• Title/Summary/Keyword: NiTi alloy

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Effects of Ti on High Temperature Oxidation of Ni-Based Superalloys (Ni 기지 초내열합금의 고온산화 저항성에 미치는 Ti의 영향)

  • Park, Si-Jun;Seo, Seong-Moon;Yoo, Young-Soo;Jeong, Hi-Won;Jang, HeeJin
    • Corrosion Science and Technology
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    • v.15 no.3
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    • pp.129-134
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    • 2016
  • The effects of Ti on the high temperature oxidation of Ni-based superalloys were investigated by cyclic oxidation at $850^{\circ}C$ and $1000^{\circ}C$. The oxide scale formed at $850^{\circ}C$ consists of $Cr_2O_3$, $Al_2O_3$, and $NiCr_2O_4$ layers, while a continuous $Al_2O_3$ layer was formed at $1000^{\circ}C$. The oxidation rate of the alloy with higher Ti content was higher than the alloy with less Ti content at $850^{\circ}C$, possibly due to the increase in the metal vacancy concentration in the $Cr_2O_3$ layer involved by incorporation of $Ti^{4+}$. However, Ti improved the oxidation resistance of the superalloy at $1000^{\circ}C$ by reducing oxygen vacancy concentration in $Al_2O_3$ layer.

The effect of substitution elements(Co, Cr, Fe) on the properties of Zr-based hydrogen storage alloy electrode for Ni-MH secondary battery (Ni-MH 2차 전지용 Zr계 수소저장합금전극의 특성에 미치는 치환원소(Co, Cr, Fe)의 영향)

  • Choi, Seung-Jun;Jung, So-Yi;Seo, Chan-Yeol;Choi, Jeon;Park, Choong-Nyeon
    • Journal of Hydrogen and New Energy
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    • v.10 no.3
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    • pp.185-189
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    • 1999
  • Effects of alloy modification with the $Zr_{0.6}Ti_{0.4}V_{0.4}Ni_{1.2}Mn_{0.4}$ alloy for an electrode use have been investigated. For the alloy composition, a part of Mn was substituted by Co, Cr and Fe. The experimental results showed that Co accelerated activation of alloy, and Fe and Cr improved the discharge capacity. These results agree with P-C-T curves of each alloy. But substituting Fe for Mn showed the decrease of the discharge capacity when discharged at high rate (60mA, about 1C rate). Considering both the discharge capacity and the high rate discharge property, $Zr_{0.6}Ti_{0.4}V_{0.4}Ni_{1.2}Mn_{0.3}Cr_{0.1}$ alloy was found to be the best alloy among the alloys subjected to the test.

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The Evaluation of Mechanical Properties of TiNi/Al 6061 Shape Memory Composites by Using Experimental and Finite Element Analysis (TiNi/Al 6061 형상기억복합재료의 기계적특성에 관한 실험 및 해석적 평가)

  • 박동성;박영철;이동화;이규창
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.687-691
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    • 2001
  • Al alloy matrix composite with TiNi shape memory fiber as reinforcement has been fabricated by hot pressing to investigate mechanical properties. The stress-strain behavior of the composites was evaluated at temperatures between 363K and room temperature as a function of pre-strain by using experimental and finite element analysis, and both cases showed that the tensile stress at 363K was higher than that of the room temperature. Especially, the tensile stress of this composite increases with increasing the amount of pre-strain, and it also depends on the volume fraction of fiber and heat treatment. The smartness of the composite is given due to the shape memory effect of the TiNi fiber which generates compressive residual stress in the matrix material when heated after being pre-strained.

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Study of Thermal Stability of Ni Silicide using Ni-V Alloy

  • Zhong, Zhun;Oh, Soon-Young;Lee, Won-Jae;Zhang, Ying-Ying;Jung, Soon-Yen;Li, Shi-Guang;Lee, Ga-Won;Wang, Jin-Suk;Lee, Hi-Deok;Kim, Yeong-Cheol
    • Transactions on Electrical and Electronic Materials
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    • v.9 no.2
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    • pp.47-51
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    • 2008
  • In this paper, thermal stability of Nickel silicide formed on p-type silicon wafer using Ni-V alloy film was studied. As compared with pure Ni, Ni-V shows better thermal stability. The addition of Vanadium suppresses the phase transition of NiSi to $NiSi_2$ effectively. Ni-V single structure shows the best thermal stability compared with the other Ni-silicide using TiN and Co/TiN capping layers. To enhance the thermal stability up to $650^{\circ}C$ and find out the optimal thickness of Ni silicide, different thickness of Ni-V was also investigated in this work.