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Sample records for body titanium alloy

  1. Titanium and titanium alloy forgings

    International Nuclear Information System (INIS)

    The specification covers nine grades of annealed titanium and titanium alloy forgings as follows: Grade F-1, F-2, F-3, and F-4 unalloyed titanium; Grade F-5 titanium alloy (6% aluminum, 4% vanadium); Grade F-6 titanium alloy (5% aluminum, 2.5% tin); Grade F-7 and F-11 unalloyed titanium plus palladium; Grade F-12 titanium alloy (0.3% molybdenum, 0.8% nickel). The specification includes ordering information, manufacture, chemical requirements, mechanical requirements, nondestructive tests, dimensions and permissible variations, finish, certification, packaging, and marking

  2. Superplasticity in titanium alloys

    OpenAIRE

    J. Sieniawski; Motyka, M.

    2007-01-01

    Purpose: The paper reports characteristic of superplasticity phenomenon in titanium alloys and possibility of its applications.Design/methodology/approach: The main objective of the paper is to show features of superplastic forming of titanium alloys and current research trends aiming at widespread application of this technology.Findings: In the paper characteristic of selected superplastic titanium alloys was presented. The effect of microstructural parameters on superplasticity was consider...

  3. 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.

  4. IN VIVO SEVERE CORROSION AND HYDROGEN EMBRITTLEMENT OF RETRIEVED MODULAR BODY TITANIUM ALLOY HIP-IMPLANTS

    OpenAIRE

    Danieli C. Rodrigues; Urban, Robert M.; Jacobs, Joshua J; Gilbert, Jeremy L.

    2009-01-01

    Titanium alloys are widely used in total-joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differen...

  5. Productive Machining of Titanium Alloys

    OpenAIRE

    Čejka, Libor

    2013-01-01

    This diploma thesis is focused on a productive machining of titanium alloys. At the beginning it deals about titanium and its alloys. It describes chip generation mechanism, tool blunting and surface quality. Further it contains modern strategies of efficient titanium alloys machining. Then it analyzes contemporary manufacturing technology of hinge made of titanium alloy Ti-6Al-4V in Frentech Aerospace s.r.o. company, and at the end finds possibility of savings by inovation of roughing process.

  6. Microstructure and Slip Character in Titanium Alloys

    OpenAIRE

    Banerjee, D.; Williams, J. C.

    1986-01-01

    Influence of microstructures in titanium alloys on the basic parameters of deformation behaviour such as slip character, slip length and slip intensity have been explored. Commercial titanium alloys contain the hexagonal close packed (alpha) and body centred cubic (bita) phases. Slip in these individual phases is shown to be dependent on the nature of alloying elements through their effect on phase stability as related to decomposition into ordered or w structures. When alpha and bita coexist...

  7. Machining of Titanium Alloys

    OpenAIRE

    Karásek, Jan

    2008-01-01

    The main goal of this work is the analysis of manufacturing costs for the component of wheel´s blower. Followed by setting up the size of specific cutting force for milling operation of the titanium alloy Ti-Al6-Mo2-Cr2-Fe-Si, the used tool was a milling cutter which is made out of sintered carbide with conical and spherical face. The final values which are at intervals of 1500 to 1800 MPa were compared with the values of the Sandvik Coromant firm kc = 1690 MPa, for titanium alloy with the st...

  8. Titanium and titanium alloys fundamentals and applications

    CERN Document Server

    Peters, Manfred

    2003-01-01

    This handbook is an excellent reference for materials scientists and engineers needing to gain more knowledge about these engineering materials. Following introductory chapters on the fundamental materials properties of titanium, readers will find comprehensive descriptions of the development, processing and properties of modern titanium alloys. There then follows detailed discussion of the applications of titanium and its alloys in aerospace, medicine, energy and automotive technology.

  9. High-temperature Titanium Alloys

    OpenAIRE

    A.K. Gogia

    2005-01-01

    The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase eq...

  10. In vivo severe corrosion and hydrogen embrittlement of retrieved modular body titanium alloy hip-implants.

    Science.gov (United States)

    Rodrigues, Danieli C; Urban, Robert M; Jacobs, Joshua J; Gilbert, Jeremy L

    2009-01-01

    Titanium alloys are widely used in total-joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity, and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differential aeration of the surface. Titanium alloys are also known to be susceptible to hydrogen absorption, which can induce precipitation of hydrides and subsequent brittle failure. In this work, the surface of three designs of retrieved hip-implants with Ti-6Al-4V/Ti-6Al-4V modular taper interfaces in the stem were investigated for evidence of severe corrosion and precipitation of brittle hydrides during fretting-crevice corrosion in the modular connections. The devices were retrieved from patients and studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), and chemical analysis. The surface qualitative investigation revealed severe corrosion attack in the mating interfaces with evidence of etching, pitting, delamination, and surface cracking. In vivo hydrogen embrittlement was shown to be a mechanism of degradation in modular connections resulting from electrochemical reactions induced in the crevice environment of the tapers during fretting-crevice corrosion. PMID:18683224

  11. High-temperature Titanium Alloys

    Directory of Open Access Journals (Sweden)

    A.K. Gogia

    2005-04-01

    Full Text Available The development of high-temperature titanium alloys has contributed significantly to the spectacular progress in thrust-to-weight ratio of the aero gas turbines. This paper presents anoverview on the development of high-temperature titanium alloys used in aero engines and potential futuristic materials based on titanium aluminides and composites. The role of alloychemistry, processing, and microstructure, in determining the mechanical properties of titanium alloys is discussed. While phase equilibria and microstructural stability consideration haverestricted the use of conventional titanium alloys up to about 600 "C, alloys based on TiPl (or,, E,AINb (0, TiAl (y, and titaniumltitanium aluminides-based composites offer a possibility ofquantum jump in the temperature capability of titanium alloys.

  12. Hydrogen in titanium alloys

    International Nuclear Information System (INIS)

    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 5000C. 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 1500C 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

  13. 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

  14. Titanium and titanium alloy strip, sheet, and plate

    International Nuclear Information System (INIS)

    The specification covers annealed titanium and titanium alloy strip, sheet, and plate as follows: Grade 1 to 4 unalloyed titanium Grade 5, 6, 10, and 12 titanium alloy; and Grade 7 and 11 unalloyed titanium plus palladium. The specification includes basis of purchase, chemical requirements, mechanical properties, permissible variations in dimensions, finish, sampling for chemical analysis, methods of chemical analysis, rejection, reports, marking, and packaging

  15. Fiber reinforced titanium alloy composites

    International Nuclear Information System (INIS)

    The more important titanium matrix composites studied to date are composed of titanium alloy matrices, such as Ti 6Al--4V, reinforced with filaments of boron, silicon carbide, or sapphire, as well as with wires of beryllium or refractory metal alloys. The primary fabrication techniques for these materials involve vacuum hot pressing at 1300 to 16000F, alternate layers of titanium alloy matrix foils, and suitably aligned filament mats. The more ductile reinforcements such as beryllium, have been incorporated into titanium matrix composites by coextrusion. Fabrication of composite gas turbine engine fan blades from both boron (SiC coated) and beryllium reinforced Ti 6Al--4V alloy is described. Feasibility studies have been made in the fabrication of Boron/Ti 6Al--4V composite rings for possible gas turbine engine disc applications. Mechanical properties of various titanium matrix composite systems are presented and demonstrate the attractive elevated temperature properties of some systems to 10000F. (35 fig, 6 tables) (U.S.)

  16. LASER GAS NITRIDING OF TITANIUM AND TITANIUM ALLOYS

    OpenAIRE

    J. J. DAI; Hou, S. Q.

    2009-01-01

    Titanium and titanium alloys are widely used in many fields due to some of their characteristics such as light density, high strength, and excellent corrosion resistance. However, poor mechanical performances limit their practical applications. Laser gas nitriding is a promising method used to improve the surface properties of components. Recent developments on laser gas nitriding of titanium and titanium alloys are reviewed. The processing parameters have important effects on the resulting c...

  17. Nanodispersed boriding of titanium alloy

    International Nuclear Information System (INIS)

    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 T2B, TiB, TiB2 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

  18. Tensile and creep properties of titanium-vanadium, titanium-molybdenum, and titanium-niobium alloys

    Science.gov (United States)

    Gray, H. R.

    1975-01-01

    Tensile and creep properties of experimental beta-titanium alloys were determined. Titanium-vanadium alloys had substantially greater tensile and creep strength than the titanium-niobium and titanium-molybdenum alloys tested. Specific tensile strengths of several titanium-vanadium-aluminum-silicon alloys were equivalent or superior to those of commercial titanium alloys to temperatures of 650 C. The Ti-50V-3Al-1Si alloy had the best balance of tensile strength, creep strength, and metallurgical stability. Its 500 C creep strength was far superior to that of a widely used commercial titanium alloy, Ti-6Al-4V, and almost equivalent to that of newly developed commercial titanium alloys.

  19. Beta titanium alloys and their role in the titanium industry

    Science.gov (United States)

    Bania, Paul J.

    1994-07-01

    The class of titanium alloys generically referred to as the beta alloys is arguably the most versatile in the titanium family. Since these alloys offer the highest strength-to-weight ratios and deepest hardenability of all titanium alloys, one might expect them to compete favorably for a variety of aerospace applications. To the contrary, however, except for one very successful application (Ti-13V-11Cr-3Al on the SR-71), the beta alloys have remained a very small segment of the industry. As a perspective on this situation, this article reviews some past and present applications of titanium alloys. It also descibes some unique new alloys and applications that promise to reverse historical trends.

  20. Lightweight Protective Coatings For Titanium Alloys

    Science.gov (United States)

    Wiedemann, Karl E.; Taylor, Patrick J.; Clark, Ronald K.

    1992-01-01

    Lightweight coating developed to protect titanium and titanium aluminide alloys and titanium-matrix composite materials from attack by environment when used at high temperatures. Applied by sol-gel methods, and thickness less than 5 micrometers. Reaction-barrier and self-healing diffusion-barrier layers combine to protect titanium alloy against chemical attack by oxygen and nitrogen at high temperatures with very promising results. Can be extended to protection of other environmentally sensitive materials.

  1. Titanium alloys Russian aircraft and aerospace applications

    CERN Document Server

    Moiseyev, Valentin N

    2005-01-01

    This text offers previously elusive information on state-of-the-art Russian metallurgic technology of titanium alloys. It details their physical, mechanical, and technological properties, as well as treatments and applications in various branches of modern industry, particularly aircraft and aerospace construction. Titanium Alloys: Russian Aircraft and Aerospace Applications addresses all facets of titanium alloys in aerospace and aviation technology, including specific applications, fundamentals, composition, and properties of commercial alloys. It is useful for all students and researchers interested in the investigation and applications of titanium.

  2. Recycling potential of titanium alloys

    International Nuclear Information System (INIS)

    This study examines just how long one must contain radioactive titanium before it can be safely reprocessed. It was assumed that the spent first wall and blanket structural material would be completely reprocessed in a standard manufacturing facility capable of both primary and secondary fabrication. It was found that reprocessing could occur when the chemical hazard associated with inhalation was greater than the hazard associated with inhalating the same amount of radioactive species. This conclusion allowed the use of the threshold limiting value (TLV) to set a limit on the airborne concentration of the elements. Then by calculating the time required for that amount of material to decay to the same diluent factor indicated by the biological hazard potential (BHP) in air, the time for reprocessing was determined. Based on these assumptions, it was determined that it is feasible to think of titanium, and some of its alloying elements as being recyclable in a relatively short time period

  3. Laser repair hardfacing of titanium alloy turbine

    OpenAIRE

    A. Klimpel; D. Janicki; A. Lisiecki; A. Rzeźnikiewicz

    2011-01-01

    Purpose: of this paper: work out repair technology of worn abutments of aircraft jet engine blades forged of titanium alloy WT3-1.Design/methodology/approach: The study were based on the analysis of laser HPDL powder surfacing of titanium alloy plates using wide range chemical composition consumables of titanium alloys and mixtures of pure titanium and spherical powder of WC indicated that very hard and highest quality deposits are provided by powder mixture of 40-50%Ti+60-50%WC.Findings: It ...

  4. Corrosion resistance of titanium alloys for dentistry

    International Nuclear Information System (INIS)

    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)

  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. 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.

  7. Casting of Titanium and its Alloys

    Directory of Open Access Journals (Sweden)

    R. L. Saha

    1986-04-01

    Full Text Available 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.

  8. Effect of titanium content and aging temperature on the properties of uranium-titanium alloys

    International Nuclear Information System (INIS)

    The mechanical properties and microstructures of four uranium-titanium alloys were examined as functions of titanium content and aging temperature. Titanium alloy content was varied from 0.41 to 0.79 weight percent. Aging temperatures from 350 to 4500C (all for six hours) were evaluated for each alloy in addition to tests in the unaged conditions. Titanium and aging temperature were both shown to be strong effects in determining alloy properties. It was determined that the uranium-0.41 weight percent titanium alloy underwent extensive age-hardening even though the alloy did not exhibit a martensitic microstructure characteristic of the alloys richer in titanium

  9. Initial cytotoxicity of novel titanium alloys.

    Science.gov (United States)

    Koike, M; Lockwood, P E; Wataha, J C; Okabe, T

    2007-11-01

    We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super-TIX(R) 800, Super-TIX(R) 51AF, TIMETAL(R) 21SRx, and Ti-6Al-4V (ASTM grade 5)] and three experimental titanium alloys [Ti-13Cr-3Cu, Ti-1.5Si and Ti-1.5Si-5Cu] were tested. Specimens (n = 6; 5.0 x 5.0 x 3.0 mm(3)) were cast in a centrifugal casting machine using a MgO-based investment and polished to 600 grit, removing 250 mum from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short-term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments. PMID:17385227

  10. An Oxygen-Permeation Treatment for Hardening Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    MA Hong-yan; WANG Mao-cai; WEI Zheng; XIN Gong-chun

    2004-01-01

    In this paper, the characterization of oxygen permeation (OP) in titanium alloy TC11 at high temperature and the influence of oxygen solution layer on performances of substrate were characterized with the help of apparatus, such as TGA,SEM/EDAX, XRD, EPMA, Micro-hardness Tester, Two-body Abrasion Tester, Amsler Wear Test Machine, Potentiostat/Galvanostat Model 273 system. The results showed that there was a little shift in X-ray diffraction peaks of α and β phase during the OPT process as a result of oxygen solution. The OP treatment can significantly increase the surface hardness of titanium alloys and, accordingly, the abrasive wear resistance was improved. Titanium alloys with oxygen solution layer exhibited improved corrosion resistance both in 3.5 % NaCl and in 5 % HCl solution. Oxidation resistance of TC11 with oxygen solution layer at high temperature was also enhanced. The solution and hardening mechanisms were discussed based on the experimental results.

  11. Electrochemical Behavior of Titanium and Its Alloys as Dental Implants in Normal Saline

    OpenAIRE

    Olson, David L.; Brajendra Mishra; Shaily M. Bhola; Rahul Bhola

    2009-01-01

    The electrochemical behavior of pure titanium and titanium alloys in a simulated body fluid (normal saline solution) has been tested, and the results have been reported. The significance of the results for dental use has been discussed. The tests also serve as a screening test for the best alloy system for more comprehensive long-term investigations.

  12. Oxidation resistant coating for titanium alloys and titanium alloy matrix composites

    Science.gov (United States)

    Brindley, William J. (Inventor); Smialek, James L. (Inventor); Rouge, Carl J. (Inventor)

    1992-01-01

    An oxidation resistant coating for titanium alloys and titanium alloy matrix composites comprises an MCrAlX material. M is a metal selected from nickel, cobalt, and iron. X is an active element selected from Y, Yb, Zr, and Hf.

  13. Double Glow Plasma Surface Alloyed Burn-resistant Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping-ze; XU Zhong; HE Zhi-yong; ZHANG Gao-hui

    2004-01-01

    Conventional titanium alloy may be ignited and burnt under high temperature, high pressure and high gas flow velocity condition. In order to avoid this problem, we have developed a new kind of burn-resistant titanium alloy-double glow plasma surface alloying burn-resistant titanium alloy. Alloying element Cr, Mo, Cu are induced into the Ti-6Al-4V and Ti-6.5Al-0.3Mo-l.5Zr-0.25Si substrates according to double glow discharge phenomenon, Ti-Cr ,Ti-Mo, Ti-Cu binary burn-resistant alloy layers are formed on the surface of Ti-6Al-4V and Ti-6.5Al-0.3Mo-l.5Zr-0.25Si alloys. The depth of the surface burn-resistant alloy layer can reach to above 200 microns and alloying element concentration can reach 90%.Burn-resistant property experiments reveal that if Cr concentration reach to 14%, Cu concentration reach to 12%, Mo concentration reach to 10% in the alloying layers, ignition and burn of titanium alloy can be effectively avoided.

  14. Double Glow Plasma Surface Alloyed Burn-resistant Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANGPing-ze; XUZhong; HEZhi-yong; ZHANGGao-hui

    2004-01-01

    Conventional titanium alloy may be ignited and burnt under high temperature, high pressure and high gas flow velocity condition. In order to avoid this problem, we have developed a new kind of burn-resistant titanium alloy-double glow plasma surface alloying burn-resistant titanium alloy. Alloying element Cr, Mo, Cu are induced into the Ti-6A1-4V and Ti-6.5Al-0.3Mo-1.5Zr-0.25Si substrates according to double glow discharge phenomenon, Ti-Cr ,Ti-Mo, Ti-Cu binary burn-resistant alloy layers are formed on the surface of Ti-6A1-4V and Ti-6.5Al-0.3Mo-1.5Zr-0.25Si alloys. The depth of the surface burn-resistant alloy layer can reach to above 200 microns and alloying element concentration can reach 90%. Burn-resistant property experiments reveal that if Cr concentration reach to 14%, Cu concentration reach to 12%, Mo concentration reach to 10% in the alloying layers, ignition and burn of titanium alloy can be effectively avoided.

  15. Passivation of alloys on titanium base

    International Nuclear Information System (INIS)

    Results of passivation studies on Ti-base alloys show that the inhibition of anodic processes on these alloys is determined not by the total thickness of passive film, but by its barrier layer. The protective properties of the barrier layer increase if the passive film is formed at anodic potentials more positive than +1.4V. They were determined not by chemical stability of barrier layer, but by an inhibition which is produced by this layer for ionic current along the anodic direction. The protective properties are related to character defectiveness and semiconductor properties of the barrier layer. Additions of Al, V, Mo, Zr, and Nb to titanium increase the anodic current in the passive state. Additions of Cr and Mn decrease this current, and Sn does not influence it. The direct electrochemical transition of titanium ions into solution (as TiO2+) is a main anodic process of titanium dissolution and its low alloyed alloys in the passive state. Double phase titanium alloys (after tempering) have a lower corrosion resistance than those in the homogeneous single phase state (after hardening). The less passive phase of double phase alloys dissolves perferentially. The less passive phases are: in the active state, α-phase; in transpassive state for Ti--Mo alloys, β-phase, containing in a high Mo percentage; and for Ti--Cr alloys, γ-phase, having more chromium. (U.S.)

  16. On Silicides in High Temperature Titanium Alloys

    OpenAIRE

    Ramachandra, C.; Vakil Singh; P. Rama Rao

    1986-01-01

    High temperature titanium alloys like IMI 685 contain small amounts of silicon (~ 0.25 wt. per cent) to improve creep resistance. Different types of silicides, namely Ti5Si3 (TiZr)5Si3(S1) and (TiZr)6 Si3 (S2), have been observed to precipitate in various silicon-bearing titanium alloys depending upon their composition and heat treatment. The precipitation of silicides, their orientation relationship with the matrix in different alloys, and the beneficial influence of thermo-mechanical treatm...

  17. Titanium alloys. Advances in alloys, processes, products and applications

    OpenAIRE

    Blenkinsop, P.

    1993-01-01

    The last few years have been a period of consolidation of existing alloys and processes. While the aerospace industry remains the principal driving force for alloy development, the paper illustrates examples of new markets being established in "older" alloys, by a combination of product/process development and a re-examination of engineering design parameters. Considerable attention is still being directed towards the titanium aluminide systems, but other more conventional alloy developments ...

  18. Advances of Titanium Alloys and Its Biological Surface Modification

    Institute of Scientific and Technical Information of China (English)

    XU Ke-wei; HUANG Ping

    2004-01-01

    This paper reviews the past, present and future of surface modification of titanium alloy from the point of view of preparation of hard tissue replacement implants. The development of titanium alloy is also described.

  19. The Progress on Laser Surface Modification Techniques of Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    LIANG Cheng; PAN Lin; Al Ding-fei; TAO Xi-qi; XIA Chun-huai; SONG Yan

    2004-01-01

    Titanium alloy is widely used in aviation, national defence, automobile, medicine and other fields because of their advantages in lower density, corrosion resistance, and fatigue resistance etc. As titanium alloy is higher friction coefficients, weak wear resistance, bad high temperature oxidation resistance and lower biocompatibility, its applications are restricted. Using laser surface modification techniques can significantly improve the surface properties of titanium alloy. a review is given for progress on laser surface modification techniques of titanium alloy in this paper.

  20. Development and application of titanium alloy casting technology in China

    Institute of Scientific and Technical Information of China (English)

    NAN Hai; XIE Cheng-mu; ZHAO Jia-qi

    2005-01-01

    The development and research of titanium cast alloy and its casting technology, especially its application inaeronautical industry in China are presented. The technology of molding, melting and casting of titanium alloy, casting quality control are introduced. The existing problems and development trend in titanium alloy casting technology are also discussed.

  1. Effect of whitening toothpaste on titanium and titanium alloy surfaces

    Directory of Open Access Journals (Sweden)

    Adriana Cláudia Lapria Faria

    2012-12-01

    Full Text Available Dental implants have increased the use of titanium and titanium alloys in prosthetic applications. Whitening toothpastes with peroxides are available for patients with high aesthetic requirements, but the effect of whitening toothpastes on titanium surfaces is not yet known, although titanium is prone to fluoride ion attack. Thus, the aim of the present study was to compare Ti-5Ta alloy to cp Ti after toothbrushing with whitening and conventional toothpastes. Ti-5Ta (%wt alloy was melted in an arc melting furnace and compared with cp Ti. Disks and toothbrush heads were embedded in PVC rings to be mounted onto a toothbrushing test apparatus. A total of 260,000 cycles were carried out at 250 cycles/minute under a load of 5 N on samples immersed in toothpaste slurries. Surface roughness and Vickers microhardness were evaluated before and after toothbrushing. One sample of each material/toothpaste was analyzed by Scanning Electron Microscopy (SEM and compared with a sample that had not been submitted to toothbrushing. Surface roughness increased significantly after toothbrushing, but no differences were noted after toothbrushing with different toothpastes. Toothbrushing did not significantly affect sample microhardness. The results suggest that toothpastes that contain and those that do not contain peroxides in their composition have different effects on cp Ti and Ti-5Ta surfaces. Although no significant difference was noted in the microhardness and roughness of the surfaces brushed with different toothpastes, both toothpastes increased roughness after toothbrushing.

  2. Rapidly solidified titanium alloys by melt overflow

    Science.gov (United States)

    Gaspar, Thomas A.; Bruce, Thomas J., Jr.; Hackman, Lloyd E.; Brasmer, Susan E.; Dantzig, Jonathan A.; Baeslack, William A., III

    1989-01-01

    A pilot plant scale furnace was designed and constructed for casting titanium alloy strips. The furnace combines plasma arc skull melting techniques with melt overflow rapid solidification technology. A mathematical model of the melting and casting process was developed. The furnace cast strip of a suitable length and width for use with honeycomb structures. Titanium alloys Ti-6Al-4V and Ti-14Al-21 Nb were successfully cast into strips. The strips were evaluated by optical metallography, microhardness measurements, chemical analysis, and cold rolling.

  3. Current research situation of titanium alloys in China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Titanium and its alloys possess excellent comprehensive properties, and they are widely used in many fields. China pays great attentions to the research on new titanium alloys. This paper mainly reviews the research on new Ti alloys in China, for example, high strength and high toughness Ti alloys, burn resistant Tialloys, high temperature Ti alloys, low cost Ti alloys and so on.New basic theories on Ti alloys developed in China in recent years are also reviewed.

  4. Environmental Studies on Titanium Aluminide Alloys

    Science.gov (United States)

    Brindley, William J.; Bartolotta, Paul A.; Smialek, James L.; Brady, Michael P.

    2005-01-01

    Titanium aluminides are attractive alternatives to superalloys in moderate temperature applications (600 to 850 C) by virtue of their high strength-to-density ratio (high specific strength). These alloys are also more ductile than competing intermetallic systems. However, most Ti-based alloys tend to degrade through interstitial embrittlement and rapid oxidation during exposure to elevated temperatures. Therefore, their environmental behavior must be thoroughly investigated before they can be developed further. The goals of titanium aluminide environmental studies at the NASA Lewis Research Center are twofold: characterize the degradation mechanisms for advanced structural alloys and determine what means are available to minimize degradation. The studies to date have covered the alpha 2 (Ti3Al), orthorhombic (Ti2AlNb), and gamma (TiAl) classes of alloys.

  5. On Silicides in High Temperature Titanium Alloys

    Directory of Open Access Journals (Sweden)

    C. Ramachandra

    1986-04-01

    Full Text Available High temperature titanium alloys like IMI 685 contain small amounts of silicon (~ 0.25 wt. per cent to improve creep resistance. Different types of silicides, namely Ti5Si3 (TiZr5Si3(S1 and (TiZr6 Si3 (S2, have been observed to precipitate in various silicon-bearing titanium alloys depending upon their composition and heat treatment. The precipitation of silicides, their orientation relationship with the matrix in different alloys, and the beneficial influence of thermo-mechanical treatment on the distribution of silicides have been pointed out. The effect of silicides on mechanical properties and fracture of the commercial alloy IMI 685 is also indicated.

  6. DEVELOPMENT OF OXIDATION RESISTANT TITANIUM ALLOYS BY NIOBIUM ADDITION

    OpenAIRE

    Ackland, Graeme; Siemers, Carsten; Tegner, Bengt E.; Saksl, K.; Brunke, F.; Kohnke, M,

    2014-01-01

    The application of titanium alloys is limited to 550°C due to their poor oxidation resistance. It is known that the addition of niobium improves the oxidation resistance of titanium whereas elements like vanadium do not support titanium’s oxidation behaviour. Hence, the underlying mechanisms are not understood. In the present study, different binary titanium-niobium and titanium-vanadium alloys as well as commercially pure titanium were investigated. Oxidation experiments were carried out at ...

  7. Diffusion welding of commercial titanium alloys

    International Nuclear Information System (INIS)

    The weldability is studied of several industrial titanium alloys variously combined one to another in vacuum diffusion welding. Experimental results have been analyzed with reference to a model of electron localization. It is shown that the weldability is best in pairs, in which the electron exchange is conducive to electron localization, whereas the optimum temperatures of welding are those which enhance electron localization

  8. Copper and nickel adherently electroplated on titanium alloy

    Science.gov (United States)

    Brown, E. E.

    1967-01-01

    Anodic treatment of titanium alloy enables electroplating of tightly adherent coatings of copper and nickel on the alloy. The alloy is treated in a solution of hydrofluoric and acetic acids, followed by the electroplating process.

  9. Advanced Surface Engineering of Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    H. Dong

    2000-01-01

    Despite their outstanding combination of properties, titanium and its alloys are very susceptible to severe adhesive wear in rubbing with most engineering surfaces and can exhibit poorcorrosion resistance in some aggressive environments. Surface engineering research centred at the University of Birmingham has been focused on creating designer surfaces for titanium components via surface engineering.Great progress has been made recently through the development of such advanced surface engineering techniques as thermal oxidation, palladium-treated thermal oxidation, oxygen boost diffusion and duplex systems.Such advances thus provide scope for designing titanium components for a diversified range of engineering application, usually as direct replacements for steel components. By way of example, some of the successful steps towards titanium designer surfaces are demonstrated. To data, the potential of these advanced technologies has been realised first in auto-sport and off-shore industrials.

  10. Welding of gamma titanium aluminide alloys

    Science.gov (United States)

    Smashey, Russell W. (Inventor); Kelly, Thomas J. (Inventor); Snyder, John H. (Inventor); Sheranko, Ronald L. (Inventor)

    1998-01-01

    An article made of a gamma titanium aluminide alloy is welded, as for example in the weld repair of surface cracks, by removing foreign matter from the area to be welded, first stress relieving the article, cooling the entire article to a welding temperature of from about 1000.degree. F. to about 1400.degree. F., welding a preselected region in an inert atmosphere at the welding temperature, and second stress relieving the article. Welding is preferably accomplished by striking an arc in the preselected region so as to locally melt the alloy in the preselected region, providing a filler metal having the same composition as the gamma titanium aluminide alloy of the article, and feeding the filler metal into the arc so that the filler metal is melted and fused with the article to form a weldment upon solidification.

  11. Laser repair hardfacing of titanium alloy turbine

    Directory of Open Access Journals (Sweden)

    A. Klimpel

    2011-12-01

    Full Text Available Purpose: of this paper: work out repair technology of worn abutments of aircraft jet engine blades forged of titanium alloy WT3-1.Design/methodology/approach: The study were based on the analysis of laser HPDL powder surfacing of titanium alloy plates using wide range chemical composition consumables of titanium alloys and mixtures of pure titanium and spherical powder of WC indicated that very hard and highest quality deposits are provided by powder mixture of 40-50%Ti+60-50%WC.Findings: It was found that it is possible to achieve high quality deposits, free of any defects. HPDL technology can be used to repair worn turbine blade.Research limitations/implications: It was found that it is possible to repair the worn areas abutments of blades of zero compression stage of aircraft engine turbine by HPDL laser surfacing with using composite powder mixture of 50%Ti+50%WC as an additional material.Practical implications: The technology can be applied for repair worn abutments of aircraft jet engine blades.Originality/value: Repairing worn abutments of aircraft jet engine blades.

  12. Thermal coatings for titanium-aluminum alloys

    Science.gov (United States)

    Cunnington, George R.; Clark, Ronald K.; Robinson, John C.

    1993-01-01

    Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer.

  13. Dry face milling of titanium alloys

    Institute of Scientific and Technical Information of China (English)

    Ahmed Hassan; Zhenqiang Yao

    2004-01-01

    In machining titanium alloys, cutting tools generally wear out very rapidly because of the high cutting temperature resulted from the low thermal conductivity and density of the work material. In order to increase the tool life, it is necessary to suppress the cutting heat as much as possible by applying an abundant amount of coolant, but this will entail serious techno-environmental and biological problems. To study the performance and avoid these limitations, a PVD-coated insert was used to the dry face mill of (α +β) titanium alloys. As a result it was found that the inserts exhibit an excellent cutting performance at low cutting speeds and feed rates, and there is no significant difference in the dominant insert failure mode between the wet and dry cutting in discontinuous cutting.

  14. Sustainable cooling method for machining titanium alloy

    Science.gov (United States)

    Boswell, B.; Islam, M. N.

    2016-02-01

    Hard to machine materials such as Titanium Alloy TI-6AI-4V Grade 5 are notoriously known to generate high temperatures and adverse reactions between the workpiece and the tool tip materials. These conditions all contribute to an increase in the wear mechanisms, reducing tool life. Titanium Alloy, for example always requires coolant to be used during machining. However, traditional flood cooling needs to be replaced due to environmental issues, and an alternative cooling method found that has minimum impact on the environment. For true sustainable cooling of the tool it is necessary to account for all energy used in the cooling process, including the energy involved in producing the coolant. Previous research has established that efficient cooling of the tool interface improves the tool life and cutting action. The objective of this research is to determine the most appropriate sustainable cooling method that can also reduce the rate of wear at the tool interface.

  15. Hydrogen embrittlement of titanium and its alloys - a literature review

    International Nuclear Information System (INIS)

    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)

  16. ROUGH SURFACES OF TITANIUM AND TITANIUM ALLOYS FOR IMPLANTS AND PROSTHESES

    OpenAIRE

    Conforto, Egle; Aronsson, Bjorn-Owe; Salito, A.; Crestou, Catherine; Caillard, Daniel

    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 a...

  17. 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.

  18. Niobium-titanium oxide alloys

    International Nuclear Information System (INIS)

    Oxide dispersion strengthening of niobium with TiO2 has lead to a material which combines superior mechanical properties with the excellent biocompatibility and corrosion resistance of the soft metal niobium. Modern analytical tools including TEM with advanced analysis features (EDX and EELS) were used to clarify the mechanism being a dissolution of the oxide at sintering temperatures and a controlled precipitation by proper aging. The influence of variations of the oxide content, the sintering conditions and the aging treatment were investigated in order to optimize the alloy. The best combination of properties was found with a Nb-1%TiO2 variant with optimized oxygen content. Strength can very well be correlated with TEM data of dispersion parameters. Applications for this ODS niobium alloy are seen in the field of high-load bearing medical implants but also in chemical engineering wherever the good corrosion resistance of niobium is needed in combination with higher mechanical and thermal strength. 14 refs., 17 figs., 3 tabs. (Author)

  19. Fretting fatigue studies of titanium nitride-coated biomedical titanium alloys

    Science.gov (United States)

    Vadiraj, Aravind; Kamaraj, M.

    2006-10-01

    Fretting fatigue is an adhesive wear mechanism caused by repetitive tangential micro-oscillation between two contacting materials pressed together under cyclic load. Bioimplants, such as hip joints and bone plates, are prone to undergo fretting fatigue failures during their service within the body. This article presents the fretting fatigue damage characterization of physical vapor deposition (PVD) TiN-coated biomedical titanium alloys (Ti-6Al-4V and Ti-6Al-7Nb) subjected to cyclic loads. The PVD TiN layer delayed the damage because of superior tribological properties compared with uncoated alloys. Delamination and abrasive wear damage of TiN at contact caused failure of the alloy. Friction coefficient curves of the PVD TiN-coated pair showed an irregular pattern caused by the influence of wear particulates and Ringer fluid at the contact.

  20. Atomic absorption analysis of serial titanium alloys

    International Nuclear Information System (INIS)

    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 + HBF4 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 FeCl3 into the solution. Being as precise, as the classic analytical methods, the atom absorption technique is about 5 times more efficient

  1. Amorphous Alloy Surpasses Steel and Titanium

    Science.gov (United States)

    2004-01-01

    In the same way that the inventions of steel in the 1800s and plastic in the 1900s sparked revolutions for industry, a new class of amorphous alloys is poised to redefine materials science as we know it in the 21st century. Welcome to the 3rd Revolution, otherwise known as the era of Liquidmetal(R) alloys, where metals behave similar to plastics but possess more than twice the strength of high performance titanium. Liquidmetal alloys were conceived in 1992, as a result of a project funded by the California Institute of Technology (CalTech), NASA, and the U.S. Department of Energy, to study the fundamentals of metallic alloys in an undercooled liquid state, for the development of new aerospace materials. Furthermore, NASA's Marshall Space Flight Center contributed to the development of the alloys by subjecting the materials to testing in its Electrostatic Levitator, a special instrument that is capable of suspending an object in midair so that researchers can heat and cool it in a containerless environment free from contaminants that could otherwise spoil the experiment.

  2. Microstructure Evolution of a Multifunctional Titanium Alloy

    Science.gov (United States)

    Tian, Yu Xing; Hao, Yu Lin

    2016-03-01

    To optimize both mechanical and functional properties of multifunctional titanium alloys via grain refinement, an example of such alloys termed as Ti2448 is adopted to investigate its microstructure evolution and strain rate sensitivity by compression in the single β-phase field. The results show that flow stress and strain rate follow a bilinear relation, which is in sharp contrast with other metallic materials exhibiting a monotonic linearity. Below the critical strain of 1 s-1, the alloy has a normal strain rate sensitivity factor of 0.265. Above the critical value, its hardening rate is ultra-low with a factor of 0.03. Inspite of ultra-low hardening, the alloy is plastic stable under the tested conditions. With the aid of electron back-scattering diffraction and transmission electron microscopy analyses, microstructure evolution via several mechanisms such as dynamic recovery and recrystallization is evaluated by quantitative measurements of grain misorientation and its distribution, sub-grain formation, and localized grain refinement. These results are helpful to obtain the homogenous ultrafine-grained alloy by multi-step thermo-mechanical processing.

  3. 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 ...

  4. Cryogenic acoustic loss of pure and alloyed titanium

    Science.gov (United States)

    Matacz, A. L.; Veitch, P. J.; Blair, D. G.

    Low acoustic loss, high yield strength cryogenic materials are required for various high precision experiments, resonant-bar gravitational radiation antennae in particular. We report here acoustic loss measurements of commerically pure and alloyed titanium samples between 4.2 and 300 K. It is shown that machining damage of the surface significantly increased the acoustic loss of pure titanium, particularly below 100 K, and that the high strength alloy Ti-6AI-4V had significantly greater acoustic loss than pure titanium.

  5. Titanium alloys and porous coatings for orthopaedic applications

    OpenAIRE

    Vettorel, Matteo

    2014-01-01

    The project deals with titanium and titanium alloys as biomaterials for implants applications, focusing on their mechanical response under dynamic stresses occurring during common human activities. In the first part, the biomaterials requirements for orthopaedic implants, the properties and the processing of titanium alloys are described. From the combined biomechanics requirements, mechanical behaviour of the materials and the bone is analysed and the additional poroelastic behaviour is adde...

  6. Laser Welding of TC-1 Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    Hanbin DU; Lunji HU; Xiyuan HU; Jianhua LIU

    2003-01-01

    The technology of CO2 laser welding and joint properties of titanium alloy were investigated. The problem of moltenpool protection was resolved by designing a shielding trailer and a special clamp. Joints with silvery appearance wereobtained, which have no pore and crack. In addition, the welding speed could reach 3 m/min for the plate of 1.5 mmthickness being penetrated. The reason of the porosity formation in partial penetration joints is that the keyholescan be easily cut apart in the radial direction, which makes the gas enclosed in the molten pool. The surface oxideof specimens can not affect the porosity formation in welds directly.

  7. Titanium alloy corrosion in nuclear waste environments

    International Nuclear Information System (INIS)

    A corrosion study has been conducted on the titanium alloys Ti-50A, TiCode 12, and Ti-Pd to evaluate their suitability as a long lifetime (300 to 600 year) canister material for the isolation of nuclear wastes. TiCode 12, selected as the primary candidate material, is shown to be very resistant to environmental attack. Results of electrochemical, general corrosion, and stress corrosion cracking experiments are presented. These data, including those from severe overtests, have shown that TiCode 12 is a viable candidate material for long-term waste isolation. 17 figures

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

    OpenAIRE

    Mitsuo Niinomi

    2003-01-01

    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 f...

  9. Titanium aluminide intermetallic alloys with improved wear resistance

    Science.gov (United States)

    Qu, Jun; Lin, Hua-Tay; Blau, Peter J.; Sikka, Vinod K.

    2014-07-08

    The invention is directed to a method for producing a titanium aluminide intermetallic alloy composition having an improved wear resistance, the method comprising heating a titanium aluminide intermetallic alloy material in an oxygen-containing environment at a temperature and for a time sufficient to produce a top oxide layer and underlying oxygen-diffused layer, followed by removal of the top oxide layer such that the oxygen-diffused layer is exposed. The invention is also directed to the resulting oxygen-diffused titanium aluminide intermetallic alloy, as well as mechanical components or devices containing the improved alloy composition.

  10. ALLOYING OF TITANIUM BY OXYGEN DURING CHAMBER ELECTROSLAG REMELTING

    OpenAIRE

    RYABTSEV ANATOLIY D.; TROYANSKYY OLEKSANDR A.; PASHYNSKYI VOLODYMYR V.; SNIZHKO OLGA A.

    2014-01-01

    The paper presents the results of alloying titanium by oxygen in the process of chamber electroslag remelting. As an oxygen-containing ligature, we used the electrodes-satellite from the reaction mass residues mixture from the retort lid for magnesium thermal reduction of a titanium sponge, a specially prepared gaseous argon oxygen mixture containing 30% oxygen applied directly to the melting space, micro-size (10-15 mm) powder particles of titanium oxide and titanium oxide nanopowder with a ...

  11. In-vitro evaluation of corrosion resistance of nitrogen ion implanted titanium simulated body fluid

    International Nuclear Information System (INIS)

    Titanium and its alloy Ti6Al4V enjoy widespread use in various biomedical applications because of favourable local tissue response, higher corrosion resistance and fatigue strength than the stainless steels and cobalt-chromium alloy previously used. The study reported in this paper aims to optimize the conditions of nitrogen ion implantation on commercially pure titanium and to correlate the implantation parameters to the corrosion resistance. X-ray photoelectron spectroscopy was used to analyse surface concentration and the implantation processes. An improvement in the electrochemical behaviour of the passive film was shown to occur with nitrogen ion implantation on titanium, in simulated body fluids. (UK)

  12. Chrome-plating of titanium alloys and their performance

    International Nuclear Information System (INIS)

    The impact of technological parameters by electrochemical chrome-plating of titanium alloys on their mechanical properties, wear resistance, fatigue resistance, antifriction characteristics, hydridation and hydrogen distribution in the base and coating is studied. The evaluation of the alloys and coatings overgrowing with microorganisms is given. The rational compositions of solutions and regimes of titanium alloys treatment by their multiple (up to 6 times) chrome-plating are determined

  13. Recent Advances in the Hot Working of Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    DANG Xiao-ling

    2012-01-01

    In this paper, recent advances in titanium alloy processing are reviewed. The casting, superplastic forming, friction stir welding and thermohydrogen processing of titanium alloys are developed. The great cost saving results from using casting comparing with the conventional machining for rings. The superplastic forming of titanium alloys is a feasible manufacturing technology for civil and military aircraft. The friction stir welding leds to the production of fully-formed, high quality friction stirwelds. In thermohydrogen processing, the high diffusivity of hydrogen in titanium is firstly used to add hydrogen to titanium alloys by controlled diffusion from a hydrogen environment , after thermohydrogen processing, to remove it by a controlled vacuum anneal so as to improve processing and mechanical properties.

  14. Titanium Alloys and Processing for High Speed Aircraft

    Science.gov (United States)

    Brewer, William D.; Bird, R. Keith; Wallace, Terryl A.

    1996-01-01

    Commercially available titanium alloys as well as emerging titanium alloys with limited or no production experience are being considered for a variety of applications to high speed commercial aircraft structures. A number of government and industry programs are underway to improve the performance of promising alloys by chemistry and/or processing modifications and to identify appropriate alloys and processes for specific aircraft structural applications. This paper discusses some of the results on the effects of heat treatment, service temperatures from - 54 C to +177 C, and selected processing on the mechanical properties of several candidate beta and alpha-beta titanium alloys. Included are beta alloys Timetal 21S, LCB, Beta C, Beta CEZ, and Ti-10-2-3 and alpha-beta alloys Ti-62222, Ti-6242S, Timetal 550, Ti-62S, SP-700, and Corona-X. The emphasis is on properties of rolled sheet product form and on the superplastic properties and processing of the materials.

  15. Residual stress state in titanium alloy remelted using GTAW method

    OpenAIRE

    Dudek, A.; Z. Balaga

    2009-01-01

    Test materials comprised two-phase titanium alloy Ti6Al4V (Grade5). The surface of the tested alloy was remelted by means of TIG welding method using variable current-voltage parameters. The investigations aimed to determine surface geometry and residual stresses in the remelted surface layer in the investigated alloy.

  16. Radiation-induced segregation in titanium alloys

    International Nuclear Information System (INIS)

    Radiation-induced segregation (RIS) of V, Mo, Nb, Ta, Zr, and Sn in binary titanium alloys was investigated to test the solute size effect correlation in hcp alloys. Undersize Mo segregates weakly toward the sinks. Nb and Ta, which are slightly oversize in Ti, undergo little or no RIS. Oversize Zr solute in Ti segregates away from the sinks, whereas undersize Ti solute in Zr is enriched at sinks. All of these results are in accord with the solute size effect correlation. Surprisingly, Sn, which is significantly oversize in Ti, appears to segregate very little. The postirradiation annealing of Ti-3V and Ti-8Al-1V-1Mo confirmed that segregation of undersize V toward sinks is radiation-induced. Measurements of temperature and dose dependence in binary and complex alloys showed that the degree of V segregation has a maximum at proportional6000C and obeys parabolic growth kinetics in its early stages but probably saturates at a rather low dose (proportional0.8 dpa). (orig.)

  17. Surface modification of titanium alloys by intense pulsed electron beams

    International Nuclear Information System (INIS)

    The influence of intense pulsed electron beam (IPEB) treatment on the chemical composition and structure of titanium alloys surface layers is reviewed. The fatigue and oxidation behaviour of irradiated titanium alloys is analyzed. It is shown that IPEB processing allows one to improve service properties of titanium alloys dramatically. The recycling of some aircraft components after their 'long life' operation have to be realized using IPEB treatment at high values of the energy density in a pulse is also described. The application of IPEB processing is illustrated for compressor blades of aircraft engines

  18. Titanium alloy nanosecond vs. femtosecond laser marking

    International Nuclear Information System (INIS)

    Highlights: ► We analyze nanosecond (commercial) and femtosecond laser marks, using SEM and EDAX. ► Elevated repetitive thermal gradients leads to structural defects for double crosses. ► Femtolaser engraving forms amorphous structures, composed of spherical particles. ► We conduct X-ray diffractometry to detect internal micro and residual stresses. ► No internal stresses modification occurred for nano and femtosecond laser marking. - Abstract: There are few papers which aim to analyze the effects of laser marking for traceability on various materials; therefore, the present paper proposes a study of the influences of such radiation processing on a titanium alloy, a vastly used material base within several industry fields. For the novelty impact, femtolaser marking has been carried out, besides the commercial nanosecond standard engraving. All marks have been analyzed using scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry.

  19. A Novel Surface Treatment for Titanium Alloys

    Science.gov (United States)

    Lowther, S. E.; Park, C.; SaintClair, T. L.

    2004-01-01

    High-speed commercial aircraft require a surface treatment for titanium (Ti) alloy that is both environmentally safe and durable under the conditions of supersonic flight. A number of pretreatment procedures for Ti alloy requiring multi-stages have been developed to produce a stable surface. Among the stages are, degreasing, mechanical abrasion, chemical etching, and electrochemical anodizing. These treatments exhibit significant variations in their long-term stability, and the benefits of each step in these processes still remain unclear. In addition, chromium compounds are often used in many chemical treatments and these materials are detrimental to the environment. Recently, a chromium-free surface treatment for Ti alloy has been reported, though not designed for high temperature applications. In the present study, a simple surface treatment process developed at NASA/LaRC is reported, offering a high performance surface for a variety of applications. This novel surface treatment for Ti alloy is conventionally achieved by forming oxides on the surface with a two-step chemical process without mechanical abrasion. This acid-followed-by-base treatment was designed to be cost effective and relatively safe to use in a commercial application. In addition, it is chromium-free, and has been successfully used with a sol-gel coating to afford a strong adhesive bond after exposure to hot-wet environments. Phenylethynyl containing adhesives were used to evaluate this surface treatment with sol-gel solutions made of novel imide silanes developed at NASA/LaRC. Oxide layers developed by this process were controlled by immersion time and temperature and solution concentration. The morphology and chemical composition of the oxide layers were investigated using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Bond strengths made with this new treatment were evaluated using single lap shear tests.

  20. Corrosion of gold alloys and titanium in artificial saliva

    International Nuclear Information System (INIS)

    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 46Sc assuming particulate matter to be deteriorated from the titanium surface. (author)

  1. Solid State Joining of Dissimilar Titanium Alloys

    Science.gov (United States)

    Morton, Todd W.

    Solid state joining of titanium via friction stir welding and diffusion bonding have emerged as enablers of efficient monolithic structural designs by the eliminations fasteners for the aerospace industry. As design complexity and service demands increase, the need for joints of dissimilar alloys has emerged. Complex thermomechanical conditions in friction stir weld joints and high temperature deformation behavior differences between alloys used in dissimilar joints gives rise to a highly variable flow pattern within a stir zone. Experiments performed welding Ti-6Al-4V to beta21S show that mechanical intermixing of the two alloys is the primary mechanism for the generation of the localized chemistry and microstructure, the magnitude of which can be directly related to pin rotation and travel speed weld parameters. Mechanical mixing of the two alloys is heavily influenced by strain rate softening phenomena, and can be used to manipulate weld nugget structure by switching which alloy is subjected to the advancing side of the pin. Turbulent mixing of a weld nugget and a significant reduction in defects and weld forces are observed when the beta21S is put on the advancing side of the weld where higher strain rates are present. Chemical diffusion driven by the heat of weld parameters is characterized using energy dispersive x-ray spectroscopy (EDS) and is shown to be a secondary process responsible for generating short-range chemical gradients that lead to a gradient of alpha particle structures. Diffusion calculations are inconsistent with an assumption of steady-state diffusion and show that material interfaces in the weld nugget evolve through the break-down of turbulent interface features generated by material flows. A high degree of recrystallization is seen throughout the welds, with unique, hybrid chemistry grains that are generated at material interfaces in the weld nugget that help to unify the crystal structure of dissimilar alloys. The degree of

  2. Measurement of Thermodynamic Properties of Titanium Aluminum Alloys

    Science.gov (United States)

    Mehrotra, Gopal

    1995-01-01

    This final report is a summary of the work done by Professor Mehrotra at NASA Lewis Research Center. He has worked extensively on the measurement of thermodynamic properties of titanium aluminum alloys over the past six years.

  3. ATOM PROBE STUDY OF TITANIUM BASE ALLOYS : PRELIMINARY RESULTS

    OpenAIRE

    Menand, A.; Chambreland, S.; Martin, C

    1986-01-01

    Two different titanium base alloys, Ti46 Al54 and Ti88.8 Cu2.3, Al8.9, have been studied by atom probe microanalysis. A precipitate of Ti2 Al was analysed in the binary alloys. Micro-analysis of Ti Cu Al alloy revealed the presence of Copper enriched zones. The study has also exhibited a penetration of Hydrogen in the samples, probably due to preparation technique. The results demonstrate the feasibility of studies on titanium base alloys by mean of atom probe.

  4. Surface Corrosion Resistance in Turning of Titanium Alloy

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2015-01-01

    Full Text Available This work addresses the issues associated with implant surface modification. We propose a method to form the oxide film on implant surfaces by dry turning to generate heat and injecting oxygen-rich gas at the turning-tool flank. The morphology, roughness, composition, and thickness of the oxide films in an oxygen-rich atmosphere were characterized using scanning electron microscopy, optical profiling, and Auger electron spectroscopy. Electrochemical methods were used to study the corrosion resistance of the modified surfaces. The corrosion resistance trends, analyzed relative to the oxide film thickness, indicate that the oxide film thickness is the major factor affecting the corrosion resistance of titanium alloys in a simulated body fluid (SBF. Turning in an oxygen-rich atmosphere can form a thick oxide film on the implant surface. The thickness of surface oxide films processed at an oxygen concentration of 80% was improved to 4.6 times that of films processed at an oxygen concentration of 21%; the free corrosion potential shifted positively by 0.357 V, which significantly improved the corrosion resistance of titanium alloys in the SBF. Therefore, the proposed method may (partially replace the subsequent surface oxidation. This method is significant for biomedical development because it shortens the process flow, improves the efficiency, and lowers the cost.

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

    OpenAIRE

    Klimenov, Vasily Aleksandrovich; Vlasov, V.A.; Borozna, Vyacheslav Yurievich; Klopotov, A. A.

    2015-01-01

    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 x100 nm, depending on the brand of titanium alloy.

  6. Studies on the corrosion and wear behavior of the laser nitrided biomedical titanium and its alloys

    International Nuclear Information System (INIS)

    The effects of laser nitriding on surface hardness, corrosion and wear behavior of the conventional biomedical implants such as commercially available pure titanium and Ti-13Nb-13Zr alloy is reported. The influence of alloying elements such as Zr and Nb on nitride formation was also studied by nitriding the newly developed alloy (Ti-13Nb-13Zr). The surface modified samples were characterized using optical microscope (OM), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) techniques. Corrosion rate, wear rate and coefficient of friction were made under simulated body condition for commercially available pure titanium and Ti-13Nb-13Zr alloy. The high speed processing of these alloys enabled smooth and crack free surface.

  7. Selection of crucible oxides in molten titanium and titanium aluminum alloys by thermo-chemistry calculations

    OpenAIRE

    Kostov A.; Friedrich B

    2005-01-01

    Titanium and its alloys interstitially dissolve a large amount of impurities such as oxygen and nitrogen, which degrade the mechanical and physical properties of alloys. On the other hand crucible oxides based on CaO, ZrO2 Y2O3, etc., and their spinels (combination of two or more oxides) can be used for melting titanium and its alloys. However, the thermodynamic behavior of calcium, zirconium, yttrium on the one side, and oxygen on the other side, in molten Ti and Ti-Al alloys have not been m...

  8. COMPARATIVE CORROSION BEHAVIOR OF TWO PALLADIUM-CONTAINING TITANIUM ALLOYS

    International Nuclear Information System (INIS)

    The ASTM standard B 265 provides the requirements for the chemical composition of titanium (Ti) alloys. It is planned to use corrosion resistant and high strength titanium alloys to fabricate the drip shield at the proposed Yucca Mountain Repository. Titanium grade (Gr) 7 (R52400) and other Ti alloys are currently being characterized for this application. Ti Gr 7 contains 0.15% Palladium (Pd) to increase its corrosion performance. In this article we report results on the comparative short term corrosion behavior of Ti Gr 7 and a Ruthenium (Ru) containing alloy (Ti Gr 33). Ti Gr 33 also contains a small amount of Pd. Limited electrochemical testing such as polarization resistance and cyclic potentiodynamic curves showed that both alloys have a similar corrosion behavior in the tested environments

  9. Comparative Corrosion Behavior of Two Palladium Containing Titanium Alloys

    International Nuclear Information System (INIS)

    The ASTM standard B 265 provides the requirements for the chemical composition of titanium (Ti) alloys. It is planned to use corrosion resistant and high strength titanium alloys to fabricate the drip shield at the proposed Yucca Mountain Repository. Titanium grade (Gr) 7 (R52400) and other Ti alloys are currently being characterized for this application. Ti Gr 7 contains 0.15% Palladium (Pd) to increase its corrosion performance. In this article we report results on the comparative short term corrosion behavior of Ti Gr 7 and a Ruthenium (Ru) containing alloy (Ti Gr 33). Ti Gr 33 also contains a small amount of Pd. Limited electrochemical testing such as polarization resistance and cyclic potentiodynamic curves showed that both alloys have a similar corrosion behavior in the tested environments

  10. Corrosion of alloys of the niobium--titanium--aluminium system

    International Nuclear Information System (INIS)

    The mechanical properties and corrosion resistance of niobium--titanium--aluminum alloys in 20 percent HCl and 40--75 percent H2SO4 at 40 and 1000C are considered. Current density vs potential and corrosion rate vs potential potentiostatic curves plotted in 75 percent H2SO4 at 1400C 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 H2SO4 at 1400C is an exponential function of the atomic content of the alloying components (Ti, Al) in them; aluminum vitiates the corrosion resistance very strongly

  11. COMPARATIVE CORROSION BEHAVIOR OF TWO PALLADIUM CONTAINING TITANIUM ALLOYS

    Energy Technology Data Exchange (ETDEWEB)

    T. Lian, T. Yashiki, T. Nakayama, T. Nakanishi, R. B. Rebak

    2006-07-23

    The ASTM standard B 265 provides the requirements for the chemical composition of titanium (Ti) alloys. It is planned to use corrosion resistant and high strength titanium alloys to fabricate the drip shield at the proposed Yucca Mountain Repository. Titanium grade (Gr) 7 (R52400) and other Ti alloys are currently being characterized for this application. Ti Gr 7 contains 0.15% Palladium (Pd) to increase its corrosion performance. In this article we report results on the comparative short term corrosion behavior of Ti Gr 7 and a Ruthenium (Ru) containing alloy (Ti Gr 33). Ti Gr 33 also contains a small amount of Pd. Limited electrochemical testing such as polarization resistance and cyclic potentiodynamic curves showed that both alloys have a similar corrosion behavior in the tested environments.

