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Sample records for titanium 60

  1. 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

  2. Titanium

    DEFF Research Database (Denmark)

    Fage, Simon W; Muris, Joris; Jakobsen, Stig S

    2016-01-01

    Exposure to titanium (Ti) from implants and from personal care products as nanoparticles (NPs) is common. This article reviews exposure sources, ion release, skin penetration, allergenic effects, and diagnostic possibilities. We conclude that human exposure to Ti mainly derives from dental...... and medical implants, personal care products, and foods. Despite being considered to be highly biocompatible relative to other metals, Ti is released in the presence of biological fluids and tissue, especially under certain circumstances, which seem to be more likely with regard to dental implants. Although...... most of the studies reviewed have important limitations, Ti seems not to penetrate a competent skin barrier, either as pure Ti, alloy, or as Ti oxide NPs. However, there are some indications of Ti penetration through the oral mucosa. We conclude that patch testing with the available Ti preparations...

  3. Neutron diffraction study of the formation of ordered antiphase domains in cubic titanium carbide TiC0.60

    International Nuclear Information System (INIS)

    Khidirov, I.; Parpiev, A. S.

    2013-01-01

    A series of superstructural reflections (described within the sp. gr. Fd3m) are found to be split into three symmetric parts in the neutron powder diffraction pattern of titanium carbide TiC 0.60 annealed at a temperature of 600°C. No splitting of superstructural reflections is observed in the neutron diffraction pattern of TiC 0.60 annealed at relatively high temperatures (780°C). This phenomenon can be explained by that fact that the ordering of carbon atoms at relatively high temperatures (780°C) is accompanied by the formation of randomly oriented rather large antiphase domains (APDs) (450 Å). At relatively low temperatures (600°C), stacking faults arise in the arrangement of partially ordered carbon atoms. In this case, relatively small ordered APDs (290 Å) are formed, along with disordered ones.

  4. Synthesis and structure of the first fullerene complex of titanium Cp{sub 2}Ti({eta}{sup 2}-C{sub 60})

    Energy Technology Data Exchange (ETDEWEB)

    Burlakov, V.V.; Usatov, A.V.; Lyssenko, K.A.; Antipin, M.Yu.; Novikov, Yu.N.; Shur, V.B. [Russian Academy of Sciences, Moscow (Russian Federation). A.N. Nesmeyanov Inst. of Organoelement Compounds

    1999-11-01

    The first fullerene complex of titanium Cp{sub 2}Ti({eta}{sup 2}-C{sub 60}) has been synthesized by reaction of the bis(trimethylsilyl)-acetylene complex of titanocene Cp{sub 2}Ti({eta}{sup 2}-Me{sub 3}SiC{sub 2}SiMe{sub 3}) with an equimolar amount of fullerene-60 in toluene at room temperature under argon. An X-ray diffraction study of the complex has shown that it has the structure of a titanacyclopropane derivative. (orig.)

  5. Microstructure and mechanical properties of a novel near-α titanium alloy Ti6.0Al4.5Cr1.5Mn

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong-bin [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Shanghai Special Casting Engineering Technology Research Center, Shanghai 201605 (China); Wang, Shu-sen; Gao, Peng-yue; Jiang, Tao [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Lu, Xiong-gang; Li, Chong-he [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Shanghai Special Casting Engineering Technology Research Center, Shanghai 201605 (China)

    2016-08-30

    Based on previous Ti-Al-Cr-Mn quaternary system thermodynamic database, a novel near-α titanium alloy Ti-6.0Al-4.5Cr-1.5Mn alloy was designed and successfully prepared by the water-cooled copper crucible. Microscopic observation showed that both as-cast and annealing status consist of α phase, which coincides with the theoretical expectation. The mechanical properties at room temperature were measured and this alloy possesses good mechanical properties, its average yield-strength reaches 1051.5 MPa and tensile-strength is up to 1091.2 MPa while its average elongation is just 8.3%. Compared with the TA15, it has better mechanical strength and worse elongation. In the new alloy Laves phase Cr{sub 2}Ti were detected by XRD pattern and TEM, which may cause the alloy's poor plasticity.

  6. Microstructure and mechanical properties of a novel near-α titanium alloy Ti6.0Al4.5Cr1.5Mn

    International Nuclear Information System (INIS)

    Wang, Hong-bin; Wang, Shu-sen; Gao, Peng-yue; Jiang, Tao; Lu, Xiong-gang; Li, Chong-he

    2016-01-01

    Based on previous Ti-Al-Cr-Mn quaternary system thermodynamic database, a novel near-α titanium alloy Ti-6.0Al-4.5Cr-1.5Mn alloy was designed and successfully prepared by the water-cooled copper crucible. Microscopic observation showed that both as-cast and annealing status consist of α phase, which coincides with the theoretical expectation. The mechanical properties at room temperature were measured and this alloy possesses good mechanical properties, its average yield-strength reaches 1051.5 MPa and tensile-strength is up to 1091.2 MPa while its average elongation is just 8.3%. Compared with the TA15, it has better mechanical strength and worse elongation. In the new alloy Laves phase Cr 2 Ti were detected by XRD pattern and TEM, which may cause the alloy's poor plasticity.

  7. Fate and biological effects of silver, titanium dioxide, and C60 (fullerene) nanomaterials during simulated wastewater treatment processes

    International Nuclear Information System (INIS)

    Wang, Yifei; Westerhoff, Paul; Hristovski, Kiril D.

    2012-01-01

    As engineered nanomaterials (NMs) become used in industry and commerce their loading to sewage will increase. In this research, sequencing batch reactors (SBRs) were operated with hydraulic (HRT) and sludge (SRT) retention times representative of full-scale biological WWTPs for several weeks. Under environmentally relevant NM loadings and biomass concentrations, NMs had negligible effects on ability of the wastewater bacteria to biodegrade organic material, as measured by chemical oxygen demand (COD). Carboxy-terminated polymer coated silver nanoparticles (fn-Ag) were removed less effectively (88% removal) than hydroxylated fullerenes (fullerols; >90% removal), nano TiO 2 (>95% removal) or aqueous fullerenes (nC 60 ; >95% removal). Experiments conducted over 4 months with daily loadings of nC 60 showed that nC 60 removal from solution depends on the biomass concentration. Under conditions representative of most suspended growth biological WWTPs (e.g., activated sludge), most of the NMs will accumulate in biosolids rather than in liquid effluent discharged to surface waters. Significant fractions of fn-Ag were associated with colloidal material which suggests that efficient particle separation processes (sedimentation or filtration) could further improve removal of NM from effluent.

  8. 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.

  9. Titanium Alloys for Critical Ordnance Components. Producers Coordination Meeting on Titanium Materials for Davy Crockett and Other Weapon Systems Held at Watertown Arsenal, Watertown 72, Mass., 14 Apr 60 and Fabricators Coordination Meeting on Titanium Materials for Davy Crockett and Other Weapon Systems Held at Watervliet Arsenal, Watervliet, NY, 15 Apr 1960

    Science.gov (United States)

    1960-01-01

    Title Agenda and AV^stracts - Watertown Arsenal, Watnrtovm, Mass. llj April i960 - Producers Coordination Meeting, "Titanium Materials for Davy...u.nd J.i’.l~.Jhr!l’ Scicnti~’ic Comp::1.~1y1 Chlc::-.~~o, IJ~~nois. oth :r c~tUl’ll~nt and 1Jl’Occ1t.G.~cn !.Jn.y be uoed if :J..CCC:t.> td )le to

  10. Lactobacillusassisted synthesis of titanium nanoparticles

    Directory of Open Access Journals (Sweden)

    Jha Anal

    2007-01-01

    Full Text Available AbstractAn eco-friendlylactobacillussp. (microbe assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

  11. 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...

  12. 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)

  13. Development of a model for the anodic behavior of T60 titanium in chlorinated and oxygenated aqueous media. Application to the specific conditions of hydrothermal oxidation (1 MPa

    International Nuclear Information System (INIS)

    Frayret, C.; Jaszay, Th.; Lestienne, B.; Delville, M.H.

    2003-01-01

    This work evaluates the anodic electrochemical behavior of titanium metal in hydrothermal oxidation conditions (up to 400 deg. C and 28 MPa) in chlorinated media in order to estimate the supercritical water oxidation reactors reliability for the treatment of less than 10% organic-waste waters. The titanium room temperature dissolution mechanism in chlorinated acidic medium (pH 2 oxide formation with a very limited tetravalent dissolution). In hydrothermal oxidation (pH>1), only the second branch is effective. The titanium protection is directly related to the oxide stability in high pH systems. The mechanism model is expressed in terms of 'current-potential' laws, which provide kinetic parameters using optimization calculations. The different elementary steps reaction rates were estimated as well as the evolution of the reaction intermediates coverage ratios with the potential. The quantification of each elementary step was performed to understand and/or orient the materials behavior according to different factors (pH, chloride ions contents, potentials...)

  14. 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...

  15. 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).

  16. 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)

  17. 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...

  18. Growth of anatase titanium dioxide nanotubes via anodization

    Directory of Open Access Journals (Sweden)

    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.

  19. 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...

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Titanium and zirconium alloys

    International Nuclear Information System (INIS)

    Pinard Legry, G.

    1994-01-01

    Titanium and zirconium pure and base alloys are protected by an oxide film with anionic vacancies which gives a very good resistance to corrosion in oxidizing medium, in some ph ranges. Results of pitting and crevice corrosion are given for Cl - , Br - , I - ions concentration with temperature and ph dependence, also with oxygenated ions effect. (A.B.). 32 refs., 6 figs., 3 tabs

  13. Titanium implants in irradiated dog mandibles

    International Nuclear Information System (INIS)

    Schweiger, J.W.

    1989-01-01

    The use of osseointegrated titanium implants has been a great benefit to selected cancer patients who otherwise would not be able to wear conventional and/or maxillofacial prostheses. Cognizant of the risk of osteoradionecrosis, we used an animal model to seek experimental evidence for successful osseointegration in bone irradiated to tumoricidal levels. Five healthy male beagle dogs received 60 gray to a previously edentulated and healed area of the right hemimandible. The left hemimandible was kept as a nonirradiated control. After 9 months, titanium implants were placed and allowed an additional 5 1/2 months to osseointegrate. At that time, block specimens were obtained, radiographed, photographed, and analyzed histologically. Although statistical significance cannot be attached to the results, osseointegration was achieved in half of the irradiated specimens

  14. 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

  15. Candida albicans biofilm on titanium: effect of peroxidase precoating

    Directory of Open Access Journals (Sweden)

    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

  16. 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.

  17. Kruger 60

    Science.gov (United States)

    Knapp, Wilfried; Nanson, John

    2018-01-01

    As announced in our report “Measurements of WDS Objects found in images taken for detecting CPM pairs in the LSPM catalog” we present here a report on Kruger 60. This multiple is listed in WDS with such a large number of components that we thought it deserves a separate report.

  18. 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.

  19. 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.)

  20. 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.

  1. 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...

  2. 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+.

  3. 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...

  4. 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

  5. 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.)

  6. 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 ...

  7. 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.

  8. Intermetallic Nickel-Titanium Alloys for Oil-Lubricated Bearing Applications

    Science.gov (United States)

    DellaCorte, C.; Pepper, S. V.; Noebe, R.; Hull, D. R.; Glennon, G.

    2009-01-01

    An intermetallic nickel-titanium alloy, NITINOL 60 (60NiTi), containing 60 wt% nickel and 40 wt% titanium, is shown to be a promising candidate material for oil-lubricated rolling and sliding contact applications such as bearings and gears. NiTi alloys are well known and normally exploited for their shape memory behavior. When properly processed, however, NITINOL 60 exhibits excellent dimensional stability and useful structural properties. Processed via high temperature, high-pressure powder metallurgy techniques or other means, NITINOL 60 offers a broad combination of physical properties that make it unique among bearing materials. NITINOL 60 is hard, electrically conductive, highly corrosion resistant, less dense than steel, readily machined prior to final heat treatment, nongalling and nonmagnetic. No other bearing alloy, metallic or ceramic encompasses all of these attributes. Further, NITINOL 60 has shown remarkable tribological performance when compared to other aerospace bearing alloys under oil-lubricated conditions. Spiral orbit tribometer (SOT) tests were conducted in vacuum using NITINOL 60 balls loaded between rotating 440C stainless steel disks, lubricated with synthetic hydrocarbon oil. Under conditions considered representative of precision bearings, the performance (life and friction) equaled or exceeded that observed with silicon nitride or titanium carbide coated 440C bearing balls. Based upon this preliminary data, it appears that NITINOL 60, despite its high titanium content, is a promising candidate alloy for advanced mechanical systems requiring superior and intrinsic corrosion resistance, electrical conductivity and nonmagnetic behavior under lubricated contacting conditions.

  9. Hydrogen in titanium alloys

    International Nuclear Information System (INIS)

    Wille, G.W.; Davis, J.W.

    1981-04-01

    The titanium alloys that offer properties worthy of consideration for fusion reactors are Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242S) and Ti-5Al-6Sn-2Zr-1Mo-Si (Ti-5621S). The Ti-6242S and Ti-5621S are being considered because of their high creep resistance at elevated temperatures of 500 0 C. Also, irradiation tests on these alloys have shown irradiation creep properties comparable to 20% cold worked 316 stainless steel. These alloys would be susceptible to slow strain rate embrittlement if sufficient hydrogen concentrations are obtained. Concentrations greater than 250 to 500 wppm hydrogen and temperatures lower than 100 to 150 0 C are approximate threshold conditions for detrimental effects on tensile properties. Indications are that at the elevated temperature - low hydrogen pressure conditions of the reactors, there would be negligible hydrogen embrittlement

  10. 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

  11. Phase transformation order-disorder in nonstoichiometric titanium carbide

    International Nuclear Information System (INIS)

    Vlasov, V.A.; Karmo, Yu.S.; Kustova, L.V.

    1986-01-01

    Titanium carbide delta-phase is studied using the methods of electric conductivity and differential thermal analysis (DTA). It is shown on the Ti-C system phase diagram that two regions of TiCsub(0.46-0.60) and TiCsub(0.65-1.00) compositions, different in their properties, correspond to delta-phase. Both ordered and disordered phases exist within the TiCsub(0.046-0.60) concentration range, and in equilibrium heating or cooling one phase converts to another at 590 deg C (the first order phase transformation). Samples of the TiCsub(0.65-1.00) composition are characterized by low electric conductivity stability, that is explained by strong titanium carbide electric conductivity sensitivity to defects and impurities

  12. 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)

  13. 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.

  14. Manufacturing techniques for titanium aluminide based alloys and metal matrix composites

    Science.gov (United States)

    Kothari, Kunal B.

    -sized titanium aluminide powders were rapidly consolidated to form near-net shape titanium aluminide parts in form of small discs and tiles. The rapidly consolidated titanium aluminide parts were found to be fully dense. The microstructure morphology was found to vary with consolidation conditions. The mechanical properties were found to be significantly dependent on microstructure morphology and grain size. Due to rapid consolidation, grain growth during consolidation was limited, which in turn led to enhanced mechanical properties. The high temperature mechanical properties for the consolidated titanium aluminide samples were characterized and were found to retain good mechanical performance up to 700°C. Micron-sized titanium aluminide powders with slightly less Aluminum and small Nb, and Cr additions were rapidly consolidated into near-net shape parts. The consolidated parts were found to exhibit enhanced mechanical performance in terms of ductility and yield strength. The negative effect of Oxygen on the flexural strength at high temperatures was found to be reduced with the addition of Nb. In an effort to further reduce the grain size of the consolidated titanium aluminide samples, the as-received titanium aluminide powders were milled in an attrition mill. The average powder particle size of the powders was reduced by 60% after milling. The milled powders were then rapidly consolidated. The grain size of the consolidated parts was found to be in the sub-micrometer range. The mechanical properties were found to be significantly enhanced due to reduction of grain size in the sub-micrometer range. In order to develop a metal matrix composite based on titanium aluminide matrix reinforced with titanium boride, an experiment to study the effect of rapid consolidation on titanium diboride powders was conducted. Micron-sized titanium diboride powders were consolidated and were found to be 93% dense and exhibited minimal grain growth. The low density of the consolidated part was

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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.)

  12. On structural recrystallization in titanium

    International Nuclear Information System (INIS)

    Mirzaev, D.A.; Schastlivtsev, V.M.; Shtejnberg, M.M.; Ul'yanov, V.G.; AN SSSR, Sverdlovsk. Inst. Fiziki Metallov)

    1984-01-01

    The effect of preliminary superfast quenching on structural changes at inverse α→β transformation in titanium is studied. Cooling at rates more than 10 4 deg/s results in grain refining at succeeding annealing in β- and α- regions. The obtained effect is explained by additional phase transformation-induced hardening conditioned by decrease of the transformation point at superfast cooling

  13. 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

  14. 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.

  15. Structure and amphoteric properties of titanium dioxide gels

    International Nuclear Information System (INIS)

    Kertesz, C.

    1991-01-01

    Mechanisms responsible for the in-solution ion retention by titanium dioxide are studied. Mineral oxide gel formation and structure are described and various titanium dioxide gel synthesis modes are presented. A two-phase model, taking into account the porous nature of the solid and allowing for the application of the mass action law, is adopted. The oxide amphoteric properties are studied with the potentiometric titration technique. Hysteresis loops are imputed to the slowness of the acid-basic neutralization reaction. The main characteristics are determined: isoelectric point, cation and anion retention capacity. Depending on the suspension agitation, the speed limiting factor may be the diffusion in the film or the diffusion in the particle. 60 fig., 128 ref

  16. In situ disordering of monoclinic titanium monoxide Ti5O5 studied by transmission electron microscope TEM.

    Science.gov (United States)

    Rempel, А А; Van Renterghem, W; Valeeva, А А; Verwerft, M; Van den Berghe, S

    2017-09-07

    The superlattice and domain structures exhibited by ordered titanium monoxide Ti 5 O 5 are disrupted by low energy electron beam irradiation. The effect is attributed to the disordering of the oxygen and titanium sublattices. This disordering is caused by the displacement of both oxygen and titanium atoms by the incident electrons and results in a phase transformation of the monoclinic phase Ti 5 O 5 into cubic B1 titanium monoxide. In order to determine the energies required for the displacement of titanium or oxygen atoms, i.e. threshold displacement energies, a systematic study of the disappearance of superstructure reflections with increasing electron energy and electron bombardment dose has been performed in situ in a transmission electron microscope (TEM). An incident electron energy threshold between 120 and 140 keV has been observed. This threshold can be ascribed to the displacements of titanium atoms with 4 as well as with 5 oxygen atoms as nearest neighbors. The displacement threshold energy of titanium atoms in Ti 5 O 5 corresponding with the observed incident electron threshold energy lies between 6.0 and 7.5 eV. This surprisingly low value can be explained by the presence of either one or two vacant oxygen lattice sites in the nearest neighbors of all titanium atoms.

  17. Bacterial adherence to anodized titanium alloy

    International Nuclear Information System (INIS)

    Peremarch, C Perez-Jorge; Tanoira, R Perez; Arenas, M A; Matykina, E; Conde, A; De Damborenea, J J; Gomez Barrena, E; Esteban, J

    2010-01-01

    The aim of this study was to evaluate Staphylococcus sp adhesion to modified surfaces of anodized titanium alloy (Ti-6Al-4V). Surface modification involved generation of fluoride-containing titanium oxide nanotube films. Specimens of Ti-6Al-4V alloy 6-4 ELI-grade 23- meets the requirements of ASTM F136 2002A (AMS 2631B class A1) were anodized in a mixture of sulphuric/hydrofluoric acid at 20 V for 5 and 60 min to form a 100 nm-thick porous film of 20 nm pore diameter and 230 nm-thick nanotube films of 100 nm in diameter. The amount of fluorine in the oxide films was of 6% and of 4%, respectively. Collection strains and six clinical strains each of Staphylococcus aureus and Staphylococcus epidermidis were studied. The adherence study was performed using a previously published protocol by Kinnari et al. The experiments were performed in triplicates. As a result, lower adherence was detected for collection strains in modified materials than in unmodified controls. Differences between clinical strains were detected for both species (p<0.0001, Kruskal-Wallis test), although global data showed similar results to that of collection strains (p<0.0001, Kruskal-Wallis test). Adherence of bacteria to modified surfaces was decreased for both species. The results also reflect a difference in the adherence between S. aureus and S. epidermidis to the modified material. As a conclusion, not only we were able to confirm the decrease of adherence in the modified surface, but also the need to test multiple clinical strains to obtain more realistic microbiological results due to intraspecies differences.

  18. 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.

  19. 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)

  20. Pilot plant studies on the production of ductile titanium sponge from pure titanium tetrachloride

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, H S; Kulkarni, A P; Vijay, P L; Subramanian, C; Swaminathan, K; Rajagopalan, P K; Rao, Ch S; Sundaram, C V

    1974-12-31

    Three different routes were examined, namely: (i) magnesium reduction and pyro-vacuum treatment, (ii) magnesium reduction and acid leaching, and (iii) two-stage reduction with sodium, followed by aqueous processing. Magnesium- reduced and vacuumtreated titanium sponge was of uniformly good quality, contained less than 1000 ppm oxygen, and corresponded to a button hardness of 90 to 100 VPN. Acid-leached sponge from magnesium reduction had a relatively higher oxygen content (l000 to 1500 ppm), but was still of acceptable quality (hardness 125 VPN). A significant portion of the metal from sodium reduction was in the form of shiny crystals, of very low button hardness (60 to 90 VPN). The operations established the satisfactory performance of the various equipment designs and also the optimum process conditions. (auth)

  1. Titanium gettering in Doublet III

    International Nuclear Information System (INIS)

    de Grassie, J.S.; Callis, R.; Campbell, G.

    1980-08-01

    The application of mild titanium gettering in the Doublet III tokamak has led to a significant improvement in the obtainable operating regimes and discharge parameters for all of the many plasma cross-sectional shapes studied. With gettering, low-Z impurities and radiated power are greatly reduced. The maximum line averaged electron density has increased 50% (anti n/sub e max/ approx. 1 x 10 20 /m 3 ), corresponding to a Murakami coefficient of nearly 6

  2. 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...

  3. 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

  4. 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)

  5. 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.

  6. 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

  7. Titanium distribution in swimming pool water is dominated by dissolved species

    International Nuclear Information System (INIS)

    David Holbrook, R.; Motabar, Donna; Quiñones, Oscar; Stanford, Benjamin; Vanderford, Brett; Moss, Donna

    2013-01-01

    The increased use of titanium dioxide nanoparticles (nano-TiO 2 ) in consumer products such as sunscreen has raised concerns about their possible risk to human and environmental health. In this work, we report the occurrence, size fractionation and behavior of titanium (Ti) in a children's swimming pool. Size-fractionated samples were analyzed for Ti using ICP-MS. Total titanium concentrations ([Ti]) in the pool water ranged between 21 μg/L and 60 μg/L and increased throughout the 101-day sampling period while [Ti] in tap water remained relatively constant. The majority of [Ti] was found in the dissolved phase (<1 kDa), with only a minor fraction of total [Ti] being considered either particulate or microparticulate. Simple models suggest that evaporation may account for the observed variation in [Ti], while sunscreen may be a relevant source of particulate and microparticule Ti. Compared to diet, incidental ingestion of nano-Ti from swimming pool water is minimal. -- Highlights: •Total titanium concentrations in unfiltered swimming pool water ranged between 21 and 60 μg/L. •Evaporation of the swimming pool water is suspected of causing a temporal increase in [Ti]. •The vast majority of Ti is found in the dissolved phase (<1 kD). •Swimming pools are not a significant Ti source for human exposure via ingestion. -- In children's swimming pool water, the majority of titanium is found in the dissolved phase

  8. Carbonate effects on hexavalent uranium removal from water by nanocrystalline titanium dioxide

    International Nuclear Information System (INIS)

    Wazne, Mahmoud; Meng, Xiaoguang; Korfiatis, George P.; Christodoulatos, Christos

    2006-01-01

    A novel nanocrystalline titanium dioxide was used to treat depleted uranium (DU)-contaminated water under neutral and alkaline conditions. The novel material had a total surface area of 329 m 2 /g, total surface site density of 11.0 sites/nm 2 , total pore volume of 0.415 cm 3 /g and crystallite size of 6.0 nm. It was used in batch tests to remove U(VI) from synthetic solutions and contaminated water. However, the capacity of the nanocrystalline titanium dioxide to remove U(VI) from water decreased in the presence of inorganic carbonate at pH > 6.0. Adsorption isotherms, Fourier transform infrared (FTIR) spectroscopy, and surface charge measurements were used to investigate the causes of the reduced capacity. The surface charge and the FTIR measurements suggested that the adsorbed U(VI) species was not complexed with carbonate at neutral pH values. The decreased capacity of titanium dioxide to remove U(VI) from water in the presence of carbonate at neutral to alkaline pH values was attributed to the aqueous complexation of U(VI) by inorganic carbonate. The nanocrystalline titanium dioxide had four times the capacity of commercially available titanium dixoide (Degussa P-25) to adsorb U(VI) from water at pH 6 and total inorganic carbonate concentration of 0.01 M. Consequently, the novel material was used to treat DU-contaminated water at a Department of Defense (DOD) site

  9. 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.

  10. 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.

  11. Titanium Matrix Composite Pressure Vessel, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — For over 15 years, FMW Composite Systems has developed Metal Matrix Composite manufacturing methodologies for fabricating silicon-carbide-fiber-reinforced titanium...

  12. 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

  13. 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

  14. 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

  15. Nanotubular topography enhances the bioactivity of titanium implants.

    Science.gov (United States)

    Huang, Jingyan; Zhang, Xinchun; Yan, Wangxiang; Chen, Zhipei; Shuai, Xintao; Wang, Anxun; Wang, Yan

    2017-08-01

    Surface modification on titanium implants plays an important role in promoting mesenchymal stem cell (MSC) response to enhance osseointegration persistently. In this study, nano-scale TiO 2 nanotube topography (TNT), micro-scale sand blasted-acid etched topography (SLA), and hybrid sand blasted-acid etched/nanotube topography (SLA/TNT) were fabricated on the surfaces of titanium implants. Although the initial cell adherence at 60 min among TNT, SLA and TNT/SLA was not different, SLA and SLA/TNT presented to be rougher and suppressed the proliferation of MSC. TNT showed hydrophilic surface and balanced promotion of cellular functions. After being implanted in rabbit femur models, TNT displayed the best osteogenesis inducing ability as well as strong bonding strength to the substrate. These results indicate that nano-scale TNT provides favorable surface topography for improving the clinical performance of endosseous implants compared with micro and hybrid micro/nano surfaces, suggesting a promising and reliable surface modification strategy of titanium implants for clinical application. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Nickel-titanium alloys: stress-related temperature transitional range.

    Science.gov (United States)

    Santoro, M; Beshers, D N

    2000-12-01

    The inducement of mechanical stress within nickel-titanium wires can influence the transitional temperature range of the alloy and therefore the expression of the superelastic properties. An analogous variation of the transitional temperature range may be expected during orthodontic therapy, when the archwires are engaged into the brackets. To investigate this possibility, samples of currently used orthodontic nickel-titanium wires (Sentalloy, GAC; Copper Ni-Ti superelastic at 27 degrees C, 35 degrees C, 40 degrees C, Ormco; Nitinol Heat-Activated, 3M-Unitek) were subjected to temperature cycles ranging between 4 degrees C and 60 degrees C. The wires were mounted in a plexiglass loading device designed to simulate clinical situations of minimum and severe dental crowding. Electrical resistivity was used to monitor the phase transformations. The data were analyzed with paired t tests. The results confirmed the presence of displacements of the transitional temperature ranges toward higher temperatures when stress was induced. Because nickel-titanium wires are most commonly used during the aligning stage in cases of severe dental crowding, particular attention was given to the performance of the orthodontic wires under maximum loading. An alloy with a stress-related transitional temperature range corresponding to the fluctuations of the oral temperature should express superelastic properties more consistently than others. According to our results, Copper Ni-Ti 27 degrees C and Nitinol Heat-Activated wires may be considered suitable alloys for the alignment stage.

  17. 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

  18. Surface Modification of Porous Titanium Granules for Improving Bioactivity.

    Science.gov (United States)

    Karaji, Zahra Gorgin; Houshmand, Behzad; Faghihi, Shahab

    The highly porous titanium granules are currently being used as bone substitute material and for bone tissue augmentation. However, they suffer from weak bone bonding ability. The aim of this study was to create a nanostructured surface oxide layer on irregularly shaped titanium granules to improve their bioactivity. This could be achieved using optimized electrochemical anodic oxidation (anodizing) and heat treatment processes. The anodizing process was done in an ethylene glycol-based electrolyte at an optimized condition of 60 V for 3 hours. The anodized granules were subsequently annealed at 450°C for 1 hour. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) were used to characterize the surface structure and morphology of the granules. The in vitro bioactivity of the samples was evaluated by immersion of specimens in simulated body fluid (SBF) for 1, 2, and 3 weeks. The human osteoblastic sarcoma cell line, MG63, was used to evaluate cell viability on the samples using dimethylthiazol-diphenyl tetrazolium bromide (MTT) assay. The results demonstrated the formation of amorphous nanostructured titanium oxide after anodizing, which transformed to crystalline anatase and rutile phases upon heat treatment. After immersion in SBF, spherical aggregates of amorphous calcium phosphate were formed on the surface of the anodized sample, which turned into crystalline hydroxyapatite on the surface of the anodized annealed sample. No cytotoxicity was detected among the samples. It is suggested that anodic oxidation followed by heat treatment could be used as an effective surface treatment procedure to improve bioactivity of titanium granules implemented for bone tissue repair and augmentation.

