Types of Alnico Magnets
Alnico magnets are a type of permanent magnet made from the combination of aluminum, nickel and cobalt. They are available in isotropic or anisotropic forms with Neodymium (NdFeb) Pot Magnets.
These types of magnets are very strong and are used for sensor applications. They are also used in guitar pickups and loudspeakers.
1. Sintered Alnico
Alnico magnets are a popular choice for applications that require precision, such as tacho-generators and clocks. These magnets are made from a combination of aluminium, nickel and cobalt.
Typically, a mixture of these elements are ground into a powder and pressed under tonnes of pressure to form a die that closely resembles the shape desired by the customer. The powder is then sintered in a furnace heated to over 1200oC to fuse all of the pressed particles together.
Sintered Alnico magnets are the most common type of Alnico available and are used in a variety of industrial applications. They are generally stronger than cast Alnico and can be manufactured in larger quantities with a semi-automatic production process. They are also more durable and can be processed into a range of different shapes.
2. Cast Alnico
Alnico magnets as well as Neodymium magnets are made through either casting or sintering processes using a mixture of aluminum, nickel, and cobalt. Iron, copper, and titanium are also often added to enhance the magnetic properties of the final magnets.
Cast alnico magnets are formed by pouring a molten alloy into a mold and processing it through various heat-treat cycles. The resulting magnets have a rough exterior and may require further treatment, such as machining (grinding).
Sintered alnico magnets are produced by compacting fine alnico powder into a press, and then sintering the pressed material to form a strong magnet. The sintering process is suited to large production runs, and the resulting parts are structurally stronger than cast magnets.
Alnico magnets are characterized by excellent temperature stability, high residual induction, and relatively high energies. These properties make them useful in a variety of applications, including watt hour meters, instruments, and sensing devices.
3. Sintered Neodymium
Neodymium magnets are the strongest type of permanent magnet commercially available, and have a wide range of applications. They are widely used in power tools, motors, audio and video equipment, computers, electronics and household appliances.
Sintered neodymium magnets are manufactured using a powder metallurgy process. The raw materials are finely ground into particles and then pressed under enormous pressure into a die that closely resembles the desired shape.
These magnets are then heated and sintered in a furnace at over 1200oC to fuse the pressed particles together. This creates a strong, anisotropic magnet with a specific orientation that can be easily produced in a variety of shapes.
Neodymium magnets are prone to corrosion and require an outer coating or plating. These can be nickel-copper-nickel or epoxy depending on the application. They are also very brittle and must be treated with extreme caution.
4. Injection Molded Alnico
Injection molded Alnico magnets offer a combination of dimensional accuracy and magnetic properties unmatched by other types of custom magnets. They are manufactured by mixing a magnetic alloy (NdFeB, ferrite) with a plastic binder (typically nylon or PPS).
Injection Molding is the most commonly used process for producing custom magnets, especially those with complex shapes and thin walls. It is also a cost-effective and time-saving method of producing parts that require high volume production.
Custom manufacturer of injection molded neodymium iron boron (NdFeB) & samarium cobalt magnets for use in motors with Alnico magnets and other applications. Available in various remanences, coercive forces, intrinsic coercivities, energies and operating temperatures.
Serves the aerospace, automotive, medical and commercial industries. Services include engineering, designing, prototyping, system integration, fabrication, calibration and testing. Warehousing and JIT delivery available.
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