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acyclic alkenes and intramolecular pathway on dicarbonyl compounds to yield ... Table 1, substituted benzofurans 2a-g were obtained in good yield and in the .... The titanium-induced synthesis of benzofurans has proved to be the method of ...

Friction Welding of Titanium and Carbon Steel

OpenAIRE

Atsushi, HASUI; Yoichi, KIRA; Faculty of Science and Technology, Keio University; Ishikawajima-Harima Heavy Industries, Co., Ltd.

1985-01-01

Titanium-steel is a combination of dissimilar materials, which are difficult to weld in general, owing to inevitable formation of brittle intermetallic compounds. A prominent feature of friction welding process is ability to weld dissimilar materials in many kinds of combinations. This report deals with friction weldabilily of pure titanium and S25C steel, which are 12 mm in diameter. Main results are summarized as follows; (1) Suitable welding conditions to obtain a sound weld, which has a j...

Influence of Alkali Treatment on Anodized Titanium Alloys in Wollastonite Suspension

Directory of Open Access Journals (Sweden)

Alicja Kazek-Kęsik

2017-08-01

Full Text Available The surface modification of titanium alloys is an effective method to improve their biocompatibility and tailor the material to the desired profile of implant functionality. In this work, technologically-advanced titanium alloys—Ti-15Mo, Ti-13Nb-13Zr and Ti-6Al-7Nb—were anodized in suspensions, followed by treatment in alkali solutions, with wollastonite deposition from the powder phase suspended in solution. The anodized samples were immersed in NaOH or KOH solution with various concentrations with a different set of temperatures and exposure times. Based on their morphologies (observed by scanning electron microscope, the selected samples were investigated by Raman and X-ray photoelectron spectroscopy (XPS. Titaniate compounds were formed on the previously anodized titanium surfaces. The surface wettability significantly decreased, mainly on the modified Ti-15Mo alloy surface. Titanium alloy compounds had an influence on the results of the titanium alloys’ surface modification, which caused the surfaces to exhibit differential physical properties. In this paper, we present the influence of the anodization procedure on alkali treatment effects and the properties of obtained hybrid coatings.

Phase equilibria, phases and compounds in the Ti-C system

International Nuclear Information System (INIS)

Gusev, Aleksandr I

2002-01-01

The results of experimental and theoretical investigations of the phase equilibria in the titanium-carbon system are generalised. The generalised thermodynamic characteristics of disordered titanium carbide TiC y , are reported. Peculiarities of the crystal structures of all the known and hypothetical compounds of titanium with carbon are considered in detail. The X-ray diffraction patterns which allow identification of all these compounds are presented. The phase diagrams of the Ti-C system constructed with allowance for atomic ordering of non-stoichio metric carbide, TiC y , and for the existence of the molecular cluster-like compounds Ti 8 C 12 and Ti 13 C 22 (TiC 2 ) are discussed. The bibliography includes 142 references.

Phase equilibria, phases and compounds in the Ti-C system

International Nuclear Information System (INIS)

Gusev, A.I.

2002-01-01

The results of experimental and theoretical investigations related to the phase equilibria in the titanium-carbon system are generalized. The generalized thermodynamic characteristics of the disordered titanium carbide TiC y are given. The crystal structure of all the discovered and hypothetical compounds of titanium with carbon are considered in detail. The x-ray diffraction patterns which allow one to identify all these compounds are given. The phase diagrams of the Ti-C system constructed with allowance for atomic ordering of non-stoichiometric TiC y carbide and for the existence of the compounds Ti 8 C 12 and Ti 13 C 22 (TiC 2 ) of the molecule cluster type are discussed [ru

Titanium

Science.gov (United States)

Woodruff, Laurel G.; Bedinger, George M.; Piatak, Nadine M.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Titanium is a mineral commodity that is essential to the smooth functioning of modern industrial economies. Most of the titanium produced is refined into titanium dioxide, which has a high refractive index and is thus able to impart a durable white color to paint, paper, plastic, rubber, and wallboard. Because of their high strength-to-weight ratio and corrosion resistance, titanium metal and titanium metal alloys are used in the aerospace industry as well as for welding rod coatings, biological implants, and consumer goods.Ilmenite and rutile are currently the principal titanium-bearing ore minerals, although other minerals, including anatase, perovskite, and titanomagnetite, could have economic importance in the future. Ilmenite is currently being mined from two large magmatic deposits hosted in rocks of Proterozoic-age anorthosite plutonic suites. Most rutile and nearly one-half of the ilmenite produced are from heavy-mineral alluvial, fluvial, and eolian deposits. Titanium-bearing minerals occur in diverse geologic settings, but many of the known deposits are currently subeconomic for titanium because of complications related to the mineralogy or because of the presence of trace contaminants that can compromise the pigment production process.Global production of titanium minerals is currently dominated by Australia, Canada, Norway, and South Africa; additional amounts are produced in Brazil, India, Madagascar, Mozambique, Sierra Leone, and Sri Lanka. The United States accounts for about 4 percent of the total world production of titanium minerals and is heavily dependent on imports of titanium mineral concentrates to meet its domestic needs.Titanium occurs only in silicate or oxide minerals and never in sulfide minerals. Environmental considerations for titanium mining are related to waste rock disposal and the impact of trace constituents on water quality. Because titanium is generally inert in the environment, human health risks from titanium and titanium

Optical detections from worn and unworn titanium compound surfaces

DEFF Research Database (Denmark)

Rasmussen, Inge Lise; Guibert, M.; Martin, J.-M.

2010-01-01

of a titanium nitride (TiN) layer we obtain an increase in the reflected light as a result of wear. The relative change of reflectance of light from the tribological TiAlN coated surface to the underlying layer of TiN is similar for non-worn surfaces and for surfaces exposed to an abrasive wear process...... of a residual thickness of realistic tribological coatings prior to complete wear....

Opportunities in the electrowinning of molten titanium from titanium dioxide

CSIR Research Space (South Africa)

Van Vuuren, DS

2005-10-01

Full Text Available used, the following forms of titanium are produced: titanium sponge, sintered electrode sponge, powder, molten titanium, electroplated titanium, hydride powder, and vapor-phase depos- ited titanium. Comparing the economics of alter- native...-up for producing titanium via the Kroll process is approximately as follows: ilmenite ($0.27/kg titanium sponge); titanium slag ($0.75/kg titanium sponge); TiCl4 ($3.09/kg titanium sponge); titanium sponge raw materials costs ($5.50/kg titanium sponge); total...

Thermochemically active iron titanium oxide materials

Energy Technology Data Exchange (ETDEWEB)

Coker, Eric Nicholas; Miller, James E.

2018-01-16

A thermal oxidation-reduction cycle is disclosed that uses iron titanium oxide as the reactive material. The cycle may be used for the thermal splitting of water and/or carbon dioxide to form hydrogen and/or carbon monoxide. The formed compounds may be used as syngas precursors to form fuels.

Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

International Nuclear Information System (INIS)

Huppmann, T.; Leonhardt, S.; Krampe, E.; Wintermantel, E.; Yatsenko, S.; Radovanovic, I.; Bastian, M.

2014-01-01

To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO 2 ) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO 2 for antimicrobial efficacy is to deposit a thin TiO 2 coating on the surface. In contrast to the common way of applying a coating, TiO 2 particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects that could lead to surface defects. The filler material (Aeroxide® TiO 2 P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO 2 -PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result

Characterization polyethylene terephthalate nanocomposites mixing with nano-silica and titanium oxide

Directory of Open Access Journals (Sweden)

Rusu Mircea A.

2017-01-01

Full Text Available Polyethylene terephthalate (PET based nanocomposites containing nano-silica (Aerosil (Degusa and titanium oxide (TiO2 (Merk were prepared by melt compounding. Influence of nano-silica and titanium oxide on properties of the resulting nanocomposites was investigated by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR and atomic force microscopy (AFM. The possible interaction between nano-silica and titanium oxide particles with PET functional groups at bulk and surface was elucidated by transmission of FTIR-ATR spectroscopy. AFM studies of the resulting nanocomposites showed an increased surface roughness compared to pure PET. SEM images illustrated that nano-silica particles have tendency to migrate to the surface of the PET matrix much more than titanium oxide powder.

Cell Attachment Following Instrumentation with Titanium and Plastic Instruments, Diode Laser, and Titanium Brush on Titanium, Titanium-Zirconium, and Zirconia Surfaces.

Science.gov (United States)

Lang, Melissa S; Cerutis, D Roselyn; Miyamoto, Takanari; Nunn, Martha E

2016-01-01

The aim of this study was to evaluate the surface characteristics and gingival fibroblast adhesion of disks composed of implant and abutment materials following brief and repeated instrumentation with instruments commonly used in procedures for implant maintenance, stage-two implant surgery, and periimplantitis treatment. One hundred twenty disks (40 titanium, 40 titaniumzirconium, 40 zirconia) were grouped into treatment categories of instrumentation by plastic curette, titanium curette, diode microlaser, rotary titanium brush, and no treatment. Twenty strokes were applied to half of the disks in the plastic and titanium curette treatment categories, while half of the disks received 100 strokes each to simulate implant maintenance occurring on a repetitive basis. Following analysis of the disks by optical laser profilometry, disks were cultured with human gingival fibroblasts. Cell counts were conducted from scanning electron microscopy (SEM) images. Differences in surface roughness across all instruments tested for zirconia disks were negligible, while both titanium disks and titaniumzirconium disks showed large differences in surface roughness across the spectrum of instruments tested. The rotary titanium brush and the titanium curette yielded the greatest overall mean surface roughness, while the plastic curette yielded the lowest mean surface roughness. The greatest mean cell counts for each disk type were as follows: titanium disks with plastic curettes, titanium-zirconium disks with titanium curettes, and zirconia disks with the diode microlaser. Repeated instrumentation did not result in cumulative changes in surface roughness of implant materials made of titanium, titanium-zirconium, or zirconia. Instrumentation with plastic implant curettes on titanium and zirconia surfaces appeared to be more favorable than titanium implant curettes in terms of gingival fibroblast attachment on these surfaces.

Formation and characterization of titanium nitride and titanium carbide films prepared by reactive sputtering

International Nuclear Information System (INIS)

Sundgren, J.-E.

1982-01-01

Titanium has been reactively r.f. sputtered in mixed Ar-N 2 and Ar-CH 4 discharges on to substrates held at 775 K. The films obtained have been characterized by scanning electron microscopy, X-ray diffraction and by measurements of hardness and electrical resistivity. The compositions of the films have been determined using Auger electron spectroscopy. The processes occurring both on substrates and target surfaces have been studied and it is shown that the latter is of great importance for the composition and structure of deposited films. Titanium nitride films of full density and with electrical resistivity and hardness values close to those of bulk TiN were only obtained in a narrow range close to the stoichiometric composition. Titanium carbide films grown on non-biased substrates were found to have an open structure and thus a low density. A bias applied to the substrate, however, improved the quality of the films. It is also shown that the heat of formation of the compounds plays an important role in the formation of carbides and nitrides. A large value promotes the development of large grains and dense structures. (Auth.)

Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

Energy Technology Data Exchange (ETDEWEB)

Huppmann, T., E-mail: teresa.huppmann@tum.de; Leonhardt, S., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de; Krampe, E., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de; Wintermantel, E., E-mail: wintermantel@tum.de [Institute of Medical and Polymer Engineering, Technische Universität München (Germany); Yatsenko, S., E-mail: s.yatsenko@skz.de; Radovanovic, I., E-mail: i.radovanovic@skz.de, E-mail: m.bastian@skz.de; Bastian, M., E-mail: i.radovanovic@skz.de, E-mail: m.bastian@skz.de [SKZ- German Plastics Center, Würzburg (Germany)

2014-05-15

To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO{sub 2}) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO{sub 2} for antimicrobial efficacy is to deposit a thin TiO{sub 2} coating on the surface. In contrast to the common way of applying a coating, TiO{sub 2} particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects that could lead to surface defects. The filler material (Aeroxide® TiO{sub 2} P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO{sub 2}-PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result.

Welding of titanium and nickel alloy by combination of explosive welding and spark plasma sintering technologies

Energy Technology Data Exchange (ETDEWEB)

Malyutina, Yu. N., E-mail: iuliiamaliutina@gmail.com; Bataev, A. A., E-mail: bataev@adm.nstu.ru; Shevtsova, L. I., E-mail: edeliya2010@mail.ru [Novosibirsk State Technical University, Novosibirsk, 630073 (Russian Federation); Mali, V. I., E-mail: vmali@mail.ru; Anisimov, A. G., E-mail: anis@hydro.nsc.ru [Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk, 630090 (Russian Federation)

2015-10-27

A possibility of titanium and nickel-based alloys composite materials formation using combination of explosive welding and spark plasma sintering technologies was demonstrated in the current research. An employment of interlayer consisting of copper and tantalum thin plates makes possible to eliminate a contact between metallurgical incompatible titanium and nickel that are susceptible to intermetallic compounds formation during their interaction. By the following spark plasma sintering process the bonding has been received between titanium and titanium alloy VT20 through the thin powder layer of pure titanium that is distinguished by low defectiveness and fine dispersive structure.

Properties of titanium-alloyed DLC layers for medical applications

Science.gov (United States)

Joska, Ludek; Fojt, Jaroslav; Cvrcek, Ladislav; Brezina, Vitezslav

2014-01-01

DLC-type layers offer a good potential for application in medicine, due to their excellent tribological properties, chemical resistance, and bio-inert character. The presented study has verified the possibility of alloying DLC layers with titanium, with coatings containing three levels of titanium concentration prepared. Titanium was present on the surface mainly in the form of oxides. Its increasing concentration led to increased presence of titanium carbide as well. The behavior of the studied systems was stable during exposure in a physiological saline solution. Electrochemical impedance spectra practically did not change with time. Alloying, however, changed the electrochemical behavior of coated systems in a significant way: from inert surface mediating only exchange reactions of the environment in the case of unalloyed DLC layers to a response corresponding rather to a passive surface in the case of alloyed specimens. The effect of DLC layers alloying with titanium was tested by the interaction with a simulated body fluid, during which precipitation of a compound containing calcium and phosphorus - basic components of the bone apatite - occurred on all doped specimens, in contrast to pure DLC. The results of the specimens' surface colonization with cells test proved the positive effect of titanium in the case of specimens with a medium and highest content of this element. PMID:25093457

Adsorption performance of titanium dioxide (TiO2) coated air filters for volatile organic compounds.

Science.gov (United States)

Zhong, Lexuan; Lee, Chang-Seo; Haghighat, Fariborz

2012-12-01

The photocatalytic oxidation (PCO) technology as an alternative method for air purification has been studied for decades and a variety of PCO models indicate that the adsorption of reactants on the catalyst surface is one of the major physical and chemical processes occurring at a heterogeneous photocatalytic reaction. However, limited study explored the adsorption effect of a photocatalyst. This study carried out a systematic evaluation of adsorption performance of titanium dioxide (TiO(2)) coated fiberglass fibers (FGFs), TiO(2) coated carbon cloth fibers (CCFs), and original CCFs air filters at various relative humidity conditions for nine volatile organic compounds. TiO(2)/FGFs, TiO(2)/CCFs, and CCFs were characterized by SEM for morphology and N(2) adsorption isotherm for BET surface area and pore structure. A bench-scale adsorption test setup was constructed and adsorption tests were performed at various relative humidity conditions and four different injected concentrations for each compound. The isothermal adsorption curves at low concentration levels were obtained and they were well described by Langmuir isotherm model. It was noticed that there were significant differences between the adsorption behaviors and photocatalytic activities of TiO(2)/FGFs and TiO(2)/CCFs. It was concluded that adsorption performance is closely related to the characteristics of substrates and therefore, the development of a substrate with high adsorption ability is a promising trend for improving the performance of the UV-PCO technology. Copyright © 2012 Elsevier B.V. All rights reserved.

Properties of tritium and its compounds

International Nuclear Information System (INIS)

Belovodskij, L.F.; Gaevoj, V.K.; Grishmanovskij, V.I.

1985-01-01

Ways of tritium preparation and different aspects of its application are considered. Physicochemical properties of this isotope and some compounds of it - tritium oxides, lithium, titanium, zirconium, uranium tritides, tritium organic compounds - are discussed. In particular, diffusion of tritium and its oxide through different materials, tritium oxidation processes, decomposition of tritium-containing compounds under the action of self-radiation are considered. Main radiobiological tritium properties are described

Nanodispersed boriding of titanium alloy

International Nuclear Information System (INIS)

Kostyuk, K.O.; Kostyuk, V.O.

2015-01-01

The problem of improving the operational reliability of machines is becoming increasingly important due to the increased mechanical, thermal and other loads on the details. There are many surface hardening methods for machines parts which breakdown begins with surface corruption. The most promising methods are chemical-thermal treatment. The aim of this work is to study the impact of boriding on the structure and properties of titanium alloy. Materials and Methods: The material of this study is VT3-1 titanium alloy. The boriding were conducted using nanodispersed powder blend based on boric substances. It is established that boriding of paste compounds allows obtaining the surface hardness within 30 - 29 GPa and with declining to 27- 26 GPa in layer to the transition zone (with total thickness up to 110 μm) owing to changes of the layer phase composition where T 2 B, TiB, TiB 2 titanium borides are formed. The increasing of chemical-thermal treatment time from 15 minutes to 2 hours leads to thickening of the borated layer (30 - 110 μm) and transition zone (30 - 190 μm). Due to usage of nanodispersed boric powder, the boriding duration is decreasing in 2 - 3 times. This allows saving time and electric energy. The developed optimal mode of boriding the VT3-1 titanium alloy allows obtaining the required operational characteristics and to combine the saturation of the surface layer with atomic boron and hardening

Spark plasma sintering of titanium aluminide intermetallics and its composites

Science.gov (United States)

Aldoshan, Abdelhakim Ahmed

Titanium aluminide intermetallics are a distinct class of engineering materials having unique properties over conventional titanium alloys. gamma-TiAl compound possesses competitive physical and mechanical properties at elevated temperature applications compared to Ni-based superalloys. gamma-TiAl composite materials exhibit high melting point, low density, high strength and excellent corrosion resistance. Spark plasma sintering (SPS) is one of the powder metallurgy techniques where powder mixture undergoes simultaneous application of uniaxial pressure and pulsed direct current. Unlike other sintering techniques such as hot iso-static pressing and hot pressing, SPS compacts the materials in shorter time (< 10 min) with a lower temperature and leads to highly dense products. Reactive synthesis of titanium aluminide intermetallics is carried out using SPS. Reactive sintering takes place between liquid aluminum and solid titanium. In this work, reactive sintering through SPS was used to fabricate fully densified gamma-TiAl and titanium aluminide composites starting from elemental powders at different sintering temperatures. It was observed that sintering temperature played significant role in the densification of titanium aluminide composites. gamma-TiAl was the predominate phase at different temperatures. The effect of increasing sintering temperature on microhardness, microstructure, yield strength and wear behavior of titanium aluminide was studied. Addition of graphene nanoplatelets to titanium aluminide matrix resulted in change in microhardness. In Ti-Al-graphene composites, a noticeable decrease in coefficient of friction was observed due to the influence of self-lubrication caused by graphene.

Titanium ; dream new material

International Nuclear Information System (INIS)

Lee, Yong Tae; Kim Seung Eon; Heoon, Yong Taek; Jung, Hui Won

2001-11-01

The contents of this book are history of Titanium, present situation of Titanium industry, property of Titanium alloy, types of it, development of new alloy of Titanium smelting of Titanium, cast of Titanium and heat treatment of Titanium, Titanium alloy for plane, car parts, biological health care, and sport leisure and daily life, prospect, and Titanium industrial development of Titanium in China.

In vivo evaluation of an antibacterial coating containing halogenated furanone compound-loaded poly(l-lactic acid) nanoparticles on microarc-oxidized titanium implants.

Science.gov (United States)

Cheng, Yicheng; Gao, Bo; Liu, Xianghui; Zhao, Xianghui; Sun, Weige; Ren, Huifang; Wu, Jiang

2016-01-01

To prevent peri-implant infection, a new antibacterial coating containing a halogenated furanone compound, (Z-)-4-bromo-5-(bromomethylene)-2(5H)-furanone-loaded poly(l-lactic acid) nanoparticles, has been fabricated. The current study was designed to evaluate the preventive effect of the antibacterial coating under a simulated environment of peri-implant infection in vivo. Microarc-oxidized titanium implants treated with minocycline hydrochloride ointment were used as positive control group, and microarc-oxidized titanium implants without any treatment were used as blank control group. Three kinds of implants were implanted in dogs' mandibles, and the peri-implant infection was simulated by silk ligation and feeding high sugar diet. After 2-month implantation, the results showed that no significant differences were detected between the experimental and positive control groups (P>0.05), but the data of clinical measurements of the blank control group were significantly higher than those of the other two groups (Pmicroscope observation and histological examination showed that more new bone was formed on the surface of the experimental and positive control groups. It can be concluded that the antibacterial coating fabricated on implants has remarkable preventive effect on peri-implant infection at the early stage.

Spectroscopic studies on Titanium ion binding to the apo lactoferrin

International Nuclear Information System (INIS)

Moshtaghie, A.A.; Ani, M.; Arabi, M.H.

2006-01-01

Titanium is a relatively abundant element that has found growing applications in medical science and recently some of Titanium compounds are introduced as anticancer drugs. In spite of very limited data which exist on the Titanium metabolism, some proteins might be involved in the mechanism of action of Titanium up to our knowledge, there is not any report in the literature concerning binding of Titanium to apo lactoferrin. Binding of apo lactoferrin with Ti(IV)-citrate was studied by spectroflourimeterey and spectrophotometery techniques under physiological conditions. The spectroflourimeteric studies revealed a significant fluorescence quenching, that indicated binding of apo lactoferrin with Ti(IV). The same reaction was monitored through spectrophotometry technique; this represents a characteristic UV difference band at 267 nm, which is different from lac-Fe (III). Titration studies how that lactoferrin specifically binds two moles Ti(IV) as complex with citrate per mol protein. Spectroflourimeterey and spectrophotometery techniques indicated that Ti(IV) ions cause a reduction (13%-14%) in binding of Fe(III) to lactoferrin. In overall, we may come to this conclusion that this element might be involved in the iron metabolism

Research on development and application of titanium and zirconium alloys

International Nuclear Information System (INIS)

Suzuki, Toshiyuki; Sasano, Hisaoki; Uehara, Shigeaki; Nakano, Osamu; Shibata, Michio

1983-01-01

It can be said that titanium and zirconium are new metals from the viewpoint of the history of metals, but both have grown to the materials supporting modern industries, titanium alloys in aerospace and ocean development, and zirconium alloys in nuclear power application. However, the properties of both alloys have not yet been clarified. In this study, the synthesis of TiNi and its properties, precipitation hardening type titanium alloys, and the effect of oxygen on the mechanical properties of both alloys were examined. TiNi is the typical intermetallic compound which shows the peculiar properties. The method of its synthesis by diffusion was examined, and it was clarified that it is useful as a structural material and also as a functional material. Precipitation hardening type alloys have not been developed in titanium alloys, but in this study, the feasibility of several alloy systems was found. Both titanium and zirconium have large affinity to oxygen, and the oxygen absorbed in the manufacturing process cannot be reduced. The tensile property of both alloys was examined in wide temperature range, and the effect of oxygen was clarified. (Kako, I.)

EUGENOL POLYMER MODIFIED TITANIUM ELECTRODE FOR THE ANALYSIS OF CARBOCYSTEINE

OpenAIRE

S. EL QOUATLI; R. T. NGONO; R. NAJIH; A. CHTAINI

2012-01-01

A eugenol polymer immobilized electrode was developed for the assay of the carbocysteine compound. The electrochemical sensor was made by in situ electropolymerization of eugenol at titanium electrode. Cyclic voltamperometry at prepared electrode permitted to point out a reversible pattern for carbocysteine electrooxidation.

Synthesis of Cyclododecatriene from 1,3-Butadiene by Trimerization over Amine-Titanium Complex Catalyst

International Nuclear Information System (INIS)

Park, Da Min; Kim, Gye Ryung; Lee, Ju Hyun; Kim, Geon-Joong; Cho, Deuk Hee

2013-01-01

The new complex catalysts were synthesized by the reaction of titanium compounds (titanium chloride or titanium butoxide) and diamines in this work, and they showed very high catalytic activities for the cyclododecatriene (CDT) synthesis from 1,3-butadiene through trimerization. CDT synthetic reaction was performed in an autoclave reactor, and the effects of reaction temperature, type of catalyst, catalyst amount added into the system, the mole ratio of Al/Ti and immobilization method were investigated on the yield of product CDT. The titanium complex catalyst combined to diamine with 1:1 ratio showed high selectivity to CDT more than 90%. The ratio of TTT-CDT/TTC-CDT isomers in the product revealed as different values, depending on the type of diamine combined to titanium and Ti/diamine ratios. Those homogeneous complexes could be used as a heterogenized catalyst after anchoring on the supports, and the immobilized titanium catalyst retained the catalytic activities for several times in the recycled reactions without leaching. The carbon support containing titanium has exhibited superior activity to the silica support. Especially, when the titanium complex was anchored on the support which was fabricated by the hydrolysis of tripropylaminosilane itself, the resulting titanium catalyst showed the highest BD conversion and CDT selectivity

Comparative study about hydrogen sorption in sponge and powder titanium

International Nuclear Information System (INIS)

Vasut, Felicia; Preda, Anisoara; Zamfirache, Marius; Ducu, Catalin; Malinovschi, Viorel

2005-01-01

Currently, hydrogen may be stored as a compressed gas or a cryogenic liquid. Neither method appears to be practical for many applications in which hydrogen use would otherwise be attractive. For example, gaseous storage of stationary fuel is not feasible because of the large volume or weight of the storage vessels. Liquid hydrogen could be use extensively but the liquefaction process is relatively expensive. The hydrogen can be stored for a long term with a high separation factor, as a solid metal hydride. Using hydride-forming metals and intermetallic compounds, for example, recovery, purification and storage of heavy isotopes in tritium containing system, can solve many problems arising in the nuclear-fuel cycle. The paper presents a comparative study about hydrogen sorption on two titanium structures: powder and sponge. Also, it is presented the characterization, by X-Ray diffraction, of two structures, before and after sorption process. From our results, one can conclude that sorption method is efficient for both samples. Kinetic curves indicates that sorption rate for titanium powder is lower than for sponge titanium. This is the effect of reaction surface, which is larger for powder titanium. Sorption capacity for hydrogen is lower in powder titanium for identical experimental conditions. The difference between storage capacities could be explained by activation temperature, which was lower for titanium powder than for sponge. (authors)

Oxochloroalkoxide of the Cerium (IV and Titanium (IV as oxides precursor

Directory of Open Access Journals (Sweden)

Machado Luiz Carlos

2002-01-01

Full Text Available The Cerium (IV and Titanium (IV oxides mixture (CeO2-3TiO2 was prepared by thermal treatment of the oxochloroisopropoxide of Cerium (IV and Titanium (IV. The chemical route utilizing the Cerium (III chloride alcoholic complex and Titanium (IV isopropoxide is presented. The compound Ce5Ti15Cl16O30 (iOPr4(OH-Et15 was characterized by elemental analysis, FTIR and TG/DTG. The X-ray diffraction patterns of the oxides resulting from the thermal decomposition of the precursor at 1000 degreesC for 36 h indicated the formation of cubic cerianite (a = 5.417Å and tetragonal rutile (a = 4.592Å and (c = 2.962 Å, with apparent crystallite sizes around 38 and 55nm, respectively.

EUGENOL POLYMER MODIFIED TITANIUM ELECTRODE FOR THE ANALYSIS OF CARBOCYSTEINE

Directory of Open Access Journals (Sweden)

S. EL QOUATLI

2012-06-01

Full Text Available A eugenol polymer immobilized electrode was developed for the assay of the carbocysteine compound. The electrochemical sensor was made by in situ electropolymerization of eugenol at titanium electrode. Cyclic voltamperometry at prepared electrode permitted to point out a reversible pattern for carbocysteine electrooxidation.

Effects of Admixed Titanium on Densification of 316L Stainless Steel Powder during Sintering

Directory of Open Access Journals (Sweden)

Aslam Muhammad

2014-07-01

Full Text Available Effects of admixed titanium on powder water atomized (PWA and powder gas atomized (PGA 316L stainless steel (SS have been investigated in terms of densification. PGA and PWA powders, having different shapes and sizes, were cold pressed and sintered in argon atmosphere at 1300°C. The admixed titanium compacts of PGA and PWA have shown significant effect on densification through formation of intermetallic compound and reducing porosity during sintering process. PWA, having particle size 8 μm, blended with 1wt% titanium has exhibited higher sintered density and shrinkage as compared to gas atomized powder compacts. Improved densification of titanium blended PGA and PWA 316L SS at sintering temperature 1300°C is probably due to enhanced diffusion kinetics resulting from stresses induced by concentration gradient in powder compacts.

Sealing glasses for titanium and titanium alloys

Science.gov (United States)

Brow, Richard K.; McCollister, Howard L.; Phifer, Carol C.; Day, Delbert E.

1997-01-01

Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B.sub.2 O.sub.3), barium oxide (BaO), lanthanum oxide (La.sub.2 O.sub.3), and at least one other oxide selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), calcium oxide (CaO), lithium oxide (Li.sub.2 O), sodium oxide (Na.sub.2 O), silicon dioxide (SiO.sub.2), or titanium dioxide (TiO.sub.2). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900.degree. C., and generally about 700.degree.-800.degree. C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

Surface modification of titanium and titanium alloys by ion implantation.

Science.gov (United States)

Rautray, Tapash R; Narayanan, R; Kwon, Tae-Yub; Kim, Kyo-Han

2010-05-01

Titanium and titanium alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, titanium and its alloys cannot meet all of the clinical requirements. Therefore, to improve the biological, chemical, and mechanical properties, surface modification is often performed. In view of this, the current review casts new light on surface modification of titanium and titanium alloys by ion beam implantation. (c) 2010 Wiley Periodicals, Inc.

Gentamicin-Eluting Titanium Dioxide Nanotubes Grown on the Ultrafine-Grained Titanium.

Science.gov (United States)

Nemati, Sima Hashemi; Hadjizadeh, Afra

2017-08-01

Titanium (Ti)-based materials is the most appropriate choices for the applications as orthopedic and dental implants. In this regard, ultrafine-grained (UFG) titanium with an enhanced mechanical properties and surface energy has attracted more attention. Titanium dioxide (TiO 2 ) nanotubes grown on the titanium could enhance bone bonding, cellular response and are good reservoirs for loading drugs and antibacterial agents. This article investigates gentamicin loading into and release from the TiO 2 nanotubes, grown on the UFG compared to coarse-grained (CG) titanium substrate surfaces. Equal Channel Angular Pressing (ECAP) was employed to produce the UFG structure titanium. TiO 2 nanotubes were grown by the anodizing technique on both UFG and CG titanium substrate surfaces. Scanning electron microscopy (SEM) imaging confirmed TiO 2 nanotube growth on the surface. The UV-vis spectroscopy analysis results show that the amount of gentamicin load-release in the anodized UFG titanium sample is higher than that of CG one which can be explained in terms of thicker TiO 2 nanotube arrays layer formed on UFG sample. Moreover, the anodized UFG titanium samples released the drug in a longer time than CG (1 day for the UFG titanium vs. 3 h for the CG one). Regarding wettability analysis, anodized UFG titanium sample showed more enhanced hydrophilicity than CG counterpart. Therefore, the significantly smaller grain size of pure titanium provided by the ECAP technique coupled with appropriate subsequent anodization treatment not only offers a good combination of biocompatibility and adequate mechanical properties but also it provides a delayed release condition for gentamicin.

Vapor pressure and evaporation rate of certain heat-resistant compounds in a vacuum at high temperatures

Science.gov (United States)

Bolgar, A. S.; Verkhoglyadova, T. S.; Samsonov, G. V.

1985-01-01

The vapor pressure and evaporation rate of borides of titanium, zirconium, and chrome; and of strontium and carbides of titanium, zirconium, and chrome, molybdenum silicide; and nitrides of titanium, niobium, and tantalum in a vacuum were studied. It is concluded that all subject compounds evaporate by molecular structures except AlB sub 12' which dissociates, losing the aluminum.

Lanthanum titanium perovskite compound: Thin film deposition and high frequency dielectric characterization

International Nuclear Information System (INIS)

Le Paven, C.; Lu, Y.; Nguyen, H.V.; Benzerga, R.; Le Gendre, L.; Rioual, S.; Benzegoutta, D.; Tessier, F.; Cheviré, F.

2014-01-01

Perovskite lanthanum titanium oxide thin films were deposited on (001) MgO, (001) LaAlO 3 and Pt(111)/TiO 2 /SiO 2 /(001)Si substrates by RF magnetron sputtering, using a La 2 Ti 2 O 7 homemade target sputtered under oxygen reactive plasma. The films deposited at 800 °C display a crystalline growth different than those reported on monoclinic ferroelectric La 2 Ti 2 O 7 films. X-ray photoelectron spectroscopy analysis shows the presence of titanium as Ti 4+ ions, with no trace of Ti 3+ , and provides a La/Ti ratio of 1.02. The depositions being performed from a La 2 Ti 2 O 7 target under oxygen rich plasma, the same composition (La 2 Ti 2 O 7 ) is proposed for the deposited films, with an unusual orthorhombic cell and Cmc2 1 space group. The films have a textured growth on MgO and Pt/Si substrates, and are epitaxially grown on LaAlO 3 substrate. The dielectric characterization displays stable values of the dielectric constant and of the losses in the frequency range [0.1–20] GHz. No variation of the dielectric constant has been observed when a DC electric field up to 250 kV/cm was applied, which does not match a classical ferroelectric behavior at high frequencies and room temperature for the proposed La 2 Ti 2 O 7 orthorhombic phase. At 10 GHz and room temperature, the dielectric constant of the obtained La 2 Ti 2 O 7 films is ε ∼ 60 and the losses are low (tanδ < 0.02). - Highlights: • Lanthanum titanium oxide films were deposited by reactive magnetron sputtering. • A La 2 Ti 2 O 7 chemical composition is proposed, with an unusual orthorhombic cell. • At 10 GHz, the dielectric losses are lower than 0.02. • No variation of the dielectric constant is observed under DC electric biasing

Preparation of Heat Treated Titanium Dioxide (TiO2) Nanoparticles for Water Purification

Science.gov (United States)

Araoyinbo, A. O.; Abdullah, M. M. A. B.; Rahmat, A.; Azmi, A. I.; Vizureanu, P.; Rahim, W. M. F. Wan Abd

2018-06-01

Photocatalysis using the semiconductor titanium dioxide (TiO2) has proven to be a successful technology for waste water purification. The photocatalytic treatment is an alternative method for the removal of soluble organic compounds in waste water. In this research, titanium dioxide nanoparticles were synthesized by sol-gel method using titanium tetraisopropoxide (TTIP) as a precursor. The sol was dried in the oven at 120°C after aging for 24 hours. The dried powder was then calcined at 400°C and 700°C with a heating rate of 10°C/min. The phase transformation of the heat treated titanium dioxide nanoparticles were characterized by X-Ray Diffraction (XRD, and the surface morphology by Scanning Electron Microscopy (SEM). The photocatalytic activity of the heat treated titanium dioxide nanoparticles in the degradation of methyl orange (MO) dye under ultraviolet (UV) light irradiation has been studied. At calcination temperature of 400°C, only anatase phase was observed, as the calcination temperature increases to 700°C, the rutile phase was present. The SEM images show the irregular shape of titanium dioxide particles and the agglomeration which tends to be more significant at calcined temperature of 700°C. Degradation of methyl orange by 5 mg heat treated titanium dioxide nanoparticles gives the highest percentage of degradation after irradiation by UV lamp for 4 hours.

Cesium titanium silicate and method of making

Science.gov (United States)

Balmer, Mari L.

1997-01-01

The invention is the new material, a ternary compound of cesium, silica, and titania, together with a method of making the ternary compound, cesium titanium silicate pollucite. More specifically, the invention is Cs.sub.2 Ti.sub.2 Si.sub.4 O.sub.13 pollucite which is a new crystalline phase representing a novel class of Ti-containing zeolites. Compositions contain relatively high Cs.sub.2 O and TiO.sub.2 loadings and are durable glass and ceramic materials. The amount of TiO.sub.2 and Cs.sub.2 that can be incorporated into these glasses and crystalline ceramics far exceeds the limits set for the borosilicate high level waste glass.

New Titanium-Based Catalysts for the Synthesis of Poly(ethylene terephthalate)

International Nuclear Information System (INIS)

Yang, Youngkeun; Yoon, Seungwoong; Hwang, Yongtaek; Song, Bogeun

2012-01-01

Poly(ethylene terephthalate) (PET) is a polymer with relatively low cost and high performance, which is widely used in various applications such as bottles, textile fibers, films and engineering plastics for automobiles and electric industries. Commercial catalysts used for synthesis of PET are in general antimony (Sb) compounds. Antimony(III) oxide, antimony(III) acetate and antimony(III) glycolate are used as a catalyst in 95% of PET manufacturing industries worldwide. The few organoantimony compounds that have been identified in environmental and biological samples are all in the form of methylated Sb-species. The Sb trace element is extremely toxic to mammals, and interferes with embryonic and fetal development, also, carcinogenic to humans. In addition to being found in drinking water, food packaging and soft-drink bottles. According to the World Health Organization (WHO), Sb species concentration lower than 20 ppb are acceptable for drinking water. According to a recent study, in 14 brands of bottled water from Canada, Sb concentrations increased on average 19% during 6 months storage at room temperature, but 48 brands of water from 11 European countries increased on average 90% under identical conditions. Therefore, a very important challenge for polyester catalysis is to come-up with a new Sb-free catalysts with low environmental impact. Intensive efforts have been made to find other stable and more environmental friendly non-antimony catalysts, such as those based on titanium. Titanium-based catalysts have been known for many years and actually are used for polybutylene terephthalate (PBT) and polypropylene terephthalate (PPT) production, however, polycondensation (PC) of PET manufacture is not well studied in literature. To date, only few esterification processes have been applied for the synthesis of PET by titanium catalysts. Herein, we report an efficient synthesis characterization and polymerization of PET for a series of new nontoxic organotitanium

Localized and collectivized behaviour of d-electrons in complicated titanium, vanadium and niobium oxides

International Nuclear Information System (INIS)

Bazuev, G.V.; Shvejkin, G.P.

1980-01-01

On the basis of investigation of electric and magnetic properties of oxide compounds of transition metals made are the conclusions on the degree of localization and delocalization of d-electrons in them. Generalized are the investigation results of complicated titanium, vanadium, niobium oxide compounds in low degrees of oxidation with rare earth and alkaline earth elements belonging to the two structural types: perovskite and pyrochlore. Presented are the results of investigations of perovskite-like solid solutions and of variable-content phases containing cations of transition metals in two different oxidation degrees: oxide niobium bronzes of two-valent europium and titanium bronzes of rare-earth elements, as well as Lnsub(1-x)Msub(x)Vsub(1-x)sup(3+)Vsub(x)sup(4+)Osub(3), where M is an alkaline earth element

Titanium metal: extraction to application

Energy Technology Data Exchange (ETDEWEB)

Gambogi, Joseph (USGS, Reston, VA); Gerdemann, Stephen J.

2002-09-01

In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium. In this paper, we discuss all aspects of the titanium industry from ore deposits through extraction to present and future applications. The methods of both primary (mining of ore, extraction, and purification) and secondary (forming and machining) operations will be analyzed. The chemical and physical properties of titanium metal will be briefly examined. Present and future applications for titanium will be discussed. Finally, the economics of titanium metal production also are analyzed as well as the advantages and disadvantages of various alternative extraction methods.

Characterization of electron beam evaporated carbon films and compound formation on titanium and silicon

International Nuclear Information System (INIS)

Luthin, J.; Linsmeier, C.

2001-01-01

The formation of carbon-based mixed materials is unavoidable on the plasma-facing components (e.g. first wall and divertor) of fusion devices when carbon is used together with other materials. On the surfaces of these components very different conditions with respect to particle and energy impact occur. To predict the mixed material formation under these conditions the precise knowledge of the fundamental mechanisms governing these interactions is essential. In this paper we present the results of carbon interaction with titanium and silicon, as model substances for metallic and covalent carbides, during thermal treatment. To perform basic studies of the reactions of carbon with different elements, thin carbon films are produced by electron beam evaporation on the different substrates under UHV conditions. All measurements for chemical analysis are performed using X-ray photoelectron spectroscopy (XPS). We discuss first the properties of the deposited carbon films. The carbon films are characterized on inert gold surfaces and are compared to bulk graphite. Annealing of the carbon films up to 970 K leads to a transition from a disordered carbon network into a graphitic structure. Preparation of carbon films at room temperature on titanium or silicon leads to a limited carbide formation at the carbon/substrate interface. Carbon deposited in excess of several monolayers is present in elementary form. Annealing of the samples leads to complete carbidization consuming the available carbon in both cases. Titanium reacts to TiC and additional substoichiometric carbide, silicon forms SiC with exact stoichiometry. (orig.)

Synthesis of gels with basis of titanium tungstates as matrixes of radioactive generators

International Nuclear Information System (INIS)

Galico C, L.

2005-01-01

The heteropolyanions, compounds formed by the union of molybdates or tungstates polyanions with atoms of metals like zirconium, titanium, cerium, thorium, tin, etc., have been used as generator matrixes of 99m Tc or 188 Re. Particularly they have been studied and produced successfully in our laboratory, generators of 99 Mo/ 99 m Tc at basis of gels zirconium molybdates and titanium molybdates. Considering that the molybdenum and tungsten, as well as the technetium and the rhenium, its belong to the same groups of transition metals, it is feasible that gels can be synthesized at basis of titanium tungstates, continuing a methodology similar to that of the gels titanium molybdates or zirconium molybdates, to produce generators 188 W/ 188 Re. The 188 Re possess nuclear characteristics that make it attractive for therapeutic applications, since, it emits β - particles of a great energy (2.12 MeV); joined to the possibility of being able to unite to different ligands (bifunctional agents) and biomolecules (antibodies or fragments of proteins), as it makes the 99m Tc, useful in radioimmunotherapy. Commercially the 188 Re generators use a chromatographic column loaded with alumina where the 188 Re, it is adsorbed and eluted the 188 ReO 4 - by means of a saline solution The alumina adsorbs around 0.2% of the 188 Re, situation that forces to use 188 Re of a high specific activity. The use of the gels technology, allows to work with medium or low specific activities of 188 Re, opening the possibility of their production in countries whose nuclear capacity is medium or low. In particular, the synthesized gels with basis of titanium offer the possibility of being synthesized with non active material, for later on to be irradiated and directly produce the generator, since, the titanium 51 Ti, unique radioisotope produced by the titanium, has a half life of 5.79 min. This synthesis method avoids the manipulation of radioactive material during the synthesis of the gels, process

Oxidation of refractory sulfur compounds over Ti-containing mesoporous molecular sieves prepared by using a fluorosilicon compound.

Science.gov (United States)

Jeong, Kwang-Eun; Cho, Chin-Soo; Chae, Ho-Jeong; Kim, Chul-Ung; Jeong, Soon-Yong

2010-05-01

Titanium containing mesoporous molecular sieve (Ti-MMS) catalysts were studied for the oxidative desulfurization of refractory sulfur compounds. Ti-MMS catalysts were synthesized from fluorosilicon compounds and Ti with the hydrolysis reaction of H2SiF6 in an ammonia-surfactant mixed solution. The solid products were characterized by XRD, XRF, nitrogen adsorption, and diffuse reflectance UV-vis spectroscopy. Effects of Ti loading and oxidant/sulfur mole ratio, and sulfur species on ODS activity were investigated.

Titanium disilicide formation by sputtering of titanium on heated silicon substrate

Science.gov (United States)

Tanielian, M.; Blackstone, S.

1984-09-01

We have sputter deposited titanium on bare silicon substrates at elevated temperatures. We find that at a substrate temperature of about 515 °C titanium silicide is formed due to the reaction of the titanium with the Si. The resistivity of the silicide is about 15 μΩ cm and it is not etchable in a selective titanium etch. This process can have applications in low-temperature, metal-oxide-semiconductor self-aligned silicide formation for very large scale integrated

Diffusion of titanium and nickel in B2 NiTi

Czech Academy of Sciences Publication Activity Database

Divinski, S.V.; Stloukal, Ivo; Král, Lubomír; Herzig, Ch.

289-292, - (2009), s. 377-382 ISSN 1012-0386. [DIMAT 2008, International Conference on Diffusion in Materials /7./. Lanzarote, Canary Islands , 28.10.2008-31.10.2008] Institutional research plan: CEZ:AV0Z20410507 Keywords : intermetallic compound NiTi * nickel nad titanium diffusion * diffusion mechanism Subject RIV: BJ - Thermodynamics http://www.scientific.net/DDF.289-292.377/

Lanthanum titanium perovskite compound: Thin film deposition and high frequency dielectric characterization

Energy Technology Data Exchange (ETDEWEB)

Le Paven, C., E-mail: claire.lepaven@univ-rennes1.fr [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); Lu, Y. [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); Nguyen, H.V. [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); CEA LETI, Minatec Campus, 38054 Grenoble (France); Benzerga, R.; Le Gendre, L. [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); Rioual, S. [Laboratoire de Magnétisme de Brest (EA CNRS 4522), Université de Bretagne Occidentale, 29000 Brest (France); Benzegoutta, D. [Institut des Nanosciences de Paris (INSP, UMR CNRS 7588), Université Pierre et Marie Curie, 75005 Paris (France); Tessier, F.; Cheviré, F. [Institut des Sciences Chimiques de Rennes (ISCR, UMR-CNRS 6226), Equipe Verres et Céramiques, Université de Rennes 1, 35000 Rennes (France); and others

2014-02-28

Perovskite lanthanum titanium oxide thin films were deposited on (001) MgO, (001) LaAlO{sub 3} and Pt(111)/TiO{sub 2}/SiO{sub 2}/(001)Si substrates by RF magnetron sputtering, using a La{sub 2}Ti{sub 2}O{sub 7} homemade target sputtered under oxygen reactive plasma. The films deposited at 800 °C display a crystalline growth different than those reported on monoclinic ferroelectric La{sub 2}Ti{sub 2}O{sub 7} films. X-ray photoelectron spectroscopy analysis shows the presence of titanium as Ti{sup 4+} ions, with no trace of Ti{sup 3+}, and provides a La/Ti ratio of 1.02. The depositions being performed from a La{sub 2}Ti{sub 2}O{sub 7} target under oxygen rich plasma, the same composition (La{sub 2}Ti{sub 2}O{sub 7}) is proposed for the deposited films, with an unusual orthorhombic cell and Cmc2{sub 1} space group. The films have a textured growth on MgO and Pt/Si substrates, and are epitaxially grown on LaAlO{sub 3} substrate. The dielectric characterization displays stable values of the dielectric constant and of the losses in the frequency range [0.1–20] GHz. No variation of the dielectric constant has been observed when a DC electric field up to 250 kV/cm was applied, which does not match a classical ferroelectric behavior at high frequencies and room temperature for the proposed La{sub 2}Ti{sub 2}O{sub 7} orthorhombic phase. At 10 GHz and room temperature, the dielectric constant of the obtained La{sub 2}Ti{sub 2}O{sub 7} films is ε ∼ 60 and the losses are low (tanδ < 0.02). - Highlights: • Lanthanum titanium oxide films were deposited by reactive magnetron sputtering. • A La{sub 2}Ti{sub 2}O{sub 7} chemical composition is proposed, with an unusual orthorhombic cell. • At 10 GHz, the dielectric losses are lower than 0.02. • No variation of the dielectric constant is observed under DC electric biasing.

Leaching of Titanium and Silicon from Low-Grade Titanium Slag Using Hydrochloric Acid Leaching

Science.gov (United States)

Zhao, Longsheng; Wang, Lina; Qi, Tao; Chen, Desheng; Zhao, Hongxin; Liu, Yahui; Wang, Weijing

2018-05-01

Acid-leaching behaviors of the titanium slag obtained by selective reduction of vanadium-bearing titanomagnetite concentrates were investigated. It was found that the optimal leaching of titanium and silicon were 0.7% and 1.5%, respectively. The titanium and silicon in the titanium slag were firstly dissolved in the acidic solution to form TiO2+ and silica sol, and then rapidly reprecipitated, forming hydrochloric acid (HCl) leach residue. Most of the silicon presented in the HCl leach residue as floccules-like silica gel, while most of the titanium was distributed in the nano-sized rod-like clusters with crystallite refinement and intracrystalline defects, and, as such, 94.3% of the silicon was leached from the HCl leach residue by alkaline desilication, and 96.5% of the titanium in the titanium-rich material with some rutile structure was then digested by the concentrated sulfuric acid. This provides an alternative route for the comprehensive utilization of titanium and silicon in titanium slag.

Titanium and titanium alloys: fundamentals and applications

National Research Council Canada - National Science Library

Leyens, C; Peters, M

2003-01-01

... number of titanium alloys have paved the way for light metals to vastly expand into many industrial applications. Titanium and its alloys stand out primarily due to their high specific strength and excellent corrosion resistance, at just half the weight of steels and Ni-based superalloys. This explains their early success in the aerospace and the...

Spectra of soft X-ray excitation potentials of titanium and vanadium compounds with carbon and nitrogen of a variable composition

International Nuclear Information System (INIS)

Brytov, I.A.; Bleher, B. Eh.; Neshpor, V.S.

1979-01-01

Lsub(3,2) spectra of excitation potentials (SEP) of a soft X-ray radiation of titanium and vanadium carbides and titanium nitrides in their homogeneity range, as well as solid solutions of nitrogen in α-titanium, are studied. The binding energies of electrons of the exciting levels relatively to the Fermi level are determined, adequacy of different quantomechanical calculations is experimentally proved. The observed changes in SEP at the variation of the metalloid concentration are explained by a quantitative transformation model of valent state energetic spectra when metalloid vacancies and connected with them local levels form

Synthesis of Titanium Oxycarbide from Titanium Slag by Methane-Containing Gas

Science.gov (United States)

Dang, Jie; Fatollahi-Fard, Farzin; Pistorius, Petrus Christiaan; Chou, Kuo-Chih

2018-02-01

In this study, reaction steps of a process for synthesis of titanium oxycarbide from titanium slag were demonstrated. This process involves the reduction of titanium slag by a methane-hydrogen-argon mixture at 1473 K (1200 °C) and the leaching of the reduced products by hydrofluoric acid near room temperature to remove the main impurity (Fe3Si). Some iron was formed by disproportionation of the main M3O5 phase before gaseous reduction started. Upon reduction, more iron formed first, followed by reduction of titanium dioxide to suboxides and eventually oxycarbide.

Structural formation of aluminide phases on titanium alloy during annealing

International Nuclear Information System (INIS)

Mamaeva, A.A.; Romankov, S.E.; Sagdoldina, Zh.

2006-01-01

Full text: The aluminum layer on the surface of titanium alloy has been formed by thermal deposition. The structural formation of aluminide phases on the surface has been studied. The sequence of structural transformations at the Ti/Al interface is limited by the reaction temperature and time. The sequence of aluminide phase formation is occurred in compliance with Ti-Al equilibrium phase diagram. At the initial stages at the Ti/Al interface the Al3Ti alloy starts forming as a result of interdiffusion, and gradually the whole aluminum films is spent on the formation of this layer. The Al3Ti layer decomposes with the increase of temperature (>600C). At 800C the two-phase (Ti3Al+TiAl) layer is formed on the titanium surface. The TiAl compound is unstable and later on with the increase of the exposure time at 800C gradually transforms into the Ti3Al. The chain of these successive transformations leads to the formation of the continuous homogeneous layer consisting of the Ti3Al compound on the surface. At temperatures exceeding the allotropic transformation temperature (>900C) the Ti3Al compound starts decomposing. All structural changes taking place at the Ti/Al interface are accompanied by considerable changes in micro hardness. The structure of initial substrate influences on kinetics of phase transformation and microstructure development. (author)

Titanium by design: TRIP titanium alloy

Science.gov (United States)

Tran, Jamie

Motivated by the prospect of lower cost Ti production processes, new directions in Ti alloy design were explored for naval and automotive applications. Building on the experience of the Steel Research Group at Northwestern University, an analogous design process was taken with titanium. As a new project, essential kinetic databases and models were developed for the design process and used to create a prototype design. Diffusion kinetic models were developed to predict the change in phase compositions and microstructure during heat treatment. Combining a mobility database created in this research with a licensed thermodynamic database, ThermoCalc and DICTRA software was used to model kinetic compositional changes in titanium alloys. Experimental diffusion couples were created and compared to DICTRA simulations to refine mobility parameters in the titanium mobility database. The software and database were able to predict homogenization times and the beta→alpha plate thickening kinetics during cooling in the near-alpha Ti5111 alloy. The results of these models were compared to LEAP microanalysis and found to be in reasonable agreement. Powder metallurgy was explored using SPS at GM R&D to reduce the cost of titanium alloys. Fully dense Ti5111 alloys were produced and achieved similar microstructures to wrought Ti5111. High levels of oxygen in these alloys increased the strength while reducing the ductility. Preliminary Ti5111+Y alloys were created, where yttrium additions successfully gettered excess oxygen to create oxides. However, undesirable large oxides formed, indicating more research is needed into the homogeneous distribution of the yttrium powder to create finer oxides. Principles established in steels were used to optimize the beta phase transformation stability for martensite transformation toughening in titanium alloys. The Olson-Cohen kinetic model is calibrated to shear strains in titanium. A frictional work database is established for common alloying

Corrosion of titanium and titanium alloys in spent fuel repository conditions - literature review

International Nuclear Information System (INIS)

Aho-Mantila, I.; Haenninen, H.; Aaltonen, P.; Taehtinen, S.

1985-03-01

The spent nuclear fuel is planned to be disposed in Finnish bedrock. The canister of spent fuel in waste repository is one barrier to the release of radionuclides. It is possible to choose a canister material with a known, measurable corrosion rate and to make it with thickness allowing corrosion to occur. The other possibility is to use a material which is nearly immune to general corrosion. In this second category there are titanium and titanium alloys which exhibit a very high degree of resistance to general corrosion. In this literature study the corrosion properties of unalloyed titanium, titanium alloyed with palladium and titanium alloyed with molybdenum and nickel are reviewed. The two titanium alloys own in addition to the excellent general corrosion properties outstanding properties against localized corrosion like pitting or crevice corrosion. Stress corrosion cracking and corrosion fatique of titanium seem not to be a problem in the repository conditions, but the possibilities of delayed cracking caused by hydrogen should be carefully appreciated. (author)

Titanium Dioxide Nanoparticles: a Risk for Human Health?

Science.gov (United States)

Grande, Fedora; Tucci, Paola

2016-01-01

Titanium dioxide (TiO2) is a natural oxide of the element titanium with low toxicity, and negligible biological effects. The classification as bio-inert material has given the possibility to normal-sized (>100 nm) titanium dioxide particles (TiO2-NPs) to be extensively used in food products and as ingredients in a wide range of pharmaceutical products and cosmetics, such as sunscreens and toothpastes. Therefore, human exposure may occur through ingestion and dermal penetration, or through inhalation route, during both the manufacturing process and use. In spite of the extensively use of TiO2-NPs, the biological effects and the cellular response mechanisms are still not completely elucidated and thus a deep understanding of the toxicological profile of this compound is required. The main mechanism underlining the toxicity potentially triggered by TiO2-NPs seems to involve the reactive oxygen species (ROS) production, resulting in oxidative stress, inflammation, genotoxicity, metabolic change and potentially carcinogenesis. The extent and type of cell damage strongly depend on chemical and physical characteristics of TiO2-NPs, including size, crystal structure and photo-activation. In this mini-review, we would like to discuss the latest findings on the adverse effects and on potential human health risks induced by TiO2-NPs exposure.

Interaction between titanium and sulfuric acid in the electrodeposition of chalcogenide semiconductors

International Nuclear Information System (INIS)

Ortega, J.

1992-01-01

Some chalcogenide electrodeposition problems in the cathodic potential range from -0.30 V to-0.65 V vs SCE may be related to the Titanium corrosion-passivation process in aqueous solutions of sulfuric acid. This feature was discovered accidentally when it was attempted to electrodeposit Cd-Hg-Te compounds from a ternary plating bath; an anodic current of about 10 m/cm 2 was produced in the Titanium cathode at -0.50 V vs SCE, while at -0.40 and -0.60 V vs SCE the current was cathodic. In order to explain this feature, a first study has been carried out to determine the influence of the temperature and sulfuric acid concentration on the passivation current density, passivation potential and Flade potential for passivation. From Arrhenius plots of the passivation currents an apparent activation energy of 63.8 kJ/mole for Titanium passivation in sulfuric acid at -0.50 V vs SCE was obtained. The electrochemical stability of passivated Titanium was explained by assuming that the oxide film formed exhibits n-type semiconducting character, since passivation data was in good agreement with interfacial energetics for n-TiO 2 in aqueous solutions of sulfuric acid.(Author)

Improved antibacterial behavior of titanium surface with torularhodin–polypyrrole film

International Nuclear Information System (INIS)

Ungureanu, Camelia; Popescu, Simona; Purcel, Gabriela; Tofan, Vlad; Popescu, Marian; Sălăgeanu, Aurora; Pîrvu, Cristian

2014-01-01

The problem of microorganisms attaching and proliferating on implants and medical devices surfaces is still attracting interest in developing research on different coatings based on antibacterial agents. The aim of this work is centered on modifying titanium (Ti) based implants surfaces through incorporation of a natural compound with antimicrobial effect, torularhodin (T), by means of a polypyrrole (PPy) film. This study tested the potential antimicrobial activity of the new coating against a range of standard bacterial strains: Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis and Pseudomonas aeruginosa. The morphology, physical and electrochemical properties of the synthesized films were assessed by SEM, AFM, UV–Vis, FTIR and cyclic voltammetry. In addition, biocompatibility of this new coating was evaluated using L929 mouse fibroblast cells. The results showed that PPy–torularhodin composite film acts as a corrosion protective coating with antibacterial activity and it has no harmful effect on cell viability. - Highlights: • Modification of titanium surfaces by incorporating a natural compound • new PPy - torularhodin corrosion protective composite coatings • antibacterial activity for the new PPy - torularhodin coating • cytocompatibility of new coating was demonstrated using mouse fibroblast cells

Improved antibacterial behavior of titanium surface with torularhodin–polypyrrole film

Energy Technology Data Exchange (ETDEWEB)

Ungureanu, Camelia; Popescu, Simona; Purcel, Gabriela [University POLITEHNICA of Bucharest, 1-7 Polizu, 011061 Bucharest (Romania); Tofan, Vlad [“Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, 103 Splaiul Independentei, Sector 5, 050096 Bucharest (Romania); Popescu, Marian [University POLITEHNICA of Bucharest, 1-7 Polizu, 011061 Bucharest (Romania); National Institute for Research and Development in Microtechnologies, 126A, Erou Iancu Nicolae Street, 077190 Bucharest (Romania); Sălăgeanu, Aurora [“Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, 103 Splaiul Independentei, Sector 5, 050096 Bucharest (Romania); Pîrvu, Cristian, E-mail: c_pirvu@chim.pub.ro [University POLITEHNICA of Bucharest, 1-7 Polizu, 011061 Bucharest (Romania)

2014-09-01

The problem of microorganisms attaching and proliferating on implants and medical devices surfaces is still attracting interest in developing research on different coatings based on antibacterial agents. The aim of this work is centered on modifying titanium (Ti) based implants surfaces through incorporation of a natural compound with antimicrobial effect, torularhodin (T), by means of a polypyrrole (PPy) film. This study tested the potential antimicrobial activity of the new coating against a range of standard bacterial strains: Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis and Pseudomonas aeruginosa. The morphology, physical and electrochemical properties of the synthesized films were assessed by SEM, AFM, UV–Vis, FTIR and cyclic voltammetry. In addition, biocompatibility of this new coating was evaluated using L929 mouse fibroblast cells. The results showed that PPy–torularhodin composite film acts as a corrosion protective coating with antibacterial activity and it has no harmful effect on cell viability. - Highlights: • Modification of titanium surfaces by incorporating a natural compound • new PPy - torularhodin corrosion protective composite coatings • antibacterial activity for the new PPy - torularhodin coating • cytocompatibility of new coating was demonstrated using mouse fibroblast cells.

