Dept Math & Mech, St Petersburg 198504, Russia

[2] Russian Acad Sci, Inst Problems Mech Engn, St Petersburg 199178, Russia

[3] St Petersburg State Polytechn Univ, St Petersburg 195251, Russia

来源：

REVIEWS ON ADVANCED MATERIALS SCIENCE | 2015年 / 41卷 / 1-2期

关键词：

SEVERE PLASTIC-DEFORMATION; STRENGTH; MODE;

D O I：

暂无

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

A special mechanism/mode of plastic deformation occurring through stress-driven rotations of deformation-distorted grain boundaries (GBs) in nanowires, micropillars, thin films and subsurface areas of bulk solids with nanocrystalline and ultrafine-grained structures is theoretically described. The suggested approach serves as a generalization of the theoretical model [Bobylev and Ovid'ko, Phys. Rev. Lett. 109, 175501 (2012)] describing stress-driven rotations of regular (non-distorted) low-angle tilt boundaries composed of periodically arranged lattice dislocations in crystals. In the exemplary case of nickel specimens with nanocrystalline and ultrafine-grained structures, it is found that the rotations of deformation-distorted GBs are energetically favorable processes in wide range of GB parameters. Each energetically favorable GB rotation is specified by its equilibrium rotation angle phi(eq) associated with the energy minimum. Dependences of phi(eq) on applied stress, GB misorientation and other geometric characteristics of a rotating GB are calculated which show the trends in realization of stress-driven rotations of deformation-distorted GBs in nanocrystalline and ultrafine-grained solids. Also, combined splitting and rotations of deformation-distorted GBs are theoretically described as energetically favorable processes in wide ranges of parameters characterizing GB configuration. These processes result in formation of nanoscale grains in nanocrystalline and ultrafine-grained solids. Our theory is consistent with the corresponding experimental data reported in the literature.

引用

页码：20 / 34

页数：15

共 43 条

[11] Nanoscale gold pillars strengthened through dislocation starvation [J].

Greer, Julia R. ;

Nix, William D. .

PHYSICAL REVIEW B, 2006, 73 (24)

[12]

Hirth JP, 1992, The Theory of Dislocations, V4, P57

[13] Size-induced weakening and grain boundary-assisted deformation in 60 nm grained Ni nanopillars [J].

Jang, Dongchan ;

Greer, Julia R. .

SCRIPTA MATERIALIA, 2011, 64 (01) :77-80

[14] Mechanical and electronic properties of strained Ge nanowires using ab initio real-space pseudopotentials [J].

Lee, Alex J. ;

Kim, Minjung ;

Lena, Charles ;

Chelikowsky, James R. .

PHYSICAL REVIEW B, 2012, 86 (11)

[15]

Liu G, 2013, NAT MATER, V12, P344, DOI [10.1038/NMAT3544, 10.1038/nmat3544]

[16] The effect of solute segregation on strain localization in nanocrystalline thin films: Dislocation glide vs. grain-boundary mediated plasticity [J].

Lohmiller, Jochen ;

Kobler, Aaron ;

Spolenak, Ralph ;

Gruber, Patric A. .

APPLIED PHYSICS LETTERS, 2013, 102 (24)

[17] Superplastic extensibility of nanocrystalline copper at room temperature [J].

Lu, L ;

Sui, ML ;

Lu, K .

SCIENCE, 2000, 287 (5457) :1463-1466

[18]

Morozov NF, 2014, REV ADV MATER SCI, V37, P29

[19] Effect of grain size on the competition between twinning and detwinning in nanocrystalline metals [J].

Ni, S. ;

Wang, Y. B. ;

Liao, X. Z. ;

Li, H. Q. ;

Figueiredo, R. B. ;

Ringer, S. P. ;

Langdon, T. G. ;

Zhu, Y. T. .

PHYSICAL REVIEW B, 2011, 84 (23)

[20] Dislocation emission from deformation-distorted grain boundaries in ultrafine-grained materials [J].

Ovid'ko, I. A. ;

Sheinerman, A. G. ;

Valiev, R. Z. .

SCRIPTA MATERIALIA, 2014, 76 :45-48

← 1 2 3 4 5 →