Plastic Deformation of Bicrystals composed of <100>, <111>, and Single Glide Oriented Aluminum Crystals

Abstract

When two crystal grains having large different deformation-modes are adjacent to each other, their compatibility at the boundary plane becomes extremely confused. Therefore, it is thought that such a grain boundary condition plays an important role on several phenomena of the materials containing it. In this study, three kinds of bicrystals composed of two crystals within three kinds of single crystals (a common single crystal for single glide, a single crystal with <100> tensile orientation and a single crystal with <111> tensile orientation), are prepared and tested by tension. The additional slips on {110} are activated, and the boundary strength is positive in the bicrystals composed of a crystal for single glide and a crystal with <100> tensile orientation. In the bicrystals composed of a crystal for single glide and a crystal with <111> tensile orientation, a few clustered slips occur from the grain boundary in the grain with <111> tensile orientation. The boundary strength is negative. Some micro-cracks are observed along the grain boundary of bicrystals composed of a crystal with <100> tensile orientation and a crystal with <111> tensile orientation. The boundary strength is found to be zero.