How to choose the coating of NdFeB magnets?

The coating of NdFeB magnets is to add a protective layer on the surface, which plays the role of anti-corrosion, anti-rust, and prolonging the service life. There are three most common coatings for NdFeB magnets, namely zinc plating, nickel plating, and epoxy coating.

1 In terms of price, galvanized coating is extremely advantageous, and the prices are ranked from low to high as zinc, nickel, and epoxy coatings.

2 After the nickel-plated surface treatment, the corrosion resistance of the magnet is higher, up to 96H salt spray without rusting, while the galvanized coating can only achieve 48H salt spray without rusting. Now the commonly used nickel-copper- Nickel plating method can achieve 120-200 hours of salt spray without rusting.

3 Compared with nickel plating, zinc plating has different surface coatings and different corrosion resistance, and its service life is lower than that of nickel plating. After a long time, the surface plating will easily fall off, causing the magnet to oxidize, thereby affecting the magnetic force.

4 Nickel plating is better than galvanizing in polishing, and the color is brighter. For those with high requirements on product appearance, nickel plating is generally selected. For some non-exposed magnets, galvanizing treatment is enough.

5 Epoxy resin coating: As the name implies, it is to add a layer of resin paint to the outside after nickel plating. In recent years, it has developed rapidly, and many buyers choose it. The advantage is that it can achieve the color you want.

No matter what kind of coating it is, it has its advantages, and the one that best meets your needs is the best.

How to easily distinguish between hard magnetic and soft magnetic?

Magnetic materials are now mainly divided into two categories, one is soft magnetic materials, the other is hard magnetic materials (permanent magnetic materials).

Soft magnetic material: high permeability, easy to be magnetized and easy to demagnetize. In the saturation state, the magnetic flux is large, the coercivity (Hc) is small, the total area of the hysteresis loop is narrow and long, and the loss is small (the total area of HdB is small). Contains magnetic pure iron, silicon steel sheet, (Fe, Ni) ferrite core, etc.

They are suitable for automotive relays, motors, transformer skeletons and magnetic rings of various high-frequency magnetic induction components.

Soft magnetic materials are easy to be magnetized and easy to demagnetize, and their main functions are magnetic conductivity, conversion and transmission of electromagnetic energy, and are widely used in various electrical energy conversion equipment. 

Soft ferrite is the most used in inductance components. Soft ferrite is a kind of composite oxide. It is a composite body sintered by some metal oxides through a ceramic process. It is higher than metal materials, so the eddy current loss is extremely small, and it can work under high frequency conditions. However, because the electromagnetic characteristics are affected by temperature, it is not suitable for high-power electromagnetic devices, and it is only suitable for working under medium-high-frequency and low-power conditions.

Hard magnetic material: large magnetic energy product (Hc) (>102A/m), large magnetic loss Br, large total area of hysteresis loop, and large loss. Such as tungsten steel material, carbon steel, AlNiCo alloy, etc. After being magnetized, it can maintain strong magnetism for a long time, and is suitable for making permanent magnets in magnetoelectric watt-hour meters, electromagnets in mobile phone earphones, and rare earth permanent magnet speakers.

At present, our factory produces hard magnetic materials, that is, permanent magnet materials, including AlNiCo, SmCo, ferrite and NdFeB. Among them, the most expensive is SmCo magnet, and the cheapest is ferrite.The one with the highest performance is the NdFeB magnet, but the one with the most stable performance and the best temperature coefficient is the AlNiCo magnet.You can choose different hard magnetic products according to different needs.


Those household magnets you didn't know about

Magnet is used in many places in the home, it is actually in every corner of our life, but we do not find it.

Why is it so widely used? Because a lot of electrical appliances if there is no magnet, there is no way to work, I will introduce some common products to you from several aspects, you can have a look!


1. Microwave magnet: Almost every family has a microwave oven, which brings a lot of convenience to our daily life, but have you ever thought that the magnet plays a very important role in the microwave oven?

Normally, microwave ovens have two magnets in the magnetron that guide electrons to heat food.


2.Magnetic Knife Holder: Proper placement of sharp kitchen utensils, such as knives and forks, is a constant headache for many people. We all know that keeping a sharp knife in a drawer is very dangerous. Magnet manufacturers tell you that with the help of magnets, sharp knives and forks can be safely fixed to the wall of the knife holder.


3.Speaker magnets: Speakers are one of the most important pieces of equipment in our home audio system. You can find magnets in all speakers. Magnets can interact with coils in the speaker to produce sound. To produce a powerful sound, some small, powerful speakers use neodymium magnets.


4.Treadmill Magnets: Treadmills are a great choice for home exercise equipment. When we run on a treadmill, a magnet passes through a sensor to count revolutions as the machine moves.And convert it into distance information.


5.Laptop Magnets: Many of the gadgets in our regular laptops use magnets. Magnets, for example, are used in laptop speakers and small fan motors. In addition, you can find a magnet on the laptop's hard drive (usually on the lid) so that the computer can know whether the lid is open or closed.


6.Telephone magnets: We often use magnets on our mobile phones, while microphones and speakers use small magnets to capture and produce sound.


7.Handbag Magnets: Many girls like handbags not only because they are useful, but also because they are a fashion statement. Handbags are known for their use of magnets. These magnets can be assembled easily because of magnetism.


The magnet of vacuum cleaner: The magnet is also one of the important parts of vacuum cleaner. A vacuum cleaner works by using an electric motor to drive the blades to spin at high speed and generate negative pressure air in a sealed housing to collect dust. Vacuum cleaners' motors use powerful neodymium magnets to generate high suction.