The deposition properties of the tetrahedral amorphous carbon coating on the piston ring at different incident angles and substrate bias voltages: Molecular dynamics simulation

Abstract

To reduce the friction and wear of the piston ring-cylinder liner system in the internal combustion engine, the tetrahedral amorphous carbon (ta-C) coating is deposited onto the piston ring. The deposition model is established and deposition process is simulated using molecular dynamics simulation. The visualization of simulation results is obtained using open visualization tool. The second nearest-neighbor modified embedded-atom method potential and Tersoff potential are employed to describe the interactions among the atoms and ions. The deposition properties of the ta-C coating at different incident angles and substrate bias voltages are studied. The layer coverage function, interface mixing, surface morphology, radial distribution function, layer density, layer sp3 fraction, and normal stress of the ta-C coating on the piston ring are analyzed. The simulation results show that a ta-C coating on the piston ring with a smooth surface, a dense amorphous structure, a high sp3 fraction, and a uniform mixing area can be obtained. The minimum RMS roughness is 0.539 Å at −150 V, maximum layer density is 3.560 g/cm3 at −1 V, and maximum layer sp3 fraction is 0.972 at 30°. This study provides theoretical support for the selection of experimental parameters.