How Magnets for MRI Machines Are Made

How Magnets for MRI Machines Are Made

Blog Article

The manufacturing process for magnets begins with the sourcing of raw materials. In the case of rare earth magnets such as neodymium magnets, this involves mining rare earth elements like neodymium, praseodymium, and dysprosium. These elements are typically extracted from mineral ores such as monazite or bastnasite, most commonly found in regions like China, Australia, and the United States. Once the ore is mined, it undergoes a series of chemical treatments and separations to extract the desired rare earth elements in pure form. These raw materials are then alloyed with other metals to create the desired magnetic properties.

Once the alloy is prepared, it is melted and cast into ingots. These ingots are then ground into a fine powder using a technique called hydrogen decrepitation. This powder is then subjected to a process known as sintering, which involves pressing the powder into molds under high pressure and then heating it in a controlled environment. This step allows the powder particles Plate Magnets to fuse together into a solid mass without melting, preserving the material’s crystalline structure and magnetic properties. The resulting blocks are called sintered magnets and can be machined or cut to the desired shape and size.

Magnetic orientation is another crucial step during manufacturing. This involves aligning the magnetic domains in the material in a specific direction before or during the sintering process. Applying a magnetic field at this stage allows the final product to achieve maximum magnetic performance in the desired direction. In some methods, the orientation is done during compaction, while in others, it is applied immediately after the material is pressed. The orientation process is vital because it determines the magnet’s strength and stability in real-world applications.

After sintering and orientation, the magnets are often brittle and require precision machining. Cutting, grinding, and shaping are done using diamond-coated tools to ensure accuracy while preserving the magnet's strength. Because magnets are hard and fragile, this step requires careful handling and advanced equipment. Any mechanical stress can lead to micro-cracks or loss of magnetization, so precision and experience are essential.