The deformation mechanisms of twin-structured metallic materials have attracted great interest.Though previous theoretical predictions have suggested that the repulsive force of the twin boundary(TB)can significantly ...The deformation mechanisms of twin-structured metallic materials have attracted great interest.Though previous theoretical predictions have suggested that the repulsive force of the twin boundary(TB)can significantly affect the deformation of twinstructured metals,it remains unclear whether this prediction applies to experimental conditions.In this paper,the atomic-scaled deformation process of twin-structured Pt nanocrystals was in situ observed using our home-made device in a high-resolution transmission electron microscope.We have shown that the plastic deformation of the twin-structured Pt nanocrystals was governed by full dislocation generation as well as Lomer dislocation(LD)lock formation and destruction.After LD locks were destructed,these full dislocations tended to move towards the surface of the nanocrystals.The findings revealed that due to the ultra-high repulsive force of TB on dislocation,there was no dislocation-TB reaction during the deformation.These findings can enrich our understanding of the dislocation behaviors of twin-structured nanocrystals.展开更多
基金the National Key R&D Program of China(Grant No.2017YFB0305501)the Beijing Outstanding Young Scientist Projects(Grant No.BJJWZYJH01201910005018)+3 种基金the National Natural Science Foundation of China(Grant Nos.11722429,51771104,91860202)“111”Project(Grant No.DB18015)the Beijing Natural Science Foundation(Grant No.Z180014)the Fok Ying-Tong Education Foundation of China(Grant No.151006)。
文摘The deformation mechanisms of twin-structured metallic materials have attracted great interest.Though previous theoretical predictions have suggested that the repulsive force of the twin boundary(TB)can significantly affect the deformation of twinstructured metals,it remains unclear whether this prediction applies to experimental conditions.In this paper,the atomic-scaled deformation process of twin-structured Pt nanocrystals was in situ observed using our home-made device in a high-resolution transmission electron microscope.We have shown that the plastic deformation of the twin-structured Pt nanocrystals was governed by full dislocation generation as well as Lomer dislocation(LD)lock formation and destruction.After LD locks were destructed,these full dislocations tended to move towards the surface of the nanocrystals.The findings revealed that due to the ultra-high repulsive force of TB on dislocation,there was no dislocation-TB reaction during the deformation.These findings can enrich our understanding of the dislocation behaviors of twin-structured nanocrystals.
