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 [10 (1) over bar0] 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 [10 (1) over bar0] directions, respectively. Resistance of material to structural deformations is higher for [1010] direction compared to [0001]. Three wave fronts develop in shock wave profile in the material. The shock velocity U-s- 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 [10 (1) over bar0] 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.
NSTL
Elsevier