  12. Effect of titanium addition on fracture toughness behavior of ZL108 alloy

    Institute of Scientific and Technical Information of China (English)

    WENG Yong-gang; LI Zi-jing; LIU Zhi-yong; LIU Wen-cai; WANG Ming-xing; SONG Tian-fu

    2006-01-01

    Two different titanium alloying methods were applied to ZL108 alloy for preparing specimens containing titanium. The specimens were tested on the MTS 810 material test system for studying their behavior of the plane strain fracture toughness KIC. The experimental data were analyzed by the statistical significance tests. The results show that the fracture toughness of the ZL108 alloy containing titanium is superior to that of common ZL108 alloy containing no titanium, but there is no significant difference for different titanium alloying methods. Therefore titanium addition is an effective method for improving the fracture toughness of the alloy ZL108.

  13. Low-cyclic fatigue properties of electrolytic low-titanium A356 alloys

    Institute of Scientific and Technical Information of China (English)

    LIU Zhong-xia; SONG Mou-sheng; WENG Yong-gang; WANG Ming-xing; SONG Tian-fu; LIU Zhi-yong

    2006-01-01

    The low-cycle fatigue (LCF) behavior of two kinds of A356 alloys produced by different titanium alloying methods was investigated and compared. The effect of titanium content and titanium alloying methods on LCF behavior is analyzed with plastic strain energy density. The results show that all alloys exhibit the cyclic hardening behavior. Raising Ti content can obviously increase the cyclic hardening ability. But the effect of Ti alloying method isn't distinct. Whether for the EA356 alloys or for MA356 alloys,the alloys with low titanium content have longer low-cycle fatigue life than that of the alloys with high titanium content. This is because that the alloys with low titanium content can consume higher cyclic plastic strain energy during cyclic deformation compared with alloys with high titanium content.

  14. Modeling corrosion behavior of gas tungsten arc welded titanium alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The pitting corrosion characteristics of pulse TIG welded Ti-6Al-4V titanium alloy in marine environment were explained.Besides the rapid advance of titanium metallurgy, this is also due to the successful solution of problems associated with the development of titanium alloy welding. The preferred welding process of titanium alloy is frequently gas tungsten arc(GTA) welding due to its comparatively easier applicability and better economy. In the case of single pass GTA welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advantages over the conventional continuous current process. The benefit of the process is utilized to obtain better quality titanium weldments. Four factors, five levels, central composite, rotatable design matrix are used to optimize the required number of experiments. The mathematical models have been developed by response surface method(RSM). The results reveal that the titanium alloy can form a protective scale in marine environment and is resistant to pitting corrosion. Experimental results are provided to illustrate the proposed approach.

  15. High temperature protective silicide coatings for titanium-niobium alloys

    International Nuclear Information System (INIS)

    The accomplished investigation of heat resistance of silicide coatings on titanium - (30-50)% niobium alloys has revealed that the coatings ensure reliable corrosion protection up to 1100 deg due to formation of heat resistant disilicides and a silicon dioxide layer on alloy surface. Silicide coatings possess particular ductility

  16. 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.

  17. Casting behavior of titanium alloys in a centrifugal casting machine.

    Science.gov (United States)

    Watanabe, K; Miyakawa, O; Takada, Y; Okuno, O; Okabe, T

    2003-05-01

    Since dental casting requires replication of complex shapes with great accuracy, this study examined how well some commercial titanium alloys and experimental titanium-copper alloys filled a mold cavity. The metals examined were three types of commercial dental titanium [commercially pure titanium (hereinafter noted as CP-Ti), Ti-6Al-4V (T64) and Ti-6Al-7Nb (T67)], and experimental titanium-copper alloys [3%, 5% and 10% Cu (mass %)]. The volume percentage filling the cavity was evaluated in castings prepared in a very thin perforated sheet pattern and cast in a centrifugal casting machine. The flow behavior of the molten metal was also examined using a so-called "tracer element technique." The amounts of CP-Ti and all the Ti-Cu alloys filling the cavity were similar; less T64 and T67 filled the cavity. However, the Ti-Cu alloys failed to reach the end of the cavities due to a lower fluidity compared to the other metals. A mold prepared with specially designed perforated sheets was effective at differentiating the flow behavior of the metals tested. The present technique also revealed that the more viscous Ti-Cu alloys with a wide freezing range failed to sequentially flow to the end of the cavity. PMID:12593955

  18. Investigation of surface properties of high temperature nitrided titanium alloys

    OpenAIRE

    Koyuncu, E.; F. Kahraman; Ö. Karadeniz

    2009-01-01

    Purpose: The purpose of paper is to investigate surface properties of high temperature nitrided titanium alloys.Design/methodology/approach: In this study, surface modification of Ti6Al4V titanium alloy was made at various temperatures by plasma nitriding process. Plasma nitriding treatment was performed in 80% N2-20% H2 gas mixture, for treatment times of 2-15 h at the temperatures of 700-1000°C. Surface properties of plasma nitrided Ti6Al4V alloy were examined by metallographic inspection, ...

  19. Influence of titanium content on wear resistance of electrolytic low-titanium eutectic Al-Si piston alloys

    OpenAIRE

    Yan Shuqing; Xie Jingpei; Wang Jiefang

    2008-01-01

    The wear resistance of six kinds of the electrolytic low-titanium eutectic Al-Si piston alloys with various Ti content ranging from 0.00wt.% to 0.21wt.% has been studied. A new method of adding Ti is adopted in the electrolytic low-titanium aluminum alloy ingots. The electrolytic low-titanium eutectic Al-Si piston alloys are produced by remelting the electrolytic low-titanium aluminum alloy, crystal silicon, pure magnesium, Al-50%Cu and Al-10%Mn master alloy. The wear experiments are conducte...

  20. Strength of inserts in titanium alloy machining

    Science.gov (United States)

    Kozlov, V.; Huang, Z.; Zhang, J.

    2016-04-01

    In this paper, a stressed state of a non-worn cutting wedge in a machined titanium alloy (Ti6Al2Mo2Cr) is analyzed. The distribution of contact loads on the face of a cutting tool was obtained experimentally with the use of a ‘split cutting tool’. Calculation of internal stresses in the indexable insert made from cemented carbide (WC8Co) was carried out with the help of ANSYS 14.0 software. Investigations showed that a small thickness of the cutting insert leads to extremely high compressive stresses near the cutting edge, stresses that exceed the ultimate compressive strength of cemented carbide. The face and the base of the insert experience high tensile stresses, which approach the ultimate tensile strength of cemented carbide and increase a probability of cutting insert destruction. If the thickness of the cutting insert is bigger than 5 mm, compressive stresses near the cutting edge decrease, and tensile stresses on the face and base decrease to zero. The dependences of the greatest normal and tangential stresses on thickness of the cutting insert were found. Abbreviation and symbols: m/s - meter per second (cutting speed v); mm/r - millimeter per revolution (feed rate f); MPa - mega Pascal (dimension of specific contact loads and stresses); γ - rake angle of the cutting tool [°] α - clearance angle of the sharp cutting tool [°].

  1. Titanium Alloy Strong Back for IXO Mirror Segments

    Science.gov (United States)

    Byron, Glenn P.; Kai-Wang, Chan

    2011-01-01

    A titanium-alloy mirror-holding fixture called a strong back allows the temporary and permanent bonding of a 50 degree D263 glass x-ray mirror (IXO here stands for International X-ray Observatory). The strong back is used to hold and position a mirror segment so that mounting tabs may be bonded to the mirror with ultra-low distortion of the optical surface. Ti-15%Mo alloy was the material of choice for the strong back and tabs because the coefficient of thermal expansion closely matches that of the D263 glass and the material is relatively easy to machine. This invention has the ability to transfer bonded mounting points from a temporary location on the strong back to a permanent location on the strong back with minimal distortion. Secondly, it converts a single mirror segment into a rigid body with an acceptable amount of distortion of the mirror, and then maneuvers that rigid body into optical alignment such that the mirror segment can be bonded into a housing simulator or mirror module. Key problems are that the mirrors are 0.4-mm thick and have a very low coefficient of thermal expansion (CTE). Because the mirrors are so thin, they are very flexible and are easily distorted. When permanently bonding the mirror, the goal is to achieve a less than 1-micron distortion. Temperature deviations in the lab, which have been measured to be around 1 C, have caused significant distortions in the mirror segment.

  2. Potentiality of the “Gum Metal” titanium-based alloy for biomedical applications

    International Nuclear Information System (INIS)

    In this study, the “Gum Metal” titanium-based alloy (Ti–23Nb–0.7Ta–2Zr–1.2O) was synthesized by melting and then characterized in order to evaluate its potential for biomedical applications. Thus, the mechanical properties, the corrosion resistance in simulated body fluid and the in vitro cell response were investigated. It was shown that this alloy presents a very high strength, a low Young's modulus and a high recoverable strain by comparison with the titanium alloys currently used in medicine. On the other hand, all electrochemical and corrosion parameters exhibited more favorable values showing a nobler behavior and negligible toxicity in comparison with the commercially pure Ti taken as reference. Furthermore, the biocompatibility tests showed that this alloy induced an excellent response of MC3T3-E1 pre-osteoblasts in terms of attachment, spreading, viability, proliferation and differentiation. Consequently, the “Gum Metal” titanium-based alloy processes useful characteristics for the manufacturing of highly biocompatible medical devices. - Highlights: • The Gum Metal alloy composition was synthesized by melting in this study. • Appropriate mechanical properties for biomedical applications were obtained. • High corrosion resistance in simulated body fluids was observed. • Excellent in-vitro cell response was evidenced

  3. Potentiality of the “Gum Metal” titanium-based alloy for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gordin, D.M. [Institut des Sciences Chimiques de Rennes (UMR CNRS 6226), INSA Rennes, 20 Avenue des Buttes de Coësmes, F-35043 Rennes Cedex (France); Ion, R. [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Vasilescu, C.; Drob, S.I. [Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania); Cimpean, A. [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Gloriant, T., E-mail: Thierry.Gloriant@insa-rennes.fr [Institut des Sciences Chimiques de Rennes (UMR CNRS 6226), INSA Rennes, 20 Avenue des Buttes de Coësmes, F-35043 Rennes Cedex (France)

    2014-11-01

    In this study, the “Gum Metal” titanium-based alloy (Ti–23Nb–0.7Ta–2Zr–1.2O) was synthesized by melting and then characterized in order to evaluate its potential for biomedical applications. Thus, the mechanical properties, the corrosion resistance in simulated body fluid and the in vitro cell response were investigated. It was shown that this alloy presents a very high strength, a low Young's modulus and a high recoverable strain by comparison with the titanium alloys currently used in medicine. On the other hand, all electrochemical and corrosion parameters exhibited more favorable values showing a nobler behavior and negligible toxicity in comparison with the commercially pure Ti taken as reference. Furthermore, the biocompatibility tests showed that this alloy induced an excellent response of MC3T3-E1 pre-osteoblasts in terms of attachment, spreading, viability, proliferation and differentiation. Consequently, the “Gum Metal” titanium-based alloy processes useful characteristics for the manufacturing of highly biocompatible medical devices. - Highlights: • The Gum Metal alloy composition was synthesized by melting in this study. • Appropriate mechanical properties for biomedical applications were obtained. • High corrosion resistance in simulated body fluids was observed. • Excellent in-vitro cell response was evidenced.

  4. Galvanic corrosion behavior of titanium implants coupled to dental alloys.

    Science.gov (United States)

    Cortada, M; Giner, L; Costa, S; Gil, F J; Rodríguez, D; Planell, J A

    2000-05-01

    The corrosion of five materials for implant suprastructures (cast-titanium, machined-titanium, gold alloy, silver-palladium alloy and chromium-nickel alloy), was investigated in vitro, the materials being galvanically coupled to a titanium implant. Various electrochemical parameters E(CORR), i(CORR) Evans diagrams, polarization resistance and Tafel slopes) were analyzed. The microstructure of the different dental materials was observed before and after corrosion processes by optical and electron microscopy. Besides, the metallic ions released in the saliva environment were quantified during the corrosion process by means of inductively coupled plasma-mass spectrometry technique (ICP-MS). The cast and machined titanium had the most passive current density at a given potential and chromium-nickel alloy had the most active critical current density values. The high gold content alloys have excellent resistance corrosion, although this decreases when the gold content is lower in the alloy. The palladium alloy had a low critical current density due to the presence of gallium in this composition but a selective dissolution of copper-rich phases was observed through energy dispersive X-ray analysis. PMID:15348025

  5. TEMPORARILY ALLOYING TITANIUM TO FACILITATE FRICTION STIR WELDING

    Energy Technology Data Exchange (ETDEWEB)

    Hovanski, Yuri

    2009-05-06

    While historically hydrogen has been considered an impurity in titanium, when used as a temporary alloying agent it promotes beneficial changes to material properties that increase the hot-workability of the metal. This technique known as thermohydrogen processing was used to temporarily alloy hydrogen with commercially pure titanium sheet as a means of facilitating the friction stir welding process. Specific alloying parameters were developed to increase the overall hydrogen content of the titanium sheet ranging from commercially pure to 30 atomic percent. Each sheet was evaluated to determine the effect of the hydrogen content on process loads and tool deformation during the plunge phase of the friction stir welding process. Two materials, H-13 tool steel and pure tungsten, were used to fabricate friction stir welding tools that were plunged into each of the thermohydrogen processed titanium sheets. Tool wear was characterized and variations in machine loads were quantified for each tool material and weld metal combination. Thermohydrogen processing was shown to beneficially lower plunge forces and stabilize machine torques at specific hydrogen concentrations. The resulting effects of hydrogen addition to titanium metal undergoing the friction stir welding process are compared with modifications in titanium properties documented in modern literature. Such comparative analysis is used to explain the variance in resulting process loads as a function of the initial hydrogen concentration of the titanium.

  6. Microstructure and tensile properties of low cost titanium alloys at different cooling rate

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Titanium and titanium alloys have several advantages, but the cost of titanium alloys is very expensive compared with the traditional metal materials. This article introduces two new low-cost titanium alloys Ti-2.1Cr-1.3Fe (TCF alloy) and Ti-3Al-2.1Cr-1.3Fe (TACF alloy). In this study, we used Cr-Fe master alloy as one of the raw materials to develop the two new alloys. We introduce the microstructure and tensile properties of the two new alloys from β solution treated with different cooling methods. Optica...

  7. Influence of surface modification on corrosion and biocompatibility of titanium alloys

    Science.gov (United States)

    Rahman, Zia Ur

    Titanium alloys are playing a vital role in the field of biomaterials due to their excellent corrosion resistance and biocompatibility. These alloys enhance the quality and longevity of human life by replacing or treating various parts of the body. However, as these materials are in constant contact with the aggressive body fluids, corrosion leads to metal ions dissolution. These ions leach to the adjacent tissues and causes adverse reactions. Surface modifications are used to improve corrosion resistance and biological activity without changing their bulk properties. In this investigation, electropolishing, magnetoelectropolishing, titanium coating and hydroxiapatitecoating were carried out on commercially pure titanium (CPTi), Ti6Al4V and Ti6Al4V-ELI (Extra Low Interstitials). These surface modifications are known to effect surface charge, chemistry, morphology; wettability, corrosion resistance and biocompatibility of these materials. In vitro cyclic potentiodynamic polarization tests were conducted in phosphate buffer saline in compliance with ASTM standard. The surface morphology, roughness and wettability of these alloys were studied using scanning electron microscope, atomic force microscope and contact angle meter, respectively. Moreover, biocompatibility of titanium alloys was assessed by growing MC3T3 pre-osteoblast cells on their surfaces

  8. Titanium-alloy enhances bone-pedicle screw fixation: mechanical and histomorphometrical results of titanium-alloy versus stainless steel

    OpenAIRE

    Christensen, F.B.; Dalstra, M.; Sejling, F.; Overgaard, S.; Bünger, C.

    2000-01-01

    Several types of pedicle screw systems have been utilized to augment lumbar spine fusion. The majority of these systems are made of stainless steel (Ss), but titanium-alloy (Ti-alloy) devices have recently been available on the market. Ti-alloy implants have several potential advantages over Ss ones. High bioactivity and more flexibility may improve bone ingrowth and mechanical fixation, and the material also offers superior magnetic resonance imaging (MRI) and computed tomography (CT) resolu...

  9. Method for the production of strongly adhesive films on titanium and titanium alloys with a metallization process

    Science.gov (United States)

    Hahn, H. J.

    1986-01-01

    A process for the spray-application of a strongly adhesive, thick antifriction layer on titanium and titanium alloys is proposed. The titanium/titanium alloy component to be coated is first subjected to cleaning in a pickling bath with reducing additives and sand-blasting, then coated with an intermediate layer of nickel, after which the final layer is applied. The formation of TiNi at the interface ensures strong bonding of the antifriction layer.

  10. An Oxidation-Resistant Coating Alloy for Gamma Titanium Aluminides

    Science.gov (United States)

    Brady, Michael P.; Smialek, James L.; Brindley, William J.

    1997-01-01

    Titanium aluminides based on the g-phase (TiAl) offer the potential for component weight savings of up to 50 percent over conventional superalloys in 600 to 850 C aerospace applications. Extensive development efforts over the past 10 years have led to the identification of "engineering" gamma-alloys, which offer a balance of room-temperature mechanical properties and high-temperature strength retention. The gamma class of titanium aluminides also offers oxidation and interstitial (oxygen and nitrogen) embrittlement resistance superior to that of the alpha(sub 2) (Ti3Al) and orthorhombic (Ti2AlNb) classes of titanium aluminides. However, environmental durability is still a concern, especially at temperatures above 750 to 800 C. Recent work at the NASA Lewis Research Center led to the development of an oxidation-resistant coating alloy that shows great promise for the protection of gamma titanium aluminides.

  11. 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.

  12. Rough surfaces of titanium and titanium alloys for implants and prostheses

    International Nuclear Information System (INIS)

    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

  13. Detonation nanodiamonds biofunctionalization and immobilization to titanium alloy surfaces as first steps towards medical application

    Directory of Open Access Journals (Sweden)

    Juliana P. L. Gonçalves

    2014-11-01

    Full Text Available Due to their outstanding properties nanodiamonds are a promising nanoscale material in various applications such as microelectronics, polishing, optical monitoring, medicine and biotechnology. Beyond the typical diamond characteristics like extreme hardness or high thermal conductivity, they have additional benefits as intrinsic fluorescence due to lattice defects without photobleaching, obtained during the high pressure high temperature process. Further the carbon surface and its various functional groups in consequence of the synthesis, facilitate additional chemical and biological modification. In this work we present our recent results on chemical modification of the nanodiamond surface with phosphate groups and their electrochemically assisted immobilization on titanium-based materials to increase adhesion at biomaterial surfaces. The starting material is detonation nanodiamond, which exhibits a heterogeneous surface due to the functional groups resulting from the nitrogen-rich explosives and the subsequent purification steps after detonation synthesis. Nanodiamond surfaces are chemically homogenized before proceeding with further functionalization. Suspensions of resulting surface-modified nanodiamonds are applied to the titanium alloy surfaces and the nanodiamonds subsequently fixed by electrochemical immobilization. Titanium and its alloys have been widely used in bone and dental implants for being a metal that is biocompatible with body tissues and able to bind with adjacent bone during healing. In order to improve titanium material properties towards biomedical applications the authors aim to increase adhesion to bone material by incorporating nanodiamonds into the implant surface, namely the anodically grown titanium dioxide layer. Differently functionalized nanodiamonds are characterized by infrared spectroscopy and the modified titanium alloys surfaces by scanning and transmission electron microscopy. The process described shows an

  14. Hydrogen embrittlement and galvanic corrosion of titanium alloys

    International Nuclear Information System (INIS)

    The material properties including the fracture behavior of titanium alloys used as a steam generator tube in SMART can be degraded de to the hydrogen embrittlement and the galvanic corrosion occurring as a result of other materials in contact with titanium alloys in a conducting corrosive environment. In this report the general concepts and trends of hydrogen embrittlement are qualitatively described to adequately understand and expect the fracture behavior from hydrogen within the bulk of materials and under hydrogen containing environments because hydrogen embrittlement may be very complicated process. And the characteristics of galvanic corrosion closely related to hydrogen embrittlement is qualitatively based on wimple electrochemical theory

  15. High strength beta titanium alloys: New design approach

    International Nuclear Information System (INIS)

    A novel approach for development of high strength and ductile beta titanium alloys was proposed and successfully applied. The microstructure of the designed alloys is fully composed of a bcc β-Ti phase exhibiting dendritic morphology. The new Ti68.8Nb13.6Cr5.1Co6Al6.5 (at%) alloy (BETAtough alloy) exhibits a maximum tensile strength of 1290±50 MPa along with 21±3% of fracture strain. The specific energy absorption value upon mechanical deformation of the BETAtough alloy exceeds that of Ti-based metallic glass composites and commercial high strength Ti-based alloys. The deformation behavior of the new alloys was correlated with their microstructure by means of in-situ studies of the microstructure evolution upon tensile loading in a scanning electron microscope

  16. Alloying effect on the titanium alloys tendency to the salt corrosion

    International Nuclear Information System (INIS)

    Salt corrosion tendency of commercial titanium alloys, such as OT4, 0T4-1 (the Ti-Al-Mn system); VT14, VT16 (the Ti-Al-Mo-V system) and VT30 (the Ti-Mo-Sn-Zr system) is compared with the intensity of salt corrosion of VT1-0 titanium and experimental alloys of the Ti-Al and Ti-Mo systems. It is established that the salt corrosion tendency of alloys of the Ti-Al system increases when they are alloyed with manganese and decreases when they are alloyed with vanadium and molybdenum in combination. Alloys of the Ti-Mo system have no tendency to salt corrosion. Alloying with zirconium and tin brings about the propagation of salt corrosion in the alloys

  17. Microstructure and Mechanical Properties of Friction Welding Joints with Dissimilar Titanium Alloys

    OpenAIRE

    Yingping Ji; Sujun Wu; Dalong Zhao

    2016-01-01

    Titanium alloys, which are important in aerospace application, offer different properties via changing alloys. As design complexity and service demands increase, dissimilar welding of the titanium alloys becomes a particular interest. Linear friction welding (LFW) is a relatively novel bond technique and has been successfully applied for joining titanium alloys. In this paper, dissimilar joints with Ti-6Al-4V and Ti-5Al-2Sn-2Zr-4Mo-4Cr alloys were produced by LFW process. Microstructure was s...

  18. Effect of hydrogen on mechanical properties of -titanium alloys

    Indian Academy of Sciences (India)

    H-J Christ; A Senemmar; M Decker; K Prüßner

    2003-06-01

    Conflicting opinions exist in the literature on the manner in which hydrogen influences the mechanical properties of -titanium alloys. This can be attributed to the -stabilizing effect of hydrogen in these materials leading to major changes in the microstructure as a result of hydrogen charging. The resulting (extrinsic) effect of hydrogen on the mechanical properties can possibly cover up the direct (intrinsic) influences. On the basis of experimentally determined thermodynamic and kinetic data regarding the interaction of hydrogen with -titanium alloys, hydrogen concentrations of up to 8 at.% were established in three commercial alloys by means of hydrogen charging from the gas phase. In order to separate intrinsic and extrinsic effects the charging was carried out during one step of the two-step heat treatment typical of metastable -titanium alloys, while the other step was performed in vacuum. The results on the single-phase condition represent the intrinsic hydrogen effect. Monotonic and cyclic strength increase at the expense of ductility with increasing hydrogen concentration. The brittle to ductile transition temperature shifts to higher values and the fatigue crack propagation threshold value decreases. The microstructure of the metastable, usually two-phase -titanium alloys is strongly affected by hydrogen, although the extent of this effect depends not only on the hydrogen concentration but also on the temperature of charging. This microstructural influence (extrinsic effect) changes the mechanical properties in the opposite direction as compared to the intrinsic hydrogen effect.

  19. Environmental protection to 922K (1200 F) for titanium alloys

    Science.gov (United States)

    Groves, M. T.

    1973-01-01

    Evaluations are presented of potential coating systems for protection of titanium alloys from hot-salt stress-corrosion up to temperatures of 755 K (900 F) and from oxidation embrittlement up to temperature of 922 K (1200 F). Diffusion type coatings containing Si, Al, Cr, Ni or Fe as single coating elements or in various combinations were evaluated for oxidation protection, hot-salt stress-corrosion (HSSC) resistance, effects on tensile properties, fatigue properties, erosion resistance and ballistic impact resistance on an alpha and beta phase titanium alloy (Ti-6Al-2Sn-4Zr-2Mo). All of the coatings investigated demonstrated excellent oxidation protectiveness, but none of the coatings provided protection from hot-salt stress-corrosion. Experimental results indicated that both the aluminide and silicide types of coatings actually decreased the HSSC resistance of the substrate alloy. The types of coatings which have typically been used for oxidation protection of refractory metals and nickel base superalloys are not suitable for titanium alloys because they increase the susceptibility to hot-salt stress-corrosion, and that entirely new coating concepts must be developed for titanium alloy protection in advanced turbine engines.

  20. Thermodynamics of Titanium-Aluminum-Oxygen Alloys Studied

    Science.gov (United States)

    Copland, Evan H.; Jacobson, Nathan S.

    2001-01-01

    Titanium-aluminum alloys are promising intermediate-temperature alloys for possible compressor applications in gas-turbine engines. These materials are based on the a2-Ti3Al + g-TiAl phases. The major issue with these materials is high oxygen solubility in a2-Ti3Al, and oxidation of unsaturated alloys generally leads to mixed non-protective TiO2+Al2O3 scales. From phase diagram studies, oxygen saturated a2-Ti3Al(O) is in equilibrium with Al2O3; however, oxygen dissolution has a detrimental effect on mechanical properties and cannot be accepted. To better understand the effect of oxygen dissolution, we examined the thermodynamics of titanium-aluminum-oxygen alloys.

  1. Implantation-plasma treatment of martensitic steel and titanium alloy

    International Nuclear Information System (INIS)

    One of the effective methods of deep modification of the surface of steels and alloys is the combination of ion implantation and plasma nitriding. In this work, the long-range effect is demonstrated in the case of combination of the effect of high- and low-energy ions of nitrogen on a martensitic steel for each ion implantation is usually not effective, and a titanium alloy used widely in industry

  2. Ion implantation of titanium alloys for improved fretting resistance

    International Nuclear Information System (INIS)

    Fretting is a major problem with titanium alloy aerospace components. A fretting apparatus was designed to generate low amplitude motions for testing of various flat and cylindrical geometries. Using it, ion-implanted coupons of Ti-6Al-4V and Ti-Al alloys were compared for fretting performance against untreated specimens. Surface profilometry was used as the primary method of analytical evaluation. The ion implantation treatment provided improvements in fretting reduction. (orig.)

  3. Improvement of tribological properties of titanium alloys by ion implantation

    International Nuclear Information System (INIS)

    Influence of implantation regimes on mechanical and tribotechnical properties of surface layer of VT6 titanium alloy were studied. Interrupted beams Cu+ ions with 15 Hz frequency and 60 keV energy were used for implantation. After implantation of VT6 alloy samples the wearability rate of the polymer sample decreases almost by 3 times and the friction coefficient by 1.5 times

  4. Ultra high strength beta titanium alloy for fasteners

    International Nuclear Information System (INIS)

    A new high strength titanium alloy has been developed primarily intended for fastener applications. While Ti-6Al-4V is used extensively as a fastener alloy in the aerospace industry, its shear strength allowable is limited to 655 MPa (95 ksi). For higher shear strength requirements, various steels or nickel-based alloys are used (up to 860 MPa (125 ksi)), but with the attendant density penalty. This new alloy is intended to provide the 860 MPa shear strength at roughly a 40% weight savings. After screening various alloy systems, the optimum chemistry has been selected as follows: Ti-6.0V-6.2Mo-5.7Fe-3Al. In light of its 125 ksi shear strength goal, the alloy has been designated TIMETAL reg-sign 125

  5. Mechanical properties of titanium alloys with strengthened surface layers

    Directory of Open Access Journals (Sweden)

    I.M. Pohreliuk

    2011-12-01

    Full Text Available Influence of oxinitriding and boriding on the mechanical properties (ultimate strength to destruction at uniaxial tension, plasticity, tendency to delayed destruction, fatigue resistance at bending with rotation, fatigue life at lowcycle pure bending of titanium alloys is studied.

  6. ON STRAIN RATE SENSITIVITY OF BETA-TITANIUM ALLOYS

    OpenAIRE

    Kobayashi, A.; Takeda, N.; Ogihara, S.; Li, Y.

    1991-01-01

    Ti-15V-3Cr-3A1-3Sn beta-titanium alloys are subjected to 103/s tensile strain rate by the one bar method to investigate strain rate sensitivity. It is found that the ultimate strength, the total elongation and the absorbed energy, all increase with the increase in strain rate. Dynamical stress-strain curves are also obtained.

  7. LATTICE CORRESPONDANCE AND CRYSTALLOGRAPHY OF MARTENSITES IN TITANIUM ALLOYS

    OpenAIRE

    Mukherjee, K.; Kato, M.

    1982-01-01

    Lattice correspondence, crystallography and internal structure of various martensites in titanium alloys are discussed in a unified manner. Strain energy minimization criterion is applied to discuss the orientation of habit planes and lattice invariant strains. A comparison of the present analysis with experimental observations has been carried out.

  8. Study of the Phase Transfer in Titanium-Skandium Alloys

    Czech Academy of Sciences Publication Activity Database

    Brožek, V.; Dufek, V.; Rohan, Pavel; Ettmayer, P.

    Ostrava : TANGER, Ostrava, 2002, s. E-19. [International Metalurgical & Materials Conference /11th./ METAL 2002.. Hradec nad Moravicí (CZ), 14.05.2002-16.05.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : titanium- scandium alloys Subject RIV: BL - Plasma and Gas Discharge Physics

  9. Development of Low Density Titanium Alloys for Structural Applications

    Science.gov (United States)

    Froes, F. H.; Suryanarayana, C.; Powell, C.; Ward-Close, C. Malcolm; Wilkes, D. M. J.

    1996-01-01

    In this report the results of a program designed to reduce the density of titanium by adding magnesium are presented. Because these two elements are immiscible under conventional ingot metallurgy techniques, two specialized powder metallurgy methods namely, mechanical alloying (MA) and physical vapor deposition (PVD) were implemented. The mechanical alloying experiments were done both at the University of Idaho and at the Defense Research Agency in UK. Since titanium is reactive with interstitial elements, a secondary goal of this research was to correlate solubility extensions with interstitial contamination content, especially oxygen and nitrogen. MA was carried out in SPEX 8000 shaker mils and different milling containers were utilized to control the level of contamination. Results showed that solubilities of Mg in Ti were obtained up to 28 at.% (16.4 wt. %) Mg in Ti for Ti-39.6 at. % (25 wt. %) Mg alloys, which greatly exceed those obtained under equilibrium conditions. This reflects a density reduction of approximately 26 %. Contamination of oxygen and nitrogen seemed to increase the solubility of magnesium in titanium in some cases; however, we were not able to make a clear correlation between contamination levels with solubilities. Work at the DRA has emphasized optimization of present PVD equipment, specifically composition and temperature control. Preliminary PVD data has shown Ti-Mg deposits have successfully been made up to 2 mm thick and that solubility extensions were achieved. The potential for density reduction of titanium by alloying with magnesium has been demonstrated; however, this work has only scratched the surface of the development of such low density alloys. Much research is needed before such alloys could be implemented into industry. Further funding is required in order to optimize the MA/PVD processes including contamination control, determination of optimal alloy compositions, microstructure development, and mechanical property

  10. Phase evolution and alloying mechanism of titanium aluminide nanoparticles

    International Nuclear Information System (INIS)

    Highlights: • An evolution of phase composition of TiAl alloy nanoparticles was investigated. • An alloying mechanism was analyzed according to the variation of phase composition. • The alloying reaction was possible to perform between the small clusters of Ti and Al. • The alloying product is determined by the temperature of Ti and Al small clusters. • The alloying mechanism can be explained based on Gibbs free energy of alloying reaction. - Abstract: The evolution of phase composition of titanium aluminide nanoparticles synthesized by the flow-levitation method was systematically investigated by adjustment of the evaporating temperature of the mixed metallic droplet and the X-ray diffraction spectrum. Their alloying mechanism was analyzed according to the variation of phase composition. ε(h, l)-TiAl3, γ-TiAl and α2-Ti3Al phases are gradually formed in TiAl alloy nanoparticles with the increasing of evaporating temperature of the mixed droplet. The alloying reaction is possible to perform between the small clusters of Ti and Al during the cooling process with high cooling rate. And the alloying mechanism can be explained based on the Gibbs free energy of alloying reaction of Ti and Al small clusters

  11. Phase evolution and alloying mechanism of titanium aluminide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Luo, J.S.; Li, K.; Li, X.B. [Research Center of Laser Fusion, Science and Technology on Plasma Physics Laboratory, China Academy of Engineering Physics, Mianyang 621900 (China); Shu, Y.J. [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900 (China); Tang, Y.J., E-mail: tangyongjian2000@sina.com [Research Center of Laser Fusion, Science and Technology on Plasma Physics Laboratory, China Academy of Engineering Physics, Mianyang 621900 (China)

    2014-12-05

    Highlights: • An evolution of phase composition of TiAl alloy nanoparticles was investigated. • An alloying mechanism was analyzed according to the variation of phase composition. • The alloying reaction was possible to perform between the small clusters of Ti and Al. • The alloying product is determined by the temperature of Ti and Al small clusters. • The alloying mechanism can be explained based on Gibbs free energy of alloying reaction. - Abstract: The evolution of phase composition of titanium aluminide nanoparticles synthesized by the flow-levitation method was systematically investigated by adjustment of the evaporating temperature of the mixed metallic droplet and the X-ray diffraction spectrum. Their alloying mechanism was analyzed according to the variation of phase composition. ε(h, l)-TiAl{sub 3,} γ-TiAl and α{sub 2}-Ti{sub 3}Al phases are gradually formed in TiAl alloy nanoparticles with the increasing of evaporating temperature of the mixed droplet. The alloying reaction is possible to perform between the small clusters of Ti and Al during the cooling process with high cooling rate. And the alloying mechanism can be explained based on the Gibbs free energy of alloying reaction of Ti and Al small clusters.

  12. Wear behavior of tetragonal zirconia polycrystal versus titanium and titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kanbara, Tsunemichi; Yajima, Yasutomo [Department of Oral Implantology, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502 (Japan); Yoshinari, Masao, E-mail: yosinari@tdc.ac.jp [Division of Oral Implant Research, Oral Health Science Center, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502 (Japan)

    2011-04-15

    The aim of this study was to clarify the influence of tetragonal zirconia polycrystal (TZP) on the two-body wear behavior of titanium (Ti). Two-body wear tests were performed using TZP, two grades of cp-Ti or Ti alloy in distilled water, and the cross-sectional area of worn surfaces was measured to evaluate the wear behavior. In addition, the surface hardness and coefficient of friction were determined and an electron probe microanalysis performed to investigate the underlying mechanism of wear. The hardness of TZP was much greater than that of Ti. The coefficient of friction between Ti and Ti showed a higher value than the Ti/TZP combination. Ti was more susceptible to wear by both TZP and Ti than TZP, indicating that the mechanism of wear between TZP and Ti was abrasive wear, whereas that between Ti and Ti was adhesive wear. No remarkable difference in the amount of wear in Ti was observed between TZP and Ti as the opposite material, despite the hardness value of Ti being much smaller than that of TZP. (communication)

  13. Titanium-zirconium-phosphonate hybrid film on 6061 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Shuanghong WANG; Lei WANG; Changsheng LIU

    2011-01-01

    Three titanium-zirconium-phosphonate hybrid films were formed on AA6061 aluminum alloy by immersing in fluorotitanic acid and fluorozirconic acid based solution containing different phosphonic acids for protective coatings of aluminium alloy. The corrosion resistance of three hybrid films as the substitute for chromate film were evaluated and compared. The neutral salt spray test was explored,the immersion test was conducted and electrochemical test was also executed. The hybrid films exhibited well-pleasing corrosion resistance and adhesion to epoxy resin paints. It was found out that the hybrid films could efficiently be a substitute for chromate based primer over aluminium alloy.

  14. Producing Foils From Direct Cast Titanium Alloy Strip

    Science.gov (United States)

    Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

    1996-01-01

    This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

  15. Improved adherence of sputtered titanium carbide coatings on nickel- and titanium-base alloys

    Science.gov (United States)

    Wheeler, D. R.; Brainard, W. A.

    1979-01-01

    Rene 41 and Ti-6Al-4V alloys were radio frequency sputter coated with titanium carbide by several techniques in order to determine the most effective. Coatings were evaluated in pin-on-disk tests. Surface analysis by X-ray photoelectron spectroscopy was used to relate adherence to interfacial chemistry. For Rene 41, good coating adherence was obtained when a small amount of acetylene was added to the sputtering plasma. The acetylene carburized the alloy surface and resulted in better bonding to the TiC coating. For Ti-6Al-4V, the best adherence and wear protection was obtained when a pure titanium interlayer was used between the coating and the alloy. The interlayer is thought to prevent the formation of a brittle, fracture-prone, aluminum oxide layer.

  16. Degradation mode survey of titanium-base alloys

    International Nuclear Information System (INIS)

    Of the materials reviewed, commercially pure titanium, Ti Gr 2, is the most susceptible to crevice corrosion. Ti Gr 7, 12, and 16 are likely to be resistant to crevice corrosion under the current expected Yucca Mountain repository conditions. Although Grade 7 has the greatest resistance to crevice corrosion it is also the most expensive. Although the possibility of sustained loads cracking exists, it has not yet been observed in a Ti alloys. For hydride precipitation to occur 100 degrees C, the hydrogen concentration would need to be relatively high, much higher than the maximum amount of hydrogen allowed during the manufacture of (α Ti alloys (0.0 15 wt%). A large amount of (SCC) stress corrosion cracking data accumulated at SNL and BNL for the WIPP program and by the Canadian Waste Management Program on titanium grades 2 and 12 indicates that there is no SCC at naturally occurring potentials in various brines. Hydride-induced cracking of titanium is a possibility and therefore, further investigation of this phenomenon under credible repository conditions is warranted. One disadvantage of titanium and its alloys is that their strengths decrease rather rapidly with temperature. This is due to the strong temperature dependence of interstitial solute strengthening mechanisms. Ti Gr 12 and 16 are recommended for further consideration as candidate materials for high level nuclear waste containers

  17. Wire electrochemical machining with axial electrolyte flushing for titanium alloy

    Institute of Scientific and Technical Information of China (English)

    Qu Ningsong; Fang Xiaolong; Li Wei; Zeng Yongbin; Zhu Di

    2013-01-01

    Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge.Electrochemical machining is an important issue in the fabrication of titanium and titanium alloys.Wire electrochemical machining (WECM) is mainly used for workpiece cutting under the condition of different thickness plates.It has a great advantage over wire electro-discharge machining,which is the absence of heat-affected zone around the cutting area.Moreover,the wire electrode in WECM could be used repetitively because it is not worn out.Thus,much attention has been paid to WECM.The effective way of removing electrolysis products is of importance to WECM.In this paper,the axial electrolyte flushing is presented to WECM for removing electrolysis products and renewing electrolyte.The Taguchi experiment is conducted to optimize the machining parameters,such as wire feedrate,machining voltage,electrolyte concentration,etc.Experimental results show that WECM with axial electrolyte flushing is a promising issue in the fabrication of titanium alloy (TC1).The feasibility of multi-wire electrochemical machining is also demonstrated to improve the machining productivity of WECM.

  18. Corrosion resistance improvement of titanium base alloys

    Directory of Open Access Journals (Sweden)

    Mihai V. Popa

    2010-01-01

    Full Text Available The corrosion resistance of the new Ti-6Al-4V-1Zr alloy in comparison with ternary Ti-6Al-4V alloy in Ringer-Brown solution and artificial Carter-Brugirard saliva of different pH values was studied. In Ringer-Brown solution, the new alloy presented an improvement of all electrochemical parameters due to the alloying with Zr; also, impedance spectra revealed better protective properties of its passive layer. In Carter-Brugirard artificial saliva, an increase of the passive film thickness was proved. Fluoride ions had a slight negative influence on the corrosion and ion release rates, without to affect the very good stability of the new Ti-6Al-4V-1Zr alloy.

  19. Hydrothermal treatment of titanium alloys for the enhancement of osteoconductivity

    International Nuclear Information System (INIS)

    The surface wettability of implants is a crucial factor in their osteoconductivity because it influences the adsorption of cell-attached proteins onto the surface. In this study, a single-step hydrothermal surface treatment using distilled water at a temperature of 180 °C for 3 h was applied to titanium (Ti) and its alloys (Ti–6Al–4V, Ti–6Al–7Nb, Ti–29Nb–13Ta–4.6Zr, Ti–13Cr–1Fe–3Al; mass%) and compared with as-polished Ti implants and with implants produced by anodizing Ti in 0.1 M of H3PO4 with applied voltages from 0 V to 150 V at a scanning rate of 0.1 V s−1. The surface-treated samples were stored in a five time phosphate buffered saline (× 5 PBS(−)) solution to prevent increasing the water contact angle (WCA) with time. The surface characteristics were evaluated using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Auger electron spectroscopy, surface roughness, and contact angle measurement using a 2 μL droplet of distilled water. The relationship between WCA and osteoconductivity at various surface modifications was examined using in vivo tests. The results showed that a superhydrophilic surface with a WCA ≤ 10° and a high osteoconductivity (RB–I) of up to 50% in the cortical bone part, about four times higher than the as-polished Ti and Ti alloys, were provided by the combination of the hydrothermal surface treatment and storage in × 5 of PBS(−). - Highlights: • Hydrothermal treatment in distilled water was applied to titanium alloys. • Surface characteristics and osteoconductivity by in vivo test were evaluated. • Water contact angles of titanium alloys were decreased by hydrothermal treatment. • Osteoconductivity of titanium alloys improved notably by hydrothermal treatment after stored in × 5 of PBS (−)

  20. Hydroxyapatite coating by biomimetic method on titanium alloy using concentrated SBF

    Indian Academy of Sciences (India)

    S Bharati; M K Sinha; D Basu

    2005-10-01

    This article reports a biomimetic approach for coating hydroxyapatite on titanium alloy at ambient temperature. In the present study, coating was obtained by soaking the substrate in a 5 times concentrated simulated body fluid (5XSBF) solution for different periods of time with and without the use of CaO–SiO2 based glass as a possible source of nucleating agent of apatite formation. Optical microscopic and SEM observations revealed the deposition of Ca–P layer on the titanium alloy by both the methods. Thickness of coating was found to increase with the increase in immersion time. The use of glass did not help the formation of apatite nuclei on the substrate and the coating obtained by this method was also not uniform. EDX analysis indicated that the coating consisted of Ca–P based apatite globules, mostly in agglomerated form, and its crystallinity was poor as revealed by XRD.

  1. Mechanodynamical analysis of nickel-titanium alloys for orthodontics application

    International Nuclear Information System (INIS)

    Nickel-titanium alloys may coexist in more than one crystalline structure. There is a high temperature phase, austenite, and a low temperature phase, martensite. The metallurgical basis for the superelasticity and the shape memory effect relies in the ability of these alloys to transform easily from one phase to another. There are three essential factors for the orthodontist to understand nickel-titanium alloys behaviour: stress; deflection; and temperature. These three factors are related to each other by the stress-deflection, stress-temperature and deflection-temperature diagrams. This work was undertaken with the objective to analyse commercial nickel-titanium alloys for orthodontics application, using the dynamical mechanical analyser - DMA. Four NiTi 0,017 X 0,025'' archwires were studied. The archwires were Copper NiTi 35 deg C (Ormco), Neo Sentalloy F200 (GAC), Nitinol Superelastic (Unitek) and NiTi (GAC). The different mechanodynamical properties such as elasticity and damping moduli were evaluated. Each commercial material was evaluated with and without a 1 N static force, aiming to evaluate phase transition temperature variation with stress. The austenitic to martensitic phase ratio, for the experiments without static force, was in the range of 1.59 to 1.85. For the 1 N static force tests the austenitic to martensitic phase ratio, ranged from 1.28 to 1.57 due to the higher martensite elasticity modulus. With elastic modulus variation with temperature behaviour, the orthodontist has the knowledge of the force variation applied in the tooth in relation to the oral cavity temperature change, for nickel-titanium alloys that undergo phase transformation. The damping capacity of the studied alloys depends on the materials state: martensitic phase; austenitic phase or during phase transformation. The martensitic phase shows higher dumping capacity. During phase transformation, an internal friction peak may be observed for the CuNiTi 35 deg C and Neo Sentalloy F

  2. Nanoprecipitation in a beta-titanium alloy

    International Nuclear Information System (INIS)

    Highlights: • In-situ SANS has been applied to study precipitation in β -Ti alloy. • Rate of precipitation is far more rapid in the cold-rolled alloy than non cold-rolled. • The rapid precipitation dramatically improves the alloy hardness. • Extensive ω phase is present after 400 °C/16 h heat-treatment. • SANS modelling and TEM-EDX shows the precipitates are Ti rich. - Abstract: This paper represents the first application of small angle neutron scattering (SANS) to the study of precipitate nucleation and growth in β-Ti alloys in an attempt to observe both the precipitation process in-situ and to quantify the evolving microstructure that affects mechanical behaviour. TEM suggests that athermal ω can be induced by cold-rolling Gum metal, a β-Ti alloy. During thermal exposure at 400°C, isothermal ω particles precipitate at a greater rate in cold-rolled material than in the recovered, hot deformed state. SANS modelling is consistent with disc shaped nanoparticles, with length and radius under 6nm after thermal exposures up to 16h. Modelling suggests that the nanoprecipitate volume fraction and extent of Nb partitioning to the β matrix is greater in the cold-rolled material than the extruded. The results show that nucleation and growth of the nanoprecipitates impart strengthening to the alloy

  3. Nanoprecipitation in a beta-titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Coakley, James, E-mail: j.coakley06@imperial.ac.uk [Department of Materials, Imperial College, South Kensington, London SW7 2AZ, England (United Kingdom); Vorontsov, Vassili A. [Department of Materials, Imperial College, South Kensington, London SW7 2AZ, England (United Kingdom); Littrell, Kenneth C. [Oak Ridge National Laboratory, Chemical and Engineering Materials Division, Oak Ridge, TN 37831 (United States); Heenan, Richard K. [Rutherford Appleton Laboratory, Didcot, Oxon OX11 0QX, England (United Kingdom); Ohnuma, Masato [Laboratory of Quantum Beam System Engineering, Hokkaido University, Sapporo 060-0808 (Japan); Jones, Nicholas G. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ, England (United Kingdom); Dye, David [Department of Materials, Imperial College, South Kensington, London SW7 2AZ, England (United Kingdom)

    2015-02-25

    Highlights: • In-situ SANS has been applied to study precipitation in β -Ti alloy. • Rate of precipitation is far more rapid in the cold-rolled alloy than non cold-rolled. • The rapid precipitation dramatically improves the alloy hardness. • Extensive ω phase is present after 400 °C/16 h heat-treatment. • SANS modelling and TEM-EDX shows the precipitates are Ti rich. - Abstract: This paper represents the first application of small angle neutron scattering (SANS) to the study of precipitate nucleation and growth in β-Ti alloys in an attempt to observe both the precipitation process in-situ and to quantify the evolving microstructure that affects mechanical behaviour. TEM suggests that athermal ω can be induced by cold-rolling Gum metal, a β-Ti alloy. During thermal exposure at 400°C, isothermal ω particles precipitate at a greater rate in cold-rolled material than in the recovered, hot deformed state. SANS modelling is consistent with disc shaped nanoparticles, with length and radius under 6nm after thermal exposures up to 16h. Modelling suggests that the nanoprecipitate volume fraction and extent of Nb partitioning to the β matrix is greater in the cold-rolled material than the extruded. The results show that nucleation and growth of the nanoprecipitates impart strengthening to the alloy.

  4. Plasma surface alloying of titanium alloy for enhancing burn-resistant property

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping-ze; XU Zhong; ZHANG Gao-hui; HE Zhi-yong; YAO Zheng-jun

    2006-01-01

    Conventional titanium alloy may be ignited and burnt under high temperature, high pressure and high gas flow velocity condition. In order to avoid this problem, burn-resistant alloying layers were made on the surface of Ti-6Al-4V and Ti-6.5Al-0.3Mo-1.5Zr-0.25Si titanium alloys by using double glow plasma surface alloying technology (DG Technology). Two typical burn-resistant layers Ti-Cr and Ti-Mo were made by DG plasma chromizing and DG plasma molybdenizing, respectively. Burn-resistant properties were tested by layer ignition method using 2 kW laser machine. Ignition experiments result reveals that the ignition temperature of alloyed layer with Mo and Cr concentration above 10% is about 200℃ higher than ignition temperature of Ti-6Al-4V substrate.

  5. Modeling and research of temperature distribution in surface layer of titanium alloy workpiece during AEDG and conventional grinding

    Science.gov (United States)

    Gołąbczak, M.; Gołąbczak, A.; Konstantynowicz, A.; Święcik, R.

    2016-06-01

    Titanium and its alloys are widely recognized as the hardly machinable materials, especially due to their relatively high hardness, low thermal conductivity and possible subcritical superplasticity. Then, a thorough control of the machining process parameters shall be maintained. In this paper, we have concentrated on the grinding of the Ti6Al4V titanium alloy using cBN (boron nitride) grinding wheel combined with the AEDG (abrasive electrodischarge grinding) process. The mathematical model we have dealt with has been based mainly on Jaeger model of the heat taking over between sliding bodies with substantial upgrades related to: estimation of the frictional heat generating based on friction forces distribution,

  6. Producing titanium-niobium alloy by high energy beam

    Energy Technology Data Exchange (ETDEWEB)

    Sharkeev, Yu. P., E-mail: sharkeev@ispms.tsc.ru [Institute of Strength Physics and Materials Science, SB RAS, 2/4 Akademicheski Prosp., Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Golkovski, M. G., E-mail: golkoski@mail.ru [Budker Institute of Nuclear Physics, 11 Akademika Lavrentiev Prosp., Novosibirsk, 630090 (Russian Federation); Glukhov, I. A., E-mail: gia@ispms.tsc.ru; Eroshenko, A. Yu., E-mail: eroshenko@ispms.tsc.ru; Fortuna, S. V., E-mail: s-fortuna@mail.ru [Institute of Strength Physics and Materials Science, SB RAS, 2/4 Akademicheski Prosp., Tomsk, 634055 (Russian Federation); Bataev, V. A., E-mail: bataev@vadm.ustu.ru [Novosibirsk State Technical University, 20 K. Marx Prosp., Novosibirsk, 630073 (Russian Federation)

    2016-01-15

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element.

  7. Producing titanium-niobium alloy by high energy beam

    International Nuclear Information System (INIS)

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element

  8. Producing titanium-niobium alloy by high energy beam

    Science.gov (United States)

    Sharkeev, Yu. P.; Golkovski, M. G.; Glukhov, I. A.; Eroshenko, A. Yu.; Bataev, V. A.; Fortuna, S. V.

    2016-01-01

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element.

  9. Environmental protection of titanium alloys at high temperatures

    Science.gov (United States)

    Wright, I. G.; Wood, R. A.; Seltzer, M. S.

    1974-01-01

    Various concepts were evaluated for protecting titanium alloys from oxygen contamination at 922 K (1200 F) and from hot-salt stress-corrosion at 755 K (900 F). It is indicated that oxygen-contamination resistance can be provided by a number of systems, but for hot-salt stress-corrosion resistance, factors such as coating integrity become very important. Titanium aluminides resist oxygen ingress at 922 K through the formation of alumina (on TiAl3) or modified TiO2 (on Ti3Al, TiAl) scales. TiAl has some resistance to attack by hot salt, but has limited ductility. Ductile Ti-Ni and Ti-Nb-Cr-Al alloys provide limited resistance to oxygen ingress, but are not greatly susceptible to hot-salt stress-corrosion cracking.

  10. Low-Temperature Forming of Beta Titanium Alloys

    Science.gov (United States)

    Kaneko, R. S.; Woods, C. A.

    1983-01-01

    Low cost methods for titanium structural fabrication using advanced cold-formable beta alloys were investigated for application in a Mach 2.7 supersonic cruise vehicle. This work focuses on improving processing and structural efficiencies as compared with standard hot formed and riveted construction of alpha-beta alloy sheet structure. Mechanical property data and manufacturing parameters were developed for cold forming, brazing, welding, and processing Ti-15V-3Cr-3Sn-3Al sheet, and Ti-3Al-8V-6Cr-4Zr on a more limited basis. Cost and structural benefits were assessed through the fabrication and evaluation of large structural panels. The feasibility of increasing structural efficiency of beta titanium structure by selective reinforcement with metal matrix composite was also explored.

  11. Tool Failure Analysis in High Speed Milling of Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiuxu; MEYER Kevin; HE Rui; YU Cindy; NI Jun

    2006-01-01

    In high speed milling of titanium alloys the high rate of tool failure is the main reason for its high manufacturing cost. In this study, fractured tools which were used in a titanium alloys 5-axis milling process have been observed both in the macro scale using a PG-1000 light microscope and in the micro scale using a Scanning Electron Microscope (SEM) respectively. These observations indicate that most of these tool fractures are the result of tool chipping. Further analysis of each chipping event has shown that beachmarks emanate from points on the cutting edge. This visual evidence indicates that the cutting edge is failing in fatigue due to cyclical mechanical and/or thermal stresses. Initial analyses explaining some of the outlying conditions for this phenomenon are discussed. Future analysis regarding determining the underlying causes of the fatigue phenomenon is then outlined.

  12. Biocompatibility evaluation of nickel-titanium shape memory metal alloy

    OpenAIRE

    Ryhänen, J. (Jorma)

    1999-01-01

    Abstract The shape memory effect, superelasticity, and good damping properties, uncommon in other implant alloys, make the nickel-titanium shape memory metal alloy (Nitinol or NiTi) a fascinating material for surgical applications. It provides a possibility to make self-locking, self-expanding and self-compressing implants. The purpose of this work was to determine if NiTi is a safe material for surgical implant applications. The primary cytotoxicity and the corrosion rate of NiTi were...

  13. Abrasive water-jet: controlled depth milling of titanium alloys

    OpenAIRE

    Fowler, Gary

    2003-01-01

    Abrasive waterjet (AWJ) technology is used in a routine manner in manufacturing industry to cut materials that are difficult to cut by other methods. Whilst the technology for through cutting of materials is mature, the process is also being developed for controlled depth milling (CDM) of materials. The aerospace industry have a requirement to remove redundant material from components manufactured from difficult to machine Ti6Al4V and titanium aluminide alloys and thus reduce component w...

  14. Stabilisation Treatment of Titanium Alloy VT9

    Directory of Open Access Journals (Sweden)

    B.K. Singh

    1999-04-01

    Full Text Available Systematic investigations of tensile properties of alpha + beeta type high temperature Ti alloy VT9 (Ti-6 Al-3.3 Mo-1.65 Zr-0.3 Si wt. per cent developed on ageing at 803, 823 and 853 K for 2, 6 and 121 hr, respectively following the solution treatment in alpha + beeta phase field at 1233 K for 1 hr and air cooling, show that the highest tensile strength values are obtained on ageing at 823 K for 6 or 12 hr. In view of the shorter duration of ageing, the ageing treatment at 823 K for 6 hr is considered appropriate stabilisation treatment for this alloy. The tensile strength values of the alloy VT9 from the newly-established stabilisation treatment are considerably higher than those resulting from the earlier reported stabilisation treatment (at 803 K for 6 hr, in particular at room temperature.

