AlNiCo = AL - Aluminium, Ni - Nickel and Co - Cobalt The general composition of Alnico alloys is Aluminum- 8-12%, Nickel- 15-26%, and Cobalt- 5-24%. It may also contain up to 6% copper (Cu), and up to 1% titanium (Ti).
Alnico is made by a pressed powder process. First the mix of metal powders is pressed into a mold that is very close to the final shape. The resulting “green” magnet is then heated at around 1260 degrees Celsius in a hydrogen atmosphere to fuse the powder together. The magnets are actually structurally stronger than cast Alnico. Generally, Alnico magnets are small, weighing less than 30 grams.
What are the uses for AlNiCo? AlNiCo magnets are used in industrial and consumer applications where strong permanent magnets are needed; examples are electric motors, electric guitar pickups, microphones, sensors and loudspeakers.
Types of AlNiCo - Based on the process of preparation, and the different uses, AlNiCo alloys can be classified into three main Types: 1. Cast AlNiCo, 2. Sintered AlNiCo, 3. Bar AlNiCo
Development of AlNiCo - Began in japan in 1931. T. Mishima was the first person to discover the alloy of aluminum, nickel and cobalt. This discovery of AlNiCo was double the magnetic field strength at the time.
Facts: AlNiCo materials have low coercivities, so they are easily demagnetized. Quite costly as they contain both nickel and cobalt. AlNiCo materiel does not corrode.