Физико-механические свойства наноструктурированных материалов и их радиационная стойкость

Abstract

Предложена методика и проведены расчёты модуля упругости Юнга наноструктурированных материалов в зависимости от размеров и концентрации наночастиц. Определяющую роль здесь играют модули упругости матрицы и самих нановключений. Исследована кинетика дефектной системы с учётом рекомбинационных процессов и действия стоков, которыми являются наночастицы. Установлено наличие корреляции между упругими и радиационными свойствами наноструктурированных материалов = One of the ways to improve the strength properties, the temperature and radiation resistance of materials is the synthesis of nanocomposite systems, which in the simplest case are a matrix structured by nanoscale particles. The change in physical, mechanical, magnetic, thermophysical and other properties of nanoparticles can be related to deformation of the material due to surface tension, reduction of the coordination number in the near-surface layer, change in its symmetry group, restructuring the architecture of electronic shells, changing binding energy. A significant influence on the physical properties of nanoobjects can also have various structural defects. The dependence of Young's modulus of elasticity on the radius of a nanoparticle was determined in treatise [3]. In order to determine the Young's modulus of elasticity of a nanostructured material, the resulting formula for E(R) must be transformed into a power law. Similar to the Hall-Petch law. Moreover, A and m are defined on the interval 0≤R≤R0 (where R0 is the boundary value of R, when exceeded, the Young's modulus is equal to the value of E0 for the bulk material). Then, according to [3], we can write: , where E1 is the Young's modulus of the matrix, G1 is the shear modulus of the matrix material, E2 ≡ E(R), ns is the volume fraction of the nanoparticles, Ens is the Young's modulus of the nanostructured material. During the experiments it was shown that nanostructured materials have a higher radiation resistance. This is associated primarily with the generating capacity of nanoscale inclusions. Let the rate of generation of elementary defects in a unit volume (vacancies (v) and interstitial atoms (i)) be equal to I when the nanostructured material is irradiated, for example, by neutrons. Then the rate of change in the concentration of v and i in the volume can be described by the following equation: . An analysis of this equation shows that, as in the case of simple materials, the nanostructured systems also have a correlation between physico-mechanical and radiation properties. However, the correlation mechanisms are different in both cases.