An experimental study on atomic-level unified criterion for brittle fracture

[摘要] The aim of this study is to experimentally seek a unification of brittle fracture by an atomic-level criterion. In situ fracture experiments are carried out in transmission electron microscope by using notched nano-cantilever specimens of single-crystal silicon. On the basis of atomic fracture mechanics, the critical atomic energy release rate G(AFM)(C), at fracture is experimentally determined by combining finite element method and molecular statics calculations. It is found that G(AFM)(C), of which the magnitude remains at a certain level regardless of the notch size, is an effective parameter to describe brittle fracture of a blunt notch. The comparison of the present G(AFM)(C) with those of macro-Mano-cracks reveals a good consistency, and this experimentally demonstrates a possible unification of brittle fracture of both a blunt notch and an ideal crack. (C) 2020 Elsevier Ltd. All rights reserved.

[发布日期] 2020-12-01

[关键词] Atomic-level unified criterion;Brittle fracture;Notch;Crack;Nano-silicon