Study on the tribocorrosion behavior of Ti₃C₂Tₓ MXene-reinforced PAI/PI/EP composite coatings: Microscopic and macroscopic analysis

To enhance the tribological and corrosion performance of engine bearings in acidic oil environments, a PAI/PI/EP composite coating (MX-PPE) reinforced with Ti₃C₂Tₓ MXene was designed and fabricated. Its frictional and corrosion behaviors were systematically evaluated through tribological tests, electrochemical measurements, and molecular dynamics simulations. The 1%MX-PPE coating reduced the friction coefficient by 8.9–24.3% and the wear rate by 4–17.1% under loads of 2–6 N, compared to pure PPE. This improvement is attributed to interfacial sliding facilitated by the layered MXene structure and synergistic interactions among coating constituents. In formic acid media, the dense MXene network acted as a physical barrier, while surface functional groups adsorbed acid molecules, forming a stable layer that blocks corrosive pathways. With increasing acid concentration, corrosion impedance rose due to stronger MXene-acid interactions. These findings provide mechanistic insights for the design of MXene-based coatings with durable tribological and anti-corrosion performance in complex engine environments. • The 1%MX-PPE coating consistently demonstrates optimal friction performance under various loads. • MXene significantly enhances the tribological and corrosion resistance performance of the coating. • MXene adsorbs formic acid and forms a dense barrier.