Low-temperature crystallization caused by ultrasound in Pd_(42.5)Ni_(7.5)Cu_(30)P_(20) and Pd_(40)Ni_(40)P_(20) bulk metallic glasses

摘要

Crystallization behavior of Pd_(42.5)Ni_(7.5)Cu_(30)P_(20) and Pd_(40)Ni_(40)P_(20) (number indicate at.%) bulk metallic glasses under ultrasonic (US) vibrations of sub/low-MHz frequencies has been systematically investigated. It was found that, when the glassy sample was subjected to the US vibrations for a long duration, the crystallization occurred even (near) below the glass transition temperature T_g. The microstructural features of the US-accelerated crystalline phases are presented, and the mechanism of the US-accelerated crystallization is briefly discussed in terms of β relaxation.