Abstract

MARULANDA AREVALO, José Luddey; PEREZ TRUJILLO, Francisco Javier  and  REMOLINA MILLAN, Aduljay. Aluminum-Silicon Coatings Made by Chemical Vapor Deposition in Fluidized Bed on Stainless Steel AISI 316. Rev. Fac. ing. [online]. 2013, vol.22, n.34, pp.63-70. ISSN 0121-1129.

The aluminum-silicon coatings were deposited on stainless steel AISI 316, by chemical vapor deposition, in fluidized bed reactors (CVDFBR), in the 540 to 560°C temperature range, using a bed formed by a 2.5 g silicon and 7.5 g aluminum powder and 90 g inert bed (alumina), which was fluidized with Ar. As activators were used a mixture of HCl/H₂ in ratios of 1/10 to 1/16. Furthermore, the coatings deposition time was varied between 45 minutes to 1.5 hours, with a volume ratio of 50% active gases, and 50% neutral gases. A thermodynamic simulation was conducted with the software Thermocalc for information about the possible composition and the amount of material deposited, for the selected conditions. Among the coatings are FeAl₂Si, FeAl₂ and Fe₂Al₅. Aluminum-silicon coatings were heat treated to improve their mechanical properties and behavior against oxidation. The inter diffusion of the alloying elements and the heat treatment causes the aluminum to diffuse into the substrate and the iron diffuse into the coating surface, achieving the above compounds transformation in FeAl, Al₂FeSi, Cr₃Si, and AlFeNi AlCrFe.

Keywords : Aluminum-Silicon Coating; Chemical Vapor Deposition; Stainless Steel; Intermetallic; Fluidized bed.

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