Thermophysical properties of bulk metallic glass forming alloys in the stable and undercooled liquid - A microgravity investigation

The results of an investigation of the thermophysical properties in the sta ble and undercooled liquid state of the glass forming metallic alloys Zr64N i36, Zr65Al7.5 Cu17.5Ni10 and Zr60Al10Cu18Ni9Co3 is described. In order to make accessible a large range of liquid undercooling and to provide for ext ended experimentation in the liquid phase the experiments have been perform ed under the condition of reduced gravity with an electromagnetic levitatio n device onboard spacelab. Aspects of the experimental method as well as re sults regarding the thermophysical properties investigated shall be describ ed. Properties investigated included the specific heat and enthalpy of fusi on allowing evaluation of the thermodynamic functions, and as such a compar ison of the thermodynamic contribution to glass forming ability among diffe rent 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 resisti vity indicate a temperature dependent chemical short range order.