Production of Aluminides Layers on AISI 304 Stainless Steel in Low Temperatures Using the Slurry Process

Intermetallic compounds such as iron aluminides exhibit excellent oxidation and corrosion resistance, as well as, great metallurgical bonding with the substrate. In this work the coating process was applied by deeping into slurry, in which AISI 304 stainless steel samples were immersed in a solution consisting of polyvinyl butyral (PVB), ethyl alcohol and a powder composed of Al, AlCl₃ and Al₂O₃, dried and then placed in sealed crucibles without further protection. These samples were treated at temperatures of 500 °C and 650 °C for 2, 4, 6 and 8 hours and then air-cooled. Flat and homogeneous layers were obtained with the substrate and increase of thicknesses according as temperature and treatment time were increased. Considering that the traditional treatments of aluminization by the pack process are done at temperatures close to 900 °C and use larger amounts of material, the treatment used in this work are highly attractive economically.