Commonly used hardware materials are made of five metals: gold, silver, copper, iron and aluminum.
1. Gold in its monomers (free form), commonly known as gold, is a popular precious metal that has been used for many centuries as currency, security and jewelry.
In nature, gold occurs as a single substance in the form of gold nuggets or grains in rocks, underground veins and alluvial deposits. Gold is also one of the monetary metals. Gold's monomers are solid at room temperature, dense, soft, bright, corrosion-resistant, and second only to platinum in ductility.
2, silver (Argentum), a transition metal. Chemical symbol Ag. Silver is one of the metals known and utilized in ancient times, is an important precious metal.
Silver in nature, there are monomers, but the vast majority of them are in the form of chemical compounds present in the silver ore. The physical and chemical properties of silver are more stable, thermal and electrical conductivity is very good, soft, rich ductility. Its reflectivity is extremely high, up to 99% or more. There are many important uses.
3, copper is a transition element, chemical symbol Cu, English copper, atomic number 29. pure copper is a soft metal, the surface is just cut for the red-orange with a metallic luster, the monomers were purple-red.
Good ductility, thermal conductivity and high electrical conductivity, so in the cable and electrical, electronic components is the most commonly used materials, can also be used as building materials, can be composed of numerous kinds of alloys. Copper alloys have excellent mechanical properties and low electrical resistivity, the most important of which are bronze and brass. In addition, copper is also a durable metal, can be recycled many times without losing its mechanical properties.
4, iron (iron) is a metal element, atomic number 26, iron monomers chemical formula: Fe. pure iron is white or silver-white, with a metallic luster. Melting point 1538 ° C, boiling point 2750 ° C, can be dissolved in strong and medium-strength acids, insoluble in water. Iron has 0-valent, +2-valent, +3-valent and +6-valent, of which +2-valent and +3-valent are more common and +6-valent is rare.
5, aluminum, silver-white light metal. Have ductility. Commodities are often made into rods, sheets, foils, powders, ribbons and filaments. In humid air can form a layer of metal corrosion prevention of oxide film. Aluminum powder heated in the air can burn violently, and emit dazzling white flame.
Easily soluble in dilute sulfuric acid, nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solution, insoluble in water. Relative density 2.70. melting point 660℃. Boiling point 2327℃.
Expanded Information:
Modern Hardware:
History into the modern industrial society, metal-hardware products industry is the rapid development of the hardware industry in the development of the national economy has played an inestimable role, hardware has become an indispensable industrial manufacturing The hardware industry plays an invaluable role in the development of national economy, and hardware products have become an indispensable part of industrial manufacturing.
Rather, they are used as supporting products for industrial manufacturing, semi-finished products and tools used in the production process. Only a small portion of daily-use hardware products are necessary tools for people's lives as consumer goods.
In the National Bureau of Statistics National Economic Industry Classification, the manufacturing industry is ranked in the third largest category of industries. It includes: the production and manufacture of means of living, such as: agricultural and sideline products, food and beverage, tobacco, textile, clothing and leather, wood and furniture, printing and sporting goods, as well as pharmaceutical manufacturing and so on.
Manufacturing of means of production, such as: petrochemicals, chemical fibers, rubber and plastic, non-metallic products manufacturing, metal smelting and processing, metal products manufacturing, general equipment manufacturing, industry-specific equipment manufacturing, as well as transportation equipment manufacturing, electrical equipment, telecommunications electronics and so on.
And the manufacturing of metal products and general equipment manufacturing in the classification of general-purpose parts and so on in the relevant products are composed of the usual sense of the "small hardware". Thus, 'small hardware' is not a pre-existing industry categories, but several metal products - hardware products cross combination.
And in the manufacturing industry as a whole, 'hardware' is responsible for providing parts and tools to manufacturing companies, not as end-use industry-specific equipment. Nevertheless, we can not deny the important role of "small hardware" in the social production process: "small hardware" and manufacturing industry is intertwined with the inseparable whole.
Baidu Encyclopedia - Hardware