  19. New surface modification method of bio-titanium alloy by EB polishing

    International Nuclear Information System (INIS)

    Okada, Akira; Uno, Yoshiyuki; Iio, Atsuo; Fujiwara, Kunihiko; Doi, Kenji

    2008-01-01

    A new surface modification for bio-titanium alloy products by electron beam (EB) polishing is proposed. In this EB polishing method, high energy density EB can be irradiated without concentrating the beam. Therefore, large-area EB with a maximum diameter of 60 mm can be used for instantaneously melting or evaporating metal surface. Experimental results made it clear that surface characteristics, such as repellency, corrosion resistance and coefficient of friction could be improved simultaneously with the surface smoothing in a few minutes under a proper condition. Therefore, EB polishing method has a possibility of high efficient surface smoothing and surface modification process for bio-titanium alloy. (author)

  20. 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)

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. Titanium dioxide nanomaterials for photocatalysis

    International Nuclear Information System (INIS)

    Liu, Yan; Li, Zhe; Green, Michael; Just, Michael; Chen, Xiaobo; Li, Yang Yang

    2017-01-01

    Titanium dioxide (TiO 2 ) has been long regarded as one of the more promising photocatalysts to remove environmental pollution and to generate hydrogen from water under sunlight irradiation via photocatalysis. TiO 2 is environmentally benign and thus is considered a ‘green’ catalyst. In this review we present a short introduction to the physical and electronic properties of TiO 2 , its photocatalytic mechanisms, and some recent examples of various TiO 2 materials used for photocatalysis; these examples include 0, 1, 2, 3D, faceted, defected, composited, and hydrogenated TiO 2 materials. (topical review)

  6. 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

  7. 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.

  8. Titanium distribution in swimming pool water is dominated by dissolved species.

    Science.gov (United States)

    David Holbrook, R; Motabar, Donna; Quiñones, Oscar; Stanford, Benjamin; Vanderford, Brett; Moss, Donna

    2013-10-01

    The increased use of titanium dioxide nanoparticles (nano-TiO2) in consumer products such as sunscreen has raised concerns about their possible risk to human and environmental health. In this work, we report the occurrence, size fractionation and behavior of titanium (Ti) in a children's swimming pool. Size-fractionated samples were analyzed for Ti using ICP-MS. Total titanium concentrations ([Ti]) in the pool water ranged between 21 μg/L and 60 μg/L and increased throughout the 101-day sampling period while [Ti] in tap water remained relatively constant. The majority of [Ti] was found in the dissolved phase (microparticulate. Simple models suggest that evaporation may account for the observed variation in [Ti], while sunscreen may be a relevant source of particulate and microparticule Ti. Compared to diet, incidental ingestion of nano-Ti from swimming pool water is minimal. Published by Elsevier Ltd.

  9. Effect of Q-switched Laser Surface Texturing of Titanium on Osteoblast Cell Response

    Science.gov (United States)

    Voisey, K. T.; Scotchford, C. A.; Martin, L.; Gill, H. S.

    Titanium and its alloys are important biomedical materials. It is known that the surface texture of implanted medical devices affects cell response. Control of cell response has the potential to enhance fixation of implants into bone and, in other applications, to prevent undesired cell adhesion. The potential use of a 100W Q-switched YAG laser miller (DMG Lasertec 60 HSC) for texturing titanium is investigated. A series of regular features with dimensions of the order of tens of micrometers are generated in the surface of titanium samples and the cell response to these features is determined. Characterisation of the laser milled features reveals features with a lengthscale of a few microns superposed on the larger scale structures, this is attributed to resolidification of molten droplets generated and propelled over the surface by individual laser pulses. The laser textured samples are exposed to osteoblast cells and it is seen that cells do respond to the features in the laser textured surfaces.

  10. Positron annihilation in hydrogenated and electron-irradiated titanium alloys

    International Nuclear Information System (INIS)

    Mukashev, K.M.; Zaikin, Yu.A.

    2002-01-01

    Important information on hydrogen behavior in titanium can be obtained from studies of radiation damage in previously hydrogenated metal. For this purpose annealed titanium samples were hydrogenated at the temperature 500 deg. C during 1 hour. Then both the original annealed samples and hydrogenated samples were irradiated by 4 MeV electrons in the fluence range 3·10 7 -1·10 19 cm - 2 at the temperature 60 deg. C. It is known that electron irradiation in these conditions predominantly creates vacancy-type defects with an average radius R ν =0.81 Angstrom. It was stated that annihilation probability after electron irradiation of previously hydrogenated titanium samples always has some intermediate values between those characteristic for hydrogenated and irradiated states of previously annealed metal. This is a reason to suppose that radiation defects of the vacancy type in previously hydrogenated titanium combine with hydrogen atoms in favorable conditions of their partial ionization. The estimated value of the average radius for such a complex is R ν =1.1 Angstrom, that is higher than vacancy size but lower than an atom radius. No dose dependence of hydrogen interaction with radiation defects was observed in our experiments.The results of isochrone annealing of the materials under study have shown that the single annealing recovery stage with activation energy E a equal to 1.22 eV is observed in electron irradiated but not previously hydrogenated titanium in the temperature range 170-240 deg. C. Electron irradiation of the previously hydrogenated metal shifts beginning of the first recovery stage to the temperature about 225-230 deg. C and finishes near the temperature 330 deg. C. Therefore, the bound state vacancy-hydrogen in titanium is characterized by higher temperature range of dissociation and annealing with activation energy equal to 1.38 eV. However, subsequent measurements, of the angular distribution of annihilation photons (ADAP) have demonstrated

  11. [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.

  12. Titanium oxide fever; De titaniumoxidekoorts

    Energy Technology Data Exchange (ETDEWEB)

    De Jonge, D.; Visser, J. [Afdeling Luchtkwaliteit, GGD Amsterdam, Amsterdam (Netherlands)

    2012-02-15

    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?. [Dutch] Een van de maatregelen om de luchtkwaliteit te verbeteren is het aanbrengen van fotokatalytische stoffen waarmee NOx kan worden afgevangen op bijvoorbeeld wegdek of op geluidsschermen langs wegen. Over het effect van titaniumoxidehoudende straatklinkers en hierop aangebrachte coatings verscheen in mei 2011 het rapport 'Demonstration project of air-purifying pavement in Hengelo, The Netherlands'. Dit artikel gaat over de manier waarop de effectiviteit in het hiervoor genoemde onderzoek is bepaald. Kunnen titaniumoxidehoudende klinkers en coatings inderdaad NOx afvangen?.

  13. Adsorption of hydrogen in titanium

    International Nuclear Information System (INIS)

    Martinez R, T.

    1995-01-01

    In this work the absorption of hydrogen in titanium plates using a constant volume system has been realized. The changes of temperature and pressure were used to monitor the progress of the absorption. A stainless steel vacuum chamber with volume of 4,333 cm 3 was used. A titanium sample of 45 x 5.4 x 0.3 cm was located in the center of the chamber. The sample was heated by an electrical source connected to the system. The sample was preconditioned with a vacuum-thermal treatment at 10 -6 mbar and 800 Centigrade degrees for several days. Absorption was observed at room temperature and also at higher temperatures. The room temperature absorption was in the pressure range of 1.0 x 10 3 to 2.5 x 10 3 mbar, and other absorptions were from 180 to 630 Centigrade degrees at 3.5 x 10 -1 to 1.3 x 10 3 mbar. It was found that the gas absorbed was function of the vacuum-thermal pre-conditioned treatment, pressure and temperature. When the first absorption was developed, additional absorptions were realized in short time. We measured the electrical resistivity of the sample in the experiments but we could not see important changes due to the absorption. (Author)

  14. 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.

  15. 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)

  16. 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.

  17. [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.

  18. 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

  19. 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)

  20. Nickel-Titanium Alloys: Corrosion "Proof" Alloys for Space Bearing, Components and Mechanism Applications

    Science.gov (United States)

    DellaCorte, Christopher

    2010-01-01

    An intermetallic nickel-titanium alloy, 60NiTi (60 wt% Ni, 40 wt% Ti), is shown to be a promising candidate tribological material for space mechanisms. 60NiTi offers a broad combination of physical properties that make it unique among bearing materials. 60NiTi is hard, electrically conductive, highly corrosion resistant, readily machined prior to final heat treatment, and is non-magnetic. Despite its high Ti content, 60NiTi is non-galling even under dry sliding. No other bearing alloy, metallic or ceramic, encompasses all of these attributes. Since 60NiTi contains such a high proportion of Ti and possesses many metallic properties, it was expected to exhibit poor tribological performance typical of Ti alloys, namely galling type behavior and rapid lubricant degradation. In this poster-paper, the oil-lubricated behavior of 60NiTi is presented.

  1. 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

  2. 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

  3. Titanium exposure and yellow nail syndrome

    Directory of Open Access Journals (Sweden)

    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.

  4. 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.

  5. Current assisted superplastic forming of titanium alloy

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. Non-chapped, vertically well aligned titanium dioxide nanotubes fabricated by electrochemical etching

    Science.gov (United States)

    Loan Nguyen, Thu; Dieu Thuy Ung, Thi; Liem Nguyen, Quang

    2014-06-01

    This paper reports on the fabrication of non-chapped, vertically well aligned titanium dioxide nanotubes (TONTs) by using electrochemical etching method and further heat treatment. Very highly ordered metallic titanium nanotubes (TNTs) were formed by directly anodizing titanium foil at room temperature in an electrolyte composed of ammonium fluoride (NH4F), ethylene glycol (EG), and water. The morphology of as-formed TNTs is greatly dependent on the applied voltage, NH4F content and etching time. Particularly, we have found two interesting points related to the formation of TNTs: (i) the smooth surface without chaps of the largely etched area was dependent on the crystalline orientation of the titanium foil; and (ii) by increasing the anodizing potential from 15 V to 20 V, the internal diameter of TNT was increased from about 50 nm to 60 nm and the tube density decreased from 403 tubes μm-2 down to 339 tubes μm-2, respectively. For the anodizing duration from 1 h to 5 h, the internal diameter of each TNT was increased from ˜30 nm to 60 nm and the tube density decreased from 496 tubes μm-2 down to 403 tubes μm-2. After annealing at 400 °C in open air for 1 h, the TNTs were transformed into TONTs in anatase structure; further annealing at 600 °C showed the structural transformation from anatase to rutile as determined by Raman scattering spectroscopy.

  8. 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.

  9. 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.

  10. 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

  11. Analysis of separation quality of scandium-46 and titanium using silica gel column

    International Nuclear Information System (INIS)

    Muhamad Basit Febrian; Yanuar Setiadi; Duyeh Setiawan; Titin Sri Mulyati; Nana Suherman

    2015-01-01

    In this study, quality test of scandium and titanium mixture separation system using a silica gel column has been conducted. This system will be used in the separation of medical radioisotopes of 47 Sc from TiO 2 enriched targets. 20 mg of TiO 2 and 5 mg of Sc 2 O 3 dissolved using 0.5 mL of 50% HF solvent with gentle heating at 60°C - 80°C for 1 hour then 4.5 mL H 2 O was added. Sc and Ti mixture is separated by passing it through a column of silica gel. In the determination of scandium released from silica gel, Sc-46 radiotracer was used. Only 51.60 ± 4.5% of 5 mg of scandium could be retained in the silica gel column. From 51.60% of absorbed scandium in the column, 98.29 ± 3.4% were eluted with 5 mL of H 2 O eluent. During elution of scandium from silica gel column, 2.81 grams of 20 mg of titanium came apart as breakthrough. In determination of recovery of titanium from silica gel, 51.76 ± 5.5% of the 20 mg Ti can be recovered from silica gel column using 5M HCl eluent, whereas remaining Ti were eluted using 40 ml of HCl 5M. Based on those result, it can be concluded that there are still titanium portion in scandium after the separation using a silica gel column. Further purification step using fresh silica gel column, can separate escaped titanium from scandium. (author)

  12. Titanium Aluminide Casting Technology Development

    Science.gov (United States)

    Bünck, Matthias; Stoyanov, Todor; Schievenbusch, Jan; Michels, Heiner; Gußfeld, Alexander

    2017-12-01

    Titanium aluminide alloys have been successfully introduced into civil aircraft engine technology in recent years, and a significant order volume increase is expected in the near future. Due to its beneficial buy-to-fly ratio, investment casting bears the highest potential for cost reduction of all competing production technologies for TiAl-LPTB. However, highest mechanical properties can be achieved by TiAl forging. In view of this, Access e.V. has developed technologies for the production of TiAl investment cast parts and TiAl die cast billets for forging purposes. While these parts meet the highest requirements, establishing series production and further optimizing resource and economic efficiency are present challenges. In order to meet these goals, Access has recently been certified according to aircraft standards, aiming at qualifying parts for production on technology readiness level 6. The present work gives an overview of the phases of development and certification.

  13. Erbium diffusion in titanium dioxide

    Directory of Open Access Journals (Sweden)

    Louise Basse

    2017-04-01

    Full Text Available The diffusivity of erbium in the anatase phase of titanium dioxide (TiO2 has been studied for various temperatures ranging from 800 °C to 1, 000 °C. Samples of TiO2, with a 10 nm thick buried layer containing 0.5 at% erbium, were fabricated by radio-frequency magnetron sputtering and subsequently heat treated. The erbium concentration profiles were measured by secondary ion mass spectrometry, allowing for determination of the temperature-dependent diffusion coefficients. These were found to follow an Arrhenius law with an activation energy of ( 2.1 ± 0.2 eV. X-ray diffraction revealed that the TiO2 films consisted of polycrystalline grains of size ≈ 100 nm.

  14. Carbon nanotube-based coatings on titanium

    Indian Academy of Sciences (India)

    Administrator

    mon method is the deposition of bioactive ceramic mate- rials on the metal ... tion of nanoparticle layer, including carbon nanoparti- ... Coatings made of CNTs provide implants with .... reaches composite of CNT built into titanium oxide formed.

  15. Titanium Brazing for Structures and Survivability

    National Research Council Canada - National Science Library

    Doherty, Kevin J; Tice, Jason R; Szewczyk, Steven T; Glide, Gary A

    2007-01-01

    .... While welding is the typical joining method for titanium, vacuum brazing is an option in areas that are difficult to access for welding as well as areas near other nonmetallic materials, such as ceramics...

  16. 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

  17. 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.

  18. Titanium Heat Pipe Thermal Plane, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase II program is to complete the development of the titanium heat pipe thermal plane and establish all necessary steps for production of this...

  19. Titanium Nanocomposite: Lightweight Multifunction Structural Material

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to research and develop lightweight metal matrix nanocomposites (MMnC) using a Titanium (Ti) metal matrix. Ti MMnC will crosscut the advancement of both...

  20. 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)

  1. 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.

  2. 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

  3. 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...

  4. Lactam inhibiting Streptococcus mutans growth on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, J.G.; Geremias, T.C.; Montero, J.F.D. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis/SC, 88040-900 (Brazil); Vahey, B.R. [Herman Ostrow School of Dentistry of USC, 925 W 34 St, Los Angeles, CA 90089 (United States); Benfatti, C.A.M.; Souza, J.C.M.; Magini, R.S. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis/SC, 88040-900 (Brazil); Pimenta, A.L., E-mail: andrea@intelab.ufsc.br [Department of Biologia, ERRMECe, Université de Cergy Pontoise, 2, Av. Adolphe Chauvin 95302 Cergy, Pontoise (France); Integrated Laboratories Technologies (InteLab), Dept. Chemical and Food Engineering (EQA), Federal University of Santa Catarina - UFSC, Florianópolis/SC, 88040-970 (Brazil)

    2016-11-01

    The aim of this work was to analyze the activity of novel synthetic lactams on preventing biofilm formation on titanium surfaces. Titanium (Ti6Al4V) samples were exposed to Streptococcus mutans cultures in the presence or absence of a synthetic lactam. After 48 h incubation, planktonic growth was determined by spectrophotometry. Biofilm was evaluated by crystal violet staining and colony forming units (CFU·ml{sup −1}), followed by scanning electron microscopy (SEM). Results showed that the average of adhered viable cells was approximately 1.5 × 10{sup 2} CFU/ml in the presence of lactam and 4 × 10{sup 2} CFU/ml in its absence. This novel compound was considerable active in reducing biofilm formation over titanium surfaces, indicating its potential for the development of antimicrobial drugs targeting the inhibition of the initial stages of bacterial biofilms on dental implants abutments. - Highlights: • A novel synthetic compound is tested on preventing biofilm formation on titanium surfaces • Biofilm inhibition has been achieved on titanium surfaces containing the novel compound. • Planktonic growth of S. mutans was not affected by the presence of lactams on titanium.

  5. Lactam inhibiting Streptococcus mutans growth on titanium

    International Nuclear Information System (INIS)

    Xavier, J.G.; Geremias, T.C.; Montero, J.F.D.; Vahey, B.R.; Benfatti, C.A.M.; Souza, J.C.M.; Magini, R.S.; Pimenta, A.L.

    2016-01-01

    The aim of this work was to analyze the activity of novel synthetic lactams on preventing biofilm formation on titanium surfaces. Titanium (Ti6Al4V) samples were exposed to Streptococcus mutans cultures in the presence or absence of a synthetic lactam. After 48 h incubation, planktonic growth was determined by spectrophotometry. Biofilm was evaluated by crystal violet staining and colony forming units (CFU·ml −1 ), followed by scanning electron microscopy (SEM). Results showed that the average of adhered viable cells was approximately 1.5 × 10 2 CFU/ml in the presence of lactam and 4 × 10 2 CFU/ml in its absence. This novel compound was considerable active in reducing biofilm formation over titanium surfaces, indicating its potential for the development of antimicrobial drugs targeting the inhibition of the initial stages of bacterial biofilms on dental implants abutments. - Highlights: • A novel synthetic compound is tested on preventing biofilm formation on titanium surfaces • Biofilm inhibition has been achieved on titanium surfaces containing the novel compound. • Planktonic growth of S. mutans was not affected by the presence of lactams on titanium.

  6. Conduction mechanism in bismuth silicate glasses containing titanium

    International Nuclear Information System (INIS)

    Dult, Meenakshi; Kundu, R.S.; Murugavel, S.; Punia, R.; Kishore, N.

    2014-01-01

    Bismuth silicate glasses mixed with different concentrations of titanium dioxide having compositions xTiO 2 –(60−x)Bi 2 O 3 –40SiO 2 with x=0, 5, 10, 15 and 20 were prepared by the normal melt quench technique. The frequency dependence of the ac electrical conductivity of different compositions of titanium bismuth silicate glasses has been studied in the frequency range 10 −1 Hz to 10 MHz and in the temperature range 623–703 K. The temperature and frequency dependent conductivity is found to obey Jonscher's universal power law for all the compositions of titanium bismuth silicate glass system. The dc conductivity (σ dc ), so called crossover frequency (ω H ), and frequency exponent (s) have been estimated from the fitting of experimental data of ac conductivity with Jonscher's universal power law. Enthalpy to dissociate the cation from its original site next to a charge compensating center (H f ) and enthalpy of migration (H m ) have also been estimated. The conductivity data have been analyzed in terms of different theoretical models to determine the possible conduction mechanism. Analysis of the conductivity data and the frequency exponent shows that the correlated barrier hopping of electrons between Ti 3+ and Ti 4+ ions in the glasses is the most favorable mechanism for ac conduction. The temperature dependent dc conductivity has been analyzed in the framework of theoretical variable range hopping model (VRH) proposed by Mott which describe the hopping conduction in disordered semiconducting systems. The various polaron hopping parameters have also been deduced. Mott's VRH model is found to be in good agreement with experimental data and the values of inverse localization length of s-like wave function (α) obtained by this model with modifications suggested by Punia et al. are close to the ones reported for a number of oxide glasses

  7. Novel D2EHPA-polysiloxane-based sorbent for titanium (IV) extraction and separation

    International Nuclear Information System (INIS)

    Mendoza R, L. G.; Rodriguez de San Miguel, E.; Pardo G, D. Y.; De Gyves, J.; Sanchez G, J. P.

    2011-01-01

    In this work the synthesis, characterization and evaluation of a novel sorbent material used for the solid-phase extraction of titanium (IV) from hydrochloric acid medium is described. The material was prepared by the sol-gel route incorporating bis(2-ethylhexyl phosporic acid) (D2EHPA) as extractant within a polymeric matrix based on polysiloxanes and characterized through Ftir-Atr, XRD, 29 Si and 31 P NMR, TGA and DSC. In studies of titanium sorption and desorption in batch mode several factors related with the extraction and back-extraction operations were evaluated, such as: contact time, titanium concentration, nature and composition of the aqueous media, and extractant concentration in the sorbent. The maximum sorption was observed at 30 min of contact time in a 1 mol L -1 HCl + 0.1% KCl medium, while the maximum desorption was observed at 60 min in a 1.5 mol L -1 H 2 SO 4 + 20% v/v H 2 O 2 medium when titanium concentration was 70 mg L -1 . Under optimal conditions the recovered percent of titanium was nearly 90%. In addition, the characterization of the extraction equilibrium was performed. The selectivity of the method was studied adding Al(III), Fe(III) and V(v) to the extraction medium. A high selectivity for Ti over Al and Fe was observed, even at high concentrations of the interferences; 50% of Ti, only 7% of Fe, 3% of Al and less than 1% of V were recovered under the established conditions. The method was finally applied for titanium recovery from a certified fly ash sample generated from a municipal incineration plant. (Author)

  8. Novel D2EHPA-polysiloxane-based sorbent for titanium (IV) extraction and separation

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza R, L. G.; Rodriguez de San Miguel, E.; Pardo G, D. Y.; De Gyves, J. [UNAM, Facultad de Quimica, Departamento de Quimica Analitica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Sanchez G, J. P., E-mail: degyves@unam.mx [Instituto Mexicano del Petroleo, Laboratorio de Evaluacion Molecular, Eje Central Norte Lazaro Cardenas No. 152, Apdo. Postal 14-805, 07730 Mexico D. F. (Mexico)

    2011-07-01

    In this work the synthesis, characterization and evaluation of a novel sorbent material used for the solid-phase extraction of titanium (IV) from hydrochloric acid medium is described. The material was prepared by the sol-gel route incorporating bis(2-ethylhexyl phosporic acid) (D2EHPA) as extractant within a polymeric matrix based on polysiloxanes and characterized through Ftir-Atr, XRD, {sup 29}Si and {sup 31}P NMR, TGA and DSC. In studies of titanium sorption and desorption in batch mode several factors related with the extraction and back-extraction operations were evaluated, such as: contact time, titanium concentration, nature and composition of the aqueous media, and extractant concentration in the sorbent. The maximum sorption was observed at 30 min of contact time in a 1 mol L{sup -1} HCl + 0.1% KCl medium, while the maximum desorption was observed at 60 min in a 1.5 mol L{sup -1} H{sub 2}SO{sub 4} + 20% v/v H{sub 2}O{sub 2} medium when titanium concentration was 70 mg L{sup -1}. Under optimal conditions the recovered percent of titanium was nearly 90%. In addition, the characterization of the extraction equilibrium was performed. The selectivity of the method was studied adding Al(III), Fe(III) and V(v) to the extraction medium. A high selectivity for Ti over Al and Fe was observed, even at high concentrations of the interferences; 50% of Ti, only 7% of Fe, 3% of Al and less than 1% of V were recovered under the established conditions. The method was finally applied for titanium recovery from a certified fly ash sample generated from a municipal incineration plant. (Author)

  9. 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

  10. Calculation of phase equilibria in Ti-Al-Cr-Mn quaternary system for developing lower cost titanium alloys

    International Nuclear Information System (INIS)

    Lu, X.G.; Li, C.H.; Chen, L.Y.; Qiu, A.T.; Ding, W.Z.

    2011-01-01

    Highlights: → This paper is about the concept of designing the lower cost titanium alloy. → The thermodynamic database of Ti-Al-Cr-Mn system is built up by Calphad method. → The pseudobinary sections with Cr: Mn = 3:1 and Al = 3, 4.5 and 6.0 wt% are calculated. → This may provide the theoretical support for designing the lower cost titanium alloy. - Abstract: The Ti-Al-Cr-Mn system is a potentially useful system for lower cost titanium alloy development; however, there are few reports about the experimental phase diagrams and the thermodynamical assessment for this system. In this study, the previous investigations for the thermodynamic descriptions of the sub-systems in the Ti-Al-Cr-Mn system are reviewed, our previous assessment for the related sub-systems in this quaternary system is summarized, the thermodynamical database of this quaternary system is built up by directly extrapolating from all sub-systems assessed by means of the Calphad method, then the pseudobinary sections with Cr:Mn = 3:1 and Al = 0.0, 3.0, 4.5 and 6.0 wt% are calculated, respectively. These pseudobinary phase diagrams may provide the theoretical support for designing the lower cost titanium alloys with different microstructures (α, α + β, and β titanium alloy).

  11. 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.

  12. Plasma arc melting of titanium-tantalum alloys

    International Nuclear Information System (INIS)

    Dunn, P.; Patterson, R.A.; Haun, R.

    1994-01-01

    Los Alamos has several applications for high temperature, oxidation and liquid-metal corrosion resistant materials. Further, materials property constraints are dictated by a requirement to maintain low density; e.g., less than the density of stainless steel. Liquid metal compatibility and density requirements have driven the research toward the Ti-Ta system with an upper bound of 60 wt% Ta-40 wt% Ti. Initial melting of these materials was performed in a small button arc melter with several hundred grams of material; however, ingot quantities were soon needed. But, refractory metal alloys whose constituents possess very dissimilar densities, melting temperatures and vapor pressures pose significant difficulty and require specialized melting practices. The Ti-Ta alloys fall into this category with the density of tantalum 16.5 g/cc and that of titanium 4.5 g/cc. Melting is further complicated by the high melting point of Ta(3020 C) and the relatively low boiling point of Ti(3287 C). Previous electron beam melting experience with these materials resulted, in extensive vaporization of the titanium and poor chemical homogeneity. Vacuum arc remelting(VAR) was considered as a melting candidate and discarded due to density and vapor pressure issues associated with electron beam. Plasma arc melting offered the ability to supply a cover gas to deal with vapor pressure issues as well as solidification control to help with macrosegregation in the melt and has successfully produced high quality ingots of the Ti-Ta alloys

  13. 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

  14. 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.

  15. Amorphous titanium-oxide supercapacitors

    Science.gov (United States)

    Fukuhara, Mikio; Kuroda, Tomoyuki; Hasegawa, Fumihiko

    2016-10-01

    The electric capacitance of an amorphous TiO2-x surface increases proportionally to the negative sixth power of the convex diameter d. This occurs because of the van der Waals attraction on the amorphous surface of up to 7 mF/cm2, accompanied by extreme enhanced electron trapping resulting from both the quantum-size effect and an offset effect from positive charges at oxygen-vacancy sites. Here we show that a supercapacitor, constructed with a distributed constant-equipment circuit of large resistance and small capacitance on the amorphous TiO2-x surface, illuminated a red LED for 37 ms after it was charged with 1 mA at 10 V. The fabricated device showed no dielectric breakdown up to 1,100 V. Based on this approach, further advances in the development of amorphous titanium-dioxide supercapacitors might be attained by integrating oxide ribbons with a micro-electro mechanical system.

  16. Titanium template for scaphoid reconstruction.

    Science.gov (United States)

    Haefeli, M; Schaefer, D J; Schumacher, R; Müller-Gerbl, M; Honigmann, P

    2015-06-01

    Reconstruction of a non-united scaphoid with a humpback deformity involves resection of the non-union followed by bone grafting and fixation of the fragments. Intraoperative control of the reconstruction is difficult owing to the complex three-dimensional shape of the scaphoid and the other carpal bones overlying the scaphoid on lateral radiographs. We developed a titanium template that fits exactly to the surfaces of the proximal and distal scaphoid poles to define their position relative to each other after resection of the non-union. The templates were designed on three-dimensional computed tomography reconstructions and manufactured using selective laser melting technology. Ten conserved human wrists were used to simulate the reconstruction. The achieved precision measured as the deviation of the surface of the reconstructed scaphoid from its virtual counterpart was good in five cases (maximal difference 1.5 mm), moderate in one case (maximal difference 3 mm) and inadequate in four cases (difference more than 3 mm). The main problems were attributed to the template design and can be avoided by improved pre-operative planning, as shown in a clinical case. © The Author(s) 2014.

  17. Opioid Prescribing PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the July 2017 CDC Vital Signs report. Higher opioid prescribing puts patients at risk for addiction and overdose. Learn what can be done about this serious problem.

  18. 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 ...

  19. 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

  20. 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)

  1. The effect of ultrafast fiber laser application on the bond strength of resin cement to titanium.

    Science.gov (United States)

    Ates, Sabit Melih; Korkmaz, Fatih Mehmet; Caglar, Ipek Satıroglu; Duymus, Zeynep Yeşil; Turgut, Sedanur; Bagis, Elif Arslan

    2017-07-01

    The purpose of this study was to investigate the effect of ultrafast fiber laser treatment on the bond strength between titanium and resin cement. A total of 60 pure titanium discs (15 mm × 2 mm) were divided into six test groups (n = 10) according to the surface treatment used: group (1) control, machining; group (2) grinding with a diamond bur; group (3) ultrafast fiber laser application; group (4) resorbable blast media (RBM) application; group (5) electro-erosion with copper; and group (6) sandblasting. After surface treatments, resin cements were applied to the treated titanium surfaces. Shear bond strength testing of the samples was performed with a universal testing machine after storing in distilled water at 37 °C for 24 h. One-way ANOVA and Tukey's HSD post hoc test were used to analyse the data (P < 0.05). The highest bond strength values were observed in the laser application group, while the lowest values were observed in the grinding group. Sandblasting and laser application resulted in significantly higher bond strengths than control treatment (P < 0.05). Ultrafast fiber laser treatment and sandblasting may improve the bond strength between resin cement and titanium.

  2. 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...

  3. 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)

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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)

  16. 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...

  17. 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

  18. 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....

  19. 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

  20. 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.

  1. 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.

  2. Characterization of the porous structures of the green body and sintered biomedical titanium scaffolds with micro-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Arifvianto, B., E-mail: b.arifvianto@tudelft.nl; Leeflang, M.A.; Zhou, J.

    2016-11-15

    The present research was aimed at gaining an understanding of the porous structure changes from the green body through water leaching and sintering to titanium scaffolds. Micro-computed tomography (micro-CT) was performed to generate 3D models of titanium scaffold preforms containing carbamide space-holding particles and sintered scaffolds containing macro- and micro-pores. The porosity values and structural parameters were determined by means of image analysis. The result showed that the porosity values, macro-pore sizes, connectivity densities and specific surface areas of the titanium scaffolds sintered at 1200 °C for 3 h did not significantly deviate from those of the green structures with various volume fractions of the space holder. Titanium scaffolds with a maximum specific surface area could be produced with an addition of 60–65 vol% carbamide particles to the matrix powder. The connectivity of pores inside the scaffold increased with rising volume fraction of the space holder. The shrinkage of the scaffolds prepared with > 50 vol% carbamide space holder, occurring during sintering, was caused by the reductions of macro-pore sizes and micro-pore sizes as well as the thickness of struts. In conclusion, the final porous structural characteristics of titanium scaffolds could be estimated from those of the green body. - Highlights: •Porous structures of green body and sintered titanium scaffolds was studied. •Porous structures of both samples were quantitatively characterized with micro-CT. •Porous structures of scaffolds could be controlled from the green body. •Shrinkage mechanisms of titanium scaffolds during sintering was established.

