Work Hardening of Copper Single Crystals with Multiple Glide Orientations

Abstract

Copper single crystals with deformation axes in [001], [112], [111], [212], [101], [102], and [213] were extended in the temperature range between −195 and 800°C, and some compression tests were supplemented. The stress-strain behaviour and its variation with temperature were observed systematically. The crystal orientations after tensile deformations were determined by the slip lines on the specimen surfaces which were chemically polished after prestrain and extended by a few percent. The results showed that the tensile axes of the [101] and the [212] crystals rotated into the direction for the [111] axis up to around the [434] axis. The work-hardening rates of the [101] crystals under compression tests were about twice those under tensile tests.
From the analysis of the observed results, it was concluded that the work-hardening characteristics of copper single crystals are classified into four types ([001], [111], [101]–[212], and [112]) depending on the combination of the active slip systems.