Alnico is an alloy produced by mixing aluminum, nickel and cobalt with certain addition of other metals like copper, iron and titanium. Capable of producing strong magnetic field, it has an excellent linear temperature characteristics and has wide industrial applications.
Types of Alnico Magnets
On the basis of manufacturing process and application alnico can be grouped into following types:
- Cast Alnico
- Sintered Alnico
- Bar Alnico
Alnico magnets can be fabricated into many shapes and types:
- Alnico horseshoe magnets
- AlNiCo rod magnets uncoated
Features & Characteristics of Alnico Magnets:
Alnico magnets are used primarily in technical applications, where temperature stability is critical.
Characteristics: Excellent for high temperature applications up to 1,000°F, high residual induction, and corrosion resistant. Cast alnico magnets can also be produced in relatively complex shapes.
Sizes and Shapes: Discs, Rods, bars, and horseshoes.
Applications: Commonly used in Meters, and for specialized holding, high-temperature applications.
Alnico magnet alloy is largely comprised of Aluminum, Iron, Cobalt and Nickel. Alnico is a moderately expensive magnet material because of the Cobalt and Nickel content. Alnico magnet alloy has high maximum operating temperature and very good corrosion resistance. Magnets made with this alloy are available in a variety of grades and dimensions and are usually cast and finish ground to size. Alnico magnet material is an older technology and it has a rather low Energy Product (BHmax). Alnico magnet alloy is now mainly used in military, aerospace, older proprietary designs and in applications where the magnet will be exposed to elevated temperatures.
- What are the main characteristics of alnico magnets? Alnico magnets offer high magnetic strength, energies but low coercivities. They are less brittle than Rare Earth magnets, are highly resistant to corrosion, have excellent temperature stability and can be used at very high temperatures. Manufactured through either a casting or sintering process, they can be made into complex shapes (such as horseshoe shapes) that are not possible with other magnet materials.
- What grades & shapes are available for alnico magnets? Grades 5 and 8 are the most commonly used Alnico grades. Non-standard shapes can be custom fabricated to blueprint specifications from raw stock in sintered, or cast forms, & we can custom manufacture virtually any shape & size to meet your specialty requirements. Send us a request for quote, and we'll work with you to determine the most economical way to manufacture your specialty project.
- Are there machining constraints for alnico magnets? Alnico magnets are hard and brittle, and prone to chipping & cracking. They require very careful machining & it is not generally recommended that these materials be used for structural or decorative purposes. Machining or drilling cannot be accomplished by ordinary methods. Cutting & grinding should be done prior to magnetizing. Holes must be made by EDM methods. We are fully equipped to machine these materials to your blueprint specifications.
- What are some common applications for alnico magnets? Instrumentation, meters, microwave devices, actuators, holding devices, sensors, are among the most common applications for Alnico magnets. (top)
- Do alnico magnets require surface treatments? Alnico magnets do not typically require a protective coating or plating since they exhibit excellent resistance to corrosion.
- What are some safety precautions that should be taken into consideration when working with alnico magnets? Special care should be taken to assure that these magnets are not subjected to adverse repelling fields, since these could partially demagnetize the magnets. If Alnicos are partially demagnetized, they may be easily re-magnetized.
- What is a permanent magnet? Permanent magnets represent the majority of magnetic materials available today. A permanent magnet is made from ferromagnetic materials, which have magnetic fields that do not turn on and off like electromagnets. We carry a large stock inventory of permanent magnets; neodymium, alnico, ceramic (ferrite) and samarium cobalt, in a wide range of sizes, shapes and grades.
- Alnico's are the strong magnets which can produce strong magnetic fields.
- Excellent resistance to corrosion
- They have superior thermal stability
- These magnets have some of the highest curie points of any magnetic material ranging around 800oC
- Some type of Alnico's are isotropic
- They have high magnetic flux density
Alnico magnets have applications in the following areas:
- Electric motors
- Electric guitar pickups
- Cow magnets
- Automotive and electronic sensors
- Hall effect sensors
- Reed switches
- TWT aomplifiers
Casting or sintering process is applied for making alnico magnets. The first step involves the pouring of molten metal alloys into moulds. Later it is passed through various heat cycles. The resultant magnets have rough surface which after machining gives a glossy look. Sintered magnets are produced by compacting fine alnico powder in a press, and then sintering the compacted powder into a solid magnet. Alnico magnets can only be magnetized only in the field having magnetizing fields of about 3 kOe. Since these magnets have low coercivity they, must be protected from the adverse repelling fields as this could partially demagnetize the magnets.
After the tolerance magnetizing is effected. As alnico magnets are brittle, they must be protected from hard blows and handled with care. It should be magnetized in a proper magnetic field and must be prevented from the repelling fields as it is prone to demagnetization.
Who supplies high quality Alnico Magnets?
Magnosphere offers best priced Alnico magnets globally to all industries, including Automotive, Aerospace, Military, Advertising, Design House, Electronic and Academic/R&D. Please inquire for custom Neodymium magnets or magnetic assembly.
Buy Magnets and Magnet Material at Magnosphere and get a better deal!
We can also custom manufacture these to fit your exact specifications using our in-house global manufacturing facilities and team of experienced engineers. Need high quantities of magnets at the lowest and fairest price possible? Just let us know what you are looking for and contact our Customer Care Team by sending us a request for quote! We'll work with you to determine the most economical way of providing you with what you need.