Self‐Repairing Effect of Nanoserpentine Mineral Powder as an Additive on Steel/Aluminum Alloy Tribological Interface Under Oil Lubrication

The influence of nanoserpentine as a lubricant additive on the friction‐reducing and anti‐wear characteristics of GCr15 steel/aluminum alloy tribopairs is investigated. The micromorphology, elemental distribution, chemical state, microstructure, and mechanical properties of the worn surface are analyzed utilizing scanning electron microscopy, energy‐dispersive spectroscopy, X‐ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation. The results demonstrate that the addition of nanoserpentine reduces the friction coefficient and wear volume of aluminum alloy by 41.37%–58.1% and 18.91%–76.3%, respectively. Serpentine undergoes complex tribochemical reactions with aluminum alloys, steel, and lubricant oil, generating a nonconductive self‐repairing layer composed of metal oxides, hard ceramic particles, intermetallic compounds, graphite, and organic compounds. The thickness of the layer ranges from 2.2 to 5.44 μm, exhibiting a double‐layer nanocrystalline structure, high hardness, and good resistance to elastic deformation. Concurrently, a frictional transfer film forms on the worn surface of the GCr15 steel balls. The formation of the self‐repairing layer and transfer film effectively isolates the direct contact of the tribopairs, suppresses the transfer of Al and Fe, repairs microdamage on the worn surface, and significantly enhances the tribological properties of the aluminum alloy, providing new ideas and methods for the development of high‐performance lubrication technologies for aluminum alloys.