The Raw Material Composition and Efficacy of Sintered NdFeB

We all know that the main raw materials of sintered NdFeB permanent magnets are the three elements: neodymium, iron, and boron. However, in addition, many other elements are added to the raw materials, each playing different roles in the sintered NdFeB magnets. Manufacturers often design products based on users' needs, and the raw material formulas are considered top secret information by various manufacturers.

The dozen or so elements in sintered NdFeB are a kin to the various seasonings added when preparing a dish. It is the scientific and regular combination of these elements, each with different inherent characteristics and functions, that gives rise to the various grades and properties of sintered NdFeB. Understanding the significance of each element is crucial for better comprehension of the performance and manufacturing costs of different grades. Below, we briefly introduce the value of these elements.

Three Types of Elements in Sintered NdFeB

• The main elements of sintered NdFeB: RE (Ce, Gd, Nd, Dy, etc.), Fe, and B, which are chiefly responsible for forming the RE2Fe14B main phase grains.

• Minor elements like Al, Co, Ga, and Zr, which mainly optimize the coating of the main phase grains relative to the grain boundaries.

• Impurity elements in sintered NdFeB, such as carbon and oxygen, which are unavoidably introduced in raw materials and production.

Usually, during the production process, to enhance the performance effects of different formulas, we still need to inspect and treat the raw materials to meet some basic requirements before use.

Characteristics of Elements in Sintered NdFeB Magnets

The introduction of La and Ce elements can reduce the remanence Br and coercivity Hcj of the magnet, but their prices are very cheap, which can reduce costs;

Pure Nd element replacing PrNd in forming REFeB has very high saturation magnetization and can be used to prepare ultra-high remanence magnets;

The introduction of Tb element can markedly enhance the Hcj of the magnet, but its cost is extremely high;

The Gd element is relatively cheap, and the REFeB it forms has the highest Curie temperature, making it suitable for preparing high-temperature resistant magnets, but it significantly reduces Br.

To figure out how to combine elements to produce magnets that meet required grades at the lowest cost, we need to understand the characteristics of each element in sintered NdFeB.