Raw Material Preparation:

The production of Alnico magnets begins with gathering and preparing the raw materials, which typically include:

• Aluminum (Al)
• Nickel (Ni)
• Cobalt (Co)
• Iron (Fe)
• Copper (Cu)
• sometimes small amounts of other elements like titanium (Ti).

These materials are selected and measured based on the desired composition of the final magnet, which can vary depending on the specific application requirements.

Alloying Process:

The prepared raw materials are then melted together in a furnace under controlled conditions. This process is crucial to ensure thorough mixing and alloying of the metals to achieve the desired composition.

The alloying process typically involves:

• Melting: Heating the raw materials to their melting points to form a homogeneous molten alloy.
• Alloy Adjustment: Fine-tuning the alloy composition to meet specific magnetic and mechanical properties required for the application.

Forming Process:

Once the alloy is properly mixed and adjusted, it is formed into the shape of the magnet. There are two primary methods for forming Alnico magnets:

Casting Process:

• Mould Preparation: The molten alloy is poured into moulds that are shaped according to the final magnet design. These moulds can be made of steel or other materials capable of withstanding the high temperatures involved.
• Cooling and Solidification: After pouring, the alloy cools and solidifies within the moulds, taking the shape of the mould cavity. This process allows for complex shapes and precise dimensions to be achieved.

Sintering Process:

• Powder Preparation: Alternatively, the alloy can be processed into fine powder form through crushing and milling operations.
• Pressing: The powdered alloy is then compacted into a green compact using a press. This step applies pressure to the powder to form a solid shape, which is still fragile but retains the magnet's structure.
• Sintering: The green compacts are heated in a furnace at temperatures typically ranging from 1,000 to 1,300°C. During sintering, the particles within the compact bond together without melting, forming a dense and strong magnet structure.

Heat Treatment Process:

After forming, Alnico magnets often undergo a heat treatment process called ageing. Ageing involves heating the magnets to a specific temperature and then cooling them in the presence of a magnetic field. This process helps to optimize the magnetic properties of the magnets, improving their strength and stability.

Machining and Finishing Process:

Once the magnets are fully processed, they may undergo additional machining operations to achieve the final desired dimensions and surface finishes. This can include cutting, grinding, and polishing to ensure the magnets meet precise tolerances and surface quality standards.

Surface Coating Process:

To protect against corrosion and enhance durability, Alnico magnets may be coated with a layer of protective material. Common coatings include nickel, epoxy, or other specialized coatings depending on the application requirements.

Quality Control Process:

Throughout the manufacturing process, rigorous quality control measures are implemented to ensure that the Alnico magnets meet the required specifications and standards. This includes testing the magnetic properties, dimensions, and surface conditions of the magnets before they are packaged and shipped to customers.