• Title/Summary/Keyword: NiAl alloy

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Kinetic Parameter Analysis of Hydrogen Diffusion Reaction for Hydrogen Storage Alloy of Fuel Cell System (연료전지의 수소저장용 합금에 대한 수소확산반응의 속도론적 해석)

  • Kim, Ho-Sung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.2
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    • pp.45-49
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    • 2006

  • Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

  • https://doi.org/10.5207/JIEIE.2006.20.2.045 인용 PDF KSCI

The Effect of Additive Elements on the Formation of Oxide Skins of AI-10wt.% Si Alloy Melts (용융 Al-10wt.%Si 합금의 산화피 형성에 미치는 첨가원)

  • 최재영;양정식;백영남
    • Journal of the Korean institute of surface engineering
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    • v.22 no.4
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    • pp.179-184
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    • 1989

  • This study seeks to the morphological changes in the oxide skin of the Al-10wt.%si alloy melts. These changes depend on the oxidation time and the temperature of the molten alloy, as well as the effects of adding Mg, Cu and Ni. Thess affects observed by X-ray diffractometer(XRD) and scanning electron microscope(SEM)' Very litte oxide skins on Al-10wtwt.%Si alloy melts can be detected by XRD because it is less than the measuring capabillity of the XRD, or the formation of noncrystalline oxide skins oxide skins canbe deteced by SEM. The addition of 1%Mg and 1%Cu-1%Mg-2.5%Ni to this base alloy crystallized the structure of the oxide skins and increased the oxidation in proportion to the length of time, but adding 3% had hardiy anyaffect at all on the crystal structure of the oxide skins.

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Fabrication and Mechanical Property of $Al_2$O$_.3$/Al Composite by Pressureless Infiltration (무가압 침윤법에 의한 $Al_2$O$_.3$/Al 복합재료 제조와 기계적 특성)

  • 이동윤;박상환;이동복
    • Journal of the Korean Ceramic Society
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    • v.35 no.3
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    • pp.303-309
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    • 1998

  • The fabrication of Al2O3/Al composite by pressureless infiltration was investigated by the change of Mg and Si content in Al alloy infiltration process and infiltration atmosphere. The effect of alloying elements infiltration atmosphere and interfacial reactants between Al alloy matrix and Al2O3 particles were in-vestigated in terms of bendingstrength and harness test,. The fabrication of Al2O3/Al composite by the vestigated in terms of bending strength and hardness test. The fabrication of Al2O3/Al composite by the pressureless infiltration was done in nitrogen atmosphere with Mg in Al alloy. It was successfully fabricated at $700^{\circ}C$ according to Mg contents in Al alloy and infiltration condition. Because Mg in the Al alloy and ni-trogen atmosphere of infiltratio condition produced Mg-N compound(Mg3N2) it decreased the wetting an-gle between molten Al alloy and Al2O3 particles by coating on surface of Al2O3 particles. The fracture strength of Al2O3/Al-Mg composite was 800MPa and Al2O3/Al-Si-Mg composite was 400MPa. Si in Al alloy decreased the interfacial strength between Al alloy matrix and Al2O3 particles.

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The effect of the process parameters on the electrical properties of Ni/Cr/Al/Cu alloy thin film (공정변수에 의한 Ni/Cr/Al/Cu계 박막의 전기적 특성)

  • 이붕주;박상무;박구범;박종관;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.725-728
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    • 2001

  • We have fabricated thin films using the DC/RF magnetron sputtering of 74wt%Ni-l8wt%Cr-4wt%Al-4wt%Cu alloy target and studied the effect of the process parameters on the electrical properties for low TCR(Temperature Coefficient of Resistance) films. In sputtering process, pressure, power and substrate temperature, are varied as controllable parameter. The films are annealed to 400$^{\circ}C$ in air and nitrogen atmosphere. The sheet resistance, TCR of the films increases with increasing annealing temperature. It abruptly increased as annealing temperature increased over 300$^{\circ}C$ in air atmosphere. From XRD, it is found that these results are due to the existence of NiO on film surface formed by annealing. As a results of them, TCR can be controlled by variation of sputter process parameter and annealing of thin film.

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