ENHANCEMENT OF MAGNETIC PROPERTIES AND CRYSTAL STRUCTURE OF SOFT MAGNETIC MATERIALS FABRICATED BY DIRECTED ENERGY DEPOSITION

抄録

Additive manufacturing (AM) allows objects to be designed and formed directly from three-dimensional data. Directed energy deposition (DED), an AM method, can produce near net shape parts, which can reduce lead time and material waste, resulting in lower costs. From the growing interest in vehicle electrification, usage of AM technology for functional materials such as soft magnetic materials has been attracting attention. Performance indicators of soft magnetic materials are high saturation polarization, high susceptibility, and low coercivity. These properties depend on microstructure and crystal texture. In this research, experiments were carried out to find ideal process parameters of DED using two soft magnetic materials, FeSi and FeCoV. Crystal orientation of both materials showed anisotropic properties with columnar grains in the build direction. Six process parameters, laser power, feed rate of nozzle head, dwell time, rotational speed of disc in powder pod, powder supply rate, and carrier gas speed were adjusted to perform a screening test. It was found that dwell time and powder supply rate have a large influence on the shape of deposit. Also, higher deposit density is achieved by higher laser power and lower feed rate. Consequently, optimal process parameters of both FeSi and FeCoV deposits were obtained.