  3. Childhood Obesity PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the August 2013 CDC Vital Signs report. The rate of obesity among low-income preschoolers has declined, but one in eight is still obese. This program briefly discusses what can be done.

  4. Be Brave PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2011-08-04

    In this 60-second public service announcement, gynecologic cancer survivor, Jenny Allen, urges women to see a doctor if symptoms last two weeks or more.  Created: 8/4/2011 by National Center for Chronic Disease Prevention and Health Promotion.   Date Released: 8/4/2011.

  5. Opioid Prescribing PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2017-07-06

    This 60 second public service announcement is based on the July 2017 CDC Vital Signs report. Higher opioid prescribing puts patients at risk for addiction and overdose. Learn what can be done about this serious problem.  Created: 7/6/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 7/6/2017.

  6. HIV Testing PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the December 2017 CDC Vital Signs report. In the U.S., about 15 percent of people who have HIV don't know they have it. Learn about the importance of testing, early diagnosis, and treatment.

  7. Heroin Epidemic PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the July 2015 CDC Vital Signs report. Heroin use and heroin-related overdose deaths are increasing. Most people are using it with other drugs, especially prescription opioid painkillers. Learn what can be done to prevent and treat the problem.

  8. Secondhand Smoke PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the February 2015 CDC Vital Signs report. Secondhand smoke kills more than 400 infants and 41,000 adult nonsmokers every year. Learn what can be done to prevent secondhand smoke exposure.

  9. Legionnaires' Disease PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the June 2017 CDC Vital Signs report. Legionnaires' disease is a serious, often deadly lung infection. People most commonly get it by breathing in water droplets containing Legionella germs. Learn how to prevent infections from Legionella.

  10. Preventing Melanoma PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the June 2015 CDC Vital Signs report. Skin cancer is the most common form of cancer in the U.S. In 2011, there were more than 65,000 cases of melanoma, the most deadly form of skin cancer. Learn how everyone can help prevent skin cancer.

  11. Babesiosis PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2012-04-25

    This 60 second PSA describes babesiosis, a preventable and treatable tickborne disease, including the signs and symptoms of infection and ways to prevent it.  Created: 4/25/2012 by Center for Global Health, Division of Parasitic Diseases and Malaria.   Date Released: 4/26/2012.

  12. 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)

  13. 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.

  14. 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

  15. 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

  16. Imaging and dosimetric considerations for titanium prosthesis implanted within the irradiated region by high photon beams

    International Nuclear Information System (INIS)

    Indogo, V.

    2014-07-01

    The aim of this research was to observe dose distributions in the vicinity of titanium prosthetic implants during radiotherapy procedures. Data were obtained using a locally fabricated tissue equivalent phantom CT images, and in blue water phantom with titanium prosthesis which was irradiated with 60 Co gamma radiation and Elekta Platform photon beams. Images obtained were loaded into Prowess Panther and Oncentra treatment planning systems (TPSs) for dose simulations. Prowess TPS (1.25 MeV) estimated lesser errors whilst Oncentra (6 and 15 MV) dose simulations yielded large variations. Proximal ends of the metal recorded slight increase in doses as a rcsult of backscatter with dose increment below acceptable tolerance of ±3%. Doses measured decreases on the distal side of the prosthesis at a distance less than d max from the plate on each beam energy. Beyond certain depth along the axis, depth doses increased slightly mainly due to increase in electron fluence by portions receiving unperturbed dose. An increase in the plate thickness showed a corresponding decrease on percentage depth dose. A reduction in the above trend was also noticed with an increase in beam energy primarily because scattered photons are more forwardly directed. Prowess TPS (convolution superposition algorithm) was found to be better at reducing dose variation than OMP (collapse cone algorithm) when correction for artifact. Manual calculations on blue phantom data agree with results from Prowess. Oncentra is not capable of simulating dose around titanium prosthesis as its range of densities, 0.00121 to 2.83, excludes titanium density (rED for titanium is 3.74). (au)

  17. 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.

  18. 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

  19. 40 CFR 60.381 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... control device. Control device means the air pollution control equipment used to reduce particulate matter..., copper, gold, iron, lead, molybdenum, silver, titanium, tungsten, uranium, zinc, and zirconium. This...

  20. SHORT COMMUNICATION TITANIUM-INDUCED SYNTHESIS OF ...

    African Journals Online (AJOL)

    Preferred Customer

    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 ...

  1. 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.

  2. Manufacture of titanium and zirconium hydrides

    International Nuclear Information System (INIS)

    Mares, F.; Hanslik, T.

    1973-01-01

    A method is described of manufacturing titanium and zirconium hydrides by hydrogenation of said metals characterized by the reaction temperature ranging between 250 to 500 degC, hydrogen pressure of 20 to 300 atm and possibly by the presence of a hydride of the respective metal. (V.V.)

  3. Titanium impregnated borosilicate zeolites for epoxidation catalysis

    Czech Academy of Sciences Publication Activity Database

    Přech, Jan; Vitvarová, Dana; Lupínková, Lenka; Kubů, Martin; Čejka, Jiří

    2015-01-01

    Roč. 212, AUG 2015 (2015), s. 28-34 ISSN 1387-1811 R&D Projects: GA ČR GAP106/11/0819 Institutional support: RVO:61388955 Keywords : borosilicate * titanium impregnation * epoxidation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.349, year: 2015

  4. Challenges of titanium metal injection moulding

    CSIR Research Space (South Africa)

    Benson, JM

    2007-11-01

    Full Text Available Titanium has fired the imagination of engineers and designers for decades by its ‘ideal’ combination of high strength, low density and good corrosion resistance. However, its application has unfortunately been limited to those niche markets where...

  5. Evaluating the Johanson theory for titanium powder

    CSIR Research Space (South Africa)

    Chikosha, S

    2015-05-01

    Full Text Available . In this study, the Johanson theory was used to determine the rolling parameters of titanium powder. Preliminary results of the nip angle, nip pressures and maximum horizontal pressures of the mill for the powder rolled on a 55mm diameter roll with roll gap sizes...

  6. 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

  7. 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.

  8. Obtention of titanium and zirconium metallic

    International Nuclear Information System (INIS)

    Santos, P.R.G.; Rover, C.F.S.; Amaral, F.L.L.

    1988-01-01

    The development works of techniques and equipments for titanium and zirconium sponges obtention are mentioned. The Kroll Process used for the sponges production is described, consisting in the reduction of the metal tetracloride with magnesium in an inert atmosphere of helium or argon. (C.G.C.) [pt

  9. The Redox Balance in Erythrocytes, Plasma, and Periosteum of Patients with Titanium Fixation of the Jaw

    Directory of Open Access Journals (Sweden)

    Jan Borys

    2017-06-01

    Full Text Available Titanium miniplates and screws are commonly used for fixation of jaw fractured or osteotomies. Despite the opinion of their biocompatibility, in clinical practice symptoms of chronic inflammation around the fixation develop in some patients, even many years after the application of miniplates and screws. The cause of these complications is still an unanswered question. Taking into account that oxidative stress is one of the toxic action of titanium, we have evaluated the antioxidant barrier as well as oxidative stress in the erythrocytes, plasma and periosteum covering the titanium fixation of the jaw. The study group was composed of 32 patients aged 20–30 with inserted miniplates and screws. The antioxidant defense: catalase (CAT, glutathione peroxidase (GPx, superoxide dismutase-1 (SOD1, uric acid (UA, total antioxidant capacity (TAC, as well as oxidative damage products: advanced oxidation protein products (AOPP, advanced glycation end products (AGE, dityrosine, kynurenine, N-formylkynurenine, tryptophan, malondialdehyde (MDA, 4-hydroxynonenal (4-HNE, total oxidant status (TOS, and oxidative status index (OSI were evaluated. SOD1 activity (↓37%, and tryptophan levels (↓34% showed a significant decrease while AOPP (↑25%, TOS (↑80% and OSI (↑101% were significantly elevated in maxillary periosteum of patients who underwent bimaxillary osteotomies as compared to the control group. SOD-1 (↓55%, TAC (↓58.6%, AGE (↓60% and N-formylkynurenine (↓34% was statistically reduced while AOPP (↑38%, MDA (↑29%, 4-HNE (↑114%, TOS (↑99%, and OSI (↑381% were significantly higher in the mandibular periosteum covering miniplates/screw compared with the control tissues. There were no correlations between antioxidants and oxidative stress markers in the periosteum of all patients and the blood. As exposure to the Ti6Al4V titanium alloy leads to disturbances of redox balance in the periosteum surrounding titanium implants of the maxilla

  10. 60th Anniversary

    CERN Multimedia

    Staff Association

    2015-01-01

      The Staff Association is happy to announce the start of the festivities for its 60th anniversary. To mark this event, we asked a graphic designer, Kevin Moles, who works with the support of Fabienne Marcastel/DG, to create an anniversary logo. This is the model which was chosen. From now on, you can find the new logo on all our sites, and materials related to the anniversary. We would like to thank Kevin for his work and help. More details of the celebration will be communicated later, but please already reserve the evening of May 21, and come celebrate with us and help us blow out the 60 candles of the Staff Association.

  11. 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

  12. Secondhand Smoke PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2015-02-03

    This 60 second public service announcement is based on the February 2015 CDC Vital Signs report. Secondhand smoke kills more than 400 infants and 41,000 adult nonsmokers every year. Learn what can be done to prevent secondhand smoke exposure.  Created: 2/3/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 2/3/2015.

  13. Heroin Epidemic PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2015-07-07

    This 60 second public service announcement is based on the July 2015 CDC Vital Signs report. Heroin use and heroin-related overdose deaths are increasing. Most people are using it with other drugs, especially prescription opioid painkillers. Learn what can be done to prevent and treat the problem.  Created: 7/7/2015 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 7/7/2015.

  14. HIV Testing PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2017-11-28

    This 60 second public service announcement is based on the December 2017 CDC Vital Signs report. In the U.S., about 15 percent of people who have HIV don't know they have it. Learn about the importance of testing, early diagnosis, and treatment.  Created: 11/28/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 11/28/2017.

  15. Childhood Obesity PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2013-08-06

    This 60 second public service announcement is based on the August 2013 CDC Vital Signs report. The rate of obesity among low-income preschoolers has declined, but one in eight is still obese. This program briefly discusses what can be done.  Created: 8/6/2013 by Centers for Disease Control and Prevention (CDC).   Date Released: 8/6/2013.

  16. Heart Age PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the September 2015 CDC Vital Signs report. Your heart age is the age of your heart and blood vessels as a result of your risk factors for heart attack and stroke. If you smoke or have high blood pressure, your heart age will be much higher than your actual age. Learn what you can do to lower your heart age and keep it low.

  17. Hispanic Health PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the May 2015 CDC Vital Signs report. About one in six people living in the U.S. are Hispanic. The two leading causes of death in this group are heart disease and cancer, accounting for two out of five deaths. Unfortunately, many Hispanics face considerable barriers to getting high quality health care, including language and low income. Learn what can be done to reduce the barriers.

  18. Mechanical behavior and microstructure properties of titanium powder consolidated by high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Zhilyaev, Alexander P. [Institute for Metals Superplasticity Problems, Khalturina 39, Ufa 450001 (Russian Federation); Fundació CTM Centre Tecnològic, Plaça de la Ciencia 2, Manresa, Barcelona 08242 (Spain); Research Laboratory for Mechanics of New Nanomaterials, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, St. Petersburg 195251 (Russian Federation); Ringot, Geoffrey [École Nationale Supérieure des Ingénieurs en Arts Chimiques et Technologiques (ENSIACET), National Polytechnic Institute of Toulouse (INPT), 31077 Toulouse Cedex 04 (France); Huang, Yi [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Maria Cabrera, Jose [Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, ETSEIB – Universitat Politècnica de Catalunya, Av. Diagonal 647, Bacelona 08028 (Spain); Langdon, Terence G., E-mail: langdon@usc.edu [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Departments of Aerospace & Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453 (United States)

    2017-03-14

    Research was conducted to investigate the potential for consolidating titanium powder using high-pressure torsion (HPT) at room temperature. The nanostructured samples processed by HPT were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show there is a significant refinement of the Ti powder and it consolidates into bulk nanostructured titanium with a mean grain size estimated by TEM as ~200–300 nm and a mean crystallite size measured by XRD as ~20–30 nm. Microhardness measurements and tensile testing show high strength and low ductility after consolidation under a pressure of 6.0 GPa for 5 revolutions. Additional short annealing at a temperature of 300 °C for 10 min leads to a significant enhancement in ductility while maintaining the high strength.

  19. Drilling of Hybrid Titanium Composite Laminate (HTCL with Electrical Discharge Machining

    Directory of Open Access Journals (Sweden)

    M. Ramulu

    2016-09-01

    Full Text Available An experimental investigation was conducted to determine the application of die sinker electrical discharge machining (EDM as it applies to a hybrid titanium thermoplastic composite laminate material. Holes were drilled using a die sinker EDM. The effects of peak current, pulse time, and percent on-time on machinability of hybrid titanium composite material were evaluated in terms of material removal rate (MRR, tool wear rate, and cut quality. Experimental models relating each process response to the input parameters were developed and optimum operating conditions with a short cutting time, achieving the highest workpiece MRR, with very little tool wear were determined to occur at a peak current value of 8.60 A, a percent on-time of 36.12%, and a pulse time of 258 microseconds. After observing data acquired from experimentation, it was determined that while use of EDM is possible, for desirable quality it is not fast enough for industrial application.

  20. Nickel-titanium wire in circumferential suture of a flexor tendon repair: a comparison to polypropylene.

    Science.gov (United States)

    Karjalainen, T; He, M; Chong, A K S; Lim, A Y T; Ryhanen, J

    2010-07-01

    Nickel-titanium (NiTi) has been proposed as an alternative material for flexor tendon core suture. To our knowledge, its suitability as a circumferential suture of flexor tendon repair has not been investigated before. The purpose of this ex vivo study was to investigate the biomechanical properties of NiTi circumferential repairs and to compare them with commonly used polypropylene. Forty porcine flexor tendons were cut and repaired by simple running or interlocking mattress technique using 100 microm NiTi wire or 6-0 polypropylene. The NiTi circumferential repairs showed superior stiffness, gap resistance, and load to failure when compared to polypropylene repairs with both techniques. Nickel-titanium wire seems to be a potential material for circumferential repair of flexor tendons. Copyright 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  1. Drilling of Hybrid Titanium Composite Laminate (HTCL) with Electrical Discharge Machining.

    Science.gov (United States)

    Ramulu, M; Spaulding, Mathew

    2016-09-01

    An experimental investigation was conducted to determine the application of die sinker electrical discharge machining (EDM) as it applies to a hybrid titanium thermoplastic composite laminate material. Holes were drilled using a die sinker EDM. The effects of peak current, pulse time, and percent on-time on machinability of hybrid titanium composite material were evaluated in terms of material removal rate (MRR), tool wear rate, and cut quality. Experimental models relating each process response to the input parameters were developed and optimum operating conditions with a short cutting time, achieving the highest workpiece MRR, with very little tool wear were determined to occur at a peak current value of 8.60 A, a percent on-time of 36.12%, and a pulse time of 258 microseconds. After observing data acquired from experimentation, it was determined that while use of EDM is possible, for desirable quality it is not fast enough for industrial application.

  2. DC diode sputtering of titanium: determination of optimal deposition conditions by electrical and spectroscopic investigations

    International Nuclear Information System (INIS)

    Poitevin, J.M.; Lemperiere, G.; Fourrier, C.

    1976-01-01

    An argon DC glow discharge in a diode sputtering system fitted with a titanium cathode is investigated. The first results fix the boundaries of good working conditions for the discharge; mathematical relations are established for the pressure range 40 to 120 mTorr, anode-cathode lengths from 15 to 60 mm and current densities from 0.6 to 2 mA cm -2 . The deposition rate is found to be proportional to the electrical power if the product pd is kept constant, but the ratio of the deposition rate to discharge power exhibits a maximum for d approximately equal 1.5 lsub(e). Spectroscopic studies of the discharge close to the substrate surface show that the intensity of some arc and spark lines of titanium is also proportional to the deposition rate. Emission spectroscopy shows that hydrogen is produced and quickly pumped during the presputtering stage; its evacuation is necessary to obtain good metallic films. (author)

  3. 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

  4. Trucker Safety PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2015-03-03

    This 60 second public service announcement is based on the March 2015 CDC Vital Signs report. In 2012 in the United States, about 317,000 motor vehicle crashes involved a large truck. Twenty-six thousand truck drivers and their passengers were injured in these crashes, and about 700 died. Learn what can be done to help truck drivers stay safe.  Created: 3/3/2015 by National Institute for Occupational Safety and Health (NIOSH).   Date Released: 3/3/2015.

  5. Heart Age PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2015-09-01

    This 60 second public service announcement is based on the September 2015 CDC Vital Signs report. Your heart age is the age of your heart and blood vessels as a result of your risk factors for heart attack and stroke. If you smoke or have high blood pressure, your heart age will be much higher than your actual age. Learn what you can do to lower your heart age and keep it low.  Created: 9/1/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 9/1/2015.

  6. Preventing Melanoma PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2015-06-02

    This 60 second public service announcement is based on the June 2015 CDC Vital Signs report. Skin cancer is the most common form of cancer in the U.S. In 2011, there were more than 65,000 cases of melanoma, the most deadly form of skin cancer. Learn how everyone can help prevent skin cancer.  Created: 6/2/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 6/2/2015.

  7. Hispanic Health PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2015-05-05

    This 60 second public service announcement is based on the May 2015 CDC Vital Signs report. About one in six people living in the U.S. are Hispanic. The two leading causes of death in this group are heart disease and cancer, accounting for two out of five deaths. Unfortunately, many Hispanics face considerable barriers to getting high quality health care, including language and low income. Learn what can be done to reduce the barriers.  Created: 5/5/2015 by Office of Minority Health & Health Equity (OMHHE).   Date Released: 5/5/2015.

  8. GOMA 6.0 :

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, Peter Randall; Rao, Rekha Ranjana; Chen, Ken S; Labreche, Duane A.; Sun, Amy Cha-Tien; Hopkins, Matthew M; Moffat, Harry K.; Roach, Robert Allen; Hopkins, Polly L.; Notz, Patrick K.; Roberts, Scott Alan; Sackinger, Philip A.; Subia, Samuel Ramirez; Wilkes, Edward Dean; Baer, Thomas A.; Noble, David R.; Secor, Robert B.

    2013-07-01

    Goma 6.0 is a finite element program which excels in analyses of multiphysical processes, particularly those involving the major branches of mechanics (viz. fluid/solid mechanics, energy transport and chemical species transport). Goma is based on a full-Newton-coupled algorithm which allows for simultaneous solution of the governing principles, making the code ideally suited for problems involving closely coupled bulk mechanics and interfacial phenomena. Example applications include, but are not limited to, coating and polymer processing flows, super-alloy processing, welding/soldering, electrochemical processes, and solid-network or solution film drying. This document serves as a users guide and reference.

  9. 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

  10. Structural and mechanical properties of titanium and titanium diboride monolayers and Ti/TiB2 multilayers

    International Nuclear Information System (INIS)

    Chu, K.; Lu, Y.H.; Shen, Y.G.

    2008-01-01

    Nano-multilayers represent a new class of engineering materials that are made up of alternating nanometer scale layers of two different components. In the present work a titanium (Ti) monolayer was combined with titanium diboride (TiB 2 ) to form a Ti/TiB 2 nano-multilayer. Designed experimental parameters enabled an evaluation of the effects of direct current bias voltage (U b ) and bilayer thickness (Λ) during multilayer deposition on the mechanical properties of reactively sputtered Ti/TiB 2 multilayer films. Their nanostructures and mechanical properties were characterized and analyzed using X-ray photoelectron spectroscopy (XPS), low-angle and high-angle X-ray diffraction (XRD), plan-view and cross-sectional high-resolution transmission electron microscopy (HRTEM), and microindentation measurements. Under the optimal bias voltage of U b = - 60 V, it was found that Λ (varied from 1.1 to 9.8 nm) was the most important factor which dominated the nanostructure and hardness. The hardness values obtained varied from 12 GPa for Ti and 15 GPa for TiB 2 monolayers, up to 33 GPa for the hardest Ti/TiB 2 multilayer at Λ = 1.9 nm. The observed hardness enhancement correlated to the layer thickness, followed a relation similar to the Hall-Petch strengthening dependence, with a generalized power of ∼ 0.6. In addition, the structural barriers between two materials (hcp Ti/amorphous TiB 2 ) and stress relaxation at interfaces within multilayer films resulted in a reduction of crack propagation and high-hardness

  11. Two phase titanium aluminide alloy

    Science.gov (United States)

    Deevi, Seetharama C.; Liu, C. T.

    2001-01-01

    A two-phase titanic aluminide alloy having a lamellar microstructure with little intercolony structures. The alloy can include fine particles such as boride particles at colony boundaries and/or grain boundary equiaxed structures. The alloy can include alloying additions such as .ltoreq.10 at % W, Nb and/or Mo. The alloy can be free of Cr, V, Mn, Cu and/or Ni and can include, in atomic %, 45 to 55% Ti, 40 to 50% Al, 1 to 5% Nb, 0.3 to 2% W, up to 1% Mo and 0.1 to 0.3% B. In weight %, the alloy can include 57 to 60% Ti, 30 to 32% Al, 4 to 9% Nb, up to 2% Mo, 2 to 8% W and 0.02 to 0.08% B.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. Microstructure evolution of titanium after tensile test

    International Nuclear Information System (INIS)

    Wronski, S.; Wierzbanowski, K.; Jędrychowski, M.; Tarasiuk, J; Wronski, M.; Baczmanski, A.; Bacroix, B.

    2016-01-01

    The qualitative and quantitative behavior of titanium T40 during tensile loading with a special emphasis on the presence of deformation twins in the observed microstructures is described. The samples for tensile tests were cut out from the rolled titanium sheet along the rolling and transverse directions. Several microstructure maps were determined using Electron Backscatter Diffraction technique (EBSD). These data were used to obtain crystallographic textures, misorientation distributions, grain size, twin boundary length, grain orientation spread, low and high angle boundary fractions and Schmid and Taylor factors. The deformation mechanisms and microstructure characteristics are different in the samples stretched along rolling and transverse directions. A strong appearance of tensile twins was observed in the samples deformed along transverse direction. On the other hand, more frequent subgrain formation and higher orientation spread was observed in the sample deformed along rolling direction, which caused’‘orientation blurring’ leading to an increase of grain size with deformation, as determined from OIM analysis.

  17. Requirements of titanium alloys for aeronautical industry

    Science.gov (United States)

    Ghiban, Brânduşa; Bran, Dragoş-Teodor; Elefterie, Cornelia Florina

    2018-02-01

    The project presents the requirements imposed for aeronatical components made from Titanium based alloys. Asignificant portion of the aircraft pylons are manufactured from Titanium alloys. Strength, weight, and reliability are the primary factors to consider in aircraft structures. These factors determine the requirements to be met by any material used to construct or repair the aircraft. Many forces and structural stresses act on an aircraft when it is flying and when it is static and this thesis describes environmental factors, conditions of external aggression, mechanical characteristics and loadings that must be satisfied simultaneously by a Ti-based alloy, compared to other classes of aviation alloys (as egg. Inconel super alloys, Aluminum alloys). For this alloy class, the requirements are regarding strength to weight ratio, reliability, corrosion resistance, thermal expansion and so on. These characteristics additionally continue to provide new opportunities for advanced manufacturing methods.

  18. Aeronautical Industry Requirements for Titanium Alloys

    Science.gov (United States)

    Bran, D. T.; Elefterie, C. F.; Ghiban, B.

    2017-06-01

    The project presents the requirements imposed for aviation components made from Titanium based alloys. A significant portion of the aircraft pylons are manufactured from Titanium alloys. Strength, weight, and reliability are the primary factors to consider in aircraft structures. These factors determine the requirements to be met by any material used to construct or repair the aircraft. Many forces and structural stresses act on an aircraft when it is flying and when it is static and this thesis describes environmental factors, conditions of external aggression, mechanical characteristics and loadings that must be satisfied simultaneously by a Ti-based alloy, compared to other classes of aviation alloys (as egg. Inconel super alloys, Aluminum alloys).For this alloy class, the requirements are regarding strength to weight ratio, reliability, corrosion resistance, thermal expansion and so on. These characteristics additionally continue to provide new opportunities for advanced manufacturing methods.

  19. Characterization of titanium alloys for cryogenic applications

    International Nuclear Information System (INIS)

    Reytier, M.; Kircher, F.; Levesy, B.

    2002-01-01

    Titanium alloys are employed in the design of superconducting magnet support systems for their high mechanical strength associated with their low thermal conductivity. But their use requires a careful attention to their crack tolerance at cryogenic temperature. Measurements have been performed on two extra low interstitial materials (Ti-5Al-2.5Sn ELI and Ti-6Al-4V ELI) with different thickness and manufacturing process. The investigation includes the tensile properties at room and liquid helium temperatures using smooth and notched samples. Moreover, the fracture toughness has been determined at 4.2 K using Compact Tension specimens. The microstructure of the different alloys and the various fracture surfaces have also been studied. After a detailed description of the experimental procedures, practical engineering characteristics are given and a comparison of the different titanium alloys is proposed for cryogenic applications

  20. Titanium(IV), zirconium, hafnium and thorium

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    Titanium can exist in solution in a number of oxidation states. The titanium(IV) exists in acidic solutions as the oxo-cation, TiO 2+ , rather than Ti 4+ . Zirconium is used in the ceramics industry and in nuclear industry as a cladding material in reactors where its reactivity towards hydrolysis reactions and precipitation of oxides may result in degradation of the cladding. In nature, hafnium is found together with zirconium and as a consequence of the contraction in ionic radii that occurs due to the 4f -electron shell, the ionic radius of hafnium is almost identical to that of zirconium. All isotopes of thorium are radioactive and, as a consequence of it being fertile, thorium is important in the nuclear fuel cycle. The polymeric hydrolysis species that have been reported for thorium are somewhat different to those identified for zirconium and hafnium, although thorium does form the Th 4 (OH) 8 8+ species.

  1. Biofunctionalization of titanium for dental implant

    Directory of Open Access Journals (Sweden)

    Takao Hanawa

    2010-08-01

    Full Text Available Surface modification is an important and predominant technique for obtaining biofunction in metals for biomedical use including dentistry. One surface modification technique is a process that changes the surface composition, structure, and morphology of a material, leaving the bulk mechanical properties intact. A tremendous number of surface modification techniques to improve the hard tissue compatibility of titanium have been developed. Hydroxyapatite layer, titanium oxide layer, and calcium titanate layer with various morphologies are deposited using electrochemical treatment including micro-arc oxidation. Also, surface modification layers without hydroxyapatite and calcium phosphate are chemically formed that accelerate bone formation. Other approach is the immobilization of biofunctional molecules such as poly(ethylene glycol to the metal surface to control the adsorption of proteins and adhesion of cells, platelets, and bacteria. In the case of immobilization of biomolecules such as collagen and peptide, bone formation and soft tissue adhesion are improved.

  2. Characterization of the titanium Kβ spectral profile

    International Nuclear Information System (INIS)

    Chantler, C T; Smale, L F; Kinnane, M N; Illig, A J; Kimpton, J A; Crosby, D N

    2013-01-01

    Transition metals have Kα and Kβ characteristic radiation possessing complex asymmetric spectral profiles. Instrumental broadening normally encountered in x-ray experiments shifts features of profiles used for calibration, such as peak energy, by many times the quoted accuracies. We measure and characterize the titanium Kβ spectral profile. The peak energy of the titanium Kβ spectral profile is found to be 4931.966 ± 0.022 eV prior to instrumental broadening. This 4.5 ppm result decreases the uncertainty over the past literature by a factor of 2.6 and is 2.4 standard deviations from the previous standard. The spectrum is analysed and the resolution-free lineshape is extracted and listed for use in other experiments. We also incorporate improvement in analysis applied to earlier results for V Kβ. (paper)

  3. Antibacterial Titanium Produced Using Selective Laser Melting

    Science.gov (United States)

    Macpherson, Andrew; Li, Xiaopeng; McCormick, Paul; Ren, Ling; Yang, Ke; Sercombe, Timothy B.

    2017-12-01

    Titanium and titanium alloys used in current medical and dental applications do not possess antibacterial properties, and therefore, postoperative infection remains a significant risk. Recently, the addition of silver and copper to conventional biomaterials has been shown to produce a material with good antibacterial properties. In this article, we investigate selective laser melting as a method of producing antibacterial Ti-6Al-4V containing elemental additions of Cu or Ag. The addition of Ag had no effect on the microstructure or strength, but it did result in a 300% increase in the ductility of the alloy. In contrast, the addition of Cu resulted in an increase in strength but in a decrease in ductility, along with a change in the structure of the material. The Cu-containing alloy also showed moderate antibacterial properties and was superior to the Ag-containing alloy.

  4. Standard digital reference images for titanium castings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 The digital reference images provided in the adjunct to this standard illustrate various types and degrees of discontinuities occurring in titanium castings. Use of this standard for the specification or grading of castings requires procurement of the adjunct digital reference images, which illustrate the discontinuity types and severity levels. They are intended to provide the following: 1.1.1 A guide enabling recognition of titanium casting discontinuities and their differentiation both as to type and degree through digital radiographic examination. 1.1.2 Example digital radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications and drawings. 1.2 The digital reference images consist of seventeen digital files each illustrating eight grades of increasing severity. The files illustrate seven common discontinuity types representing casting sections up to 1-in. (25.4-mm). 1.3 The reference radiographs were developed for casting sections up to 1...

