Tungsten discharge needle is a product of refractory metal tungsten. With its excellent physical and chemical properties, it has become one of the most popular discharge needles in modern times. The tungsten discharge needle is one of the most important parts in the ion fan. In addition to being polluted after working for a long time, it will affect the anti-static effect and ion balance of the fan, its quality will also directly affect the anti-static performance of the fan.
At present, the more widely used discharge needles are stainless steel needles and tungsten discharge needles. Not only does this make the filament weaker due to it losing mass, but it will also start to have an impact on the light output of the bulb since there will then be a small layer of tungsten throughout the entire inside of the glass bulb.
The way they went about solving this problem was to start putting in an inert gas into the bulb. Before this they used to make the inside of the bulb a vacuum in order to prevent any sort of combustion between the immense heat and oxygen. However, it is also possible to put gases into the bulb, but it is important to be careful of which gas you choose for this. Most gases would also end up in a combustion just like oxygen would, which is why an inert gas has to be used instead.
The gas most commonly used in these bulbs is argon. The effect of filling the bulb with glass is rather simple but very effective. What it does is that it gives the detaching tungsten atoms something to bounce off of, instead of just shooting straight out into the glass bulb. If we give the tungsten something to bounce off of, chances are that it will bounce back into the filament again. This would cause the atom to combine with the filament again and continue to work like it did before.
After seeing some of the properties of the material used in this you might begin to wonder if there are other viable options for a bulb filament like this.
There have in fact been a few others that were contenders of being the bulb filament. There was a fair amount of trial and error with other materials before finding that tungsten was the best option. Some of the materials used were iridium, molybdenum, chromium, carbonized paper and many more. Most of the materials tested were simply not good enough for the task at hand though. The vast majority of the materials tested got dismissed for at least one of the following reasons:.
The lifespan being too short. The material being too fragile. Commercial use of the Images will be charged at a rate based on the particular use, prices on application. In such cases we would ask you to sign a Visual Elements licence agreement, tailored to the specific use you propose. The RSC makes no representations whatsoever about the suitability of the information contained in the documents and related graphics published on this Site for any purpose.
All such documents and related graphics are provided "as is" without any representation or endorsement made and warranty of any kind, whether expressed or implied, including but not limited to the implied warranties of fitness for a particular purpose, non-infringement, compatibility, security and accuracy. In no event shall the RSC be liable for any damages including, without limitation, indirect or consequential damages, or any damages whatsoever arising from use or loss of use, data or profits, whether in action of contract, negligence or other tortious action, arising out of or in connection with the use of the material available from this Site.
Nor shall the RSC be in any event liable for any damage to your computer equipment or software which may occur on account of your access to or use of the Site, or your downloading of materials, data, text, software, or images from the Site, whether caused by a virus, bug or otherwise. Jump to main content. Periodic Table. Glossary Allotropes Some elements exist in several different structural forms, called allotropes. Discovery date Discovered by Juan and Fausto Elhuyar Origin of the name The name is derived from the Swedish 'tung sten' meaning heavy stone.
Glossary Group A vertical column in the periodic table. Fact box. Glossary Image explanation Murray Robertson is the artist behind the images which make up Visual Elements. Appearance The description of the element in its natural form.
Biological role The role of the element in humans, animals and plants. Natural abundance Where the element is most commonly found in nature, and how it is sourced commercially. Uses and properties. Image explanation. The symbol used reflects the once common use of the element in light bulbs. Tungsten was used extensively for the filaments of old-style incandescent light bulbs, but these have been phased out in many countries.
This is because they are not very energy efficient; they produce much more heat than light. Tungsten has the highest melting point of all metals and is alloyed with other metals to strengthen them. Tungsten and its alloys are used in many high-temperature applications, such as arc-welding electrodes and heating elements in high-temperature furnaces.
Tungsten carbide is immensely hard and is very important to the metal-working, mining and petroleum industries. Biological role. Tungsten is the heaviest metal to have a known biological role. Some bacteria use tungsten in an enzyme to reduce carboxylic acids to aldehydes. Natural abundance. The principal tungsten-containing ores are scheelite and wolframite.
The metal is obtained commercially by reducing tungsten oxide with hydrogen or carbon. Help text not available for this section currently. Elements and Periodic Table History.
More than years ago, porcelain makers in China incorporated a unique peach colour into their designs by means of a tungsten pigment that was not known in the West.
Indeed it was not for another century that chemists in Europe became aware of it. In , Peter Woulfe examined a mineral from Sweden and concluded it contained a new metal, but he did not separate it. Then in , Wilhelm Scheele investigated it and succeeded in isolating an acidic white oxide and which he rightly deduced was the oxide of a new metal. The credit for discovering tungsten goes to the brothers, Juan and Fausto Elhuyar, who were interested in mineralogy and were based at the Seminary at Vergara, in Spain, they produced the same acidic metal oxide and even reduced it to tungsten metal by heating with carbon.
Atomic data. Glossary Common oxidation states The oxidation state of an atom is a measure of the degree of oxidation of an atom. Oxidation states and isotopes. Glossary Data for this section been provided by the British Geological Survey. Relative supply risk An integrated supply risk index from 1 very low risk to 10 very high risk.
Recycling rate The percentage of a commodity which is recycled. Substitutability The availability of suitable substitutes for a given commodity. Reserve distribution The percentage of the world reserves located in the country with the largest reserves. Political stability of top producer A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators.
Political stability of top reserve holder A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators. Supply risk. Relative supply risk 9. Young's modulus A measure of the stiffness of a substance.
Shear modulus A measure of how difficult it is to deform a material. Bulk modulus A measure of how difficult it is to compress a substance. Vapour pressure A measure of the propensity of a substance to evaporate. Pressure and temperature data — advanced. Listen to Tungsten Podcast Transcript :.
You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry. Hello, this week supersonic steels, fast formula cars and upset Spanish scientists. But what are they arguing about? It raised the attention of people that how to protect them from the harm of radiation. Radiation sources must be blocked in order to protect the patients, doctors, nurses and others in the hospital.
The radiation level of the radioactive materials must be control low enough, lest produce harmful ionizing radiation, so as not to cause lung cancer, skin cancer and other cancers. Lead and iron are traditional radiation shielding materials, but there is no doubt that a high proportion of tungsten alloy blocks is the best choice. The reason of choosing high-density tungsten alloy shielding as shielding material is that tungsten alloy has excellent ray absorption capacity, high density density is twice of lead as well as good corrosion resistance.
The property of radiation shielding is closely related to the density of the material. Higher density means better ray absorption and radiation shielding ability. Due to the higher density of tungsten alloy than other materials, the ray absorption and block ability of which are better than other traditional shielding materials, such as lead.
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