Effect of cooperative grain boundary sliding and migration on emission of dislocations from a crack tip in nanocrystalline materials
Interaction of the cooperative grain boundary sliding and migration with a crack in deformed nanocrystalline materials is investigated using the complex variable method.Effects of the two disclination dipoles produced by the cooperative deformation on the emission of lattice dislocations from the crack tip are theoretically described.The complex form expressions of the stress field and the force field are divided.The critical stress intensity factors for the first dislocation emission are calculated.Influences of disclination strength,grain size,locations of the two disclination dipoles as well as crack length on the critical stress intensity factors are discussed in detail.Results show that,the cooperative deformation has great influence on dislocation emission from the crack tip.In general,the cooperative deformation can promote the lattice dislocation emission from the crack tip,thus improve the toughness of the nanocrystalline materials.
nanocrystalline materials crack grain boundary sliding grain boundary migration dislocation emission
H. Feng Q.H. Fang Y.W. Liu
State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body(Hunan University),Changsh State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body(Hunan University),Changsh
国际会议
北京
英文
1-12
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）