A high-throughput calculation method for the ideal strength of crystalline materials in lattice perturbation mode

Abstract

The invention discloses a high-throughput calculation method for the ideal strength of a crystal material in a lattice disturbance mode. The method analyzes the crystal structure of the material and performs tensile deformation or shear deformation on the material structure to obtain crystal structure information; Random atomic perturbation is applied to the test object to break the symmetry constraints, so as to realize the capture of the ground state of the structure energy, calculate the stress-strain curve of the crystal structure with a series of uniform strains after random perturbation, determine and compare the typical crystallographic direction or slip system The anisotropic ideal tensile strength or shear strength of , and then find the minimum value of the ideal tensile strength and shear strength. Through high-throughput calculations, construct a material system with increased atomic random disturbance; use high-throughput technology to realize the calculation of the ideal strength in any direction of the crystal under the random disturbance of atoms, and the ideal strength calculated by the perturbation method is closer to the actual material The strength is essential for better measuring the mechanical properties of materials; at the same time, being able to screen two-dimensional or three-dimensional materials with excellent mechanical properties has guiding significance for the design of strong solid materials.

Description

technical field [0001] The invention belongs to the field of materials, and in particular relates to a high-throughput calculation method for the ideal strength of crystal materials in a lattice disturbance mode. Background technique [0002] Crystalline materials are industrial materials that consist entirely or mostly of crystals. Material strength refers to the ability of a material to resist external damage, and is used to characterize the stress of a material under a fixed load as the strain increases until failure occurs. There are also many physical quantities to measure the strength of materials, such as tensile strength, flexural strength, and shear strength. The ideal strength of the material is obviously different from the hardness in response to plastic deformation, but according to the Peyner model in the plastic deformation theory, the resistance of the crystal to slip is closely related to the ideal strength and shear modulus, so the research The ideal stren...

AI Technical Summary

Problems solved by technology

But in the perturbation-free approach, the symmetry constraints of the original cell may lead to the preservation of the lattice energy at the unstable saddle point of the potential energy surface

Therefore, the use of perturbation methods to explore premature instability related to phonons is very necessary, but also missing

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