Abstract Delta Air Lines, Inc. has been conducting a research project regarding the capabilities of High Velocity Oxy-Fuel (HVOF) Thermal Coatings. Based on this research and industry development, Landing Gear components are replacing chrome plating with HVOF carbide cobalt chrome (WC-Co-Cr) coatings on several line-of-sight applications on Landing Gear components. Landing Gear intends on converting all line-of-site chrome applications, and possibly some other liner, plating and plasma applications, pending ongoing testing and service evaluations on Landing Gear components. Several HVOF coatings look promising for additional applications on other aircraft and engine components and are currently being evaluated. This paper discusses the process and facility needs, approval qualification, equipment selection and implementation of an HVOF operation at an airline. It focuses on HVOF WC-Co-Cr coatings which proved to be Delta's coating of choice for Landing Gear and most aircraft applications after research and service evaluations. Paper includes a German-language abstract.

Abstract HVOF cermet layers are increasingly viewed as an alternative to galvanic hard chrome layers for applications with high demands on wear and corrosion protection. The WC-Co-Cr layer is one of them. The WC-Co-Cr layers were produced with different HVOF systems: Jet-Kote, Diamond Jet, and JP5000. With all three systems, dense and well-adhering layers could be produced. This article considers HVOF sprayed WC-10Co- 4Cr as a generic coating type for replacing hard chrome plating. The friction, wear, adhesion, and corrosion performance of the HVOF WC-10Co-4Cr coatings are compared against the performance of a commercial hard chrome coating system. The article also evaluates effect on the coating adhesion of corrosion through the coating and penetrating along the interface at the coating edge. Paper includes a German-language abstract.

Abstract Thermal sprayed coatings of the intermetallic TiAl were applied on ferritic steels using plasma spraying and HVOF spraying methods. The specimens were investigated under reducing sulfidizing conditions in an Ar-H2-H2S- and a CH4-CO-CO2-H2-H2S-atmosphere. The experiments were carried out at 700°C for up to 1000 h. A very good corrosion resistance could be achieved in the Ar-H2-H2S-atmosphere. The coating remained well adherent and free of cracks or spallation. On the surface and along the coating lamellae slow growing Al- and Ti-oxides and Ti-sulfides had formed. The substrate material remained free of attack. The high carbon activity of the CH4-containing atmosphere led to a deposition of carbon within the coating lamellae and to subsequent formation of Ti-carbides which caused a severe degradation of the coating due to their high growth rate. In this case a sealing of the surface porosity e.g. by laser treatment has to be applied. Paper text in German.

Abstract Corrosion damage to concrete structures is widespread and usually requires extensive repair and maintenance work. The installation of active corrosion protection systems is therefore a useful tool for preventing corrosion. The application of thermally sprayed zinc layers on the concrete surface, which are used as anode to protect the steel reinforcement, was transferred from steel construction. Such systems are advantageous because of their simplicity and low cost. These systems can already be used in novel construction and after the repair of concrete structures. In this paper, novel results from long-term studies are presented. The result of the investigations suggest that sprayed zinc coatings are practically always suitable whenever structural elements are to be protected by cathodic protection. Paper includes a German-language abstract.