Tungsten Oxide

In the process of hydrogen reduction of tungsten oxide , the effect of the reduction is not only the metal elements, there are some trace elements, such as rare earth elements. The effects of trace elements are related not only to quantity, but also to the shape and location of individual elements and the entry stage, for example, the elements that form fine grain particles at grain boundaries are different from the same elements in solid solutions. They are soluble in the bonding phase and different from the tungsten carbide grains. Some scholars believe that the addition of lanthanum or yttrium (La) (Y) in hydrogen reduction of tungsten oxide, can play a similar role to that of Al. In the process of research, scholars used the doping method of wet mixing and flow drying to prepare the blue tungsten powder, and push the boat by reverse hydrogen, the decomposition process is performed in two stages, namely at 500 °C, 850 °C, 900 °C, 950 °C, 1000 °C temperature point fi...

In the production of tungsten metal by powder metallurgy, the chemical purity is especially important because the subsequent sintering process can only be achieved by evaporation to a certain extent. With the development of industry, the requirement of the purity of tungsten powder is increasing day by day, because the impurities left after the sintering of tungsten powder have a great influence on the processability and properties of the final products. In the production process of tungsten concentrate to tungsten powder, tungsten purity is constantly improved, and the purity is high when APT is made. However, when APT is processed into tungsten powder, the purity decreases. Why? According to the study, tungsten powder impurities mainly from the material and the reduction of the furnace tube and metal boat contact, as a result, the impurity content is increased, and these impurities are present in a heterogeneous form, the result is the increase in impurity conte...

Nano tungsten trioxide is a high quality n-type semiconductor material, with excellent gas sensitivity to H 2 S, NH 3 , H 2 O 3  and other gases are sensitive. In modern industry is often used to produce gas sensors and electrochromic device. A gas sensor is a device that converts the type of gas and its associated information into electrical signals so that it can detect, monitor, and alarm. Tungsten trioxide (WO 3 ) is a n-type semiconductor with wide band gap, its excellent sensitivity and selectivity makes it becomes the main material of the sensor elements. In the field of coal, petroleum, chemical, power and other production, using tungsten trioxide as a component of the sensor can be timely and accurate to flammable, explosive, toxic, harmful gas detection and automatic control. Tungsten trioxide sensor was first used to detect H 2 S and H 2 , Japanese scholars in 1992 for the first time reported WO 3  sintered coating on the very low concentrati...

With the development of alloy industry, there is also a polarizing demand for tungsten powder. Not only has ultrafine tungsten powder, but also has ultra coarse tungsten powder. In industrial production, ultrafine tungsten powder is widely used, and the preparation of ultrafine tungsten powder is complicated. Therefore, it has been studied more. However, ultra coarse tungsten powder also has a specific use.  Ultra coarse tungsten powder is a coarser tungsten powder with a particle size greater than 20 microns. It has the advantages of good strength and toughness. It is widely used in the field of oil drilling, mining tools, stamping die, hard material etc. How to prepare ultra coarse tungsten? Just reverse the thinking of preparing ultrafine tungsten powder. The traditional scheme of preparing ultra coarse tungsten powder is based on the preparation of ultrafine tungsten powder as negative teaching material. 1. Try to improve fisher particle size of...