• Title, Summary, Keyword: titanium

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Effect of Titanium-Ion on the Growth of Various Bacterial Species

  • Yu, Tae-Shick
    • Journal of Microbiology
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    • v.42 no.1
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    • pp.47-50
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    • 2004
  • There are a number of studies that explain the metabolism and roles of metallic titanium and titanium-ion. One of the most intriguing results from these studies is the finding of metallic titanium having no bacteriostatic effects on oral bacterial species. In this research, the effects of titanium-ion on the growth of twenty-two bacterial species, some of which are commonly found in foods such as yoghurt, kimchi, and soy fermented products, were investigated. All but two bacteria, Escherichia coli and Pseudomonas aeruginosa appeared to be sensitive to titanium-ion. These two species were grown on 360 $\mu\textrm{g}$/$m\ell$ of titanium-ions, and they were found to be resistant to the titanium-ion. Both the wild-type and plasmid-cured E. coli showed good growth in a medium with 200 $\mu\textrm{g}$/$m\ell$ of titanium-ions. These results suggest that titanium-resistance was independent from the effects of the plasmid in E. coli.

Apatite formation on the surface treated-titanium plate in a simulated body fluid (생체유사액 침적에 따른 표면 처리된 titanium plate에 아파타이트 형성)

  • Lee, Chang-Hoon;Jin, Hyeng-Ho;Park, Hong-Chae;Yoon, Seog-Young
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.1
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    • pp.19-24
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    • 2009
  • The purpose of this study was to investigate the formation of apatite layer on two different titanium substrate treated with biomimetic method, Titanium plates were heat-treated at different temperatures of $400^{\circ}C$, $600^{\circ}C$, and $800^{\circ}C$ for 5 h in air atmosphere, And then, that plates were chemically treated with an alkali solution of 1 M sodium hydroxide (NaOH), The pre-treated titanium plates were soaked in the simulated body fluid (SBF) of Kokubo's recipe, After soaking for 7 days and 21 days in SBF, the coated layers formed on the titanium plates were characterized and compared with the morphology and chemical composition, The apatite formation was more activated on the titanium plates chemically treated with NaOH compared with the only heat-treated titanium plates.

Effect of Oxygen on Mechanical Properties of Metal Injection Molded Titanium and Titanium Alloy

  • Doi, Kenji;Hanami, Kazuki;Tanaka, Hideki;Teraoka, Tsuneo;Terauchi, Shuntaro
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • pp.771-772
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    • 2006
  • Mechanical properties of metal injection molded titanium and titanium alloy parts were investigated in this study. Material powders with low oxygen content and spherical shape were obtained by electrode induction-melting gas atomization which could melt and atomize titanium and titanium alloy bars with no touch on crucible or tundish. Tensile specimens were fabricated from obtained powders by metal injection molding process. Tensile strength of the specimens increases with increasing oxygen content. This result corresponds to a tendency of wrought metal.

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A study on Titanium Hydride Formation of Used Titanium Aircraft Scrap for Metal Foaming Agents

  • Hur, Bo-Yong;Ahn, Duck-Kyu;Kim, Sang-Youl;Jeon, Sung-Hwan;Park, Su-Han;Ahn, Hyo-Jun;Park, Chan-Ho;Yoon, Ik-Sub
    • Proceedings of the IEEK Conference
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    • pp.209-212
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    • 2001
  • Aircraft industry is developed very fast so titanium scrap was generated to manufacture. Titanium scrap was wasted and used to deoxidize cast iron so we are study recycling of it. In this research were studied that metal hydride of reacted in hydrogen chamber of AMS4900, 4901, return scrap titanium alloy and sponge titanium granule. The temperature of hydrogenation was 40$0^{\circ}C$ in the case of pure sponge titanium but return scrap titanium alloy were step reaction temperature at 40$0^{\circ}C$ and 50$0^{\circ}C$, and after the hydride of titanium alloy were crushed by ball mill for 5h. Titanium hydride contains to 4wt.% of hydrogen theoretically as theory. It was determined by heating and cooling curve in reaction chamber. The result of XRD was titanium hydride peak only that it was similar to pure titanium. Titanium hydride Powder particle size was about 45${\mu}{\textrm}{m}$, and recovery ratio was 95w% compared with scrap weight for a aluminum foam agent.

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Effect of Ti Intermediate Layer on Properties of HAp Plasma Sprayed Biocompatible Coatings

  • Take, Seisho;Otabe, Tusyoshi;Ohgake, Wataru;Atsumi, Taro
    • Corrosion Science and Technology
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    • v.19 no.2
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    • pp.51-56
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    • 2020
  • The objective of this study was to improve properties of plasma sprayed HAp layer to titanium substrate by introducing an intermediate layer with two different methods. Before applying Zn doped HAp coating on titanium substrate, an intermediate layer was introduced by titanium plasma spray or titanium anodization. Heat treatments were conducted for some samples after titanium intermediate layer was formed. Zn doped HAp top layer was applied by plasma spraying. Three-point bending test and pull-off adhesion test were performed to determine the adhesion of Zn doped HAp coatings to substrates. Long-term credibility of Zn doped HAp plasma sprayed coatings on titanium was assessed by electrochemical impedance measurements in Hanks' solution. It was found that both titanium plasma sprayed and titanium anodized intermediate layer had excellent credibility. Strong adhesion to the titanium substrate was confirmed after 12 weeks of immersion for coating samples with titanium plasma sprayed intermediate layer. Samples with titanium anodized intermediate layer showed good bending strength. However, they showed relatively poor resistance against pulling off. The thickness of titanium anodized intermediate layer can be controlled much more precisely than that of plasma sprayed one, which is important for practical application.

