The equilibrium EMF's were measured for the Al-Ti solid alloys in the region of o:(Ti) phase by means of the concentration cells. Experiments were conducted at the temperatures 923 K, I O 14 K, 1041 K and 1061 Kand in the concentration range from XA1 = 0.0222 to 0.1237. Next, the temperature-concentration dependence of excess Gibbs energy of Al was worked out (Red I ichKi ster relation) and used to calculate the partial and integral thermodynamic functions (excess Gibbs energy, enthalpy of solutions, excess entropy and activity of aluminium and titanium, integral enthalpy of mixing and excess entropy).

Using the dilatometric method the densities of the solid Al-Li-Mg alloys were measured for two constant values oft=0.85 and 0.95, where t =X Al/ (X A 1 +X Mg) and for Li concentrations changing from O to 0.25 mole fraction. The experiments were carried out in the temperature ranges: 293-818 Kand 293-718 K fort= 0.05 and O. 15, respectively. The temperature dependences of density were described by the parabolic equation of the form y =a+ bT + cT 2. The parameters a, b, and c were calculated using the least squares method. It was found that the density isotherms fort= 0.95 show slight negative deviation from the linear behaviour, while fort= 0.85 an almost linear change is observed when plotting the density from Al-Mg alloys to pure Li density. The molar volume isotherms of Al-Li-Mg solid alloys calculated at the same temperatures as for the density are characterised by slow decreasing with the increase of Li content, except that calculated at 700 K for t = 0.85 showing an opposite trend.

The galvanostatic method used in previous measurements of the chemical diffusion coefficient in the Al-rich aluminium-lithium alloys has given a numerical values of the above coefficient at four imposed temperatures. This directly measured values of diffusion coefficient is compared with the value obtained indirectly from the measurement of the Li-solute redistribution within the Al-3.5Li alloy solidified directionally in the Bridgman system. The adequate theoretical considerations dealing with the description of solute redistribution in eutectic system has been made to calculate the value of back-diffusion parameter for the performed 2D experiment. The definition of back-diffusion parameter has been rearranged to calculate the numerical value of the diffusion coefficient in the solid. It has been shown that back-diffusion parameter plays essential role in the model of solute redistribution which is discussed from the viewpoint of the application of current model for redistribution to calculation of the solidification path.