What is a laminated magnet?

Magnetism is an invisible force of attraction and repulsion that has fascinated mankind for centuries. Its applications range from the ancient compass to cutting-edge technologies such as MRI machines and electric motors. In recent years, a new advancement in the field of magnetic materials has emerged - laminated magnets. These innovations combine the fundamentals of magnetism with the benefits of laminated structures, ushering in a new era of efficient and customisable magnetic solutions. In this article, we will delve into the world of laminated magnets, exploring their composition, benefits and applications.

Magnetism Basics

Before we delve into the intricacies of laminated magnets, let's review the basics of magnetism. Essentially, magnetism is the result of the arrangement of magnetic domains within a material. These magnetic domains consist of clusters of atoms, each with its own magnetic moment. In an unmagnetised material, these magnetic domains are randomly oriented, resulting in no net magnetic field. However, when most of these magnetic domains are aligned in the same direction, a magnetic field is created, resulting in a magnet.

Conventional magnets are usually made of materials such as iron, nickel and cobalt, which are highly magnetic. These materials can be magnetised by various methods, such as exposing them to a strong external magnetic field or subjecting them to a specific temperature.

What are laminated magnets?

Laminated magnets, also known as laminated composite magnets, represent a unique departure from traditional magnet manufacturing techniques. Rather than relying solely on the inherent properties of the magnetic material, laminated magnets use a layered composite structure to enhance their magnetic properties.

Key components of laminated magnets:

Magnetic Layers: The core of a laminated magnet consists of multiple layers of magnetic material, typically ferromagnetic or subferromagnetic. These layers are carefully designed to optimise magnetic properties such as strength and coercivity.

Non-magnetic insulating layers: between the magnetic layers are non-magnetic insulating layers. These layers serve several important purposes, including preventing magnetic short circuits, controlling eddy current losses, and enabling customisable designs.

Adhesive: The adhesive bonds the layers together and ensures the structural integrity of the laminated magnet. The choice of adhesive affects the overall performance of the magnet.

Benefits of Laminated Magnets

Incorporating a laminated structure into a magnet offers several distinct advantages over traditional monolithic magnets:

Reduced Eddy Current Loss: One of the main advantages of laminated magnets is the ability to mitigate eddy current losses. Eddy currents are induced electrical currents that circulate within a magnetic material when exposed to a changing magnetic field. In conventional magnets, these currents can lead to significant energy losses in high frequency applications. Laminated magnets have a non-magnetic insulating layer that effectively suppresses eddy current losses, making them very efficient in applications such as electric motors and generators.

Customisable magnetism: Laminated magnets offer greater flexibility in tailoring magnetism to specific requirements. By adjusting the thickness and composition of each layer, engineers can optimise magnetic field strength, coercivity and other characteristics to suit a wide range of applications.

Improved thermal performance: The layered structure of laminated magnets also enhances their thermal performance. The insulating layers act as a thermal barrier, reducing heat transfer between the magnetic layers. This makes laminated magnets ideal for applications in high-temperature environments, such as electric vehicle motors and renewable energy systems.

Enhanced Mechanical Strength: Laminated magnets exhibit higher mechanical strength and resilience than conventional magnets. The layered structure can withstand mechanical stress and vibration more effectively, extending the life of the magnet.

Stacked magnets represent a major breakthrough in the field of magnetic materials. Their composite structure combines magnetic and non-magnetic layers and offers significant advantages such as reduced eddy current losses, enhanced thermal performance and customisable magnetic properties. These properties have led to widespread adoption in key industries such as power transport, renewable energy and medical technology. As researchers and engineers continue to innovate in this field, we can expect laminated magnets to play an increasingly important role in shaping the technologies of the future, providing efficient, customised magnetic solutions for a wide range of applications.