Factors affecting the quality of NdFeB magnets
In recent years, with the rapid development of industry, a large number of industrial products will use high-performance NdFeB permanent magnet materials to replace ferrite permanent magnet materials, and the proportion of NdFeB is increasing rapidly. The demand of NdFeB strong magnet is more and more vigorous. What factors will affect the quality of NdFeB strong magnet?
1. The properties of magnets are determined by the composition of raw materials.
As the name suggests, NdFeB high intensity magnetic material is made of rare earth metal neodymium, pure iron and boron by powder metallurgy process. In order to further improve the magnetic properties of NdFeB, other elements can be added on the basis of ternary system Nd-Fe-B material, but the effect of element addition on the performance of magnet may be bidirectional, and the materials used by magnet manufacturers should meet the national standards.
2. During the production of sintered NdFeB, the main problem is to prevent the precipitation of α – Fe phase and the oxidation of alloy, so it is difficult to obtain the ideal microstructure. New methods and processes are emerging, such as: adding antioxidants and lubricants, and using the rapid quenching strip casting method to prepare magnets; ingot homogenization treatment and sheet casting process; two-phase preparation process; wet compression molding process, etc.
3. Whether the quality control is in place or not, many manufacturers are not strict with the product quality supervision, resulting in the performance and quality of magnetic materials are not up to standard.
4. The technology of coating strong magnet. The surface of NdFeB magnet without electroplating treatment is easy to rust and corrode, so it is better for NdFeB magnet to have electroplating surface treatment, so as to prolong its service life.
General daily magnet electroplating is nickel plating or zinc plating, some products due to environmental factors may also adopt multi-layer electroplating and other methods. Specific customers can decide according to their own product environment.
Generally, when purchasing NdFeB magnets, we suggest customers to sample first, and then place an order for production after the samples are qualified, which can reduce unnecessary trouble.