A number of structure, physical and thermal properties (viscosity, density, surface tension, enthalpy and heat capacity) is studied in detail for both solid and molten state of the multicomponent aluminum alloys. It is shown that the structure of molten metal is very important for forming the structure and properties of castings. Form of crystal growth of the solid solution is being changed during crystallization from high-temperature metastable states as well as dispersity and morphology of primary and secondary phases. This essentially influence the mechanical properties of blanks.