Substructure and interface of the superstructure martensite in Zr50Cu50 High temperature shape memory alloy

The interface and substructure of martensite in the Zr50Cu50 alloy have been investigated by high-resolution electron microscopy (HREM). The intervariant structure in Zr50Cu50 alloy is (021) type I twin, while the dominant substructures inside the martensite variant are the (001) compound twins and (001) stacking faults. The (001) stacking faults are considered to be account for the origin of (001) compound twin. The boundaries of both (021) type I and (001) compound twins are straight but with a lot of atom scale steps. The magnitudes of twinning shear of both the (021) type I and the (001) compound twins are more than 0.5.