Abstract
Electrodeposition of Ni-W alloys was conducted from an unagitated sulfate solution containing citric acid at pH 5 and 60 °C under coulostatic (9.0×105) and galvanostatic (100-5000 A·m-2) conditions onto steel sheets with an initial Ni plating, and the effect of initial Ni plating on the structure and hardness of deposited Ni-W alloys was investigated before and after annealing. The precipitates of Ni4W and NiW were observed in deposits obtained at all the current densities after annealing, irrespective of having undergone initial Ni plating or not. Without initial Ni plating, a lot of large precipitates occurred in the vicinity of steel substrate, while the fine precipitates occurred with initial Ni plating. Without initial Ni plating, the W content in deposits increased in the vicinity of steel substrate due to diffusion of Ni in deposits into steel substrate during annealing. With initial Ni plating, the W content in deposits in the vicinity of Ni plating decreased due to diffusion of Ni in Ni plating into deposits during annealing. Before annealing, W content in deposits was lower with initial Ni plating than that without Ni plating. With initial Ni plating, W content in deposits was lower and Ni diffused from Ni plating to deposits during annealing, as a result, the formation of large precipitates of Ni4W and NiW seems to be suppressed. The hardness of deposited Ni-W alloys after annealing increased when the precipitates of Ni4W and NiW became uniform and fine.
| Original language | English |
|---|---|
| Pages (from-to) | 590-597 |
| Number of pages | 8 |
| Journal | Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan |
| Volume | 101 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Jan 1 2015 |
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Metals and Alloys
- Materials Chemistry
Cite this
Effect of initial Ni plating on the structure and hardness of electrodeposited Ni-W alloys with and without annealing. / Hayata, Shinichiro; Oue, Satoshi; Takahashi, Takehiro; Nakanono, Hiroaki.
In: Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan, Vol. 101, No. 11, 01.01.2015, p. 590-597.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of initial Ni plating on the structure and hardness of electrodeposited Ni-W alloys with and without annealing
AU - Hayata, Shinichiro
AU - Oue, Satoshi
AU - Takahashi, Takehiro
AU - Nakanono, Hiroaki
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Electrodeposition of Ni-W alloys was conducted from an unagitated sulfate solution containing citric acid at pH 5 and 60 °C under coulostatic (9.0×105) and galvanostatic (100-5000 A·m-2) conditions onto steel sheets with an initial Ni plating, and the effect of initial Ni plating on the structure and hardness of deposited Ni-W alloys was investigated before and after annealing. The precipitates of Ni4W and NiW were observed in deposits obtained at all the current densities after annealing, irrespective of having undergone initial Ni plating or not. Without initial Ni plating, a lot of large precipitates occurred in the vicinity of steel substrate, while the fine precipitates occurred with initial Ni plating. Without initial Ni plating, the W content in deposits increased in the vicinity of steel substrate due to diffusion of Ni in deposits into steel substrate during annealing. With initial Ni plating, the W content in deposits in the vicinity of Ni plating decreased due to diffusion of Ni in Ni plating into deposits during annealing. Before annealing, W content in deposits was lower with initial Ni plating than that without Ni plating. With initial Ni plating, W content in deposits was lower and Ni diffused from Ni plating to deposits during annealing, as a result, the formation of large precipitates of Ni4W and NiW seems to be suppressed. The hardness of deposited Ni-W alloys after annealing increased when the precipitates of Ni4W and NiW became uniform and fine.
AB - Electrodeposition of Ni-W alloys was conducted from an unagitated sulfate solution containing citric acid at pH 5 and 60 °C under coulostatic (9.0×105) and galvanostatic (100-5000 A·m-2) conditions onto steel sheets with an initial Ni plating, and the effect of initial Ni plating on the structure and hardness of deposited Ni-W alloys was investigated before and after annealing. The precipitates of Ni4W and NiW were observed in deposits obtained at all the current densities after annealing, irrespective of having undergone initial Ni plating or not. Without initial Ni plating, a lot of large precipitates occurred in the vicinity of steel substrate, while the fine precipitates occurred with initial Ni plating. Without initial Ni plating, the W content in deposits increased in the vicinity of steel substrate due to diffusion of Ni in deposits into steel substrate during annealing. With initial Ni plating, the W content in deposits in the vicinity of Ni plating decreased due to diffusion of Ni in Ni plating into deposits during annealing. Before annealing, W content in deposits was lower with initial Ni plating than that without Ni plating. With initial Ni plating, W content in deposits was lower and Ni diffused from Ni plating to deposits during annealing, as a result, the formation of large precipitates of Ni4W and NiW seems to be suppressed. The hardness of deposited Ni-W alloys after annealing increased when the precipitates of Ni4W and NiW became uniform and fine.
UR - http://www.scopus.com/inward/record.url?scp=84946882069&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84946882069&partnerID=8YFLogxK
U2 - 10.2355/tetsutohagane.TETSU-2015-050
DO - 10.2355/tetsutohagane.TETSU-2015-050
M3 - Article
AN - SCOPUS:84946882069
VL - 101
SP - 590
EP - 597
JO - Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
JF - Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
SN - 0021-1575
IS - 11
ER -