Research paper 46 © Copyright by International OCSCO World Press. All rights reserved. 2006 VOLUME 16 ISSUE 1-2 May-June 2006 of Achievements in Materials and Manufacturing Engineering of Achievements in Materials and Manufacturing Engineering The corrosion resistance of HVOF sprayed coatings with intermetallic phases in aggressive environments B. Formanek a, *, J. Cizner b , B. Szczucka-Lasota a , R. Przeliorz a a Department of Materials Science, Faculty of Materials Science and Metallurgy, Silesian University of Technology, ul. Krasińskiego 8, 40-019 Katowice, Poland b SWUM a.s., Laboratory For High Temperature Corrosion, Areal VU, P.O. BOX c.17, 19011, Praha 9 -Bechovice, Czech Republic * Corresponding author: E-mail boleslaw.formanek@polsl.pl Received 15.11.2005; accepted in revised form 15.04.2006 Properties ABSTRACT Purpose: The cyclic corrosion behavior of coatings with intermetallic matrix ( FeAl, NiAl and FeAl-TiAl) was investigated in aggressive gases. Design/methodology/approach: The composite coatings strengthened by a fine dispersive Al 2 O 3 and other ceramic phases were thermally sprayed by HVOF method in Jet Kote 2 system. A kinetics test was carried out by periodic method for exposure times of up to 500 hours. Mass changes of the studied coatings during the corrosion test are presented. The surfaces of the composite coatings after the corrosion test in aggressive environments were analyzed by scanning microscopy observation. Findings: All the results confirm good heat proofness of HVOF sprayed coatings with an AlFe and AlNi intermetallics. Practical implications: Owing to the properties of intermetallic phases and HVOF sprayed coatings, they are anticipated to be applied for the protection of super heater tubes in conventional boilers or in boilers burning multicomponent waste, and combusted biomass including chlorides. Originality/value: The results show that the coatings with AlFe and AlNi intermetallic phases have very good corrosion resistance and they are the best coatings from all the coatings investigated in aggressive environments. Keywords: Intermetallic phases; Ceramic phases; Composite powders; HVOF coatings; Corrosion resistance 1. Introduction Intermetallic phases show advantageous strength properties at high temperatures [1-10]. They show resistance to the action of many aggressive environments at an elevated temperature and at ambient temperature. As regards Fe-Al, relatively low costs of components have made intermetallic phase based alloys become a prospective constructional material [9]. Intermetallic phase based alloys with an aluminium fraction belong to the new generation of heat-resisting metal materials characterized by unique physicochemical and mechanical properties. Over the past years, a lot of research has been conducted, aimed at better learning of the properties and strength of intermetallic phases at high temperatures, inter alia of aluminides of such elements as: nickel, iron, titanium, niobium or cobalt [1-10]. Aluminides of intermetals have a high aluminium concentration, which allows the formation of a continuous, adhering aluminium film in the surface, in atmospheres with 1. Introduction