Coatings protecting against aviation piston engine seizure

The article presents the basics of manufacturing porous (16%) composite coatings based on phenolic resin reinforced with glassy carbon particles (30 wt%). These coatings, when applied to a steel push rod surface, prepared by sandblasting, of the timing system of an aircraft piston internal combustion engine, prevent seizure of the contact in conditions of lubrication failure up to 10 h (μ≈0.1 by p = 8 MPa, v = 0.5 m/s), extending the last stage of flight time of the aircraft. The reference coating undergone seizure, μ> 1 after 5 h. The conditions and results of laboratory tests on a pin-on-disc tribological tester and tests on an engine test bench are described. The dependencies of the coefficient of friction and wear of the push rod on the glassy carbon content, thinner viscosity and sandblasting pressure, described by the equations of the second degree, allowed the optimal conditions to be determined to the produce coatings. The test results of the developed composite porous coatings were compared with the results of non-porous commercial coatings. The wear of developed coating compared to reference one and matrix coatings was respectively ΔmCC = −1.63 mg (mass increase), ΔmRC = 1.3 mg and ΔmMC = 5.56 mg. •Composite coating with 30% glassy carbon can increase flight time of last stage up to 10 h under poor lubrication.•Porous coating absorbs oil micro quantities which prevent against seizure of sliding contact at pressure up to 8 MPa.•Glassy carbon microparticles (d