Massively Parallel Molecular Dynamics Simulations of Tribology of Nanocrystalline SiC

Maneesh Mishra, Izabela Szlufarska, Materials Science Program

Silicon Carbide is an excellent material for MEMS and NEMS devices under extreme conditions. SiC has a lower oxidation rate than Si-based MEMS and has a higher band gap making it a choice for high temperature electronics. Although mechanical properties (hardness, fracture toughness) of SiC have shown to be largely superior to those of polycrystalline or bulk SiC, tribological properties of nanocrystalline SiC not yet known.

During this project, models of realistic structures of nanocrystalline SiC with different grain sizes will be set up by large scale MD simulations. MD simulations of sliding SiC tip across surfaces of nc-SiC samples will be done to characterize trends in the tribological response. 

                                         SiC (100) surface with H monolayer (MD simulation results)

Multi-scale computer simulations of tribological properties of nanocrystalline SiC will be performed with the goal of understanding fundamental nature of friction at these interfaces and its relation to micro and nano-structure. Multimillion atom parallel molecular dynamics simulations will be carried out to study friction and wear and the results will be compared to ab initio calculations done by another student in our group, Yun Liu.

The effect of oxide layer (a-SiO2 on SiC surface) on the tribological properties will be investigated. We will also determine the effect of dopant atoms on tribological properties of SiC surface.

This project will help unravel the nanostructure-friction dependence of technologically relevant material and extract general rules that can be transferred to a broader class of materials.