DENSITIES OF SOLID ALUMINUM-LITHIUM (AL-LI) ALLOYS

Densities of solid Al and Al-Li alloys were measured by the dilatometr ic 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 invest igated alloys. Results could be described by parabolic equations. The molar volumes of Al-Li alloys were calculated from the density measure ments. It has been found that the densities of solid Al-LI alloys init ially show slightly negative deviations from linearity that reverse to positive above 0.075 mole fraction of Li, Molar volume exhibits negat ive deviation from linear dependence for all samples in the experiment al concentration range. Power series were used to fit the dependences of density on temperature and concentration. Coefficients of volume ex pansion were calculated and discussed. The density of the beta phase a long the (alpha + beta)/beta boundary was calculated and described by a temperature-dependent polynomial.