High-resolution electron-microscopic in situ observation of the motion of intervariant interfaces in Cu-Zn-Al thermoelastic martensite

Abstract

The motion of intervariant interfaces under the action of applied stress in a thermoelastic martensite in a Cu-Zn-Al shape-memory alloy has been observed directly using in situ deformation experiments in an electron microscope. An AC interface moves smoothly, keeping its shape during the motion, while an AD interface moves in a jerky way. In addition, the motion of the AC interface is little affected by the presence of 2H stacking disorders while the motion of the AD interface is retarded substantially by the presence of such stacking disorders. The difference is discussed based on a difference in the energies of interfaces of various types.