  5. Precipitated nanosized titanium dioxide for electrochemical applications

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, S.A. [Joint Department of Electrochemical Energy Systems, 38A Vernadsky Ave., 03142 Kyiv (Ukraine); Institute for Sorption and Problems of Endoecology, 13 Gen. Naumov St., 03164 Kyiv (Ukraine); Lisnycha, T.V. [Institute for Sorption and Problems of Endoecology, 13 Gen. Naumov St., 03164 Kyiv (Ukraine); Chernukhin, S.I. [Joint Department of Electrochemical Energy Systems, 38A Vernadsky Ave., 03142 Kyiv (Ukraine)

    2011-02-15

    Two types of titanium dioxide samples precipitated from aqueous solutions of titanium tetrachloride are investigated. Crystalline materials are obtained by means of neutralization of TiCl{sub 4} with the solution of an alkali metal hydroxide. The change of the order of mixing leads to amorphous materials. The evolution of the samples upon the thermal treatment is characterized using XRD, SEM, TEM and porosity studies. The application of crystalline TiO{sub 2} as an electrode material in lithium-ion 2016 sample cells enable one to yield specific currents up to 3350 mA g{sup -1}. On the other hand, the thermal treatment of initially amorphous materials does not lead to complete crystallization, and the presence of amorphous TiO{sub 2} is well seen as the so-called capacity behavior of cyclic voltammetry curves. (author)

  6. Temperature effect on surface oxidation of titanium

    International Nuclear Information System (INIS)

    Vaquilla, I.; Barco, J.L. del; Ferron, J.

    1990-01-01

    The effect of temperature on the first stages of the superficial oxidation of polycrystalline titanium was studied using both Auger electron spectroscopy (AES) and emission shreshold (AEAPS). The number of compounds present on the surface was determined by application of the factor analysis technique. Reaction evolution was followed through the relative variation of Auger LMM and LMV transitions which are characteristic of titanium. Also the evolution of the chemical shift was determined by AEAPS. The amount of oxygen on the surface was quantified using transition KLL of oxygen. It was found that superficial oxidation depends on temperature. As much as three different compounds were determined according to substrate temperature and our exposure ranges. (Author). 7 refs., 5 figs

  7. 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)

  8. Fatigue Strength of Titanium Risers - Defect Sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Babalola, Olusegun Tunde

    2001-07-01

    This study is centred on assessment of the fatigue strength of titanium fusion welds for deep-water riser's applications. Deep-water risers are subjected to significant fatigue loading. Relevant fatigue data for titanium fusion welds are very scarce. Hence there is a need for fatigue data and life prediction models for such weldments. The study has covered three topics: Fatigue testing, Fractography and defect assessment, and Fracture Mechanics modelling of fatigue crack growth. Two series of welded grade of titanium consisting of 14 specimens in each series were fatigue tested under constant amplitude loading. Prior to fatigue testing, strain gauge measurements of some specimens was conducted to enable the definition of stress range in the fatigue assessment procedure. The results were compared with finite solid element analysis and related to fatigue stresses in a riser pipe wall. Distribution and geometry of internal and surface defects both in the as-welded and in the post-weld machined conditions were assessed using fractography. This served as a tool to determine the fatigue initiation point in the welds. Fracture mechanics was applied to model fatigue strength of titanium welds with initiation from weld defects. Two different stress intensity factor formulations for embedded eccentrically placed cracks were used for analysis of elliptical cracks with the major axis parallel and close to one of the free surfaces. The methods were combined to give a satisfactory model for crack growth analysis. The model analyses crack growth of elliptical and semi-elliptical cracks in two directions, with updating of the crack geometry. Fatigue strength assessment was conducted using two crack growth models, the Paris-Erdogan relation with no threshold and the Donahue et al. relation with an implied threshold. The model was validated against experimental data, with a discussion on the choice of crack growth model. (author)

  9. Titanium 󈨠: Science and Technology. Volume 3

    Science.gov (United States)

    1993-01-01

    Impurities in titanium which affect the performance of LSI devices are alkaline metals (Na, K), radioactive metals(U,Th), and heavy metals (Fe, Ni, Cr...protection system just started, can help to solve this problem and water polution . Of course mother kind of paint is now proposed. Ti remains also...treattent was set with 3 or 4 repeats at randoi arrangeient. The results of tests were lade with latheiathlcal signifi- cant evalution.The radioactive

  10. Titanium Brazing for Structures and Survivability

    Science.gov (United States)

    2007-05-01

    first method ( Weld +HIP) was a tungsten inert gas ( TIG ) weld around the exterior of the Ti- 6Al-4V blocks followed by hot isostatic pressing (HIP) at...beam welding plus hot isostatic pressing (E-beam+HIP) process in the encapsulation of a ceramic within a titanium structure. The testing of the...different joining methods highlighted some definite candidates for the replacement of the E-beam+HIP process , such as the Weld +HIP, and demonstrated

  11. Innovations: laser-cutting nickel-titanium

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, T.R.; Moore, B.; Toyama, N. [LPL Systems, Inc., Mountain View, CA (United States)

    2002-07-01

    Laser-cutting is well established as the preferred method for manufacturing many endovascular medical devices. Sometimes laser processing has been poorly understood by nickel-titanium (NiTi) material suppliers, medical device manufacturers, and device designers, but the field has made important strides in the past several years. A variety of sample, nonspecific applications are presented for cutting tubing and sheet stock. Limiting constraints, key considerations, and areas for future development are identified. (orig.)

  12. Highly Stable [C60AuC60]+/- Dumbbells.

    Science.gov (United States)

    Goulart, Marcelo; Kuhn, Martin; Martini, Paul; Chen, Lei; Hagelberg, Frank; Kaiser, Alexander; Scheier, Paul; Ellis, Andrew M

    2018-05-17

    Ionic complexes between gold and C 60 have been observed for the first time. Cations and anions of the type [Au(C 60 ) 2 ] +/- are shown to have particular stability. Calculations suggest that these ions adopt a C 60 -Au-C 60 sandwich-like (dumbbell) structure, which is reminiscent of [XAuX] +/- ions previously observed for much smaller ligands. The [Au(C 60 ) 2 ] +/- ions can be regarded as Au(I) complexes, regardless of whether the net charge is positive or negative, but in both cases, the charge transfer between the Au and C 60 is incomplete, most likely because of a covalent contribution to the Au-C 60 binding. The C 60 -Au-C 60 dumbbell structure represents a new architecture in fullerene chemistry that might be replicable in synthetic nanostructures.

  13. 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.

  14. 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.

  15. 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

  16. 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 ...

  17. 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

  18. 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 ...

  19. 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 ...

  20. 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.

  1. 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

  2. Titanium oxidation by rf inductively coupled plasma

    International Nuclear Information System (INIS)

    Valencia-Alvarado, R; López-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

    2014-01-01

    The development of titanium dioxide (TiO 2 ) films in the rutile and anatase phases is reported. The films have been obtained from an implantation/diffusion and sputtering process of commercially pure titanium targets, carried out in up to 500 W plasmas. The experimental outcome is of particular interest, in the case of anatase, for atmospheric pollution degradation by photocatalysis and, as to the rutile phase, for the production of biomaterials required by prosthesis and implants. The reactor employed consists in a cylindrical pyrex-like glass vessel inductively coupled to a 13.56 MHz RF source. The process takes place at a 5×10 −2 mbar pressure with the target samples being biased from 0 to -3000 V DC. The anatase phase films were obtained from sputtering the titanium targets over glass and silicon electrically floated substrates placed 2 cm away from the target. The rutile phase was obtained by implantation/diffusion on targets at about 700 °C. The plasma was developed from a 4:1 argon/oxygen mixture for ∼5 hour processing periods. The target temperature was controlled by means of the bias voltage and the plasma source power. The obtained anatase phases did not require annealing after the plasma oxidation process. The characterization of the film samples was conducted by means of x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy

  3. Fabrication and performance tests of a prototype in-situ coating machine for JT-60

    International Nuclear Information System (INIS)

    Obara, Kenjiro; Abe, Tetsuya; Murakami, Yoshio

    1987-09-01

    Prior to the design and construction of the JT-60's in-situ coating device, a prototype machine was fabricated and tested to confirm the applicability of proposed driving methods and mechanical elements to the device which would be operated in very severe conditions including high ambient temperature and high vacuum. The machine basically consists of an in-vessel manipulator, a fiberscope and an ohmically heated titanium evaporator. From the test results, we recommended to use the combination of Inconel 625 and a self-lubricating alloy for the solid-lubricated bearings and MoS 2 -coated Inconel 625 for the solid-lubricated gears. It was also found that TiC coating showed a effect for the prevention of welding between bolts and nuts. In order to optimize the operating parameters of the machine, many wall inspection tests and titanium evaporation tests were carried out in a large vacuum vessel by simulating the JT-60 conditions. (author)

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. Cannabis sativa smoke inhalation decreases bone filling around titanium implants: a histomorphometric study in rats.

    Science.gov (United States)

    Nogueira-Filho, Getulio da R; Cadide, Tiago; Rosa, Bruno T; Neiva, Tiago G; Tunes, Roberto; Peruzzo, Daiane; Nociti, Francisco Humberto; César-Neto, João B

    2008-12-01

    Although the harmful effect of tobacco smoking on titanium implants has been documented, no studies have investigated the effects of cannabis sativa (marijuana) smoking. Thus, this study investigated whether marijuana smoke influences bone healing around titanium implants. Thirty Wistar rats were used. After anesthesia, the tibiae surface was exposed and 1 screw-shaped titanium implant was placed bilaterally. The animals were randomly assigned to one of the following groups: control (n = 15) and marijuana smoke inhalation (MSI) 8 min/d (n = 15). Urine samples were obtained to detect the presence of tetra-hidro-cannabinoid. After 60 days, the animals were killed. The degree of bone-to-implant contact and the bone area within the limits of the threads of the implant were measured in the cortical (zone A) and cancellous bone (zone B). Tetra-hidro-cannabinoid in urine was positive only for the rats of MSI group. Intergroup analysis did not indicate differences in zone A-cortical bone (P > 0.01), however, a negative effect of marijuana smoke (MSI group) was observed in zone B-cancellous bone for bone-to-implant contact and bone area (Student's t test, P smoke on bone healing may represent a new concern for implant success/failure.

  9. Identification of radiopure titanium for the LZ dark matter experiment and future rare event searches

    Science.gov (United States)

    Akerib, D. S.; Akerlof, C. W.; Akimov, D. Yu.; Alsum, S. K.; Araújo, H. M.; Arnquist, I. J.; Arthurs, M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Balashov, S.; Barry, M. J.; Belle, J.; Beltrame, P.; Benson, T.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boast, K. E.; Bolozdynya, A.; Boxer, B.; Bramante, R.; Brás, P.; Buckley, J. H.; Bugaev, V. V.; Bunker, R.; Burdin, S.; Busenitz, J. K.; Carels, C.; Carlsmith, D. L.; Carlson, B.; Carmona-Benitez, M. C.; Chan, C.; Cherwinka, J. J.; Chiller, A. A.; Chiller, C.; Cottle, A.; Coughlen, R.; Craddock, W. W.; Currie, A.; Dahl, C. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edberg, T. K.; Edwards, W. R.; Emmet, W. T.; Faham, C. H.; Fiorucci, S.; Fruth, T.; Gaitskell, R. J.; Gantos, N. J.; Gehman, V. M.; Gerhard, R. M.; Ghag, C.; Gilchriese, M. G. D.; Gomber, B.; Hall, C. R.; Hans, S.; Hanzel, K.; Haselschwardt, S. J.; Hertel, S. A.; Hillbrand, S.; Hjemfelt, C.; Hoff, M. D.; Holbrook, B.; Holtom, E.; Hoppe, E. W.; Hor, J. Y.-K.; Horn, M.; Huang, D. Q.; Hurteau, T. W.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kaboth, A.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Khazov, A.; Khromov, A. V.; Konovalov, A. M.; Korolkova, E. V.; Koyuncu, M.; Kraus, H.; Krebs, H. J.; Kudryavtsev, V. A.; Kumpan, A. V.; Kyre, S.; Lee, C.; Lee, H. S.; Lee, J.; Leonard, D. S.; Leonard, R.; Lesko, K. T.; Levy, C.; Liao, F.-T.; Lin, J.; Lindote, A.; Linehan, R. E.; Lippincott, W. H.; Liu, X.; Lopes, M. I.; Lopez Paredes, B.; Lorenzon, W.; Luitz, S.; Majewski, P.; Manalaysay, A.; Manenti, L.; Mannino, R. L.; Markley, D. J.; Martin, T. J.; Marzioni, M. F.; McConnell, C. T.; McKinsey, D. N.; Mei, D.-M.; Meng, Y.; Miller, E. H.; Mizrachi, E.; Mock, J.; Monzani, M. E.; Morad, J. A.; Mount, B. J.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; Nikkel, J. A.; O'Dell, J.; O'Sullivan, K.; Olcina, I.; Olevitch, M. A.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Piepke, A.; Powell, S.; Preece, R. M.; Pushkin, K.; Ratcliff, B. N.; Reichenbacher, J.; Reichhart, L.; Rhyne, C. A.; Richards, A.; Rodrigues, J. P.; Rose, H. J.; Rosero, R.; Rossiter, P.; Saba, J. S.; Sarychev, M.; Schnee, R. W.; Schubnell, M.; Scovell, P. R.; Shaw, S.; Shutt, T. A.; Silva, C.; Skarpaas, K.; Skulski, W.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Sosnovtsev, V. V.; Stancu, I.; Stark, M. R.; Stephenson, S.; Stiegler, T. M.; Stifter, K.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Temples, D.; Terman, P. A.; Thomas, K. J.; Thomson, J. A.; Tiedt, D. R.; Timalsina, M.; To, W. H.; Tomás, A.; Tope, T. E.; Tripathi, M.; Tvrznikova, L.; Va'Vra, J.; Vacheret, A.; van der Grinten, M. G. D.; Verbus, J. R.; Vuosalo, C. O.; Waldron, W. L.; Wang, R.; Watson, R.; Webb, R. C.; Wei, W.-Z.; While, M.; White, D. T.; Whitis, T. J.; Wisniewski, W. J.; Witherell, M. S.; Wolfs, F. L. H.; Woodward, D.; Worm, S.; Xu, J.; Yeh, M.; Yin, J.; Zhang, C.; Lux-Zeplin (LZ) Collaboration

    2017-11-01

    The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of 238Ue < 1.6 mBq/kg, 238Ul < 0.09 mBq/kg, 232The = 0.28 ± 0.03 mBq/kg, 232Thl = 0.25 ± 0.02 mBq/kg, 40K < 0.54 mBq/kg, and 60Co < 0.02 mBq/kg (68% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of 0.160 ± 0.001(stat) ± 0.030(sys) counts.

  10. Detection of tightly closed flaws by nondestructive testing (NDT) methods in steel and titanium

    Science.gov (United States)

    Rummel, W. D.; Rathke, R. A.; Todd, P. H., Jr.; Tedrow, T. L.; Mullen, S. J.

    1976-01-01

    X-radiographic, liquid penetrant, ultrasonic, eddy current and magnetic particle testing techniques were optimized and applied to the evaluation of 4340 steel (180 KSI-UTS) and 6Al-4V titanium (STA) alloy specimens. Sixty steel specimens containing a total of 176 fatigue cracks and 60 titanium specimens containing a total of 135 fatigue cracks were evaluated. The cracks ranged in length from .043 cm (0.017 inch) to 1.02 cm (.400 inch) and in depth from .005 cm (.002 inch) to .239 cm (.094 inch) for steel specimens. Lengths ranged from .048 cm (0.019 inch) to 1.03 cm (.407 inch) and depths from 0.010 cm (.004 inch) to .261 cm (0.103 inch) for titanium specimens. Specimen thicknesses were nominally .152 cm (0.060 inch) and 0.635 cm (0.250 inch) and surface finishes were nominally 125 rms. Specimens were evaluated in the "as machined" surface condition, after etch surface and after proof loading in a randomized inspection sequence.

  11. Development of a Fabrication Process Using Suspension Plasma Spray for Titanium Oxide Photovoltaic Device

    Directory of Open Access Journals (Sweden)

    Hsian Sagr Hadi A

    2017-03-01

    Full Text Available In order to reduce the high costs of conventional materials, and to reduce the power necessary for the deposition of titanium dioxide, titanium tetrabutoxide has been developed in the form of a suspension of TiO2 using water instead of expensive ethanol. To avoid sedimentation of hydroxide particles in the suspension, mechanical milling of the suspension was conducted in order to create diffusion in colloidal suspension before using it as feedstock. Consequently, through the creation of a colloidal suspension, coating deposition was able to be conducted without sedimentation of the hydroxide particles in the suspension during the deposition process. Though an amorphous as-deposited coating was able to be deposited, through post heat treatment at 630 °C for 60 min, the chemical structure became anatase rich. In addition, it was confirmed that the post heat treated anatase rich coating had enough photo-catalytic activity to decolor methylene-blue droplets. From these results, this technique was found to have high potential in the low cost photo-catalytic titanium coating production process.

  12. 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

  13. Acknowledgment - Issue 60

    Directory of Open Access Journals (Sweden)

    Executive Editor

    2015-11-01

    Full Text Available Biblios wish to acknowledge the support of the following professionals who participated in the review process of submissions for our issue 60.ReviewersAndré Ancona Lopez (Universidade de Brasília - UnB, BrasilGildenir Carolino Santos (Universidade Estadual de Campinas - UNICAMP, BrasilJacira Gil Bernardes (Universidade Federal do Rio Grande do Sul - UFRGS, BrasilRodrigo Donoso Vegas (Universidad de Chile - UCHILE, ChileSaúl Hiram Souto Fuentes (Universidad de Monterrey - UDEM, MéxicoReviewers invitedAlejandro Uribe Tirado (Universidad de Antioquia - UDEA, ColombiaFernanda Passini Moreno (Universidade de Brasília - UnB, BrasilJosé Bernal Rivas Fernández (Universidad de Costa Rica - UCR, Costa RicaMarta Lígia Pomim Valentim (Universidade Estadual Paulista - UNESP, BrasilOrlando Corzo Cauracurí (Universidad Nacional Mayor de San Marcos - UNMSM, PerúTerezinha Elisabeth da Silva (Universidade Estadual de Londrina - UEL, BrasilZaira Regina Zafalon (Universidade Federal de São Carlos - UFSCAR, BrasilIn the same way our acknowledge to University Library System (University of Pittsburgh - PITTS, USA by constant technical support and advice for our journal.

  14. 60 years of celebrations

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    The first celebration of CERN's anniversary featured in the CERN Bulletin, 1979. As CERN wraps up a month of events surrounding its 60th anniversary, the Bulletin looks back on September 29ths that have come and gone. What was hitting the CERN headlines when the Organization turned 15 - 30 - 45? Brace yourselves for a trip back in time with previous birthday editions of the CERN (a.k.a. "Weekly") Bulletin.      Bulletin Issue No.1/1965  - Bulletin Issue No. 40/1969 The very first edition of the Weekly Bulletin arrived on CERN desktops on 29 March 1965. The Organization was only just out of its first decade, but it was already a hub of activity, as demonstrated by the various seminars and training events that graced the cover of the first Bulletin. By the time CERN turned 15 in 1969, the Organization was preparing for its second Open Day. Discussion of the event made the cover of the Bulletin, announcing that sections of the ISR were to be ...

  15. 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.

  16. Optical, Physical, and Chemical Properties of Surface Modified Titanium Dioxide Powders

    Science.gov (United States)

    2011-02-01

    PROPERTIES OF SURFACE MODIFIED TITANIUM DIOXIDE POWDERS fwn Scivrxc fa SciWcrrs Brendan G. DeLacy RESEARCH AND TECHNOLOGY DIRECTORATE David R. Redding ...NUMBER 5c PROGRAM ELEMENT NUMBER 6. AUTHOR(S) DeLacy, Brendan G. (SAIC) Redding , David R. (ECBC); and Matthews. Joshua 5d. PROJECT NUMBER...X3,300?t>5flm* ** aJI ^-15 SEf Figure 7 - SEM Image #1 of CR-470 •i i .#1. • ^ iW i > hp ^•R^^^Ay *£ $ ^&#60 W^# K HB8 %^ vj\\ X

  17. Effect of laser welding on the titanium ceramic tensile bond strength

    Directory of Open Access Journals (Sweden)

    Rodrigo Galo

    2011-08-01

    Full Text Available Titanium reacts strongly with elements, mainly oxygen at high temperature. The high temperature of titanium laser welding modifies the surface, and may interfere on the metal-ceramic tensile bond strength. OBJECTIVE: The influence of laser welding on the titanium-ceramic bonding has not yet been established. The purpose of this in vitro study was to analyze the influence of laser welding applied to commercially pure titanium (CpTi substructure on the bond strength of commercial ceramic. The influence of airborne particle abrasion (Al2O3 conditions was also studied. MATERIAL AND METHODS: Forty CpTi cylindrical rods (3 mm x 60 mm were cast and divided into 2 groups: with laser welding (L and without laser welding (WL. Each group was divided in 4 subgroups, according to the size of the particles used in airborne particle abrasion: A - Al2O3 (250 µm; B - Al2O3 (180 µm; C - Al2O3 (110 µm; D - Al2O3 (50 µm. Ceramic rings were fused around the CpTi rods. Specimens were invested and their tensile strength was measured at fracture with a universal testing machine at a crosshead speed of 2.0 mm/min and 200 kgf load cell. Statistical analysis was carried out with analysis of variance and compared using the independent t test (p<0.05. RESULTS: Significant differences were found among all subgroups (p<0.05. The highest and the lowest bond strength means were recorded in subgroups WLC (52.62 MPa and LD (24.02 MPa, respectively. CONCLUSION: Airborne particle abrasion yielded significantly lower bond strength as the Al2O3 particle size decreased. Mechanical retention decreased in the laser-welded specimens, i.e. the metal-ceramic tensile bond strength was lower.

  18. Comparison of mechanical and biological properties of zirconia and titanium alloy orthodontic micro-implants.

    Science.gov (United States)

    Choi, Hae Won; Park, Young Seok; Chung, Shin Hye; Jung, Min Ho; Moon, Won; Rhee, Sang Hoon

    2017-07-01

    The aim of this study was to compare the initial stability as insertion and removal torque and the clinical applicability of novel orthodontic zirconia micro-implants made using a powder injection molding (PIM) technique with those parameters in conventional titanium micro-implants. Sixty zirconia and 60 titanium micro-implants of similar design (diameter, 1.6 mm; length, 8.0 mm) were inserted perpendicularly in solid polyurethane foam with varying densities of 20 pounds per cubic foot (pcf), 30 pcf, and 40 pcf. Primary stability was measured as maximum insertion torque (MIT) and maximum removal torque (MRT). To investigate clinical applicability, compressive and tensile forces were recorded at 0.01, 0.02, and 0.03 mm displacement of the implants at angles of 0°, 10°, 20°, 30°, and 40°. The biocompatibility of zirconia micro-implants was assessed via an experimental animal study. There were no statistically significant differences between zirconia micro-implants and titanium alloy implants with regard to MIT, MRT, or the amount of movement in the angulated lateral displacement test. As angulation increased, the mean compressive and tensile forces required to displace both types of micro-implants increased substantially at all distances. The average bone-to-implant contact ratio of prototype zirconia micro-implants was 56.88 ± 6.72%. Zirconia micro-implants showed initial stability and clinical applicability for diverse orthodontic treatments comparable to that of titanium micro-implants under compressive and tensile forces.

  19. 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.

  20. 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)

  1. 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

  2. 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.

  3. 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.)

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. 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.

  11. 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 ...

  12. Fabrication and anisotropic wettability of titanium-coated microgrooves

    Science.gov (United States)

    Gui, N.; Xu, W.; Tian, J.; Rosengarten, G.; Brandt, M.; Qian, M.

    2018-03-01

    Surface wettability plays a critical role in a variety of key areas including orthopaedic implants and chemical engineering. Anisotropy in wettability can arise from surface grooves, which are of particular relevance to orthopaedic implants because they can mimic collagen fibrils that are the basic components of the extracellular matrix. Titanium (Ti) and its alloys have been widely used for orthopaedic and dental implant applications. This study is concerned with the fabrication of Ti-coated microgrooves with different groove widths and the characterisation of the anisotropy in wettability through measuring water contact angles, compared with both the Wenzel and Cassie models. Experimental results revealed that there existed significant anisotropy in the wettability of Ti-coated microgrooves, and the degree of anisotropy (Δθ) increased with an increasing groove width from 5 μm to 20 μm. On average, the contact angle measured parallel to the groove direction (θ//) was about 50°-60° smaller than that measured perpendicular to the groove direction (θ⊥). In general, the Wenzel model predicted the contact angles along the surface groove direction reasonably, and so did the Cassie model for the contact angles perpendicular to the groove direction. Osteoblast spreading was affected by the anisotropy in wettability, which occurred preferably along, rather than perpendicular to, the groove direction. These findings are informative for the design of Ti implant surfaces when anisotropy in wettability matters.

  13. IMMUNOTOXICOLOGICAL ASPECTS OF BIOCOMPATIBILITY OF TITANIUM

    Directory of Open Access Journals (Sweden)

    Maya Lyapina

    2017-05-01

    Full Text Available Titanium (Ti is a non-essential metal element. TiO2 is used predominantly in the form of micro and nanoparticles in consumer products, including cosmetics and food. Because of its excellent biocompatibility, the trade-pure titan and its alloys are widely used as an alternative to certain metals in invasive medicine, surgery, dental medicine. Contemporary data concerning the sources of exposure to titanium, immune reactions to Ti alloys, current knowledge and perspectives of diagnosis of sensitization or allergic reactions to titanium are discussed. Conclusion: TiO2 is much more stable than pure Ti and alloys used in the implants, that should be taken into account when conducting research and analysing the results. The evidence of possible toxic effects is insufficient. It is difficult to assess the frequency of Ti allergy due to the uncertainty of diagnostic methods, but it is believed that it is very low. This is supported by the evidence that Ti and TiO2 (often as NP doesn’t penetrate through the healthy skin. Skin patch testing with currently available formulations of Ti and TiO2 has no significant value in clinical practice, and currently, it is assumed that there is no reliable method for diagnosis Ti allergy. The functional analysis of cytokine release and investigation of genetic characteristics could be useful for individual risk assessment in dental implantology. Such studies may also help to investigate separately early and late implant loss, as well as to develop new diagnostic tools.

  14. Antibacterial iodine-supported titanium implants.

    Science.gov (United States)

    Shirai, T; Shimizu, T; Ohtani, K; Zen, Y; Takaya, M; Tsuchiya, H

    2011-04-01

    Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti-I(2)) and its impact on post-implant infection, as well as determining the potential suitability of Ti-I(2) as a biomaterial. External fixation pins were used in this experiment as trial implants because of the ease of making the septic models. The antibacterial activity of the metal was measured using a modification of the Japanese Industrial Standards method. Activity was evaluated by exposing the implants to Staphylococcus aureus or Escherichia coli and comparing reaction of pathogens to Ti-I(2) vs. stainless steel and titanium controls. Ti-I(2) clearly inhibited bacterial colonization more than the control metals. In addition, cytocompatibility was assessed by counting the number of colonies that formed on the metals. The three metals showed the same amount of fibroblast colony formation. Japanese white rabbits were used as an in vivo model. Three pins were inserted into both femora of six rabbits for histological analysis. Pin sites were inspected and graded for infection and inflammation. Fewer signs of infection and inflammatory changes were observed in conjunction with the Ti-I(2) pins. Furthermore, osteoconductivity of the implant was evaluated with osteoid formation surface of the pin. Consecutive bone formation was observed around the Ti-I(2) and titanium pins, while little osteoid formation was found around the stainless steel pins. These findings suggest that Ti-I(2) has antimicrobial activity and exhibits cytocompatibility. Therefore, Ti-I(2) substantially reduces the incidence of implant infection and shows particular promise as a biomaterial. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. 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

  16. [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.

  17. ZIRCONIUM-TITANIUM-BERYLLIUM BRAZING ALLOY

    Science.gov (United States)

    Gilliland, R.G.; Patriarca, P.; Slaughter, G.M.; Williams, L.C.

    1962-06-12

    A new and improved ternary alloy is described which is of particular utility in braze-bonding parts made of a refractory metal selected from Group IV, V, and VI of the periodic table and alloys containing said metal as a predominating alloying ingredient. The brazing alloy contains, by weight, 40 to 50 per cent zirconium, 40 to 50 per cent titanium, and the balance beryllium in amounts ranging from 1 to 20 per cent, said alloy having a melting point in the range 950 to 1400 deg C. (AEC)

  18. Crystallization of modified hydroxyapatite on titanium implants

    International Nuclear Information System (INIS)

    Golovanova, O A; Izmailov, R R; Zaits, A V; Ghyngazov, S A

    2016-01-01

    Carbonated-hydroxyapatite (CHA) and Si-hydroxyapatite (Si-HA) precipitation have been synthesized from the model bioliquid solutions (synovial fluid and SBF). It is found that all the samples synthesized from the model solutions are single-phase and represent hydroxyapatite. The crystallization of the modified hydroxyapatite on alloys of different composition, roughness and subjected to different treatment techniques was investigated. Irradiation of the titanium substrates with the deposited biomimetic coating can facilitate further growth of the crystal and regeneration of the surface. (paper)

  19. Laser-TIG Welding of Titanium Alloys

    Science.gov (United States)

    Turichin, G.; Tsibulsky, I.; Somonov, V.; Kuznetsov, M.; Akhmetov, A.

    2016-08-01

    The article presents the results of investigation the technological opportunity of laser-TIG welding of titanium alloys. The experimental stand for implementation of process with the capability to feed a filler wire was made. The research of the nature of transfer the filler wire into the welding pool has been demonstrated. The influence of distance between the electrode and the surface of the welded plates on the stability of the arc was shown. The relationship between welding velocity, the position of focal plane of the laser beam and the stability of penetration of plates was determined.

  20. Diastereoselectivity in scalemic tartrate/titanium epoxidations.

    Science.gov (United States)

    Brown, J M; Leppard, S J; Oakes, J; Thornthwaite, D

    2000-06-01

    Nonlinearity in the diastereoselectivity of epoxidation of allylic alcohols with mixtures of titanium isopropoxide, tertbutyl hydroperoxide, and diethyl tartrate was observed. Racemic and enantiomerically pure alcohols E-2-methyl-4-hexen-3-ol and E-1-methoxy-5-(O-tertbutyldimethylsilyloxy)-2-penten-4-ol were prepared. Epoxidation reactions were carried out with Ti(OPri)4 and ButOOH accompanied by diethyl tartrate of varying enantiomeric purity. The simplest explanation of these results is that a dimeric epoxidation reagent is involved, with significantly different reactivity for the homochiral and racemic forms. Copyright 2000 Wiley-Liss, Inc.

