• 공업화학
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• 제31권5호
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• pp.552-559
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• 2020

Activated carbon-nickel (II) oxide (AC-NiO) electrodes were studied as materials for the capacitive deionization (CDI) of aqueous sodium chloride solution. AC-NiO electrodes were fabricated through physical mixing and low-temperature heating of precursor materials. The amount of NiO in the electrodes was varied and its effect on the deionization performance was investigated using a single-pass mode CDI setup. The pure activated carbon electrode showed the highest specific surface area among the electrodes. However, the AC-NiO electrode with approximately 10 and 20% of NiO displayed better deionization performance. The addition of a dielectric material like NiO to the carbon material resulted in the enhancement of the electric field, which eventually led to an improved deionization performance. Among all as-prepared electrodes, the AC-NiO electrode with approximately 10% of NiO gave the highest salt adsorption capacity and charge efficiency, which are equal to 7.46 mg/g and 90.1%, respectively. This finding can be attributed to the optimum enhancement of the physical and chemical characteristics of the electrode brought by the addition of the appropriate amount of NiO.

• 한국표면공학회지
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• 제9권3호
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• pp.1-4
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• 1976

In order to get high wear-resistant gold alloy plating on electronic parts, on attempt has been made, in which Cu, Ni, and Zn EDTA salts were added in gold palting solution. The results obtained on the wear resistance are as follows: 1. The addition of 0.5g/ι or over Cu in plating solution, showed 1.5 times more wear resistance than in case of no addition. 2. The addition of 1.5g/ι or over Ni, showed 3.5 times more wear-resistance . 3. The addition of 1.5g/ι and 4.0g/ι Zn , showed 3.5 times and 6.8 times more wear resistance , respectively. 4. The addition of 1.5g/ι Ni and 1.0g/ι Zn simultaneously , showed about 10 times more wear resistance than in case of no addition.

• 한국환경과학회지
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• 제22권8호
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• pp.1019-1027
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• 2013

Sulfur hexa-fluoride has been used as a etching gas in semiconductor industry. From the globally environmental issues, it is urgent to control the emissions of this significant greenhouse gas. The main objective of this experimental investigation was to find the effective catalyst for $SF_6$ decomposition. The precursor catalyst of hexa-aluminate was prepared to investigate the catalytic activity and stability. The precursor catalyst of hexa-aluminate was modified with Ni to enhance the catalytic activities and stability. The catalytic activity for $SF_6$ decomposition increased by the addition of Ni and maximized at 6wt% addition of Ni. The addition of 6wt% Ni in precursor catalyst of hexa-aluminate improved the resistant to the HF and reduced the crystallization and phase transition of catalyst.

• 한국주조공학회지
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• 제18권3호
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• pp.271-274
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• 1998

Effects of Si and Ni addition on the microstructure and mechanical properties of the Cu-12wt.%Al-5wt.%Fe-1wt.%Mn alloy have been investigated experimentally. Microstructure of the as-cast specimen is found to be refined markedly by additions of Ni and Si. By the addition of Ni, volume fraction of the ${\kappa}$ phase is increased, but volume fraction of the ${\gamma}$ phase is decreased. Hardness is increased with the addition of Ni, due to increasing of ${\kappa}$ phase which is harder than ${\gamma}$ phase. However, Charpy impact value is not significally decreased possibly due to the formation of isolate ${\kappa}$ phase.

• 한국표면공학회지
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• 제31권5호
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• pp.297-303
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• 1998

The influences of vanadium addition on the cavitation erosion resistance pf Fe-Cr-Ni-Si-C hardfacing alloy were investigated using a vibratory apparatus up to 30 hrs. It was shown that 1wt.%V additioned alloy improved the resistance to cavitation damage. However, further increase in V content up to 2wt.% reduced the cavitation erosion resistance. It was considered that the addition of V developed the cavitation erosion resistance by reducing the stacking fault energy of Fe-Cr-Ni-Si-C alloy. However, the further increase in V content seemed to reduce the cavitation erosion resistance by increasing the matrix/carbide interfacial area, which was the preferential sites of the cavitation damage.

• 한국세라믹학회지
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• 제40권6호
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• pp.560-565
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• 2003

방전 플라즈마 소결법(SPS: Spark Plasma Sintering)을 이용하여 800~100$0^{\circ}C$의 낮은 소결 온도에서 완전 치밀화를 이루는 M-doped ZnO를 (M=Al, Ni) 제조하여 그 소결 특성과 미세구조를 분석하였다. 전자현미경 분석 결과, NiO의 첨가는 ZnO 결정격자와의 고용체 형성을 촉진시키고 결정립 성장을 유발하였고, A1$_2$O$_3$는 순수한 ZnO 소결 시 나타나는 입계에서의 증발현상을 제어하고, 이차상 형성을 통하여 결정립 성장을 억제함을 확인할 수 있었다 NiO와 $Al_2$O$_3$를 동시에 첨가한 시편이 가장 우수한 미세구조가 형성됨을 확인하였고, SEM-EBSP (Electron Back-scattered Diffraction Pattern) 분석 결과 또한 우수한 결정립계 분포를 가지고 있음을 확인하였다. 이러한, 소결체의 우수한 미세구조적 특징은 carrier 농도 증가에 따른 전기 전도도와 증가 및 phonon scattering 효과에 의한 열전도도의 감소 효과를 유발하여 ZnO의 열전 특성을 향상시키리라 사료된다.

