Al₂O₃ coatings on stainless steel using pulsed-pressure MOCVD

Alumina coatings were deposited by pulsed-pressure metalorganic chemical vapour deposition (PP-MOCVD). A single-source liquid aluminium isopropoxide (C₉H₂₁O₃Al) precursor solution in toluene was used. As-machined type 304L stainless steel substrates were coated over a range of deposition temperatures from 450°C to 800°C. Coatings were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD) and Rutherford backscattering spectroscopy (RBS). The coatings conformally and uniformly coated the micro-rough steel surface with no evidence of cracking. All of the coatings were amorphous, and no carbon was detected in the films.