Large-scale generation and characterization of amorphous boron nitride and its mechanical properties in atomistic simulations

Abstract In this paper, a simple and effective strategy for generating the microstructure of a-BN is firstly proposed based on classical molecular dynamics methods, and then is validated by characterizing the microstructure. The characterization analysis show that: i) a-BN with different densities and microstructures could be successfully generated mainly composed of the B3N3 hexagonal ring; ii) a-BN constructed by the combinations of the basic structural units with small size is more reasonable; iii) high-density a-BN, obtained at either high annealing temperature or high initial density, has discretely distributed micro-voids with larger scattering size distribution. The microstructure of the generated a-BN is subjected to tensile loading simulation, and the results showed the Young's modulus and fracture strength increase with increasing annealing temperature or initial density. During the tensile process, the micro-voids in high-density of a-BN gradually undergoes expansion, elongation, and mergence stages, and the ultimate fracture of a-BN.