Additive manufacturing of magnetic materials using selective laser melting

摘要

Magnetic material is the key component in lot of electromagnetically-based optical to microwave applications. In the case of radio-frequencies/microwave applications, passive components are developed using planar design to facilitate their fabrication while 3D geometries are the best shapes to improve components properties. But nowadays, 3D printing technologies are coming up in industries and 3D design of passive components grows in interest. But 3D shaping of magnetic material remains a problem which has to be solved before considering industrial implementation.In this work, we demonstrate the possibility of 3D shaping ferrite magnetic powder using Selective laser melting/sintering in ambient air. A ferrimagnetic powder of Yttrium Iron Garnet (YIG) was used to form a 10-layers stack of magnetic material. A simple method for small surface (10×10mm~2) deposition of powder was developed by dispersing the YIG powder into ethanol. A drop is then deposited on top of a substrate. Ethanol evaporates and an homogeneous layer is obtained. A 1064nm-nanosecond laser combined to a scanning lens is used to irradiate the powder layer and induce melting/sintering of the powder at ambient temperature and in ambient air. Chemical and structural changes induced by the laser process were studied using Raman spectroscopy. Results show that a part of the YIG was decomposed into a weakly magnetic phase of Fe_3O_4. Vibrating Sample Magnetometry was then used to compare the magnetic behavior of the YIG multilayer and the YIG powder. The multilayer always exhibit a magnetic behavior whatever the substrate is: YIG powder, YIG bulk or Al bulk.