Electron beam/physical vapor deposition

Reproducibility of film preparation and stability of the resulting films are important issues for practical applications. Cleanliness of the IRE before metal deposition can play a decisive role in determining reproducibility. Depending on the conditions, metal films may not be stable and may peel off (36,37). The stability and reproducibility of metal films can be enhanced by evaporating a metal oxide support material (such as AI2O3) prior to evaporation of the desired metal. Contaminants on the IRE are covered or displaced by evaporation of the metal oxide. It was reported that a 50-100-nm-thick AI2O3 layer deposited on a Ge IRE by electron beam physical vapor deposition hardly affected the reflectivity in an ATR experiment. Thin platinum films directly deposited onto it were found to be rather stable under catalytic reaction conditions (26,38). 

Electron beam physical vapor deposition (EB-PVD) is accomplished by directing a narrow beam of high-powered ( 20 kV, 500 mA) electrons at the source material. The energy released by these electrons when they are absorbed by the source material causes local melting in the source material. The entire source material is not melted, only the portion irradiated by the electron beam. This production of a small pocket of melted source material contained within solid source material is sometimes referred to as skulling. Hence, the vapor produced does not suffer contamination from the vessel containing the source material. Singh and Wolfe (2005) reviewed the use of electron beam—physical vapor deposition for the fabrication of nano- and macro-structured components. 

C. Leyens, U. Schulz, B. A, Pint and I. G. Wright, Influence of electron beam physical vapor deposited thermal barrier coating microstmcture on thermal barrier coating system performance under cyclic oxidation conditions, Surf Coat. Tech., 120, 68-76 (1999),... 

SYNTHESIS OF POROUS AND DENSE ELEMENTS OF SOFC BY ELECTRON BEAM PHYSICAL VAPOR DEPOSITION (EBPVD)... 

A diagram of UE-204 electron beam physical vapor deposition which was adapted to produce two-layer discs of Zr02(Y203) -l- Ni or Ni -l-Zr02(Y203) of 0.5m diameter and different thickness of the microporous layer (0.5-1.5 mm) and dense layer (5-20 im) is shown in Figure 4. 

Wolfe, D. E. and J. Singh. 2000. Titanium carbide coatings deposited by reactive ion beam-assisted, electron beam-physical vapor deposition. Surface and Coatings Technology 124 142-153. 

At an industrial applications, the TBC coverings can be produced by thermal spraying method in the air plasma spray (APS) atmosphere, at lowered pressure low pressure plasma spray (EPPS) from APS or by the electron beam physical vapor deposition method (EB-PVD), these are all dry-route processes. By these processes, coatings have different microstructures lamellar microstructure consisting... 

Singh J, Wolfe D. Review nano and macro-structured component fabrication by electron beam-physical vapor deposition (EB-PVD). J Mater Sci 2005 40 1-26. 

Figure 1.18 Thermal conductivity of various composition electron beam physical vapor deposition oxide defect-cluster coatings as a function of total dopant concentration [215].

The thin film of chromium nitrides was prepared by physical techniques such as magnetron sputtering on mild steel substrate (57) and electron beam physical vapor deposition (63). 

Fig. 5.1. A cross-sectional micrograph of an electron-beam physical vapor deposited yttria-stablized zirconia film which is partially delaminated from the nickel-base superalloy substrate. This ceramic layer and the interlayers comprising the bond-coat and thermally grown oxide serve as the thermal-barrier coating system in gas turbine engines, as described in Section 1.2.4. Reproduced with permission from Padture et al. (2002).

Electron-beam physical vapor deposition (EB-PVD) of rhenium on graphite has been demonstrated at The Pennsylvania State University. With EB-PVD technology, two or more materials ean be co-evaporated or deposited in layers to form functionally tailored coatings with improved properties and performance. Because rhenium is compatible not only with carbon but with platinum, palladium, ihodium, ruthenium, osmium, and iridium, it follows that EB-PVD technology can produce coatings with improved rhenium properties. For instance, deposition by electron-beam co-evaporation of rhenium with iridium will most likely provide high-temperature oxidation resistance. (Note that, presently, high-temperature, 2500 K, oxidation resistance is commercially achieved by vapor deposition of 50- to 250-pm-thick iridium films on rhenium.2... 

Xiaodong, H., Bin, M., Yue, S., Bochao, L. Mingwei, L. (2008). Electron beam physical vapor deposition of YSZ electrolyte coatings for SOFCs. Applied Surface Science. Vol. 254, pp. 7159. 

Xu Z, He, S, He L, Mu R, Huang G, Cao X. Novel thermal barrier coatings based on La2(Zro7Ceo3)2Q7/8YSZ double-ceramic-layer systems deposited by electron beam physical vapor deposition. Journal of Alloys and Compounds. 2011 509 4273-4283. 

Electron-beam physical-vapor deposited thermal barrier coatings... 

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