Mechanical behavior of twinned SiC nanowires under combined tension-torsion and compression-torsion strain

Abstract

The mechanical behavior of twinned silicon carbide (SiC) nanowires under combined tension-torsion and compression-torsion is investigated using molecular dynamics simulations with an empirical potential. The simulation results show that both the tensile failure stress and buckling stress decrease under combined tension-torsional and combined compression-torsional strain, and they decrease with increasing torsional rate under combined loading. The torsion rate has no effect on the elastic properties of the twinned SiC nanowires. The collapse of the twinned nanowires takes place in a twin stacking fault of the nanowires.

Growth and properties of coherent twinning superlattice nanowires

“…However, some conflicting observations exist in the relationship between twinning and strength because it was reported that addition of twins can both increase and decrease the ultimate strength of SiC NWs compared to twin-free SiC NWs. [46][47][48] This discrepancy can be interpreted by the possible dispersion in mechanical strength due to differences in surface morphology. 49,50 It was also predicted theoretically that nucleation of cracks on a zinc-blende NW is made easier due to the stress singularities that occur at the intersection of two opposing {111} facets.…”

Atomic Simulation of the Melting and Mechanical Behaviors of Silicon Nanowires

“…When these nanowires are used in the nano-electromechanical system (NEMS) as active components, such as nanorelays, nanoresonators, or switches (ON-OFF devices), the mechanical properties play an essential role in the reliability and manufacturability of these nano-devices under processing and working conditions. Therefore, it has become increasingly important to understand the mechanical properties of these nanowires, and many investigations have been reported on mechanical behaviors, including the elasticity [9][10][11], anelasticity [12], plasticity [13,14] and strength [15] of these components.…”

Molecular-dynamic Investigation of Silicon Carbide Fracture Under External Mechanical Loads

“…There are a significant number of papers devoted to the study of SiC nanowires under external loads [7][8][9][10]. In the paper [8] the behavior of 3C-SiC under the different kind of quasi-static external loading (tension, compression, torsion and their different combination) was studied.…”

“…Under torsion strain nanowire collapses with phase transformation from solid to amorphous structure. In [9] twinned SiC nanowires behavior was studied. Influence of segment thickness and diameter under different kind of external loading was investigated.…”