ICMCTF2006 Session TS2: Coatings for Aerospace Applications

Monday, May 1, 2006 10:30 AM in Room Sunset

Monday Morning

Start	Invited?	Item
10:30 AM		TS2-1 Low Thermal Conductivity Thermal Barrier Coating Deposited by the Solution Precursor Plasma Spray Process X. Ma, J. Roth (Inframat Corporation); F. Wu, M. Gell, E. Jordan (University of Connecticut) This work seeks to develop an innovative thermal barrier coating (TBC) that will exhibit low thermal conductivity and high durability compared with that of today’s TBCs. To achieve the objectives, multiple component co-doped zirconia chemistry was selected for the topcoat of the TBC system, and a new TBC process - Solution Precursor Plasma Spray (SPPS) was employed to produce desirable microstructural features: high volume porosity and vertical cracks, for lower conductivity and better durability, respectively. Test results verified a low thermal conductivity λ of 0.55~0.66W/K m at a temperature range of R.T. to 1300°C, 1/3-1/2X that of EB-PVD 7YSZ TBCs, and its thermal cycling lifetime over 1,000 cycles/hours between R.T and 2050°F. In addition, the SPPS-TBC has shown excellent sintering resistance after isothermally aging and high heat flux exposure. This low thermal conductivity TBC, made by the SPPS process, has demonstrated favorable material and processing characteristics.
10:50 AM		TS2-2 Deposition of Thick Nitrides and Carbonitrides for Sand Erosion Protection R. Wei, E. Langa, C. Rincon, J. Arps (Southwest Research Institute) Thick nitrides (TiN, CrN and ZrN) and carbonitrides (TiSiCN and ZrSiCN) have been deposited using a Plasma Enhanced Magnetron Sputtering (PEMS) technique. The technique combines conventional magnetron sputtering and externally generated plasma from which high current density can be obtained. By using heavy ion bombardment prior to and during deposition to increase the coating adhesion and limit columnar growth, single-layered thick nitrides of TiN, CrN, and ZrN coatings up to 80 micrometers and thick carbonitride coatings of TiSiCN and ZrSiCN up to 30 micrometers have been obtained. In this paper, we will discuss the deposition technology and the effect of ion bombardment on the coating microstructure. Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray analysis (EDX), Transmission Electron Microscopy (TEM), and X-Ray Diffractometry (XRD) were used to study the microstructure and morphology of these coatings. The nanoindentation was conducted to determine the hardness and Youngs modulus, while a sand erosion test was conducted to rank the erosion resistance of the coatings. It was observed that TiSiCN rendered the best erosion resistance - nearly 25 times lower than the uncoated stainless steel of Ti-6Al-4V and about 5-10 times lower than all other nitrides. The technology may be applied to protect turbine engine compressor blades, vanes and rotor blades in advanced aircraft and fluid pump impellers as well as piston rings for heavy-duty diesel engines.
11:10 AM		TS2-3 Novel TiN Multilayer Coating System for Compressor Airfoil Sand Erosion Protection A. Feuerstein (Praxair Surface Technologies, Inc.) Frequently, aircraft, tank and helicopter gas turbine engines are operated in a desert environment where the gas turbine compressor rotor blades and vanes are exposed to erosive media such as sand and dust. These erosion effects lead to increased fuel consumption, efficiency loss, and can cause damage to compressor and turbine hardware. Erosion resistant coatings such as TiN, TiCN, TiZrN, TiZrCN, TiAlN and TiAlCN, applied by cathodic arc physical vapor deposition, can be used to prolong the life of compressor airfoils in a sand erosion environment. Praxair Surface Technologies, Inc. has developed unique multilayered TiN coating system with optimized erosion resistance compared to conventional mono block layers. Recently, because of the increased demand in erosion coatings for desert environment, Praxair has established a production facility to cost effectively apply this coating to helicopter engine compressor blades. The key features of the coating system are outlined. Selected erosion performance data are presented. The aspects of a high quality mass production are addressed.
11:30 AM	Invited	TS2-4 Coatings for Space Applications: Emphasis on Tribology and Radiation Protection P.D. Fleischauer (The Aerospace Corporation) Coatings are used for numerous applications on space systems, including protection for optics, thermal control and radiator surfaces, and solar cells, filters for optics, and lubricants for moving mechanical assemblies. Coating types range from adsorbed layers to multilayer hard or soft thin films. Examples of various uses of coatings on space systems will be presented and discussed, together with issues of preparation, chemical and physical properties, environmental effects, and testing for reliable operation. Strong emphasis will be placed on performance and reliability of coatings for long-life, unattended operation in different space environments (i.e., low earth orbits, geosynchronous orbits, and exploratory missions). Differences in orbital requirements and in mechanical properties for tribological applications will be discussed.