Tungsten Oxide

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...