Molecular Dynamics Simulation of the Sintering Behavior of Hollow Mesoporous Nanoparticles

ABSTRACT Porous nanoparticles (NPs) play a vital role in constructing dense bulk materials due to their substantially larger surface‐to‐volume ratio compared to their solid counterparts. However, their application is hindered by an insufficient theoretical understanding and a lack of critical experimental data. In this study, we employ molecular dynamics simulation to systematically investigate the sintering behavior of hollow mesoporous SiC (H‐mSiC) NPs during spark plasma sintering. Using the Vashishta potential, models with varying shell thicknesses (1–3 nm) were constructed and sintered at 2400 K under 60 MPa. Results demonstrate that the hollow mesoporous structure significantly enhances sintering activity, exhibiting superior atomic diffusion from the heating stage, the largest potential energy reduction (0.29 eV), and a high final relative density exceeding 98%, consistent with experimental findings. Shell thickness critically governs the sintering path: a 1 nm shell enables rapid multipath fragmentation and densification, whereas a 3 nm shell resists complete collapse, leading to pore retention and hindered densification. Mesopores serve a dual role by facilitating atomic diffusion and acting as stress concentrators that induce early stage fragmentation. Nanoindentation simulations reveal that the deformation mechanism is dominated by multipath brittle fracture and grain boundary sliding, with limited amorphization. This work provides atomic‐scale insights for designing highly active hollow mesoporous NPs for low‐temperature fabrication of high‐performance ceramics.