NdFeB element types

We all know that the main raw materials of sintered NdFeB permanent magnets are neodymium, iron, and boron. In addition, many other elements are added to the raw materials. These elements play different roles in the magnets. Manufacturers often design product formulas based on user needs. The raw material formula can be said to be top secret information of each manufacturer.   The dozen or so elements in sintered NdFeB are like the various seasonings we add to a delicious dish. It is precisely because of the scientific and regular combination of these elements with different intrinsic characteristics and functions that we have achieved various grades and properties of NdFeB. Understanding the significance of each element is of great significance to our better understanding of the performance and manufacturing costs of different grades.   For easier understanding, we can divide the constituent elements of NdFeB into three categories: First, the main elements RE (Ce, Gd, Nd, Dy, etc.), Fe, and B, which are primarily responsible for forming the RE2Fe14B primary phase grains. Second, minor elements such as Al, Co, Ga, and Zr which are primarily responsible for optimizing the coating of the grain boundaries around the primary phase grains. Third, impurity elements, such as carbon and oxygen, are inevitably introduced from raw materials and during production.   The schematic diagram of NdFeB element types is shown below:     During use, we must carefully consider the actual content of each batch as specified in the quality inspection form. Each element in NdFeB magnets has its own unique properties, such as:   1. The introduction of La and Ce reduces the magnet's remanent magnetization (Br) and coercivity (Hcj), but their low cost can reduce costs. 2. Re-element Fe-B (REFeB), composed of pure Nd replacing PrNd, has a very high saturation magnetization and can be used to produce ultra-high remanence magnets. 3. The introduction of Tb can significantly increase the magnet's Hcj, but its cost is extremely high. 4. Gd is relatively inexpensive, and the REFeB it forms has the highest Curie temperature, making it suitable for producing high-temperature-resistant magnets, but it significantly reduces the Br content.   By having an in-depth understanding of the characteristics of the above elements and figuring out the influence of various elements on the sintering process, sintering density, aging process, and product performance, we can produce NdFeB products with high cost performance.