• 제목/요약/키워드: Titanium chloride

검색결과 66건 처리시간 0.024초

이산화타이타늄의 용융염 전기분해 반응기구 규명에 관한 연구 (A Study on the Examination of Reaction Mechanism for Molten Salt Electrolysis of Titanium Dioxide)

  • 조성구;정재영
    • 대한금속재료학회지
    • /
    • 제47권3호
    • /
    • pp.182-187
    • /
    • 2009
  • The molten salt electrolysis is applied to reduce titanium dioxide to titanium metal using calcium chloride as an electrolyte and the reaction mechanism of the reduction process is examined by analyzing the reaction products. The process conditions to obtain titanium metal for $900^{\circ}C$ correspond to 2.9~3.2 V and 24 hours. The reaction products for 2.9 V at $900^{\circ}C$ include irregular-shaped titanium oxides such as $Ti_4O_7$, $Ti_3O_5$ and $Ti_2O_3$ and polyhedral $CaTiO_3$. Using these microstructure analysis, the sequential reaction mechanism for the electrochemical reduction of titanium dioxide to titanium is proposed.

인공 체액 조건에서 임플랜트용 티타늄 소재의 부식 특성 (Corrosion Behavior of Titanium for Implant in Simulated Body Fluids)

  • 이중배;최기열
    • 한국표면공학회지
    • /
    • 제37권2호
    • /
    • pp.110-118
    • /
    • 2004
  • The corrosion of pure titanium (CP- Ti Grade 2) and titanium alloy (Ti6Al4V ELI) were studied under various conditions of simulated body fluids. The static immersion test and the electrochemical test were performed in accordance with ISO 10271 : 2001. For the electrochemical test, the open circuit potential was monitored as a function of time, and the cyclic polarization curve was recorded. The corrosion resistance was evaluated from the values of corrosion potential, passivation current density, breakdown potential, and the shape of hysteresis etc. The effects of alloy type, surface condition, temperature, oxygen, and constituents in the fluids such as acid, chloride were estimated. Both specimens had extremely low dissolution rate in the static immersion test. They showed strong passivation characteristics in the electrochemical test. They maintained negligible current density throughout the wide anodic potential range. The passive layer was not broken up to 2.0 V (vs. SCE). The hysteresis and the shift of passivation potential toward the anodic direction was observed during the reversed scan. The passivation process appeared to be accelerated by oxygen in air or that dissolved in the fluids. The passivation also proceeded without oxygen by the reaction of constituents in the fluids. Acid or chloride in the fluids, specially later weakened the passive layer, and then induced higher passivation current density and less shift of passivation potential in the reversed scan. CP-Ti Grade 2 was more reactive than Ti6Al4V ELI in the fluids containing acid or chloride, but thicker layer produced on its surface provided higher corrosion resistance.

Effects of pH and Chloride Concentration on Corrosion Behavior of Duplex Stainless Steel and Titanium Alloys Ti 6Al 2Nb 1Ta 1Mo at Elevated Temperature for Pump Impeller Applications

  • Aymen A., Ahmed;Ammar Yaseen, Burjes;Ammar Yaseen, Burjes
    • Corrosion Science and Technology
    • /
    • 제21권6호
    • /
    • pp.454-465
    • /
    • 2022
  • The objective of this study was to determine effects of temperatures and pH of sodium chloride solution with MgCl2 ions on corrosion resistance of duplex stainless-steel X2CrNiMoN22-5-3 (DSS) and Ti 6Al 2Nb1Ta1Mo (Ti). Effects of sodium chloride concentration on corrosion resistance were also studied. Corrosion behavior and pitting morphology of duplex stainless steel (DSS) and Ti alloys were evaluated through potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). It was found that a decrease in pH significantly reduced the corrosion resistance of both alloys. Changes in chloride concentration and temperature had more substantial impact on corrosion behavior of DSS than on Ti alloys. Pitting corrosion was formed on DSS samples under all conditions, whereas crevice corrosion was developed on Ti samples with the presence of magnesium chloride at 90 ℃. In conclusion, magnesium chloride ions in an exceedingly strong acidity solution appear to interact with re-passivation process at the surface of these alloys and influence the resulting surface topography.

