Powder tungsten

Processing. Tungsten carbide is made by heating a mixture of lampblack with tungsten powder in such proportions that a compound with a combined carbon of 6.25 wt % is obtained. The ratio of free-to-combined carbon is of extreme importance. Tantalum and titanium carbides are made by heating a mixture of carbon with the metal oxide. Multicarbide powders, such as M02C—WC, TaC—NbC, and TiC—TaC—WC, are made by a variety of methods, the most important of which is carburization of powder mixtures. 

Sulfides. Tungsten disulfide [12138-09-9] WS2, although found in nature, is usually prepared by heating tungsten powder with sulfur at 900°C. 

Iron, nickel, cobalt, molybdenum, and tungsten powders produced by the pyrolysis of the respective metal carbonyl (see Ch. 3).P 1... 

Cooledge A process for forming tungsten powder into wire, important in the development of the electric light bulb. Developed in 1908. 

SAQ 10.1 The following data refer to the adsorption of butane at 0°C onto tungsten powder (area 16.7 m2g 1). Calculate the number of moles adsorbed in a monolayer, and hence the molecular area for the adsorbed butane (at monolayer coverage) and compare it with the value of 32 x 10 20 m2 estimated from the density of liquid butane. 

By virtue of its high specific gravity, barite (barium sulfate)-filled PBT grades can be used to produce very dense, X-ray opaque, ceramic-like parts [37], Recently, metal-filled PBT resins using copper or tungsten powder have been used to prepare blends with very high specific gravity. 

Hydrogen Isobars on Evaporated Tungsten Films and on Tungsten Powder ... 

Sodium tungstate is crystallized, separated from any impurities in the solution, and digested again with hydrochloric acid to form tungstic acid in purified form. The pure acid is dried, ignited and reduced with carbon to form tungsten powder from which most non-ferrous alloys are made. 

The APT may directly be reduced with hydrogen to produce tungsten powder. The powder may be pressed, sintered and fabricated to produce tungsten metal and alloy products.The tungsten powder may be heated with carbon to form tungsen carbides which may be converted to cast carbides or certain grades of cemented carbides. Or the tungsten powder may be alloyed with specific metals to form various non-ferrous alloys. 

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