Chitosan patterning on titanium alloys

OpenAIRE

Gilabert Chirivella, Eduardo; Pérez Feito, Ricardo; Ribeiro, Clarisse; Ribeiro, Sylvie; Correia, Daniela; González Martin, María Luisa; Manero Planella, José María; Lanceros Méndez, Senentxu; Gallego Ferrer, Gloria; Gómez Ribelles, José Luis

2017-01-01

Titanium and its alloys are widely used in medical implants because of their excellent properties. However, bacterial infection is a frequent cause of titanium-based implant failure and also compromises its osseointegration. In this study, we report a new simple method of providing titanium surfaces with antibacterial properties by alternating antibacterial chitosan domains with titanium domains in the micrometric scale. Surface microgrooves were etched on pure titanium disks at i...

On the use of titanium hydride for powder injection moulding of titanium-based alloys

International Nuclear Information System (INIS)

Carrenoo-Morelli, E.; Bidaux, J.-E.

2009-01-01

Full text: Titanium and titanium-based alloys are excellent materials for a number of engineering applications because of their high strength, lightweight, good corrosion resistance, non magnetic characteristic and biocompatibility. The current processing steps are usually costly, and there is a growing demand for net-shape solutions for manufacturing parts of increasing complexity. Powder injection moulding is becoming a competitive alternative, thanks to the advances in production of good quality base-powders, binders and sintering facilities. Titanium hydride powders, have the attractiveness of being less reactive than fine titanium powders, easier to handle, and cheaper. This paper summarizes recent advances on PIM of titanium and titanium alloys from TiH2 powders, including shape-memory NiTi alloys. (author)

Classification of titanium dioxide

International Nuclear Information System (INIS)

Macias B, L.R.; Garcia C, R.M.; Maya M, M.E.; Ita T, A. De; Palacios G, J.

2002-01-01

In this work the X-ray diffraction (XRD), Scanning Electron Microscopy (Sem) and the X-ray Dispersive Energy Spectroscopy techniques are used with the purpose to achieve a complete identification of phases and mixture of phases of a crystalline material as titanium dioxide. The problem for solving consists of being able to distinguish a sample of titanium dioxide being different than a titanium dioxide pigment. A standard sample of titanium dioxide with NIST certificate is used, which indicates a purity of 99.74% for the TiO 2 . The following way is recommended to proceed: a)To make an analysis by means of X-ray diffraction technique to the sample of titanium dioxide pigment and on the standard of titanium dioxide waiting not find differences. b) To make a chemical analysis by the X-ray Dispersive Energy Spectroscopy via in a microscope, taking advantage of the high vacuum since it is oxygen which is analysed and if it is concluded that the aluminium oxide appears in a greater proportion to 1% it is established that is a titanium dioxide pigment, but if it is lesser then it will be only titanium dioxide. This type of analysis is an application of the nuclear techniques useful for the tariff classification of merchandise which is considered as of difficult recognition. (Author)

Corrosion behaviour and galvanic coupling of titanium and welded titanium in LiBr solutions

International Nuclear Information System (INIS)

Blasco-Tamarit, E.; Igual-Munoz, A.; Garcia Anton, J.; Garcia-Garcia, D.

2007-01-01

Corrosion resistance and galvanic coupling of Grade 2 commercially pure titanium in its welded and non-welded condition were systematically analyzed in LiBr solutions. Galvanic corrosion was evaluated through two different methods: anodic polarization (according to the Mixed Potential Theory) and electrochemical noise (using a zero-resistance ammeter). Samples have been etched to study the microstructure. The action of lithium chromate as corrosion inhibitor has been evaluated. Titanium and welded titanium showed extremely low corrosion current densities and elevated pitting potential values (higher than 1 V). The results of both methods, anodic polarization and electrochemical noise, showed that the welded titanium was always the anodic element of the pair titanium-welded titanium, so that its corrosion resistance decreases due to the galvanic effect

Electrowinning molten titanium from titanium dioxide

CSIR Research Space (South Africa)

Van Vuuren, DS

2005-10-01

Full Text Available the Manufacturing and Materials Industry in it quest for global competitiveness CSIR Manufacturing and Materials Technology 3 Rationale – Titanium Cost Build-up Material Cost Ilmenite $0.27/kg Ti sponge Titanium slag $0.75/kg Ti Sponge TiCl4 and TiO2 $3....10/kg Ti Sponge Ti Sponge raw materials costs $5.50/kg Ti Sponge Total Ti Sponge cost $9-$11/kg Ti Sponge Ti ingot $15-17/kg Ti Aluminium $1.7/kg Al Supporting the Manufacturing and Materials Industry in its quest for global competitivenessorting...

Plasmonic Titanium Nitride Nanostructures via Nitridation of Nanopatterned Titanium Dioxide

DEFF Research Database (Denmark)

Guler, Urcan; Zemlyanov, Dmitry; Kim, Jongbum

2017-01-01

Plasmonic titanium nitride nanostructures are obtained via nitridation of titanium dioxide. Nanoparticles acquired a cubic shape with sharper edges following the rock-salt crystalline structure of TiN. Lattice constant of the resulting TiN nanoparticles matched well with the tabulated data. Energy...

Nonstoichiometric Titanium Oxides via Pulsed Laser Ablation in Water

Directory of Open Access Journals (Sweden)

Chen Shuei-Yuan

2010-01-01

Full Text Available Abstract Titanium oxide compounds TiO,Ti2O3, and TiO2 with a considerable extent of nonstoichiometry were fabricated by pulsed laser ablation in water and characterized by X-ray/electron diffraction, X-ray photoelectron spectroscopy and electron energy loss spectroscopy. The titanium oxides were found to occur as nanoparticle aggregates with a predominant 3+ charge and amorphous microtubes when fabricated under an average power density of ca. 1 × 108W/cm2 and 1011W/cm2, respectively followed by dwelling in water. The crystalline colloidal particles have a relatively high content of Ti2+ and hence a lower minimum band gap of 3.4 eV in comparison with 5.2 eV for the amorphous state. The protonation on both crystalline and amorphous phase caused defects, mainly titanium rather than oxygen vacancies and charge and/or volume-compensating defects. The hydrophilic nature and presumably varied extent of undercoordination at the free surface of the amorphous lamellae accounts for their rolling as tubes at water/air and water/glass interfaces. The nonstoichiometric titania thus fabricated have potential optoelectronic and catalytic applications in UV–visible range and shed light on the Ti charge and phase behavior of titania-water binary in natural shock occurrence.

Fluorescent Hydrogel Generated Conveniently from a Perylene Tetracarboxylate Derivative of Titanium(IV) Alkoxide.

Science.gov (United States)

Zou, Dan-Hong; Wang, Peng; Luo, Wen; Hou, Jin-Le; Zhu, Qin-Yu; Dai, Jie

2018-02-05

Organic gelators and metal-coordination frameworks based on perylene derivatives as functional materials have attracted great attention because of their intense fluorescence emission as well as unique electronic and photonic properties. We report here the structures and properties of a luminescent titanium(IV) coordination compound of a perylene tetracarboxylate (PTC) derivative, [Ti 2 (O i Pr) 6 (L 1 )(phen) 2 ] (1), along with its two naphthalene analogues, [Ti 2 (O i Pr) 6 (L 2 )(phen) 2 ] (2) and [Ti 2 (O i Pr) 6 (L 2 )(bpy) 2 ] (3), where L 1 = 3,9-dicarboxylate-(4,10-diisopropanolcarboxylate)perylene, phen = 1,10-phenanthroline, L 2 = 1,5-dicarboxylate-(2,6-diisopropanolcarboxylate)naphthalene, and bpy = 2,2'-bipyridine. Compound 1 is a rare early-transition-metal PTC coordination compound that can be simply prepared in one pot as crystals by a low-heat synthesis. Unlike those of paramagnetic late-transition-metal PTC compounds, compound 1 showed intense fluorescence emission. More remarkably, the crystals of 1 can be turned immediately to a fluorescent hydrogel just through a simple procedure, putting the crystals in water and then treating with ultrasound. No acid catalyst or pH adjustment is needed. Hydrolysis of the titanium isopropanol group in water and π-π interaction of the perylene and phen play important roles in the gelation process. The film prepared from the gel can be used as a visual fluorescence sensor for aromatic amines and phenols, which are hazards for the human and environment.

Artefacts in multimodal imaging of titanium, zirconium and binary titanium-zirconium alloy dental implants: an in vitro study.

Science.gov (United States)

Smeets, Ralf; Schöllchen, Maximilian; Gauer, Tobias; Aarabi, Ghazal; Assaf, Alexandre T; Rendenbach, Carsten; Beck-Broichsitter, Benedicta; Semmusch, Jan; Sedlacik, Jan; Heiland, Max; Fiehler, Jens; Siemonsen, Susanne

2017-02-01

To analyze and evaluate imaging artefacts induced by zirconium, titanium and titanium-zirconium alloy dental implants. Zirconium, titanium and titanium-zirconium alloy implants were embedded in gelatin and MRI, CT and CBCT were performed. Standard protocols were used for each modality. For MRI, line-distance profiles were plotted to quantify the accuracy of size determination. For CT and CBCT, six shells surrounding the implant were defined every 0.5 cm from the implant surface and histogram parameters were determined for each shell. While titanium and titanium-zirconium alloy induced extensive signal voids in MRI owing to strong susceptibility, zirconium implants were clearly definable with only minor distortion artefacts. For titanium and titanium-zirconium alloy, the MR signal was attenuated up to 14.1 mm from the implant. In CT, titanium and titanium-zirconium alloy resulted in less streak artefacts in comparison with zirconium. In CBCT, titanium-zirconium alloy induced more severe artefacts than zirconium and titanium. MRI allows for an excellent image contrast and limited artefacts in patients with zirconium implants. CT and CBCT examinations are less affected by artefacts from titanium and titanium-zirconium alloy implants compared with MRI. The knowledge about differences of artefacts through different implant materials and image modalities might help support clinical decisions for the choice of implant material or imaging device in the clinical setting.

Rough surfaces of titanium and titanium alloys for implants and prostheses

International Nuclear Information System (INIS)

Conforto, E.; Aronsson, B.-O.; Salito, A.; Crestou, C.; Caillard, D.

2004-01-01

Titanium and titanium alloys for dental implants and hip prostheses were surface-treated and/or covered by metallic or ceramic rough layers after being submitted to sand blasting. The goal of these treatments is to improve the surface roughness and consequently the osteointegration, the fixation, and the stability of the implant. The microstructure of titanium and titanium alloys submitted to these treatments has been studied and correlated to their mechanical behavior. As-treated/covered and mechanically tested surfaces were characterized by scanning electron microscopy (SEM). Structural analyses performed by transmission electron microscopy (TEM), mainly in cross-section, reveal the degree of adherence and cohesion between the surface layer and the substrate (implant). We observed that, although the same convenient surface roughness was obtained with the two types of process, many characteristics as structural properties and mechanical behavior are very different

Rapid PMR determination of hydrogen in titanium hydride and dehydrogenated titanium powders

International Nuclear Information System (INIS)

Il'enko, V.S.; Demidenko, L.M.

1987-01-01

Proton magnetic resonance (PMR) enables determining hydrogen quantitatively in titanium hydride and dehydrogenated titanium powders without destroying the specimen and is also more informative than high-temperature extraction methods. PMR provides data on the electron-nuclear interactions and the activation energies for hydrogen diffusion while also providing conclusions on the forms and positives of the hydrogen in the lattice and the binding to the metal atoms. The authors have developed a rapid method for determining hydrogen in titanium hydride and dehydrogenated titanium powders which reduces the analysis time and improves the metrological characteristics. The authors use a YaMR-5535 spectrometer working at 40 MHz upgraded for use with hydrogen in solids. The authors used specimens of mass about 2 g ground to 0.1 mm powder

Photocatalytic oxidation of organic compounds via waveguide-supported titanium dioxide films

Science.gov (United States)

Miller, Lawrence W.

A photochemical reactor based on titanium dioxide (TiO2)-coated silica optical fibers was constructed to explore the use of waveguide-supported TiO2 films for photocatalytic oxidation of organic compounds. The reactor was used for the photocatalytic oxidation of 4-chlorophenol in water. It was confirmed that TiO2 films could be securely attached to silica optical fibers. The 4-chlorophenol (100 mumol/L in water) was successfully oxidized on the TiO2 surface when UV light (310 nm--380 nm) was propagated through the fibers to the films. Rates of 4-chlorophenol oxidation and UV light flux to the fibers were measured. The quantum efficiency of 4-chlorophenol oxidation [defined as the change in 4-chlorophenol concentration divided by the UV light absorbed by the catalyst] was determined as a function of TiO2 catalyst film thickness and internal incident angle of propagating UV light. A maximum quantum efficiency of 2.8% was measured when TiO2 film thickness was ca. 80 nm and the maximum internal incident angle of propagating light was 84°. Quantum efficiency increased with increasing internal angle of incidence of propagating light and decreased with TiO2 film thickness. UV-Visible internal reflection spectroscopy was used to determine whether UV light propagated through TiO2-coated silica waveguides in an ATR mode. Propagation of UV light in an ATR mode was confirmed by the similarities between internal reflection spectra of phenolphthalein obtained with uncoated and TiO2-coated silica crystals. Planar silica waveguides coated with TiO2 were employed in a photocatalytic reactor for the oxidation of formic acid (833 mumol/L in water). It was shown that the quantum yield of formic acid oxidation [defined as the moles of formic acid oxidized divided by the moles of UV photons absorbed by the catalyst] on the waveguide-supported TiO2 surface is enhanced when UV light propagates through the waveguides in an ATR mode. A maximum quantum yield of 3.9% was found for formic

Solvent extraction of titanium (IV) from sulphuric acid media by cyanex 921 and tri-butylphosphate

International Nuclear Information System (INIS)

Nayl, A.A.; Aly, H.F.

2009-01-01

titanium and its compounds found different useful applications in the nuclear and radioactive waste treatment fields. extraction behavior of titanium (IV) from sulfuric acid by commercial tri-octylphosphine oxide (CYANEX 921) and tributylphosphate (TBP)has been investigated. effects of contact time, sulfuric acid concentration in the aqueous phase, the extractants concentration in the organic phase, and the temperature on the extraction of titanium by the two systems were studied. it is found that extraction equilibrium of titanium is reached after 10-15 min and 4 min for CYANEX 921 and TBP, respectively . the extraction of Ti(IV) by 0.15 M CYANEX 921 in kerosene increases with the increase in sulfuric acid concentration to reach a maximum extraction of 91% at 7.0 m acid concentration. for the TBP system, the maximum extraction of titanium was 79% using 1.0 M TBP in kerosene from 4.0 m H 2 SO 4 solution . the effect of temperature was also evaluated. Na 2 CO 3 was used as a good stripping agent compared with other reagents. the interaction of Ti(IV) in sulfate medium and different sulfate species in sulfuric acid are reviewed. within the literature survey together with analysis of the extraction results , it can be concluded that titanium extracted by CYANEX 921 as Ti O (HSO 4 ) 2 .2 CYANEX 921 whereby in case of TBP, the extracted species is TiOSO 4 .2 TBP

Chemical changes of titanium and titanium dioxide under electron bombardment

Directory of Open Access Journals (Sweden)

Romins Brasca

2007-09-01

Full Text Available The electron induced effect on the first stages of the titanium (Ti0 oxidation and titanium dioxide (Ti4+ chemical reduction processes has been studied by means of Auger electron spectroscopy. Using factor analysis we found that both processes are characterized by the appearance of an intermediate Ti oxidation state, Ti2O3 (Ti3+.

Osseointegration is improved by coating titanium implants with a nanostructured thin film with titanium carbide and titanium oxides clustered around graphitic carbon

International Nuclear Information System (INIS)

Veronesi, Francesca; Giavaresi, Gianluca; Fini, Milena; Longo, Giovanni; Ioannidu, Caterina Alexandra; Scotto d'Abusco, Anna; Superti, Fabiana; Panzini, Gianluca; Misiano, Carlo; Palattella, Alberto; Selleri, Paolo; Di Girolamo, Nicola; Garbarino, Viola; Politi, Laura; Scandurra, Roberto

2017-01-01

Titanium implants coated with a 500 nm nanostructured layer, deposited by the Ion Plating Plasma Assisted (IPPA) technology, composed of 60% graphitic carbon, 25% titanium oxides and 15% titanium carbide were implanted into rabbit femurs whilst into the controlateral femurs uncoated titanium implants were inserted as control. At four time points the animals were injected with calcein green, xylenol orange, oxytetracycline and alizarin. After 2, 4 and 8 weeks femurs were removed and processed for histology and static and dynamic histomorphometry for undecalcified bone processing into methylmethacrylate, sectioned, thinned, polished and stained with Toluidine blue and Fast green. The overall bone-implant contacts rate (percentage of bone-implant contacts/weeks) of the TiC coated implant was 1.6 fold than that of the uncoated titanium implant. The histomorphometric analyses confirmed the histological evaluations. More precisely, higher Mineral Apposition Rate (MAR, μm/day) (p < 0.005) and Bone Formation Rate (BFR, μm 2 /μm/day) (p < 0.0005) as well as Bone Implant Contact (Bic) and Bone Ingrowth values (p < 0.0005) were observed for the TiC coated implants compared to uncoated implants. In conclusion the hard nanostructured TiC layer protects the bulk titanium implant against the harsh conditions of biological tissues and in the same time, stimulating adhesion, proliferation and activity of osteoblasts, induces a better bone-implant contacts of the implant compared to the uncoated titanium implant. - Highlights: • Ti implants were coated with a nanostructured film composed of C gr , TiC and TiO x . • The TiC layer stimulates adhesion, proliferation and activity of osteoblasts. • Uncoated and TiC coated titanium implants were implanted in rabbit femurs. • Bone-implant contacts of TiC coated implants were higher than that of uncoated. • Mineral Apposition Rate of TiC coated implants were higher than that of uncoated.

Pyrolytic carbon coating for cytocompatibility of titanium oxide nanoparticles: a promising candidate for medical applications

International Nuclear Information System (INIS)

Behzadi, Shahed; Simchi, Abdolreza; Imani, Mohammad; Yousefi, Mohammad; Galinetto, Pietro; Amiri, Houshang; Stroeve, Pieter; Mahmoudi, Morteza

2012-01-01

Nanoparticles for biomedical use must be cytocompatible with the biological environment that they are exposed to. Current research has focused on the surface functionalization of nanoparticles by using proteins, polymers, thiols and other organic compounds. Here we show that inorganic nanoparticles such as titanium oxide can be coated by pyrolytic carbon (PyC) and that the coating has cytocompatible properties. Pyrolization and condensation of methane formed a thin layer of pyrolytic carbon on the titanium oxide core. The formation of the PyC shell retards coalescence and sintering of the ceramic phase. Our MTT assay shows that the PyC-coated particles are cytocompatible at employed doses. (paper)

Titanium fasteners. [for aircraft industry

Science.gov (United States)

Phillips, J. L.

1972-01-01

Titanium fasteners are used in large quantities throughout the aircraft industry. Most of this usage is in aluminum structure; where titanium structure exists, titanium fasteners are logically used as well. Titanium fasteners offer potential weight savings to the designer at a cost of approximately $30 per pound of weight saved. Proper and least cost usage must take into consideration type of fastener per application, galvanic couples and installation characteristics of protective coatings, cosmetic appearance, paint adhesion, installation forces and methods available and fatigue performance required.

Titanium for salt water service

International Nuclear Information System (INIS)

Gadiyar, H.S.; Shibad, P.R.

1980-01-01

Titanium has potential as major material of construction in desalination plants, in condensers and heat exchangers, in view of its excellent corrosion resistance to salt water upto at least 120deg C. The advantages of titanium in such applications are brought out. The various specific problems such as pitting, crevice and galvanic corrosion and the preventive methods, for adopting titanium have been discussed. The hydriding problem can be overcome by suitably controlling the operating parameters such as temperature and surface preparation. A case has been made to prove the economic viability of titanium in comparison to Al-brass and Cu-Ni alloy. The future of titanium seems to be very promising in view of the negligible tube failures and outages. (auth.)

[The surface roughness analysis of the titanium casting founding by a new titanium casting investment material].

Science.gov (United States)

Liang, Qin-ye; Wu, Xia-yi; Lin, Xue-feng

2012-04-01

To investigate the surface roughness property of the titanium castings cast in a new investment for titanium casting. Six wax patterns (20 mm × 20 mm × 0.5 mm) were invested using two investments: three in a new titanium investment material and three in the control material (Rematitan Plus). Six titanium specimens were obtained by conventional casting. After casting, surface roughness of the specimens were evaluated with a surface profilometer. The surface roughness of the specimens cast in new titanium investment material was (1.72 ± 0.08) µm, which was much smaller than that from Rematitan Plus [(1.91 ± 0.15) µm, P cast using these two investment materials are both smooth enough to fulfill the demand of the titanium precision-casting for prosthodontic clinical use.

Acute Inhalation Exposure to Titanium Ethanolate as a Possible Cause of Metal Fume Fever

Directory of Open Access Journals (Sweden)

M Ahmadimanesh

2014-04-01

Full Text Available Occupational inhalation exposure to noxious agents is not uncommon. Herein, we present a 26-year-old male student who had accidental acute inhalation exposure to a large quantity of titanium ethanolate and hydrogen chloride in chemistry lab. He was referred to the emergency department of our hospital with low-grade fever, dyspnea, headache, fatigue and myalgia. After 24 hrs of symptomatic treatment (oxygen therapy and acetaminophen, the fever was subsided and the patient discharged home in a good clinical condition. The presented symptoms could be interpreted as a form of metal fume fever. It can therefore be concluded that organo-metallic compound of titanium metal may have the potential to produce metal fume fever in human.

Numerical assessment of bone remodeling around conventionally and early loaded titanium and titanium-zirconium alloy dental implants.

Science.gov (United States)

Akça, Kıvanç; Eser, Atılım; Çavuşoğlu, Yeliz; Sağırkaya, Elçin; Çehreli, Murat Cavit

2015-05-01

The aim of this study was to investigate conventionally and early loaded titanium and titanium-zirconium alloy implants by three-dimensional finite element stress analysis. Three-dimensional model of a dental implant was created and a thread area was established as a region of interest in trabecular bone to study a localized part of the global model with a refined mesh. The peri-implant tissues around conventionally loaded (model 1) and early loaded (model 2) implants were implemented and were used to explore principal stresses, displacement values, and equivalent strains in the peri-implant region of titanium and titanium-zirconium implants under static load of 300 N with or without 30° inclination applied on top of the abutment surface. Under axial loading, principal stresses in both models were comparable for both implants and models. Under oblique loading, principal stresses around titanium-zirconium implants were slightly higher in both models. Comparable stress magnitudes were observed in both models. The displacement values and equivalent strain amplitudes around both implants and models were similar. Peri-implant bone around titanium and titanium-zirconium implants experiences similar stress magnitudes coupled with intraosseous implant displacement values under conventional loading and early loading simulations. Titanium-zirconium implants have biomechanical outcome comparable to conventional titanium implants under conventional loading and early loading.

Anodic growth of titanium dioxide nanostructures

DEFF Research Database (Denmark)

2010-01-01

Disclosed is a method of producing nanostructures of titanium dioxide (TiO 2 ) by anodisation of titanium (Ti) in an electrochemical cell, comprising the steps of: immersing a non-conducting substrate coated with a layer of titanium, defined as the anode, in an electrolyte solution...... an electrical contact to the layer of titanium on the anode, where the electrical contact is made in the electrolyte solution...

Synthesis, characterization and photo catalytic activity of titanium oxide modified with nitrogen; Sintesis, caracterizacion y actividad fotocatalitica de oxido de titanio modificado con nitrogeno

Energy Technology Data Exchange (ETDEWEB)

Hernandez Enriquez, J. M.; Garcia Alamilla, R.; Garcia Serrano, L. A.; Cueto Hernandez, A.

2011-07-01

Titanium oxides (TiO{sub 2}) were synthesized by precipitation of titanium tetrachloride (TiCl{sub 4}) using ammonium hydroxide (NH{sub 4}OH). The synthesized materials were characterized by means of nitrogen physisorption, X-ray diffraction, infrared spectroscopy, U.V.-visible diffuse reflectance spectroscopy and the photo catalytic activity of the samples were measured by the degradation of the methyl orange. By means of this synthesis method we have doped the titanium oxide structure with nitrogen (N-TiO{sub 2}), stabilizing the anatase phase and obtaining meso porous and nanocrystalline materials. The titanium oxide with higher specific surface area (132 m{sup 2}/g) degraded the azo-compound to 100% in 180 min of reaction. (Author) 33 refs.

Human in vivo and in vitro studies on gastrointestinal absorption of titanium dioxide nanoparticles.

Science.gov (United States)

Jones, Kate; Morton, Jackie; Smith, Ian; Jurkschat, Kerstin; Harding, Anne-Helen; Evans, Gareth

2015-03-04

The study was designed to conduct human in vivo and in vitro studies on the gastrointestinal absorption of nanoparticles, using titanium dioxide as a model compound, and to compare nanoparticle behaviour with that of larger particles. A supplier's characterisation data may not fully describe a particle formulation. Most particles tested agreed with their supplied characterisation when assessed by particle number but significant proportions of 'nanoparticle formulations' were particles >100nm when assessed by particle weight. Oral doses are measured by weight and it is therefore important that the weight characterisation is taken into consideration. The human volunteer studies demonstrated that very little titanium dioxide is absorbed gastrointestinally after an oral challenge. There was no demonstrable difference in absorption for any of the three particle sizes tested. All tested formulations were shown to agglomerate in simulated gastric fluid, particularly in the smaller particle formulations. Further agglomeration was observed when dispersing formulations in polymeric or elemental foods. Virtually no translocation of titanium dioxide particles across the cell layer was demonstrated. This study found no evidence that nanoparticulate titanium dioxide is more likely to be absorbed in the gut than micron-sized particles. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

Osseointegration is improved by coating titanium implants with a nanostructured thin film with titanium carbide and titanium oxides clustered around graphitic carbon

Energy Technology Data Exchange (ETDEWEB)

Veronesi, Francesca [Laboratory of Preclinical and Surgical Studies, Rizzoli Orthopedic Institute, Via Di Barbiano 1/10, Bologna 40136 (Italy); Giavaresi, Gianluca; Fini, Milena [Laboratory of Preclinical and Surgical Studies, Rizzoli Orthopedic Institute, Via Di Barbiano 1/10, Bologna 40136 (Italy); Laboratory of Biocompatibility, Innovative Technologies and Advanced Therapies, Department Rizzoli RIT, Via Di Barbiano 1/10, Bologna 40136 (Italy); Longo, Giovanni [CNR Istituto di Struttura della Materia, CNR, Via del Fosso del Cavaliere 100, 00133 Roma (Italy); Ioannidu, Caterina Alexandra; Scotto d' Abusco, Anna [Dept. of Biochemical Sciences, Sapienza University of Roma, Ple A. Moro 5, 00185 Roma (Italy); Superti, Fabiana; Panzini, Gianluca [Dept. of Technologies and Health, Istituto Superiore di Sanità, Viale Regina Elena, 299 Roma (Italy); Misiano, Carlo [Romana Film Sottili, Anzio, Roma (Italy); Palattella, Alberto [Dept. of Clinical Sciences and Translational Medicine, Tor Vergata University, Via Montpellier 1, 00133 Roma (Italy); Selleri, Paolo; Di Girolamo, Nicola [Exotic Animals Clinic, Via S. Giovannini 53, 00137 Roma (Italy); Garbarino, Viola [Dept. of Radiology, S.M. Goretti Hospital, Via G. Reni 2, 04100 Latina (Italy); Politi, Laura [Dept. of Biochemical Sciences, Sapienza University of Roma, Ple A. Moro 5, 00185 Roma (Italy); Scandurra, Roberto, E-mail: roberto.scandurra@uniroma1.it [Dept. of Biochemical Sciences, Sapienza University of Roma, Ple A. Moro 5, 00185 Roma (Italy)

2017-01-01

Titanium implants coated with a 500 nm nanostructured layer, deposited by the Ion Plating Plasma Assisted (IPPA) technology, composed of 60% graphitic carbon, 25% titanium oxides and 15% titanium carbide were implanted into rabbit femurs whilst into the controlateral femurs uncoated titanium implants were inserted as control. At four time points the animals were injected with calcein green, xylenol orange, oxytetracycline and alizarin. After 2, 4 and 8 weeks femurs were removed and processed for histology and static and dynamic histomorphometry for undecalcified bone processing into methylmethacrylate, sectioned, thinned, polished and stained with Toluidine blue and Fast green. The overall bone-implant contacts rate (percentage of bone-implant contacts/weeks) of the TiC coated implant was 1.6 fold than that of the uncoated titanium implant. The histomorphometric analyses confirmed the histological evaluations. More precisely, higher Mineral Apposition Rate (MAR, μm/day) (p < 0.005) and Bone Formation Rate (BFR, μm{sup 2}/μm/day) (p < 0.0005) as well as Bone Implant Contact (Bic) and Bone Ingrowth values (p < 0.0005) were observed for the TiC coated implants compared to uncoated implants. In conclusion the hard nanostructured TiC layer protects the bulk titanium implant against the harsh conditions of biological tissues and in the same time, stimulating adhesion, proliferation and activity of osteoblasts, induces a better bone-implant contacts of the implant compared to the uncoated titanium implant. - Highlights: • Ti implants were coated with a nanostructured film composed of C{sub gr}, TiC and TiO{sub x}. • The TiC layer stimulates adhesion, proliferation and activity of osteoblasts. • Uncoated and TiC coated titanium implants were implanted in rabbit femurs. • Bone-implant contacts of TiC coated implants were higher than that of uncoated. • Mineral Apposition Rate of TiC coated implants were higher than that of uncoated.

The vapour phase deposition of boron on titanium by the reaction between gaseous boron trichloride and titanium metal. Final report

International Nuclear Information System (INIS)

Cameron, D.J.; Shelton, R.A.J.

1965-03-01

The reaction, between boron trichloride vapour and titanium has been investigated in the temperature range 200 - 1350 deg. C. It has been found that an initial reaction leads to the formation of titanium tetrachloride and the deposition of boron on titanium, but that except for reactions between 900 and 1000 deg. C, the system is complicated by the formation of lower titanium chlorides due to secondary reactions between the titanium and titanium tetrachloride

Doped titanium dioxide nanocrystalline powders with high photocatalytic activity

International Nuclear Information System (INIS)

Castro, A.L.; Nunes, M.R.; Carvalho, M.D.; Ferreira, L.P.; Jumas, J.-C.; Costa, F.M.; Florencio, M.H.

2009-01-01

Doped titanium dioxide nanopowders (M:TiO 2 ; M=Fe, Co, Nb, Sb) with anatase structure were successfully synthesized through an hydrothermal route preceded by a precipitation doping step. Structural and morphological characterizations were performed by powder XRD and TEM. Thermodynamic stability studies allowed to conclude that the anatase structure is highly stable for all doped TiO 2 prepared compounds. The photocatalytic efficiency of the synthesized nanopowders was tested and the results showed an appreciable enhancement in the photoactivity of the Sb:TiO 2 and Nb:TiO 2 , whereas no photocatalytic activity was detected for the Fe:TiO 2 and Co:TiO 2 nanopowders. These results were correlated to the doping ions oxidation states, determined by Moessbauer spectroscopy and magnetization data. - Graphical abstract: Doped titanium dioxide nanopowders (M:TiO 2 ; M=Fe, Co, Nb, Sb) with highly stable anatase structure were successfully synthesized through an hydrothermal route. The photocatalytic efficiencies of the synthesized nanopowders were tested and the results show an appreciable enhancement in the photoactivity of the Sb:TiO 2 and Nb:TiO 2 .

Process for making a titanium diboride-chromium diboride-yttrium titanium oxide ceramic composition

Science.gov (United States)

Holcombe, C.E.; Dykes, N.L.

1992-04-28

A ceramic composition is described. The ceramic composition consists essentially of from about 84 to 96 w/o titanium diboride, from about 1 to 9 w/o chromium diboride, and from about 3 to about 15 w/o yttrium-titanium-oxide. A method of making the ceramic composition is also described. The method of making the ceramic composition comprises the following steps: Step 1--A consolidated body containing stoichiometric quantities of titanium diboride and chromium diboride is provided. Step 2--The consolidated body is enclosed in and in contact with a thermally insulated package of yttria granules having a thickness of at least 0.5 inches. Step 3--The consolidated body enclosed in the thermally insulated package of yttria granules is heated in a microwave oven with microwave energy to a temperature equal to or greater than 1,900 degrees centigrade to sinter and uniformly disperse yttria particles having a size range from about 1 to about 12 microns throughout the consolidated body forming a densified body consisting essentially of titanium diboride, chromium diboride, and yttrium-titanium-oxide. The resulting densified body has enhanced fracture toughness and hardness. No Drawings

[Effect of sintering gold paste coating on the bonding strength of pure titanium and three low-fusing porcelains].

Science.gov (United States)

Zhang, Ya-li; Luo, Xiao-ping; Zhou, Li

2012-05-01

To study the effect of sintering gold paste coating of pure titanium on the adhesion of three porcelains following the protocol ISO 9693, and to investigate the titanium-porcelains interfaces. Sixty machined pure titanium samples were prepared in a rectangular shape according to ISO 9693 and divided equally into six groups. Half of the strips were coated with gold paste (Deckgold) and sintered. Three ultra-low-fusing dental porcelains (I: Initial Ti, S: Super porcelain Ti-22, T: TitanKeramik) were fused onto the titanium surfaces. A thin layer of bonding agent was only applied on the surfaces of uncoated gold specimens. The interface of the porcelain and titanium was observed with a field emission scanning electron microscope (FE-SEM) after metallographic preparation and sputtered with a very thin carbon layer of the embedded titanium-porcelain interface. After three-point bending test was performed, optical stereomicroscope was used to characterize the titanium-porcelains adhesion and determine the mode of failure. FE-SEM illustrated intermetallic compounds of Au-Ti formed with some visible microcracks in the gold layer and the interface of gold layer and ceramic. All the uncoated gold titanium-porcelain system showed predominately adhesive fracture at the titanium oxidation, whereas the failure modes in all gold coated systems were cohesive and adhesive, mainly cohesive. The three-point-bending test showed that the bonding strength of GS and GI groups [(37.08 ± 4.32) and (36.20 ± 2.40) MPa] were higher than those in uncoated groups [(31.56 ± 3.74) and (30.88 ± 2.60) MPa, P 0.05). The gold paste intermediate coatings can improve bond strengths of Super porcelain Ti-22 system and Initial Ti system, which have potential applications in clinical fields.

40 CFR 180.1195 - Titanium dioxide.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or on...

Advances in cost effective processing of titanium

International Nuclear Information System (INIS)

Nelson, O.E.

1993-01-01

Recently an industry expert pointed out that one of the greatest hindrances to the growth of titanium usage has been the low percentage of material usable in the final product. Due to the extensive processing, forming, and machining operations typically performed on titanium, yield losses are high. This is especially true in aerospace applications where most titanium is used. In engine components, the start to finish ratio, known as the buy to fly ratio, is often as high as 7 to 1. This can be illustrated by looking at the use of titanium in Pratt and Whitney engines. In the JT-8D-217 used on Boeing's 737-200, the titanium buyweight is 5,385 pounds, whereas the finished titanium, flyweight is just 758 pounds. This start to finish ratio is 7.1:1, giving titanium 17.0% of total engine weight. (orig.)

Electron beam melting of sponge titanium

International Nuclear Information System (INIS)

Kanayama, Hiroshi; Kusamichi, Tatsuhiko; Muraoka, Tetsuhiro; Onouye, Toshio; Nishimura, Takashi

1991-01-01

Fundamental investigations were done on electron beam (EB) melting of sponge titanium by using 80 kW EB melting furnace. Results obtained are as follows: (1) To increase the melting yield of titanium in EB melting of sponge titanium, it is important to recover splashed metal by installation of water-cooled copper wall around the hearth and to decrease evaporation loss of titanium by keeping the surface temperature of molten metal just above the melting temperature of titanium without local heating. (2) Specific power consumption of drip melting of pressed sponge titanium bar and hearth melting of sponge titanium are approximately 0.9 kWh/kg-Ti and 0.5-0.7 kWh/kg-Ti, respectively. (3) Ratios of the heat conducted to water-cooled mould in the drip melting and to water-cooled hearth in the hearth melting to the electron beam input power are 50-65% and 60-65%, respectively. (4) Surface defects of EB-melted ingots include rap which occurs when the EB output is excessively great, and transverse cracks when the EB output is excessively small. To prevent surface defects, the up-down withdrawal method is effective. (author)

Production of titanium tetrachloride

International Nuclear Information System (INIS)

Perillo, P.M.; Botbol, O.

1990-01-01

This report presents a summary of results from theoperation of a laboratory scale for the production in batches of approximately 100 gs of titanium tetrachloride by chlorination with chloroform and carbon tetrachloride between 340 deg C and 540 deg C. Chlorination agent vapors were passed through a quartz column reacting with titanium oxide powder agglomerated in little spheres. Obtained titanium tetrachloride was condensed in a condenser, taken in a ballon and then purified by fractional distillation. Optimun temperature for chloroform was 400 deg C with 74 % yield and for carbon tetrachloride was 500 deg C with 69 % yield. (Author) [es

Ti 2p and O 1s core levels and chemical bonding in titanium-bearing oxides

International Nuclear Information System (INIS)

Atuchin, Victor V.; Kesler, Valery G.; Pervukhina, Natalia V.; Zhang, Zhaoming

2006-01-01

A set of available experimental data on the binding energies of Ti 2p 3/2 and O 1s core levels in titanium-bearing oxides has been presented by using the binding energy difference (O 1s-Ti 2p 3/2 ) as a robust parameter to characterize these compounds. An empirical relationship between the (O 1s-Ti 2p 3/2 ) values measured with XPS and the mean chemical bond length L(Ti-O) in these crystals has been discussed for Ti 4+ -compounds

Uranium fluorides analysis. Titanium spectrophotometric determination

International Nuclear Information System (INIS)

Anon.

Titanium determination in uranium hexafluoride in the range 0.7 to 100 microgrammes after transformation of uranium fluoride in sulfate. Titanium is separated by extraction with N-benzoylphenylhydroxylamine, reextracted by hydrochloric-hydrofluoric acid. The complex titanium-N-benzoylphenylhydroxylamine is extracted by chloroform. Spectrophotometric determination at 400 nm [fr

21 CFR 73.2575 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the requirements...

Titanium oxide nanocoating on a titanium thin film deposited on a glass substrate

Energy Technology Data Exchange (ETDEWEB)

Kotsedi, L., E-mail: kotsedi@tlabs.ac.za [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS, National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape (South Africa); Nuru, Z.Y. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS, National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape (South Africa); Eaton, S.M. [Physics Department, Politecnico di Milano, Piazza Leonardo Da Vinci, 32, 20133 Milano (Italy); Cummings, F.R. [University of the Western Cape, Electron Microscopy Unit, Physics Department, Bellville 7535, Cape Town (South Africa); Turco, S. Lo; Ntwaeaborwa, O.M. [Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Milano, Italy Via Giovanni Pascoli, 70/3, 20133 Milano (Italy); Ramponi, R. [Institute for Photonics and Nanotechnologies (IFN)-CNR, Piazza Leonardo Da Vinci, 32, 20133 Milano (Italy); Maaza, M. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS, National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape (South Africa)

2016-03-31

Thin films of titanium were deposited on a glass substrate using electron beam evaporator. Femtosecond laser pulses were focused on the surface of the films, and the samples were scanned while mounted on the motorized computer-controlled motion stage to produce an areal modification of the films. X-ray diffraction of the laser-patterned samples showed evidence of the formation of a γ-Ti{sub 3}O{sub 5} with a monoclinic phase. Rutherford backscattering spectrometry simulation showed that there is an increase in the oxygen concentration as the average laser fluence is increased. Time of flight secondary ions mass spectrometry analysis showed an even distribution of the titanium and oxygen ions on the sample and also ionized molecules of the oxides of titanium were observed. The formation of the oxide of titanium was further supported using the UV–Vis-NIR spectroscopy, which showed that for 0.1 J/cm{sup 2} fluence, the laser-exposed film showed the electron transfer band and the d–d transition peak of titanium was observed at lower wavelengths. - Highlights: • γ-Ti{sub 3}O{sub 5} formed using femtosecond laser. • Fluence and oxygen relation were studied. • Nanoflakes of γ-Ti{sub 3}O{sub 5} were observed under HRSEM.

21 CFR 73.1575 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the requirements...

Adhesive-Bonded Tab Attaches Thermocouples to Titanium

Science.gov (United States)

Cook, C. F.

1982-01-01

Mechanical strength of titanium-alloy structures that support thermocouples is preserved by first spotwelding thermocouples to titanium tabs and then attaching tabs to titanium with a thermosetting adhesive. In contrast to spot welding, a technique previously used for thermocouples, fatigue strength of the titanium is unaffected by adhesive bonding. Technique is also gentler than soldering or attaching thermocouples with a tap screw.

A hybrid Taguchi-artificial neural network approach to predict surface roughness during electric discharge machining of titanium alloys

Energy Technology Data Exchange (ETDEWEB)

Kumar, Sanjeev; Batish, Ajay [Thapar University, Patiala (India); Singh, Rupinder [GNDEC, Ludhiana (India); Singh, T. P. [Symbiosis Institute of Technology, Pune (India)

2014-07-15

In the present study, electric discharge machining process was used for machining of titanium alloys. Eight process parameters were varied during the process. Experimental results showed that current and pulse-on-time significantly affected the performance characteristics. Artificial neural network coupled with Taguchi approach was applied for optimization and prediction of surface roughness. The experimental results and the predicted results showed good agreement. SEM was used to investigate the surface integrity. Analysis for migration of different chemical elements and formation of compounds on the surface was performed using EDS and XRD pattern. The results showed that high discharge energy caused surface defects such as cracks, craters, thick recast layer, micro pores, pin holes, residual stresses and debris. Also, migration of chemical elements both from electrode and dielectric media were observed during EDS analysis. Presence of carbon was seen on the machined surface. XRD results showed formation of titanium carbide compound which precipitated on the machined surface.

Criterion of titanium aviation alloy application

International Nuclear Information System (INIS)

Stasyunas, O.P.

1976-01-01

The most significant statistic mechanical characteristics are presented of titanium as compared with those of aluminium and steel. Based on these data one can draw conclusions as to the advantages and disadvantages of titanium. High chemical activity and diffusivity of titanium place limitations on the use of its alloys. Despite the promising features of a needle-like structure, specifications still keep relying on a globular structure, which is explained by the easeiness of the production. Titanium is expensive, sometimes its cost may by a factor of 20 exceed that of other aviation materials

21 CFR 73.575 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.575 Section 73.575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.575 Titanium dioxide. (a) Identity. (1) The color additive titanium dioxide is synthetically prepared TiO2, free from admixture with other substances. (2) Color...

21 CFR 73.3126 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891, shall...

Welding and Joining of Titanium Aluminides

Science.gov (United States)

Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai

2014-01-01

Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials. PMID:28788113

Ti 2p and O 1s core levels and chemical bonding in titanium-bearing oxides

Energy Technology Data Exchange (ETDEWEB)

Atuchin, Victor V. [Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation)]. E-mail: atuchin@thermo.isp.nsc.ru; Kesler, Valery G. [Technical Centre, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation); Pervukhina, Natalia V. [Laboratory of Crystal Chemistry, Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Zhang, Zhaoming [Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)

2006-06-15

A set of available experimental data on the binding energies of Ti 2p{sub 3/2} and O 1s core levels in titanium-bearing oxides has been presented by using the binding energy difference (O 1s-Ti 2p{sub 3/2}) as a robust parameter to characterize these compounds. An empirical relationship between the (O 1s-Ti 2p{sub 3/2}) values measured with XPS and the mean chemical bond length L(Ti-O) in these crystals has been discussed for Ti{sup 4+}-compounds.

Welding and Joining of Titanium Aluminides

Directory of Open Access Journals (Sweden)

Jian Cao

2014-06-01

Full Text Available Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

Process for production of a borohydride compound

Science.gov (United States)

Allen, Nathan Tait; Butterick, III, Robert; Chin, Arthur Achhing; Millar, Dean Michael; Molzahn, David Craig

2014-08-19

A process for production of a borohydride compound M(BH.sub.4).sub.y. The process has three steps. The first step combines a compound of formula (R.sup.1O).sub.yM with aluminum, hydrogen and a metallic catalyst containing at least one metal selected from the group consisting of titanium, zirconium, hafnium, niobium, vanadium, tantalum and iron to produce a compound of formula M(AlH.sub.3OR.sup.1).sub.y, wherein R.sup.1 is phenyl or phenyl substituted by at least one alkyl or alkoxy group; M is an alkali metal, Be or Mg; and y is one or two; wherein the catalyst is present at a level of at least 200 ppm based on weight of aluminum. The second step combines the compound of formula M(AlH.sub.3OR.sup.1).sub.y with a borate, boroxine or borazine compound to produce M(BH.sub.4).sub.y and a byproduct mixture containing alkali metal and aluminum aryloxides. The third step separates M(BH.sub.4).sub.y from the byproduct mixture.

Analysis of titanium content in titanium tetrachloride solution

Science.gov (United States)

Bi, Xiaoguo; Dong, Yingnan; Li, Shanshan; Guan, Duojiao; Wang, Jianyu; Tang, Meiling

2018-03-01

Strontium titanate, barium titan and lead titanate are new type of functional ceramic materials with good prospect, and titanium tetrachloride is a commonly in the production such products. Which excellent electrochemical performance of ferroelectric tempreature coefficient effect.In this article, three methods are used to calibrate the samples of titanium tetrachloride solution by back titration method, replacement titration method and gravimetric analysis method. The results show that the back titration method has many good points, for example, relatively simple operation, easy to judgment the titration end point, better accuracy and precision of analytical results, the relative standard deviation not less than 0.2%. So, it is the ideal of conventional analysis methods in the mass production.

Ultrasonic effects on titanium tanning of leather.

Science.gov (United States)

Peng, Biyu; Shi, Bi; Sun, Danhong; Chen, Yaowen; Shelly, Dennis C

2007-03-01

The effects of ultrasound on titanium tanning of leather were investigated. Either 20 or 40 kHz ultrasound was applied to the titanium tanning of pigskins. Five different treatment conditions were carried out and the effects were examined, such as leather shrinkage temperature (T(s)), titanium content and titanium distribution in the leather. Overall heat loading was carefully controlled. Results showed that 20 kHz ultrasound effectively improves titanium agent penetration into the hide and increases the leather's shrinkage temperature. Doubling the frequency to 40 kHz produced negligible enhancements. An impressive 105.6 degrees C T(s) was achieved using 20 kHz ultrasound pretreatment of the tanning liquor followed by 20 kHz ultrasound in the tanning mixture (liquor plus pigskins) in a special salt-free medium. Finally, using a unique ultrasonic tanning drum with 26.5 kHz ultrasound, the T(s) reached a record level of 106.5 degrees C, a value not achieved in conventional (no ultrasound) titanium tanning. The ultrasonic effects on titanium tanning of leather are judged to make a superior mineral tanned leather.

Titanium nanostructures for biomedical applications

Science.gov (United States)

Kulkarni, M.; Mazare, A.; Gongadze, E.; Perutkova, Š.; Kralj-Iglič, V.; Milošev, I.; Schmuki, P.; Iglič, A.; Mozetič, M.

2015-02-01

Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.

Titanium nanostructures for biomedical applications

International Nuclear Information System (INIS)

Kulkarni, M; Gongadze, E; Perutkova, Š; A Iglič; Mazare, A; Schmuki, P; Kralj-Iglič, V; Milošev, I; Mozetič, M

2015-01-01

Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO 2 ) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO 2 nanotubes in cell interactions is based on the fact that TiO 2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO 2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties. (topical review)

A new method for production of titanium vapor and synthesis of titanium nitride coatings

Science.gov (United States)

Grigoriev, Sergey N.; Melnik, Yury A.; Metel, Alexander S.; Volosova, Marina A.

2018-03-01

It is proposed to synthesize on machine parts and cutting tools wear-resistant titanium nitride coatings with the help of the hollow-cathode glow discharge, a molybdenum crucible for titanium evaporation being used as the anode of the discharge and a process vacuum chamber being used as the hollow cathode. The research revealed that at the anode surface area less than a critical value S* = (2m/M)1/2S, where S is the area of the chamber walls, m is the mass of electrons and M is the mass of ions, the anode fall of potential is positive and grows from ˜50 V at argon pressure p = 0.2 Pa to ˜2 kV at p = 0.02 Pa. At the discharge current I = 0.6 A electrons accelerated by the anode fall of 0.9 kV transport into the crucible with the inner diameter of 12 mm the power of ˜0.54 kW, which allows the titanium evaporation and the coating deposition rate of 5 µm·h-1 on a substrate distanced from the crucible at 100 mm. After the argon is replaced with the nitrogen, titanium nitride coating without titanium droplets is synthesized the deposition rate amounting to about the same value.

Appcelerator Titanium patterns and best practices

CERN Document Server

Pollentine, Boydlee

2013-01-01

The book takes a step-by-step approach to help you understand CommonJS and Titanium architecture patterns, with easy to follow samples and plenty of in-depth explanations If you're an existing Titanium developer or perhaps a new developer looking to start off your Titanium applications "the right way", then this book is for you. With easy to follow examples and a full step-by-step account of architecting a sample application using CommonJS and MVC, along with chapters on new features such as ACS, you'll be implementing enterprise grade Titanium solutions in no time. You should have some JavaSc

Structure and properties of Titanium for dental implants

Directory of Open Access Journals (Sweden)

M. Greger

2009-10-01

Full Text Available This paper describes manufacture of nano-structural titanium, its structure and properties. Nano-titanium has higher specific strength properties than ordinary (coarse-grained titanium. Nano-titanium was produced by the equal-channel angular pressing (ETAP process. The research it self was focused on physical base of strengthening and softening processes and developments occurring at the grain boundaries during the ECAP process at half-hot temperature. Strength of nano-titanium varies around 960 MPa, grain size around 300 nm.

Research and Development on Titanium Alloys

Science.gov (United States)

1949-10-31

information concerning the runs made * * In order to check the general operation of the train and furnace, a number of qualitative runs were made. These runs... General Technique. * . . * * . 109 The Analysis of Titanium . . . . ... ... 112 Notes and Comments, . . . .. . .. . . . 113 The Results from Vacuum...described in this report are as follows: 1. Arc ielting Titanium-Base Alloys. 2. Evaluation of Experimental Titanium-Base Alloys. 3. Investigation of

Titanium oxide fever

International Nuclear Information System (INIS)

De Jonge, D.; Visser, J.

2012-01-01

One measure to improve air quality is to apply photo-catalytic substances that capture NOx onto the road surface or onto baffle boards alongside the roads. The effect of titanium oxide containing clinkers with coating was discussed in the report 'Demonstration project of air-purifying pavement in Hengelo, The Netherlands' that was published in May 2011. This article examines the way in which the effectiveness of this study was determined. Can titanium oxide containing clinkers and coatings indeed capture NOx?. [nl

Functionalization of nanoparticle titanium dioxide with different bifunctional organic molecules and trimers of transition compounds for obtaining new materials

International Nuclear Information System (INIS)

Rivera Martinez, Maria Cinthya

2012-01-01

Functionalization of titanium dioxide in nanoporous anatase phase is investigated for obtaining new nanomaterials. Functionalizations were performed using two heating methods: the conventional of refluxing heating method and microwave irradiation with bifunctional organic molecules is used to study how to anchor molecules and the change in the wettability of the material. Besides, reactions with organic molecules were performed as the derived from nanoproxene. The growth layer by layer is performed using the bifunctional molecules previous for the immobilization of cobalt trimers. Functionalized molecules were characterized by infrared spectroscopy, X-ray diffraction, contact angle, scanning electron microscopy, x-ray elemental analysis, plasma atomic emission spectroscopy coupled inductively, x-ray photoelectron spectroscopy and thermogravimetric analysis. This type of functionalizations on nanoporous titanium dioxide could potentially improve optical sensitivity and activity of this nanomaterial in the visible region. (author) [es

Formation of titanium diboride coatings during the anodic polarization of titanium in a chloride melt with a low boron oxide content

Science.gov (United States)

Elshina, L. A.; Malkov, V. B.; Molchanova, N. G.

2015-02-01

The corrosion-electrochemical behavior of titanium in a molten eutectic mixture of cesium and sodium chlorides containing up to 1 wt % boron oxide is studied in the temperature range 810-870 K in an argon atmosphere. The potential, the current, and the rate of titanium corrosion are determined. The optimum conditions of forming a dense continuous titanium diboride coating on titanium with high adhesion to the metallic base are found for the anodic activation of titanium in the molten electrolyte under study.

Creating nanoshell on the surface of titanium hydride bead

Directory of Open Access Journals (Sweden)

PAVLENKO Vyacheslav Ivanovich

2016-12-01

Full Text Available The article presents data on the modification of titanium hydride bead by creating titanium nanoshell on its surface by ion-plasma vacuum magnetron sputtering. To apply titanium nanoshell on the titanium hydride bead vacuum coating plant of multifunctional nanocomposite coatings QVADRA 500 located in the center of high technology was used. Analysis of the micrographs of the original surface of titanium hydride bead showed that the microstructure of the surface is flat, smooth, in addition the analysis of the microstructure of material surface showed the presence of small porosity, roughness, mainly cavities, as well as shallow longitudinal cracks. The presence of oxide film in titanium hydride prevents the free release of hydrogen and fills some micro-cracks on the surface. Differential thermal analysis of both samples was conducted to determine the thermal stability of the initial titanium hydride bead and bead with applied titanium nanoshell. Hydrogen thermal desorption spectra of the samples of the initial titanium hydride bead and bead with applied titanium nanoshell show different thermal stability of compared materials in the temperature range from 550 to 860о C. Titanium nanoshells applied in this way allows increasing the heat resistance of titanium hydride bead – the temperature of starting decomposition is 695о C and temperature when decomposition finishes is more than 1000о C. Modified in this way titanium hydride bead can be used as a filler in the radiation protective materials used in the construction or upgrading biological protection of nuclear power plants.

Laser-induced oxidation of titanium substrate: Analysis of the physicochemical structure of the surface and sub-surface layers

Energy Technology Data Exchange (ETDEWEB)

Antończak, Arkadiusz J., E-mail: arkadiusz.antonczak@pwr.edu.pl [Laser and Fiber Electronics Group, Faculty of Electrical Engineering, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Skowroński, Łukasz; Trzcinski, Marek [Institute of Mathematics and Physics, University of Technology and Life Sciences, Kaliskiego 7, 85-789 Bydgoszcz (Poland); Kinzhybalo, Vasyl V. [Wroclaw Research Centre EIT+, Stabłowicka 147, 54-066 Wrocław (Poland); Institute of Low Temperature and Structure Research, Okólna 2, 50-422 Wrocław (Poland); Łazarek, Łukasz K.; Abramski, Krzysztof M. [Laser and Fiber Electronics Group, Faculty of Electrical Engineering, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland)

2015-01-15

Highlights: • Chemical structure of the films induced by laser on titanium surface was analyzed. • It was shown that outer layer of this films consist of oxides doped with nitrogen. • The optical properties of the laser-induced oxynitride films were characterized. • We found that the films demonstrated significant absorption in the band of 300–580 nm. • The morphology of the layers as a function of the laser fluence was investigated. - Abstract: This paper presents the results of the analysis of the complex chemical structure of the layers made on titanium in the process of the heating of its surfaces in an atmospheric environment, by irradiating samples with a nanosecond-pulsed laser. The study was carried out for electroplated, high purity, polycrystalline titanium substrates using a Yb:glass fiber laser. All measurements were made for samples irradiated in a broad range of accumulated fluence, below the ablation threshold. It has been determined how the complex index of refraction of both the oxynitride layers and the substrate vary as a function of accumulated laser fluence. It was also shown that the top layer of the film produced on titanium, which is transparent, is not a pure TiO{sub 2} as had been supposed before. The XPS and XRD analyses confirmed the presence of nitrogen compounds and the existence of nonstoichiometric compounds. By sputtering of the sample's surface using an Ar{sup +} ion gun, the changes in the concentration of individual elements as a function of the layer's cross-section were determined. Lastly, an analysis of the surface morphology has also been carried out, explaining why the layers crack and exfoliate from their substrate.