  1. Titanium tungsten coatings for bioelectrochemical applications

    DEFF Research Database (Denmark)

    Wierzbicki, Rafal; Amato, Letizia; Łopacińska, J.

    2011-01-01

    This paper presents an assessment of titanium tungsten (TiW) coatings and their applicability as components of biosensing systems. The focus is put on using TiW as an electromechanical interface layer between carbon nanotube (CNT) forests and silicon nanograss (SiNG) cell scaffolds. Cytotoxicity......, applicability to plasma-enhanced chemical vapor deposition (PECVD) of aligned CNT forests, and electrochemical performance are investigated. Experiments include culturing of NIH3T3 mouse embryonic fibroblast cells on TiW coated silicon scaffolds, CNT growth on TiW substrates with nickel catalyst, and cyclic...

  2. Terminal solid solubility of hydrogen in titanium

    International Nuclear Information System (INIS)

    Giroldi, J.P.; Vizcaino, Pablo; Banchik, Abraham David

    2003-01-01

    A Research and Development program to build a data base is currently under progress to support the local titanium fabrication. In the present work the temperature of the Terminal Solid Solubility on dissolution (TSSd) and precipitation (TSSp) of titanium hydrides in the Ti α-phase were both measured in the same thermal cycle with a Differential Scanning Calorimeter (DSC). The local titanium producer (FAESA) provided ASTM grade 1 pure Ti bars of about 2,5 cm in diameter. Samples weighting between 50 to 200 mg were cut with a diamond disc and the parallelepiped faces were all carefully ground with SiC papers, then picked in a HNO 3 plus HF aqueous solution and finally dried out with ethanol and hot air. Pairs of (TSSd, TSSp) values for α + δ → α and α → α + δ transformation temperatures in titanium were determined with the same calorimetric procedure already used to calculate the TSS values in zirconium. Data were taken from the same sample during the heating up and cooling down cycle of the second calorimeter run made with the same rate of 20 C degrees / minute. The Cathodic Charging technique was used to charge the samples at different hydrogen concentrations between the 'as fabricated' value and the concentration corresponding to the eutectoid temperature. A mixture of glycerin and phosphoric acid in a 2:1 ratio and a current density of 0,05 to 0,1 Amp/cm 2 were applied to different samples during 24 to 96 hours to get a wide range of hydrogen concentrations. A homogenization heat treatment at 400 C degrees for 45 minutes -made at open air in an electric furnace- was applied to each sample to dissolve the massive hydrides at the sample surfaces and diffuse them into the bulk of the sample. The hydrogen concentration of each sample was measured after the final calorimetric run using the Extraction Method in Liquid State under an inert atmosphere using a Leco RH-404 model Hydrogen Determinator. The experimental data follows a linear relationship -with a

  3. Hydrogen in niobium-titanium alloys

    International Nuclear Information System (INIS)

    Silva, J.R.G. da; Cabral, F.A.O.; Florencio, O.

    1985-01-01

    High purity Nb-Ti polycrystalline alloys were doped with hydrogen in equilibrium with the gaseous atmosphere at a pressure of 80 torr. at different temperatures. The partial molar enthalpy and entropy of the hydrogen solution at high dilution, ΔH sup(-) 0 and ΔS sup(-) 0 , were calculated from the equilibrium solubility data. The ΔH sup(-) 0 values are compared with the electron screened proton model of metal-hydrogen solutions. The addition of titanium to niobium has the effect to increase the hydrogen solubility at a given equilibrium temperature. (Author) [pt

  4. 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

  5. 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)

  6. 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.

  7. Modular titanium alloy neck adapter failures in hip replacement - failure mode analysis and influence of implant material

    Directory of Open Access Journals (Sweden)

    Bloemer Wilhelm

    2010-01-01

    Full Text Available Abstract Background Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery. The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68 of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years and the average weight 102.3 kg (75 to 130 kg. The failures of neck adapters were divided into 66% with small CCD of 130° and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. Methods A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Results Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck

  8. Nickel-titanium alloys: a systematic review

    Directory of Open Access Journals (Sweden)

    Marcelo do Amaral Ferreira

    2012-06-01

    Full Text Available OBJECTIVE: A systematic review on nickel-titanium wires was performed. The strategy was focused on Entrez-PubMed-OLDMEDLINE, Scopus and BioMed Central from 1963 to 2008. METHODS: Papers in English and French describing the behavior of these wires and laboratorial methods to identify crystalline transformation were considered. A total of 29 papers were selected. RESULTS: Nickel-titanium wires show exceptional features in terms of elasticity and shape memory effects. However, clinical applications request a deeper knowledge of these properties in order to allow the professional to use them in a rational manner. In addition, the necessary information regarding each alloy often does not correspond to the information given by the manufacturer. Many alloys called "superelastic" do not present this effect; they just behave as less stiff alloys, with a larger springback if compared to the stainless steel wires. CONCLUSIONS: Laboratory tests are the only means to observe the real behavior of these materials, including temperature transition range (TTR and applied tensions. However, it is also possible to determine in which TTR these alloys change the crystalline structure.

  9. Ballistic Limit Equation for Single Wall Titanium

    Science.gov (United States)

    Ratliff, J. M.; Christiansen, Eric L.; Bryant, C.

    2009-01-01

    Hypervelocity impact tests and hydrocode simulations were used to determine the ballistic limit equation (BLE) for perforation of a titanium wall, as a function of wall thickness. Two titanium alloys were considered, and separate BLEs were derived for each. Tested wall thicknesses ranged from 0.5mm to 2.0mm. The single-wall damage equation of Cour-Palais [ref. 1] was used to analyze the Ti wall's shielding effectiveness. It was concluded that the Cour-Palais single-wall equation produced a non-conservative prediction of the ballistic limit for the Ti shield. The inaccurate prediction was not a particularly surprising result; the Cour-Palais single-wall BLE contains shield material properties as parameters, but it was formulated only from tests of different aluminum alloys. Single-wall Ti shield tests were run (thicknesses of 2.0 mm, 1.5 mm, 1.0 mm, and 0.5 mm) on Ti 15-3-3-3 material custom cut from rod stock. Hypervelocity impact (HVI) tests were used to establish the failure threshold empirically, using the additional constraint that the damage scales with impact energy, as was indicated by hydrocode simulations. The criterion for shield failure was defined as no detached spall from the shield back surface during HVI. Based on the test results, which confirmed an approximately energy-dependent shield effectiveness, the Cour-Palais equation was modified.

  10. Atomic absorption analysis of serial titanium alloys

    International Nuclear Information System (INIS)

    Gorlova, M.N.; Feofanova, N.M.; Kornyushkova, Yu.D.

    1977-01-01

    Atom-absorption technique is described, which makes it possible to rapidly and precisely determine the following alloying elements and admixtures in titanium alloys: Al (2.0 - 8.5%); Mo (0.5 - 8%); Cr (0.5 - 12%); Si (0.2 - 0.5%); Mn(0.2 - 2.5%); V(0.5 - 6%); Sn(2.0 - 3.0%); Fe(0.1 - 1.0%); Zr(2.0 - 12.0%). The atom absorption method with flame atomization of the sample provides for best results if the alloy is dissolved in a mixture HCl + HBF 4 in the ratio 2:1. In order to obtain correct results the standard solutions must contain titanium in concentrations corresponding to the weight of the sample being analyzed. Sensitivity of zirconium determination may be increased approximately twofold by adding 10 mg/ml of FeCl 3 into the solution. Being as precise, as the classic analytical methods, the atom absorption technique is about 5 times more efficient

  11. Synthesis of titanium sapphire by ion implantation

    International Nuclear Information System (INIS)

    Morpeth, L.D.; McCallum, J.C.; Nugent, K.W.

    1998-01-01

    Since laser action was first demonstrated in titanium sapphire (Ti:Al 2 O 3 ) in 1982, it has become the most widely used tunable solid state laser source. The development of a titanium sapphire laser in a waveguide geometry would yield an elegant, compact, versatile and highly tunable light source useful for applications in many areas including optical telecommunications. We are investigating whether ion implantation techniques can be utilised to produce suitable crystal quality and waveguide geometry for fabrication of a Ti:Al 2 O 3 waveguide laser. The implantation of Ti and O ions into c-axis oriented α-Al 2 O 3 followed by subsequent thermal annealing under various conditions has been investigated as a means of forming the waveguide and optimising the fraction of Ti ions that have the correct oxidation state required for laser operation. A Raman Microprobe is being used to investigate the photo-luminescence associated with Ti 3+ ion. Initial photoluminescence measurements of ion implanted samples are encouraging and reveal a broad luminescence profile over a range of ∼ .6 to .9 μm, similar to that expected from Ti 3+ . Rutherford Backscattering and Ion Channelling analysis have been used to study the crystal structure of the samples following implantation and annealing. This enables optimisation of the implantation parameters and annealing conditions to minimise defect levels which would otherwise limit the ability of light to propagate in the Ti:Al 2O 3 waveguide. (authors)

  12. Additive Manufacturing of Metastable Beta Titanium Alloys

    Science.gov (United States)

    Yannetta, Christopher J.

    Additive manufacturing processes of many alloys are known to develop texture during the deposition process due to the rapid reheating and the directionality of the dissipation of heat. Titanium alloys and with respect to this study beta titanium alloys are especially susceptible to these effects. This work examines Ti-20wt%V and Ti-12wt%Mo deposited under normal additive manufacturing process parameters to examine the texture of these beta-stabilized alloys. Both microstructures contained columnar prior beta grains 1-2 mm in length beginning at the substrate with no visible equiaxed grains. This microstructure remained constant in the vanadium system throughout the build. The microstructure of the alloy containing molybdenum changed from a columnar to an equiaxed structure as the build height increased. Eighteen additional samples of the Ti-Mo system were created under different processing parameters to identify what role laser power and travel speed have on the microstructure. There appears to be a correlation in alpha lath size and power density. The two binary alloys were again deposited under the same conditions with the addition of 0.5wt% boron to investigate the effects an insoluble interstitial alloying element would have on the microstructure. The size of the prior beta grains in these two alloys were reduced with the addition of boron by approximately 50 (V) and 100 (Mo) times.

  13. Characterizations of additive manufactured porous titanium implants.

    Science.gov (United States)

    Basalah, Ahmad; Shanjani, Yaser; Esmaeili, Shahrzad; Toyserkani, Ehsan

    2012-10-01

    This article describes physical, chemical, and mechanical characterizations of porous titanium implants made by an additive manufacturing method to gain insight into the correlation of process parameters and final physical properties of implants used in orthopedics. For the manufacturing chain, the powder metallurgy technology was combined with the additive manufacturing to fabricate the porous structure from the pure tanium powder. A 3D printing machine was employed in this study to produce porous bar samples. A number of physical parameters such as titanium powder size, polyvinyl alcohol (PVA) amount, sintering temperature and time were investigated to control the mechanical properties and porosity of the structures. The produced samples were characterized through porosity and shrinkage measurements, mechanical compression test and scanning electron microscopy (SEM). The results showed a level of porosity in the samples in the range of 31-43%, which is within the range of the porosity of the cancelluous bone and approaches the range of the porosity of the cortical bone. The results of the mechanical test showed that the compressive strength is in the wide range of 56-509 MPa implying the effect of the process parameters on the mechanical strengths. This technique of manufacturing of Ti porous structures demonstrated a low level of shrinkage with the shrinkage percentage ranging from 1.5 to 5%. Copyright © 2012 Wiley Periodicals, Inc.

  14. Structure of titanium-doped goethite rust

    International Nuclear Information System (INIS)

    Nakayama, Takenori; Ishikawa, Tatsuo; Konno, Toyohiko J.

    2005-01-01

    To investigate the influence of titanium addition on the formation and structure of goethite (α-FeOOH) rust which is one of main corrosion products of weathering steel, the artificially synthesized α-FeOOH rusts were prepared by hydrolysis of aqueous solutions of Fe(III) containing Ti(IV) at different atomic ratios (Ti/Fe) in the range 0-0.1. The obtained rusts particles were observed by TEM. Characterization by XRD, N 2 absorption, Moessbauer spectroscopy was also done. TEM observation revealed that the α-FeOOH rust particle size increased with the increase of Ti/Fe, and that Ti-enriched poorly crystalline particles were formed around the rust particles. XRD confirmed that the crystallite size increased with the increase of Ti/Fe, while the XRD peaks decreased in intensity. Specific surface area obtained by N 2 absorption increased with the increase of Ti/Fe. It is deduced from the obtained results that the addition of Ti(IV) increases the crystallite size of α-FeOOH, and produces double domain particles consisting of the particle core and a porous poorly crystalline shell. It is thought that such unique rust structure produced by titanium addition contributes to the protective properties of rust layer of the weathering steel

  15. Nanomaterial Case Studies: Nanoscale Titanium Dioxide in ...

    Science.gov (United States)

    EPA announced the availability of the final report, Nanomaterial Case Studies: Nanoscale Titanium Dioxide in Water Treatment and in Topical Sunscreen. This report is a starting point to determine what is known and what needs to be known about selected nanomaterials as part of a process to identify and prioritize research to inform future assessments of the potential ecological and health implications of these materials. Two specific applications of nanoscale titanium dioxide (nano-TiO2) are considered: (1) as an agent for removing arsenic from drinking water; and (2) as an active ingredient in topical sunscreen. These case studies are organized around a comprehensive environmental assessment (CEA) framework that combines a product life cycle perspective with the risk assessment paradigm. They are intended to help identify what may need to be known in order to conduct a comprehensive environmental assessment of the potential risks related to nano-TiO2. These “case studies” do not represent completed or even preliminary assessments, nor are they intended to serve as a basis for risk management decisions in the near term on these specific uses of nano TiO2. Rather, the intent is to use this document in developing the scientific and technical information needed for future assessment efforts.

  16. Molecular and physiological responses to titanium dioxide ...

    Science.gov (United States)

    - Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to two widely-used engineered metal oxide nanoparticles, titanium dioxide (nano-titanium) and cerium dioxide (nano-cerium). Microarray analyses confirmed that exposure to either nanoparticle altered the transcriptomes of rosette leaves and roots, with comparatively larger numbers of differentially expressed genes (DEGs) found under nano-titania exposure. Nano-titania induced more DEGs in rosette leaves, whereas roots had more DEGs under nano-ceria exposure. MapMan analyses indicated that while nano-titania up-regulated overall and secondary metabolism in both tissues, metabolic processes under nano-ceria remained mostly unchanged. Gene enrichment analysis indicated that both nanoparticles mainly enriched ontology groups such as responses to stress (abiotic and biotic), and defense responses (pathogens), and responses to endogenous stimuli (hormones). Nano-titania specifically induced genes associated with photosynthesis, whereas nano-ceria induced expression of genes related to activating transcription factors, most notably those belonging to the ethylene responsive element binding protein family. Interestingly, there were also increased numbers of rosette leaves and plant biomass under nano-ceria exposure, but not under nano-titania. Other transcriptomic responses did not clearly relate to responses observed at the organism level. This may b

  17. 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

  18. Titanium dioxide induced inflammation in the small intestine

    Science.gov (United States)

    Nogueira, Carolina Maciel; de Azevedo, Walter Mendes; Dagli, Maria Lucia Zaidan; Toma, Sérgio Hiroshi; Leite, André Zonetti de Arruda; Lordello, Maria Laura; Nishitokukado, Iêda; Ortiz-Agostinho, Carmen Lúcia; Duarte, Maria Irma Seixas; Ferreira, Marcelo Alves; Sipahi, Aytan Miranda

    2012-01-01

    AIM: To investigate the effects of titanium dioxide (TiO2) nanoparticles (NPTiO2) and microparticles (MPTiO2) on the inflammatory response in the small intestine of mice. METHODS: Bl 57/6 male mice received distilled water suspensions containing TiO2 (100 mg/kg body weight) as NPTiO2 (66 nm), or MPTiO2 (260 nm) by gavage for 10 d, once a day; the control group received only distilled water. At the end of the treatment the duodenum, jejunum and ileum were extracted for assessment of cytokines, inflammatory cells and titanium content. The cytokines interleukin (IL)-1b, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, IL-23, tumor necrosis factor-α (TNF-α), intracellular interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were evaluated by enzyme-linked immunosorbent assay in segments of jejunum and ileum (mucosa and underlying muscular tissue). CD4+ and CD8+ T cells, natural killer cells, and dendritic cells were evaluated in duodenum, jejunum and ileum samples fixed in 10% formalin by immunohistochemistry. The titanium content was determined by inductively coupled plasma atomic emission spectrometry. RESULTS: We found increased levels of T CD4+ cells (cells/mm2) in duodenum: NP 1240 ± 139.4, MP 1070 ± 154.7 vs 458 ± 50.39 (P < 0.01); jejunum: NP 908.4 ± 130.3, MP 813.8 ± 103.8 vs 526.6 ± 61.43 (P < 0.05); and ileum: NP 818.60 ± 123.0, MP 640.1 ± 32.75 vs 466.9 ± 22.4 (P < 0.05). In comparison to the control group, the groups receiving TiO2 showed a statistically significant increase in the levels of the inflammatory cytokines IL-12, IL-4, IL-23, TNF-α, IFN-γ and TGF-β. The cytokine production was more pronounced in the ileum (mean ± SE): IL-12: NP 33.98 ± 11.76, MP 74.11 ± 25.65 vs 19.06 ± 3.92 (P < 0.05); IL-4: NP 17.36 ± 9.96, MP 22.94 ± 7.47 vs 2.19 ± 0.65 (P < 0.05); IL-23: NP 157.20 ± 75.80, MP 134.50 ± 38.31 vs 22.34 ± 5.81 (P < 0.05); TNFα: NP 3.71 ± 1.33, MP 5.44 ± 1.67 vs 0.99 ± 019 (P < 0.05); IFNγ: NP 15.85 ± 9

  19. Analysis of clinical efficacy and complications of titanium mini plate internal fixation and reconstructive surgery for patients with orbital fracture

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-07-01

    Full Text Available AIM: To analyze the clinical efficacy and complications of titanium mini plate internal fixation and reconstructive surgery for patients with orbital fracture. METHODS: Fifty-seven cases(60 eyeswith orbital fracture from March 2013 to April 2014 in our hospital were researched. According to the random number table method, the patients were divided into observation group(29 cases with 30 eyesand control group(28 cases with 30 eyes. The control group was treated with hydroxyapatite artificial bone plate for internal fixation, and the observation group with titanium mini plate internal fixation and reconstructive surgery. The diplopia grading, grading of ocular movement disorder before and at 1, 3mo after treatment and postoperative complications(prolapse, dislocation, infectionwere compared between the two groups. RESULTS: In both group, all the 60 eyes were healed without scar formation. The rate of diplopia grading as grade 0 1mo postoperatively of observation group and the control groups were 63% and 40%(PPPCONCLUSION: The clinical curative effect of titanium mini plate internal fixation and reconstructive surgery has a good effect for orbital fractures, which can improve the therapeutic effect and reduce the incidence of adverse reactions.

  20. 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.

  1. 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

  2. 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)

  3. 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

  4. 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.

  5. Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein.

    Directory of Open Access Journals (Sweden)

    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

  6. Electrochemical, Polarization, and Crevice Corrosion Testing of Nitinol 60, A Supplement to the ECLSS Sustaining Materials Compatibility Study

    Science.gov (United States)

    Lee, R. E.

    2016-01-01

    In earlier trials, electrochemical test results were presented for six noble metals evaluated in test solutions representative of waste liquids processed in the Environmental Control and Life Support System (ECLSS) aboard the International Space Station (ISS). Subsequently, a seventh metal, Nitinol 60, was added for evaluation and subjected to the same test routines, data analysis, and theoretical methodologies. The previous six test metals included three titanium grades, (commercially pure, 6Al-4V alloy and 6Al-4V low interstitial alloy), two nickel-chromium alloys (Inconel(RegisteredTrademark) 625 and Hastelloy(RegisteredTrademark) C276), and one high-tier stainless steel (Cronidur(RegisteredTrademark) 30). The three titanium alloys gave the best results of all the metals, indicating superior corrosive nobility and galvanic protection properties. For this current effort, the results have clearly shown that Nitinol 60 is almost as noble as titanium, being very corrosion-resistant and galvanically compatible with the other six metals electrochemically and during long-term exposure. is also quite noble as it is very corrosion resistant and galvanically compatible with the other six metals from both an electrochemical perspective and long-term crevice corrosion scenario. This was clearly demonstrated utilizing the same techniques for linear, Tafel and cyclic polarization, and galvanic coupling of the metal candidate as was done for the previous study. The high nobility and low corrosion susceptibility for Nitinol 60 appear to be intermediate to the nickel/chromium alloys and the titanium metals with indications that are more reflective of the titanium metals in terms of general corrosion and pitting behavior.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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.)

  13. The use of titanium and stainless steel in fracture fixation.

    Science.gov (United States)

    Hayes, J S; Richards, R G

    2010-11-01

    The use of metal in fracture fixation has demonstrated unrivalled success for many years owing to its high stiffness, strength, biological toleration and overall reliable function. The most prominent materials used are electropolished stainless steel and commercially pure titanium, along with the more recent emergence of titanium alloys. Despite the many differences between electropolished stainless steel and titanium, both materials provide a relatively predictable clinical outcome, and offer similar success for fulfilling the main biomechanical and biological requirements of fracture fixation despite distinctive differences in implant properties and biological responses. This article explores these differences by highlighting the limitations and advantages of both materials, and addresses how this translates to clinical success.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Antimicrobial effect, frictional resistance, and surface roughness of stainless steel orthodontic brackets coated with nanofilms of silver and titanium oxide: a preliminary study.

    Science.gov (United States)

    Ghasemi, Tania; Arash, Valiollah; Rabiee, Sayed Mahmood; Rajabnia, Ramazan; Pourzare, Amirhosein; Rakhshan, Vahid

    2017-06-01

    Nano-silver and nano-titanium oxide films can be coated over brackets in order to reduce bacterial aggregation and friction. However, their antimicrobial efficacy, surface roughness, and frictional resistance are not assessed before. Fifty-five stainless-steel brackets were divided into 5 groups of 11 brackets each: uncoated brackets, brackets coated with 60 µm silver, 100 µm silver, 60 µm titanium, and 100 µm titanium. Coating was performed using physical vapor deposition method. For friction test, three brackets from each group were randomly selected and tested. For scanning electron microscopy and atomic-force microscopy assessments, one and one brackets were selected from each group. For antibacterial assessment, six brackets were selected from each group. Of them, three were immediately subjected to direct contact with S. mutans. Colonies were counted 3, 6, 24, and 48 h of contact. The other three were stored in water for 3 months. Then were subjected to a similar direct contact test. Results pertaining to both subgroups were combined. Groups were compared statistically. Mean (SD) friction values of the groups 'control, silver-60, silver-100, titanium-60, and titanium-100' were 0.55 ± 0.14, 0.77 ± 0.08, 0.82 ± 0.11, 1.52 ± 0.24, and 1.57 ± 0.41 N, respectively (p = .0004, Kruskal-Wallis). Titanium frictions were significantly greater than control (p  .05, Dunn). In the uncoated group, colony count increased exponentially within 48 h. The coated groups showed significant reductions in colony count (p < .05, two-way-repeated-measures ANOVA). In conclusions, all four explained coatings reduce surface roughness and bacterial growth. Nano-titanium films are not suitable for friction reduction. Nano-silver results were not conclusive and need future larger studies. © 2016 Wiley Periodicals, Inc.

  19. Retention of 60Co, 85Sr and 137Cs on inorganic ion exchangers

    International Nuclear Information System (INIS)

    Dozol, J.F.; Eymard, S.

    1983-11-01

    The aim of the study is the treatment of radioactive wastes produced in plutonium fuel fabrication or in spent fuel reprocessing by inorganic ion exchangers for ultimate storage. This rapport, gives the distribution coefficients of 60 Co, 85 Sr, 137 Cs (in sodium nitrate medium at different concentration of sodium: .23g/l, 1 g/l, 10 g/l) obtained with different inorganic exchangers: titanium oxyde, sodium titanate, sodium zirconate, sodium niobate, sodium tantalate, titanium phosphate, zirconium phosphate, ammonium phosphotungstate in zirconium phosphate, polyantimonic acid amorphous aluminosilicate and several zeolites (ZBS 15 from OXYMIN, ZEOLON 400, ZEOLON 500, ZEOLON 900 from Norton, IE 96, A 51, 13 X from Union Carbide) [fr

  20. 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.

  1. 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.)

  2. Fullerene C[sub 60

    Energy Technology Data Exchange (ETDEWEB)

    Koruga, D; Hameroff, S; Sundareshan, M [Univ. of Arizona, Tucson, AZ (United States); Withers, J; Loutfy, R [MER Corp., Tucson, AZ (United States)

    1993-01-01

    This book, one of the first to be published in the exciting field of fullerenes, includes a short history of scientific discovery, as well as one possible answer to the question: for what purposes can C[sub 60] be utilized. The book opens with a review of the life of Buckminster Fuller. Modern history of fivefold symmetry and the icosahedron began between 1984 and 1985, when Shechtman and his research team opened a new branch in crystallography (fivefold symmetry) and when the Kroto/Smalley research team discovered the C[sub 60] molecule (truncated icosahedron). Production of solid C[sub 60] by the Huffman/Kraeschner research team in 1990 provided a new stimulus for research by producing C[sub 60] in macroscopic amounts for use by the scientific and technological community. This achievement led to developments such as Koruga's August 1992 creation of the dimer C[sub 116] using scanning tunneling engineering and Loutfy's hydrogenation of C[sub 60] and construction of the first Ni/C[sub 60] rechargeable batteries in December 1992. New inventions based on C[sub 60] will continue to be forthcoming, particularly in the areas of superconductivity, quantum devices, and molecular electronic devices. Discovery of the C[sub 60] molecule (Kroto/Smalley), production of solid C[sub 60] (Huffman/Kraeschmer) and technological inventions such as C[sub 116] (Koruga) have been chance discoveries. A short history of these discoveries is detailed in the book along with the results of the authors' Fullerene research efforts, including atomic resolution images of Fullerene C[sub 60], Ni/C[sub 60] batteries, nanotechnology of C[sub 60], comparison of C[sub 60] with biological systems, and others. As Fullerene C[sub 60] will require control engineering, an overview of control systems, in particular, general and optimal control of the Schroedinger equation, is contained. Some experimental and theoretical work of other researchers are also presented. 140 figs., 4 tabs., 342 refs.

  3. 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

  4. Storage characteristics of hydrogen by titanium

    International Nuclear Information System (INIS)

    Lee, S. H.; Kang, H. S.; Back, S. W.; Choi, H. J.; Kim, K. R.; An, D. H.; Lee, H. S.; Jung, H. S.

    2000-01-01

    Hydrogen absorption experiments were performed by the sponge, strip and rod types of titanium(Ti) for investigating the absorption characteristics of hydrogen. From experimental results, Ti sponge showed the high hydrogen absorption capacity inspite of low reaction temperature(25 .deg. C), the H/M, which mean the capacity of hydrogen absorption was measured 2.0 for Ti sponge at 25 .deg. C. However, in case of strip and rod type of Ti, the hydrogen absorption capacities were very low in the experimental condition of 25 .deg. C. The pulverizing phenomena after metal hydriding reaction was observed in both Ti strip and Ti rod. However, the pulverizing phenomena was not observed in the Ti sponges because of high surface area

  5. 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.

  6. Production of titanium carbide from ilmenite

    Directory of Open Access Journals (Sweden)

    Sutham Niyomwas

    2008-03-01

    Full Text Available The production of titanium carbide (TiC powders from ilmenite ore (FeTiO3 powder by means of carbothermal reduction synthesis coupled with hydrochloric acid (HCl leaching process was investigated. A mixture of FeTiO3 and carbon powders was reacted at 1500oC for 1 hr under flowing argon gas. Subsequently, synthesized product of Fe-TiC powders were leached by 10% HCl solutions for 24 hrs to get final product of TiC powders. The powders were characterized using X-ray diffraction, scanning electron and transmission electron microscopy. The product particles were agglomerated in the stage after the leaching process, and the size of this agglomerate was 12.8 μm with a crystallite size of 28.8 nm..

  7. Shape memory effect for titanium nickelide semiproducts

    International Nuclear Information System (INIS)

    Chernov, D.B.; Fatkullina, L.P.; Smirnova, Z.I.; Timonin, G.D.; Olejnikova, S.V.

    1978-01-01

    The thermomechanical properties of titanium nickelide semi-finished products obtained by garnissage melting followed by arc remelting have been studied for the purpose of investigating the NiTi ''form memory'' mechanism. The ingots were subjected to stepped pressing to produce rods. Calcined rods were tension tested. Investigation of the elastic and thermomechanical free return after deformation has shown that the share of elastic return increases as the preliminary deformation degree is increased. The return to the original form began at about 150 deg C; at 200 deg C the process rate decreases and at 300 deg C it stops. The degree of form recovery decreases with the increase of preliminary deformation. The return stress versus preliminary deformation degree relationship has a maximum at 11% strain degree. Maximum thermomechanical return stresses are observed at about 300 deg C. It is noted that yield strength decreases with the increasing degree of deformation to which the semi-finished products are subjected

  8. Cleaning graphene with a titanium sacrificial layer

    International Nuclear Information System (INIS)

    Joiner, C. A.; Roy, T.; Hesabi, Z. R.; Vogel, E. M.; Chakrabarti, B.

    2014-01-01

    Graphene is a promising material for future electronic applications and chemical vapor deposition of graphene on copper is a promising method for synthesizing graphene on the wafer scale. The processing of such graphene films into electronic devices introduces a variety of contaminants which can be difficult to remove. An approach to cleaning residues from the graphene channel is presented in which a thin layer of titanium is deposited via thermal e-beam evaporation and immediately removed. This procedure does not damage the graphene as evidenced by Raman spectroscopy, greatly enhances the electrical performance of the fabricated graphene field effect transistors, and completely removes the chemical residues from the surface of the graphene channel as evidenced by x-ray photoelectron spectroscopy.

  9. Hydrous titanium oxide-supported catalysts

    International Nuclear Information System (INIS)

    Dosch, R.G.; Stohl, F.V.; Richardson, J.T.

