• Title/Summary/Keyword: Titanium film

Search Result 382, Processing Time 0.026 seconds

Corrosion of Titanium Alloys in High Temperature Seawater

  • Pang, J.J.;Blackwood, D.J.
    • Corrosion Science and Technology
    • /
    • v.14 no.4
    • /
    • pp.195-199
    • /
    • 2015
  • Materials of choice for offshore structures and the marine industry have been increasingly favoring materials that offer high strength-to-weight ratios. One of the most promising families of light-weight materials is titanium alloys, but these do have two potential Achilles' heels: (i) the passive film may not form or may be unstable in low oxygen environments, leading to rapid corrosion; and (ii) titanium is a strong hydride former, making it vulnerable to hydrogen embrittlement (cracking) at high temperatures in low oxygen environments. Unfortunately, such environments exist at deep sea well-heads; temperatures can exceed $120^{\circ}C$, and oxygen levels can drop below 1 ppm. The present study demonstrates the results of investigations into the corrosion behavior of a range of titanium alloys, including newly developed alloys containing rare earth additions for refined microstructure and added strength, in artificial seawater over the temperature range of $25^{\circ}C$ to $200^{\circ}C$. Tests include potentiodynamic polarization, crevice corrosion, and U-bend stress corrosion cracking.

Ellipso-Microscopic Observation of Titanium Surface under UV-Light Irradiation

  • Fushimi, K.;Kurauchi, K.;Nakanishi, T.;Hasegawa, Y.;Ueda, M.;Ohtsuka, T.
    • Corrosion Science and Technology
    • /
    • v.15 no.6
    • /
    • pp.265-270
    • /
    • 2016
  • The ellipso-microscopic observation of a titanium surface undergoing anodization in $0.05mol\;dm^{-3}$ of $H_2SO_4$ was conducted. During irradiation by ultra-violet (UV) light with a wavelength of 325 nm, the titanium surface allowed for the flow of a photo-induced current and showed up as a bright, patch-like image on an ellipso-microscopic view. The brightness and patch-pattern in the image changed with flowing photo-induced current. The changes in the brightness and the image corresponded to the formation and/or degradation of titanium oxide due to the photo-electrochemical reaction of the oxide. An in situ monitoring using the ellipso-microscope revealed that the film change was dependent on the irradiation light power, by UV-light increases the anodic current and results in the initiation of pitting at lower potentials as compared with the non-irradiated condition.

Study on the Composition Analysis and Electrical Properties of Chemical Vapor Deposited PbTiO3 Thin Film (화학증착법에 의한 PbTiO3박막의 조성분석 및 전기적성질에 관한 연구)

  • 이혜용;윤순길;김호기
    • Journal of the Korean Ceramic Society
    • /
    • v.26 no.5
    • /
    • pp.670-676
    • /
    • 1989
  • The PbTiO3 is well known materials having remarkable ferroelectric, piezoelectric, and pyroelectric properties. PbTiO3 thin films with a perovskite structure were successfully fabricated on titanium substrate by chemical vapor deposition. These films were characterized according to composition, crystal structure, and electrical properties. Semi-quantitative compositional analysis of the deposited films was made by Auger Electron Spectroscopy(AES). The PbTiO3 film deposited on titanium substrate at the deposition temperature 75$0^{\circ}C$, the Ti(C2H5O)4 fraction 0.15, and O2 partial pressure 0.06atm, has a columnar structure and grows with(001) preferred orientation, and has stoichiometric composition. A clear dielectric transition and offset in the dc conductivity near the transition temperature(48$0^{\circ}C$) were observed in the deposited lead titanate film.

  • PDF

INVESTIGATION OF MULTI-ARC PLASMA PLATING FILM EQUIPMENT BULAT-6 AND ITS TECHNICAL CHARACTERISTICS

  • Wen Xueya;Ma Te2ngcai;Hu Shejun
    • Journal of the Korean Vacuum Society
    • /
    • v.6 no.S1
    • /
    • pp.133-136
    • /
    • 1997
  • In this paper multi-arc plasma plating film equipment Bulat-6 and its technical characteristics were analyzed in detail. This machine is the first of its kind in China. Influential factors and reducing methods on microdroplets of titanium were investigated. By method of electromagnetic field control and ion beam enhanced deposition excellent titanium nitride film could be obtained. Bicrohardness and adhesion were 250Mpa and 6.5Kg respectively.

  • PDF

Photo-catalytic Characteristics of Sol-Gel Synthesized TiO2 Thin Film (졸-겔법을 이용한 TiO2 박막의 광촉매 특성)

  • Choi, Kyu-Man;Kim, Yeo-Hwan;Lim, Hae-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.14 no.2
    • /
    • pp.846-849
    • /
    • 2013
  • Thin film of $TiO_2$ was obtained by the sol-gel dip method on the brosilicate glass substrate. It was found that the film was about $1.5{\mu}m$ thick as obtained by 4 successive coatings and annealed at varied temperatures ranged from $300^{\circ}C$ to $1100^{\circ}C$ for 2 hrs. The substrate used was having the surface area of $100mm^2$. Increasing the annealing temperature caused to change in mineralogical phase of titanium oxide i.e., amorphous, crystalline antase to rutile phases. The particle size of the titanium oxide film were ranged from $0.1{\sim}0.54{\mu}m$ estimated by the SEM analysis. The material showed an absorbance maximum at the wavelength 390nm obtained by UV-visible spectrophotometer. These results therefore, indicated that the $TiO_2$ film obtained relatively at low annealing temperature consisted predominantly with anatase phase; possessed higher photocatalytic behavior i.e., 2.4 times higher than that of only UV lamp irradiation.