The determination of iron, chromium, titanium, and tungsten by x-ray-fluorescence spectrometry

International Nuclear Information System (INIS)

Austen, C.E.

1977-01-01

An accurate and precise method is described for the determination of iron and chromium in chromite, iron and titanium in ilmenite, and tungsten in tungsten ores. Samples are prepared for analysis by fusion with sodium peroxide or sodium tetraborate and leaching of the melt in a solution of tartaric or hydrochloric acid. Matrix correction and calibration are achieved by means of the single-standard calibration method with reference solutions prepared from compounds of the elements determined

Titanium electroplating of copper in molten salt media

International Nuclear Information System (INIS)

Renaud, Denis

1985-01-01

After a bibliographical survey on electroplating in molten salt media and on the electrolytic production of titanium, the author explains the reasons for the choice of the LiF-NaF-KF eutectic mix as solvent. He recalls the main properties which are used, and describes the conventional and convolutional processing of data obtained by linear volt-amperometry. He presents the electrolyte preparation mode which takes into account the existence of titanium ions with intermediate oxidation degree, and the reactivity of titanium with oxygenated species. Experimental results are discussed. Then, after the study of the mechanism of reduction of trivalent titanium into titanium on molybdenum (intermetallic diffusion is here negligible), he reports the study of this mechanism on copper (it is a more complicated situation, due to combinations between titanium and copper). The effect of different parameters (electrolyte purity, current density, electrode potential and temperature) is interpreted in order to identify optimal conditions for titanium electroplating of copper [fr

Laser shock peening of titanium 6-4 alloy

International Nuclear Information System (INIS)

Brar, N.S.; Hopkins, A.; Laber, M.W.

2000-01-01

Laser shock peening of titanium 6-4 has been shown to improve its high cycle fatigue life. Residual compressive stresses generated on the surface of titanium 6-4, as a result of laser shocking, have shown dramatic improvement in the performance of aircraft turbine blades. Laser shocking of titanium was carried out with a 20 ns pulse width, 50 joule pulsed laser, operated by LSP Technologies, Columbus, OH. Titanium disks, 20-mm in diameter, and ranging in thicknesses from zero (bare LiF) to 3-mm were subjected to laser shock to monitor amplitude and temporal stress profiles of the pulsed laser. Laser shock stress amplitudes on the back of titanium disks were monitored with VISAR using LiF as the window material. The peak shock stress produced in LiF (titanium thickness zero) was measured to be 16±1 GPa. The laser shock amplitude decays to about 2.7 GPa while propagating through 3-mm thick disk of titanium 6-4

Strength and structure of nanocrystalline titanium

International Nuclear Information System (INIS)

Noskova, N.I.; Pereturina, I.A.; Elkina, O.A.; Stolyarov, V.V.

2004-01-01

Investigation results on strength and plasticity of nanocrystalline titanium VT-1 are presented. Specific features of plastic deformation on tension of this material specimens in an electron microscope column are studied in situ. It is shown that nanocrystalline titanium strength and plasticity at room temperature are dependent on the structure and nanograin size. It is revealed that deformation processes in nanocrystalline titanium are characterized by activation of deformation rotational modes and microtwinning [ru

Rapid prototyped porous nickel–titanium scaffolds as bone substitutes

Directory of Open Access Journals (Sweden)

Waldemar Hoffmann

2014-06-01

Full Text Available While calcium phosphate–based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel–titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel–titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel–titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel–titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel–titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel–titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold’s pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel–titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used

Mechanical properties and fracture of titanium hydrides

International Nuclear Information System (INIS)

Koketsu, Hideyuki; Taniyama, Yoshihiro; Yonezu, Akio; Cho, Hideo; Ogawa, Takeshi; Takemoto, Mikio; Nakayama, Gen

2006-01-01

Titanium hydrides tend to suffer fracture when their thicknesses reach a critical thickness. Morphology and mechanical property of the hydrides are, however, not well known. The study aims to reveal the hydride morphology and fracture types of the hydrides. Chevron shaped plate hydrides were found to be produced on the surface of pure titanium (Grade 1) and Grade 7 titanium absorbing hydrogen. There were tree types of fracture of the hydrides, i.e., crack in hydride layer, exfoliation of the layer and shear-type fracture of the hydride plates, during the growth of the hydrides and deformation. We next estimated the true stress-strain curves of the hydrides on Grade 1 and 7 titanium using the dual Vickers indentation method, and the critical strain causing the Mode-I fine crack by indentation. Fracture strength and strain of the hydrides in Grade 1 titanium were estimated as 566 MPa and 4.5%, respectively. Those of the hydride in Grade 7 titanium were 498 MPa and 16%. Though the fracture strains estimated from the plastic instability of true stress-strain curves were approximately the half of those estimated by finite element method, the titanium hydrides were estimated to possess some extent of toughness or plastic deformation capability. (author)

Synthesis and characterization of a ferrous compound material obtained by combustion of ferroboron and ferrotitanium mixtures

International Nuclear Information System (INIS)

Bejar, M.A; Fuenzalida, J.L

2008-01-01

A ferrous compound material was synthesized in this work, by the air auto-combustion of mixtures of powdered ferroboron and ferrotitanium, compacted under pressures of 79 and 93 MPa and preheated to a temperature of about 1000 o C. The synthesized compounds were characterized by XRD analysis, and macro and micro-hardness tests. The formation of titanium diboride was found in all the synthesized test pieces (au)

Preparation of titanium oxide and metal titanates as powders, thin films, and microspheres by complex sol-gel process

International Nuclear Information System (INIS)

Deptula, A.; Olczak, T.; Lada, W.; Chmielewski, A.G.; Jakubaszek, U.; Sartowska, B.; Goretta, K.C.; Alvani, C.; Casadio, S.; Contini, V.

2006-01-01

Titanium oxide, for many years an important pigment, has recently been applied widely as a photocatalyst or as supports for metallic catalysts, gas sensors, photovoltaic solar cells, and water and air purification devices. Titanium oxide (TiO 2 ) and titanates based on Ba, Sr and Ca were prepared from commercial solutions of TiCl 4 and HNO 3 . The main preparation steps for the sols consisted of elimination of Cl - by distillation with HNO 3 and addition of metal hydroxides for the titanates. Resulting sols were gelled and used to: (a) prepare irregularly shaped powders by evaporation; (b) produce by a dipping technique thin films on glass, Ag or Ti supports; (c) produce spherical powders (diameters <100 μm) by solvent extraction. Results of thermal and X-ray-diffraction analyses indicated that the temperatures required to form the various compounds were lower than those necessary to form the compounds by conventional solid-state reactions and comparable to those required with use of organometallic based sol-gel methods. Temperatures of formation could be further reduced by addition of ascorbic acid (ASC) to the sols

Kinetic study of synthesis of Titanium carbide by methano thermal reduction of Titanium dioxide

International Nuclear Information System (INIS)

Alizadeh, R.; Ostrovski, O.

2011-01-01

Reduction of the Titanium dioxide, TiO 2 , by methane was investigated in this work. The thermodynamic of reaction was examined and found favorable. The reaction of titanium dioxide with methane was carried out in the temperature range 1150 d egree C to 1450 d egree C at atmospheric pressure with industrial high porosity pellets prepared from titanium dioxide powder. The evolved gas analyzing method was used for determination of the extent of reduction rate. The gas products of the reaction are mostly CO and trace amount of CO 2 and H 2 O. The synthesized product powder was characterized by X-ray diffraction for elucidating solid phase compositions. The effect of varying temperature was studied during the reduction. The conversion-time data have been interpreted by using the grain model. For first order reaction with respect to methane concentration, the activation energy of titanium dioxide reduction by methane is found to be 51.4 kcal/g mole. No detailed investigation of kinetic and mechanism of the reaction was reported in literatures.

The effect of doping titanium dioxide nanoparticles on phase transformation, photocatalytic activity and anti-bacterial properties

Science.gov (United States)

Buzby, Scott Edward

Nanosized titanium dioxide has a variety of important applications in everyday life including a photocatalyst for pollution remediation, photovoltaic devices, sunscreen, etc. This study focuses on the various properties of titanium dioxide nanoparticles doped with various cation and anion species. Samples were produced by various methods including metalorganic chemical vapor deposition (MOCVD), plasma assisted metalorganic chemical vapor deposition (PA-MOCVD) and sol-gel. Numerous techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy both scanning (SEM) and transmission (TEM) were used for physical characterization. Photocatalytic properties were determined by the oxidation of methylene blue dye and 2-chlorophenol in water as well as gaseous formic acid with results analyzed by high performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and ultra violet - visible spectroscopy (UV-VIS). For the purpose of enhancement of the photocatalytic activity of titanium dioxide nanoparticles, the effect of anion doping and the anatase-rutile phase ratio were studied. Although anatase, rutile and mixed crystallite phases all show some degree of activity in photocatalytic reactions, these results show that anatase is better suited for the degradation of organic compounds in an aqueous medium any advantage in photocatalytic activity gained through the enhancement in optical response from the smaller band gap by addition of rutile was overcome by the negatives associated with the rutile phase. Furthermore substitutional nitrogen doping showed significant improvement in UV photocatalysis as well as allowing for visible light activation of the catalyst. Further studies on the phase transitions in titanium dioxide nanoparticles were carried out by synthesizing various cation doped samples by sol-gel. Analysis of the phases by XRD showed an inverse relationship between dopant size and rutile percentage

In situ formation of titanium carbide using titanium and carbon-nanotube powders by laser cladding

International Nuclear Information System (INIS)

Savalani, M.M.; Ng, C.C.; Li, Q.H.; Man, H.C.

2012-01-01

Titanium metal matrix composite coatings are considered to be important candidates for high wear resistance applications. In this study, TiC reinforced Ti matrix composite layers were fabricated by laser cladding with 5, 10, 15 and 20 wt% carbon-nanotube. The effects of the carbon-nanotube content on phase composition, microstructure, micro-hardness and dry sliding wear resistance of the coating were studied. Microstructural observation using scanning electron microscopy showed that the coatings consisted of a matrix of alpha-titanium phases and the reinforcement phase of titanium carbide in the form of fine dendrites, indicating that titanium carbide was synthesized by the in situ reaction during laser irradiation. Additionally, measurements on the micro-hardness and dry sliding wear resistance of the coatings indicated that the mechanical properties were affected by the amount of carbon-nanotube in the starting precursor materials and were enhanced by increasing the carbon-nanotube content. Results indicated that the composite layers exhibit high hardness and excellent wear resistance.

In situ formation of titanium carbide using titanium and carbon-nanotube powders by laser cladding

Energy Technology Data Exchange (ETDEWEB)

Savalani, M.M., E-mail: mmfsmm@inet.polyu.edu.hk [Department of Industrial and Systems Engineering, Hong Kong Polytechnic University (Hong Kong); Ng, C.C.; Li, Q.H.; Man, H.C. [Department of Industrial and Systems Engineering, Hong Kong Polytechnic University (Hong Kong)

2012-01-15

Titanium metal matrix composite coatings are considered to be important candidates for high wear resistance applications. In this study, TiC reinforced Ti matrix composite layers were fabricated by laser cladding with 5, 10, 15 and 20 wt% carbon-nanotube. The effects of the carbon-nanotube content on phase composition, microstructure, micro-hardness and dry sliding wear resistance of the coating were studied. Microstructural observation using scanning electron microscopy showed that the coatings consisted of a matrix of alpha-titanium phases and the reinforcement phase of titanium carbide in the form of fine dendrites, indicating that titanium carbide was synthesized by the in situ reaction during laser irradiation. Additionally, measurements on the micro-hardness and dry sliding wear resistance of the coatings indicated that the mechanical properties were affected by the amount of carbon-nanotube in the starting precursor materials and were enhanced by increasing the carbon-nanotube content. Results indicated that the composite layers exhibit high hardness and excellent wear resistance.

Surface Modification of Silica Nanoparticles with Titanium Tetraisopropoxide and Evaluation of their Photocatalytic Activity

Directory of Open Access Journals (Sweden)

Leila Mazaheri

2012-12-01

Full Text Available Silica nanoparticles were modified with titanium tetraisopropoxide (TTIP via atwo-step sol-gel route. The modified silica nanoparticles were characterized using FTIR spectroscopy, thermal gravimetric analysis (TGA and EDAX elemental analysis. Photocatalytic activity of the modified nanocomposites was evaluated by photo-activated degradation of Rhodamine B (Rh.B dyestuff, as a colorant model, in distilled water. Reduction in Rh.B concentration in aqueous solution was evaluated by UV-visible spectroscopy and with the aid of visual observations. The FTIR spectroscopy results confirmed the formation of Ti-O-Si chemical bond on the surfaceof silica nanoparticles. TGA test results showed that the weight loss of the modified sample is due to deterioration of the alkoxy groups of the SiO2 surface. According to the results of EDAX elemental analysis, the presence of carbon and titanium in the structure of the modified samples and also reduction in oxygen levels are attributed to the chemical interactions due to surface chemical modification. Carbon detection in the composition can be attributed to the presence of isopropoxide in titanium tetraisopropoxide compound. The results also revealed that, with TiO2 grafting on the silica nanoparticles surface, absorption in UV region is increased and that the silica nanoparticles modified with titanate compound show photocatalytic characteristics and degradation ability of Rh.B dyestuff under UV light irradiation. It became also evident that the photocatalytic activity of the modified nanoparticles is less than TiO2 nanoparticles. However, by inclusion of modified silica nanoparticles into the polymeric coating, the photocatalytic properties of the coating can be established. Although modified silica nanoparticles have less photocatalytic activity compared to TiO2 nanoparticles, but they cause less damage to the polymer matrix.

The investigation of the effect of niobium artificial doping with titanium on Nb3Sn superconductors properties

International Nuclear Information System (INIS)

Nikulin, A.; Shikov, A.; Beliakov, N.; Semin, M.

1997-01-01

The effect on titanium doping of Nb filaments, and thus on the properties of bronze processed multifilamentary Nb 3 Sn wires and wires with internal tin sources with copper volume fraction up to 65 %, has been analysed. Either titanium rods or rods of the Nb-50Ti alloy, inserted in the axial area of each filament, were used as a source of titanium. The influence of doping on the quantity, composition, structure and superconducting properties of intermetallic compound Nb 3 Sn after heat treatments at 570-750 degrees C with duration up to 350 h was investigated by means of electrical measurements, optical metallography and methods of microanalysis and X-ray analysis. It was shown that the non-copper critical current density of the doped wires attained 600 and 270 A/mm 2 in 12.5 and 16 T respectively for bronze processed wires and 800 and 300 A/mm 2 for wires with internal tin source. Upper critical field calculated in accordance with Kramer's extrapolation was equal to 29-32 T

Experimental Technique of Titanium Fire in Aero-engine

Directory of Open Access Journals (Sweden)

MI Guangbao

2016-06-01

Full Text Available Titanium fire is the typical catastrophic fault in the aero-engine. Aiming at the urgent demand for experimental technique of titanium fire from advanced high thrust-weight ratio aero-engine, the combustion technology and theory of titanium alloy based on friction oxygen concentration method (FOC were systematically studied. The evaluation method of fireproof property and the friction ignition model were built, and the fireproof mechanism was illustrated. By generalizing recent progress in experimental technique of titanium fire from three levels, including evolutionary rule, mechanism and prevention and control technology, the ideas and directions of experimental technique associated with the application research of titanium fire in the future were proposed, namely overall evaluation of fireproof property close to air flow environment of the aero-engine, prediction model of fireproof property and experimental verification of fireproof technique under the air flow environment of aero-engine. It is necessary to establish the prevention system of titanium fire in aero-engine, which contributes to the realization of "full titanium" in compressor and to the increase of high thrust-weight ratio.

Relationship between surface properties (roughness, wettability) of titanium and titanium alloys and cell behaviour

International Nuclear Information System (INIS)

Ponsonnet, L.; Reybier, K.; Jaffrezic, N.; Comte, V.; Lagneau, C.; Lissac, M.; Martelet, C.

2003-01-01

Cell attachment and spreading to titanium-based alloy surfaces is a major parameter in implant technology. In this paper, substratum surface hydrophobicity, surface free energy, interfacial free energy and surface roughness were investigated to ascertain which of these parameters is predominant in human fibroblast spreading. Two methods for contact angle measurement were compared: the sessile drop method and the captive bubble two-probe method. The relationship between surface roughness and the sessile drop contact angles of various engineered titanium surfaces such as commercial pure titanium (cp-Ti), titanium-aluminium-vanadium alloy (Ti-6Al-4V), and titanium-nickel (NiTi), was shown. Surface free energy (SFE) calculations were performed from contact angles obtained on smooth samples based on the same alloys in order to eliminate the roughness effect. SFE of the surfaces have been calculated using the Owens-Wendt (OW) and Van Oss (VO) approaches with the sessile drop method. The OW calculations are used to obtain the dispersive (γ d ) and polar (γ p ) component of SFE, and the VO approach allows to reach the apolar (γ LW ) and the polar acid-base component (γ ab ) of the surface. From captive bubble contact angle experiments (air or octane bubble under water), the interfacial free energy of the different surfaces in water was obtained. A relationship between cell spreading and the polar component of SFE was found. Interfacial free energy values were low for all the investigated surfaces indicating good biocompatibility for such alloys

Analogy and differences between aluminium and titanium electrowinning

CSIR Research Space (South Africa)

Van Vuuren, DS

2006-09-01

Full Text Available larger market. The authors have tested this route experimentally, but could not produce pure titanium. The failure of electrowinning pure, molten titanium has been interpreted in terms of the analogy and differences between aluminium and titanium...

Direct dynamic synthesis of nanodispersed phases of titanium oxides upon sputtering of electrodischarge titanium plasma into an air atmosphere

Science.gov (United States)

Sivkov, A. A.; Gerasimov, D. Yu.; Nikitin, D. S.

2017-01-01

Experimental investigations of the possibility of directly synthesizing nanodispersed crystalline phases of titanium dioxides with rutile and anatase structures in a hypervelocity jet of electroerosion plasma generated by a coaxial magnetoplasma accelerator with titanium electrodes are presented. A powder product containing nanosized polymorphic phases of titanium dioxide with a spherical shape of particles has been manufactured.

Titanium application to power plant condensers

International Nuclear Information System (INIS)

Itoh, H.

1987-01-01

Recently, the growth of operating performance and construction plan of titanium-tubed condensers in thermal and unclear power plants has been very impressive. High-quality, thinner welded titanium tubes used for cooling tubes, matching design specifications of condensers, have been stably supplied through mass production. It now can be said that various technical problems for titanium-tubed condensers have been solved, but data on operating performance in large-scale commercial plants are still scarce, and site-by-site information needs be exchanged more frequently and on a larger scale. Projects to replace existing condenser cooling tubes with those of corrosion-resistant titanium have been actively furthered, with the only remaining barrier to full employment being cost effectiveness. It is hoped that condenser and tube manufacturers will conduct more joint value analyses

Stress corrosion cracking of titanium alloys

Science.gov (United States)

May, R. C.; Beck, F. H.; Fontana, M. G.

1971-01-01

Experiments were conducted to study (1) the basic electrochemical behavior of titanium in acid chloride solutions and (2) the response of the metal to dynamic straining in the same evironment. The aim of this group of experiments was to simulate, as nearly as possible, the actual conditions which exist at the tip of a crack. One of the foremost theories proposed to explain the propagation of stress corrosion cracks is a hydrogen embrittlement theory involving the precipitation of embrittling titanium hydrides inside the metal near the crack tip. An initial survey of the basic electrochemical literature indicated that surface hydrides play a critical role in the electrochemistry of titanium in acid solutions. A comprehensive analysis of the effect of surface films, particularly hydrides, on the electrochemical behavior of titanium in these solution is presented.

Titanium di-oxide films using a less hygroscopic colloidal precursor

Energy Technology Data Exchange (ETDEWEB)

Vandana,, E-mail: vandana1@nplindia.org; Batra, Neha; Kumar, Praveen; Sharma, Pooja; Singh, P.K., E-mail: pksingh@nplindia.org

2014-04-01

We report the study of titanium dioxide films (TiO{sub 2}) using titanium di-isopropoxyl di-2ethyl hexanoate Ti(OC{sub 3}H{sub 7}){sub 2} (C{sub 7}H{sub 15}COO){sub 2} colloidal precursor. This compound is less hygroscopic in nature and easy to use with processes like spin or dip coating. Thin films of TiO{sub 2} are made on silicon substrates and their structural and optical properties are studied. The effect of Ti content in the precursor, sintering temperature and its duration on film thickness and refractive index are investigated. Refractive index shows an increasing trend with the rise in the sintering temperature but remains unchanged with the time. The film thickness decreases with both sintering temperature and time and increases with Ti content in the precursor. Reflectivity measurements show marked reduction in the reflection losses compared to bare silicon surface wherein the film thickness is altered by spin speed. XRD results show anatase phase in the samples sintered at lower temperature (<680 °C), however, a mix of anatase, brookite and rutile phases is seen above this temperature. In the samples sintered above 1100 °C, rutile phase is dominant. These results are supported by the X-ray photoelectron spectroscopy. Atomic force microscopy reveals larger grain size at higher sintering temperature. The titanium dioxide films of desirable thickness and refractive index could be used as an antireflection coating on solar cells. - Highlights: • TiO{sub 2} films are made using titanium di-isopropoxyl di-2ethyl hexanoate precursor. • Effect of Ti content in the precursor, sintering temperature and time is studied. • Refractive index (μ) increases with sintering temperature but is independent of time. • Films of desired thickness and μ could be used as an antireflection coating. • XRD results show that rutile phase dominates in samples sintered above 1100 °C.

Titanium Metal Powder Production by the Plasma Quench Process

Energy Technology Data Exchange (ETDEWEB)

R. A. Cordes; A. Donaldson

2000-09-01

The goals of this project included the scale-up of the titanium hydride production process to a production rate of 50 kg/hr at a purity level of 99+%. This goal was to be achieved by incrementally increasing the production capability of a series of reactor systems. This methodic approach was designed to allow Idaho Titanium Technologies to systematically address the engineering issues associated with plasma system performance, and powder collection system design and performance. With quality powder available, actual fabrication with the titanium hydride was to be pursued. Finally, with a successful titanium production system in place, the production of titanium aluminide was to be pursued by the simultaneously injection of titanium and aluminum precursors into the reactor system. Some significant accomplishments of the project are: A unique and revolutionary torch/reactor capable of withstanding temperatures up to 5000 C with high thermal efficiency has been operated. The dissociation of titanium tetrachloride into titanium powder and HC1 has been demonstrated, and a one-megawatt reactor potentially capable of producing 100 pounds per hour has been built, but not yet operated at the powder level. The removal of residual subchlorides and adsorbed HC1 and the sintering of powder to form solid bodies have been demonstrated. The production system has been operated at production rates up to 40 pounds per hour. Subsequent to the end of the project, Idaho Titanium Technologies demonstrated that titanium hydride powder can indeed be sintered into solid titanium metal at 1500 C without sintering aids.

The effect of titanium surface treatment on the interfacial strength of titanium – Thermoplastic composite joints

NARCIS (Netherlands)

Su, Yibo; de Rooij, Matthijn; Grouve, Wouter; Akkerman, Remko

2017-01-01

Co-consolidated titanium – carbon fibre reinforced thermoplastic composite hybrid joints show potential for application in aerospace structures. The strength of the interface between the titanium and the thermoplastic composite is crucial for the strength of the entire hybrid joint. Application of a

A new ternary magnesium-titanium hydride Mg{sub 7}TiH{sub x} with hydrogen desorption properties better than both binary magnesium and titanium hydrides

Energy Technology Data Exchange (ETDEWEB)

Kyoi, Daisuke; Sato, Toyoto; Roennebro, Ewa; Kitamura, Naoyuki; Ueda, Atsushi; Ito, Mikio; Katsuyama, Shigeru; Hara, Shigeta; Noreus, Dag; Sakai, Tetsuo

2004-06-09

A magnesium based titanium doped hydride was prepared in a high-pressure anvil cell by reacting a mixture of MgH{sub 2} and TiH{sub 1.9} at 8 GPa and 873 K. The metal structure has a Ca{sub 7}Ge type structure (a=9.532(2) A, space group Fm3-barm (no. 225), Z=4, V=866.06 A{sup 3}). The refined metal atom composition Mg{sub 7}Ti was almost in line with EDS analysis. This means that the new magnesium-titanium hydride has a structure that is more related to TiH{sub 1.9} than to MgH{sub 2}. The thermal properties of the new compound were also studied by TPD analysis. The new hydride, Mg{sub 7}TiH{sub x} exhibits 5.5 mass% (x{approx}12.7) and decomposes into Mg and TiH{sub 1.9} upon releasing 4.7 mass% of hydrogen around 605 K, that is at a 130 and 220 K lower desorption temperature compared to MgH{sub 2} and TiH{sub 1.9}, respectively.

Titanium. Properties, raw datum surface, physicochemical basis and fabrication technique

International Nuclear Information System (INIS)

Garmata, V.A.; Petrun'ko, A.N.; Galitskij, N.V.; Olesov, Yu.G.; Sandler, R.A.

1983-01-01

On the nowadays science and technology achievements the complex of titanium metallurgy problems comprising raw material base, physico-chemical basis and fabrication technique, properties and titanium usage fields is considered for the first time. A particular attention is given to raw material base, manufacturing titanium concentrates and titanium tetrachloride, metallothermal reduction, improvement of metal quality. Data on titanium properties are given, processes of titanium powder metallurgy, scrap and waste processing, problems of economics and complex raw material use are considered

Titanium Dioxide Nanoparticle Penetration into the Skin and Effects on HaCaT Cells.

Science.gov (United States)

Crosera, Matteo; Prodi, Andrea; Mauro, Marcella; Pelin, Marco; Florio, Chiara; Bellomo, Francesca; Adami, Gianpiero; Apostoli, Pietro; De Palma, Giuseppe; Bovenzi, Massimo; Campanini, Marco; Filon, Francesca Larese

2015-08-07

Titanium dioxide nanoparticles (TiO2NPs) suspensions (concentration 1.0 g/L) in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue(®) and propidium iodide, PI, uptake assays) was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 μg/cm(2)) while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 μg/cm(2)). Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10(-4) M (MTT assay), 3.8 × 10(-5) M (AlamarBlue(®) assay), and 7.6 × 10(-4) M (PI uptake, index of a necrotic cell death). Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.

Introduction to powder metallurgy processes for titanium manufacturing

International Nuclear Information System (INIS)

Esteban, P. G.; Bolzoni, L.; Ruiz-Navas, E. M.; Gordo, E.

2011-01-01

The development of new extraction processes to produce titanium in powder form leads Powder Metallurgy to an advantage position among the manufacturing processes for titanium. The cost reduction of base material, coupled with the economy of the powder metallurgy processes, give titanium industry the chance to diversify its products, which could lead to production volumes able to stabilise the price of the metal. This work reviews some of the Powder Metallurgy techniques for the manufacturing of titanium parts, and describes the two typical approaches for titanium manufacturing: Blending Elemental and Prealloyed Powders. Among others, conventional pressing and sintering are described, which are compared with cold and hot isostatic pressing techniques. Real and potential applications are described. (Author) 71 refs.

Microwave assisted scalable synthesis of titanium ferrite nanomaterials

Science.gov (United States)

Shukla, Abhishek; Bhardwaj, Abhishek K.; Singh, S. C.; Uttam, K. N.; Gautam, Nisha; Himanshu, A. K.; Shah, Jyoti; Kotnala, R. K.; Gopal, R.

2018-04-01

Titanium ferrite magnetic nanomaterials are synthesized by one-step, one pot, and scalable method assisted by microwave radiation. Effects of titanium content and microwave exposure time on size, shape, morphology, yield, bonding nature, crystalline structure, and magnetic properties of titanium ferrite nanomaterials are studied. As-synthesized nanomaterials are characterized by X-ray diffraction (XRD), ultraviolet-visible absorption spectroscopy (UV-Vis), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, transmission electron microscopy (TEM), and vibrating sample magnetometer measurements. XRD measurements depict the presence of two phases of titanium ferrite into the same sample, where crystallite size increases from ˜33 nm to 37 nm with the increase in titanium concentration. UV-Vis measurement showed broad spectrum in the spectral range of 250-600 nm which reveals that its characteristic peaks lie between ultraviolet and visible region; ATR-FTIR and Raman measurements predict iron-titanium oxide structures that are consistent with XRD results. The micrographs of TEM and selected area electron diffraction patterns show formation of hexagonal shaped particles with a high degree of crystallinity and presence of multi-phase. Energy dispersive spectroscopy measurements confirm that Ti:Fe compositional mass ratio can be controlled by tuning synthesis conditions. Increase of Ti defects into titanium ferrite lattice, either by increasing titanium precursor or by increasing exposure time, enhances its magnetic properties.

Adaptive mesh refinement in titanium

Energy Technology Data Exchange (ETDEWEB)

Colella, Phillip; Wen, Tong

2005-01-21

In this paper, we evaluate Titanium's usability as a high-level parallel programming language through a case study, where we implement a subset of Chombo's functionality in Titanium. Chombo is a software package applying the Adaptive Mesh Refinement methodology to numerical Partial Differential Equations at the production level. In Chombo, the library approach is used to parallel programming (C++ and Fortran, with MPI), whereas Titanium is a Java dialect designed for high-performance scientific computing. The performance of our implementation is studied and compared with that of Chombo in solving Poisson's equation based on two grid configurations from a real application. Also provided are the counts of lines of code from both sides.

Vacuum brazing of TiAl48Cr2Nb2 casting alloys based on TiAl (γ intermetallic compound

Directory of Open Access Journals (Sweden)

Z. Mirski

2010-01-01

Full Text Available A growing interest in modern engineering materials characterised by increasingly better operational parameters combined with a necessity to obtain joints of such materials representing good operation properties create important research and technological problems of today. These issues include also titanium joints or joints of titanium alloys based on intermetallic compounds. Brazing is one of the basic and sometimes even the only available welding method used for joining the aforesaid materials in production of various systems, heat exchangers and, in case of titanium alloys based on intermetallic compounds, turbine elements and space shuttle plating etc. This article presents the basic physical and chemical properties as well as the brazability of alloys based on intermetallic compounds. The work also describes the principle and mechanisms of diffusion-brazed joint formation as well as reveals the results of metallographic and strength tests involving diffusion-welded joints of TiAl48Cr3Nb2 casting alloy based on TiAl (γ phase with the use of sandwich-type layers of silver-based parent metal (grade B- Ag72Cu-780 (AG 401 and copper (grade CF032A. Structural examination was performed by means of light microscopy, scanning electron microscope (SEM and energy dispersion spectrometer (EDS. Furthermore, the article reveals the results of shear strength tests involving the aforementioned joints.

[The bonding characteristic of titanium and RG experiment porcelain].

Science.gov (United States)

Ren, Wei-hong; Guo, Tian-wen; Tian, Jie-mo; Zhang, Yun-long

2003-07-01

To study the bonding characteristic of Titanium and RG experiment porcelain. 5 specimens with a size of 10 mm x 5 mm x 1.4 mm were cast from pure titanium. Then 1 mm of RG experiment opaque and body porcelain were fused on the surface of the titanium specimens. The interface of titanium and porcelain was analyzed with a scanning electron microscope with energy-despersive spectrometry; 6 metal specimens with the size of 25 mm x 3 mm x 0.5 mm were cast from Ni-Cr alloy and a uniform thickness of 1 mm of VMK 99 porcelain was veneered on the central area of 8 mm x 3 mm 18 metal specimens as the same size were cast from pure titanium. The uniform thickness of 1 mm of VITA TITANKERAMIK porcelain, of Noritake super porcelain Ti-22 and of RG experiment porcelain were veneered on every 6 specimens respectively in the central area of 8 mm x 3 mm. The specimens were subjected to a three-point bending test on a load-test machine with a span of 20 mm, then the failure loads were recorded and statistically analysised. The RG porcelain/titanium crown was fabricated by fusing RG opaque porcelain and body porcelain to cast titanium substrate crown. The SEM results show no porosity and crackle were found in the interface. The energy-dispersive spectrometry show that there are Si, Ti and O in the 1 micro m layer between porcelain and titanium, which suggesting titanium and experiment porcelain bonding well. The three point test showed the fracture force for the combinations of titanium/VITA TITANKERAMIK porcelain, titanium/Noritake super porcelain Ti-22 and titanium/RG experiment porcelain were (7.233 +/- 2.539) N, (5.533 +/- 1.199) N and (6.316 +/- 1.433) N respectively. There were not statistically significant differences among them (t test, P porcelain combination (12.733 +/- 3.297) N was significantly greater than those of the cast titanium/porcelain (t test, P > 0.05). The crown was translucent with no crack. RG porcelain is well compatible with titanium.

Formation of titanium nitride layers on titanium metal: Results of XPS and AES investigations

International Nuclear Information System (INIS)

Moers, H.; Pfennig, G.; Klewe-Nebenius, H.; Penzhorn, R.D.; Sirch, M.; Willin, E.

1988-09-01

The reaction of titanium metal with gaseous nitrogen and ammonia at temperatures of 890 0 C leads to the formation of nitridic overlayers on the metallic substrate. The thicknesses of the overlayers increase with increasing reaction time. Under comparable conditions ammonia reacts much slower than nitrogen. XPS and AES depth profile analyses show continuous changes of the in-depth compositions of the overlayers. This can be interpreted in terms of a very irregular thickness of the overlayers, an assumption which is substantiated by local AES analyses and by the observation of a pronounced crystalline structure of the substrate after annealing pretreatment, which can give rise to locally different reaction rates. The depth profile is also influenced by the broad ranges of stability of the titanium nitride phases formed during the reaction. The quantitative analysis of the titanium/nitrogen overlayers by AES is difficult because of the overlap of titanium and nitrogen Auger peaks. In quantitative XPS analysis problems arise due to difficulties in defining Ti 2p peak areas. This work presents practical procedures for the quantitative evaluation by XPS and AES of nitridic overlayers with sufficient accuracy. (orig.) [de

Clinical bending of nickel titanium wires

Directory of Open Access Journals (Sweden)

Stephen Chain

2015-01-01

Full Text Available Since the evolution and the involvement of Nickel Titanium wires in the field of Orthodontics. The treatment plan has evolved with the use of low force Nickel Titanium wires. Because of their high springback, low stiffness, they are the key initial wires in leveling and alignment but have poor formability. Since poor formability limits its ability to create variable arch forms thus; limits the form of treatment. We have devised a method to bend the Nickel Titanium wires to help in our inventory but also customized the wire according to the treatment.

Isothermal deformation of gamma titanium aluminide

International Nuclear Information System (INIS)

Srinivasan, R.; Singh, J.P.; Tuval, E.; Weiss, I.

1996-01-01

Gamma titanium aluminide has received considerable attention in recent years from the automotive industry as a potential material for making rotating and reciprocating components to produce a quieter and more efficient engine. The objectives of this study were to identify processing routes for the manufacture of automobile valves from gamma titanium aluminide. The issues considered were microstructure and composition of the material, and processing parameters such as deformation rates, temperatures, and total deformation. This paper examines isothermal deformation of gamma titanium aluminide in order to develop a processing window for this type of material

Bringing Radiotracing to Titanium-Based Antineoplastics: Solid Phase Radiosynthesis, PET and ex Vivo Evaluation of Antitumor Agent [45Ti](salan)Ti(dipic)

DEFF Research Database (Denmark)

Severin, Gregory; Nielsen, Carsten H.; Jensen, Andreas Tue Ingemann

2015-01-01

We present a novel solid-phase based 45Ti radiolabeling methodology and the implementation of 45Ti-PET in titanium-based antineoplastics using the showcase compound [45Ti](salan)Ti(dipic). This development is intended to allow elucidation of the biodistribution and pharmacokinetics of promising new...

Printing of Titanium implant prototype

International Nuclear Information System (INIS)

Wiria, Florencia Edith; Shyan, John Yong Ming; Lim, Poon Nian; Wen, Francis Goh Chung; Yeo, Jin Fei; Cao, Tong

2010-01-01

Dental implant plays an important role as a conduit of force and stress to flow from the tooth to the related bone. In the load sharing between an implant and its related bone, the amount of stress carried by each of them directly related to their stiffness or modulus. Hence, it is a crucial issue for the implant to have matching mechanical properties, in particular modulus, between the implant and its related bone. Titanium is a metallic material that has good biocompatibility and corrosion resistance. Whilst the modulus of the bulk material is still higher than that of bone, it is the lowest among all other commonly used metallic implant materials, such as stainless steel or cobalt alloy. Hence it is potential to further reduce the modulus of pure Titanium by engineering its processing method to obtain porous structure. In this project, porous Titanium implant prototype is fabricated using 3-dimensional printing. This technique allows the flexibility of design customization, which is beneficial for implant fabrication as tailoring of implant size and shape helps to ensure the implant would fit nicely to the patient. The fabricated Titanium prototype had a modulus of 4.8-13.2 GPa, which is in the range of natural bone modulus. The compressive strength achieved was between 167 to 455 MPa. Subsequent cell culture study indicated that the porous Titanium prototype had good biocompatibility and is suitable for bone cell attachment and proliferation.

Iron-titanium-mischmetal alloys for hydrogen storage

Science.gov (United States)

Sandrock, Gary Dale

1978-01-01

A method for the preparation of an iron-titanium-mischmetal alloy which is used for the storage of hydrogen. The alloy is prepared by air-melting an iron charge in a clay-graphite crucible, adding titanium and deoxidizing with mischmetal. The resultant alloy contains less than about 0.1% oxygen and exhibits a capability for hydrogen sorption in less than half the time required by vacuum-melted, iron-titanium alloys.

Production of titanium from ilmenite: a review

Energy Technology Data Exchange (ETDEWEB)

Kohli, R.

1981-12-01

The general principles for beneficiation of titanium ores are reviewed and the specific processes used in individual units in various countries are discussed. This is followed by a critical evaluation of various current and potential reduction methods for the production of titanium metal from the processed concentrates. Finally, the report outlines a research program for the development of a commercially viable alternative method for the production of titanium metal.

Corrosion resistance of titanium alloys for dentistry

International Nuclear Information System (INIS)

Laskawiec, J.; Michalik, R.

2001-01-01

Titanium and its alloys belong to biomaterials which the application scope in medicine increases. Some properties of the alloys, such as high mechanical strength, low density, low Young's modulus, high corrosion resistance and good biotolerance decide about it. The main areas of the application of titanium and its alloys are: orthopedics and traumatology, cardiosurgery, faciomaxillary surgery and dentistry. The results of investigations concerning the corrosion resistance of the technical titanium and Ti6Al14V alloy and comparatively a cobalt alloy of the Vitallium type in the artificial saliva is presented in the work. Significantly better corrosion resistance of titanium and the Ti6Al14V than the Co-Cr-Mo alloy was found. (author)

On the solubility of hydrogen in the systems titanium-aluminium-hydrogen, titanium-vanadium-hydrogen and titanium-aluminium-vanadium-hydrogen in the temperature region of 800 to 1,0000C at hydrogen pressures of 0.1 to 400 mm.Hg

International Nuclear Information System (INIS)

Kauder, G.W.

1973-01-01

The hydrogen concentrations on Ti-Al, Ti-V and Ti-Al-V alloys were determined in the temperature region from 800 to 1,000 0 C and at hydrogen pressures of 0.1 to 400 mm.Hg using a gravimetric measuring process. The thus obtained results allowed the drawing of hydrogen activity slopes in the titanium rich corner of the systems titanium-hydrogen, titanium-aluminium-hydrogen, titanium-vanadium-hydrogen and such for the technical titanium alloys Ti-6Al-4V and Ti-6Al-6V. In spite of the antagonistic effects of the elements aluminium and vanadium on the stabilization of the α and β phase regions of titanium, a hydrogen-activity-increasing effect was always found in which the aluminium influence was greater than that of vanadium. Breaks occured in the hydrogen activity curves and phase boundaries, and phase regions were determined over their positions. Isothermal phase diagrams for the titanium-rich corner of the system titanium-aluminium-hydrogen at 800, 850 and 900 0 C and for the titanium-rich corner of the titanium-vanadium-hydrogen system at 900, 950 and 1,000 0 C were drawn up from the hydrogen activity curves. (orig./LH) [de

Ball bearings comprising nickel-titanium and methods of manufacture thereof

Science.gov (United States)

DellaCorte, Christopher (Inventor); Glennon, Glenn N. (Inventor)

2012-01-01

Disclosed herein is a friction reducing nickel-titanium composition. The nickel-titanium composition includes a first phase that comprises nickel and titanium in an atomic ratio of about 0.45:0.55 to about 0.55:0.45; a second phase that comprises nickel and titanium in an atomic ratio of about 0.70:0.30 to about 0.80:0.20; and a third phase that comprises nickel and titanium in an atomic ratio of about 0.52:0.48 to about 0.62:0.38. A bearing for reducing friction comprising a nickel-titanium composition comprising a first phase that comprises nickel and titanium in an atomic ratio of about 0.45:0.55 to about 0.55:0.45; a second phase that comprises nickel and titanium in an atomic ratio of about 0.70:0.30 to about 0.80:0.20; and a third phase that comprises nickel and titanium in an atomic ratio of about 0.52:0.48 to about 0.62:0.38; where the bearing is free from voids and pinholes.

Machining of titanium alloys

CERN Document Server

2014-01-01

This book presents a collection of examples illustrating the resent research advances in the machining of titanium alloys. These materials have excellent strength and fracture toughness as well as low density and good corrosion resistance; however, machinability is still poor due to their low thermal conductivity and high chemical reactivity with cutting tool materials. This book presents solutions to enhance machinability in titanium-based alloys and serves as a useful reference to professionals and researchers in aerospace, automotive and biomedical fields.

Titanium (III) cation selective electrode based on synthesized tris(2pyridyl) methylamine ionophore and its application in water samples

Science.gov (United States)

Rezayi, Majid; Karazhian, Reza; Abdollahi, Yadollah; Narimani, Leila; Sany, Seyedeh Belin Tavakoly; Ahmadzadeh, Saeid; Alias, Yatimah

2014-04-01

The introduction of low detection limit ion selective electrodes (ISEs) may well pave the way for the determination of trace targets of cationic compounds. This research focuses on the detection of titanium (III) cation using a new PVC-membrane sensor based on synthesized tris(2pyridyl) methylamine (tpm) ionophore. The application and validation of the proposed sensor was done using potentiometric titration, inductively coupled plasma atomic emission spectrometry (ICP-AES), and atomic absorption spectrometry (AAS). The membrane sensor exhibited a Nernstian response to the titanium (III) cation over a concentration range of 1.0 × 10-6-1.0 × 10-2 M and pH range from 1-2.5. The Nernstian slope, the lower of detection (LOD), and the response time (t95%) of the proposed sensor were 29.17 +/- 0.24 mV/dec, 7.9 × 10-7 M, and 20 s, respectively. The direct determination of 4-39 μg/ml of titanium (III) standard solution showed an average recovery of 94.60 and a mean relative standard deviation of 1.8 at 100.0 μg/ml. Finally, the utilization of the electrodes as end-point indicators for potentiometric titration with EDTA solutions for titanium (III) sensor was successfully carried out.

Influence of TiO2 Nanoparticles on Growth and Phenolic Compounds Production in Photosynthetic Microorganisms

Directory of Open Access Journals (Sweden)

Mattia Comotto

2014-01-01

Full Text Available The influence of titanium dioxide nanoparticles (pure anatase and 15% N doped anatase on the growth of Chlorella vulgaris, Haematococcus pluvialis, and Arthrospira platensis was investigated. Results showed that pure anatase can lead to a significant growth inhibition of C. vulgaris and A. platensis (17.0 and 74.1%, resp., while for H. pluvialis the nanoparticles do not cause a significant inhibition. Since in these stress conditions photosynthetic microorganisms can produce antioxidant compounds in order to prevent cell damages, we evaluated the polyphenols content either inside the cells or released in the medium. Although results did not show a significant difference in C. vulgaris, the phenolic concentrations of two other microorganisms were statistically affected by the presence of titanium dioxide. In particular, 15% N doped anatase resulted in a higher production of extracellular antioxidant compounds, reaching the concentration of 65.2 and 68.0 mg gDB-1 for H. pluvialis and A. platensis, respectively.

High pressure sintering (HP-HT) of diamond powders with titanium and titanium carbide

International Nuclear Information System (INIS)

Jaworska, L.

1999-01-01

Polycrystalline diamond compacts for cutting tools are mostly manufactured using high pressure sintering (HP-HT). The standard diamond compacts are prepared by diamond powders sintering with metallic binding phase. The first group of metallic binder are metals able to solve carbon - Co, Ni. The second group of metal binders are carbide forming elements - Ti, Cr, W and others. The paper describes high pressure sintering of diamond powder with titanium and nonstoichiometry titanium carbide for cutting tool application. A type of binding phase has the significant influence on microstructure and mechanical properties of diamond compacts. Very homogeneous structure was achieved in case of compacts obtained from metalized diamond where diamond-TiC-diamond connection were predominant. In the case of compacts prepared by mechanical mixing of diamond with titanium powders the obtained structure was nonhomogeneous with titanium carbide clusters. They had more diamond to diamond connections. These compacts compared to the compact made of metallized diamond have greater wear resistance. In the case of the diamond and TiC 0.92 sintering the strong bonding of TiC diamond grains was obtained. The microstructure observations for diamond with 5% wt. Ti and diamond with 5% wt. TiC 0.92 (the initial composition) compacts were performed in transmission microscope. For two type of compacts the strong bonding phase TiC without defects is creating. (author)

UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

Directory of Open Access Journals (Sweden)

Saita M

2016-01-01

Full Text Available Makiko Saita,1 Takayuki Ikeda,1,2 Masahiro Yamada,1,3 Katsuhiko Kimoto,4 Masaichi Chang-Il Lee,5 Takahiro Ogawa1 1Division of Advanced Prosthodontics, Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, CA, USA; 2Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Yokosuka, Japan; 3Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan; 4Department of Prosthodontics and Oral Rehabilitation, 5Yokosuka-Shonan Disaster Health Emergency Research Center and ESR Laboratories, Kanagawa Dental University Graduate School of Dentistry, Yokosuka, Japan Background: Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability.Methods and results: Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light were immersed in simulated body fluid (SBF for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition

Cadmium Telluride-Titanium Dioxide Nanocomposite for Photodegradation of Organic Substance.

Science.gov (United States)

Ontam, Areeporn; Khaorapapong, Nithima; Ogawa, Makoto

2015-12-01

Cadmium telluride-titanium dioxide nanocomposite was prepared by hydrothermal reaction of sol-gel derived titanium dioxide and organically modified cadmium telluride. The crystallinity of titanium dioxide in the nanocomposite was higher than that of pure titanium dioxide obtained by the reaction under the same temperature and pressure conditions, showing that cadmium telluride induced the crystallization of titanium dioxide. Diffuse reflectance spectrum of the nanocomposite showed the higher absorption efficiency in the UV-visible region due to band-gap excitation of titanium dioxide. The nanocomposite significantly showed the improvement of photocatalytic activity for 4-chlorophenol with UV light.

Industrial experience with titanium

Energy Technology Data Exchange (ETDEWEB)

Ikeda, B M; Shoesmith, D W

1997-09-01

Titanium is a reference material for the construction of waste containers in the Canadian Nuclear Fuel Waste Management Program. It has been in industrial service for over 30 a, often in severe corrosion environments, but it is still considered a relatively exotic material with limited operating history. This has arisen because of the aerospace applications of this material and the misconception that the high strength-to-weight ratio dominates the choice of this material. In fact, the advantage of titanium lies in its high reliability and excellent corrosion resistance. It has a proven record in seawater heat exchanger service and a demonstrated excellent reliability even in polluted water. For many reasons it is the technically correct choice of material for marine applications. In this report we review the industrial service history of titanium, particularly in hot saline environments, and demonstrate that it is a viable waste container material, based upon this industrial service history and operating experience. (author) 83 refs., 17 tabs., 3 figs.

Industrial experience with titanium

International Nuclear Information System (INIS)

Ikeda, B.M.; Shoesmith, D.W.

1997-09-01

Titanium is a reference material for the construction of waste containers in the Canadian Nuclear Fuel Waste Management Program. It has been in industrial service for over 30 a, often in severe corrosion environments, but it is still considered a relatively exotic material with limited operating history. This has arisen because of the aerospace applications of this material and the misconception that the high strength-to-weight ratio dominates the choice of this material. In fact, the advantage of titanium lies in its high reliability and excellent corrosion resistance. It has a proven record in seawater heat exchanger service and a demonstrated excellent reliability even in polluted water. For many reasons it is the technically correct choice of material for marine applications. In this report we review the industrial service history of titanium, particularly in hot saline environments, and demonstrate that it is a viable waste container material, based upon this industrial service history and operating experience. (author)

An Insoluble Titanium-Lead Anode for Sulfate Electrolytes

Energy Technology Data Exchange (ETDEWEB)

Ferdman, Alla

2005-05-11

The project is devoted to the development of novel insoluble anodes for copper electrowinning and electrolytic manganese dioxide (EMD) production. The anodes are made of titanium-lead composite material produced by techniques of powder metallurgy, compaction of titanium powder, sintering and subsequent lead infiltration. The titanium-lead anode combines beneficial electrochemical behavior of a lead anode with high mechanical properties and corrosion resistance of a titanium anode. In the titanium-lead anode, the titanium stabilizes the lead, preventing it from spalling, and the lead sheathes the titanium, protecting it from passivation. Interconnections between manufacturing process, structure, composition and properties of the titanium-lead composite material were investigated. The material containing 20-30 vol.% of lead had optimal combination of mechanical and electrochemical properties. Optimal process parameters to manufacture the anodes were identified. Prototypes having optimized composition and structure were produced for testing in operating conditions of copper electrowinning and EMD production. Bench-scale, mini-pilot scale and pilot scale tests were performed. The test anodes were of both a plate design and a flow-through cylindrical design. The cylindrical anodes were composed of cylinders containing titanium inner rods and fitting over titanium-lead bushings. The cylindrical design allows the electrolyte to flow through the anode, which enhances diffusion of the electrolyte reactants. The cylindrical anodes demonstrate higher mass transport capabilities and increased electrical efficiency compared to the plate anodes. Copper electrowinning represents the primary target market for the titanium-lead anode. A full-size cylindrical anode performance in copper electrowinning conditions was monitored over a year. The test anode to cathode voltage was stable in the 1.8 to 2.0 volt range. Copper cathode morphology was very smooth and uniform. There was no

Casting of Titanium and its Alloys

OpenAIRE

R. L. Saha; K. T. Jacob

1986-01-01

Titaniuni and its alloys have many applications in aerospace, marine and other engineering industries. Titanium requires special melting techniques because of its high reactivity at elevated temperatures and needs special mould materials and methods for castings. This paper reviews the development of titanium casting technology.

Comparative in vitro biocompatibility of nickel-titanium, pure nickel, pure titanium, and stainless steel: genotoxicity and atomic absorption evaluation.

Science.gov (United States)

Assad, M; Lemieux, N; Rivard, C H; Yahia, L H

1999-01-01

The genotoxicity level of nickel-titanium (NiTi) was compared to that of its pure constituents, pure nickel (Ni) and pure titanium (Ti) powders, and also to 316L stainless steel (316L SS) as clinical reference material. In order to do so, a dynamic in vitro semiphysiological extraction was performed with all metals using agitation and ISO requirements. Peripheral blood lymphocytes were then cultured in the presence of all material extracts, and their comparative genotoxicity levels were assessed using electron microscopy-in situ end-labeling (EM-ISEL) coupled to immunogold staining. Cellular chromatin exposition to pure Ni and 316L SS demonstrated a significantly stronger gold binding than exposition to NiTi, pure Ti, or the untreated control. In parallel, graphite furnace atomic absorption spectrophotometry (AAS) was also performed on all extraction media. The release of Ni atoms took the following decreasing distribution for the different resulting semiphysiological solutions: pure Ni, 316L SS, NiTi, Ti, and controls. Ti elements were detected after elution of pure titanium only. Both pure titanium and nickel-titanium specimens obtained a relative in vitro biocompatibility. Therefore, this quantitative in vitro study provides optimistic results for the eventual use of nickel-titanium alloys as surgical implant materials.

Microstructural characterization of silicon added titanium aluminide

International Nuclear Information System (INIS)

Khan, A.N.

2009-01-01

Titanium aluminides intermetallic compounds have received great attention during the past decade, since they have the potential, in aircraft and automotive engines, to replace the high density Ni-base superalloys However, these intermetallics possess poor oxidation properties at high temperatures. Previous studies showed that protective alumina scale formation on gamma-TiAl can be obtained by small additions (around 2 at.%) of Ag. In the present study, a number of cast Ti-Al-Si alloys were investigated in relation to transient oxide formation in air at 1300 deg. C. After various oxidation times the oxide composition, microstructure and morphology were studied by combining a number of analysis techniques. The TiAl-Si alloys appear to form Al Ti and Si oxides. However, the formation of silicon oxide at the interface of base metal and scale slows down the oxidation rate significantly. (author)

Corrosion resistance of stainless steel, nickel-titanium, titanium molybdenum alloy, and ion-implanted titanium molybdenum alloy archwires in acidic fluoride-containing artificial saliva: An in vitro study

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Venith Jojee Pulikkottil

2016-01-01

Full Text Available Objective: (1 To evaluate the corrosion resistance of four different orthodontic archwires and to determine the effect of 0.5% NaF (simulating high fluoride-containing toothpaste of about 2250 ppm on corrosion resistance of these archwires. (2 To assess whether surface roughness (Ra is the primary factor influencing the corrosion resistance of these archwires. Materials and Methods: Four different archwires (stainless steel [SS], nickel-titanium [NiTi], titanium molybdenum alloy [TMA], and ion-implanted TMA were considered for this study. Surface characteristics were analyzed using scanning electron microscopy, atomic force microscopy (AFM, and energy dispersive spectroscopy. Linear polarization test, a fast electrochemical technique, was used to evaluate the corrosion resistance, in terms of polarization resistance of four different archwires in artificial saliva with NaF concentrations of 0% and 0.5%. Statistical analysis was performed by one-way analysis of variance. Results: The potentiostatic study reveals that the corrosion resistance of low-friction TMA (L-TMA > TMA > NiTi > SS. AFM analysis showed the surface Ra of TMA > NiTi > L-TMA > SS. This indicates that the chemical composition of the wire is the primary influential factor to have high corrosion resistance and surface Ra is only secondary. The corrosion resistance of all wires had reduced significantly in 0.5% acidic fluoride-containing artificial saliva due to formation of fluoride complex compound. Conclusion: The presence of 0.5% NaF in artificial saliva was detrimental to the corrosion resistance of the orthodontic archwires. Therefore, complete removal of residual high-fluorinated toothpastes from the crevice between archwire and bracket during tooth brushing is mandatory.

Manufacturing techniques for titanium aluminide based alloys and metal matrix composites

Science.gov (United States)

Kothari, Kunal B.

Dual phase titanium aluminides composed vastly of gamma phase (TiAl) with moderate amount of alpha2 phase (Ti3Al) have been considered for several high temperature aerospace and automobile applications. High specific strength coupled with good high temperature performance in the areas of creep and oxidation resistance makes titanium aluminides "materials of choice" for next generation propulsion systems. Titanium alumnides are primarily being considered as potential replacements for Ni-based superalloys in gas turbine engine components with aim of developing more efficient and leaner engines exhibiting high thrust-to-weight ratio. Thermo-mechanical treatments have shown to enhance the mechanical performance of titanium aluminides. Additionally, small additions of interstitial elements have shown further and significant improvement in the mechanical performance of titanium alumnide alloys. However, titanium aluminides lack considerably in room temperature ductility and as a result manufacturing processes of these aluminides have greatly suffered. Traditional ingot metallurgy and investment casting based methods to produce titanium aluminide parts in addition to being expensive, have also been unsuccessful in producing titanium aluminides with the desired mechanical properties. Hence, the manufacturing costs associated with these methods have completely outweighed the benefits offered by titanium aluminides. Over the last two decades, several powder metallurgy based manufacturing techniques have been studied to produce titanium aluminide parts. These techniques have been successful in producing titanium aluminide parts with a homogeneous and refined microstructure. These powder metallurgy techniques also hold the potential of significant cost reduction depending on the wide market acceptance of titanium aluminides. In the present study, a powder metallurgy based rapid consolidation technique has been used to produce near-net shape parts of titanium aluminides. Micron

Preparation of titanium diboride powders from titanium alkoxide and ...

Indian Academy of Sciences (India)

Administrator

Department of Materials and Manufacturing Process, Malek Ashtar University of Technology, Tehran. 15875-1744, Iran ... Titanium diboride is a hard refractory material with a high melting point ... (λ = 1⋅540598 Å) radiation. Morphology of the ...

Mineral resource of the month: titanium

Science.gov (United States)

Gambogi, Joseph

2011-01-01

Titanium is hip - at least when it comes to airplanes and jewelry. Known for its high strength-to weight ratio and its resistance to corrosion, titanium and its alloys can also be found in everything from knee replacements to eyeglass frames to baseball bats to fighter planes.

Physical metallurgy of titanium alloys

International Nuclear Information System (INIS)

Collings, E.W.

1988-01-01

Researches in electric, magnetic, thermophysical properties of titanium alloys in the wide range of temperatures (from helium upto elevated one), as well as stability of phases in alloys of different types are generalized. Fundamental description of physical properties of binary model alloys is given. Acoustic emission, shape memory and Bauschinger effects, pseudoelasticity, aging and other aspects of physical metallurgy of titanium alloys are considered

Cold Spraying of Armstrong Process Titanium Powder for Additive Manufacturing

Science.gov (United States)

MacDonald, D.; Fernández, R.; Delloro, F.; Jodoin, B.

2017-04-01

Titanium parts are ideally suited for aerospace applications due to their unique combination of high specific strength and excellent corrosion resistance. However, titanium as bulk material is expensive and challenging/costly to machine. Production of complex titanium parts through additive manufacturing looks promising, but there are still many barriers to overcome before reaching mainstream commercialization. The cold gas dynamic spraying process offers the potential for additive manufacturing of large titanium parts due to its reduced reactive environment, its simplicity to operate, and the high deposition rates it offers. A few challenges are to be addressed before the additive manufacturing potential of titanium by cold gas dynamic spraying can be reached. In particular, it is known that titanium is easy to deposit by cold gas dynamic spraying, but the deposits produced are usually porous when nitrogen is used as the carrier gas. In this work, a method to manufacture low-porosity titanium components at high deposition efficiencies is revealed. The components are produced by combining low-pressure cold spray using nitrogen as the carrier gas with low-cost titanium powder produced using the Armstrong process. The microstructure and mechanical properties of additive manufactured titanium components are investigated.

