Abstract
The electrodeposition of Ni-W alloys was conducted from an unagitated sulfate solution containing citric acid at pH 5 and 60°C under coulostatic (3.44-6.22×105 C/m2) and galvanostatic (30-5 000 A/m2) conditions. Before annealing, the lattice constant of Ni increased linearly with an increase in W content up to 40.7 mass% in accordance with Vegard's law. This shows that the W formed a supersaturated solid solution in Ni. At W contents of <37.1 mass%, the deposit morphologies showed a field-oriented texture, with a preferred orientation of the specific plane towards the electric field during deposition, and platelet crystal edges exposed at the surface. At W contents of >40.7 mass% of the solid solubility limit, the cross section of the deposits showed a layered morphology, with a smooth surface and small granular crystals. After annealing, Ni4W precipitated with deposits of W contents of 32.6 and 37.1 mass%. Fine precipitates of Ni4W and NiW formed over the entire surface with W contents of 40.7-45.3 mass%. Before annealing, the hardness of the deposits increased with W content, and the increase was particularly large at a W content of 40.7 mass%. The hardness was almost constant regardless of the current density for W contents of >40.7 mass%. The alloy composition required to change the hardness of the deposits corresponded with that required to change the deposit structures. The hardness of the deposits increased for all W contents by annealing, with the increase being particularly large for W contents of >40.7 mass%.
| Original language | English |
|---|---|
| Pages (from-to) | 1083-1090 |
| Number of pages | 8 |
| Journal | isij international |
| Volume | 55 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Jan 1 2015 |
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All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry
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Effect of annealing on the structure and hardness of electrodeposited Ni-W alloys. / Hayata, Shinichiro; Oue, Satoshi; Nakano, Hiroaki; Takahashi, Takehiro.
In: isij international, Vol. 55, No. 5, 01.01.2015, p. 1083-1090.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of annealing on the structure and hardness of electrodeposited Ni-W alloys
AU - Hayata, Shinichiro
AU - Oue, Satoshi
AU - Nakano, Hiroaki
AU - Takahashi, Takehiro
PY - 2015/1/1
Y1 - 2015/1/1
N2 - The electrodeposition of Ni-W alloys was conducted from an unagitated sulfate solution containing citric acid at pH 5 and 60°C under coulostatic (3.44-6.22×105 C/m2) and galvanostatic (30-5 000 A/m2) conditions. Before annealing, the lattice constant of Ni increased linearly with an increase in W content up to 40.7 mass% in accordance with Vegard's law. This shows that the W formed a supersaturated solid solution in Ni. At W contents of <37.1 mass%, the deposit morphologies showed a field-oriented texture, with a preferred orientation of the specific plane towards the electric field during deposition, and platelet crystal edges exposed at the surface. At W contents of >40.7 mass% of the solid solubility limit, the cross section of the deposits showed a layered morphology, with a smooth surface and small granular crystals. After annealing, Ni4W precipitated with deposits of W contents of 32.6 and 37.1 mass%. Fine precipitates of Ni4W and NiW formed over the entire surface with W contents of 40.7-45.3 mass%. Before annealing, the hardness of the deposits increased with W content, and the increase was particularly large at a W content of 40.7 mass%. The hardness was almost constant regardless of the current density for W contents of >40.7 mass%. The alloy composition required to change the hardness of the deposits corresponded with that required to change the deposit structures. The hardness of the deposits increased for all W contents by annealing, with the increase being particularly large for W contents of >40.7 mass%.
AB - The electrodeposition of Ni-W alloys was conducted from an unagitated sulfate solution containing citric acid at pH 5 and 60°C under coulostatic (3.44-6.22×105 C/m2) and galvanostatic (30-5 000 A/m2) conditions. Before annealing, the lattice constant of Ni increased linearly with an increase in W content up to 40.7 mass% in accordance with Vegard's law. This shows that the W formed a supersaturated solid solution in Ni. At W contents of <37.1 mass%, the deposit morphologies showed a field-oriented texture, with a preferred orientation of the specific plane towards the electric field during deposition, and platelet crystal edges exposed at the surface. At W contents of >40.7 mass% of the solid solubility limit, the cross section of the deposits showed a layered morphology, with a smooth surface and small granular crystals. After annealing, Ni4W precipitated with deposits of W contents of 32.6 and 37.1 mass%. Fine precipitates of Ni4W and NiW formed over the entire surface with W contents of 40.7-45.3 mass%. Before annealing, the hardness of the deposits increased with W content, and the increase was particularly large at a W content of 40.7 mass%. The hardness was almost constant regardless of the current density for W contents of >40.7 mass%. The alloy composition required to change the hardness of the deposits corresponded with that required to change the deposit structures. The hardness of the deposits increased for all W contents by annealing, with the increase being particularly large for W contents of >40.7 mass%.
UR - http://www.scopus.com/inward/record.url?scp=84930157840&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84930157840&partnerID=8YFLogxK
U2 - 10.2355/isijinternational.55.1083
DO - 10.2355/isijinternational.55.1083
M3 - Article
AN - SCOPUS:84930157840
VL - 55
SP - 1083
EP - 1090
JO - ISIJ International
JF - ISIJ International
SN - 0915-1559
IS - 5
ER -