Permanent Magnets Used in the Foundry Industry

Industrial Application of Magnets

Permanent Magnets are common items in our world today. But to a lot of people, what mostly comes to mind at the mention of magnets may be stickers on refrigerator doors or something that sticks together with metallic components. But there is a whole world of special magnets classified as industrial magnets out there. These types of magnets are found in electronics, such as audio speakers and telecommunication devices, sensors, generators, jewelry, and many other essential applications. Permanent magnets are typically made from neodymium and samarium cobalt, otherwise known as rare-earth magnets, ceramic magnets, electromagnets, and alnico magnets.

The Foundry Industry

Although not very common, one of the many important industrial applications of magnets today is in the foundry industry. The foundry industry is a branch of industry that produces castings by filling molds with molten alloys. It has grown steadily over the past decades to become a major focus when it comes to alloys, steel, and metal casting. With more than 100 million tonnes produced annually, the foundry industry attracts plenty of attention from manufacturers across the globe.

Metal Casting Process Image Source: Metal Museum

One major challenge faced by manufacturers in the foundry industry is the presence of ferric materials in alloy castings. This has given rise to the need for a more effective and economic way to eliminate the scrap iron components in important materials like aluminum castings. This will help to facilitate the production of higher-quality metal castings.

How Magnets are Used in the Foundry Industry

From medicine and additive manufacturing to casting and mining industries, permanent magnets are used in a wide variety of settings. In the foundry industry, magnets are used in the following ways.

Improved Aluminum Recycling

It has been found that trace elements of ferrous materials in secondary aluminum can make the final material brittle, and limit its use for high-value automotive or aerospace applications. Producers of aluminum casting take the issue of metallurgical quality quite seriously. Consequently, a researcher at the University of Birmingham, School of Metallurgy and Materials, Dr. Biao Cai, has developed a method for identifying and separating ferric materials from secondary aluminum using magnets and temporary gradients. Iron is usually detrimental to aluminum alloys, leading to the formation of intermetallic. Due to the concentration of iron in successive recyclings, it makes the recycled aluminum brittle which makes it not suitable for premium applications, such as aircraft. The invention of magnetic removal of the iron from aluminum casting makes it easy for manufacturers to produce premium aluminum castings at less cost. The existing methods for eliminating iron from aluminum during recycling are either very expensive or very effective.

Pressure-low Aluminum Casting Process

Cast aluminum is used for lightweight industrial construction; the low-pressure cast technology can be optimized by applying a magnetic field and short-circuit current at the end of the riser, just before the die ingress. This brings about the low-pressure process for aluminum casting. The magnetic field applied in the process is controllable, allowing for targeted influencing of the casting process. Permanent magnets can be used in this process.

Magnetic Separator for Machining and Foundry Process

Magnets are also applied in the production of various machining tools and devices for the foundry industry, as well as many machining processes. Magnetic separators are typically designed to enable the removal of tiny particles as small as 1 micrometer from liquids with high content of ferromagnetic contaminants. They are used for material testing and are capable of automatic cleaning to ensure high processing capacity. Magnetic separators also help in the minimization of costs needed for hazardous waste disposal in the foundry industry.

Types of Magnets Used In Metal Casting Process

In most cases, the best type of magnet applied in the foundry industry is the permanent magnet. Here are common examples of magnets used in the processes, such as aluminum casting.

• Ceramic or ferrite magnets
• Neodymium iron boron magnets
• Alnico magnets
• Samarium cobalt magnets
• Flexible magnets
• Injection-molded magnets

Finally, it should be noted that custom magnetic technology may be necessary for certain casting processes. This means that we could have a combination of two or more of these in a magnetic separator. This is to ensure maximum removal of unwanted components from the final products.

Conclusion

Thank you for reading our article and we hope it can help you to have a better understanding of how permanent magnets are used in the foundry industry. If you want to learn more about magnets, we would like to advise you to visit Stanford Magnets for more information. As a leading magnet supplier across the world, Stanford Magnets has been involved in the R&D, manufacturing, and sales of magnets since the 1990s. It provides customers with high-quality permanent magnets like SmCo magnets, neodymium magnets, AlNiCo magnets, and ferrite magnets (ceramic magnets) at a very competitive price.