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Wohlen, Switzerland

Curry N.,University College West | Markocsan N.,University College West | Ostergren L.,GKN plc | Li X.-H.,Siemens AG | Dorfman M.,Sulzer Metco
Journal of Thermal Spray Technology

The aim of this study was the further development of dysprosia-stabilized zirconia coatings for gas turbine applications. The target for these coatings was a longer lifetime and higher insulating performance compared to today's industrial standard thermal barrier coating. Two morphologies of ceramic top coat were studied: one using a dual-layer system and the second using a polymer to generate porosity. Evaluations were carried out using a laser flash technique to measure thermal properties. Lifetime testing was conducted using thermo-cyclic fatigue testing. Microstructure was assessed with SEM and Image analysis was used to characterize porosity content. The results show that coatings with an engineered microstructure give performance twice that of the present reference coating. © 2013 ASM International. Source

Curry N.,University College West | Markocsan N.,University College West | Li X.-H.,Siemens AG | Tricoire A.,Volvo | Dorfman M.,Sulzer Metco
Journal of Thermal Spray Technology

The aim of this study is to develop the next generation of production ready air plasma sprayed thermal barrier coating with a low conductivity and long lifetime. A number of coating architectures were produced using commercially available plasma spray guns. Modifications were made to powder chemistry, including high purity powders, dysprosia stabilized zirconia powders, and powders containing porosity formers. Agglomerated & sintered and homogenized oven spheroidized powder morphologies were used to attain beneficial microstructures. Dual layer coatings were produced using the two powders. Laser flash technique was used to evaluate the thermal conductivity of the coating systems from room temperature to 1200 °C. Tests were performed on as-sprayed samples and samples were heat treated for 100 h at 1150 °C. Thermal conductivity results were correlated to the coating microstructure using image analysis of porosity and cracks. The results show the influence of beneficial porosity on reducing the thermal conductivity of the produced coatings. © 2010 ASM International. Source

Chen D.,Sulzer Metco | Liu Y.,University of Connecticut | Jordan E.,University of Connecticut
Science of Advanced Materials

Y 3Al 5O 12:Eu 3+ (YAG:Eu 3+) phosphor powders were synthesized by a novel and simple sol-gel combustion process using aluminum sec-butoxide and yttrium acetate as precursors and triethanolamine as chelating agent and fuel. The phase composition, microstructure and photoluminescent properties of the as-synthesized YAG:Eu 3+ powders were investigated. XRD analysis indicated the combustion synthesized powders are amorphous and transform to pure YAG crystalline phase at 900 °C. The dependence of photoluminescent intensity on Eu 3+ concentration and powder heat treatment temperature were also studied. The YAG:Eu 3+ powder shows the strongest emission intensity with 5 at% Eu 3+ doping concentration after heat treatment at 1300 °C. © 2010 American Scientific Publishers. Source

Fiala P.,Sulzer Metco | Hajmrle K.,Sulzer Metco
Proceedings of the ASME Turbo Expo

Some cobalt based coatings have excellent antifretting properties when rubbed against titanium alloy hardware. The coatings are presently used in the gas turbine industry for specific antifretting applications. Their superior performance compared to the current art CuNiIn coatings has been demonstrated. This paper discusses the influence of coating structure on its mechanical properties and antifretting performance. The coating structure can be greatly modified by changing the coating application method (HVOF or plasma spraying). HVOF (High Velocity Oxygen-Fuel) and plasma spray equipment together with TriplexPro™ 200 gun configured to spray HVOF and plasma type coatings were used. The resulting coating properties can be tailored to specific application requirements encountered in aircraft engines and other industrial applications. Copyright © 2010 by ASME. Source

Barth A.,Sulzer Metco | Chen D.,Sulzer Metco | Dambra C.,Sulzer Metco
Welding and Cutting

Wear and corrosion protection are the main applications for carbide cermet coatings which are most commonly applied by HVOF in the field of thermal spray technology [1, 2, 3]. The TriplexPro-200 offers to produce carbide coatings economically and at an outstanding quality level. The influence of spray parameters, material composition and morphology was investigated and put into comparison to the established HVOF process. Two spray parameters for the TriplexPro-200 were used: standard setup in which the particle velocities around 200 to 280 m/s and the high-velocity setup reaching particle velocities above 550 m/s. Materials with different morphologies were tested showing influences on coating structure and residual stress. The material compositions are WC-Co and WC-CoCr as they are widely used in wear and corrosion resistance. Source

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