Non-Contact Thermophysical Property Measurements of Liquid and Undercooled Alumina

The density and the isobaric heat capacity of alumina in its liquid and undercooled states were measured using an electrostatic levitation furnace. Over the 2175 to 2435 K temperature interval, the density can be expressed as ρ(T)=2.93×103-0.12(T-T m) (kg·m-3) with T m=2327 K, yielding a volume expansion coefficient α(T)=4.1×10-5 (K-1). In addition, the isobaric heat capacity can be estimated as C P(T)=153.5+3.1×10-3(T-T m) (J·mol-1·K-1) if the hemispherical total emissivity of the liquid remains constant at 0.8 over the 2120 K to 2450 K interval. The enthalpy and entropy of fusion have also been calculated respectively as 109.0 kJ·mol-1 and 46.8 J·mol-1·K-1.