Effect of deposition current density and annealing temperature on the microstructure and magnetic properties of nanostructured Ni-Fe-W-Cu alloys
Ni-Fe-W-Cu alloy powders were obtained by electrodeposition from an ammonium citrate bath at current densities ranging between 70 and 600 mA cm-2. As the deposition current density increased, the contents of Fe and W in the alloy increased, and those of Ni and Cu decreased. The total cathod...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
International Institute for the Science of Sintering, Beograd
2019-01-01
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| Series: | Science of Sintering |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/0350-820X/2019/0350-820X1902209S.pdf |
| Summary: | Ni-Fe-W-Cu alloy powders were obtained by electrodeposition from an ammonium
citrate bath at current densities ranging between 70 and 600 mA cm-2. As the
deposition current density increased, the contents of Fe and W in the alloy
increased, and those of Ni and Cu decreased. The total cathodic polarization
curve was recorded, and partial polarization curves for Ni, Fe and W
deposition and hydrogen evolution were determined. The current efficiency of
alloy deposition was measured. The powders contained an amorphous matrix and
FCC nanocrystals of the solid solution of Fe, W and Cu in Ni. At high
current densities, small-sized nanocrystals exhibiting high internal
microstrain values were formed. Powder particles were dendrite- and
cauliflower-shaped. The dendrites had a large number of secondary branches
and higher-order branches containing interconnected globules. The density of
branches was higher in particles formed at high current densities. The
powders formed at high current densities exhibited higher magnetization.
Annealing at temperatures up to 460°C resulted in structural relaxation,
accompanied by an increase in magnetization. At temperatures above 460°C,
amorphous matrix crystallization and FCC crystal growth took place,
accompanied by a decrease in magnetization. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172057] |
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| ISSN: | 0350-820X 1820-7413 |