Characteristics of Neodymium Magnets – This type of magnet achieves the highest magnetic energy of all permanent magnets now in practical use. The main phase of the magnetism of rare-earth magnets developed conventionally was a two-component alloy. However, neodymium magnets combine neodymium with iron and boron to constitute a three-component, anisotropic-sintered rare-earth magnet with an atomic ratio of Nd 2 Fe 14 B 1.
The neodymium magnet exhibits excellent performance in terms of size reduction, thinning, weight reduction and enhancing the efficiency of applied equipment. However, its magnetic characteristics and corrosion-resistance performance require caution in use of the product at high temperature. For the dynamic characteristics of the product at high temperature, the Br temperature characteristics of the magnet must be sufficiently considered.
– The main characteristics of neodymium magnets are as follows:
a) Its maximum energy product (BH max) far exceeds that of ferrite (4.5 MGOe) and samarium-cobalt magnets (30 MGOe). Some models even exceed 48 MGOe.
b) Since it consists mainly of relatively inexpensive neodymium and iron, it offers better cost performance than samarium-cobalt magnets that contain much cobalt, and poses no concern over availability.
c) Although these magnets have temperature characteristics inferior to those of samarium-cobalt magnets, heat-resistant materials have been developed with higher magnetic coercive force for the following: NF-H series, NF-SH series and NF-UH series.
d) Of the main components, iron accounts for nearly 70%. To ensure rustproofing, these magnets are equipped with Ni electrolytic plating as standard.
* Caution that you should exercise
For high-temperature demagnetization, refer to the Hcj temperature characteristics of the magnets. For the NF series, we therefore provide different materials with various Hcj levels. Even with the same material, these magnets vary in demagnetization characteristics according to shape. These materials also make the magnets prone to rusting.
Therefore, the products should undergo surface treatment
Surface treatment – Characteristics of Neodymium Magnets
Our standard surface treatment is done by electrolytic nickel plating. We can also deliver magnets with other specifications that meet the uses of magnet users, such as gold plating, epoxy resin coating and fluororesin coating.
N series magnets undergo surface treatment. These magnets are characterized by the advantages of very powerful magnetism and iron composition of nearly 70%; the latter of which requires rustproofing.
N series magnets undergo surface treatment by electrolytic nickel plating. Electrolytic nickel plating is the most common and highly reliable of all surface treatment methods used for neodymium magnets. We are committed to this particular method of surface treatment, and dispatch Japanese engineers to a special-purpose factory (in Beijing) for introducing technology and quality control proven in Japan.
This electrolytic nickel plating comes in two types depending on magnet shape: single-layer nickel plating (Ni) and copper + nickel plating (Cu + Ni). It is particularly notable that we are the only company based in China that owns the technology for plating neodymium magnets directly with copper. This technology makes it possible to form a reliable film on ring-type magnets having small inner diameters for use in vibration motors and similar equipment.
Lightweight magnets are realized by using a rotary barrel system, while heavyweight ones rely on a suspension system. Electrolytic nickel plating is made reliable as follows:
Reliability testing: pressure cooker test (PCT) acceleration testing conducted
120°C, 100% RH, 20 hours
PCT in No.1 is usually conducted. Acceleration testing in No.2 is also conducted in many cases depending on specifications agreed upon with some clients.
This acceleration testing ensures good surface treatment performance for 8 to 9 years under normal operating conditions (i.e., annual average temperature and humidity in New Jersey).
|No.||Acceleration testing conditions||Test time||Testing apparatus|
|1||120°C, 100%RH||20 hours||PCT tester|
|2||85°C, 100%RH||250 hours||Thermo-hygrostat tester under high humidity|
|3||60°C, 100%RH||1250 hours||Thermo-hygrostat tester under high humidity|
|4||40°C, 100%RH||5500 hours||Thermo-hygrostat tester under high humidity|
Sintered NdFeB Ring Speaker Magnets, Sintered NdFeB (Neodymium Iron Boron) Ring Magnet, Loundspeaker Neo Rings, Headphone Magnets, Telephone Magnets, China Megaphone Neodymium Magnets We mainly produced sintered NdFeB Ring Speaker Magnets because it is the one widely used in many fields. The coercive force of Sintered NdFeB is very high and its Bhmax is about ten […]
Nickel Coating Speaker Ring Magnets, Magnetic Ring, NdFeB Ring Magnets, Custom Magnets, Neodymium Ring Speaker Magnets, Permanent Magnets, Loundspeaker Ndfeb Magnets HSMAG Nickel Coating Speaker Ring Magnets features: a. The magnet grades in N series are available from N35 to N52 grade (Residual magnetism is from 11.7KGs to 14.8KGs); b. Competitive prices; c. Reasonable delivery time; […]
Ring Gold Coating Neo Magnets, Golden Plated Ring Neodymium Rare Earth Magnets, Powerful Speaker Permanent Magnets, Golden Coating NdFeB Ring Magnet Ring Gold Coating Neo Magnets Feature: 1. Part No.: HSND-GNMR-(Size)-(Grade) for example: HSND-GNMR-5*3*2-N35 2. Grade: N35 – N52, 30M – 50M, 30H – 48H, 30SH – 45SH, 28UH – 40UH, 30EH – 35EH, 30AH – […]
Color Zinc Plating Sintered NdFeB Ring Magnet, N45 Ring Shape Neodymium Magnet OD60 x ID50 x 6.0mm, Ring Magnet for Permanent Magnet Filter, Loudspeaker NdFeB Magnet, Ring Magnet FOR Headphones Color Zinc Plating Sintered NdFeB Ring Magnet Feature: Magnet Material : NdFeB or Neodymium Iron Boron Magnet Shape: Ring Magnet Grade: N45 Outer diameter: 60.0 mm […]