Characterization of flame-sprayed Al2O3-based coatings with a low amount of Cr2O3 and SiC content deposited on steels

Abstract

This study explores the use of the flame spray technique to deposit alumina-based coatings enhanced with small additions of chromia (Cr₂O₃) and silicon carbide (SiC). Alumina is widely recognized for its high thermal resistance and durability, and the incorporation of limited amounts of Cr₂O₃ and SiC is intended to improve its overall mechanical and protective properties. Coatings were applied to metallic substrates using flame spraying, and the resulting layers were examined for structural integrity, surface morphology, phase composition, hardness, and adhesion. The experimental results show that even low concentrations (≤10 wt.%) of Cr₂O₃ and SiC contribute to better hardness and thermal performance, while maintaining low porosity and strong bonding with the substrate. The findings suggest that these composite coatings could be suitable for industrial applications requiring resistance to wear and high temperatures, offering a cost-effective and efficient surface modification approach.