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Alnico alloys are composed primarily of aluminium, nickel and cobalt (hence the term al-ni-co) with the addition of iron, copper, and sometimes titanium. Alnico alloys make strong permanent magnets. They can be magnetized to produce strong magnetic fields. Of the more commonly available magnets, only rare-earth magnets such as neodymium and samarium-cobalt are stronger. Alnico magnets produce magnetic field strength at their poles as high as 1500 gauss (0.15 tesla), or about 3000 times the strength of Earth's magnetic field. Alnico alloys have some of the highest Curie points of any magnetic material, around 800 °C. This property, as well as its brittleness and high melting point, is the result of the strong tendency toward order due to intermetallic bonding between aluminium and its other constituents. Some types of Alnico are isotropic, meaning they can be efficiently magnetized in any direction. Other types, such as Alnico 5 and Alnico 8, are anisotropic, meaning that they have a preferred direction of magnetization, or orientation. Anisotropic alloys generally have greater magnetic capacity in their preferred orientation than isotropic types. Anisotropic Alnico magnets are oriented by heating them above a critical temperature, and cooling them in the presence of a magnetic field. • = Magnet is painted red and has a keeper. All dimensions approximate and as cast with pole faces ground smooth. Unless otherwise specified, our tolerances on alnico material meet and often exceed International Magnetics Association (IMA, formerly MMPA) standards. For unfinished surfaces (as cast) the following tolerances apply: Finished surfaces are normally ground to ± .005 (See MMPA standards for more details.) Alnico is a very hard and brittle material and does not lend itself to conventional machining. The Magnet Source™ employs experienced machinists and the proper equipment to grind alnico to its required dimensions. Attributes of Cast Alnico Material * Size parameters range from 1 ounce to about 70 pounds * Will cast to a variety of shapes and sizes Attributes of Sintered Alnico Material * Size parameters range from about one ounce of material up to one cubic inch * Pressed to close tolerance/minimal grinding to finish * Mechanically strongest of alnico Attributes of Both Cast and Sintered Alnico * Very temperature stable, great for high heat applications * Maximum working temperature 975° - 1020° F * Does not lend itself to conventional machining (hard and brittle) * High residual induction and energy product compared to ceramic material * Low coercive force compared to ceramic and rare earth materials (more subject to demagnetization) * Most common grades of alnico are 5 and 8 Applications of Alnico Magnets Normal* Maximum Operating Temp. (We do not proofread any ads submitted by members) |
tmitchell@desmoines-classifieds.com (Ted Mitchell) for more information. Your emails will be instantly forwarded to the poster's private address.
