• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.71-75
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• 2022

In this research, Fe-Ni alloy films were electrodeposited on stainless steel (SS304 and SS430) and Ti plates to investigate the effects of surface conditions of cathode on deposits. The Ti plates were electropolished in 3 M H₂SO₄-methanol electrolytes at various conditions before electrodeposition, and unpolished Ti and the optimized specimen, polished at 10 V for 8 min, were used as cathode. The anomalous codeposition, the phenomenon which more active Fe is reduced preferentially, occurred on all substrate, however, there were differences in composition of all deposits. As the results of potential monitoring during electrodeposition, it was confirmed that the larger overpotential was applied to the deposition cell when using Ti cathode, leading to high Fe content of deposits from unpolished Ti due to increase in nucleation of Fe. Also, it was founded that the polished Ti can reduced deposition overpotential.

• Korean Journal of Materials Research
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• v.7 no.11
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• pp.942-950
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• 1997

NiAI기 산화물 분산강화(Oxide Dispersion Strengthende:ODS)합금을 기계적 합금화 (Mechanical Alloying: MA)방법으로 제조하였으며, 열간압축방법으로 성형하였다. 연이어 단순항온처리에 의한 정상결정립성장과 특성조건에서의 thermomechanical treatment 에 의한 이차재결정화를 유도하였다. 결정립 조대화된 ODSD MA NiAI의 creep 성질 및 이에 조대화된 미세조직은 creep 성질이 저하된 반면, 이차재결정화된 MA NiAI의 creep성질은 크게 향상되었다. 이 creep 성질의 향상은 이차재결정화의 특성인 급격한 결정립의 조대화, 분산상의 성장억제 및 grain aspect ratio의 증가에 기인한 것으로 사료되었다. 이차재결정화된 ODS MA NiAI의 creep또는 glide controlled dislocation creep임을 제시하지만, 전체 creep속도가 결정립 크기 및 grain aspect ratio의 영향을 크게 받은 것을 볼 때, 결정립계 미끄럼기구가 주 creep 기구와 조합되어 MA NiAI의 전체 creep기구에 영향을 준 것으로 추정할 수 있었다.

• Electronics and Telecommunications Trends
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• v.28 no.5
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• pp.24-33
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• 2013

형상기억 물질은 임의의 형상을 유지하다 외부의 자극에 의하여 원래의 형상으로 회복되는 물질이다. 이와 같은 형상기억 물질은 형상기억합금과 형상기억고분자로 대별되며, 형상기억효과를 응용하려는 용도 및 특성에 따라 선택되어 사용되고 있다. 본고에서는 형상기억합금과 형상기억고분자의 특성 및 원리에 대해 정리하였으며, 형상기억합금에 비해 가볍고 저렴하며 외부 자극의 종류도 다양하게 선택할 수 있는 형상기억고분자의 용도를 정리하였다. 향후 형상기억고분자는 wearable 디스플레이, 태양광 패널 및 비침습성 의학소자 등 그 용도가 다양할 것으로 전망된다.

• Journal of Korea Foundry Society
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• v.24 no.2
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• pp.101-107
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• 2004

회주철 및 구상흑연주철에 있어서 압탕방안 및 합금원소가 수축결함의 생성에 미치는 영향을 연구하였다. 두 종류의 압탕방안으로 실린더형상의 계단상시편을 제조하였으며 회주철의 경우 5조성(ISO 150, 200, 250, 300, 350), 구상흑연주철의 경우 6조성(SG 10, 20, 30, 40, 50, 60)을 사용하였다. 회주철 및 구상흑연주칠 공히, 1차 압탕방안의 경우 액상수축에 의한 1차수축결함이 후육부의 표면에 발생하였으며 수축결함의 내면은 매끄러웠다. 회주철의 경우 응고수축에 의한 2차수축결함은 생성되지 않았으나 구상흑연주철의 경우 모든 시편의 내부열점에 2차수축결함이 발생하였고 그 내면은 거칠었다. 2차압탕방안의 경우 회주철의 모든 시편에서는 1차 및 2차수축결함이 발생되지 않았다. 그러나 구상흑연주철의 경우 탄화물 생성원소가 첨가된 SG 40, 50 및 60의 3조성에서 2차수축결함이 열점에 생성되었다. 견고한 ���V주형을 사용하였기 때문에 주형벽이동으로 인한 표면팽창은 어느 경우에도 관찰되지 않았다.

• 전기의세계
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• v.42 no.9
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• pp.20-27
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• 1993

1. 철근출막은 결정자기이방성의 영향이 작기 때문에, 자기특성이 막의 기하학적구조에 의해 거의 결정되고 그것에 의하여 자성막의 설계가 가능하다. 2. 코발트 근출막은 결정자기이방성이 자기특성에 영향은 크기때문에 코발트 결정의 자화용역축(C축)의 배향에 의하여 자기특성은 크게 변한다. 따라서 이 C축의 배향성을 변화시켜 석출입자의 형태를 바꾸지 않고 작은 포아직경에서도 항자력의 제어가 가능하였다. 3. 코발트-철합금신출막은 조성변화에 의하여 자기특성을 제어할 수 있다. 또 ㅈ포화자화, 항자력도 철을 석출한 자성막에 비해서 높은 값을 나타냄을 물론, 우수한 각형화(Mr/Ms)로 얻어지는 큰 자기에너지적으로 수직 자기기록방식의 고정밀의 로타리 엔코다에의 응용이 유망하다.

