Tungsten Oxide

Tungsten disulfide is an excellent solid lubricant material, it has high application value in the field of super solid lubrication. Tungsten disulfide membrane have layered structure, it has lower hardness and better stability under high temperature, it is suitable to be used as a solid lubricant for friction parts in special environment. There are three main methods for preparing tungsten disulfide membrane which include RF sputtering method, reactive magnetron sputtering method, chemical deposition method. The method of RF sputtering crystal growth is the method of using RF sputtering to make the components of the crystal material gasified and then recrystallized to grow the crystal. RF sputtering is a sputtering deposition method suitable for all kinds of metal and nonmetal materials, the frequency range is 5~30MHz, the frequency of 13.56MHz is commonly used internationally. It is mainly used to prepare thin membranes and also to prepare small size crystals. WS2 powder with 99.99%

  Solid lubrication is a method of coating or plating on the surface of the friction pairs to form a thin film and reducing friction. The technique of using solid lubricants to lubricate is called solid lubrication.  Tungsten disulfide and molybdenum disulfide are excellent solid lubricating materials, in the field of ultra-solid lubrication has a very high value, this technology is applied to the hard disk drive bearing of computer, such as rotation and sliding in ultra high vacuum system. Molybdenum disulfide has a graphite-like structure, molybdenum and sulfur through the covalent bond to form a hexagonal structure, each molybdenum is surrounded by six sulfur atoms, the molecular layer surface only sulfur atoms, each layer molecular layer thickness of 0.626nm. The thermal stability of MoS 2  is better in the air environment lower than 400 degrees. When the temperature is higher than 400 degrees, MoS 2  will be oxidized to MoS 3  in a short time, MoS 3  is a granular material with hi

The structure of tungsten disulfide is a hexagonal layered structure with excellent electrical properties. In tungsten disulfide, the interaction between the W atoms in the layer and the surrounding S atoms is strong, and the interaction between the tungsten disulfide layer and the layer is weak. The thermal stability of two tungsten sulfide is stronger than that of molybdenum disulfide. The temperature range is wide, and it is not easy to decompose. Oxidation occurs at 539 degrees centigrade. Therefore, tungsten disulfide is an excellent semiconductor material for indirect bandgap semiconductors. When the thickness of tungsten disulfide is reduced to a single layer, it changes into a direct band gap, which means that tungsten disulfide can effectively pass through the bandgap transition absorb or emit photons. The band gap of monolayer tungsten disulfide is about 2eV. This electrical performance characteristic is the main advantage of tungsten disulfide in semiconductor tubes, transi

Thermal sprayed tungsten carbide / cobalt cermet is widely used in aerospace, metallurgy, machinery and other fields due to its good hardness and toughness. Thermal spraying (spray welding), surfacing and other processes are gradually becoming the commonly used alloy, steel material anti-wear and surface corrosion technology measures. Tungsten carbide / cobalt thermal spraying technology has a simple process compared with other thin film and coating preparation technology, the coating and substrate have a wide range of selection, a large range of coating thickness, high deposition efficiency and easy to form composite coating.  The wear resistance of alloy is a systematic engineering problem. The material is only an important aspect to measure the grindability. In addition, it is also related to the stress state, surface structure, lubrication conditions, environmental temperature and other factors. The characteristics of thermal spraying powder vary with the milling process. The usua

The modification of zinc tungstate by doping rare earth elements is an effective way to improve its luminescent properties. The single crystal of zinc tungstate is rose red, the color makes the luminous efficiency decrease and the decoloration effect is obvious. After annealing for a long time, the ZnWo 4  crystal will disappear gradually, but the annealing of the bulk crystal still has difficulties which can not be overcome. The main problem is that the defect is incomplete and the defects are introduced into the annealing process.  In single doped rare earth crystals, only cerium doped Ce 3+  can recede the color of the crystal, both doped cerium Ce 3+  and lithium li 3+  have obvious decoloration effect on zinc tungstate crystal, especially, the former can obtain colorless crystal by proper doping. The removal mechanism of zinc tungstate may be due to the decomposition of CO 2  in Li 2 CO 3  crystals, CO 2  molecules will be partially retained in the lattice, CO 2  molecules and O

In life, silver-nickel contact materials are widely used in relays, circuit breakers for low current ratings because of their good ductility and low contact resistance. When current levels exceed 20 A, conventional AgNi contact materials exhibit weaker resistance to soldering and erosion, limiting their range of application. However, by adding a small amount of additives, the electrical properties can be improved, thus expanding its application area. Some scholars have studied that adding tungsten or tungsten oxide can improve the performance of AgNi contact materials.  The W or WO 3 , which accounts for 1.5% of the total, was made into silver-nickel contacts (containing 85% of silver content) by powder mixing, isostatic pressing, sintering, extrusion, subsequent wire drawing and riveting. Each contact material was repeated 5 times using the same resistive load in the test. The current and mechanical structure ensured that all tests had comparable arcing energy with supply voltages and

The contradiction between the increase of organic nitrides and sulfides in oil and the heavy crude oil. The strict environmental protection regulations are becoming more and more serious, so it is necessary to conduct deep hydrofining for oil products. The research shows that although the traditional molybdenum sulfide based catalyst is effective in hydrotreating process, it is far from meeting the requirements of deep hydrodesulfurization. The current approach is to retrofit existing catalysts and find new catalysts that can be used to meet the need for deep hydrotreating of crude oils. In 1990s, the synthesis and performance of tungsten nitride hydrodesulfurization catalyst have been reported abroad, and the structure and desulfurization performance of P, Ni, W catalyst with phosphorus as auxiliary agent have been studied. However, the research on tungsten phosphide seems to be few. Therefore, the Chinese scholars also try to use tungsten phosphide for hydrodesulfurization test, so a

With the continuous strengthening of human environmental awareness, the quality of living environment has aroused widespread concern. All countries have formulated strict standards for the quality indicators of sulfur, nitrogen and other harmful substances in petroleum products. The clean production process and green products have become the mainstream trend in the development of petroleum refining and chemical production. In recent years, the transition metal nitrides hydrotreating catalyst has become a hot topic in the field of new catalysts because of its excellent deep hydrodesulfurization, denitrification activity and selectivity. Some scholars believe that the current research on oil desulfurization catalyst is too focused on the cobalt molybdenum series earlier, and has excellent mechanical and thermal stability and anti poisoning characteristics of nickel tungsten catalysts study less, but in fact, the nickel tungsten nitrogen catalyst has more potential applications.  By using