Tungsten wire mesh

Tungsten wire mesh is a special mesh made of pure tungsten wire with tungsten content greater than or equal to 99.95%, also known as tungsten wire shielding mesh, tungsten filter mesh, high temperature tungsten mesh.

Characteristics of tungsten wire mesh

Tungsten wire mesh is a pure tungsten wire product with high melting point, high hardness, high strength, high resistivity, low vapor pressure, low evaporation rate, good high temperature resistance (can withstand high temperature of 3400 degrees), and excellent impact resistance, so it is widely used in various mechanical equipment, such as as electromagnetic shielding mesh, vacuum furnace heat treatment grille, RF electromagnetic shielding, light wave filtering, etc.

Tungsten wire mesh can be divided into wolfram wire mesh and wolfram wire mesh according to the different surfaces. Generally, black tungsten wire is used to weave first, and then if the demand is for white wire mesh, the graphite layer on its surface is removed by electrolytic alkaline washing to make its surface appear metallic and bright.

The tungsten wire mesh is woven with tight structure, square and even hole shape, no broken head in the effective working area, no deformation and mature process. The most common tungsten wire mesh weaving process is plain weave and twill weave; the woven wire mesh is flat and free of oil and broken wires; tungsten wire mesh has high resistance, high melting point, high density and superior performance, which is very suitable for light wave blocking, electromagnetic shielding, etc.

Specification of tungsten wire mesh

The specifications of woven tungsten wire mesh can be as fine as φ0.03mm in wire diameter and as wide as 2000mm in width, which can be customized in size or cut into circles, squares, strips, etc. for customized needs. Another important specification indicator of the wire mesh specification is expressed by the number of mesh, which can be made into 10, 20, 30, 37, 40, 50, 80, 100, 150, 200 mesh, etc.

Does tungsten wire mesh react in the air?

Under normal conditions, tungsten wire mesh is a very good physicochemically stable product and will not react with air or oxygen. However, when the outside temperature rises (heated in air), the color of tungsten wire mesh starts to change from steel gray or silvery white to dark gray-black; when the temperature rises to 400°C, tungsten will start to oxidize, and as the temperature rises, the oxidation reaction will become more and more violent, which will gradually produce tungsten trioxide. However, when the air humidity is high, even at room temperature tungsten powder will be gradually oxidized by the set, covering its surface with a blue-purple intermediate oxide film.

Tungsten trioxide is a light yellow rhombohedral crystalline powder with the chemical formula WO3, specific gravity 7.16g/cm3, melting point 1473°C, boiling point 1750°C, and will sublimate significantly at 850°C. Tungsten trioxide is easily reduced by various reducing agents. At room temperature, even a small amount of organic matter can make it reduce and change its color. However, when heated in air, the original color is restored. At 700~900℃, tungsten trioxide is easily reduced to tungsten metal by hydrogen, carbon monoxide and carbon. WO3 is tetragonal above 740°C, orthorhombic from 330-740°C, monoclinic from 17-330°C, and triclinic from -50-17°C. The color of tungsten trioxide changes with temperature, and the crystal structure also depends on temperature.

Applications of tungsten wire mesh

Tungsten wire mesh is widely used in vacuum furnace tungsten mesh heaters, heat treatment support mesh, various machinery, electrical appliances, air conditioners, filters and electromagnetic shielding mesh, vacuum furnace heat treatment grids, light wave filters, etc.

Tungsten wire in the vacuum, even at high temperature, can maintain the essence of tungsten, and the tungsten itself has a high melting point, the melting point is 3410 degrees, the fusing time depends on the evaporation rate of tungsten, so it is not easy to break; and once exposed to the air, in use, the high temperature tungsten wire will react with the oxygen in the air and deteriorate, generating tungsten oxide, and the melting point of tungsten oxide, WO3, is 1400-1600 degrees. Once this temperature is exceeded WO3 vaporizes rapidly at this temperature, so that the tungsten wire quickly fuses in the air.

In addition, it is worth noting that if the tungsten wire mesh is constantly heated in an oxygenated environment, its toughness will become worse and worse, while its brittleness will become greater and greater, and it will be extremely easy to fracture under impact or vibration.  

However, in a vacuum even at high temperature, tungsten wire mesh can maintain the essence of tungsten, i.e., the melting point is high, and the time of fusing depends mainly on the evaporation rate of tungsten, so it is not easy to fuse.