The main reason why NdFeB magnets are vulnerable is caused by their crystal structure and composition characteristics.
NdFeB magnets are intermetallic compounds, whose crystal structure is hexagonal closest packing (HCP), and contain a lot of neodymium. This crystal structure and composition make NdFeB magnets have the following brittle characteristics:
Brittle grain boundary: The interface of the grain in the NdFeB magnet is easy to become the starting point of brittle fracture, and the stress concentration and uneven structure of the grain boundary will lead to easy fracture.
High hardness: NdFeB magnet has a high hardness, under the action of external force, its internal crystal structure is difficult to produce plastic deformation, thus prone to brittle fracture.
Low toughness: Due to the crystal structure and composition characteristics of NdFeB magnets, their toughness is relatively low, that is, the ability to absorb deformation energy is poor, so it is easy to break when subjected to external force.
Therefore, when using NdFeB magnets, attention needs to be paid to avoid collision, vibration and sudden force loading to reduce the risk of brittle fracture. At the same time, when manufacturing and processing NdFeB magnets, it is also necessary to take appropriate process measures to control the grain boundary structure and stress distribution to improve its toughness and brittleness resistance.
