Tungsten boat can also be called evaporating tungsten boat or coated tungsten boat. It is formed by high temperature stamping of tungsten sheet, stamping boat, folding boat, etc. It is widely used in vacuum coating industry and sintering furnace or vacuum annealing ship industry.
Tungsten boat is widely used in gold plating, evaporator, development control mirror, heating container, electron beam painting, household appliances (outer casing), mobile phones, toys, and various decorative vacuum coating occupations and sintering furnaces or vacuum annealing vessels. In the industry. In an ideal (vacuum, dry) state, the wires are connected at both ends of the tungsten boat and energized, and the low-melting metal is placed in the middle recess. When the temperature rises below 2000 degrees, the metal will evaporate into a gas and be plated on it. On the surface of the workpiece.
Tungsten is a pure metal with a high melting point (about 3400 ° C). It is stable at normal temperature in hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, aqua regia and alkali. However, tungsten is cold and brittle at room temperature, making it difficult to process; together, it is easily oxidized when heated to high temperatures in air, which limits its expansion. Adding an alloy to tungsten can significantly improve strength, plasticity, and oxidation resistance. At 1900 ° C, the strength of tungsten alloy can reach 440 MPa, while other metals have already melted, so tungsten alloy can be used as high-temperature structural data, such as jet engine nozzles, inlet and outlet casings and spacecraft engine propellers.
High-speed east-west steel is a high-carbon alloy steel (such as W18Cr4V) with more tungsten added. Its heat resistance, wear resistance and toughness are much better than ordinary east-west steel. It is widely used in high-speed cutting things such as turning tools and twists. Drills, milling cutters, etc.
Commonly used cemented carbides contain more tungsten carbide with high hardness, high melting point and high wear resistance. They maintain high hardness and wear resistance at around 1000 °C, and are more wear-resistant and heat-resistant than high-speed steel. The cutting speed can be increased to about 200m/s.
The tungsten-copper alloy and the tungsten-silver alloy prepared by the powder metallurgy method have both the high conductivity of copper and silver and the wear resistance of tungsten, and are the aspiration contact materials for making knife-type switches, circuit breakers, spot welding electrodes, and the like.
Metal tungsten wire, thin strips and dense metal tungsten parts are widely used in the electrical lighting and electronics industries. Tungsten wire is the ambition of incandescent filament, because of its high operating temperature, high luminous efficiency, low transpiration speed and long life. Tungsten wire also serves as the hot cathode and grid of the electron tube, the cathode of the high-voltage rectifier tube, and the heater of the indirect heating cathode in various instruments; tungsten can also serve as a target for x-ray tubes, gas discharge tubes, various electrical contacts, and The electrode of tungsten argon arc welding is also used as a heating element of a high temperature furnace, and its working temperature is above 3000 °C.
