Simulation-aided development of magnetic-aligned compaction process with pulsed magnetic field

In order to develop a new magnetic-aligned compaction process using a pulsed magnetic field for the most recent high performance magnetic powder and to understand the mechanism of particle orientation behavior in the magnetic field, visualization of particle motion and prediction of the degree of alignment were performed by using a three-dimensional particle-based simulation method developed by the authors. This simulation study revealed that the degree of alignment changed significantly in a time on the order of milliseconds during the application of the pulsed magnetic field. Furthermore, preparation of a highly oriented green compact required millisecond-level synchronization control of the application of the pulsed magnetic field and the compacting action. Based on the simulation results, a magnetic-aligned compacting apparatus capable of synchronizing the application of the magnetic field and the compacting action with accuracy on the order of milliseconds was developed. As a result, the optimum aligned condition in experiments and the simulation was consistent. By using the proposed synchronization method, the degree of alignment was improved and the maximum magnetic energy product was increased by about 9% and 15%, respectively, compared with the conventional method. (C) 2018 Elsevier B.V. All rights reserved.