Using high-resolution electron microscopy, localized solid-state amorphization was observed in a nanocrystalline Al solid solution (4.2Cu-0.3wt%Mn) subjected to surface mechanical attrition. It was found that the deformation-induced solid-state amorphization may occur at the grain boundary where either the high density dislocations or dislocation complexes were present. It was suggested that lattice instability due to elastic distortion within the dislocation core region plays a significant role in the initiation of the localized solid-state amorphization at defective sites. Meanwhile, the grain boundaries of severely deformed nanocrystalline grains exhibited a continuously varying atomic structure in such a way that, while most of the grain boundary was ordered but revealed corrugated configurations, localized amorphization could occur along the same grain boundary.

Localized Solid-State Amorphization at Grain Boundaries in a Nanocrystalline Al Solid Solution Subjected to Surface Mechanical Attrition. X.Wu, N.Tao, Y.Hong, J.Lu, K.Lu: Journal of Physics D, 2005, 38[22], 4140-3