Tungsten is the most widely used refractory metal. It’s melting point is 3410℃, so it still has good conductivity and thermal conductivity under the conditions of low thermal expansion, low vapor pressure, and high temperature. As a form of wire, its high-temperature performance is crucial for the production of lighting products and other products.
In addition to a small amount of tungsten wire used as heating material of high-temperature furnace, the heating element of electron tube and reinforcing bar of composite material, most of the tungsten wire is used for making filament of various incandescent lamp and halogen tungsten lamp and electrode of the gas discharge lamp. The tungsten wire with the thick specification is usually treated and cut into several rods after straightening, which is widely used in the lighting and electronics industry as a glass-metal sealing element.
At present, the main uses of tungsten wire in modern industry are as follows.
Tungsten wire is mainly used as filament in an incandescent lamp. An incandescent lamp heats a tungsten wire to incandescence by means of heat radiation that emits visible light, and the filament in an incandescent bulb is made of ultra-thin tungsten wire. The normal working temperature of the lamp reaches more than 2000℃, which is not enough to reach the melting point of the tungsten wire 3370℃, but this high temperature can make a part of the tungsten wire surface atoms evaporate.
The chemical properties of tungsten filament are very stable and strong in oxidation resistance, and should not be changed with other substances in the air, which enhances the life of tungsten bulb.
Tungsten wire is used as an electrode wire in photocopiers. The main type used is gold-plated tungsten wire, refers to the tungsten wire coated with a layer of gold. It is a special tungsten wire, and the main purpose of gold plating is to prevent corrosion. In the surface sense, the gold-plated tungsten wire becomes more beautiful, and the surface is brighter than the wolframite, scheelite and sprayed tungsten wire. In a deeper sense, the corrosion resistance of gold-plated tungsten wire is much higher than that of ordinary tungsten wire. In addition to the electrode used in photocopiers, gold-plated tungsten wire can also be used as an ideal corrosion-resistant electron emission material, which can be widely used in scientific research fields such as high-energy physics and meteorology.
Tungsten wire is used as the heater wire of the hairdryer to generate heat and send out hot air. The hairdryer is made up of a group of tungsten wire as a heating wire and a small fan. When electrified, the heating wire will generate heat, and the windblown by the fan will pass through the heating wire and become the hot wind. If only a small fan turns, but the heating wire is not hot, then it will only blow out the wind and not hot.
The blower drives the rotor directly by an electric motor to drive the wind blades to rotate. When the wind blades rotate, the air is drawn in from the air inlet, and the resulting centrifugal airflow is then blown out from the front nozzle of the blower. When air passes through, if the tungsten wire on the heating bracket installed in the wind mouth has been electrified and heated, it will blow out hot air; if the switch does not energize the heating wire, it will blow out cold air. A hairdryer is through this way to achieve drying and shaping purposes.
The heating element of the blower is made of tungsten wire, which is installed in the air outlet of the blower. The air discharged by the motor is heated by the heating wire in the air outlet, and then it is sent out as hot air. Tungsten wire is used as the heating wire mainly because only tungsten has a melting point of more than 3,400 degrees Celsius, which is the highest melting point of the metal, as well as high-temperature resistance, corrosion resistance, low thermal expansion coefficient, good winding performance, not sagging and other excellent characteristics. From a theoretical point of view, it is possible that the hairdryer can’t blow hot air because the tungsten wire in the hairdryer will be thinner, the resistance becomes smaller and the heating ability becomes weaker after a period of time.
In addition to a small amount of tungsten wire used as heating materials of the high-temperature furnace, heating elements of electron tube and reinforcing bars of composite materials, most of the tungsten wire is used for making various filament of incandescent lamp, iodine tungsten lamp and electrode of the gas discharge lamp. The tungsten filament made by forging and drawing tungsten bar is mainly used in the incandescent lamp, halogen tungsten lamp, and other electric light sources. Iodine tungsten lamp has the characteristics of high brightness and long life. Ordinary iodine tungsten lamp is often used as a lighting source for cinematography, stage, factories, buildings, and squares.
Iodine tungsten lamp not only reduces the evaporation of tungsten, extends the service life, but also improves the working temperature and luminous efficiency. In size, the iodine tungsten lamp is very small and delicate. The same 500-watt bulb is only 1 percent of the volume of an incandescent bulb. In addition to iodine, the glass shell is filled with inert gas, which is small and strong. The gas pressure is up to 1.5 to 10 atmospheres.
Tungsten wire is used as a heating wire for charging lighters. Here, instead of flint and fuel, resistance coils and tiny batteries work in much the same way as cigarette lighters in cars. What’s more, the most suitable point for IT professionals to sit in front of the computer is that its battery can be charged through the USB port.
The excellent heat resistance of tungsten wire greatly improves the performance of charging lighter. The tungsten wire heats up when the switch is turned on, and when it is red, it can be used to light cigarettes. Tungsten wire can play a role in combustion, generally with no obvious flame. The ordinary flame lighter is direct combustion steam body, which has the obvious flame to blow out. Tungsten is usually used to make filament s because it has a high melting point and does not fuse easily. The tungsten wire is heated with electricity, making the air expand, and then when it reaches a certain pressure, it spurts out. Butane gas used in cigarette lighters is reduced in volume to make it liquid and stored in cigarette lighters, which has the advantage of reducing the volume and facilitating storage and transportation.
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