Multilevel-structured phase-responsive solid–liquid composite lubricating coating and its tribological and anti-corrosion performance

Laser-induced graphene (LIG) has attracted widespread attention owing to its excellent solid-lubricating property, chemical stability, and designable surface structure, and has shown broad application prospects in fields such as friction reduction and corrosion protection. However, its limited structural stability and lubricant-storage capability restrict its practical application. In this work, a multifunctional composite lubricating surface integrating LIG, epoxy resin, laser surface texturing, and phase-change paraffin wax (PW@LST@E-LIG) was developed. The LIG structure was firstly optimized by tuning the laser power, followed by epoxy resin infiltration to enhance structural stability. Subsequently, laser-textured micropore arrays were introduced and combined with phase-change paraffin wax to establish a thermally responsive lubrication system, thereby achieving the synergistic enhancement of tribological and anti-corrosion performance. Compared with the original LIG, the optimized sample exhibited a reduction in coefficient of friction (COF) of 45–55% (approximately 0.09) and the wear depth decreased by approximately 90% under the same load. Anti-corrosion performance tests showed that the interfacial charge-transfer resistance increased to 105 Ω cm2, while the corrosion current density decreased to 10−7 A·cm⁻2. The corrosion current density decreased by more than two orders of magnitude compared with that of the substrate, resulting in an inhibition efficiency of 99.54%. Through the coupling of structural design and phase-change materials, this study achieved the synergistic enhancement of wear resistance, lubrication, lubricant-storage capability, and anti-corrosion performance, providing a new strategy for the design of multifunctional surfaces for diverse service conditions.