Cavities in amorphous materials studied under negative pressure
The paper was published in Journal of Physics: Condensed Matter.
The process of formation of nanometer-sized cracks in solids is poorly understood, primarily due to the lack of methods to correctly identify these cavities and track their size changes.
“Existing theoretical methods are mostly applied to the study of first-order phase transitions such as crystallization and condensation, and these methods are not adapted to the case of formation of voids where there is not a single atom. In our study, we show that the choice of an appropriate technique for identifying these voids allows us to adapt existing theoretical methods, such as the classical theory of nucleation, to describe the processes of cavity formation. Thus, we can correctly determine such important characteristics as the critical cavity size, the excess of which triggers a chain reaction of material destruction, as well as the time and rate of cavity formation,” explains Associate Professor Bulat Galimzyanov.
A single-component amorphous metallic system belonging to the family of isotropic solids was chosen as the object of study. In such solids, the appearance of defects is minimized.
“The results elucidate the physical processes underlying the occurrence of fracture sites in homogeneous amorphous materials. The destruction of these materials proceeds in a completely different way than crystalline ones, which were previously studied in sufficient detail. Based on the data, a theoretical model was developed that describes the initial stages of crack formation in these materials. Despite the fact that we are conducting fundamental research in the field of physical materials science, the potential practical significance of our results is quite obvious. In particular, understanding the mechanisms that lead to the destruction of a particular material makes it possible to develop methods aimed at improving its strength characteristics, as well as to develop controlled destruction methods, which, for example, is important for obtaining a working material for 3D printers,” adds project lead, Professor Anatolii Mokshin.
The work was carried out within the framework of the project ‘Theoretical, simulation and experimental studies of the physical and mechanical features of amorphous systems with inhomogeneous local viscoelastic properties’, supported by a grant from the Russian Science Foundation.