Removal of Humic Acid Using Titania Film with Oxygen Plasma and Rapid Thermal Annealing (산소플라즈마와 급속열처리에 의해 제조된 티타니아 박막의 휴믹산 제거)

  • Jang, Jun-Won;Park, Jae-Woo
    • Journal of Soil and Groundwater Environment
    • /
    • v.12 no.3
    • /
    • pp.29-35
    • /
    • 2007
  • Titanium was oxidized with oxygen plasma and calcinated with rapid thermal annealing for degradation of humic acid dissolved in water. Titania photocatalytic plate was produced by titanium surface oxidized with oxygen plasma by Plasma Enhanced Chemical Vapor Deposition (PECVD). RF-power and deposition condition is controlled under 100 W, 150 W, 300 W and 500 W. Treatment time was controlled by 5 min and 10 min. The film properties were evaluated by the X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). From the experimental results, we found the optimal condition of titania film which exhibited good performance. Moreover photocatalytic capacity was about twice better than thermal spray titania film, and also as good as titania powder.

Dry Etching Characteristics of TiN Thin Films in BCl3-Based Plasma

  • Woo, Jong-Chang;Park, Jung-Soo;Kim, Chang-Il
    • Transactions on Electrical and Electronic Materials
    • /
    • v.12 no.3
    • /
    • pp.106-109
    • /
    • 2011
  • We investigated the etching characteristics of titanium nitride (TiN) thin film in $BCl_3$/Ar inductively coupled plasma. The etching parameters were the gas mixing ratio, radio frequency (RF) power, direct current (DC)-bias voltages and process pressures. The standard conditions were as follows: total flow rate = 20 sccm, RF power = 500 W, DC-bias voltage = -100 V, substrate temperature = $40^{\circ}C$, and process pressure = 15 mTorr. The maximum etch rate of TiN thin film and the selectivity of TiN to $Al_2O_3$ thin film were 54 nm/min and 0.79. The results of X-ray photoelectron spectroscopy showed no accumulation of etch byproducts from the etched surface of TiN thin film. The TiN film etch was dominated by the chemical etching with assistance by Ar sputtering in reactive ion etching mechanism, based on the experimental results.

A Wrapping Method for Inserting Titanium Micro-Mesh Implants in the Reconstruction of Blowout Fractures

  • Choi, Tae Joon;Burm, Jin Sik;Yang, Won Yong;Kang, Sang Yoon
    • Archives of Plastic Surgery
    • /
    • v.43 no.1
    • /
    • pp.84-87
    • /
    • 2016
  • Titanium micro-mesh implants are widely used in orbital wall reconstructions because they have several advantageous characteristics. However, the rough and irregular marginal spurs of the cut edges of the titanium mesh sheet impede the efficacious and minimally traumatic insertion of the implant, because these spurs may catch or hook the orbital soft tissue, skin, or conjunctiva during the insertion procedure. In order to prevent this problem, we developed an easy method of inserting a titanium micro-mesh, in which it is wrapped with the aseptic transparent plastic film that is used to pack surgical instruments or is attached to one side of the inner suture package. Fifty-four patients underwent orbital wall reconstruction using a transconjunctival or transcutaneous approach. The wrapped implant was easily inserted without catching or injuring the orbital soft tissue, skin, or conjunctiva. In most cases, the implant was inserted in one attempt. Postoperative computed tomographic scans showed excellent placement of the titanium micro-mesh and adequate anatomic reconstruction of the orbital walls. This wrapping insertion method may be useful for making the insertion of titanium micro-mesh implants in the reconstruction of orbital wall fractures easier and less traumatic.

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

  • Liu, Xianghuai;Zhang, Feng;Zheng, Zhihong;Huang, Nan
    • Journal of the Korean Vacuum Society
    • /
    • v.6 no.S1
    • /
    • pp.1-15
    • /
    • 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.

  • PDF

High Photocatalytic Activity of Gd2O2S:Tb Modified Titanium Dioxide Films

  • Kim, Bum-Goo;Lee, Hak-Guen;Kim, Hee-Sung;Kim, Young-Soon
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.3
    • /
    • pp.675-678
    • /
    • 2009
  • $Fe_2O_3,\;Ag_2O,\;CaWO_4$ and $Gd_2O_2S$:Tb loaded on titanium dioxide photocatalysts (P25, Degussa) were prepared by a calcination. Their composite films containing water-born polyurethane used as a material for immobilization were obtained by spray coating technique. The photocatalytic activity of the titanium dioxide films was characterized by decrease of UV-vis absorption spectra for methylene blue and gas chromatography for photocatalytic decomposition of formaldehyde diluted in water. It was shown that the $Gd_2O_2S$:Tb modified titanium dioxide films had good photocatalytic properties and followed the first-order kinetic model with regard to photocatalytic decoloration of methylene blue. Especially in formaldehyde photodegradation experiment, decrease rate of concentration of the titanium dioxide films with $Gd_2O_2S$:Tb modifying was about 35% larger than that of the unloaded titanium dioxide film.