Tungsten Oxide

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...

A thin film material is a film material with a thickness less than 1 microns. It is mainly used for semiconductor functional devices and optical coatings. At present, the field has been involved in computer storage equipment, pharmaceuticals, high temperature insulation products, thin-film batteries, solar cells etc.. Compared with traditional block materials, thin film materials have incomparable advantages, such as small grains, large specific surface area and special surface structure. Therefore, zirconium tungstate is a kind of excellent negative thermal expansion material. The thin films prepared with zirconium tungstate can be conveniently used in the compensation layer of thermal stable structures or into large capacity heat driven devices, This is also the other general material is difficult to take advantage of it, so these years the zirconium tungstate thin film or zirconium tungstate composite thin film has also been concerned and research hot spots.  It is ...

Thermal expansion and contraction are common physical phenomena. However, there are some materials which do not act according to common sense and show the opposite phenomenon of thermal expansion and cold expansion, such materials are known as negative thermal expansion materials, and zirconium tungstate is one of the negative thermal expansion materials. The results show that the zirconium tungstate ZrW 2 O 8  has a stable negative thermal expansion performance in the range of 0.3 to 1050.0K in the temperature range, negative thermal expansion coefficient alpha can reach -9 * 10 -6 K -1 , and is isotropic. Therefore, zirconium tungstate can be used alone as a heat shrinkable material, and can also be mixed with other materials to form composite material. Zirconium tungstate metal substrate is using a powder metallurgy method principle, adding zirconium tungstate composite material in the metal. Because of its excellent conductivity and thermal conductivity, the compo...

Thermal expansion and contraction are common physical phenomena. However, in industrial practice, it is found that zirconium tungstate is a heterogeneous species. It is shown by the "heat shrinkable cold expansion". This phenomenon is called "negative thermal expansion" of zirconium tungstate. It should not be underestimated in zirconium tungstate. It can be used in industrial production. The results show that the zirconium tungstate ZrW 2 O 8  has a stable negative thermal expansion performance in the range of 0.3 to 1050.0K in the temperature range, negative thermal expansion coefficient alpha can reach -9 * 10 -6 K -1 , and is isotropic. Therefore, zirconium tungstate can be used alone as a heat shrinkable material, and can also be mixed with other materials to form composite material. The material obtained by the composite process of ceramic and zirconium tungstate is called zirconium tungstate composite based on ceramic. The ceramic based zirconiu...

Zirconium tungstate is a new kind of negative thermal expansion material, which is different from common physical phenomena of thermal expansion and cold contraction. In nature, it exhibits the physical phenomenon of "heat expansion and cold expansion", which is quite uncommon and unusual. Zirconium tungstate has attracted much attention in industrial production. In the field of industry, the traditional negative thermal expansion materials are aluminum, titanium, zirconium, polymer resin and so on. In general, polymerized resins are used mainly in traditional electronic circuits, as well as in instrumentation, packaging materials, and protective coatings. For a long time, the polymerization of resin with its easy to obtain, the advantages of low prices and become the first choice for industrial applications, however, there is a great thermal expansion coefficient in the process of polymerization into resins. In recent years, with the advent of zirconium t...

Some asphalt pavements often have long, thin, split cracks or web, this kind of situation, we usually call it "cracking". There are many reasons for cracking, and some vehicles overrun the load too much, and some asphalt material reasons, here we discuss briefly the material factors. In general, the cause of asphalt pavement cracking of pavement is extreme temperature or temperature fatigue effect. In short, the asphalt pavement has experienced a large expansion and contraction, and once the temperature stress exceeds the fracture strength of asphalt concrete, cracks will arise. Moreover, the cracks in the road is just the beginning, the days later, more sun and rain and traffic rolling, asphalt mixture on the temperature changes will become increasingly sensitive, when the ambient temperature is too high, resulting in high temperature rut; temperature is too low, crack extension re-cracking. It will soon turn into a pothole, and eventually a collapse or even more se...

Expansion and contraction is a common physical phenomenon. However, there are some materials do not follow the routines, showing the opposite nature of the heat shrinkage, this phenomenon is called "negative thermal expansion", these materials are collectively referred to as negative thermal expansion materials. In the industrial field, the traditional commonly used negative thermal expansion materials are aluminum, titanium, zirconium, synthetic resin, zirconium tungstate is ammonium paratungstate and zirconium oxychloride synthesis of products, it's a new kind of material with negative thermal expansion coefficients over conventional materials. The study shows that zirconium tungstate ZrW 2 O 8  is a kind of negative thermal expansion material with excellent properties, zirconium tungstate has cubic appearance at normal temperature. It has stable negative thermal expansion performance in the whole range of temperature range from 0.3 to 1050.0K, the neg...