Titanium metal obtention by fused salts electrolysis

International Nuclear Information System (INIS)

Perillo, P.M.; Ares, Osvaldo; Botbol, Jose.

1989-01-01

Potassium fluorotitanate dissolved in fused sodium chloride or potassium chloride may be electrolyzed under an inert gas atmosphere. Solid electrolysis products are formed on the cathode which contains titanium metal, sodium chloride, lower fluorotitanates and small quantities of alkali metal fluorotitanate. The extraction of titanium from the electrolysis products may be carried out by aqueous leaching (removal of chloride salts of alkali metals and a certain amount of fluorotitanates). Titanium metal obtained is relatively pure. (Author)

Difference in surface reactions between titanium and zirconium in Hanks' solution to elucidate mechanism of calcium phosphate formation on titanium using XPS and cathodic polarization

International Nuclear Information System (INIS)

Tsutsumi, Y.; Nishimura, D.; Doi, H.; Nomura, N.; Hanawa, T.

2009-01-01

Titanium and zirconium were immersed in Hanks' solution with and without calcium and phosphate ions, and the surfaces were characterized with X-ray photoelectron spectroscopy (XPS) to determine the mechanism of calcium phosphate formation on titanium in simulated body fluids and in a living body. In addition, they were cathodically polarized in the above solutions. XPS characterization and cathodic polarization revealed differences in the surface properties in the ability of calcium phosphate formation between titanium and zirconium. The surface oxide film on titanium is not completely oxidized and is relatively reactive; that on zirconium is more passive and protective than that on titanium. Neither calcium nor phosphate stably exists alone on titanium, and calcium phosphate is naturally formed on it; calcium phosphate formed on titanium is stable and protective. On the other hand, calcium is never incorporated on zirconium, while zirconium phosphate, which is easily formed on zirconium, is highly stable and protective. Our study presents new information regarding the surface property of titanium and demonstrates that the characteristics of titanium and zirconium may be applied to various medical devices and new surface modification techniques.

Appcelerator Titanium business application development cookbook

CERN Document Server

Bahrenberg, Benjamin

2013-01-01

Presented in easy to follow, step by step recipes, this guide is designed to lead you through the most important aspects of application design.Titanium developers who already have a basic knowledge of working with Appcelerator Titanium but want to further develop their knowledge for use with business applications

Titanium Dioxide Nanoparticle Penetration into the Skin and Effects on HaCaT Cells

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Matteo Crosera

2015-08-01

Full Text Available Titanium dioxide nanoparticles (TiO2NPs suspensions (concentration 1.0 g/L in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue® and propidium iodide, PI, uptake assays was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 μg/cm2 while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 μg/cm2. Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10−4 M (MTT assay, 3.8 × 10−5 M (AlamarBlue® assay, and 7.6 × 10−4 M (PI uptake, index of a necrotic cell death. Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.

Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

International Nuclear Information System (INIS)

Kado, T.; Hidaka, T.; Aita, H.; Endo, K.; Furuichi, Y.

2012-01-01

Highlights: ► Cell-adhesive molecules were covalently immobilized on a Ti surface. ► Immobilized cell-adhesive molecules maintained native function on the Ti surface. ► Immobilized collagen enhanced adhesion of periodontal ligament cells to the Ti. - Abstract: A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface

Enhanced osteoblast adhesion to drug-coated anodized nanotubular titanium surfaces

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George E Aninwene II

2008-06-01

Full Text Available George E Aninwene II1, Chang Yao2, Thomas J Webster21Department of Biochemical Engineering, University of Maryland, Baltimore, MD; 2Division of Engineering, Brown University, Providence, RI, USAAbstract: Current orthopedic implants have functional lifetimes of only 10–15 years due to a variety of reasons including infection, extensive inflammation, and overall poor osseointegration (or a lack of prolonged bonding of the implant to juxtaposed bone. To improve properties of titanium for orthopedic applications, this study anodized and subsequently coated titanium with drugs known to reduce infection (penicillin/streptomycin and inflammation (dexamethasone using simple physical adsorption and the deposition of such drugs from simulated body fluid (SBF. Results showed improved drug elution from anodized nanotubular titanium when drugs were coated in the presence of SBF for up to 3 days. For the first time, results also showed that the simple physical adsorption of both penicillin/streptomycin and dexamethasone on anodized nanotubular titanium improved osteoblast numbers after 2 days of culture compared to uncoated unanodized titanium. In addition, results showed that depositing such drugs in SBF on anodized titanium was a more efficient method to promote osteoblast numbers compared to physical adsorption for up to 2 days of culture. In addition, osteoblast numbers increased on anodized titanium coated with drugs in SBF for up to 2 days of culture compared to unanodized titanium. In summary, compared to unanodized titanium, this preliminary study provided unexpected evidence of greater osteoblast numbers on anodized titanium coated with either penicillin/streptomycin or dexamethasone using simple physical adsorption or when coated with SBF; results which suggest the need for further research on anodized titanium orthopedic implants possessing drug-eluting nanotubes.Keywords: anodization, titanium, adhesion, simulated body fluid, nanotubes

Custom-made laser-welded titanium implant prosthetic abutment.

Science.gov (United States)

Iglesia-Puig, Miguel A

2005-10-01

A technique to create an individually modified implant prosthetic abutment is described. An overcasting is waxed onto a machined titanium abutment, cast in titanium, and joined to it with laser welding. With the proposed technique, a custom-made titanium implant prosthetic abutment is created with adequate volume and contour of metal to support a screw-retained, metal-ceramic implant-supported crown.

Titanium exposure and yellow nail syndrome

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Ali Ataya

2015-01-01

Full Text Available Yellow nail syndrome is a rare disease of unclear etiology. We describe a patient who develops yellow nail syndrome, with primary nail and sinus manifestations, shortly after amalgam dental implants. A study of the patient's nail shedding showed elevated nail titanium levels. The patient had her dental implants removed and had complete resolution of her sinus symptoms with no change in her nail findings. Since the patient's nail findings did not resolve we do not believe titanium exposure is a cause of her yellow nail syndrome but perhaps a possible relationship exists between titanium exposure and yellow nail syndrome that requires further studies.

Titanium dioxide. An effective additive for minimisation of alkali vaporisation; Titandioxidadditiv. En effektiv tillsats foer att minska alkalifoeraangning

Energy Technology Data Exchange (ETDEWEB)

Wiinikka, Henrik; Groenberg, Carola; Oehrman, Olov

2008-10-15

more titanium dioxide was introduced to the straw pellets. However, in the same time the concentration of phosphorous was increased from 1 mg/Nm3 to 9 mg/Nm3. This result indicates that the vaporisation of potassium was reduced and phosphorous was increased from the fuel bed when titanium dioxide was introduced to the straw pellets during the combustion process. The ash that was collected in the pellet burner was defined as bottom ash in the investigation. The amount of bottom ash increased when more titanium dioxide was added to the pellets since titanium is a refractory material. The Si/K and Ca/K ratios in the bottom ash were reduced when titanium dioxide was introduced to the fuel. Since both Si and Ca are refractory elements that do not vaporise during combustion, this indicates that the vaporisation of potassium from the fuel is reduced when more titanium dioxide is introduced to the straw pellets. From the analyses of the flue gas and the bottom ash the degree of vaporised potassium from one experiment could be estimated. From the analysis of the bottom ash, 31 % of the potassium in the original fuel has been vaporised during combustion of pure straw. When titanium dioxide was introduced to the fuel the vaporisation of potassium reduced significantly and for a Ti/K ratio between 1.0-1.4 only 14-18 % of the potassium vaporised, i.e. a 50 % reduction of potassium release. From the analysis of the flue gas instead, 11.3 % of the potassium was released to the gas phase during combustion of clean straw. The degree of vaporised potassium was reduced to about 7 % for a Ti/K ratio between 1.0-1.4, i.e. a 40 % reduction of potassium release. The amount of vaporised potassium during combustion of straw was clearly reduced when titanium dioxide was introduced as additive to the fuel. This means that the potassium in the fuel reacts with the titanium in the fuel bed and form a very temperature stable compound. From the XRD investigation, the crystalline phase KTi{sub 8O16

Thermoexpanded graphite modification by titanium dioxide

International Nuclear Information System (INIS)

Semko, L.S.; Gorbik, P.P.; Chujko, O.O.; Kruchek, Ya.Yi.; Dzyubenko, L.S.; Orans'ka, O.Yi.

2006-01-01

A method of the synthesis of thermoexpanded graphite (TEG) powders coated by titanium dioxide is developed. The conversion of n-buthylorthotitanate into TiO 2 on the TEG surface is investigated. The optimal parameters of the synthesis and the structure of titanium dioxide clusters on the TEG surface are determined

Treatment of pediatric femoral shaft fractures by stainless steel and titanium elastic nail system: A randomized comparative trial.

Science.gov (United States)

Gyaneshwar, Tank; Nitesh, Rustagi; Sagar, Tomar; Pranav, Kothiyal; Rustagi, Nitesh

2016-08-01

Literature suggests that the lower modulus of elasticity of titanium makes it ideal for use in children compared with stainless steel. Better fracture stability was observed in association with titanium nails on torsional and axial compression testing. However, stainless steel nails are stiffer than titanium counterparts, which may provide a rigid construct when fixing paediatric femoral shaft fractures. Complications have been observed more frequently by various researchers when titanium nails are used for fracture fixation in patients with increasing age or weight. The concept of this study was to compare the functional outcome after internal fixation with titanium elastic nail system and stainless steel elastic nail system in paediatric femoral shaft fractures. The study was conducted on 34 patients admitted in the department of orthopaedics, LLRM Medical College & SVBP Hospital, Meerut, India from January 2013 to August 2014. We included patients aged 5-12 years with fracture of the femoral shaft, excluding compound fractures, pathological fractures and other lower limb fractures. Patients were treated by titanium (n=17) or stainless steel (n=17) elastic nail system and followed up for one year. The clinical parameters like range of motion at hip and knee joints, time to full weight bearing on the operated limb and radiological parameters like time to union were compared between two groups. A special note was made of intra- and post-operative complications. Functional outcomes were analysed according to Flynn criteria. Based on the Flynn criteria, 59% of patients had excellent results, 41% had satisfactory results, and no one showed poor results. There was no clinically significant difference between the two groups with respect to time to union and full weight bearing. But the incidence of puncture of the opposite cortex while inserting the nail and trying to advance it through the diaphysis during operation is greatly different. Only one such case was observed

Comparison of galvanic corrosion potential of metal injection molded brackets to that of conventional metal brackets with nickel-titanium and copper nickel-titanium archwire combinations.

Science.gov (United States)

Varma, D Praveen Kumar; Chidambaram, S; Reddy, K Baburam; Vijay, M; Ravindranath, D; Prasad, M Rajendra

2013-05-01

The aim of the study is to investigate the galvanic corrosion potential of metal injection molding (MIM) brackets to that of conventional brackets under similar in vitro conditions with nickel-titanium and copper nickel-titanium archwires. Twenty-five maxillary premolar MIM stainless steel brackets and 25 conventional stainless steel brackets and archwires, 0.16 inch, each 10 mm length, 25 nickeltitanium wires, 25 copper nickel-titanium wires were used. They were divided into four groups which had five samples each. Combination of MIM bracket with copper nickel-titanium wire, MIM bracket with nickel-titanium wire and conventional stainless steel brackets with copper nickel-titanium wire and conventional stainless steel brackets with nickel-titanium wires which later were suspended in 350 ml of 1 M lactic acid solution media. Galvanic corrosion potential of four groups were analyzed under similar in vitro conditions. Precorrosion and postcorrosion elemental composition of MIM and conventional stainless steel bracket by scanning electron microscope (SEM) with energy dispersive spectroscope (EDS) was done. MIM bracket showed decreased corrosion susceptibility than conventional bracket with copper nickeltitanium wire. Both MIM and conventional bracket showed similar corrosion resistance potential in association with nickel-titanium archwires. It seems that both brackets are more compatible with copper nickel-titanium archwires regarding the decrease in the consequences of galvanic reaction. The EDS analysis showed that the MIM brackets with copper nickel-titanium wires released less metal ions than conventional bracket with copper nickeltitanium wires. MIM brackets showed decreased corrosion susceptibility, copper nickel-titanium archwires are compatible with both the brackets than nickel-titanium archwires. Clinically MIM and conventional brackets behaved more or less similarly in terms of corrosion resistance. In order to decrease the corrosion potential of MIM

Trial manufacturing of titanium-carbon steel composite overpack

International Nuclear Information System (INIS)

Honma, Nobuyuki; Chiba, Takahiko; Tanai, Kenji

1999-11-01

This paper reports the results of design analysis and trial manufacturing of full-scale titanium-carbon steel composite overpacks. The overpack is one of the key components of the engineered barrier system, hence, it is necessary to confirm the applicability of current technique in their manufacture. The required thickness was calculated according to mechanical resistance analysis, based on models used in current nuclear facilities. The Adequacy of the calculated dimensions was confirmed by finite-element methods. To investigate the necessity of a radiation shielding function of the overpack, the irradiation from vitrified waste has been calculated. As a result, it was shown that shielding on handling and transport equipment is a more reasonable and practical approach than to increase thickness of overpack to attain a self-shielding capability. After the above investigation, trial manufacturing of full-scale model of titanium-carbon steel composite overpack has been carried out. For corrosion-resistant material, ASTM Grade-2 titanium was selected. The titanium layer was bonded individually to a cylindrical shell and fiat cover plates (top and bottom) made of carbon steel. For the cylindrical shell portion, a cylindrically formed titanium layer was fitted to the inner carbon steel vessel by shrinkage. For the flat cover plates (top and bottom), titanium plate material was coated by explosive bonding. Electron beam welding and gas metal arc welding were combined to weld of the cover plates to the body. No significant failure was evident from inspections of the fabrication process, and the applicability of current technology for manufacturing titanium-carbon steel composite overpack was confirmed. Future research and development items regarding titanium-carbon steel composite overpacks are also discussed. (author)

Classification of titanium dioxide; Clasificacion del dioxido de titanio

Energy Technology Data Exchange (ETDEWEB)

Macias B, L.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Garcia C, R.M.; Maya M, M.E. [Secretaria de Hacienda y Credito Publico de Mexico, Mexico (Mexico); Ita T, A. De [Universidad Autonoma Metropolitana Azcapotzalco, Mexico (Mexico); Palacios G, J. [Instituto Politecnico Nacional (Mexico)

2002-07-01

In this work the X-ray diffraction (XRD), Scanning Electron Microscopy (Sem) and the X-ray Dispersive Energy Spectroscopy techniques are used with the purpose to achieve a complete identification of phases and mixture of phases of a crystalline material as titanium dioxide. The problem for solving consists of being able to distinguish a sample of titanium dioxide being different than a titanium dioxide pigment. A standard sample of titanium dioxide with NIST certificate is used, which indicates a purity of 99.74% for the TiO{sub 2}. The following way is recommended to proceed: a)To make an analysis by means of X-ray diffraction technique to the sample of titanium dioxide pigment and on the standard of titanium dioxide waiting not find differences. b) To make a chemical analysis by the X-ray Dispersive Energy Spectroscopy via in a microscope, taking advantage of the high vacuum since it is oxygen which is analysed and if it is concluded that the aluminium oxide appears in a greater proportion to 1% it is established that is a titanium dioxide pigment, but if it is lesser then it will be only titanium dioxide. This type of analysis is an application of the nuclear techniques useful for the tariff classification of merchandise which is considered as of difficult recognition. (Author)

Formation of Biomimetic Hydroxyapatite Coating on Titanium Plates

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Ievgen Volodymyrovych PYLYPCHUK

2014-09-01

Full Text Available Hydroxyapatite (HA has long been used as a coating material in the implant industry for orthopedic implant applications. HA is the natural inorganic constituent of bone and teeth. By coating titanium (base material of implant engineering because of its lightness and durability with hydroxyapatite, we can provide higher biocompatibility of titanium implants, according to HA ability to form a direct biochemical bond with living tissues. This article reports a biomimetic approach for coating hydroxyapatite with titanium A method of modifying the surface of titanium by organic modifiers (for creating functional groups on the surface, followed by formation "self-assembled" layer of biomimetic hydroxyapatite in simulated body fluid (SBF. FTIR and XPS confirmed the formation of hydroxyapatite coatings on titanium surface. Comparative study of the formation of HA on the surface of titanium plates modified by different functional groups: Ti(≡OH, Ti/(≡Si-OH and Ti/(≡COOH is conducted. It was found that the closest to natural stoichiometric hydroxyapatite Ca/P ratio was obtained on Ti/(≡COOH samples. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4974

Current assisted superplastic forming of titanium alloy

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Wang Guofeng

2015-01-01

Full Text Available Current assisted superplastic forming combines electric heating technology and superplastic forming technology, and can overcome some shortcomings of traditional superplastic forming effectively, such as slow heating rate, large energy loss, low production efficiency, etc. Since formability of titanium alloy at room temperature is poor, current assisted superplastic forming is suitable for titanium alloy. This paper mainly introduces the application of current assisted superplastic forming in the field of titanium alloy, including forming technology of double-hemisphere structure and bellows.

Comparison of titanium cable tension band and nickel-titanium patella concentrator for patella fractures.

Science.gov (United States)

Zhao, Quan-Ming; Gu, Xiao-Feng; Cheng, Li; Feng, De-Hong

2017-07-01

Patellar fractures account for approximately 1% of all fractures. Due to the patella's importance as regards the extensor mechanism, effort should be made to preserve the patella. Several operative treatment methods have been introduced for patella fractures. This study aims to compare the clinical effect of a titanium cable tension band and nickeltitanium (NiTi) patella concentrator (NT-PC) in treating patella fractures. Thirty-nine patients with patella fractures were enrolled in this retrospective study. All the patients were treated via the open reduction internal fixation procedure using a titanium cable tension band or NT-PC. All the patients were followed up over an average period of 13 months. The main outcome measures were operation time, time of fracture union, postoperative complications, and Böstman knee scores. Statistical analyses were conducted between the 2 groups. All the patients were operated on successfully. The operation time of the NT-PC treatment group was less than that of the titanium cable tension band treatment group (p cable tension band and NT-PC groups, respectively. No significant difference was observed between the excellent and good results (p > 0.05). Both titanium cable tension band and NT-PC showed good efficacy for the treatment of patellar fractures. NT-PC fixation, a new option for the treatment of patella fractures, is a simple and effective fixation method.

Research progress on laser surface modification of titanium alloys

International Nuclear Information System (INIS)

Tian, Y.S.; Chen, C.Z.; Li, S.T.; Huo, Q.H.

2005-01-01

Recent developments on laser surface modification of titanium and its alloys are reviewed. Due to the intrinsic properties of high coherence and directionality, laser beam can be focus onto metallic surface to perform a broad range of treatments such as remelting, alloying and cladding, which are used to improve the wear and corrosion resistance of titanium alloys. In addition, the fabrication of bioactive films on the surface of titanium alloys to improve their biocompatibility can be performed by the method of laser ablation deposition. The effect of some laser processing parameters on the resulting surface properties of titanium alloys is discussed. The problems to be solved and the prospects in the field of laser modification of titanium and its alloys are elucidated

Chemistry of titanium, zirconium and thorium picramates

International Nuclear Information System (INIS)

Srivastava, R.S.; Agrawal, S.P.; Bhargava, H.N.

1976-01-01

Picramates of titanium, zirconium and thorium are prepared by treating the aqueous sulphate, chloride and nitrate solutions with sodium picramate. Micro-analysis, colorimetry and spectrophotometry are used to establish the compositions (metal : ligand ratio) of these picramates as 1 : 2 (for titanium and zirconium) and 1 : 4 (for thorium). IR studies indicate H 2 N → Me coordination (where Me denotes the metal). A number of explosive properties of these picramates point to the fact that the zirconium picramate is thermally more stable than the picramates of titanium and thorium. (orig.) [de

Growth of anatase titanium dioxide nanotubes via anodization

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Ed Adrian Dilla

2012-06-01

Full Text Available In this work, titanium dioxide nanotubes were grown via anodization of sputtered titanium thin films using different anodization parameters in order to formulate a method of producing long anatase titanium dioxide nanotubes intended for solar cell applications. The morphological features of the nanotubes grown via anodization were explored using a Philips XL30 Field Emission Scanning Electron Microscope. Furthermore, the grown nanotubes were also subjected to X-ray diffraction and Raman spectroscopy in order to investigate the effect of the predominant crystal orientation of the parent titanium thin film on the crystal phase of the nanotubes. After optimizing the anodization parameters, nanotubes with anatase TiO2 crystal phase and tube length more than 2 microns was produced from parent titanium thin films with predominant Ti(010 crystal orientation and using ammonium fluoride in ethylene glycol as an electrolyte with a working voltage equal to 60V during 1-hour anodization runs.

Sorption of cesium on titanium and zirconium phosphates

International Nuclear Information System (INIS)

Lebedev, V.N.; Mel'nik, N.A.; Rudenko, A.V.

2003-01-01

Titanium and zirconium phosphates were prepared from mineral raw materials of the Kola Peninsula. Their capability to recover cesium cations from the model solutions and liquid radioactive waste (LRW) was studied. Titanium phosphate prepared from solutions formed by titanite breakdown demonstrates greater distribution coefficients of cesium as compared to zirconium phosphate. Titanium phosphate as a cheaper agent featuring greater sorption capacity was recommended for treatment of LRW to remove cesium [ru

Thermogravimetric experiments with titanium

International Nuclear Information System (INIS)

Porter, L.J.; Longhurst, G.R.

1991-02-01

In the process of preparing for pyrophoricity experiments involving uranium, we conducted hydriding and air-exposure experiments on titanium. In these experiments the hydriding reactions and response to air-exposure was generally within the range expected based on work reported by others. One aberrant behavior was a sudden weight gain followed by a significant weight loss. We speculate that loss may be due to hydrogen evolution from the TiH 2 resulting from local heating by oxidation reactions. We verified that titanium is not pyrophoric at temperatures less than 750 degree C. 18 refs. 1 fig

Candida albicans biofilm on titanium: effect of peroxidase precoating

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Mohamed Ahariz

2010-08-01

Full Text Available Mohamed Ahariz1, Philippe Courtois1,21Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, 2UER de Biologie Médicale, Haute Ecole Francisco Ferrer, Brussels, BelgiumAbstract: The present study aimed to document Candida albicans biofilm development on titanium and its modulation by a peroxidase-precoated material which can generate antimicrobials, such as hypoiodite or hypothiocyanite, from hydrogen peroxide, iodide, or thiocyanate. For this purpose, titanium (powder or foil was suspended in Sabouraud liquid medium inoculated with C. albicans ATCC10231. After continuous stirring for 2–21 days at room temperature, the supernatant was monitored by turbidimetry at 600 nm and titanium washed three times in sterile Sabouraud broth. Using the tetrazolium salt MTT-formazan assay, the titanium-adherent fungal biomass was measured as 7.50 ± 0.60 × 106 blastoconidia per gram of titanium powder (n = 30 and 0.50 ± 0.04 × 106 blastoconidia per cm² of titanium foil (n = 12. The presence of yeast on the surface of titanium was confirmed by microscopy both on fresh preparations and after calcofluor white staining. However, in the presence of peroxidase systems (lactoperoxidase with substrates such as hydrogen peroxide donor, iodide, or thiocyanate, Candida growth in both planktonic and attached phases appeared to be inhibited. Moreover, this study demonstrates the possible partition of peroxidase systems between titanium material (peroxidase-precoated and liquid environment (containing peroxidase substrates to limit C. albicans biofilm formation.Keywords: adhesion, material, oral, yeast

Titanium pigmentation. An electron probe microanalysis study

International Nuclear Information System (INIS)

Dupre, A.; Touron, P.; Daste, J.; Lassere, J.; Bonafe, J.L.; Viraben, R.

1985-01-01

A patient had an unusual pigmentary disease induced by titanium dioxide. The use of a topical cream containing titanium dioxide caused a xanthomalike appearance on the patient's penis. Electron probe microanalysis was valuable in establishing the cause of this balanitis

High temperature evaporation of titanium, zirconium and hafnium carbides

International Nuclear Information System (INIS)

Gusev, A.I.; Rempel', A.A.

1991-01-01

Evaporation of cubic nonstoichiometric carbides of titanium, zirconium and hafnium in a comparatively low-temperature interval (1800-2700) with detailed crystallochemical sample certification is studied. Titanium carbide is characterized by the maximum evaporation rate: at T>2300 K it loses 3% of sample mass during an hour and at T>2400 K titanium carbide evaporation becomes extremely rapid. Zirconium and hafnium carbide evaporation rates are several times lower than titanium carbide evaporation rates at similar temperatures. Partial pressures of metals and carbon over the carbides studied are calculated on the base of evaporation rates

Narrow titanium oxide nanowires induced by femtosecond laser pulses on a titanium surface

Energy Technology Data Exchange (ETDEWEB)

Li, Hui; Li, Xian-Feng [Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China); Zhang, Cheng-Yun [School of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510006 (China); Tie, Shao-Long [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Lan, Sheng, E-mail: slan@scnu.edu.cn [Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China)

2017-02-28

Highlights: • Titanium oxide nanowires with a feature width as narrow as ∼20 nm were induced on a titanium surface by using femtosecond laser pulses at 400 nm. • An evolution of the surface structure from a high spatial frequency laser-induced periodic structure parallel to the laser polarization to a low spatial frequency one perpendicular to the laser polarization was observed with increasing irradiation pulse number. • The formation of the titanium oxide nanowires was confirmed by the energy dispersive spectroscopy measurements and the evolution of the surface structure was successfully interpreted by using the efficacy factor theory. - Abstract: The evolution of the nanostructure induced on a titanium (Ti) surface with increasing irradiation pulse number by using a 400-nm femtosecond laser was examined by using scanning electron microscopy. High spatial frequency periodic structures of TiO{sub 2} parallel to the laser polarization were initially observed because of the laser-induced oxidation of the Ti surface and the larger efficacy factor of TiO{sub 2} in this direction. Periodically aligned TiO{sub 2} nanowires with featured width as small as 20 nm were obtained. With increasing pulse number, however, low spatial frequency periodic structures of Ti perpendicular to the laser polarization became dominant because Ti possesses a larger efficacy factor in this direction. The competition between the high- and low-spatial frequency periodic structures is in good agreement with the prediction of the efficacy factor theory and it should also be observed in the femtosecond laser ablation of other metals which are easily oxidized in air.

Hydrogen embrittlement of titanium tested with fracture mechanics specimens

International Nuclear Information System (INIS)

Aho-Mantila, I.; Rahko, P.

1990-11-01

Titanium is one of the possible canister materials for spent nuclear fuel. The aim of this study is to determine whether the hydrogen embrittlement of titanium could be a possible deterioration mechanism of titanium canisters. This experimental study was preceded by a literature review and an experimental study on crack nucleation. Tests in this study were carried out with hydrogen charged fracture mechanics specimens. The studied hydrogen contents were as received, 100 ppm, 200 ppm, 500 ppm and 700 ppm and the types of the studied titanium were ASTM Grades 2 and 12. Test methods were slow tensile test (0.027 mm/h) and fatigue test (stress ratio 0.7 or 0.8 and frequency 5 Hz). According to the literature titanium may be embrittled by hydrogen at slow strain rates and cracking may occur under sustained load. In this study no evidence of hydrogen embrittlement was noticed in slow strain rate tension with bulk hydrogen contents up to 700 ppm. The fatigue tests of titanium Grades 2 and 12 containing 700 ppm hydrogen showed even slower crack growth compared to the as received condition. Very high hydrogen contents well in eccess of 700 ppm on the surface of titanium can, however, facilitate surface crack nucleation and crack growth, as shown in the previous study

Physical and chemical characterization of titanium-alginate samples for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Morani, L.M.; Ribeiro, A.A.; Oliveira, M.V. de; Dantas, F.M.L., E-mail: marize.varella@int.gov.b [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil); Leao, M.H.M.R. [Universidade Federal do Rio de Janeiro (EQ/UFRJ), RJ (Brazil). Escola de Quimica

2010-07-01

The sol-gel technique combined with powder metallurgy may be an alternative to produce titanium parts for bioengineering, with the advantage of eliminating the powder compaction step, which may introduce defects. The present work introduces a system consisted of titanium powder and sodium alginate suspension, which undergoes reticulation in contact with a calcium salt solution, obtaining titanium/calcium alginate hydrogel with granule morphology. The characterization of the raw materials and granules of calcium alginate and titanium/calcium alginate was performed by x-ray fluorescence spectroscopy and thermogravimetric analysis. The granules topography was analyzed by scanning electron microscopy/EDS. Titanium and sodium alginate chemical composition were adequate for use as raw materials, showing that the methodology used is suitable for processing titanium samples for further consolidation by sintering, in order to produce titanium parts. (author)

Corrosion Behavior of Titanium Based Ceramic Coatings Deposited on Steels

OpenAIRE

Ali, Rania

2016-01-01

Titanium based ceramic films are increasingly used as coating materials because of their high hardness, excellent wear resistance and superior corrosion resistance. Using electrochemical and spectroscopic techniques, the electrochemical properties of different coatings deposited on different steels under different conditions were examined in this study. Thin films of titanium nitride (TiN), titanium diboride (TiB2), and titanium boronitride with different boron concentrations (TiBN-1&2) w...

The characteristics of corrosion, radiation degradation and dissolution of titanium alloys

International Nuclear Information System (INIS)

Sung, K. W.; Na, J. W.; Choi, B. S.; Lee, D. J.; Chang, M. H.

2001-12-01

In order to establish the technical bases of water chemistry design requirement related titanium alloys, we investigated the characteristics of corrosion, activation, radiation degradation, radiation hydrogen embrittlement of titanium alloys and dissolution of titanium dioxide. Titanium alloys generally have high corrosion resistance. Corrosion product release from PT-7M and PT-3V titanium alloy surface for 18 months of operation is negligible, and the corrosion penetration for about 30 years is about 1 μm, while the corrosion rates is not higher than one third of that of austenitic steel. Titanium only converts into Sc-46 with 85 day halflife after neutron irradiation, and its radioactivity is not higher than one thousandth of that produced from nickel. Therefore, under the condition without any neutron irradiation, the radiation damage of titanium alloys would have no problem. Titanium dioxide, that protects the metals from the corrosion, has retrograde solubility in neutral solutions. It does not form any complexes with ligands such as ammonia, but Ti(IV) gets more stable by complexing with water molecules. In conclusion, it is estimated that titanium alloys such as PT-7M would be applicable to steam generator materials

Radiolysis of titanium potassium oxalate in aqueous solution. [. gamma. rays

Energy Technology Data Exchange (ETDEWEB)

Bundo, Y; Ono, I [Industrial Research Inst. of Kanagawa Prefecture, Yokohama (Japan); Ogawa, T

1975-01-01

The dissolution state of titanium potassium oxalate in aqueous solution is different according to the pH. The yellowish brown titanium complex produced by the reaction of titanium potassium oxalate and hydrogen peroxide seems to be different in its structure according to the pH. Considering these points, gamma-ray irradiation was carried out on the sample by dissolving titanium potassium oxalate in purified water under the conditions of oxygen saturation and nitrogen saturation, and the relation between irradiation dose and the production of titanium complex was determined. On the basis of the experimental result, the mechanism of forming hydrogen peroxide was presumed. The radiation source used was 2,000 Ci of /sup 60/Co. For photometric analysis, a 139 type photoelectric spectrophotometer of Hitachi Ltd. was used. From the experimental results, in neutral water, titanium potassium oxalate exists in the state that two oxalic acid ions are coordinated to titanyl ion, while in case of the pH lowered by the addition of sulfuric acid, it can exist in the state that one oxalic acid ion is coordinated to titanyl ion. The yield of hydrogen peroxide produced by irradiating titanium potassium oxalate aqueous solution with gamma-ray is the sum of the molecular product from water and the radiolysis product from titanium potassium oxalate.

In vitro assessment of artifacts induced by titanium, titanium-zirconium and zirconium dioxide implants in cone-beam computed tomography.

Science.gov (United States)

Sancho-Puchades, Manuel; Hämmerle, Christoph H F; Benic, Goran I

2015-10-01

The aim of this study was to test whether or not the intensity of artifacts around implants in cone-beam computed tomography (CBCT) differs between titanium, titanium-zirconium and zirconium dioxide implants. Twenty models of a human mandible, each containing one implant in the single-tooth gap position 45, were cast in dental stone. Five test models were produced for each of the following implant types: titanium 4.1 mm diameter (Ti4.1 ), titanium 3.3 mm diameter (Ti3.3 ), titanium-zirconium 3.3 mm diameter (TiZr3.3 ) and zirconium dioxide 3.5-4.5 mm diameter (ZrO3.5-4.5 ) implants. For control purposes, three models without implants were produced. Each model was scanned using a CBCT device. Gray values (GV) were recorded at eight circumferential positions around the implants at 0.5 mm, 1 mm and 2 mm from the implant surface (GVT est ). GV were assessed in the corresponding volumes of interest (VOI) in the control models without implants (GVC ontrol ). Differences of gray values (ΔGV) between GVT est and GVC ontrol were calculated as percentages. One-way ANOVA and post hoc tests were applied to detect differences between implant types. Mean ΔGV for ZrO3.5-4.5 presented the highest absolute values, generally followed by TiZr3.3 , Ti4.1 and Ti3.3 implants. The differences of ΔGV between ZrO3.5-4.5 and the remaining groups were statistically significant in the majority of the VOI (P ≤ 0.0167). ΔGV for TiZr3.3 , Ti4.1 and Ti3.3 implants did not differ significantly in the most VOI. For all implant types, ΔGV showed positive values buccally, mesio-buccally, lingually and disto-lingually, whereas negative values were detected mesially and distally. Zirconium dioxide implants generate significantly more artifacts as compared to titanium and titanium-zirconium implants. The intensity of artifacts around zirconium dioxide implants exhibited in average the threefold in comparison with titanium implants. © 2014 John Wiley & Sons A/S. Published by John Wiley

Synthesis of gels with basis of titanium tungstates as matrixes of radioactive generators; Sintesis de geles a base de titanio tungstenatos como matrices de generadores radiactivos

Energy Technology Data Exchange (ETDEWEB)

Galico C, L

2005-07-01

The heteropolyanions, compounds formed by the union of molybdates or tungstates polyanions with atoms of metals like zirconium, titanium, cerium, thorium, tin, etc., have been used as generator matrixes of {sup 99m} Tc or {sup 188} Re. Particularly they have been studied and produced successfully in our laboratory, generators of {sup 99} Mo/ {sup 99}m Tc at basis of gels zirconium molybdates and titanium molybdates. Considering that the molybdenum and tungsten, as well as the technetium and the rhenium, its belong to the same groups of transition metals, it is feasible that gels can be synthesized at basis of titanium tungstates, continuing a methodology similar to that of the gels titanium molybdates or zirconium molybdates, to produce generators {sup 188} W/ {sup 188} Re. The {sup 188} Re possess nuclear characteristics that make it attractive for therapeutic applications, since, it emits {beta}{sup -} particles of a great energy (2.12 MeV); joined to the possibility of being able to unite to different ligands (bifunctional agents) and biomolecules (antibodies or fragments of proteins), as it makes the {sup 99m} Tc, useful in radioimmunotherapy. Commercially the {sup 188} Re generators use a chromatographic column loaded with alumina where the {sup 188} Re, it is adsorbed and eluted the {sup 188} ReO{sub 4}{sup -} by means of a saline solution The alumina adsorbs around 0.2% of the {sup 188} Re, situation that forces to use {sup 188} Re of a high specific activity. The use of the gels technology, allows to work with medium or low specific activities of {sup 188} Re, opening the possibility of their production in countries whose nuclear capacity is medium or low. In particular, the synthesized gels with basis of titanium offer the possibility of being synthesized with non active material, for later on to be irradiated and directly produce the generator, since, the titanium {sup 51} Ti, unique radioisotope produced by the titanium, has a half life of 5.79 min. This

Diffusion bonding of transition structures for integral aluminium-fibre reinforced polymer (FRP) compounds

Energy Technology Data Exchange (ETDEWEB)

Hehl, A. von [IWT - Stiftung Institut fuer Werkstofftechnik, Hauptabteilung Werkstofftechnik, Bremen (Germany); Syassen, F. [Airbus Operations GmbH, Metal Technology, Bremen (Germany); Schimanski, K.

2012-04-15

Components in hybrid design become more and more important in terms of their lightweight potential. In this context the demand for weight saving in aerospace leads to increasing numbers of applications of fibre composites for primary structural components. In consequence the use of FRP-metal compounds is necessary. Within the investigations of the researcher group ''Schwarz Silber'' (FOR 1224) founded by the DFG (German Research Foundation) material optimised interface structures for advanced CFRP-aluminium compounds are currently being studied. Within their work the researcher group focussed on three concepts realizing the transition structures: the usage of wires (titanium), foils (titanium) and fibres (glass fibre) as transition elements between CFRP and aluminium. For the connection of the aluminium sheet and the transition element die-casting and laser beam welding are basically used. As a possible alternative to the both liquid phase processes a feasibility study haven been done focussing the solid state processes diffusion bonding. The experimental results show the high potential of this process in view of the transferable loads for integral transition structures. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Stainless Steel to Titanium Bimetallic Transitions

Energy Technology Data Exchange (ETDEWEB)

Kaluzny, J. A. [Fermilab; Grimm, C. [Fermilab; Passarelli, D. [Fermilab

2015-01-01

In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.

Hydrogen embrittlement of titanium and its alloys - a literature review

International Nuclear Information System (INIS)

Aho-Mantila, I.; Haemaelaeinen, H.

1986-05-01

Hydrogen embrittlement data of titanium and its alloys is reviewed. Especially the results obtained in spent nuclear fuel repository conditions with commercially pure titanium and TiCode-12 alloy are examined. The results show that the mechanical properties of titanium are not much affected by hydrogen when tested by smooth specimens. Much greater effects can be expected with notched fracture mechanics specimens. However, only limeted data is available. Hydrogen distribution in titanium is affected by stress, alloy composition and temperature gradients. In order to model the hydrogen-induced crack growth in titanium much more mechanistic work is needed especially to understand the behaviour of hydrogen in crack tip stress field. (author)

Array of titanium dioxide nanostructures for solar energy utilization

Science.gov (United States)

Qiu, Xiaofeng; Parans Paranthaman, Mariappan; Chi, Miaofang; Ivanov, Ilia N; Zhang, Zhenyu

2014-12-30

An array of titanium dioxide nanostructures for solar energy utilization includes a plurality of nanotubes, each nanotube including an outer layer coaxial with an inner layer, where the inner layer comprises p-type titanium dioxide and the outer layer comprises n-type titanium dioxide. An interface between the inner layer and the outer layer defines a p-n junction.

Grain growth in ultrafine titanium powders during sintering

International Nuclear Information System (INIS)

Panigrahi, B.B.; Godkhindi, M.M.

2006-01-01

Grain growth behaviour of fine (∼3 μm) and attrition milled nanocrystalline (∼32 nm) titanium powers during sintering have been studied. The activation energies of grain growth (Q g ) in fine titanium were found to be 192.9 and 142.4 kJ/mol at lower and higher temperature ranges, respectively. The nanocrystalline titanium showed very low values of Q g (54.6 kJ/mol) at lower temperatures and it increased to 273.2 kJ/mol at higher temperatures. The constant (n) in nano Ti system was found to have unusually very high values of 6.5-8.2. The grain boundary rotation along with the diffusional processes could be the grain growth mechanism in nanocrystalline and in fine titanium powders

The titanium oxide phi system

Science.gov (United States)

Galehouse, D. C.; Davis, S. P.

1980-01-01

The phy system of titanium oxide has been studied in emission in the near-infrared, with the Fourier transform spectrometer at a resolution of 8000,000. Approximately 3000 lines from 25 bands of this system have been identified, including all five 0-0 and 0-1 bands corresponding to the five natural titanium isotopes. Eleven vibrational levels have been observed, and all bands have been rotationally analyzed. Band intensities are agreement with known isotopic abundances and calculated Franck-Condon factors.

Thermomechanical treatment of titanium alloys

International Nuclear Information System (INIS)

Khorev, A.K.

1979-01-01

The problems of the theory and practical application of thermomechanical treatment of titanium alloys are presented. On the basis of the systematic investigations developed are the methods of thermomechanical treatment of titanium alloys, established are the optimum procedures and produced are the bases of their industrial application with an account of alloy technological peculiarities and the procedure efficiency. It is found that those strengthening methods are more efficient at which the contribution of dispersion hardening prevails over the strengthening by phase hardening

[Effects of laser welding on bond of porcelain fused cast pure titanium].

Science.gov (United States)

Zhu, Juan-fang; He, Hui-ming; Gao, Bo; Wang, Zhong-yi

2006-04-01

To investigate the influence of the laser welding on bond of porcelain fused to cast pure titanium. Twenty cast titanium plates were divided into two groups: laser welded group and control group. The low-fusing porcelain was fused to the laser welded cast pure titanium plates at fusion zone. The bond strength of the porcelain to laser welded cast pure titanium was measured by the three-point bending test. The interface of titanium and porcelain was investigated by scanning electron microscopy (SEM) and energy depressive X-ray detector (EDX). The non-welded titanium plates were used as comparison. No significant difference of the bond strength was found between laser-welded samples [(46.85 +/- 0.76) MPa] and the controls [(41.71 +/- 0.55) MPa] (P > 0.05). The SEM displayed the interface presented similar irregularities with a predominance. The titanium diffused to low-fusing porcelain, while silicon and aluminum diffused to titanium basement. Laser welding does not affect low-fusing porcelain fused to pure titanium.

Phase equilibria and thermodynamic studies in the titanium-nickel and titanium-nickel-oxygen systems

International Nuclear Information System (INIS)

Chattopadhyay, G.; Kleykamp, H.; Laumer, W.

1983-01-01

The isothermal section of the Ti-Ni-O system was examined at 1200 K in the regions between the Ni(Ti) solid solution and the binary oxides of titanium. The relative partial Gibbs energies of oxygen over the Ti 2 O 3 -Ti 3 O 5 region and of titanium in the Ni(Ti) solid solution as well as the Gibbs energies of formation of NiTiO 3 , Ti 3 O 5 and TiNi 3 were determined between 1100 and 1300 K by use of solid electrolyte galvanic cells. (orig.) [de

On reaction of titanium polonides with carbon dioxide

International Nuclear Information System (INIS)

Abakumov, A.S.; Malyshev, M.L.; Reznikova, N.F.

1986-01-01

The reaction between titanium polonides and carbon dioxide has been studied by comparing titanium polonide thermal resistance in vacuum and in carbon dioxide. The investigation has shown that titanium mono- and semipolonides fail at temperatures below 350 deg C. Temperature dependence of polonium vapor pressure prepared at failure of the given polonides is determined by the radiotensiometry in carbon dioxide. Enthalpy calculated for this dependence is close to the enthalpy of elementary polonium evaporation in vacuum

Feasibility of long-life and corrosion-resistant canister with titanium cladding

International Nuclear Information System (INIS)

Furuya, Masahiro; Tokiwai, Moriyasu; Saegusa, Toshiari

2008-01-01

In order to store nuclear spent fuels for a long term, we propose the concept of stainless steel canister with titanium cladding. The stainless canister is first brazed to titanium plates, and then the brazed joints are covered with other titanium plates. A MIG brazing for titanium and stainless steel was demonstrated with a brazing metal of Cu-1Mn-3Si alloy (MG960). JIS G 0601 shear strength, tensile shear stress and peel strength tests are conducted for the optimized MIG brazing conditions. These results showed the MIG brazing specimens possess adequate structural strength. After the salt spray test on the basis of JIS Z 2371, there were no pitting and general corrosions on a TIG welding specimen between titanium plates. The corrosion resistance is therefore, sufficiently high. Manufacturing cost estimation suggests that the titanium cladding concept is feasible thereby using 1-mm-thick titanium plates to reduce the material cost. In addition to this concept, we propose another concept of the canister by using titanium-stainless steel cladding plates to reduce a number of brazing joints. (author)

Cranioplasty with individual titanium implants

Science.gov (United States)

Mishinov, S.; Stupak, V.; Sadovoy, M.; Mamonova, E.; Koporushko, N.; Larkin, V.; Novokshonov, A.; Dolzhenko, D.; Panchenko, A.; Desyatykh, I.; Krasovsky, I.

2017-09-01

Cranioplasty is the second procedure in the history of neurosurgery after trepanation, and it is still relevant despite the development of civilization and progress in medicine. Each cranioplasty operation is unique because there are no two patients with identical defects of the skull bones. The development of Direct Metal Laser Sintering (DMLS) technique opened up the possibility of direct implant printing of titanium, a biocompatible metal used in medicine. This eliminates the need for producing any intermediate products to create the desired implant. We have produced 8 patient-specific titanium implants using this technique for patients who underwent different decompressive cranioectomies associated with bone tumors. Follow-up duration ranged from 6 to 12 months. We observed no implant-related reactions or complications. In all cases of reconstructive neurosurgery we achieved good clinical and aesthetic results. The analysis of the literature and our own experience in three-dimensional modeling, prototyping, and printing suggests that direct laser sintering of titanium is the optimal method to produce biocompatible surgical implants.

Studies of U-Pu-C-Ti compounds

International Nuclear Information System (INIS)

Milet, C.

1967-01-01

The U-Pu-C-Ti compounds (5 to 20 atoms per cent Ti) have been studied in order to improve some properties of U-Pu-C carbides and to extend the existence field of the (U, Pu) C phase. The Pu/(U+Pu) ratio has been fixed to 15 per cent. All the alloys were elaborated and cast in an arc furnace. A two-phases field (U, Pu) C + Ti C exists which permits to avoid di- and sesqui-carbides and the (U, Pu) phase. An eutectic between (U, Pu) C and Ti C was found around 15 atoms per cent Ti. Practically the whole of the titanium is in Ti C form, titanium solubility in (U, Pu) C being inferior to 1 atom per cent. The most promising alloy are those containing two phases: (U, Pu) C+ Ti C. In comparison with the (U, Pu) C phase, titanium addition does not change very much the thermal expansion coefficients nor the thermal cycling behaviour between 160 and 1000 Celsius degrees which is excellent. On the other hand atmospheric corrosion behaviour is improved; compatibility with stainless steel is better; thermal conductivity, calculated from electrical resistivity K is enhanced: for U(0.85)-Pu(0.15)-C alloy we have K 0.179 W/cm.C at 1000 C and K = 0.187 W/cm.C at 1500 C, for U-Pu-C-Ti (10 atoms % Ti) alloy we have K = 0.193 W/cm.C at 1000 C and K = 0.205 W/cm.C at 1500 C. (author) [fr

All welded titanium condenser adopted in atomic power plants

International Nuclear Information System (INIS)

Iwai, Nagao; Itabashi, Yukihiko

1980-01-01

Condensers in power plants are shell-and-tube type heat exchangers. Most condensers use seawater as a coolant. Their tube and tube Sheets have usually been made of brass, which resists corrosion but cannot completely prevent it; as a result, tubes sometimes corrode or erode, allowing seawater to leak into the turbine cycle. As is well known, titanium has almost complete corrosion resistance against seawater; for this reason titanium tubes have replaced brass ones in some condensers operating in Europe and the USA. Even in such condensers, though, the tube plates have still been made of brass, tightly fitted to the titanium tubes, and it has proved impossible to eliminate seawater leakage at the junctions between tubes and tube Sheets. In order to eliminate such leakage completely, the tube Sheets must be made of titanium too, and the tubes and plates must be welded together. However, the welding of titanium requires an extremely celan atmosphere, a condition very difficult to fulfill at power plant construction sites, and the use of whole welded titanium tube condensers has long been considered a practical impossibility. Such all-titanium welded condensers have now been successfully constructed and installed in two 600 MW fossil power plants and one 1100 MW nuclear power plant. This paper describes the techniques used, add in addition reviews the various materials that have been used in condenser tubes. (author)

Differential cytotoxicity induced by the Titanium(IV)Salan complex Tc52 in G2-phase independent of DNA damage

International Nuclear Information System (INIS)

Pesch, Theresa; Schuhwerk, Harald; Wyrsch, Philippe; Immel, Timo; Dirks, Wilhelm; Bürkle, Alexander; Huhn, Thomas; Beneke, Sascha

2016-01-01

Chemotherapy is one of the major treatment modalities for cancer. Metal-based compounds such as derivatives of cisplatin are in the front line of therapy against a subset of cancers, but their use is restricted by severe side-effects and the induction of resistance in treated tumors. Subsequent research focused on development of cytotoxic metal-complexes without cross-resistance to cisplatin and reduced side-effects. This led to the discovery of first-generation titanium(IV)salan complexes, which reached clinical trials but lacked efficacy. New-generation titanium (IV)salan-complexes show promising anti-tumor activity in mice, but their molecular mechanism of cytotoxicity is completely unknown. Four different human cell lines were analyzed in their responses to a toxic (Tc52) and a structurally highly related but non-toxic (Tc53) titanium(IV)salan complex. Viability assays were used to reveal a suitable treatment range, flow-cytometry analysis was performed to monitor the impact of dosage and treatment time on cell-cycle distribution and cell death. Potential DNA strand break induction and crosslinking was investigated by immunostaining of damage markers as well as automated fluorometric analysis of DNA unwinding. Changes in nuclear morphology were analyzed by DAPI staining. Acidic beta-galactosidase activity together with morphological changes was monitored to detect cellular senescence. Western blotting was used to analyze induction of pro-apoptotic markers such as activated caspase7 and cleavage of PARP1, and general stress kinase p38. Here we show that the titanium(IV)salan Tc52 is effective in inducing cell death in the lower micromolar range. Surprisingly, Tc52 does not target DNA contrary to expectations deduced from the reported activity of other titanium complexes. Instead, Tc52 application interferes with progression from G2-phase into mitosis and induces apoptotic cell death in tested tumor cells. Contrarily, human fibroblasts undergo senescence in a

Near-Net Shape Fabrication Using Low-Cost Titanium Alloy Powders

Energy Technology Data Exchange (ETDEWEB)

Dr. David M. Bowden; Dr. William H. Peter

2012-03-31

The use of titanium in commercial aircraft production has risen steadily over the last half century. The aerospace industry currently accounts for 58% of the domestic titanium market. The Kroll process, which has been used for over 50 years to produce titanium metal from its mineral form, consumes large quantities of energy. And, methods used to convert the titanium sponge output of the Kroll process into useful mill products also require significant energy resources. These traditional approaches result in product forms that are very expensive, have long lead times of up to a year or more, and require costly operations to fabricate finished parts. Given the increasing role of titanium in commercial aircraft, new titanium technologies are needed to create a more sustainable manufacturing strategy that consumes less energy, requires less material, and significantly reduces material and fabrication costs. A number of emerging processes are under development which could lead to a breakthrough in extraction technology. Several of these processes produce titanium alloy powder as a product. The availability of low-cost titanium powders may in turn enable a more efficient approach to the manufacture of titanium components using powder metallurgical processing. The objective of this project was to define energy-efficient strategies for manufacturing large-scale titanium structures using these low-cost powders as the starting material. Strategies include approaches to powder consolidation to achieve fully dense mill products, and joining technologies such as friction and laser welding to combine those mill products into near net shape (NNS) preforms for machining. The near net shape approach reduces material and machining requirements providing for improved affordability of titanium structures. Energy and cost modeling was used to define those approaches that offer the largest energy savings together with the economic benefits needed to drive implementation. Technical

Development and Evaluation of Titanium Spacesuit Bearings

Science.gov (United States)

Rhodes, Richard; Battisti, Brian; Ytuarte, Raymond, Jr.; Schultz, Bradley

2016-01-01

The Z-2 Prototype Planetary Extravehicular Space Suit Assembly is a continuation of NASA's Z-series of spacesuits, designed with the intent of meeting a wide variety of exploration mission objectives, including human exploration of the Martian surface. Incorporating titanium bearings into the Z-series space suit architecture allows us to reduce mass by an estimated 23 lbs per suit system compared to the previously used stainless steel bearing race designs, without compromising suit functionality. There are two obstacles to overcome when using titanium for a bearing race- 1) titanium is flammable when exposed to the oxygen wetted environment inside the space suit and 2) titanium's poor wear properties are often challenging to overcome in tribology applications. In order to evaluate the ignitability of a titanium space suit bearing, a series of tests were conducted at White Sands Test Facility (WSTF) that introduced the bearings to an extreme test profile, with multiple failures imbedded into the test bearings. The testing showed no signs of ignition in the most extreme test cases; however, substantial wear of the bearing races was observed. In order to design a bearing that can last an entire exploration mission (approx. 3 years), design parameters for maximum contact stress need to be identified. To identify these design parameters, bearing test rigs were developed that allow for the quick evaluation of various bearing ball loads, ball diameters, lubricants, and surface treatments. This test data will allow designers to minimize the titanium bearing mass for a specific material and lubricant combination and design around a cycle life requirement for an exploration mission. This paper reviews the current research and testing that has been performed on titanium bearing races to evaluate the use of such materials in an enriched oxygen environment and to optimize the bearing assembly mass and tribological properties to accommodate for the high bearing cycle life for an

Present status of titanium removable dentures--a review of the literature.

Science.gov (United States)

Ohkubo, C; Hanatani, S; Hosoi, T

2008-09-01

Although porcelain and zirconium oxide might be used for fixed partial dental prostheses instead of conventional dental metals in the near future, removable partial denture (RPD) frameworks will probably continue to be cast with biocompatible metals. Commercially pure (CP) titanium has appropriate mechanical properties, it is lightweight (low density) compared with conventional dental alloys, and has outstanding biocompatibility that prevents metal allergic reactions. This literature review describes the laboratory conditions needed for fabricating titanium frameworks and the present status of titanium removable prostheses. The use of titanium for the production of cast RPD frameworks has gradually increased. There are no reports about metallic allergy apparently caused by CP titanium dentures. The laboratory drawbacks still remain, such as the lengthy burn-out, inferior castability and machinability, reaction layer formed on the cast surface, difficulty of polishing, and high initial costs. However, the clinical problems, such as discoloration of the titanium surfaces, unpleasant metal taste, decrease of clasp retention, tendency for plaque to adhere to the surface, detachment of the denture base resin, and severe wear of titanium teeth, have gradually been resolved. Titanium RPD frameworks have never been reported to fail catastrophically. Thus, titanium is recommended as protection against metal allergy, particularly for large-sized prostheses such as RPDs or complete dentures.

Preparation procedure for spherical titanium powders by RF induction plasma

International Nuclear Information System (INIS)

Gu Zhongtao; Jin Yuping; Ye Gaoying

2011-01-01

The paper uses the single-factor method for the study of spherical titanium powder preparation process. Titanium powders with excellent sphericity can be prepared through controlling and regulating the radio frequency plasma anode working current and voltage, central gas flow rate, sheath gas flow rate, powder-carrying gas flow rate, negative ventilation pressure and powder feed rate, etc. Spheroidization of titanium powders with a size of (17.0±2.0) μm is performed by radio frequency plasma technology. With the increase of negative ventilation pressure, the spheroidization rate of titanium powders increases firstly and then decreases rapidly at the turning point around 1800 Pa. With the rate of powder feed increasing, the spheroidization rate of titanium powders increases firstly. When the powder feed rate is greater than 90.0 g/min, the spheroidization rate of titanium powders reduces rapidly as the powder feed rate increases. (authors)

Surface characterization of nickel titanium orthodontic arch wires

Science.gov (United States)

Krishnan, Manu; Seema, Saraswathy; Tiwari, Brijesh; Sharma, Himanshu S.; Londhe, Sanjay; Arora, Vimal

2015-01-01

Background Surface roughness of nickel titanium orthodontic arch wires poses several clinical challenges. Surface modification with aesthetic/metallic/non metallic materials is therefore a recent innovation, with clinical efficacy yet to be comprehensively evaluated. Methods One conventional and five types of surface modified nickel titanium arch wires were surface characterized with scanning electron microscopy, energy dispersive analysis, Raman spectroscopy, Atomic force microscopy and 3D profilometry. Root mean square roughness values were analyzed by one way analysis of variance and post hoc Duncan's multiple range tests. Results Study groups demonstrated considerable reduction in roughness values from conventional in a material specific pattern: Group I; conventional (578.56 nm) > Group V; Teflon (365.33 nm) > Group III; nitride (301.51 nm) > Group VI (i); rhodium (290.64 nm) > Group VI (ii); silver (252.22 nm) > Group IV; titanium (229.51 nm) > Group II; resin (158.60 nm). It also showed the defects with aesthetic (resin/Teflon) and nitride surfaces and smooth topography achieved with metals; titanium/silver/rhodium. Conclusions Resin, Teflon, titanium, silver, rhodium and nitrides were effective in decreasing surface roughness of nickel titanium arch wires albeit; certain flaws. Findings have clinical implications, considering their potential in lessening biofilm adhesion, reducing friction, improving corrosion resistance and preventing nickel leach and allergic reactions. PMID:26843749

Resorbable versus titanium plates for orthognathic surgery.

Science.gov (United States)

Agnihotry, Anirudha; Fedorowicz, Zbys; Nasser, Mona; Gill, Karanjot S

2017-10-04

Recognition of some of the limitations of titanium plates and screws used for the fixation of bones has led to the development of plates manufactured from bioresorbable materials. Whilst resorbable plates appear to offer clinical advantages over metal plates in orthognathic surgery, concerns remain about the stability of fixation and the length of time required for their degradation and the possibility of foreign body reactions. This review compares the use of titanium versus bioresorbable plates in orthognathic surgery and is an update of the Cochrane Review first published in 2007. To compare the effects of bioresorbable fixation systems with titanium systems used during orthognathic surgery. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 20 January 2017); the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 11) in the Cochrane Library (searched 20 January 2017); MEDLINE Ovid (1946 to 20 January 2017); and Embase Ovid (1980 to 20 January 2017). We searched the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (clinicaltrials.gov; searched 20 January 2017), and the World Health Organization International Clinical Trials Registry Platform (searched 20 January 2017) for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised controlled trials comparing bioresorbable versus titanium fixation systems used for orthognathic surgery in adults. Two review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies. We resolved disagreement by discussion. Clinical heterogeneity between the included trials precluded pooling of data, and only a descriptive summary is presented. This review included two trials, involving 103 participants, one comparing titanium with resorbable plates and screws and

Influence of heat treatment on hardness and kinetics of growth of intermetallic compound interlayer in titanium-steel composite material

International Nuclear Information System (INIS)

Shmorgun, V.G.; Slaustin, O.V.; Trykov, Yu.P.

