Direct Ink Writing 3D Printing of Special-Shaped Permanent Magnets via Room Temperature Fast-Curing NdFeB Slurry

Abstract

Specially shaped permanent magnet structures can satisfy the requirements of equipment with limited space or unique shapes. Thereby, these optimize the distribution of magnetic fields. However, traditional manufacturing methods are limited by the mold design and insufficient material utilization. In this study, a polymer-based Nd 2 Fe 14 B (NdFeB) magnetic slurry was developed based on direct ink writing (DIW) 3D printing technology. A rapidly volatilizable magnetic slurry was used to achieve 3D oriented controllable layering, thus realizing the direct molding fabrication of NdFeB permanent magnets with complex structures. By exploring and optimizing the 3D printing process parameters, specially shaped bonded NdFeB permanent magnet structures with high precision and shape fidelity were prepared. The test results indicated that the remnant magnetization of the printed magnets was proportional to the NdFeB content in the slurry, the coercivity closely matched that of the original powder, and the mechanical properties of the printed magnets were favorable. Building on this, a magnetically driven helical-structure robot was designed and printed to achieve stable motion in low-Reynolds-number fluids. This paper presents a new, low-cost solution for the room-temperature preparation of shape-bonded NdFeB permanent magnets.