금속염용액의 분무열분해에 의한 TiC/Co복합분말 제조 (Synthesis of TiC/Co Composite Powder by the Spray Thermal Conversion of Metallic Salt Solution)

  • 이길근;문창민;김병기
    • 한국분말재료학회지
    • /
    • 제10권4호
    • /
    • pp.228-234
    • /
    • 2003
  • In the present study, the focus is on the synthesis of titanium carbide/cobalt composite powder by the spray thermal conversion process using metallic salt solution as the raw materials. Two types of oxide powders of Ti-Co-O system were prepared by the spray drying of two types of metallic salt solutions : titanium chloride-cobalt nitrate and $TiO_2$ powder-cobalt nitrate solutions. These oxide powders were mixed with carbon black, and then these mixtures were carbothermal reduced under a flowing argon atmosphere. The changes in the phase structure and thermal gravity of the mixtures during carbothermal reduction were analysed using XRD and TG-DTA. In the case of using the titanium chloride-cobalt nitrate solution, it could not be obtained TiC/Co composite powder due to contamination of the impurities during the spray drying of the solution. However, in tile case of using the $TiO_2$ powder-cobalt nitrate scullion, TiC-15 wt. %Co composite powder could be synthesized by the spray thermal conversion process. The synthesized TiC-15 wt. %Co composite powder at 120$0^{\circ}C$ for 2 hours has average particle size of 150 nm.

도전체 매개반응(EMR)법에 의한 Ti 분말 제조 (Production of Titanium Powder by Electronically Mediated Reaction (EMR))

  • 박일;추용호;이철로;이오연
    • 한국재료학회지
    • /
    • 제14권12호
    • /
    • pp.857-862
    • /
    • 2004
  • Production of titanium powder directly from tantalum oxides ($TiO_2$) pellet through an electronically mediated reaction (EMR) by calciothermic reduction has been investigated. Feed material ($TiO_2\;pellet$) and reductant (Ca-Ni alloy) were charged into electronically isolated locations in a molten calcium chloride ($CaCl_2$) bath at $950^{\circ}C$. The current flow through an external circuit between the feed (cathode) and reductant (anode) locations was monitored during the reduction of $TiO_2$. The current approximately 3.2A was measured during the reaction in the external circuit connecting cathode and anode location. After the reduction experiment, pure titanium powder with low nickel content was obtained even though Ca-Ni alloy was used as a reductant. These results demonstrate that titanium powder can be produced without direct physical contact between the feed and reductant. In certain experimental conditions, pure titanium powder with approximately $99.5\;mass\%$ purity was successfully obtained.

합성식용색소의 정량분석법에 관한 검토 (Studies on the Determination of Synthetic Food Colors)

  • 엄애선;이헌옥;심재영;신동화;김용석;이영환;방정호;신재욱;이달수;홍기형;박성관;최장덕;김희연
    • 한국식품위생안전성학회지
    • /
    • 제20권2호
    • /
    • pp.73-76
    • /
    • 2005
  • 국내에 유통되는 식용 타르색소 9종 및 그 알루미늄레이크 6종의 색소 함량을 한국, 일본, 미국 및 JECFA의 색소정량법에 따라 비교$\cdot$검토하였다. 색소정량법은 한국과 일본이 삼염화티탄에 의한 적정법, 미국은 KiPP generator를 이용한 삼염화티탄법과 spectrophotomete법의 평균값을 구하여 나타냈고, JECFA는 미국방법 중 삼염화티탄법을 사용하였다. 또한 색소의 종류에 따라 함량에 대한 규격기준이 달랐으며 분석 시료의 색소물질 함량은 $85.08-96.40\%$, 식용색소레이크의 함량은 $10.00-36.86\%$로서 모두 규격기준에 적합한 것으로 나타났다.

