• Journal of the Korean institute of surface engineering
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• v.28 no.3
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• pp.142-151
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• 1995

In this research, a thin layer of Cr was coated on the pure Ni and Inconel 601 by PECVD (Plasma Enhanced Chemical Vapor Deposition) in order to study the effect of Cr on the oxidation behavior at high temperature. Cr coated Inconel 601, which was oxidized at $1100^{\circ}C$ for 24 hours, formed a protective $Cr_2O_3$ oxide layer and the resistance to isothermai oxidation was improved. On the other hand, oxidation resistance of Cr coated Inconel 601 at 100$0^{\circ}C$ was not significantly improved, probably due to the formation or insufficient $Cr_2O_3$ layer. But, when oxidized at $1000^{\circ}C$ and $1100^{\circ}C$ for 100 hours, Cr coated Inconel 601 improved isothermal oxidation resistance by the formation of continuous $Cr_2O_3$ external scale and by the development of $Al_2O_3$ subscales. Cr coated Ni formed inner layer of $Cr_2O_3$ within almost pure NiO, which provided additional cation vacancies, thus increasing the mobility of Ni ions in this region. It is believed that this doping effect resulted in an increase in the observed oxidation rate compared with pure Ni and did not improve the oxidation resistance.

• Journal of the Korean institute of surface engineering
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• v.31 no.6
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• pp.379-388
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• 1998

The iron-zinc interfacial reaction and corrosin properties in galvanizing bath containning Ni have been intestigated. The substrate steel plates were galvanized in Zn or Zn-0.018Al baths with various Ni contents. The corrosion resistance of galvanized specimens was also evaluated by $60^{\circ}$bending test for galvannealing speaaimens. The corrosion resistance was improved with Ni addition in pure Zn bath, while deteriorated with Ni addition in Zn-0.18Al bath. The anti-powdering property, on thhe otherhand, was improved with Ni addition in Zn-0.18Al bath, while deteriorated with Ni addition in pure Zn. It was found that the anti-powdering property was improved with increasing $\xi$ phase ratio in reaction layer.

• Korean Journal of Metals and Materials
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• v.46 no.1
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• pp.33-38
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• 2008

The interfacial reactions and shear strength of pure Sn solder bump were investigated with different under bump metallizations (UBMs) and reflow numbers. Two different UBMs were employed in this study: Cu and Ni. Cu6Sn5 and Cu3Sn intermetallic compounds (IMCs) were formed at the bump/Cu UBM interface, whereas only a Ni3Sn4 IMC was formed at the bump/Ni UBM interface. These IMCs grew with increasing reflow number. The growth of the Cu-Sn IMCs was faster than that of the Ni-Sn IMC. These interfacial reactions greatly affected the shear properties of the bumps.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.263-264
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• 2013

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.106-110
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• 2004

Nickel oxide (NiO) thin films were prepared on Si(100) substrates at room temperature by RF magnetron sputtering using a NiO target. The effects of oxygen flow ratio for the plasma gas on the preferred orientation and surface morphology of the NiO films were investigated. Highly crystalline NiO film with (100) orientation was obtained when it was deposited in pure Ar gas. For NiO film deposited in pure O$_2$ gas, on the other hand, the orientation of the film changed from (100) to (111) and its deposition rate decreased. The origin of the preferred orientation of the films was discussed. NiO films also showed different surface morphologies and roughnesses with the oxygen flow ratio.

• Transactions of the Korean hydrogen and new energy society
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• v.9 no.4
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• pp.143-150
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• 1998

The hydriding and dehydriding properties of a Mg-10wt.%Ni mixture, mechanically-alloyed in order to improve the hydriding and dehydriding kinetics of pure Mg, were investigated. The $Mg_2Ni$ phase develops along with hydriding-dehydriding cycling. The principal effects of mechanical alloying in a planetary mill and hydriding-dehydriding cycling are considered to be the augmentation in the density of defects and the enlargement in the specific surface area. The mechanically-alloyed Mg-10wt.%Ni mixture is activated easily. It has much higher hydriding rate and hydrogen-storage capacity and relatively high dehydriding rate as compared with the pure Mg, the Mg-10wt.%Ni alloy, the Mg-25wt.%Ni alloy and the $Mg_2Ni$ alloy.