Drawing Process Design and Mechanical Properties Control for High Strengthening of CP Titanium (순수 타이타늄 고강도화를 위한 인발공정설계 및 기계적 특성 제어 기술)

  • Choi, Seong Woo;Park, Chan Hee;Lee, Sang Won;Yeom, Jong Taek;Hong, Jae Keun
    • Journal of the Korean Society for Precision Engineering
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    • v.34 no.2
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    • pp.77-81
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    • 2017
  • CP (Commercially Pure) titanium has been widely used in various industries such as in energy plants and bio-materials because of an excellent corrosion resistance and its non-toxicity to the human body. But there are limitations for usage as structural materials due to low strength. The tensile properties of CP titanium could be improved by microstructure refinement such as in a SPD (Severe Plastic Deformation) process. However, high strengthening of CP titanium wire is impossible by SPD processes like ECAP (Equal Channel Angular Pressing), HPT (High-Pressure Torsion), and the ARB (Accumulative Roll Bonding) process. The study purposes are to increase the strength of CP titanium wire by optimization of the cold drawing process and the harmonization with mechanical properties by heat treatments for the next forming process. The optimization process was investigated with regard to the design of drawing dies and the reduction ratio of cross sections. The elongations of high strength CP titanium were controlled by heat treatment.

Experimental study on the combustion characteristics of titanium alloy (티타늄 합금 폐기물의 연소 특성에 관한 실험적 연구)

  • Lee, Jun-Sik;Nam, Ki-Hun
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.2
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    • pp.105-110
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    • 2019
  • Most titanium alloy waste with cutting oil was discarded without recycling process so that it can be caused by metal and oil fires. However, there is no fire management system and studies on the titanium or titanium alloy waste in spite of high fire risk. The purpose of this experimental study is to identify the fire risk of the titanium alloy waste with cutting oil. We collected the 120g waste which was made in the biomedical titanium alloy cutting process. The waste was burned and conducted thermal image analysis with infrared camera. The experimental results which illustrated the process, characteristics, and trends of fire are presented. Firstly, the cutting oil was burned and partially the titanium alloy waste was burned. The maximum temperature of the fire was more than $650^{\circ}C$ in some specific spots. These results means when a lot of titanium alloy waste with cutting oil was ignited, this fire could connect the titanium fire. In other words, the fire has a flammable liquid fire and combustible metal fire at the same time. The experimental study could be used fire prevention, response, and investigation of the titanium alloy waste.

Surface Coatings to Enhance Bonding Strength of Dental Titanium-Ceramic Restorative System (치과용 타타늄-세라믹 수복시스템의 결합강도 향상을 위한 표면 코팅)

  • Lee, Hae-Hyoung
    • Journal of the Korean Ceramic Society
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    • v.45 no.10
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    • pp.600-604
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    • 2008
  • Although titanium-ceramic systems have gained substantial interests in dental prosthetic field, bonding problem between porcelain and titanium has not been solved. Main obstacle in titanium-porcelain bonding is excessive oxidation of titanium during porcelain firing. The effects of several coating materials on the bonding strength of titanium-porcelain system were investigated in this study. RF sputtering and electroplating of platinum significantly increased the bonding strength of porcelain-titanium specimen. However, coatings of Ni-Au, Ir, and ceramics(zirconia and hydroxyapatite) did not showed a significant effect on bonding strength. Platinum might be a promising material for the protective layer of excessive oxidation of titanium during porcelain firing, resulting in increase in the bonding strength.

Excretion, Tissue Distribution and Toxicities of Titanium Oxide Nanoparticles in Rats after Oral Administration over Five Consecutive Days (티타늄나노입자의 랫드 5일 반복 경구투여 후 배설, 조직분포 및 독성에 관한 평가연구)

  • Kim, Hyejin;Park, Kwangsik
    • Journal of Environmental Health Sciences
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    • v.40 no.4
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    • pp.294-303
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    • 2014
  • Objectives: Excretion and tissue distribution of titanium oxide nanoparticles were evaluated in rats after oral administration. The relation between toxicity and systemic concentration of nanoparaticles was investigated. Methods: Rats were orally treated with titanium oxide nanoparticles (10, 100 mg/kg) for five consecutive days. General toxicity, blood chemistry, and serum biochemical analysis were analyzed. Titanium concentration in liver, kidney, lung, urine and feces were measured and histopathology was performed in these organs. Results: Induction of toxicological parameters was not observed and titanium nanoparticles were excreted via feces. Conclusion: Absorption of titanium oxide nanoparticles via the gastrointestinal tract after oral administration was very poor and systemic concentration of titanium oxide nanoparticles was not elevated. Titanium oxide nanoparticles did not cause toxicities in rats after oral administration.

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

  • Jo, Sung-Koo;Jung, Jae-Young
    • Korean Journal of Metals and Materials
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    • v.47 no.3
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    • pp.182-187
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    • 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.