Features of the occurrence and development of cracks in polycrystalline aluminum samples with different grain sizes

Abstract

The results of the study of the regularities of the occurrence and development of cracks during plastic deformation of polycrystalline aluminum samples which contain only through grain boundaries (parquet structure) are presented. It was experimentally shown that in the studied polycrystalline aluminum samples, the average size of which varied from 1 to 15 mm grain-boundary, transcrystalline and mixed failure can occur. The regularities of the occurrence and development of cracks and the physical mechanisms for various types of failure of polycrystalline aluminum samples are determined. It has been shown that grain-boundary failure is caused by the presence of pores in the grain bound aries of a general type, and transcrystalline failure is caused by the deformational boundaries or a well-developed rotational structure that occurs during sample deformation.