폴리메틸렌 가지로 연결된 이핵 아릴옥시 티타늄 화합물을 이용한 스티렌의 신디오탁틱 중합 (Syndiotactic Polymerization of Styrene Catalyzed by Dinuclear (Cyclopentadienyl) (Aryloxy) Titanium(IV) Complexes with Polymethylene Bridge)

  • 금돈호;정우성;김경식;노석균;이동호;류원석
    • 폴리머
    • /
    • 제30권1호
    • /
    • pp.64-69
    • /
    • 2006
  • 길이가 다른 폴리메틸렌 가지로 연결되고 chloride 대신 aryloxy 기가 치환된 dinuclear half-titanocene $[(\eta^5-cyclopentadienyl)(aryloxy)TiCl_2]_2[(CH_2)_n]$ (n=3, n=6, n=0)를 합성하고 이들의 중합특성을 조사하였다. Chloride 대신 치환된 aryloxy기는 2,6-diisopropylphenoxy를 사용하였다. 합성된 3 종류의 dinuclear half-titanocene은 $^1H\;NMR,\;^{13}C\;NMR$, 원소분석, 그리고 질량분석을 통해 구조와 조성을 규명하였다 3가지 화합물의 중합특성을 비교 조사하기 위해 조촉매(MMAO) 존재 하에서 스티렌의 중합실험을 수행하였으며, 그 결과 (i) 합성된 3 가지 촉매들은 모두 스티렌 중합으로부터 SPS(syndiotactic polystyrene)를 제조하는데 성공적인 촉매였고, (ii) 3화합물 중에서 다리리간드의 길이가 가장 긴 화합물 6이 가장 높은 활성을 나타내었으나 가장 낮은 분자량의 SPS를 생성하였으며, (iii) aryloxy로 치환된 촉매가 치환되기 전의 chloride화합물에 비해 더 높은 활성을 보이는 치환체의 효과가 관찰되었다 이 결과들은 dinuclear half-titanocene에 있어서의 촉매 특성은 다리리간드의 종류와 함께 티타늄에 결합된 음이온의 특성도 촉매의 중합특성에 중요한 영향을 미치는 것임을 보여주는 것이다.

Methylthymolblue(MTB)에 依한 Ti(IV)의 吸光光度分析 (Spectrophotometric Determination of Ti(IV) by means of Methylthymolblue(MTB) Complex)

  • 박두원;이종남
    • 대한화학회지
    • /
    • 제7권4호
    • /
    • pp.299-303
    • /
    • 1963
  • A method of the colorimetric determination of titanium has been developed, based on the fact (IV) forms a stable blue complex with methylthymolblue(MTB) which is suitable for spectrophotometric determination of titanium in the concentration range of 0.2 to 22 $\mu$g per ml as $TiO_2$. The determination was carried out in the solution of pH range of 2.6 to 3.6, and the absorbancy of complex was at 600m$\mu$ with Coleman spectrophotometer. Titanium forms a 1:1 complex with MTB, which has a molar absorptivity, $1.1{\times}10^4$ at 600m\mu$. The effects of hydrogen ion concentration, reagent concentration, stability of complex, and hydrolysis were studied. Most of cations do not interfere seriously; however, many of anions such as oxalate, citrate, phosphate, chloride interfere in this determination.

  • PDF

Fabrication of Hybrid Films Using Titanium Chloride and 2,4-hexadiyne-1,6-diol by Molecular Layer Deposition

  • 윤관혁;성명모
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
    • /
    • pp.418-418
    • /
    • 2012
  • We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.

  • PDF

Sol-Gel and photoreduction 공정에 의한 Au 미립자분산 $TiO_{2}$ 박막 제조 (Preparation of Au fine particle dispersedf $TiO_{2}$ film by sol-gel and photoreduction process)

  • 현부성;김병일;강원호
    • 한국결정성장학회지
    • /
    • 제9권1호
    • /
    • pp.23-28
    • /
    • 1999
  • Au 미립자가 분산된 $TiO_{2}$ 박막을 졸겔담금법과 열처리공정으로 실리카 유리기판위에 제조하였다. $TiO_{2}$ 박막제조는 titanium tetraisopropoxide-EtOH-HCl-$H_{2}O$-hydrogen tetrachloroaurat (III) tetrahydrate계를 이용하였다. 고농도로 Au 화합물을 함유하면서 투명한 코팅용액을 형성하는 조건을 검토하였다. Au 금속미립자의 크기를 조절하기 위하여 광환원공정을 채택하였다. UV 조사에 따른 Au 입자의 변화와 $TiO_{2}$ 매트릭스의 상전이과정을 XRD, SEM, TEM and UV-visible spectrophotometer로 관찰하였다. 분산제로서 CPCl (Cetylpyridinium chloride monohydrate)의 효과를 평가하였다.

  • PDF