Alloy is a macroscopically homogeneous metal material consisting of a mixture of two or more chemical elements with a predominance of metal components .
Alloys consist of a base (one or several metals), small additives specially introduced into the alloy of alloying and modifying elements, and also of non-removed impurities (natural, technological and random).
Alloys are one of the main structural materials. Among them, the most important are alloys based on iron and aluminum . The technique employs more than 5 thousand alloys.
Content
- 1 Types of alloys
- 2 Alloy properties
- 3 Alloys used in industry
- 4 Literature
- 5 Links
Types of alloys
According to the method of manufacturing alloys, cast and powder alloys are distinguished. Cast alloys are obtained by crystallization of the melt of mixed components. Powder - by pressing a mixture of powders, followed by sintering at high temperature. The components of a powder alloy can be not only powders of simple substances , but also powders of chemical compounds . For example, the main components of carbides are tungsten or titanium carbides .
According to the method of obtaining the workpiece (product), there are foundry (for example, cast iron, silumins), wrought (for example, steel) and powder alloys.
In the solid state of aggregation, the alloy can be homogeneous (homogeneous, single-phase - consists of crystallites of the same type) and heterogeneous (heterogeneous, multiphase). Solid solution is the basis of the alloy (matrix phase). The phase composition of a heterogeneous alloy depends on its chemical composition. The alloy may contain: interstitial solid solutions , solid solutions of substitution , chemical compounds (including carbides, nitrides, intermetallic compounds) and crystallites of simple substances .
Alloy Properties
The properties of metals and alloys are completely determined by their structure (crystalline phase structure and microstructure). The macroscopic properties of alloys are determined by the microstructure and always differ from the properties of their phases , which depend only on the crystal structure. Macroscopic homogeneity of multiphase ( heterogeneous ) alloys is achieved due to the uniform distribution of phases in the metal matrix. Alloys exhibit metallic properties, for example: electrical conductivity and thermal conductivity , reflectivity (metallic luster) and ductility. The most important characteristic of alloys is weldability.
Alloys used in industry
Alloys are distinguished by purpose: structural, tool and special.
Structural alloys:
- become
- cast iron
- duralumin
Structural with special properties (for example, intrinsic safety, antifriction properties):
- bronze
- brass
For filling bearings:
- babbit
For measuring and electric heating equipment:
- manganin
- nichrome
For the manufacture of cutting tools:
- will win
The industry also uses heat-resistant , low-melting and corrosion - resistant alloys, thermoelectric and magnetic materials , as well as amorphous alloys .
- Zeygerovanie
- Metal construction
- ASM International
- Materials Science
- Metal science
- Steel
- Metals
Literature
- Lakhtin Yu.M. Metallurgy and heat treatment of metals: Textbook for universities. - 3rd. - M .: Metallurgy, 1983 .-- 360 p.
- Geller Yu.A. , Rakhstadt A.G. Materials Science. - M .: Metallurgy, 1975 .-- 445 p.
- Kolachev B.A. , Livanov V.A. , Elagin V.I. Metallurgy and heat treatment of non-ferrous metals and alloys. - M .: Metallurgy, 1972. - 480 p.
Links
- Fusion - an article from the Great Soviet Encyclopedia .
- Alloys - an article from the Chemical Encyclopedia
- Alloys - an article from the Physical Encyclopedia
- Alloys - an article from the Encyclopedia "Around the World"
- Alloys on the site XuMuK.ru