Registration Number
0223U002255,
0118U001040
, R & D reports
Title
Electron conception of surfactants' effect on mechanical properties of metals and its application for the design of alloys for the aerospace industry.
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Head
Gavriljuk Valentin Gennadievich, д.т.н.
Shyvaniuk Vladyslav M., Доктор фізико-математичних наук
Registration Date
14-02-2023
Organization
Institute of Metal Physics. G.V. Kurdyumov of the National Academy of Sciences of Ukraine
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A complex of studies of Fe-, Al-, Ti- and Ni-based alloys was carried out of their interaction with surfactants (SAs), which include I, Ga, Li, and H. It is shown that embrittlement caused by SAs and hydrogen embrittlement (HE) of metallic materials have a similar mechanism, the nature of which lies in the effect of SAs on the electronic structure of metals and alloys. SAs increase the density of states at the Fermi level, which is equivalent to an increase in the concentration of free electrons. The latter was experimentally confirmed using the electron spin resonance method. Thus, the metallic character of the interatomic bond is strengthened, which is accompanied by a decrease in elastic moduli, an increase in the mobility of dislocations, and in conditions of uneven distribution of elements or short-range atomic arrangement - localization of plastic deformation and premature failure.
The effect of Li, which is a SA for Al and is used as an alloying element in alloys for aircraft construction, strictly depends on its concentration and aging conditions. Li reduces the plasticity of Al alloys, changes the type of their failure, and increases the concentration of free electrons in the quenched state, that is, when it is in a solid solution. Aging of alloys leads to the formation of dispersed particles, reducing the Li concentration in the solid solution, reducing the concentration of free electrons and changing the deformation mechanism, significantly increasing the yield strength and plasticity.
Some aspects of the action of hydrogen as a SA on the electronic structure of Ni, Ti, Nb, phase transformations and thermodynamic stability in Ni were also studied; the mechanism for the enhanced flow of H along the grain boundaries and the positive effect of H on fatigue tests at a high H concentration were clarified.
In general, the obtained results create a scientific basis for the development of new alloy compositions resistant to the influence of active environments.
Product Description
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Berezina Alla Leonidivna
Davydenko Oleksandr A.
Movchan Denys Mykolayovych
Mohylnyi Georgiy S
Molebnyy Oleh Anatoliyovych
Oleksiuk Hanna A.
Skoblik Oleksandr Petrovich
Tarusin Evgen Valentynovych
Teus Sergiy Mironovich
Tyshchenko Andriy Ivanovych
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2023-02-14
