Mechanical properties of boron nitride nanocones

Abstract

Using classic molecular dynamics simulation, the mechanical properties of boron nitride nanocones (BNNCs) have been systematically investigated. The influences of the apex angle, cone height on tensile, and compressive behavior of BNNCs under axial strains are analyzed. The failure strains and strain energy per atom of BNNCs decrease with the increasing cone height, whereas the failure forces almost remain constant for BNNCs under axial tensile strains. For the buckling analyses of BNNCs, the critical strain and critical axial force reduce significantly with the increase of the apex angle. The increasing cone height can also significantly decrease the critical strain of BNNCs and only slightly affects the critical force of BNNCs. The cone height has little influence on the resulting buckling patterns; however, the apex angle has a significant effect on the buckling patterns of the BNNCs. From the computational analyses, it is noted that there exist three deformation patterns, i.e., fourfold rotational symmetric, threefold rotational symmetric, and reflection symmetric modes for the BNNC with an apex angle of 83.6° and the former pattern will gradually transform to the latter pattern during the postbuckling stage. On the contrary, there is only one reflection symmetric fin-like buckling pattern for the BNNC with an apex angle of 39.8°.