2005-01-01

The effect of heat treatment conditions on microhardness and diffusion interlayer thickness is studied for composite material of titanium VT1-O + steel 08kp + titanium VT1-O. Heat treatments are carried out at temperatures of 800-1000 deg C and holding at heat for 3 h in a vacuum furnace (1 x 10 -4 mmHg) as well as in an electric furnace with coating a dual protective layer. It is stated that the hardness and the thickness of the interlayer are higher after heat treatment in an ordinary electric furnaces as compared to vacuum heating. all other things being equal. Annealed in electric furnace specimens are water quenched from temperatures of 600-950 deg C. It is shown that the hardness of the interlayer increases sharply when hardening from 650 deg C comparing with annealed specimens (from 4.5-5.2 to 7-9 GPa). The quenching from 700 and 800 deg C results in an interlayer hardness decrease down to 4.8-5.4 and 3.1-3 GPa respectively. A quenching temperature increase up to 800-900 deg C is accompanied by a monotonic enhancement of hardness from 3.5-4.8 up to 5.1-6.8 GPa [ru

Sorption kinetics of cesium on hydrous titanium dioxide

International Nuclear Information System (INIS)

Altas, Y.; Tel, H.; Yaprak, G.

2003-01-01

Two types of hydrous titanium dioxide possessing different surface properties were prepared and characterized to study the sorption kinetics of cesium. The effect of pH on the adsorption capacity were determined in both type sorbents and the maximum adsorption percentage of cesium were observed at pH 12. To elucidate the kinetics of ion-exchange reaction on hydrous titanium dioxide, the isotopic exchange rates of cesium ions between hydrous titanium dioxides and aqueous solutions were measured radiochemically and compared with each other. The diffusion coefficients of Cs + ion for Type1 and Type2 titanium dioxides at pH 12 were calculated as 2.79 x 10 -11 m 2 s -1 and 1.52 x 10 -11 m 2 s -1 , respectively, under particle diffusion controlled conditions. (orig.)

Tribological investigations of perfluoroalkylsilanes monolayers deposited on titanium surface

International Nuclear Information System (INIS)

Cichomski, Michał

2012-01-01

Therefore the present work reports a systematic study of titanium modification by fluoroalkylsilanes and surface characterization from the tribological point of view. The vapor phase deposition method was used to modify titanium surfaces by fluoroalkylsilanes and the influence of the used modifier on the tribological properties is presented. The modification procedure efficiency, surface structure and morphology were characterized by secondary ion mass spectrometry, infrared spectroscopy and atomic force microscopy. The effectiveness of modification of the titanium surface was monitored by the measurement of the wetting contact angle and the surface free energy. The increase of surface hydrophobicity was observed upon the modification by increasing the wetting contact angle and reducing the surface free energy. The tribological performance of various perfluoroalkylsilanes films on the titanium surface was investigated in mili- and nano-newton load ranges. Dependence of the adhesive force and coefficient of friction values obtained in nano- and micro-scale on fluoroalkyl chain length was observed. Nano- and micro-tribological measurements show that titanium modified by fluoroalkylsilanes has lower adhesion and coefficient of friction than unmodified one. The investigation also indicates a decrease of the friction coefficient with increasing fluoric alkyl chain length. It was found that the titanium modified by fluoroalkylsilanes with longer alkyl chains is a prime candidate for practical use as a lubricant in biomedical and electronic applications. -- Highlights: ► Titanium surface modification by perfluoroalkylsilanes was investigated. ► The effectiveness of modification was monitored by the surface free energy. ► The modification procedure correctness was characterized by ToF-SIMS, AFM, FT-IR measurements. ► The tribological performance of modified titanium in differed scale was studied.

Enthalpy of formation of titanium diboride

International Nuclear Information System (INIS)

Akhachinskij, V.V.; Chirin, N.A.

1975-01-01

The values given in the literature for the enthalpy of the formation of titanium diboride, as obtained experimentally and by theoretical estimation, range between -32 and -74.4 kcal/mol. In this paper the authors use the method of direct synthesis from elements in a Calvet calorimeter to determine the enthalpy of formation, ΔHsub(f) 0 , sub(298), of titanium diboride with the composition Tisub(1.000+-0.002)Bsub(2.056+-0.006)Csub(0.009)Nsub(0.003), which was found to be -76.78+-0.83 kcal/mol. They calculate that ΔHsub(f,298) (TiBsub(2.056)=-76.14+-0.85 kcal/mol. The procedure employed makes it possible to carry out the titanium diboride synthesis reaction with the calorimeter at room temperature

Adhesion of osteoblasts to a nanorough titanium implant surface

Directory of Open Access Journals (Sweden)

Gongadze E

2011-08-01

Full Text Available Ekaterina Gongadze1, Doron Kabaso2, Sebastian Bauer3, Tomaž Slivnik2, Patrik Schmuki3, Ursula van Rienen1, Aleš Iglič21Institute of General Electrical Engineering, University of Rostock, Rostock, Germany; 2Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia; 3Department of Materials Science, Friedrich-Alexander University of Erlangen-Nurenberg, Erlangen, GermanyAbstract: This work considers the adhesion of cells to a nanorough titanium implant surface with sharp edges. The basic assumption was that the attraction between the negatively charged titanium surface and a negatively charged osteoblast is mediated by charged proteins with a distinctive quadrupolar internal charge distribution. Similarly, cation-mediated attraction between fibronectin molecules and the titanium surface is expected to be more efficient for a high surface charge density, resulting in facilitated integrin mediated osteoblast adhesion. We suggest that osteoblasts are most strongly bound along the sharp convex edges or spikes of nanorough titanium surfaces where the magnitude of the negative surface charge density is the highest. It is therefore plausible that nanorough regions of titanium surfaces with sharp edges and spikes promote the adhesion of osteoblasts.Keywords: osteoblasts, nanostructures, adhesion, titanium implants, osteointegration

The immunomodulatory effects of titanium dioxide and silver nanoparticles.

Science.gov (United States)

Lappas, Courtney M

2015-11-01

Due to their characteristic physical, chemical and optical properties, titanium dioxide and silver nanoparticles are attractive tools for use in a wide range of applications. The use of nanoparticles for biological applications is, however, dependent upon their biocompatibility with living cells. Because of the importance of inflammation as a modulator of human health, the safe and efficacious in vivo use of titanium dioxide and silver nanoparticles is inherently linked to a favorable interaction with immune system cells. However, both titanium dioxide and silver nanoparticles have demonstrated potential to exert immunomodulatory and immunotoxic effects. Titanium dioxide and silver nanoparticles are readily internalized by immune system cells, may accumulate in peripheral lymphoid organs, and can influence multiple manifestations of immune cell activity. Although the factors influencing the biocompatibility of titanium dioxide and silver nanoparticles with immune system cells have not been fully elucidated, nanoparticle core composition, size, concentration and the duration of cell exposure seem to be important. Because titanium dioxide and silver nanoparticles are widely utilized in pharmaceutical, commercial and industrial products, it is vital that their effects on human health and immune system function be more thoroughly evaluated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Recent trend of titanium-clad steel plate/sheet (NKK)

International Nuclear Information System (INIS)

Kimura, Hideto

1997-01-01

The roll-bonding process for titanium-clad steel production enabled the on-line manufacturing and quality control of the products which are usually applied for the production of steel plate and sheet by the steel producers. The recent trend of roll-bonded titanium-clad steel which has an excellent corrosion resistance together with the advantage in cost-saving are mainly described in this article as to the demand, production technique and new application aspects. Though the predominant usage of titanium-clad steel plate has been in power-generating plants, enlargeing utilization in the chemical plants such as terephthalic acid production plants is leading the growth in the market of titanium-clad steel plate. Also, the application of titanium-clad steel plates and sheets for the lining the marine structures is expected as one of the best solution to long-term surface protection for their outstanding corrosion resistance against sea water. (author)

Titanium Isotopes Provide Clues to Lunar Origin

Science.gov (United States)

Taylor, G. J.

2012-05-01

The idea that the Moon formed as the result of the giant impact of a Mars-sized impactor with the still-growing Earth explains two central facts about the Earth-Moon system: its total angular momentum (Earth's spin and the Moon's orbital motion), and the sizes of the metallic cores of the Earth (large) and Moon (tiny). This gives cosmochemists some confidence in the hypothesis, but they would greatly appreciate additional compositional tests. One undisputed point is the identical abundance of the three oxygen isotopes in Earth and Moon. Junjun Zhang and colleagues at the University of Chicago (USA) and the University of Bern (Switzerland) have added another isotopic system to the cosmochemical testing tool kit, titanium isotopes. They find that the ratio of titanium-50 to titanium-47 is identical in Earth and Moon to within four parts per million. In contrast, other solar system materials, such as carbonaceous chondrites, vary by considerably more than this-- up to 150 times as much. The identical oxygen and titanium isotopic compositions in Earth and Moon are surprising in light of what we think we know about planet formation and formation of the Moon after a giant impact. The variations in oxygen and titanium isotopes among meteorite types suggest that it is unlikely that the Moon-forming giant impactor would have had the same isotopic composition as the Earth. Simulations show that the Moon ends up constructed mostly (40-75%) from the impactor materials. Thus, the Moon ought to have different isotopic composition than does Earth. The isotopes might have exchanged in the complicated, messy proto-lunar disk (as has been suggested for oxygen isotopes), making them the same. However, Zhang and colleagues suggest that this exchange is unlikely for a refractory element like titanium. Could the impact simulations be greatly overestimating the contributions from the impactor? Was the mixing of building-block materials throughout the inner solar system much less than

Determination of the Titanium Contents in the Winter Oilseed Rape Plants (Brassica napus L. by the Application of Fertilizer Containing Titanium

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Peter Kováčik

2016-01-01

Full Text Available In order to obtain the information about changes of titanium contents in the phytomass during the growing season of winter oilseed rape and about the titanium contents drawn by the rape yield during two farming years the small plot field trial was established. In the trial the fertilizer Mg-Titanit (MgTi containing 8.5 g of titanium in 1 liter was used. The experiment consisted of 5 treatments. 0 – control treatment without MgTi fertilizer; 2xTi0.2 – two applications of MgTi in the dose of 0.2 l/ha; 3xTi0.2 – three applications of MgTi in the dose of 0.2 l/ha; 2xTi0.4 – two applications of MgTi in the dose of 0.4 l/ha; 3xTi0.4 – three applications of MgTi in the dose of 0.4 l/ha. The fertilizer was applied in spring during two, or three different growth stages: BBCH 50, BBCH 59, BBCH 66. The first plant sampling was carried out shortly before the first application of fertilizer (BBCH 50. The second, third and fourth sampling was taken 2–3 weeks after the application of Mg-Titanitu (BBCH 59, BBCH 66, BBCH 71. The obtained results showed that the titanium content in the phytomass of rape was falling during the monitored period. The titanium content in the rape aboveground phytomass varied in the interval from 16.81 to 67.6 mg/kg and in the root in the interval from 56.6 to 258.81 mg/kg. The titanium application on plant leaves in the quantities from 3.4 to 10.2 g per hectare of soil did not have the unambiguous impact on the titanium content in the rape phytomass. In the yield of one tonne of seed and appropriate quantity of rape straw on average 20 grams of titanium was taken in.

Radius scaling of titanium wire arrays on the Z accelerator

International Nuclear Information System (INIS)

Coverdale, C.A.; Denney, C.; Spielman, R.B.

1999-01-01

The 20 MA Z accelerator has made possible the generation of substantial radiation (> 100 kJ) at higher photon energies (4.8 keV) through the use of titanium wire arrays. In this paper, the results of experiments designed to study the effects of initial load radius variations of nickel-clad titanium wire arrays will be presented. The load radius was varied from 17.5 mm to 25 mm and titanium K-shell (4.8 keV) yields of greater than 100 kJ were measured. The inclusion of the nickel cladding on the titanium wires allows for higher wire number loads and increases the spectral broadness of the source; kilovolt emissions (nickel plus titanium L-shell) of 400 kJ were measured in these experiments. Comparisons of the data to calculations will be made to estimate pinched plasma parameters such as temperature and participating mass fraction. These results will also be compared with previous pure titanium wire array results

Colloidal Plasmonic Titanium Nitride Nanoparticles: Properties and Applications

DEFF Research Database (Denmark)

Guler, Urcan; Suslov, Sergey; Kildishev, Alexander V.

2015-01-01

Optical properties of colloidal plasmonic titanium nitride nanoparticles are examined with an eye on their photothermal and photocatalytic applications via transmission electron microscopy and optical transmittance measurements. Single crystal titanium nitride cubic nanoparticles with an average ...

Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein.

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Andreas Baranowski

Full Text Available Orthopedic implant failure due to aseptic loosening and mechanical instability remains a major problem in total joint replacement. Improving osseointegration at the bone-implant interface may reduce micromotion and loosening. Bone sialoprotein (BSP has been shown to enhance bone formation when coated onto titanium femoral implants and in rat calvarial defect models. However, the most appropriate method of BSP coating, the necessary level of BSP coating, and the effect of BSP coating on cell behavior remain largely unknown. In this study, BSP was covalently coupled to titanium surfaces via an aminosilane linker (APTES, and its properties were compared to BSP applied to titanium via physisorption and untreated titanium. Cell functions were examined using primary human osteoblasts (hOBs and L929 mouse fibroblasts. Gene expression of specific bone turnover markers at the RNA level was detected at different intervals. Cell adhesion to titanium surfaces treated with BSP via physisorption was not significantly different from that of untreated titanium at any time point, whereas BSP application via covalent coupling caused reduced cell adhesion during the first few hours in culture. Cell migration was increased on titanium disks that were treated with higher concentrations of BSP solution, independent of the coating method. During the early phases of hOB proliferation, a suppressive effect of BSP was observed independent of its concentration, particularly when BSP was applied to the titanium surface via physisorption. Although alkaline phosphatase activity was reduced in the BSP-coated titanium groups after 4 days in culture, increased calcium deposition was observed after 21 days. In particular, the gene expression level of RUNX2 was upregulated by BSP. The increase in calcium deposition and the stimulation of cell differentiation induced by BSP highlight its potential as a surface modifier that could enhance the osseointegration of orthopedic implants

Mean-square displacement of atomic complex in titanium carbonitrides TiCxNy

International Nuclear Information System (INIS)

Khidirov, I.; Sultanova, S.Kh.; Mukhtarova, N.N.; Tokhtashev, B.

2004-01-01

Full text: The atomic mean-square displacement (MSD) is one of important characteristics of solids, and one can use it for determination of a number of other characteristics of substances. In this work the MSD of atomic complex were determined for a number of compositions of the cubic titanium carbonitrides TiC x N y using the neutron powder diffraction data. The error of MSD determination was less than 3 %. When determining intensity of diffraction maximum a correction for the thermal diffusion dispersion (TDD) was included in the neutron diffraction patterns. The contribution of TDD in the intensity of diffraction maxima was found to be less than the experiment error (no more than 1,5 %). Such small value of the TDD correction is explained by refractory of materials. The values of MSD in titanium carbonitrides for a number of compositions, determined by the neutron powder diffraction measurements, are given. It is shown, that the dependence of MSD on the concentration (C+N)/Ti has a complex character. With decrease of the total content of metalloids MSD decreases at first, reaching a minimum about concentration (C+N)/Ti≅0.80, and then increases. MSD consists of dynamic and static distortions, where the static distortions in the compounds with variable composition increase with increasing of deviation from stoichiometry. The above anomaly in the dependence of MSD on the total concentration of metalloids, apparently, point to prevalence of dynamic distortions over static ones and to complex character of concentration dependence of interatomic interactions in the titanium carbonitrides. This work was supported by the Supporting Fund for Fundamental Researches of Uzbekistan Academy of Sciences (Grant No. 6-04)

Low temperature study of nonstoichiometric titanium carbide

International Nuclear Information System (INIS)

Tashmetov, M.Yu.

2005-05-01

By low temperature neutron diffraction method was studied structure in nonstoichiometric titanium carbide from room temperature up to 12K. It is found of low temperature phase in titanium carbide- TiC 0.71 . It is established region and borders of this phase. It is determined change of unit cell parameter. (author)

A Modified Porous Titanium Sheet Prepared by Plasma-Activated Sintering for Biomedical Applications

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Yukimichi Tamaki

2010-01-01

Full Text Available This study aimed to develop a contamination-free porous titanium scaffold by a plasma-activated sintering within an originally developed TiN-coated graphite mold. The surface of porous titanium sheet with or without a coated graphite mold was characterized. The cell adhesion property of porous titanium sheet was also evaluated in this study. The peak of TiC was detected on the titanium sheet processed with the graphite mold without a TiN coating. Since the titanium fiber elements were directly in contact with the carbon graphite mold during processing, surface contamination was unavoidable event in this condition. The TiC peak was not detectable on the titanium sheet processed within the TiN-coated carbon graphite mold. This modified plasma-activated sintering with the TiN-coated graphite mold would be useful to fabricate a contamination-free titanium sheet. The number of adherent cells on the modified titanium sheet was greater than that of the bare titanium plate. Stress fiber formation and the extension of the cells were observed on the titanium sheets. This modified titanium sheet is expected to be a new tissue engineering material in orthopedic bone repair.

Multicycle mechanical performance of titanium and stainless steel transpedicular spine implants.

Science.gov (United States)

Pienkowski, D; Stephens, G C; Doers, T M; Hamilton, D M

1998-04-01

This was a prospective in vitro study comparing titanium alloy and stainless steel alloy in transpedicular spine implants from two different manufactures. To compare the multicycle mechanical performance of these two alloys, used in each of two different implant designs. Transpedicular spine implants primarily have been manufactured from stainless steel, but titanium alloy offers imaging advantages. However, the notch sensitivity of titanium alloy has caused concern regarding how implants made from this material will compare in stiffness and fatigue life with implants made from stainless steel. Twenty-four implants (two alloys, two designs, six implants per group) were mounted in machined polyethylene wafers and repetitively loaded (up to 1 million cycles) from 80 N to 800 N using a 5-Hertz sinusoidal waveform. Load and displacement data were automatically and periodically sampled throughout the entire test. Implant stiffness increased with cycle load number, reached a steady state, then declined just before fatigue failure. Stiffness varied less in titanium transpedicular spine implants than in their stainless counterparts. All stainless steel implant types were stiffer (steady-state value, P titanium alloy counterparts. One titanium implant design failed with fewer (P stainless steel counterpart, whereas a stainless steel implant of another design failed with fewer (P titanium counterpart. Overall, fatigue life, i.e., the total number of load cycles until failure, was related to implant type (P implant material. A transpedicular spine implant's fatigue lifetime depends on both the design and the material and cannot be judged on material alone. Stainless steel implants are stiffer than titanium alloy implants of equal design and size; however, for those designs in which the fatigue life of the titanium alloy version is superior, enlargement of the implant's components can compensate for titanium's lower modulus of elasticity and result in an implant equally stiff

Processing of spent pickling liquor formed during treatment of titanium products

Science.gov (United States)

Bykovsky, N. A.; Rahman, P. A.; Puchkova, L. N.; Fanakova, N. N.

2017-10-01

The article presents the research findings on processing of spent acid pickling liquor (SAPL) formed during etching of titanium products. The processing includes neutralizing the SAPL with alkali, filtering, drying and calcining the titanium hydroxide precipitate as well as electrochemical processing of the filtrate in an ion-exchange membrane cell. The proposed SAPL processing procedure allows obtaining titanium dioxide, sodium hydroxide and a mixture of acids. Titanium dioxide can be used in paint-and-varnish industry. The alkali can be used in neutralizing the SAPL. A mixture of acids is suitable for use in etching process of titanium products.

A Novel Technique for the Connection of Ceramic and Titanium Implant Components Using Glass Solder Bonding

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Enrico Mick

2015-07-01

Full Text Available Both titanium and ceramic materials provide specific advantages in dental implant technology. However, some problems, like hypersensitivity reactions, corrosion and mechanical failure, have been reported. Therefore, the combining of both materials to take advantage of their pros, while eliminating their respective cons, would be desirable. Hence, we introduced a new technique to bond titanium and ceramic materials by means of a silica-based glass ceramic solder. Cylindrical compound samples (Ø10 mm × 56 mm made of alumina toughened zirconia (ATZ, as well as titanium grade 5, were bonded by glass solder on their end faces. As a control, a two-component adhesive glue was utilized. The samples were investigated without further treatment, after 30 and 90 days of storage in distilled water at room temperature, and after aging. All samples were subjected to quasi-static four-point-bending tests. We found that the glass solder bonding provided significantly higher bending strength than adhesive glue bonding. In contrast to the glued samples, the bending strength of the soldered samples remained unaltered by the storage and aging treatments. Scanning electron microscopy (SEM and energy-dispersive X-ray (EDX analyses confirmed the presence of a stable solder-ceramic interface. Therefore, the glass solder technique represents a promising method for optimizing dental and orthopedic implant bondings.

Corrosion of gold alloys and titanium in artificial saliva

International Nuclear Information System (INIS)

Brune, D.; Evje, D.

1982-01-01

Two types of gold alloys and one type of pure titanium have been submitted to corrosion in artificial saliva for periods of up to about 2 months. The release of copper, gold and silver from the gold alloys as well as titanium from the titanium matrix was measured with nuclear tracer technique. The physical/chemical state of the corrosion products of gold alloys referring to the ionic state or presence in particulate form has been examined retaining the particulate matter on a glass filter. Copper was observed to be mainly present in the ionic state. Considerable amounts of gold were observed to be retained on the glass filter explained by the presence of gold in particulate form or as a compentent of a dispersed collloidal phase. The estimation of the release of titanium was registered by the tracer nuclide 46 Sc assuming particulate matter to be deteriorated from the titanium surface. (author)

Characterization for rbs of Titanium Oxide thin films grown by Dip Coating in a coloidal suspension of nano structured Titanium Oxide

International Nuclear Information System (INIS)

Pedrero, E.; Vigil, E.; Zumeta, I.

1999-01-01

The depth of Titanium Oxide thin films grown by Dip Coating in a coloidal suspension of nano structured Titanium Oxide was characterized using Rutherford Backscattering Spectrometry. Film depths are compared in function of bath and suspension parameters

Nonmetal effect on ordering structures in titanium carbide

International Nuclear Information System (INIS)

Tashmetov, M.Yu.; Ehm, V.T.; Savenko, B.M.

1997-01-01

The effect of oxygen and nitrogen atoms on formation of intermediate, cubic and trigonal ordering structures in the titanium carbide is studied through the roentgenography and neutron radiography methods. Metal atoms in the TiC 0.545 O 0.08 , TiC 0.545 N 0.09 samples under study are shifted from ideal positions in the direction from vacancies to metalloid atoms. In the intermediate cubic phase the values of the titanium atoms free parameter in both samples are identical, but they differ from analogous values in the titanium carbide

On the principles of microstructure scale development for titanium alloys

International Nuclear Information System (INIS)

Kolachev, B.A.; Mal'kov, A.V.; Gus'kova, L.N.

1982-01-01

Analysis of an existing standard scale of microstructures for two-phase (α+#betta#)-titanium alloy semiproducts is given. The basic principles of development of control microstructure scales for titanium alloys are presented on the base of investigations and generalization of literature data on connection of microstructure of titanium intermediate products from (α+#betta#)-alloys with their mechanical properties and service life characteristics. A possibilities of changing mechanical and operating properties at the expense of obtaining qualitatively and quantitatively regulated microstructure in the alloy are disclosed on the example of the (α+#betta#)-titanium alloy

Laser induced single spot oxidation of titanium

Energy Technology Data Exchange (ETDEWEB)

Jwad, Tahseen, E-mail: taj355@bham.ac.uk; Deng, Sunan; Butt, Haider; Dimov, S.

2016-11-30

Highlights: • A new high resolution laser induced oxidation (colouring) method is proposed (single spot oxidation). • The method is applied to control oxide films thicknesses and hence colours on titanium substrates in micro-scale. • The method enable imprinting high resolution coloured image on Ti substrate. • Optical and morphological periodic surface structures are also produced by an array of oxide spots using the proposed method. • Colour coding of two colours into one field is presented. - Abstract: Titanium oxides have a wide range of applications in industry, and they can be formed on pure titanium using different methods. Laser-induced oxidation is one of the most reliable methods due to its controllability and selectivity. Colour marking is one of the main applications of the oxidation process. However, the colourizing process based on laser scanning strategies is limited by the relative large processing area in comparison to the beam size. Single spot oxidation of titanium substrates is proposed in this research in order to increase the resolution of the processed area and also to address the requirements of potential new applications. The method is applied to produce oxide films with different thicknesses and hence colours on titanium substrates. High resolution colour image is imprinted on a sheet of pure titanium by converting its pixels’ colours into laser parameter settings. Optical and morphological periodic surface structures are also produced by an array of oxide spots and then analysed. Two colours have been coded into one field and the dependencies of the reflected colours on incident and azimuthal angles of the light are discussed. The findings are of interest to a range of application areas, as they can be used to imprint optical devices such as diffusers and Fresnel lenses on metallic surfaces as well as for colour marking.

Laser induced single spot oxidation of titanium

International Nuclear Information System (INIS)

Jwad, Tahseen; Deng, Sunan; Butt, Haider; Dimov, S.

2016-01-01

Highlights: • A new high resolution laser induced oxidation (colouring) method is proposed (single spot oxidation). • The method is applied to control oxide films thicknesses and hence colours on titanium substrates in micro-scale. • The method enable imprinting high resolution coloured image on Ti substrate. • Optical and morphological periodic surface structures are also produced by an array of oxide spots using the proposed method. • Colour coding of two colours into one field is presented. - Abstract: Titanium oxides have a wide range of applications in industry, and they can be formed on pure titanium using different methods. Laser-induced oxidation is one of the most reliable methods due to its controllability and selectivity. Colour marking is one of the main applications of the oxidation process. However, the colourizing process based on laser scanning strategies is limited by the relative large processing area in comparison to the beam size. Single spot oxidation of titanium substrates is proposed in this research in order to increase the resolution of the processed area and also to address the requirements of potential new applications. The method is applied to produce oxide films with different thicknesses and hence colours on titanium substrates. High resolution colour image is imprinted on a sheet of pure titanium by converting its pixels’ colours into laser parameter settings. Optical and morphological periodic surface structures are also produced by an array of oxide spots and then analysed. Two colours have been coded into one field and the dependencies of the reflected colours on incident and azimuthal angles of the light are discussed. The findings are of interest to a range of application areas, as they can be used to imprint optical devices such as diffusers and Fresnel lenses on metallic surfaces as well as for colour marking.

Environmental effects in titanium aluminide alloys

International Nuclear Information System (INIS)

Thompson, A.W.

1991-01-01

Environmental effects on titanium aluminide alloys are potentially of great importance for engineering applications of these materials, although little has been published to date on such effects. The primary emphasis in this paper is on hydrogen effects, with a brief reference to oxygen effects. Hydrogen is readily absorbed at elevated temperature into all the titanium aluminide compositions studied to date, in amounts as large as 10 at.%, and on cooling virtually all this hydrogen is precipitated as a hydride phase or phases. The presence of these precipitated hydride plates affects mechanical properties in ways similar to what is observed in other hydride forming materials, although effects per unit volume of hydride are not particularly severe in the titanium aluminides. Microstructure, and thus thermal and mechanical history, plays a major role in controlling the severity of hydrogen effects

Spectroscopy and titanium gettering in SPHEX

International Nuclear Information System (INIS)

Cunningham, G.; Giroud, C.; Summers, H.; Commission of the European Communities, Abingdon

1994-01-01

SPHEX is a spheromak wherein the toroidal and poloidal currents are generated and sustained by direct current injection from a Marshall gun, and organised by the effect of magnetic relaxation. In the past it has not achieved high temperature (Langmuir probes indicate a flat profile of about 20 eV), and this was thought to be due to radiation from impurities originating in the Marshall gun. For this paper, titanium has been applied to the plasma-facing surface of the flux conserver in an attempt to reduce impurity levels and plasma density. Calibrated spectrometers were used to measure plasma properties and impurity levels, both before and after application of titanium. The titanium is also found to have a surprisingly large effect on the magnetic properties, which gives some evidence regarding the relaxation mechanism. 7 refs., 2 figs., 1 tab

Effect of cathodic polarization on coating doxycycline on titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Geißler, Sebastian; Tiainen, Hanna; Haugen, Håvard J., E-mail: h.j.haugen@odont.uio.no

2016-06-01

Cathodic polarization has been reported to enhance the ability of titanium based implant materials to interact with biomolecules by forming titanium hydride at the outermost surface layer. Although this hydride layer has recently been suggested to allow the immobilization of the broad spectrum antibiotic doxycycline on titanium surfaces, the involvement of hydride in binding the biomolecule onto titanium remains poorly understood. To gain better understanding of the influence this immobilization process has on titanium surfaces, mirror-polished commercially pure titanium surfaces were cathodically polarized in the presence of doxycycline and the modified surfaces were thoroughly characterized using atomic force microscopy, electron microscopy, secondary ion mass spectrometry, and angle-resolved X-ray spectroscopy. We demonstrated that no hydride was created during the polarization process. Doxycycline was found to be attached to an oxide layer that was modified during the electrochemical process. A bacterial assay using bioluminescent Staphylococcus epidermidis Xen43 showed the ability of the coating to reduce bacterial colonization and planktonic bacterial growth. - Highlights: • Titanium hydride was found not to be involved in immobilization of doxycycline. • Doxycycline coating was strongly bound to a modified surface oxide layer. • Effect of coatings tested using a dynamic bacteria assay based on bioluminescence. • Topmost layer of adsorbed doxycycline was shown to have strong antibacterial effect.

Reaction of titanium polonides with carbon dioxide

International Nuclear Information System (INIS)

Abakumov, A.S.; Malyshev, M.L.; Reznikova, N.F.

1987-01-01

It has been ascertained that heating titanium and tantalum in carbon dioxide to temperatures of 500 or 800 0 C alters the composition of the gas phase, causing the advent of carbon monoxide and lowering the oxygen content. Investigation of the thermal stability of titanium polonides in a carbon dioxide medium has shown that titanium mono- and hemipolonides are decomposed at temperatures below 350 0 C. The temperature dependence of the vapor pressure of polonium produced in the decomposition of these polonides in a carbon dioxide medium have been determined by a radiotensimetric method. The enthalpy of the process, calculated from this relationship, is close to the enthalpy of vaporization of elementary polonium in vacuo

Electrodeposition of amine-terminatedpoly(ethylene glycol) to titanium surface

International Nuclear Information System (INIS)

Tanaka, Yuta; Doi, Hisashi; Iwasaki, Yasuhiko; Hiromoto, Sachiko; Yoneyama, Takayuki; Asami, Katsuhiko; Imai, Hachiro; Hanawa, Takao

2007-01-01

The immobilization of poly(ethylene glycol), PEG, to a solid surface is useful to functionalize the surface, e.g., to prevent the adsorption of proteins. No successful one-stage technique for the immobilization of PEG to base metals has ever been developed. In this study, PEG in which both terminals or one terminal had been modified with amine bases was immobilized onto a titanium surface using electrodeposition. PEG was dissolved in a NaCl solution, and electrodeposition was carried out at 310 K with - 5 V for 300 min. The thickness of the deposited PEG layer was evaluated using ellipsometry, and the bonding manner of PEG to the titanium surface was characterized using X-ray photoelectron spectroscopy after electrodeposition. The results indicated that a certain amount of PEG was adsorbed on titanium through both electrodeposition and immersion when PEG was terminated by amine. However, terminated amines existed at the surface of titanium and were combined with titanium oxide as N-HO by electrodeposition, while amines randomly existed in the molecule and showed an ionic bond with titanium oxide by immersion. The electrodeposition of PEG was effective for the inhibition of albumin adsorption. This process is useful for materials that have electroconductivity and a complex morphology

Lysophosphatidic acid-functionalised titanium as a superior surface for supporting human osteoblast (MG63 maturation

Directory of Open Access Journals (Sweden)

JP Mansell

2012-05-01

Full Text Available Covalent modifications of titanium with small molecules known to promote human osteoblast maturation are especially attractive in developing superior biomaterials. An important step in securing competent bone formation at implant sites is promoting the formation of mature osteoblasts, either from committed pre-osteoblasts or from their mesenchymal progenitors. To this end our research has focussed on identifying molecules that enhance human osteoblast formation and maturation and to develop ways of covalently attaching these molecules to implant surfaces so that they are more likely to withstand the rigors of the implantation process whilst still retaining their bioactivity. Herein we report the novel production of lipid-functionalised titanium using lysophosphatidic acid or a related compound, (3S 1-fluoro-3-hydroxy-4-butyl-1-phosphonate. Both lipids were especially effective at co-operating with calcitriol to promote human osteoblast maturation at these modified Ti surfaces in vitro. The novel findings presented offer enticing new developments towards the fabrication of next-generation implant devices with the potential to significantly enhance the osseointegration process and with it improvements in future prosthesis performance and longevity.

Electroplating on titanium alloy

Science.gov (United States)

Lowery, J. R.

1971-01-01

Activation process forms adherent electrodeposits of copper, nickel, and chromium on titanium alloy. Good adhesion of electroplated deposits is obtained by using acetic-hydrofluoric acid anodic activation process.

Machinability evaluation of titanium alloys.

Science.gov (United States)

Kikuchi, Masafumi; Okuno, Osamu

2004-03-01

In the present study, the machinability of titanium, Ti-6Al-4V, Ti-6A1-7Nb, and free-cutting brass was evaluated using a milling machine. The metals were slotted with square end mills under four cutting conditions. The cutting force and the rotational speed of the spindle were measured. The cutting forces for Ti-6Al-4V and Ti-6Al-7Nb were higher and that for brass was lower than that for titanium. The rotational speed of the spindle was barely affected by cutting. The cross sections of the Ti-6Al-4V and Ti-6Al-7Nb chips were more clearly serrated than those of titanium, which is an indication of difficult-to-cut metals. There was no marked difference in the surface roughness of the cut surfaces among the metals. Cutting force and the appearance of the metal chips were found to be useful as indices of machinability and will aid in the development of new alloys for dental CAD/CAM and the selection of suitable machining conditions.

Titanium Dioxide Nanoparticles in Food and Personal Care Products

Science.gov (United States)

Weir, Alex; Westerhoff, Paul; Fabricius, Lars

2012-01-01

Titanium dioxide is a common additive in many food, personal care, and other consumer products used by people, which after use can enter the sewage system, and subsequently enter the environment as treated effluent discharged to surface waters or biosolids applied to agricultural land, incinerated wastes, or landfill solids. This study quantifies the amount of titanium in common food products, derives estimates of human exposure to dietary (nano-) TiO2, and discusses the impact of the nanoscale fraction of TiO2 entering the environment. The foods with the highest content of TiO2 included candies, sweets and chewing gums. Among personal care products, toothpastes and select sunscreens contained 1% to >10% titanium by weight. While some other crèmes contained titanium, despite being colored white, most shampoos, deodorants, and shaving creams contained the lowest levels of titanium (TiO2 (E171) suggests that approximately 36% of the particles are less than 100 nm in at least one dimension and that it readily disperses in water as fairly stable colloids. However, filtration of water solubilized consumer products and personal care products indicated that less than 5% of the titanium was able to pass through 0.45 or 0.7 μm pores. Two white paints contained 110 μg Ti/mg while three sealants (i.e., prime coat paint) contained less titanium (25 to 40 μg Ti/mg). This research showed that while many white-colored products contained titanium, it was not a prerequisite. Although several of these product classes contained low amounts of titanium, their widespread use and disposal down the drain and eventually to WWTPs deserves attention. A Monte Carlo human exposure analysis to TiO2 through foods identified children as having the highest exposures because TiO2 content of sweets is higher than other food products, and that a typical exposure for a US adult may be on the order of 1 mg Ti per kilogram body weight per day. Thus, because of the millions of tons of titanium based

Crystalline hydroxyapatite coatings synthesized under hydrothermal conditions on modified titanium substrates

International Nuclear Information System (INIS)

Suchanek, Katarzyna; Bartkowiak, Amanda; Gdowik, Agnieszka; Perzanowski, Marcin; Kąc, Sławomir; Szaraniec, Barbara; Suchanek, Mateusz; Marszałek, Marta

2015-01-01

Hydroxyapatite coatings were successfully produced on modified titanium substrates via hydrothermal synthesis in a Ca(EDTA) 2− and (NH 4 ) 2 HPO 4 solution. The morphology of modified titanium substrates as well as hydroxyapatite coatings was studied using scanning electron microcopy and phase identification by X-ray diffraction, and Raman and FTIR spectroscopy. The results show that the nucleation and growth of hydroxyapatite needle-like crystals with hexagonal symmetry occurred only on titanium substrates both chemically and thermally treated. No hydroxyapatite phase was detected on only acid etched Ti metal. This finding demonstrates that only a particular titanium surface treatment can effectively induce the apatite nucleation under hydrothermal conditions. - Highlights: • Bioactivation of titanium substrate by chemical and heat treatments • Precipitation of hydroxyapatite on modified titanium plates • Hydrothermal crystallization of hydroxyapatite by chelate decomposition method

Effect of titanium on microstructural changes in SUS 316 stainless steels

International Nuclear Information System (INIS)

Kawanishi, H.; Yamada, M.; Fukuya, K.; Ishino, S.

1982-01-01

The microstructural changes have been examined in order to study the effect of titanium addition to type 316 stainless steels on void swelling. Titanium ions of 400 keV from an accelerator have been implanted at room temperature to solution treated SUS 316 stainless steels which have the original titanium content of 0.02 wt.% to the concentration increase of titanium by 0.01, 0.02 and 0.1 wt.%. Following the preinjection of 20 at.ppm helium at ambient temperature, 400 keV-aluminium ions have been irradiated to the specimen to 40 dpa at 550, 625 and 675 0 C. The TEM observations have revealed that the void number density is drastically increased in the specimen with the content of implanted titanium of more than 0.01 wt.%, whereas the void diameter is remarkably decreased with the titanium content. (orig.)

Biocompatibility of titanium based implants treated with plasma immersion ion implantation

International Nuclear Information System (INIS)

Maendl, S.; Sader, R.; Thorwarth, G.; Krause, D.; Zeilhofer, H.-F.; Horch, H.H.; Rauschenbach, B.

2003-01-01

In this work, the biocompatibility of titanium before and after oxygen PIII is investigated using a rat animal model. Pure titanium (grade 2) and pre-anodized titanium were implanted with oxygen at elevated temperatures between 200 and 550 deg. C and subsequently analyzed for oxygen content and phase composition. No deterioration of the tensile strength and the yield strength was detected after the implantation. The mechanical stability of the osseointegration was determined with a pull-out test, where an increased shear strength was measured after PIII treatment. Only a slight improvement of the bone contact area, from an already excellent starting value, was observed for pure titanium. In contrast, a significant improvement was found for anodized titanium after PIII treatment. This astonishing difference can be explained with the surface topography and the phase composition of the anodized titanium samples

Crystalline hydroxyapatite coatings synthesized under hydrothermal conditions on modified titanium substrates

Energy Technology Data Exchange (ETDEWEB)

Suchanek, Katarzyna, E-mail: Katarzyna.Suchanek@ifj.edu.pl [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland); Bartkowiak, Amanda [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland); Gdowik, Agnieszka [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow (Poland); Perzanowski, Marcin [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland); Kąc, Sławomir [Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Mickiewica 30, 30-059 Krakow (Poland); Szaraniec, Barbara [Department of Biomaterials, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow (Poland); Suchanek, Mateusz [Department of Chemistry and Physics, University of Agriculture in Krakow, Mickiewicza 21, 31-120 Krakow (Poland); Marszałek, Marta [The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Street 152, 31-342 Krakow (Poland)

2015-06-01

Hydroxyapatite coatings were successfully produced on modified titanium substrates via hydrothermal synthesis in a Ca(EDTA){sup 2−} and (NH{sub 4}){sub 2}HPO{sub 4} solution. The morphology of modified titanium substrates as well as hydroxyapatite coatings was studied using scanning electron microcopy and phase identification by X-ray diffraction, and Raman and FTIR spectroscopy. The results show that the nucleation and growth of hydroxyapatite needle-like crystals with hexagonal symmetry occurred only on titanium substrates both chemically and thermally treated. No hydroxyapatite phase was detected on only acid etched Ti metal. This finding demonstrates that only a particular titanium surface treatment can effectively induce the apatite nucleation under hydrothermal conditions. - Highlights: • Bioactivation of titanium substrate by chemical and heat treatments • Precipitation of hydroxyapatite on modified titanium plates • Hydrothermal crystallization of hydroxyapatite by chelate decomposition method.

[Corrosion resistant properties of different anodized microtopographies on titanium surfaces].

Science.gov (United States)

Fangjun, Huo; Li, Xie; Xingye, Tong; Yueting, Wang; Weihua, Guo; Weidong, Tian

2015-12-01

To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies. Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid. Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr. Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.

Fiscal 1998 achievement report on regional consortium research and development project. Research and development for developing basic technologies of composite laser-aided metal machining into highly advanced system (Technology of machining process systematization for furnishing titanium and titanium alloys with advanced functions - 2nd year); 1998 nendo fukugo laser nado ni yoru kinzoku kako kiban gijutsu no kodo system ka no kenkyu kaihatsu seika hokokusho. 2. Chitan oyobi chitan gokin eno kokino fuyo kako system ka gijutsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the creation of new industries and for their expansion to the consumer market, efforts are made to develop laser-aided technology of bonding titanium with other metals and CAD/CAM (computer-aided design/computer-aided manufacture)-aided technology of high-precision multidimensional laser machining for titanium. In the development of technology for bonding titanium and other metals, combinations of titanium and stainless steel and titanium and copper are examined, and a dissimilar metal joint is successfully manufactured, free of cracks at a tension shear strength level of approximately 4200N/40mm and shear stress of 200MPa or higher. In the study of the mechanism of bonding, it is found that a sound weld metal is created with the formation of intermetallic compounds well inhibited by allowing titanium to be on the upper surface. In the study of laser-aided titanium cutting, a dross-free cutting process is realized by optimizing cutting conditions such as those involving laser excitation and assist gas application. Three-dimensional laser-aided cutting is carried out in compliance with a 3-dimensional laser cutting program incorporating metal pattern data, and the process is found to reduce the number of necessary dies to 1/4 to shorten and simplify the process. (NEDO)

Lifetime of titanium filament at constant current

International Nuclear Information System (INIS)

Chou, T.S.; Lanni, C.

1981-01-01

Titanium Sublimation Pump (TSP) represents the most efficient and the least expensive method to produce Ultra High Vacuum (UHV) in storage rings. In ISABELLE, a proton storage accelerator under construction at Brookhaven National Laboratory, for example, TSP provides a pumping speed for hydrogen of > 2 x 10 6 l/s. Due to the finite life of titanium filaments, new filaments have to be switched in before the end of filament burn out, to ensure smooth operation of the accelerator. Therefore, several operational modes that can be used to activate the TSP were studied. The constant current mode is a convenient way of maintaining constant evaporating rate by increasing the power input while the filament diameter decreases as titanium evaporates. The filaments used in this experiment were standard Varian 916-0024 filaments made of Ti 85%, Mo 15% alloy. During their lifetime at a constant current of 48 amperes, the evaporation rate rose to a maximum at about 10% of their life and then flattened out to a constant value, 0.25 g/hr. The maximum evaporation rate occurs coincidently with the recrystallization of 74% Ti 26% Mo 2 from microstructure crystalline at higher titanium concentration to macrostructure crystalline at lower titanium concentration. As the macrocrystal grows, the slip plane develops at the grain boundary resulting in high resistance at the slip plane which will eventually cause the filament burn out due to local heating

Influence of stoichiometry on electrochromic cerium-titanium oxide compounds

International Nuclear Information System (INIS)

Kullman, L.; Richardson, T.; Rubin, M.; Slack, J.; Rottkay, K. von

1997-01-01

CeO 2 -TiO 2 finds use as passive counter-electrode in electrochromic devices. Thin films were produced by de-sputtering in a wide range of compositions. Influence of total pressure and oxygen partial pressure on the optical constants of TiO 2 was investigated. Slightly substoichiometric Ti0 2 films exhibit a red-shift of the bandgap. The Ti0 2 content in the compound essentially determines the degree of cathodical coloring upon Li + intercalation [1]. However, pure TiO 2 films with comparable visible transmittance in the clear state behave differently during electrochemical cycling depending on oxygen stoichiometry. Films that are deposited at higher total pressure are more oxygen rich and require initial formatting until current voltage cycles become stable. CeO 2 -Ti0 2 films of intermediate compositions have the relatively highest charge capacity. Comparison with atomic force microscopy indicates a correlation of small grain size with high charge capacity

Method for synthesis of titanium dioxide nanotubes using ionic liquids

Science.gov (United States)

Qu, Jun; Luo, Huimin; Dai, Sheng

2013-11-19

The invention is directed to a method for producing titanium dioxide nanotubes, the method comprising anodizing titanium metal in contact with an electrolytic medium containing an ionic liquid. The invention is also directed to the resulting titanium dioxide nanotubes, as well as devices incorporating the nanotubes, such as photovoltaic devices, hydrogen generation devices, and hydrogen detection devices.

Highly selective enrichment of phosphorylated peptides using titanium dioxide

DEFF Research Database (Denmark)

Thingholm, Tine; Jørgensen, Thomas J D; Jensen, Ole N

2006-01-01

-column. Although phosphopeptide enrichment can be achieved by using TFA and acetonitrile alone, the selectivity is dramatically enhanced by adding DHB or phthalic acid since these compounds, in conjunction with the low pH caused by TFA, prevent binding of nonphosphorylated peptides to TiO2. Using an alkaline...... a protocol for selective phosphopeptide enrichment using titanium dioxide (TiO2) chromatography. The selectivity toward phosphopeptides is obtained by loading the sample in a 2,5-dihydroxybenzoic acid (DHB) or phthalic acid solution containing acetonitrile and trifluoroacetic acid (TFA) onto a TiO2 micro...... solution (pH > or = 10.5) both monophosphorylated and multiphosphorylated peptides are eluted from the TiO2 beads. This highly efficient method for purification of phosphopeptides is well suited for the characterization of phosphoproteins from both in vitro and in vivo studies in combination with mass...

A novel approach to fabrication of three-dimensional porous titanium with controllable structure

Energy Technology Data Exchange (ETDEWEB)

Wang, Dong; Li, Qiuyan; Xu, Mingqin; Jiang, Guofeng; Zhang, Yunxia [Shanghai Key Laboratory of Materials Laser Processing and Modification, and State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); He, Guo, E-mail: ghe@sjtu.edu.cn [Shanghai Key Laboratory of Materials Laser Processing and Modification, and State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240 (China)

2017-02-01

A new approach to fabrication of porous titanium by using the molybdenum wire as space holder was developed, in which titanium liquid was cast into the entangled molybdenum wires in a vacuum environment, and followed by etching off the space holder material in an aqua regia solution. This infiltration casting and acid corrosion method fabricated the porous titanium with different porosities with a pore diameter of 0.4 mm. The porous titanium with the porosity of 32–47% exhibited the Young's modulus in the range of 23–62 GPa and the yielding strength in the range of 76–192 MPa. The adhesion and spreadability of the bovine osteoblast cells on the porous titanium were also evaluated in vitro. The porous titanium with 47% porosity has great potential for implant applications. - Highlights: • A new approach to fabrication of porous titanium was developed. • The 3D morphology of the interconnected porous structure can be exactly controlled. • The as-prepared porous titanium exhibits adequate yielding strength. • The elastic modulus of the porous titanium matches well with that of cortical bone. • The as-prepared porous titanium has great potential for implant applications.

Influence of friction stir welding parameters on titanium-aluminum heterogeneous lap joining configuration

Science.gov (United States)

Picot, Florent; Gueydan, Antoine; Hug, Éric

2017-10-01

Lap joining configuration for Friction Stir Welding process is a methodology mostly dedicated to heterogeneous bonding. This welding technology was applied to join pure titanium with pure aluminum by varying the rotation speed and the movement speed of the tool. Regardless of the process parameters, it was found that the maximum strength of the junction remains almost constant. Microstructural observations by means of Scanning Electron Microscopy and Energy Dispersive Spectrometry analysis enable to describe the interfacial join and reveal asymmetric Cold Lap Defects on the sides of the junction. Chemical analysis shows the presence of one exclusive intermetallic compound through the interface identified as TiAl3. This compound is responsible of the crack spreading of the junction during the mechanical loading. The original version of this article supplied to AIP Publishing contained an accidental inversion of the authors, names. An updated version of this article, with the authors names formatted correctly was published on 20 October 2017.

In situ hydride formation in titanium during focused ion milling.

Science.gov (United States)

Ding, Rengen; Jones, Ian P

2011-01-01

It is well known that titanium and its alloys are sensitive to electrolytes and thus hydrides are commonly observed in electropolished foils. In this study, focused ion beam (FIB) milling was used to prepare thin foils of titanium and its alloys for transmission electron microscopy. The results show the following: (i) titanium hydrides were observed in pure titanium, (ii) the preparation of a bulk sample in water or acid solution resulted in the formation of more hydrides and (iii) FIB milling aids the precipitation of hydrides, but there were never any hydrides in Ti64 and Ti5553.

Local heating with titanium nitride nanoparticles

DEFF Research Database (Denmark)

Guler, Urcan; Ndukaife, Justus C.; Naik, Gururaj V.

2013-01-01

We investigate the feasibility of titanium nitride (TiN) nanoparticles as local heat sources in the near infrared region, focusing on biological window. Experiments and simulations provide promising results for TiN, which is known to be bio-compatible.......We investigate the feasibility of titanium nitride (TiN) nanoparticles as local heat sources in the near infrared region, focusing on biological window. Experiments and simulations provide promising results for TiN, which is known to be bio-compatible....

Calcium phosphate-based coatings on titanium and its alloys.

Science.gov (United States)

Narayanan, R; Seshadri, S K; Kwon, T Y; Kim, K H

2008-04-01

Use of titanium as biomaterial is possible because of its very favorable biocompatibility with living tissue. Titanium implants having calcium phosphate coatings on their surface show good fixation to the bone. This review covers briefly the requirements of typical biomaterials and narrowly focuses on the works on titanium. Calcium phosphate ceramics for use in implants are introduced and various methods of producing calcium phosphate coating on titanium substrates are elaborated. Advantages and disadvantages of each type of coating from the view point of process simplicity, cost-effectiveness, stability of the coatings, coating integration with the bone, cell behavior, and so forth are highlighted. Taking into account all these factors, the efficient method(s) of producing these coatings are indicated finally.

Laser beam welding of titanium nitride coated titanium using pulse-shaping

Directory of Open Access Journals (Sweden)

Milton Sergio Fernandes de Lima

2005-09-01

Full Text Available A new welding method which allows the assembly of two titanium nitride coated titanium parts is proposed. The welding procedure utilizes the possibility for pulse-shaping in order to change the energy distribution profile during the laser pulse. The pulse-shaping is composed of three elements: a a short high power pulse for partial ablation at the surface; b a long pulse for thermal penetration; and c a quenching slope for enhanced weldability. The combination of these three elements produces crack-free welds. The weld microstructure is changed in comparison to normal welding, i.e. with a rectangular pulse, as the nitrogen and the microhardness are more homogenously distributed in the weld under pulse-shaping conditions. This laser pulse dissolves the TiN layer and allows nitrogen to diffuse into the melt pool, also contributing to an enhanced weldability by providing suitable thermal conditions.

Electrochemical Characterization of Surface Reactions on Biomedical Titanium alloys

OpenAIRE

Alkhateeb, Emad Hashim

2008-01-01

Titanium and its alloys are successfully used as implant materials for dental, orthopedic and osteosynthesis applications. The processes that take place at the implant tissue interface are important for the acceptance and integration of the implant. This thesis is divided into two parts: the first part deals with surface modification of titanium to improve the osseointegration, and the second part studies metastable pitting of titanium and its alloys. The weakly attached layer of a bone-like ...

Vanadium and titanium determination by resorcinalhydrazide of salicylic acid

Energy Technology Data Exchange (ETDEWEB)

Karpova, O I; Pilipenko, A T; Lukachina, V V [AN Ukrainskoj SSR, Kiev. Inst. Kolloidnoj Khimii i Khimii Vody

1979-02-01

The complexing of titanium and vanadium with resorcinalhydrazyl of salicylic acid (RHSA) in water-organic media is studied. Titanium (4) forms a complex at pH 0.8-1.8, vanadium - at pH 2.5-5.6, and at pH 7.6-9.8. The complexes are well extracted by polar and nonpolar solvents from acid solutions. The techniques are developed for the determination of titanium and vanadium by the RHSA agent in nickel alloys.

Titanium nitride plasma-chemical synthesis with titanium tetrachloride raw material in the DC plasma-arc reactor

Science.gov (United States)

Kirpichev, D. E.; Sinaiskiy, M. A.; Samokhin, A. V.; Alexeev, N. V.

2017-04-01

The possibility of plasmochemical synthesis of titanium nitride is demonstrated in the paper. Results of the thermodynamic analysis of TiCl4 - H2 - N2 system are presented; key parameters of TiN synthesis process are calculated. The influence of parameters of plasma-chemical titanium nitride synthesis process in the reactor with an arc plasmatron on characteristics on the produced powders is experimentally investigated. Structure, chemical composition and morphology dependencies on plasma jet enthalpy, stoichiometric excess of hydrogen and nitrogen in a plasma jet are determined.

Effect of surface reaction layer on grindability of cast titanium alloys.

Science.gov (United States)

Ohkubo, Chikahiro; Hosoi, Toshio; Ford, J Phillip; Watanabe, Ikuya

2006-03-01

The purpose of this study was to investigate the effect of the cast surface reaction layer on the grindability of titanium alloys, including free-machining titanium alloy (DT2F), and to compare the results with the grindability of two dental casting alloys (gold and Co-Cr). All titanium specimens (pure Ti, Ti-6Al-4V and DT2F) were cast using a centrifugal casting machine in magnesia-based investment molds. Two specimen sizes were used to cast the titanium metals so that the larger castings would be the same size as the smaller gold and Co-Cr alloy specimens after removal of the surface reaction layer (alpha-case). Grindability was measured as volume loss ground from a specimen for 1 min using a handpiece engine with a SiC abrasive wheel at 0.1 kgf and four circumferential wheel speeds. For the titanium and gold alloys, grindability increased as the rotational speed increased. There was no statistical difference (p>0.05) in grindability for all titanium specimens either with or without the alpha-case. Of the titanium metals tested, Ti-6 Al-4V had the greatest grindability at higher speeds, followed by DT2F and CP Ti. The grindability of the gold alloy was similar to that of Ti-6 Al-4V, whereas the Co-Cr alloy had the lowest grindability. The results of this study indicated that the alpha-case did not significantly affect the grindability of the titanium alloys. The free-machining titanium alloy had improved grindability compared to CP Ti.

Thermochemical stability of zirconia-titanium nitride as mixed ionic-electronic composites

DEFF Research Database (Denmark)

Silva, P. S. M.; Esposito, V.; Marani, D.

2018-01-01

Dense zirconia (8% molar yttria-stabilized ZrO2)-titanium nitride (TiN) composites are fabricated to obtain mixed ionic-electronic conducting ceramic systems with high degree of electronic and thermal conductivity. The composites are consolidated by spark plasma sintering (SPS), starting from pure...... the composites, high electrical conductivity is attained. Samples exhibit metallic behavior, showing an unexpected percolation of TiN in the YSZ matrix for volume fraction ≤ 25 wt% (27 vol%). Chemical degradation and electrical properties of the compounds were monitored under oxidative (air) and inert (Ar...... transport properties of the composite can be tuned by both the relative volume fraction of phases and controlled oxidative treatments. Adjusting such parameters different electric behaviors were observed ranging from predominant electronic conductors, to temperature-independent resistivity...

Recent research and development in titanium alloys for biomedical applications and healthcare goods

Directory of Open Access Journals (Sweden)

Mitsuo Niinomi

2003-01-01

Full Text Available Nb, Ta and Zr are the favorable non-toxic alloying elements for titanium alloys for biomedical applications. Low rigidity titanium alloys composed of non-toxic elements are getting much attention. The advantage of low rigidity titanium alloy for the healing of bone fracture and the remodeling of bone is successfully proved by fracture model made in tibia of rabbit. Ni-free super elastic and shape memory titanium alloys for biomedical applications are energetically developed. Titanium alloys for not only implants, but also dental products like crowns, dentures, etc. are also getting much attention in dentistry. Development of investment materials suitable for titanium alloys with high melting point is desired in dental precision castings. Bioactive surface modifications of titanium alloys for biomedical applications are very important for achieving further developed biocompatibility. Low cost titanium alloys for healthcare goods, like general wheel chairs, etc. has been recently proposed.

Determination of local constitutive properties of titanium alloy matrix in boron-modified titanium alloys using spherical indentation

International Nuclear Information System (INIS)

Sreeranganathan, A.; Gokhale, A.; Tamirisakandala, S.

2008-01-01

The constitutive properties of the titanium alloy matrix in boron-modified titanium alloys are different from those of the corresponding unreinforced alloy due to the microstructural changes resulting from the addition of boron. Experimental and finite-element analyses of spherical indentation with a large penetration depth to indenter radius ratio are used to compute the local constitutive properties of the matrix alloy. The results are compared with that of the corresponding alloy without boron, processed in the same manner

Production of titanium alloys with uniform distribution of heat resisting metals

International Nuclear Information System (INIS)

Reznichenko, V.A.; Goncharenko, T.V.; Khalimov, F.B.; Vojtechova, E.A.