• Journal of Powder Materials
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• v.31 no.3
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• pp.220-225
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• 2024

Molten salt reactors represent a promising advancement in nuclear technology due to their potential for enhanced safety, higher efficiency, and reduced nuclear waste. However, the development of structural materials that can survive under severe corrosion environments is crucial. In the present work, pure Ni was deposited on the surface of 316H stainless steel using a directed energy deposition (DED) process. This study aimed to fabricate pure Ni alloy layers on an STS316H alloy substrate. It was observed that low laser power during the deposition of pure Ni on the STS316H substrate could induce stacking defects such as surface irregularities and internal voids, which were confirmed through photographic and SEM analyses. Additionally, the diffusion of Fe and Cr elements from the STS316H substrate into the Ni layers was observed to decrease with increasing Ni deposition height. Analysis of the composition of Cr and Fe components within the Ni deposition structures allows for the prediction of properties such as the corrosion resistance of Ni.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.205-206
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• 2006

The microstructural evolutions and shear properties of the pure Sn solder bumps with Ni UBMs were investigated during multiple reflows and high temperature storage(HTS) tests. Only a $Ni_3Sn_4$ IMC was found at the bump/Ni UBM interface after 1 reflow. The layer thickness of these IMCs increased with increasing reflow number and testing time. The solder bumps showed a good reliability during multiple reflows and HTS tests.

• Progress in Superconductivity
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• v.6 no.1
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• pp.64-68
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• 2004

We fabricated cube-textured Ni and Ni-W alloy substrates for coated conductors and characterized the effects of W addition on microstructure, mechanical strength, and magnetic properties of the substrate. Pure Ni and Ni-(2, 3, 5at.%)W alloys were prepared by plasma arc melting, heavily cold rolled and then annealed at various temperatures of $600-1300^{\circ}C$. The texture was evaluated by pole-figure and orientation distribution function (ODF) analysis. Mechanical properties were investigated by micro Vickers hardness and tension test. Ferromagnetism of the substrate was measured by physical property measurement system (PPMS). It was observed that Ni-W substrates had sharp cube texture, and the full-width at half-maximums (FWHMs) of in-plane texture was $^{\circ}$-5.57$4.42^{\circ}$, which is better than that of pure Ni substrate. In addition cube texture of Ni-W substrates was retained at higher temperature up to $1300^{\circ}C$. Microstructural observation showed that the Ni-W substrates had fine grain size and higher mechanical properties than the pure Ni substrate. These improvements are probably due to strengthening mechanisms such as solid solution hardening and/or grain size strengthening. PPMS analysis showed that addition of W effectively reduced saturation magnetization in applied magnetic field and Curie temperature.

• Corrosion Science and Technology
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• v.6 no.6
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• pp.311-315
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• 2007

The anodic polarization behavior of equiatomic TiNi shape memory alloy with pure titanium as a reference material was investigated by means of open circuit potential measurement and potentiodynamic polarization technique. And the structure of passive films on TiNi intermetallic compounds was also conducted using AES and ESCA. While the dissolved Ni(II) ion did not affect the dissolution rate and passivation of TiNi alloy, the dissolved Ti(III) ion was oxidated to Ti(IV) ion on passivated TiNi surface at passivation potential. It has also been found that the Ti(IV) ion increases the steady state potential, and passivates TiNi alloy at a limited concentration of Ti(IV) ion. The analysis by AES showed that passive film of TiNi alloy was composed of titanium oxide and nickel oxide, and the content of titanium was three times higher than that of nickel in outer side of passive film. According to the ESCA analysis, the passive film was composed of $TiO_2$ and NiO. It seems reasonable to suppose that NiO could act as unstabilizer to the oxide film and could be dissolved preferentially. Therefore, nickel oxide contained in the passive film may promote the dissolution of the film, and it could be explained the reason of higher pitting susceptibility of TiNi alloy than pure Ti.