Nano-projectiles impact on graphene/SiC laminates

The ballistic performance of graphene/silicon carbide laminates under nano-projectile impact is studied using molecular dynamics method, where graphene acts as a barrier coating for its unique intra-layer honeycomb-like structure and interlayer coupling effects. We reveal that under nano-indentation two-layer graphene with AB stacking on 4H-silicon carbide(0001) exhibits the highest hardness, 140.06 GPa, comparable to diamond. During impact, the specific total penetration energy of laminates increases with the number of graphene layers n, though the partial of graphene decreases as n <= 3, which results from the van der Waals coupling effect of graphene on silicon carbide substrate. The ballistic limit velocity of silicon carbide coated by five-layer graphene is 69.4% higher than that of bare silicon carbide, leading to an increase of specific total penetration energy, 43.3%. It is interesting that the ballistic performance of two-layer graphene/silicon carbide is enhanced by the formed sp3 bonds and residual bending deformation under secondary impact (after the first low-velocity impact treatment), with the ballistic limit velocity and specific total penetration energy increased by 6.5% and 14.3%, respectively. Graphene is a promising coating that can preserve the functional integrity of materials underneath against hypervelocity impact.

Automated summary

The ballistic performance of graphene/silicon carbide laminates under nano-projectile impact is studied. Graphene acts as a barrier coating, enhancing the hardness and total penetration energy of the laminates. Increasing the number of graphene layers further increases the total penetration energy. The ballistic performance of graphene/silicon carbide is enhanced under secondary impact due to the formed sp3 bonds and residual bending deformation.