Permanent magnet Alnico is an iron alloy, in addition to iron, aluminum (Al), nickel (Ni), cobalt (Co) and a small number of other magnetic enhancement components are added.
The English term "Alnico" is a combination of the element symbols of the three main additions.
The alloy was coercivity and at high Curie temperature.
The al - Ni - Co alloy is hard and brittle and cannot be cold worked, but must be made through a casting or Sintering process.
Aluminum-nickel-cobalt alloy can generate magnetic fields up to 0.15 Tesla.
An example of an intermediate anisotropic aluminum-nickel-cobalt alloy, alnico-6 consists of 8% Al, 16% Ni, 24% Co, 3% Cu, 1% Ti, and the rest is Fe.
The maximum magnetic energy product (BHmax) of Alnico-6 was 3.9 Megagauss-Oesteds (MG·Oe), the remanent was 780 Oersted, the Curie temperature was 860 °C, and the maximum operating temperature was 525 °C.
In 1931, Mishima, a Japanese materials expert, discovered an aluminum-nickel-cobalt alloy (58% Fe, 30%Ni, 12%Al) with a very high level of coercion, twice as high as the best magnetic steel of the period.
 Prior to the discovery of rare earth magnets in the 1970s, aluminum-nickel-cobalt alloy was the strongest permanent magnet material.