Structural Analysis and Application in Dip Coating of Alumina Powder

Abstract

This study focuses on producing alumina using a modified citrate method. The process involves thermally activating a chelate through biphasic drops between hydrated aluminum nitrate and citric acid. Thermal analysis via DSC/TGA followed by FTIR revealed absorption bands at varying temperatures until the formation of white crystallized alumina powder at 1000°C. XRD analysis indicated that the resulting sample has a refined hexagonal structure with the space group R-3c. SEM/EDAX analysis displayed a morphology resembling overlapping hives with a major chemical composition of Al and O. The dip-coating method applied a semi-colloidal Al-citric acid sol onto E335 steel substrate at a stable processing temperature of 700°C, confirmed by XRD analysis showing the formation of new crystals like AlFeO₃ and Al₁₁Fe₇. This structural configuration influenced dislocation density and microstrain inversely with grain size. SEM and EDS analysis confirmed the adhesion of alumina to the substrate through intermetallic phases.