• 분석과학
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• 제5권2호
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• pp.203-211
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• 1992

Ni-36.5at.%Al 합금에서 결정립계에서의 scavenging 원소로 알려진 V를 첨가하여 이 합금의 파괴거동 및 마르텐사이트 미세조직에 미치는 V의 영향에 대해 조사하였다. 시편의 파단면은 주사전자현미경으로 관찰하였고 EDX spectrometer를 사용하여 파단면의 조성을 분석하였으며 투과전자현미경으로 마르텐사이트 내부조직의 변화에 대해 조사하였다. V의 첨가로 입계파괴에서 입내파괴로 파괴 모드의 변화를 나타내었으며 EDX spectrometer로 분석한 결과 입내에 비해 입계에 Al의 함량이 상대적으로 증가되는 양상을 보여 주었다. Ni-36.5at.%Al 합금의 경우 마르텐사이트 플레이트는 내부쌍정으로 이루어져 있으나 V의 첨가에 따라 twinned 마르텐사이트 조직은 사라지며 stacking fault와 고밀도의 전위를 가진 modulated 조직이 점차 지배적으로 형성되는 것이 관찰되었다. Stacking fault를 분석한 결과 Al과 V의 치환에 따른 extrinsic fault였으며 high-energy 상태인 이 stacking fault가 있는 부위에 유해 원소인 S가 편석됨으로써 결정립계에서의 파괴를 줄일 수 있었다.

• 한국재료학회지
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• 제23권7호
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• pp.385-391
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• 2013

The influence of Cu and Ni on the ductile-brittle transition behavior of metastable austenitic Fe-18Cr-10Mn-N alloys with N contents below 0.5 wt.% was investigated in terms of austenite stability and microstructure. All the metastable austenitic Fe-18Cr-10Mn-N alloys exhibited a ductile-brittle transition behavior by unusual low-temperature brittle fracture, irrespective of Cu and/or Ni addition, and deformation-induced martensitic transformation occasionally occurred during Charpy impact testing at lower temperatures due to reduced austenite stability resulting from insufficient N content. The formation of deformation-induced martensite substantially increased the ductile-brittle transition temperature(DBTT) by deteriorating low-temperature toughness because the martensite was more brittle than the parent austenite phase beyond the energy absorbed during transformation, and its volume fraction was too small. On the other hand, the Cu addition to the metastable austenitic Fe-18Cr-10Mn-N alloy increased DBTT because the presence of ${\delta}$-ferrite had a negative effect on low-temperature toughness. However, the combined addition of Cu and Ni to the metastable austenitic Fe-18Cr-10Mn-N alloy decreased DBTT, compared to the sole addtion of Ni or Cu. This could be explained by the fact that the combined addition of Cu and Ni largely enhanced austenite stability, and suppressed the formation of deformation-induced martensite and ${\delta}$-ferrite in conjunction with the beneficial effect of Cu which may increase stacking fault energy, so that it allows cross-slip to occur and thus reduces the planarity of the deformation mechanism.

• Metals and materials international
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• 제24권6호
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• pp.1202-1212
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• 2018

The effects of Nickle (Ni) addition on bainitic transformation and property of ultrahigh strength bainitic steels are investigated by three austempering processes. The results indicate that Ni addition hinders the isothermal bainite transformation kinetics, and decreases the volume fraction of bainite due to the decrease of chemical driving force for nucleation and growth of bainite transformation. Moreover, the product of tensile strength and total elongation (PSE) of high carbon bainitic steels decreases with Ni addition at higher austempering temperatures (220 and $250^{\circ}C$), while it shows no significant difference at lower austempering temperature ($200^{\circ}C$). For the same steel (Ni-free or Ni-added steel), the amounts of bainite and RA firstly increase and then decrease with the increase of the austempering temperature, resulting in the highest PSE in the sample austempered at temperature of $220^{\circ}C$. In addition, the effects of austempering time on bainite amount and property of high carbon bainitic steels are also analyzed. It indicates that in a given transformation time range of 30 h, more volume of bainite and better mechanical property in high carbon bainitic steels can be obtained by increasing the isothermal transformation time.

• 한국자기학회지
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• 제7권4호
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• pp.205-211
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• 1997

E-Beam Evaporator로 제조된 CoCrTa/CrNi 자성박막에서 하지층인 Cr에 대한 소량첨가원소인 Ni이 자성박막의 자기적 성질에 어떤 영향을 미치는가를 조사하였다. 상온에서 제조된 시편에서 소량의 첨가원소 Ni의 영향은 보자력의 증가를 가져왔음을 알 수 있었다. 이러한 보자력 증가의 원인을 XRD와 AFM으로 그 결정배향성과 미세구조를 통하여 살펴보았다. Cr 하지층에 Ni의 첨가시 결정립의 크기가 증가함을 알 수 있었다. 280 .deg. C 기판온도에서는 CrNi 하지층을 갖는 박막이 오히려 낮은 보자력 값을 나타내었고 이것은 결정립 크기의 증가때문으로 생각된다. 높은 기판온도에서는 결정배향성보다 Cr의 편석이 보자력에 대한 주요한 기구인 것으로 생각된다.