Acoustic analysis of the amorphous phase of annealed Zr55Cu30Ni5Al10 glassy alloy, using diffracted SH ultrasonic waves

The propagation characteristics of a shear horizontally polarized SH wave, (which proceeds horizontally with respect to free surfaces in isotropic materials) passing through an annealed Zr55Cu30Ni5Al10 glassy alloy were investigated in terms of the acoustic determination of phases during annealing. The received wave patterns distinguished two phases; a nanocrystalline and an amorphous phase. The amorphous phase was composed of three kinds of structural colonies, 0.24, 0.59 and 0.72 mm in size. The ordering of the amorphous phase is related to increase in wave velocity, damping ratio, phase degree and wavelength, accompanied by frequency conversion. Thus, the acoustic analysis method using diffracted SH ultrasonic waves can act a useful probe for determining the amorphous phase of glassy alloys, and is more precise than the X-ray diffraction method.