Last modified: 14. 07. 2025
Abstract
Soft magnetic composites (SMCs) are valuable materials due to their impressive magnetic properties. The aim of this research is to investigate the influence of the ball to powder ratio (BPR) during mechanical milling and innovative method of powder surface treatment on the magnetic properties of these materials. We have prepared six powder samples of pure Fe (99.98% purity) by mechanical milling with different BPR (3:1, 6:1, 9:1) and by the surface smoothing process. Magnetic properties were evaluated by measured hysteresis loops and initial magnetization curves. The magnetic results show that the best soft magnetic properties at 200 K and 300 K based on shape of the hysteresis loops, maximum magnetization, and initial magnetization curve has been exhibited by sample with BPR 3:1 and powder surface treatment. A sample with a high magnetic moment is with BPR 9:1 and we can expect that increasing the BPR creates many internal structural defects during mechanical milling, but also creates a larger amount of small particles, which generally means smaller domain walls. We can confirm that mechanical milling and subsequently surface treatment of milled powder is suitable pre-cursor of prepared powdered material for further hot or cold compaction and to obtain of required shape of soft magnetic material with excellent magnetic properties.
Acknowledgement: This research was supported by the Scientific Grant Agency of the Ministry of Education of Slovak Republic and the Slovak Academy of Science (grant numbers VEGA 1/0403/23 and KEGA 006TUKE-4/2025) and by Ulysseus: Seed Fund Call for Teachers. Collaborative Online International Learning (COIL), 2024-2025.