Industry News
Sintered NdFeB magnets feature ultra-high magnetic energy density (up to 1.5 T in the current market) and excellent service performance, making them widely used in household appliances, transportation, healthcare, aerospace and other fields.
To meet the application requirements of NdFeB magnets in various sectors and objectively evaluate their applicability and quality, a variety of indicator tests are generally required. The testing items are usually divided into three categories:
- Appearance, dimensions and physical properties;
- Magnetic properties;
- Supplementary performance testing items.
Inspection of Appearance, Dimensions and Physical Properties
The appearance, dimensions and physical properties of NdFeB products are fundamental requirements for their application. Qualified products must not only meet the magnetic performance specifications, but also satisfy the practical demands concerning dimensions, coating, mechanical properties and so on, so as to ensure proper assembly and service under different environmental conditions.
Product dimensions and tolerances not only affect assembly performance, but also influence the consistency deviation of magnetic properties, as well as the operational stability and energy consumption of motors. Therefore, they have attracted increasing attention from customers in practical applications.
Magnetic Performance Testing
The magnetic performance of NdFeB magnets is the primary requirement for their application. Only products that strictly meet the magnetic performance specifications can fully function and be applied reliably in the required fields. This necessitates strict testing of the magnetic performance indicators of NdFeB magnets.
Magnetic Performance Testing
In terms of magnetic properties, attention was previously focused only on two indicators: remanence and intrinsic coercivity . Today, however, more and more customers are turning their attention to magnetic moment and thermal demagnetization loss.
In practice, the two key characteristics we rely on for magnetic steels are:
- Magnetic energy density per unit volume
- Magnetic stability under high-temperature operation
Assessing performance using magnetic moment and thermal demagnetization is more rational. Magnetic steels screened based on thermal demagnetization indicators will undoubtedly deliver better service reliability and higher cost-effectiveness.
Supplementary Testing Items for NdFeB Magnets
The supplementary testing items for NdFeB magnets are mainly used to verify whether the product performance meets expectations during production and to identify defects in the manufacturing process. They are also applied to analyze and confirm the material composition and appearance of products when abnormalities occur or during new product development.
Supplementary Testing Items
*Source: WeChat Official Account – Zhao Magic Magnets (找磁材)