Alumina layer using low-cost direct liquid injection metal organic chemical vapor deposition (DLI-MOCVD) on AISI 1018 steel

Amorphous alumina layers were deposited on low carbon steel (AISI 1018) substrates by the direct liquid injection metal organic chemical vapor deposition (DLI-MOCVD) technique. For the DLI-MOCVD technique, two temperatures were used: a vaporization chamber temperature of 180 °C and a reaction chamber temperature of 370 °C. Liquid precursor aluminum tri-sec-butoxide was introduced in form of atomized liquid, each pulse of 1 Hz frequency and 3 ms opening time, the solution was pressurized at 40 psi under inert Argon atmosphere. 200 sccm of Argon were used as continuous carrier gas during all the deposition process. Microscopy and XRD techniques were used to characterize the deposited material. The thickness of the alumina coatings was of 100 µm, approximately.