Synthesis of Nano-Alumina Thin Film Coating on Phosphated Surface of Inconel 718 Alloy and Investigation of its Tribological and Corrosion Properties

Abstract

In this research, Aluminum Oxide nanoparticles were made using the Sol-Gel methods,
coating on phosphated substrate on Inconel 718. The study crystal structure and
surface morphology respectively by FE-SEM and XRD Analysis were performed.
Evaluate the properties of abrasion, by Test Pin-on-disc and calculated hardness
variations by Microhardness test was performed on the coatings. The Polarization tests
were used for study the corrosion resistance properties coating. The XRD results of
coatings heat treated in 300, 500 and 800 °C, confirmed was amorphous nature of
coatings. Just in the coating heat treated at 800 ° C can be weak peaks of gamma phase
alumina (γ-Al2O3) can be seen. The FE-SEM images of the samples indicate, Coating
particle size contains 46 nm and just uniform structure and free of porosity can be
observed in the coating heat treated at 300 °C. The results of the test abrasion showed
that phosphate substrate surface increases the wear resistance of the alumina Coating.
The corrosion tests showed that the synthesis of nano-alumina Coating on phosphate
surface of Inconel 718 alloy had a great effect on increasing corrosion resistance.