The Kinetic Theory of Growth of Zr-Sn Diffusion Layers on Zr55 Cu30 Al10 Ni5 Metallic Glass

Abstract

The growth kinetics of the intermetallic compound layer between molten pure Sn and Zr55 Cu30 Al10 Ni5 bulk metallic glass (BMG) is mainly controlled by the diffusion mechanism at stage I at which the value of the time exponent is approximately 1/2, also there is unusual or unique stage II whose time exponent of the growth is suppressed to 1/3. It is deduced that phase transition such as nucleation, coalescence occurring in the vicinity of the interface of the diffusion layer within the BMG and the average size growing as one-third power of time, called the Lifshitz—Slezov law. A more elegant means of attack is based upon the Fokker—Planck approach, which permits us to calculate directly the probability of the distribution of steady-state thickness fluctuations. Physical implications of the analytical results also give the one-third power of time of distance scale. The transmission of Sn particles through a disorder system of the BMG, scattered by the local fluctuation levels, is the source of the time exponent from 1/2 to 1/3 as a macroscopic cumulative effect.