Alnico Magnet

AlNiCo magnets are iron-based permanent magnets which are composed primarily of Aluminum (Al), Nickel (Ni) and Cobalt (Co). They also include iron (Fe), copper (Cu) and sometimes titanium (Ti). During production, isotropic and anisotropic magnets can be manufactured with different magnetic properties. They have substantial magnetic stability against temperature influences (up to 500 °C) and a high remanence level.

Chemical resistance

Permanent AlNiCo magnets have an high level of corrosion resistance and are also resistant to oil, organic solvents, petrol and alcohol; they have a limited resistance to acetic acid, organic acids with a concentration level of < 10 %; they are not resistant to inorganic acids, salt water, citric acid, tartaric acid, strong alkaline solutions.

Cast Alnico magnet - Sintered Alnico Magnet

Cast Alnico & Sintered Alnico Magnet

There are two production methods for AlNiCo magnets, one is cast AlNiCo, which uses a melting furnace to melt aluminum, nickel, cobalt, copper, titanium, iron, and other raw materials into molten steel, pour it into a sand mold to complete the shape, and then use the heat treatment process to manufacture properties and meet the size requirements through wire cutting, grinding, and other processing methods. The other is sintered AlNiCo, using a powder metallurgy process, the raw materials are mixed in the form of powder, then shaped by a press machine, and then sintered in a vacuum sintering furnace, and then the performance is manufactured through heat treatment and the size requirements are achieved through wire cutting, grinding, and other processing methods.

Cast Alnico Magnet Sintered Alnico Magnet

Alnico magnet Grades

There are several standards for the magnetic properties of alnico magnets, one is the North American standard MMPA, the British standard IEC 60404-8-1 commonly used in Europe, and the standard used in China.

Alnico Magnet Grades

Alnico Magnet Production Process

There are two production methods for AlNiCo magnets. Casting AlNiCo magnets is formed by melting materials in a sand mold, while sintered AlNiCo is a powder metallurgy process that is formed by a press and sintered in a vacuum sintering furnace.

Cast Alinco Process Sintered Alnico Process

Working Temperature and Temperature Coefficient

AlNiCo magnets are characterized by the lowest temperature coefficient of -0.02 % per Kelvin thus enabling a constant magnetic field even in case of considerable changes of temperature (operating temperatures between -270 °C up to +550 °C are possible without generating metallurgical modification).

Temperature