Tungsten copper electrode can be classified into 3 types.

1. Tungsten copper (Class 10) is used for flash and butt welding electrodes in applications in which high heat resistance, higher electrical and thermal conductivity, high malleability, and low thermal expansion are required. This metal is created by combining 45% copper and 55% tungsten, resulting in a dense and hard metal with superior wear resistance and strength.

2. Tungsten copper (Class 11) contains 25% copper and 75% tungsten. Like Class 10, it has superior wear resistance and strength and good thermal and electrical conductivity. However, it is harder than Class 10 and used in applications that require moderate pressure.

Common uses include projection welding electrodes, flash and butt welding electrodes, light upsetting and seam welding bushings, and spot welding low conductivity steels. It is also widely used in chip carriers, substrates, flanges, and frames for power semiconductor devices.

3. Tungsten copper (Class 12) contains 20% copper and 80% tungsten, being stronger than Class 10 and 11 tungsten copper, it is commonly used in heavy duty projection welding electrodes, and cross wire welding. It is also used in the liners of some specialty shaped explosive charges for the defense and oil and gas industries.

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The electron spin resonance spectrum of the S-state ion Gd3+ in a calcium tungstate host lattice has been examined at 37.5 GHz over the temperature range 290 K to 4.2 K. Low concentration Czochralski-grown single crystals having gadolinium concentrations of about 100 ppm were used to ensure substitution by Gd3+ in calcium sites; the crystals were vacancy compensated. Although the general features of the 290 K spectrum agreed well with that reported previously by Hempstead and Bowers, extra lines were observed very close to the main ΔM=1 transitions. Examination in theφ-plane showed that the extra lines were most pronounced nearφ=55° and that their intensites relative to those of the main transitions increased as the temperature was reduced. The extra lines are explained in terms of the ordering of oxygen vacancies.

 

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Gamma irradiation of calcium tungstate at 77°K produces two paramagnetic species in high yield. Measurements of yields and of rates of disappearance upon warming indicate the two species are formed and disappear upon warming in one to one correspondence. The principal axis directions and gtensors have been measured and indicate that one species contains a surplus electron while the other is electron‐deficient (hole). Hyperfine effects of W¹⁸³ have been observed. The electron‐deficient species contains two tungsten atoms with small isotropic hyperfineinteractions. Its unpaired electron must be highly localized in orbitals of atoms other than tungsten. The electron‐surplus species contains one tungsten atom with an anisotropichyperfineinteraction. This center could be WO₄ ^3-, but from the lack of symmetry of the measured g values it must be formed near a lattice defect. Experiments with heat‐treated crystals indicate lattice defects to be important in the radiation effect.


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The energy levels of the ⁵I ground term of Ho³⁺ in single crystals of CaWO₄ were established by absorption and fluorescence spectra measurements. The measurements were made using crystals at temperatures near 2, 20, and 85°K. Most of the observed transitions can be accounted for by the electric dipole selection rules. Magnetic dipole selection rules cannot be ruled out for some of the lower energy transitions, however. Calculations were made to determine the effects of the crystalline host material on the Ho³⁺ energy levels. An effective Hamiltonian of the form suggested by Karayianis was diagonalized in a basis of Russell–Saunders wavefunctions to obtain the calculated energy levels and wavefunctions for Ho³⁺. Such a calculation takes into account the complete J mixing of the states within the ground term and is equivalent to determining the effects of the spin–orbit interaction to better than second order. In the calculation, an rms deviation of 10 cm−1 was found as the best agreement between the theoretical and experimental energy levels using the Hamiltonian, H = λ1(L⋅S) + λ2(L⋅S)² + λ3(L⋅S)³ + ΣlmB+lmClm. The empirically determined parameters yielding this rms deviation are (in cm⁻¹): λ₁= − 487.9, λ₂ = − 6.601, λ₃ = − 0.1801, B₂₀ = 436, B₄₀ = − 664, B₄₄ = 779, B₆₀ = − 33,ReB₆₄ = 558, and ImB₆₄ = 196. The g_‖ factor for the ground state of Ho³⁺ in CaWO₄ was calculated to be 13.675. This is in agreement to within 0.12% of the experimental value of 13.691 ± 0.006 reported by Kirton.

 

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Tungsten carbide powder (WC) is kind of dark gray powder, which using proportional tungsten powder and carbon black mixture as raw material to produce tungsten carbide powder. And in tungsten carbide powder the carbon atoms embedded tungsten metal lattice gap and did not destroy the original metal lattice, but to form interstitial solid solution, also known as interstitial compound. It is mainly used in produce tungsten carbide alloy.
The production of tungsten carbide powder is mainly through mix metal tungsten powder and carbon black as raw materials which according to a certain proportion of formulated. And then putting mixture into the graphite boat and placed in the carbon tube furnace or a sense of high-frequency electric furnace with a certain temperature to carbonization, and then by ball milling, screening to obtain tungsten carbide powder.
Tungsten carbide powder should be stored in dry, ventilation and acid-free atmosphere, to prevent oxidation, in which the storage period should not exceed six months. The external package of tungsten carbide should be drum and the internal packaging should be polyethylene bags, tightly sealed. According to fsss's size, tungsten carbide powder can be divided into 12 grades, as shown below.