    1990-01-01

    Catalysts were prepared on hydrous titanium oxide (HTO) supports by ion exchange of an active metal for Na + ions incorporated in the HTO support during preparation by reaction with the parent Ti alkoxide. Strong active metal-HTO interactions as a result of the ion exchange reaction can require significantly different conditions for activation as compared to catalysts prepared by more widely used incipient wetness methods. The latter catalysts typically involve conversion or while the HTO catalysts require the alteration of electrostatic bonds between the metal and support with subsequent alteration of the support itself. In this paper, the authors discuss the activation, via sulfidation or reduction, of catalysts consisting of Co, Mo, or Ni-Mo dispersed on HTO supports by ion exchange. Correlations between the activation process and the hydrogenation, hydrodeoxygenation, and hydrodesulfurization activities of the catalysts are presented

  10. Surface modification of titanium by plasma nitriding

    Directory of Open Access Journals (Sweden)

    Kapczinski Myriam Pereira

    2003-01-01

    Full Text Available A systematic investigation was undertaken on commercially pure titanium submitted to plasma nitriding. Thirteen different sets of operational parameters (nitriding time, sample temperature and plasma atmosphere were used. Surface analyses were performed using X-ray diffraction, nuclear reaction and scanning electron microscopy. Wear tests were done with stainless steel Gracey scaler, sonic apparatus and pin-on-disc machine. The obtained results indicate that the tribological performance can be improved for samples treated with the following conditions: nitriding time of 3 h; plasma atmosphere consisting of 80%N2+20%H2 or 20%N2+80%H2; sample temperature during nitriding of 600 or 800 degreesC.

  11. Ordering effects in nonstoichiometric titanium carbide

    International Nuclear Information System (INIS)

    Lipatnikov, V.N.; Zueva, L.V.; Gusev, A.I.; Kottar, A.

    2000-01-01

    The effect of nonstoichiometry and ordering on crystalline structure and specific electric resistance (ρ) of TiC y (0.52≤y≤0.98) is studied within the temperature range of 300-1100 K. It is shown that the titanium carbide ordering in the areas 0.52≤y≤0.55, 0.56≤y≤0.58 and 0.62≤y≤0.68 leads to formation of the Ti 2 C cubic and trigonal ordered phase and the Ti 3 C 2 rhombic ordered phase correspondingly. Availability of hysteresis on the ρ(T) dependences in the area of the disorder-order reversible equilibrium transition points out to the fact that the TiC y ↔Ti 2 C and TiC y ↔Ti 3 C 2 transformations are the first order phase transitions [ru

  12. Machinability of cast commercial titanium alloys.

    Science.gov (United States)

    Watanabe, I; Kiyosue, S; Ohkubo, C; Aoki, T; Okabe, T

    2002-01-01

    This study investigated the machinability of cast orthopedic titanium (metastable beta) alloys for possible application to dentistry and compared the results with those of cast CP Ti, Ti-6Al-4V, and Ti-6Al-7Nb, which are currently used in dentistry. Machinability was determined as the amount of metal removed with the use of an electric handpiece and a SiC abrasive wheel turning at four different rotational wheel speeds. The ratios of the amount of metal removed and the wheel volume loss (machining ratio) were also evaluated. Based on these two criteria, the two alpha + beta alloys tested generally exhibited better results for most of the wheel speeds compared to all the other metals tested. The machinability of the three beta alloys employed was similar or worse, depending on the speed of the wheel, compared to CP Ti. Copyright 2002 Wiley Periodicals, Inc.

  13. Swelling in neutron-irradiated titanium alloys

    International Nuclear Information System (INIS)

    Peterson, D.T.

    1982-04-01

    Immersion density measurements have been performed on a series of titanium alloys irradiated in EBR-II to a fluence of 5 x 10 22 n/cm 2 (E > 0.1 MeV) at 450 and 550 0 C. The materials irradiated were the near-alpha alloys Ti-6242S and Ti-5621S, the alpha-beta alloy Ti-64, and the beta alloy Ti-38644. Swelling was observed in all alloys with the greater swelling being observed at 550 0 C. Microstructural examination revealed the presence of voids in all alloys. Ti-38644 was found to be the most radiation resistant. Ti-6242S and Ti-5621S also displayed good radiation resistance, whereas considerable swelling and precipitation were observed in Ti-64 at 550 0 C

  14. 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)

  15. Preparation and integration of nanostructured titanium dioxide

    KAUST Repository

    Zeng, Hua Chun

    2011-10-01

    Titanium dioxide (TiO2) is a chemically stable nontoxic transition-metal oxide associated with a wide range of existing chemical engineering processes. In this short review, recent research endeavors in preparation and integration of nanostructured TiO2 materials system will be featured and discussed for their potential new applications. Because material development always plays pivotal roles in the progress of a particular engineering discipline, the reviewed subjects will provide useful information to stimulate nanoscale research of chemical engineering, linking established fundamentals with practical applications. Some critical issues and challenges regarding further development of this important functional material for nanotechnology will also be addressed. © 2011 Elsevier Ltd. All rights reserved.

  16. Plasma electrolytic oxidation of Titanium Aluminides

    International Nuclear Information System (INIS)

    Morgenstern, R; Sieber, M; Lampke, T; Grund, T; Wielage, B

    2016-01-01

    Due to their outstanding specific mechanical and high-temperature properties, titanium aluminides exhibit a high potential for lightweight components exposed to high temperatures. However, their application is limited through their low wear resistance and the increasing high-temperature oxidation starting from about 750 °C. By the use of oxide ceramic coatings, these constraints can be set aside and the possible applications of titanium aluminides can be extended. The plasma electrolytic oxidation (PEO) represents a process for the generation of oxide ceramic conversion coatings with high thickness. The current work aims at the clarification of different electrolyte components’ influences on the oxide layer evolution on alloy TNM-B1 (Ti43.5Al4Nb1Mo0.1B) and the creation of compact and wear resistant coatings. Model experiments were applied using a ramp-wise increase of the anodic potential in order to show the influence of electrolyte components on the discharge initiation and the early stage of the oxide layer growth. The production of PEO layers with technically relevant thicknesses close to 100 μm was conducted in alkaline electrolytes with varying amounts of Na 2 SiO 3 ·5H 2 O and K 4 P 2 O 7 under symmetrically pulsed current conditions. Coating properties were evaluated with regard to morphology, chemical composition, hardness and wear resistance. The addition of phosphates and silicates leads to an increasing substrate passivation and the growth of compact oxide layers with higher thicknesses. Optimal electrolyte compositions for maximum coating hardness and thickness were identified by statistical analysis. Under these conditions, a homogeneous inner layer with low porosity can be achieved. The frictional wear behavior of the compact coating layer is superior to a hard anodized layer on aluminum. (paper)

  17. Electrochemical capacitance performance of titanium nitride nanoarray

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yibing, E-mail: ybxie@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Suzhou Research Institute of Southeast University, Suzhou 215123 (China); Wang, Yong [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Du, Hongxiu [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Suzhou Research Institute of Southeast University, Suzhou 215123 (China)

    2013-12-01

    Highlights: • TiN nanoarray is formed by a nitridation process of TiO{sub 2} in ammonia atmosphere. • TiN nanoarray exhibits much higher EDLC capacitance than TiO{sub 2} nanoarray. • The specific capacitance of TiN nanoarray achieves a high level of 99.7 mF cm{sup −2}. • A flexible solid-state supercapacitor is constructed by TiN nanoarray and PVA gel. -- Abstract: In this study, titanium nitride (TiN) nanoarrays with a short nanotube and long nanopore structure have been prepared by an anodization process of ultra thin titanium foil in ethylene glycol (EG) solution containing ammonium fluoride, subsequent calcination process in an air atmosphere, and final nitridation process in an ammonia atmosphere. The morphology and microstructure characterization has been conducted using field emission scanning electron microscope and X-ray diffraction. The electrochemical properties have been investigated through cyclic voltammetry and electrochemical impedance spectrum measurements. The electrochemical capacitance performance has been investigated by galvanostatic charge–discharge measurements in the acidic, neural and alkali electrolyte solution. Well-defined TiN nanoarrays contribute a much higher capacitance performance than titania (TiO{sub 2}) in the supercapacitor application due to the extraordinarily improved electrical conductivity. Such an electrochemical capacitance can be further enhanced by increasing aspect ratio of TiN nanoarray from short nanotubes to long nanopores. A flexible supercapacitor has been constructed using two symmetrical TiN nanoarray electrodes and a polyvinyl alcohol (PVA) gel electrolyte with H{sub 2}SO{sub 4}–KCl–H{sub 2}O–EG. Such a supercapacitor has a highly improved potential window and still keeps good electrochemical energy storage. TiN nanoarray with a high aspect ratio can act well as an ultra thin film electrode material of flexible supercapacitor to contribute a superior capacitance performance.

  18. BRIC-60: Biological Research in Canisters (BRIC)-60

    Science.gov (United States)

    Richards, Stephanie E. (Compiler); Levine, Howard G.; Romero, Vergel

    2016-01-01

    The Biological Research in Canisters (BRIC) is an anodized-aluminum cylinder used to provide passive stowage for investigations evaluating the effects of space flight on small organisms. Specimens flown in the BRIC 60 mm petri dish (BRIC-60) hardware include Lycoperscion esculentum (tomato), Arabidopsis thaliana (thale cress), Glycine max (soybean) seedlings, Physarum polycephalum (slime mold) cells, Pothetria dispar (gypsy moth) eggs and Ceratodon purpureus (moss).

  19. 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.

  20. Titanium Loop Heat Pipes for Space Nuclear Radiators, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will develop titanium Loop Heat Pipes (LHPs) that can be used in low-mass space nuclear radiators, such as...

  1. Hollow Mill for Extraction of Stripped Titanium Screws: An Easy ...

    African Journals Online (AJOL)

    countries. The known alternative in such condition is ... Key words: Hollow mill, stripped screws, titanium locked plates ... used a locally manufactured stainless steel hollow mill, ... head ‑ plate hole” assembly as a mono‑block single unit. In.

  2. 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.

  3. 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)

  4. Lunar-derived titanium alloys for hydrogen storage

    Science.gov (United States)

    Love, S.; Hertzberg, A.; Woodcock, G.

    1992-01-01

    Hydrogen gas, which plays an important role in many projected lunar power systems and industrial processes, can be stored in metallic titanium and in certain titanium alloys as an interstitial hydride compound. Storing and retrieving hydrogen with titanium-iron alloy requires substantially less energy investment than storage by liquefaction. Metal hydride storage systems can be designed to operate at a wide range of temperatures and pressures. A few such systems have been developed for terrestrial applications. A drawback of metal hydride storage for lunar applications is the system's large mass per mole of hydrogen stored, which rules out transporting it from earth. The transportation problem can be solved by using native lunar materials, which are rich in titanium and iron.

  5. 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

  6. 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

  7. Mechanical strength and stiffness of biodegradable and titanium osteofixation systems

    NARCIS (Netherlands)

    Buijs, Gerrit J.; van der Houwen, Eduard B.; Bos, Rudulf R. M.; Verkerke, Gijsbertus J.

    Purpose: To present relevant mechanical data to simplify the selection of an osteofixation system for situations requiring immobilization in oral and maxillofacial surgery. Materials and Methods: Seven biodegradable and 2 titanium osteofixation systems were investigated. The plates and screws were

  8. 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

  9. Development and Characterization of Titanium Compound N anostructures

    Science.gov (United States)

    Zhou, Zhou

    The development and characterization of titanium compound nanostructures have been achieved, for potential applications in energy industry. Oil and gas, one of the traditional industry fields, observes accumulating demands on active implementations of nanotechnology, for the numerous advantages that nanomaterials can introduce to both product performances and field operations. By using chemical vapor deposition and liquid exfoliation, various titanium compound nanostructures have been synthesized through this project. Attractively, these two material fabrication methods have been recognized to be industrial friendly in terms of cost efficiency and productivity. The development of nanostructures, aiming at oil and gas field applications, presents novel solutions for existing issues, such as low durability of drilling tools, high friction in mechanical operations and ineffective heat dissipation. Titanium compound nanostructures, including titanium borides, nitrides and sulfides are therefore investigated for such applications as protective coating, lubrication and thermal management.

  10. Green oxidations: Titanium dioxide induced tandem oxidation coupling reactions

    OpenAIRE

    Jeena, Vineet; Robinson, Ross S

    2009-01-01

    Summary The application of titanium dioxide as an oxidant in tandem oxidation type processes is described. Under microwave irradiation, quinoxalines have been synthesized in good yields from the corresponding ?-hydroxyketones.

  11. One half of a prototype titanium vacuum chamber

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    Designed and constructed in the ISR Department, it could be for general use at intersection regions. The use of titanium instead of stainless steel increases the "transparency" to particles by a factor of about two for the same wall thickness.

  12. Contact Stress Design Parameters for Titanium Bearings, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Air-Lock's Phase I effort tested the effects of ball induced contact stresses on Titanium bearing races. The contact stress design limit that would achieve a...

  13. Titanium Nanosurface Modification by Anodization for Orthopedic Applications

    National Research Council Canada - National Science Library

    Yao, Chang; Slamovich, Elliott B; Webster, Thomas J

    2005-01-01

    .... For this reason, the objective of the present in vitro study was to modify the surface of conventional titanium to include nanostructured surface features that promote the functions of osteoblasts (bone-forming cells...

  14. Synthesis and characterization of nano silicon and titanium nitride ...

    Indian Academy of Sciences (India)

    The characterization techniques indicated ... Scalable synthesis; microwave plasma; chemical synthesis; nanoparticles. 1. Introduction ... used but very few methods are available to produce silicon and titanium ... current (A). (m3/h). 1. Si. 2.1.

  15. 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.)

  16. Titanium dioxide nanoparticles cause genotoxicity in human lung epithelial cells

    Science.gov (United States)

    The use of engineered nanoparticles in consumer products is steadily increasing. However, the health effects of exposure to these nanoparticles are not thoroughly understood. This study investigated the genotoxicity of six titanium dioxide and two cerium oxide nanoparticles of va...

  17. Laser Cladding of TiC for Better Titanium Components

    OpenAIRE

    Sampedro, Jesús; Pérez, I; CÁRCEL GONZÁLEZ, BERNABÉ; Ramos, José Antonio; Amigó Borrás, Vicente

    2011-01-01

    Pure commercial titanium is widely used because of its high corrosion resistance and lower cost compared with other titanium alloys, in particular when there is no high wear requirements. Nevertheless, the wear resistance is poor and surface damage usually occurs in areas under contact loadings. Laser cladding is a suitable technique for manufacturing precise and defect free coatings of a dissimilar material with higher wear and corrosion resistance. In this work a good understanding of laser...

  18. LASER SURFACE MODIFICATION OF TITANIUM ALLOYS — A REVIEW

    OpenAIRE

    Y. S. TIAN; C. Z. CHEN; D. Y. WANG; T. Q. LEI

    2005-01-01

    Recent developments of laser surface modification of titanium alloys for increasing their corrosion, wear and oxidation resistance are introduced. The effects of laser processing parameters on the resulting surface properties of titanium alloys are reviewed. The problems to be solved and the prospects in the field of laser modification of Ti alloys are discussed. Due to the intrinsic properties, a laser beam can be focused onto the metallic surface to produce a broad range of treatments depen...

  19. Study of aging and ordering processes in titanium carbide

    International Nuclear Information System (INIS)

    Arbuzov, M.P.; Khaenko, B.V.; Kachkovskaya, Eh.T.

    1977-01-01

    Aging and ordering processes in titanium carbide were investigated on monocrystals (fragments of alloys) with the aid of roentgenographic method. The sequence of phase transformations during aging was ascertained,and a monoclinic structure of the carbon atoms ordering is suggested. The microhardness of titanium carbide was studied as a function of the heat treatment of alloys and the main factors (ordering and dislocation structure) which govern the difference in the microhardness of hardened and aged (annealed) specimens were determined

  20. 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)

  1. 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...

  2. 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.

  3. Corrosion stability of cermets on the base of titanium nitride

    International Nuclear Information System (INIS)

    Kajdash, O.N.; Marinich, M.A.; Kuzenkova, M.A.; Manzheleev, I.V.

    1991-01-01

    Corrosion resistance of titanium nitride and its cermets in 5% of HCl, 7% of HNO 3 , 10% of H 2 SO 4 is studied. It is established that alloys TiN-Ni-Mo alloyed with chromium (from 10 to 15%) possess the highest corrosion resistance. Cermet TiN-Cr has the higher stability than titanium nitride due to formation of binary nitride (Ti, Cr)N

  4. Enhanced ultrasonically assisted turning of a β-titanium alloy.

    Science.gov (United States)

    Maurotto, Agostino; Muhammad, Riaz; Roy, Anish; Silberschmidt, Vadim V

    2013-09-01

    Although titanium alloys have outstanding mechanical properties such as high hot hardness, a good strength-to-weight ratio and high corrosion resistance; their low thermal conductivity, high chemical affinity to tool materials severely impair their machinability. Ultrasonically assisted machining (UAM) is an advanced machining technique, which has been shown to improve machinability of a β-titanium alloy, namely, Ti-15-3-3-3, when compared to conventional turning processes. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Ultrasonic Surface Treatment of Titanium Alloys. The Submicrocrystalline State

    Science.gov (United States)

    Klimenov, V. A.; Vlasov, V. A.; Borozna, V. Y.; Klopotov, A. A.

    2015-09-01

    The paper presents the results of the research on improvement of physical-and- mechanical properties of titanium alloys VT1-0 and VT6 by modification of surfaces using ultrasonic treatment, and a comprehensive study of the microstructure and mechanical properties of modified surface layers. It has been established that exposure to ultrasonic treatment leads to formation in the surface layer of a structure with an average size of elements 50 - 100 nm, depending on the brand of titanium alloy.

  6. Laser colouring on titanium alloys: characterisation and potential applications

    OpenAIRE

    Franceschini, Federica; Demir, Ali Gökhan; Dowding, Colin; Previtali, Barbara; Griffiths, Jonathan David

    2014-01-01

    Oxides of titanium exhibit vivid colours that can be generated naturally or manipulated through controlled oxidation processes. The application of a laser beam for colouring titanium permits flexible manipulation of the oxidized geometry with high spatial resolution. The laser-based procedure can be applied in an ambient atmosphere to generate long-lasting coloured marks. Today, these properties are largely exploited in artistic applications such as jewellery, eyewear frames, watch components...

  7. Correlation of lattice distortion with photocatalytic activity of titanium dioxide

    International Nuclear Information System (INIS)

    Wang Xia; Shui Miao; Li Rongsheng; Song Yue

    2008-01-01

    The photocatalytic activity of titanium dioxide dispersions on X-3B pigment degradation has been investigated. A variety of factors that would influence the photocatalytic activity such as crystallite size, lattice distortion, and anatase content are discussed in detail. It is found that lattice distortion is the most important one among these factors and is expected to inhibit the hole and electron pair recombination. It determines, to some extent, the photocatalytic efficiency of titanium dioxide dispersions

  8. Titanium zirconium and hafnium coordination compounds with vanillin thiosemicarbazone

    International Nuclear Information System (INIS)

    Konunova, Ts.B.; Kudritskaya, S.A.

    1987-01-01

    Coordination compounds of titanium zirconium and hafnium tetrachlorides with vanillin thiosemicarbazone of MCl 4 x nLig composition, where n=1.5, 4 for titanium and 1, 2, 4 for zirconium and hafnium, are synthesized. Molar conductivity of ethanol solutions is measured; IR spectroscopic and thermochemical investigation are carried out. The supposition about ligand coordination via sulfur and azomethine nitrogen atoms is made. In all cases hafnium forms stable compounds than zirconium

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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)

  16. 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

  17. 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

  18. [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.

  19. 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

  20. Formation of Biomimetic Hydroxyapatite Coating on Titanium Plates

    Directory of Open Access Journals (Sweden)

    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

  1. 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

  2. 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.

  3. Nanoporous hydroxyapatite/sodium titanate bilayer on titanium implants for improved osteointegration.

    Science.gov (United States)

    Carradò, A; Perrin-Schmitt, F; Le, Q V; Giraudel, M; Fischer, C; Koenig, G; Jacomine, L; Behr, L; Chalom, A; Fiette, L; Morlet, A; Pourroy, G

    2017-03-01

    The aim of this study was to improve the strength and quality of the titanium-hydroxyapatite interface in order to prevent long-term failure of the implanted devices originating from coating delamination and to test it in an in-vivo model. Ti disks and dental commercial implants were etched in Kroll solution. Thermochemical treatments of the acid-etched titanium were combined with sol-gel hydroxyapatite (HA) coating processes to obtain a nanoporous hydroxyapatite/sodium titanate bilayer. The sodium titanate layer was created by incorporating sodium ions onto the Ti surface during a NaOH alkaline treatment and stabilized using a heat treatment. HA layer was added by dip-coating in a sol-gel solution. The bioactivity was assessed in vitro with murine MC3T3-E1 and human SaOs-2 cells. Functional and histopathological evaluations of the coated Ti implants were performed at 22, 34 and 60days of implantation in a dog lower mandible model. Nanoporous hydroxyapatite/sodium titanate bilayer on titanium implants was sensitive neither to crack propagation nor to layer delamination. The in vitro results on murine MC3T3-E1 and human SaOs-2 cells confirm the advantage of this coating regarding the capacity of cell growth and differentiation. Signs of progressive bone incorporation, such as cancellous bone formed in contact with the implant over the existing compact bone, were notable as early as day 22. Overall, osteoconduction and osteointegration mean scores were higher for test implants compared to the controls at 22 and 34 days. Nanoporous hydroxyapatite/sodium titanate bilayer improves the in-vivo osteoconduction and osteointegration. It prevents the delamination during the screwing and it could increase HA-coated dental implant stability without adhesive failures. The combination of thermochemical treatments with dip coating is a low-cost strategy. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Increasing Wear Resistance of Titanium Alloys by Anode Plasma Electrolytic Saturation with Interstitial Elements

    Science.gov (United States)

    Belkin, P. N.; Kusmanov, S. A.; Dyakov, I. G.; Silkin, S. A.; Smirnov, A. A.

    2017-05-01

    In our previous studies, we have shown that anode plasma electrolytic saturation of titanium alloys with nitrogen and carbon can improve their tribological properties. Obtained structure containing oxide layer and solid solution of diffused element in titanium promotes the enhancement of running-in ability and the decrease in the wear rate in some special cases. In this paper, further investigations are reported regarding the tribological properties of alpha- and beta-titanium alloys in wear test against hardened steel (50 HRC) disk using pin-on-disk geometry and balls of Al2O3 (6.25 mm in diameter) or bearing steel (9.6 mm in diameter) with ball-on-plate one and normal load from 5 to 209 N. Reproducible results were obtained under testing samples treated by means of the plasma electrolytic nitriding (PEN) with the mechanical removal of the oxide layer. Friction coefficient of nitrided samples is 0.5-0.9 which is somewhat higher than that for untreated one (0.48-0.75) during dry sliding against Al2O3 ball. An increase in the sliding speed results in the polishing of nitrided samples and reduction of their wear rate by 60 times. This result is obtained for 5 min at 850 °C using PEN in electrolyte containing 5 wt.% ammonia and 10 wt.% ammonium chloride followed by quenching in solution. Optical microscope was employed to assist in the evaluation of the wear behavior. Sizes of wear tracks were measured by profilometer TR200.

  5. Temperature-modulated DSC provides new insight about nickel-titanium wire transformations.

    Science.gov (United States)

    Brantley, William A; Iijima, Masahiro; Grentzer, Thomas H

    2003-10-01

    Differential scanning calorimetry (DSC) is a well-known method for investigating phase transformations in nickel-titanium orthodontic wires; the microstructural phases and phase transformations in these wires have central importance for their clinical performance. The purpose of this study was to use the more recently developed technique of temperature-modulated DSC (TMDSC) to gain insight into transformations in 3 nickel-titanium orthodontic wires: Neo Sentalloy (GAC International, Islandia, NY), 35 degrees C Copper Ni-Ti (Ormco, Glendora, Calif) and Nitinol SE (3M Unitek, Monrovia, Calif). In the oral environment, the first 2 superelastic wires have shape memory, and the third wire has superelastic behavior but not shape memory. All wires had cross-section dimensions of 0.016 x 0.022 in. Archwires in the as-received condition and after bending 135 degrees were cut into 5 or 6 segments for test specimens. TMDSC analyses (Model 2910 DSC, TA Instruments, Wilmington, Del) were conducted between -125 degrees C and 100 degrees C, using a linear heating and cooling rate of 2 degrees C per min, an oscillation amplitude of 0.318 degrees C with a period of 60 seconds, and helium as the purge gas. For all 3 wire alloys, strong low-temperature martensitic transformations, resolved on the nonreversing heat-flow curves, were not present on the reversing heat-flow curves, and bending appeared to increase the enthalpy change for these peaks in some cases. For Neo Sentalloy, TMDSC showed that transformation between martensitic and austenitic nickel-titanium, suggested as occurring directly in the forward and reverse directions by conventional DSC, was instead a 2-step process involving the R-phase. Two-step transformations in the forward and reverse directions were also found for 35 degrees C Copper Ni-Ti and Nitinol SE. The TMDSC results show that structural transformations in these wires are complex. Some possible clinical implications of these observations are discussed.

  6. Preventing Norovirus Outbreaks PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the June 2014 CDC Vital Signs report. Norovirus infects about 20 million Americans each year. Learn how to protect yourself and your family from this very contagious, potentially serious illness.

  7. Preventing Stroke Deaths PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the July 2017 CDC Vital Signs report. Higher opioid prescribing puts patients at risk for addiction and overdose. Learn what can be done about this serious problem.

  8. Arthritis in America PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the March 2017 CDC Vital Signs report. Many adults in the United States have arthritis. Learn how to reduce the pain of arthritis, as well as manage the condition.

  9. 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

  10. Effect of a defect structure on the static and long-term strength of submicrocrystalline VT1-0 titanium fabricated by plastic deformation during screw and lengthwise rolling

    Czech Academy of Sciences Publication Activity Database

    Betekhtin, V. I.; Kolobov, Yu. R.; Sklenička, Václav; Kadomtsev, A. G.; Narykova, M. V.; Dvořák, Jiří; Golosov, E. V.; Kardashev, B. K.; Kuz'menko, I. N.

    2015-01-01

    Roč. 60, č. 1 (2015), s. 66-71 ISSN 1063-7842 Institutional support: RVO:68081723 Keywords : titanium * nanoporosity * carbide dispersion * thermal stability * severe plastic deformation Subject RIV: JJ - Other Materials Impact factor: 0.569, year: 2015

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Osseointegration of titanium, titanium alloy and zirconia dental implants: current knowledge and open questions.

    Science.gov (United States)

    Bosshardt, Dieter D; Chappuis, Vivianne; Buser, Daniel

    2017-02-01

    Bone healing around dental implants follows the pattern and sequence of intramembraneous osteogenesis with formation of woven bone first of all followed later by formation of parallel-fibered and lamellar bone. Bone apposition onto the implant surface starts earlier in trabecular bone than in compact bone. While the first new bone may be found on the implant surface around 1 week after installation, bone remodeling starts at between 6 and 12 weeks and continues throughout life. Bone remodeling also involves the bone-implant interface, thus transiently exposing portions of the implant surface. Surface modifications creating micro-rough implant surfaces accelerate the osseointegration process of titanium implants, as demonstrated in numerous animal experiments. Sandblasting followed by acid-etching may currently be regarded as the gold standard technique to create micro-rough surfaces. Chemical surface modifications, resulting in higher hydrophilicity, further increase the speed of osseointegration of titanium and titanium-zirconium implants in both animals and humans. Surface modifications of zirconia and alumina-toughened zirconia implants also have an influence on the speed of osseointegration, and some implant types reach high bone-to-implant contact values in animals. Although often discussed independently of each other, surface characteristics, such as topography and chemistry, are virtually inseparable. Contemporary, well-documented implant systems with micro-rough implant surfaces, placed by properly trained and experienced clinicians, demonstrate high long-term survival rates. Nevertheless, implant failures do occur. A low percentage of implants are diagnosed with peri-implantitis after 10 years in function. In addition, a low number of implants seem to be lost for primarily reasons other than biofilm-induced infection. Patient factors, such as medications interfering with the immune system and bone cells, may be an element contributing to continuous bone

  16. Titanium dioxide solid phase for inorganic species adsorption and determination: the case of arsenic.

    Science.gov (United States)

    Vera, R; Fontàs, C; Anticó, E

    2017-04-01

    We have evaluated a new titanium dioxide (Adsorbsia As600) for the adsorption of both inorganic As (V) and As (III) species. In order to characterize the sorbent, batch experiments were undertaken to determine the capacities of As (III) and As (V) at pH 7.3, which were found to be 0.21 and 0.14 mmol g -1 , respectively. Elution of adsorbed species was only possible using basic solutions, and arsenic desorbed under batch conditions was 50 % when 60 mg of loaded titanium dioxide was treated with 0.5 M NaOH solution. Moreover, its use as a sorbent for solid-phase extraction and preconcentration of arsenic species from well waters has been investigated, without any previous pretreatment of the sample. Solid-phase extraction was implemented by packing several minicolumns with Adsorbsia As600. The method has been validated showing good accuracy and precision. Acceptable recoveries were obtained when spiked waters at 100-200 μg L -1 were measured. The presence of major anions commonly found in waters did not affect arsenic adsoption, and only silicate at 100 mg L -1 level severely competed with arsenic species to bind to the material. Finally, the measured concentrations in water samples containing arsenic from the Pyrinees (Catalonia, Spain) showed good agreement with the ICP-MS results.

  17. Graphitic carbon in a nanostructured titanium oxycarbide thin film to improve implant osseointegration

    International Nuclear Information System (INIS)

    Zanoni, R.; Ioannidu, C.A.; Mazzola, L.; Politi, L.; Misiano, C.; Longo, G.; Falconieri, M.; Scandurra, R.

