Round magnets are objects that produce a magnetic field, acting as a magnetic dipole, capable of attracting ferromagnetic materials such as iron, nickel, and cobalt. Round magnets can be a natural product, also known as natural magnetite, or they can be artificially manufactured. Temporary magnets only exhibit magnetism under certain conditions. Let's discuss the aspects of handling round magnets.

One: Conversion Film

The conversion coating of round magnets mainly includes phosphatization and passivation coatings. Since conversion coatings serve as intermediate protection layers, they are intended for long-term use. Many products may exhibit flash rusting phenomena as a result.

Electroplating

The electroplating of round magnets primarily involves nickel and zinc plating.

Nickel plating is categorized based on the structure of the coating, including single nickel, double nickel, and nickel-copper-nickel types; and according to the appearance color, into dark nickel, semi-polished nickel, and bright nickel. Generally, bright nickel and semi-polished nickel, which are nickel-copper-nickel coatings, are most common. The advantages of nickel plating include better wear resistance and environmental durability. The drawback is that nickel layers are ferromagnetic materials, which can be affected by magnets, especially noticeable in thin and small products. An improvement involves using some copper layers instead. Chemical nickel and electroplated nickel-phosphorus alloys have weaker ferromagnetism, but they are麻烦 to strip, and thus are not commonly used as mainstream coatings. Chemical nickel is relatively more uniform than electroplated nickel in terms of layer thickness, but it cannot be directly plated onto neodymium-iron-boron substrates. Moreover, chemical nickel requires large amounts of complexing agents and reductants, has a short bath life, low plating driving force, and high energy consumption, making it unsuitable as a mainstream coating.

III. Coating

The coatings referred to here include electro-phoresis, spraying, brushing, and dipping processes, excluding vapor coatings. The most common coatings are epoxy paint coatings, followed by Everlube, Teflon, and chrome-free Dacromet coatings. The epoxy coatings vary in salt spray resistance, hardness, and color due to different types of paints.