• Title/Summary/Keyword: FeNi alloy

Search Result 443, Processing Time 0.027 seconds

Magnetic Properties of Three-layered Ferromagnetic Films with a NiFeCuMo Intermediately Super-soft Magnetic Layer (강자성층 사이에 초연자성 NiFeCuMo 중간층을 삽입한 3층 박막구조의 자기적 특성)

  • Choi, Jong-Gu;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
    • /
    • v.20 no.4
    • /
    • pp.129-133
    • /
    • 2010
  • Two-layered ferromagnetic alloy films (NiFe, CoFe) with a Conetic (NiFeCuMo) intermediately soft magnetic layer of different thickness were investigated to correlate the coercivity values and magnetization process with the strength of saturation field of hard axis. Thickness dependence of the $H_{EC}$ (coercivity of easy axis), $H_{HS}$ (saturation field of hard axis.), and X (susceptibility) of NiFe and NiFeCuMo thin films for the glass/Ta(5 nm)/[CoFe or NiFe(5 nm-t/2)]/NiFeCuMo(t = 0, 4, 6, 8, 10 nm)/[CoFe or NiFe(5 nm-t/2)]/Ta(5 nm) films prepared by the ion beam deposition method was measured. The magnetic properties $H_{EC}$, $H_{HS}$, and X of two-layered ferromagnetic CoFe, NiFe films with a NiFeCuMo intermediately super-soft magnetic layer were strongly depended on the thickness of NiFeCuMo layer. The value of the coercivity and magnetic susceptibility of the NiFeCuMo film decreased by 25% and doubled relative to that of the NiFe film.

The electrochemical properties of Zr-Ti-V-Ni-Mn hydrogen storage alloys with various compositions for an electrode of Ni-MH secondary battery (Ni-MH 2차 전기 전극용 Zr-Ti-V-Ni-Mn계 수소저장합금의 조성에 따른 전기화학적 특성)

  • Choi, Seung-Jun;Jung, So-Yi;Park, Choong-Nyeon
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.10 no.4
    • /
    • pp.219-224
    • /
    • 1999
  • Effects of alloy modification for the $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$ alloy as an electrode materials have been investigated. When Ti in the alloy was partially substituted by Zr, the hydrogen storage capacity and subsequently the discharge capacity increased significantly, however, the activation characteristic and rate capability decreased. By substituting Mn with other elements (Cr, Co and Fe) in the alloy, discharge capacity decreased but the cycle life and rate capability were improved. Considering both the discharge capacity, the high rate discharge property and cycle life, the $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.3}Cr_{0.1}$ alloy among the alloys subjected to the test was found to be a prominent alloy for a practical usage.

  • PDF

Outer Diameter Stress Corrosion Cracking Susceptibility of Steam Generator Tubing Materials (증기발생기 전열관 재료의 2차측 응력부식균열 민감성)

  • Kim, Dong-Jin;Kim, Hyun Wook;Kim, Hong Pyo
    • Corrosion Science and Technology
    • /
    • v.10 no.4
    • /
    • pp.118-124
    • /
    • 2011
  • Alloy 600 (Ni 75 wt%, Cr 15 wt%, Fe 10 wt%) as a heat exchanger tube of the steam generator (SG) in nuclear power plants (NPP) has been degraded by various corrosion mechanism during the long-term operation. Especially lead (Pb) is known to be one of the most deleterious species in the secondary system causing outer diameter stress corrosion cracking (ODSCC). Oxide formation and breakdown is requisite for SCC initiation and propagation. Therefore it is expected that a property change of the oxide formed on SG tubing materials by lead addition into a solution is closely related to PbSCC. In the present work, the SCC susceptibility was assessed by using a slow strain rate test (SSRT) in caustic solutions with and without lead for Alloy 600 and Alloy 690 (Ni 60 wt%, Cr 30 wt%, Fe 10 wt%) used as an alternative of Alloy 600 because of outstanding superiority to SCC. The results were discussed in view of the oxide property formed on Alloy 600 and Alloy 690. The oxides formed on Alloy 600 and Alloy 690 in aqueous solutions with and without lead were examined by using a transmission electron microscopy (TEM), equipped with an energy dispersive x-ray spectroscopy (EDXS).

NANO-STRUCTURAL AND NANO-CHEMICAL ANALYSIS OF NI-BASE ALLOY/LOW ALLOY STEEL DISSIMILAR METAL WELD INTERFACES

  • Choi, Kyoung-Joon;Shin, Sang-Hun;Kim, Jong-Jin;Jung, Ju-Ang;Kim, Ji-Hyun
    • Nuclear Engineering and Technology
    • /
    • v.44 no.5
    • /
    • pp.491-500
    • /
    • 2012
  • The dissimilar metal joints welded between Ni-based alloy, Alloy 690 and low alloy steel, A533 Gr. B with Alloy 152 filler metal were characterized by using optical microscope, scanning electron microscope, transmission electron microscope, secondary ion mass spectrometry and 3-dimensional atom probe tomography. It was found that in the weld root region, the weld was divided into several regions including unmixed zone in Ni-base alloy, fusion boundary, and heat-affected zone in the low alloy steel. The result of nanostructural and nanochemical analyses in this study showed the non-homogeneous distribution of elements with higher Fe but lower Mn, Ni and Cr in A533 Gr. B compared with Alloy 152, and the precipitation of carbides near the fusion boundary.