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which altogether characterize corrosive damage depending on the environment and
surface atoms. This allows us to unravel the mechanisms of corrosion and explain
the efficiency of anti-corrosive protection (mainly by inhibitors) of metals when
the barrier layers on their surfaces are perturbed.
Next, using quantum-chemical calculations, we have determined the
interaction between the intermetallic phases of aluminum alloys Al 2Cu and
Al 2CuMg and corrosive environment, which allowed to propose an alternative
mechanism for alloy corrosion and to explain the existing experimental results. We
have shown that their corrosion dissolution is mainly caused by the layered
structure of the phases with the distances between atoms A1-A1 increased by 5-
10% (as compared to the pure aluminium) and also by crystal-oriented areas with
local corrosive adsorption centers evolved due to the partial electron transfer.
These centers lower the activation barrier of aluminium and magnesium atoms
release into the environment.
We have also shown that corrosive resistance of an intermetallide in the
alkaline environment is rather defined by the net charge of the surface than by the
adsorption properties of hydroxide ions. This data was obtained by analyzing the
calculated energies of interatomic bonds in the intermetallide cluster Al 2Cu during
its charge change from Q= –3 to Q= +3, which then defines the electrode
polarization, and by accessing the influence of the corrosion-active ions. We note
that during corrosion the interatomic bond Al-Al is significantly weakened in the
–
–
row of H 2O < OH < Cl while chloride ions decrease the energy of interatomic
interactions almost three times when the surface charge is shifted to the positive
value.
We have studied in details the influence of elastic deformation of
intermetallides on their corrosive interaction with a chloride-containing
environment, which is defined by the layered surface structure (110) of Al 2Cu and
Al 2CuMg, the higher adsorption capability of the chloride-ion as compared to the
surface, and by the increase in the relative bond energy by 20-25% while the
tension deformation of intermetallide clusters reaches 2%. This finding indicates