Interface contributions to anelasticity in metallic glasses

Mechanical-spectroscopy thermal-cycling studies were conducted on a Zr57Cu20Al10Ni8Ti5 (at.%) bulk amorphous alloy. Four internal friction peaks, namely P1, P2, P3, and P4, each accompanied with modulus softening, have been observed after a number of cycles. These peaks depend on the strain amplitude, heating rate and frequency. P1 and P2 shift in temperature with frequency, indicating contributions from thermally activated phenomena with the activation energy of about 1 eV. The four peaks have similar features to those that occur during crystallization of amorphous alloys and the martensitic transformation in shape memory alloys. These similarities provide strong evidence for interface motions in glassy structures.