Synthesis and Thermal Stability of Nanocrystalline Nickel Coatings by Direct Current Electrodeposition

AbstractIn this study, the effect of grain size distribution on the thermal stability of electrodeposited nanocrystalline nickel was investigated by pre-annealing material such that a limited amount of abnormal grain growth was introduced. This work was done in an effort to understand the previously reported, unexpected effect, of increasing thermal stability with decreasing grain size seen in some nanocrystalline systems. Pre-annealing produced a range of grain size distributions in materials with relatively unchanged crystallographic texture and total solute content. Subsequent thermal analysis of the pre-annealed samples by differential scanning calorimetry showed that the activation energy of further grain growth was unchanged from the as-deposited nanocrystalline nickel.

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Pulsed direct current field-induced thermal stability and phase transformation of nanodiamonds to carbon onions

RSC Advances ◽

10.1039/c9ra01022j ◽

2019 ◽

Vol 9 (25) ◽

pp. 14360-14371 ◽

Cited By ~ 4

Author(s):

Faming Zhang ◽

Kuowei Fan ◽

Jin Yu ◽

Farhad Saba ◽

Jing Sun

Keyword(s):

Thermal Stability ◽

Phase Transformation ◽

Direct Current ◽

Current Field ◽

Detailed Understanding ◽

Pulsed Dc ◽

Carbon Onions ◽

Pulsed Direct Current ◽

Thermal Stability Of

The pulsed DC field-induced thermal stability of nanodiamonds (NDs) and their transformation to carbon onions lack detailed understanding.

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Improved Hardness and Thermal Stability of Nanocrystalline Nickel Electrodeposited with the Addition of Cysteine

Nanomaterials ◽

10.3390/nano10112254 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2254

Author(s):

Tamás Kolonits ◽

Zsolt Czigány ◽

László Péter ◽

Imre Bakonyi ◽

Jenő Gubicza

Keyword(s):

Thermal Stability ◽

Grain Size ◽

Dislocation Density ◽

Nickel Sulfate ◽

Fault Probability ◽

Nanocrystalline Nickel ◽

Twin Fault ◽

Cysteine Content ◽

Heating Up ◽

Thermal Stability Of

Experiments were conducted for the study of the effect of cysteine addition on the microstructure of nanocrystalline Ni films electrodeposited from a nickel sulfate-based bath. Furthermore, the thermal stability of the nanostructure of Ni layers processed with cysteine addition was also investigated. It was found that with increasing cysteine content in the bath, the grain size decreased, while the dislocation density and the twin fault probability increased. Simultaneously, the hardness increased due to cysteine addition through various effects. Saturation in the microstructure and hardness was achieved at cysteine contents of 0.3–0.4 g/L. Moreover, the texture changed from (220) to (200) with increasing the concentration of cysteine. The hardness of the Ni films processed with the addition of 0.4 g/L cysteine (∼6800 MPa) was higher than the values obtained for other additives in the literature (<6000 MPa). This hardness was further enhanced to ∼8400 MPa when the Ni film was heated up to 500 K. It was revealed that the hardness remained as high as 6000 MPa even after heating up to 750 K, while for other additives, the hardness decreased below 3000 MPa at the same temperature.

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