1976-01-01

Consideration is given to the process of the formation of a titanium sponge alloyed with niobium or tantalum, in the joint metallic reduction of titanium, niobium and tantanum chlorides. A percentage composition of the phases observed and the structure of the alloyed sponge have been studied. It is shown that after one remelting operation of the alloyed sponge the alloys of titanium with niobium and tantalum have a uniform component distribution. At the stage of chloride reduction there appear solid solutions based on titanium and an alloying component. The stage of vacuum separation of the reaction mass is associated with a mutual dissolution of the primary phases and the formation of the solid solutions of the alloyed titanium sponge, which, by their composition, are close to the desired alloy composition. The principal features of the formation of a titanium sponge alloyed with niobium and tantalum are in a perfect agreemet with those typical of Ti-Mo and Ti-W sponges, therefore it can be assumed that these features will be also common to the other cases of the metallic reduction of titanium and refractory metals chlorides

Production of titanium alloys with uniform distribution of heat resisting metals

Energy Technology Data Exchange (ETDEWEB)

Reznichenko, V A; Goncharenko, T V; Khalimov, F B; Voitechova, E A

1976-01-01

Consideration is given to the process of the formation of a titanium sponge alloyed with niobium or tantalum, in the joint metallic reduction of titanium, niobium and tantanum chlorides. A percentage composition of the phases observed and the structure of the alloyed sponge have been studied. It is shown that after one remelting operation of the alloyed sponge the alloys of titanium with niobium and tantalum have a uniform component distribution. At the stage of chloride reduction there appear solid solutions based on titanium and an alloying component. The stage of vacuum separation of the reaction mass is associated with a mutual dissolution of the primary phases and the formation of the solid solutions of the alloyed titanium sponge, which, by their composition, are close to the desired alloy composition. The principal features of the formation of a titanium sponge alloyed with niobium and tantalum are in a perfect agreemet with those typical of Ti-Mo and Ti-W sponges, therefore it can be assumed that these features will be also common to the other cases of the metallic reduction of titanium and refractory metals chlorides.

Microstructural control of thin-film diffusion-brazed titanium

International Nuclear Information System (INIS)

Wells, R.R.

1976-01-01

This study was designed to determine what parameters should be controlled to achieve quality joints of good toughness and high strength in titanium alloys. Emphasis was placed upon studying those parameters which provided tough joints compatible with the titanium base metal being joined. This paper is concerned with thin-film diffusion brazing based upon the eutectic system formed between copper and titanium. In order to control the joint microstructure, the copper diffusion rates and the beta-phase decomposition kinetics were studied. This information was used to produce various types of microstructures in test specimens. These were then evaluated to select the best microstructures for toughness and strength which were compatible with the titanium alloys. Results show that it is possible to accurately control properties of joints produced by thin-film diffusion brazing. This is done by controlling the initial copper content and the time-temperature parameters used in processing. Alloys studied were Ti--8Al--1Mo--1V and Ti--6Al--4V

Anodization: a promising nano-modification technique of titanium implants for orthopedic applications.

Science.gov (United States)

Yao, Chang; Webster, Thomas J

2006-01-01

Anodization is a well-established surface modification technique that produces protective oxide layers on valve metals such as titanium. Many studies have used anodization to produce micro-porous titanium oxide films on implant surfaces for orthopedic applications. An additional hydrothermal treatment has also been used in conjunction with anodization to deposit hydroxyapatite on titanium surfaces; this is in contrast to using traditional plasma spray deposition techniques. Recently, the ability to create nanometer surface structures (e.g., nano-tubular) via anodization of titanium implants in fluorine solutions have intrigued investigators to fabricate nano-scale surface features that mimic the natural bone environment. This paper will present an overview of anodization techniques used to produce micro-porous titanium oxide structures and nano-tubular oxide structures, subsequent properties of these anodized titanium surfaces, and ultimately their in vitro as well as in vivo biological responses pertinent for orthopedic applications. Lastly, this review will emphasize why anodized titanium structures that have nanometer surface features enhance bone forming cell functions.

Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

Energy Technology Data Exchange (ETDEWEB)

Parcharoen, Yardnapar [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Kajitvichyanukul, Puangrat [Center of Excellence on Environmental Research and Innovation, Faculty of Engineering, Naresuan University, Phitsanulok (Thailand); Sirivisoot, Sirinrath [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Termsuksawad, Preecha, E-mail: preecha.ter@kmutt.ac.th [Division of Materials Technology, School of Energy, Environment and Materials, King Mongkut' s University of Technology Thonburi, 126 Pracha Uthit Rd., Bang Mod, ThungKhru, Bangkok 10140 (Thailand)

2014-08-30

Highlights: • We found that different anodization time of titanium significantly effects on nanotube length which further impacts adhesion strength of hydroxyapatite coating layers. • Adhesion strength of Hydroxyapatite (HA) coated on titanium dioxide nanotubes is better than that of HA coated on titanium plate. • Hydroxyapatite coated on titanium dioxide nanotubes showed higher cell density and better spreading of MC3T3-E1 cells (bone-forming cells) than that coated on titanium plate surface. - Abstract: Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO{sub 2}) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO{sub 2} nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH{sub 4}F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO{sub 2} nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO{sub 2} nanotubes were found when high viscous electrolyte, NH{sub 4}F in glycerol, was used. Negative voltage (−4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO{sub 2} nanotubes was significantly increased by times. The TiO{sub 2} nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO{sub 2} nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that

An improved biofunction of titanium for keratoprosthesis by hydroxyapatite-coating.

Science.gov (United States)

Dong, Ying; Yang, Jingxin; Wang, Liqiang; Ma, Xiao; Huang, Yifei; Qiu, Zhiye; Cui, Fuzhai

2014-03-01

Titanium framework keratoprosthesis has been commonly used in the severe corneal blindness, but the tissue melting occurred frequently around titanium. Since hydroxyapatite has been approved to possess a good tissue integration characteristic, nanostructured hydroxyapatite was coated on the surface of titanium through the aerosol deposition method. In this study, nanostructured hydroxyapatite coating was characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and auger electronic spectrometer. Biological evaluations were performed with rabbit cornea fibroblast in vitro and an animal model in vivo. The outcomes showed the coating had a grain-like surface topography and a good atomic mixed area with substrate. The rabbit cornea fibroblasts appeared a good adhesion on the surface of nanostructured hydroxyapatite in vitro. In the animal model, nanostructured hydroxyapatite-titanium implants were stably retained in the rabbit cornea, and by contrast, the corneal stroma became thinner anterior to the implants in the control. Therefore, our findings proved that nanostructured hydroxyapatite-titanium could not only provide an improved bond for substrate but also enhance the tissue integration with implants in host. As a promising material, nanostructured hydroxyapatite-titanium-based keratoprosthesis prepared by the aerosol deposition method could be utilized for the corneal blindness treatment.

Advances in titanium alloys

International Nuclear Information System (INIS)

Seagle, S.R.; Wood, J.R.

1993-01-01

As described above, new developments in the aerospace market are focusing on higher temperature alloys for jet engine components and higher strength/toughness alloys for airframe applications. Conventional alloys for engines have reached their maximum useful temperature of about 1000 F (540 C) because of oxidation resistance requirements. IMI 834 and Ti-1100 advanced alloys show some improvement, however, the major improvement appears to be in gamma titanium aluminides which could extend the maximum usage temperature to about 1500 F (815 C). This puts titanium alloys in a competitive position to replace nickel-base superalloys. Advanced airframe alloys such as Ti-6-22-22S, Beta C TM , Ti-15-333 and Ti-10-2-3 with higher strength than conventional Ti-6-4 are being utilized in significantly greater quantities, both in military and commercial applications. These alloys offer improved strength with little or no sacrifice in toughness and improved formability, in some cases. Advanced industrial alloys are being developed for improved corrosion resistance in more reducing and higher temperature environments such as those encountered in sour gas wells. Efforts are focused on small precious metal additions to optimize corrosion performance for specific applications at a modest increase in cost. As these applications develop, the usage of titanium alloys for industrial markets should steadily increase to approach that for aerospace applications. (orig.)

The promotion of osseointegration of titanium surfaces by coating with silk protein sericin.

Science.gov (United States)

Nayak, Sunita; Dey, Tuli; Naskar, Deboki; Kundu, Subhas C

2013-04-01

A promising strategy to influence the osseointegration process around orthopaedic titanium implants is the immobilization of bioactive molecules. This recruits appropriate interaction between the surface and the tissue by directing cells adhesion, proliferation, differentiation and active matrix remodelling. In this study, we aimed to investigate the functionalization of metallic implant titanium with silk protein sericin. Titanium surface was immobilized with non-mulberry Antheraea mylitta sericin using glutaraldehyde as crosslinker. To analyse combinatorial effects the sericin immobilized titanium was further conjugated with integrin binding peptide sequence Arg-Gly-Asp (RGD) using ethyl (dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide as coupling agents. The surface of sericin immobilized titanium was characterized biophysically. Osteoblast-like cells were cultured on sericin and sericin/RGD functionalized titanium and found to be more viable than those on pristine titanium. The enhanced adhesion, proliferation, and differentiation of osteoblast cells were observed. RT-PCR analysis showed that mRNA expressions of bone sialoprotein, osteocalcin and alkaline phosphatase were upregulated in osteoblast cells cultured on sericin and sericin/RGD immobilized titanium substrates. Additionally, no significant amount of pro-inflammatory cytokines TNF-α, IL-1β and nitric oxide production were recorded when macrophages cells and osteoblast-macrophages co culture cells were grown on sericin immobilized titanium. The findings demonstrate that the sericin immobilized titanium surfaces are potentially useful bioactive coated materials for titanium-based medical implants. Copyright © 2013 Elsevier Ltd. All rights reserved.

A sourcebook of titanium alloy superconductivity

CERN Document Server

Collings, E W

1983-01-01

In less than two decades the concept of supercon­ In every field of science there are one or two ductivity has been transformed from a laboratory individuals whose dedication, combined with an innate curiosity to usable large-scale applications. In the understanding, permits them to be able to grasp, late 1960's the concept of filamentary stabilization condense, and explain to the rest of us what that released the usefulness of zero resistance into the field is all about. For the field of titanium alloy marketplace, and the economic forces that drive tech­ superconductivity, such an individual is Ted Collings. nology soon focused on niobium-titanium alloys. They His background as a metallurgist has perhaps given him are ductile and thus fabricable into practical super­ a distinct advantage in understanding superconduc­ conducting wires that have the critical currents and tivity in titanium alloys because the optimization of fields necessary for large-scale devices. More than superconducting parameters in ...

Interfacial reactions between titanium and borate glass

Energy Technology Data Exchange (ETDEWEB)

Brow, R.K. [Sandia National Labs., Albuquerque, NM (United States); Saha, S.K.; Goldstein, J.I. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Materials Science

1992-12-31

Interfacial reactions between melts of several borate glasses and titanium have been investigated by analytical scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). A thin titanium boride interfacial layer is detected by XPS after short (30 minutes) thermal treatments. ASEM analyses after longer thermal treatments (8--120 hours) reveal boron-rich interfacial layers and boride precipitates in the Ti side of the interface.

Lubrication for hot working of titanium alloys

International Nuclear Information System (INIS)

Gotlib, B.M.

1980-01-01

The isothermal lubrication of the following composition is suggested, wt. %: aluminium powder 4-6, iron scale 15-25, vitreous enamel up to 100. The lubricant improves forming and decreases the danger of the metal fracture when titanium alloys working. It is advisable to use the suggested lubrication when stamping thin-walled products of titanium alloys at the blank temperature from 700 to 1000 deg C [ru

Cathodic arc sputtering of functional titanium oxide thin films, demonstrating resistive switching

Energy Technology Data Exchange (ETDEWEB)

Shvets, Petr, E-mail: pshvets@innopark.kantiana.ru; Maksimova, Ksenia; Demin, Maxim; Dikaya, Olga; Goikhman, Alexander

2017-05-15

The formation of thin films of the different stable and metastable titanium oxide phases is demonstrated by cathode arc sputtering of a titanium target in an oxygen atmosphere. We also show that sputtering of titanium in vacuum yields the formation of titanium silicides on the silicon substrate. The crystal structure of the produced samples was investigated using Raman spectroscopy and X-ray diffraction. We conclude that cathode arc sputtering is a flexible method suitable for producing the functional films for electronic applications. The functionality is verified by the memory effect demonstration, based on the resistive switching in the titanium oxide thin film structure.

Plasma synthesis of titanium nitride, carbide and carbonitride nanoparticles by means of reactive anodic arc evaporation from solid titanium

International Nuclear Information System (INIS)

Kiesler, D.; Bastuck, T.; Theissmann, R.; Kruis, F. E.

2015-01-01

Plasma methods using the direct evaporation of a transition metal are well suited for the cost-efficient production of ceramic nanoparticles. In this paper, we report on the development of a simple setup for the production of titanium-ceramics by reactive anodic arc evaporation and the characterization of the aerosol as well as the nanopowder. It is the first report on TiC X N 1 − X synthesis in a simple anodic arc plasma. By means of extensive variations of the gas composition, it is shown that the composition of the particles can be tuned from titanium nitride over a titanium carbonitride phase (TiC X N 1 − X ) to titanium carbide as proven by XRD data. The composition of the plasma gas especially a very low concentration of hydrocarbons around 0.2 % of the total plasma gas is crucial to tune the composition and to avoid the formation of free carbon. Examination of the particles by HR-TEM shows that the material consists mostly of cubic single crystalline particles with mean sizes between 8 and 27 nm

Colloidal Plasmonic Titanium Nitride Nanoparticles: Properties and Applications

Directory of Open Access Journals (Sweden)

Guler Urcan

2015-01-01

Full Text Available Optical properties of colloidal plasmonic titanium nitride nanoparticles are examined with an eye on their photothermal and photocatalytic applications via transmission electron microscopy and optical transmittance measurements. Single crystal titanium nitride cubic nanoparticles with an average size of 50 nm, which was found to be the optimum size for cellular uptake with gold nanoparticles [1], exhibit plasmon resonance in the biological transparency window and demonstrate a high absorption efficiency. A self-passivating native oxide at the surface of the nanoparticles provides an additional degree of freedom for surface functionalization. The titanium oxide shell surrounding the plasmonic core can create new opportunities for photocatalytic applications.

Water leaching of titanium from ore flotation residue.

Science.gov (United States)

Jaworska, Malgorzata M; Guibal, Eric

2003-01-01

Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g(-1), but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

Characterization and Sintering of Armstrong Process Titanium Powder

Science.gov (United States)

Xu, Xiaoyan; Nash, Philip; Mangabhai, Damien

2017-04-01

Titanium and titanium alloys have a high strength to weight ratio and good corrosion resistance but also need longer time and have a higher cost on machining. Powder metallurgy offers a viable approach to produce near net-shape complex components with little or no machining. The Armstrong titanium powders are produced by direct reduction of TiCl4 vapor with liquid sodium, a process which has a relatively low cost. This paper presents a systematic research on powder characterization, mechanical properties, and sintering behavior and of Armstrong process powder metallurgy, and also discusses the sodium issue, and the advantages and disadvantages of Armstrong process powders.

Inhibitor effect on corrosion of titanium alloys in muriatic solutions of titanium-magnesium production

International Nuclear Information System (INIS)

Dobrunov, Yu.V.; Volynskij, V.V.; Kolobov, G.A.; Kuznetsov, S.I.

1977-01-01

Corrosion tests of titanium alloys VTI-0, OT4, VT5-1 and steel Kh18N1OT in 10% and 18% HCl with additions of carnallite at 40 deg C have been carried out. It has been established that titanium alloys in 10% and 18% HCl containing 5 and 10% carnallite are sufficiently corrosion resistant in the presence of 0.1-1% FeCl or HNO 3 and can be used for manufacturing the equipment of recirculation gas scrubbers. Steel Kh18N10T is unstable in all the media tested. It is subjected to intensive pitting. Specimens of steel Kh18N10T have also revealed edge cracking

Molecular geometries and relative stabilities of titanium oxide and gold-titanium oxide clusters

Energy Technology Data Exchange (ETDEWEB)

Hudson, Rohan J.; Falcinella, Alexander; Metha, Gregory F., E-mail: greg.metha@adelaide.edu.au

2016-09-30

Titanium oxide and gold-titanium oxide clusters of stoichiometry M{sub x}O{sub y} (M{sub x} = Ti{sub 3}, Ti{sub 4} & AuTi{sub 3}; y = 0 − (2x + 2)) have been investigated using density functional theory. Geometries of determined global energy minimum structures are reported and other isomers predicted up to 0.5 eV higher in energy. The Ti{sub 3}O{sub n} geometries build upon a triangular Ti{sub 3} motif, while Ti{sub 4}O{sub n} stoichiometries template upon a pseudo-tetrahedral Ti{sub 4} structure. Addition of a gold atom to the Ti{sub 3}O{sub n} series does not significantly alter the cluster geometry, with the gold atom preferentially binding to titanium atoms over oxygen atoms. Adiabatic ionization energies, electron affinities and HOMO/LUMO energies increase in magnitude with increasing oxygenation. The HOMO-LUMO energy gaps reach the bulk anatase band gap energy at stoichiometry (Au)Ti{sub m}O{sub 2m−1}, and increase above this upon further oxygen addition. The most stable structural moieties are found to be a cage-like, C{sub 3v} symmetric Ti{sub 4}O{sub 6/7} geometry and a Ti{sub 3}O{sub 6} structure with an η{sup 3}-bound oxygen atom.

Hydroxyapatite coating by biomimetic method on titanium alloy ...

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 28; Issue 6. Hydroxyapatite coating by biomimetic method on titanium alloy using concentrated SBF. S Bharati M K Sinha ... Optical microscopic and SEM observations revealed the deposition of Ca–P layer on the titanium alloy by both the methods. Thickness of coating ...

Titanium reinforced boron-polyimide composite

Science.gov (United States)

Clark, G. A.; Clayton, K. I.

1969-01-01

Processing techniques for boron polyimide prepreg were developed whereby composites could be molded under vacuum bag pressure only. A post-cure cycle was developed which resulted in no loss in room temperature mechanical properties of the composite at any time during up to 16 hours at 650 F. A design utilizing laminated titanium foil was developed to achieve a smooth transition of load from the titanium attachment points into the boron-reinforced body of the structure. The box beam test article was subjected to combined bending and torsional loads while exposed to 650 F. Loads were applied incrementally until failure occurred at 83% design limit load.

Methods for determination of zirconium in titanium alloys

International Nuclear Information System (INIS)

1985-01-01

Two methods for determining zirconium content in titanium alloys are specified in this standard. One is the ion-exchange/mandelic acid gravimetry for Zr content below 20 % down to 1 % while the other is the mandelic acid gravimetry for Zr content below 20 % down to 0.5 %. In the former, a specimen is decomposed by hydrochloric acid and hydrofluoric acid. After substances such as titanium are oxidized by adding nitric acid, the liquid is adjusted into a 4N hydrochloric acid - gN hydrofluoric acid solution, which is them passed through an ion-exchange column. The niobium and tantalum contents are absorbed while the titanium and zirconium contents flow out. Perchloric acid and sulfuric acid are poured in the solution to remove hydrofluoric acid. Aqueous ammonia is added to produce hydroxide of titanium and zirconium, which is then filtered out. The hydroxyde is dissolved in hydrochloric acid, and mandelic acid is poured to precipitate the zirconium content. The precipitate is ignited and the weight of the oxide formed is measured. The coprecipitated titanium content is determined by the absorptiometric method using hydrogen peroxide. Finally, the weight of the oxide is corrected. In the latter determination method, on the other hand, only several steps of the above procedure are used, namely, decomposition by hydrochloric acid, precipitation of zirconium, ignition of precipitate, measurement of oxide weight and weight correction. (Nogami, K.)

Biocorrosion and uptake of titanium by human osteoclasts.

Science.gov (United States)

Cadosch, Dieter; Al-Mushaiqri, Mohamed S; Gautschi, Oliver P; Meagher, James; Simmen, Hans-Peter; Filgueira, Luis

2010-12-15

All metals in contact with a biological system undergo corrosion through an electrochemical redox reaction. This study investigated whether human osteoclasts (OC) are able to grow on titanium and aluminum, and directly corrode the metals leading to the release of corresponding metal ions, which are believed to cause inflammatory reactions and activate osteoclastic differentiation. Scanning electron microscopy analysis demonstrated long-term viable OC cultures on the surface of titanium and aluminum foils. Atomic emission spectrometry investigations showed significantly increased levels of aluminum in the supernatant of OC cultured on aluminum; however, all measurements in the supernatants of cell cultures on titanium were below detection limits. Despite this, confocal microscopy analysis with Newport Green DCF diacetate ester staining depicted intense fluorescence throughout the cytoplasm and nucleolus of OC cultured on titanium foils. Comparable fluorescence intensities were not observed in monocytes and control cells cultured on glass. The present study demonstrated that human osteoclast precursors are able to grow and differentiate toward mature OC on titanium and aluminum. Furthermore, it established that the mature cells are able to directly corrode the metal surface and take up corresponding metal ions, which subsequently may be released and thereby induce the formation of osteolytic lesions in the periprosthetic bone, contributing to the loosening of the implant. Copyright © 2010 Wiley Periodicals, Inc.

Nanoscale Bonding between Human Bone and Titanium Surfaces: Osseohybridization

Directory of Open Access Journals (Sweden)

Jun-Sik Kim

2015-01-01

Full Text Available Until now, the chemical bonding between titanium and bone has been examined only through a few mechanical detachment tests. Therefore, in this study, a sandblasted and acid-etched titanium mini-implant was removed from a human patient after 2 months of placement in order to identify the chemical integration mechanism for nanoscale osseointegration of titanium implants. To prepare a transmission electron microscopy (TEM specimen, the natural state was preserved as much as possible by cryofixation and scanning electron microscope/focused ion beam (SEM-FIB milling without any chemical treatment. High-resolution TEM (HRTEM, energy dispersive X-ray spectroscopy (EDS, and scanning TEM (STEM/electron energy loss spectroscopic analysis (EELS were used to investigate the chemical composition and structure at the interface between the titanium and bone tissue. HRTEM and EDS data showed evidence of crystalline hydroxyapatite and intermixing of bone with the oxide layer of the implant. The STEM/EELS experiment provided particularly interesting results: carbon existed in polysaccharides, calcium and phosphorus existed as tricalcium phosphate (TCP, and titanium existed as oxidized titanium. In addition, the oxygen energy loss near edge structures (ELNESs showed a possibility of the presence of CaTiO3. These STEM/EELS results can be explained by structures either with or without a chemical reaction layer. The possible existence of the osseohybridization area and the form of the carbon suggest that reconsideration of the standard definition of osseointegration is necessary.

Titanium diffusion in shinbone of rats with osseointegrated implants.

Science.gov (United States)

Grenón, Miriam S; Robledo, José; Ibáñez, Juan Carlos; Sánchez, Héctor J

2016-11-01

Dental implants are composed of commercially pure Ti (which is actually an alloy of titanium, and minor or trace components such as aluminium and vanadium). When the implant is inserted, its surface undergoes a number of chemical and mechanical processes, releasing particles of titanium to the medium. The metabolism of free ions of titanium is uncertain; the uptaking processes in the body are not well known, nor their toxic dose. In addition, physical properties of newly formed bone, such as diffusivity and activation energy, are scarce and rarely studied. In this study, we analysed the diffusion of titanium in the titanium-implanted shinbones of six adult male Wistar rats by spatially resolved micro x-ray fluorescence. The measurements were carried out at the microfluorescence station of the x-ray fluorescence (XRF) beamline of the Brazilian synchrotron facility LNLS (from Portuguese 'Laboratorio Nacional de Luz Sincrotron'). For each sample, XRF spectra were taken by linear scanning in area near the new bone formed around the Ti implant. The scanning line shows a clear effect of titanium diffusion whereas calcium intensity presents a different behaviour. Moreover, a clear correlation among the different structures of bones is observed in the Ti and Ca intensities. The results obtained in these measurements may allow determining quantitatively the parameters of diffusion rates and other physical properties of new bone like diffusion coefficients. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Modification of Titanium Substrates with Chimeric Peptides Comprising Antimicrobial and Titanium-Binding Motifs Connected by Linkers To Inhibit Biofilm Formation.

Science.gov (United States)

Liu, Zihao; Ma, Shiqing; Duan, Shun; Xuliang, Deng; Sun, Yingchun; Zhang, Xi; Xu, Xinhua; Guan, Binbin; Wang, Chao; Hu, Meilin; Qi, Xingying; Zhang, Xu; Gao, Ping

2016-03-02

Bacterial adhesion and biofilm formation are the primary causes of implant-associated infection, which is difficult to eliminate and may induce failure in dental implants. Chimeric peptides with both binding and antimicrobial motifs may provide a promising alternative to inhibit biofilm formation on titanium surfaces. In this study, chimeric peptides were designed by connecting an antimicrobial motif (JH8194: KRLFRRWQWRMKKY) with a binding motif (minTBP-1: RKLPDA) directly or via flexible/rigid linkers to modify Ti surfaces. We evaluated the binding behavior of peptides using quartz crystal microbalance (QCM) and atomic force microscopy (AFM) techniques and investigated the effect of the modification of titanium surfaces with these peptides on the bioactivity of Streptococcus gordonii (S. gordonii) and Streptococcus sanguis (S. sanguis). Compared with the flexible linker (GGGGS), the rigid linker (PAPAP) significantly increased the adsorption of the chimeric peptide on titanium surfaces (p chimeric peptide with the rigid linker exhibited more effective antimicrobial ability than the peptide with the flexible linker. This finding was ascribed to the ability of the rigid linker to separate functional domains and reduce their interference to the maximum extent. Consequently, the performance of chimeric peptides with specific titanium-binding motifs and antimicrobial motifs against bacteria can be optimized by the proper selection of linkers. This rational design of chimeric peptides provides a promising alternative to inhibit the formation of biofilms on titanium surfaces with the potential to prevent peri-implantitis and peri-implant mucositis.

Mechanical stability of titanium and plasma polymer nanoclusters in nanocomposite coatings

Energy Technology Data Exchange (ETDEWEB)

Palesch, E. [Institute of Materials Chemistry, Brno University of Technology, Brno (Czech Republic); Marek, A. [HVM Plasma, spol. s r.o., Prague (Czech Republic); Solar, P.; Kylian, O. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic); Vyskocil, J. [HVM Plasma, spol. s r.o., Prague (Czech Republic); Biederman, H. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic); Cech, V., E-mail: cech@fch.vutbr.cz [Institute of Materials Chemistry, Brno University of Technology, Brno (Czech Republic)

2013-10-01

The mechanical stability of nanoclusters embedded in nanocomposite coatings was investigated by scratch and wear tests supported by atomic force microscopy using surface topography mode. Titanium and plasma polymer nanoclusters were deposited on planar substrates (glass, titanium) using a magnetron-based gas aggregation cluster source. The deposited clusters were overcoated with a thin titanium film of different thicknesses to stabilize the position of the clusters in the nanocomposite coating. Nanotribological measurements were carried out to optimize the thickness of the overcoating film for sufficient interfacial adhesion of the cluster/film system. - Highlights: ► Titanium and plasma polymer nanoclusters were overcoated with thin titanium film. ► The mechanical stability of nanoclusters was characterized by nanotribological tests. ► The film thickness was optimized to stabilize the position of the clusters in coating.

Macrophage proinflammatory response to the titanium alloy equipment in dental implantation.

Science.gov (United States)

Chen, X; Li, H S; Yin, Y; Feng, Y; Tan, X W

2015-08-07

Titanium alloy and stainless steel (SS) had been widely used as dental implant materials because of their affinity with epithelial tissue and connective tissue, and good physical, chemical, biological, mechanical properties and processability. We compared the effects of titanium alloy and SS on macrophage cytokine expression as well as their biocompatibility. Mouse macrophage RAW264.7 cells were cultured on titanium alloy and SS surfaces. Cells were counted by scanning electron microscopy. A nitride oxide kit was used to detect released nitric oxide by macrophages on the different materials. An enzyme linked immunosorbent assay was used to detect monocyte chemoattractant protein-1 levels. Scanning electron microscopy revealed fewer macrophages on the surface of titanium alloy (48.2 ± 6.4 x 10(3) cells/cm(2)) than on SS (135 ± 7.3 x 10(3) cells/cm(2)). The nitric oxide content stimulated by titanium alloy was 22.5 mM, which was lower than that stimulated by SS (26.8 mM), but the difference was not statistically significant (P = 0.07). The level of monocyte chemoattractant protein-1 released was significantly higher in the SS group (OD value = 0.128) than in the titanium alloy group (OD value = 0.081) (P = 0.024). The transforming growth factor-b1 mRNA expression levels in macrophages after stimulation by titanium alloy for 12 and 36 h were significantly higher than that after stimulation by SS (P = 0.31 and 0.25, respectively). Macrophages participate in the inflammatory response by regulating cytokines such as nitric oxide, monocyte chemoattractant protein-1, and transforming growth factor-b1. There were fewer macrophages and lower inflammation on the titanium alloy surface than on the SS surface. Titanium alloy materials exhibited better biological compatibility than did SS.

Causes and mechanisms of thermal embrittlement and corrosion cracking of complex α-titanium alloys

International Nuclear Information System (INIS)

Ushkov, S.S.; Rybin, V.V.; Razuvaeva, I.N.; Nesterova, E.V.; Gunbina, O.A.

1995-01-01

Effect of aging under 500 deg C on mechanical and corrosion-mechanical properties of Ti-6Al base titanium α-alloys with zirconium and carbon additions is studied. Using electron microscopy one determines the reasons of reduction of plasticity and of corrosion-mechanical strength of alloys after aging. It is determined that in the given alloys there are two different processes with occurrence different kinetics: the first one-formation of grain-boundary precipitations of Ti 2 (Fe, Ni) intermetallic compound responsible for plasticity reduction; and the second one-homogeneous decomposition of Ti-Al solid solution responsible for reduction of corrosion-mechanical properties. 14 refs., 6 figs

Investigation of Titanium Sesquioxide Ti2O3: Synthesis and Physical Properties

KAUST Repository

Li, Yangyang

2016-01-01

Titanium is one of the earth-abundant elements, and its oxides including titanium dioxide (TiO2) and strontium titanium oxide (SrTiO3) are widely used in technologies of electronics, energy conversion, catalysis, sensing, and so on. Generally

40 CFR 415.220 - Applicability; description of the titanium dioxide production subcategory.

Science.gov (United States)

2010-07-01

... titanium dioxide production subcategory. 415.220 Section 415.220 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Titanium Dioxide Production Subcategory § 415.220 Applicability; description of the titanium dioxide production subcategory. This subpart applies to discharges to waters of the United States...

Nickel contaminated titanium weld wire study

International Nuclear Information System (INIS)

Coffin, G.R.; Sumstine, R.L.

1979-01-01

Attachment of thermocouples to fuel rod welding problems at Exxon Nuclear Company and INEL prompted an investigation study of the titanium filler wire material. It was found that the titanium filler wire was contaminated with nickel which was jacketed on the wire prior to the drawing process at the manufacturers. A method was developed to 100% inspect all filler wire for future welding application. This method not only indicates the presence of nickel contamination but indicates quantity of contamination. The process is capable of high speed inspection necessary for various high speed manufacturing processes

Creating mobile apps with Appcelerator Titanium

CERN Document Server

Brousseau, Christian

2013-01-01

Creating Mobile Apps with Appcelerator Titanium provides a hands-on approach and working examples on creating apps and games as well as embedding them onto a social networking website. Developers can then move on from there to develop their own applications based on the ones they have developed throughout the course of this book.""Creating Mobile Apps with Appcelerator Titanium"" is for developers who have experience with modern languages and development environments. Also, if you are familiar with the concepts of Object-oriented Programming (OOP), reusable components, AJAX closures, and so on

Porous titanium bases for osteochondral tissue engineering

Science.gov (United States)

Nover, Adam B.; Lee, Stephanie L.; Georgescu, Maria S.; Howard, Daniel R.; Saunders, Reuben A.; Yu, William T.; Klein, Robert W.; Napolitano, Anthony P.; Ateshian, Gerard A.

2015-01-01

Tissue engineering of osteochondral grafts may offer a cell-based alternative to native allografts, which are in short supply. Previous studies promote the fabrication of grafts consisting of a viable cell-seeded hydrogel integrated atop a porous, bone-like metal. Advantages of the manufacturing process have led to the evaluation of porous titanium as the bone-like base material. Here, porous titanium was shown to support the growth of cartilage to produce native levels of Young’s modulus, using a clinically relevant cell source. Mechanical and biochemical properties were similar or higher for the osteochondral constructs compared to chondral-only controls. Further investigation into the mechanical influence of the base on the composite material suggests that underlying pores may decrease interstitial fluid pressurization and applied strains, which may be overcome by alterations to the base structure. Future studies aim to optimize titanium-based tissue engineered osteochondral constructs to best match the structural architecture and strength of native grafts. Statement of Significance The studies described in this manuscript follow up on previous studies from our lab pertaining to the fabrication of osteochondral grafts that consist of a bone-like porous metal and a chondrocyte-seeded hydrogel. Here, tissue engineered osteochondral grafts were cultured to native stiffness using adult chondrocytes, a clinically relevant cell source, and a porous titanium base, a material currently used in clinical implants. This porous titanium is manufactured via selective laser melting, offering the advantages of precise control over shape, pore size, and orientation. Additionally, this manuscript describes the mechanical influence of the porous base, which may have applicability to porous bases derived from other materials. PMID:26320541

Super titanium blades for advanced steam turbines

International Nuclear Information System (INIS)

Coulon, P.A.

1990-01-01

In 1986, the Alsthom Steam Turbines Department launched the manufacture of large titanium alloy blades: airfoil length of 1360 mm and overall length of 1520 mm. These blades are designed for the last-stage low pressure blading of advanced steam turbines operating at full speed (3000 rpm) and rating between 300 and 800 MW. Using titanium alloys for steam turbine exhaust stages as substitutes for chrome steels, due to their high strength/density ratio and their almost complete resistance to corrosion, makes it possible to increase the length of blades significantly and correspondingly that steam passage section (by up to 50%) with a still conservative stresses level in the rotor. Alsthom relies on 8 years of experience in the field of titanium, since as early as 1979 large titanium blades (airfoil length of 1240 mm, overall length of 1430 mm) were erected for experimental purposes on the last stage of a 900 MW unit of the Dampierre-sur-Loire power plant and now totals 45,000 operating hours without problems. The paper summarizes the main properties (chemical, mechanical and structural) recorded on very large blades and is based in particular on numerous fatigue corrosion test results to justify the use of the Ti 6 Al 4 V alloy in a specific context of micrographic structure

Primary Stability of Zirconium vs Titanium Implants: An In Vitro Comparison

Science.gov (United States)

2015-06-05

of any copyrighted material in the thesis manuscript entitled: Primary Stability of Zirconium vs Titanium Implants: An In Vitro Comparison Is...Uniformed Services University Date: 02/20/2015 Primary Stability of Zirconium vs Titanium Implants: An In Vitro Comparison By...the thesis manuscript entitled: Primary Stability of Zirconium vs Titanium Implants: An In Vitro Comparison Is appropriately acknowledged

Joining of Gamma Titanium Aluminides

National Research Council Canada - National Science Library

Baeslack, William

2002-01-01

.... Although organized and presented by joining process, many of the observations made and relationships developed, particularly those regarding the weldability and welding metallurgy of gamma titanium...

Compatibility of niobium, titanium, and vanadium metals with LMFBR cladding

International Nuclear Information System (INIS)

Wilson, C.N.

1975-10-01

A series of laboratory capsule annealing experiments were conducted to assess the compatibility of niobium, vanadium, and titanium with 316 stainless steel cladding in the temperature range of 700 to 800 0 C. Niobium, vanadium, and titanium are cantidate oxygen absorber materials for control of oxygen chemistry in LMFBR fuel pins. Capsule examination indicated good compatibility between niobium and 316 stainless steel at 800 0 C. Potential compatibility problems between cladding and vanadium or titanium were indicated at 800 0 C under reducing conditions. In the presence of Pu/sub 0.25/U/sub 0.75/O/sub 1.98/ fuel (Δanti G 02 congruent to -160 kcal/mole) no reaction was observed between vanadium or titanium and cladding at 800 0 C

Influence of titanium volume fraction on the mechanical properties of Mg-Ti composites

Energy Technology Data Exchange (ETDEWEB)

Perez, Pablo; Garces, Gerardo; Adeva, Paloma [Centro Nacional de Investigaciones Metalurgicas (CENIM, CSIC), Madrid (Spain). Dept. de Metalurgia Fisica

2009-03-15

The influence of titanium volume fraction on the mechanical properties of Mg-Ti composites prepared through a powder metallurgy route has been evaluated. Titanium was added as particles smaller than 25 {mu}m and volume fractions ranging from 5 to 15%. The increase in the volume fraction of titanium particles results in a slight decrease in the maximum strength. In contrast to this, the ductility of all composites was significantly enhanced by titanium additions. The mechanical properties can be explained on the basis of texture changes induced by the presence of titanium particles. The decrease in the basal texture along the extrusion direction as the amount of titanium is progressively increased accounts for the decrease in the maximum strength. (orig.)

Hydrogen content in titanium and a titanium–zirconium alloy after acid etching

Energy Technology Data Exchange (ETDEWEB)

Frank, Matthias J.; Walter, Martin S. [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, P.O. Box 1109, Blindern, NO-0317 Oslo (Norway); Institute of Medical and Polymer Engineering, Chair of Medical Engineering, Technische Universität München, Boltzmannstrasse 15, 85748 Garching (Germany); Lyngstadaas, S. Petter [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, P.O. Box 1109, Blindern, NO-0317 Oslo (Norway); Wintermantel, Erich [Institute of Medical and Polymer Engineering, Chair of Medical Engineering, Technische Universität München, Boltzmannstrasse 15, 85748 Garching (Germany); Haugen, Håvard J., E-mail: h.j.haugen@odont.uio.no [Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, P.O. Box 1109, Blindern, NO-0317 Oslo (Norway)

2013-04-01

Dental implant alloys made from titanium and zirconium are known for their high mechanical strength, fracture toughness and corrosion resistance in comparison with commercially pure titanium. The aim of the study was to investigate possible differences in the surface chemistry and/or surface topography of titanium and titanium–zirconium surfaces after sand blasting and acid etching. The two surfaces were compared by X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, scanning electron microscopy and profilometry. The 1.9 times greater surface hydrogen concentration of titanium zirconium compared to titanium was found to be the major difference between the two materials. Zirconium appeared to enhance hydride formation on titanium alloys when etched in acid. Surface topography revealed significant differences on the micro and nanoscale. Surface roughness was increased significantly (p < 0.01) on the titanium–zirconium alloy. High-resolution images showed nanostructures only present on titanium zirconium. - Highlights: ► TiZr alloy showed increased hydrogen levels over Ti. ► The alloying element Zr appeared to catalyze hydrogen absorption in Ti. ► Surface roughness was significantly increased for the TiZr alloy over Ti. ► TiZr alloy revealed nanostructures not observed for Ti.

Surface modification of porous titanium with rice husk as space holder

Science.gov (United States)

Wang, Xinsheng; Hou, Junjian; Liu, Yanpei

2018-06-01

Porous titanium was characterized after its surface modification by acid and alkali solution immersion. The results show that the acid surface treatment caused the emergence of flocculent sodium titanate and induced apatite formation. The surface modification of porous titanium promotes biological activation, and the application of porous titanium is also improved as an implant material because of the existence of C and Si.

Niobium Titanium and Copper wire samples

CERN Multimedia

2009-01-01

Two wire samples, both for carrying 13'000Amperes. I sample is copper. The other is the Niobium Titanium wiring used in the LHC magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair. The cables carry up to 12’500 amps and must withstand enormous electromagnetic forces. At full field, the force on one metre of magnet is comparable ...

Computational and Physical Analysis of Catalytic Compounds

Science.gov (United States)

Wu, Richard; Sohn, Jung Jae; Kyung, Richard

2015-03-01

Nanoparticles exhibit unique physical and chemical properties depending on their geometrical properties. For this reason, synthesis of nanoparticles with controlled shape and size is important to use their unique properties. Catalyst supports are usually made of high-surface-area porous oxides or carbon nanomaterials. These support materials stabilize metal catalysts against sintering at high reaction temperatures. Many studies have demonstrated large enhancements of catalytic behavior due to the role of the oxide-metal interface. In this paper, the catalyzing ability of supported nano metal oxides, such as silicon oxide and titanium oxide compounds as catalysts have been analyzed using computational chemistry method. Computational programs such as Gamess and Chemcraft has been used in an effort to compute the efficiencies of catalytic compounds, and bonding energy changes during the optimization convergence. The result illustrates how the metal oxides stabilize and the steps that it takes. The graph of the energy computation step(N) versus energy(kcal/mol) curve shows that the energy of the titania converges faster at the 7th iteration calculation, whereas the silica converges at the 9th iteration calculation.

Models for the adsorption of uranium on titanium dioxide

International Nuclear Information System (INIS)

Jaffrezic-Renault, N.; Poirier-Andrade, H.; Trang, D.H.

1980-01-01

A hydrated titanium oxide whose acid-base properties are well defined has been used to study the retention mechanism of uranium as UO 2 2+ (in acidic media) and as UO 2 (CO 3 ) 3 4- (in carbonate media). The influence of various parameters on the distribution coefficient of uranium (pH, [CO 3 2- ]) and of the adsorption of uranium on the electrophoretic mobilities of the titanium oxide have been investigated. It is shown that, in both media, coordinative TiO-UO 2 bonds are formed. These strong bonds explain the high affinity of the titanium oxide for uranium. (orig.)

Understanding the mechanical response of built-up welded beams made from commercially pure titanium and a titanium alloy

Energy Technology Data Exchange (ETDEWEB)

Patnaik, Anil K., E-mail: Patnaik@uakron.edu [Department of Civil Engineering, The University of Akron, Akron, OH 44325 (United States); Poondla, Narendra [Department of Civil Engineering, The University of Akron, Akron, OH 44325 (United States); Department of Mechanical Engineering, The University of Akron, Akron, OH 44325 (United States); Menzemer, Craig C. [Department of Civil Engineering, The University of Akron, Akron, OH 44325 (United States); Srivatsan, T.S. [Department of Mechanical Engineering, The University of Akron, Akron, OH 44325 (United States)

2014-01-10

During the last two decades, titanium has gradually grown in stature, strength and significance to take on the recognition of being a modern and high performance metal that is noticeably stronger and concurrently lighter than the most widely chosen and used steels in a spectrum of industrial applications. Technological innovations have necessitated reduction of part weight, cost and lead time, including concurrent enhancement of performance of structural parts and components made using titanium and its alloys. This has provided the impetus to develop economically viable structural design methodologies and specifications, while at the same time bringing forth innovative and economically affordable manufacturing and fabricating techniques with the primary purpose of both producing and promoting the use of cost-effective titanium structures. The experimental results of a recent study on built-up welded beams are presented in this paper with the primary objective of enabling design, facilitating fabrication, and implementation of large structural members for potential applications in the structural and defense-industry.

Predictions of titanium alloy properties using thermodynamic modeling tools

Science.gov (United States)

Zhang, F.; Xie, F.-Y.; Chen, S.-L.; Chang, Y. A.; Furrer, D.; Venkatesh, V.

2005-12-01

Thermodynamic modeling tools have become essential in understanding the effect of alloy chemistry on the final microstructure of a material. Implementation of such tools to improve titanium processing via parameter optimization has resulted in significant cost savings through the elimination of shop/laboratory trials and tests. In this study, a thermodynamic modeling tool developed at CompuTherm, LLC, is being used to predict β transus, phase proportions, phase chemistries, partitioning coefficients, and phase boundaries of multicomponent titanium alloys. This modeling tool includes Pandat, software for multicomponent phase equilibrium calculations, and PanTitanium, a thermodynamic database for titanium alloys. Model predictions are compared with experimental results for one α-β alloy (Ti-64) and two near-β alloys (Ti-17 and Ti-10-2-3). The alloying elements, especially the interstitial elements O, N, H, and C, have been shown to have a significant effect on the β transus temperature, and are discussed in more detail herein.

Matrix-reinforcement reactivity in P/M titanium matrix composites

International Nuclear Information System (INIS)

Amigo, V.; Romero, F.; Salvador, M. D.; Busquets, D.

2007-01-01

The high reactivity of titanium and the facility of the same one to form intermetallics makes difficult obtaining composites with this material and brings the need in any case of covering the principal fibres used as reinforcement. To obtain composites of titanium reinforced with ceramic particles ins proposed in this paper, for this reason it turns out to be fundamental to evaluate the reactivity between the matrix and reinforcement. Both titanium nitride and carbide (TiN and TiC) are investigated as materials of low reactivity whereas titanium silicide (TiSi 2 ) is also studied as materials of major reactivity, already stated by the scientific community. This reactivity will be analysed by means of scanning electron microscopy (SEM) there being obtained distribution maps of the elements that allow to establish the possible influence of the sintering temperature and time. Hereby the matrix-reinforcement interactions are optimized to obtain suitable mechanical properties. (Author) 39 refs

Geologic structure of Gofitsky deposit of titanium and zirconium and perspectives of the reserve base of titanium and zirconium in Russia

Science.gov (United States)

Kukhmazov, Iskander

2016-04-01

With the fall of the Soviet Union, all the mining deposits of titanium and zirconium appeared outside of Russian Federation. Therefore the studying of deposits of titanium and zirconium in Russia is very important nowadays. There is a paradoxical situation in the country: in spite of possible existence of national mineral resource base of Ti-Zr material, which can cover needs of the country, Russia is the one of the largest buyers of imported Ti-Zr material in the world. Many deposits are not mined, and those which are in the process of mining have poor reserves. Demand for this raw material is very great not only for Russia, but also for the world in general. Today there is a scarcity of zircon around the world and it will only increase through time. Therefore prices of products of titanium and zirconium also increase. Consequently Russian deposits of titanium and zirconium with higher content than foreign may become competitive. Russia is forced to buy raw materials (zirconium and titanium production) from former Soviet Union countries at prices higher than the world's and thus incur huge losses, including customs charges. Russia should create its own mineral resource base of Ti-Zr. Studied titanium-zirconium deposits of Stavropol region may become the basis for the south part of Russia. At first, Beshpagirsky deposit should be pointed out. It has large reserves of ore sands with high content of Ti-Zr. A combination of favorable geographical position of the area with developed industrial infrastructure makes it very beneficial as an object for high priority development. Gofitsky deposit should be pointed out as well. Its sands have a wide areal distribution and a high content of titanium and zirconium. Chokrak, Karagan-Konksk and Sarmatian sediments of the Miocene of Gofitsky deposit are productive for titanium and zirconium placers within Stavropol region of Russia. Gofitsky deposit was evaluated from financial and economic point of view and the following data

Karakteristik kawat TMA (titanium molybdenum alloy) dan penggunaannya dalam perawatan ortodonti

OpenAIRE

Arifiani, Putri; Erwin Siregar, Erwin Siregar

2016-01-01

Kawat merupakan salah satu piranti yang penting dalam perawatan ortodonsia. Perkembangan terkini dari kawat ortodonsia menghasilkan beberapa jenis kawat dengan karakteristik yang berbeda-beda. Studi pustaka membahas karakteristik kawat ortodonsi beta titanium atau Titanium Molybdenum Alloy (TMA) dan penggunaannya dalam perawatan ortodonsi. Perbedaan karakteristik tiap kawat menjadi hal yang perlu dipertimbangkan secara klinis. Kawat beta titanium atau sering disebut juga dengan kawat TMA (Tit...

The Sustainable Improvement of Manufacturing for Nano-Titanium

Directory of Open Access Journals (Sweden)

Chia-Nan Wang

2016-04-01

Full Text Available Scientists have found that nanomaterials possess many outstanding features in their tiny grain structure compared to other common materials. Titanium at the nano-grain scale shows many novel characteristics which demonstrate suitability for use in surgical implants. In general, equal channel angular pressing (ECAP is the most popular and simple process to produce nano-titanium. However, ECAP is time-consuming, power-wasting, and insufficiently produces the ultrafine grain structure. Therefore, the objective of this research is to propose a new method to improve the ECAP’s performances to reach the ultrafine grain structure, and also to save production costs, based on the innovation theory of Teoriya Resheniya Izobreatatelskih Zadatch (TRIZ. Research results show that the process time is reduced by 80%, and 94% of the energy is saved. Moreover, the grain size of the diameter for nano-titanium can be reduced from 160 nanometers (nm to 80 nm. The results are a 50% reduction of diameter and a 75% improvement of volume. At the same time, the method creates a refined grain size and good mechanical properties in the nano-titanium. The proposed method can be applied to produce any nanomaterial as well as biomaterials.

Diameter of titanium nanotubes influences anti-bacterial efficacy

International Nuclear Information System (INIS)

Ercan, Batur; Taylor, Erik; Webster, Thomas J; Alpaslan, Ece

2011-01-01

Bacterial infection of in-dwelling medical devices is a growing problem that cannot be treated by traditional antibiotics due to the increasing prevalence of antimicrobial resistance and biofilm formation. Here, due to changes in surface parameters, it is proposed that bacterial adhesion can be prevented through nanosurface modifications of the medical device alone. Toward this goal, titanium was created to possess nanotubular surface topographies of highly controlled diameters of 20, 40, 60, or 80 nm, sometimes followed by heat treatment to control chemistry and crystallinity, through a novel anodization process. For the first time it was found that through the control of Ti surface parameters including chemistry, crystallinity, nanotube size, and hydrophilicity, significantly changed responses of both Staphylococcus epidermidis and Staphylococcus aureus (pathogens relevant for orthopaedic and other medical device related infections) were measured. Specifically, heat treatment of 80 nm diameter titanium tubes produced the most robust antimicrobial effect of all surface treatment parameters tested. This study provides the first step toward understanding the surface properties of nano-structured titanium that improve tissue growth (as has been previously observed with nanotubular titanium), while simultaneously reducing infection without the use of pharmaceutical drugs.

Diameter of titanium nanotubes influences anti-bacterial efficacy

Energy Technology Data Exchange (ETDEWEB)

Ercan, Batur; Taylor, Erik; Webster, Thomas J [School of Engineering, Brown University, Providence, RI 02917 (United States); Alpaslan, Ece, E-mail: thomas_webster@brown.edu [Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul (Turkey)

2011-07-22

Bacterial infection of in-dwelling medical devices is a growing problem that cannot be treated by traditional antibiotics due to the increasing prevalence of antimicrobial resistance and biofilm formation. Here, due to changes in surface parameters, it is proposed that bacterial adhesion can be prevented through nanosurface modifications of the medical device alone. Toward this goal, titanium was created to possess nanotubular surface topographies of highly controlled diameters of 20, 40, 60, or 80 nm, sometimes followed by heat treatment to control chemistry and crystallinity, through a novel anodization process. For the first time it was found that through the control of Ti surface parameters including chemistry, crystallinity, nanotube size, and hydrophilicity, significantly changed responses of both Staphylococcus epidermidis and Staphylococcus aureus (pathogens relevant for orthopaedic and other medical device related infections) were measured. Specifically, heat treatment of 80 nm diameter titanium tubes produced the most robust antimicrobial effect of all surface treatment parameters tested. This study provides the first step toward understanding the surface properties of nano-structured titanium that improve tissue growth (as has been previously observed with nanotubular titanium), while simultaneously reducing infection without the use of pharmaceutical drugs.

Diameter of titanium nanotubes influences anti-bacterial efficacy

Science.gov (United States)

Ercan, Batur; Taylor, Erik; Alpaslan, Ece; Webster, Thomas J.

2011-07-01

Bacterial infection of in-dwelling medical devices is a growing problem that cannot be treated by traditional antibiotics due to the increasing prevalence of antimicrobial resistance and biofilm formation. Here, due to changes in surface parameters, it is proposed that bacterial adhesion can be prevented through nanosurface modifications of the medical device alone. Toward this goal, titanium was created to possess nanotubular surface topographies of highly controlled diameters of 20, 40, 60, or 80 nm, sometimes followed by heat treatment to control chemistry and crystallinity, through a novel anodization process. For the first time it was found that through the control of Ti surface parameters including chemistry, crystallinity, nanotube size, and hydrophilicity, significantly changed responses of both Staphylococcus epidermidis and Staphylococcus aureus (pathogens relevant for orthopaedic and other medical device related infections) were measured. Specifically, heat treatment of 80 nm diameter titanium tubes produced the most robust antimicrobial effect of all surface treatment parameters tested. This study provides the first step toward understanding the surface properties of nano-structured titanium that improve tissue growth (as has been previously observed with nanotubular titanium), while simultaneously reducing infection without the use of pharmaceutical drugs.

Microstructure and high temperature oxidation resistance of Ti-Ni gradient coating on TA2 titanium alloy fabricated by laser cladding

Science.gov (United States)

Liu, Fencheng; Mao, Yuqing; Lin, Xin; Zhou, Baosheng; Qian, Tao

2016-09-01

To improve the high temperature oxidation resistance of TA2 titanium alloy, a gradient Ni-Ti coating was laser cladded on the surface of the TA2 titanium alloy substrate, and the microstructure and oxidation behavior of the laser cladded coating were investigated experimentally. The gradient coating with a thickness of about 420-490 μm contains two different layers, e.g. a bright layer with coarse equiaxed grain and a dark layer with fine and columnar dendrites, and a transition layer with a thickness of about 10 μm exists between the substrate and the cladded coating. NiTi, NiTi2 and Ni3Ti intermetallic compounds are the main constructive phases of the laser cladded coating. The appearance of these phases enhances the microhardness, and the dense structure of the coating improves its oxidation resistance. The solidification procedure of the gradient coating is analyzed and different kinds of solidification processes occur due to the heat dissipation during the laser cladding process.

Osteoblastic response to pectin nanocoating on titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Gurzawska, Katarzyna, E-mail: kagu@sund.ku.dk [Research Center for Ageing and Osteoporosis, Departments of Medicine and Diagnostics, Copenhagen University Hospital Glostrup, Ndr. Ringvej 57, 2600 Glostrup (Denmark); Institute of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 20, 2200 Copenhagen N (Denmark); Svava, Rikke [Department of Plant Environment Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Copenhagen Center for Glycomics, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N (Denmark); Yihua, Yu; Haugshøj, Kenneth Brian [Microtechnology and Surface Analysis, Danish Technological Institute, Gregersensvej 8, 2630 Taastrup (Denmark); Dirscherl, Kai [Dansk Fundamental Metrologi A/S, Matematiktorvet 307, 2800 Lyngby (Denmark); Levery, Steven B. [Copenhagen Center for Glycomics, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N (Denmark); Byg, Inge [Department of Plant Environment Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Damager, Iben [Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd (Denmark); Nielsen, Martin W. [Department of Systems Biology, Technical University of Denmark, Matematiktorvet, Building 301, Kgs. Lyngby DK-2800 (Denmark); Jørgensen, Bodil [Department of Plant Environment Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Jørgensen, Niklas Rye [Research Center for Ageing and Osteoporosis, Departments of Medicine and Diagnostics, Copenhagen University Hospital Glostrup, Ndr. Ringvej 57, 2600 Glostrup (Denmark); and others

2014-10-01

Osseointegration of titanium implants can be improved by organic and inorganic nanocoating of the surface. The aim of our study was to evaluate the effect of organic nanocoating of titanium surface with unmodified and modified pectin Rhamnogalacturonan-Is (RG-Is) isolated from potato and apple with respect to surface properties and osteogenic response in osteoblastic cells. Nanocoatings on titanium surfaces were evaluated by scanning electron microscopy, contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy. The effect of coated RG-Is on cell adhesion, cell viability, bone matrix formation and mineralization was tested using SaOS-2 cells. Nanocoating with pectin RG-Is affected surface properties and in consequence changed the environment for cellular response. The cells cultured on surfaces coated with RG-Is from potato with high content of linear 1.4-linked galactose produced higher level of mineralized matrix compared with control surfaces and surfaces coated with RG-I with low content of linear 1.4-linked galactose. The study showed that the pectin RG-Is nanocoating not only changed chemical and physical titanium surface properties, but also specific coating with RG-Is containing high amount of galactan increased mineralized matrix formation of osteoblastic cells in vitro. - Highlights: • Surface nanocoating with plant-derived Rhamnogalacturonan-I (RG-I) is proposed. • Titanium surface became more hydrophilic after RG-Is nanocoating. • RG-Is with high galactose content resulted in high level of mineralized matrix. • RG-I is a new candidate for improvement of bone healing and osseointegration.

Effect of Nanosheet Surface Structure of Titanium Alloys on Cell Differentiation

Directory of Open Access Journals (Sweden)

Satoshi Komasa

2014-01-01

Full Text Available Titanium alloys are the most frequently used dental implants partly because of the protective oxide coating that spontaneously forms on their surface. We fabricated titania nanosheet (TNS structures on titanium surfaces by NaOH treatment to improve bone differentiation on titanium alloy implants. The cellular response to TNSs on Ti6Al4V alloy was investigated, and the ability of the modified surfaces to affect osteogenic differentiation of rat bone marrow cells and increase the success rate of titanium implants was evaluated. The nanoscale network structures formed by alkali etching markedly enhanced the functions of cell adhesion and osteogenesis-related gene expression of rat bone marrow cells. Other cell behaviors, such as proliferation, alkaline phosphatase activity, osteocalcin deposition, and mineralization, were also markedly increased in TNS-modified Ti6Al4V. Our results suggest that titanium implants modified with nanostructures promote osteogenic differentiation, which may improve the biointegration of these implants into the alveolar bone.

Titanium minerals of placer deposits as a source for new materials

Science.gov (United States)

Kotova, Olga; Ponaryadov, Alexey

2015-04-01

Heavy mineral deposits are a source of the economic important element titanium, which is contained in ilmenite and leucoxene. The mineral composition of placer titanium ore and localization pattern of ore minerals determine their processing and enriching technologies. New data on the mineralogy of titanium ores from modern coastal-marine placer in Stradbroke Island, Eastern Australia, and Pizhma paleoplacer in Middle Timan, Russia, and materials on their basis are presented. The samples were studied by the following methods: optical-mineralogical (stereomicroscope MBS-10, polarizing microscope POLAM L-311), semiquantitative x-ray phase analysis (x-ray difractometer X'Pert PRO MPD). Besides microprobe (VEGA 3 TESCAN) and x-ray fluorescent analysis (XRF-1800 Shimadzu) were used. By the mineralogical composition ores of the both deposits are complex: enriched by valuable minerals. Apart from main ore concentrates it is possible to obtain accompanying nonmetallic products. This will increase the efficiency of deposit exploitation. Ilmenite dominates in ore sands of Stradbroke Island, and leucoxene dominates in the ores of the Pizhma titanium deposit. Australian ilmenite and its altered varieties are mainly characterized by a very high MnO content (from 5.24 to 11.08 %). The irregular distribution of iron oxides, titanium and manganese in the altered ilmenite was shown in the paper. E.g., in the areas of substitution of ilmenite by pseudorutile the concentrations of the given elements are greatly various due to various ratios of basic components in each grain. Their ratios are equal in the area of rutile evolution. Moreover, the high content of gold, diamonds and also rare earth elements (REE) and rare metals (their forms are not determined) were studied. We found native copper on the surface of minerals composing titanium-bearing sandstones of the Pizhma placer. According to the technological features of rocks (density and magnetic) studied placers are close. The

Enhancement of catalyst performance in the direct propene epoxidation: a study into gold-titanium synergy

NARCIS (Netherlands)

Chen, J.; Halin, S.J.A.; Pidko, E.A.; Verhoeven, M.W.G.M.; Perez Ferrandez, D.M.; Hensen, E.J.M.; Schouten, J.C.; Nijhuis, T.A.

