Vacuum-arc

Eig. 3. Coasumable-electrode melting ia the vacuum-arc furnace (13). A, arc B, buttoa E, electrode I, iagot L, Hd M, water-cooled mold and P, pool of... 

Vacuum arc remelting often is used to develop optimum solidification stmctures. Electroslag remelting, which utilizes a molten pool of slag in which the electrode is immersed, yields a cleaner and purer material. 

Fig. 12. Arc vaporization source configurations (a) vacuum arc/molten anode, and (b) cathodic arc.

Component Consumable vacuum-arc melt Plasma Plasma cold-hearth melt melt Electron-beam cold-hearth melt Induction melt... 

Region Company Sponge, 10 t Vacuum arc, 10 t Cold hearth, 10 t... 

J. M. Lafferty, ed.. Vacuum Arcs Theory and Application,]o m Wiley Sons, Inc., New York, 1980. 

There are several vacuum processes such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), sputtering, and anodic vacuum arc deposition. Materials other than metals, ie, tetraethylorthosiHcate, silane, and titanium aluminum nitride, can also be appHed. 

HANDBOOK OF VACUUM ARC SCIENCE AND TECHNOLOGY edited by Raymond L. Boxman, Philip J. Martin, and David M. Sanders... 

DEC coating was first prepared by Aisenberg and Chabot using ion beam deposition in 1971 [2]. At present, PVD, such as ion beam deposition, sputtering deposition, cathodic vacuum arc deposition, pulsed laser deposition, and CVD, like plasma enhanced chemical vapor deposition are the most popular methods to be selected to fabricate DEC coatings. 

Vacuum arc can also be initiated by pulsed laser, as shown in Fig. 4 [15,16]. The target material is first vaporized into plasma by pulsed laser, and vacuum arc is subsequently initiated and more plasma is generated under the function of the electric field between the anode and the cathode (target). Since the arc is controllable, the surface quality might be evi-... 

Rolo, M. C., Andujar, J. L., Robertson, J., and MUne, W. I., Preparation of Tetrahedral Amorphous Carbon Films by Filtered Cathodic Vacuum Arc Deposition," Diamond Relat. Mater., Vol. 9,2000, pp. 668-661. 

Koskinen, J., Hirvonen, J. P., Levoska, J., andTorri, R, "Tribological Characterization of Carbon-Nitrogen Coatings Deposited by Using Vacuum Arc Discharge, Diamond Relat. Mater., Vo. 5, No. 6-8,1996,pp. 669-673. 

Husein, F., Imad, Zhou, YuanZhong, Li, Fan, Ryne, C., AUen, Chung Chan, Jacob, I., Kleiman, Yu, Gudimenko, and Clark, V, Cooper, Synthesis of Carbon Nitride Thin Film by Vacuum Arcs, Mater. Sci. Eng., A, Vol. 209,1996, pp. 10-15. 

Fedulov, V.I. Concerning Regularities of Particle s Driving in Potential Fields (on example of electron s movement in electrical field with distributed potential) in ARW977788 Emerging Applications of Vacuum-Arc-Produced Plasma, Ion and Electron Beams , edited by E.M. Oks and I.G. Brown (Kluwer Academic Publishers, Dordrecht, the Netherlands), 213, 2003. 

Double-stranded RNA (dsRNA) in yeast, 26 451—452 Double-stranded RNA viruses, 3 135 Double-suction pumps, 21 60, 63 Double tipping pan vacuum filter, 11 352 Double titration method, 15 145 Double vacuum-arc remelting (VAR), in titanium sponge consolidation, 24 854 Double wall nanotubes (DWNT), 26 737 Double-wall tanks, 24 296 Doubly smart block copolymers,... 

Nanocarbon emitters behave like variants of carbon nanotube emitters. The nanocarbons can be made by a range of techniques. Often this is a form of plasma deposition which is forming nanocrystalline diamond with very small grain sizes. Or it can be deposition on pyrolytic carbon or DLC run on the borderline of forming diamond grains. A third way is to run a vacuum arc system with ballast gas so that it deposits a porous sp2 rich material. In each case, the material has a moderate to high fraction of sp2 carbon, but is structurally very inhomogeneous [29]. The material is moderately conductive. The result is that the field emission is determined by the field enhancement distribution, and not by the sp2/sp3 ratio. The enhancement distribution is broad due to the disorder, so that it follows the Nilsson model [26] of emission site distributions. The disorder on nanocarbons makes the distribution broader. Effectively, this means that emission site density tends to be lower than for a CNT array, and is less controllable. Thus, while it is lower cost to produce nanocarbon films, they tend to have lower performance. 

C. Li, N. Wang, S. Wong, C. Lee, and S. Lee, Metal silicide/silicon nanowires from metal vapor vacuum arc implantation, Adv. Mater. 14, 218-221 (2002). 

Yttrium also finds application in titanium alloys where at concentrations of the order of 200 ppm it improves the ductility and ease of fabrication of vacuum arc-melted alloys. It is also used to improve the strength of magnesium castings and when used in combination with zirconium, as little as 100 ppm yttrium increases the conductivity of aluminium transmission lines by as much as 50%. 

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