  15. Effect of Nanosheet Surface Structure of Titanium Alloys on Cell Differentiation

    OpenAIRE

    Satoshi Komasa; Tetsuji Kusumoto; Yoichiro Taguchi; Hiroshi Nishizaki; Tohru Sekino; Makoto Umeda; Joji Okazaki; Takayoshi Kawazoe

    2014-01-01

    Titanium alloys are the most frequently used dental implants partly because of the protective oxide coating that spontaneously forms on their surface. We fabricated titania nanosheet (TNS) structures on titanium surfaces by NaOH treatment to improve bone differentiation on titanium alloy implants. The cellular response to TNSs on Ti6Al4V alloy was investigated, and the ability of the modified surfaces to affect osteogenic differentiation of rat bone marrow cells and increase the success rate ...

  16. Modelling of the Mechanical Behaviour of Ultra-Fine Grained Titanium Alloys at High Strain Rates

    OpenAIRE

    Halle, T.; Herzig, N.; Krüger, L; Meyer, L.W.; Musch, D.; Razorenov, S. V.; Skripnyak, E. G.; Skripnyak, V. A.

    2008-01-01

    Results of numerical simulations of the mechanical behaviour of coarse grained and UFG titanium alloys under quasi-static uniaxial compression and plane shock wave loading are presented in this paper. Constitutive equations predict the strain hardening behaviour, the strain rate sensitivity of the flow stress and the temperature softening of titanium alloys with a range of grain sizes from 20 µm to 100 nm. Characteristics of the mechanical behaviour of UFG a and a+ß titanium alloys in wide ra...

  17. Mechanical properties and corrosion resistance of some titanium alloys in marine environment

    OpenAIRE

    Dupuis Jennifer; Chenon M.; Faure S.; Razan F.; Gloriant T.

    2013-01-01

    Titanium alloys are used in several fields such as aerospace industry or biomedical. They are increasingly used in marine applications, a highly corrosive environment. We chose titanium alloys for their good properties such as high mech. strength, low d. and excellent corrosion resistance. This study is focused on titanium alloys potentially interesting to be used in marine transports, and mainly for the boats fittings such as a winch for example. [on SciFinder(R)

  18. Ultrasonic Welding of Aluminium to Titanium: Microstructure, Properties, and Alloying Effects

    OpenAIRE

    Zhang, Chaoqun

    2015-01-01

    Use of welded titanium alloy to aluminium alloy structures in the aerospace industry has a number of potential benefits for both cost and weight saving by enabling titanium to be used only in the most critical parts, with the cheaper and lighter aluminum alloy making up the rest of the structure. However, due to the formation of brittle intermetallic compounds (IMC) at interface and the enormous gap in melting point, the welding of titanium to aluminium remains a major challenge. Solid state ...

  19. Carbon effect on the structure and plasticity characteristics of titanium β-alloys

    International Nuclear Information System (INIS)

    In this paper a study is made of the structure and mechanical properties of the β alloy system Ti-Mo-Zr-Sn (the composition of which is equivalent to the β III alloy used abroad) containing different amounts of carbon. Study of the β-titanium alloy containing 0.1% C revealed the presence of particles of titanium carbide. Separation of the titanium carbide promotes a reduction in impact strength, an increased tendency toward cold shortness, and poorer workability. (author)

  20. Hot deformation behavior of TC18 titanium alloy

    Directory of Open Access Journals (Sweden)

    Jia Bao-Hua

    2013-01-01

    Full Text Available Isothermal compression tests of TC18 titanium alloy at the deformation temperatures ranging from 25°C to 800°C and strain rate ranging from 10-4 to 10-2 s-1 were conducted by using a WDW-300 electronic universal testing machine. The hot deformation behavior of TC18 was characterized based on an analysis of the true stress-true strain curves of TC18 titanium alloy. The curves show that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the strain rate play an important role in the flow stress when increasing the temperatures. By taking the effect of strain into account, an improved constitutive relationship was proposed based on the Arrhenius equation. By comparison with the experimental results, the model prediction agreed well with the experimental data, which demonstrated the established constitutive relationship was reliable and can be used to predict the hot deformation behavior of TC18 titanium alloy.

  1. Effect of alloy composition on the volume fraction of beta phase in duplex titanium alloys

    International Nuclear Information System (INIS)

    Titanium alloys are strong, light, corrosion resistant and superplastic. While many of them show superplastic behavior, working and forging temperatures are still high, 850-925 degree C, and their range is narrow. Moreover, the material's resistance to deformation is not negligible and, therefore, the cost of making dies and presses for forging or hot deformation is high and it poses a serious problem. To increase the efficiency and to reduce the temperature of hot deformation, increasing the volume fraction of the beta phase present in duplex titanium alloys is suggested. With the introduction of the beta-modified Ti-6Al-4V alloy the decrease in the temperature and the increase in the strain rate of the superplastic regime promise to make superplastic forming of this alloy even more economical, and many researches have been made. In this study, efforts are put on designing new duplex alloys based on the Ti-6Al-4V and Ti-Al-Fe systems, which will have a beta volume fraction of 40-50 percent at around 800 degree C. To accomplish this, experimental volume fractions of the beta phase in several titanium alloys are being compared with predicted and calculated ones using phase equilibria analyses and some suggestions will be made on modifying the alloy compositions. For comparison, the quaternary Ti-V-Fe-Al system and their subsystems are chosen due to availability of both experimental and thermodynamic data

  2. Titanium distribution in uranium--titanium alloys. [0. 5 and 0. 75 wt % Ti

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, R. L.

    1976-11-01

    Electron-beam microprobe analyses were used to assess the uniformity of titanium distribution in both as-cast and heat-treated uranium-0.5 weight percent titanium (U-0.5 Ti) and uranium-0.75 weight percent titanium (U-0.75 Ti) alloys. Microsegregation due to coring was readily smoothed by heat treatment, but long-range variability remained (on the order of 0.1 wt percent). An attempt was made to examine titanium macrosegregation by a scanning image analysis measurement of the volume fraction of U/sub 2/Ti in an equilibrium microstructure, but a method for consistently obtaining resolvable U/sub 2/Ti particles could not be developed. As judged by tensile properties, a homogenization heat treatment of 1000/sup 0/ C for 24 hours was apparently the most effective of those tried for homogenizing the U-0.75 Ti alloy. The large grain size of the as-cast tensile bars apparently caused variability in the tensile-test results such that it was difficult to closely assess the optimum values of the heat-treatment parameters. 8 tables, 25 fig. (auth)

  3. Laser cladding of titanium alloy coating on titanium aluminide alloy substrate

    Institute of Scientific and Technical Information of China (English)

    徐子文; 黄正; 阮中健

    2003-01-01

    A new diffusion bonding technique combined with laser cladding process was developed to join TiAl alloy to itself and Ti-alloys. In order to enhance the weldability of TiAl alloys, Ti-alloy coatings were fabricated by laser cladding on the TiAl alloy. Ti powder and shaped Ti-alloy were respectively used as laser cladding materials. The materials characterization was carried out by OM, SEM, EDS and XRD analysis. The results show that the laser cladding process with shaped Ti-alloy remedy the problems present in the conventional process with powder, such as impurities, cracks and pores. The diffusion bonding of TiAl alloy with Ti-alloy coating to itself and Ti-alloy was carried out with a Gleeble 1500 thermal simulator. The sound bonds of TiAl/TiAl, TiAl/Ti were obtained at a lower temperature and with shorter time.

  4. Welding of titanium alloy by different types of lasers

    Directory of Open Access Journals (Sweden)

    A. Lisiecki

    2012-12-01

    Full Text Available Purpose: of this paper was focused on comparing the welding modes during laser welding of butt joints of titanium alloy Ti6Al4V sheets 1.5 and 2.0 mm thick with direct diode laser and Disk solid state laser.Design/methodology/approach: Bead-on-plate welds were produced at different parameters of laser welding, different welding speed, different output laser power resulted in different heat input of laser welding process. The test welds were investigated by visual test, metallographic observations including macro and microstructure analysis. Additionally mechanical test were carried out such as tensile tests and technological bending test of the joints. The influence of basic laser welding parameters on the penetration depth, shape of fusion zone, width of welds and width of heat affected zones were studied. Additionally the phenomena of laser heating and melting of the welded sheets were analyzed.Findings: It was found that the mechanism of HPDL laser welding of titanium alloy differs distinctly from the mechanism of Disk laser welding. The test welds produced by HPDL laser were high quality. Welds produced by the Disk laser are characterized by a columnar shape of fusion zones, very narrow with narrow and fine structure heat affected zone.Research limitations/implications: In further investigations of laser welding of titanium alloys applying the key-hole welding mode a special care must be taken to the shielding of the weld zone and protection the weld pool and weld metal against the harmful gases from air atmosphere.Practical implications: Results of investigations presented in this paper may be applied directly for welding high quality butt joints of titanium alloy with the HPDL laser. In a case of laser welding with the Disk laser practical application requires further study, especially concentrated on the effectiveness of gas protection of the welding area including the key-hole, weld pool and surrounding regions of metal

  5. Electrochemical Surface Treatment of a β-titanium Alloy to Realize an Antibacterial Property and Bioactivity

    Directory of Open Access Journals (Sweden)

    Yusuke Tsutsumi

    2016-03-01

    Full Text Available In this study, micro-arc oxidation (MAO was performed on a β-type titanium alloy, namely, Ti-29Nb-13Ta-4.6Zr alloy (TNTZ, to improve not only its antibacterial property but also bioactivity in body fluids. The surface oxide layer formed on TNTZ by MAO treatment in a mixture of calcium glycerophosphate, calcium acetate, and silver nitrate was characterized using surface analyses. The resulting porous oxide layer was mainly composed of titanium oxide, and it also contained calcium, phosphorus, and a small amount of silver, all of which were incorporated from the electrolyte during the treatment. The MAO-treated TNTZ showed a strong inhibition effect on anaerobic Gram-negative bacteria when the electrolyte contained more than 0.5 mM silver ions. The formation of calcium phosphate on the surface of the specimens after immersion in Hanks’ solution was evaluated to determine the bioactivity of TNTZ with sufficient antibacterial property. As a result, thick calcium phosphate layers formed on the TNTZ specimen that underwent MAO treatment, whereas no precipitate was observed on TNTZ without treatment. Thus, the MAO treatment of titanium-based alloys is confirmed to be effective in realizing both antibacterial and bioactive properties.

  6. Wettability Modification for Biosurface of Titanium Alloy by Means of Sequential Carburization

    Institute of Scientific and Technical Information of China (English)

    Yong Luo; Shirong Ge; Zhong-min Jin

    2009-01-01

    Microporous titanium carbide coating was successfully synthesized on medical grade titanium alloy by using sequential carburization. Changes in the surface morphology of titanium alloy occasioned by sequential carburization were characterized and the wettability characteristics were quantified. Furthermore, the dispersion forces were calculated and discussed. The results indicate that sequential carburization is an effective way to modify the wettability of titanium alloy. After the carburization the surface dispersion force of titanium alloy increased from 76.5 × 10-3 J·m-2 to 105.5 × 10-3 J·m-2, with an enhancement of 37.9 %. Meanwhile the contact angle of titanium alloy decreased from 83° to 71.5°, indicating a significant improvement of wettability, which is much closer to the optimal water contact angle for cell adhesion of 70°.

  7. Novel Phenylethynyl Imide Silanes as Coupling Agents for Titanium Alloy

    Science.gov (United States)

    Park, C.; Lowther, S. E.; Smith, J. G., Jr.; Conell, J. W.; Hergenrother, P. M.; SaintClair, T. L.

    2004-01-01

    The durability of titanium (Ti) alloys bonded with high temperature adhesives such as polyimides has failed to attain the level of performance required for many applications. The problem to a large part is attributed to the instability of the surface treatment on the Ti substrate. Although Ti alloy adhesive specimens with surface treatments such as chromic acid anodization, Pasa-Jell, Turco, etc. have provided high initial mechanical properties, these properties have decreased as a function of aging at ambient temperature and faster, when aged at elevated temperatures or in a hot-wet environment. As part of the High Speed Civil Transport program where Ti honeycomb sandwich structure must perform for 60,000 hours at 177 C, work was directed to the development of environmentally safe, durable Ti alloy surface treatments.

  8. Laser Cladding of γ-TiAl Intermetallic Alloy on Titanium Alloy Substrates

    Science.gov (United States)

    Maliutina, Iuliia Nikolaevna; Si-Mohand, Hocine; Piolet, Romain; Missemer, Florent; Popelyukh, Albert Igorevich; Belousova, Natalya Sergeevna; Bertrand, Philippe

    2016-01-01

    The enhancement of titanium and titanium alloy's tribological properties is of major interest in many applications such as the aerospace and automotive industry. Therefore, the current research paper investigates the laser cladding of Ti48Al2Cr2Nb powder onto Ti6242 titanium alloy substrates. The work was carried out in two steps. First, the optimal deposition parameters were defined using the so-called "combined parameters," i.e., the specific energy E specific and powder density G. Thus, the results show that those combined parameters have a significant influence on the geometry, microstructure, and microhardness of titanium aluminide-formed tracks. Then, the formation of dense, homogeneous, and defect-free coatings based on optimal parameters has been investigated. Optical and scanning electron microscopy techniques as well as energy-dispersive spectroscopy and X-ray diffraction analyses have shown that a duplex structure consisting of γ-TiAl and α 2-Ti3Al phases was obtained in the coatings during laser cladding. Moreover, it was shown that produced coatings exhibit higher values of microhardness (477 ± 9 Hv0.3) and wear resistance (average friction coefficient is 0.31 and volume of worn material is 5 mm3 after 400 m) compared to those obtained with bare titanium alloy substrates (353 Hv0.3, average friction coefficient is 0.57 and a volume of worn material after 400 m is 35 mm3).

  9. Modification of the titanium alloy surface in electroexplosive alloying with boron carbide and subsequent electron-beam treatment

    International Nuclear Information System (INIS)

    The modification of the VT6 titanium alloy surface in electroexplosion alloying with plasma being formed in titanium foil with a weighed powder of boron carbide with subsequent irradiation by a pulsed electron beam has been carried out. An electroexplosive alloying zone of a thickness up to 50 μm with a gradient structure is found to form. The subsequent electron-beam treatment of the alloying zone results in smoothing of the alloying surface and is accompanied by the formation of the multilayer structure with alternating layers of various alloying degree at a depth of 30 μm

  10. Modification of the titanium alloy surface in electroexplosive alloying with boron carbide and subsequent electron-beam treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gromov, Victor E., E-mail: gromov@physics.sibsiu.ru; Budovskikh, Evgeniy A., E-mail: budovskikh-ea@physics.sibsiu.ru; Bashchenko, Lyudmila P., E-mail: gromov@physics.sibsiu.ru; Kobzareva, Tatyana Yu., E-mail: gromov@physics.sibsiu.ru; Semin, Alexander P., E-mail: gromov@physics.sibsiu.ru [Siberian State Industrial University, Novokuznetsk, 654007 (Russian Federation); Ivanov, Yurii F., E-mail: yufi55@mail.ru [Institute of High Current Electronics SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Wang, Xinli, E-mail: wangxl520@hotmail.com [Northeastern University, Liaoning, Shenyang 110819 China (China)

    2015-10-27

    The modification of the VT6 titanium alloy surface in electroexplosion alloying with plasma being formed in titanium foil with a weighed powder of boron carbide with subsequent irradiation by a pulsed electron beam has been carried out. An electroexplosive alloying zone of a thickness up to 50 μm with a gradient structure is found to form. The subsequent electron-beam treatment of the alloying zone results in smoothing of the alloying surface and is accompanied by the formation of the multilayer structure with alternating layers of various alloying degree at a depth of 30 μm.

  11. Modification of the titanium alloy surface in electroexplosive alloying with boron carbide and subsequent electron-beam treatment

    Science.gov (United States)

    Gromov, Victor E.; Budovskikh, Evgeniy A.; Ivanov, Yurii F.; Bashchenko, Lyudmila P.; Wang, Xinli; Kobzareva, Tatyana Yu.; Semin, Alexander P.

    2015-10-01

    The modification of the VT6 titanium alloy surface in electroexplosion alloying with plasma being formed in titanium foil with a weighed powder of boron carbide with subsequent irradiation by a pulsed electron beam has been carried out. An electroexplosive alloying zone of a thickness up to 50 μm with a gradient structure is found to form. The subsequent electron-beam treatment of the alloying zone results in smoothing of the alloying surface and is accompanied by the formation of the multilayer structure with alternating layers of various alloying degree at a depth of 30 μm.

  12. Alloy Design and Thermomechanical Processing of a Beta Titanium Alloy for a Heavy Vehicle Application

    Energy Technology Data Exchange (ETDEWEB)

    Blue, C.A.; Peter, W.H.

    2010-07-02

    With the strength of steel, but at half the weight, titanium has the potential to offer significant benefits in the weight reduction of heavy vehicle components while possibly improving performance. However, the cost of conventional titanium fabrication is a major barrier in implementation. New reduction technologies are now available that have the potential to create a paradigm shift in the way the United States uses titanium, and the economics associated with fabrication of titanium components. This CRADA project evaluated the potential to develop a heavy vehicle component from titanium powders. The project included alloy design, development of manufacturing practices, and modeling the economics associated with the new component. New Beta alloys were designed for this project to provide the required mechanical specifications while utilizing the benefits of the new fabrication approach. Manufacturing procedures were developed specific to the heavy vehicle component. Ageing and thermal treatment optimization was performed to provide the desired microstructures. The CRADA partner established fabrication practices and targeted capital investment required for fabricating the component out of titanium. Though initial results were promising, the full project was not executed due to termination of the effort by the CRADA partner and economic trends observed in the heavy vehicle market.

  13. Hydrothermal treatment of titanium alloys for the enhancement of osteoconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Zuldesmi, Mansjur, E-mail: mzuldesmi@yahoo.com [Department of Materials Science & Engineering, Graduate School of Engineering, Nagoya University, Nagoya (Japan); Department of Mechanical Engineering, Manad State University (UNIMA) (Indonesia); Waki, Atsushi [Department of Materials Science & Engineering, Graduate School of Engineering, Nagoya University, Nagoya (Japan); Kuroda, Kensuke; Okido, Masazumi [EcoTopia Science Institute, Nagoya University, Nagoya (Japan)

    2015-04-01

    The surface wettability of implants is a crucial factor in their osteoconductivity because it influences the adsorption of cell-attached proteins onto the surface. In this study, a single-step hydrothermal surface treatment using distilled water at a temperature of 180 °C for 3 h was applied to titanium (Ti) and its alloys (Ti–6Al–4V, Ti–6Al–7Nb, Ti–29Nb–13Ta–4.6Zr, Ti–13Cr–1Fe–3Al; mass%) and compared with as-polished Ti implants and with implants produced by anodizing Ti in 0.1 M of H{sub 3}PO{sub 4} with applied voltages from 0 V to 150 V at a scanning rate of 0.1 V s{sup −1}. The surface-treated samples were stored in a five time phosphate buffered saline (× 5 PBS(−)) solution to prevent increasing the water contact angle (WCA) with time. The surface characteristics were evaluated using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Auger electron spectroscopy, surface roughness, and contact angle measurement using a 2 μL droplet of distilled water. The relationship between WCA and osteoconductivity at various surface modifications was examined using in vivo tests. The results showed that a superhydrophilic surface with a WCA ≤ 10° and a high osteoconductivity (R{sub B–I}) of up to 50% in the cortical bone part, about four times higher than the as-polished Ti and Ti alloys, were provided by the combination of the hydrothermal surface treatment and storage in × 5 of PBS(−). - Highlights: • Hydrothermal treatment in distilled water was applied to titanium alloys. • Surface characteristics and osteoconductivity by in vivo test were evaluated. • Water contact angles of titanium alloys were decreased by hydrothermal treatment. • Osteoconductivity of titanium alloys improved notably by hydrothermal treatment after stored in × 5 of PBS (−)

  14. Comparative description of structure and properties of Ti-6Al-4V titanium alloy for biomedical applications produced by two methods: conventional (molding and innovative (injection ones

    Directory of Open Access Journals (Sweden)

    J. Klimas

    2013-12-01

    Full Text Available Purpose: In paper characterized two methods produced titanium alloy: hitherto used in industry – conti-casting and innovative method of obtaining solid amorphous alloy by injection casting. The results of studies comparing the structure and properties of the alloy Ti-6Al-4V produced by both methods. Design/methodology/approach: Test samples were titanium alloy Ti-6Al-4V produced by two methods: conventional and injection. To achieve the objective pursued performed the following tests: microstructure observation was carried out, the analysis of mechanical properties (microhardness and corrosion resistance tests were performed in Ringer’s liquid, which simulates the human body fluids. Findings: Microstructural study allowed to observe that titanium alloy T-6Al-4V produced by conventional method has crystalline ordered structure which is characteristic for materials obtained by drawing, with oriented grains and elongated in the direction of drawing. Same alloy produced by injection casting has amorphous structure with occurrences of the single-crystal seeds, that kind of structure has lack of order and regularity. The microhardness study showed, that titanium alloy Ti-6Al-4V produced by drawing has a hardness of less than twice for the same alloy produced by the injection. The corrosion tests conducted in an environment that simulates human body fluids, revealed showed that the materials made by injection have significantly corrosion potential than alloy obtained by drawing. Originality/value: The paper presents a comparative study of titanium alloy produced by drawing and massive amorphous alloy produced by unconventional method – injection casting. By the results proved that the alloy produced by injection has much better properties than alloy produced by drawing.

  15. Modification Of The Structure And Properties Of The Titanium Alloy Ti6Al4V In Biomedical Applications

    OpenAIRE

    Klimas J.; Łukaszewicz A.; Szota M.; Nabiałek M.

    2015-01-01

    From the time when Per-Ingvar Brånemark discovered oseointegration properties of titanium in 1952 a large-scale studies on the issue of usability this metal in surgery were started. Thanks to the parallel research conducted on independent centers managed to get a number of metal alloys which were implanted into the human body in the form of implants. Among the alloys produced appeared alloy of aluminum and vanadium Ti6Al4V. The mechanical properties, high biocompatibility, low density and for...

  16. Characterization of hydrogen barrier coatings for titanium-base alloys

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the barrier efficiency of a thick thermal spray deposit on the α-titanium alloy, Ti-5Al-2.4Sn against hydrogen penetration. Therefore, a duplex coating has been applied by plasma spraying using a Sulzer Metco F4 gun. The selected duplex coating system consisted of a 0.1-0.2 mm thick tantalum bond layer and a chromium oxide top layer doped with 3 wt% titanium oxide. The achieved thickness of the top layer was about 0.6 mm. The coated specimens have been characterized with regard to bond strength, hardness and microstructure. Hydrogen charging experiments were performed in a Sievert's apparatus

  17. Crack path in aeronautical titanium alloy under ultrasonic torsion loading

    Directory of Open Access Journals (Sweden)

    A. Nikitin

    2016-01-01

    Full Text Available This paper discusses features of fatigue crack initiation and growth in aeronautical VT3-1 titanium alloy under pure torsion loading in gigacycle regime. Two materials: extruded and forged VT3-1 titanium alloys were studied. Torsion fatigue tests were performed up to fatigue life of 109 cycles. The results of the torsion tests were compared with previously obtained results under fully reversed axial loading on the same alloys. It has been shown that independently on production process as surface as well subsurface crack initiation may appear under ultrasonic torsion loading despite the maximum stress amplitude located at the specimen surface. In the case of surface crack initiation, a scenario of crack initiation and growth is similar to HCF regime except an additional possibility for internal crack branching. In the case of subsurface crack, the initiation site is located below the specimen surface (about 200 μm and is not clearly related to any material flaw. Internal crack initiation is produced by shear stress in maximum shear plane and early crack growth is in Mode II. Crack branching is limited in the case of internal crack initiation compared to surface one. A typical ‘fish-eye’ crack can be observed at the torsion fracture surface, but mechanism of crack initiation seems not to be the same than under axial fatigue loading.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-27

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

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

    International Nuclear Information System (INIS)

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

  20. 76 FR 72929 - Decision To Evaluate a Petition To Designate a Class of Employees From Titanium Alloys...

    Science.gov (United States)

    2011-11-28

    ... HUMAN SERVICES Decision To Evaluate a Petition To Designate a Class of Employees From Titanium Alloys... class of employees from Titanium Alloys Manufacturing in Niagara Falls, New York, to be included in the... evaluation, is as follows: Facility: Titanium Alloys Manufacturing. Location: Niagara Falls, New York....

  1. Corrosion behavior of β titanium alloys for biomedical applications

    International Nuclear Information System (INIS)

    The corrosion behavior of biocompatible β titanium alloys Ti-13Mo-7Zr-3Fe (TMZF) and Ti-35Nb-7Zr-5Ta (TiOsteum) was investigated in 0.9% NaCl and 5 M HCl solutions. Extra-low-interstitial Ti-6Al-4V, which is also a candidate material for biomedical applications, was studied for comparison. The as-received TiOsteum and TMZF alloys exhibited single-phase β and α + β microstructures, respectively, so the latter was also investigated in the solutionized and quenched condition. In 0.9% NaCl solution, all three alloys exhibited spontaneous passivity and very low corrosion rates. Ti-6Al-4V and the as-received TMZF exhibited active-passive transitions in 5 M HCl whereas TiOsteum and TMZF in the metastable β condition showed spontaneous passivity. Potentiodynamic polarization tests, weight loss and immersion tests revealed that TiOsteum exhibited the best corrosion resistance in 5 M HCl. Analysis of surfaces of the corroded specimens indicated that the α/β phase boundaries were preferential sites for corrosion in Ti-6Al-4V while the β phase was preferentially attacked in the two-phase TMZF. The performance of the alloys in corrosive environment was discussed in terms of the volume fraction of the constituent phases and partitioning of alloying elements between these phases.

  2. Corrosion behavior of {beta} titanium alloys for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Atapour, M. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States); Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Pilchak, A.L. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States); Air Force Research Laboratory, Materials and Manufacturing Directorate/RXLM, Wright Patterson Air Force Base, OH 45433 (United States); Universal Technology Corporation, Dayton OH 45432 (United States); Frankel, G.S., E-mail: frankel.10@osu.edu [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States); Williams, J.C. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43210 (United States)

    2011-07-20

    The corrosion behavior of biocompatible {beta} titanium alloys Ti-13Mo-7Zr-3Fe (TMZF) and Ti-35Nb-7Zr-5Ta (TiOsteum) was investigated in 0.9% NaCl and 5 M HCl solutions. Extra-low-interstitial Ti-6Al-4V, which is also a candidate material for biomedical applications, was studied for comparison. The as-received TiOsteum and TMZF alloys exhibited single-phase {beta} and {alpha} + {beta} microstructures, respectively, so the latter was also investigated in the solutionized and quenched condition. In 0.9% NaCl solution, all three alloys exhibited spontaneous passivity and very low corrosion rates. Ti-6Al-4V and the as-received TMZF exhibited active-passive transitions in 5 M HCl whereas TiOsteum and TMZF in the metastable {beta} condition showed spontaneous passivity. Potentiodynamic polarization tests, weight loss and immersion tests revealed that TiOsteum exhibited the best corrosion resistance in 5 M HCl. Analysis of surfaces of the corroded specimens indicated that the {alpha}/{beta} phase boundaries were preferential sites for corrosion in Ti-6Al-4V while the {beta} phase was preferentially attacked in the two-phase TMZF. The performance of the alloys in corrosive environment was discussed in terms of the volume fraction of the constituent phases and partitioning of alloying elements between these phases.

  3. The use of β titanium alloys in the aerospace industry

    Science.gov (United States)

    Boyer, R. R.; Briggs, R. D.

    2005-12-01

    Beta titanium alloys have been available since the 1950s (Ti-13V-11Cr-3Mo or B120VCA), but significant applications of these alloys, beyond the SR-71 Blackbird, have been slow in coming. The next significant usage of a β alloy did not occur until the mid-1980s on the B-1B bomber. This aircraft used Ti-15V-3Cr-3Al-3Sn sheet due to its capability for strip rolling, improved formability, and higher strength than Ti-6Al-4V. The next major usage was on a commercial aircraft, the Boeing 777, which made extensive use of Ti-10V-2Fe-3Al high-strength forgings. Ti-15V-3Cr-3Al-3Sn environmental control system ducting, castings, and springs were also used, along with Ti-3Al-8V-6Cr-4Mo-4Zr (β-C) springs. Beta-21S was also introduced for high-temperature usage. More recent work at Boeing has focused on the development of Ti-5Al-5Mo-5V-3Cr, a high-strength alloy that can be used at higher strength than Ti-10V-2Fe-3Al and is much more robust; it has a much wider, or friendlier, processing window. This, along with additional studies at Boeing, and from within the aerospace industry in general will be discussed in detail, summarizing applications and the rationale for the selection of this alloy system for aerospace applications.

  4. Phase composition and some properties of titanium carbonitride-titanium nickelide alloys with Al2O3 nanoparticles

    Science.gov (United States)

    Ermakov, A. N.; Misharina, I. V.; Grigorov, I. G.; Pushin, V. G.; Zainulin, Yu. G.

    2009-02-01

    The phase formation in and the microstructure of titanium carbonitride-titanium nickelide alloys with aluminum oxide Al2O3 nanopowder additions are studied by X-ray diffraction, electron-microscopic, and electron-probe microanalyses. The phase interaction is characterized by the redistribution of nonmetallic elements and aluminum between refractory and binding phases with the formation of a nonstoichiometric titanium-aluminum (Ti,Al)(C,N) carbonitride and a titanium-aluminum nickelide. The number of forming phases and their compositions are controlled by the kinetic parameters of the process.

  5. Discoloration of a titanium alloy removable partial denture: a clinical report.

    Science.gov (United States)

    Sutton, A J; Rogers, P M

    2001-06-01

    With recent advances in dental technology, titanium is currently used for fabrication of crowns, fixed partial dentures, implant frameworks, and removable partial denture frameworks. The use of titanium-aluminum-vanadium (Ti-6Al-4V) alloy assumes that it imparts similar anti-corrosion characteristics to the commercially pure titanium. This clinical report describes a patient who experienced discoloration of a Ti-6Al-4V alloy removable partial denture. PMID:11512116

  6. Biomedical titanium alloys with Young's moduli close to that of cortical bone.

    Science.gov (United States)

    Niinomi, Mitsuo; Liu, Yi; Nakai, Masaki; Liu, Huihong; Li, Hua

    2016-09-01

    Biomedical titanium alloys with Young's moduli close to that of cortical bone, i.e., low Young's modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti-29Nb-13Ta-4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young's modulus of the whole implant and a high Young's modulus of the deformed part of implant, titanium alloys with changeable Young's modulus, which are also β-type titanium alloys, for instance Ti-12Cr, have been developed. In this review article, by focusing on TNTZ and Ti-12Cr, the biological and mechanical properties of the titanium alloys with low Young's modulus and changeable Young's modulus are described. In addition, the titanium alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the alloys have also been briefly introduced. PMID:27252887

  7. Biomedical titanium alloys with Young’s moduli close to that of cortical bone

    Science.gov (United States)

    Niinomi, Mitsuo; Liu, Yi; Nakai, Masaki; Liu, Huihong; Li, Hua

    2016-01-01

    Biomedical titanium alloys with Young’s moduli close to that of cortical bone, i.e., low Young’s modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti–29Nb–13Ta–4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young’s modulus of the whole implant and a high Young’s modulus of the deformed part of implant, titanium alloys with changeable Young’s modulus, which are also β-type titanium alloys, for instance Ti–12Cr, have been developed. In this review article, by focusing on TNTZ and Ti–12Cr, the biological and mechanical properties of the titanium alloys with low Young’s modulus and changeable Young’s modulus are described. In addition, the titanium alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the alloys have also been briefly introduced. PMID:27252887

  8. Review about laser nitriding of titanium alloys; Revision sobre nitruraciones laser de aleaciones de titanio

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Artieda, M.G.; Fernandez-Carrasquilla, J.

    2010-07-01

    A common technique used to improve the wear response of titanium alloys is to nitride the surface, using chemical or physical vapour deposition, ion implantation or surface remelting in a nitrogen atmosphere. In this revision nitriding systems with laser technology are studied, used in titanium alloys surface treatments.For high temperature, high strength applications, titanium based alloys are an attractive light-weight alternative to steel, due to their high strength to weight ratio and corrosion resistance. In applications that require good wear resistance, titanium alloys pose a problem due to their poor tribological characteristics.Titanium alloys used with a suitable nitriding treatment could allow the replacement of steel in different applications, obtaining weight savings in fabricated components. (Author). 68 refs.

  9. Influence of titanium content on wear resistance of electrolytic low-titanium eutectic Al-Si piston alloys

    Institute of Scientific and Technical Information of China (English)

    Wang Jiefang; Xie Jingpei; Yan Shuqing; Liu Zhongxia; Weng Yonggang; Wang Mingxing; Song Tianfu

    2008-01-01

    The wear resistance of six kinds of the electrolytic low-titanium eutectic Al-Si piston alloys with various Ti content ranging from 0.00wt.% to 0.21wt.% has been studied. A new method of adding Ti is adopted in the electrolytic low-titanium aluminum alloy ingots. The electrolytic low-titanium eutectic AI-Si piston alloys are produced by remelting the electrolytic low-titanium aluminum alloy, crystal silicon, pure magnesium, Al-50%Cu and Al-10%Mn master alloy. The wear experiments are conducted using MM200 wear testing machine under lubricating condition. The results indicate that the better wear resistance and the less weight loss are achieved in the study for the eutectic AI-Si piston alloys with 0.08wt.%-0.12wt.% Ti content. The highest ultimate tensile strength of 135.94 MPa at 300℃ and HV141.70 hardness of the alloys are obtained at 0.12wt.% and 0.08wt.% Ti content, respectively. The wear mechanism of the eutectic Al-Si piston alloys under lubricating condition is abrasive wear.

  10. Influence of titanium content on wear resistance of electrolytic low-titanium eutectic Al-Si piston alloys

    Directory of Open Access Journals (Sweden)

    Yan Shuqing

    2008-11-01

    Full Text Available The wear resistance of six kinds of the electrolytic low-titanium eutectic Al-Si piston alloys with various Ti content ranging from 0.00wt.% to 0.21wt.% has been studied. A new method of adding Ti is adopted in the electrolytic low-titanium aluminum alloy ingots. The electrolytic low-titanium eutectic Al-Si piston alloys are produced by remelting the electrolytic low-titanium aluminum alloy, crystal silicon, pure magnesium, Al-50%Cu and Al-10%Mn master alloy. The wear experiments are conducted using MM200 wear testing machine under lubricating condition. The results indicate that the better wear resistance and the less weight loss are achieved in the study for the eutectic Al-Si piston alloys with 0.08wt.%–0.12wt.% Ti content. The highest ultimate tensile strength of 135.94 MPa at 300℃ and HV141.70 hardness of the alloys are obtained at 0.12wt.% and 0.08wt.% Ti content, respectively. The wear mechanism of the eutectic Al-Si piston alloys under lubricating condition is abrasive wear.

  11. Welding of titanium alloy by different types of lasers

    OpenAIRE

    A. Lisiecki

    2012-01-01

    Purpose: of this paper was focused on comparing the welding modes during laser welding of butt joints of titanium alloy Ti6Al4V sheets 1.5 and 2.0 mm thick with direct diode laser and Disk solid state laser.Design/methodology/approach: Bead-on-plate welds were produced at different parameters of laser welding, different welding speed, different output laser power resulted in different heat input of laser welding process. The test welds were investigated by visual test, metallographic observat...

  12. Effect of Carburization on the Mechanical Properties of Biomedical Grade Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    Yong Luo; Haibo Jiang; Gang Cheng; Hongtao Liu

    2011-01-01

    Titanium cermets were successfully synthesized on the surface of biomedical grade titanium alloys by using sequential carburization method. The mechanical properties such as hardness, fracture toughness and plasticity were measured to estimate the potential application of titanium cermets. The results show that after carburization the surface hardness of titanium cermets was 778 HV, with a significant improvement of 128% compared with that of titanium alloys. In addition, the fracture toughness of titanium cermets was 21.5×106 Pa·m1/2, much higher than that of other ceramics. Furthermore, the analysis of the loading-unloading curve in the nanoindentation test also indicates that the plasticity of titanium cermet reached 32.1%, a relatively high value which illustrates the combination of the metal and ceramics properties. The results suggest that sequential carburization should be an efficient way to produce titanium cermets with hard surface, high toughness and plasticity.

  13. Development of Oxidation Protection Coatings for Gamma Titanium Aluminide Alloys

    Science.gov (United States)

    Wallace, T. A.; Bird, R. K.; Sankaran, S. N.

    2003-01-01

    Metallic material systems play a key role in meeting the stringent weight and durability requirements for reusable launch vehicle (RLV) airframe hot structures. Gamma titanium aluminides (gamma-TiAl) have been identified as high-payoff materials for high-temperature applications. The low density and good elevated temperature mechanical properties of gamma-TiAl alloys make them attractive candidates for durable lightweight hot structure and thermal protection systems at temperatures as high as 871 C. However, oxidation significantly degrades gamma-TiAl alloys under the high-temperature service conditions associated with the RLV operating environment. This paper discusses ongoing efforts at NASA Langley Research Center to develop durable ultrathin coatings for protecting gamma-TiAl alloys from high-temperature oxidation environments. In addition to offering oxidation protection, these multifunctional coatings are being engineered to provide thermal control features to help minimize heat input into the hot structures. This paper describes the coating development effort and discusses the effects of long-term high-temperature exposures on the microstructure of coated and uncoated gamma-TiAl alloys. The alloy of primary consideration was the Plansee alloy gamma-Met, but limited studies of the newer alloy gamma-Met-PX were also included. The oxidation behavior of the uncoated materials was evaluated over the temperature range of 704 C to 871 C. Sol-gel-based coatings were applied to the gamma-TiAl samples by dipping and spraying, and the performance evaluated at 871 C. Results showed that the coatings improve the oxidation resistance, but that further development is necessary.

  14. Biomedical titanium alloys with Young’s moduli close to that of cortical bone

    OpenAIRE

    Niinomi, Mitsuo; Liu, Yi; Nakai, Masaki; Liu, Huihong; Li, Hua

    2016-01-01

    Biomedical titanium alloys with Young’s moduli close to that of cortical bone, i.e., low Young’s modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti–29Nb–13Ta–4.6Zr referred to as TNTZ, which is highly expected to be us...

  15. Effect of shotpeening on sliding wear and tensile behavior of titanium implant alloys

    OpenAIRE

    Ganesh, B.K.C.; Sha, W; Ramanaiah, N.; A. Krishnaiah

    2014-01-01

    Titanium has good biocompatibility and so its alloys are used as implant materials, but they suffer from having poor wear resistance. This research aims to improve the wear resistance and the tensile strength of titanium alloys potentially for implant applications. Titanium alloys Ti–6Al–4V and Ti–6Al–7Nb were subjected to shotpeening process to study the wear and tensile behavior. An improvement in the wear resistance has been achieved due to surface hardening of these alloys by the process ...

  16. Effect of coupling asynchronous acoustoelectric effects on the corrosion behavior, microhardness and biocompatibility of biomedical titanium alloy strips.

    Science.gov (United States)

    Ye, Xiaoxin; Tang, Guoyi

    2015-01-01

    The coupling asynchronous acoustoelectric effects (CAAE) of the high-energy electropulsing treatment (EPT) technique and ultrasonic surface strengthening modification (USSM) are innovatively combined in improving the surface microhardness, corrosion behavior and biocompatibility of the pre-deformed titanium alloy strips. Experimental results show that EPT and USSM processes facilitate the surface grain refining and USSM brings in the micro-dimples on the materials surface, which is attributed to the atoms diffusion acceleration under EPT and severe surface plastic deformation under USSM. These microstructure changes can not only enhance the corrosion resistance in the acidic simulated body fluids and fluoridated acidic artificial saliva but also improve the biocompatibility of the titanium alloy strip materials. Moreover, the surface microhardness of the titanium alloy strips is enhanced to improve the wear resistance. Therefore, CAAE processing is a high-efficiency and energy-saving method for obtaining biomedical titanium alloys with superior anti-corrosion performance, microhardness and biocompatibility, which can be widely applied in dental implants and artificial joint. PMID:25596862

  17. Titanium alloyed with rhenium by selective laser melting

    International Nuclear Information System (INIS)

    The paper presents results of processing Ti–Re alloys by consolidating mixtures of powders of both metals with the use of selective laser melting (SLM). Ti-based alloys containing 0.5, 1.0 and 1.5 at% Re were obtained in this way. Optimum process parameters were determined by accepting the criterion of minimum porosity of manufactured parts and maximum effectiveness of dissolving Re particles in molten Ti. Density of the SLM-processed parts reached over 99.9% and 90–85% of Re powder (by volume) was dissolved. The effects of Re content on the microstructure and mechanical properties of SLM-processed parts in as-built condition were investigated. Light microscopy and X-ray diffraction examinations revealed that rhenium changed the microstructure of CP-Ti lath-type α′ martensite to acicular-shaped by lowering the temperature of martensitic transformation. A very intensive effect of strengthening titanium by the addition of small amounts of Re was found, due to α′-lattice distortion and grain refinement. Alloying with 1.5 at% Re made it possible to obtain mechanical properties similar to those of the SLM-processed Ti6Al4V alloy in as-built condition

  18. Electron Beam Freeform Fabrication of Titanium Alloy Gradient Structures

    Science.gov (United States)

    Brice, Craig A.; Newman, John A.; Bird, Richard Keith; Shenoy, Ravi N.; Baughman, James M.; Gupta, Vipul K.

    2014-01-01

    Historically, the structural optimization of aerospace components has been done through geometric methods. A monolithic material is chosen based on the best compromise between the competing design limiting criteria. Then the structure is geometrically optimized to give the best overall performance using the single material chosen. Functionally graded materials offer the potential to further improve structural efficiency by allowing the material composition and/or microstructural features to spatially vary within a single structure. Thus, local properties could be tailored to the local design limiting criteria. Additive manufacturing techniques enable the fabrication of such graded materials and structures. This paper presents the results of a graded material study using two titanium alloys processed using electron beam freeform fabrication, an additive manufacturing process. The results show that the two alloys uniformly mix at various ratios and the resultant static tensile properties of the mixed alloys behave according to rule-of-mixtures. Additionally, the crack growth behavior across an abrupt change from one alloy to the other shows no discontinuity and the crack smoothly transitions from one crack growth regime into another.

  19. Titanium alloyed with rhenium by selective laser melting

    Energy Technology Data Exchange (ETDEWEB)

    Chlebus, Edward; Kuźnicka, Bogumiła, E-mail: bogumila.kuznicka@pwr.edu.pl; Dziedzic, Robert; Kurzynowski, Tomasz

    2015-01-03

    The paper presents results of processing Ti–Re alloys by consolidating mixtures of powders of both metals with the use of selective laser melting (SLM). Ti-based alloys containing 0.5, 1.0 and 1.5 at% Re were obtained in this way. Optimum process parameters were determined by accepting the criterion of minimum porosity of manufactured parts and maximum effectiveness of dissolving Re particles in molten Ti. Density of the SLM-processed parts reached over 99.9% and 90–85% of Re powder (by volume) was dissolved. The effects of Re content on the microstructure and mechanical properties of SLM-processed parts in as-built condition were investigated. Light microscopy and X-ray diffraction examinations revealed that rhenium changed the microstructure of CP-Ti lath-type α′ martensite to acicular-shaped by lowering the temperature of martensitic transformation. A very intensive effect of strengthening titanium by the addition of small amounts of Re was found, due to α′-lattice distortion and grain refinement. Alloying with 1.5 at% Re made it possible to obtain mechanical properties similar to those of the SLM-processed Ti6Al4V alloy in as-built condition.

  20. Measurement of the superconducting transition temperature of Dural and titanium 6Al-4V alloys

    Energy Technology Data Exchange (ETDEWEB)

    Divakar, U; Henry, S; Kraus, H; Tolhurst, A J B [University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom)

    2008-06-15

    We have measured the superconducting transition temperatures of commercial alloys Dural and titanium 6Al-4V, to assess their suitability for use in the cryoEDM neutron electric dipole moment experiment. Our sample of aluminium alloy Dural became a superconductor at 0.84 {+-} 0.07 K but the titanium alloy did not show any superconducting behaviour down to the experimental limit of 0.17 {+-} 0.11 K.

  1. Evaluation of plasma nitriding efficiency of titanium alloys for medical applications

    OpenAIRE

    Frączek, T.; Olejnik, M.; Tokarz, A.

    2009-01-01

    The surface layers obtained on selected titanium alloys, used in medicine, by the nitriding under glow discharge condition were investigated. The results concern of: α- titanium alloy Grade 2 and α + β alloys Grade 5 and Grade 5 ELI nitrided in temperature below 873 K. The nitriding experiments were performed in a current glow-discharge furnace JON-600 with assisting of unconventional methods. After nitriding surface layers were characterised by surface microhardness measuremen...

  2. Peculiarities and kinetics of α2-phase growth in titanium alloys

    International Nuclear Information System (INIS)

    X-ray diffraction analysis and electron microscopy methods were used to investigate the process of embrittling α2 phase precipitation in alloys based on titanium with 6.8 and 7.5% Al and Zr, Mo, Nb, W, Si, Sn additions. It is shown, that complex alloying doesn't provide assurance of the effective suppression of Ti3Al embrittling phase precipitation, which restrains the application of titanium alloys at temperatures above 500 deg C

  3. Structural formation of aluminide phases on titanium alloy during annealing

    International Nuclear Information System (INIS)

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

  4. Corrosion behavior of titanium alloy Beta-21S coated with diamond like carbon in Hank's solution

    Science.gov (United States)

    Mohan, L.; Anandan, C.; Grips, V. K. William

    2012-06-01

    Diamond like carbon (DLC) coatings posses high hardness and low friction coefficient and also biocompatible, hence, they are of interest for enhancing the wear and corrosion resistance of bio-implant materials. Beta stabilized titanium alloys are attractive for biomedical applications because of their high specific strength and low modulus. In this work Beta-21S alloy (Ti-15Mo-3Nb-3Al-0.2Si) was implanted with carbon ions by plasma immersion ion implantation using methane and hydrogen gas mixture followed by DLC deposition by plasma enhanced chemical vapour deposition (PECVD). The implanted layers enabled deposition of adherent diamond-like carbon coatings on the titanium alloy which was otherwise not possible. The corrosion behavior of the treated and untreated samples was investigated through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies in simulated body fluid (Hank's solution). XPS, micro Raman and EDAX investigation of the samples showed the formation of a thin oxide layer on the treated samples after corrosion experiments. Corrosion resistance of the DLC coated sample is comparable with that of the untreated samples. Electrochemical impedance data of the substrate and implanted samples were fitted with two time constant equivalent circuits and that of DLC coated samples with two-layer model.

  5. Performance of Process Damping in Machining Titanium Alloys at Low Cutting Speed with Different Helix Tools

    International Nuclear Information System (INIS)

    Titanium is a strong, lustrous, corrosion-resistant and transition metal with a silver color to produce strong lightweight alloys for industrial process, automotive, medical instruments and other applications. However, it is very difficult to machine the titanium due to its poor machinability. When machining titanium alloys with the conventional tools, the wear rate of the tool is rapidly accelerate and it is generally difficult to achieve at high cutting speed. In order to get better understanding of machining titanium alloy, the interaction between machining structural system and the cutting process which result in machining instability will be studied. Process damping is a useful phenomenon that can be exploited to improve the limited productivity of low speed machining. In this study, experiments are performed to evaluate the performance of process damping of milling under different tool helix geometries. The results showed that the helix of 42° angle is significantly increase process damping performance in machining titanium alloy.

  6. Phase Stability and Stress-Induced Transformations in Beta Titanium Alloys

    Science.gov (United States)

    Kolli, R. Prakash; Joost, William J.; Ankem, Sreeramamurthy

    2015-06-01

    In this article, we provide a brief review of the recent developments related to the relationship between phase stability and stress-induced transformations in metastable body-centered-cubic β-phase titanium alloys. Stress-induced transformations occur during tensile, compressive, and creep loading and influence the mechanical response. These transformations are not fully understood and increased understanding of these mechanisms will permit future development of improved alloys for aerospace, biomedical, and energy applications. In the first part of this article, we review phase stability and discuss a few recent developments. In the second section, we discuss the current status of understanding stress-induced transformations and several areas that require further study. We also provide our perspective on the direction of future research efforts. Additionally, we address the occurrence of the hcp ω-phase and the orthorhombic α″-martensite phase stress-induced transformations.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-01

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

  8. EFFECTS OF ALLOYING ELEMENTS ON TWINNING IN ALPHA-TITANIUM ALLOYS

    OpenAIRE

    Fitzner, Arnas Gerald

    2015-01-01

    It has been found that commercially pure (CP) Titanium (Ti) undergoes substantial amount of deformation twinning during plastic forming in a wide range of temperatures and strain rates giving CP-Ti good ductility and allowing up to 90% thickness reduction by cold rolling. Aluminium (Al) rich ! Ti-alloys lack this superior ductility but exhibit therefore up to five times higher yield strength, which was connected experimentally to reduced activity of deformation twinning with addition of Al to...

  9. Cooperative effect of silicon and other alloying elements on creep resistance of titanium alloys: insight from first-principles calculations

    Science.gov (United States)

    Li, Yang; Chen, Yue; Liu, Jian-Rong; Hu, Qing-Miao; Yang, Rui

    2016-01-01

    Creep resistance is one of the key properties of titanium (Ti) alloys for high temperature applications such as in aero engines and gas turbines. It has been widely recognized that moderate addition of Si, especially when added together with some other elements (X), e.g., Mo, significantly improves the creep resistance of Ti alloys. To provide some fundamental understandings on such a cooperative effect, the interactions between Si and X in both hexagonal close-packed α and body-centered cubic β phases are systematically investigated by using a first-principles method. We show that the transition metal (TM) atoms with the number of d electrons (Nd) from 3 to 7 are attractive to Si in α phase whereas those with Nd > 8 and simple metal (SM) alloying atoms are repulsive to Si. All the alloying atoms repel Si in the β phase except for the ones with fewer d electrons than Ti. The electronic structure origin underlying the Si-X interaction is discussed based on the calculated electronic density of states and Bader charge. Our calculations suggest that the beneficial X-Si cooperative effect on the creep resistance is attributable to the strong X-Si attraction. PMID:27466045

  10. Dynamic powder compaction of rapidly solidified Path A alloy with increased carbon and titanium content

    International Nuclear Information System (INIS)

    The objective of this study is to show the potential of the dynamic powder compaction technique to consolidate rapidly solidified Path A alloys and to develop microstructures with improved irradiation performance in the fusion environment. Samples of rapidly solidified and dynamically compacted Path A alloy with increased carbon and titanium content have been included in alloy development irradiation experiments

  11. Effect of ion-implantation on surface characteristics of nickel titanium and titanium molybdenum alloy arch wires

    OpenAIRE

    Manu Krishnan; Seema Saraswathy; Kalathil Sukumaran; Kurian Mathew Abraham

    2013-01-01

    Aim: To evaluate the changes in surface roughness and frictional features of ′ion-implanted nickel titanium (NiTi) and titanium molybdenum alloy (TMA) arch wires′ from its conventional types in an in-vitro laboratory set up. Materials and Methods: ′Ion-implanted NiTi and low friction TMA arch wires′ were assessed for surface roughness with scanning electron microscopy (SEM) and 3 dimensional (3D) optical profilometry. Frictional forces were studied in a universal testing machine. Surface ...

  12. Hydrogen and fatigue behavior in a near alpha titanium alloy

    International Nuclear Information System (INIS)

    The beta processed near alpha titanium alloys were developed for high performance applications in gas turbines. The principal requirement was an enhanced temperature capability coupled with competitive fatigue strength at lower temperatures. Paradoxically, these creep resistant alloys can give inferior fatigue performance at near ambient temperatures when the applied cycle has a dwell period at peak stress. This characteristic has obvious implications for components with operating envelopes that include long hold periods at relatively high static stress. Several factors have been implicated in the dwell sensitivity including plastic strain accumulation, biaxial and triaxial stress fields and microstructural condition. One particularly important consideration is hydrogen concentration. It has been argued that the life decrement is due to hydride formation at slip bands or crack tips. The fact that hydrogen diffusion is promoted by stress gradients can account for critical levels for hydride precipitation being reached in material with non-dangerous average concentration levels. The research was carried out on IMI685 (Ti-6Al-5Zr-0.5Mo-0.25Si), a typical representative of this class of material. The alloy was evaluated with an aligned alpha microstructure, since this is considered to be its most susceptible condition. Hydrogen concentrations were varied in the range 20--275 ppm. The research covered both tension and torsion loading modes but attention is given to the former only in this publication. The work clearly demonstrates specific regimes of behavior associated with the various hydrogen contents

  13. In vitro biocompatibility of titanium-nickel alloy with titanium oxide film by H2O2 oxidation

    Institute of Scientific and Technical Information of China (English)

    HU Tao; CHU Cheng-lin; YIN Li-hong; PU Yao-pu; DONG Yin-sheng; GUO Chao; SHENG Xiao-bo; CHUNG Jonathan-CY; CHU Paul-K

    2007-01-01

    Titanium oxide film with a graded interface to NiTi matrix was synthesized in situ on NiTi shape memory alloy(SMA) by oxidation in H2O2 solution. In vitro studies including contact angle measurement, hemolysis, MTT cytotoxicity and cell morphology tests were employed to investigate the biocompatibility of the H2O2-oxidized NiTi SMAs with this titanium oxide film. The results reveal that wettability, blood compatibility and fibroblasts compatibility of NiTi SMA are improved by the coating of titanium oxide film through H2O2 oxidation treatment.

  14. Influence of system and degree of alloying on the parameters of shape-memory effect in titanium alloys

    International Nuclear Information System (INIS)

    The influence of chemical composition, compression degree, heating rate on characteristics of shape memory effect of Ti-Nb, Ti-V, Ti-Al-V, Ti-Al-V-Cr is studied. A comparative analysis is made between experimentally defined values of restitution deformation degree and calculated values of crystographically reversible deformation of martensitic transformation. Main reasons for non complete restitution of form in the titanium base alloy are as the formation of embrittling ω-phase in titanium alloys of critical composition with a β-stabilizer; the proximity of martensitic transformation-induced stresses and sliding ones on deformation; low thermal stability of β- and α''-phase of titanium alloys in the range of temperatures of reverse martensitic transformation. Aluminium and chromium alloying of titanium alloys permits increasing the value of restitution deformation due to the suppression of ω-phase formation during quenching of critical composition alloys and the increase of sliding stresses. The optimal composition of the titanium alloy is proposed

  15. PM-Composites with Nickel-Titanium Shape Memory Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, W.; Schuermann, A. [Ruhr-University Bochum, Chair of Materials Technology, D-44780 Bochum (Germany)

    2004-05-01

    Starting from NiTi-powders, composites of nickel-titanium shape memory alloys (NiTi-SMA) and different stainless steels (1.4301, 1.4404, 1.4571) as well as of different NiTi-SMAs were produced by using the process of hot isostatic pressing (HIP). Metallographic investigations focussed on the interface between NiTi-SMA and stainless steel with special emphasis placed on the characterization of the typical structure of the diffusion zones in both components. (Abstract Copyright [2004], Wiley Periodicals, Inc.) [German] Ausgehend von NiTi-Pulver wurden Schichtverbundwerkstoffe aus Nickel-Titan Formgedaechtnislegierungen (NiTi-FGL) und verschiedenen nichtrostenden Staehlen (1.4301, 1.4404, 1.4571) sowie aus verschiedenen NiTi-FGL durch heissisostatisches Pressen (HIP) hergestellt und metallographisch untersucht. Dabei lag das Augenmerk auf der Ausbildung der Grenzflaeche und der speziellen Struktur der Diffusionszonen in beiden Verbundkomponenten. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  16. Determination of titanium in U-Ti alloy by spectrophotometry

    International Nuclear Information System (INIS)

    An interference free spectrophotometric determination of titanium (Ti) was developed for material characterization of U-Ti alloy. Ti was detected and quantified in H2SO4 medium in presence of H2O2 where it forms TiO2 (SO4)22- complex having a maximum absorbance at 410 nm. The spectroscopic interference of UO22+ in the 400-450 nm range was carefully eliminated by its selective extraction using TBP/CCl4 medium at optimized acidity of 4M HNO3. Three synthetically prepared U-Ti sample solutions were examined to validate the methodology. A total of ten real U-Ti samples were characterized for their Ti content with %RSD varying between 2-4% (1σ). (author)

  17. Deposition of functional cellulose films on titanium alloy surfaces

    International Nuclear Information System (INIS)

    Titanium alloy (TiAl6V4) surfaces were treated with ultraviolet (UV) radiation to remove organic 'contamination' molecules which remained on the surfaces after conventional cleaning processes. The UV-technique simultaneously revealed reactive surface hydroxyl groups at the metal surface which were monitored by the reaction with perfluorooctanoylchloride and application of Fourier-Transform infrared reflection-absorption spectroscopy and contact angle measurements, respectively. Two different cellulose polymers each made soluble in methanol by functionalized hydroxylalkyl-spacer groups and their mixtures were deposited on UV-treated TiAl6V4 surfaces. Atomic force microscopy measurements could reveal polymer films which covered the metal surfaces completely without defects. Differences were indicated in the surface structure, especially between the pure cellulose phosphate films and cinnamate containing cellulose films

  18. Electrochemical process for the manufacturing of titanium alloy matrix composites

    Directory of Open Access Journals (Sweden)

    V. Soare

    2009-07-01

    Full Text Available The paper presents a new method for precursors’ synthesis of titanium alloys matrix composites through an electrochemical process in molten calcium chloride. The cathode of the cell was made from metallic oxides powders and reinforcement ceramic particles, which were pressed and sintered into disk form and the anode from graphite. The process occurred at 850 °C, in two stages, at 2,7 / 3,2 V: the ionization of the oxygen in oxides and the reduction with calcium formed by electrolysis of calcium oxide fed in the electrolyte. The obtained composite precursors, in a form of metallic sponge, were consolidated by pressing and sintering. Chemical and structural analyses on composites samples were performed.

