Friction Reduction Benefits in Valve-Train System Using IF-MoS₂ Added Engine Oil

Abstract

The development of new advanced lubricants is a key factor for the production of cleaner and more durable internal combustion engines. New improved antifriction and antiwear additives are required. The inclusion of nanoparticles known as solid lubricants (MoS₂ and WS₂ inorganic fullerenes) in fully formulated engine oils could help to improve the performance of the lubricant and of the engine.

The AddNano Consortium, partially funded by the European Commission, investigated the possibility of including inorganic fullerenes in the formulation of engine oils. MoS₂ nanoparticles integrated in the additive package of an SAE 5W30 engine oil showed a 50% reduction in the coefficient of friction in tribological lab-scale experiments. The nano-oil was formulated by modifying the additive package in order to stably disperse the nanoparticles and avoid counterproductive interactions with the other components of the package (antifoam, antioxidant, detergents, antiwear and antifriction additives).

In the present work, characterization of the nanolubricants on a bench test simulating the real tribological conditions encountered in the valve-train of a diesel engine is reported. transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the nanoparticles and the rubbed surfaces.

KEY WORDS:

• Inorganic Fullerenes
• Nanolubricant
• Friction Reduction
• X-Rays Photolectron Spectroscopy