The Effect of Temperature on the Yield Properties of an Internally Oxidized Copper-Aluminium Alloy

摘要

The experimental techniques employed in a study of the yield properties of internally oxidized copper alloys are described and the results for Cu-0.47 wt% Al are given. Single crystals of the internally oxidized alloy were pulled in a tensile testing machine to plastic strains of about .004 at various temperatures from 78 to 1173K. The effect of sudden changes in strain rate on the flow stress was studied at 673 and 873 K. Electron microscope specimens were prepared from some of the strained specimens to determine the dislocation arrangements and the size and spacing of oxide particles. It was concluded that up to 500 K most dislocations remained in their original slip planes and passed particles by bowing between them, but at higher temperatures yield was thermally activated and most probably occurred by a cross-slip mechanism. (Author)