Progress of Multidimensional Nano-Additives under Dry/Liquid Wear: A Review

Abstract

An investigation of the interaction between multidimensional nano-additives and tribofilms is crucial for enhancing mechanical efficiency, extending equipment lifespan, and reducing environmental impacts. Improved tribofilm performance is obtained via several mechanisms: filling surface defects with 0D nano-additives, directional lubrication for 1D nano-additives, interlayer slippage for 2D nano-additives, and improved film durability for 3D nano-additives. Under dry lubrication, the formation of tribofilms via mechanical mixing is influenced by material hardness, surface roughness, and frictional conditions, with their thicknesses increasing by 20–30% under high loading. Conversely, liquid-lubricated films result from the physical adsorption and chemical reactions of the lubricants, with extremely high pressure additives reducing the friction coefficient by 30–50% at high pressure. A greater understanding of these mechanisms is beneficial for optimizing industrial technologies and developing efficient, eco-friendly lubrication systems.