  19. Titanium-Zirconium-Nickel Alloy Inside Marshall's Electrostatic Levitator (ESL)

    Science.gov (United States)

    2003-01-01

    This Photo, which appeared on the July cover of `Physics Today', is of the Electrostatic Levitator (ESL) at NASA's Marshall Space Flight Center (MSFC). The ESL uses static electricity to suspend an object (about 3-4 mm in diameter) inside a vacuum chamber allowing scientists to record a wide range of physical properties without the sample contracting the container or any instruments, conditions that would alter the readings. Once inside the chamber, a laser heats the sample until it melts. The laser is then turned off and the sample cools, changing from a liquid drop to a solid sphere. In this particular shot, the ESL contains a solid metal sample of titanium-zirconium-nickel alloy. Since 1977, the ESL has been used at MSFC to study the characteristics of new metals, ceramics, and glass compounds. Materials created as a result of these tests include new optical materials, special metallic glasses, and spacecraft components.

  20. Laser welding of an advanced rapidly-solidified titanium alloy

    Science.gov (United States)

    Baeslack, W. A., III; Chiang, S.; Albright, C. A.

    1990-06-01

    The laser weldability of a complex RS titanium alloy containing yttrium is investigated by evaluating comparatively the microstructures, mechanical properties, and fracture characteristics of the base metal and the rapidly solidified weld fusion zone. To prevent atmospheric contamination the specimen was enclosed in a helium-purged plastic bag during the welding process. After welding, the coupons were sectioned transverse to the laser beam direction of traverse, epoxy mounted, polished down to 0.05 micron SiO2 and etched with Kroll's reagent for examination utilizing light and SEM and energy-dispersive X-ray analysis. Results indicate that laser welding is effective in producing a fine fusion zone dispersoid structure in the RS Ti composite.

  1. Deoxidation Limits of Titanium Alloys during Pressure Electro Slag Remelting

    Science.gov (United States)

    Bartosinski, M.; Hassan-Pour, S.; Friedrich, B.; Ratiev, S.; Ryabtsev, A.

    2016-07-01

    This paper focuses on deoxidation of titanium alloys produced by aluminothermic reduction (ATR) and subsequent homogenizing and alloying by vacuum induction melting (VIM). The main goal of the performed research work is to outline the deoxidation limit during pressure electro slag remelting (PESR) of the described material. To obtain electrodes for deoxidation, a Ti-24Al-16V masteralloy was produced by ATR and afterwards melted in a 0.5 litre calcium- zirconate (lab scale) or 14 litres high purity calcia (pilot scale) crucibles with continuous addition of Ti-sponge after reaching liquid state in order to obtain a final Ti-6Al-4V alloy. During melting, in both cases evaporation of calcium was noticed. The cast ingots were analysed for oxygen using inert gas fusion method, matrix and alloying elements were analysed by XRF. Results show oxygen levels between 0.5 and 0.95 wt.-% for the ingots which were melted in calcium-zirconate crucibles and approx. 1 - 1.2 wt.-% for the material produced by utilization of calcia crucibles. The subsequent deoxidation was carried out in lab and pilot scale electroslag remelting furnaces using a commercially pure calcium fluoride slag and metallic calcium as deoxidation agent. It could be shown, that deoxidation of the highly contaminated material is possible applying this method to a certain limit. Pilot scale trials showed a reduction of oxygen contents by 1500 - 3500 ppm. Oxygen levels in lab scale trials showed weaker deoxidation effects. In order to describe the achieved deoxidation effects in a quantitative way, the analyzed oxygen contents of the obtained ingots are compared with calculated data resulting from a mathematical kinetic model. The modelled datasets are in good agreement with experimental oxygen values.

  2. 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.

  3. Chemical vapor deposition coatings for oxidation protection of titanium alloys

    Science.gov (United States)

    Cunnington, G. R.; Robinson, J. C.; Clark, R. K.

    1991-01-01

    Results of an experimental investigation of the oxidation protection afforded to Ti-14Al-21Nb and Ti-14Al-23Nb-2V titanium aluminides and Ti-17Mo-3Al-3Nb titanium alloy by aluminum-boron-silicon and boron-silicon coatings are presented. These coatings are applied by a combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes. The former is for the application of aluminum, and the latter is for codeposition of boron and silicon. Coating thickness is in the range of 2 to 7 microns, and coating weights are 0.6 to 2.0 mg/sq cm. Oxidation testing was performed in air at temperatures to 1255 K in both static and hypersonic flow environments. The degree of oxidation protection provided by the coatings is determined from weight change measurements made during the testing and post test compositional analyses. Temperature-dependent total normal emittance data are also presented for four coating/substrate combinations. Both types of coatings provided excellent oxidation protection for the exposure conditions of this investigation. Total normal emittances were greater than 0.80 in all cases.

  4. Surface Functionalization of Titanium Alloy with miR-29b Nanocapsules To Enhance Bone Regeneration.

    Science.gov (United States)

    Meng, Yubin; Li, Xue; Li, Zhaoyang; Liu, Chaoyong; Zhao, Jin; Wang, Jianwei; Liu, Yunde; Yuan, Xubo; Cui, Zhenduo; Yang, Xianjin

    2016-03-01

    Titanium and its alloys have been widely used over the past 3 decades as implants for healing bone defects. Nevertheless, the bioinert property of titanium alloy limits its clinical application and surface modification method is frequently performed to improve the biological and chemical properties. Recently, the delivery of microRNA with osteogenesis capability has been recognized as a promising tool to enhance bone regeneration of implants. Here, we developed a biodegradable coating to modify the titanium surface in order to enhance osteogenic bioactivity. The previous developed nanocapsules were used as the building blocks, and then a bioactive titanium coating was designed to entrap the miR-29b nanocapsules. This coating was not only favorable for cell adhesion and growth but also provided sufficient microRNA transfection efficacy and osteoinductive potential, resulting in a significant enhancement of bone regeneration on the surface of bioinert titanium alloy. PMID:26887789

  5. The two steps thermal decomposition of titanium hydride and two steps foaming of Al alloy

    Institute of Scientific and Technical Information of China (English)

    SHANG; Jintang; HE; Deping

    2005-01-01

    Two steps foaming (TSF) technique was proposed to prepare shaped Al alloy foam. Based on the thermal decomposition kinetics equation of titanium hydride, the relationship between two steps thermal decomposition kinetics of titanium hydride and two steps foaming Al alloy melt was studied. Two steps thermal decomposition curve of titanium hydride under increasing and constant temperature was calculated respectively. The hydrogen mass needed in the second foaming step was also calculated. Results showed that the hydrogen mass of the second thermal decomposition of titanium hydride is enough for the second foaming step in the condition of as-received Al melt foaming. Experimental and theoretical results indicate that two steps foaming technique can be used to prepare Al alloy foam with high porosity, shaped components and sandwich with Al alloy foam core.

  6. Effect of temperature on vacuum hot bulge forming of BT20 titanium alloy cylindrical workpiece

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Temperature is one of the key parameters for BT20 titanium alloy cylindrical workpiece manufactured by vacuum hot bulge forming. A two-dimensional nonlinear thermo-mechanical coupled FE model was established. Numerical simulation of vacuum hot bulge forming process of titanium alloy cylindrical workpiece was carried out using FE analysis software MSC Marc. The effects of temperature on vacuum hot bulge forming of BT20 titanium alloy cylindrical workpiece were analyzed by numerical simulation.The simulated results show that the Y-direction displacement and the equivalent plastic strain of the workpiece increase with increasing bulge temperature. The residual stress decreases with increasing bulge temperature. The optimal temperature range of BT20 titanium alloy during vacuum hot bulge forming is 750-850 ℃. The corresponding experiments were carried out. The simulated results agreed well with the experimental results.

  7. Study of deformation mechanisms in forming and heating shape memory titanium alloys

    International Nuclear Information System (INIS)

    Wire specimens of a typical shape memory alloy Ti - 50.6 % (at.) Ni as well as commercial alloys VT22I and Ti-10-2-3 were used to investigate the mechanisms of inelasticity at various stages of manifestation of shape memory effect. The investigation results show that the process of forming in titanium nickelide and titanium base alloys can proceed according to martensitic, combined and dislocation mechanisms. Mechanism changing takes place at the first and the second critical deformation degree respectively. The values of critical strains are determined by the nature of phases participating in martensitic transformation and by the structural state of alloys

  8. Low-Temperature Interface Reaction between Titanium and the Eutectic Silver-Copper Brazing Alloy

    OpenAIRE

    Andrieux, J; Dezellus, Olivier; Bosselet, F.; Viala, J.C.

    2009-01-01

    Reaction zones formed at 790 °C between solid titanium and liquid Ag-Cu eutectic alloys (pure and Ti-saturated) have been characterized. When pure Ag-Cu eutectic alloy with 40 at.% Cu is used, the interface reaction layer sequence is: alpha-Ti / Ti2Cu / TiCu / Ti3Cu4 / TiCu4 / L. Because of the fast dissolution rate of Ti in the alloy, the reaction zone remains very thin (3-6 µm) whatever the reaction time. When the Ag-Cu eutectic alloy is saturated in titanium, dissolution no longer proceeds...

  9. Mechanical characteristics of hydrides in titanium and titanium-palladium alloy

    International Nuclear Information System (INIS)

    With the aim of estimating of stress-strain curve and fracture strain of thin layer hydrides of pure titanium (Gr.1) and titanium-palladium alloy (Gr.17), we utilized dual indentation method and advanced indentation machine equipped with acoustic emission (AE) monitoring system. We first estimated stress-strain curves of two base metals and two hydrides utilizing the dual indentation method. Next we estimated the fracture strain of two hydrides by FEM method using the critical indentation force to cause the Mode-I crack in hydrides during indentation tests. The critical force was correctly determined by waveform analysis of AEs detected during indentation test. The fracture strain of hydride of Gr.1 was estimated as 8.1% and larger than that (4.3%) of Gr.17 hydride. Fracture strains of two hydrides appear to be due to the chemical composition of the hydrides. Gr.1 produced a TiH2 hydride, while Gr.1 did a TiH1.971. (author)

  10. Effects of hydrogen on ELI titanium alloy Ti-5Al-2.5Sn

    Science.gov (United States)

    Chandler, W. T.; Hensley, W. E.

    1970-01-01

    Tensile tests on titanium alloy, following abrasion under hydrogen and temperature cycling, reveal lowered tensile strength, increased ductility, and no embrittlement. Fretting the metal on itself in flowing hydrogen or abrading with an iron file in flowing hydrogen produces titanium hydride.

  11. A new titanium based alloy Ti-27Nb-13Zr produced by powder metallurgy with biomimetic coating for use as a biomaterial.

    Science.gov (United States)

    Mendes, Marcio W D; Ágreda, Carola G; Bressiani, Ana H A; Bressiani, José C

    2016-06-01

    Titanium alloys are widely used in biomedical applications due to their excellent properties such as high strength, good corrosion resistance and biocompatibility. Titanium alloys with alloying elements such as Nb and Zr are biocompatible and have Young's modulus close to that of human bone. To increase the bioactivity of titanium alloy surfaces is used chemical treatment with NaOH followed by immersion in simulated body fluid (SBF). The purpose of this study was to produce the alloy Ti-27Nb-13Zr with low Young's modulus by powder metallurgy using powders produced by the HDH process. The formation of biomimetic coatings on samples immersed in SBF for 3, 7, 11 and 15 days was evaluated. Characterization of the coating was performed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and scanning electron microscope. The microstructure and composition of the alloy were determined using SEM and XRD, while the mechanical properties were evaluated by determining the elastic modulus and the Vickers microhardness. The sintered alloys were composed of α and β phases, equiaxed grains and with density around 97.8% of its theoretical density. The Vickers microhardness and elasticity modulus of the alloy were determined and their values indicate that this alloy can be used as a biomaterial. Analysis of the coating revealed the presence of calcium phosphate layers on samples immersed for >3 days in the SBF solution. PMID:27040264

  12. Laser welding of thin-walled constructions made of titanium alloys along laser cut

    International Nuclear Information System (INIS)

    OT4 titanium alloy samples 0.3-0.4 mm thick were used in welding and cutting experiments. It is shown that the quality of laser beam cutting of thin-well titanium alloys satisfier the current requirements for assembly of workpieces (without mechining of their edges) and strength properties of joints, produced by the subsequent welding, are close to the properties of the basic material

  13. Analysis of plastic properties of titanium alloys under severe deformation conditions in machining

    OpenAIRE

    Alexander I. Khaimovich; Andrey V. Balaykin

    2014-01-01

    The present paper presents a method of analysis of titanium alloys plastic properties under severe deformation conditions during milling with registration of the cutting force components Fx, Fy, Fz in real time using a special stand. The obtained constitutive relations in the form the Johnson-Cook law for stresses and dependence for a friction coefficient describing the titanium alloy VT9 plastic properties under simulate operating conditions.

  14. On the Quantitative Evaluation of Adiabatic Shear Banding Sensitivity of Various Titanium Alloys

    OpenAIRE

    Mazeau, C.; Beylat, L.; Longère, P.; Louvigné, P.

    1997-01-01

    Titanium alloys exhibit attractive ballistic performances due to their low density and their high mechanical properties. They are unfortunately very sensitive to adiabatic shear localization. This study aims to determine an empirical parameter which allows to characterise the sensitivity to the adiabatic shear banding of different grades of titanium alloys. Dynamic punching tests by split Hopkinson pressure bar are performed on disc shaped specimen to obtain shear bands. This article deals wi...

  15. Interrelation of material microstructure, ultrasonic factors, and fracture toughness of two phase titanium alloy

    Science.gov (United States)

    Vary, A.; Hull, D. R.

    1982-01-01

    The pivotal role of an alpha-beta phase microstructure in governing fracture toughness in a titanium alloy, Ti-662, is demonstrated. The interrelation of microstructure and fracture toughness is demonstrated using ultrasonic measurement techniques originally developed for nondestructive evaluation and material property characterization. It is shown that the findings determined from ultrasonic measurements agree with conclusions based on metallurgical, metallographic, and fractographic observations concerning the importance of alpha-beta morphology in controlling fracture toughness in two phase titanium alloys.

  16. COMPARISON OF STATISTICALLY CONTROLLED MACHINING SOLUTIONS OF TITANIUM ALLOYS USING USM

    OpenAIRE

    Singh, R.

    2010-01-01

    The purpose of the present investigation is to compare the statistically controlled machining solution of titanium alloys using ultrasonic machining (USM). In this study, the previously developed Taguchi model for USM of titanium and its alloys has been investigated and compared. Relationships between the material removal rate, tool wear rate, surface roughness and other controllable machining parameters (power rating, tool type, slurry concentration, slurry type, slurry temperature and slurr...

  17. DEVELOPMENT OF LASER CLADDING WEAR-RESISTANT COATING ON TITANIUM ALLOYS

    OpenAIRE

    RUILIANG BAO; HUIJUN YU; CHUANZHONG CHEN; BIAO QI; LIJIAN ZHANG

    2006-01-01

    Laser cladding is an advanced surface modification technology with broad prospect in making wear-resistant coating on titanium alloys. In this paper, the influences of laser cladding processing parameters on the quality of coating are generalized as well as the selection of cladding materials on titanium alloys. The microstructure characteristics and strengthening mechanism of coating are also analyzed. In addition, the problems and precaution measures in the laser cladding are pointed out.

  18. Ablation experiment and threshold calculation of titanium alloy irradiated by ultra-fast pulse laser

    OpenAIRE

    Buxiang Zheng; Gedong Jiang; Wenjun Wang; Kedian Wang; Xuesong Mei

    2014-01-01

    The interaction between an ultra-fast pulse laser and a material's surface has become a research hotspot in recent years. Micromachining of titanium alloy with an ultra-fast pulse laser is a very important research direction, and it has very important theoretical significance and application value in investigating the ablation threshold of titanium alloy irradiated by ultra-fast pulse lasers. Irradiated by a picosecond pulse laser with wavelengths of 1064 nm and 532 nm, the surface morphology...

  19. Analysis of Titanium in D9 alloy- an inter comparison study and application to radioactive sample

    International Nuclear Information System (INIS)

    Titanium modified austenitic stainless steel alloy (D9) is well known for its swelling resistance under demanding reactor ambience. Chemical characterization of such important alloy carries much larger role in the quality control aspects. This work compares various analytical procedures and techniques envisaged to determine titanium concentration in D9 samples and further extending the analysis to radioactive D9 wrapper and clad of MOX test fuel sub assembly. (author)

  20. Heat and Radiofrequency Plasma Glow Discharge Pretreatment of a Titanium Alloy Promote Bone Formation and Osseointegration

    OpenAIRE

    MacDonald, Daniel E.; Rapuano, Bruce E.; Vyas, Parth; Lane, Joseph M.; Meyers, Kathleen; Wright, Timothy

    2013-01-01

    Orthopedic and dental implants manifest increased failure rates when inserted into low density bone. We determined whether chemical pretreatments of a titanium alloy implant material stimulated new bone formation to increase osseointegration in vivo in trabecular bone using a rat model. Titanium alloy rods were untreated or pretreated with heat (600°C) or radiofrequency plasma glow discharge (RFGD). The rods were then coated with the extracellular matrix protein fibronectin (1 nM) or left unc...

  1. Analysis of plastic properties of titanium alloys under severe deformation conditions in machining

    Directory of Open Access Journals (Sweden)

    Alexander I. Khaimovich

    2014-10-01

    Full Text Available The present paper presents a method of analysis of titanium alloys plastic properties under severe deformation conditions during milling with registration of the cutting force components Fx, Fy, Fz in real time using a special stand. The obtained constitutive relations in the form the Johnson-Cook law for stresses and dependence for a friction coefficient describing the titanium alloy VT9 plastic properties under simulate operating conditions.

  2. EXPERIMENTAL INVESTIGATION ON ELECTRICAL DISCHARGE MACHINING OF TITANIUM ALLOY USING COPPER, BRASS AND ALUMINUM ELECTRODES

    Directory of Open Access Journals (Sweden)

    S. DHANABALAN

    2015-01-01

    Full Text Available In the present study, an evaluation has been done on Material Removal Rate (MRR, Surface Roughness (SR and Electrode Wear Rate (EWR during Electrical Discharge Machining (EDM of titanium alloy using copper, brass and aluminum electrodes. Analyzing previous work in this field, it is found that electrode wear and material removal rate increases with an increase current. It is also found that the electrode wear ratio increases with an increase in current. The higher wear ratio is found during machining of titanium alloy using a brass electrode. An attempt has been made to correlate the thermal conductivity and melting point of electrode with the MRR and electrode wear. The MRR is found to be high while machining titanium alloy using brass electrode. During machining of titanium alloy using copper electrodes, a comparatively smaller quantity of heat is absorbed by the work material due to low thermal conductivity. Due to the above reason, the MRR becomes very low. Duringmachining of titanium alloy using aluminium electrodes, the material removal rate and electrode wear rate are only average value while machining of titanium alloy using brass and copper electrodes.

  3. SURFACE CHARACTERIZATION OF ANODICALLY TREATED β TITANIUM ALLOY FOR BIOMEDICAL APPLICATIONS

    OpenAIRE

    Bhola, R.; Bhola, S.; Mishra, B.; Ayers, R.; Olson, D; Ohno, T

    2011-01-01

    The cellular response of anodically treated titanium alloys was investigated using cell attachment, morphological and surface analytical techniques. The behavior of a β Ti15Mo alloy has been compared with the conventional mixed alloy, Ti6Al4V and the a alloy, Ti2. Ti15Mo β alloy demonstrated a higher cell count and a thicker oxide on its surface. The presence of Ca and P was detected in all the alloys after the invitro cell culture test. TiO 2 was present as the dominant oxide in all three al...

  4. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    DEFF Research Database (Denmark)

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham;

    2016-01-01

    The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family......, the quaternary Ti-Nb-Zr-Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that...... must be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by...

  5. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    Science.gov (United States)

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham; Sarri, Gianluca; Ng, Chi-Ho; Sharba, Ahmed; Man, Hau-Chung

    2016-03-01

    The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti-Nb-Zr-Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing incidence X-ray diffraction (GI-XRD) and X-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks' solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT.

  6. Thermohydrogen processing (THP) of titanium alloy and titanium-aluminum alloys

    Science.gov (United States)

    Qazi, Javaid Iqbal

    The microstructures, phases and phase transformations occurring in cast and Hot Isostatic Pressed (HIP'd) Ti-6Al-4V-H and the blended elemental (BE) TiAl-H systems were investigated. In this work, the existing Ti-6Al-4V-H phase diagram was revised and the time-temperature-transformation (TTT) diagrams for beta-phase (isothermal) and martensite (quench plus aging) decomposition were determined at different hydrogen concentrations. Alloying with hydrogen decreases the nose temperatures for the start of both the beta/martensite decompositions in a linear fashion and increases the nose times for both of these in a non-linear fashion. During aging at temperatures below the beta transus temperature, the martensite decomposes into alpha+betaM (metastable beta) and on quenching, from the aging temperature, the betaM transforms to martensite + beta R (residual beta) with the amount of latter increasing with increasing hydrogen content. Microstructures varying from alpha-lamellar laths to fine equiaxed alpha-grains were produced in the Ti-6Al-4V alloy, by using different thermohydrogen processing (THP) treatments. A microstructure consisting of mixed equiaxed and elongated alpha-grains were only produced in samples containing 30at.%H after the complete decomposition of the beta/martensite below a critical temperature (Tc), followed by dehydrogenation. A mixture consisting of partially equiaxed alpha-grains thus produced by THP, increased the tensile strength from 841MPa (starting Ti-6Al-4V) to 965MPa after THP and also increased the % elongation from 7.5% to 10.5%. In addition to other THP parameters, the final microstructure also depends on the starting microstructure and recommendations are made for future work in this regard. Initial results of temperature cycling treatments, which involved heat treating of Ti-6Al-4V samples containing 30at.%H at 680°C for 5 minutes followed by water quenching and repetition of the same treatment for 10 cycles, did not show a decrease in

  7. Effect of yttrium on microstructure and mold filling capacity of a near-α high temperature titanium alloy

    OpenAIRE

    Zhao Ertuan; Chen Yuyong; Kong Fantao

    2012-01-01

    The addition of rare earth yttrium (Y) can improve the performances of high temperature titanium alloys, such as the tensile ductility, thermal stability and creep property, etc. However, few studies on the effect of Y on the castability of titanium alloys have been carried out, which is significant to fabrication of thin-walled complex titanium castings by investment casting. In this study, the microstructure and mold filling capacity of a Ti-1100 alloy with different Y additions (0, 0.1wt.%...

  8. A study on the porosity of CO2 laser welding of titanium alloy

    Institute of Scientific and Technical Information of China (English)

    Chen Li; Hu Lunji; Gong Shuili

    2006-01-01

    The CO2 laser welding of BT20 titanium alloy and Ti-23Al-17Nb titanium aluminide was conducted to investigate into the porosity in titanium alloy weld. The results show that there are two sorts of porosities observed in welds of titanium alloy laser welding based on the microscopic characteristics of the porosities. One is the metallurgical porosity with round and smooth inner wall, which results from the surface contamination. The other is the processing porosity with irregular and rough inner wall that displays the trace of the pool flowing, which results from the ruffle on the keyhole wall gathering together locally and closing down the gas in the keyhole into bubbles because of the keyhole fluctuating. The CO2 laser welding could break down easily the surface oxide film and produce little metallurgical porosity, but produces easily processing porosity when partial penetration or unstable-full penetration laser welding is conducted, which always occurs in the center of weld.

  9. Effect of hydrogen on the mechanical properties of titanium and its alloys

    Science.gov (United States)

    Beck, F. H.

    1975-01-01

    Occluded hydrogen resulting from cathodic charging of commercially pure titanium and titanium alloys, Ti-8Al-1Mo-1V and Ti-6Al-4V, was shown to cause embrittlement of the alloys. Embrittlement was a function of the interstitial hydrogen content rather than the amount of precipitated titanium hydride. The effects of hydrogen concentration on the critical strain for plastic instability along pure shear directions was determined for alloys Ti-8Al-1Mo-1V and Ti-5Al-2.5Sn. Hydrogen, in concentrations below that necessary for spontaneous hydride precipitation, increased the strain necessary for instability formation or instability failure. The strain rate sensitivity also increased with increasing hydrogen concentration. The effect of hydrogen on slip and twinning was determined for titanium single crystals. The critical resolved shear stress for prism slip was increased and the critical resolved shear stress for twinning was decreased with increasing hydrogen concentration.

  10. Carbon plasma immersion ion implantation of nickel-titanium shape memory alloys.

    Science.gov (United States)

    Poon, R W Y; Yeung, K W K; Liu, X Y; Chu, P K; Chung, C Y; Lu, W W; Cheung, K M C; Chan, D

    2005-05-01

    Nickel-titanium (NiTi) shape memory alloys possess super-elasticity in addition to the well-known shape memory effect and are potentially suitable for orthopedic implants. However, a critical concern is the release of harmful Ni ions from the implants into the living tissues. We propose to enhance the corrosion resistance and other surface and biological properties of NiTi using carbon plasma immersion ion implantation and deposition (PIII&D). Our corrosion and simulated body fluid tests indicate that either an ion-mixed amorphous carbon coating fabricated by PIII&D or direct carbon PIII can drastically improve the corrosion resistance and block the out-diffusion of Ni from the materials. Our tribological tests show that the treated surfaces are mechanically more superior and cytotoxicity tests reveal that both sets of plasma-treated samples favor adhesion and proliferation of osteoblasts. PMID:15585228

  11. Surface and corrosion characteristics of carbon plasma implanted and deposited nickel-titanium alloy

    Science.gov (United States)

    Poon, R. W. Y.; Liu, X. Y.; Chung, C. Y.; Chu, P. K.; Yeung, K. W. K.; Lu, W. W.; Cheung, K. M. C.

    2005-05-01

    Nickel-titanium shape memory alloys (NiTi) are potentially useful in orthopedic implants on account of their super-elastic and shape memory properties. However, the materials are prone to surface corrosion and the most common problem is out-diffusion of harmful Ni ions from the substrate into body tissues and fluids. In order to improve the corrosion resistance and related surface properties, we used the technique of plasma immersion ion implantation and deposition to deposit an amorphous hydrogenated carbon coating onto NiTi and implant carbon into NiTi. Both the deposited amorphous carbon film and carbon plasma implanted samples exhibit much improved corrosion resistances and surface mechanical properties and possible mechanisms are suggested.

  12. In vivo apatite formation induced on titanium metal and its alloys by chemical treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kokubo, T.; Kim, H.M. [Kyoto Univ. (Japan). Dept. of Material Chemistry; Nishiguchi, S.; Nakamura, T. [Kyoto Univ. (Japan). Dept. of Orthopaedic Surgery

    2001-07-01

    NaOH and heat treatments form an amorphous sodium titanate layer with a graded structure on the surfaces of titanium metal and its alloys. These treatments give no adverse effect on mechanical properties of the metals. Thus treated metals form an apatite layer on their surfaces in the living body by taking the calcium and phosphate ions from the surrounding fluid. This apatite layer is tightly integrated to the metal substrates through a graded structure, and bonds to the living bone in a short period, because of its structure and composition analogous to those of the bone mineral. This kind of bioactive metals are believed to be useful as bone substitutes even under load bearing conditions such as hip joints and dental implants. (orig.)

  13. Composite materials and bodies including silicon carbide and titanium diboride and methods of forming same

    Science.gov (United States)

    Lillo, Thomas M.; Chu, Henry S.; Harrison, William M.; Bailey, Derek

    2013-01-22

    Methods of forming composite materials include coating particles of titanium dioxide with a substance including boron (e.g., boron carbide) and a substance including carbon, and reacting the titanium dioxide with the substance including boron and the substance including carbon to form titanium diboride. The methods may be used to form ceramic composite bodies and materials, such as, for example, a ceramic composite body or material including silicon carbide and titanium diboride. Such bodies and materials may be used as armor bodies and armor materials. Such methods may include forming a green body and sintering the green body to a desirable final density. Green bodies formed in accordance with such methods may include particles comprising titanium dioxide and a coating at least partially covering exterior surfaces thereof, the coating comprising a substance including boron (e.g., boron carbide) and a substance including carbon.

  14. Evaluation of plasma nitriding efficiency of titanium alloys for medical applications

    Directory of Open Access Journals (Sweden)

    T. Frączek

    2009-04-01

    Full Text Available The surface layers obtained on selected titanium alloys, used in medicine, by the nitriding under glow discharge condition were investigated. The results concern of: α- titanium alloy Grade 2 and α + β alloys Grade 5 and Grade 5 ELI nitrided in temperature below 873 K. The nitriding experiments were performed in a current glow-discharge furnace JON-600 with assisting of unconventional methods. After nitriding surface layers were characterised by surface microhardness measurements, chemical depth profiles, microhardness depth profiles and wear resistance tests.

  15. Synchrotron X-ray diffraction study of the phase transformations in titanium alloys

    OpenAIRE

    Malinov, Savko; Sha, Wei; Guo, Z.; Tang, C.C.; Long, Adrian

    2002-01-01

    High-resolution synchrotron X-ray diffraction was used to study the phase transformations in titanium alloys. Three titanium alloys were investigated: Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-0.08Si and beta21s. Both room and high temperature measurements were performed. The room temperature experiments were performed to study the structure of the alloys after different heat treatments, namely as received (AR), furnace cooling (FC), water quenching (WQ) and water quenching followed by ageing. The alpha,...

  16. A Low-Cost Hierarchical Nanostructured Beta-Titanium Alloy with High Strength

    Energy Technology Data Exchange (ETDEWEB)

    Devaraj, Arun; Joshi, Vineet V.; Srivastava, Ankit; Manandhar, Sandeep; Moxson, Vladimir S.; Duz, Volodymr; Lavender, Curt A.

    2016-04-09

    Lightweighting of automobiles by use of novel low-cost, high strength-to-weight ratio structural materials can reduce the consumption of fossil fuels and in turn CO2 emission. Working towards this goal we achieved high strength in a low cost β-titanium alloy, Ti-1Al-8V-5Fe (Ti185), by hierarchical nanostructure consisting of homogenous distribution of micron-scale and nanoscale α-phase precipitates within the β-phase matrix. The sequence of phase transformation leading to this hierarchical nanostructure is explored using electron microscopy and atom probe tomography. Our results suggest that the high number density of nanoscale α-phase precipitates in the β-phase matrix is due to ω assisted nucleation of α resulting in high tensile strength, greater than any current commercial titanium alloy. Thus hierarchical nanostructured Ti185 serves as an excellent candidate for replacing costlier titanium alloys and other structural alloys for cost-effective lightweighting applications.

  17. Internal state variable models for micro-structure in high temperature deformation of titanium alloys

    Institute of Scientific and Technical Information of China (English)

    LUO Jiao; LI MiaoQuan; LI XiaoLi

    2008-01-01

    There exists an interaction between microstructural evolution and deformation behavior in high temperature deformation of titanium alloys. And the microstruc-ture of titanium alloys is very sensitive to the process parameters of plastic de-formation process. In this paper, on the basis of plastic deformation mechanism of metals and alloys, a microstructural model including dislocation density rate equa-tion and grain growth rate equation is established with the dislocation density rate being an internal state variable. Applying the model to the high temperature de-formation process of Ti60 titanium alloy, the average relative errors of grain sizes between the experiments and the predictions are 9.47% for sampled data, and 13.01% for non-sampled data.

  18. Internal state variable models for micro- structure in high temperature deformation of titanium alloys

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    There exists an interaction between microstructural evolution and deformation behavior in high temperature deformation of titanium alloys. And the microstruc- ture of titanium alloys is very sensitive to the process parameters of plastic de- formation process. In this paper, on the basis of plastic deformation mechanism of metals and alloys, a microstructural model including dislocation density rate equa- tion and grain growth rate equation is established with the dislocation density rate being an internal state variable. Applying the model to the high temperature de- formation process of Ti60 titanium alloy, the average relative errors of grain sizes between the experiments and the predictions are 9.47% for sampled data, and 13.01% for non-sampled data.

  19. A low-cost hierarchical nanostructured beta-titanium alloy with high strength

    Science.gov (United States)

    Devaraj, Arun; Joshi, Vineet V.; Srivastava, Ankit; Manandhar, Sandeep; Moxson, Vladimir; Duz, Volodymyr A.; Lavender, Curt

    2016-04-01

    Lightweighting of automobiles by use of novel low-cost, high strength-to-weight ratio structural materials can reduce the consumption of fossil fuels and in turn CO2 emission. Working towards this goal we achieved high strength in a low cost β-titanium alloy, Ti-1Al-8V-5Fe (Ti185), by hierarchical nanostructure consisting of homogenous distribution of micron-scale and nanoscale α-phase precipitates within the β-phase matrix. The sequence of phase transformation leading to this hierarchical nanostructure is explored using electron microscopy and atom probe tomography. Our results suggest that the high number density of nanoscale α-phase precipitates in the β-phase matrix is due to ω assisted nucleation of α resulting in high tensile strength, greater than any current commercial titanium alloy. Thus hierarchical nanostructured Ti185 serves as an excellent candidate for replacing costlier titanium alloys and other structural alloys for cost-effective lightweighting applications.

  20. The effect of grain boundaries state on the thermal stability of a submicrocrystalline titanium alloy structure

    Science.gov (United States)

    Chuvil'deev, V. N.; Kopylov, V. I.; Nokhrin, A. V.; Lopatin, Yu. G.; Kozlova, N. A.; Tabachkova, N. Yu.; Semenycheva, A. V.; Smirnova, E. S.; Gryaznov, M. Yu.; Pirozhnikova, O. E.

    2015-06-01

    The thermal stability of the structure and the mechanical properties of submicrocrystalline (SMC) titanium alloy Ti-4Al-2V (industrial designation PT3V) are investigated. The alloy was produced by equal-channel angular pressing (ECAP). It is demonstrated that the enhanced thermal stability of the SMC alloy structure is associated with a change in the concentration of aluminum at the grain boundaries during ECAP.

  1. X-ray fluorescence analysis of titanium alloys.

    Science.gov (United States)

    Vassilaros, G L; McKaveney, J P

    1969-02-01

    An X-ray solution method is proposed for determining major amounts of Mo, Sn and Zr in Ti alloys. The method utilizes adjacent elements in the periodic table as internal standards and has been successfully applied to levels of 3-10% Sn, 11-40% Mo and 6-20% Zr. The procedure involves three steps: dissolving the sample with a suitable acid mixture; adding the suitable internal standard at the concentration levels experimentally found to give optimum accuracy and precision; analysing the resulting solution mixture by X-ray fluorescence. Antimony was found to be a suitable internal standard for its adjacent element tin at a concentration ratio of 3:1 Sb:Sn. Niobium was successfully used for both its adjacent elements, molybdenum and zirconium, at 2:1 concentration ratios, Nb:Mo and Nb:Zr. A number of elements non-adjacent to tin, molybdenum and zirconium (i.e., copper, bromine, titanium, bismuth and tantalum) were experimentally found unsuitable as internal standards. Concentration factors of the internal standard and the adjacent elements sought were found to affect significantly the precision of analysis. PMID:18960488

  2. Structure, castability and mechanical properties of commercially pure and alloyed titanium cast in graphite mould.

    Science.gov (United States)

    Cheng, W W; Ju, C P; Lin, J H Chern

    2007-07-01

    This report is a study of structure, castability, mechanical properties as well as corrosion behaviour of titanium doped with up to 5 weight percentage (wt%) of a series of alloy elements, including Ta, Mo, Nb, Hf, Zr, Sn, Bi and Ag. The results indicate that, with addition of 1 wt% alloy element, Bi and Mo were most effective in enhancing the castability of titanium. With more alloy elements added, the castability values of most alloys more or less decreased. Except Ti-Mo system, all Ti alloys with a fine acicular morphology had the same crystal structure (hcp) as that of c.p. Ti with a typical lath type morphology. When 3 wt% or more Mo was added, a finer orthorhombic alpha'' phase was formed. The microhardness and bending strength values of Ti alloys were all higher than those of c.p. Ti. Among all alloys, Ti-Mo system exhibited the highest hardness and strength level. For a certain alloy, the bending strength did not necessarily increase with its alloy content. Except Ti-5Zr and Ti-Mo alloys, the bending moduli of most alloy systems were not much different from that of c.p. Ti. All alloys showed an excellent resistance to corrosion in Hanks' solution at 37 degrees C. PMID:17559621

  3. The surface nanostructures of titanium alloy regulate the proliferation of endothelial cells

    Directory of Open Access Journals (Sweden)

    Min Lai

    2014-02-01

    Full Text Available To investigate the effect of surface nanostructures on the behaviors of human umbilical vein endothelial cells (HUVECs, surface nanostructured titanium alloy (Ti-3Zr2Sn-3Mo-25Nb, TLM was fabricated by surface mechanical attrition treatment (SMAT technique. Field emission scanning electron microscopy (FE-SEM, atomic force microscopy (AFM, transmission electron microscopy (TEM and X-ray diffraction (XRD were employed to characterize the surface nanostructures of the TLM, respectively. The results demonstrated that nano-crystalline structures with several tens of nanometers were formed on the surface of TLM substrates. The HUVECs grown onto the surface nanostructured TLM spread well and expressed more vinculin around the edges of cells. More importantly, HUVECs grown onto the surface nanostructured TLM displayed significantly higher (p < 0.01 or p < 0.05 cell adhesion and viabilities than those of native titanium alloy. HUVECs cultured on the surface nanostructured titanium alloy displayed significantly higher (p < 0.01 or p < 0.05 productions of nitric oxide (NO and prostacyclin (PGI2 than those of native titanium alloy, respectively. This study provides an alternative for the development of titanium alloy based vascular stents.

  4. Effect of hydrogen on the behavior of metals II - Hydrogen embrittlement of titanium alloy TV13CA - effect of oxygen - comparison with non-alloyed titanium

    International Nuclear Information System (INIS)

    The effect of oxygen on the hydrogen embrittlement of non-alloyed titanium and the metastable β titanium alloy, TV13 CA, was studied during dynamic mechanical tests, the concentrations considered varying from 1000 to 5000 ppm (oxygen) and from 0 to 5000 ppm (hydrogen) respectively. TV13 CA alloy has a very high solubility for hydrogen. The establishment of a temperature range and a rate of deformation region in which the embrittlement of the alloy is maximum leads to the conclusion that an embrittlement mechanism occurs involving the dragging and accumulation of hydrogen by dislocations. This is the case for all annealings effected in the medium temperature range, which, by favoring the re-establishment of the stable two-phase α + β state of the alloy, produce hardening. The same is true for oxygen which, in addition to hardening the alloy by the solid solution effect, tends to increase its instability and, in consequence, favors the decomposition of the β phase. Nevertheless oxygen concentrations of up to 1500 ppm contribute to increasing the mechanical resistance without catastrophically reducing the deformation capacity. In the case of non-alloyed titanium, the hardening effect also leads to an increase in E0.2pc and R, and to a reduction in the deformation capacity. Nevertheless, hydrogen is only very slightly soluble at room temperature and a distribution of the hydride phase linked to the thermal history of the sample predominates. Thus a fine acicular structure obtained from the β phase by quenching, enables an alloy having a good mechanical resistance to be conserved even when large quantities of hydrogen are present; the deformation capacity remains small. On the other hand, when the hydride phase separates the metallic phase into large grains, a very small elongation leads to a breakdown in mechanical resistance. (author)

  5. Sol gel derived hydroxyapatite coatings on titanium and its alloy Ti6Al4V

    Science.gov (United States)

    Stoch, A.; Jastrzebski, W.; Długoń, E.; Lejda, W.; Trybalska, B.; Stoch, G. J.; Adamczyk, A.

    2005-06-01

    Titanium has been used for many medical and dental applications; however, its joining to a living bone is not satisfactorily good or the implant integration with bone tissue takes several months.The aim of this work is to produce hydroxyapatite (HAP) coatings on titanium and its alloy for facilitating and shortening the processes towards osseointegration. HAP coatings were obtained by sol-gel method with sol solutions prepared from calcium nitrate tetrahydrate and triammonium phosphate trihydrate as the calcium and phosphorous sources. Two types of gelatine were added to the sol: agar-agar or animals gelatine. Both were found to enhance the formation and stability of amorphous HAP using soluble salts as the sources of calcium and phosphate. HAP coatings were deposited from HAP-GEL sol using dip-withdrawal technique, then the plates were dried and annealed at temperatures 460-750 °C. FTIR spectroscopy and XRD analysis were used to study the phase composition of phosphate coatings. Morphology and chemical analysis of HAP layers was performed using a scanning electron microscope equipped with an energy dispersive X-ray analyser (SEM+EDX). The biological activity of sol-gel phosphate coatings was observed during thermostatic held in simulated body fluid (SBF). It was found that chemical composition and structure of HAP coatings depends on pH and final thermal treatment of the layer.

  6. Effects of sodium tartrate anodizing on fatigue life of TA15 titanium alloy

    Directory of Open Access Journals (Sweden)

    Fu Chunjuan

    2015-08-01

    Full Text Available Anodizing is always used as an effective surface modification method to improve the corrosion resistance and wear resistance of titanium alloy. The sodium tartrate anodizing is a new kind of environmental anodizing method. In this work, the effects of sodium tartrate anodizing on mechanical property were studied. The oxide film was performed on the TA15 titanium alloy using sodium tartrate as the film former. The effects of this anodizing and the traditional acid anodizing on the fatigue life of TA15 alloy were compared. The results show that the sodium tartrate anodizing just caused a slight increase of hydrogen content in the alloy, and had a slight effect on the fatigue life. While, the traditional acid anodizing caused a significant increase of hydrogen content in the substrate and reduced the fatigue life of the alloy significantly.

  7. Comparative study on welding characteristics of laser-additional current hybrid welded T-joint of aluminium and titanium alloy

    Directory of Open Access Journals (Sweden)

    Zhang Xinge

    2015-01-01

    Full Text Available In order to improve the properties of laser overlap welded T-joint, laser-additional current hybrid welding process is put forward. In this paper, the welding characteristics of laser-additional current hybrid welded aluminum and titanium alloy T-joint were conducted and compared. The weld width at faying surface increase, which results in tensile shear load increasing compared with those of laser welding for both aluminum and titanium alloy, but the effect of current on aluminum alloy is more obvious. The porosity defect within the laser-additional current hybrid welded joint sharply reduces compared with that within laser welding. The tensile shear load of aluminum alloy and titanium alloy hybrid welded joints respectively increase 21% and 15%. The effects of additional current on welding characteristics of aluminum alloy and titanium alloy are compared and analyzed.

  8. Imprecise knowledge based design and development of titanium alloys for prosthetic applications.

    Science.gov (United States)

    Datta, S; Mahfouf, M; Zhang, Q; Chattopadhyay, P P; Sultana, N

    2016-01-01

    Imprecise knowledge on the composition-processing-microstructure-property correlation of titanium alloys combined with experimental data are used for developing rule based models for predicting the strength and elastic modulus of titanium alloys. The developed models are used for designing alloys suitable for orthopedic and dental applications. Reduced Space Searching Algorithm is employed for the multi-objective optimization to find composition, processing and microstructure of titanium alloys suitable for orthopedic applications. The conflicting requirements attributes of the alloys for this particular purpose are high strength with low elastic modulus, along with adequate biocompatibility and low costs. The 'Pareto' solutions developed through multi-objective optimization show that the preferred compositions for the fulfilling the above objectives lead to β or near β-alloys. The concept of decision making employed on the solutions leads to some compositions, which should provide better combination of the required attributes. The experimental development of some of the alloys has been carried out as guided by the model-based design methodology presented in this research. Primary characterizations of the alloys show encouraging results in terms of the mechanical properties. PMID:26398780

  9. Grain refinement effects of Al based alloys with low titanium content produced by electrolysis

    Institute of Scientific and Technical Information of China (English)

    刘志勇; 王明星; 翁永刚; 宋天福; 谢敬佩; 霍裕平

    2002-01-01

    A series of Al based alloys with low titanium contents (mass fraction) from 0.178% to 0.526% were directly produced in ordinary industrial electrolyzer. The electrolyzing results show that producing Al based alloys with titanium contents of less than 0.30% without great loss of electrolysis efficiency is possible. The quantitative analysis shows that this method has a great refining effect on transiting the coarse columnar grains in pure Al to equiaxed grains. The grain sizes decrease with the increase of titanium content and tend to a low limit at about 130μm. During the solidification, the non-equilibrium distribution of titanium leads to a great growth-restricting effect and a constitutional under-cooling zone in front of the growing liquid /solid interface.

  10. Effect of nanotube diameters on bioactivity of a multifunctional titanium alloy

    Science.gov (United States)

    Hao, Y. Q.; Li, S. J.; Hao, Y. L.; Zhao, Y. K.; Ai, H. J.

    2013-03-01

    Ti-24Nb-4Zr-8Sn (abbreviated as Ti2448) is a multifunctional β type titanium alloy consisting of nontoxic alloying elements and possessing better balanced biomechanical properties of high strength and low elastic modulus. To improve its bioactivity, the anodic oxidation of Ti2448 alloy in neutral electrolyte containing small amounts of NH4F was applied to produce the nanotubes consisting of the amorphous mixed oxides of TiO2, Nb2O5, SnO2 and ZrO2. The in vitro studies of the oestoblast-like MG-63 cells were performed to evaluate the biological behavior of the nanotubes with the outer diameters of 30, 50, 70 and 90 nm in comparison with the polished pure titanium and Ti2448 alloy. The results showed that the smaller diameter of 30 nm promoted the cell adhesion, proliferation and differentiation whereas the larger diameter of 90 nm had the worst cell viability with small spreading area of cytoskeletal actin. Although the nanotubes of Ti2448 alloy consist of the amorphous mixed oxides, it exhibits similar biological behavior with that of the amorphous TiO2 of pure titanium. This suggests that the topography of the amorphous nanotube plays important role on cell response. Additionally, the studies did not detect statistical difference of the bioactivity for the polished pure titanium and Ti2448 alloy.

  11. Two-Phase (TiAl+TiCrAl) Coating Alloys for Titanium Aluminides

    Science.gov (United States)

    Brady, Michael P. (Inventor); Smialek, James L. (Inventor); Brindley, William J. (Inventor)

    1998-01-01

    A coating for protecting titanium aluminide alloys, including the TiAl gamma + Ti3Al (alpha(sub 2)) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000 C. is disclosed. This protective coating consists essentially of titanium, aluminum. and chromium in the following approximate atomic ratio: Ti(41.5-34.5)Al(49-53)Cr(9.5-12.5)

  12. Comparative Analysis of Selected Eddy Current Transducers for Titanium Alloy Evaluation

    Science.gov (United States)

    Chady, T.; Sikora, R.; Baniukiewicz, P.; Lopato, P.; Kowalczyk, J.; Psuj, G.; Caryk, M.

    2010-02-01

    Titanium alloy based details due to their mechanical properties continue to be in extensive use in various structures (mainly aerospace, automotive and petro-chemical industrial applications). In this paper comparative study of various types of eddy current NDT transducers for testing titanium elements was done. Probes of absolute, differential and array configurations were constructed and analyzed. Two and three dimensional numerical analysis (FEM) were done in order to find the best type and configuration of the proposed transducers.

  13. Surface microhardness and wear resistance change of titanium alloy under ion nitriding

    International Nuclear Information System (INIS)

    The influence of ion implantation on the mechanical properties of titanium alloy OT-4 has been investigated. Implantation with 1016-1017 120 keV, N, Ar ions/cm2 and their mixture causes the titanium surfaces microhardness and wear resistance increase. Possible mechanisms for the change of metal surface layers as a result of ion implantation have been discussed using the results and investigations with the help of Rutherford backscattering and scanning electron microscope

  14. Deformation behaviour and new constitutive equation utilising the grain size of commercial TC6 titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, M.Q.; Xiong, A.M. [Northwestern Polytechnical Univ., Coll. of Materials Science and Engineering, Xi' an (China); Wang, H.R.; Su, S.B.; Shen, L.C. [Xi' an Aero-Engine Co. Ltd., Xi' an (China)

    2004-10-01

    Isothermal compression tests on a commercial TC6 titanium alloy have been conducted at deformation temperatures of about 800 - 1040 deg C, strain rates of 0.001 - 50 s{sup -1} and height reductions of 30 - 50%. The microstructural evolution is represented through the measured grain size of the prior {alpha}-phase. Meanwhile, a new constitutive equation, which includes the grain size, is established for high temperature deformation behaviour. The procedure required to formulate a constitutive equation from the experimental results is presented. The constitutive equation to model the behaviour of the TC6 titanium alloy during high temperature deformation is validated and its formulation is presented. The results show that the present equation is satisfactory for describing the behaviour of the TC6 titanium alloy during high temperature deformation. The maximum difference between the calculated and the experimental results is less than 15%. (Author)

  15. Development of the Dynamic Globularization Prediction Model for Ti-17 Titanium Alloy Using Finite Element Method

    Science.gov (United States)

    Jia, Zhiqiang; Zeng, Weidong; Xu, Jianwei; Zhou, Jianhua; Wang, Xiaoying

    2015-04-01

    In this work, a finite element method (FEM) model for predicting dynamic globularization of Ti-17 titanium alloy is established. For obtaining the microstructure evolution during dynamic globularization under varying processing parameters, isothermal hot compression tests and quantitative metallographic analysis were conducted on Ti-17 titanium alloy with initial lamellar microstructure. The prediction model, which quantitatively described the non-linear relationship between the dynamic globularization fraction and the deformation strain, temperature, and strain rate, was developed on the basis of the Avrami equation. Then the developed model was incorporated into DEFORM software as a user subroutine. Finally, the large-sized step-shaped workpiece was isothermally forged and corresponding FEM simulation was conducted to verify the reliability and accuracy of the integrated FEM model. The reasonable coincidence of the predicted results with experimental ones indicated that the established FEM model provides an easy and a practical method to predict dynamic globularization for Ti-17 titanium alloy with complex shape.

  16. Standard Test Method for Stress-Corrosion of Titanium Alloys by Aircraft Engine Cleaning Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method establishes a test procedure for determining the propensity of aircraft turbine engine cleaning and maintenance materials for causing stress corrosion cracking of titanium alloy parts. 1.2 The evaluation is conducted on representative titanium alloys by determining the effect of contact with cleaning and maintenance materials on tendency of prestressed titanium alloys to crack when subsequently heated to elevated temperatures. 1.3 Test conditions are based upon manufacturer's maximum recommended operating solution concentration. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see and .

  17. An X-ray Fourier line shape analysis in cold-worked hexagonal titanium base alloys

    International Nuclear Information System (INIS)

    X-ray diffraction is an established technique for the analysis of microstructural parameters such as domain sizes, microstrains within the domains, and deformation fault densities in the deformed state of metals and alloys. These microstructural parameters influence the flow of dislocation in the lattice under deformation and thus regulate the strength and hardenability of the materials. The evaluation of such microdefects is this necessary for understanding the mechanical behavior of materials. In the present study, considering the wide applicability of titanium-base alloys in aviation industry, two alloy systems, i.e., titanium-base aluminum and titanium-base zirconium, have been selected. A number of X-ray diffraction profiles belonging to both fault-affected (H - K = 3N ± 1) and fault-unaffected (H - K = 3N) reflections have been recorded by a SIEMENS Kristolloflex-4 diffractometer using Cu Kα radiation, and the profiles have been analyzed to evaluate the microstructural parameters

  18. First-principles study on the effect of alloying elements on the elastic deformation response in β-titanium alloys

    International Nuclear Information System (INIS)

    Theoretical deformation response of hypothetical β-titanium alloys was investigated using first-principles calculation technique under periodic boundary conditions. Simulation was carried out on hypothetical 54-atom supercell of Ti–X (X = Cr, Mn, Fe, Zr, Nb, Mo, Al, and Sn) binary alloys. The results showed that the strength of Ti increases by alloying, except for Cr. The most effective alloying elements are Nb, Zr, and Mo in the current simulation. The mechanism of bond breaking was revealed by studying the local structure around the alloying element atom with respect to volume change. Moreover, the effect of alloying elements on bulk modulus and admissible strain was investigated. It was found that Zr, Nb, and Mo have a significant effect to enhance the admissible strain of Ti without change in bulk modulus

  19. First-principles study on the effect of alloying elements on the elastic deformation response in β-titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gouda, Mohammed K., E-mail: mohamed.kamal@ejust.edu.eg; Gepreel, Mohamed A. H. [Materials Science and Engineering Department, Egypt-Japan University of Science and Technology, Borg El Arab, Alexandria 21934 (Egypt); Nakamura, Koichi [Materials Science and Engineering Department, Egypt-Japan University of Science and Technology, Borg El Arab, Alexandria 21934 (Egypt); Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 615-8540 (Japan)

    2015-06-07

    Theoretical deformation response of hypothetical β-titanium alloys was investigated using first-principles calculation technique under periodic boundary conditions. Simulation was carried out on hypothetical 54-atom supercell of Ti–X (X = Cr, Mn, Fe, Zr, Nb, Mo, Al, and Sn) binary alloys. The results showed that the strength of Ti increases by alloying, except for Cr. The most effective alloying elements are Nb, Zr, and Mo in the current simulation. The mechanism of bond breaking was revealed by studying the local structure around the alloying element atom with respect to volume change. Moreover, the effect of alloying elements on bulk modulus and admissible strain was investigated. It was found that Zr, Nb, and Mo have a significant effect to enhance the admissible strain of Ti without change in bulk modulus.

