Influence of Liquid Temperature on the Crystallization Behavior in Zr–Al–Cu–Pd Amorphous Alloy

Abstract

The glass transition temperature (T g ), crystallization temperature (T x ), peak temperature of crystallization exothermic reaction (T p ) and ΔT x (= T x - T g ) of an amorphous Zr 60 Al 10 Cu 20 Pd 10 alloy were found to show a distinct increase with increasing liquid temperature (T L ). On the other hand, there are no appreciable changes in the T g , T x , T p and ΔT x with T L for an amorphous Zr 60 Al 10 Cu 30 alloy. The crystallized structure consists of Zr 2 Cu+ZrPd+ZrPd 2 +Zr 2 Al for the Zr-Al-Cu-Pd alloy and Zr 2 Cu + Zr 2 Al for the Zr-Al-Cu alloy. The absence of the T L dependence for the latter ternary alloy indicates that the dissolution of their crystalline phases into the liquid phase by heating takes place easily, leading to the formation of a homogeneously mixed liquid phase. However, the ZrPd and ZrPd 2 compounds have difficulty to dissolve into the liquid owing to the stronger bonding nature resulting from much larger negative heats of mixing as compared with Zr-Cu and Zr-Al pairs. The significant change in the thermal properties with T L is attributed to the residual existence of the Zr-Pd pair.