화학공학소재연구정보센터
Journal of Chemical Thermodynamics, Vol.34, No.12, 1929-1942, 2002
Thermophysical properties of vanadium at high temperature measured with an electrostatic levitation furnace
Four thermophysical properties of both solid and liquid vanadium: the density, thermal expansion coefficient, molar heat capacity at constant pressure, and hemispherical total emissivity, are reported. These thermophysical properties were measured over a wide temperature range, including the undercooled state, with an electrostatic levitation furnace developed by the National Space Development Agency of Japan. Over the (18402240) K temperature range, the density of the liquid can be expressed as p(T)/(kg m(-3)) = 5.46 (.) 10(3) -0.49. (T - T-fus)/K with T-fus = 2183 K, yielding a volume expansion coefficient of the liquid a(T) = 8.9 (.) 10(-5) K-1. Similarly, over the (1700-2180) K temperature range, the density of the solid can be expressed as p(T)/(kg m(-3)) = 5.72 (.) 10(3) - 0.52 (.) (T - T-fus)/K, giving a volume expansion coefficient of the solid alpha(T) = 9.1 (.) 10(-5) K-1. The molar heat capacity at constant pressure of the liquid phase can be estimated as C-p,C-m(T)/(JK(-1) mol(-1)) = 48.78 + 2.75 (.) 10(-3) (T - T-fus)/K over the (1825-2225) K temperature range if the hemispherical total emissivity of the liquid phase remains constant at 0.32 over the temperature interval. Over the (1350-2180) K temperature span, the hemispherical total emissivity of the solid phase can be expressed as epsilon(T)(T) = 0.38-2.52 (.) 10(-4 .) (T/K) + 9.90 (.) 10(-8 .) (T-2/K-2). The enthalpy of fusion has also been measured as 26.5 kJ mol(-1).