Molecular Dynamics Study on the Influence of Strain Rate, Temperature, and Defect Density on the Mechanical Properties of Nb 2 C MXene

This study employs atomistic molecular dynamics simulations to investigate the anisotropic mechanical behavior of pristine and vacancy-induced Nb2C MXene under varying temperatures (300–1500 K), strain rates (0.003–0.025 ps⁻¹), and point vacancy concentrations (1–5%). Using a modified embedded-atom method (MEAM) potential, the study reveals significant directional dependence in elastic modulus and tensile strength, with the [100] direction exhibiting a Young’s modulus of 282.54 GPa and tensile strength of 23.10 GPa—both substantially higher than in the [010] direction. This indicates that the tensile strength along the [100] direction is 35.36% higher than the [010] direction, suggesting an anisotropic mechanical behavior. The mechanical performance degrades with increasing temperature, as evidenced by reductions in Young’s modulus and ultimate tensile strength, supported by partial radial distribution function (RDF) analysis. Furthermore, higher strain rates enhance tensile strength, indicating strain-rate sensitivity. The introduction of Nb and C point vacancies significantly diminishes mechanical integrity, with effects more pronounced under elevated thermal conditions. These findings provide critical insights into the mechanical resilience and design considerations of Nb2C-based nanodevices for applications in energy storage, flexible electronics, and sensing platforms.