  20. AN EVALUATION OF HYDROGEN INDUCED CRACKING SUSCEPTIBILITY OF TITANIUM ALLOYS IN US HIGH-LEVEL NUCLEAR WASTE REPOSITORY ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    G. De; K. Mon; G. Gordon; D. Shoesmith; F. Hua

    2006-02-21

    This paper evaluates hydrogen-induced cracking (HIC) susceptibility of titanium alloys in environments anticipated in the Yucca Mountain nuclear waste repository with particular emphasis on the. effect of the oxide passive film on the hydrogen absorption process of titanium alloys being evaluated. The titanium alloys considered in this review include Ti 2, 5 , 7, 9, 11, 12, 16, 17, 18, 24 and 29. In general, the concentration of hydrogen in a titanium alloy can increase due to absorption of atomic hydrogen produced from passive general corrosion of that alloy or galvanic coupling of it to a less noble metal. It is concluded that under the exposure conditions anticipated in the Yucca Mountain repository, the HIC of titanium drip shield will not occur because there will not be sufficient hydrogen in the metal even after 10,000 years of emplacement. Due to the conservatisms adopted in the current evaluation, this assessment is considered very conservative.

  1. AN EVALUATION OF HYDROGEN INDUCED CRACKING SUSCEPTIBILITY OF TITANIUM ALLOYS IN US HIGH-LEVEL NUCLEAR WASTE REPOSITORY ENVIRONMENTS

    International Nuclear Information System (INIS)

    This paper evaluates hydrogen-induced cracking (HIC) susceptibility of titanium alloys in environments anticipated in the Yucca Mountain nuclear waste repository with particular emphasis on the. effect of the oxide passive film on the hydrogen absorption process of titanium alloys being evaluated. The titanium alloys considered in this review include Ti 2, 5 , 7, 9, 11, 12, 16, 17, 18, 24 and 29. In general, the concentration of hydrogen in a titanium alloy can increase due to absorption of atomic hydrogen produced from passive general corrosion of that alloy or galvanic coupling of it to a less noble metal. It is concluded that under the exposure conditions anticipated in the Yucca Mountain repository, the HIC of titanium drip shield will not occur because there will not be sufficient hydrogen in the metal even after 10,000 years of emplacement. Due to the conservatisms adopted in the current evaluation, this assessment is considered very conservative

  2. Research on depositing Ni45 alloy on titanium alloy surface by electrospark deposition

    Institute of Scientific and Technical Information of China (English)

    You Tao; Zhang Chunhui; Su Guiqiao; Yan Ping

    2008-01-01

    Taking Ni45 bar as electrode, a strengthened layer of thickness up to 50 pm was built up on BT20 titanium alloy matrix by means of electrospark deposition. Results of phase analysis by using of X-ray diffraction confirmed that the deposition layer was composed mostly of three phases, NiTi, NiTi2layer was up to 910 HV0.05, about 2.7 times as high as that of the matrix. The hardness at the cross-section of the entire deposition layer showed a gradient distribution. The effects of capacitance and deposition time on thickness of deposition layer were also studied, and results showed that with relatively low capacity and short deposition time the deposition layer without cracks can be obtained.

  3. Ablation experiment and threshold calculation of titanium alloy irradiated by ultra-fast pulse laser

    Directory of Open Access Journals (Sweden)

    Buxiang Zheng

    2014-02-01

    Full Text Available The interaction between an ultra-fast pulse laser and a material's surface has become a research hotspot in recent years. Micromachining of titanium alloy with an ultra-fast pulse laser is a very important research direction, and it has very important theoretical significance and application value in investigating the ablation threshold of titanium alloy irradiated by ultra-fast pulse lasers. Irradiated by a picosecond pulse laser with wavelengths of 1064 nm and 532 nm, the surface morphology and feature sizes, including ablation crater width (i.e. diameter, ablation depth, ablation area, ablation volume, single pulse ablation rate, and so forth, of the titanium alloy were studied, and their ablation distributions were obtained. The experimental results show that titanium alloy irradiated by a picosecond pulse infrared laser with a 1064 nm wavelength has better ablation morphology than that of the green picosecond pulse laser with a 532 nm wavelength. The feature sizes are approximately linearly dependent on the laser pulse energy density at low energy density and the monotonic increase in laser pulse energy density. With the increase in energy density, the ablation feature sizes are increased. The rate of increase in the feature sizes slows down gradually once the energy density reaches a certain value, and gradually saturated trends occur at a relatively high energy density. Based on the linear relation between the laser pulse energy density and the crater area of the titanium alloy surface, and the Gaussian distribution of the laser intensity on the cross section, the ablation threshold of titanium alloy irradiated by an ultra-fast pulse laser was calculated to be about 0.109 J/cm2.

  4. Ablation experiment and threshold calculation of titanium alloy irradiated by ultra-fast pulse laser

    International Nuclear Information System (INIS)

    The interaction between an ultra-fast pulse laser and a material's surface has become a research hotspot in recent years. Micromachining of titanium alloy with an ultra-fast pulse laser is a very important research direction, and it has very important theoretical significance and application value in investigating the ablation threshold of titanium alloy irradiated by ultra-fast pulse lasers. Irradiated by a picosecond pulse laser with wavelengths of 1064 nm and 532 nm, the surface morphology and feature sizes, including ablation crater width (i.e. diameter), ablation depth, ablation area, ablation volume, single pulse ablation rate, and so forth, of the titanium alloy were studied, and their ablation distributions were obtained. The experimental results show that titanium alloy irradiated by a picosecond pulse infrared laser with a 1064 nm wavelength has better ablation morphology than that of the green picosecond pulse laser with a 532 nm wavelength. The feature sizes are approximately linearly dependent on the laser pulse energy density at low energy density and the monotonic increase in laser pulse energy density. With the increase in energy density, the ablation feature sizes are increased. The rate of increase in the feature sizes slows down gradually once the energy density reaches a certain value, and gradually saturated trends occur at a relatively high energy density. Based on the linear relation between the laser pulse energy density and the crater area of the titanium alloy surface, and the Gaussian distribution of the laser intensity on the cross section, the ablation threshold of titanium alloy irradiated by an ultra-fast pulse laser was calculated to be about 0.109 J/cm2

  5. Modification Of The Structure And Properties Of The Titanium Alloy Ti6Al4V In Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Klimas J.

    2015-09-01

    Full Text Available From the time when Per-Ingvar Brånemark discovered oseointegration properties of titanium in 1952 a large-scale studies on the issue of usability this metal in surgery were started. Thanks to the parallel research conducted on independent centers managed to get a number of metal alloys which were implanted into the human body in the form of implants. Among the alloys produced appeared alloy of aluminum and vanadium Ti6Al4V. The mechanical properties, high biocompatibility, low density and for this relatively low-cost, caused that the alloy began to be used as a material for biomedical applications. In the present article analyzed the possibility of modifying the properties of the alloy, by choosing another method of producing – method of injection casting with suction. A comparative analysis of the input material - the alloy commercially produced in the form of a rod of the same material melted by injection under vacuum and in air were carried out. The studies results indicate that using method of injection casting with suction to produce the final item influence on significant improvement in mechanical properties as a result of fragmentation of the grains at the element surface. The mechanical properties play a key role in a tissue-implant-bone system.

  6. Effect of high-temperature hydrogen treatment on the microstructure and properties of titanium alloy Ti-6Al-4V

    Energy Technology Data Exchange (ETDEWEB)

    Sozanska, M, E-mail: maria.sozanska@polsl.pl [Department of Materials Science, Silesian University of Technology, Krasinskiego 8, 40-019, Katowice (Poland)

    2011-05-15

    The influence of hydrogen on the structure of titanium alloys is a complex phenomenon, which, depending on the circumstances, may be negative or positive. Negative effects of hydrogen on the properties of titanium alloys primarily manifest themselves in a decrease in plastic properties and impact resistance and the formation of cracks in the structure. The positive effect of hydrogen on the titanium alloy properties is manifested in the high-temperature hydrogen treatment (HTM-Hydrogen Treatment of Materials), where hydrogen is a temporary alloying component. Because of the high values of its diffusion coefficient, hydrogen can be easily introduced into the titanium and just as easily removed from it. The HTM plays an important role in the forming and fragmentation of titanium hydride. Because the diameter of a hydrogen atom is very small, the hydrogen atoms occupy the interstitial sites. Titanium and its alloys exhibit a high affinity for hydrogen absorption, about 60 at.% hydrogen at 600 deg. C. Because the specific volume of titanium hydride is about 13-17% higher compared to that of the {alpha} phase, high stresses in the crystal lattice of the titanium hydride phase leads to local plastic deformation and a highly deformed phase. These developments lead to changes in the structure of titanium alloys and their mechanical properties. This paper presents characterization studies of the structure of two-phase titanium alloy Ti-6Al-4V after hydrogen treatment. This hydrogen treatment consisted of three stages: hydrogenation in a hydrogen gas atmosphere at 850 deg. C, a cyclic hydrogen treatment (1 or 3 cycles at 250 deg. C) and dehydrogenation in a vacuum (550 deg. C). It was shown that hydrogen appreciably changed the microstructure of the surface layer of the tested titanium alloy. Qualitative analyses of the structure using secondary electrons in a scanning electron microscope (SEM) were carried out. Image analysis helped to determine a quantitative description

  7. Characterization of hydrogen interactions with the surface of alpha-2 titanium aluminide alloys

    Science.gov (United States)

    Shanabarger, Mickey R.

    1990-01-01

    The interaction of hydrogen at the surface of alpha-2 titanium aluminide alloys with Nb additions has been investigated with Auger electron spectroscopy (AES) and reflected electron energy loss (REELS) spectroscopy. The hydrogen was either adsorbed onto the alloy surface from the gas phase or it was pre-charged into the alloy forming an alpha-2 hydride. No effect of either adsorbed or absorbed hydrogen was observed in the Auger spectra. A shift in the bulk plasmon loss energy (observed with REELS) was measured for both conditions. The potential significance of these results in relation to hydrogen interactions in this alloy is discussed.

  8. Effect of Indium Content on the Microstructure, Mechanical Properties and Corrosion Behavior of Titanium Alloys

    OpenAIRE

    Mi-Kyung Han; Jae-Bong Im; Moon-Jin Hwang; Bong-Jun Kim; Hae-Young Kim; Yeong-Joon Park

    2015-01-01

    Ti-xIn (x = 0, 5, 10, 15 and 20 wt%) alloys were prepared to investigate the effect of indium on the microstructure, mechanical properties, and corrosion behavior of titanium with the aim of understanding the relationship between phase/microstructure and various properties of Ti-xIn alloys. The Ti-xIn alloys exhibited a lamellar α-Ti structure at an indium content of up to 20 wt%. High-resolution TEM images of the Ti-xIn alloys revealed that all the systems contained a fine, acicular martensi...

  9. Thermal decomposition kinetics of titanium hydride and Al alloy melt foaming process

    Institute of Scientific and Technical Information of China (English)

    YANG; Donghui; HE; Deping; YANG; Shangrun

    2004-01-01

    A temperature programmed decomposition (TPD) apparatus with metal tube structure, in which Ar is used as the carrier gas, is established and the TPD spectrum of titanium hydride is acquired. Using consulting table method (CTM), spectrum superposition method (SSM) and differential spectrum technique, TPD spectrum of titanium hydride is separated and a set of thermal decomposition kinetics equations are acquired. According to these equations, the relationship between decomposition quantity and time for titanium hydride at the temperature of 940 K is obtained and the result well coincides with the Al alloy melt foaming process.

  10. Electrochemical assessment of some titanium and stainless steel implant dental alloys

    Directory of Open Access Journals (Sweden)

    Echevarría, A.

    2003-12-01

    Full Text Available Commercially pure titanium alloy, Ti-6Al-4V alloy and stainless steel screw implants were evaluated in both Ringer and synthetic saliva physiological solutions at body temperature by EIS (Electrochemical Impedance Spectroscopy with immersion times of 30 d. Results were simulated as a "sandwich system" composed by four capacitors-resistances connected in series with the solution resistance. A model explaining the results in terms of the porosity and thickness of four different layers, was proposed.

    Se utilizó la técnica de la Espectroscopia de Impedancia Electroquímica para evaluar en soluciones fisiológicas artificiales (Ringer y saliva sintética muestras extraídas de tornillos de implantes dentales certificados de titanio comercialmente puro, aleación Ti-6Al-W y acero inoxidable a temperatura corporal, con tiempos de inmersión hasta de 30 d. Los resultados se simularon mediante un modelo del tipo sandwich de cuatro elementos RC, conectados en serie con una resistencia de la solución. A partir de de esta simulación, se propone un modelo que explica los resultados obtenidos en términos de la evolución de la porosidad y el espesor de cuatro diferentes capas que se desarrollan en la superficie de los materiales evaluados.

  11. The Microstructure and Capacitance Characterizations of Anodic Titanium Based Alloy Oxide Nanotube

    OpenAIRE

    Po Chun Chen; Sheng Jen Hsieh; Chien Chon Chen; Jun Zou

    2013-01-01

    This paper presents a simple anodization process to fabricate ordered nanotubes (NTs) of titanium and its alloys (Ti-Mo and Ti-Ta). TiO2, MoO3, and Ta2O5 are high dielectric constant materials for ultracapacitor application. The anodic titanium oxide contains a compact layer on the NT film and a barrier layer under the NT film. However, the microstructure of oxide films formed by anodic Ti-Mo and Ti-Ta alloys contains six layers, including a continuous compact layer, a continuous partial poro...

  12. Optimization of Cutting Parameters for Face Milling Titanium Alloy Using MQL

    Institute of Scientific and Technical Information of China (English)

    AHMED Hassan; YAO Zhen-qiang

    2005-01-01

    When using MQL as a cooling technique, many parameters have to be adjusted. The Taguchi method was used in this study to investigate the cutting characteristics of face milling of titanium alloys using PVD-coated inserts. To find the optimal volume removed and surface roughness, an orthogonal array, the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed. The optimum cutting parameters was obtained. Throughout this study, it was found that the feed rate is the most influencing cutting parameter in the face milling of titanium alloys.

  13. Multi-objective Optimization in the Milling of Titanium Alloys Using the MQL Technique

    Institute of Scientific and Technical Information of China (English)

    Ahmed Hassan; YAO Zhen-qiang

    2004-01-01

    The process for face milling of (α+β) titanium alloy while using minimum quantity librication (MQL) as the cooling technique was optimized by using of the Taguchi method to improve characteristics.The cutting speed, feed rate, and depth of cut were optimized with consideration of multiple performance characteristics including tool life, volume removed and surface roughness. The experimental results show that the multiple performance characteristics can be simultaneously improved through this approach, and the feed rate is the most influential cutting parameter in the face milling of titanium alloys.

  14. A Review of Titanium Zirconium (TiZr) Alloys for Use in Endosseous Dental Implants

    OpenAIRE

    Michel Dard; H. Michelle Grandin; Simon Berner

    2012-01-01

    Dental implants made from binary titanium-zirconium (TiZr) alloys have shown promise as a high strength, yet biocompatible alternative to pure titanium, particularly for applications requiring small diameter implants. The aim of this review is to summarize existing literature reporting on the use of binary TiZr alloys for endosseous dental implant applications as tested in vitro, in animals and clinically. And furthermore to show that TiZr is “at least as good as” pure ti...

  15. Fatigue modification of TA15 titanium alloy weldments by an ultrasonic impact treatment

    DEFF Research Database (Denmark)

    Gao, Yukui; Zhong, Zheng; Zhang, Xiaodan;

    2014-01-01

    The welded components of TA15 titanium alloy were ultrasonically impact treated. The fatigue lives were investigated under the same test conditions. The fatigue strength was determined by stair-step method and the residual stresses were analyzed by an X-ray diffraction stress tester. The results...... show that the fatigue properties of TA15 titanium alloy welded components are sensitive to the surface treatment and ultrasonic impacting can prolong the fatigue lives. The effect of fatigue strength improvement mainly depends on compressive residual stresses and grain refinement....

  16. [Bio-tribological properties of dental prosthesis made of nitriding titanium alloy material].

    Science.gov (United States)

    Li, Hong; Luo, Jingcong; Qin, Tingwu; Li, Juan; Feng, Jielin; Huang, Wei; He, Xin

    2004-04-01

    Titanium alloy material (TC4) samples were treated with nitriding technique. The dynamic friction and wear behavior of the modified layer were examined on a reciprocating sliding rig in artificial saliva. Microhardness, depth profile and wear mechanisms were investigated by means of MVK-H12, TALYSURF6, XPS and microscopy. The results demonstrate that after being treated with nitriding technique the titanium alloy material (TC4) has better tribological behavior and up-graded wear resistance. The wear mechanism involves adhesion. PMID:15143554

  17. NUMERICAL SIMULATION OF CONTROLLING IN TITANIUM ALLOY SHEETS WELDING RESIDUAL STRESS BY TRAILING PEENING

    Institute of Scientific and Technical Information of China (English)

    X.S. Liu; H. Y. Fang; W.L. Xu; Z.B. Dong; D.Y. Yu

    2004-01-01

    It is a promising and new technology to apply welding with trailing peening to control welding stress and distortion of titanium alloy. Numerical simulation of conventional welding and welding with trailing peening of the titanium alloy sheet is carried out,using nonlinear finite element theory and the engineering analysis software MARC.The result shows that welding with trailing peening technology reduces longitudinal residual stress in welding joint effectively, and it is more effective to reduce residual stress to peen the weld than to peen the weld toe. It is a effective result that other technology and method used in welding can never achieved.

  18. The technology of precision casting of titanium alloys by centrifugal process

    Directory of Open Access Journals (Sweden)

    A. Karwiński

    2011-07-01

    Full Text Available The article describes the development of a procedure for the preparation of foundry ceramic moulds and making first test castings. The presented studies included:development of technological parameters of the ceramic mould preparation process using water-based zirconium binders and zirconia ceramic materials, where moulds are next used for the centrifugal casting of titanium alloys melted in vacuum furnaces, designing of pouring process using simulation software, making test castings,testing and control of the casting properties. The technological process described in this paper enables making castings in titanium alloys weighing up to about 500 g and used in the majority of technical applications.

  19. Characterization of Coatings Created on Selected Titanium Alloys by Plasma Electrolytic Oxidation

    OpenAIRE

    Rokosz K.; Hryniewicz T.; Malorny W.

    2016-01-01

    The SEM and EDS results of coatings obtained on pure niobium and titanium alloys (NiTi and Ti6Al4V) by Plasma Electrolytic Oxidation in the electrolytes containing of 300 g and 600 g copper nitrate in 1 litre of concentrated phosphoric acid at 450 V for 3 minutes, are presented. The obtained coatings are porous and consist mainly of phosphorus within titanium and copper. For each coating, the Cu/P ratios were calculated. The maximum of that coefficient was found for niobium and Ti6Al4V alloy ...

  20. A Very High-Cycle Fatigue Test and Fatigue Properties of TC17 Titanium Alloy

    Science.gov (United States)

    Jiao, Shengbo; Gao, Chao; Cheng, Li; Li, Xiaowei; Feng, Yu

    2016-03-01

    The present work studied the very high-cycle fatigue (VHCF) test and fatigue properties of TC17 titanium alloy. The specimens for bending vibration were designed using the finite element method and the VHCF tests were conducted by using the ultrasonic fatigue testing system. The results indicated that there is no the fatigue limit for TC17 titanium alloy, and the S-N curve shows a continuously descending trend. The fatigue crack initiates at the specimen surface within the range of VHCF and the VHCF lives follow the log-normal distribution more closely.

  1. Method of making multilayered titanium ceramic composites

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, George T., II; Hansen; Jeffrey S.; Oden; Laurance L.; Turner; Paul C.; Ochs; Thomas L.

    1998-08-25

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body follwed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet.

  2. Contact damage failure analyses of fretting wear behavior of the metal stem titanium alloy-bone cement interface.

    Science.gov (United States)

    Zhang, Lanfeng; Ge, Shirong; Liu, Hongtao; Wang, Qingliang; Wang, Liping; Xian, Cory J

    2015-11-01

    Although cemented titanium alloy is not favored currently in the Western world for its poor clinical and radiography outcomes, its lower modulus of elasticity and good biocompatibility are instrumental for its ability supporting and transforming physical load, and it is more suitable for usage in Chinese and Japanese populations due to their lower body weights and unique femoral characteristics. Through various friction tests of different cycles, loads and conditions and by examining fretting hysteresis loops, fatigue process curves and wear surfaces, the current study investigated fretting wear characteristics and wear mechanism of titanium alloy stem-bone cement interface. It was found that the combination of loads and displacement affected the wear quantity. Friction coefficient, which was in an inverse relationship to load under the same amplitude, was proportional to amplitudes under the same load. Additionally, calf serum was found to both lubricate and erode the wear interface. Moreover, cement fatigue contact areas appeared black/oxidative in dry and gruel in 25% calf serum. Fatigue scratches were detected within contact areas, and wear scars were found on cement and titanium surfaces, which were concave-shaped and ring concave/ convex-shaped, respectively. The coupling of thermoplastic effect and minimal torque damage has been proposed to be the major reason of contact damage. These data will be important for further studies analyzing metal-cement interface failure performance and solving interface friction and wear debris production issues. PMID:26241891

  3. The Development of Titanium Alloys for Application in the Space Shuttle Main Engine

    Science.gov (United States)

    Halchak, John A.; Jerman, Gregory A.; Zimmerman, Frank R.

    2010-01-01

    The high-strength-to-weight ratio of titanium alloys, particularly at cryogenic temperatures, make them attractive for application in rocket engines - offering the potential of superior performance while minimizing component weight. This was particularly attractive for rotating components, such as pump impellers, where titanium alloys presented the potential to achieve a major advance in rotational tip speed, with a reduction in stages and resultant saving in pump weight and complexity. The investigation into titanium alloys for application in cryogenic turbopumps began in the early 1960's. However, it was found that the reactivity of titanium limited applications and produced unique processing challenges. Specialized chemical compositions and processing techniques had to be developed. A substantial amount of material properties testing and trials in experimental turbopumps occurred, ultimately leading to application in the Space Shuttle Main Engine. One particular alloy stood out for use at liquid hydrogen temperatures, Ti-5Al-2.5Sn ELI. This alloy was employed for several critical components. This presentation deals with the development effort, the challenges that were encountered and operational experiences with Ti-5Al-2.5Sn ELI in the SSME.

  4. 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.

  5. Surface mechanical properties, corrosion resistance, and cytocompatibility of nitrogen plasma-implanted nickel-titanium alloys: a comparative study with commonly used medical grade materials.

    Science.gov (United States)

    Yeung, K W K; Poon, R W Y; Chu, P K; Chung, C Y; Liu, X Y; Lu, W W; Chan, D; Chan, S C W; Luk, K D K; Cheung, K M C

    2007-08-01

    Stainless steel and titanium alloys are the most common metallic orthopedic materials. Recently, nickel-titanium (NiTi) shape memory alloys have attracted much attention due to their shape memory effect and super-elasticity. However, this alloy consists of equal amounts of nickel and titanium, and nickel is a well known sensitizer to cause allergy or other deleterious effects in living tissues. Nickel ion leaching is correspondingly worse if the surface corrosion resistance deteriorates. We have therefore modified the NiTi surface by nitrogen plasma immersion ion implantation (PIII). The surface chemistry and corrosion resistance of the implanted samples were studied and compared with those of the untreated NiTi alloys, stainless steel, and Ti-6Al-4V alloy serving as controls. Immersion tests were carried out to investigate the extent of nickel leaching under simulated human body conditions and cytocompatibility tests were conducted using enhanced green fluorescent protein mice osteoblasts. The X-ray photoelectron spectroscopy results reveal that a thin titanium nitride (TiN) layer with higher hardness is formed on the surface after nitrogen PIII. The corrosion resistance of the implanted sample is also superior to that of the untreated NiTi and stainless steel and comparable to that of titanium alloy. The release of nickel ions is significantly reduced compared with the untreated NiTi. The sample with surface TiN exhibits the highest amount of cell proliferation whereas stainless steel fares the worst. Compared with coatings, the plasma-implanted structure does not delaminate as easily and nitrogen PIII is a viable way to improve the properties of NiTi orthopedic implants. PMID:17295246

  6. Relationships between processing parameters, microstructure and properties after gas nitriding of commercial titanium alloys

    International Nuclear Information System (INIS)

    Aimed to improve surface properties of commercial titanium alloys the process of gas nitriding is used. Four widespread alloys are investigated: Ti-6% Al-4% V, Ti-6% Al-2% Sn-4% Zr-2% Mn, Ti-8% Al-1% Mo-1% V and Ti-10% V-3% Fe-3% Al. The nitriding is carried out in a nitrogen environment at temperatures of 950 and 1050 deg C for1; 3 and 5 h. As a result, a noticeable (3-5 times) increase of titanium alloy surface hardness is detected. This occurs due to a change of phase composition in a surface layer with formation of nitrogen solid solution in α-Ti phase, TiN nitride and TiO2 dioxide. An analysis is made into effects of processing parameters and alloy chemical composition on phase composition, microstructure, microhardness and thickness of the surface layer

  7. On the increasing of adhesive strength of nanotube layers on beta titanium alloys for medical applications

    Science.gov (United States)

    Fojt, Jaroslav; Filip, Vladimir; Joska, Ludek

    2015-11-01

    The nanostructuring of titanium and its alloys surfaces is used inter alia for increasing the medical implants osseointegration. Many papers about this topic were published. However, in most cases there were no informations about nanostructures adhesion to the surface, which is crucial from the application point of view. The aim of this study was to prepare nanostructures on titanium beta alloy and optimized its adhesion to the alloy surface. Nanotubes were formed by anodic polarization in electrolyte containing fluoride ions. The composition of the nanotubes was described by X-ray photoelectron spectroscopy. Nanostructures adhesion was tested by pull-of method. The nanotubes on the Ti-36Nb-6Ta beta alloy surface were prepared by anodization. The nanostructures properties were modified by electrochemical process parameters. The adhesion of the nanotubes prepared in this work was satisfactory for implantological applications.

  8. Comparative study on welding characteristics of laser-additional current hybrid welded T-joint of aluminium and titanium alloy

    OpenAIRE

    Zhang Xinge; Li Liqun; Chen Yanbin; Zhu Xiaocui; Li Yansheng; Guo Xinjian

    2015-01-01

    In order to improve the properties of laser overlap welded T-joint, laser-additional current hybrid welding process is put forward. In this paper, the welding characteristics of laser-additional current hybrid welded aluminum and titanium alloy T-joint were conducted and compared. The weld width at faying surface increase, which results in tensile shear load increasing compared with those of laser welding for both aluminum and titanium alloy, but the effect of current on aluminum alloy is mor...

  9. Microstructures and mechanical property of laser butt welding of titanium alloy to stainless steel

    International Nuclear Information System (INIS)

    Highlights: • The laser direct butt welding of titanium alloy to stainless steel is realized. • The interfacial microstructures of the joints are confirmed. • The weldability is better when laser beam is offset toward titanium than steel. • The highest tensile strength of the joint reaches to 150 MPa. - Abstract: Laser butt welding of titanium alloy to stainless steel was performed. The effect of laser-beam offsetting on microstructural characteristics and fracture behavior of the joint was investigated. It was found that when the laser beam is offset toward the stainless steel side, it results in a more durable joint. The intermetallic compounds have a uniform thickness along the interface and can be divided into two layers. One consists of FeTi + α-Ti, and other consists of FeTi + Fe2Ti + Ti5Fe17Cr5. When laser beam is offset by 0 mm and 0.3 mm toward the titanium alloy side, the joints fracture spontaneously after welding. Durable joining is achieved only when the laser beam is offset by 0.6 mm toward the titanium alloy. From the top to the bottom of the joint, the thickness of intermetallic compounds continuously decreases and the following interfacial structures are found: FeAl + α-Ti/Fe2Ti + Ti5Fe17Cr5, FeAl + α-Ti/FeTi + Fe2Ti + Ti5Fe17Cr5 and FeAl + α-Ti, in that order. The tensile strength of the joint is higher when the laser beam is offset toward the stainless steel than toward the titanium alloy, the highest observed value being 150 MPa. The fracture of the joint occurs along the interface between two adjacent intermetallic layers

  10. Study of the titanium alloys surfaces used in orthopaedic systems

    International Nuclear Information System (INIS)

    Total hip prosthesis (THP) is a highly successful orthopaedic device. However, its durability is generally limited to a few decades due to difficult conditions in the human body and huge demands it is subjected to. A hip prosthesis is deteriorating due to high surface pressures caused by mechanical movements of the body. The aim of this project is to improve the characteristics of hip prostheses, in order to increase their functionality and their life span. This paper presents an analysis regarding the topography and tribological parameters of femoral heads structures and of femoral heads coated with TiN. We studied the tribological properties of the surfaces of some femoral heads made of Ti alloys or coated with TiN. These femoral heads were obtained from some prostheses after revision surgery. Afterwards, we used TiN nanostructured coatings for reducing the wear process. TiN thin films were deposited using physical vapour deposition (PVD) and some scratch tests have been realized on these coatings surfaces. The study of coatings surfaces was made using atomic force microscopy (AFM) that offers the possibility to obtain nanometric 3D control of thin films. Main result of these researches is that used coatings offer the possibility to improve the system properties. (authors)

  11. Environmental protection of titanium alloys in centrifugal compressors at 500°C in saline atmosphere

    OpenAIRE

    Béguin, Jean-Denis; Faure, Pierre; Adrian, Denise; Alexis, Joël; Petit, Jacques-Alain; Belaygue, Philippe; Fournier, Dominique

    2004-01-01

    The use of the titanium alloy Ti-6246 (Ti-6Al-2Sn-4Zr-6Mo, wt-%) for gas turbine compressors allows an increase in working temperature and stress level. Under severe service conditions, the material experiences combined high temperature and high mechanical stress and, in saline atmospheres, stress corrosion cracking (SCC) can occur, leading to catastrophic mechanical failure. The present study was performed to evaluate the potential of several surface treatments to protect Ti-6246 alloy, afte...

  12. Laser shock peening of titanium 6-4 alloy

    Science.gov (United States)

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

    2000-04-01

    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.

  13. Strain localization during tensile Hopkinson bar testing of commercially pure titanium and Ti6Al4V titanium alloy

    Directory of Open Access Journals (Sweden)

    Moćko Wojciech

    2015-01-01

    Full Text Available The goal of the analysis was to determine the strain localization for various specimen shapes (type A and type B according to PN-EN ISO 26203-1 standard and different loading conditions, i.e. quasi- static and dynamic. Commercially pure titanium (Grade 2 and titanium alloy Ti6Al4V (Grade 5 were selected for the tests. Tensile loadings were applied out using servo-hydraulic testing machine and tensile Hopkinson bar with pre-tension. The results were recorded using ARAMIS system cameras and fast camera Phantom V1210, respectively at quasi-static and dynamic loading conditions. Further, specimens outline was determined on the basis of video data using TEMA MOTION software. The strain distribution on the specimen surface was estimated using digital image correlation method. The larger radius present in the specimen of type B in comparison to specimen of type A, results in slight increase of the elongation for commercially pure titanium at both quasi-static and dynamic loading conditions. However this effect disappears for Ti6Al4V alloy. The increase of the elongation corresponds to the stronger necking effect. Material softening due to increase of temperature induced by plastic work was observed at dynamic loading conditions. Moreover lower elongation at fracture point was found at high strain rates for both materials.

  14. Titanium-35niobium alloy as a potential material for biomedical implants: In vitro study.

    Science.gov (United States)

    de Andrade, Dennia Perez; de Vasconcellos, Luana Marotta Reis; Carvalho, Isabel Chaves Silva; Forte, Lilibeth Ferraz de Brito Penna; de Souza Santos, Evelyn Luzia; Prado, Renata Falchete do; Santos, Dalcy Roberto Dos; Cairo, Carlos Alberto Alves; Carvalho, Yasmin Rodarte

    2015-11-01

    Research on new titanium alloys and different surface topographies aims to improve osseointegration. The objective of this study is to analyze the behavior of osteogenic cells cultivated on porous and dense samples of titanium-niobium alloys, and to compare them with the behavior of such type of cells on commercial pure titanium. Samples prepared using powder metallurgy were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and metallographic and profilometer analyses. Osteogenic cells from newborn rat calvaria were plated over different groups: dense or porous samples composed of Ti or Ti-35niobium (Nb). Cell adhesion, cell proliferation, MTT assay, cell morphology, protein total content, alkaline phosphatase activity, and mineralization nodules were assessed. Results from XRD and EDS analysis confirmed the presence of Ti and Nb in the test alloy. Metallographic analysis revealed interconnected pores, with pore size ranging from 138 to 150μm. The profilometer analysis detected the greatest rugosity within the dense alloy samples. In vitro tests revealed similar biocompatibility between Ti-35Nb and Ti; furthermore, it was possible to verify that the association of porous surface topography and the Ti-35Nb alloy positively influenced mineralized matrix formation. We propose that the Ti-35Nb alloy with porous topography constitutes a biocompatible material with great potential for use in biomedical implants. PMID:26249625

  15. Effects of hydrogen on fatigue life of Ti-4Al-2V titanium alloy

    Institute of Scientific and Technical Information of China (English)

    何晓; 岳俊; 沈保罗; 曹建玲; 邱绍宇; 邹红

    2003-01-01

    Four hydrogen contents were employed to investigate the effects of hydrogen on fatigue life of Ti-4Al-2V titanium alloy by means of section-varied samples. Results reveal that the fatigue life of the materials with (116~280)×10-6 hydrogen is higher than that of natural hydrogen material provided that the fatigue load Δσ is over 550MPa. At higher Δσ, the content of hydrogen has small effects on fatigue life within (116-280)×10-6 hydrogen. For material containing 280×10-6 hydrogen, fatigue cracks tend to initiate at sample edges at higher load, in contrast, to initiate at sites of hydrides at lower load. The interstitial hydrogen atoms softening the persistent slip bands(PSB) and hydrides separating from the body become the cause of decrease in fatigue life. Hydrides resolved into the body is observed at lower Δσ for material with 280×10-6 hydrogen, which is the result of concentration of hydrogen atoms at crack tips and stress-induced re-precipitation of hydrides.

  16. Dynamic process of angular distortion between aluminum and titanium alloys with TIG welding

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; LIANG Zhen-xin; ZHANG Jian-xun

    2008-01-01

    The dynamic process of welding angular distortion in the overlaying welding of 5A12 aluminum alloy and BT20 titanium alloy was investigated. Information of dynamic distortion was got via self-made welding dynamic measuring system. Research results show that the characteristics of dynamic distortions at various positions of the plate edge parallel to the weld of 5A12 and BT20 alloy are different. Comparison between 5A12 and BT20 alloy shows that transverse shrinkage and downward longitudinal bending are main factors influencing the dynamic angular distortion processes of 5A12 and BT20 alloy under welding heat input of 0.32 kJ/mm. The angular distortion of 5A12 alloy is completely inversed with welding heat input increasing to 0.4 kJ/mm, and the position of weld center and buckling distortion become the primary factors.

  17. Mechanical properties of multicomponent cast high-strength martensitic titanium alloys

    International Nuclear Information System (INIS)

    The investigation of mechanical properties and workability of titanium alloys of the Ta-Al-Mo-V-Sn-Zn-Cu-Fe system with the purpose of alloy development for mold castings with σsub(u) >= 1100 MPa and high resistance to repeated static loads is performed. As optimum alloy for manufacturing power packs and details the alloy of the following composition is chosen: 5.5%Al, 3% Mo; 1.5% V; 1.0% Cu; 0.8% Fe; 1.5% Sn; 3.5% Zr (VT26L) having high stringth σsub(U)=1100... 1250 MPa, satisfactory plasticity ( delta=4...8%, PHI=8... 12%) resistance to repeated-static loads at the VT22 alloy level and satisfactory casting properties. It is established that the VT26L alloy has high level of properties upon casting, without any heat treatment

  18. Characterization of a new beta titanium alloy, Ti-12Mo-3Nb, for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, S.B., E-mail: sinara@metalmat.ufrj.br [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalurgica de Materiais, C.P. 68505, Rio de Janeiro (RJ) 21945-970 (Brazil); Centro Universitario de Volta Redonda, Volta Redonda (RJ) (Brazil); Panaino, J.V.P. [Centro Universitario de Volta Redonda, Volta Redonda (RJ) (Brazil); Santos, I.D. [Pontificia Universidade Catolica do Rio de Janeiro, Rio de Janeiro (RJ) (Brazil); Araujo, L.S. [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalurgica de Materiais, C.P. 68505, Rio de Janeiro (RJ) 21945-970 (Brazil); Mei, P.R. [Universidade Estadual de Campinas, Campinas (SP) (Brazil); Almeida, L.H. de [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalurgica de Materiais, C.P. 68505, Rio de Janeiro (RJ) 21945-970 (Brazil); Nunes, C.A. [Universidade de Sao Paulo, Departamento de Engenharia de Materiais, C.P. 116, Lorena (SP) 12.600-970 (Brazil)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer This paper focused on the development of Ti-12Mo-3Nb alloy for it to be used as a bone substitute. Black-Right-Pointing-Pointer The alloy show good mechanical properties and exhibit spontaneous passivity. Black-Right-Pointing-Pointer The Ti-12Mo-3Nb alloy can be a promising alternative for biomedical application. - Abstract: In recent years, different beta titanium alloys have been developed for biomedical applications with a combination of mechanical properties including a low Young's modulus, high strength, fatigue resistance and good ductility with excellent corrosion resistance. From this perspective, a new metastable beta titanium Ti-12Mo-3Nb alloy was developed with the replacement of both vanadium and aluminum from the traditional Ti-6Al-4V alloy. This paper presents the microstructure, mechanical properties and corrosion resistance of the Ti-12Mo-3Nb alloy heat-treated at 950 Degree-Sign C for 1 h. The material was characterized by X-ray diffraction and by scanning electron microscopy. Tensile tests were carried out at room temperature. Corrosion tests were performed using Ringer's solution at 25 Degree-Sign C. The results showed that this alloy could potentially be used for biomedical purposes due to its good mechanical properties and spontaneous passivation.

  19. Iodide titanium - perspective material for shape memory alloys and hydrogen-resistant alloys for heat-exchange equipment of nuclear power installations

    International Nuclear Information System (INIS)

    The work presents the results of investigations aimed at assessment of furnace charge materials impact on stoichiometry of shape memory alloy (TH1 grade) on the basis of nickelide titanium. It is shown that highly pure iodide titanium of TI grade and electrolytic nickel of H-0 grade are the most appropriate precursors for generation of nickelide titanium with fixed temperature of shape recovery. Iodide titanium, if used as furnace charge component in the process of melting of hydrogen-resistant α-alloys for heat-exchange equipment of nuclear power installations, will contribute to the increase of major devices service life.

  20. Effect of high density electropulsing treatment on formability of TC4 titanium alloy sheet

    Institute of Scientific and Technical Information of China (English)

    SONG Hui; WANG Zhong-jin; GAO Tie-jun

    2007-01-01

    An annealed TC4 titanium alloy sheet was treated by high density electropulsing (Jmax=(5.09-5.26)×103A/mm2, tp=110 μs) under ambient conditions. The effect of electropulsing treatment(EPT) on the plastic deformation behavior of TC4 titanium alloy sheet was studied using uniaxial tension tests. The experimental results indicate that electropulsing treatment significantly changes the mechanical properties of sheet metal: the uniform elongation is increased by 35%, the yield stress is decreased by 19.8% and the yield to tensile ratio is decreased by 17.6%. It is of significant meaning to improve the formability of TC4 titanium alloy sheet. The optical microscope and scanning electron microscope(SEM) were used to examine the changes of the microstructure and the fracture morphology before and after the electropulsing treatment. It is found that recrystallization occurs in the sheet metal and dimples in fracture surface are large and deep after the electropulsing treatment. The research results show that the electropulsing treatment is an effective method to improve the formability of titanium alloy sheets.

  1. Mechanical poperties of biomedical beta titanium alloys with increased oxygen content

    Czech Academy of Sciences Publication Activity Database

    Stránský, J.; Janeček, M.; Harcuba, P.; Landa, Michal

    Praha : Department of Physics of Materials, Charles University in Prague, 2014. [ISPMA /13./. 31.08.2014-04.09.2014, Praha] R&D Projects: GA ČR GB14-36566G Institutional support: RVO:61388998 Keywords : titanium alloys * elastic properties Subject RIV: BM - Solid Matter Physics ; Magnetism

  2. Investigation of Corrosion Behavior of Bioactive Coverings on Commercially Pure Titanium and its Alloys

    Directory of Open Access Journals (Sweden)

    M.Yu. Gazizova

    2015-12-01

    Full Text Available A microporous and macroporous bioactive coatings on boimedical titanium alloys (VT1-0, VT6, Ti-6Al-7Nb were formed by a micro-arc oxidation method. The effect of the phase composition of microporous and macroporous coatings on corrosion behavior titanium and its alloys was investigated. The results show that phase composition of the coatings microporous presented only titanium oxides: anatase and rutile, at that the phase composition macroporous coatings consists of anatase, rutile and calcium phosphate compounds: tricalcium phosphate (TCP α-Ca3(PO42 and calcium deficient hydroxyapatite Ca9HPO4(PO45OH. Corrosion behavior of MAO coatings was investigated in solution 0.9 % NaCl using potentiodynamic polarization tests. The microporous coatings exhibited a more highest corrosion resistance than macroporous coatings, it is connected with containing calcium phosphate compounds in macroporous coatings.

  3. Design of a nitrogen-implanted titanium-based superelastic alloy with optimized properties for biomedical applications

    International Nuclear Information System (INIS)

    In this study, a superelastic Ni-free Ti-based biomedical alloy was treated in surface by the implantation of nitrogen ions for the first time. The N-implanted surface was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and secondary ion mass spectroscopy, and the superficial mechanical properties were evaluated by nano-indentation and by ball-on-disk tribological tests. To investigate the biocompatibility, the corrosion resistance of the N-implanted Ti alloy was evaluated in simulated body fluids (SBF) complemented by in-vitro cytocompatibility tests on human fetal osteoblasts. After implantation, surface analysis methods revealed the formation of a titanium-based nitride on the substrate surface. Consequently, an increase in superficial hardness and a significant reduction of friction coefficient were observed compared to the non-implanted sample. Also, a better corrosion resistance and a significant decrease in ion release rates have been obtained. Cell culture experiments indicated that the cytocompatibility of the N-implanted Ti alloy was superior to that of the corresponding non-treated sample. Thus, this new functional N-implanted titanium-based superelastic alloy presents the optimized properties that are required for various medical devices: superelasticity, high superficial mechanical properties, high corrosion resistance and excellent cytocompatibility. - Highlights: • A superelastic Ni-free Ti-based biomedical alloy was treated in surface by implantation of nitrogen ions. • Much higher superficial hardness and wear resistance were obtained. • A clear enhancement of the corrosion resistance in SBF was observed. • In-vitro tests performed on human fetal osteoblasts indicated an excellent level of cytocompatibility

  4. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    International Nuclear Information System (INIS)

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute α grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase (α and β) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase α and near-α (Ti Gr 12) alloys

  5. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.

    1997-12-01

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute {alpha} grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase ({alpha} and {beta}) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase {alpha} and near-{alpha} (Ti Gr 12) alloys.

  6. Cytotoxicity and antibacterial property of titanium alloy coated with silver nanoparticle-containing polyelectrolyte multilayer

    International Nuclear Information System (INIS)

    Silver nanoparticle (AgNP) was incorporated into dopamine-modified alginate/chitosan (DAL/CHI) polyelectrolyte multilayer to modify the surface of titanium alloy and improve its antibacterial property. Scanning electron microscopy showed that AgNP with the size of 50 nm embedded in DAL/CHI multilayers homogeneously. X-ray photoelectron spectroscopy analysis indicated that the nanoparticles were silver (0) with peaks at 368.4 and 374.4 eV, respectively. The formation of silver (0) without the addition of reductants was due to the self-polymerization of dopamine, which can reduce the silver cation into neutral metal. The polyelectrolyte multilayer coating enhanced the wettability of titanium alloy and promoted the fibroblast proliferation significantly, which could be attributed to the excellent biocompatibility of DAL/CHI. Despite the slight fall of L929 cell activity after AgNP incorporation, AgNP-DAL/CHI multilayer inhibited the growth of both Escherichia coli and Staphylococcus aureus. The above results demonstrate that dopamine decoration is a simple and effective way to induce the in-situ formation of AgNP within polyelectrolyte multilayer. Furthermore, the AgNP-containing multilayer considerably enhances the antibacterial activity of titanium alloy. The fabrication of AgNP-DAL/CHI multilayer on the surface of titanium implant might have great potential in orthopedic use. - Highlights: • Polyelectrolyte multilayer was fabricated through layer-by-layer assembly. • AgNP was formed in-situ and embedded within polyelectrolyte multilayer. • Surface of titanium was modified by AgNP-DAL/CHI multilayer with a facile method. • AgNP-DAL/CHI multilayer enhanced antibacterial activity of titanium alloy

  7. Enhancement in mechanical properties of a β-titanium alloy by high-pressure torsion

    OpenAIRE

    Katarzyna Sharman; Piotr Bazarnik; Tomasz Brynk; Asli Gunay Bulutsuz; Malgorzata Lewandowska; Yi Huang; Terence G. Langdon

    2015-01-01

    Titanium alloys, mainly Ti–6Al–4V, are commonly used in biomedical applications as orthopedic implants. Due to the potential toxic influence of V and Al cations on health, a new alloy composition, Ti–24Nb–4Zr–8Sn, was introduced. However, Ti–24Nb–4Zr–8Sn has a much lower tensile strength by comparison with the Ti–6Al–4V alloy. The aim of this research was to determine whether high-pressure torsion (HPT) can be an efficient method for obtaining the desired properties in the case of the Ti–24Nb...

  8. Brazing of zirconia to titanium using Ag-Cu and Au-Ni filler alloys

    OpenAIRE

    Jean S. Pimenta; Augusto J. A. Buschinelli; Rubens M. do Nascimento; Augusto E. Martinelli; Joseph Remmel

    2013-01-01

    Advanced ceramic is usually joined to metal by the well-known direct brazing process, where costly active filler alloys can be considered a limitation. Brazing using active-metal-free filler alloy as insert between the joint components is an attempt to overcome it. The active metal diffusion from the titanium member through the bulk of molten filler to the ceramic was responsible to produce an active filler alloy in loco and promote reduction of the zirconium oxide to improve wetting on the c...

  9. The effect of thermohydrogen treatment on the structure and properties of casts obtained from titanium alloys

    International Nuclear Information System (INIS)

    The method based on the combination of high temperature gas-static and thermal hydrogen treatments is suggested to increase mechanical properties of cast pseudo-α and (α+β)-titanium alloys. The study is carried out using alloys VT20L, VT23L and alloy Ti-6%Al-2%Mo-4%Zr-2%Sn. It is shown that the method proposed provides the change in a cast structure, an increase in density of castings, an increase of strength properties by 10-20% and fatigue by a factor of 1.5-2 at satisfactory ductility and impact strength

  10. Plasma immersion ion implantation and deposition hybrid process on aluminum and titanium alloy

    International Nuclear Information System (INIS)

    Because of their variety excellent properties, aluminum and titanium alloy are widely used in aerospace, airplane, ship manufacture, energy source and chemical engineering. However, both of them show a low wear resistance. In our research, plasma immersion ion implantation and deposition was utilized to improve their wear resistance. The method of ion implantation + transition layer deposition + wear resistance layer deposition was applied on these alloys. And by employing the wear testing method, the influences of the structure and thickness of the transition layer on wear resistance were obtained. The experimental results reveal that the wear resistance of these alloys can be improved significantly by optimizing the processing window. (authors)

  11. Low cycle fatigue improvement of powder metallurgy titanium alloy through thermomechanical treatment

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; LIU Yong; HE Xiao-yu; TANG Hui-ping; CHEN Li-fang

    2008-01-01

    A low-cost β type Ti-1.5Fe-6.8Mo-4.8Al-1.2Nd (mass fraction, %)(T12LCC) alloy was produced by blended elemental powder metallurgy(P/M) method and subsequent thermomechanical treatment. Low cycle fatigue(LCF) behavior of P/M T12LCC alloy before and after thermomechanical treatment was studied. The results show that the LCF resistance of P/M titanium alloy is significantly enhanced through the thermomechanical treatment. The mechanisms for the improvement of LCF behavior are attributed to the elimination of residual pores, the microstructure refining and homogenization.

  12. Biofilm formation on titanium alloy and anatase-Bactercline® coated titanium healing screws: an in vivo human study

    Directory of Open Access Journals (Sweden)

    Antonio Scarano

    2013-03-01

    Full Text Available Aim Bacterial adherence to implants is considered to be an important event in the pathogenesis of bacterial infections. In fact, this infection process is a first stage of peri-implant mucositis and peri-implantitis, and a positive correlation has been found between oral hygiene and marginal bone loss around implants in the edentulous mandible. Surface properties of transgingival implant components are important determinants in bacterial adhesion. The purpose of this study was to characterize the biofilm formation, in vivo, on healing screws made of titanium alloy or coated with a combination of anatase and Bactercline® product. Materials and methods Twenty-five patients, between 21- 37 years, in excellent systemic health, participated in this study. In each of the 25 participants, one anatase-Bactercline® coated healing screw (Test and one titanium alloy (TI6Al4V healing screw (Control were adapted to two different implants. Quantitative and qualitative biofilm formation on healing abutments was analyzed by culture method.Results Bacterial adherence to the two different healing screws used in this study were compared. Statistically significant differences were found between the Control and the Test group for both aerobic and anaerobic bacterial counts (p<0,05. The microflora consisted both of Gram-positive and Gram-negative bacteria, and displayed a high variability. The anaerobic S. intermedius, potentially “pathogenic”, was isolated only from the Control group. Both healing screws harbored primarily Gram-positive rods as Actinomyces spp, A. naeslundii, A. viscosus and the Gram-negative rods (Fusobacterium spp, Prevotella spp, Capnocythophaga spp were mostly found on the Control healing screws.Conclusion Anatase-Bactercline® coated healing screws reduce the number of initially adhering bacteria, formed mainly of Gram-positive microorgnisms, while, on the contrary, the microflora covering the titanium alloy healing screws was, for the

  13. Interfacial reaction kinetics of coated SiC fibers with various titanium alloys

    Science.gov (United States)

    Gundel, D. B.; Wawner, F. E.

    1991-01-01

    The kinetics of the reaction between the silicon carbide fibers and the titanium-based alloy matrix was investigated at temperatures from 800 to 1000 C for several titanium-based alloys (including Ti-1100 alloy and BETA 21S) and unalloyed Ti, reinforced with coated silicon carbide fiber SCS-6. The reaction zone growth kinetics was studied by exposing vacuum encapsulated samples to temperatures from 700 to 1000 C for times up to 150 hrs, followed by SAM observations of samples which were polished perpendicular to the fiber axis and etched. It was found that the reaction zone growth kinetics of the alpha (hcp) and beta (bcc) phases of unalloyed titanium reacting with SCS-6 fibers exhibited different values of the apparent activation energy and of the preexponential factor. Additions of other metals to Ti was found to slow down the reaction kinetics. Among the alloys studied, the Ti-1100 was the slowest reacting conventional alloy and the Ti-14Al-21Nb (in wt pct) was the slowest overall.

  14. Comparative MRI compatibility of 316 L stainless steel alloy and nickel-titanium alloy stents.

    Science.gov (United States)

    Holton, Andrea; Walsh, Edward; Anayiotos, Andreas; Pohost, Gerald; Venugopalan, Ramakrishna

    2002-01-01

    The initial success of coronary stenting is leading to a proliferation in peripheral stenting. A significant portion of the stents used in a clinical setting are made of 316 low carbon stainless steel (SS). Other alloys that have been used for stent manufacture include tantalum, MP35N, and nickel-titanium (NiTi). The ferromagnetic properties of SS cause the production of artifacts in magnetic resonance imaging (MRI). The NiTi alloys, in addition to being known for their shape memory or superelastic properties, have been shown to exhibit reduced interference in MRI. Thus, the objective of this study was to determine the comparative MRI compatibility of SS and NiTi stents. Both gradient echo and spin-echo images were obtained at 1.5 and 4.1 T field strengths. The imaging of stents of identical geometry but differing compositions permitted the quantification of artifacts produced due to device composition by normalizing the radio frequency shielding effects. These images were analyzed for magnitude and spatial extent of signal loss within the lumen and outside the stent. B1 mapping was used to quantify the attenuation throughout the image. The SS stent caused significant signal loss and did not allow for visibility of the lumen. However, the NiTi stent caused only minor artifacting and even allowed for visualization of the signal from within the lumen. In addition, adjustments to the flip angle of standard imaging protocols were shown to improve the quality of signal from within the lumen. PMID:12549230

  15. Determination of five kinds of impurity elements such as titanium in uranium titanium alloy by ICP-OES

    International Nuclear Information System (INIS)

    New description is given of an ICP-OES method in which 5 impurities, Ti, Fe, Ni, Cu, and Al in U-Ti alloy can be determined simultaneously. Studying the dissolution of the sample preparation, separation condition of impurity elements; determining analysis of instrument line, detection limit and detection lower limit; eliminating the matrix effect of Ti and TiO2 on the measurement of precipitation; standard addition method verify the method accuracy and precision. The results show: taking Uranium titanium alloys containing 0.1000 g sample, 5 kinds of elements Ti detection lower limits is 0.2-0.7 μg·g-1, recovery were in the range of 98.8%-102.1%, and RSD'S found were less than 8%. The method of measurement proved is accurate and reliable. (authors)

  16. Stress corrosion in titanium alloys and other metallic materials

    Science.gov (United States)

    Harkins, C. G. (Editor); Brotzen, F. R.; Hightower, J. W.; Mclellan, R. B.; Roberts, J. M.; Rudee, M. L.; Leith, I. R.; Basu, P. K.; Salama, K.; Parris, D. P.

    1971-01-01

    Multiple physical and chemical techniques including mass spectroscopy, atomic absorption spectroscopy, gas chromatography, electron microscopy, optical microscopy, electronic spectroscopy for chemical analysis (ESCA), infrared spectroscopy, nuclear magnetic resonance (NMR), X-ray analysis, conductivity, and isotopic labeling were used in investigating the atomic interactions between organic environments and titanium and titanium oxide surfaces. Key anhydrous environments studied included alcohols, which contain hydrogen; carbon tetrachloride, which does not contain hydrogen; and mixtures of alcohols and halocarbons. Effects of dissolved salts in alcohols were also studied. This program emphasized experiments designed to delineate the conditions necessary rather than sufficient for initiation processes and for propagation processes in Ti SCC.