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Tungsten carbide powder (WC) as a black hexagonal crystal with a metallic luster, a dark gray powder, the hardness close to diamond, is the main raw material for the produce tungsten carbide. Its physical characteristics are as follows: chemical formula: WC, melting point: 2870 ℃, boiling point: 6000 ℃, the relative density of 15.63 (18 ℃), it does not dissolve in water, hydrochloric acid and sulfuric acid, easily dissolved in mixture acid of nitric acid and hydrofluoric acid which is a good conductor of electricity and heat. Tungsten carbide is fragile, if adding a small amount of infiltration of titanium such as cobalt, titanium and other metals can reduce brittleness, but also make the tungsten carbide used in more areas. Using tungsten carbide as steel cutting tools used often adding titanium carbide, tantalum or they mixtures in order to improve the anti-knock capacity.
Tungsten carbide powder may be dissolved in a variety of carbide, especially in titanium carbide forming solid solution TIC-WV. Another compound of tungsten and carbon is tungsten dioxide carbide, the formula W2C, a melting point of 2860 ℃, boiling point of 6000 ℃, the relative density of 17.15, while its properties, preparation method, use of tungsten carbide powder and similar.

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Tungsten hexafluoride (WF6) is only stable varieties in tungsten fluoride which can produce by industrial. It is mainly used in the chemical vapor deposition of tungsten, the chemical equation for this reaction is: WF6 + 3H2 → W + 6HF. The reduction of tungsten hexafluoride can be restore to metallic tungsten and HF by hydrogen or other reducing gas (such as GeH4, SiH2F2 and diethylsilane etc.) at high temperatures. Tungsten hexafluoride as a raw material widely used in the electronics industry as base of tungsten metal chemical vapor deposition (CVD) process technology, such as using WSi2 as wiring materials of LSI which is made by WF6. Besides, using CVD technology of mixing metal to produce tungsten and the rhenium complex coating may be used to manufacture X-rays emitter electrode of a solar absorber. What’s more WF6 in the electronics industry still mainly used as a semiconductor electrode and the conductive paste and other raw materials.
In addition to applications in the electronics industry, tungsten hexafluoride used in non-electronic aspect is also very broad. By CVD technology to generate hard tungsten carbide on the surface of the steel can improve the surface properties of the steel. Additionally, tungsten hexafluoride is also widely used in fluorinating agent, polymerization catalyst and feedstock of optical materials to manufacture low resistance and high melting point interconnect lines or some components, such as tungsten tube and crucibles.

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There are many synthetic methods tungsten hexafluoride. The following introduce chemical reactions which use tungsten, halogen and HF to react then to form tungsten hexafluoride. Tungsten hexafluoride formed by the react of tungsten, halogen and HF where the chemical reaction equation is as follows: W + 3X2 + 6HF - WF6 + 6HX. Wherein the X2 is a halogen, usually Cl2 or Br2, the reaction is carried out in an autoclave which make by monel alloy.
Using Cl2 as example, in order to ensure that the product has a good yield, generally make Cl2 and HF appropriate excess, in the theory chlorine and tungsten hexafluoride molar ratio of 3: 1, while in the experiment used 3~6: 1. Theory hydrogen fluoride and tungsten hexafluoride molar ratio of 6: 1, is used in the experiment used 6~10: 1, the reaction temperature is controlled at 150 ~ 450 ℃. While increasing the reaction temperature can make the reaction quickly but the temperature is too high will cause severe corrosion of equipment and WF6 partially decomposed.
By the way this method often has by-product, it is not a good way for produce tungsten hexafluoride not only by environmental protection or economic efficiency.

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Currently, there are there methods for synthesis tungsten hexafluoride which are common used. The first is by direct reaction of fluorine gas and tungsten to generate tungsten hexafluoride. The second is tungsten and nitrogen trifluoride (NF3) direct reaction to produce tungsten hexafluoride. The third method is to generate tungsten hexafluoride by react halogen, tungsten and HF. The following is introducing the reaction of using tungsten and nitrogen trifluoride to produce tungsten hexafluoride and in this reaction NF3 as fluorinating agent.
The reaction equations of tungsten and nitrogen trifluoride reaction is as follows: W + 2NF3 - WF6 + 3N2, the reaction conditions at temperatures greater than 400 ℃ decomposition of NF3 to produce F2. F2 reacts with the metal to generate tungsten hexafluoride. Besides the NF3 moisture content which used in reaction direct related to the purity of the product. That is need high-purity NF3 to produce tungsten hexafluoride. But the high-purity NF3 requires cryogenic condensation method to cool NF3 at -130℃~ -70℃, after water solidified to separate to make it. What’s more the reactor should make by nickel or monel. But this will lead to increased production costs, and a higher investment risk, which are not suitable for applied industrial production.

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Tungsten hexafluoride is a strong fluorinating agent, with the exception of nickel, monel and stainless steel, make many metal fluoride at room temperature. In the dry state it has low corrode for glass, but able to respond quickly in heavy moisture. Tungsten hexafluoride and ionic halide react can form complex compound at a high temperature to reduce tungsten by hydrogen.
There are three methods for synthesis of tungsten hexafluoride, is described below using fluorine gas as the fluorinating agent in the process to produce tungsten hexafluoride: making tungsten and fluorine gas (F2) direct reaction to synthesis tungsten hexafluoride, in order to prevent the erosion container wall of fluorine, the reaction vessel material should be monel, nickel or stainless steel. Chemical reaction equation is as follows: W + 3F2 - WF6.
This reaction is carried out under the conditions of 400 ℃, tungsten direct reacts with F2 to  produce tungsten hexafluoride, because the nature of F2 is too lively, in order to make the reaction proceed smoothly requires a certain proportion of nitrogen added. Generally the tungsten metal is added by tungsten powder to make the gas-solid phase contact area as large as possible, and then collect tungsten hexafluoride into another low temperature container by liquid form.

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