Ballistic resistance of twisted bilayer graphene with interlayer sp3-bonding on SiC substrate

Carbon occurs in various allotropes due to its bonding flexibility, including diamond-like structures formed by tuning the interlayer spacing of twisted bilayer graphene (TBG), which changes moire pattern and the fraction of sp(3)-hybridized interlayer-bonded C atoms as well. Molecular dynamics simulation is employed to explore the ballistic performance of TBG with interlayer sp(3)-bonding on SiC. We find the specific penetration energy E-p* is kept high for diamond-like TBG with a high fraction of sp(3) bonds at small twist angles, e.g., E-p* of SiC coated by diamond-like TBG structure (formed at the twist angle and interlayer spacing equaling 0.7. and 1.79 angstrom, respectively) is increased by 43.89% and 16.62% compared with bare SiC and bilayer-graphene-coated SiC at room temperature. The kinetic energy transferred to diamond-like TBG/SiC target is absorbed by (i) phase transition in the strike area and destruction until local penetration, (ii) folding deformation of diamond-like structure, and (iii) conic deformation of SiC substrate coupled/driven by the rapid propagation of cone wave in hard coating. Our studies uncover the dynamic protective mechanisms of TBG with interlayer sp(3)-bonding on SiC substrate, and shed light on the design of lightweight structures for coatings.

Automated summary

Diamond-like twisted bilayer graphene (TBG) with interlayer sp(3)-bonding shows high specific penetration energy and dynamic protective mechanisms, making it a promising material for coating design on SiC substrates.