  17. Dynamic powder compaction of rapidly solidified Path A alloy with increased carbon and titanium content

    International Nuclear Information System (INIS)

    Different techniques for consolidation of rapidly solidified alloys which are available or are under study at the present time include conventional consolidation techniques (hot extrusion, HIP,...), high velociy consolidation of atomized partially solidified particulates and dynamic powder compaction (DPC). This report describes the results of dynamic compaction of Path A alloy with increased carbon and titanium content. The microstructure of the as-compated alloy is highly complex, evidencing an extreme degree of deformation. TEM revealed very high dislocation and twin density reflecting high hardness of the as-compacted alloy. Annealing studies revealed that recovery and recrystallization processes in dynamically compacted alloy are slower than in conventionally treated materials. High dislocation density appears to be an intrinsic property of the dynamic compaction process and it may be potentially useful in developing materials for irradiation performance. Other potential applications of dynamic compaction include preparation of graded materials and ceramic materials

  18. Passive behavior of niobium and niobium-titanium alloys in sulfuric acid solutions

    International Nuclear Information System (INIS)

    The electrochemical behavior of niobium and niobium-titanium alloys has been investigated in dearated aqueous 0.1 mol/L H2SO4 solutions, at 25 C. The studies were carried out through cyclic voltammetry, potentiostatic technique and electrochemical impedance spectroscopy. The analyses of cyclic voltammograms indicate that the metal and alloys behave like valve metals and a passivating film grows on the metal surface during the anodic polarization. The corrosion current density for Nb and Nb-47 % Ti alloy decreases as the potential increases. With Nb-2% Ti alloy an increase in steady-state current density with the potential is observed. The passivating film resistance for Nb and alloys varies between 5 and 50 MΩ, depending on the final potential for the formation of oxide film. From the impedance data it was possible to propose the existence of a duplex film on Nb-2 % Ti surface

  19. Multilayer, hybrid PVD coatings on Ti6Al4V titanium alloy

    Directory of Open Access Journals (Sweden)

    W. Pawlak

    2009-12-01

    Full Text Available Purpose: The main purpose of this paper was to develop hybrid PVD technology of deposition wear resistant, multilayer coatings onto diffusion-hardened Ti6Al4V titanium alloy. Titanium and its alloys are desirable materials in modern constructions and vehicles. They have a high specific strength and very good corrosion resistance and biocompatibility. On the other hand, they have a low load-bearing capacity and poor tribological properties, as, for example, high friction coefficient, low resistance to adhesive and abrasive wear and tendency to galling. Development of multiplex coatings depositions techniques is vital for expanding of areas of titanium alloys usage.Design/methodology/approach: In the present work a new approach to coatings deposition onto diffusion hardened in glow discharge plasma (in Ar+O2 atmosphere Ti6Al4V titanium alloy was proposed by means of a hybrid PVD method including three coatings deposition methods: Reactive Magnetron Sputtering (RMS, Filtered Cathodic Arc Evaporation (FCAE and Pulsed Cathodic Arc Deposition (PCAD. The main aim of the work was to develop multilayer coatings combined of sublayers of titanium or chromium carbonitrides or of pure, hard carbon ones.Findings: It was concluded from the results of investigations that not every proposed multilayer structure ensure good frictional properties of Ti6Al4V alloy even when the coating posses very high hardness. The lowest value of wear and friction coefficient was determined for multilayer coating with (TiC/Cx3 structure.Research limitations/implications: Further research is necessary for a better understanding of the mechanisms of friction and wear as well as the origin of superhardness of particular multilayers.Practical implications: Multilayer coatings deposited by means of the hybrid PVD technique can be used for low friction and wear protection of titanium alloys.Originality/value: Originality value of this paper consists in use in one process of three

  20. Tensile properties of cast titanium alloys: Titanium-6Al-4V ELI and Titanium-5Al-2.5Sn ELI

    Science.gov (United States)

    Billinghurst, E. E., Jr.

    1992-01-01

    This work was performed to determine the tensile properties of cast, hot isostatic pressed (HIP'ed), and annealed titanium alloys, Ti-6Al-4V ELI and Ti-5Al-2.5Sn ELI, that are candidate materials for the space transportation main engine (STME) liquid hydrogen turbopump impeller. Samples of the cast alloys were HIP'ed, annealed, and machined into tensile specimens. The specimens were tested in air at ambient temperature (70 F) and also at -423 F in liquid hydrogen. The Ti-6Al-4V alloy had an average ultimate strength of 129.1 ksi at 70 F and 212.2 ksi at -423 F. The Ti-5Al-2.5Sn alloy had an average ultimate strength of 108.4 ksi at 70 degrees F and 185.0 ksi at -423 F. The ductility, as measured by reduction of area, for the Ti-6Al-4V averaged 15.2 percent at 70 F and 8.7 percent at -423 F, whereas for the Ti-5Al-2.5Sn alloy average reduction of area was 24.6 percent at 70 F and 11.7 percent at -423 F.

  1. [Corrosion behavior of dental alloys coated with titanium niobium oxinitride].

    Science.gov (United States)

    Thull, R

    1991-11-01

    Dental alloys coated with (Ti,Nb)ON using the ion are PVD technique exhibit galvanic corrosion current densities of considerably less than Jg = 1 microA/cm2. These measurements were taken on plane surfaces. The results show no signs of local corrosion, which might impair the long-term intraoral stability of dental constructions or the health of the patients. Irrespective of the dental alloys used, the coatings exhibit pores extending down to the alloy. The alloy thus wetted on the one hand, and the coated areas on the other, act as galvanic elements with high source resistances and very low short circuit currents. It may therefore be concluded that the coating will effectively reduce allergic reactions to the components of the dental alloys. PMID:1817869

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

    International Nuclear Information System (INIS)

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

  3. Investigation of photocatalytic activity of titanium dioxide coating deposited on aluminium alloy substrate by plasma technique

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Soyama, Juliano; Dirscherl, Kai;

    2011-01-01

    Nowadays, there is an increased need for functionalized surfaces with self-cleaning and antibacterial properties. Titanium dioxide (TiO2) in the anatase crystalline structure is one of the most powerful photocatalytic materials available today, which can provide above functionalities. The....... Literature consists of large number of publications on titanium dioxide coating for self-cleaning applications, with glass as the main substrate. Only little work is available on TiO2 coating of metallic alloys used for engineering applications. Engineering materials, such as light-weight aluminium and steel...

  4. Building cross-platform apps using Titanium, Alloy, and Appcelerator cloud services

    CERN Document Server

    Saunders, Aaron

    2014-01-01

    Skip Objective-C and Java to get your app to market faster, using the skills you already have Building Cross-Platform Apps using Titanium, Alloy, and Appcelerator Cloud Services shows you how to build cross-platform iOS and Android apps without learning Objective-C or Java. With detailed guidance given toward using the Titanium Mobile Platform and Appcelerator Cloud Services, you will quickly develop the skills to build real, native apps- not web apps-using existing HTML, CSS, and JavaScript know-how. This guide takes you step-by-step through the creation of a photo-sharing app that leverages

  5. Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

    Institute of Scientific and Technical Information of China (English)

    GENG Duan-yang; ZUO Hong-fu; ZHENG Bai-zhan; XU Tong

    2006-01-01

    By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.

  6. Titanium Oxide: A Bioactive Factor in Osteoblast Differentiation

    OpenAIRE

    Santiago-Medina, P.; Sundaram, P.A.; Diffoot-Carlo, N.

    2015-01-01

    Titanium and titanium alloys are currently accepted as the gold standard in dental applications. Their excellent biocompatibility has been attributed to the inert titanium surface through the formation of a thin native oxide which has been correlated to the excellent corrosion resistance of this material in body fluids. Whether this titanium oxide layer is essential to the outstanding biocompatibility of titanium surfaces in orthopedic biomaterial applications is still a moot point. To study ...

  7. Adhesion enhancement of titanium nitride coating on aluminum casting alloy by intrinsic microstructures

    Science.gov (United States)

    Nguyen, Chuong L.; Preston, Andrew; Tran, Anh T. T.; Dickinson, Michelle; Metson, James B.

    2016-07-01

    Aluminum casting alloys have excellent castability, high strength and good corrosion resistance. However, the presence of silicon in these alloys prevents surface finishing with conventional methods such as anodizing. Hard coating with titanium nitride can provide wear and corrosion resistances, as well as the aesthetic finish. A critical factor for a durable hard coating is its bonding with the underlying substrate. In this study, a titanium nitride layer was coated on LM25 casting alloy and a reference high purity aluminum substrate using Ion Assisted Deposition. Characterization of the coating and the critical interface was carried out by a range of complementing techniques, including SIMS, XPS, TEM, SEM/EDS and nano-indentation. It was observed that the coating on the aluminum alloy is stronger compared to that on the pure aluminum counterpart. Silicon particles in the alloy offers the reinforcement though mechanical interlocking at microscopic level, even with nano-scale height difference. This reinforcement overcomes the adverse effect caused by surface segregation of magnesium in aluminum casting alloys.

  8. Enhancement in mechanical properties of a β-titanium alloy by high-pressure torsion

    Directory of Open Access Journals (Sweden)

    Katarzyna Sharman

    2015-01-01

    Full Text Available Titanium alloys, mainly Ti–6Al–4V, are commonly used in biomedical applications as orthopedic implants. Due to the potential toxic influence of V and Al cations on health, a new alloy composition, Ti–24Nb–4Zr–8Sn, was introduced. However, Ti–24Nb–4Zr–8Sn has a much lower tensile strength by comparison with the Ti–6Al–4V alloy. The aim of this research was to determine whether high-pressure torsion (HPT can be an efficient method for obtaining the desired properties in the case of the Ti–24Nb–4Zr–8Sn β-titanium alloy. This paper presents an analysis of the microstructural and mechanical properties of the Ti–24Nb–4Zr–8Sn alloy processed by HPT with various processing parameters. The obtained microstructures were examined using transmission electron microscopy (TEM. Mechanical properties, such as hardness and tensile strength, were also measured. The study demonstrates that HPT of the Ti–24Nb–4Zr–8Sn alloy leads to a significant reduction of grain size and this grain refinement gives a major improvement in tensile strength and hardness.

  9. Microtwin formation in the α phase of duplex titanium alloys affected by strain rate

    International Nuclear Information System (INIS)

    Research highlights: → The long and dense twins in α phase of SP700 alloy occurring at lower strain rates promote a good ductility. → The deformation in SP700 alloy changed to micro twins-controlled mechanism in α as the strain rate decreases. → The material has time to redistribute the deformed strain between α and β as the strain rate decreases. - Abstract: The effect of tensile strain rate on deformation microstructure was investigated in Ti-6-4 (Ti-6Al-4V) and SP700 (Ti-4.5Al-3V-2Mo-2Fe) of the duplex titanium alloys. Below a strain rate of 10-2 s-1, Ti-6-4 alloy had a higher ultimate tensile strength than SP700 alloy. However, the yield strength of SP700 was consistently greater than Ti-6-4 at different strain rates. The ductility of SP700 alloy associated with twin formation (especially at the slow strain rate of 10-4 s-1), always exceeded that of Ti-6-4 alloy at different strain rates. It is caused by a large quantity of deformation twins took place in the α phase of SP700 due to the lower stacking fault energy by the β stabilizer of molybdenum alloying. In addition, the local deformation more was imposed on the α grains from the surrounding β-rich grains by redistributing strain as the strain rate decreased in SP700 duplex alloy.

  10. In vitro biocompatibility of titanium after plasma surface alloying with boron.

    Science.gov (United States)

    Kaczmarek, Mariusz; Jurczyk, Mieczysława U; Miklaszewski, Andrzej; Paszel-Jaworska, Anna; Romaniuk, Aleksandra; Lipińska, Natalia; Żurawski, Jakub; Urbaniak, Paulina; Jurczyk, Karolina

    2016-12-01

    Recently, the effect of different sizes of precursor powders during surface plasma alloying modification on the properties of titanium surface was studied. In this work we show in vitro test results of the titanium (α-Ti) after plasma surface alloying with boron (B). Ti-B nanopowders with 2 and 10wt% B were deposited onto microcrystalline Ti substrate. The in vitro cytocompatibility of these biomaterials was evaluated and compared with a conventional microcrystalline Ti. During the studies, established cell line of human gingival fibroblasts and osteoblasts were cultured in the presence of tested materials, and its survival rate and proliferation activity were examined. For this purpose, MTT assay, flow cytometric and fluorescent microscopic evaluation were made. Biocompatibility tests carried out indicate that the Ti after plasma surface alloying with B could be a possible candidate for dental implants and other medicinal applications. Plasma alloying is a promising method for improving the properties of titanium, thus increasing the field of its applications. PMID:27612822

  11. A low-cost hierarchical nanostructured beta-titanium alloy with high strength.

    Science.gov (United States)

    Devaraj, Arun; Joshi, Vineet V; Srivastava, Ankit; Manandhar, Sandeep; Moxson, Vladimir; Duz, Volodymyr A; Lavender, Curt

    2016-01-01

    Lightweighting of automobiles by use of novel low-cost, high strength-to-weight ratio structural materials can reduce the consumption of fossil fuels and in turn CO2 emission. Working towards this goal we achieved high strength in a low cost β-titanium alloy, Ti-1Al-8V-5Fe (Ti185), by hierarchical nanostructure consisting of homogenous distribution of micron-scale and nanoscale α-phase precipitates within the β-phase matrix. The sequence of phase transformation leading to this hierarchical nanostructure is explored using electron microscopy and atom probe tomography. Our results suggest that the high number density of nanoscale α-phase precipitates in the β-phase matrix is due to ω assisted nucleation of α resulting in high tensile strength, greater than any current commercial titanium alloy. Thus hierarchical nanostructured Ti185 serves as an excellent candidate for replacing costlier titanium alloys and other structural alloys for cost-effective lightweighting applications. PMID:27034109

  12. Additive manufacturing of a high niobium-containing titanium aluminide alloy by selective electron beam melting

    International Nuclear Information System (INIS)

    Additive manufacturing (AM) offers a radical net-shape manufacturing approach for titanium aluminide alloys but significant challenges still remain. A study has been made of the AM of a high niobium-containing titanium aluminide alloy (Ti–45Al–7Nb–0.3W, in at% throughout the paper) using selective electron beam melting (SEBM). The formation of various types of microstructural defects, including banded structures caused by the vaporization of aluminum, was investigated with respect to different processing parameters. To avoid both micro- and macro-cracks, the use of higher preheating temperatures and an intermediate reheating process (to reheat each solidified layer during SEBM) was assessed in detail. These measures enabled effective release of the thermal stress that developed during SEBM and therefore the avoidance of cracks. In addition, the processing conditions for the production of a fine full lamellar microstructure were identified. As a result, the Ti–45Al–7Nb–0.3W alloy fabricated showed outstanding properties (compression strength: 2750 MPa; strain-to-fracture: 37%). SEBM can be used to fabricate high performance titanium aluminide alloys with appropriate processing parameters and pathways

  13. Surface characterization and cytotoxicity analysis of plasma sprayed coatings on titanium alloys.

    Science.gov (United States)

    Rahman, Zia Ur; Shabib, Ishraq; Haider, Waseem

    2016-10-01

    In the realm of biomaterials, metallic materials are widely used for load bearing joints due to their superior mechanical properties. Despite the necessity for long term metallic implants, there are limitations to their prolonged use. Naturally, oxides of titanium have low solubilities and form passive oxide film spontaneously. However, some inclusion and discontinuity spots in oxide film make implant to adopt the decisive nature. These defects heighten the dissolution of metal ions from the implant surface, which results in diminishing bio-integration of titanium implant. To increase the long-term metallic implant stability, surface modifications of titanium alloys are being carried out. In the present study, biomimetic coatings of plasma sprayed hydroxyapatite and titanium were applied to the surface of commercially pure titanium and Ti6Al4V. Surface morphology and surface chemistry were studied using scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Cyclic potentiodynamic polarization and electrochemical impedance spectroscopy were carried out in order to study their electrochemical behavior. Moreover, cytotoxicity analysis was conducted for osteoblast cells by performing MTS assay. It is concluded that both hydroxyapatite and titanium coatings enhance corrosion resistance and improve cytocompatibility. PMID:27287167

  14. Surface hardening of titanium alloys by oxygen-diffusion-permeation

    Institute of Scientific and Technical Information of China (English)

    马红岩; 王茂才; 张松; 辛公春; 魏政

    2003-01-01

    The surface oxygen-diffusion-permeation behaviors of Ti based alloys were investigated. MEF4A opticalmicroscopy and HMV-2000 micro-hardness tester were employed to characterize the microstructure and micro-hard-ness of the oxygen-permeated alloys. The results show that the micro-hardness of Ti based alloys are sharply en-hanced by the permeation of oxygen. The microstructure and micro-hardness of oxygen-permeated layer are stronglyrelated to the oxygen-diffusion-permeation techniques. The solid solution of oxygen in α phase can improve thetransformation temperature from α phase to β phase and enlarge the region of α phase so as to improve the micro-hardness of surface layer. Therefore, surface oxygen-diffusion-permeation would be a feasible method to reinforce Tibased alloys based on the solid solution of oxygen in α-Ti. At last, a diffusion-solution model was put forward.

  15. Isothermal oxidation behavior of alpha-2 titanium aluminide alloys

    International Nuclear Information System (INIS)

    Monolithic alpha-2 alloys are being considered for applications in gas turbine engines at temperature between 593 and 705C. The alpha-2 alloys have better creep and oxidation resistance than conventional Ti alloys in this temperature range, but concerns over low temperature mechanical properties, interstitial embrittlement and hot salt stress corrosion cracking have limited the application of these alloys. Protective coatings address environmental concerns, while improved processing and chemistry may improve mechanical properties. The compositions of alpha-2 alloys have evolved over time to obtain a better balance of properties. Two prospective alpha-2 compositions are Ti-25Al-10Nb-3V-1Mo and Ti-24.5Al-12.5Nb-1.5Mo. This work characterizes the isothermal oxidation behavior of these two alloys in the 593-705C temperature range and discusses observed differences. The isothermal oxidation behavior in air of Ti-24.5Al-12.5Nb-1.5Mo was superior to Ti-25Al-10Nb-3V-1Mo and T-6242 in the temperature range of 593-705C. The 12.5-1.5 alloy was better because an external alumina scale formed which grew more slowly than the TiO2-based scales observed on the 10-3-1 and Ti-6242. The alumina scale formed on the 12.5-1.5 alloy because interstitials like O, N and C lower the thermodynamic activity of Ti to levels where Al2O3 formation is favored. In the absence of microstructural effects, the V in 10-3-1 prevented continuous external alumina from forming

  16. Superplastic Forming and Diffusion Bonding of Titanium Alloys

    OpenAIRE

    A. K. Ghosh; C. H. Hamilton

    1986-01-01

    New and advanced fabrication methods for titanium components are emerging today to replace age-old fabrication processes and reduce component cost. Superplastic forming and diffusion bonding are two such advanced fabrication technologies which when applied individually or in combination can provide significant cost and weight benefits and a rather broad manufacturing technology base. This paper briefly reviews the state of understanding of the science and technology of super plastic forming o...

  17. Microstructure evolution model based on deformation mechanism of titanium alloy in hot forming

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-li; LI Miao-quan

    2005-01-01

    The microstructure evolution in hot forming will affect the mechanical properties of the formed product.However, the microstructure is sensitive to the process variables in deformation process of metals and alloys. A microstructure evolution model of a titanium alloy in hot forming, which included dislocation density rate and primary α phase grain size, was presented according to the deformation mechanism and driving forces, in which the effect of the dislocation density rate on the grain growth was studied firstly. Applying the model to the high temperature deformation process of a TC6 alloy with deformation temperature of 1 133 - 1 223 K, strain rate of 0.01 -50 s-1 and height reduction of 30%, 40% and 50%, the material constants in the present model were calculated by the genetic algorithm(GA) based objective optimization techniques. The calculated results of a TC6 alloy are in good agreement with the experimental ones.

  18. A yttrium-containing high-temperature titanium alloy additively manufactured by selective electron beam melting

    Institute of Scientific and Technical Information of China (English)

    逯圣路; 汤慧萍; 马前; 洪权; 曾立英

    2015-01-01

    A yttrium-containing high-temperature titanium alloy (Ti-6Al-2.7Sn-4Zr-0.4Mo-0.45Si-0.1Y, mass fraction, %) has been additively manufactured using selective electron beam melting (SEBM). The resulting microstructure and textures were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and electron backscattered diffraction (EBSD) and compared with the conventionally manufactured form. A notable distinct difference of microstructures is that additive manufacturing by SEBM enables homogeneous precipitation of fine Y2O3 dispersoids in the size range of 50−250 nm throughout the as-fabricated alloy, despite the presence of just trace levels of oxygen (7×10−4, mass fraction) and yttrium (10−3, mass fraction) in the alloy. In contrast, the conventionally manufactured alloy shows inhomogeneously distributed coarse Y2O3 precipitates, including cracked or debonded Y2O3 particles.

  19. Titanium-alloy, metallic-fluid heat pipes for space service

    Science.gov (United States)

    Morris, J. F.

    1979-01-01

    Reactivities of titanium limit its long-term terrestrial use for unprotected heat-pipe envelopes to about 870 K (1100 F). But this external thermochemical limitation disappears when considerations shift to space applications. In such hard-vacuum utilization much higher operating temperatures are possible. Primary restrictions in space environment result from vaporization, thermal creep, and internal compatibilities. Unfortunately, a respected head-pipe reference indicates that titanium is compatible only with cesium from the alkali-metal working-fluid family. This problem and others are subjects of the present paper which advocates titanium-alloy, metallic-fluid heat pipes for long-lived, weight-effective space service between 500 and 1300 K (440 and 1880 F).

  20. Environmental hydrogen embrittlement of an alpha-beta titanium alloy - Effect of microstructure.

    Science.gov (United States)

    Nelson, H. G.; Williams, D. P.; Stein, J. E.

    1972-01-01

    Study of environmental hydrogen embrittlement of a Ti-6 Al-4 alloy as a function of test displacement rate and of variations in alpha-beta microstructure. Embrittlement in low-pressure (about 1 atm) gaseous hydrogen was inversely dependent on test displacement rate and strongly dependent on microstructure. At a given displacement rate, microstructures having a continuous alpha-phase matrix were less severely embrittled than those having a continuous beta-phase matrix. Further, brittle fracture occurred in the former microstructures by transgranular cleavage and in the latter microstructures by intergranular separation. These observations are consistent with previous studies made on slow strain-rate embrittlement of hydrogen-charged titanium alloys and are explained in terms of relative hydrogen transport rates within the alpha-phase and beta-phase titanium.

  1. Finishing of additively manufactured titanium alloy by shape adaptive grinding (SAG)

    Science.gov (United States)

    Beaucamp, Anthony T.; Namba, Yoshiharu; Charlton, Phillip; Jain, Samyak; Graziano, Arthur A.

    2015-06-01

    In recent years, rapid prototyping of titanium alloy components for medical and aeronautics application has become viable thanks to advances in technologies such as electron beam melting (EBM) and selective laser sintering (SLS). However, for many applications the high surface roughness generated by additive manufacturing techniques demands a post-finishing operation to improve the surface quality prior to usage. In this paper, the novel shape adaptive grinding process has been applied to finishing titanium alloy (Ti6Al4V) additively manufactured by EBM and SLS. It is shown that the micro-structured surface layer resulting from the melting process can be removed, and the surface can then be smoothed down to less than 10 nm Ra (starting from 4-5 μm Ra) using only three different diamond grit sizes. This paper also demonstrates application of the technology to freeform shapes, and documents the dimensional accuracy of finished artifacts.

  2. Some experiments on cold fusion by deuterium hydrogen gas infusion in titanium metal alloy

    International Nuclear Information System (INIS)

    New results on cold fusion are reported where three different experimental situations have been tried: a) deuterium gas loaded titanium; b) deuterium gas loaded Ti0.8Zr0.2CrMn alloy and c) titanium and the Ti0.8Zr0.2CrMn alloy loaded with a mixture of deuterium and hydrogen gases. With these experiments, new thermodynamical non equilibrium conditions were achieved and the possibility of cold fusion between protons and deuterons was also tested. Three independent neutron detectors and one NaI(Tl) were utilized. Despite some large values reported in the literature for the fusion rate, an upper limit of only 8 x 10-24 fusions/sper deuterium pair or per deuterium-hydrogen pair was determined within the attained accuracy. (author)

  3. Finishing of additively manufactured titanium alloy by shape adaptive grinding (SAG)

    International Nuclear Information System (INIS)

    In recent years, rapid prototyping of titanium alloy components for medical and aeronautics application has become viable thanks to advances in technologies such as electron beam melting (EBM) and selective laser sintering (SLS). However, for many applications the high surface roughness generated by additive manufacturing techniques demands a post-finishing operation to improve the surface quality prior to usage. In this paper, the novel shape adaptive grinding process has been applied to finishing titanium alloy (Ti6Al4V) additively manufactured by EBM and SLS. It is shown that the micro-structured surface layer resulting from the melting process can be removed, and the surface can then be smoothed down to less than 10 nm Ra (starting from 4–5 μm Ra) using only three different diamond grit sizes. This paper also demonstrates application of the technology to freeform shapes, and documents the dimensional accuracy of finished artifacts. (paper)

  4. Evaluation of a hydrogen resistant titanium aluminide alloy

    Science.gov (United States)

    Chan, K. S.

    1991-01-01

    The Ti-24Al-11Nb (Ti-24-11) alloy heat treated to the fine basketweave microstructure was shown previously to be hydrogen tolerant. In order to assess its limit of hydrogen tolerance, the tensile, creep, fracture toughness, and sustained load crack growth behaviors of this alloy were studied as a function of hydrogen content. All test specimens were thermally charged with internal hydrogen and tested at 25 and 600 C. Coupon specimens were used for developing the hydrogen charging procedures and for studying compatibility of the alloy with high temperature, high pressure gaseous hydrogen. The mechanical test results indicated that the fine basketweave microstructure was tolerant to hydride embrittlement for hydrogen contents up to approximately 1500 wt. ppm, providing that the hydride formed was of the TiH2 type. On the other hand, hydrogen charging experiments indicated that the Ti-24-11 alloy was severely cracked and pulverized under zero load when the hydrogen content exceeded 3000 wt. ppm. X-ray diffraction results revealed that the dichotomous behaviors might be due to the formation of TiH(1.924) type hydrides at higher hydrogen contents. Thus, hydrogen embrittlement in the Ti-24-11 alloy with the fine basketweave microstructure depends on hydrogen content and the nature of the hydrides formed.

  5. Development of new ferritic alloys reinforced by nano titanium nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Mathon, M.H., E-mail: marie-helene.mathon@cea.fr [Laboratoire Léon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif-sur-Yvette (France); Perrut, M., E-mail: mikael.perrut@onera.fr [Laboratoire Léon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif-sur-Yvette (France); Poirier, L., E-mail: poirier@nitruvid.com [Bodycote France and Belgium, 9 r Jean Poulmarch, 95100 Argenteuil (France); Ratti, M., E-mail: mathieu.ratti@snecma.fr [CEA, DEN, Service de Recherches Métallurgiques Appliquées, F91191 Gif-sur-Yvette (France); Hervé, N., E-mail: nicolas.herve@cea.fr [CEA, DRT, LITEN, F38054 Grenoble (France); Carlan, Y. de, E-mail: yann.decarlan@cea.fr [CEA, DEN, Service de Recherches Métallurgiques Appliquées, F91191 Gif-sur-Yvette (France)

    2015-01-15

    Nano-reinforced steels are considered for future nuclear reactors or for application at high temperature like the heat exchangers tubes or plates. Oxide Dispersion Strengthened (ODS) alloys are the most known of the nano-reinforced alloys. They exhibit high creep strength as well as high resistance to radiation damage. This article deals with the development of new nano reinforced alloys called Nitride Dispersed Strengthened (NDS). Those are also considered for nuclear applications and could exhibit higher ductility with a simplest fabrication way. Two main fabrication routes were studied: the co-milling of Fe–18Cr1W0.008N and TiH{sub 2} powders and the plasma nitration at low temperature of a Fe–18Cr1W0.8Ti powder. The materials were studied mainly by Small Angle Neutron Scattering. The feasibility of the reinforcement by nano-nitride particles is demonstrated. The final size of the nitrides can be similar (few nanometers) to the nano-oxides observed in ODS alloys. The mechanical properties of the new NDS show an amazing ductility at high temperature for a nano-reinforced alloy.

  6. Microstructural Characterization Of Quenched And Plastically Deformed Two-Phase α+β Titanium Alloys

    Directory of Open Access Journals (Sweden)

    Motyka M.

    2015-09-01

    Full Text Available Development of microstructure in two-phase α+β titanium alloys is realized by thermomechanical processing – sequence of heat treatment and plastic working operations. Analysis of achieved results indicates that hot plastic deformation – depending on deformation degree – causes significant elongation of α phase grains. Following heat treatment and plastic deformation processes lead to their fragmentation and spheroidization. Characterization of microstructure morphology changes during thermomechanical processing of quenched Ti-6Al-4V and Ti-6Al-2Mo-2Cr alloys is presented in the paper. The effect of martensitic phase α’(α” on microstructure development in plastic deformation process was confirmed.

  7. The Solidification Velocity of Undercooled Nickel and Titanium Alloys with Dilute Solute

    Science.gov (United States)

    Algoso, Paul R.; Altgilbers, A. S.; Hofmeister, William H.; Bayuzick, Robert J.

    2003-01-01

    The study of solidification velocity is important for two reasons. First, understanding the manner in which the degree of undercooling of the liquid and solidification velocity affect the microstructure of the solid is fundamental. Second, there is disagreement between theoretical predictions of the relationship between undercooling and solidification velocity and experimental results. Thus, the objective of this research is to accurately and systematically quantify the solidification velocity as a function of undercooling for dilute nickel-and titanium-based alloys. The alloys chosen for study cover a wide range of equilibrium partition coefficients, and the results are compared to current theory.

  8. Effect of ripple loads on sustained-load cracking in titanium alloys

    International Nuclear Information System (INIS)

    In the present paper, the authors have extended their study on the effect of the ripple loads on the sustained-load cracking (SLC) behavior of two titanium alloys, Ti-6Al-4V (an α-β alloy) and Ti-15V-3Cr-3Al-3Sn (a β-α alloy), in an ambient air environment. The methodology which has been used successfully to treat ripple effects on stress-corrosion cracking (SCC) is employed again to address the influence of ripple loads on sustained-load cracking. Ripple loads can significantly reduce the apparent sustained load cracking resistance of titanium alloys in a relatively benign environment such as ambient air. For a ripple-load amplitude equal to 5% of the sustained load, the ripple-load cracking thresholds (KIRLC) of beta-annealed Ti-6Al-4V and Ti-15V-3Cr-3al-3Sn are less than half of the respective sustained-load cracking thresholds (KISLC). The extent of ripple-load degradation for these alloys in ambient air -- relative to KISLC, were found comparable to those observed in a much more aggressive 3.5% NaCl aqueous solution

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-31

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

  10. LASER Additive Manufacturing of Titanium-Tantalum Alloy Structured Interfaces for Modular Orthopedic Devices

    Science.gov (United States)

    Fuerst, Jacob; Medlin, Dana; Carter, Michael; Sears, James; Vander Voort, George

    2015-04-01

    Tantalum is recognized to have better biocompatibility and osseointegrative properties than other more commonly used orthopedic grade alloys. There are several novel methods that tantalum or tantalum-titanium could be used to augment orthopedic implants. A tantalum or tantalum-titanium alloy at the bone/implant or modular component interfaces would substantially increase the longevity and performance of modular devices. Bonding a functional tantalum coating to a titanium orthopedic device is inherently difficult because of the small difference between the melting temperature of tantalum, 3017°C, and the boiling point of titanium, 3287°C. LASER powder deposition (LPD) is a fusion operation using an Nd:YAG to melt a small volume of substrate into which metal powder is sprayed achieving high temperature with a high solidification rate. LPD of Ti-Ta onto a Ti-6Al-4V substrate produced both a solid surface and structured coating with a pore size in the optimal 350-500 μm range.

  11. Micromechanical Characterization and Texture Analysis of Direct Cast Titanium Alloys Strips

    Science.gov (United States)

    2000-01-01

    This research was conducted to determine a post-processing technique to optimize mechanical and material properties of a number of Titanium based alloys and aluminides processed via Melt Overflow Solidification Technique (MORST). This technique was developed by NASA for the development of thin sheet titanium and titanium aluminides used in high temperature applications. The materials investigated in this study included conventional titanium alloy strips and foils, Ti-1100, Ti-24Al-11Nb (Alpha-2), and Ti-48Al-2Ta (Gamma). The methodology used included micro-characterization, heat-treatment, mechanical processing and mechanical testing. Characterization techniques included optical, electron microscopy, and x-ray texture analysis. The processing included heat-treatment and mechanical deformation through cold rolling. The initial as-cast materials were evaluated for their microstructure and mechanical properties. Different heat-treatment and rolling steps were chosen to process these materials. The properties were evaluated further and a processing relationship was established in order to obtain an optimum processing condition. The results showed that the as-cast material exhibited a Widmanstatten (fine grain) microstructure that developed into a microstructure with larger grains through processing steps. The texture intensity showed little change for all processing performed in this investigation.

  12. Biocompatibility of corrosion-resistant zeolite coatings for titanium alloy biomedical implants.

    Science.gov (United States)

    Bedi, Rajwant S; Beving, Derek E; Zanello, Laura P; Yan, Yushan

    2009-10-01

    Titanium alloy, Ti6Al4V, is widely used in dental and orthopedic implants. Despite its excellent biocompatibility, Ti6Al4V releases toxic Al and V ions into the surrounding tissue after implantation. In addition, the elastic modulus of Ti6Al4V ( approximately 110GPa) is significantly higher than that of bone (10-40GPa), leading to a modulus mismatch and consequently implant loosening and deosteointegration. Zeolite coatings are proposed to prevent the release of the toxic ions into human tissue and enhance osteointegration by matching the mechanical properties of bone. Zeolite MFI coatings are successfully synthesized on commercially pure titanium and Ti6Al4V for the first time. The coating shows excellent adhesion by incorporating titanium from the substrate within the zeolite framework. Higher corrosion resistance than the bare titanium alloy is observed in 0.856M NaCl solution at pHs of 7.0 and 1.0. Zeolite coatings eliminate the release of cytotoxic Al and V ions over a 7 day period. Pluripotent mouse embryonic stem cells show higher adhesion and cell proliferation on the three-dimensional zeolite microstructure surface compared with a two-dimensional glass surface, indicating that the zeolite coatings are highly biocompatible. PMID:19433139

  13. Subsurface deformation during precision turning of a near-alpha titanium alloy

    International Nuclear Information System (INIS)

    Precision turning is an energy-intensive, yet important machining operation for critical aero-structural titanium alloy parts. High-resolution electron backscatter diffraction reveals an increase in induced subsurface deformation with increasing surface speed, contradicting observations when applying standard surface integrity techniques. Subsurface microstructural damage, such as mechanical twins and intense slip bands, provides nucleation sites for silicide precipitation during thermal exposure at 750 °C, indicating that creep and fatigue strength could be locally reduced at the machined surface.

  14. Tailoring the mechanical properties of titanium alloys via plasticity induced transformations

    OpenAIRE

    Neelakantan, S.

    2010-01-01

    Titanium alloys possess good corrosion properties, high temperature stability and high strength-to-weight ratio. However, they fall short in providing the optimum strength-ductility relation in the most demanding structural applications, including the aerospace sector. Inspired by the possibility of enhancing the strength-ductility relation in steels through the TRIP effect, the thesis elucidates at: i) identifying and quantifying the key factors that effectively control and/or promote such e...

  15. The technology of precision casting of titanium alloys by centrifugal process

    OpenAIRE

    A. Karwiński; W. Leśniewski; S. Pysz; P. Wieliczko

    2011-01-01

    The article describes the development of a procedure for the preparation of foundry ceramic moulds and making first test castings. The presented studies included:development of technological parameters of the ceramic mould preparation process using water-based zirconium binders and zirconia ceramic materials, where moulds are next used for the centrifugal casting of titanium alloys melted in vacuum furnaces, designing of pouring process using simulation software, making test castings,testing ...

  16. Thermodynamics, Solubility, and Diffusivity of Oxygen in Titanium and Ti-Al Alloys

    Science.gov (United States)

    Mehrotra, Gopal M.

    1992-01-01

    Titanium aluminides and titanium aluminide-based composites are attractive candidate materials for high-temperature structural applications. As these materials may be exposed to oxidizing environments durine their use at elevated temperatures, it is essential that they possess a good oxidation resistance. Previous studies have shown that the oxidation resistance of Al-rich alloys in the Ti-Al system is superior to that of the Ti-rich alloys. The scales formed on the surface of the Al-rich and Ti-rich alloys have been reported to be predominantly Al2O3 and TiO2, respectively. Since the relative stabilities of the oxides of Al and Ti at various temperatures and oxygen pressures can be assessed from their thermodynamic data, it is possible, With the help of thermodynamic calculations, to determine the compositions of the alloys which would form scales of Al2O3, TiO(x) or a ternary oxide such as TiAl2O5 during oxidation at a given temperature. The thermodynamic calculations require reliable activity data for the Ti-Al system. These data have not been determined for the entire composition and temperature range of interest. Using the data available in the literature, recently performed thermodynamic calculations and concluded that the stable oxide changed from TiO to Al2O3 in the existence region of the tial phase. In the case of titanium aluminide-based composites, another major concern is the mutual chemical compatibility of the matrix material with the reinforcement phase. Fibers of SiC, TiB2 and Al2O3 are currently being investigated for reinforcement of titanium aluminide matrices.

  17. Fracture of an {alpha}/{beta} titanium alloy under stress triaxiality states at 773 K

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, M.; Feaugas, X.; Clavel, M. [Univ. de Technologie de Compiegne (France). Division Mecanique

    1996-05-01

    This study has shown that the fracture of titanium alloy 6246 at high temperature is very sensitive to the loading path. In addition, it is demonstrated that the concept of the critical void size, provided by Rice and Tracey`s approach, is only applicable to high triaxialities ({chi} > 0.9). Under low triaxiality ({chi} {le} 0.9) the plastic flow instigates the damage process, favoring shearing instability in prior {beta} grain.

  18. Simulation of YAG pulse laser welding of titanium alloy (TA6V)

    OpenAIRE

    Robert, Yannick

    2007-01-01

    This work is a part of study which goal is to realize a computer modelling of the thermomechanical phenomena occurring during the YAG pulse laser welding of titanium alloy (TA6V). The filet welding has different heterogeneities (microstructural and mechanical). In fact, the temperature causes microstructural changes (phase transformations, precipitation...) and modifies the mechanical properties. Thermomechanical modelling has thus to be established for the welding of TA6V. In this study, we ...

  19. A novel proposal to manipulate the properties of titanium parts by laser surface alloying

    International Nuclear Information System (INIS)

    A novel proposal is presented to increase the fatigue strength of titanium parts by applying a less rigid coating, which is expected to lower the tensile stresses at the surface and delay the onset of fatigue cracking. Niobium was introduced into the surface layer by laser surface alloying and, depending on the process parameters, β and α″ phases were obtained, resulting in a reduction of approximately 30% in Young’s modulus and a more than 100% increase in hardness

  20. The surface nanostructures of titanium alloy regulate the proliferation of endothelial cells

    OpenAIRE

    Min Lai; Xiaofang Yang; Qing Liu; Jinghua Li; Yanhua Hou; Xiuyong Chen; Kaiyong Cai

    2014-01-01

    To investigate the effect of surface nanostructures on the behaviors of human umbilical vein endothelial cells (HUVECs), surface nanostructured titanium alloy (Ti-3Zr2Sn-3Mo-25Nb, TLM) was fabricated by surface mechanical attrition treatment (SMAT) technique. Field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were employed to characterize the surface nanostructures of the TLM, respectively. Th...

  1. Mesenchymal stem cell adhesion and spreading on microwave plasma-nitrided titanium alloy

    OpenAIRE

    Clem, William C.; Konovalov, Valery V.; Chowdhury, S.; Vohra, Yogesh K.; Catledge, Shane A.; Bellis, Susan L

    2006-01-01

    Improved methods to increase surface hardness of metallic biomedical implants are being developed in an effort to minimize the formation of wear debris particles that cause local pain and inflammation. However, for many implant surface treatments, there is a risk of film delamination due to the mismatch of mechanical properties between the hard surface and the softer underlying metal. In this article, we describe the surface modification of titanium alloy (Ti-6Al-4V), using microwave plasma c...

  2. In vitro behavior of human osteoblast-like cells (SaOS2) cultured on surface modified titanium and titanium-zirconium alloy

    International Nuclear Information System (INIS)

    In this study, titanium (Ti) and titanium-zirconium (TiZr) alloy samples fabricated through powder metallurgy were surface modified by alkali-heat treatment and calcium (Ca)-ion-deposition. The alteration of the surface morphology and the chemistry of the Ti and TiZr after surface modification were examined. The bioactivity of the Ti and TiZr alloys after the surface modification was demonstrated. Subsequently, the cytocompatibility of the surface modified Ti and TiZr was evaluated via in vitro cell culture using human osteoblast-like cells (SaOS2). The cellular attachment, adhesion and proliferation after cell culture for 14 days were characterized by scanning electron microscopy (SEM) and MTT assay. The relationship between surface morphology and chemical composition of the surface modified Ti and TiZr and cellular responses was investigated. Results indicated that the surface-modified Ti and TiZr alloys exhibited excellent in vitro cytocompatibility together with satisfactory bioactivity. Since osteoblast adhesion and proliferation are essential prerequisites for a successful implant in vivo, these results provide evidence that Ti and TiZr alloys after appropriate surface modification are promising biomaterials for hard tissue replacement. Highlights: → Titanium (Ti) and titanium-zirconium (TiZr) alloy for load-bearing implant applications. → Implant applications. → Alkali-heat treatment and calcium (Ca)-ion-deposition as surface modification methods. → Surface modified Ti and TiZr exhibited excellent biocompatibility and bioactivity.

  3. Comparative assessment of marginal accuracy of grade II titanium and Ni–Cr alloy before and after ceramic firing: An in vitro study

    OpenAIRE

    Patil, Abhijit; Singh, Kishan; Sahoo, Sukant; Suvarna, Suraj; Kumar, Prince; Singh, Anupam

    2013-01-01

    Objective: The aims of the study are to assess the marginal accuracy of base metal and titanium alloy casting and to evaluate the effect of repeated ceramic firing on the marginal accuracy of base metal and titanium alloy castings. Materials and Methods: Twenty metal copings were fabricated with each casting material. Specimens were divided into 4 groups of 10 each representing base metal alloys castings without (Group A) and with metal shoulder margin (Group B), titanium castings without (Gr...

  4. Improving the properties of titanium alloys by ion implantation

    International Nuclear Information System (INIS)

    The 'Ionguard' ion-implantation process for the enhancement of Ti alloys' wear, corrosion-resistance, and other surface properties has found use in orthopedic implant, ball valve, turbine blade, specialty fastener, and threaded component applications. The application of the Ironguard process to finished components does not jeopardize their dimensional integrity or surface finish. Ironguard is, moreover, a low-temperature process which leaves the bulk properties of products unaffected. Nitrogen is often used as an implant by the process; attention is given to results obtained for the Ti-6Al-4V alloy. 6 refs

  5. Inducing TiAl3 in titanium alloys by electric pulse heat treatment improves mechanical properties

    International Nuclear Information System (INIS)

    Highlights: ► EPH treatment is employed to modulate microstructure of titanium alloy. ► TiAl3 precipitations induce an unusual refinement behavior for alpha plates. ► Diffusion and accumulation of Al atoms attribute the formation mechanism of TiAl3. ► The susceptibility to adiabatic shear banding is reduced significantly. - Abstract: Titanium alloy is well known with its susceptibility to adiabatic shear banding, which limits its application unavoidably. In the current study, the electric pulse heat treatment is employed to modulate lamellar microstructure of a newly developed titanium alloy Ti–6Al–4V–4Zr–Mo. It is found that novel lath-shaped and nano-sized TiAl3 precipitations are formed within alpha plates. Diffusion of Al atoms, promoted by the electric pulse, and subsequent local atom accumulation attribute the underlying formation mechanism of TiAl3, which induces an unusual refinement effect by dividing the alpha plates into much tinier pieces, and provides an intriguing effect to dramatically reduce the susceptibility to adiabatic shear banding.

  6. Titanium Alloy Cage Implantation for the Treatment of Ischemic Necrosis of Femoral Head in Dogs

    Institute of Scientific and Technical Information of China (English)

    Ruiying WANG; Yan GAO; Shuhua YANG; Cao YANG

    2008-01-01

    To study the effect of titanium alloy cage on the treatment of the ischemic necrosis of femoral head in dog, the model of the ischemic necrosis of femoral head was made with the liquid nitrogon in 15 hybrid adult dogs. The titanium alloy cage made of a hollow cylinder was driven into the subchondral bone of necrotic femoral head via central channel. The dogs were divided into 3 groups, each group was sacrificed 3, 6, 12 weeks after the operation respectively. No collapse of femoral head was observed after the operation. The position of the cages was good on radiograph. Microscopically, the cancellous bone of necrotic femoral head rebuilt gradually and grew into cage. After 12 weeks of creeping substitution, the cancellous bone filled up the hollow cavity and holes of the cages. It is concluded that the titanium alloy cage can provide structural support for the subchondral bone and prevent collapse and can be used for the treatment of the ischemic necrosis of femoral head.

  7. Effect of alloy chemistry and exposure conditions on the oxidation of titanium

    Science.gov (United States)

    Unnam, J.; Shenoy, R. N.; Clark, R. K.

    1984-01-01

    Multiwall is a new thermal protection system concept for advanced space transportation vehicles. The system consists of discrete panels made up of multiple layers of foil gage metal. Titanium is the proposed candidate metal for multiwall panels in the reentry temperature range up to 675 C. Oxidation and embrittlement are the principal concerns related to the use of Ti in heat shield applications. The results of a broad study on the oxidation kinetics of several titanium alloys subjected to different exposure conditions are described. The alloys include commercially pure titanium, Ti-6Al-4V, and Ti-6Al-2Sn-4Zr-2Mo. Oxidation studies were performed on these alloys exposed at 704 C in 5-760 torr air pressure and 0 to 50% relative humidity. The resulting weight gains were correlated with oxide thickness and substrate contamination. The contamination depth and weight gains due to solid solutioning were obtained from microhardness depth profiles and hardness versus weight percent oxygen calibration data.

  8. Brazing of zirconia to titanium using Ag-Cu and Au-Ni filler alloys

    Directory of Open Access Journals (Sweden)

    Jean S. Pimenta

    2013-12-01

    Full Text Available Advanced ceramic is usually joined to metal by the well-known direct brazing process, where costly active filler alloys can be considered a limitation. Brazing using active-metal-free filler alloy as insert between the joint components is an attempt to overcome it. The active metal diffusion from the titanium member through the bulk of molten filler to the ceramic was responsible to produce an active filler alloy in loco and promote reduction of the zirconium oxide to improve wetting on the ceramic surface. Unalloyed titanium was joined in a high-vacuum furnace (<3x10-5 mbar to yttria-tetragonal zirconia polycristals (Y-TZP and zirconia partially stabilized with magnesia (Mg-PSZ, where commercial fillers Ag-28Cu and Au-18Ni with respective thermal cycles were evaluated. Helium gas leak detection test was performed at the ceramic/metal interface at room temperature; samples from reliable vacuum tight joints were examined by microstructural analysis techniques and energy dispersive X-ray analysis at the joint cross-section. Tight joints were produced with eutectic Ag-Cu filler, revealing an intermetallic layer and a dark reaction layer near the ceramic surface; titanium diffusion was efficient for superficial chemical interactions between individual components. Brazing joints were also tested using three-point flexure testing.

  9. Experimental investigation of laser peening on Ti17 titanium alloy for rotor blade applications

    International Nuclear Information System (INIS)

    Highlights: • Laser peening on Ti17 titanium alloys is investigated. • Roughness and residual stress value were grown on laser energy and impact times. • Hardened layer depth increases significantly with laser peening impact times. • Laser peening is effectively in lower fatigue stress level. • Laser peening makes the microstructures evolution. - Abstract: Laser peening is an innovative surface treatment technique, and can significantly improve the mechanical performance of metallic components. To investigate the fatigue life of Ti17 titanium alloy by laser peening, laser peening experiment was undertaken using Nd:YAG laser system with the pulse-width of 15 ns and max pulse-energy of 7 J. Firstly, the mechanical properties and microstructure with different laser peening parameters were investigated, which were measured and observed by Vickers indenter, X-ray diffraction, scanning electron microscope and transmission electron microscope. Micro-hardness and compressive residual stress distribution was remarkably improved. High-density dislocations and fine-grains were observed in the surface layer. Then, several stress levels were chosen to be applied on the tension and compression fatigue specimens. The fatigue life and fracture mechanism of the specimens without- and with-laser peened were compared, and the strengthening mechanism was indicated by analyzing the effects on the microstructure and residual stress evolution. The results demonstrate that laser peening could effectively improve the fatigue life of Ti17 titanium alloy

  10. Susceptibility to stress corrosion cracking of zirconium and titanium alloy in nitric acid

    International Nuclear Information System (INIS)

    The susceptibility to stress corrosion cracking (SCC) of zirconium and titanium alloys used in nuclear fuel reprocessing plants was examined by the slow strain rate tensile test (SSRT) in nitric acid solutions by referencing those results obtained in silicone oil. Titanium alloys like Zr-39%Ti, Zr-15%Ti and Zr-5%Ti, Ti-5%Ta were used. Titanium alloys have not the susceptibility to SCC in nitric acid solutions. On the other hand zirconium have the susceptibility to SCC in the same solutions. In comparison with SSRT results of zirconium specimens with a notch in oil, the reduction ratio of time to failure in nitric acid solutions decreased with increasing temperature. The quasi-cleavage type SCC fracture morphology was observed on the fracture surface of specimens tested in nitric acid. In order to evaluate the effect of crystal anisotropy on SCC, L type specimens and C type specimens, which were machined out parallel and perpendicular to the rolling direction respectively were examined. The susceptibility to SCC of C type notched specimens was higher than that of L type notched specimens, because of the preferential texture of quasi-cleavage planes oriented along the cracking path. (author)

  11. Titanium alloys (AoN) and their involvement in osseointegration

    OpenAIRE

    Matteo Danza; Ilaria Zollino; Valentina Candotto; Francesca Cura; Francesco Carinci

    2012-01-01

    Background: Osseointegration is essential for a long-term successful and inflammation-free dental implant. Such a result depends on osteoblastic cells growth and differentiation at the tissue-implant interface. The aim of this study was to compare two different AoN titanium layers (GR4 and GR5) to investigate which one had a greater osteoconductive power using human osteoblasts (HOb) culture at two different time-points. Materials and Methods: The expression levels of some bone-related (A...

  12. Effect of Alloying Elements in Hot-Rolled Metastable β-Titanium Alloys. Part II: Mechanical Properties

    Science.gov (United States)

    Manda, Premkumar; Chakkingal, Uday; Singh, A. K.

    2016-07-01

    This paper describes the tensile properties, flow and work-hardening behavior of four metastable β-titanium alloys Ti-5Al-5Mo-5V-3Cr (A1), Ti-5Al-3.5Mo-7.2V-3Cr (A2), Ti-5Al-5Mo-8.6V-1.5Cr (A3), and Ti-5Al-3.5Mo-5V-3.94Cr (A4) in α+β hot-rolled condition. The decreasing order of average strength parameters ( σ YS and σ UTS) is A4, A2, A1, and A3. The maximum strength observed in alloy A4 is due to the presence of highest wt. fraction of Cr. The elongation is the maximum and minimum in alloys A3 and A4, respectively. These alloys display moderate to high percent in-plane anisotropy ( A IP) and reasonably low anisotropic index ( δ) values. Both the A IP and δ values are maximum and minimum in alloys A1 and A3, respectively. The yield locus plots also exhibit the presence of anisotropy due to relatively large differences in yield strength values along tension and compression directions. The flow behavior of alloys A1, A2, and A4 follows Swift equation, while the alloy A3 displays best fit with Holloman equation. The presence of prestrain ( ɛ 0) in hot-rolled materials before tensile testing has an important bearing on the flow curves of A1, A2, and A4 alloys. The instantaneous work-hardening rate curves of the alloys A1, A2, and A3 exhibit all the three typical stages (stage I, stage II, and stage III) in RD samples, while the alloy A4 shows the presence of only stage I and stage III. The 45 deg to RD and TD samples of alloys A1, A2, and A4 display only stage I. The stages I and III as well as I and II are present in alloy A3 in 45 deg to RD and TD samples, respectively. Dislocation-controlled strain hardening occurs in all the three stages of these alloys in the absence of stress-induced martensitic transformation (α″) and twinning. Slip is the predominant deformation mechanism during tensile testing. Three types of slip lines, i.e., planar, wavy, and intersecting have been observed close to fracture surfaces of post tensile-tested specimens.

  13. Effect of Alloying Elements in Hot-Rolled Metastable β-Titanium Alloys. Part II: Mechanical Properties

    Science.gov (United States)

    Manda, Premkumar; Chakkingal, Uday; Singh, A. K.

    2016-04-01

    This paper describes the tensile properties, flow and work-hardening behavior of four metastable β-titanium alloys Ti-5Al-5Mo-5V-3Cr (A1), Ti-5Al-3.5Mo-7.2V-3Cr (A2), Ti-5Al-5Mo-8.6V-1.5Cr (A3), and Ti-5Al-3.5Mo-5V-3.94Cr (A4) in α+β hot-rolled condition. The decreasing order of average strength parameters (σ YS and σ UTS) is A4, A2, A1, and A3. The maximum strength observed in alloy A4 is due to the presence of highest wt. fraction of Cr. The elongation is the maximum and minimum in alloys A3 and A4, respectively. These alloys display moderate to high percent in-plane anisotropy (A IP) and reasonably low anisotropic index (δ) values. Both the A IP and δ values are maximum and minimum in alloys A1 and A3, respectively. The yield locus plots also exhibit the presence of anisotropy due to relatively large differences in yield strength values along tension and compression directions. The flow behavior of alloys A1, A2, and A4 follows Swift equation, while the alloy A3 displays best fit with Holloman equation. The presence of prestrain (ɛ 0) in hot-rolled materials before tensile testing has an important bearing on the flow curves of A1, A2, and A4 alloys. The instantaneous work-hardening rate curves of the alloys A1, A2, and A3 exhibit all the three typical stages (stage I, stage II, and stage III) in RD samples, while the alloy A4 shows the presence of only stage I and stage III. The 45 deg to RD and TD samples of alloys A1, A2, and A4 display only stage I. The stages I and III as well as I and II are present in alloy A3 in 45 deg to RD and TD samples, respectively. Dislocation-controlled strain hardening occurs in all the three stages of these alloys in the absence of stress-induced martensitic transformation (α″) and twinning. Slip is the predominant deformation mechanism during tensile testing. Three types of slip lines, i.e., planar, wavy, and intersecting have been observed close to fracture surfaces of post tensile-tested specimens.

  14. Ab-initio simulation and experimental validation of beta-titanium alloys

    OpenAIRE

    Raabe, D.; Sander, B.; Friák, M.; Ma, D.; Neugebauer, J.

    2008-01-01

    In this progress report we present a new approach to the ab-initio guided bottom up design of beta-Ti alloys for biomedical applications using a quantum mechanical simulation method in conjunction with experiments. Parameter-free density functional theory calculations are used to provide theoretical guidance in selecting and optimizing Ti-based alloys with respect to three constraints: (i) the use of non-toxic alloy elements; (ii) the stabilization of the body centered cubic beta phase at roo...

  15. Influence of thermal and mechanical cycling on the flexural strength of ceramics with titanium or gold alloy frameworks

    NARCIS (Netherlands)

    Oyafuso, Denise Kanashiro; Ozcan, Mutlu; Bottino, Marco Antonio; Itinoche, Marcos Koiti

    2008-01-01

    Objectives. The aim of this study was to evaluate the effect of thermal and mechanical cycling alone or in combination, on the flexural strength of ceramic and metallic frameworks cast in gold alloy or titanium. Methods. Metallic frameworks (25 mm x 3 mm x 0.5 mm) (N = 96) cast in gold alloy or comm

  16. Modeling of cryogenic frictional behaviour of titanium alloys using Response Surface Methodology approach

    International Nuclear Information System (INIS)

    The potential of cryogenic effect on frictional behaviour of newly developed titanium alloy Ti-5Al-4V-0.6Mo-0.4Fe (Ti54) sliding against tungsten carbide was investigated and compared with conventional titanium alloy Ti6Al4V (Ti64). In this study, four models were developed to describe the interrelationship between the friction coefficient (response) and independent variables such as speed, load, and sliding distance (time). These variables were investigated using the design of experiments and utilization of the response surface methodology (RSM). By using this method, it was possible to study the effect of main and mixed (interaction) independent variables on the friction coefficient (COF) of both titanium alloys. Under cryogenic condition, the friction coefficient of both Ti64 and Ti54 behaved differently, i.e. an increase in the case of Ti64 and decrease in the case of Ti54. For Ti64, at higher levels of load and speed, sliding in cryogenic conditions produces relatively higher friction coefficients compared to those obtained in dry air conditions. On contrary, introduction of cryogenic fluid reduces the friction coefficients of Ti54 at all tested conditions of load, speed, and time. The established models demonstrated that the mixed effect of load/speed, time/speed, and load/time consistently decrease the COF of Ti54. However this was not the case for Ti64 whereas the COF increased up to 20% when the Ti64 was tested at higher levels of load and sliding time. Furthermore, the models indicated that interaction of loads and speeds was more effective for both Ti-alloy and have the most substantial influence on the friction. In addition, COF for both alloys behaved linearly with the speed but nonlinearly with the load.

