Keywords

Detergents, Dynamic Modelling, Additive Deposition, Computational Chemistry

Ultra-Accelerated Quantum Chemical Molecular Dynamics Simulation of Overbased Detergent Interaction with Brass Synchronizer Surface

The ultra-accelerated quantum chemical molecular dynamics (UA-QCMD) simulator has been developed and applied to various industrially relevant tribological systems.  In the present study, it was applied to model the interaction of overbased sulfonate detergents with manual transmission synchronizer rings (brass) and cones (steel). Overbased detergents are used in manual transmission fluids to control friction and minimize wear in brass and molybdenum synchronizers. Using a computational method based on UA-QCMD, it was found that the interaction of oxygen in calcium carbonate with Cu and Zn in brass is stronger than that with Fe in steel. This is consistent with the experimental observation that thick calcium oxide/carbonate deposits are formed on the surface of brass synchronizers and not on the steel cones. In addition, the UA-QCMD calculations show that the detergent micelle is heated under shear, which may explain the conversion of calcium carbonate to oxide.

Authors and Company/Institution

Akira Miyamoto, Yukiko Obara, Masayuki Miyano and Nozomu Hatakeyama, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
Nina De Britto, Tomoya Higuchi, Keita Ishizaki and Shuichi Kawatari, Lubrizol Japan Limited, Taketoyocho, Japan
Monica Ford, Christopher Friend, Michael Huston, Christopher McFadden, James Schwind and Elisa Seddon, Lubrizol Corporation, Wickliffe, OH
Gary M. Walker, Lubrizol Limited, Hazelwood, United Kingdom