The elastic energy storing capability of bulk metallic glasses was evaluated by employing depth-sensing nanoindentation. The elastic energy densities of four glassy alloys, determined by nanoindentation measurements, are fairly close to their theoretical values estimated from elastic modulus and theoretical strength. This study provides an accurate and quick method to measure the elastic properties of bulk metallic glasses.

A body-centered tetragonal (bct) twin martensite has been found in Co 39 Ni 33 Al 28 ferromagnetic shape memory alloy by transmission electron microscope (TEM) observation. The twin lamellae have AE ¼ 25 (01 " 1 1) twin boundaries and slip system ½011 == ð01 " 1 1Þ. Periodic appearance of the twin lamellae resulted in a modulated structure with a repeat periodicity of 56d01 " 1 1 perpendicular to the twin interface. The twinning mechanism during martensite transformation is discussed briefly.