  17. Functional and structural fatigue of titanium tantalum high temperature shape memory alloys (HT SMAs)

    International Nuclear Information System (INIS)

    Due to their high work output and good mechanical properties, actuators made from shape memory alloys (SMAs) are used in numerous applications. Unfortunately, SMAs such as nickel–titanium (Ni–Ti) can only be employed at temperatures up to about 100 °C. Lately, high-temperature shape memory alloys (HT SMAs) have been introduced to overcome this limitation. Ternary systems based on Ni–Ti have been intensively characterized and alloys are available that can operate at elevated temperatures. However, these alloys either contain substantial amounts of expensive noble elements like platinum and palladium, or the materials are brittle. The titanium–tantalum (Ti–Ta) system has been developed to overcome these issues. Binary Ti–Ta provides relatively high MS temperature combined with excellent workability, but it suffers from fast cyclic degradation. By alloying with third elements this drawback can be overcome: The ternary Ti–Ta–Al alloy shows overall promising properties as will be shown in the present work. In-situ thermo-mechanical cycling experiments were conducted and allowed for evaluation of the factors affecting the functional and structural fatigue of this alloy. Functional fatigue is dominated by ω-phase evolution, while structural fatigue is triggered by an interplay of ω-phase induced embrittlement and deformation constraints imposed by unsuitable texture. In addition, a concept for fatigue life extension proposed very recently for binary Ti–Ta, is demonstrated to be also applicable for the ternary Ti–Ta–Al

  18. Effect of activity differences on hydrogen migration in dissimilar titanium alloy welds

    International Nuclear Information System (INIS)

    The effect of alloy composition on hydrogen activity was measured for seven titanium alloys as a means to determine the tendency for hydrogen migration within dissimilar metal welds. The alloys were: Ti-CP (unalloyed Ti), Ti-3Al-2.5V, Ti-3Al-2.5V-3Zr, Ti-3Al-2Nb-1Ta, Ti-6Al, Ti-6Al-4V, and Ti-6Al-2Nb-1Ta-0.8Mo. Hydrogen pressure-hydrogen concentration relationships were determined for temperatures from 600 C to 800 C and hydrogen concentrations up to approximately 3.5 at. pct (750 wppm). Fusion welds were made between Ti-CP and Ti-CP and between Ti-CP and Ti-6Al-4V to observe directly the hydrogen redistribution in similar and dissimilar metal couples. Hydrogen activity was found to be significantly affected by alloying elements, particularly Al in solid solution. At a constant Al content and temperature, an increase in the volume fraction of β reduced the activity of hydrogen in α-β alloys. Activity was also found to be strongly affected by temperature. The effect of temperature differences on hydrogen activity was much greater than the effects resulting from alloy composition differences at a given temperature. Thus, hydrogen redistribution should be expected within similar metal couples subjected to extreme temperature gradients, such as those peculiar to fusion welding. Significant hydrogen redistribution in dissimilar alloy weldments also can be expected for many of the compositions in this study. Hydride formation stemming from these driving forces was observed in the dissimilar couple fusion welds. In addition, a basis for estimating hydrogen migration in titanium welds, based on hydrogen activity data, is described

  19. Corrosion resistance, surface mechanical properties, and cytocompatibility of plasma immersion ion implantation-treated nickel-titanium shape memory alloys.

    Science.gov (United States)

    Yeung, K W K; Poon, R W Y; Liu, X Y; Ho, J P Y; Chung, C Y; Chu, P K; Lu, W W; Chan, D; Cheung, K M C

    2005-11-01

    Nickel-titanium shape memory alloys are promising materials in orthopedic applications because of their unique properties. However, for prolonged use in a human body, deterioration of the corrosion resistance of the materials becomes a critical issue because of the increasing possibility of deleterious ions released from the substrate to living tissues. We have investigated the use of nitrogen, acetylene, and oxygen plasma immersion ion implantation (PIII) to improve the corrosion resistance and mechanical properties of the materials. Our results reveal that the corrosion resistance and mechanical properties such as hardness and elastic modulus are significantly enhanced after surface treatment. The release of nickel is drastically reduced as compared with the untreated control. In addition, our in vitro tests show that the plasma-treated surfaces are well tolerated by osteoblasts. Among the three types of samples, the best biological effects are observed on the nitrogen PIII samples. PMID:16078209

  20. Bone apposition to a titanium-zirconium alloy implant, as compared to two other titanium-containing implants

    Directory of Open Access Journals (Sweden)

    N Saulacic

    2012-04-01

    Full Text Available Implants made of commercially pure titanium (cpTi are widely and successfully used in dentistry. For certain indications, diameter-reduced Ti alloy implants with improved mechanical strength are highly desirable. The aim was to compare the osseointegration of titanium-zirconium (TiZr and cpTi implants with a modified sandblasted and acid-etched (SLActive surface and with a Ti6Al4V alloy that was sand-blasted and acid-washed. Cylindrical implants with two, 0.75 mm deep, circumferential grooves were placed in the maxilla of miniature pigs and allowed to heal for 1, 2, 4 and 8 weeks. Undecalcified toluidine blue-stained ground sections were produced. Surface topography, area fraction of tissue components, and bone-to-implant contact (BIC were determined. All materials showed significantly different surface roughness parameters. The amount of new bone within the implant grooves increased over time, without significant differences between materials. However, BIC values were significantly related to the implant material and the healing period. For TiZr and cpTi implants, the BIC increased over time, reaching values of 59.38 % and 76.15 % after 2 weeks, and 74.50 % and 84.67 % after 8 weeks, respectively. In contrast, the BIC for Ti6Al4V implants peaked with 42.29 % after 2 weeks followed by a decline to 28.60 % at 8 weeks. Significantly more surface was covered by multinucleated giant cells on Ti6Al4V implants after 4 and 8 weeks. In conclusion, TiZr and cpTi implants showed faster osseointegration than Ti6Al4V implants. Both chemistry and surface topography might have influenced the results. The use of diameter-reduced TiZr implants in more challenging clinical situations warrants further documentation in long-term clinical studies.

  1. Dynamic strain aging of metastable beta titanium alloys

    International Nuclear Information System (INIS)

    Two Ti alloys were studied: RMI 38644 (3.4 Al, 8.3 V, 5.8 Cr, 3.9 Zr) solution treated at 9270C, and Beta-III (10.2 Mo, 5.8 Zr, 4.7 Sn) solution treated at 732, 787, 871, or 9820C. Serrated yielding appeared at 2000C and above for Beta-III solution treated at 9820C; no such serrations were observed for RMI 38644 above 2600C. Load/stress drop associated with dynamic yielding increased with temperature for both alloys. Results indicate a β--ω transformation mechanism in Beta-III and a dislocation--interstitial interaction mechanism in RMI 38644. (U.S.)

  2. KINETIC STUDY OF AGING IN A URANIUM-TITANIUM EUTECTOID ALLOY USING THERMOELECTRIC POWER MEASUREMENT

    International Nuclear Information System (INIS)

    Considerable attention has been given to the study of microstructure evolution and mechanical properties of dilute U-Ti alloys. A typical procedure of heat treatment of the eutectoid uranium-titanium alloy consists of solution treatment in the γ phase, obtaining of soft α' martensitic metastable structure by water quenching to room temperature and precipitation hardening by aging at 300-550 deg. C. Depending on employed temperature and time the aging results in GP zone formation through the precipitation reaction α'→α+δ. The δ phase is a hexagonal U2Ti intermetallic compound, responsible for the significant increase in the level of the micro-strain in the metastable α' matrix. Thermoelectric power (TEP) measurements have recently gained a growing attention for the characterization of metallurgical properties in steels and other alloys. These measurements, which are based on the Seebeck effect, are sensitive to changes in the electronic structure of the material as result of various metallurgical processes. In the current research, TEP measurement technique was applied as a non destructive assessment technique to characterize the aging kinetics of the quenched uranium-titanium binary alloy. Good correlation has been found between measured TEP, micro-strain evolution, as obtained by using XRD, and hardness values at different heat treatment stages. A reasonable explanation of the correlation between the crystallography changes, micro-strain, TEP measurements and properties is presented

  3. Hydrogen embrittlement and fracture toughness of a titanium alloy with surface modification by hard coatings

    International Nuclear Information System (INIS)

    The effect of hydrogen embrittlement on the fracture toughness of a titanium alloy with different surface modifications was investigated. Disk-shaped compact-tension specimens were first coated with different hard films and then hydrogen charged by an electrochemical method. Glow discharge optical spectrometry (GDOS), scanning electron microscopy (SEM), and x-ray diffractometry (XRD) were applied to analyze the surface characteristics. The results revealed that fracture toughness of the as-received titanium alloy decreased with the increase of hydrogen charging time. Fracture toughness of the alloy after plasma nitriding or ion implantation, which produced a TiNx layer, decreased as well, but to a lesser extent after cathodic charging. The best result obtained was for the alloy coated with a CrN film where fracture toughness was sustained even after hydrogen charging for 144 h. Obviously the CrN film acted as a better barrier to regard hydrogen permeation, but it was at the sacrifice of the CrN film itself

  4. Manufacturing of Titanium and Aluminium Light alloys by powder metallurgy

    OpenAIRE

    Gordo Odériz, Elena; Ruiz Navas, Elisa María

    2008-01-01

    The Group of Powder Technology (GTP) of the University Carlos III has a wide experience in the development and processing of new materials by Powder Metallurgy (PM). The mechanical alloying (MA) process, or high energy milling, allows the attainment of powders with compositions impossible to produce by other techniques, with improved properties for structural applications, where mechanical properties are the main requirement, and for applications where other specific properties are needed....

  5. A New Aging Treatment Way for Near α High Temperature Titanium Alloys

    Institute of Scientific and Technical Information of China (English)

    Jun Zhang; Na Peng; Qingjiang Wang; Xinan Wang

    2009-01-01

    Two near a titanium alloys, Ti-5.6AI-4.8Sn-2.0Zr-lMo-0.35Si (1#) and Ti-6.0AI-4.8Sn-2.0Zr-1Mo-0.35Si (2#), were solution-treated in the upper α+β phase fields, and the duplex mixture microstructures consisting of the less volume fraction primary α phase (αp) and the transformed β phase (βt) were obtained. The aging treatments were carried out at 700℃ for 1# alloy and 760℃ for 2# alloy under varied terms, respectively. It guaranteed α2 ordered phase to precipitate only in αp but not in βt for the two alloys. The slower precipitation and growth of the α2 ordered phase and silicide was observed in 1# alloy in comparison with 2# alloy. The mechanical properties including tensile strength and ductility, the creep and lasting properties at 600℃ were investigated. Prolonging aging time did not predominantly change the tensile strength and ductility for the two alloys. The 600℃/100 h thermal exposure caused a notable decrease of tensile ductility in 2# alloy though no distinct decrease could be observed in 1# alloy after the thermal exposure. The lasting property of 1# alloy was increased with prolonging aging time and finally was equal to or even better than that of 2# alloy. Nevertheless, no evident increase emerged in 2# alloy with prolonging aging time. Similarly, the creep property of 1# alloy monotonously increased with increasing aging time and finally was equal to or even better than that of 2# alloy. No evident increase could be observed for 2# alloy. It can be deduced that the overgrowth of α2 ordered phase and silicide is unable to enhance hot strength properties but cause an unacceptable damage to tensile ductility. The optimum equilibrium of the comprehensive properties depending on the proper control of α2 ordered phase and silicide can be achieved by properly selecting aging temperature and time.

  6. NDE of titanium alloy MMC rings for gas turbine engines

    Energy Technology Data Exchange (ETDEWEB)

    Baaklini, G.Y.; Percival, L.D.; Yancey, R.N.; Kautz, H.E.

    1993-09-01

    Progress in the processing and fabrication of metal matrix composites (MMC's) requires appropriate mechanical and nondestructive testing methods. These methods are needed to characterize properties, assess integrity, and predict the life of engine components such as compressor rotors, blades, and vanes. Capabilities and limitations of several state-of-the-art nondestructive evaluation (NDE) technologies are investigated for characterizing titanium MMC rings for gas turbine engines. The use of NDE technologies such as x-ray computed tomography, radiography, and ultrasonics in identifying fabrication-related problems that caused defects in components is examined. Acousto-ultrasonics was explored to assess degradation of material mechanical properties by using stress wave factor and ultrasonic velocity measurements before and after the burst testing of the rings.

  7. NDE of titanium alloy MMC rings for gas turbine engines

    Science.gov (United States)

    Baaklini, George Y.; Percival, Larry D.; Yancey, Robert N.; Kautz, Harold E.

    1993-01-01

    Progress in the processing and fabrication of metal matrix composites (MMC's) requires appropriate mechanical and nondestructive testing methods. These methods are needed to characterize properties, assess integrity, and predict the life of engine components such as compressor rotors, blades, and vanes. Capabilities and limitations of several state-of-the-art nondestructive evaluation (NDE) technologies are investigated for characterizing titanium MMC rings for gas turbine engines. The use of NDE technologies such as x-ray computed tomography, radiography, and ultrasonics in identifying fabrication-related problems that caused defects in components is examined. Acousto-ultrasonics was explored to assess degradation of material mechanical properties by using stress wave factor and ultrasonic velocity measurements before and after the burst testing of the rings.

  8. Phase transformations in aged beta III titanium alloy

    International Nuclear Information System (INIS)

    Specimens of Beta III Titanium (11.5 percent Mo, 6 percent Zr, 45 percent Sn, balance Ti) were solution treated at 15000F for 30 minutes, then quenched into water and aged at temperatures between 205 and 4800C for periods of 1/2 to 50 hours. Thin foil specimens for electron microscopy were prepared by a jet polishing technique. Selected area diffraction pattern, bright and dark field imaging of specimens aged at 425 and 4800C indicate that β, ω and α phases coexist for long aging times. Analysis of the selected area diffraction patterns indicate that the ω phase directly transforms to α. Observations of β/ω interface structure which supports this mechanism are presented. 6 figures

  9. Gentamicin coating of plasma chemical oxidized titanium alloy prevents implant-related osteomyelitis in rats.

    Science.gov (United States)

    Diefenbeck, M; Schrader, C; Gras, F; Mückley, T; Schmidt, J; Zankovych, S; Bossert, J; Jandt, K D; Völpel, A; Sigusch, B W; Schubert, H; Bischoff, S; Pfister, W; Edel, B; Faucon, M; Finger, U

    2016-09-01

    Implant related infection is one of the most feared and devastating complication associated with the use of orthopaedic implant devices. Development of anti-infective surfaces is the main strategy to prevent implant contamination, biofilm formation and implant related osteomyelitis. A second concern in orthopaedics is insufficient osseointegration of uncemented implant devices. Recently, we reported on a macroporous titanium-oxide surface (bioactive TiOB) which increases osseointegration and implant fixation. To combine enhanced osseointegration and antibacterial function, the TiOB surfaces were, in addition, modified with a gentamicin coating. A rat osteomyelitis model with bilateral placement of titanium alloy implants was employed to analyse the prophylactic effect of gentamicin-sodiumdodecylsulfate (SDS) and gentamicin-tannic acid coatings in vivo. 20 rats were randomly assigned to four groups: (A) titanium alloy; PBS inoculum (negative control), (B) titanium alloy, Staphylococcus aureus inoculum (positive control), (C) bioactive TiOB with gentamicin-SDS and (D) bioactive TiOB plus gentamicin-tannic acid coating. Contamination of implants, bacterial load of bone powder and radiographic as well as histological signs of implant-related osteomyelitis were evaluated after four weeks. Gentamicin-SDS coating prevented implant contamination in 10 of 10 tibiae and gentamicin-tannic acid coating in 9 of 10 tibiae (infection prophylaxis rate 100% and 90% of cases, respectively). In Group (D) one implant showed colonisation of bacteria (swab of entry point and roll-out test positive for S. aureus). The interobserver reliability showed no difference in the histologic and radiographic osteomyelitis scores. In both gentamicin coated groups, a significant reduction of the histological osteomyelitis score (geometric mean values: C = 0.111 ± 0.023; D = 0.056 ± 0.006) compared to the positive control group (B: 0.244 ± 0.015; p osteomyelitis scores confirmed these

  10. Chimeric Peptides as Implant Functionalization Agents for Titanium Alloy Implants with Antimicrobial Properties

    Science.gov (United States)

    Yucesoy, Deniz T.; Hnilova, Marketa; Boone, Kyle; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

    2015-04-01

    Implant-associated infections can have severe effects on the longevity of implant devices and they also represent a major cause of implant failures. Treating these infections associated with implants by antibiotics is not always an effective strategy due to poor penetration rates of antibiotics into biofilms. Additionally, emerging antibiotic resistance poses serious concerns. There is an urge to develop effective antibacterial surfaces that prevent bacterial adhesion and proliferation. A novel class of bacterial therapeutic agents, known as antimicrobial peptides (AMPs), are receiving increasing attention as an unconventional option to treat septic infection, partly due to their capacity to stimulate innate immune responses and for the difficulty of microorganisms to develop resistance towards them. While host and bacterial cells compete in determining the ultimate fate of the implant, functionalization of implant surfaces with AMPs can shift the balance and prevent implant infections. In the present study, we developed a novel chimeric peptide to functionalize the implant material surface. The chimeric peptide simultaneously presents two functionalities, with one domain binding to a titanium alloy implant surface through a titanium-binding domain while the other domain displays an antimicrobial property. This approach gains strength through control over the bio-material interfaces, a property built upon molecular recognition and self-assembly through a titanium alloy binding domain in the chimeric peptide. The efficiency of chimeric peptide both in-solution and absorbed onto titanium alloy surface was evaluated in vitro against three common human host infectious bacteria, Streptococcus mutans, Staphylococcus epidermidis, and Escherichia coli. In biological interactions such as occur on implants, it is the surface and the interface that dictate the ultimate outcome. Controlling the implant surface by creating an interface composed chimeric peptides may therefore

  11. Alloying of surface layer of the Ti-6Al-4V titanium alloy through the laser treatment

    Directory of Open Access Journals (Sweden)

    R. Filip

    2006-02-01

    Full Text Available Purpose: The purpose of this paper is modification of the Ti-6Al-4V titanium alloy surface layer properties through laser alloying technology.Design/methodology/approach: Laser treatment was performed on the samples coated by graphite and BN powders in stream of nitrogen. Thopography of the surface of laser melted layer was investigated. Microstructure,fracture surface and chemical composition analysis were made by using Epiphot 300 optical microscope and Novascan 30 scanning electron microscope equipped with EDS X-ray detector. Phase composition was determined using X-ray diffractometry (Philips with CuKα radiation. The Vickers hardness under load of 1.96 N and thermo-electric power was measured on the surface of cross-sections.Findings: Laser treatment has produced a surface layer which consists of hard ceramic TiC, TiN and TiB particles spaced in ductile martensitic matrix. Under the layer, the heat affected zone containing martensitic Tiα’ phase is present. The hardness obtained on cross-sectioned layer increases clearly in comparison with the base material. The high hardness level (HV 920 - 570 can be attributed to the formation of TiN, TiC and TiB phases. The thermoelectric power decreases noticeably with hardness increase and enables alloying process evaluation.Research limitations/implications: Research range was limited to investigation of microstructure, phase composition and hardness effects of laser alloying process. In order to estimate the influence of the laser alloying technology on durability of the layer, supplementary wear resistance tests will be performed in future research.Practical implications: The surface alloying by laser irradiation is investigated as a process capable to produce coatings composed of metallic matrix reinforced by ceramic particles and this can increase durability of elements made of titanium alloys.Originality/value: The wide range of investigations contained microstructure, phase and chemical

  12. Aging properties and microstructures of Ti-B20 titanium alloy

    Institute of Scientific and Technical Information of China (English)

    GE Peng; ZHAO Yong-qing; ZHOU Lian

    2006-01-01

    A new metastable beta titanium alloy of Ti-Al-Mo-V-Cr-Fe-Zr-Sn system was designed and named Ti-B20. In order to investigate the aging properties and microstructures of the new alloy subjected to different solution treatments, the tensile and Vickers hardness tests were carried out and the optical microscope and scanning electron microscope analysis were performed. The results show that the new alloy displays rapid aging response, high age strengthening effect and fine deposition. In addition, beta solution results in ultra high age hardening effect with low tensile ductility, whereas excellent combination of aging strength and ductility can be obtained after solution treated below beta transus temperature.

  13. Effect of spinning deformation on microstructure evolution and mechanical property of TA 15 titanium alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Hot spinning of tubular workpiece of TA15 alloy was conducted on a CNC spinning machine, and the microstructure evolution during hot spinning and annealing was observed and mechanical properties of spun tubes were tested. The results show that with the increase of spinning pass, the fiber microstructure comes into being gradually in axial direction and the circumferential microstructure also stretches obviously along circumferential direction. At the same time, the tensile strength increases and elongation decreases not only in axial direction but also in circumferential direction. When the reduction ratio of wall thickness rises close to or over 40%, tensile strength increases and elongation decreases more rapidly, which means that tubular workpiece of titanium alloy can be strengthened bi-directionally by power spinning. The ductility of spun workpiece of TAI5 alloy could be improved by annealing at the temperature no higher than recrystallization temperature with slight decrease of tensile strength.

  14. Composite layers on titanium and Ti6Al4V alloy for medical applications

    Directory of Open Access Journals (Sweden)

    B. Surowska

    2010-11-01

    Full Text Available Purpose: The paper presents the possibility of creating biomaterials through designing bioceramic composite layers on cpTi and Ti6Al4V alloy by hybrid method. TiN+Ti2N+αTi(N and SiO2-TiO2 intermediate layer were produced by glow-discharge nitriding and sol-gel methods, respectively. Finally, hydroxyapatite nano-film deposited by electrophoresis.Design/methodology/approach: The composite bioceramic systems were characterized from the standpoint of microstructure and morphology analysis of surface layers. The study was performed by X-ray diffraction technique, IR-fourier transform, SEM, AFM and in SBF (bioactivity. Wear resistance in environmental conditions (laboratory air and in simulated body fluid (SBF were carried out by pin-on-disc method.Findings: The suggested innovative hybrid method allows the manufacture of the bioceramic composite layers with definite microstructure, phasic and chemical composition and surface topography. The intermediate layers are characterized by low thickness, good structural homogeneity, satisfying bonding with a metal substrate, whereas, external hydroxyapatite layer is very thin, homogenous, bioactive and durable.Research limitations/implications: It seems necessary to conduct further investigation in the field of adhesion of composite systems and, particularly, biological study of capabilities of bone tissue and bacteriological behaviour in the environment of implant with studied layers.Practical implications: The high layer quality, bioactivity and possibility of improving the mechanical properties of hydroxyapatite, it is advantageous to produce composite systems with TiN+Ti2N+αTi and SiO2-TiO2 intermediate layers.Originality/value: The modification of the surface of metal substrate, produced by the hybrid method, may be an effective way to form a new generation of titanium biomaterials.

  15. Comparative description of structure and properties of Ti-6Al-4V titanium alloy for biomedical applications produced by two methods: conventional (molding) and innovative (injection) ones

    OpenAIRE

    Klimas, J; M. Szota; M. Nabiałek; A. Łukaszewicz; Bukowska, A.

    2013-01-01

    Purpose: In paper characterized two methods produced titanium alloy: hitherto used in industry – conti-casting and innovative method of obtaining solid amorphous alloy by injection casting. The results of studies comparing the structure and properties of the alloy Ti-6Al-4V produced by both methods. Design/methodology/approach: Test samples were titanium alloy Ti-6Al-4V produced by two methods: conventional and injection. To achieve the objective pursued performed the following...

  16. Composition and Performance of Nanostructured Zirconium Titanium Conversion Coating on Aluminum-Magnesium Alloys

    Directory of Open Access Journals (Sweden)

    Sheng-xue Yu

    2013-01-01

    Full Text Available Nanostructured conversion coating of Al-Mg alloy was obtained via the surface treatment with zirconium titanium salt solution at 25°C for 10 min. The zirconium titanium salt solution is composed of tannic acid 1.00 g·L−1, K2ZrF6 0.75 g·L−1, NaF 1.25 g·L−1, MgSO4 1.0 g/L, and tetra-n-butyl titanate (TBT 0.08 g·L−1. X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared spectrum (FT-IR were used to characterize the composition and structure of the obtained conversion coating. The morphology of the conversion coating was obtained by atomic force microscopy (AFM and scanning electron microscopy (SEM. Results exhibit that the zirconium titanium salt conversion coating of Al-Mg alloy contains Ti, Zr, Al, F, O, Mg, C, Na, and so on. The conversion coating with nm level thickness is smooth, uniform, and compact. Corrosion resistance of conversion coating was evaluated in the 3.5 wt.% NaCl electrolyte through polarization curves and electrochemical impedance spectrum (EIS. Self-corrosion current density on the nanostructured conversion coating of Al-Mg alloy is 9.7×10-8A·cm-2, which is only 2% of that on the untreated aluminum-magnesium alloy. This result indicates that the corrosion resistance of the conversion coating is improved markedly after chemical conversion treatment.

  17. Ordered nano-scale dimple pattern formation on a titanium alloy (Ti-6Al-4V

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2012-09-01

    Full Text Available Due to the many applications of nanostructured surfaces – including in biomaterials – there is a strong interest in cost- and time-efficient methods for their fabrication. Previously, our group established a simple electrochemical method generating nanoscale patterns on large areas of a number of different metal surfaces. They consist of dimples that are around 6-10 nm deep and hexagonally closed packed with a tunable periodicity of around 50 nm. Ordering requires careful tuning of the surface chemistry, which makes the translation of these findings to multi-component alloys non-obvious. Here, we demonstrate for the first time that such a pattern can also be achieved on the surface of an alloy, namely Ti-6Al-4V. This alloy is of particular interest for biomedical implants. While dimple formation on the main component metals titanium and aluminum has previously been reported (albeit under conditions that differ from each other, we now also report dimple formation on pure vanadium surfaces to occur under very different conditions. Dimple formation occurs preferentially on the (dominant α-phase grains of the alloy. The size of dimples of the alloy material is subject to the electropolishing potential, electrolyte concentration and surface chemical composition, which gives us the opportunity to control the surface features. Since a main application of this alloy are biomedical implants, this level of control will be an important tool for accommodating cell growth.

  18. Corrosion considerations of high-nickel alloys and titanium alloys for high-level radioactive waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; McCright, R.D.

    1991-07-01

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project`s high-level radioactive waste disposal containers. High nickel alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion of how various parameters affect it will be necessary for adequate performance assessments of candidate container materials. Examples of some of the concerns involving candidate container materials. Examples of some of the concerns of involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250{degrees}C) are presented. Also some mechanistic considerations of localized corrosion are given. 31 refs., 1 tab.

  19. Corrosion considerations of high-nickel alloys and titanium alloys for high-level radioactive waste disposal containers

    International Nuclear Information System (INIS)

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project's high-level radioactive waste disposal containers. High nickel alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion of how various parameters affect it will be necessary for adequate performance assessments of candidate container materials. Examples of some of the concerns involving candidate container materials. Examples of some of the concerns of involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250 degrees C) are presented. Also some mechanistic considerations of localized corrosion are given. 31 refs., 1 tab

  20. Fatigue crack propagation of new aluminum lithium alloy bonded with titanium alloy strap

    Institute of Scientific and Technical Information of China (English)

    Sun Zhenqi; Huang Minghui

    2013-01-01

    A new type of aluminum lithium alloy (A1-Li alloy) Al-Li-S-4 was investigated by test in this paper.Alloy plate of 400 mm × 140 mm × 6 mm with single edge notch was made into samples bonded with Ti-6Al-4V alloy (Ti alloy) strap by FM 94 film adhesive after the surface was treated.Fatigue crack growth of samples was investigated under cyclic loading with stress ratio (R) of 0.1 and load amplitude constant.The results show that Al-Li alloy plate bonded with Ti alloy strap could retard fatigue crack propagation.Retardation effect is related with width and thickness of strap.Flaws have an observable effect on crack propagation direction.

  1. Effects of heat treatment and hot deformation on the secondary α phase evolution of TC8 titanium alloy

    International Nuclear Information System (INIS)

    To investigate the effect of heat treatment and hot deformation on the secondary α phase evolution, the heat treatment and isothermal compression were carried out for the as-received TC8 titanium alloy respectively. An optical microscope (OM) and a scanning electron microscope (SEM) were used to examine the microstructure. In the heat treatment, the secondary α phase can precipitate only as the TC8 titanium alloy is heat treated at a heating temperature of 980 °C followed by air cooling. In the isothermal compression, the secondary α phase precipitates as an irregular morphology due to the high dislocation content in the deformed β phase at a low deformation temperature of 860 °C, while as a regular lamellar colony due to the high supersaturation in the deformed β phase at a high deformation temperature of 940 °C. Meanwhile, the height reduction has a significant effect on the content and morphology of secondary α phase in the isothermally compressed TC8 titanium alloy. Comparing the secondary α phase evolution in the isothermal compression with that in the heat treatment of TC8 titanium alloy, it can be concluded that the hot deformation has a promoting effect on the precipitation of secondary α phase due to the deformation heat, crystal defect and dynamic recrystallization of β phase generated in the isothermal compression of TC8 titanium alloy

  2. Effects of heat treatment and hot deformation on the secondary α phase evolution of TC8 titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, K.; Li, M.Q., E-mail: honeymli@nwpu.edu.cn

    2014-09-08

    To investigate the effect of heat treatment and hot deformation on the secondary α phase evolution, the heat treatment and isothermal compression were carried out for the as-received TC8 titanium alloy respectively. An optical microscope (OM) and a scanning electron microscope (SEM) were used to examine the microstructure. In the heat treatment, the secondary α phase can precipitate only as the TC8 titanium alloy is heat treated at a heating temperature of 980 °C followed by air cooling. In the isothermal compression, the secondary α phase precipitates as an irregular morphology due to the high dislocation content in the deformed β phase at a low deformation temperature of 860 °C, while as a regular lamellar colony due to the high supersaturation in the deformed β phase at a high deformation temperature of 940 °C. Meanwhile, the height reduction has a significant effect on the content and morphology of secondary α phase in the isothermally compressed TC8 titanium alloy. Comparing the secondary α phase evolution in the isothermal compression with that in the heat treatment of TC8 titanium alloy, it can be concluded that the hot deformation has a promoting effect on the precipitation of secondary α phase due to the deformation heat, crystal defect and dynamic recrystallization of β phase generated in the isothermal compression of TC8 titanium alloy.

  3. Nickel-titanium alloy: Cytotoxicity evaluation on microorganism culture

    International Nuclear Information System (INIS)

    High purity nickel (Ni) and titanium (Ti) targets have been used to form well-defined thin films of nitinol on Ti substrate by pulsed laser deposition (PLD) technique. Their chemical composition, crystalline structure and surface properties have been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). We have shown that by varying the deposition parameters such as laser fluence and number of laser pulses, we are able to control the film thickness as well as film's uniformity and roughness. Cytocompatibility tests have been performed through in vitro assays using microorganisms culture cells such as yeasts (Saccharomyces cerevisiae) and bacteria (Escherichia coli), in order to determine the thin film's toxic potential at the in vitro cellular level. Microorganism's adhesion on the nitinol surface was observed and the biofilm formation has been analyzed and quantified. Our results have shown no reactivity detected in cell culture exposed to NiTi films in comparison with the negative controls and a low adherence of the microorganisms on the nitinol surface that is an important factor for biofilm prevention. We can, therefore, conclude that NiTi is a good candidate material to be used for implants and medical devices

  4. Impact of irradiation on the tensile and fatigue properties of two titanium alloys

    International Nuclear Information System (INIS)

    The attachment of the first wall modules of the ITER FEAT fusion reactor is designed using flexible connectors made from titanium alloys.. An assessment of the tensile and fatigue performance of two candidate alloys, a classical two phase Ti6Al4V alloy and a monophase α alloy Ti5Al2.5Sn, has been carried out using 590 MeV protons for the simulation of the fusion neutrons. The dose deposited was up to 0.3 dpa and the irradiation temperature was between 40 deg. C and 350 deg. C. The unirradiated tensile performances of both alloys are roughly identical. The radiation hardening is much stronger in the α+β alloy compared with the α alloy, and the ductility is correspondingly strongly reduced. A very fine precipitation observed by TEM in the primary and secondary α grains of the dual phase alloy seems to be the cause of the intense radiation hardening observed. Two different regimes have been observed in the behaviour of the cyclic stresses. At a high imposed strain, the softening is small in the Ti6Al4V and larger in the Ti5Al2.5Sn. At a low imposed strain, and for both alloys, cyclic softening occurs up to about 800 cycles, but then a transition occurs, after which a regime of cyclic hardening appears. This cyclic hardening disappears after irradiation. In both materials, and for all test conditions, the compressive stress of the hysteresis loop was found to be larger than the tensile stress. The stress asymmetry seems to be triggered by the plastic deformation. The fatigue resistance of the Ti5Al2.5Sn alloy is slightly better than that of the Ti6Al4V alloy. The irradiation did not significantly affect the fatigue performance of both alloys, except for high imposed strains, where a life reduction was observed in the case of the Ti6Al4V alloy. SEM micrographs showed that the fractures were transgranular and pseudo-brittle

  5. Reactive spark plasma sintering (SPS) of nitride reinforced titanium alloy composites

    International Nuclear Information System (INIS)

    Highlights: • In situ nitridation of Ti-5wt%V alloys has been achieved by introducing reactive nitrogen gas during SPS sintering. • Ti-V-N composites sintered at 1300 °C exhibit only a nitrogen enriched α(Ti,N) phase. • Ti-V-N composites sintered at 1400 °C exhibit both stoichiometric δ-TiN precipitates and the α(Ti,N) phase. • Both δ-TiN nitrides as well as the α(Ti,N) phase improves the microhardness of these composites. - Abstract: Coupled in situ alloying and nitridation of titanium–vanadium alloys, has been achieved by introducing reactive nitrogen gas during the spark plasma sintering (SPS) of blended titanium and vanadium elemental powders, leading to a new class of nitride reinforced titanium alloy composites. The resulting microstructure includes precipitates of the δ-TiN phase with the NaCl structure, equiaxed (or globular) precipitates of a nitrogen enriched hcp α(Ti,N) phase with a c/a ratio more than what is expected for pure hcp Ti, and fine scale plate-shaped precipitates of hcp α-Ti, distributed within a bcc β matrix. During SPS processing, the δ-TiN phase appears to form at a temperature of 1400 °C, while only hcp α(Ti,N) and α-Ti phases form at lower processing temperatures. Consequently, the highest microhardness is exhibited by the composite processed at 1400 °C while those processed at 1300 °C or below exhibit lower values. Processing at temperatures below 1300 °C, resulted in an incomplete alloying of the blend of titanium and vanadium powders. These δ-TiN precipitates act as heterogeneous nucleation sites for the α(Ti,N) precipitates that appear to engulf and exhibit an orientation relationship with the nitride phase at the center. Furthermore, fine scale α-Ti plates are precipitated within the nitride precipitates, presumably resulting from the retrograde solubility of nitrogen in titanium

  6. Standard specification for titanium and titanium alloy strip, sheet, and plate

    International Nuclear Information System (INIS)

    Standard specifications for annealed Ti and Ti-alloy strip, sheet, and plate are included in 13 tables. These include specifications for chemical requirements; tensile and bend requirements; permissible variations in weight, thickness, width and length; permissible variations from a flat surface for annealed Ti plates; and permissible variations in width and length of sheared, rectangular Ti plate. These specifications apply to unalloyed Ti, Ti-6 percent Al-4 percent V, Ti-5 percent Al-2.5 percent Sn, Ti + Pd, and Ti-11.5 percent Mo-6 percent Zr-4.5 percent Sn

  7. A probabilistic framework for the modeling of fatigue in a lamellar XDTM gamma titanium aluminide alloy

    International Nuclear Information System (INIS)

    This paper presents a probabilistic framework for the modeling of fatigue damage in a gamma titanium aluminide alloy (Ti-45Al-2Mn-2Nb+0.8 vol% TiB2). This includes: empirical stress-life and fracture mechanics approaches to the estimation of material reliability or the risk of failure. Empirical reliability functions are obtained initially from multiple stress-life experiments designed to identify the statistical distributions that best describe the measured variabilities in fatigue life. Fracture mechanics-based reliability functions are also derived using statistical distributions that characterize the measured variabilities in fatigue crack growth data obtained from fatigue crack growth experiments in the long crack regime. The anomalous behavior of short cracks is then discussed before assessing the implications of the current work for the design of engineering structures and components from gamma-based titanium aluminides. (orig.)

  8. Problems Associated with Attaching Strain Gages to Titanium Alloy Ti-61-4V

    Science.gov (United States)

    Jenkins, J. M.; Lemcoe, M. M.

    1977-01-01

    Weldable strain gages have shown excellent high temperature characteristics for supersonic cruise aircraft application. The spotwelding attachment method, however, has resulted in serious reductions in the fatigue life of titanium alloy (Ti-6Al-4V) fatigue specimens. The reduction is so severe that the use of weldable strain gages on operational aircraft must be prohibited. The cause of the fatigue problem is thought to be a combination of the microstructure changes in the material caused by spotwelding and the presence of the flange of the stain gage. Brazing, plating, and plasma spraying were investigated as substitutes for spotwelding. The attachment of a flangeless gage by plasma spraying provided the most improvement in the fatigue life of the titanium.

  9. Numerical simulation and its application of rheological forming of titanium alloy vane disk

    Institute of Scientific and Technical Information of China (English)

    YU Min; LUO Ying-she; PENG Xiang-hua; QIN Yin-hui

    2006-01-01

    The hot rheological forming method was proposed to form the second titanium alloy vane disk. The hot rheological forming process of the TC11 titanium vane disk under a certain temperature and different strain rates was investigated by using the bulk forming software of DEFORM 3D. A series of results including temperature field,equivalent strain distribution,load-stroke curve and rheology procedure were obtained by this finite element method. The rheological forming characteristics were well realized and the forming parameters were determined. The results and analysis show that with decreasing strain rate,the metal flow more equably and the filling of the vane shape is also better. Moreover,the mechanical properties and microstructures of the products produced by this new technique are improved evidently compared with that produced by traditional method.

  10. Polarographic determination of the titanium and niobium content of zirconium alloys

    International Nuclear Information System (INIS)

    A method is described for the polarographic determination of titanium and niobium in zirconium alloys in the concentration range of 0.1% to 4% of each of the determined metals. To assure the complete dissolution of the sample a mixture of nitric acid and hydrofluoric acid is used. After evaporating these acids in the presence of sulphuric acid, the contents are determined polarographically with a supporting electrolyte solution of 0.1M EDTA, 0.33M potassium sulfate and 0.4M sodium acetate, buffered to pH 4 with acetic acid. The half-wave potential (Esub(1/2)) of titanium is -0.35V and that of niobium is -0.67 V. (author)

  11. Diffusion research between Ni3Al coating and titanium alloy produced by plasma spraying process

    International Nuclear Information System (INIS)

    A Ni3Al coating was prepared by plasma spraying technique on the surface of titanium alloy. Ni-Al mixed powders, coatings and reaction products were investigated by scanning electron microscope, EDS, DSC and XRD. A tight bonding between the coating and the substrate was formed. The X-ray diffraction analysis of the patterns showed that the coating not only had Ni3Al phase, but also had NiO and Al2O3 phase microcontent. Comparing Ni coated Al to Ni3Al at 900 deg. C, the diffusion was stronger and the diffusion layer was thicker. A minute pore structure was formed at 1200 deg. C in the front edge of solid-state reaction layer. So Ni3Al restrained the solid-state reaction of the coating with the substrate, and as a whole weakened the entry of oxygen atoms into the substrate and quenched the out-diffusion of titanium.

  12. Production of a low young modulus titanium alloy by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Dalcy Roberto dos Santos

    2005-12-01

    Full Text Available Titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. A blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. The process employs hydride-dehydride (HDH powders as raw material. In this work, results of the Ti-35Nb alloy sintering are presented. This alloy due to its lower modulus of elasticity and high biocompatibility is a promising candidate for aerospace and medical use. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by isochronal sintering between 900 up to 1600 °C, in vacuum. Sintering behavior was studied by means of microscopy and density. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. Samples sintered at high temperatures display a fine plate-like alpha structure and intergranular beta. A few remaining pores are still found and density above 90% for specimens sintered in temperatures over 1500 °C is reached.

  13. Evolution of commercial titanium alloys microstructure under neutron and ion irradiation

    International Nuclear Information System (INIS)

    Results of neutron and ion irradiation on microstructure of titanium alloys of V T-9, V T-12, O T4-1 trade-marks are considered. Samples with 8·4·2 mm3 sizes were irradiated by neutrons in wet channel of WWR-K reactor (E>0,1 MeV) under temperatures below than 80 deg C up different influences. Neutron energy is made up 2,35 MeV (flow 6,5·1016 m-2·c-1). Ion irradiation was carried out on impulse accelerator with energy of accelerated ions 60 keV (impulse duration 250 μs, frequency 3-25 Hz). It was defined that phase recrystallization is taking place in the result of neutron irradiation influence on structure of phases in dilute heterogeneous commercial α+β alloys of titanium-aluminium system. The recrystallization has both the quantitative ratio of phase partials and characteristics of fine structure each of it. It was shown that irradiation of V T-14 alloys by ions on the initial stages up to fluence 2·1017 ion/sm2 conduits to increasing of microhardness up to 60 %. 7 refs., 7 figs

  14. Hot corrosion behavior of TC11 titanium alloy treated by laser shock processing

    International Nuclear Information System (INIS)

    The aim of this research is to improve the hot corrosion resistance of TC11 titanium alloy by laser shock processing. Specimens were treated by laser shock processing on the whole surface. The hot corrosion resistance beneath Na2SO4 containing 20 wt.% NaCl salt deposits at 650 °C, 800 °C and 900 °C in air was investigated. The effects of LSP impacts on surface microstructure, residual stress, and microstructure after hot corrosion were investigated by transmission electron microscope, X-ray diffraction technology, and scanning electron microscope. Results show that laser shock processing can induce −295 MPa compressive residual stresses. The microstructure after LSP was characterized by a high amount of twins and highly tangled and dense dislocation arrangements. We even observed nano-crystallization. More protective oxidation films were remained on the surface of laser shocked specimens after hot corrosion, and it mainly consists of TiO2, Al2O3, MoO3, etc. The average corrosion rate of TC11 titanium alloy treated by laser shock processing is more than 50% lower than that of the untreated alloy

  15. Characterization of Coatings Created on Selected Titanium Alloys by Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Rokosz K.

    2016-03-01

    Full Text Available The SEM and EDS results of coatings obtained on pure niobium and titanium alloys (NiTi and Ti6Al4V by Plasma Electrolytic Oxidation in the electrolytes containing of 300 g and 600 g copper nitrate in 1 litre of concentrated phosphoric acid at 450 V for 3 minutes, are presented. The obtained coatings are porous and consist mainly of phosphorus within titanium and copper. For each coating, the Cu/P ratios were calculated. The maximum of that coefficient was found for niobium and Ti6Al4V alloy oxidised in the electrolyte containing 600 g of Cu(NO32 in 1 dm3 of H3PO4 and equaling to 0.22 (wt% | 0.11 (at%. The minimum of Cu/P ratio was recorded for NiTi and Ti6Al4V alloys oxidised by PEO in electrolyte consisting of 300 g of copper nitrate in 1 dm3 of concentrated phosphoric acid and equals to 0.12 (wt% | 0.06 (at%. The middle value of that ratio was recorded for NiTi and it equals to 0.16 (wt% | 0.08 (at%.

  16. Phase development in near-ϐ titanium alloy Ti1Al-8v-5Fe

    International Nuclear Information System (INIS)

    The near-β titanium alloy Ti-1Al-8V-5Fe (mass-%) exhibits excellent mechanical properties which are very sensitive to their microstructure. To control the microstructure during the processing, it is very important to have knowledge about the thermodynamics and kinetics of the phase transformations taking place under different conditions. The thermodynamics are already well developed, but research on the kinetics of these alloys is limited. An important strengthening mechanism involving both thermomechanical and heat treatment processes is the formation and precipitation of a phase. Fine-scale a precipitates will form during low temperature deformation or annealing, leading to an improvement in the mechanical properties. The volume fraction, size and distribution of these a precipitates highly depend on deformation conditions. Nucleation can occur at dislocations, grain boundaries, vacancies or at another phase, such as the ω phase. The role of ω precipitates on the nucleation of α in the β phase of titanium alloys is still not well understood. For determining the influence of varying process parameters in the thermomechanical processing on the phase evolutions in Ti-1Al-8V-5Fe a diffraction study has been executed. An emphasis was laid on the usage of WOMBAT the high intensity diffractometer which allowed characterising the β-ω-α phase transformations in-situ.

  17. Gelatin functionalised porous titanium alloy implants for orthopaedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Vanderleyden, E. [Polymer Chemistry and Biomaterials Research Group, Department of Organic Chemistry, University of Ghent, Krijgslaan 281 S4, 9000 Ghent (Belgium); Van Bael, S. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Department of Mechanical Engineering, Division of Biomechanics and Engineering Design, Katholieke Universiteit Leuven, Celestijnenlaan 300c, Box 2419, 3001 Heverlee (Belgium); Chai, Y.C. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Tissue Engineering Laboratory, Skeletal Biology and Engineering Research Center, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Kruth, J.-P. [Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Schrooten, J. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, Bus 2450, 3001 Leuven (Belgium); Dubruel, P., E-mail: pbmugent@gmail.com [Polymer Chemistry and Biomaterials Research Group, Department of Organic Chemistry, University of Ghent, Krijgslaan 281 S4, 9000 Ghent (Belgium)

    2014-09-01

    In the present work, we studied the immobilisation of the biopolymer gelatin onto the surface of three dimensional (3D) regular Ti6Al4V porous implants to improve their surface bio-activity. The successful immobilisation of the gelatin coating was made possible by a polydopamine interlayer, a polymer coating inspired by the adhesive nature of mussels. The presence of both coatings was first optimised on two dimensional titanium (2D Ti) substrates and confirmed by different techniques including X-ray photelectron spectroscopy, contact angle measurements, atomic force microscopy and fluorescence microscopy. Results showed homogeneous coatings that are stable for at least 24 h in phosphate buffer at 37 °C. In a next step, the coating procedure was successfully transferred to 3D Ti6Al4V porous implants, which indicates the versatility of the applied coating procedure with regard to complex surface morphologies. Furthermore, the bio-activity of these stable gelatin coatings was enhanced by applying a third and final coating using the cell-attractive protein fibronectin. The reproducible immobilisation process allowed for a controlled biomolecule presentation to the surrounding tissue. This newly developed coating procedure outperformed the previously reported silanisation procedure for immobilising gelatin. In vitro cell adhesion and culture studies with human periosteum-derived cells showed that the investigated coatings did not compromise the biocompatible nature of Ti6Al4V porous implants, but no distinct biological differences between the coatings were found. - Highlights: • Ti6Al4V porous implants were produced by selective laser melting. • A procedure to obtain a stable gelatin coating was developed. • Successful transfer of the coating procedure from 2D to 3D Ti6Al4V porous implants. • In vitro cell studies showed that the developed coatings supported cell growth.

  18. Gelatin functionalised porous titanium alloy implants for orthopaedic applications

    International Nuclear Information System (INIS)

    In the present work, we studied the immobilisation of the biopolymer gelatin onto the surface of three dimensional (3D) regular Ti6Al4V porous implants to improve their surface bio-activity. The successful immobilisation of the gelatin coating was made possible by a polydopamine interlayer, a polymer coating inspired by the adhesive nature of mussels. The presence of both coatings was first optimised on two dimensional titanium (2D Ti) substrates and confirmed by different techniques including X-ray photelectron spectroscopy, contact angle measurements, atomic force microscopy and fluorescence microscopy. Results showed homogeneous coatings that are stable for at least 24 h in phosphate buffer at 37 °C. In a next step, the coating procedure was successfully transferred to 3D Ti6Al4V porous implants, which indicates the versatility of the applied coating procedure with regard to complex surface morphologies. Furthermore, the bio-activity of these stable gelatin coatings was enhanced by applying a third and final coating using the cell-attractive protein fibronectin. The reproducible immobilisation process allowed for a controlled biomolecule presentation to the surrounding tissue. This newly developed coating procedure outperformed the previously reported silanisation procedure for immobilising gelatin. In vitro cell adhesion and culture studies with human periosteum-derived cells showed that the investigated coatings did not compromise the biocompatible nature of Ti6Al4V porous implants, but no distinct biological differences between the coatings were found. - Highlights: • Ti6Al4V porous implants were produced by selective laser melting. • A procedure to obtain a stable gelatin coating was developed. • Successful transfer of the coating procedure from 2D to 3D Ti6Al4V porous implants. • In vitro cell studies showed that the developed coatings supported cell growth

  19. Effects of alloying elements on nitrogen diffusion behavior around TiN/Ti interface α region in as-cast titanium alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To characterize the effects of alloying elements on inclusion dissolution of titanium nitride, the content profiles of elements around TiN/Ti boundary α phase regions in liquid titanium alloys have been experimentally carried out. Four kinds of commercial alloys of CpTi, Ti64, Ti17 and Ti6242 containing different α-stabilizing or β-stabilizing elements are examined through artificially embedding the TiN sponge particle into liquid alloys in VAR conditions. The content profiles of nitrogen and alloying elements around TiN/Ti boundary were measured by WDX and microprobe for as-cast samples. The content profiles of nitrogen and alloying elements around N-containing solid in αTi region of these alloys show a common features of a steep change. In particular, the content profiles of elements for Ti6242 demonstrate unique change of a more gentle change tendency and further deeper into the alloy matrix. The experiment results show that, the differences among composite effects of alloying elements in different alloys within nitrogen-induced diffusion α region result in different dissolution and diffusion behaviors to overcome the α phase region barriers.

  20. Effect of ion-implantation on surface characteristics of nickel titanium and titanium molybdenum alloy arch wires

    Directory of Open Access Journals (Sweden)

    Manu Krishnan

    2013-01-01

    Full Text Available Aim: To evaluate the changes in surface roughness and frictional features of ′ion-implanted nickel titanium (NiTi and titanium molybdenum alloy (TMA arch wires′ from its conventional types in an in-vitro laboratory set up. Materials and Methods: ′Ion-implanted NiTi and low friction TMA arch wires′ were assessed for surface roughness with scanning electron microscopy (SEM and 3 dimensional (3D optical profilometry. Frictional forces were studied in a universal testing machine. Surface roughness of arch wires were determined as Root Mean Square (RMS values in nanometers and Frictional Forces (FF in grams. Statistical Analysis Used: Mean values of RMS and FF were compared by Student′s ′t′ test and one way analysis of variance (ANOVA. Results: SEM images showed a smooth topography for ion-implanted versions. 3D optical profilometry demonstrated reduction of RMS values by 58.43% for ion-implanted NiTi (795.95 to 330.87 nm and 48.90% for TMA groups (463.28 to 236.35 nm from controls. Nonetheless, the corresponding decrease in FF was only 29.18% for NiTi and 22.04% for TMA, suggesting partial correction of surface roughness and disproportionate reduction in frictional forces with ion-implantation. Though the reductions were highly significant at P < 0.001, relations between surface roughness and frictional forces remained non conclusive even after ion-implantation. Conclusion: The study proved that ion-implantation can significantly reduce the surface roughness of NiTi and TMA wires but could not make a similar reduction in frictional forces. This can be attributed to the inherent differences in stiffness and surface reactivity of NiTi and TMA wires when used in combination with stainless steel brackets, which needs further investigations.

  1. Effect of vacuum ion-plasma treatment on the electrochemical corrosion characteristics of titanium-alloy implants

    Science.gov (United States)

    Ilyin, A. A.; Skvortsova, S. V.; Petrov, L. M.; Chernyshova, Yu. V.; Lukina, E. A.

    2007-10-01

    The effect of mechanical polishing and various types of vacuum ion-plasma treatment of model implants made of VT1-0, VT20, and VT6 titanium alloys on their electrochemical corrosion characteristics in a 0.9% NaCl solution (Ringer’s solution) is studied. Ion nitriding and the evaporation of a titanium nitride coating are shown to form a surface structure that provides an increase in the hardness, wear resistance, and corrosion resistance of these implants.

  2. Positron annihilation study of aluminum, titanium, and iron alloys surface after shot peening

    International Nuclear Information System (INIS)

    Shot peening influence on alloys based on iron, aluminum, and titanium was studied using positron annihilation lifetime spectroscopy (PALS) and residual stress measurements. The PALS spectra were analyzed assuming two lifetime components. While the residual stresses change in a similar way in all the samples, the PALS results show an opposite tendency of a component relative intensities change with the time of shot peening for the Ti alloy as compared to steel or the Al alloy. A comparison between the depth profiles of positron implantation and the residual stress distribution reveals that the positron range covers a whole depth where residual stress is observed only in the Ti alloy. Based on this observation, the evolution of the defect concentration is presumed, consisting in migration of large defects away from the surface, while only smaller ones remain close to the surface. Furthermore, the positron lifetime distribution in the Al alloy was determined using the MELT program. The results showed that the initial single, wide distribution of lifetime splits into two narrower ones with increasing shot peening time. (orig.)

  3. Electrochemical behaviour of commercially pure titanium and Co-Cr alloy in Ringer's solution

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The electrochemical behaviors of commercially pure titanium (CP Ti) and Co-Cr alloy in Ringer's solution have been investigated. The results indicate that the electric potential of passive region for CP Ti is up to 3000 mV, and its passive current density is 3.078 (A/cm2. The excellent corrosion resistance of CP Ti can be attributed to the formation of TiO2 oxide film. The passive region of Co-Cr alloy is 770 mV, which is narrower than that of CP Ti. However, no hysteresis loops are found in the reverse scanning curves of Cu-Cr alloy. A complex oxide film of Co3O4, Co2O3, and Cr2O3 formed on the surface provides Co-Cr alloy with a stable electrochemistry property. The corrosion rates of the crevice samples increase with the pH value of medium decreasing. The electron probe microanalyzer (EPMA) analysis indicates that Ti in CP Ti and Co, Cr in Co-Cr alloy dissolve in crevice area due to the Sealed-Cell effect.

  4. The influence of thermomechanical processing on microstructural evolution of Ti600 titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Han Yuanfei [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Zeng Weidong, E-mail: zengwd@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Qi Yunlian; Zhao Yongqing [Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China)

    2011-11-15

    Highlights: {yields} Temperature and strain rate have great influence on the microstructure features. {yields} The formation of sub-grain and dislocation wall is the typically microstructure features observed in the {beta} single-phase. {yields} The elongated lamellar {alpha} platelets kinked increasingly and break up under the {alpha} + {beta} processing conditions. {yields} The softening mechanisms of the Ti600 alloy hot compressed at 1000-1100 deg. C are mainly dynamic recovery. - Abstract: The influences of thermomechanical processing on microstructural evolution of Ti600 alloy were studied in the temperature range of 800-1100 deg. C, and at the strain rate of 0.001-10 s{sup -1}. During the isothermal compression experiment, the flow stress-strain curves are examined in the {beta} single-phase and in the {alpha} + {beta} two-phase regions. The results show that the thermomechanical processing parameters have significant influences on the microstructure of Ti600 alloy, especially on the grain size, morphologies of {alpha} phase. Moreover, the microstructural evolution was analyzed by optical microstructure (OM) and transmission electron microscopy (TEM). It was found that typical of dynamic recovery and dynamic recrystallization phenomenon occurring in the thermomechanical processing. These results will optimize the microstructural control for hot working of Ti600 alloy and deepen the understanding of the flow softening mechanism of near-{alpha} titanium alloy.