• Journal of the Korean Magnetics Society
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• v.27 no.4
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• pp.129-134
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• 2017

Bulk-type body-centered-tetragonal Fe-Co alloy was synthesised by utilising a conventional alloy preparation technologies, such as melting, solidification, and homogenising treatments, and its magnetic properties were investigated. In the $(Fe_{100-x}Co_x)_{1-y}C_y$ alloy, the composition range, from which single phase body-centered-tetragonal alloy (martensite phase) was obtained, was severely limited: Co content x = 2.5, and C content y = 0.062. Tetragonality(c/a) of the synthesised body-centered-tetragonal $(Fe_{97.5}Co_{2.5})_{0.938}C_{0.062}$ alloy was 1.05. Magnetocrystalline anisotropy constant ($K_1$) of the body-centered-tetragonal $(Fe_{97.5}Co_{2.5})_{0.938}C_{0.062}$ alloy was measured to be $9.8{\times}10^5J/m^3$), which was 3.1 time as high as the pure iron (${\alpha}-Fe$).

• Journal of the Korean Chemical Society
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• v.47 no.4
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• pp.315-324
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• 2003

In this study, a new method is presented to produce stable hydrophobic metal alloy nanocluster in chloroform solution including surfactant NaAOT(sodium bis(2-ethylhexyl)-sulfosuccinate) via the chemical reduction of metal salt $(HAuCl_4,\AgNO_3,\Cu(NO_3)_2)$ by sodium borohydride. For the alloy nanocluster, several samples were prepared by changing the molar ratio of Au/Cu, Au/Ag alloy nanocluster, 3:1, 1:1, 1:3. The alloy nanoclusters were characterized by UV-Visible spectrophotometer, TEM(Transmission Electron Microscope), and XPS(X-ray Photoelectron Spectrometer). With the change of the mole ratio of the alloy component, the wavelengths of the surface plasmon absorption shift linearly from 520 nm of the pure Au nanocluster to 570 nm of the pure Cu nanocluster for Au/Cu alloy nanoclusters and from 405 nm to 520 nm for Au/Ag alloy nanoclusters. The chemical shifts of the Au4f, Ag3d, Cu2p XPS peaks were observed with changing the molar ratio of the alloy element. The alloy nanoclusters in chloroform solution were made uniformly in size and colloidally stable for long periods of time. These results indicate that the method here is a very effective method for synthesizing hydrophobic alloy nanoclusters with uniform or nearly uniform particle size distribution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.8-13
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• 2012

Ti-3Al-2.5V ingot was produced, processed into a titanium alloy wire of 9mm diameter, and the characteristics were studied in comparison with imported material. The ingot satisfied ASTM Grade 9 standard showing oxygen content of 0.11wt% and iron content of 0.085wt%. The hardness of the 9mm diameter titanium alloy was similar to that of the imported material showing values between 225 and 250Hv, and the tensile strength of the imported material was 804MPa while that of the domestic development was 734MPa. The elongation of the imported material was 12% while that of the domestic development was 22%. A new process of manufacturing 9.0mm diameter titanium alloy wire through forging and multi-step hot rolling process out of 400mm diameter ingot was developed.

• Analytical Science and Technology
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• v.7 no.4
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• pp.517-526
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• 1994

Large insoluble phases and dispersoids in Al-Li-Cu-Mg-Mn-Zr alloys containing Mn were analyzed with EPMA(Electron Probe Microanalyzer) and SAEM(Scanning Auger Electron Microscope). Morphology, distribution and volume fraction of the large insoluble phase were also analyzed quantitatively by optical microscopy. Mechanical properties were tested at room temperature and at $200^{\circ}C$. With increasing Mn contents, the volume fraction of the large insoluble phases increased steeply, thus decreasing ductility. Mn was found to be very effective for obtaing uniformly distributed fine-grain structures. The alloy containing 0.44 wt% Mn showed the highest tensile strength among Mn-bearing alloys tested.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.211-218
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• 2014

In this paper the magnetic field properties of the soft magnetic alloys (Fe-Si-Cr and Fe-Ni-Cr) are studied in advance for the development of electro-magnetic shielding films, which could be used in the IT Devices (NFC, mobile phone, computer, etc.).As a result each of the selected soft magnetic alloy melts of the corresponding compositions is water-dispersed into the disk-shaped grains, which are soaked in polymer resin, and of which two types of thin film of thickness 0.1mm and 1mm are made by passing through the heating calendar roller. And the magnetic permeability and the shielding effectiveness of the polymer films containing the soft magnetic alloy grains are measured over the whole frequency bands from the low frequency to 10GHz. Before the experiments of the soft magnetic alloy, a special equation is proposed to estimate the permeability of the alloy, and the equation is verified with the pre-published data by MATLAB, and from which the most optimal compositions can be decided. And the SE(Shielding Effectiveness) of the polymer films containing the soft magnetic alloy grains is simulated by the HFSS.