Ferrite magnets are significantly less expensive than neodymium and samarium cobalt magnets. For example, an anisotropic ferrite magnet costs (5 - )15 per kilogram, while a standard grade neodymium magnet costs (80 - )120 per kilogram (5 - 24 times more expensive) and a standard grade samarium cobalt magnet costs (300 - )400 per kilogram (20 - 80 times more expensive). This makes ferrite magnets the preferred choice for applications where cost is the primary consideration and high magnetic performance is not required.

However, ferrite magnets have lower magnetic properties than neodymium and samarium cobalt magnets, which limits their use in high-performance applications. For example, a ferrite magnet has an energy product of 1 - 5 MGOe, compared to 28 - 52 MGOe for neodymium magnets and 20 - 30 MGOe for samarium cobalt magnets. This means that ferrite magnets are larger and heavier than neodymium or samarium cobalt magnets for the same magnetic performance, which can be a disadvantage in applications where size and weight are critical (such as EVs, electronics, and aerospace components).

Ferrite magnets also have lower coercivity than neodymium and samarium cobalt magnets, making them more susceptible to demagnetization in the presence of external magnetic fields or high temperatures. This limits their use in applications where high resistance to demagnetization is required, such as industrial motors and medical devices.

Alnico Magnets

Alnico magnets are a type of permanent magnet composed of aluminum (Al), nickel (Ni), cobalt (Co), and iron (Fe), with small amounts of other elements such as copper (Cu) and titanium (Ti) added to improve their properties. They have a high remanence (the magnetic flux density remaining after the removal of an external magnetic field) and good thermal stability, but a lower coercivity compared to neodymium and samarium cobalt magnets. Alnico magnets are available in two main manufacturing processes: cast alnico magnets (produced by casting the alloy into a mold) and sintered alnico magnets (produced by pressing and sintering the alloy powder). Cast alnico magnets have higher magnetic properties, while sintered alnico magnets have better dimensional accuracy and are more suitable for small, complex-shaped magnets. Alnico magnets are commonly used in applications such as sensors, meters, loudspeakers, and high-temperature industrial equipment.

Cost Composition of Alnico Magnets

The cost composition of alnico magnets is influenced by the cost of their raw materials and manufacturing processes. The main raw materials used in alnico magnets are nickel, cobalt, aluminum, and iron. Nickel and cobalt are the most expensive raw materials, with nickel prices ranging from (20 - )30 per kilogram and cobalt prices ranging from (30 - )80 per kilogram (as mentioned earlier). Aluminum is relatively inexpensive, with prices ranging from (2 - )3 per kilogram, and iron is also inexpensive, with prices ranging from (0.50 - )1.00 per kilogram.

Raw material costs account for 30 - 50% of the total cost of alnico magnets. This is higher than the proportion for ferrite magnets (10 - 20%) but lower than that for samarium cobalt magnets (50 - 70%) and comparable to that for neodymium magnets (40 - 60%). The exact proportion depends on the composition of the alnico magnet, with higher cobalt content leading to higher raw material costs. For example, a high - cobalt alnico magnet (containing 20 - 25% cobalt by weight) will have higher raw material costs than a low - cobalt alnico magnet (containing 10 - 15% cobalt by weight).

Manufacturing costs are the second - largest component of the total cost of alnico magnets, accounting for 30 - 40% of the total cost. The manufacturing process for alnico magnets varies depending on whether they are cast or sintered, and both processes have unique cost implications.

Cast alnico magnets are produced by melting the alloy in a furnace (typically at temperatures around 1,600 - 1,700°C), pouring the molten alloy into a mold, and allowing it to cool and solidify. After solidification, the cast magnets undergo heat treatment to enhance their magnetic properties. The casting process requires specialized molds, which can be expensive to manufacture, especially for complex - shaped magnets. Additionally, the melting process is energy - intensive, and the heat treatment step (which involves heating the magnets to 800 - 900°C and then cooling them in a magnetic field to align the magnetic domains) adds to the manufacturing cost. Cast alnico magnets also require extensive machining after casting to achieve the desired dimensions and surface finish, as the casting process often results in dimensional inaccuracies and surface defects. This machining process is time - consuming and requires specialized equipment, increasing the manufacturing cost.

Sintered alnico magnets are produced by mixing the alloy powder, pressing the powder into a green compact, and sintering the compact at a high temperature (around 1,200 - 1,300°C). The sintering process is less energy - intensive than the casting process, and the pressed green compacts have better dimensional accuracy, reducing the need for post - sintering machining. However, the production of high - quality alnico powder requires specialized milling equipment, and the pressing process requires precise control of pressure to ensure uniform density in the green compact. These factors contribute to the manufacturing cost of sintered alnico magnets.

Overall, cast alnico magnets typically have higher manufacturing costs than sintered alnico magnets due to the complexity of the casting process and the need for extensive machining. However, cast alnico magnets have higher magnetic properties, making them more suitable for high - performance applications where their higher cost can be justified.

Energy costs account for 5 - 10% of the total cost of alnico magnets, which is similar to the proportion for samarium cobalt magnets and lower than that for neodymium and ferrite magnets. The energy - intensive steps in the manufacturing process, such as alloy melting for cast alnico magnets and sintering for both cast and sintered alnico magnets, are the main contributors to energy costs. The exact proportion depends on the manufacturing process, with cast alnico magnets having higher energy costs due to the higher melting temperature.

R&D costs account for 5 - 10% of the total cost of alnico magnets, as manufacturers invest in improving the magnetic properties, reducing the manufacturing cost, and developing new applications for alnico magnets. Overhead costs, including administrative costs, marketing costs, and transportation costs, account for the remaining 5 - 10% of the total cost.