2013-01-01

Enhanced productivity toward propene oxide in the direct propene epoxidation with hydrogen and oxygen over gold nanoparticles supported on titanium-grafted silica was achieved by adjusting the gold–titanium synergy. Highly isolated titanium sites were obtained by lowering the titanium loading

On the characteristics and application of thin wall welded titanium tubes for heat transfer

International Nuclear Information System (INIS)

Nishimura, Takashi; Miyamoto, Yoshiyuki

1985-01-01

Because of the excellent corrosion resistance, thin wall welded titanium tubes have become to be used in large number as the heat transfer tubes of condensers and seawater desalting plants using seawater in place of conventional copper alloy tubes. Especially in nuclear power plants, the all titanium condensers using thin wall welded titanium tubes and titanium tube plates were adopted in the almost all plants under construction or expected to be constructed. In this report, the various characteristics of thin wall welded titanium tubes required for using them as heat transfer tubes, such as corrosion resistance, heat transfer characteristics, fatigue strength and expanding characteristics, are outlined, and the state of use is described. At first, relatively thick seamless titanium tubes were used for chemical industry, but thereafter, due to the advance of the mass production techniques, the welded titanium tubes of less than 0.7 mm thickness and high quality have become to be supplied at low cost. In 1969, titanium tubes were used for the first time in Japan for the air cooler in the condenser of Akita Power Station, Tohoku Electric Power Co., Inc. The features of titanium are small specific gravity, small linear expansion coefficient and small Young's modulus. (Kako, I.)

Crystalline hydroxyapatite coatings synthesized under hydrothermal conditions on modified titanium substrates.

Science.gov (United States)

Suchanek, Katarzyna; Bartkowiak, Amanda; Gdowik, Agnieszka; Perzanowski, Marcin; Kąc, Sławomir; Szaraniec, Barbara; Suchanek, Mateusz; Marszałek, Marta

2015-06-01

Hydroxyapatite coatings were successfully produced on modified titanium substrates via hydrothermal synthesis in a Ca(EDTA)(2-) and (NH4)2HPO4 solution. The morphology of modified titanium substrates as well as hydroxyapatite coatings was studied using scanning electron microcopy and phase identification by X-ray diffraction, and Raman and FTIR spectroscopy. The results show that the nucleation and growth of hydroxyapatite needle-like crystals with hexagonal symmetry occurred only on titanium substrates both chemically and thermally treated. No hydroxyapatite phase was detected on only acid etched Ti metal. This finding demonstrates that only a particular titanium surface treatment can effectively induce the apatite nucleation under hydrothermal conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

STUDY OF THERMAL BEHAVIOUR ON TITANIUM ALLOYS (TI-6AL-4V

Directory of Open Access Journals (Sweden)

VASUDEVAN D

2017-08-01

Full Text Available Titanium is recognized for its strategic importance as a unique lightweight, high strength alloyed structurally efficient metal for critical, high-performance aircraft, such as jet engine and airframe components. Titanium is called as the "space age metal" and is recognized for its high strength-to-weight ratio. Today, titanium alloys are common, readily available engineered metals that compete directly with stainless steel and Specialty steels, copper alloys, nickel based alloys and composites. Titanium alloys are needed to be heat treated in order to reduce residual stress developed during fabrication and to increase the strength. Titanium (Ti-6Al-4V alloy is an alpha, beta alloy which is solution treated at a temperature of 950 ºC to attain beta phase. This beta phase is maintained by quenching and subsequent aging to increase strength. Thermal cycling process was carried out for Ti-6Al-4V specimens using forced air cooling. Heat treated titanium alloy specimen was used to carry out various tests before and after thermal cycling, The test, like tensile properties, co-efficient of thermal expansion, Microstructure, Compression test, Vickers Hardness was examined by the following test. Coefficient of Thermal expansion was measured using Dilatometer. Tensile test was carried out at room temperature using an Instron type machine. Vickers's hardness measurement was done on the same specimen as used for the microstructural observation from near the surface to the inside specimen. Compression test was carried out at room temperature using an Instron type machine. Ti‐6Al‐4V alloy is a workhorse of titanium industry; it accounts for about 60 percent of the total titanium alloy production. The high cost of titanium makes net shape manufacturing routes very attractive. Casting is a near net shape manufacturing route that offers significant cost advantages over forgings or complicated machined parts.

Shock response of a gamma titanium aluminide

International Nuclear Information System (INIS)

Shazly, Mostafa; Prakash, Vikas

2008-01-01

Potential use of γ-TiAl alloys in aerospace and other structural applications require knowledge of their impact behavior for better evaluation and modeling. In the present study plate impact experiments are conducted using a single-stage gas gun to better understand the shock behavior of the recently developed class of gamma titanium aluminide alloys--the Gamma-Met PX. The Gamma-Met PX showed superior shock properties when compared to the conventional titanium aluminide alloys. The spall strength of Gamma-Met PX is 1.8±0.09 GPa, which is four to six times higher than those reported for other gamma titanium aluminide alloys. Moreover, it has a Hugoniot elastic limit of 1.88 GPa at a target thickness of 3.86 mm, which drops to 1.15 GPa at target thickness of 15.8 mm. The decay in the elastic precursor is continuous without showing an asymptote to a constant level within the range of target thicknesses studied

Tunable functionality and toxicity studies of titanium dioxide nanotube layers

International Nuclear Information System (INIS)

Feschet-Chassot, E.; Raspal, V.; Sibaud, Y.; Awitor, O.K.; Bonnemoy, F.; Bonnet, J.L.; Bohatier, J.

2011-01-01

In this study, we have developed a simple process to fabricate scalable titanium dioxide nanotube layers which show a tunable functionality. The titanium dioxide nanotube layers were prepared by electrochemical anodization of Ti foil in 0.4 wt.% hydrofluoric acid solution. The nanotube layers structure and morphology were characterized using X-ray diffraction and scanning electron microscopy. The surface topography and wettability were studied according to the anodization time. The sample synthesized displayed a higher contact angle while the current density reached a local minimum. Beyond this point, the contact angles decreased with anodization time. Photo-degradation of acid orange 7 in aqueous solution was used as a probe to assess the photocatalytic activity of titanium dioxide nanotube layers under UV irradiation. We obtained better photocatalytic activity for the sample fabricated at higher current density. Finally we used the Ciliated Protozoan T. pyriformis, an alternative cell model used for in vitro toxicity studies, to predict the toxicity of titanium dioxide nanotube layers in a biological system. We did not observe any characteristic effect in the presence of the titanium dioxide nanotube layers on two physiological parameters related to this organism, non-specific esterases activity and population growth rate.

Anisotropic elastic and thermal properties of titanium borides by first-principles calculations

Energy Technology Data Exchange (ETDEWEB)

Sun, Liang; Gao, Yimin [State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049 (China); Xiao, Bing [Department of Physics and Quantum Theory Group, School of Science and Engineering, Tulane University, New Orleans, LA 70118 (United States); Li, Yefei, E-mail: yefeili@126.com [State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Guoliang [State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049 (China)

2013-12-05

Highlights: •Elastic properties of titanium borides are calculated by first principles calculation. •Thermodynamical stability of titanium borides is analyzed. •Heat capacity and thermal expansion coefficient for titanium borides are calculated and compared. •Grüneisen parameters of titanium borides are calculated. -- Abstract: The anisotropic elastic and thermal expansions of the titanium borides (TiB{sub 2}, Ti{sub 3}B{sub 4}, TiB{sub P}nma and TiB{sub F}m3{sup ¯}m) are calculated from first-principles using density functional theory. All borides show different anisotropic elastic properties; the bulk, shear and Young’s moduli are consistent with those determined experimentally. The temperature dependence of thermal expansions is mainly caused by the restoration of thermal energy due to phonon excitations at low temperature. When the temperature is higher than 500 K, the volumetric coefficient is increased linearly by increasing temperature. Meanwhile, the heat capacities of titanium borides are obtained based on the knowledge of thermal expansion coefficient and the elasticity, the calculations are in good agreement with the experiments.

Performance test of twised-wired titanium evaporators for in-situ Tic deposition

International Nuclear Information System (INIS)

Inagawa, Konosuke; Abe, Tetsuya; Hiroki, Seiji; Obara, Kenjiro; Murakami, Yoshio

1984-06-01

In order to establish the titanium evaporation source for in-situ TiC deposition, performance test has been made for several types of twisted-wired, ohmic-heating titanium evaporators. The evaporator which exhibited the best performance consists of three tungsten wires twisted as the core of the composite, three titanium wires and a molybdenum wire densely wound around the core, and a thin tungsten wire coarsely wound at the outermost side of the composite. The molybdenum wire around the core plays an important role in wetting the core surface uniformly with the melt of titanium. The tungsten wire at the outermost side prevents the molten titanium from dropping to the inside wall of the vacuum vessel. A typical size of the evaporator is 4 mm in diameter and 140 mm in length. In this case 2--2.5g of titanium, which corresponds to 70 - 80 % of charged amount (3.2g), can be evaporated at a rate of about 0.14 g/min. On the basis of the experimental results, the applicability of the evaporator to JT-60 is discussed. (author)

Microstructure analysis and wear behavior of titanium cermet femoral head with hard TiC layer.

Science.gov (United States)

Luo, Yong; Ge, Shirong; Liu, Hongtao; Jin, Zhongmin

2009-12-11

Titanium cermet was successfully synthesized and formed a thin gradient titanium carbide coating on the surface of Ti6Al4V alloy by using a novel sequential carburization under high temperature, while the titanium cermet femoral head was produced. The titanium cermet phase and surface topography were characterized with X-ray diffraction (XRD) and backscattered electron imaging (BSE). And then the wear behavior of titanium cermet femoral head was investigated by using CUMT II artificial joint hip simulator. The surface characterization indicates that carbon effectively diffused into the titanium alloys and formed a hard TiC layer on the Ti6Al4V alloys surface with a micro-porous structure. The artificial hip joint experimental results show that titanium cermet femoral head could not only improve the wear resistance of artificial femoral head, but also decrease the wear of UHMWPE joint cup. In addition, the carburized titanium alloy femoral head could effectively control the UHMWPE debris distribution, and increase the size of UHMWPE debris. All of the results suggest that titanium cermet is a prospective femoral head material in artificial joint.

Fundamental corrosion characterization of high-strength titanium alloys

International Nuclear Information System (INIS)

Schutz, R.W.; Grauman, J.S.

1984-01-01

Many commercially available and several developmental high-strength titanium alloys were evaluated for application in chloride-containing environments with respect to general, crevice, and stress corrosion resistance. Studies in boiling reducing and oxidizing acid chloride media permitted identification of certain high-strength titanium alloys, containing ≥4 weight % molybdenum, which are significantly more resistant than unalloyed titanium with respect to general and crevice attack. Data regression analysis suggests that molybdenum and vanadium impart a significant positive effect on alloy corrosion resistance under reducing acid chloride conditions, whereas aluminum is detrimental. Little effect of metallurgical condition (that is, annealed versus aged) on corrosion behavior of the higher molybdenum-containing alloys was noted. No obvious susceptibility to chloride and sulfide stress corrosion cracking (SCC) was detected utilizing U-bend specimens at 177 0 C

Dense and porous titanium substrates with a biomimetic calcium phosphate coating

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, A.A., E-mail: aantunesr@yahoo.com.br [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil); Balestra, R.M. [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil); Rocha, M.N. [Metallurgical and Materials Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68505, 21941-972 Rio de Janeiro, RJ (Brazil); Peripolli, S.B. [Materials Metrology Division, National Institute of Metrology, Normalization and Quality, No. 50 Nossa Senhora das Gracas Street, Building 3, 25250-020 Duque de Caxias, RJ (Brazil); Andrade, M.C. [Polytechnic Institute of Rio de Janeiro, Rio de Janeiro State University, s/n, Alberto Rangel Street, 28630-050 Nova Friburgo, RJ (Brazil); Pereira, L.C. [Metallurgical and Materials Engineering Program, COPPE, Federal University of Rio de Janeiro, P.O. Box 68505, 21941-972 Rio de Janeiro, RJ (Brazil); Oliveira, M.V. [Powder Technology Laboratory, Materials Processing and Characterization Division, National Institute of Technology, No. 82 Venezuela Avenue, Room 602, 20081-312 Rio de Janeiro, RJ (Brazil)

2013-01-15

Highlights: Black-Right-Pointing-Pointer A biomimetic coating method with simplified solution is proposed. Black-Right-Pointing-Pointer Titanium substrates are submitted to chemical and heat treatments. Black-Right-Pointing-Pointer Titanium substrates are coated with biocompatible calcium phosphate phases. Black-Right-Pointing-Pointer The simplified solution shows potential to be applied as a coating technique. - Abstract: The present work studied a biomimetic method using a simplified solution (SS) with calcium and phosphorus ions for coating titanium substrates, in order to improve their bioactivity. Commercially pure titanium dense sheet, microporous and macroporous titanium samples, both produced by powder metallurgy, were treated in NaOH solution followed by heat-treating and immersed in SS for 7, 14 or 21 days. The samples characterization was performed by quantitative metallographic analysis, confocal scanning optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and low angle X-ray diffraction. The results showed coatings with calcium phosphate precipitation in all samples, with globular or plate-like morphology, typical of hydroxyapatite and octacalcium phosphate, respectively, indicating that the solution (SS) has potential for coating titanium substrates. In addition, the different surfaces of substrates had an effect on the formed calcium phosphate phase and thickness of coatings, depending on the substrate type and imersion time in the simplified solution.

Evaluation of the sorption of Eu(III) in titanium diphosphate

International Nuclear Information System (INIS)

Ortiz O, H.B.; Ordonez R, E.; Fernandez V, S.M.

2007-01-01

In this work its are presented: the synthesis, physicochemical characterization and the surface parameters estimation that can be related with the retention properties of the titanium diphosphate for the actinides of valence III (Pu, Am, Cm among others), using the Eu 3+ like a chemical analog. The surface area, hydration time, zero charge point, density of active sites and the surface species distribution in the titanium diphosphate are reported. This information was used to explain the retention of the Eu(lll) in the surface of the titanium diphosphate. (Author)

The precipitation behavior of titanium carbide on the surface of SUS 321 stainless steel

International Nuclear Information System (INIS)

Yoshihara, Kazuhiro; Nii, Kazuyoshi

1982-01-01

The surface composition of SUS 321 stainless steel at high temperatures was observed in vacuum with Auger electron spectroscopy. The precipitation of titanium carbide was found on the surface of SUS 321. The thickness of precipitated titanium carbide layer increased in proportion to the square root of annealing time and became about 0.05 μm after heated at 1100 K for 432 ks. The precipitated titanium carbide was not replaced by the most surface active element sulfur, and remained stable on the surface. The precipitated layer, however, was not even and had many holes about 1 μm in diameter. The bottom of a hole was SUS 321, on which phosphorus, oxygen and sulfur segregated. As the annealing time was prolonged, these segregants were replaced one by one in the order of the surface activity, and finally the most surface active element, sulfur, remained on the bottom of the hole. Moreover, sulfur diffused over the outside of the hole. The precipitation of titanium carbide on the surface occurred according to the following processes: (1) The titanium and carbon which had been dissolved in the bulk diffused onto the surface of the stainless steel. (2) The titanium carbide which had been precipitated in the bulk dissolved because the concentration of titanum and carbon fell under their solubility limits in the bulk. (3) The titanium and carbon diffused onto the surface which was exposed to vacuum. (4) The titanium and carbon recombined into titanium carbide and precipitated on the surface. The growth rate of the thickness of the precipitated layer was controlled by the diffusion of titanium and carbon in the precipitated titanium carbide. (J.P.N.)

The effect of dynamic aging on the strain hardening rate of titanium

International Nuclear Information System (INIS)

Monteiro, S.N.; Reed-Hill, R.E.

1974-01-01

A study is made of the effect due to the interaction of solute atoms with mobile dislo cations, known as dynamic aging on the strain hardening characteristics of titanium between 150 and 477K. The results obtained with commercially pure titanium are compared with those obtained using high - purity titanium in order to evaluate the extent of effect [pt

Synthesis and characterization of mixtures of cobalt and titanium oxides by mechanical alloyed and Sol-Gel

International Nuclear Information System (INIS)

Basurto S, R.; Bonifacio M, J.; Fernandez V, S. M.

2009-01-01

The mechanical alloyed techniques continued by combustion and Sol-Gel method, were used for the synthesis of CoTiO 3 . With the first technique was used Co 3 O 4 obtained in a balls mill SPEX in argon atmosphere, using cobalt nitrate and urea, the combustion is realized at 400 and 500 C, the characterization by X-ray diffraction showed the obtaining of the valence oxide mixed of cobalt with crystallite size from 10 to 12.5 nm and the particle size of 60 to 75 nm was obtained by scanning electron microscopy. To prepare the CoTiO 3 , the obtained Co 3 O 4 was mixed with TiO 2 on a relationship in weight (1:1) and with a milling time of 2.5 h and the combustion at 800 C. the mixed oxide of titanium cobalt was also obtained by the Sol-Gel technique starting from cobalt chloride and titanium propoxide in acetic-water acid, the gel is burned to temperature of 300, 500, 700 and 900 C, finding that this last temperature it is that provides the compound with crystalline size from 50 to 75 nm. (Author)

The microstructure and properties of titanium dioxide films synthesized by unbalanced magnetron sputtering

International Nuclear Information System (INIS)

Leng, Y.X.; Chen, J.Y.; Yang, P.; Sun, H.; Huang, N.

2007-01-01

In this work, titanium oxide films were deposited on Ti6Al4V and Si (1 0 0) by DC unbalanced magnetron sputtering method at different oxygen pressure. X-ray diffraction (XRD), microhardness tests, pin-on-disk wear experiments, surface contact angle tests and platelet adhesion investigation were conducted to evaluate the properties of the films. The corrosion behavior of titanium dioxide films was characterized by potentiodynamic polarization. The results showed that titanium oxide films deposited by unbalance magnetron sputtering were compact and could obviously enhance microhardness, wear resistance of titanium alloy substrate. Potentiodynamic polarization curves showed that Ti-6Al-4V deposited with titanium dioxide films had lower dissolution currents than that of the uncoated one. The results of in vitro hemocompatibility analyses indicated that the blood compatibility of the titanium dioxide films with bandgap 3.2 eV have better blood compatibility

The Properties of Titanium and Its Alloys

OpenAIRE

BIŠĆAN, VLATKA; LUETIĆ, VIKTORIJA

2012-01-01

Titanium metal is silver-grey color and high gloss, the ninth element of the abundance in the Earth’s crust, and can be found in meteorites. It has a low electrical conductivity and low coefficient of thermal expansion. Since titanium has a great passivity, its physical property is a high level of corrosion resistance to most mineral acids and chlorides. It has mechanical properties such as steel, has a high melting temperature and is light. Since it is highly resistant to corrosion it is app...

Swelling behavior of titanium-modified AISI 316 alloys

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.; Puigh, R.J.

1984-01-01

It appears that titanium additions to stainless steels covering a wide compositional range around the specifications of AISI 316 result only in an increased delay period before neutron-induced void swelling proceeds. Once swelling is initiated the post transient behavior of both annealed and cold-worked titanium-modified steels is quite consistent with that of AISI 316, approaching a relatively temperature-independent swelling rate of approx. 1% per dpa

Mechanochemistry of titanium oxides

Directory of Open Access Journals (Sweden)

Veljković Ivana

2009-01-01

Full Text Available Mechanochemistry represents an alternative route in synthesis of nanomaterials. Mechanochemical routes are attractive because of their simplicity, flexibility, and ability to prepare materials by solid state reactions at room temperature. The aim of this work is the mechanochemical synthesis of nanostructured titanium oxides of different composition starting from mixtures of Ti and TiO2, TiO and TiO2 or Ti2O3 and TiO2. Emphasis is on the Magneli phases Ti4O7 and Ti5O9 because their mixture is commercially known as EBONEX material. The materials prepared were characterized by XRPD, TG/DTA analysis, SEM and optical microscopy. Titanium monoxide and several Magneli oxides, Ti4O7, Ti5O9 and Ti6O11, are successfully prepared. The results are very interesting because the EBONEX materials were prepared at lower than usual temperature, which would decrease the effective cost of production.

Nickel and titanium nanoboride composite coating

International Nuclear Information System (INIS)

Efimova, K A; Galevsky, G V; Rudneva, V V; Kozyrev, N A; Orshanskaya, E G

2015-01-01

Electrodeposition conditions, structural-physical and mechanical properties (microhardness, cohesion with a base, wear resistance, corrosion currents) of electroplated composite coatings on the base of nickel with nano and micro-powders of titanium boride are investigated. It has been found out that electro-crystallization of nickel with boride nanoparticles is the cause of coating formation with structural fragments of small sizes, low porosity and improved physical and mechanical properties. Titanium nano-boride is a component of composite coating, as well as an effective modifier of nickel matrix. Nano-boride of the electrolyte improves efficiency of the latter due to increased permissible upper limit of the cathodic current density. (paper)

Preparation of Ti3Al intermetallic compound by spark plasma sintering

Science.gov (United States)

Ito, Tsutomu; Fukui, Takahiro

2018-04-01

Sintered compacts of single phase Ti3Al intermetallic compound, which have excellent potential as refractory materials, were prepared by spark plasma sintering (SPS). A raw powder of Ti3Al intermetallic compound with an average powder diameter of 176 ± 56 μm was used in this study; this large powder diameter is disadvantageous for sintering because of the small surface area. The samples were prepared at sintering temperatures (Ts) of 1088, 1203, and 1323 K, sintering stresses (σs) of 16, 32, and 48 MPa, and a sintering time (ts) of 10 min. The calculated relative densities based on the apparent density of Ti3Al provided by the supplier were approximately 100% under all sintering conditions. From the experimental results, it was evident that SPS is an effective technique for dense sintering of Ti3Al intermetallic compounds in a short time interval. In this report, the sintering characteristics of Ti3Al intermetallic compacts are briefly discussed and compared with those of pure titanium compacts.

Removal of symptomatic craniofacial titanium hardware following craniotomy: Case series and review

Directory of Open Access Journals (Sweden)

Sheri K. Palejwala

2015-06-01

Full Text Available Titanium craniofacial hardware has become commonplace for reconstruction and bone flap fixation following craniotomy. Complications of titanium hardware include palpability, visibility, infection, exposure, pain, and hardware malfunction, which can necessitate hardware removal. We describe three patients who underwent craniofacial reconstruction following craniotomies for trauma with post-operative courses complicated by medically intractable facial pain. All three patients subsequently underwent removal of the symptomatic craniofacial titanium hardware and experienced rapid resolution of their painful parasthesias. Symptomatic plates were found in the region of the frontozygomatic suture or MacCarty keyhole, or in close proximity with the supraorbital nerve. Titanium plates, though relatively safe and low profile, can cause local nerve irritation or neuropathy. Surgeons should be cognizant of the potential complications of titanium craniofacial hardware and locations that are at higher risk for becoming symptomatic necessitating a second surgery for removal.

Photocatalytic Water Treatment by Titanium Dioxide: Recent Updates

Directory of Open Access Journals (Sweden)

Manoj A. Lazar

2012-12-01

Full Text Available Photocatalytic water treatment using nanocrystalline titanium dioxide (NTO is a well-known advanced oxidation process (AOP for environmental remediation. With the in situ generation of electron-hole pairs upon irradiation with light, NTO can mineralize a wide range of organic compounds into harmless end products such as carbon dioxide, water, and inorganic ions. Photocatalytic degradation kinetics of pollutants by NTO is a topic of debate and the mostly reporting Langmuir-Hinshelwood kinetics must accompanied with proper experimental evidences. Different NTO morphologies or surface treatments on NTO can increase the photocatalytic efficiency in degradation reactions. Wisely designed photocatalytic reactors can decrease energy consumption or can avoid post-separation stages in photocatalytic water treatment processes. Doping NTO with metals or non-metals can reduce the band gap of the doped catalyst, enabling light absorption in the visible region. Coupling NTO photocatalysis with other water-treatment technologies can be more beneficial, especially in large-scale treatments. This review describes recent developments in the field of photocatalytic water treatment using NTO.

Titanium condenser tubes. Problems and their solution for wider application to large surface condensers. [PWR

Energy Technology Data Exchange (ETDEWEB)

Sato, S; Sugiyama, S; Nagata, K; Nanba, K; Shimono, M [Sumitomo Light Metal Industries Ltd., Tokyo (Japan)

1977-06-01

The corrosion resistance of titanium in sea water is extremely excellent, but titanium tubes are expensive, and the copper alloy tubes resistant in polluted sea water were developed, therefore they were not used practically. In 1970, ammonia attack was found on the copper alloy tubes in the air-cooled portion of condensers, and titanium tubes have been used as the countermeasure. As the result of the use, the galvanic attack on copper alloy tube plates with titanium tubes as cathode and the hydrogen absorption at titanium tube ends owing to excess electrolytic protection was observed, but the corrosion resistance of titanium tubes was perfect. These problems can be controlled by the application of proper electrolytic protection. The condensers with all titanium tubes adopted recently in USA are intended to realize perfectly no-leak condensers as the countermeasure to the corrosion in steam generators of PWR plants. Regarding large condensers of nowadays, three problems are pointed out, namely the vibration of condenser tubes, the method of joining tubes and tube plates, and the tubes of no coolant leak. These three problems in case of titanium tubes were studied, and the problem of the fouling of tubes was also examined. The intervals of supporting plates for titanium tubes should be narrowed. The joining of titanium tubes and titanium tube plates by welding is feasible and promising. The cleaning with sponge balls is effective to control fouling.

Modification of titanium electrodes by a noble metal deposit

Energy Technology Data Exchange (ETDEWEB)

Devilliers, D.; Mahe, E. [Pierre et Marie Curie Univ., Paris (France). Laboratoire LI2C, UMR CNRS

2008-07-01

Titanium is commonly used as a substrate for dimensionally stable anodes (DSAs) because it is corrosion-resistant in acid media and because a passive titanium oxide (TiO2) film can be formed on the surface. This paper reported on a study in which titanium substrates were first covered by anodization with a TiO2 layer. The electrochemical properties of the Ti/TiO2 electrodes were investigated. The modification of the substrates by cathodic electrodeposition of a noble metal was described. The reactivity of the Ti/TiO2/Pt structures were illustrated by impedance spectroscopy experiments. The impedance studies performed with Ti/ TiO2 electrodes in the presence of a redox couple in solution (Fe3+/Fe2+ system in sulphuric acid) showed that the electronic transfer is very slow. It was concluded that the deposition of a noble metal coating on Ti/TiO2 substrates leads to modified titanium electrodes that exhibit electrocatalytic behaviour versus specific electrochemical reactions. 1 ref., 3 figs.

Investment casting of beta titanium alloys for aerospace applications

International Nuclear Information System (INIS)

Wheeler, D.A.; Cianci, M.S.; Vogt, R.G.

1993-01-01

The process of investment casting offers the ability to produce complex titanium components with minimal finish machining, thereby reducing their overall manufacturing cost. While aerospace applications for cast titanium have focused primarily on alpha+beta alloys, recent interest in higher strength beta alloys has prompted an examination of their suitability for investment casting. In this paper, the processing characteristics and mechanical proper-ties of Ti-1 5V-3Cr-3Al-3Sn, Ti-3Al-8V-6Cr-4Mo-4Zr, and Ti-15Mo-3Nb-3Al-0.2Si (wt.%) will be discussed. It will be shown that all three alloy compositions are readily processed using only slight modifications from current Ti-6Al-4V (wt.%) production operations. In addition, the mechanical properties of the cast product form can be manipulated through heat treatment and compare quite favorably with typical properties obtained in wrought beta titanium products. Finally, several demonstration castings are reviewed which illustrate the shape-making capabilities of the investment casting approach for beta titanium alloys

Nitrogen contribution to tribological behaviour improvement of titanium alloys

International Nuclear Information System (INIS)

Corre, Y.; Lebrun, J.P.; Douet, M.

1996-01-01

Titanium an titanium alloys are more used materials in mechanical applications. A low density and very interesting mechanical characteristics present these materials as a first choice in many fields (aeronautics, automobile precision mechanics, biomedical...). Nevertheless, their poor tribological qualities often negate them as a friction surface. Modifying their surface properties is thus a real concern. The introduction of nitrogen on the surface enables a significant improvement to the tribological behaviour of these materials. Nitrogen ionic implantation is a technique used in titanium alloy surface treatment. Industrial applications of this process are numerous (biomedical, aeronautics...) but the limitations its (essentially treatment depth) prevent its use in certain cases. The increase in treatment temperature can overcome these limitations. Thus, the analysis of the properties obtained after treatment at various temperatures (20 deg. C) enables us to find the best compromise between metallurgic, geometrical properties (surface condition, deformation) and friction properties. This compromise enables us to solve a majority of tribological problems of titanium alloys. (authors). 7 refs., 10 figs., 2 tabs., 1 photo

Ion exchanger material based on Titanium phosphate for liquid radioactive waste treatment

Energy Technology Data Exchange (ETDEWEB)

Maslova, M.; Gerasimova, L. [Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Resources, Kola Scientific Center, Russian Academy of Sciences, Apatity (Russian Federation)

2013-07-01

A comparative study of the physicochemical and service properties of samples of Ti(OH) 1.36(HPO4) 1.32 * 2.3H2O sorbent in the finely dispersed and granulated forms, mastered for commercial production, was made. The sorption of Cs and Sr cations from solutions of various, compositions was studied in batch experiments, and the diffusion coefficients of the exchanging ions were determined. The hydrolytic stability of the. sorbents was examined with the aim to determine the optimal operation conditions. Experiments showed that the cation exchangers based on titanium phosphate are the most efficient in removal from liquid radioactive waste of induced radioactive isotopes of corrosion products, which is due to formation of weakly dissociating compounds of nonferrous metal ions with functional groups of the ion exchangers in the sorbent phase. (author)

Corrosion-resistant titanium nitride coatings formed on stainless steel by ion-beam-assisted deposition

International Nuclear Information System (INIS)

Baba, K.; Hatada, R.

1994-01-01

Titanium films 70nm thick were deposited on austenitic type 316L stainless steel substrates, and these specimens were irradiated with titanium ions of energy 70kV at a fluence of 1x10 17 ioncm -2 , using a metal vapor vacuum arc (MEVVA) IV metallic ion source at room temperature. After irradiation, titanium nitride (TiN) films were deposited by titanium evaporation and simultaneous irradiation by a nitrogen ion beam, with transport ratios of Ti to N atoms from 0.5 to 10.0 and an ion acceleration voltage of 2kV. The preferred orientation of the TiN films varied from left angle 200 right angle to left angle 111 right angle normal to the surface when the transport ratio was increased. With the help of Auger electron spectroscopy, interfacial mixing was verified. Nitrogen atoms were present in the state of titanium nitride for all transport ratios from 0.5 up to 10.0. However, the chemical bonding state of titanium changed from titanium nitride to the metallic state with increasing transport ratio Ti/N. The corrosion behavior was evaluated in an aqueous solution of sulfuric acid saturated with oxygen, using multisweep cyclic voltammetry measurements. Thin film deposition of pure titanium and titanium implantation prior to TiN deposition have beneficial effects on the suppression of transpassive chromium dissolution. ((orig.))

Electrochemical surface modification of titanium in dentistry.

Science.gov (United States)

Kim, Kyo-Han; Ramaswamy, Narayanan

2009-01-01

Titanium and its alloys have good biocompatibility with body cells and tissues and are widely used for implant applications. However, clinical procedures place more stringent and tough requirements on the titanium surface necessitating artificial surface treatments. Among the many methods of titanium surface modification, electrochemical techniques are simple and cheap. Anodic oxidation is the anodic electrochemical technique while electrophoretic and cathodic depositions are the cathodic electrochemical techniques. By anodic oxidation it is possible to obtain desired roughness, porosity and chemical composition of the oxide. Anodic oxidation at high voltages can improve the crystallinity of the oxide. The chief advantage of this technique is doping of the coating of the bath constituents and incorporation of these elements improves the properties of the oxide. Electrophoretic deposition uses hydroxyapatite (HA) powders dispersed in a suitable solvent at a particular pH. Under these operating conditions these particles acquire positive charge and coatings are obtained on the cathodic titanium by applying an external electric field. These coatings require a post-sintering treatment to improve the coating properties. Cathodic deposition is another type of electrochemical method where HA is formed in situ from an electrolyte containing calcium and phosphate ions. It is also possible to alter structure and/or chemistry of the obtained deposit. Nano-grained HA has higher surface energy and greater biological activity and therefore emphasis is being laid to produce these coatings by cathodic deposition.

Effects of thickness on electronic structure of titanium thin films

Indian Academy of Sciences (India)

using near-edge X-ray absorption fine structure (NEXAFS) technique at titanium L2,3 edge in total electron yield .... the contribution of titanium L2,3 levels to the absorption co- ... all absorption coefficient of a sample is related to the atomic.

Bioactivity and Osseointegration of PEEK Are Inferior to Those of Titanium: A Systematic Review.

Science.gov (United States)

Najeeb, Shariq; Bds, Zohaib Khurshid; Bds, Sana Zohaib; Bds, Muhammad Sohail Zafar

2016-12-01

Polyetheretherketone (PEEK) has been suggested as an alternative to replace titanium as a dental implant material. However, PEEK's bioactivity and osseointegration are debatable. This review has systematically analyzed studies that have compared PEEK (or PEEK-based) implants with titanium implants so that its feasibility as a possible replacement for titanium can be determined. The focused question was: "Are the bioactivity and osseointegration of PEEK implants comparable to or better than titanium implants?" Using the key words "dental implant," "implant," "polyetheretherketone," "PEEK," and "titanium" in various combinations, the following databases were searched electronically: PubMED/MEDLINE, Embase, Google Scholar, ISI Web of Knowledge, and Cochrane Database. 5 in vitro and 4 animal studies were included in the review. In 4 out of 5 in vitro studies, titanium exhibited more cellular proliferation, angiogenesis, osteoblast maturation, and osteogenesis compared to PEEK; one in vitro study observed comparable outcomes regardless of the implant material. In all animal studies, uncoated and coated titanium exhibited a more osteogenic behavior than did uncoated PEEK, while comparable bone-implant contact was observed in HA-coated PEEK and coated titanium implants. Unmodified PEEK is less osseoconductive and bioactive than titanium. Furthermore, the majority of studies had multiple sources of bias; hence, in its unmodified form, PEEK is unsuitable to be used as dental implant. Significantly more research and long-term trials must focus on improving the bioactivity of PEEK before it can be used as dental implant. More comparative animal and clinical studies are warranted to ascertain the potential of PEEK as a viable alternative to titanium.

Kinetics of Hydrogen Absorption and Desorption in Titanium

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Suwarno Suwarno

2017-10-01

Full Text Available Titanium is reactive toward hydrogen forming metal hydride which has a potential application in      energy storage and conversion. Titanium hydride has been widely studied for hydrogen storage, thermal storage, and battery electrodes applications. A special interest is using titanium for hydrogen production in a hydrogen sorption-enhanced steam reforming of natural gas. In the present work, non-isothermal dehydrogenation kinetics of titanium hydride and kinetics of hydrogenation in gaseous flow at isothermal conditions were investigated. The hydrogen desorption was studied using temperature desorption spectroscopy (TDS while the hydrogen absorption and desorption in gaseous flow were studied by temperature programmed desorption (TPD. The present work showed that the path of dehydrogenation of the TiH2 is d®b®a hydride phase with possible overlapping steps occurred. The fast hydrogen desorption rate observed at the TDS main peak temperature were correlated with the fast transformation of the d-TiH1.41 to b-TiH0.59. In the gaseous flow, hydrogen absorption and desorption were related to the transformation of b-TiH0.59 Û d-TiH1.41 with 2 wt.% hydrogen reversible content. Copyright © 2017 BCREC Group. All rights reserved Received: 21st November 2016; Revised: 20th March 2017; Accepted: 9th April 2017; Available online: 27th October 2017; Published regularly: December 2017 How to Cite: Suwarno, S., Yartys, V.A. (2017. Kinetics of Hydrogen Absorption and Desorption in Titanium. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (3: 312-317  (doi:10.9767/bcrec.12.3.810.312-317

Comparison of porosity measurement techniques for porous titanium scaffolds evaluation

International Nuclear Information System (INIS)

Oliveira, M.V.; Ribeiro, A.A.; Moreira, A.C.; Moraes, A.M.C.; Appoloni, C.R.; Pereira, L.C.

2009-01-01

Porous titanium has been used for grafts and implant coatings as it allows the mechanical interlocking of the pores and bone. Evaluation of porous scaffolds for bone regeneration is essential for their manufacture. Porosity, pore size, pore shape and pore homogeneity are parameters that influence strongly the mechanical strength and biological functionality. In this study, porous titanium samples were manufactured by powder metallurgy by using pure titanium powders mixed with a pore former. The quantification of the porosity parameters was assessed in this work by geometric method and gamma-ray transmission, the non-destructive techniques and metallographic images processing, a destructive technique. Qualitative evaluation of pore morphology and surface topography were performed by scanning electron microscopy and optical microscopy. The results obtained and the effectiveness of the techniques used were compared in order to select those most suitable for characterization of porous titanium scaffolds. (author)

Quantifying the properties of low-cost powder metallurgy titanium alloys

International Nuclear Information System (INIS)

Bolzoni, L.; Ruiz-Navas, E.M.; Gordo, E.

2017-01-01

The extensive industrial employment of titanium is hindered by its high production costs where reduction of these costs can be achieved using cheap alloying elements and appropriate alternative processing techniques. In this work the feasibility of the production of low-cost titanium alloys is addressed by adding steel to pure titanium and processing the alloys by powder metallurgy. In particular, a spherical 4140 LCH steel powder commonly used in metal injection moulding is blended with irregular hydride-dehydride Ti. The new low-cost alloys are cold uniaxially pressed and sintered under high vacuum and show comparable properties to other wrought-equivalent and powder metallurgy titanium alloys. Differential thermal analysis and X-ray diffraction analyses confirm that Ti can tolerate the employment of iron as primary alloying element without forming detrimental TiFe-based intermetallic phases. Thus, the newly designed α+β alloys could be used for cheaper non-critical components.

Quantifying the properties of low-cost powder metallurgy titanium alloys

Energy Technology Data Exchange (ETDEWEB)

Bolzoni, L., E-mail: bolzoni.leandro@gmail.com [WaiCAM (Waikato Centre for Advanced Materials), The University of Waikato, Private Bag 3105, 3240 Hamilton (New Zealand); Ruiz-Navas, E.M.; Gordo, E. [Department of Materials Science and Engineering, University Carlos III of Madrid, Avda. de la Universidad, 30, 28911 Leganés, Madrid (Spain)

2017-02-27

The extensive industrial employment of titanium is hindered by its high production costs where reduction of these costs can be achieved using cheap alloying elements and appropriate alternative processing techniques. In this work the feasibility of the production of low-cost titanium alloys is addressed by adding steel to pure titanium and processing the alloys by powder metallurgy. In particular, a spherical 4140 LCH steel powder commonly used in metal injection moulding is blended with irregular hydride-dehydride Ti. The new low-cost alloys are cold uniaxially pressed and sintered under high vacuum and show comparable properties to other wrought-equivalent and powder metallurgy titanium alloys. Differential thermal analysis and X-ray diffraction analyses confirm that Ti can tolerate the employment of iron as primary alloying element without forming detrimental TiFe-based intermetallic phases. Thus, the newly designed α+β alloys could be used for cheaper non-critical components.

Design and Fabrication of Titanium Target for Portable Neutron Generator

International Nuclear Information System (INIS)

Lee, Cheol Ho; Oh, Byunghoon; Chang, Daesik; Jang, Dohyun; In Sang Yeol; Park, Jaewon; Hong, Kwangpyo

2014-01-01

For the neutron generator to produce a neutron flux of the above order, a target that produces fast neutrons in the generator plays an important role, and the target is used and applied to develop the generator due to its simplicity and inexpensive. Making suitable targets for neutron production, especially mono-energy neutrons, has always been of interest. These targets have been used for neutron production reaction studies, calibration of detectors, and neutron therapy. Different studies have been carried out on deuterium and tritium for making solid targets to produce mono-energy neutron from D-D and D-T reactions. A lot of investigations have been carried out on solid target properties such as lifetime, thermal stability, neutron yield, and energy. Vaporized zirconium and titanium layers on a high thermal conductivity substrate (Cu, Mo, Ag) have been used as deuterium and tritium absorbing metals. The density of titanium is smaller than zirconium and the range of charged particles in the titanium targets is more than that in zirconium targets. Thus, titanium targets have more neutron yield than zirconium targets in a low energy beam and titanium is usually used to make a target. The titanium target was designed and simulated to determine the suitable thickness of the target. As a result of the simulation, the target was fabricated to generate fast neutrons by the reaction. The thickness of the target was measured using a profiler. The thickness of the two targets is 2.108 and 2.190 μm. The target will be applied to produce neutrons in a neutron generator

Clinical experience of titanium cerebral aneurysm clips. Evaluation of artifact of CT and MRI

International Nuclear Information System (INIS)

Ninomiya, Takashi; Kato, Yoko; Sano, Hirotoshi

1996-01-01

The titanium aneurysm clips manufactured by AESCULAP Company are expected to be useful, not only for clinical applications, but also for reducing artifacts in post-operative CT and MRI. We carried out an investigation of the behavior of the new Yasargil titanium clips in a 1.5T MR imager. The new titanium clips showed considerably smaller clip-induced MR and CT artifacts than phynox and elgiloy clips. No movement of the titanium clips was seen by introducing them to the MR imager. Subsequent to these experimental studies, we applied titanium clips to 25 cerebral aneurysms. Post-operative CT, especially helical scanning CT and MR showed minimal artifacts, leading to the conclusion that the titanium clips are better than the other types of clips for the evaluation of post-operative neuroradiological images. (author)

On aging of iron-nickel-titanium alloys

International Nuclear Information System (INIS)

Vintajkin, E.Z.; Dmitriev, V.B.; Udovenko, V.A.

1978-01-01

The mechanism of structural transformations on the initial stages of aging of Fe-(26-29) at. % Ni-(2.5-5.75) at. % Ti alloys was studied by neutron radiography. It was shown that at the earliest aging stages at 550 deg C there appear ordered areas which are FCC nuclei of the Ni 3 Ti phase. The rate of nucleation depends on the content of titanium in the all. In alloys with more than 3% Ti, nuclei appear even at the hardening stage. During the subsequent aging, the nuclei are enriched with nickel and titanium

Phased Array Ultrasonic Inspection of Titanium Forgings

International Nuclear Information System (INIS)

Howard, P.; Klaassen, R.; Kurkcu, N.; Barshinger, J.; Chalek, C.; Nieters, E.; Sun, Zongqi; Fromont, F. de

2007-01-01

Aerospace forging inspections typically use multiple, subsurface-focused sound beams in combination with digital C-scan image acquisition and display. Traditionally, forging inspections have been implemented using multiple single element, fixed focused transducers. Recent advances in phased array technology have made it possible to perform an equivalent inspection using a single phased array transducer. General Electric has developed a system to perform titanium forging inspection based on medical phased array technology and advanced image processing techniques. The components of that system and system performance for titanium inspection will be discussed

Titanium nitride deposition in titanium implant alloys produced by powder metallurgy

International Nuclear Information System (INIS)

Henriques, V.A.R.; Cairo, C.A.A.; Faria, J.; Lemos, T.G.; Galvani, E.T.

2009-01-01

Titanium nitride (TiN) is an extremely hard material, often used as a coating on titanium alloy, steel, carbide, and aluminum components to improve wear resistance. Electron Beam Physical Vapor Deposition (EB-PVD) is a form of deposition in which a target anode is bombarded with an electron beam given off by a charged tungsten filament under high vacuum, producing a thin film in a substrate. In this work are presented results of TiN deposition in targets and substrates of Ti (C.P.) and Ti- 13 Nb- 13 Zr obtained by powder metallurgy. Samples were produced by mixing of hydride metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering between 900°C up to 1400 °C, in vacuum. The deposition was carried out under nitrogen atmosphere. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. It was shown that the samples were sintered to high densities and presented homogeneous microstructure, with ideal characteristics for an adequate deposition and adherence. The film layer presented a continuous structure with 15μm. (author)

Silicon-Doped Titanium Dioxide Nanotubes Promoted Bone Formation on Titanium Implants.

Science.gov (United States)

Zhao, Xijiang; Wang, Tao; Qian, Shi; Liu, Xuanyong; Sun, Junying; Li, Bin

2016-02-26

While titanium (Ti) implants have been extensively used in orthopaedic and dental applications, the intrinsic bioinertness of untreated Ti surface usually results in insufficient osseointegration irrespective of the excellent biocompatibility and mechanical properties of it. In this study, we prepared surface modified Ti substrates in which silicon (Si) was doped into the titanium dioxide (TiO₂) nanotubes on Ti surface using plasma immersion ion implantation (PIII) technology. Compared to TiO₂ nanotubes and Ti alone, Si-doped TiO₂ nanotubes significantly enhanced the expression of genes related to osteogenic differentiation, including Col-I, ALP, Runx2, OCN, and OPN, in mouse pre-osteoblastic MC3T3-E1 cells and deposition of mineral matrix. In vivo, the pull-out mechanical tests after two weeks of implantation in rat femur showed that Si-doped TiO₂ nanotubes improved implant fixation strength by 18% and 54% compared to TiO₂-NT and Ti implants, respectively. Together, findings from this study indicate that Si-doped TiO₂ nanotubes promoted the osteogenic differentiation of osteoblastic cells and improved bone-Ti integration. Therefore, they may have considerable potential for the bioactive surface modification of Ti implants.

In Vitro Evaluation of Planktonic Growth on Experimental Cement-Retained Titanium Surfaces

Science.gov (United States)

Balci, Nur; Cakan, Umut; Aksu, Burak; Akgul, Oncu; Ulger, Nurver

2016-01-01

Background The purpose of this study was to compare the effects of selected cements, or their combination with titanium, on the growth of two periodontopathic bacteria: Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn). Material/Methods This study was comprised of several experimental groups: 1) Dental luting cements (glass ionomer cement, methacrylate-based resin cement, zinc-oxide eugenol cement, eugenol-free zinc oxide cement; 2) titanium discs; and 3) titanium combination cement discs. The disks were submerged in bacterial suspensions of either Fn or Pi. Planktonic bacterial growth within the test media was measured by determining the optical density of the cultures (OD600). Mean and standard deviations were calculated for planktonic growth from three separate experiments. Results Intergroup comparison of all experimental groups revealed increased growth of Pi associated with cement-titanium specimens in comparison with cement specimens. Regarding the comparison of all groups for Fn, there was an increased amount of bacterial growth in cement-titanium specimens although the increase was not statistically significant. Conclusions The combination of cement with titanium may exacerbate the bacterial growth capacity of Pi and Fn in contrast to their sole effect. PMID:27058704

Evaluation of cyclic flexural fatigue of M-wire nickel-titanium rotary instruments.

Science.gov (United States)

Al-Hadlaq, Solaiman M S; Aljarbou, Fahad A; AlThumairy, Riyadh I

2010-02-01

This study was conducted to investigate cyclic flexural fatigue resistance of GT series X rotary files made from the newly developed M-wire nickel-titanium alloy compared with GT and Profile nickel-titanium files made from a conventional nickel-titanium alloy. Fifteen files, size 30/0.04, of each type were used to evaluate the cyclic flexural fatigue resistance. A simple device was specifically constructed to measure the time each file type required to fail under cyclic flexural fatigue testing. The results of this experiment indicated that the GT series X files had superior cyclic flexural fatigue resistance than the other 2 file types made from a conventional nickel-titanium alloy (P = .004). On the other hand, the difference between the Profile and the GT files was not statistically significant. The findings of this study suggest that size 30/0.04 nickel-titanium rotary files made from the newly developed M-wire alloy have better cyclic flexural fatigue resistance than files of similar design and size made from the conventional nickel-titanium alloy. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

In Vitro Evaluation of Planktonic Growth on Experimental Cement-Retained Titanium Surfaces.

Science.gov (United States)

Balci, Nur; Cakan, Umut; Aksu, Burak; Akgul, Oncu; Ulger, Nurver

2016-04-08

BACKGROUND The purpose of this study was to compare the effects of selected cements, or their combination with titanium, on the growth of two periodontopathic bacteria: Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn). MATERIAL AND METHODS This study was comprised of several experimental groups: 1) Dental luting cements (glass ionomer cement, methacrylate-based resin cement, zinc-oxide eugenol cement, eugenol-free zinc oxide cement; 2) titanium discs; and 3) titanium combination cement discs. The disks were submerged in bacterial suspensions of either Fn or Pi. Planktonic bacterial growth within the test media was measured by determining the optical density of the cultures (OD600). Mean and standard deviations were calculated for planktonic growth from three separate experiments. RESULTS Intergroup comparison of all experimental groups revealed increased growth of Pi associated with cement-titanium specimens in comparison with cement specimens. Regarding the comparison of all groups for Fn, there was an increased amount of bacterial growth in cement-titanium specimens although the increase was not statistically significant. CONCLUSIONS The combination of cement with titanium may exacerbate the bacterial growth capacity of Pi and Fn in contrast to their sole effect.

Electrodeposition of niobium and titanium in molten salts

International Nuclear Information System (INIS)

Sartori, A.F.; Chagas, H.C.

1988-01-01

The electrodeposition of niobium and titanium in molten fluorides from the additions of fluorine niobates and fluorine titanates of potassium is described in laboratory and pilot scale. The temperature influence, the current density and the time deposition over the current efficiency, the deposits structure and the deposits purity are studied. The conditions for niobium coating over copper and carbon steel and for titanium coating over carbon steel are also presented. (C.G.C.) [pt

Mechanism of cesium sorption on potassium titanium hexacyanoferrate

International Nuclear Information System (INIS)

Sun Yongxia; Xu Shiping; Song Chongli

1998-01-01

The mechanism of cesium sorption on potassium titanium hexacyanoferrate is described. The dependence of the sorption speed on temperature, particle granule size, and the stirring speed is studied. The results show that the sorption process is controlled by liquid film diffusion and particle diffusion. An exchange reaction occurs mainly between K + in the exchanger and Cs + in the solution, i.e. potassium titanium hexacyanoferrate, and Cs + of simulated high-level liquid waste

Long-term hearing result using Kurz titanium ossicular implants.

Science.gov (United States)

Hess-Erga, Jeanette; Møller, Per; Vassbotn, Flemming Slinning

2013-05-01

Titanium implants in middle ear surgery were introduced in the late 90s and are now frequently used in middle ear surgery. However, long-term studies of patient outcome are few and have only been published in subgroups of patients. We report the long-term effect of titanium middle ear implants for ossicular reconstruction in chronic ear disease investigated in a Norwegian tertiary otological referral centre. Retrospective chart reviews were performed for procedures involving 76 titanium implants between 2000 and 2007. All patients who underwent surgery using the Kurz Vario titanium implant were included in the study. Audiological parameters using four frequencies, 0.5, 1, 2, and 3 kHz, according to AAO-HNS guidelines, was assessed pre and postoperatively. Otosurgical procedures, complications, revisions, and extrusion rates were analyzed. The study had no dropouts. The partial ossicular replacement prosthesis (PORP) was used in 44 procedures and the total ossicular replacement prosthesis (TORP) in 32 procedures, respectively. Mean follow-up was 5.2 years (62 months). The ossiculoplasties were performed as staging procedures or in combination with other chronic ear surgery. The same surgeon performed all the procedures. A postoperative air-bone gap of ≤ 20 dB was obtained in 74 % of the patients, 82 % for the Bell (PORP) prosthesis, and 63 % for the Arial (TORP) prosthesis. The extrusion rate was 5 %. We conclude that titanium ossicular implants give stable and excellent long-term hearing results.

Human Mesenchymal Stem Cell Morphology and Migration on Micro-Textured Titanium

Directory of Open Access Journals (Sweden)

Brittany eBanik

2016-05-01

Full Text Available The implant used in spinal fusion procedures is an essential component to achieving successful arthrodesis. At the cellular level, the implant impacts healing and fusion through a series of steps: first, mesenchymal stem cells (MSCs need to adhere and proliferate to cover the implant; second, the MSCs must differentiate into osteoblasts; third, the osteoid matrix produced by the osteoblasts needs to generate new bone tissue, thoroughly integrating the implant with the vertebrate above and below. Previous research has demonstrated that micro-textured titanium is advantageous over smooth titanium and PEEK implants for both promoting osteogenic differentiation and integrating with host bone tissue; however, no investigation to date has examined the early morphology and migration of MSCs on these surfaces. This study details cell spreading and morphology changes over 24 hours, rate and directionality of migration 6 to 18 hours post seeding, differentiation markers at 10 days, and the long term morphology of MSCs at 7 days, on micro-textured, acid-etched titanium (Endoskeleton, smooth titanium, and smooth PEEK surfaces. The results demonstrate in all metrics, the two titanium surfaces outperformed the PEEK surface. Furthermore, the rough acid-etched titanium surface presented the most favorable overall results, demonstrating the random migration needed to efficiently cover a surface in addition to morphologies consistent with osteoblasts and preosteoblasts.

Evaluation of Antibacterial Activity of Titanium Surface Modified by PVD/PACVD Process.

Science.gov (United States)

Ji, Min-Kyung; Lee, Min-Joo; Park, Sang-Won; Lee, Kwangmin; Yun, Kwi-Dug; Kim, Hyun-Seung; Oh, Gye-Jeong; Kim, Ji-Hyun; Lim, Hyun-Pil

2016-02-01

The aim of this study was to evaluate the response of Streptococcus mutans (S. mutans) via crystal violet staining assay on titanium surface modified by physical vapor deposition/plasma assisted chemical vapor deposition process. Specimens were divided into the following three groups: polished titanium (control group), titanium modified by DC magnetron sputtering (group TiN-Ti), and titanium modified by plasma nitriding (group N-Ti). Surface characteristics of specimens were observed by using nanosurface 3D optical profiler and field emission scanning electron microscope. Group TiN-Ti showed TiN layer of 1.2 microm in thickness. Group N-Ti was identified as plasma nitriding with X-ray photoelectron spectroscopy. Roughness average (Ra) of all specimens had values 0.05). Within the process condition of this study, modified titanium surfaces by DC magnetron sputtering and plasma nitriding did not influence the adhesion of S. mutans.

Interaction of titanium and vanadium with carbon dioxide under heating

International Nuclear Information System (INIS)

Vlasyuk, R.Z.; Kurovskij, V.Ya.; Lyapunov, V.P.; Radomysel'skij, I.D.

1986-01-01

The methods of gravitmetric and X-ray phase analysis as well as analysis of composition of gases in the heating chamber have been used to investigate the mechanism of titanium and vanadium interaction with carbon dioxide in the 300-1000 deg C temperature range. The analogy of mechanisms of the interaction of titanium and vanadium with carbon dioxide in oxides production on the metal surface with subsequent carbidizing treatment at temperatures above 800 deg C is shown. Temperature limits of material operation on the base of titanium or vanadium in carbon dioxide must not exceed 400 or 600 deg C, respectively

Intrinsic Osteoinductivity of Porous Titanium Scaffold for Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

Maryam Tamaddon

2017-01-01

Full Text Available Large bone defects and nonunions are serious complications that are caused by extensive trauma or tumour. As traditional therapies fail to repair these critical-sized defects, tissue engineering scaffolds can be used to regenerate the damaged tissue. Highly porous titanium scaffolds, produced by selective laser sintering with mechanical properties in range of trabecular bone (compressive strength 35 MPa and modulus 73 MPa, can be used in these orthopaedic applications, if a stable mechanical fixation is provided. Hydroxyapatite coatings are generally considered essential and/or beneficial for bone formation; however, debonding of the coatings is one of the main concerns. We hypothesised that the titanium scaffolds have an intrinsic potential to induce bone formation without the need for a hydroxyapatite coating. In this paper, titanium scaffolds coated with hydroxyapatite using electrochemical method were fabricated and osteoinductivity of coated and noncoated scaffolds was compared in vitro. Alizarin Red quantification confirmed osteogenesis independent of coating. Bone formation and ingrowth into the titanium scaffolds were evaluated in sheep stifle joints. The examinations after 3 months revealed 70% bone ingrowth into the scaffold confirming its osteoinductive capacity. It is shown that the developed titanium scaffold has an intrinsic capacity for bone formation and is a suitable scaffold for bone tissue engineering.

Thermal and mechanical properties of polypropylene/titanium dioxide nanocomposite fibers

International Nuclear Information System (INIS)

Esthappan, Saisy Kudilil; Kuttappan, Suma Kumbamala; Joseph, Rani

2012-01-01

Highlights: ► Wet synthesis method was used for the synthesis of TiO 2 nano particles. ► Mechanical properties of polypropylene fibers were increased by the addition of TiO 2 nanoparticles. ► Thermal stability of polypropylene fiber was improved significantly by the addition of TiO 2 nano particles. ► TiO 2 nanoparticles dispersed well in polypropylene fibers. -- Abstract: Titanium dioxide nanoparticles were prepared by wet synthesis method and characterized by transmission electron microscopy and X-ray diffraction studies. The nanotitanium dioxide then used to prepare polypropylene/titanium dioxide composites by melt mixing method. It was then made into fibers by melt spinning and subsequent drawing. Mechanical properties of the fibers were studied using Favimat tensile testing machine with a load cell of 1200 cN capacity. Thermal behavior of the fibers was studied using differential scanning calorimetry and thermogravimetric analysis. Scanning electron microscope studies were used to investigate the titanium dioxide surface morphology and crosssection of the fiber. Mechanical properties of the polypropylene fiber was improved by the addition of titanium dioxide nanoparticles. Incorporation of nanoparticles improves the thermal stability of polypropylene. Differential scanning calorimetric studies revealed an improvement in crystallinity was observed by the addition of titanium dioxide nanoparticles.