    2015-01-01

    A nanostructured coating layer on titanium implants, able to improve their integration into bones and to protect against the harsh conditions of body fluids, was obtained by Ion Plating Plasma Assisted, a method suitable for industrial applications. A titanium carbide target was attached under vacuum to a magnetron sputtering source powered with a direct current in the 500–1100 W range, and a 100 W radio frequency was applied to the sample holder. The samples produced at 900 W gave the best biological response in terms of overexpression of some genes of proteins involved in bone turnover. We report the characterization of a reference and of an implant sample, both obtained at 900 W. Different micro/nanoscopic techniques evidenced the morphology of the substrates, and X-ray Photoelectron Spectroscopy was used to disclose the surface composition. The layer is a 500 nm thick hard nanostructure, composed of 60% graphitic carbon clustered with 15% TiC and 25% Ti oxides. - Highlights: • Nanostructured TiC protective layers were produced on Ti samples for prostheses. • Ion Plating Plasma-Assisted Deposition from TiC targets was used on Ti samples. • A model of the surface layer has been drawn from XPS, Raman, AFM, FIB/SEM, TEM. • The layer is mainly composed of graphitic carbon in addition to TiC and Ti oxides

  18. Oxidation of Catechol using Titanium Silicate (TS-1 Catalyst: Modeling and Optimization

    Directory of Open Access Journals (Sweden)

    Sonali Sengupta

    2013-12-01

    Full Text Available The oxidation of catechol was studied in an eco-friendly process with commercial titanium silicate-1 (TS-1 catalyst and hydrogen peroxide as oxidant in absence of all mass transfer effects. The process was opti-mized by Box-Behnken design in terms of three independent process variables such as reaction tempera-ture, moles of hydrogen peroxide per mole of catechol and catalyst amount whose optimum values of the process variables were found to be 60 °C, 13.2 and 1.24 g respectively for maximum conversion of 75.8 %. The effects of different process parameters such as mole ratio of hydrogen peroxide to catechol, catalyst par-ticle size, catalyst amount, temperature and reaction time were studied. A pseudo first order kinetic model was fitted with the experimental rate data. The apparent activation energy for the reaction was found to be 11.37 kJ/mole.  © 2013 BCREC UNDIP. All rights reservedReceived: 22nd April 2013; Revised: 25th October 2013; Accepted: 1st November 2013[How to Cite: Sengupta, S., Ghosal, D., Basu, J.K. (2013. Oxidation of Catechol using Titanium Silicate (TS-1 Catalyst: Modeling and Optimization. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (2: 167-177. (doi:10.9767/bcrec.8.2.4759.167-177][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.4759.167-177

  19. Effect of investment type and mold temperature on casting accuracy and titanium-ceramic bond.

    Science.gov (United States)

    Leal, Mônica Barbosa; Pagnano, Valéria Oliveira; Bezzon, Osvaldo Luiz

    2013-01-01

    This study evaluated the casting accuracy of crown margins and metal-ceramic shear bond strength (SBS) of pure titanium injected into casting molds made using 2 investment types at 3 mold temperatures. Sixty crown (30-degree beveled finish line) and 60 cylinder (5mm diameter × 8mm high) patterns were divided into 6 groups (n=10), and cast using a phosphate-bonded investment (P) and a magnesium oxide-bonded investment (U), at 400°C (groups P400 and U400), 550°C (groups P550 and U550) and 700°C (groups P700 and U700) mold temperatures. Crown margins were recorded in impression material, the degree of marginal rounding was measured and margin length deficiencies (µm) were calculated. Titanium-ceramic specimens were prepared using Triceram ceramic (2mm high) and SBS was tested. Failure modes were assessed by optical microscopy. Data were subjected to two-way ANOVA and Tukey's HSD test (α=0.05). For casting accuracy, expressed by marginal deficiency (µm), investment U provided more accurate results (64 ± 11) than P (81 ± 23) (pcasting accuracy for U700 (55 ± 7) and worse for P700 (109 ± 18). Casting accuracy at 700°C (82 ± 31) was significantly different from 400°C (69 ± 9) and 550°C (68 ± 9) (pcasting accuracy than investment P. The SBS was similar for all combinations of investments and temperatures.

  20. Influence of Coke Ratio on the Sintering Behavior of High-Chromium Vanadium-Titanium Magnetite

    Directory of Open Access Journals (Sweden)

    Songtao Yang

    2017-06-01

    Full Text Available High-chromium vanadium and titanium magnetite (HCVTM sinter has poor properties. The coke ratio has an important effect on the behavior of HCVTM sintering as it affects the mineral phases in the high-chromium vanadium and titanium sinter (HCVTS via changing the sintering temperature and atmosphere. In this work, the sintering behavior of HCVTM mixed with varying coke ratios was investigated through sintering pot tests, X-ray diffraction (XRD, gas chromatographic analysis, and mineral phase analysis. The results show that, with the increase of the coke ratio from 4.0% to 6.0%, leading to the increase of the combustion ratio of the flue gas, the vertical sintering rate and sinter productivity decrease. Meanwhile, with the change of the coke ratio, the content of magnetite, silicate, and perovskite increase, while the hematite and calcium ferrite decrease. In addition, the tumble strength and reduction ability of HCVTS decrease, and its degradation strength increase. It was found that the appropriate coke ratio for the sintering process was 5.0 wt %.

  1. Multiscale grooved titanium processed with femtosecond laser influences mesenchymal stem cell morphology, adhesion, and matrix organization.

    Science.gov (United States)

    Dumas, Virginie; Rattner, Aline; Vico, Laurence; Audouard, Eric; Dumas, Jean Claude; Naisson, Pierre; Bertrand, Philippe

    2012-11-01

    The femtosecond laser processing enabled the structuring of six types of surfaces on titanium-6aluminium-4vanadium (Ti-6Al-4V) plates. The obtained hierarchical features consisted of a combination of microgrooves and oriented nanostructures. By adjusting beam properties such as laser polarization, the width of the microgrooves (20 or 60 μm) and the orientation of the nanostructures (parallel or perpendicular to the microgrooves) can be precisely controlled. Mesenchymal stem cells (MSCs) grown on these structured surfaces produced cytoplasmic extensions with focal contacts, while on the smooth titanium, the cells were found to be well spread and without any focal contact 12 h postseeding. The 600-nm wide nanostructures on their own were sufficient to orient the MSCs. For the multiscale structured areas, when the orientation of the nanostructures was orthogonal in relation to the microgrooves, there was an important decrease in or even a loss of cell alignment signifying that cells were sensitive to the directional nanostructures in the microgrooves. At 7 days, cell proliferation was not affected but the direction of nanostructures controlled the matrix organization. The ultrafast laser, as a new method for producing micro-nanohybrid surfaces, is a promising approach to promote desired tissue organization for tissue engineering. Copyright © 2012 Wiley Periodicals, Inc.

  2. Titanium dioxide nanoparticles: synthesis, X-Ray line analysis and chemical composition study

    Energy Technology Data Exchange (ETDEWEB)

    Chenari, Hossein Mahmoudi, E-mail: mahmoudi_hossein@guilan.ac.ir, E-mail: h.mahmoudiph@gmail.com [University of Guilan, Rasht (Iran, Islamic Republic of); Seibel, Christoph; Hauschild, Dirk; Reinert, Friedrich [Karlsruhe Institute of Technology - KIT, Gemeinschaftslabor für Nanoanalytik, Karlsruhe (Germany); Abdollahian, Hossein [Nanotechnology Research Center of Urmia University, Urmia, (Iran, Islamic Republic of)

    2016-11-15

    TiO{sub 2} nanoparticles have been synthesized by the sol-gel method using titanium alkoxide and isopropanol as a precursor. The structural properties and chemical composition of the TiO{sub 2} nanoparticles were studied using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy.The X-ray powder diffraction pattern confirms that the particles are mainly composed of the anatase phase with the preferential orientation along [101] direction. The physical parameters such as strain, stress and energy density were investigated from the Williamson- Hall (W-H) plot assuming a uniform deformation model (UDM), and uniform deformation energy density model (UDEDM). The W-H analysis shows an anisotropic nature of the strain in nano powders. The scanning electron microscopy image shows clear TiO{sub 2} nanoparticles with particle sizes varying from 60 to 80nm. The results of mean particle size of TiO{sub 2} nanoparticles show an inter correlation with the W-H analysis and SEM results. Our X-ray photoelectron spectroscopy spectra show that nearly a complete amount of titanium has reacted to TiO{sub 2}. (author)

  3. Graphitic carbon in a nanostructured titanium oxycarbide thin film to improve implant osseointegration

    Energy Technology Data Exchange (ETDEWEB)

    Zanoni, R., E-mail: robertino.zanoni@uniroma1.it [Dipartimento di Chimica, Università di Roma ‘La Sapienza’ p.le Aldo Moro 5, 00185 Rome (Italy); Ioannidu, C.A.; Mazzola, L.; Politi, L. [Dipartimento di Scienze Biochimiche, Università di Roma ‘La Sapienza’, p.le Aldo Moro 5, 00185 Rome (Italy); Misiano, C. [Romana Film Sottili, Anzio, Rome (Italy); Longo, G. [Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome (Italy); Ecole Polytechnique Fédérale de Lausanne, SB IPSB LPMV, BSP 409 (Cubotron UNIL), R.te de la Sorge, CH-1015 Lausanne (Switzerland); Falconieri, M. [ENEA, Unità Tecnica Applicazioni delle Radiazioni, via Anguillarese 301, 00123 Rome (Italy); Scandurra, R. [Dipartimento di Scienze Biochimiche, Università di Roma ‘La Sapienza’, p.le Aldo Moro 5, 00185 Rome (Italy)

    2015-01-01

    A nanostructured coating layer on titanium implants, able to improve their integration into bones and to protect against the harsh conditions of body fluids, was obtained by Ion Plating Plasma Assisted, a method suitable for industrial applications. A titanium carbide target was attached under vacuum to a magnetron sputtering source powered with a direct current in the 500–1100 W range, and a 100 W radio frequency was applied to the sample holder. The samples produced at 900 W gave the best biological response in terms of overexpression of some genes of proteins involved in bone turnover. We report the characterization of a reference and of an implant sample, both obtained at 900 W. Different micro/nanoscopic techniques evidenced the morphology of the substrates, and X-ray Photoelectron Spectroscopy was used to disclose the surface composition. The layer is a 500 nm thick hard nanostructure, composed of 60% graphitic carbon clustered with 15% TiC and 25% Ti oxides. - Highlights: • Nanostructured TiC protective layers were produced on Ti samples for prostheses. • Ion Plating Plasma-Assisted Deposition from TiC targets was used on Ti samples. • A model of the surface layer has been drawn from XPS, Raman, AFM, FIB/SEM, TEM. • The layer is mainly composed of graphitic carbon in addition to TiC and Ti oxides.

  4. Uncontrolled re-entry of satellite parts after finishing their mission in LEO: Titanium alloy degradation by thermite reaction energy

    Science.gov (United States)

    Monogarov, K. A.; Pivkina, A. N.; Grishin, L. I.; Frolov, Yu. V.; Dilhan, D.

    2017-06-01

    Analytical and experimental studies conducted at Semenov Institute of Chemical Physics for investigating the use of pyrotechnic compositions, i.e., thermites, to reduce the risk of the fall of thermally stable parts of deorbiting end-of-life LEO satellites on the Earth are described. The main idea was the use of passive heating during uncontrolled re-entry to ignite thermite composition, fixed on the titanium surface, with the subsequent combustion energy release to be sufficient to perforate the titanium cover. It is supposed, that thus destructed satellite parts will lose their streamline shape, and will burn out being aerodynamically heated during further descending in atmosphere (patent FR2975080). On the base of thermodynamic calculations the most promising thermite compositions have been selected for the experimental phase. The unique test facilities have been developed for the testing of the efficiency of thermite charges to perforate the titanium TA6V cover of 0.8 mm thickness under temperature/pressure conditions duplicated the uncontrolled re-entry of titanium tank after its mission on LEO. Experiments with the programmed laser heating inside the vacuum chamber revealed the only efficient thermite composition among preliminary selected ones to be Al/Co3O4. Experimental searching of the optimal aluminum powder between spherical and flaked nano- and micron-sized ones revealed the possibility to adjust the necessary ignition delay time, according to the titanium cover temperature dependency on deorbiting time. For the titanium tank the maximum temperature is 1100 °C at altitude 68 km and pressure 60 Pa. Under these conditions Al/Co3O4 formulations with nano-Al spherical particles provide the ignition time to be 13.3 s, and ignition temperature as low as 592±5 °C, whereas compositions with the micron-sized spherical Al powder reveal these values to be much higher, i.e., 26.3 s and 869±5 °C, respectively. The analytical and experimental studies described

  5. The effect of Al intermediate layer on thermal resistance of EB-PVD yttria-stabilized zirconia coatings on titanium substrate

    Science.gov (United States)

    Panin, Alexey; Panin, Victor; Kazachenok, Marina; Shugurov, Artur; Sinyakova, Elena; Martynov, Sergey; Rusyaev, Andrey; Kasterov, Artur

    2017-12-01

    The yttria-stabilized zirconia coatings sprayed on titanium substrates by the electron beam physical vapor deposition were subjected to thermal annealing in air at 1000°C for 1, 30 and 60 min. The delamination and fracture of the coatings are studied by the scanning electron microscopy and X-ray diffraction. It is shown that a magnetron sputtered Al interlayer between the coating and the substrate considerably improves the thermal resistance of ceramic coatings.

  6. Titanium photocatalyst against human pathogenic microorganisms

    International Nuclear Information System (INIS)

    Kussovski, V.; Stefchev, P.; Kirilov, R.

    2011-01-01

    The conventional methods of disinfection are not effective in the longer term. They are time and staff intensive and use aggressive chemicals. Photocatalytic oxidation on surfaces coated with titanium dioxide (TiO 2 ) might offer a possible alternative. The antimicrobial activity of TiO 2 powder P25 and thin films of TiO 2 on glass slides against representative strains of microorganisms associated with hospital-acquired infections (Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans) was investigated in vitro. High efficiency has been found in the case of the studied bacterial strains, particularly for the P. aeruginosa. It was shown that it is possible to disinfect surfaces coated with TiO 2 and stimulated by UV-A light. The reduction efficiencies for P. aeruginosa, S. aureus and C. albicans were 3.19, 2.32 and 1.22. In all cases sublethal UV-A doses provoked an important lethality in the presence of TiO 2 . (authors)

  7. Black Titanium Dioxide Nanomaterials in Photocatalysis

    Directory of Open Access Journals (Sweden)

    Xiaodong Yan

    2017-01-01

    Full Text Available Titanium dioxide (TiO2 nanomaterials are widely considered to be state-of-the-art photocatalysts for environmental protection and energy conversion. However, the low photocatalytic efficiency caused by large bandgap and rapid recombination of photo-excited electrons and holes is a challenging issue that needs to be settled for their practical applications. Structure engineering has been demonstrated to be a highly promising approach to engineer the optical and electronic properties of the existing materials or even endow them with unexpected properties. Surface structure engineering has witnessed the breakthrough in increasing the photocatalytic efficiency of TiO2 nanomaterials by creating a defect-rich or amorphous surface layer with black color and extension of optical absorption to the whole visible spectrum, along with markedly enhanced photocatalytic activities. In this review, the recent progress in the development of black TiO2 nanomaterials is reviewed to gain a better understanding of the structure-property relationship with the consideration of preparation methods and to project new insights into the future development of black TiO2 nanomaterials in photocatalytic applications.

  8. Porous Titanium for Dental Implant Applications

    Directory of Open Access Journals (Sweden)

    Zena J. Wally

    2015-10-01

    Full Text Available Recently, an increasing amount of research has focused on the biological and mechanical behavior of highly porous structures of metallic biomaterials, as implant materials for dental implants. Particularly, pure titanium and its alloys are typically used due to their outstanding mechanical and biological properties. However, these materials have high stiffness (Young’s modulus in comparison to that of the host bone, which necessitates careful implant design to ensure appropriate distribution of stresses to the adjoining bone, to avoid stress-shielding or overloading, both of which lead to bone resorption. Additionally, many coating and roughening techniques are used to improve cell and bone-bonding to the implant surface. To date, several studies have revealed that porous geometry may be a promising alternative to bulk structures for dental implant applications. This review aims to summarize the evidence in the literature for the importance of porosity in the integration of dental implants with bone tissue and the different fabrication methods currently being investigated. In particular, additive manufacturing shows promise as a technique to control pore size and shape for optimum biological properties.

  9. Biomolecule-coated metal nanoparticles on titanium.

    Science.gov (United States)

    Christensen, Stephen L; Chatt, Amares; Zhang, Peng

    2012-02-07

    Immobilizations of nanoparticles and biomolecules on biocompatible substrates such as titanium are two promising approaches to bringing new functionalities to Ti-based biomaterials. Herein, we used a variety of X-ray spectroscopic techniques to study and better understand metal-thiolate interactions in biofunctionalized metal nanoparticle systems supported on Ti substrates. Using a facile one-step procedure, a series of Au nanoparticle samples with varied biomolecule coatings ((2-mercatopropionyl)glycine (MPG) and bovine serum albumin (BSA)) and biomolecule concentrations are prepared. Ag and Pd systems are also studied to observe change with varying metal composition. The structure and properties of these biomolecule-coated nanoparticles are investigated with scanning electron microscopy (SEM) and element-specific X-ray techniques, including extended X-ray absorption fine structure (Au L(3)-edge), X-ray absorption near-edge structure (Au L(3), Ag L(3), Pd L(3), and S K-edge), and X-ray photoelectron spectroscopy (Au 4f, Ag 3d, Pd 3d, and S 2p core level). It was found that, by comparison of SEM and X-ray spectroscopy results, the coating of metal nanoparticles with varying model biomolecule systems can have a significant effect on both surface coverage and organization. This work offers a facile chemical method for bio- and nanofunctionalization of Ti substrates as well as provides a physical picture of the structure and bonding of biocoated metal nanoparticles, which may lead to useful applications in orthopedics and biomedicine.

  10. Thermal decomposition of titanium deuteride thin films

    International Nuclear Information System (INIS)

    Malinowski, M.E.

    1983-01-01

    The thermal desorption spectra of deuterium from essentially clean titanium deuteride thin films were measured by ramp heating the films in vacuum; the film thicknesses ranged from 20 to 220 nm and the ramp rates varied from 0.5 to about 3 0 C s - 1 . Each desorption spectrum consisted of a low nearly constant rate at low temperatures followed by a highly peaked rate at higher temperatures. The cleanliness and thinness of the films permitted a description of desorption rates in terms of a simple phenomenological model based on detailed balancing in which the low temperature pressure-composition characteristics of the two-phase (α-(α+#betta#)-#betta#) region of the Ti-D system were used as input data. At temperatures below 340 0 C the model predictions were in excellent agreement with the experimentally measured desorption spectra. Interpretations of the spectra in terms of 'decomposition trajectories'' are possible using this model, and this approach is also used to explain deviations of the spectra from the model at temperatures of 340 0 C and above. (Auth.)

  11. Titanium nitride room-temperature ferromagnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Iu.G., E-mail: morozov@ism.ac.ru [Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, 8 Academician Osipyan Street, Chernogolovka, Moscow Region, 142432 (Russian Federation); Belousova, O.V. [Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, 8 Academician Osipyan Street, Chernogolovka, Moscow Region, 142432 (Russian Federation); Belyakov, O.A. [Ogarev Mordovia State University, Saransk, 68 Bol' shevistskaya Street, 430005 (Russian Federation); Parkin, I.P., E-mail: i.p.parkin@ucl.ac.uk [Department of Chemistry, Materials Chemistry Research Centre, University College London, 20 Gordon Street, London, WC1H 0AJ (United Kingdom); Sathasivam, S. [Department of Chemistry, Materials Chemistry Research Centre, University College London, 20 Gordon Street, London, WC1H 0AJ (United Kingdom); Kuznetcov, M.V., E-mail: maxim1968@mail.ru [All-Russian Research Institute on Problems of Civil Defense and Emergencies of Emergency Control Ministry of Russia (EMERCOM), 7 Davidkovskaya Street, Moscow, 121352 (Russian Federation)

    2016-08-05

    Cubic and near-spherical TiN nanoparticles ranging in average size from 20 to 125 nm were prepared by levitation-jet aerosol synthesis through condensation of titanium vapor in an inert gas flow with gaseous nitrogen injection. The nanoparticles were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), BET measurements, UV–Vis, FT-IR, Raman spectroscopy, XPS, and vibrating-sample magnetometry. Room-temperature ferromagnetism with maximum magnetization up to 2.5 emu/g was recorded for the nanoparticles. The results indicate that the observed ferromagnetic ordering was related to the defect Ti–N structures on the surface of nanoparticles. This suggestion is in good correlation with the measured spectroscopical data. - Highlights: • Levitation-jet aerosol synthesis of TiN nanoparticles (NPs). • SEM, XRD, BET, UV–vis, FT-IR, Raman, XPS and magnetic characterization of the NPs. • Correlation between optical and XPS measurements data and maximum magnetization of the NPs.

  12. Nanomaterial Case Studies: Nanoscale Titanium Dioxide ...

    Science.gov (United States)

    This draft document presents two case studies of nanoscale titanium dioxide (nano-TiO2) used (1) to remove arsenic from drinking water and (2) as an active ingredient in topical sunscreen. The draft case studies are organized around a comprehensive environmental assessment approach that combines a product life cycle framework with the risk assessment paradigm. The document does not draw conclusions about potential risks. Rather, the case studies are intended to help identify what needs to be known in order to conduct a comprehensive environmental assessment of the potential risks related to nano-TiO2. This draft document is part of a process that will inform the development of EPA’s research strategy to support nanomaterial risk assessments. The complex properties of various nanomaterials make evaluating them in the abstract or with generalizations difficult if not impossible. Thus, this document focuses on two specific uses of nano-TiO2, as a drinking water treatment and as topical sunscreen. These case studies do not represent completed or even preliminary assessments; rather, they present the structure for identifying and prioritizing research needed to support future assessments.

  13. Sample of superconducting wiring (Niobium Titanium)

    CERN Multimedia

    About NbTi cable: The cable consists of 36 strands of superconducting wire, each strand has a diameter of 0.825 mm and houses 6300 superconducting filaments of niobium-titanium (Nb-Ti, a superconducting alloy). Each filament has a diameter of about 0.006 mm, i.e. 10 times smaller than a typical human hair. The filaments are embedded in a high-purity copper matrix. Copper is a normal conducting material. The filaments are in the superconductive state when the temperature is below about -263ºC (10.15 K). When the filaments leave the superconductive state, the copper acts as conductor transports the electrical current. Each strand of The NbTi cable (at superconducting state) has a current density of up to above 2000 A/mm2 at 9 T and -271ºC (2.15 K). A cable transport a current of about 13000 A at 10 T and -271ºC (2.15 K). About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resistan...

  14. Sample of superconducting wiring (Niobium Titanium)

    CERN Multimedia

    About NbTi cable: The cable consists of 36 strands of superconducting wire, each strand has a diameter of 0.825 mm and houses 6300 superconducting filaments of niobium-titanium (Nb-Ti, a superconducting alloy). Each filament has a diameter of about 0.006 mm, i.e. 10 times smaller than a typical human hair. The filaments are embedded in a high-purity copper matrix. Copper is a normal conducting material. The filaments are in the superconductive state when the temperature is below about -263ºC (10.15 K). When the filaments leave the superconductive state, the copper acts as conductor transports the electrical current. Each strand of The NbTi cable (at superconducting state) has a current density of up to above 2000 A/mm2 at 9 T and -271ºC (2.15 K). A cable transport a current of about 13000 A at 10 T and -271ºC (2.15 K). About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resista...

  15. Fully CMOS-compatible titanium nitride nanoantennas

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, Justin A., E-mail: jabriggs@stanford.edu [Department of Applied Physics, Stanford University, 348 Via Pueblo Mall, Stanford, California 94305 (United States); Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305 (United States); Naik, Gururaj V.; Baum, Brian K.; Dionne, Jennifer A. [Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305 (United States); Petach, Trevor A.; Goldhaber-Gordon, David [Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305 (United States)

    2016-02-01

    CMOS-compatible fabrication of plasmonic materials and devices will accelerate the development of integrated nanophotonics for information processing applications. Using low-temperature plasma-enhanced atomic layer deposition (PEALD), we develop a recipe for fully CMOS-compatible titanium nitride (TiN) that is plasmonic in the visible and near infrared. Films are grown on silicon, silicon dioxide, and epitaxially on magnesium oxide substrates. By optimizing the plasma exposure per growth cycle during PEALD, carbon and oxygen contamination are reduced, lowering undesirable loss. We use electron beam lithography to pattern TiN nanopillars with varying diameters on silicon in large-area arrays. In the first reported single-particle measurements on plasmonic TiN, we demonstrate size-tunable darkfield scattering spectroscopy in the visible and near infrared regimes. The optical properties of this CMOS-compatible material, combined with its high melting temperature and mechanical durability, comprise a step towards fully CMOS-integrated nanophotonic information processing.

  16. Preliminary Investigation of the Effect of Surface Treatment on the Strength of a Titanium Carbide - 30 Percent Nickel Base Cermet

    Science.gov (United States)

    Robins, Leonard; Grala, Edward M

    1957-01-01

    Specimens of a nickel-bonded titanium carbide cermet were given the following surface treatments: (1) grinding, (2) lapping, (3) blast cleaning, (4) acid roughening, (5) oxidizing, and (6) oxidizing and refinishing. Room-temperature modulus-of-rupture and impact strength varied with the different surface treatments. Considerable strength losses resulted from the following treatments: (1) oxidation at 1600 F for 100 hours, (2) acid roughening, and (3) severe grinding with 60-grit silicon carbide abrasive. The strength loss after oxidation was partially recovered by grit blasting or diamond grinding.

  17. Orientative study in titanium - vanadium prospection from occurrence in a basic - ultrabasic complex in Poco Redondo, Sergipe

    International Nuclear Information System (INIS)

    Nascimento, J.W.B.

    1981-01-01

    This work studies the economic viability of the probable vanadium and titanium ore bodies by geochemical methods in NE of Sergipe state, Brazil. The colorimetric method to determine vanadium concentration, was studied. Through colorimetry 60 samples was selected to analyse the acid digestion and atomic absorption. The V and Ti proportion was considerated under the limits of the atomic spectrometer sensibility 50 and 300 ppm to V and Ti respectively. Compared the efficience between x-ray fluorescence method and atomic absorption method the second is more efficient. The geochemical profile elaborated through these samples suggest that the ore bodies are disposed in strait and descontinuous bands. (C.D.G.) [pt

  18. Tribological coating of titanium alloys by laser processing

    Science.gov (United States)

    Pang, Wang

    Titanium-based alloys have been used for aerospace materials for many years. Recently, these alloys are now being increasingly considered for automotive, industrial and consumer applications. Their excellent creep resistance, corrosion resistance and relative higher specific strength ratio are attractive for many applications. However, the main obstacle for the wide adoption of Ti alloys in various industries is their poor tribological properties. In slide wear, Ti deforms and adhesive wear readily occurs. Their poor tribological properties are mainly due to low hardness and absolute values of tensile and shear strength. Different surface modification techniques have been studied in order to improve the tribological characteristics of Ti alloys, i.e. PVD, nitrding, carburizing, boriding, plating etc. Coatings produced by these techniques have their own limitations such as thermal distortion and grain growth. A different approach is to introduce hard particles in the Ti alloy matrix to form a MMC coating, which has tailor-made hardness and wear resistance properties. Laser cladding or laser alloying techniques facilitate the fabrication of surface MMC on Ti alloys without thermal distortion to the substrate. In this project, the fabrication of hard and wear resistant layers of metal matrix composite on titanium alloys substrate by laser surface alloying was investigated. Powder mixtures of Mo and WC were used to form the MMC layer. By optimizing the processing parameters and pre-placed powder mixture compositions, surface MMC of different properties have been successfully fabricated on CP-Ti and Ti6A14V respectively. The structure and characteristics of the MMC surface were investigated by metallography, SEM, XRD, and E-DAX. It was found that the hardness of the laser alloyed Mo/WC MMC surface was 300% higher than that of the CP-Ti substrate Excellent metallurgical bonding with the MMC layer of the substrate has been achieved. The relative kinetic frictional tests

  19. Synthesis and characterization of titanium vanadate and vanadium antimonate and their use in treatment of some toxic waste

    International Nuclear Information System (INIS)

    Husein, W.M.M.

    2013-01-01

    Ion exchangers are insoluble solid materials, which carry exchangeable cations or anions. When the ion exchanger is in contact with an electrolyte solution, these ions are exchanged with an equivalent amount of other ions of the same sign .Synthetic inorganic ion exchangers possess good ion-exchange capacity, high chemical and radiation stabilities, reproducibility and selectivity for heavy metals. These materials were characterized using X-ray (XRD and XRF), IR, TGA-DTA and total elemental analysis studies. On the basis of distribution studies, titanium vanadate was highly selective for Cs(I) while vanadium antimonate was selective for Cu 2+ ions . Thermodynamic parameters (i.e. ΔG o , ΔS o and ΔH o ) have also been calculated for the adsorption of Cs + , Cd 2+ , Cu 2+ and Co 2+ ions on titanium vanadate and vanadium antimonate showing that the overall adsorption process is spontaneous and endothermic. The mechanism of diffusion of Co 2+ , Cu 2+ , Cd 2+ and Cs + in the H -form of titanium vanadate and vanadium antimonate cation exchanger was studied as a function of particle size, concentration of the exchanging ions, reaction temperature, drying temperature. The exchange rate was controlled by particle diffusion mechanism as a limited batch technique and is confirmed from straight lines of B versus 1/r 2 plots. The values of diffusion coefficients, activation energy and entropy of activation were calculated and their significance was discussed. The data obtained have been compared with that reported for other organic and inorganic exchangers. Exchange isotherms for H + /Co 2+ , H + /Cu 2+ , H + /Cd 2+ and H + /Cs + were determined at 25, 45 and 60±1 degree C. These isotherms showed that Co 2+ ,Cu 2+ , Cd 2+ and Cs + are chemically adsorbed. Moreover, the values of thermodynamic parameters were determined and the overall adsorption processes were found spontaneous and endothermic. Finally, removal of the above mentioned cations on titanium vanadate and

  20. Influencing Factors for the Microstructure and Mechanical Properties of Micro Porous Titanium Manufactured by Metal Injection Molding

    Directory of Open Access Journals (Sweden)

    Zhen Lu

    2016-04-01

    Full Text Available Porous titanium is a new structural and functional material. It is widely used in many fields since it integrates the properties of biomaterials with those of metallic foam. A new technology that combines both the preparation and forming of porous materials has been proposed in this paper. Moreover, a new solder was developed that could be employed in the joining of porous materials. Influencing factors for microstructure and mechanical properties of the parent material and joint interface are identified. Metal injection molding (MIM technology was used for fabricating porous materials. The feedstock for injection molding of porous titanium powders was prepared from titanium powders and a polymer-based binder system. In addition, the proportion of powder loading and binders was optimized. Through MIM technology, a porous titanium filter cartridge was prepared. For the purpose of investigating the thermal debinding technology of the filter cartridge, effects of the sintering temperature on the porosity, morphology of micropores and mechanical properties were analyzed. It could be found that when the sintering temperature increased, the relative density, bending and compression strength of the components also increased. Moreover, the porosity reached 32.28% when the sintering temperature was 1000 °C. The microstructure morphology indicated that micropores connected with each other. Meanwhile, the strength of the components was relatively high, i.e., the bending and compression strength was 65 and 60 MPa, respectively. By investigating the joining technology of porous filter cartridges, the ideal components of the solder and pressure were determined. Further research revealed that the micropore structure of the joint interface is the same as that of the parent material, and that the bending strength of the joint interface is 40 MPa.

