Tungsten-copper

Early catalysts for acrolein synthesis were based on cuprous oxide and other heavy metal oxides deposited on inert siHca or alumina supports (39). Later, catalysts more selective for the oxidation of propylene to acrolein and acrolein to acryHc acid were prepared from bismuth, cobalt, kon, nickel, tin salts, and molybdic, molybdic phosphoric, and molybdic siHcic acids. Preferred second-stage catalysts generally are complex oxides containing molybdenum and vanadium. Other components, such as tungsten, copper, tellurium, and arsenic oxides, have been incorporated to increase low temperature activity and productivity (39,45,46). 

Fig. 16. Insulator wall designs (a) peg wall (b) conducting bar wall and (c) segmented bar wall. The gas-side materials are tungsten and tungsten—copper composite, the base material, copper, and the insulators, boron nitride. Slagging grooves are shown.

Background spectrum, tungsten, copper, and nickel lines in, 229 Backlash, error due to, 285-287 Bank notes, histograms from x-ray spec-trographic chart recordings of, 225-227... 

Farrar. L.C. and J.A. Shields, Jr. Tungsten and Tungsten-Copper Applications foe Coal-Fired Magnetnhydrorlynamic Power Generation, ,/. of Metals (August 1992). Greenwood, N.N. and A. Eamshaw Chemistry of the Elements, 2nd Edition, Bulterworth-Heineniann, Inc.. Woburn, MA, 1997. 

Damzik, R.J., Neubrand, A., Rodel, J. (2000), Functionally graded materials by electrochemical processing and infiltration application to tungsten/copper composites , J. Mat. Sci., 35, 477 186. 

Typical scrap materials for hydrometallurgical treatment are grinding sludges, floor sweepings, contaminated powder qualities, tungsten-copper, and solid pieces, which can be dissolved by electrolysis. 

Acrolein conversion takes place in the presence of catalysts based on mixed oxides of molybdenum and vanadium, doped by compounds of tungsten, copper, chromium, tellurium. arsenic, etc., and designed te improve low-temperature activity, productivity, and mechanical performance. They operate aroud 250 to 280 0, at between 0.L and 0.2.10 Pa absolute, also in the presence of steam (water to acrolein molar ratio about... 

Legend Silicon Hafnium Titanium -e-Tanlalum Niobium - Tungsten Copper... 

The behavior of plastics in contact with clean metals in exemplified by the findings of Brainard and Buckley [7] for polytetrafluoroethylene (PTFE). Transfer of PTFE to clean aluminum, nickel, tungsten, copper, iron, tantalum, gold and silver was detected by the Auger electron emis-... 

Metallic Positive ions and free electrons Attraction between ions and electron gas Opaque and reflecting Electronic conductors, soluble in acids to form salts Moderately high melting, good heat conductors Tough and ductile, except tungsten Copper, iron, sodium... 

Eor Drilling-EDM different additional electrode materials are used like cemented carbide, tungsten-copper, and silver. The choice depends on the individual process characteristics in terms of low wear, high material removal rate, and good formability. Preferably an... 

Turchetta S, et al. CVD diamond insert in stone cutting. Diamond Relat Mater 2005. Glaser A, et al. Deposition of uniform and well adhesive diamond layers on planar tungsten copper substrates for heat spreading applications. Mater Sci Eng B 2006. 

In the case of tungsten-copper-nickel or tungsten-iron-nickel scrap, acidic H2O2 dissolves the other metals preferentially, allowing tungsten powder to be recovered directly [394]. 

A Kelley, WR Tyson. Tensile properties of fibre-reinforced metals copper tungsten copper/molybdenum. J Mech Phys Solids 13 329, 1965. 

Tungsten-copper-boron nitride pseudoalloy electrodes have been tested in electric discharge machining of hard alloys [101,102]. Alloys used in the manufacture of electric contacts are frequently composites of metals and a-BN, providing for increased heat durability [103]. Thus, silver cermet electrical contact material for circuit breakers is made by hot-pressing of the constituents [104 to 106]. Again, Ag/BN composite layers can also be prepared by electrodeposition [107]. Zinc alloys as used in coating sheet steel as anticorrosion layers may contain dipersed a-BN for increased weldability and corrosion resistance [108 to 111]. 

The heart of the SCR system is the SCR catalyst. Three general families of SCR catalysts are in commercial use today Vanadia. tungsten, copper zeolite, and iron... 

In the tungsten—copper and tungsten—silver systems, shrinkage and hence autohesion take place as a result of capillary forces as the pores are filled with a molten mass of the more easily melting component [445] and reach a maximum when the degree of filling equals 50-60%. 

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