Plastic Deformation of <111> Oriented Aluminum Single Crystals

Abstract

It is known that an aluminum single crystal having <111> tensile orientation shows an initial rapid hardening, and that its flow stress increases gradually until failure. However, many problems pertaining to the deformation mechanism of the <111> oriented single crystal remain unsolved. In the present study, to clarify the deformation mode of aluminum single crystals having multiple slip orientations, tensile test were performed at various temperatures on <111> oriented single crystals. At room temperature, the <111> oriented single crystal deformed only by fine multiple slips, and the flow stress increased with an increase of strain until failure. On the other hand, the coarse wavy slips composed of {111} and {100} slips occurred at high temperatures, such as 473K. In the single crystal having a tensile orientation deviated from <111> by a few degrees, the clustered slips were observed in addition to the fine multiple slips. It is concluded that the deformation mode and flow stress of the single crystal are very sensitive to the tensile oriention in the vicinity of <111>.