Porosity-Based Design and Finite-Element Analysis of Self-Lubricating Chromium-Free Passivation Film

The porosity of a self-lubricating chromium-free passivation film is evaluated by means of a novel finite element model and structural parameter, λ ( λ represents the porosity of passive film). The applicability of this equivalent model is validated via thin-film thermocouple measurements and laser interferometry. Our results revealed that the roughness of the film can be improved by a lubricating filler. A value of λ  = 0.25 yielded the optimal friction and wear characteristics of the self-lubricating chromium-free passivation film. This optimal condition corresponded to temperature values and stress values of 77.99°C (theoretical) and 81.24°C (experimental), and 1.67 × 10 5  Pa (theoretical) and 1.65 × 10 5  Pa (experimental), respectively. The close correspondence between the experimental and the theoretical results indicate that the model is reasonable.