The Resources of Pure Tungsten

Aug. 23, 2010 - PRLog -- Pure tungsten is a steel-gray to tin-white metal. Very pure tungsten can be cut with a hacksaw,  forged, spun, drawn, and extruded. The impure metal is brittle and can be worked only with difficulty. As a high performance materials, pure tungsten has high melting temperature over 1650oC, high density, low vapor pressure, low thermal expansion combined with good thermal conductivity, sufficient electrical resistance, high modulus of elasticity. The metal oxidizes in air and must be protected at elevated temperatures. It has excellent corrosion resistance and is attacked only slightly by most mineral acids. The thermal expansion is about the same as borosilicate glass, which makes the metal useful for glass-to-metal seals.
Tungsten sheets and disk are available with alkali washed or ground finish. Tungsten bar and rod stock are available with ground surfaces and as sintered or swaged condition. Large ranges of custom crucibles and single crystal ingots are offered.  
Pure Tungsten Bar for steel making                                              
Tungsten bar is mainly used to found ingredient of material, cutter and heads, tungsten wire for lights instruments, electric contact points and conductor of heat, crankshaft and cylinder barrel of advanced automobile, ingredient of kinds of heat-resistant steel. Also used for making special steels, to make guns, artillery rockets, satellite airplane and ship. It has a luster rather like that of silver in uniform color. Though the whole bar may slightly curve, the maximum height of the bend should not be more than 7mm.
Tungsten bar with impurities is used to procedure bulb filaments or electron tube filaments, which are guaranteed to have remarkable resistance to high temperature.
Specifications: 13.5×13.5×530mm, 14×14×550mm & 17×17×570mm. Any particular requirements to the products can be discussed.
Pure Tungsten Rod                                              
Tungsten's unique properties as a high performance material, including a melting point of 3410° C, low vapor pressure at elevated temperatures and low coefficient of thermal expansion, make it of value in a variety of high temperature products and processes. Among them are glass-to-metal seal parts and support parts for lighting and electronics, silicon rectifier stud mounts and high temperature furnace components.
Elmet produces pure and potassium doped (WK Type) tungsten rod. The potassium doped products are targeted for use where high temperature non-sag properties are required in smaller cross sections by the lighting and electronic industries.
Availability of Pure tungsten rods
Tungsten rod is manufactured as random length pieces or cut to customers' desired lengths in diameters ranging from .020 inches to .750 inches. Standard diameter and length tolerances are listed in the accompanying tables. Other, closer tolerances can be quoted on request. In addition, there are three different surface processes or finishes which are provided, depending upon the desired end use.
Pure tungsten is so rare and so popular, thus pure tungsten Products are widely used for Furnace parts, Semiconductor Base Plates, Components for Electron Tubes, Emission Cathodes for Electron Beam Evaporation, Cathodes and Anodes for Ion Implantation, Tubes / Boats for Sintering of Capacitors, Targets for X-ray Diagnostics, Crucibles, Heating Elements, X-ray Radiation Shielding, Sputtering Targets, Electrodes.