Emergency‐Ready Functional Coatings: Sustaining Friction Performance Through Oil Lubrication Failure

ABSTRACT To mitigate risks from abrupt transition to oil‐free lubrication, we prepared a functional solid lubricant coating demonstrating superior stability across diverse lubrication conditions. The coating is an epoxy resin as the matrix, reinforced with graphite and molybdenum disulfide (MoS 2 ) as the functional fillers. Through a systematic spraying‐sintering process, the formulated slurry yields a composite coating characterized by exceptional antifriction and wear‐resistant properties . The tribological behavior of the coating is obviously influenced by both graphite and MoS 2 . Under low loads, graphite dominates lubrication due to its lower shear resistance while MoS 2 excels under high loads by its higher load‐bearing capacity. After filler proportion is optimized, synergistic interactions between the fillers promote the formation of a continuous transfer film, effectively isolating friction surfaces and mitigating adhesive wear. Specifically, the optimal coating, comprising 14 wt% MoS 2 and 8 wt% graphite, exhibits outstanding performance. Under a load of 200 N, it exhibits an average friction coefficient of 0.041 and a specific wear rate of 4.25 × 10 −6 mm 3 /(N·m) under oil lubrication. Under oil‐free conditions, these values increase to a friction coefficient of 0.049 and a wear rate of 1.25 × 10 −5 mm 3 /(N·m). This work supports the safety of mechanical systems during abrupt transition from oil lubrication to oil‐free conditions.