Prediction of the densities of liquid Ni-based superalloys

Abstract

The molar volume of nickel and the partial molar volumes of Cr, Co, W, Ta, Al, Mo, and Re are computed from the densities of liquid nickel and liquid Ni-based binary alloys measured by the modified sessile drop method (MSDM) and the modified pycnometric method (MPM). The molar volumes of Hf, Nb, and Ti are calculated from the literature density values of these elements. A prediction model for the densities of liquid Ni-based alloys is developed based on the obtained molar/partial molar volumes of the elements in liquid Ni-based alloys. The validity of this model is verified by the density data of liquid Ni-based ternary (Ni-Co-Al), quaternary (Ni-Co-Al-Cr, Ni-Co-Al-Mo, and Ni-Cr-Al-Mo), and commercial alloys measured by both MSDM and MPM. It is also verified by the density values of liquid Ni-based commercial alloys in the literature. It has been shown that the present model can provide reasonable estimation for the density and its temperature dependency of liquid Ni-based alloys. The difference between the predicted value and the measured/cited value is within ±2.5 pct.