Effect of special rotational deformation on the dislocation emission from a branched crack tip in deformed nanocrystalline materials

He, Tengwu; Xiao, Wansheng; Zhang, Yan; Zhu, Haiping

doi:10.1007/s00707-016-1742-y

Cited by 9 publications

(1 citation statement)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These will lead to the operation of specific structural deformation and fracture mechanisms. For example, due to a large number of GB [20], GB motion [21], GB migration [22], diffusion creep, cooperative dislocation [23,24], rotational deformation [25], and nanoscale twin deformation [26,27], alternative deformation modes can effectively act on nanocrystals and ultrafine particles [28]. Recently, a special deformation mechanism that the phenomenon of nanoscale amorphization (the formation of nanoscale amorphization regions) in deformed nanocrystalline and ultrafine particle materials recorded in experiments has attracted much attention from scholars [29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Effect of nanoscale amorphization on dislocation emission from a semi-elliptical surface crack tip in nanocrystalline materials

Jiang

Peng

et al. 2021

Mathematics and Mechanics of Solids

View full text Add to dashboard Cite

An impact analysis model is built to describe the effect of nanoscale amorphization on dislocation emission from a surface semi-elliptical crack tip in nanocrystalline materials. The nanoscale amorphization is formed by the splitting transformation of grain boundary(GB)disclinations caused by the motion of GBs. The analytical solution of the model is obtained by using the complex method, and the influence of nanoscale amorphization, dislocation emission angle, crack length, and curvature radius of surface crack tip on the critical stress intensity factor (SIF) of the first dislocation emission is investigated through numerical analysis. The numerical analysis shows that the impact of nanoscale amorphization on the critical SIF corresponding to dislocation emission depends on the dislocation emission angle, the position and the size of the nanoscale amorphous, the curvature radius, and the length of surface crack. As the curvature radius of surface crack tip and the crack length increase, the normalized critical SIF increases. When the nanoscale amorphization size is small, it has a great impact on the critical SIF for dislocation, but when the size is relatively large, the effect becomes small. The effect of the increasing strength of the nanoscale amorphization on dislocation emission from the surface crack tip is related to the distance between the nanoscale amorphization and the crack tip, and there is a critical crack-junction for which the increase of dislocation strength has little effect on dislocation emission.

show abstract