High Impact Resistance of 2D MXene with Multiple Fracture Modes.

Two-dimensional (2D) transition metal carbides/nitrides (MXenes) are promising nanomaterials due to their remarkable mechanical and electrical properties. However, the out-of-plane mechanical properties of MXene under impact loading remain unclear. Here, particular impact-resistant fracture behaviors and energy dissipation mechanisms of MXene were systemically investigated via molecular dynamics (MD) simulation. Specifically, it was found that the specific penetration energy of MXene exceeds most conventional impact-resistant materials, such as aluminum and polycarbonate. Two kinds of novel energy dissipation mechanisms, including radial fracture and crushed fracture under different impact velocities, are revealed. In addition, the sandwiched atomic-layer structure of MXene can deflect cracks and restrain their propagation to some extent, enabling the cracked MXene to retain remarkable resistance. This work provides in-depth insights into the impact-resistance of MXene, laying a foundation for its future applications.