Tungsten contacts are the contact points used to make or break the circuit in switches. They are used in the contacts of AC contactors, automobiles, motorcycles, electric horns, magneto and other electrical products.
With the continuous development of the automobile manufacturing industry, the requirements for tungsten contact materials have increased rapidly. The user's requirements for tungsten contact materials are: no cracks, scratches, smooth surface; small and uniform cross-section grains, short fibers; good straightness, concentricity and roundness; high hardness, good impact toughness; vapor pressure Low, low evaporation rate, low thermal expansion coefficient, good and stable arc resistance. The physical and mechanical properties of tungsten contact materials have been done by technicians in order to meet user requirements. The splitting, brittle fracture, and uneven cross-sectional grain size produced in the production process of tungsten contact materials, the rod diameter is the same. The reasons why the O degree and flatness cannot meet the requirements are comprehensively analyzed, and a series of measures have been taken.
Tungsten is a non-ferrous metal and an important strategic metal. Tungsten ore was called "heavy stone" in ancient times. In 1781 by the Swedish chemist Karl. William. Sheyer discovered scheelite and extracted a new element acid-tungstic acid. In 1783, it was discovered by the Spanish Depuria that wolframite also extracted tungstic acid. In the same year, tungsten trioxide was reduced with carbon to obtain it Tungsten powder, and named the element. The content of tungsten in the earth's crust is 0.001%. There are 20 tungsten-containing minerals that have been discovered. Tungsten deposits are generally formed with the activity of granitic magma. After smelting, tungsten is a silver-white shiny metal with extremely high melting point and high hardness.
Tungsten is used as electrical contact or contact material, which is resistant to arc ablation; good resistance to fusion; evaporation of metal surface caused by electric heating, less transfer and consumption; strong ability to interrupt current; and good resistance to wear and movement Hit performance. Compared with other metals or alloy materials, the price is low, so tungsten contacts and tungsten wafers are widely used in various fields of industry, agriculture, science and technology and national defense.