Wire Direct Energy Deposition of Cobalt Iron Alloy
| dc.contributor.author | Salah, Mohammad | en |
| dc.contributor.committeechair | Fu, Yao | en |
| dc.contributor.committeechair | Yu, Hang | en |
| dc.contributor.committeemember | Song, Jie | en |
| dc.contributor.department | Aerospace and Ocean Engineering | en |
| dc.date.accessioned | 2025-01-24T09:00:31Z | en |
| dc.date.available | 2025-01-24T09:00:31Z | en |
| dc.date.issued | 2025-01-23 | en |
| dc.description.abstract | The presented research explores the Wire-Laser Direct Energy Deposition of Fe17Co alloy for soft magnetic applications. Process parameters starting from power, feed speed, and feed/scan ratios were optimized where a high confidence multi-factor regression model was developed correlating the processing parameters to final bead dimensions. The model showed that increasing feed speeds led to an increase in bead height and a reduction in bead width while increasing feed/scan ratio resulted in an increase of bead height and width. Interlayer cooling time for multi-layer deposition was tested and revealed, through thermal camera measurement, that increasing interlayer cooling time leads to a higher cooling rate, and generally more stable printing process. Printed samples showed single phase BCC with fine equiaxed structure and high density (>98.5%) with no pores or cracks. ASTM A773 sample rings were printed and showed that for decreasing input energy (by decreasing power or increasing feed speed) leads to a finer grain structure. The average diameter grain size of the printed samples was 18.7 microns and grew to an average of 26.5 microns after a pre-anneal heat treatment at 700°C for 2 hours followed by 850°C for 10 hours. Furthermore, using interlayer cooling time, the thermal gradient of the samples throughout the printing was increased and lead to even finer grain structure. However, this lead to increased grain growth post annealing. Printed samples showed good magnetic properties, but slightly less than that of the commercial wrought material. | en |
| dc.description.abstractgeneral | This research looks at the 3D printing of a cobalt-iron alloy for magnetic applications. This alloy is particularly interesting for Aerospace applications given its unique properties for high magnetic performance and ability to withstand high temperatures. Printing settings were adjusted to get the best results and the final samples were very dense without any holes or cracks, which is a common problem in 3D printing of metals in general. The printed samples had a uniform crystal structure and good magnetic properties, though a bit less than what the traditionally processed material is. Decreasing the energy or increasing printing cooling time made the grains in the material smaller. All the printed samples were sized in average 18.7 microns and grew to an average of 26.5 post heat treatment of a pre-anneal heat treatment at 700°C for 2 hours followed by 850°C for 10 hours. The heat treatment improved the material magnetic properties, but they were still not in-par with normally processed material. | en |
| dc.description.degree | Master of Science | en |
| dc.format.medium | ETD | en |
| dc.identifier.other | vt_gsexam:42422 | en |
| dc.identifier.uri | https://hdl.handle.net/10919/124335 | en |
| dc.language.iso | en | en |
| dc.publisher | Virginia Tech | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject | Additive Manufacturing | en |
| dc.subject | Soft Magnetics | en |
| dc.subject | Cobalt Iron | en |
| dc.subject | Hall Thrusters | en |
| dc.title | Wire Direct Energy Deposition of Cobalt Iron Alloy | en |
| dc.type | Thesis | en |
| thesis.degree.discipline | Aerospace Engineering | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | masters | en |
| thesis.degree.name | Master of Science | en |