Process window for manufacturing soft magnetic FeSi 6.5% by laser metal deposition

¹ Advanced Forming Research Centre (AFRC), University of Strathclyde, Glasgow, United Kingdom
² Design, Manufacturing and Engineering Management, University of Strathclyde, Glasgow, United Kingdom
³ School of Engineering, University of Birmingham, Birmingham, United Kingdom
⁴ Electronics and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom

^* Corresponding author: rasoul.karami@strath.ac.uk

Abstract

This study introduces Laser Metal Deposition (LMD) for the first time in manufacturing FeSi 6.5%, a crucial soft magnetic material. The investigation focuses on the impact of energy density on fabrication, emphasizing porosity, crack formation, and identifying an optimal processing window. Results reveal a significant correlation between energy density and defects. An increase in energy density from 54 to 82 J/mm^2 leads to pronounced porosity and cracks. However, within 61 to 68 J/mm^2, an optimal processing window emerges, ensuring minimal defects (< 0.3% porosity) and crack-free structures. Notably, manufacturing high silicon-content electrical steels without cracks is extremely challenging, but this study achieves it. Through systematic analysis, this research underscores the vital role of energy density in shaping the quality of FeSi 6.5% thin walls parts. These insights improve LMD parameters, advancing the manufacturing of soft magnetic materials.