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Mechanical Institute of the NAS of Ukraine, Lviv, 2018.

This dissertation provides novel insights into the theoretical evaluation and

prediction of the corrosion resistance of multicomponent metallic systems and

unravels the mechanisms of local corrosive damage of metals based on atomic-

molecular modelling of the processes in the metal-environment system. This work

also contributes to the improvement of the quantum-mechanical calculations of

multicomponent systems using the density functional method in its cluster

approximation.

In this work, we have applied a well-established quantum-chemical method

of density functional in the cluster approximation using exchange-correlation

functionals to describe the metal ion interactions. It has allowed us to obtain

atomic-molecular characteristics of interactions in the metal-environment system.

This data was generated using licensed software packages StoBe and NWChem.

To describe the absorption of the components of the corrosive environment on the

metal surface, paired potential and semi-empiric methods of quantum chemistry

(PM6 and PM7) have been used.
Based on the quantum-chemical density functional method, we have

calculated the interaction of components of a corrosive environment with a surface
and also the activation barriers of metal atoms ionization taking into account the

influence of the aqueous medium and the charge state of corrosion ions and the

surface. This approach has allowed us to evaluate the ways of metal corrosion in

alkaline and acidic environments using an aluminum alloy intermetallide as an

example substance. In addition, we could predict the corrosion-morphological

stability of binary platinum nanoparticles with the shell structure of PtMe (Me –

Cr, Fe, Co, Ni, Ru) in the low-temperature fuel cell environment.

For the first time we have proposed to evaluate the influence of the corrosive

environment on the surface using quantum-chemical calculations of dependencies

between the interaction energy of multicomponent complexes metal-environment

and their distance to the surface. Here we distinguish three distinct regions – elastic

region, bond-gap region and a free zone of bond formation with an environment,