Microstructure of Zr-Al-Cu-Ni-Ag Ingot and the Thermal Stability of Corresponding Glass

Abstract

Zr₆₅Al_7.5Ni₁₀Cu_12.5Ag₅ ingots with different microstructures are obtained by changing the number of the repeated arc melting times. Differential scanning calorimetry (DSC) traces show that when the microstructure of the mother ingot becomes finer, the thermal stability of the glassy alloy improves during the crystallization of the glass. Because of the structure heredity, the finer the mother ingot microstructure is, the smaller the average size of the (Zr,Ag)-rich short-range orders in the glassy alloy is. The decrease of the size of the short-range orders makes the rearrangement of the elements more difficult in the glassy alloy. As a result, the activation energy for precipitation and decomposition of the I-phase becomes higher.