• 제목/요약/키워드: titianium

검색결과 5건 처리시간 0.016초

Titanium Oxide Film : A New Biomaterial For Artificial Heart Valve Prepared by Ion Beam Enhanced Deposition

  • Liu, Xianghuai;Zhang, Feng;Zheng, Zhihong;Huang, Nan
    • 한국진공학회지
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    • 제6권S1호
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    • pp.1-15
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    • 1997
  • Titanium oxide films were prepared by ion beam enhanced deposition where the films were synthesized by deposition titianium atoms and simultaneously bombarding with xenon ion beam at an energy of 40 keV in an $O_2$ environ,ent. Structure and composition of titanium oxide films were investigated by X-ray Doffractopm (XRD) Ritjerfprd Backscattering Spectroscopy (RBS) and X-ray Diffraction(XRD) Rutherford Backscattering Spectroscopy (RBS) and X-ray photoelectron spectroscopy (XPS) The results show that thestructure of the prepared films exhibit a rutile phase structure wit high(200) orientation and the O/Ti ratio of the titanium oxide films was about 2:1 XPS anlysis shows that $Ti^{2+},Ti^{3+}\;and\;Ti^{4+}$ chemical states exist on the titanium oxide films. the blood compatibility of the titanium oxide films was studied by measurements of blood clotting time and platelet adhesion. The results show that the anticoagulation property of titanium oxide films improved significantly and better than that of LTI-carbon which was widely used to fabricate artificial heart valve.

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A study on Electronic Properties of Passive Film Formed on Ti

  • Kim, DongYung;Kwon, HyukSang
    • Corrosion Science and Technology
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    • 제2권5호
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    • pp.212-218
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    • 2003
  • Electronic properties of passive films formed on Ti at film formation potentials $(E_f)V_{SCE}$ in pH 8.5 buffer solution and in an artificial seawater were examined through the photocurrent measurement and Mott-Schottky analysis. The passive films formed on Ti in pH 8.5 buffer solution exhibited a n-type semiconductor with a band gap energys $(E_g);E_g^{n=2}=3.4$ eV for nondirect electron transition, and $E_g^{n=0.5}=3.7$ eV for direct electron transition. These band gap values were almost same as those for the passive films formed in artificial seawater, indicating that chloride ion ($Cl^-$ in solution did not affect the electronic structure of the passive film on Ti. $E_g$ for passive films formed on Ti were found to be greater than those ($E_g^{n=0.5}=3.1$ eV, $E_g^{n=2}=3.4$) for a thermal oxide film formed on Ti in air at $400^{\circ}C$. The disorder energy of passive film, determined from the absorption tail of photocurrent spectrum, was much greater than that for the thermal oxide film farmed on Ti in air at $400^{\circ}C$. The greater $E_g$ and the higher disorder energy for the passive film compared with those for the thermal oxide fIlm suggest that the passive film on Ti exhibited more disorded structure than the thermal oxide film. The donor density (about $2.4{\times}10^{20}cm^{-3}$) for the passive film formed in artificial seawater was greater than that (about $20{\times}10^{20}cm^{-3}$) formed in pH 8.5 buffer solution, indicating that $Cl^-$ increased the donor density for the passive film on Ti.

초소성/확산접합 기술을 이용한 티타늄 샌드위치 경량구조물 제작 (Fabrication of Lightweight Sandwich Structural Components with Superplastic Forming/Diffusion Bonding Technology)

  • 이호성;윤종훈;이영무;신동혁
    • 한국항공우주학회지
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    • 제35권9호
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    • pp.778-782
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    • 2007
  • 본 연구에서는 초소성성형/확산접합 기술을 이용하여 티타늄 부품의 설계 및 성형 공정을 개발하였다. 초소성성형/확산접합 기술은 제작비용 및 무게를 감량할 수 있는 첨단기술로서 우주항공선진국에서는 이미 실용화하여 전투기, 우주왕복선의 부품 제작에 사용하고 있다. 난 가공성 재료로 알려진 티타늄 합금을 유한요소법을 사용하여 초소성성형중의 거동을 예측하였고, 3장의 Ti-6Al-4V판재를 사용하여 티타늄 경량 샌드위치 패널의 제작공정을 확립하였다. 제작한 부품의 평가결과 이론적인 예측과 잘 일치하는 것으로 나타났다.

티타늄이 도핑된 이산화 바나듐의 열변색 특성에 관한 연구 (A Study on the Thermochromic properties of Ti-doped Vanadium Dioxide)

  • 박진욱;박성수;안병현;홍성수;이근대
    • 청정기술
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    • 제21권4호
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    • pp.235-240
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    • 2015
  • 본 연구에서는 열변색 물성을 향상시키기 위한 방안의 하나로 0~0.5 at % 범위의 티타늄을 도핑한 이산화 바나듐(Ti-VO2)을 제조하였다. Ti-VO2 입자들은 바나딜설페이트, 중탄산암모늄, 사염화 티타늄 등을 사용하여 바나듐 화합물 전구체를 제조한 후 열분해법을 이용하여 제조하였다. 제조된 시료들의 결정 구조, 형상, 화학적 구조 및 열변색 특성은 X-선 회절분석기, 전계방사 주사전자현미경, X-선 광전자 분광기, 시차주사열량분석기, 자외선-가시광선-근적외선 분광기 등을 이용하여 분석하였다. 제조된 Ti-VO2 입자들은 단사 결정계를 지니고 있고, 또한 티타늄이 이산화 바나듐 결정내에 잘 도핑되어 있음을 확인할 수 있었다. 티타늄 도핑량이 증가함에 따라 최종 Ti-VO2 입자들의 크기가 작아지고 상전이 온도가 낮아졌으며, 또한 NIR switching efficiency는 증가하였다.