The application of 3D printing technology in NdFeB magnets opens up a new direction in manufacturing.

Recently, a breakthrough in industrialization has been achieved in the Selective Laser Melting (SLM) 3D printing technology for NdFeB magnets, jointly developed by the School of Materials Science and Engineering at Beijing Institute of Technology and Zhongke Sanhuan. This technology directly molds magnets with complex structures through a metal powder bed fusion process, breaking free from the shape constraints of traditional mold stamping and providing novel magnetic components for fields such as new energy vehicle motors and precision sensors.

Traditional NdFeB magnet manufacturing relies on mold pressing, making it difficult to produce magnets with irregular shapes. The new technology employs Nd-Fe-B composite powder with particle sizes ranging from 5 to 20 microns. By using a 1064nm fiber laser for layer-by-layer sintering, it achieves three-dimensional molding with a precision of 0.1mm. The research team has developed a magnetic field-assisted printing system that applies a 0.8T directional magnetic field during the printing process, enabling the magnets to reach a magnetic energy product of 48 MGOe, approaching the level of traditional sintering processes.

Tests have shown that the mechanical properties of 3D-printed magnets are significantly improved, with a bending strength of 380 MPa, a 40% increase compared to traditional processes. Their near-net-shape characteristics have raised material utilization from 60% to 95%, while the production cycle for a single set of motor magnets has been shortened from 72 hours to 12 hours. Currently, this technology has been used to manufacture irregularly shaped magnetic yokes for servo motors in drones, with a stable batch production yield rate of 98.5%.

"This technology overturns the geometric limitations of magnet manufacturing," said an expert from the China Magnetic Materials Association. 3D printing enables the integrated manufacturing of magnets and structural components, and is expected to reduce the weight of new energy vehicle motors by 20%. The first production line with an annual capacity of 500 tons of 3D-printed magnets has been put into operation in Jiangsu, with 15 related patent technologies. In the future, it is expected to be applied in high-end fields such as magnetic levitation bearings and medical MRI equipment.