Grinfeld instability as a mechanism of the formation of self-similar structures on aluminum single-crystal foils under cyclic tension

Abstract

Based on the analysis of our results and data available in the literature, it has been shown that the formation of self-similar tweed structures on (100)[001] aluminum single-crystal foils during constrained cyclic tension occurs under conditions of the Grinfeld instability. This is confirmed by the good agreement between the theoretical estimates obtained for the period of tweed structures in terms of the Grinfeld instability model and the experimentally measured values. It has been demonstrated that the Grinfeld instability manifests itself in different boundary conditions associated with the specific features of the elasto-plastic deformation of a two-layer aluminum foil-specimen system, which is responsible for the self-similarity of tweed structures. It has been assumed that the material redistribution on the surface of foils is due to the migration of point defects that are formed during cyclic tension and exhibit a sufficient mobility at room temperature.