The behaviour of Boron Carbide under shock compression conditions: MD simulation results


Çekil H. C. , Özdemir M.

Computational Materials Science, vol.201, pp.1-14, 2021 (Journal Indexed in SCI Expanded)

  • Publication Type: Article / Article
  • Volume: 201
  • Publication Date: 2021
  • Doi Number: 10.1016/j.commatsci.2021.110872
  • Title of Journal : Computational Materials Science
  • Page Numbers: pp.1-14

Abstract

Boron Carbide (B4C) is investigated by molecular dynamics simulations to examine its mechanical behaviour on the dynamics loading. Atomistic shock compression simulations are carried out in [0001] and [101¯0] impact directions for that purpose. Interaction between atoms is defined with reactive force field (reaxFF). Hugoniot curves are obtained and Hugoniot elastic limits (HEL) are determined for both directions. HEL point occurs at about 17 and 24 GPa in [0001] and [101¯0] directions, respectively. Resistance of material to structural deformations is higher for [101¯0] direction compared to [0001]. Three wave fronts develop in shock wave profile in the material. The shock velocity Us - particle velocity Up relations in plastic region has bilinear nature. Amorphous state is observed above impact speeds 2.0 and 3.0 km/s, [0001] and [101¯0] impact directions, respectively. Buckling of C-B-C chains and lattice rotation occur before amorphization, the degree of both of which depends on impact direction and these are considered the causes of deformation. The changes in the structural order of B4C is investigated using radial distribution function (RDF) analysis. Our numerical results compare favourably with available experimental results.