  1. 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)

  2. 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.

  3. Antibacterial effect of hydrogen peroxide-titanium dioxide suspensions in the decontamination of rough titanium surfaces.

    Science.gov (United States)

    Wiedmer, David; Petersen, Fernanda Cristina; Lönn-Stensrud, Jessica; Tiainen, Hanna

    2017-07-01

    The chemical decontamination of infected dental implants is essential for the successful treatment of peri-implantitis. The aim of this study was to assess the antibacterial effect of a hydrogen peroxide-titanium dioxide (H 2 O 2 -TiO 2 ) suspension against Staphylococcus epidermidis biofilms. Titanium (Ti) coins were inoculated with a bioluminescent S. epidermidis strain for 8 h and subsequently exposed to H 2 O 2 with and without TiO 2 nanoparticles or chlorhexidine (CHX). Bacterial regrowth, bacterial load and viability after decontamination were analyzed by continuous luminescence monitoring, live/dead staining and scanning electron microscopy. Bacterial regrowth was delayed on surfaces treated with H 2 O 2 -TiO 2 compared to H 2 O 2 . H 2 O 2 -based treatments resulted in a lower bacterial load compared to CHX. Few viable bacteria were found on surfaces treated with H 2 O 2 and H 2 O 2 -TiO 2 , which contrasted with a uniform layer of dead bacteria for surfaces treated with CHX. H 2 O 2 -TiO 2 suspensions could therefore be considered an alternative approach in the decontamination of dental implants.

  4. SYNTHESIS AND STRUCTURE OF BIS(PHENYLTETRAMETHYLCYCLOPENTADIENYL)TITANIUM(III) HYDRIDE - THE FIRST MONOMERIC BIS(CYCLOPENTADIENYL)TITANIUM(III) HYDRIDE : The First Monomeric Bis(cyclopentadienyl)titanium(III) Hydride

    NARCIS (Netherlands)

    de Wolf, J.M.; Meetsma, A.; Teuben, J.H

    1995-01-01

    The first structurally characterized monomeric bis(cyclopentadienyl)titanium(III) hydride, (C(5)PhMe(4))(2)TiH (4), was synthesized by hydrogenolysis of (C(5)PhMe(4))(2)TiMe (5). Hydride 4 was found to be a monomeric bent sandwich by X-ray diffraction methods, and the pentamethylcyclopentadienyl

  5. Prescription Painkiller Overdoses PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the July 2013 CDC Vital Signs report. Prescription painkiller overdoses are an under-recognized and growing problem among women. This program includes things that women and health care providers can do to reduce the risk of overdose.

  6. The cobalt-60 container scanner

    International Nuclear Information System (INIS)

    Jigang, A.; Liye, Z.; Yisi, L.; Haifeng, W.; Zhifang, W.; Liqiang, W.; Yuanshi, Z.; Xincheng, X.; Furong, L.; Baozeng, G.; Chunfa, S.

    1997-01-01

    The Institute of Nuclear Energy Technology (INET) has successfully designed and constructed a container (cargo) scanner, which uses cobalt-60 of 100-300 Ci as radiation source. The following performances of the Cobalt-60 container scanner have been achieved at INET: a) IQI (Image Quality Indicator) - 2.5% behind 100 mm of steel; b) CI (Contrast Indicator) - 0.7% behind 100 mm of steel; c) SP (Steel Penetration) - 240 mm of steel; d) Maximum Dose per Scanning - 0.02mGy; e) Throughput - twenty 40-foot containers per hour. These performances are equal or similar to those of the accelerator scanners. Besides these nice enough inspection properties, the Cobalt-60 scanner possesses many other special features which are better than accelerator scanners: a) cheap price - it will be only or two tenths of the accelerator scanner's; b) low radiation intensity - the radiation protection problem is much easier to solve and a lot of money can be saved on the radiation shielding building; c) much smaller area for installation and operation; d) simple operation and convenient maintenance; e) high reliability and stability. The Cobalt-60 container (or cargo) scanner is satisfied for boundary customs, seaports, airports and railway stations etc. Because of the nice special features said above, it is more suitable to be applied widely. Its high properties and low price will make it have much better application prospects

  7. Preventing Stroke Deaths PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2017-09-06

    This 60 second public service announcement is based on the July 2017 CDC Vital Signs report. Higher opioid prescribing puts patients at risk for addiction and overdose. Learn what can be done about this serious problem.  Created: 9/6/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 9/6/2017.

  8. PSA (:60) Moho/ Hongos (Mold)

    Centers for Disease Control (CDC) Podcasts

    2017-10-25

    Este anuncio de servicio público de 60 segundos habla sobre la importancia de eliminar el moho (hongos) después de una emergencia.  Created: 10/25/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 10/25/2017.

  9. Photophysics of C60 Colloids

    Science.gov (United States)

    2012-11-28

    nonlinear-optical properties and excited-state dynamics of pristine, oxygen- doped , and photopolymerized C-60 in the solid-state," Physical Review B...C45 (2009). 139. E. A. Brujan, "Numerical investigation on the dynamics of cavitation nanobubbles," Microfluidics and Nanofluidics 11(5), 511-517

  10. Cancer and Obesity PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the October 2017 CDC Vital Signs report. Obesity is a leading cancer risk factor. Unfortunately, two out of three U.S. adults weigh more than recommended. Find out what can be done to help people get to and keep a healthy weight.

  11. Cobalt 60 commercial irradiation facilities

    International Nuclear Information System (INIS)

    West, G.

    1985-01-01

    The advantage of using cobalt 60 for ionizing treatment is that it has excellent penetration. Gamma plants are also very efficient, in as much as there is very little mechanical or electrical equipment in a gamma irradiation facility. The average efficiency of a gamma plant is usually around 95% of all available processing time

  12. Preventing Teen Pregnancy PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the April 2015 CDC Vital Signs report. Teen births in the U.S. have declined, but still, more than 273,000 infants were born to teens ages 15 to 19 in 2013. Learn about the most effective types of birth control.

  13. Raccoon Roundworm Infection PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2012-08-27

    This 60 second PSA describes the signs and symptoms of and ways to prevent Baylisascaris infection, a parasitic roundworm infection that is spread through raccoon feces.  Created: 8/27/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 8/28/2012.

  14. Alcohol Poisoning Deaths PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second Public Service Announcement is based on the January 2015 CDC Vital Signs report. In the United States, an average of six people die every day from alcohol poisoning. Learn what you can do to prevent binge drinking and alcohol poisoning.

  15. African American Health PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the May 2017 CDC Vital Signs report. The life expectancy of African Americans has improved, but it's still an average of four years less than whites. Learn what can be done so all Americans can have the opportunity to pursue a healthy lifestyle.

  16. Child Passenger Safety PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2014-02-04

    This 60 second public service announcement, based on the February 2014 Vital Signs release, discusses the importance of buckling up to reduce injuries and save lives.  Created: 2/4/2014 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 2/4/2014.

  17. NA60 frees the quarks

    CERN Multimedia

    2003-01-01

    Fitted with new state-of-the-art silicon detectors, NA60 is prepared to study the phase transition from confined hadronic matter to a deconfined (free) quark-gluon plasma, a state of matter which probably existed an instant after the Big Bang.

  18. ICRP 60 - the next step

    International Nuclear Information System (INIS)

    Harding, L.K.; Thomson, W.H.

    1993-01-01

    Following the publication in 1990 of the recommendations proposed by the International Commission on Radiological protection (ICRP 60), this editorial briefly highlights the advice given by the NRPB to UK government departments on how to implement those recommendations regarding occupational, medical and public exposure. (UK)

  19. 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.

  20. 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.

  1. Molecular and physiological responses to titanium dioxide and cerium oxide nanoparticles in Arabidopsis

    Science.gov (United States)

    - Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to two widely-used engineered metal oxide nanoparticles, titanium dioxide (nano-titanium) and cerium dioxide (nano-cerium). Microarray analyses confirmed that e...

  2. Challenges associated with performing environmental research on titanium dioxide nanoparticles in aquatic environments

    Science.gov (United States)

    There are challenges associated with performing research on titanium dioxide NPs in aquatic environments particularly marine systems. A critical focus for current titanium dioxide NP research in aquatic environments needs to be on optimizing methods for differentiating naturally...

  3. 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.

  4. 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

  5. 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.

  6. 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.)

  7. 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.)

  8. 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.

  9. 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.

  10. Optical properties of titanium di-oxide thin films prepared by dip coating method

    Science.gov (United States)

    Biswas, Sayari; Rahman, Kazi Hasibur; Kar, Asit Kumar

    2018-05-01

    Titanium dioxide (TiO2) thin films were prepared by sol-gel dip coating method on ITO coated glass substrate. The sol was synthesized by hydrothermal method at 90°C. The sol was then used to make TiO2 films by dip coating. After dip coating the rest of the sol was dried at 100°C to make TiO2 powder. Thin films were made by varying the number of dipping cycles and were annealed at 500°C. XRD study was carried out for powder samples that confirms the formation of anatase phase. Transmission spectra of thin films show sharp rise in the violet-ultraviolet transition region and a maximum transmittance of ˜60%. Band gap of the prepared films varies from 3.15 eV to 3.22 eV.

  11. Creep Damage Evaluation of Titanium Alloy Using Nonlinear Ultrasonic Lamb Waves

    International Nuclear Information System (INIS)

    Xiang Yan-Xun; Xuan Fu-Zhen; Deng Ming-Xi; Chen Hu; Chen Ding-Yue

    2012-01-01

    The creep damage in high temperature resistant titanium alloys Ti60 is measured using the nonlinear effect of an ultrasonic Lamb wave. The results show that the normalised acoustic nonlinearity of a Lamb wave exhibits a variation of the 'increase-decrease' tendency as a function of the creep damage. The influence of microstructure evolution on the nonlinear Lamb wave propagation has been analyzed based on metallographic studies, which reveal that the normalised acoustic nonlinearity increases due to a rising of the precipitation volume fraction and the dislocation density in the early stage, and it decreases as a combined result of dislocation change and micro-void initiation in the material. The nonlinear Lamb wave exhibits the potential for the assessment of the remaining creep life in metals

  12. Nanocomposites based on thermoplastic elastomers with functional basis of nano titanium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Yulovskaya, V. D.; Kuz’micheva, G. M., E-mail: galina-kuzmicheva@list.ru [Federal State Budget Educational Institution of Higher Education “Moscow Technological University” (Russian Federation); Klechkovskaya, V. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Orekhov, A. S.; Zubavichus, Ya. V. [National Research Centre “Kurchatov Institute” (Russian Federation); Domoroshchina, E. N.; Shegay, A. V. [Federal State Budget Educational Institution of Higher Education “Moscow Technological University” (Russian Federation)

    2016-03-15

    Nanocomposites based on a thermoplastic elastomer (TPE) (low-density polyethylene (LDPE) and 1,2-polybutadiene in a ratio of 60/40) with functional titanium dioxide nanoparticles of different nature, TiO{sub 2}/TPE, have been prepared and investigated by a complex of methods (X-ray diffraction analysis using X-ray and synchrotron radiation beams, scanning electron microscopy, transmission electron microscopy, and X-ray energy-dispersive spectroscopy). The morphology of the composites is found to be somewhat different, depending on the TiO{sub 2} characteristics. It is revealed that nanocomposites with cellular or porous structures containing nano-TiO{sub 2} aggregates with a large specific surface and large sizes of crystallites and nanoparticles exhibit the best deformation‒strength and fatigue properties and stability to the effect of active media under conditions of ozone and vapor‒air aging.

  13. Joining of dissimilar metals by diffusion bonding. Titanium alloy with aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Akca, Enes [International Univ. of Sarajevo (Bosnia and Herzegovina). Research and Development Center; International Univ. of Sarajevo (Bosnia and Herzegovina). Dept. of Mechanical Engineering; Gursel, Ali [International Univ. of Sarajevo (Bosnia and Herzegovina). Dept. of Mechanical Engineering

    2017-05-01

    This paper presents a novel diffusion bonding process of commercially pure aluminum to Ti-6Al-4V alloy at 520, 560, 600 and 640 C for 30, 45 and 60 minutes under argon gas shielding without the use of interlayer. The approach is to overcome the difficulties in fusion welding of dissimilar alloys. Diffusion bonding is a dissimilar metal welding process which can be applied to the materials without causing any physical deformations. Processed samples were metallographically prepared, optically examined followed by Vickers microhardness test and subjected to tensile test in order to determine joint strength. Scanning electron microscopy and energy dispersive spectroscopy were used in this work to investigate the compositional changes across the joint region. Elemental composition of the region has been successfully defined between titanium alloy and aluminum. The maximum tensile strength was obtained from the samples bonded at the highest temperatures of 600 and 640 C.

  14. Degradation of orange dyes and carbamazepine by soybean peroxidase immobilized on silica monoliths and titanium dioxide.

    Science.gov (United States)

    Calza, Paola; Zacchigna, Dario; Laurenti, Enzo

    2016-12-01

    In this paper, the removal of three common dyes (orange I, orange II, and methylorange) and of the anticonvulsant drug carbamazepine from aqueous solutions by means of enzymatic and photocatalytic treatment was studied. Soybean peroxidase (SBP) was used as biocatalyst, both free in solution and immobilized on silica monoliths, and titanium dioxide as photocatalyst. The combination of the two catalysts led to a faster (about two to four times) removal of all the orange dyes compared to the single systems. All the dyes were completely removed within 2 h, also in the presence of immobilized SBP. As for carbamazepine, photocatalytic treatment prevails on the enzymatic degradation, but the synergistic effect of two catalysts led to a more efficient degradation; carbamazepine's complete disappearance was achieved within 60 min with combined system, while up to 2 h is required with TiO 2 only.

  15. Numerical Study of Mechanical Response of Pure Titanium during Shot Peening

    Science.gov (United States)

    Wang, Y. M.; Cheng, J. P.; Yang, H. P.; Zhang, C. H.

    2018-05-01

    Mechanical response of pure titanium impacted by a steel ball was simulated using finite element method to investigate stress and strain evolution during shot peening. It is indicated that biaxial residual stress was obtained in the surface layer while in the interior triaxial residual stress existed because the S33 was comparable to S11 and S22. With decreasing the depth from the top surface, the stress was higher during impacting, but the stress relief extent became more significant when the ball rebounded. Therefore the maximum residual stress was formed in the subsurface layer with depth of 130 μm. As for the residual strain, it is shown that the maximum residual strain LE33 was obtained at the depth of 60 μm corresponding to the maximum shear stress during impacting.

  16. Titanium recycling in the United States in 2004, chap. Y of Sibley, S.F., ed., Flow studies for recycling metal commodities in the United States

    Science.gov (United States)

    Goonan, Thomas G.

    2010-01-01

    As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the titanium metal fraction of the titanium economy, which generates and uses titanium metal scrap in its operations. Data for 2004 were selected to demonstrate the titanium flows associated with these operations. This report includes a description of titanium metal supply and demand in the United States to illustrate the extent of titanium recycling and to identify recycling trends. In 2004, U.S. apparent consumption of titanium metal (contained in various titanium-bearing products) was 45,000 metric tons (t) of titanium, which was distributed as follows: 25,000 t of titanium recovered as new scrap, 9,000 t of titanium as titanium metal and titanium alloy products delivered to the U.S. titanium products reservoir, 7,000 t of titanium consumed by steelmaking and other industries, and 4,000 t of titanium contained in unwrought and wrought products exported. Titanium recycling is concentrated within the titanium metals sector of the total titanium market. The titanium market is otherwise dominated by pigment (titanium oxide) products, which generate dissipative losses instead of recyclable scrap. In 2004, scrap (predominantly new scrap) was the source of roughly 54 percent of the titanium metal content of U.S.-produced titanium metal products.

  17. 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...

  18. Synthesis of self-detached nanoporous titanium-based metal oxide

    International Nuclear Information System (INIS)

    Hu, F.; Wen, Y.; Chan, K.C.; Yue, T.M.; Zhou, Y.Z.; Zhu, S.L.; Yang, X.J.

    2015-01-01

    In this study, self-detached nanoporous titanium-based metal oxide was synthesized for the first time by ultrafast anodization in a fluoride-free electrolyte containing 10% HNO 3 . The nanoporous oxide has through-holes with diameters ranging from 10 to 60 nm. The as-formed oxides are amorphous, and were transformed to crystalline structures by annealing. The performance of a dye sensitized solar cell using nanoporpous Ti–10Zr oxide (TZ10) was further studied. It was found that the TZ10 film could increase both the short-circuit current and the open-circuit photovoltage of the solar cell. The overall efficiency of the solar cell was 6.99%, an increase of 20.7% as compared to that using a pure TiO 2 (P25) film. - Graphical abstract: The nanoporous Ti–xZr(x=10, 30) oxide layers are fabricated by anodizing in a dilute nitric acid solvent. The power conversion efficiency of the DSSC by a covering of a Ti–10Zr thin film is increased by 20.7%, with an η of 7.69% , a short circuit current of 12.4 mA/cm 2 , a open circuit voltage of 0.833 V, and a fill factor of 0.679. - Highlights: • Self-detached nanoporous titanium-based metal (TiZr) oxide was synthesized. • The TiZr oxides have through-hole nanopores with diameters ranging from 10 to 60 nm. • The nanoporous Ti–10Zr oxide can improve the power conversion efficiency of a DSSC

  19. Synthesis of self-detached nanoporous titanium-based metal oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hu, F. [Advanced Manufacturing Technology Research Center, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University (Hong Kong); Jiangxi Key Laboratory of Advanced Ceramic Materials, School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jiangxi 343001 (China); Wen, Y. [Jiangxi Key Laboratory of Advanced Ceramic Materials, School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jiangxi 343001 (China); Chan, K.C., E-mail: mfkcchan@inet.polyu.edu.hk [Advanced Manufacturing Technology Research Center, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University (Hong Kong); Yue, T.M. [Advanced Manufacturing Technology Research Center, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University (Hong Kong); Zhou, Y.Z. [Jiangxi Key Laboratory of Advanced Ceramic Materials, School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jiangxi 343001 (China); Zhu, S.L.; Yang, X.J. [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2015-09-15

    In this study, self-detached nanoporous titanium-based metal oxide was synthesized for the first time by ultrafast anodization in a fluoride-free electrolyte containing 10% HNO{sub 3}. The nanoporous oxide has through-holes with diameters ranging from 10 to 60 nm. The as-formed oxides are amorphous, and were transformed to crystalline structures by annealing. The performance of a dye sensitized solar cell using nanoporpous Ti–10Zr oxide (TZ10) was further studied. It was found that the TZ10 film could increase both the short-circuit current and the open-circuit photovoltage of the solar cell. The overall efficiency of the solar cell was 6.99%, an increase of 20.7% as compared to that using a pure TiO{sub 2} (P25) film. - Graphical abstract: The nanoporous Ti–xZr(x=10, 30) oxide layers are fabricated by anodizing in a dilute nitric acid solvent. The power conversion efficiency of the DSSC by a covering of a Ti–10Zr thin film is increased by 20.7%, with an η of 7.69% , a short circuit current of 12.4 mA/cm{sup 2}, a open circuit voltage of 0.833 V, and a fill factor of 0.679. - Highlights: • Self-detached nanoporous titanium-based metal (TiZr) oxide was synthesized. • The TiZr oxides have through-hole nanopores with diameters ranging from 10 to 60 nm. • The nanoporous Ti–10Zr oxide can improve the power conversion efficiency of a DSSC.

  20. Electrochemical behavior of titanium implanted with platinum

    International Nuclear Information System (INIS)

    Thompson, N.G.; Lichter, B.D.; Appleton, B.R.; Kelly, E.J.; White, C.W.

    1979-01-01

    The following conclusions apply to Ti(Pt) near-surface alloys studied. (1) Open-circuit corrosion measurements show that accumulation of platinum may occur at a surface concentration of 0.32 atomic percent Pt while no accumulation occurs at 0.16 atomic percent Pt. However, these results do not allow a distinction as to cause of accumulation to be made between concentration effects and effects due to the presence of an oxide film. (2) Potentiostatic corrosion at -0.450 V (active corrosion) establish that little or no accumulation of platinum occurs at an oxide-free surface for concentrations less than 0.086 atomic percent Pt; whereas, a large amount of accumulation occurs for a distribution with a peak concentration of 0.83 atomic percent Pt. (3) An initial distribution having a peak concentration of 0.32 atomic percent platinum is sufficient to induce natural passivity in titanium and bring a freely corroding sample to a potential of 0.269 V. This is nearly the applicable reversible potential (-0.260 V) for the hydrogen reaction in 1N H 2 SO 4 . (4) Of three samples which showed accumulation, platinum was eventually lost for two of these samples (0.32 atomic percent, open-circuit corrosion; 0.83 atomic percent, potentiostatic corrosion). The remaining sample (9.1 atomic percent, open-circuit corrosion) maintained the maximum possible potential of -0.260 V for the length of the experiment (approx. 30 days). (5) For samples which had been polarized at -0.300 to -0.340 V and which had eventually reverted to the behavior of pure Ti, post corrosion RBS measurements reveal that a substantial fraction of the Pt fluence is retained on the surface in an electrochemically inactive state

  1. Mucin secretion induced by titanium dioxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Eric Y T Chen

    2011-01-01

    Full Text Available Nanoparticle (NP exposure has been closely associated with the exacerbation and pathophysiology of many respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD and asthma. Mucus hypersecretion and accumulation in the airway are major clinical manifestations commonly found in these diseases. Among a broad spectrum of NPs, titanium dioxide (TiO(2, one of the PM10 components, is widely utilized in the nanoindustry for manufacturing and processing of various commercial products. Although TiO(2 NPs have been shown to induce cellular nanotoxicity and emphysema-like symptoms, whether TiO(2 NPs can directly induce mucus secretion from airway cells is currently unknown. Herein, we showed that TiO(2 NPs (<75 nm can directly stimulate mucin secretion from human bronchial ChaGo-K1 epithelial cells via a Ca(2+ signaling mediated pathway. The amount of mucin secreted was quantified with enzyme-linked lectin assay (ELLA. The corresponding changes in cytosolic Ca(2+ concentration were monitored with Rhod-2, a fluorescent Ca(2+ dye. We found that TiO(2 NP-evoked mucin secretion was a function of increasing intracellular Ca(2+ concentration resulting from an extracellular Ca(2+ influx via membrane Ca(2+ channels and cytosolic ER Ca(2+ release. The calcium-induced calcium release (CICR mechanism played a major role in further amplifying the intracellular Ca(2+ signal and in sustaining a cytosolic Ca(2+ increase. This study provides a potential mechanistic link between airborne NPs and the pathoetiology of pulmonary diseases involving mucus hypersecretion.

  2. 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

  3. 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

  4. 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.

  5. Mechanohydrogen processing as an element of hydrogen process of production of titanium alloy parts

    International Nuclear Information System (INIS)

    Egorova, Yu.B.; Il'in, A.A.; Levochkin, A.A.

    2002-01-01

    The regularities of the effect of hydrogen on cutting machinability of titanium alloys are generalized. The main principles of mechanohydrogen treatment are founded. The effectiveness of titanium alloys machining with the use of reversible hydrogen alloying depends on hydrogen content, hydrogen pickup temperature and cutting modes. High-performance technological processes of manufacturing parts and constructions made of titanium alloys are proposed [ru

  6. Nickel-Titanium Wire as Suture Material: A New Technique for the Fixation of Skin.

    Science.gov (United States)

    Li, Haidong; Song, Tao

    2018-01-29

    To introduce nickel-titanium wire as suture material for closure of incisions in cleft lip procedures. Closure of skin incisions using nickel-titanium wire as suture material, with postoperative follow-up wound evaluation. There was excellent patient satisfaction and good cosmetic outcome. Nickel-titanium wire is an excellent alternative for suture closure of cleft lip surgical incisions.

  7. 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

  8. 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...

  9. Investigation into boron reaction with titanium at extreme temperature gradients

    International Nuclear Information System (INIS)

    Korchagin, M.A.; Gusenko, S.N.; Aleksandrov, V.V.; Neronov, V.A.

    1981-01-01

    The mechanism of self-propagation high-temperature synthesis of titanium boride is studied using the translucent electron microscopy. Titanium interaction with boron film (approximately 1000 A thick) starts with the metal partial melting. A twozone layer of the reaction products, separating the reagents, is formed. In the zone adjacent to B, Ti 3 B 4 and fusible liquid phases are present. The second zone consists of TiB. The subsequent interaction is realized by Means of the dissolving and absorption by titanium of the layer of products during its continuous increase in boron. TiB 2 formation takes place at subsequent stages of interaction inside Ti liquid particles during their saturation by boron from the products absorbed [ru

  10. Effects of service environments on aluminum-brazed titanium (ABTi)

    Science.gov (United States)

    Cotton, W. L.

    1978-01-01

    Aluminum brazed titanium (ABTi) structures were evaluated during prolonged exposure to extreme environments: elevated temperature exposure to airline service fluids, hydraulic fluid, and seawater, followed by laboratory corrosion tests. Solid-face and perforated face honeycomb sandwich panel specimens, stressed panel assemblies, and faying surface brazed joints were tested. The corrosion resistance of ABTi is satisfactory for commercial airline service. Unprotected ABTi proved inherently resistant to attack by all of the extreme service aircraft environments except: seawater at 700 K (800 F) and above, dripping phosphate ester hydraulic fluid at 505 K (450 F), and a marine environment at ambient temperature. The natural oxides and deposits present on titanium surfaces in airline service provide protection against hot salt corrosion pitting. Coatings are required to protect titanium dripping phosphate ester fluid at elevated temperatures and to protect exposed acoustic honeycomb parts against corrosion in a marine environment.

  11. New Nomenclatures for Heat Treatments of Additively Manufactured Titanium Alloys

    Science.gov (United States)

    Baker, Andrew H.; Collins, Peter C.; Williams, James C.

    2017-07-01

    The heat-treatment designations and microstructure nomenclatures for many structural metallic alloys were established for traditional metals processing, such as casting, hot rolling or forging. These terms do not necessarily apply for additively manufactured (i.e., three-dimensionally printed or "3D printed") metallic structures. The heat-treatment terminology for titanium alloys generally implies the heat-treatment temperatures and their sequence relative to a thermomechanical processing step (e.g., forging, rolling). These designations include: β-processing, α + β-processing, β-annealing, duplex annealing and mill annealing. Owing to the absence of a thermomechanical processing step, these traditional designations can pose a problem when titanium alloys are first produced via additive manufacturing, and then heat-treated. This communication proposes new nomenclatures for heat treatments of additively manufactured titanium alloys, and uses the distinct microstructural features to provide a correlation between traditional nomenclature and the proposed nomenclature.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. Process for titanium powders spheroidization by RF induction plasma

    International Nuclear Information System (INIS)

    Gu Zhongtao; Ye Gaoying; Liu Chuandong; Tong Honghui

    2010-01-01

    Spherical titanium (Ti) particles were obtained by the process of heating irregularly shaped Ti powders under the radio frequency induction plasma (RF induction plasma) condition. The effect of feed rate, various dispersion methods and Ti particle size on the spheroidization efficiency was studied. The efficiency of the spheroidization is evaluated through the measurements of the percentage of powder spheroidized based on the electron microscopic observations and the tap density measurement of the processed powder. During the short flight of the particles in the plasma flow, of the order of a few milliseconds, the individual titanium particles of the powder are heated and melt, forming a spherical liquid droplet which upon freezing gives rise to the formation of a perfectly dense spherical solid particle. So RF induction plasma is a promising method for the preparation of spherical titanium powders with high flow ability. (authors)

  18. Superficial characterization of titanium league when submitted to abrasive blasting

    International Nuclear Information System (INIS)

    Suzuki, L.Y.; Leite, I.V.; Szesz, E.M.; Siqueira, C.J.M.

    2010-01-01

    Commercially pure titanium and some of its alloys exhibit a good biocompatibility. These characteristics are frequently used in the manufacture of orthopedic and dental implants. It is possible to modify its surface making it the bioactive using various methods, such as deposition of hydroxyapatite by plasma spray and increasing the roughness of the surface by abrasive blasting. This work is to modify the surface of titanium alloy Ti6Al4V ELI (ASTM F136: 02a) for abrasive blasting and study the morphology, crystallographic phases and the mechanical characteristics of the surface obtained. For such purpose, SEM images, diffraction of X-rays and tests of risk produced by nanoindenter. The sandblasting was done using alumina powder and blasting time of 6s. The morphology of the surfaces of Ti6Al4V ELI changed after sandblasting with increased roughness. It is possible to conclude that after sandblasting the titanium surface do not have a ductile behavior. (author)

  19. 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

  20. Discharge optimization in JT-60

    International Nuclear Information System (INIS)

    Ninomiya, H.; Hosogane, N.; Kikuchi, M.; Yoshino, R.; Seki, S.; Kurihara, K.; Kimura, T.; Shimada, R.; Matsukawa, M.

    1986-01-01

    For the optimization of the feedback control gains of the plasma control system in JT-60, the plasma modelling by the regression analysis, the matrix transfer function analysis and the simulation study are performed. The experimental results of plasma control are well consistent with these estimations and the usefulness of a modelling by the regression analysis, the matrix transfer function analysis and the simulation study is experimentally confirmed. It is also shown that the regression analysis is useful for development of the sensor algorithm of plasma shape and location of separatrix line in a feedback control system. Some topics are also presented about plasma engineering obtained in JT-60: possibility to suppress the uncontrollability of plasma density, αI/sub p/ control for plasma position and volt-sec consumption