Densities of solid aluminum-lithium (Al-Li) alloys

Abstract

Densities of solid Al and Al-Li alloys were measured by the dilatometric method for six compositions of mole fractions of lithium: 0.05,0.1,0.125,0.15,0.20, and 0.25. A curvilinear dependence of density on temperature (room temperature up to 923 K) was observed for all investigated alloys. Results could be described by parabolic equations. The molar volumes of Al-Li alloys were calculated from the density measurements. It has been found that the densities of solid Al-Li alloys initially show slightly negative deviations from linearity that reverse to positive above 0.075 mole fraction of Li. Molar volume exhibits negative deviation from linear dependence for all samples in the experimental concentration range. Power series were used to fit the dependences of density on temperature and concentration. Coefficients of volume expansion were calculated and discussed. The density of the β phase along the (α + β)/β boundary was calculated and described by a temperature-dependent polynomial.