  5. NUMERICAL SIMULATION OF INDUCTION SKULL MELTING PROCESS FOR TITANIUM-ALUMINIUM BASE ALLOY

    Institute of Scientific and Technical Information of China (English)

    Z.Y. Chen; L.J. Xu; F.T. Kong; Q. Shu; Y.Y. Chen

    2004-01-01

    The mathematics model for temperature field of water-cooling copper crucible induction skull melting process was established. The program for simulating temperature field of melting process was developed with finite element method. The temperature field of the melting process for Ti-47Al-2Cr-2Nb alloy was calculated. During melting period, the temperature is raised gradually along radius augmentation direction. The elements of the charge near the crucible wall are molten first. The center elements of the charge are molten last. The melting time of the center element is just that of all the charge melting. The melting time of Ti-47Al-2Cr-2Nb alloy is 15min. In which, the charge was heated by low power 80kW for 9min and by high power 300kW for 6min. When melting Ti-47Al-2Cr-2Nb alloy,the loading power is nearly direct proportion to melt temperature. Increasing loading power may raise melt temperature. The best melting power of Ti-47Al-2Cr-2Nb alloy is 305-310kW. This is identical with the melting test and has guidance sense to the melting process of actual titanium alloy.

  6. The influence of thermomechanical processing on microstructural evolution of Ti600 titanium alloy

    International Nuclear Information System (INIS)

    Highlights: → Temperature and strain rate have great influence on the microstructure features. → The formation of sub-grain and dislocation wall is the typically microstructure features observed in the β single-phase. → The elongated lamellar α platelets kinked increasingly and break up under the α + β processing conditions. → The softening mechanisms of the Ti600 alloy hot compressed at 1000-1100 deg. C are mainly dynamic recovery. - Abstract: The influences of thermomechanical processing on microstructural evolution of Ti600 alloy were studied in the temperature range of 800-1100 deg. C, and at the strain rate of 0.001-10 s-1. During the isothermal compression experiment, the flow stress-strain curves are examined in the β single-phase and in the α + β two-phase regions. The results show that the thermomechanical processing parameters have significant influences on the microstructure of Ti600 alloy, especially on the grain size, morphologies of α phase. Moreover, the microstructural evolution was analyzed by optical microstructure (OM) and transmission electron microscopy (TEM). It was found that typical of dynamic recovery and dynamic recrystallization phenomenon occurring in the thermomechanical processing. These results will optimize the microstructural control for hot working of Ti600 alloy and deepen the understanding of the flow softening mechanism of near-α titanium alloy.

  7. A new Ti/H phase transformation in the H2+ titanium alloy studied by x-ray diffraction, nuclear reaction analysis, elastic recoil detection analysis and scanning electron microscopy

    International Nuclear Information System (INIS)

    The titanium hydrogenation process in the H2+ implanted Ti225 titanium alloy has been studied in this work. The Ti/H phase transformation from hydrogen solid solution (hcp) to gamma phase titanium hydride (TiH(γ)) with a primitive tetragonal structure and then to a titanium dihydride (TiH2(x)) with a body centred tetragonal structure has been characterized by x-ray diffraction, nuclear reaction analysis and elastic recoil detection analysis. This process is very different from the usual hydrogenation mechanism, in which the delta phase titanium dihydride (TiH2(δ)) with a face centred cubic structure is always involved. Both of the TiH(γ) and TiH2(x) are rare phases, which are formed under extreme conditions. The TiH(γ) was considered to be a metastable phase in low hydrogen concentration titanium, and the TiH2(x) phase has not yet been notated in the present Ti/H phase list. The characteristics of the TiH2(x) are unclear, but it is very stable at room temperature and exists as a mixture state with the titanium. A saturated fraction of the hydride to titanium phase has been obtained as about 15% (H/Ti ∼ 0.3) in a H2+ implanted sample

  8. Surface characterization of titanium alloys sterilized for biomedical applications

    Science.gov (United States)

    Hernández de Gatica, Norma L.; Jones, Gary L.; Gardella, Joseph A.

    1993-05-01

    The high biocompatibility of Ti and Ti-based implants is closely related to the properties of the surface oxide formed during the implant preparation stages. During the machining process, the metal is exposed to the ambient atmosphere and oxidized. This surface oxide layer may be modified during the subsequent implant preparation steps: cleaning and sterilization. In this study, surface elemental and chemical information as well as the thickness of the oxide layer are evaluated for the Ti-6Al-4V alloy before and after different sterilization procedures: UV radiation, steam autoclaving, and radio-frequency glow-discharge (RFGD) treatment in argon atmosphere. The analytical techniques used are: X-ray photoelectron spectroscopy (XPS or ESCA) and the scanning Auger microprobe (SAM). The results of this study indicate that among steam autoclaving, UV radiation and RFGD treatment, the latter yields cleaner surfaces. Also, depth profiles of the specimens treated with RFGD in argon showed an increase in the oxide layer thickness with respect to the values observed for non-sterilized samples.

  9. Laser Cladding of Composite Bioceramic Coatings on Titanium Alloy

    Science.gov (United States)

    Xu, Xiang; Han, Jiege; Wang, Chunming; Huang, Anguo

    2016-02-01

    In this study, silicon nitride (Si3N4) and calcium phosphate tribasic (TCP) composite bioceramic coatings were fabricated on a Ti6Al4V (TC4) alloy using Nd:YAG pulsed laser, CO2 CW laser, and Semiconductor CW laser. The surface morphology, cross-sectional microstructure, mechanical properties, and biological behavior were carefully investigated. These investigations were conducted employing scanning electron microscope, energy-dispersive x-ray spectroscopy, and other methodologies. The results showed that both Si3N4 and Si3N4/TCP composite coatings were able to form a compact bonding interface between the coating and the substrate by using appropriate laser parameters. The coating layers were dense, demonstrating a good surface appearance. The bioceramic coatings produced by laser cladding have good mechanical properties. Compared with that of the bulk material, microhardness of composite ceramic coatings on the surface significantly increased. In addition, good biological activity could be obtained by adding TCP into the composite coating.

  10. SOLIDIFICATION CHARACTERISTIC OF TITANIUM CARBIDE PARTICULATE REINFORCED ALUMINIUM ALLOY MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    N. FATCHURROHMAN

    2012-04-01

    Full Text Available In this research solidification characteristic of metal matrix composites consisted of titanium carbide particulate reinforced aluminium-11.8% silicon alloy matrix is performed. Vortex mixing and permanent casting method are used as the manufacturing method to produce the specimens. Temperature measurements during the casting process are captured and solidification graphs are plotted to represent the solidification characteristic. The results show, as volume fraction of particulate reinforcement is increased, solidification time is faster. Particulate reinforcement promotes rapid solidification which will support finer grain size of the casting specimen. Hardness test is performed and confirmed that hardness number increased as more particulate are added to the system.

  11. Titanium-Nickel Shape Memory Alloy Spring Actuator for Forward-Looking Active Catheter

    OpenAIRE

    Shozo Inoue; Takahiro Miki; Takafumi Tsurui; Hiroyuki Nagasawa; Mamoru Komatsubara; Takahiro Namazu

    2011-01-01

    The fabrication and characterization of forward-looking active catheter actuated by titanium-nickel (Ti-Ni) shape memory alloy (SMA) springs are described. The catheter has been designed for wide-range observation of an affected area inside a blood vessel when the blood vessel is occluded. The developed active catheter consists of eight Ti-Ni SMA spring actuators for actuation of catheter tip, an ultrasonic transducer for forward-looking, a guide wire, a polyurethane tube for coating, and spi...

  12. Design of DLC/Titanium Alloy Bio-Functionally Gradient Coat

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The material design is used to direct the magnetron cosputtering process. At first, according to the particularity of functionally gradient coat (FGC) the thermal elastic stress analysis for FGC was carried out based on the plane stress hypothesis. It is obtained that the peak value of plane thermal stress within FGC is only determined by the physical properties of materials of FGC and substrate, the composition distribution coefficient only influences the distribution and trend of plane thermal stress. And the plane thermal stress criterion for design of FGC was presented. Then the plane thermal stress of diamond like carbon/titanium alloy FGC was calculated.

  13. Irradiation growth of titanium alloy VT1-0 under proton irradiation

    International Nuclear Information System (INIS)

    A specially developed procedure was used to study the irradiation growth of the rods of titanium alloy VT1-0 under proton irradiation. There was determined the relation between the dimensional changes induced by irradiation growth and the texture. The effect of various types of heat-treatment on the texture, structure and irradiation growth of the VT1-0 rods was studied. It is demonstrated that destruction of the initial texture of VT1-0 rods by the mechanical and microwave heat-treatment results in almost complete suppression of irradiation growth

  14. Structure of Ti-6Al-4V nanostructured titanium alloy joint obtained by resistance spot welding

    International Nuclear Information System (INIS)

    The structure of weld joints of the titanium alloy Ti-6Al-4V in the initial ultrafine-grained state, obtained by resistance spot welding, is studied using the optical and scanning electron microscopy method and the X-ray structure analysis. The carried out studies show the relationship of the metal structure in the weld zone with main joint zones. The structure in the core zone and the heat affected zone is represented by finely dispersed grains of needle-shaped martensite, differently oriented in these zones. The change in the microhardness in the longitudinal section of the weld joint clearly correlates with structural changes during welding

  15. A fundamental approach to adhesion: Synthesis, surface analysis, thermodynamics and mechanics. [titanium alloys

    Science.gov (United States)

    Chen, W.; Dwight, D. W.; Wightman, J. P.

    1978-01-01

    Various surface preparations for titanium 6-4 alloy were studied. An anodizing method was investigated, and compared with the results of other chemical treatments, namely, phosphate/fluoride, Pasa-Jell and Turco. The relative durability of the different surface treatments was assessed by monitoring changes in surface chemistry and morphology occasioned by aging at 505 K (450 F). Basic electron spectroscopic data were collected for polyimide and polyphenylquinoxaline adhesives and synthetic precursors. Fractographic studies were completed for several combinations of adherend, adhesive, and testing conditions.

  16. A General Reversible Hereditary Constitutive Model. Part 2; Application to a Titanium Alloy

    Science.gov (United States)

    Arnold, S. M.; Saleeb, A. F.; Castelli, M. G.

    1997-01-01

    Given the mathematical framework and specific viscoelastic model in Part 1 our primary goal in this second part is focused on model characterization and assessment for the specific titanium alloy, TIMETAL 21S. The model is motivated by experimental evidence suggesting the presence of significant rate/time effects in the so-called quasilinear, reversible, material response range. An explanation of the various experiments performed and their corresponding results are also included. Finally, model correlations and predictions are presented for a wide temperature range.

  17. High-cycle fatigue characterization of titanium 5Al-2.5Sn alloy

    Science.gov (United States)

    Mahfuz, H.; Xin, Yu T.; Jeelani, S.

    1993-01-01

    High-cycle fatigue behavior of titanium 5Al 2.5Sn alloy at room temperature has been studied. S-N curve characterization is performed at different stress ratios ranging from 0 to 0.9 on a subsized fatigue specimen. Both two-stress and three-stress level tests are conducted at different stress ratios to study the cumulative fatigue damage. Life prediction techniques of linear damage rule, double linear damage rule and damage curve approaches are applied, and results are compared with the experimental data. The agreement between prediction and experiment is found to be excellent.

  18. Equations of state for titanium and Ti6A14V alloy.

    Energy Technology Data Exchange (ETDEWEB)

    Kerley, Gerald Irwin (Kerley Technical Services, Appomattox, VA)

    2003-10-01

    The PANDA code is used to build tabular equations of state (EOS) for titanium and the alloy Ti4Al6V. Each EOS includes solid-solid phase transitions, melting, vaporization, and thermal electronic excitation. Separate EOS tables are constructed for the solid and fluid phases, and the PANDA phase transition model is used to construct a single multiphase table. The model explains a number of interesting features seen in the Hugoniot data, including an anomalous increase in shock velocity, recently observed near 200 GPa in Ti6Al4V. These new EOS tables are available for use with the CTH code and other hydrocodes that access the CTH database.

  19. Critical analysis of tig welded joint of titanium G-5 alloy sheet

    Czech Academy of Sciences Publication Activity Database

    Gope, D. P.; Yadav, S.; Kumar, V.; Chattopadhyaya, S.; Mandal, S.; Hloch, Sergej

    Belgrade: TEAM International Society, Faculty of Mechanical Engineering, University of Belgrade, 2015 - (Sedmak, A.), s. 411-415 ISBN 978-86-7083-877-2. [International Scientific and Expert Conference TEAM 2015 /7./. Belgrade (RS), 15.10.2015-16.10.2015] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : titanium G5 alloy * TIG welding * microstructure * micro-hardness * welding current Subject RIV: JQ - Machines ; Tools http://johanyak.hu/files/u1/publi/G_J_Survey_on_Intrusion_TEAM_2015.pdf

  20. Experimental research on electrochemical machining of titanium alloy Ti60 for a blisk

    OpenAIRE

    Chen Xuezhen; Xu Zhengyang; Zhu Dong; Fang Zhongdong; Zhu Di

    2016-01-01

    Ti60 (Ti–5.6Al–4.8Sn–2Zr–1Mo–0.35Si–0.7Nd) is a high-temperature titanium alloy that is now used for important components of aircraft engines. Electrochemical machining (ECM) is a promising technique that has several advantages, such as a high machining rate, and can be used on a wide range of difficult-to-process materials. In this paper, orthogonal experiments are conducted to investigate ECM of Ti60, with the aim of determining the influences of some electrochemical process parameters on t...

  1. Effect of povidone-iodine deposition on tribocorrosion and antibacterial properties of titanium alloy

    Science.gov (United States)

    Yan, Yu; Zhang, Yanbo; Wang, Qikui; Du, Hongwu; Qiao, Lijie

    2016-02-01

    Infection remains one of the most common causes for the early-stage failure of orthopaedic implants. Many methods have been developed to reduce the growth of bacteria. However, devices such as orthopaedic implants involve relative motion in several parts, and suffer wear from tribocorrosion processes. The surface pattern and texture can be damaged and the anti-bacterial efficiency reduced. In this paper, a two-stage method is reported. Povidone-iodine (PVP-I) was deposited on the titanium alloy surfaces and inside the pores to provide a longer release time. The results show that even under tribological tests, the anti-bacterial performance still remains satisfactory.

  2. Anomalous acoustic effect during martensitic transformations in titanium nickelide base alloys

    International Nuclear Information System (INIS)

    One carried out experiments to determine effect of external static stress on martensitic transformations and acoustic emission, Martensitic transformations in titanium nickelide base alloys under mechanical stress were determined to change nature of acoustic emission to anomalous one - cycling of transformations under gradual increase of mechanical stress during direct martensitic transformation was followed by increase of acoustic emission energy instead of reduction. The mentioned nature of acoustic emission is indicative of essential effect of external stress on martensitic transformations and energy dissipation during transformations

  3. Structure of Ti-6Al-4V nanostructured titanium alloy joint obtained by resistance spot welding

    Energy Technology Data Exchange (ETDEWEB)

    Klimenov, V. A., E-mail: klimenov@tpu.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Kurgan, K. A., E-mail: kirill-k2.777@mail.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); Chumaevskii, A. V., E-mail: tch7av@gmail.com [Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, 2/4 Akademicheskii pr., Tomsk, 634021 (Russian Federation); Klopotov, A. A., E-mail: klopotovaa@tsuab.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); National Research Tomsk State University, 36 Lenin Ave., Tomsk, 634050 (Russian Federation); Gnyusov, S. F., E-mail: gnusov@rambler.ru [National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation)

    2016-01-15

    The structure of weld joints of the titanium alloy Ti-6Al-4V in the initial ultrafine-grained state, obtained by resistance spot welding, is studied using the optical and scanning electron microscopy method and the X-ray structure analysis. The carried out studies show the relationship of the metal structure in the weld zone with main joint zones. The structure in the core zone and the heat affected zone is represented by finely dispersed grains of needle-shaped martensite, differently oriented in these zones. The change in the microhardness in the longitudinal section of the weld joint clearly correlates with structural changes during welding.

  4. Critical analysis of tig welded joint of titanium G-5 alloy sheet

    Czech Academy of Sciences Publication Activity Database

    Gope, D. P.; Yadav, S.; Kumar, V.; Chattopadhyaya, S.; Mandal, S.; Hloch, Sergej

    Belgrade : TEAM International Society, Faculty of Mechanical Engineering, University of Belgrade, 2015 - (Sedmak, A.), s. 411-415 ISBN 978-86-7083-877-2. [International Scientific and Expert Conference TEAM 2015 /7./. Belgrade (RS), 15.10.2015-16.10.2015] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : titanium G5 alloy * TIG welding * microstructure * micro-hardness * welding current Subject RIV: JQ - Machines ; Tools http://johanyak.hu/files/u1/publi/G_J_Survey_on_Intrusion_TEAM_2015.pdf

  5. Effect of heat treatments for the removal of welding and assembly stresses on the brittleness of pseudo-alpha titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Khesin, IU.D.; Bodunova, M.B.; Lanin, A.A.; Vodop' ianov, V.I.

    1992-06-01

    The objective of the study was to investigate the mechanisms of the embrittlement of alpha titanium alloys under loading in a corrosive medium following heat treatments designed to remove residual welding and assembly stresses. It is shown that the susceptibility of alpha titanium alloys to stress corrosion cracking is largely determined by the alloy composition. High contents of Al, Zr, Sn, and other elements are shown to contribute to the brittleness of alpha titanium alloys. Other important factors are the cooling rate following heating and the presence of a surface oxide film.

  6. The application of an assisting gas plasma generator for low- temperature magnetron sputtering of Ti-C-Mo-S antifriction coatings on titanium alloys

    Science.gov (United States)

    Potekaev, A. I.; Savostikov, V. M.; Tabachenko, A. N.; Dudarev, E. F.; Melnikova, E. A.; Shulepov, I. A.

    2015-11-01

    The positive effect of assisting influence of high-density gas plasma formed by an independent plasma generator PINK on mechanical and tribological characteristics of Ti-C- Mo-S magnetron coating on titanium alloys at lowered to 350°C temperature of coating regardless of alloy structural condition was revealed by methods of calotest, nanorecognition, scratch testing and frictional material tests. The coating formed by means of a combined magnetron plasma method reduces titanium alloys friction coefficient in multiple times and increases wear resistance by two orders of magnitude. At the same time the mechanical properties of ultra-fine-grained titanium alloys obtained by nanostructuring do not deteriorate.

  7. Phase Transformation Kinetics and Mechanisms in Titanium Alloys Ti-6.2.4.6,ß-CEZ and Ti-10.2.3

    OpenAIRE

    Bein, S.; BÉchet, J.

    1996-01-01

    The precipitation mechanisms and kinetics in three titanium alloys of different ß-phase stabilities - the ß-rich a α+β titanium alloy Ti-6Al-2Sn-4Zr-6Mo and the near ß-titanium alloys Ti-5Al-2Sn-2Cr-4Mo-4Zr-1Fe(ß- CEZ) and Ti-10V-2Fe-3Al - were investigated by isothermal holding in the α+β field after a ß-solution treatment. For this purpose, the amount of transformation was determined by electrical resistivity measurements. The TTT diagrams of these alloys, plotted in the whole α+β field, sh...

  8. An alternative way to orient the parent phase in the cubic/orthorhombic martensitic transformation of titanium shape memory alloys

    International Nuclear Information System (INIS)

    Titanium-based shape memory alloys undergo a cubic to orthorhombic martensitic transformation (β to α″ martensite). A new and easy way to reconstruct parent microstructure from electron backscattered diffraction data is described in this paper. It is shown that the electron backscattered patterns of the martensitic microstructure can be directly indexed as the parent phase in order to obtain the correct orientation of the high-temperature microstructure. This method is, however, specific to the cubic/orthorhombic martensitic transformation in titanium shape memory alloys

  9. Development of methods for the quantification of microstructural features in α + β-processed α/β titanium alloys

    International Nuclear Information System (INIS)

    A set of stereological procedures has been developed for the rigorous quantification of microstructural features resolvable using scanning electron microscopy in α + β-processed α/β titanium alloys. This paper identifies the four microstructural features that most likely influence the mechanical properties in α + β-processed titanium alloy, including: the size of the equiaxed alpha, the volume fraction of the equiaxed alpha, the volume fraction of total alpha, and the thickness of the Widmanstaetten alpha laths. The details regarding the quantification methodologies are provided, as are the origins of the associated uncertainties.

  10. Design and fabrication of a metastable β-type titanium alloy with ultralow elastic modulus and high strength

    Science.gov (United States)

    Guo, Shun; Meng, Qingkun; Zhao, Xinqing; Wei, Qiuming; Xu, Huibin

    2015-10-01

    Titanium and its alloys have become the most attractive implant materials due to their high corrosion resistance, excellent biocompatibility and relatively low elastic modulus. However, the current Ti materials used for implant applications exhibit much higher Young’s modulus (50 ~ 120 GPa) than human bone (~30 GPa). This large mismatch in the elastic modulus between implant and human bone can lead to so-called “stress shielding effect” and eventual implant failure. Therefore, the development of β-type Ti alloys with modulus comparable to that of human bone has become an ever more pressing subject in the area of advanced biomedical materials. In this study, an attempt was made to produce a bone-compatible metastable β-type Ti alloy. By alloying and thermo-mechanical treatment, a metastable β-type Ti-33Nb-4Sn (wt. %) alloy with ultralow Young’s modulus (36 GPa, versus ~30 GPa for human bone) and high ultimate strength (853 MPa) was fabricated. We believe that this method can be applied to developing advanced metastable β-type titanium alloys for implant applications. Also, this approach can shed light on design and development of novel β-type titanium alloys with large elastic limit due to their high strength and low elastic modulus.

  11. Influence of polyetheretherketone coatings on the Ti-13Nb-13Zr titanium alloy's bio-tribological properties and corrosion resistance.

    Science.gov (United States)

    Sak, Anita; Moskalewicz, Tomasz; Zimowski, Sławomir; Cieniek, Łukasz; Dubiel, Beata; Radziszewska, Agnieszka; Kot, Marcin; Łukaszczyk, Alicja

    2016-06-01

    Polyetheretherketone (PEEK) coatings of 70-90μm thick were electrophoretically deposited from a suspension of PEEK powder in ethanol on near-β Ti-13Nb-13Zr titanium alloy. In order to produce good quality coatings, the composition of the suspension (pH) and optimized deposition parameters (applied voltage and time) were experimentally selected. The as-deposited coatings exhibited the uniform distribution of PEEK powders on the substrate. The subsequent annealing at a temperature above the PEEK melting point enabled homogeneous, semi-crystalline coatings with spherulitic morphology to be produced. A micro-scratch test showed that the coatings exhibited very good adhesion to the titanium alloy substrate. Coating delamination was not observed even up to a maximal load of 30N. The PEEK coatings significantly improved the tribological properties of the Ti-13Nb-13Zr alloy. The coefficient of friction was reduced from 0.55 for an uncoated alloy to 0.40 and 0.12 for a coated alloy in a dry sliding and sliding in Ringer's solution, respectively. The PEEK coatings exhibited excellent wear resistance in both contact conditions. Their wear rate was more than 200 times smaller compared with the wear rate of the uncoated Ti-13Nb-13Zr alloy. The obtained results indicate that electrophoretically deposited PEEK coatings on the near-β titanium alloy exhibit very useful properties for their prospective tribological applications in medicine. PMID:27040195

  12. Preparation and Photocatalytic Activity of Potassium- Incorporated Titanium Oxide Nanostructures Produced by the Wet Corrosion Process Using Various Titanium Alloys

    Directory of Open Access Journals (Sweden)

    So Yoon Lee

    2015-08-01

    Full Text Available Nanostructured potassium-incorporated Ti-based oxides have attracted much attention because the incorporated potassium can influence their structural and physico-chemical properties. With the aim of tuning the structural and physical properties, we have demonstrated the wet corrosion process (WCP as a simple method for nanostructure fabrication using various Ti-based materials, namely Ti–6Al–4V alloy (TAV, Ti–Ni (TN alloy and pure Ti, which have 90%, 50% and 100% initial Ti content, respectively. We have systematically investigated the relationship between the Ti content in the initial metal and the precise condition of WCP to control the structural and physical properties of the resulting nanostructures. The WCP treatment involved various concentrations of KOH solutions. The precise conditions for producing K-incorporated nanostructured titanium oxide films (nTOFs were strongly dependent on the Ti content of the initial metal. Ti and TAV yielded one-dimensional nanowires of K-incorporated nTOFs after treatment with 10 mol/L-KOH solution, whereas TN required a higher concentration (20 mol/L-KOH solution to produce comparable nanostructures. The obtained nanostructures revealed a blue-shift in UV absorption spectra due to the quantum confinement effects. A significant enhancement of the photocatalytic activity was observed via the chromomeric change and the intermediate formation of methylene blue molecules under UV irradiation. This study demonstrates the WCP as a simple, versatile and scalable method for the production of nanostructured K-incorporated nTOFs to be used as high-performance photocatalysts for environmental and energy applications.

  13. Improvement of Ductility of Powder Metallurgy Titanium Alloys by Addition of Rare Earth Element

    Institute of Scientific and Technical Information of China (English)

    Yong LIU; Lifang CHEN; Weifeng WEI; Huiping TANG; Bin LIU; Baiyun HUANG

    2006-01-01

    Ti-4.5Al-6.0Mo-1.5Fe, Ti-6Al-1Mo-1Fe and Ti-6Al-4V alloys were prepared by blended elemental powder metallurgy (PM) process, and the effects of Nd on the microstructures and mechanical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD).It was found out that the addition of Nd increased the density of sintered titanium alloys slightly by a maximum increment of 1% because small amount of liquid phase occurred during sintering. The addition of Nd shows little effect on the improvement of tensile strength, while the elongation is significantly improved. For example, the elongation of Ti-4.5Al-6.0Mo-1.5Fe can be increased from 1% without addition of Nd to 13% at a Nd content of 1.2 wt pct.

  14. A set of microstructure-based constitutive equations in hot forming of a titanium alloy

    Institute of Scientific and Technical Information of China (English)

    Xiaoli Li; Miaoquan Li

    2006-01-01

    A physical model of microstructure evolution including dislocation density rate and grain growth rate was established based on the deformation mechanism for the hot forming of a class of two-phase titanium alloys. Further, a set of mechanism-based constitutive equations were proposed, in which the microstructure variables such as grain size and dislocation density were taken as internal state variables for characterizing the current material state. In the set of constitutive equations, the contributions of different mechanisms and individual phase to the deformation behavior were analyzed. The present equations have been applied to describe a correlation of the flow stress with the microstructure evolution of the TC6 alloy in hot forming.

  15. Braze Welding TIG of Titanium and Aluminium Alloy Type Al – Mg

    Directory of Open Access Journals (Sweden)

    Winiowski A.

    2016-03-01

    Full Text Available The article presents the course and the results of technological tests related to TIG-based arc braze welding of titanium and AW-5754 (AlMg3 aluminium alloy. The tests involved the use of an aluminium filler metal (Al99.5 and two filler metals based on Al-Si alloys (AlSi5 and AlSi12. Braze welded joints underwent tensile tests, metallographic examinations using a light microscope as well as structural examinations involving the use of a scanning electron microscope and an X-ray energy dispersive spectrometer (EDS. The highest strength and quality of welds was obtained when the Al99.5 filler metal was used in a braze welding process. The tests enabled the development of the most convenient braze welding conditions and parameters.

  16. Assessment of corrosion-resistant coatings for a depleted uranium-0.75 titanium alloy

    International Nuclear Information System (INIS)

    A number of different coatings (aluminum, zinc, magnesium, Al-Zn, Al-Mg, nickel, titanium, TiN and aluminum on TiN) were applied by the arc plasma physical vapor deposition technique to a depleted uranium (DU) alloy for corrosion protection assessment. The as-deposited specimens were examined by scanning electron microscopy for surface morphology and tested for adhesion. Electrochemical polarization tests and immersion tests were conducted in aerated 3.5 wt.% NaCl solution. The results of the electrochemical polarization scans and observations after long-term exposure tests indicated that the two alloys Al-Zn and Al-Mg appear to be the best sacrificial coating materials for improving the corrosion resistance of DU-0.75Ti. (orig.)

  17. Computer simulation of quenching uranium-0.75 weight per cent titanium alloy

    International Nuclear Information System (INIS)

    A ''QUENCH SIMULATOR'' has been developed which uses finite difference heat transfer and finite element stress analysis techniques to predict the behavior of a metal during quenching. The actual nonlinear temperature- and microstructure-dependent physical, thermophysical, and mechanical properties are incorporated as input into the computer model as well as the continuous cooling transformation (CCT) behavior and heats of transformation of the alloy. The final output provides the transient temperature distribution, details the final residual profile, predicts and shows where distortion occurs, and maps out the microstructure distribution throughout the entire sample. These data are available in tabulated form, contour plots, or color-coded graphics. This analysis has been demonstrated on simple shapes for unalloyed uranium and the uranium-0.75 weight per titanium alloy which undergoes a martensite transformation and is quench-rate sensitive. The results of this study are discussed in detail in addition to other applications of this analysis approach which is generic in nature

  18. A study of cyclic fatigue, damage initiation, damage propagation, and fracture of welded titanium alloy plate

    International Nuclear Information System (INIS)

    In this paper, the influence of test specimen orientation and microstructure on cyclic stress-amplitude controlled fatigue response, damage initiation, damage propagation and fracture behavior of samples taken from a welded plate of titanium alloy is presented and discussed. Test specimens from the chosen alloy were prepared from an as-welded plate of the material with the stress axis both parallel (longitudinal) and perpendicular (transverse) to the deformed (rolling) direction of the plate. The test specimens were cyclically deformed at different values of maximum stress at a constant load ratio of 0.1, and the resultant cycles-to-failure was recorded. The fracture surfaces of the deformed and failed test specimens were examined in a scanning electron microscope to establish the macroscopic fracture mode, the intrinsic features on the fatigue fracture surface and the role of applied stress-microstructural feature interactions in establishing the microscopic mechanisms governing failure.

  19. Analysis of the effect of alloy elements on martensitic transformation in titanium alloy with the use of valence electron structure parameters

    International Nuclear Information System (INIS)

    Research highlights: → Bond length difference analysis for martensite phases in Ti alloys is conducted. → Martensitic transformation is studied with the use of electron structure parameters. → The effect of alloy elements on martensitic tranformatio is analyzed. - Abstract: Because martensitic transformation in titanium alloy significantly affects properties and applications of the alloys, the analysis of the effect of alloy elements on martensitic transformation becomes primarily important. Through using the valence electron structure parameters calculated by the empirical electron theory (EET) of solids and molecules, our analysis results reveal that the addition of alloy elements (such as Zr, Nb, W, Mo, V) has the beneficial effect on the formation of orthorhombic martensite α'' as well as the addition of alloy elements (e.g., Al, Fe, Cr, Sn) has advantage to the formation of hcp-structured martensite α'. Our analysis results not only present the understanding about the effect of alloy elements on martensitic transformation at the electron structure level, but also provide a theoretical basis for the chemical composition design of titanium alloys.

  20. Effect of yttrium on microstructure and mold filling capacity of a near-α high temperature titanium alloy

    Directory of Open Access Journals (Sweden)

    Zhao Ertuan

    2012-11-01

    Full Text Available The addition of rare earth yttrium (Y can improve the performances of high temperature titanium alloys, such as the tensile ductility, thermal stability and creep property, etc. However, few studies on the effect of Y on the castability of titanium alloys have been carried out, which is significant to fabrication of thin-walled complex titanium castings by investment casting. In this study, the microstructure and mold filling capacity of a Ti-1100 alloy with different Y additions (0, 0.1wt.%, 0.3wt.%, 0.5wt.% and 1.0wt.% were investigated systematically through investment casting experiments, and the casting experiments were carried out in a centrifugal titanium casting machine. The microstructures of the alloy were observed via the optical microscopy, scanning electron microscopy and transmission electron microscopy. The mold filling capacity was tested by using of a grid pattern and was evaluated by the number of segments completely filled by the cast alloy. The results indicate that the grain size is decreased and the mold filling capacity is improved significantly with increasing the addition of Y from 0 to 1.0wt.%. The average primary β grain size of Ti-1100 alloy is reduced from 250 μm to 50 μm and the mold filling capacity is increased from 61.5% to 100%. Considering the potential harmful effect on tensile properties of titanium alloys due to high concentrations of Y, it is suggested that Y addition should be about 0.3wt.%.

  1. Laser nitriding of the surface layer of Ti6Al4V titanium alloy

    Directory of Open Access Journals (Sweden)

    R. Filip

    2008-03-01

    Full Text Available Purpose: The purpose of this paper is modification of the surface layer of the Ti6Al4V titanium alloymicrostructure and properties by laser remelting in nitrogen atmosphere.Design/methodology/approach: Laser treatment was performed on the samples in stream of nitrogen.Microstructure of laser treated layer was investigated by using Epiphot 300 optical microscope and Novascan30 scanning electron microscope. Phase composition was determined using X-ray diffractometry. The roughnessof surface of treated material was examined using topography scanning system T 8000 made by HommelwerkeGMBH. The Vickers hardness under load of 1.96 N was measured on the cross sections of surface layer. The wearproperties of alloyed zone were tested on the testing machine T 08M using ‘pin on disc’ test.Findings: Laser remelting process has produced a surface layer consists of hard ceramics particles of TiN andTi2N phases spaced in martensitic matrix. The hardness of surface layer increases clearly in comparison withuntreated alloy due to formation of TiN and Ti2N particles and depends on the volume fraction of nitrides. Theirmaximum value of the hardness (1500 HV 0.2 occurs on the surface of laser treated zone. Wear resistance of lasernitrided layer increases considerably in relation to base alloy.Research limitations/implications: Research range was limited to microstructure, phase composition,hardness, fractography and wear resistance investigations. To estimate the influence of the laser nitriding processon corrosion resistance of the layer additional examinations will be performed in future research.Practical implications: Laser remelting of titanium alloy in nitrogen atmosphere makes possible to obtain coatingscomposed of ceramic particles spaced in metallic matrix characterised by high hardness and wear resistance.Originality/value: The range of investigation included microstructure, phase composition, hardness as well asfractographic estimation and wear

  2. Laser-assisted development of titanium alloys: the search for new biomedical materials

    Science.gov (United States)

    Almeida, Amelia; Gupta, Dheeraj; Vilar, Rui

    2011-02-01

    Ti-alloys used in prosthetic applications are mostly alloys initially developed for aeronautical applications, so their behavior was not optimized for medical use. A need remains to design new alloys for biomedical applications, where requirements such as biocompatibility, in-body durability, specific manufacturing ability, and cost effectiveness are considered. Materials for this application must present excellent biocompatibility, ductility, toughness and wear and corrosion resistance, a large laser processing window and low sensitivity to changes in the processing parameters. Laser deposition has been investigated in order to access its applicability to laser based manufactured implants. In this study, variable powder feed rate laser cladding has been used as a method for the combinatorial investigation of new alloy systems that offers a unique possibility for the rapid and exhaustive preparation of a whole range of alloys with compositions variable along a single clad track. This method was used as to produce composition gradient Ti-Mo alloys. Mo has been used since it is among the few elements biocompatible, non-toxic β-Ti phase stabilizers. Alloy tracks with compositions in the range 0-19 wt.%Mo were produced and characterized in detail as a function of composition using microscale testing procedures for screening of compositions with promising properties. Microstructural analysis showed that alloys with Mo content above 8% are fully formed of β phase grains. However, these β grains present a cellular substructure that is associated to a Ti and Mo segregation pattern that occurs during solidification. Ultramicroindentation tests carried out to evaluate the alloys' hardness and Young's modulus showed that Ti-13%Mo alloys presented the lowest hardness and Young's modulus (70 GPa) closer to that of bone than common Ti alloys, thus showing great potential for implant applications.

  3. Antibacterial effect of copper-bearing titanium alloy (Ti-Cu) against Streptococcus mutans and Porphyromonas gingivalis

    Science.gov (United States)

    Liu, Rui; Memarzadeh, Kaveh; Chang, Bei; Zhang, Yumei; Ma, Zheng; Allaker, Robert P.; Ren, Ling; Yang, Ke

    2016-07-01

    Formation of bacterial biofilms on dental implant material surfaces (titanium) may lead to the development of peri-implant diseases influencing the long term success of dental implants. In this study, a novel Cu-bearing titanium alloy (Ti-Cu) was designed and fabricated in order to efficiently kill bacteria and discourage formation of biofilms, and then inhibit bacterial infection and prevent implant failure, in comparison with pure Ti. Results from biofilm based gene expression studies, biofilm growth observation, bacterial viability measurements and morphological examination of bacteria, revealed antimicrobial/antibiofilm activities of Ti-Cu alloy against the oral specific bacterial species, Streptococcus mutans and Porphyromonas gingivalis. Proliferation and adhesion assays with mesenchymal stem cells, and measurement of the mean daily amount of Cu ion release demonstrated Ti-Cu alloy to be biocompatible. In conclusion, Ti-Cu alloy is a promising dental implant material with antimicrobial/antibiofilm activities and acceptable biocompatibility.

  4. An investigation of microstructure, hardness, tensile behaviour of a titanium alloy: Role of orientation

    Indian Academy of Sciences (India)

    Mithun Kuruvilla; T S Srivatsan; M Petraroli; Lisa Park

    2008-06-01

    In this technical paper, the microstructure, hardness, tensile deformation and final fracture behaviour of an emerging titanium alloy for performance-critical applications are presented and discussed. Both longitudinal and transverse test specimens were prepared from the as-provided sheet stock of the alloy and deformed in uniaxial tension. The yield strength and tensile strength of the alloy sheet in the transverse orientation was higher than the longitudinal orientation. The ductility of the test specimens, quantified in terms of reduction-in-cross-sectional area, was higher for the transverse specimen when compared to the longitudinal counterpart. The elongation-to-failure of the test specimens was identical in the two orientations of the sheet stock. The tensile fracture behaviour of the alloy was quantified by careful examination of the fracture surfaces in a scanning electron microscope. The intrinsic fracture features on the tensile fracture surface were discussed taking into consideration the nature of loading and contribution from intrinsic microstructural features.

  5. The influence of internal stresses on plastic instabilities in {alpha}/{beta} titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Helbert, A.L.; Feaugas, X. [Univ. de Technologie de Compiegne (France). Div. Mecanique

    1997-05-01

    It is now well established that the plastic strain localization in shear bands is a natural process in the domain of large deformations. This phenomenon has been particularly studied in the last few years, especially in c.c. and c.f.c. alloys but less in h.c.p. alloys. The influence of several parameters, such as stacking fault energy, crystallographic orientation, grain size or hardening, on the nucleation and the propagation of shear bands has been largely studied. In polycrystals, it has been noted that plastic strain incompatibilities at grain boundaries promoted shear band nucleation. {alpha}/{beta} titanium alloys, which are two phase alloys, develop more plastic strain incompatibilities than the polycrystals. Also, the purpose of this work is to study the effect of these internal stresses on the nucleation and the propagation of shear bands. Besides, the plastic strain localization is not only a deformation mode but is also involved in fracture. Indeed, numerous authors have revealed that fracture could occur in shear bands. In this study, the influence of these shear bands on the fracture process under low triaxiality ({chi} < 1) will be analyzed.

  6. Joining aluminum to titanium alloy by friction stir lap welding with cutting pin

    International Nuclear Information System (INIS)

    Aluminum 1060 and titanium alloy Ti–6Al–4V plates were lap joined by friction stir welding. A cutting pin of rotary burr made of tungsten carbide was employed. The microstructures of the joining interface were observed by scanning electron microscopy. Joint strength was evaluated by a tensile shear test. During the welding process, the surface layer of the titanium plate was cut off by the pin, and intensively mixed with aluminum situated on the titanium plate. The microstructures analysis showed that a visible swirl-like mixed region existed at the interface. In this region, the Al metal, Ti metal and the mixed layer of them were all presented. The ultimate tensile shear strength of joint reached 100% of 1060Al that underwent thermal cycle provided by the shoulder. - Highlights: ► FSW with cutting pin was successfully employed to form Al/Ti lap joint. ► Swirl-like structures formed due to mechanical mixing were found at the interface. ► High-strength joints fractured at Al suffered thermal cycle were produced.

  7. The effect of alloying on the ordering processes in near-alpha titanium alloys

    International Nuclear Information System (INIS)

    The substructure of near-alpha Ti–Al–Sn–Zr–Mo–Si alloys containing up to 12.5 at% aluminum was studied by transmission electron microscopy (TEM). It was shown that long-range order sections are formed at aging temperatures up to 500 °C in alloys, high in aluminum, and the ordered phase is formed by the nucleation and growth mechanism at 700 °C aging temperatures. Causes of changing the phase transformation mechanism have been discussed, and the relationship between the structure and properties of alloys, depending on modes of heat treatment has been analyzed. Also the influence of aluminides and silicides precipitation on the mechanical alloy properties after aging was examined. It was shown that the aluminide formation led to a slight hardening and a significant viscosity decrease. The silicide particles formation reduced the heat resistance properties, due to the depletion of the solid solution by silicon

  8. The effect of alloying on the ordering processes in near-alpha titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Popov, Artemiy, E-mail: p.artemii@mail.ru [Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira Street, Ekaterinburg 620002 (Russian Federation); Rossina, Natalya [Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira Street, Ekaterinburg 620002 (Russian Federation); Popova, Maria, E-mail: pmaria777@mail.ru [Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira Street, Ekaterinburg 620002 (Russian Federation)

    2013-03-01

    The substructure of near-alpha Ti–Al–Sn–Zr–Mo–Si alloys containing up to 12.5 at% aluminum was studied by transmission electron microscopy (TEM). It was shown that long-range order sections are formed at aging temperatures up to 500 °C in alloys, high in aluminum, and the ordered phase is formed by the nucleation and growth mechanism at 700 °C aging temperatures. Causes of changing the phase transformation mechanism have been discussed, and the relationship between the structure and properties of alloys, depending on modes of heat treatment has been analyzed. Also the influence of aluminides and silicides precipitation on the mechanical alloy properties after aging was examined. It was shown that the aluminide formation led to a slight hardening and a significant viscosity decrease. The silicide particles formation reduced the heat resistance properties, due to the depletion of the solid solution by silicon.

  9. The application of an assisting gas plasma generator for low-temperature magnetron sputtering of Ti-C-Mo-S antifriction coatings on titanium alloys

    OpenAIRE

    Potekaev, A. I.; Savostikov , V. M.; Tabachenko, Aleksandr Nikitich; Dudarev, E. F.; Melnikova, E. A.; Shulepov, Ivan Anisimovich

    2015-01-01

    The positive effect of assisting influence of high-density gas plasma formed by an independent plasma generator PINK on mechanical and tribological characteristics of Ti-C-Mo-S magnetron coating on titanium alloys at lowered to 350°С temperature of coating regardless of alloy structural condition was revealed by methods of calotest, nanorecognition, scratch testing and frictional material tests. The coating formed by means of a combined magnetron plasma method reduces titanium alloys friction...

  10. Surface defects in PMD-EDM of titanium alloy, Ti-6246

    International Nuclear Information System (INIS)

    Titanium alloys which are categorized as lightweight materials, poses greater strength and toughness are usually known to create major challenges during machining. Electrical discharge machining (EDM) which is very prominent amongst the non-conventional machining methods is expected to be used quite extensively in machining titanium alloys. EDM process is known to cause surface damaged layers which consists of three types of surfaces; spattered, recast and heat affected zone. This project was undertaken to study the machining performance of EDM and powder mixed dielectric-electrical discharge machining (PMDEDM) in machining Ti-6246 with respect to the surface integrity of machined surface by using copper tungsten (CuW) electrode. The machining parameters considered are voltage (V), current (I), pulse on time(Ton), interval time (Toff) and concentration of the SiC powder (C) in dielectric fluid. The respected responses investigated include surface alteration and overcut. It was found that PMD-EDM process produced less damaging effect on the surface layer of the machined surface and widened the overcut. (author)

  11. Improvement of titanium alloy for biomedical applications by nitriding and carbonitriding processes under glow discharge conditions.

    Science.gov (United States)

    Czarnowska, E; Wierzchoń, T; Maranda-Niedbała, A; Karczmarewicz, E

    2000-02-01

    Although titanium alloys are used in medicine, they present low wear resistance. In this paper we present the results of studies on surface layers produced by nitriding at three different temperatures, and by carbonitriding under glow discharge conditions in order to improve wear resistance, hardness, and to modulate microstructure and chemical composition of surface layers. A cell culture model using human fibroblasts was chosen to study the effect of such treatments on the cytocompatibility of these materials. The results showed that nitrided and carbonitrided surface layers were cytocompatible. Modulation of surface microstructure by temperature in the nitriding process and chemical composition of surface layers by carbonitriding led to differences in cellular behaviour. Cell proliferation appeared to be slightly reduced from the 6th day of culture on nitrided surfaces produced at 730 degrees C and 1000 degrees C, however after 12 days of culture, the best growth was on surface layers produced at 850 degrees C. The best viability was observed on the carbonitrided layer. The orientation and shape of the cells corresponded to surface topography. Nitriding and carbonitriding under glow discharge conditions may constitute interesting techniques allowing the formation of surface layers on parts with sophisticated shapes. They may also permit modulating surface topography in a way improving the features of titanium alloys for various applications in medicine. PMID:15348050

  12. An experimental study of microstructure-induced ultrasonic signal fluctuations in jet-engine titanium alloys

    International Nuclear Information System (INIS)

    Ultrasonic echoes from identical defects in a metal component will vary due to the influence of the local microstructure in which each defect is embedded. Two effects are responsible: (1) the scattering of sound at nearby crystallite boundaries results in 'grain noise' which is superimposed on the defect echo; and (2) the intervening microstructure modulates or distorts the sonic field that is incident on the defect, thus modifying its echo. Both effects can be significant in engine titanium alloys, and both influence inspection reliability. In this work, a series of experiments is performed to investigate signal fluctuations primarily arising from the second effect. Arrays of nominally identical no. 1 flat-bottomed holes (FBHs) in Ti-17 and Ti 6-4 specimens are scanned using a 10-MHz, broadband, focused transducer. The peak echo amplitude of each FBH in the array is measured, and the ratio of the standard deviation of the peak amplitudes to their mean serves as a dimensionless measure of the fluctuation level. Similar measurements are performed on a fine-grained nickel specimen that serves as a reference. The fluctuation level and the apparent average ultrasonic attenuation are measured as functions of alloy, propagation direction, frequency, and inspection water path (i.e., degree of beam focusing). In addition, beam distortions are studied by analyzing the sizes and shapes of the C-scan images of the FBHs. - Specimens used in this work were supplied by the Engine Titanium Consortium under the Federal Aviation Administration Grant No. 94-G-048

  13. An experimental study of microstructure-induced ultrasonic signal fluctuations in jet-engine titanium alloys

    Science.gov (United States)

    Margetan, Frank J.; Wasan, Harpreet; Thompson, R. Bruce

    2000-05-01

    Ultrasonic echoes from identical defects in a metal component will vary due to the influence of the local microstructure in which each defect is embedded. Two effects are responsible: (1) the scattering of sound at nearby crystallite boundaries results in "grain noise" which is superimposed on the defect echo; and (2) the intervening microstructure modulates or distorts the sonic field that is incident on the defect, thus modifying its echo. Both effects can be significant in engine titanium alloys, and both influence inspection reliability. In this work, a series of experiments is performed to investigate signal fluctuations primarily arising from the second effect. Arrays of nominally identical #1 flat-bottomed holes (FBHs) in Ti-17 and Ti 6-4 specimens are scanned using a 10-MHz, broadband, focused transducer. The peak echo amplitude of each FBH in the array is measured, and the ratio of the standard deviation of the peak amplitudes to their mean serves as a dimensionless measure of the fluctuation level. Similar measurements are performed on a fine-grained nickel specimen that serves as a reference. The fluctuation level and the apparent average ultrasonic attenuation are measured as functions of alloy, propagation direction, frequency, and inspection water path (i.e., degree of beam focusing). In addition, beam distortions are studied by analyzing the sizes and shapes of the C-scan images of the FBHs.—Specimens used in this work were supplied by the Engine Titanium Consortium under the Federal Aviation Administration Grant No. 94-G-048.

  14. Enhancing the soft tissue seal around intraosseous transcutaneous amputation prostheses using silanized fibronectin titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chimutengwende-Gordon, M; Pendegrass, C; Blunn, G, E-mail: mukai.cg@mac.com [Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, University College London, Brockley Hill, Stanmore, HA7 4LP (United Kingdom)

    2011-04-15

    The success of intraosseous transcutaneous amputation prostheses (ITAP) relies on achieving a tight seal between the soft tissues and the implant in order to avoid infection. Fibronectin (Fn) may be silanized onto titanium alloy (Ti-6Al-4V) in order to promote soft-tissue attachment. The silanization process includes passivation with sulphuric acid, which alters surface characteristics. This study aimed to improve in vitro fibroblast adhesion to silanized fibronectin (SiFn) titanium alloy by omitting the passivation stage. Additionally, the study assessed the effects of SiFn on in vivo dermal attachment, comparing the results with adsorbed Fn, hydroxyapatite (HA), Fn adsorbed onto HA (HAFn) and uncoated controls. Surface topography was assessed using scanning electron microscopy, profilometry and contact angle measurement. Anti-vinculin antibodies were used to immunolocalize fibroblast adhesion sites. A histological assessment of soft-tissue attachment and cell alignment relative to implants in an in vivo ovine model was performed. Passivation resulted in rougher, more hydrophobic, microcracked surfaces and was associated with poorer fibroblast adhesion than unpassivated controls. SiFn and HAFn surfaces resulted in more favourable cell alignment in vivo, implying that dermal attachment was enhanced. These results suggest that SiFn and HAFn surfaces could be useful in optimizing the soft tissue seal around ITAP.

  15. Enhancing the soft tissue seal around intraosseous transcutaneous amputation prostheses using silanized fibronectin titanium alloy

    International Nuclear Information System (INIS)

    The success of intraosseous transcutaneous amputation prostheses (ITAP) relies on achieving a tight seal between the soft tissues and the implant in order to avoid infection. Fibronectin (Fn) may be silanized onto titanium alloy (Ti-6Al-4V) in order to promote soft-tissue attachment. The silanization process includes passivation with sulphuric acid, which alters surface characteristics. This study aimed to improve in vitro fibroblast adhesion to silanized fibronectin (SiFn) titanium alloy by omitting the passivation stage. Additionally, the study assessed the effects of SiFn on in vivo dermal attachment, comparing the results with adsorbed Fn, hydroxyapatite (HA), Fn adsorbed onto HA (HAFn) and uncoated controls. Surface topography was assessed using scanning electron microscopy, profilometry and contact angle measurement. Anti-vinculin antibodies were used to immunolocalize fibroblast adhesion sites. A histological assessment of soft-tissue attachment and cell alignment relative to implants in an in vivo ovine model was performed. Passivation resulted in rougher, more hydrophobic, microcracked surfaces and was associated with poorer fibroblast adhesion than unpassivated controls. SiFn and HAFn surfaces resulted in more favourable cell alignment in vivo, implying that dermal attachment was enhanced. These results suggest that SiFn and HAFn surfaces could be useful in optimizing the soft tissue seal around ITAP.

  16. Surface Integrity of Titanium Alloy Ti-6Al-4 V in Ball end Milling

    Science.gov (United States)

    Mhamdi, M.-B.; Boujelbene, M.; Bayraktar, E.; Zghal, A.

    With the evolution of machine tools and the emergence of new cutting tools such as cermet, CBN; and in framework of the production of parts with complex geometry, the manufacturers were able to realize more and more parts of complex shape. The multi-axis machining is the main technique for achieving the free form; in fact the multi-axis milling with ball end tools attracts the interest of the aerospace industry and the mussel industry which continues to seek ways to improve the surface quality of finished parts. The titanium alloy is widely used in aerospace industry is the subject of this study in fact, the integrity of the surfaces of parts produced by multi-axis milling is an issue more relevant than ever for the aerospace industry. This paper aims to study the influence of the tool position and the parameters cutting precisely the speed feed Vf, the engagement of the tool on the roughness 3 D, micro-hardness and microstructure alteration created in sub-surface during the milling of concave surface of titanium alloy type Ti-6Al-4 V.

  17. Dynamic Recrystallization Behavior of TA15 Titanium Alloy under Isothermal Compression during Hot Deformation

    Directory of Open Access Journals (Sweden)

    Yuanxin Luo

    2014-01-01

    Full Text Available In order to improve the understanding of the dynamic recrystallization (DRX behaviors of TA15 titanium alloy (Ti-6Al-2Zr-1Mo-1V, a series of experiments were conducted on a TMTS thermal simulator at temperatures of 1173 K, 1203 K, 1223 K, and 1273 K with the strain rates of 0.005 s−1, 0.05 s−1, 0.5 s−1, and 1 s−1. By the regression analysis for conventional hyperbolic sine equation, the activation energy of DRX in α+β two-phase region is QS=588.7 Kg/mol and in β region is QD=225.8 Kg/mol, and a dimensionless parameter controlling the stored energy was determined as Z/A=ε˙exp(588.7×103/RT/6.69×1026 in α+β two-phase region and as Z/A=ε˙exp(225.8×103/RT/5.13×1011 in β region. The DRX behaviors of TA15 titanium alloy were proposed on the strength of the experiment results. Finally, the theoretical prediction results of DRX volume fraction were shown to be in agreement with experimental observations.

  18. Deformation behavior of TC1 titanium alloy sheet under double-sided pressure

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-jin; SONG Hui; WANG Zhe

    2008-01-01

    In order to investigate the influence of normal stress through thickness on the formability of sheet metal, the viscous pressure bulge(VPB) tests of an annealed TC1 titanium alloy sheet were carried out under two different conditions: double-sided pressure bulging and conventional single-sided pressure bulging. The automated strain analysis, measurement environment (ASAME) and scanning electron microscope(SEM) were used to study the strain distributions and the fracture morphology of bulged specimens. It is found that thickness strain is increased for double-sided pressure bulging specimens, and the limiting dome height(LDH) of double-sided pressure bulging specimens is increased by 31.8% compared with conventional single-sided pressure bulging specimens. The dimples in fracture surface for double-sided pressure bulging specimens are larger and deeper than those for conventional single-sided pressure bulging specimens. The results indicate that normal stress through thickness is helpful in improving the formability of titanium alloy sheet metal.

  19. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2011-01-01

    Full Text Available Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P<10−4, and 19.3% to 77.7% at 0.1 mm, P<10−8. Carbon-fiber fragments planned to occur in the test designs, instead of producing an inflammation, stimulated bone formation and increased bone integration to the implant. In addition, low-thermal polymer processing allows incorporation of minerals and pharmaceuticals for future major tissue-engineering potential.

  20. The treatment effect of porous titanium alloy rod on the early stage talar osteonecrosis of sheep.

    Directory of Open Access Journals (Sweden)

    Xiao-Kang Li

    Full Text Available Osteonecrosis of the talus (ONT may severely affect the function of the ankle joint. Most orthopedists believe that ONT should be treated at an early stage, but a concise and effective surgical treatment is lacking. In this study, porous titanium alloy rods were prepared and implanted into the tali of sheep with early-stage ONT (IM group. The curative effect of the rods was compared to treatment by core decompression (DC group. No significant differences in bone reconstruction were observed between the two groups at 1 month after intervention. After 3 months, the macroscopic view of gross specimens of the IM group showed ordinary contours, but the specimens of the DC group showed obvious partial bone defects and cartilage degeneration. Quantitative analysis of the reconstructed trabeculae by micro-CT and histological study suggested that the curative effect of the IM group was superior to that of the DC group at 3 months after intervention. These favorable short-term results of the implantation of porous titanium alloy rods into the tali of sheep with early-stage ONT may provide insight into an innovative surgical treatment for ONT.