Thermophysical Properties of Bulk Metallic Glass Forming Alloys in the Stable and Undercooled Liquid — A Microgravity Investigation

抄録

The results of an investigation of the thermophysical properties in the stable and undercooled liquid state of the glass forming metallic alloys Zr₆₄Ni₃₆, Zr₆₅Al_7.5Cu_17.5Ni₁₀ and Zr₆₀Al₁₀Cu₁₈Ni₉Co₃ is described. In order to make accessible a large range of liquid undercooling and to provide for extended experimentation in the liquid phase the experiments have been performed under the condition of reduced gravity with an electromagnetic levitation device onboard spacelab. Aspects of the experimental method as well as results regarding the thermophysical properties investigated shall be described. Properties investigated included the specific heat and enthalpy of fusion allowing evaluation of the thermodynamic functions, and as such a comparison of the thermodynamic contribution to glass forming ability among different metallic glass forming alloys. Furthermore, transport properties such as the effective thermal conductivity and total hemispherical emissivity as well as the electrical resitivity have been investigated. The temperature dependence of the specific heat capacity and that of the electrical resistivity indicate a temperature dependent chemical short range order.