Alnico magnets were the strongest permanent magnets that existed until the introduction of rare earth magnets and, although somewhat displaced, Alnico magnets are still commonly used in various industries for specific jobs such as high temperature handling equipment and sensor manufacturing, among others.
Alnico magnets have long life, excellent temperature stability, high residual induction and relatively high energies due to their composition, a combination of aluminium (al), nickel (ni) and cobalt (co).
This development and introduction of Alnico meant that expensive electromagnets could be replaced with these permanent magnets in essential devices such as motors and generators. But despite not having the prominence of years ago, Alnico magnets still perform better than their successors in specific situations and, therefore, are still used for many applications that require a very high temperature concentration such as;
In addition, Alnico magnets are widely used in rotary machinery, meters, instruments, detection devices and retention applications, to name a few.
It should be noted that Alnico is hard and brittle. Therefore, machining or drilling cannot be done by ordinary methods. Holes are usually drilled in the foundry, magnets are molded near the final size and then machined to closer tolerances.
Likewise, Alnico magnets have high magnetic resistance and low resistance to demagnetization and remagnetization.
|Main elements of the Alnico||Percentage in weight|
|Aluminium (Al)||6% – 13%|
|Nickel (Ni)||13% 26%|
|Cobalt (Co)||0% – 42%|
|Copper (Cu)||2% – 6%|
|Titanium (ti)||0% -9%|
|Niobium (Nb)||0% -3%|
|Iron (Fe)||Balance (e.g. 30% -40%)|