Tungsten Oxide

In order to protect the environment, human efforts to develop new, efficient, low toxicity, pollution-free corrosion inhibitors, sodium tungstate quickly favored by people. Sodium tungstate was first used as a corrosion inhibitor for organic antifreeze, and subsequently developed in other functional packages. Tungstic acid can be used in different corrosive media, such as fresh water cooling water, seawater cooling water, oil recovery in the oil field, molten salt, water-cooled internal combustion engine antifreeze, adsorption type refrigerant circulating fluid and coal slurry. You can also add anti-rust paint and mold resin material from the role of corrosion inhibition. Sodium tungstate alone has some inhibition, but the corrosion rate is not high, and the amount is large, the cost is difficult to control, therefore, sodium tungstate is mixed with other organic compounds in general industry, which can significantly improve the corrosion inhibition performance and reduce the cost of ...

Polyimide (PI) is one of the best comprehensive performance of organic polymer materials, with excellent mechanical, dielectric and other properties, is widely used in many fields.\ Zirconium tungstate (ZrW 2 O 8 ) is a kind of expansive material with isotropic negative thermal excellence, modern industry it with the prepared polyimide composite, PI/ZrW 2 O 8  composite film, this film has very important applications in industry. PI/ZrW 2 O 8  composite films with ZrW 2 O 8  content of 0%, 3%, 6%, 10%, 25%, and 50% ZrW 2 O 8  were successfully prepared by in situ polymerization, through the contrast test found that after joining ZrW 2 O 8 , the high temperature strength of PI/ZrW 2 O 8  composite films had a very big impact, no change in quality and thermal effect in the wood between 200 and 450 °C. It was further verified that the polyamic acid was fully imidized at 350 °C, indicating that the material had high heat resistance and high decomposition temperatur...

Thermal expansion is a common problem in many fields, such as mechanical, electronic, optical and structural materials.    Aluminum and zirconium tungstate are negative thermal expansion materials.  Aluminum is a metal type negative thermal expansion material, which is characterized by excellent conductivity and thermal conductivity, and the material price is relatively cheap, it can deal with the general application. But in the high temperature and cold environment, but its negative thermal expansion is less than zirconium tungstate, but zirconium tungstate production cost is higher, the performance and price trade-off dilemma. Fortunately, zirconium tungstate has good compatibility and can be used to form composite particles with aluminum. The traditional preparation technology of aluminum based zirconium tungstate composite material is heating sintering and pressing. Preparation process of aluminum based zirconium tungstate composite: 1. The zirconium tungstate powder...

Among the vanadium oxides, vanadium dioxide is distinguished by its rapid and abrupt phase transition, and its phase transition temperature is 68  °C. The reversible change from low temperature monoclinic system to high temperature tetragonal system leads to great changes in physical properties such as resistivity, optical transmittance, permeability and so on. This feature makes it very promising in intelligent switches, electronic devices and optoelectronic devices. However, in daily life, the application temperature of 68 degrees is still too high, so it is necessary to reduce the VO 2  phase transition temperature, so that VO 2  can be widely used. In recent years, many studies have shown that doping of other elements in VO 2  can effectively reduce its phase transition point. Especially the high valence metal ions, such as MO 6+ , W 6+  and so on, doping effect is particularly significant. The amount of ammonium metatungstate was mixed with vanadium oxide b...

Biodiesel is usually synthesized from vegetable oils and fats and waste edible oils by simple transesterification. In the synthesis of biodiesel, the key technology is the selection of the catalyst, the traditional inorganic acid and alkali catalyst, facing strong corrosive and non renewable, easy to cause problems such as saponification reaction against the original intention of the environmental protection of bio diesel.  Phosphotungstic acid is an environmentally friendly catalyst widely used in catalysis in recent years. It has strong acidity, and many industrial processes that need to be catalyzed by inorganic acids can be replaced by phosphotungstic acid. But in the biodiesel production process, found itself acid soluble in water, for many catalytic processes of catalytic esterification, the esterification rate is generally not high, in addition, the activity of the heteropoly salt group easily lost, so that it can not be used repeatedly, which leads to high cost. Even so, t...

The ITER device is a superconducting tokamak can produce large-scale nuclear fusion reactions,  aims to create a clean and sustainable energy future of mankind. ITER uses deuterium and tritium to produce nuclear fusion. Deuterium and tritium fusion in the circulation with millions, tens of millions of billions of temperature, the circulator must be strengthened by high temperature resistant metal, from the engineering point of view, material problems determine the success or failure of fusion energy development. In fusion materials, a very important type of material is plasma facing material (PFMs), and the general requirement for PFMs is: high temperature resistance, low sputtering, low hydrogen (tritium) retention and compatibility with structural materials. Tungsten is considered to be the most promising PFMs material, which can meet many requirements in this harsh environment. However, tungsten is facing severe brittleness because of its own structural characteristics. Therefor...

Tungsten coating is mainly used in aviation, aerospace, nuclear power, machinery and other industrial fields, and the key parts of friction and movement parts wear protection. Tungsten coating is difficult to prepare because of its special properties. The basic process of high explosive loading spraying technology can be divided into three stages: 1. The use of explosive detonator is paved on the surface of the powder coating with explosives, explosive detonation wave propagation in detonation, similar to slip in explosive welding of detonation wave, high temperature and high pressure of the detonation product formation; 2. The powder of flying coating moves rapidly downward under the action of detonation wave and detonation products with high speed expansion, which can reach a higher speed. By selecting the type of explosive reasonably, controlling the distance between coating powder and matrix, the target velocity of coating powder can be controlled effectively, and the best velocity...

Tungsten has a high melting point, high density, high hardness, saturated vapor pressure, low coefficient of thermal expansion and other characteristics. Copper has high thermal conductivity properties, tungsten copper alloy combination is made known to all the materials in aerospace and military fields. The traditional preparation of tungsten copper alloy mainly adopts the method of mechanical mixing, forming and sintering of tungsten powder and copper powder, or using infiltration process. The method is relatively simple, but there are some defects, because of the great difference between tungsten and copper, tungsten and copper can only form pseudo alloy shape, and it is difficult to achieve uniform distribution of tungsten and copper in the interior, resulting in lower or unstable properties.  With the development of Aeronautics and Astronautics and military industry, the demand for tungsten copper exothermic sweating material is higher and higher, Chinese scholars created a po...