noun
definition
A rare metallic chemical element (symbol W, from Latin wolframium) with an atomic number of 74.
definition
A light bulb containing tungsten.
definition
Scheelite, calcium tungstate
Examples of tungsten in a Sentence
Similar potassium tungsten bronzes are known.
Deposits of copper, tin, iron and tungsten have been discovered, and a variety of other mineral products (graphite, mica, spodumene, coal, petroleum, &c.).
Shimizu 3 indicate that Steinmetz's formula holds for nickel and annealed cobalt up to B =3000, for cast cobalt and tungsten steel up to B =8000, and for Swedish iron up to B =18,000, the range being in all cases extended at the temperature of liquid air.
It is a member of the sixth group in the periodic classification of the elements, being included in the natural family of elements containing molybdenum, tungsten and uranium.
This subject is far from being exhausted, and it is not improbable that the alloy-producing capacity of aluminium may eventually prove its most valuable characteristic. In the meantime, ternary light alloys appear the most satisfactory, and tungsten and copper, or tungsten and nickel, seem to be the best substances to add.
Tungsten has been applied in the manufacture of filament electric lamps.
Tungsten trioxide, W0 31 occurs in nature as wolframine, a yellow mineral found in Cumberland, Limoges, Connecticut and in North Carolina.
Scheelite, another mineral of tungsten, is also found in Queensland.
Again, when tungsten hexachloride is converted into vapour it is decomposed into chlorine and a pentachloride, having a normal vapour density, but as in the majority of its compounds tungsten acts as a hexad, we apparently must regard its pentachloride as a compound in which an odd number of free affinities are disengaged.
Columbium compounds are usually prepared by fusing columbite with an excess of acid potassium sulphate, boiling out the fused mass with much water, and removing tin and tungsten from the residue by digestion with ammonium sulphide, any iron present being simultaneously converted into ferrous sulphide.
In 1858 he pointed out the isomorphism of the fluostannates and the fluosilicates, thus settling the then vexed question of the composition of silicic acid; and subsequently he studied the fluosalts of zirconium, boron, tungsten, &c., and prepared silicotungstic acid, one of the first examples of the complex inorganic acids.
The fact that energy is being used at so high a rate as Too H.P. on so small a charge of material sufficiently indicates that the furnace is only used for experimental work, or for the fusion of metals which, like tungsten or chromium, can only be melted at temperatures attainable by electrical means.
Steels containing as much as 12% of tungsten are now used as a material for tools intended for turning and planing iron and steel.
It alloys with iron, molybdenum and tungsten, but not with silver or mercury.
Of tungsten the United States was in 1907 the greatest producer in the world (1640 tons in a total of 6062).
Chrome-tungsten or High-speed Steel.-Steel with a large content of both chromium and tungsten has the very valuable property of " red-hardness," i.e.
This effect of chromium, tungsten and carbon jointly consists essentially in raising the " tempering temperature," i.e.
Uranium is chemically related to chromium, molybdenum and tungsten.
His next discovery, in 1781, was the composition of the mineral tungsten, since called scheelite (calcium tungstate), from which he obtained tungstic acid.
Tungsten steel, which usually contains from 5 to Io% of tungsten and from 1 to 2% of carbon, is used for magnets, because of its great retentivit.y.
The metals, which by combination with oxygen became oxides, were antimony, silver, arsenic, bismuth, cobalt, copper, tin, iron, manganese, mercury, molybdenum, nickel, gold, platinum, lead, tungsten and zinc; and the "simple earthy salifiable substances" were lime, baryta, magnesia, alumina and silica.
Tungsten may be prepared from wolfram by heating the powdered ore with sodium carbonate, extracting the sodium carbonate with water, filtering and adding an acid to precipitate tungstic acid, H 2 W0 4.
In the form of a powder, it is obtained by reducing the oxide with zinc and extracting with soda, or by dissolving out the manganese from its alloys with tungsten.
Tungsten dioxide, W02, formed on reducing the trioxide by hydrogen at a red heat or a mixture of the trioxide and hydrochloric acid with zinc, or by decomposing the tetrachloride with water, is a brown strongly pyrophoric powder, which must be cooled in hydrogen before being brought into contact with air.
Partial reduction of tungsten trioxide gives blue or purple-red products which are intermediate in composition between the dioxide and trioxide.
Tungsten trioxide forms two acids, tungstic acid, H 2 WO 4, and metatungstic acid, H2W4013; it also gives origin to several series of salts, to which the acids corresponding are unknown.
Tungsten forms four chlorides, viz.
Tungsten combines directly with bromine to give, when the bromine is in excess, the pentaand not a hexabromide.
By passing bromine vapour over red-hot tungsten dioxide a mixture of WO 2 Br 2 and WOBr4 is obtained, from which the latter can be removed by gently heating when it volatilizes.
The di-iodide is obtained as green metallic scales on passing iodine over red-hot tungsten.
Tungsten disulphide, W52, is obtained as soft black acicular crystals by the action of sulphur, sulphuretted hydrogen or carbon bisulphide on tungsten.
Phosphorus combines directly with the metal to form W3P4; another phosphide, W2P, results on igniting a mixture of phosphorus pentoxide and tungsten.
Tungsten is found in wolframite in Boulder county.
Minerals developed slightly, or not at all, are granite, valued at $1500 in 1905; surface salt, in the arid and semiarid regions; nickel and cobalt, in Lemhi county; tungsten, near Murray, Shoshone county; monazite and zircon, in certain sands; and some pumice.
So long as Mr. Lloyd George was Minister, Dr. Addison was his right-hand man in the strenuous labours of the office, resulting in the enormous multiplication of engines of war, and in the redeeming of many vital industries, fertilizers, tungsten and potash from German control; and when Mr. Lloyd George formed a Government himself in December 1916, he placed him at the head of the department.
Gold, silver and lead have also been produced, but the discovery of larger deposits of these metals in other states has caused the abandonment of all metal mines in Connecticut, except those of iron and tungsten.
The output gear drives the upper tungsten carbide anvil via a specially designed housing.
The quality scraper has a long lasting tungsten carbide blade and is supplied with a universal hose connector.
The tungsten bulb has a relatively large, tightly wound filament.
Home Tungsten products Tungsten carbide Powder Tungsten Carbide Powder Tungsten carbide powder is the intermediate in the line from W powder to cemented carbides.
Starter kit includes special tungsten carbide tipped router cutter, template and three spacer rings.
Sodium in a sodium lamp a stream of electrons is passed between tungsten electrodes in a tube containing sodium vapor.
Tungsten is practically the only material used for electron emitters.
A few decades ago a new design for tungsten filament lamps appeared on the scene.
A tungsten halogen source may be better with auto white balance.
I use a tungsten illuminator, so I chose Kodak tungsten 64 ISO film.
Sources of such energy include lasers, arc discharge lamps, and tungsten halogen bulbs.
Domestic tungsten - Domestic tungsten lighting has a strong yellow/orange cast, because its color spectrum is shifted toward stronger wavelengths.
These use liquid propellant set off by a jolt of high current through tungsten wire.
What Good Woodworking said... nd alcohol marketers are reaching more young viewers by focusing more attention on tungsten carbide scribe cable TV.