Estimating densities of liquid transition-metals and Ni-base superalloys

To estimate the densities of liquid Ni-base superalloys, the densities and temperature coefficients of density (dρ/dT) of the liquid transition-metals, which are used as alloy elements in Ni-base superalloys, were gathered, reviewed, and applied to a simple correlation. The correlation is particularly useful to estimate dρ/dT of many transition-metals for which there are no data available. To demonstrate how the results can be applied, the densities of liquid Ni-rich Ni-Al-Cr-Ta alloys were considered and regressed to yield the liquid density as a function of temperature and composition. As a verification of this approach, the liquid densities of five Ni-base superalloys were also estimated. By including a regression estimate of the molar mixing volume, the estimates of the liquid densities agreed with the measured values to ±2.5%.