Enthalpy of 2011 aluminum alloy is measured by the method of adiabatic drop - calorimetry over the temperature range of 370-1200K relative to 'base' temperature of 293.15 K (20°C). The main thermodynamic parameters are computed that characterize the process of transition of alloy from solid to liquid state. Melting process begins with originating the dynamic microcavities accompanied with rupture of inter-ion bonds.