Grain boundary sliding and lattice dislocation emission in nanocrystalline materials under plastic deformation

被引：16

作者：

Gutkin, MY ^{[1
]}

Ovid'ko, IA ^{[1
]}

Skiba, NV ^{[1
]}

机构：

[1] Russian Acad Sci, Inst Problems Mech, St Petersburg 119178, Russia

来源：

PHYSICS OF THE SOLID STATE | 2005年 / 47卷 / 09期

基金：

俄罗斯基础研究基金会;

关键词：

D O I：

10.1134/1.2045349

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

A theoretical model is proposed to describe the physical mechanisms of hardening and softening of nanocrystalline materials during superplastic deformation. According to this model, triple interface junctions are obstacles to glide motion of grain boundary dislocations, which are carriers of grain boundary glide deformation. Transformations of an ensemble of grain boundary dislocations that occur at triple interface junctions bring about the formation of partial dislocations and the local migration of triple junctions. The energy characteristics of these transformations are considered. Pileups of partial dislocations at triple junctions cause hardening and initiate intragrain lattice sliding. When the Burgers vectors of partial dislocations reach a critical value, lattice dislocations are emitted and glide into adjacent grains, thereby smoothing the hardening effect. The local migration of triple interface junctions (caused by grain boundary sliding) and the emission of lattice dislocations bring about softening of a nanocrystalline material. The flow stress is found as a function of the total plastic strain, and the result agrees well with experimental data. (c) 2005 Pleiades Publishing, Inc.

引用

页码：1662 / 1674

页数：13

共 35 条

[1]

[Anonymous], 1967, THEORY DISLOCATIONS

[2]

[Anonymous], 1984, SUPERPLASTICITY COMM

[3]

[Anonymous], 1981, SUPERPLASTICITY ALLO

[4] Transformations of grain boundary dislocation pile-ups in nano- and polycrystalline materials [J].

Fedorov, AA ;

Gutkin, MY ;

Ovid'ko, IA .

ACTA MATERIALIA, 2003, 51 (04) :887-898

[5] Triple junction diffusion and plastic flow in fine-grained materials [J].

Fedorov, AA ;

Gutkin, MY ;

Ovid'ko, IA .

SCRIPTA MATERIALIA, 2002, 47 (01) :51-55

[6]

Gutkin M Y, 2004, A Plastic Deformation of Nanocrystalline Materials

[7] Emission of partial dislocations by grain boundaries in nanocrystalline metals [J].

Gutkin, MY ;

Ovid'ko, IA ;

Skiba, NV .

PHYSICS OF THE SOLID STATE, 2004, 46 (11) :2042-2052

[8] Strengthening and softening mechanisms in nanocrystalline materials under superplastic deformation [J].

Gutkin, MY ;

Ovid'ko, IA ;

Skiba, NV .

ACTA MATERIALIA, 2004, 52 (06) :1711-1720

[9] Crossover from grain boundary sliding to rotational deformation in nanocrystalline materials [J].

Gutkin, MY ;

Ovid'ko, IA ;

Skiba, NV .

ACTA MATERIALIA, 2003, 51 (14) :4059-4071

[10]

GUTKIN MY, 2003, J PHYS D, V36, P647

← 1 2 3 4 →