Peroxy-Titanium Complex-based inks for low temperature compliant anatase thin films.

Science.gov (United States)

Shabanov, N S; Asvarov, A Sh; Chiolerio, A; Rabadanov, K Sh; Isaev, A B; Orudzhev, F F; Makhmudov, S Sh

2017-07-15

Stable highly crystalline titanium dioxide colloids are of paramount importance for the establishment of a solution-processable library of materials that could help in bringing the advantages of digital printing to the world of photocatalysis and solar energy conversion. Nano-sized titanium dioxide in the anatase phase was synthesized by means of hydrothermal methods and treated with hydrogen peroxide to form Peroxy-Titanium Complexes (PTCs). The influence of hydrogen peroxide on the structural, optical and rheological properties of titanium dioxide and its colloidal solutions were assessed and a practical demonstration of a low temperature compliant digitally printed anatase thin film given. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrahighly Dispersed Titanium Oxide on Silica : Effect of Precursors on the Structure and Photocatalysis

OpenAIRE

Yoshida , S.; Takenaka , S.; Tanaka , T.; Funabiki , T.

1997-01-01

The effect of precursor on the dispersion and catalytic performance of titanium oxide supported on silica has ben investigated. The catalysts were prepared by a simple impregnation method with three kinds of titanium complexes of different ligands (bis(isopropyato)-bis(pivaroylmethanato) : DPM, acetylacetonato : ACAC, tetrakis(isopropylato) : IPRO) with the aim of preparing ultrahighly dispersed titanium oxide on silica. The XAFS study revealed that titanium species in the catalyst prepared f...

Cell-laden hydrogel/titanium microhybrids: Site-specific cell delivery to metallic implants for improved integration.

Science.gov (United States)

Koenig, Geraldine; Ozcelik, Hayriye; Haesler, Lisa; Cihova, Martina; Ciftci, Sait; Dupret-Bories, Agnes; Debry, Christian; Stelzle, Martin; Lavalle, Philippe; Vrana, Nihal Engin

2016-03-01

Porous titanium implants are widely used in dental, orthopaedic and otorhinolaryngology fields to improve implant integration to host tissue. A possible step further to improve the integration with the host is the incorporation of autologous cells in porous titanium structures via cell-laden hydrogels. Fast gelling hydrogels have advantageous properties for in situ applications such as localisation of specific cells and growth factors at a target area without dispersion. The ability to control the cell types in different regions of an implant is important in applications where the target tissue (i) has structural heterogeneity (multiple cell types with a defined spatial configuration with respect to each other); (ii) has physical property gradients essential for its function (such as in the case of osteochondral tissue transition). Due to their near immediate gelation, such gels can also be used for site-specific modification of porous titanium structures, particularly for implants which would face different tissues at different locations. Herein, we describe a step by step design of a model system: the model cell-laden gel-containing porous titanium implants in the form of titanium microbead/hydrogel (maleimide-dextran or maleimide-PVA based) microhybrids. These systems enable the determination of the effect of titanium presence on gel properties and encapsulated cell behaviour as a miniaturized version of full-scale implants, providing a system compatible with conventional analysis methods. We used a fibroblast/vascular endothelial cell co-cultures as our model system and by utilising single microbeads we have quantified the effect of gel microenvironment (degradability, presence of RGD peptides within gel formulation) on cell behaviour and the effect of the titanium presence on cell behaviour and gel formation. Titanium presence slightly changed gel properties without hindering gel formation or affecting cell viability. Cells showed a preference to move towards

Solid-state (49/47)Ti NMR of titanium-based MCM-41 hybrid materials.

Science.gov (United States)

Ballesteros, Ruth; Fajardo, Mariano; Sierra, Isabel; Force, Carmen; del Hierro, Isabel

2009-11-03

Titanium solid-state NMR spectroscopy data for a series of organic-inorganic titanium MCM-41 based materials have been collected. These materials have been synthesized by first modifying the mesoporous silica MCM-41 in one step with a mixture of silanes: a triazine propyl triethoxysilane acting as functional linker and methyltrimethoxysilane or hexamethyldisilizane as capped agents to mask the remaining silanol groups. Second, the appropiate titanium precursor Ti(OPr(i))(4), [{Ti(OPr(i))(3)(OMent)}(2)] (OMent = 1R,2S,5R-(-)-menthoxo), Ti(OPr(i))(4), or [Ti(eta(5)-C(5)HMe(4))Cl(3)], has been immobilized by reaction with the modified MCM-41. Finally, after Ti(OPr(i))(4) immobilization onto the organomodified support the reaction with the chiral (+)-diethyl-l-tartrate was accomplished. The materials without functional linker have been also prepared by reaction in one step of the capped agent and the titanium precursor with the mesoporous silica. Relevant correlations of titanium NMR resonance chemical shifts and line widths can be inferred depending on different factors. The immobilization procedure used to prepare titanium-based MCM-41 hybrid materials and the choice of the silylating reagents employed to mask the silanol groups present on the silica surfaces produce significant differences in the Ti NMR spectra. Furthermore, depending on the electronic and sterical influence of the substituents directly attached to the titanium center, chemical shifts and line widths are modified providing novel information about titanium structure.

Antibacterial effects of silver-doped hydroxyapatite thin films sputter deposited on titanium

International Nuclear Information System (INIS)

Trujillo, Nathan A.; Oldinski, Rachael A.; Ma, Hongyan; Bryers, James D.; Williams, John D.; Popat, Ketul C.

2012-01-01

Since many orthopedic implants fail as a result of loosening, wear, and inflammation caused by repeated loading on the joints, coatings such as hydroxyapatite (HAp) on titanium with a unique topography have been shown to improve the interface between the implant and the natural tissue. Another serious problem with long-term or ideally permanent implants is infection. It is important to prevent initial bacterial colonization as existing colonies have the potential to become encased in an extracellular matrix polymer (biofilm) that is resistant to antibacterial agents. In this study, plasma-based ion implantation was used to examine the effects of pre-etching on plain titanium. Topographical changes to the titanium samples were examined and compared via scanning electron microscopy. Hydroxyapatite and silver-doped hydroxyapatite thin films were then sputter deposited on titanium substrates etched at − 700 eV. For silver-doped films, two concentrations of silver (∼ 0.5 wt.% and ∼ 1.5 wt.%) were used. Silver concentrations in the film were determined using energy dispersive X-ray spectroscopy. Hydroxyapatite film thicknesses were determined by measuring the surface profile using contact profilometry. Staphylococcus epidermidis and Pseudomonas aeruginosa adhesion studies were performed on plain titanium, titanium coated with hydroxyapatite, titanium coated with ∼ 0.5 wt.% silver-doped hydroxyapatite, and titanium coated with ∼ 1.5 wt.% silver-doped hydroxyapatite. Results indicate that less bacteria adhered to surfaces containing hydroxyapatite and silver; further, as the hydroxyapatite films delaminated, silver ions were released which killed bacteria in suspension. - Highlights: ► We have developed a combination of plasma-based ion implantation and ion beam sputter deposition technique. ► Silver-doped hydroxyapatite thin films on titanium were developed. ► The thin films showed the ability to control the concentration of silver that is doped within the

Surface Modification of Titanium with Heparin-Chitosan Multilayers via Layer-by-Layer Self-Assembly Technique

International Nuclear Information System (INIS)

Shu, Y.; Zou, J.; Ou, G.; Wang, L.; Li, Q.

2011-01-01

Extracellular matrix (ECM), like biomimetic surface modification of titanium implants, is a promising method for improving its biocompatibility. In this paper chitosan (Chi) and heparin (Hep) multilayer was coated on pure titanium using a layer-by-layer (LbL) self-assembly technique. The Hep-Chi multilayer growth was carried out by first depositing a single layer of positively charged poly-L-lysine (PLL) on the NaOH-treated titanium substrate (negatively charged surface), followed by alternate deposition of negatively charged Hep and positively charged Chi, and terminated by an outermost layer of Chi. The multilayer was characterized by DR-FTIR, SEM, and AFM, and osteoblasts were cocultured with the modified titanium and untreated titanium surfaces, respectively, to evaluate their cytocompatibility in vitro. The results confirmed that Hep-Chi multilayer was fabricated gradually on the titanium surface. The Hep-Chi multilayer-coated titanium improved the adhesion, proliferation and differentiation of osteoblasts. Thus, the approach described here may provide a basis for the preparation of modified titanium surfaces for use in dental or orthopedic implants

Effects of nacre-coated titanium surfaces on cell proliferation and ...

African Journals Online (AJOL)

Titanium is widely used for dental implants because of its superior mechanical properties, low modulus, excellent corrosion resistance, and good biocompatibility. However, even when they are used in combination with a protective coating, such as hydroxyapatite (HA), titanium implants have been reported to have several ...

Electrical characteristic of the titanium mesh electrode for transcutaneous intrabody communication to monitor implantable artificial organs.

Science.gov (United States)

Okamoto, Eiji; Kikuchi, Sakiko; Mitamura, Yoshinori

2016-09-01

We have developed a tissue-inducing electrode using titanium mesh to obtain mechanically and electrically stable contact with the tissue for a new transcutaneous communication system using the human body as a conductive medium. In this study, we investigated the electrical properties of the titanium mesh electrode by measuring electrode-tissue interface resistance in vivo. The titanium mesh electrode (Hi-Lex Co., Zellez, Hyogo, Japan) consisted of titanium fibers (diameter of 50 μm), and it has an average pore size of 200 μm and 87 % porosity. The titanium mesh electrode has a diameter of 5 mm and thickness of 1.5 mm. Three titanium mesh electrodes were implanted separately into the dorsal region of the rat. We measured the electrode-electrode impedance using an LCR meter for 12 weeks, and we calculated the tissue resistivity and electrode-tissue interface resistance. The electrode-tissue interface resistance of the titanium mesh electrode decreased slightly until the third POD and then continuously increased to 75 Ω. The electrode-tissue interface resistance of the titanium mesh electrode is stable and it has lower electrode-tissue interface resistance than that of a titanium disk electrode. The extracted titanium mesh electrode after 12 weeks implantation was fixed in 10 % buffered formalin solution and stained with hematoxylin-eosin. Light microscopic observation showed that the titanium mesh electrode was filled with connective tissue, inflammatory cells and fibroblasts with some capillaries in the pores of the titanium mesh. The results indicate that the titanium mesh electrode is a promising electrode for the new transcutaneous communication system.

Initial stability of a highly porous titanium cup in an acetabular bone defect model.

Science.gov (United States)

Yoshimoto, Kensei; Nakashima, Yasuharu; Wakiyama, Miyo; Hara, Daisuke; Nakamura, Akihiro; Iwamoto, Mikio

2018-04-12

The purpose of this study was to quantify the initial stability of a highly porous titanium cup using an acetabular bone defect model. The maximum torque of a highly porous titanium cup, with a pore size of 640 μm and porosity of 60%, was measured using rotational and lever-out torque testing and compared to that of a titanium-sprayed cup. The bone models were prepared using a polyurethane foam block and had three levels of bone coverage: 100, 70, and 50%. The highly porous titanium cup demonstrated significantly higher maximum torque than the titanium-sprayed cups in the three levels of bone defects. On rotational torque testing, it was found to be 1.5, 1.3, and 1.3 times stronger than the titanium-sprayed cups with 100, 70 and 50% bone coverage, respectively. Furthermore, it was found to be 2.2, 2.3, and 1.5 times stronger on lever-out testing than the titanium-sprayed cup. No breakage in the porous layers was noted during the testing. This study provides additional evidence of the initial stability of highly porous titanium cup, even in the presence of acetabular bone defects. Copyright © 2018. Published by Elsevier B.V.

Bloodcompatibility improvement of titanium oxide film modified by phosphorus ion implantation

International Nuclear Information System (INIS)

Yang, P.; Leng, Y.X.; Zhao, A.S.; Zhou, H.F.; Xu, L.X.; Hong, S.; Huang, N.

2006-01-01

Our recent investigation suggested that Ti-O thin film could be a newly developed antithrombotic material and its thromboresistance could be related to its physical properties of wide gap semiconductor. In this work, titanium oxide film was modified by phosphorus ion implantation and succeeding vacuum annealing. RBS were used to investigate phosphorus distribution profile. Contact angle test results show that phosphorus-doped titanium oxide film becomes more hydrophilic after higher temperature annealing, while its electric conductivity increases. Antithrombotic property of phosphorus-doped titanium oxide thin films was examined by clotting time and platelet adhesion tests. The results suggest that phosphorus doping is an effective way to improve the bloodcompatibility of titanium oxide film, and it is related to the changes of electron structure and surface properties caused by phosphorus doping

Titanium Powder Sintering in a Graphite Furnace and Mechanical Properties of Sintered Parts

Directory of Open Access Journals (Sweden)

Changzhou Yu

2017-02-01

Full Text Available Recent accreditation of titanium powder products for commercial aircraft applications marks a milestone in titanium powder metallurgy. Currently, powder metallurgical titanium production primarily relies on vacuum sintering. This work reported on the feasibility of powder sintering in a non-vacuum furnace and the tensile properties of the as-sintered Ti. Specifically, we investigated atmospheric sintering of commercially pure (C.P. titanium in a graphite furnace backfilled with argon and studied the effects of common contaminants (C, O, N on sintering densification of titanium. It is found that on the surface of the as-sintered titanium, a severely contaminated porous scale was formed and identified as titanium oxycarbonitride. Despite the porous surface, the sintered density in the sample interiors increased with increasing sintering temperature and holding time. Tensile specimens cut from different positions within a large sintered cylinder reveal different tensile properties, strongly dependent on the impurity level mainly carbon and oxygen. Depending on where the specimen is taken from the sintered compact, ultimate tensile strength varied from 300 to 580 MPa. An average tensile elongation of 5% to 7% was observed. Largely depending on the interstitial contents, the fracture modes from typical brittle intergranular fracture to typical ductile fracture.

Progress in Titanium Metal Powder Injection Molding

Directory of Open Access Journals (Sweden)

Randall M. German

2013-08-01

Full Text Available Metal powder injection molding is a shaping technology that has achieved solid scientific underpinnings. It is from this science base that recent progress has occurred in titanium powder injection molding. Much of the progress awaited development of the required particles with specific characteristics of particle size, particle shape, and purity. The production of titanium components by injection molding is stabilized by a good understanding of how each process variable impacts density and impurity level. As summarized here, recent research has isolated the four critical success factors in titanium metal powder injection molding (Ti-MIM that must be simultaneously satisfied—density, purity, alloying, and microstructure. The critical role of density and impurities, and the inability to remove impurities with sintering, compels attention to starting Ti-MIM with high quality alloy powders. This article addresses the four critical success factors to rationalize Ti-MIM processing conditions to the requirements for demanding applications in aerospace and medical fields. Based on extensive research, a baseline process is identified and reported here with attention to linking mechanical properties to the four critical success factors.

Surface-Induced Hybridization between Graphene and Titanium

Energy Technology Data Exchange (ETDEWEB)

Hsu, Allen L. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States).; Koch, Roland J. [Technische Universitat, Chemnitz (Germany); Ong, Mitchell T. [Stanford Univ., CA (United States); Fang, Wenjing [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Hofmann, Mario [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Kim, Ki Kang [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States).; Seyller, Thomas [Technische Universitat, Chemnitz (Germany); Dresselhaus, Mildred S. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Reed, Evan J. [Stanford Univ., CA (United States); Kong, Jing [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Palacios, Tomás [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)

2014-08-26

Carbon-based materials such as graphene sheets and carbon nanotubes have inspired a broad range of applications ranging from high-speed flexible electronics all the way to ultrastrong membranes. However, many of these applications are limited by the complex interactions between carbon-based materials and metals. In this work, we experimentally investigate the structural interactions between graphene and transition metals such as palladium (Pd) and titanium (Ti), which have been confirmed by density functional simulations. We find that the adsorption of titanium on graphene is more energetically favorable than in the case of most metals, and density functional theory shows that a surface induced p-d hybridization occurs between atomic carbon and titanium orbitals. This strong affinity between the two materials results in a short-range ordered crystalline deposition on top of graphene as well as chemical modifications to graphene as seen by Raman and X-ray photoemission spectroscopy (XPS). This induced hybridization is interface-specific and has major consequences for contacting graphene nanoelectronic devices as well as applications toward metal-induced chemical functionalization of graphene.

Nano-engineered titanium for enhanced bone therapy

Science.gov (United States)

Gulati, Karan; Atkins, Gerald J.; Findlay, David M.; Losic, Dusan

2013-09-01

Current treatment of a number of orthopaedic conditions, for example fractures, bone infection, joint replacement and bone cancers, could be improved if mechanical support could be combined with drug delivery. A very challenging example is that of infection following joint replacement, which is very difficult to treat, can require multiple surgeries and compromises both the implant and the patient's wellbeing. An implant capable of providing appropriate biomechanics and releasing drugs/proteins locally might ensure improved healing of the traumatized bone. We propose fabrication of nanoengineered titanium bone implants using bioinert titanium wires in order to achieve this goal. Titanium in the form of flat foils and wires were modified by fabrication of titania nanotubes (TNTs), which are hollow self-ordered cylindrical tubes capable of accommodating substantial drug amounts and releasing them locally. To further control the release of drug to over a period of months, a thin layer of biodegradable polymer PLGA poly(lactic-coglycolic acid) was coated onto the drug loaded TNTs. This delayed release of drug and additionally the polymer enhanced bone cell adhesion and proliferation.

Obtaining hydroxyapatite coatings on titanium by the biomimetic method

International Nuclear Information System (INIS)

Paz, A.; Martin, Y.; Pazos, L. M.; Parodi, M. B.; Ybarra, G. O.; Gonzalez, J. E.

2011-01-01

In this work, a study about the deposition of hydroxyapatite on a titanium substrate employing the biomimetic method is presented. A solution with high content of calcium and phosphorus (SCS) was used. In addition, activation of titanium with hydrogen peroxide and hydrochloric acid and a subsequent heat treatment was performed. The characterization of materials used and the coating obtained was carried out by Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). As a result of the activation processes a hydrated titanium oxide was formed. On the active surface, a coating of hydroxyapatite was obtained after a period of 24 h, which has a thickness of about 2-4 μm. (Author) 21 refs.

Corrosion of alloys of the niobium--titanium--aluminium system

International Nuclear Information System (INIS)

Andreeva, V.V.; Alekseeva, E.L.; Dontsov, S.N.; Moiseeva, I.S.

The mechanical properties and corrosion resistance of niobium--titanium--aluminum alloys in 20 percent HCl and 40--75 percent H 2 SO 4 at 40 and 100 0 C are considered. Current density vs potential and corrosion rate vs potential potentiostatic curves plotted in 75 percent H 2 SO 4 at 140 0 C for the alloys with different titanium contents at a constant content of aluminum and also for alloys with a constant titanium content at different contents of aluminum are given. It was shown that the corrosion resistance of the alloys in 75 percent H 2 SO 4 at 140 0 C is an exponential function of the atomic content of the alloying components (Ti, Al) in them; aluminum vitiates the corrosion resistance very strongly

Microstructural Evolution during Pressureless Sintering of Blended Elemental Ti-Al-V-Fe Titanium Alloys from Fine Hydrogenated-Dehydrogenated Titanium Powder

Directory of Open Access Journals (Sweden)

Changzhou Yu

2017-07-01

Full Text Available A comprehensive study was conducted on microstructural evolution of sintered Ti-Al-V-Fe titanium alloys utilizing very fine hydrogenation-dehydrogenation (HDH titanium powder with a median particle size of 8.84 μm. Both micropores (5–15 μm and macropores (50–200 μm were identified in sintered titanium alloys. Spherical micropores were observed in Ti-6Al-4V sintered with fine Ti at the lowest temperature of 1150 °C. The addition of iron can help reduce microporosity and improve microstructural and compositional homogenization. A theoretical calculation of evaporation based on the Miedema model and Langmuir equation indicates that the evaporation of aluminum could be responsible for the formation of the macropores. Although reasonable densification was achieved at low sintering temperatures (93–96% relative density the samples had poor mechanical properties due mainly to the presence of the macroporosity and the high inherent oxygen content in the as-received fine powders.

Bis(tetramethylcyclopentadienyl)titanium chemistry. Molecular structures of [(C(5)HMe(4))(mu-eta(1) : eta(5)-C(5)Me(4))Ti](2) and [(C(5)HMe(4))(2)Ti]N-2(2)

NARCIS (Netherlands)

deWolf, JM; Blaauw, R; Meetsma, A; Teuben, JH; Gyepes, R; Varga, [No Value; Mach, K; Veldman, N; Spek, AL

1996-01-01

Thermolysis of bis(tetramethylcyclopentadienyl)-stabilized titanium(III) compounds (C(5)HMe(4))(2)TiR (R = Me (2), Ph (3)) yields, in marked contrast with the bis(pentamethylcyclopentadienyl) analog, the dimeric product [(C(5)HMe(4))(mu-eta(1):eta(5)-C(5)Me(4))Ti](2) (4), With a bridging metalated

Laser beam welding of titanium additive manufactured parts

OpenAIRE

Wits, Wessel Willems; Jauregui Becker, Juan Manuel

2015-01-01

In this paper the joinability of titanium Additive Manufactured (AM) parts is explored. Keyhole welding, using a pulsed laser beam, of conventionally produced parts is compared to AM parts. Metal AM parts are notorious for having remaining porosities and other non-isotropic properties due to the layered manufacturing process. This study shows that due to these deficiencies more energy per unit weld length is required to obtain a similar keyhole geometry for titanium AM parts. It is also demon...

Low-temperature atmospheric oxidation of mixtures of titanium and carbon black or brown

International Nuclear Information System (INIS)

Elizarova, V.A.; Babaitsev, I.V.; Barzykin, V.V.; Gerusova, V.P.; Rozenband, V.I.

1984-01-01

This article reports on the thermogravimetric investigation of mixtures of titanium no. 2 and carbon black with various mass carbon contents. Adding carbon black (as opposed to boron) to titanium leads to an increase in the rate of heat release of the oxidation reaction. An attempt is made to clarify the low-temperature oxidation mechanism of titanium mixtures in air. An x-ray phase and chemical (for bound carbon) analysis of specimens of a stoichiometric Ti + C mixture after heating in air to a temperature of 650 0 C at the rate of 10 0 /min was conducted. The results indicate that the oxidation of the titanium-carbon mixture probably proceeds according to a more complex mechanism associated with the transport of the gaseous carbon oxidation products and their participation in the titanium oxidation

Titanium-Based Biomaterials for Preventing Stress Shielding between Implant Devices and Bone

Directory of Open Access Journals (Sweden)

M. Niinomi

2011-01-01

Full Text Available β-type titanium alloys with low Young's modulus are required to inhibit bone atrophy and enhance bone remodeling for implants used to substitute failed hard tissue. At the same time, these titanium alloys are required to have high static and dynamic strength. On the other hand, metallic biomaterials with variable Young's modulus are required to satisfy the needs of both patients and surgeons, namely, low and high Young's moduli, respectively. In this paper, we have discussed effective methods to improve the static and dynamic strength while maintaining low Young's modulus for β-type titanium alloys used in biomedical applications. Then, the advantage of low Young's modulus of β-type titanium alloys in biomedical applications has been discussed from the perspective of inhibiting bone atrophy and enhancing bone remodeling. Further, we have discussed the development of β-type titanium alloys with a self-adjusting Young's modulus for use in removable implants.

Effect of sintering temperatures on titanium matrix composites reinforced by ceramic particles

Energy Technology Data Exchange (ETDEWEB)

Romero, F.; Amigo, V.; Busquets, D.; Klyatskina, E. [Mechanical and Materials Engineering Department. Polytechnical University of Valencia, Valencia (Spain)

2005-07-01

Titanium and titanium composites have a potential use in aerospace and biotechnology industries, and nowadays in others like sports and fashion ones. In this work composite materials, based on titanium matrix reinforced with ceramic particles, have been developed. PM route is used to obtain compact and sintered samples. TiN and TiAl powders, are milled with Ti powder in different volumetric percentages in a ball mill. These mixtures are pressed in a uniaxial press and sintered in a vacuum furnace at different temperatures between 1180 to 1220 deg. C. Porosity of samples is analysed, before and after the sintering process, by Archimedes technique and by image analysis. Mechanical properties and the reinforcement particles influence in the titanium matrix are studied by flexion test in green and sintered states, and by hardness and microhardness tests. Complimentarily, a microstructural analysis is carried out by optical and electron microscopy, and the reactivity between the reinforce particles and titanium matrix are studied. (authors)

Determining the efficiency of ZSM-5 zeolite impregnated with nanoparticles of titanium dioxide in the photocatalytic removal of styrene vapors

Directory of Open Access Journals (Sweden)

Mojtaba Nakhaei pour

2017-03-01

Full Text Available Introduction: Styrene monomer is a volatile organic compound that has many applications particularly in plastic, rubber and paint industries. According to the harmful effects of these compounds on human and environment, reducing and controling of them seem necessary. Therefore, in this study removal of styrene was investigated using photocatalytic process of titanium dioxide nanoparticles stabilized on ZSM-5. Methods: After stabilization of titanium dioxide nanoparticles on ZSM-5 zeolite, BET, SEM and XRD analysis were used to determine the characteristics of nanoparticles. Experiments were conducted at ambient temperature in laboratory scale. Concentration of produced styrene in the experiments was 50 and 300 ppm, and input flow rate was 1 l/min. Results: images and spectra obtained through XRD and SEM-EDAX showed that  nano-catalysts are well- stabilized. The results showed that by increasing of input concentration of styrene from 50 to 300 ppm, photocatalytic removal efficiency are reduced. Also, adsorption capacity of the catalyst bed in concentrations of 50 and 300 ppm was calculated 16.3 and19.4 mg/gr of adsorbent respectively. Conclusion: The results show that the use of hybrid bed can increase the removal efficiency of contaminants. And due to low cost of application of these systems compared to conventional methods, it is recommended that more comprehensive studies to be done regarding the optimization of the parameters affecting the process of photocatalytic removal.

Aluminium effect on the physical properties of titanium

International Nuclear Information System (INIS)

Nazimov, O.P.; Il'in, A.A.; Zvonova, L.N.

1977-01-01

The effect of aluminium on the physical properties of titanium was investigated. Within the framework of the configuration model of matter it is shown that a change in physical properties with an aluminium content of up to 7.5 wt.% in alloys depends on the phase composition and electron structure. In interacting with titanium, aluminium exhibits acceptor properties, causing d→s electron transitions. The electrons which have shifted to the s-state are partly collectivized and partly localized into quasistable sp 3 configurations, with the resulting increase of the interatomic forces. An intensification of d→s transitions in alloying of titanium with aluminium stabilizes the α-phase. Predominance of d 1 configurations in the intermediate spectrum in the region of the α-solution increases the ratio of the axes of the HCP lattice and determines the electron type of conduction of alloys of the Ti-Al system

Characterization of poly(Sodium Styrene Sulfonate) Thin Films Grafted from Functionalized Titanium Surfaces

Science.gov (United States)

Zorn, Gilad; Baio, Joe E.; Weidner, Tobias; Migonney, Veronique; Castner, David G.

2011-01-01

Biointegration of titanium implants in the body is controlled by their surface properties. Improving surface properties by coating with a bioactive polymer is a promising approach to improve the biological performance of titanium implants. To optimize the grafting processes, it is important to fully understand the composition and structure of the modified surfaces. The main focus of this study is to provide a detailed, multi-technique characterization of a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film grafted from titanium surfaces via a two-step procedure. Thin titanium films (~50 nm thick with an average surface roughness of 0.9±0.2nm) prepared by evaporation onto silicon wafers were used as smooth model substrates. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) showed that the titanium film was covered with a TiO2 layer that was at least 10nm thick and contained hydroxyl groups present at the outermost surface. These hydroxyl groups were first modified with a 3-methacryloxypropyltrimethoxysilane (MPS) cross linker. XPS and ToF-SIMS showed that a monolayer of the MPS molecules were successfully attached onto the titanium surfaces. The pNaSS film was grafted from the MPS modified titanium through atom transfer radical polymerization. Again, XPS and ToF-SIMS were used to verify that the pNaSS molecules were successfully grafted onto the modified surfaces. Atomic force microscopy analysis showed that the film was smooth and uniformly covered the surface. Fourier transform infrared spectroscopy indicated an ordered array of grafted NaSS molecules were present on the titanium surfaces. Sum frequency generation vibration spectroscopy and near edge X-ray absorption fine structure spectroscopy illustrated that the NaSS molecules were grafted onto the titanium surface with a substantial degree of orientational order in the styrene rings. PMID:21892821

Effect of alkali treatment on surface morphology of titanium

Energy Technology Data Exchange (ETDEWEB)

Tan, K. J., E-mail: gd130056@siswa.uthm.edu.my; Wahab, M. A. A., E-mail: cd110006@siswa.uthm.edu.my; Mahmod, S., E-mail: cd110201@siswa.uthm.edu.my; Idris, M. I., E-mail: izwana@uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

2015-07-22

Alkali and heat treatments were first introduced by Kim et al. to prepare a bioactive surface on titanium. This method has been proven very effective and widely used in other studies to promote titanium osteointegration. This study aims to investigate further the effect of alkali treatment on surface morphology of high purity titanium. High purity titanium foils were immersed in NaOH aqueous solutions of 0.5 M, 5 M and 15 M at 60°C and 80 °C for 1, 3 and 7 days. The surface morphology was examined using Field Emission Scanning Electron Microscope (FESEM). The obtained phases were analysed using Fourier Transform Infrared Spectroscopy (FTIR) in the spectra range of 4000-600 cm{sup −1} at 4 cm{sup −1} resolution and 50 scans. At the same soaking temperature and soaking time, a thicker porous network was observed with increasing concentration of NaOH. At the same soaking temperature, a much porous structure was observed with increasing soaking time. At constant alkali concentration, more homogenously distributed porous surface structure was observed with increasing soaking temperature.

The coordination and atom transfer chemistry of titanium porphyrin complexes

Energy Technology Data Exchange (ETDEWEB)

Hays, James Allen [Iowa State Univ., Ames, IA (United States)

1993-11-05

Preparation, characterization, and reactivity of (η²- alkyne)(meso-tetratolylpoprphrinato)titanium(II) complexes are described, along with inetermetal oxygen atom transfer reactions involving Ti(IV) and Ti(III) porphyrin complexes. The η²- alkyne complexes are prepared by reaction of (TTP)TiCl₂ with LiAlH₄ in presence of alkyne. Structure of (OEP)Ti(η²-Ph-C≡C-Ph) (OEP=octaethylporphryin) was determined by XRD. The compounds undergo simple substitution to displace the alkyne and produce doubly substituted complexes. Structure of (TTP)Ti(4-picoline)₂ was also determined by XRD. Reaction of (TTP)Ti=O with (OEP)Ti-Cl yields intermetal O/Cl exchange, which is a one-electron redox process mediated by O atom transfer. Also a zero-electron redox process mediated by atom transfer is observed when (TTP)TiCl₂ is reacted with (OEP)Ti=O.

Study on super-long deep-hole drilling of titanium alloy.

Science.gov (United States)

Liu, Zhanfeng; Liu, Yanshu; Han, Xiaolan; Zheng, Wencui

2018-01-01

In this study, the super-long deep-hole drilling of a titanium alloy was investigated. According to material properties of the titanium alloy, an experimental approach was designed to study three issues discovered during the drilling process: the hole-axis deflection, chip morphology, and tool wear. Based on the results of drilling experiments, crucial parameters for the super-long deep-hole drilling of titanium alloys were obtained, and the influences of these parameters on quality of the alloy's machining were also evaluated. Our results suggest that the developed drilling process is an effective method to overcome the challenge of super-long deep-hole drilling on difficult-to-cut materials.

Plasma-sprayed titanium coating to polyetheretherketone improves the bone-implant interface.

Science.gov (United States)

Walsh, William R; Bertollo, Nicky; Christou, Chrisopher; Schaffner, Dominik; Mobbs, Ralph J

2015-05-01

Rapid and stable fixation at the bone-implant interface would be regarded as one of the primary goals to achieve clinical efficacy, regardless of the surgical site. Although mechanical and physical properties of polyetheretherketone (PEEK) provide advantages for implant devices, the hydrophobic nature and the lack of direct bone contact remains a limitation. To examine the effects of a plasma-sprayed titanium coated PEEK on the mechanical and histologic properties at the bone-implant interface. A preclinical laboratory study. Polyetheretherketone and plasma-sprayed titanium coated PEEK implants (Ti-bond; Spinal Elements, Carlsbad, CA, USA) were placed in a line-to-line manner in cortical bone and in a press-fit manner in cancellous bone of adult sheep using an established ovine model. Shear strength was assessed in the cortical sites at 4 and 12 weeks, whereas histology was performed in cortical and cancellous sites at both time points. The titanium coating dramatically improved the shear strength at the bone-implant interface at 4 weeks and continued to improve with time compared with PEEK. Direct bone ongrowth in cancellous and cortical sites can be achieved using a plasma-sprayed titanium coating on PEEK. Direct bone to implant bonding can be achieved on PEEK in spite of its hydrophobic nature using a plasma-sprayed titanium coating. The plasma-sprayed titanium coating improved mechanical properties in the cortical sites and the histology in cortical and cancellous sites. Copyright © 2015 Elsevier Inc. All rights reserved.

Strength of titanium intramedullary implant versus miniplate fixation of mandibular condyle fractures.

Science.gov (United States)

Frake, Paul C; Howell, Rebecca J; Joshi, Arjun S

2012-07-01

To test the strength of internal fixation of mandibular condyle fractures repaired with titanium miniplates versus titanium intramedullary implants. Prospective laboratory experimentation in urethane mandible models and human cadaveric mandibles. Materials testing laboratory at an academic medical center. Osteotomies of the mandibular condyle were created in 40 urethane hemimandible models and 24 human cadaveric specimens. Half of the samples in each group were repaired with traditional miniplates, and the other half were repaired with intramedullary titanium implants. Anteroposterior and mediolateral loads were applied to the samples, and the displacement was measured with reference to the applied force. Titanium intramedullary implants demonstrated statistically significant improved strength and stiffness versus miniplates in the urethane model experimental groups. Despite frequent plastic deformation and mechanical failures of the miniplates, a 1.6-mm-diameter titanium intramedullary pin did not mechanically fail in any of the cases. Intramedullary implantation failures were due to secondary fracture of the adjacent cortical bone or experimental design limitations including rotation of the smooth pin implant. Mechanical implant failures that were encountered with miniplate fixation were not seen with titanium intramedullary implants. These intramedullary implants provide stronger and more rigid fixation of mandibular condyle fractures than miniplates in this in vitro model.

Trojan-Like Internalization of Anatase Titanium Dioxide Nanoparticles by Human Osteoblast Cells.

Science.gov (United States)

Ribeiro, A R; Gemini-Piperni, S; Travassos, R; Lemgruber, L; Silva, R C; Rossi, A L; Farina, M; Anselme, K; Shokuhfar, T; Shahbazian-Yassar, R; Borojevic, R; Rocha, L A; Werckmann, J; Granjeiro, J M

2016-03-29

Dentistry and orthopedics are undergoing a revolution in order to provide more reliable, comfortable and long-lasting implants to patients. Titanium (Ti) and titanium alloys have been used in dental implants and total hip arthroplasty due to their excellent biocompatibility. However, Ti-based implants in human body suffer surface degradation (corrosion and wear) resulting in the release of metallic ions and solid wear debris (mainly titanium dioxide) leading to peri-implant inflammatory reactions. Unfortunately, our current understanding of the biological interactions with titanium dioxide nanoparticles is still very limited. Taking this into consideration, this study focuses on the internalization of titanium dioxide nanoparticles on primary bone cells, exploring the events occurring at the nano-bio interface. For the first time, we report the selective binding of calcium (Ca), phosphorous (P) and proteins from cell culture medium to anatase nanoparticles that are extremely important for nanoparticle internalization and bone cells survival. In the intricate biological environment, anatase nanoparticles form bio-complexes (mixture of proteins and ions) which act as a kind of 'Trojan-horse' internalization by cells. Furthermore, anatase nanoparticles-induced modifications on cell behavior (viability and internalization) could be understand in detail. The results presented in this report can inspire new strategies for the use of titanium dioxide nanoparticles in several regeneration therapies.

Ductile and brittle transition behavior of titanium alloys in ultra-precision machining.

Science.gov (United States)

Yip, W S; To, S

2018-03-02

Titanium alloys are extensively applied in biomedical industries due to their excellent material properties. However, they are recognized as difficult to cut materials due to their low thermal conductivity, which induces a complexity to their deformation mechanisms and restricts precise productions. This paper presents a new observation about the removal regime of titanium alloys. The experimental results, including the chip formation, thrust force signal and surface profile, showed that there was a critical cutting distance to achieve better surface integrity of machined surface. The machined areas with better surface roughness were located before the clear transition point, defining as the ductile to brittle transition. The machined area at the brittle region displayed the fracture deformation which showed cracks on the surface edge. The relationship between depth of cut and the ductile to brittle transaction behavior of titanium alloys in ultra-precision machining(UPM) was also revealed in this study, it showed that the ductile to brittle transaction behavior of titanium alloys occurred mainly at relatively small depth of cut. The study firstly defines the ductile to brittle transition behavior of titanium alloys in UPM, contributing the information of ductile machining as an optimal machining condition for precise productions of titanium alloys.

Thermo-mechanical modeling of laser treatment on titanium cold-spray coatings

Science.gov (United States)

Paradiso, V.; Rubino, F.; Tucci, F.; Astarita, A.; Carlone, P.

2018-05-01

Titanium coatings are very attractive to several industrial fields, especially aeronautics, due to the enhanced corrosion resistance and wear properties as well as improved compatibility with carbon fiber reinforced plastic (CFRP) materials. Cold sprayed titanium coatings, among the others deposition processes, are finding a widespread use in high performance applications, whereas post-deposition treatments are often used to modify the microstructure of the cold-sprayed layer. Laser treatments allow one to noticeably increase the superficial properties of titanium coatings when the process parameters are properly set. On the other hand, the high heat input required to melt titanium particles may result in excessive temperature increase even in the substrate. This paper introduces a thermo-mechanical model to simulate the laser treatment effects on a cold sprayed titanium coating as well as the aluminium substrate. The proposed thermo-mechanical finite element model considers the transient temperature field due to the laser source and applied boundary conditions using them as input loads for the subsequent stress-strain analysis. Numerical outcomes highlighted the relevance of thermal gradients and thermally induced stresses and strains in promoting the damage of the coating.

Histomorphometric and histologic evaluation of titanium-zirconium (aTiZr) implants with anodized surfaces.

Science.gov (United States)

Sharma, Ajay; McQuillan, A James; Shibata, Yo; Sharma, Lavanya A; Waddell, John Neil; Duncan, Warwick John

2016-05-01

The choice of implant surface has a significant influence on osseointegration. Modification of TiZr surface by anodization is reported to have the potential to modulate the osteoblast cell behaviour favouring more rapid bone formation. The aim of this study is to investigate the effect of anodizing the surface of TiZr discs with respect to osseointegration after four weeks implantation in sheep femurs. Titanium (Ti) and TiZr discs were anodized in an electrolyte containing DL-α-glycerophosphate and calcium acetate at 300 V. The surface characteristics were analyzed by scanning electron microscopy, electron dispersive spectroscopy, atomic force microscopy and goniometry. Forty implant discs with thickness of 1.5 and 10 mm diameter (10 of each-titanium, titanium-zirconium, anodized titanium and anodized titanium-zirconium) were placed in the femoral condyles of 10 sheep. Histomorphometric and histologic analysis were performed 4 weeks after implantation. The anodized implants displayed hydrophilic, porous, nano-to-micrometer scale roughened surfaces. Energy dispersive spectroscopy analysis revealed calcium and phosphorous incorporation into the surface of both titanium and titanium-zirconium after anodization. Histologically there was new bone apposition on all implanted discs, slightly more pronounced on anodised discs. The percentage bone-to-implant contact measurements of anodized implants were higher than machined/unmodified implants but there was no significant difference between the two groups with anodized surfaces (P > 0.05, n = 10). The present histomorphometric and histological findings confirm that surface modification of titanium-zirconium by anodization is similar to anodised titanium enhances early osseointegration compared to machined implant surfaces.

Interaction of titanium beryllide with steam at high temperatures

International Nuclear Information System (INIS)

Munakata, Kenzo; Wada, Kohei; Akimoto, Yusuke; Takeda, Haruki; Nakamura, Ayano; Kim, Jae-Hwan; Nakamichi, Masaru

2014-01-01

Highlights: • Some central and peripheral parts of a plasma sintered titanium beryllide disk were exposed to water vapor at 1273 K. • H 2 gas generation rate of the central part was found to be lower than that of the peripheral part. • Central parts of a plasma sintered titanium beryllide disk were exposed to water vapor at 1273 K with different temperature controls. • H 2 gas generation was found to be affected by thermal treatment. - Abstract: Some central and peripheral parts of a plasma sintered titanium beryllide disk were exposed to water vapor at temperatures raised up to 1273 K. Hydrogen generation and oxidation properties of the titanium beryllide were investigated. The amount of H 2 generation of the central part was found to be smaller than that of the peripheral part, and this can be attributed to difference in the larger fractions of the Be phase on their surface. Thus, different temperature programed experiments were performed using samples cut out from the central part. In an experiment, the temperature of the sample was raised stepwise and behavior of hydrogen generation was investigated. It was found that hydrogen generation does not take place at the temperatures below 1273 K and the amount of hydrogen generated is far smaller. Another experiment was carried out after a sample had been annealed under a dry Ar gas at 1273 K. In this case, the amount of hydrogen generated from the surface decreased. These results indicate the thermal treatment of the titanium beryllide samples affects their reactivity with water vapor

Research and Application of New Type of High Performance Titanium Alloy

Directory of Open Access Journals (Sweden)

ZHU Zhishou

2016-06-01

Full Text Available With the continuous extension of the application quantity and range for titanium alloy in the fields of national aviation, space, weaponry, marine and chemical industry, etc., even more critical requirements to the comprehensive mechanical properties, low cost and process technological properties of titanium alloy have been raised. Through the alloying based on the microstructure parameters design, and the comprehensive strengthening and toughening technologies of fine grain strengthening, phase transformation and process control of high toughening, the new type of high performance titanium alloy which has good comprehensive properties of high strength and toughness, anti-fatigue, failure resistance and anti-impact has been researched and manufactured. The new titanium alloy has extended the application quantity and application level in the high end field, realized the industrial upgrading and reforming, and met the application requirements of next generation equipment.

Introduction to powder metallurgy processes for titanium manufacturing; Introduccion al procesado pulvimetalurgico del titanio

Energy Technology Data Exchange (ETDEWEB)

Esteban, P. G.; Bolzoni, L.; Ruiz-Navas, E. M.; Gordo, E.

2011-07-01

The development of new extraction processes to produce titanium in powder form leads Powder Metallurgy to an advantage position among the manufacturing processes for titanium. The cost reduction of base material, coupled with the economy of the powder metallurgy processes, give titanium industry the chance to diversify its products, which could lead to production volumes able to stabilise the price of the metal. This work reviews some of the Powder Metallurgy techniques for the manufacturing of titanium parts, and describes the two typical approaches for titanium manufacturing: Blending Elemental and Prealloyed Powders. Among others, conventional pressing and sintering are described, which are compared with cold and hot isostatic pressing techniques. Real and potential applications are described. (Author) 71 refs.

Titanium dioxide in dental enamel as a trace element and its variation with bleaching.

Science.gov (United States)

Vargas-Koudriavtsev, Tatiana; Durán-Sedó, Randall; Herrera-Sancho, Óscar-Andrey

2018-06-01

Titanium is a less studied trace element in dental enamel. Literature relates an increased Titanium concentration with a decreased enamel crystal domain size, which in turn is related to a higher color value. The aim of our study was to analyze the effect of tooth bleaching agents on its concentration in dental enamel by means of confocal Raman spectroscopy. Human teeth were randomly distributed in six experimental groups (n=10) and submitted to different bleaching protocols according to the manufacturer´s instructions. Confocal Raman spectroscopy was carried out in order to identify and quantify the presence of titanium dioxide molecules in enamel prior to and during whitening. Statistical analysis included repeated measures analysis of variance ( p ≤0.05) and Bonferroni pairwise comparisons. Titanium dioxide concentration was negatively affected by the longer bleaching protocols (at-home bleaching gels). All in-office whitening products increased significantly the studied molecule ( p ≤0,05). All dental specimens depicted the presence of titanium dioxide as a trace element in dental enamel. Bleaching gels that have to be applied at higher concentrations but for shorter periods of time increase the concentration of titanium dioxide, whilst at-home whitening gels used for longer periods of time despite the lower concentration caused a loss in titanium. Key words: Bleaching, whitening, hydrogen peroxide, carbamide peroxide, Raman spectroscopy, titanium dioxide.

Thickness effect on properties of titanium film deposited by d.c. ...

Indian Academy of Sciences (India)

-beam evaporation possessed fcc symmetry with ... size, morphology, density and textures of the grains strongly depend on the .... dence for TiO2, a common titanium oxide on the surface of titanium ... diffraction peak and θ the diffraction angle.

Polypyrrole/titanium oxide nanotube arrays composites as an active material for supercapacitors.

Science.gov (United States)

Kim, Min Seok; Park, Jong Hyeok

2011-05-01

The authors present the first reported use of vertically oriented titanium oxide nanotube/polypyrrole (PPy) nanocomposites to increase the specific capacitance of TiO2 based energy storage devices. To increase their electrical storage capacity, titanium oxide nanotubes were coated with PPy and their morphologies were characterized. The incorporation of PPy increased the specific capacitance of the titanium oxide nanotube based supercapacitor system, due to their increased surface area and additional pseudo-capacitance.

Utilization of titanium sponge in H. T. G. R

Energy Technology Data Exchange (ETDEWEB)

Tone, H [Japan Atomic Energy Research Inst., Oarai, Ibaraki. Oarai Research Establishment

1977-10-01

The high temperature, gas-cooled reactor (H.T.G.R.) uses helium as a coolant and graphite as both the moderator and the fuel tube material. At first sight, there should not be any problem concerning the compatibility of these materials in the H.T.G.R. core region where temperature exceeds 700/sup 0/C, however, it is possible that the graphite core and other structural materials are oxidized by traces of impurities in the coolant. In large-power H.T.G.R., water inleakage from both heat exchangers and coolant circulation pumps will probably be the major source of impurity which will react with the graphite-producing H/sub 2/, CO and CO/sub 2/. In the near future, the nuclear heat of H.T.G.R. will be used as a major heat source for steel production and the chemical industry. For these purposes, it will be necessary to construct a reactor using a helium coolant of greater than 1000/sup 0/C. Therefore, not only the development of refractory metals as structural materials but also an effective helium coolant purification system are the keys for H.T.G.R. construction. Recently, in the helium coolant purification system of H.T.G. Reactors, which have been developed in the several nations advanced in atomic reactors, titanium sponge is used very frequently to remove hydrogen gas as an impurity in helium coolant. Titanium sponge can absorb very large quantities of hydrogen and its absorption-capacity can be very easily controlled by controlling the temperature of the titanium sponge-since titanium hydride is formed by endothermic reaction. The titanium sponge trap is used also in OGL-1 (Oarai Gas Loop-1), helium coolant purification system for large scale irradiation apparatus which is used for nuclear fuels of H.T.G.R. This apparatus has been installed in the Japan Material Testing Reactor. In this report, the coolant purification system of H.T.G.R., OGL-1 and the experimental results of the titanium sponge trap are explained briefly.

Selective laser melting-produced porous titanium scaffolds regenerate bone in critical size cortical bone defects.

Science.gov (United States)

Van der Stok, Johan; Van der Jagt, Olav P; Amin Yavari, Saber; De Haas, Mirthe F P; Waarsing, Jan H; Jahr, Holger; Van Lieshout, Esther M M; Patka, Peter; Verhaar, Jan A N; Zadpoor, Amir A; Weinans, Harrie

2013-05-01

Porous titanium scaffolds have good mechanical properties that make them an interesting bone substitute material for large bone defects. These scaffolds can be produced with selective laser melting, which has the advantage of tailoring the structure's architecture. Reducing the strut size reduces the stiffness of the structure and may have a positive effect on bone formation. Two scaffolds with struts of 120-µm (titanium-120) or 230-µm (titanium-230) were studied in a load-bearing critical femoral bone defect in rats. The defect was stabilized with an internal plate and treated with titanium-120, titanium-230, or left empty. In vivo micro-CT scans at 4, 8, and 12 weeks showed more bone in the defects treated with scaffolds. Finally, 18.4 ± 7.1 mm(3) (titanium-120, p = 0.015) and 18.7 ± 8.0 mm(3) (titanium-230, p = 0.012) of bone was formed in those defects, significantly more than in the empty defects (5.8 ± 5.1 mm(3) ). Bending tests on the excised femurs after 12 weeks showed that the fusion strength reached 62% (titanium-120) and 45% (titanium-230) of the intact contralateral femurs, but there was no significant difference between the two scaffolds. This study showed that in addition to adequate mechanical support, porous titanium scaffolds facilitate bone formation, which results in high mechanical integrity of the treated large bone defects. Copyright © 2012 Orthopaedic Research Society.

Stress transmission through Ti-Ni alloy, titanium and stainless steel in impact compression test.

Science.gov (United States)

Yoneyama, T; Doi, H; Kobayashi, E; Hamanaka, H; Tanabe, Y; Bonfield, W

2000-06-01

Impact stress transmission of Ti-Ni alloy was evaluated for biomedical stress shielding. Transformation temperatures of the alloy were investigated by means of DSC. An impact compression test was carried out with use of split-Hopkinson pressure-bar technique with cylindrical specimens of Ti-Ni alloy, titanium and stainless steel. As a result, the transmitted pulse through Ti-Ni alloy was considerably depressed as compared with those through titanium and stainless steel. The initial stress reduction was large through Ti-Ni alloy and titanium, but the stress reduction through Ti-Ni alloy was more continuous than titanium. The maximum value in the stress difference between incident and transmitted pulses through Ti-Ni alloy or titanium was higher than that through stainless steel, while the stress reduction in the maximum stress through Ti-Ni alloy was statistically larger than that through titanium or stainless steel. Ti-Ni alloy transmitted less impact stress than titanium or stainless steel, which suggested that the loading stress to adjacent tissues could be decreased with use of Ti-Ni alloy as a component material in an implant system. Copyright 2000 Kluwer Academic Publishers

Titanium and titanium alloy creep (a bibliography with abstracts). Report for 1964--Jun 1976

International Nuclear Information System (INIS)

Smith, M.F.

1976-08-01

Research is cited on creep of titanium and its alloys with regard to composition, stress corrosion, fracture, microstructure and tests. Many reports deal with applications to aircraft, spacecraft, and nuclear reactors. (This updated bibliography contains 133 abstracts, 24 of which are new entries to the previous edition.)

X-ray photoelectron spectroscopy characterization of high dose carbon-implanted steel and titanium alloys

Science.gov (United States)

Viviente, J. L.; García, A.; Alonso, F.; Braceras, I.; Oñate, J. I.

1999-04-01

A study has been made of the depth dependence of the atomic fraction and chemical bonding states of AISI 440C martensitic stainless steel and Ti-6Al-4V alloy implanted with 75 keV C + at very high doses (above 10 18 ions cm -2), by means of X-ray photoelectron spectroscopy combined with an Ar + sputtering. A Gaussian-like carbon distribution was observed on both materials at the lowest implanted dose. More trapezoidal carbon depth-profiles were found with increasing implanted doses, and a pure carbon layer was observed only on the titanium alloy implanted at the highest dose. The implanted carbon was combined with both base metal and carbon itself to form metallic carbides and graphitic carbon. Furthermore, carbon-enriched carbides were also found by curve fitting the C 1s spectra. The titanium alloy showed a higher carbidic contribution than the steel implanted at the same C + doses. A critical carbon concentrations of about 33 at.% and 23 at.% were measured for the formation of C-C bonds in Ti-6Al-4V and steel samples, respectively. The carbon atoms were bound with metal to form carbidic compounds until these critical concentrations were reached; when this C concentration was exceeded the proportion of C-C bonds increased and resulted in the growth of carbonaceous layers.

Formation of an ascorbate-apatite composite layer on titanium

Energy Technology Data Exchange (ETDEWEB)

Ito, Atsuo [National Institute of Advanced Industrial Science and Technology (AIST), Institute for Human Science and Biomedical Engineering, Central 6, Higashi 1-1-1, Tsukuba, Ibaraki 305-8566 (Japan); Sogo, Yu [National Institute of Advanced Industrial Science and Technology (AIST), Institute for Human Science and Biomedical Engineering, Central 6, Higashi 1-1-1, Tsukuba, Ibaraki 305-8566 (Japan); Ebihara, Yuko [School of Science and Technology, Waseda University, 3-4-1 Okubo, Sinjuku-ku, Tokyo 169-8050 (Japan); Onoguchi, Masahiro [School of Science and Technology, Waseda University, 3-4-1 Okubo, Sinjuku-ku, Tokyo 169-8050 (Japan); Oyane, Ayako [National Institute of Advanced Industrial Science and Technology (AIST), Nanotechnology Research Institute, Central 4, Higashi 1-1-1, Tsukuba, Ibaraki 305-8562 (Japan); Ichinose, Noboru [School of Science and Technology, Waseda University, 3-4-1 Okubo, Sinjuku-ku, Tokyo 169-8050 (Japan)

2007-09-15

An ascorbate-apatite composite layer was successfully formed on NaOH- and heat-treated titanium by coprecipitating L-ascorbic acid phosphate and low-crystalline apatite in a supersaturated calcium phosphate solution at 37 {sup 0}C for 48 h. The supersaturated calcium phosphate solutions used have chemical compositions attainable by mixing infusion fluids officially approved for clinical use. The amount of immobilized L-ascorbic acid phosphate ranged from 1.0 to 2.3 {mu}g mm{sup -2}, which is most likely to be sufficient for the in vitro osteogenic differentiation of mesenchymal stem cells on titanium. Since ascorbate is important for the collagen synthesis and subsequent osteogenesis of mesenchymal stem cells, titanium coated with the ascorbate-apatite composite layer would be useful as a scaffold in bone tissue engineering and as a bone substitute.

Formation of an ascorbate-apatite composite layer on titanium

International Nuclear Information System (INIS)

Ito, Atsuo; Sogo, Yu; Ebihara, Yuko; Onoguchi, Masahiro; Oyane, Ayako; Ichinose, Noboru

2007-01-01

An ascorbate-apatite composite layer was successfully formed on NaOH- and heat-treated titanium by coprecipitating L-ascorbic acid phosphate and low-crystalline apatite in a supersaturated calcium phosphate solution at 37 0 C for 48 h. The supersaturated calcium phosphate solutions used have chemical compositions attainable by mixing infusion fluids officially approved for clinical use. The amount of immobilized L-ascorbic acid phosphate ranged from 1.0 to 2.3 μg mm -2 , which is most likely to be sufficient for the in vitro osteogenic differentiation of mesenchymal stem cells on titanium. Since ascorbate is important for the collagen synthesis and subsequent osteogenesis of mesenchymal stem cells, titanium coated with the ascorbate-apatite composite layer would be useful as a scaffold in bone tissue engineering and as a bone substitute

Evaluation of the properties of TiO2 films on titanium

International Nuclear Information System (INIS)

Panizza, C.

2009-01-01

We report the results of laboratory tests concerning the characterization of photo catalytic properties of titanium dioxide films obtained on titanium substrates by using three different techniques for anodizing. Been investigated in scanning electron microscopy, X-ray analysis cyclic voltammetry. [it

Preparation of novel polymer–metal oxide nanocomposites with ...

Indian Academy of Sciences (India)

Administrator

inorganic compound. Nanocomposites ... ganic compound (nanophase separated structure). This ..... AFM images of (a) titanium substrate, (b) titanium substrate with polymer brush and ... titanium was observed with atomic force microscope.

Hot deformation behavior of TC18 titanium alloy

Directory of Open Access Journals (Sweden)

Jia Bao-Hua

2013-01-01

Full Text Available Isothermal compression tests of TC18 titanium alloy at the deformation temperatures ranging from 25°C to 800°C and strain rate ranging from 10-4 to 10-2 s-1 were conducted by using a WDW-300 electronic universal testing machine. The hot deformation behavior of TC18 was characterized based on an analysis of the true stress-true strain curves of TC18 titanium alloy. The curves show that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the strain rate play an important role in the flow stress when increasing the temperatures. By taking the effect of strain into account, an improved constitutive relationship was proposed based on the Arrhenius equation. By comparison with the experimental results, the model prediction agreed well with the experimental data, which demonstrated the established constitutive relationship was reliable and can be used to predict the hot deformation behavior of TC18 titanium alloy.

Tribological Properties of Surface-Textured and Plasma-Nitrided Pure Titanium Under Oil Lubrication Condition

Science.gov (United States)

Zhang, Baosen; Dong, Qiangsheng; Ba, Zhixin; Wang, Zhangzhong; Shi, Hancheng; Xue, Yanting

2018-01-01

Plasma nitriding was conducted as post-treatment for surface texture on pure titanium to obtain a continuous nitriding layer. Supersonic fine particles bombarding (SFPB) was carried out to prepare surface texture. The surface morphologies and chemical composition were analyzed using scanning electron microscope and energy disperse spectroscopy. The microstructures of modified layers were characterized by transmission electron microscope. The tribological properties of surface-textured and duplex-treated pure titanium under oil lubrication condition were systematically investigated in the ball-on-plate reciprocating mode. The effects of applied load and sliding velocity on the tribological behavior were analyzed. The results show that after duplex treatments, the grains size in modified layer becomes slightly larger, and hardness is obviously improved. Wear resistance of duplex-treated pure titanium is significantly improved referenced to untreated and surface-textured pure titanium, which is 3.22 times as much as untreated pure titanium and 2.15 times of that for surface-textured pure titanium, respectively.