Development of a new molecular dynamics method for tribochemical reaction and its application to formation dynamics of MoS_2 tribofilm

摘要

Recently we have developed a novel molecular dynamics program NEW-RYUDO-CR, which can deal with chemical reactions. The developed method has been applied to the study of tribochemical reaction dynamics of MoS_2 tribofilm on iron surface. The initially amorphous MoS_2 layer self-organized its structure as result of the tribochemical reactions and formed layered MoS_2 tribofilm. The friction coefficient significantly decreased as the MoS_2 tribofilm was formed. Besides, sliding was observed between sulfur layers of MoS_2 tribofilms which occurred due to repulsive Coulombic interaction forces between sulfur atoms. This indicates that the formation of the layered MoS_2 tribofilm is important to achieve better lubrication properties.