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Microstructure of Titanium Welds

Description: Plates of commercially pure titanium were welded and microscopically analyzed to understand the influence of joining variables on weld microstructure.
Date: February 1, 2003
Creator: Danielson, Paul; Wilson, Rick D. & Alman, David E.
Partner: UNT Libraries Government Documents Department
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Low cost titanium--myth or reality

Description: In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium, and titanium cost has prevented its use in non-aerospace applications including the automotive and heavy vehicle industries.
Date: January 1, 2001
Creator: Turner, Paul C.; Hartman, Alan D.; Hansen, Jeffrey S. & Gerdemann, Stephen J.
Partner: UNT Libraries Government Documents Department
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The Fabrication of Arc-Melted Ingots of Titanium and Titanium-Manganese Alloys into Plate

Description: Report issued by the Bureau of Mines over production of titanium-manganese alloy plates from arc-melted ingots. As stated in the summary, "for the alloy material, transformation data were obtained, and their age-hardening characteristics were studied. The temperature-impact relationship was established for rolled sections from all three ingots" (p. 1). This report includes tables, graphs, and photographs.
Date: March 1955
Creator: Huber, R. W.; Petersen, V. C. & Wiley, R. C.
Partner: UNT Libraries Government Documents Department
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Corrosion of Titanium Matrix Composites

Description: The corrosion behavior of unalloyed Ti and titanium matrix composites containing up to 20 vol% of TiC or TiB{sub 2} was determined in deaerated 2 wt% HCl at 50, 70, and 90 degrees C. Corrosion rates were calculated from corrosion currents determined by extrapolation of the tafel slopes. All curves exhibited active-passive behavior but no transpassive region. Corrosion rates for Ti + TiC composites were similar to those for unalloyed Ti except at 90 degrees C where the composites were slightly higher. Corrosion rates for Ti + TiB{sub 2} composites were generally higher than those for unalloyed Ti and increased with higher concentrations of TiB{sub 2}. XRD and SEM-EDS analyses showed that the TiC reinforcement did not react with the Ti matrix during fabrication while the TiB{sub 2} reacted to form a TiB phase.
Date: September 22, 2002
Creator: Covino, B. S., Jr. & Alman, D. E.
Partner: UNT Libraries Government Documents Department
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Titanium Metal Powder Production by the Plasma Quench Process

Description: The goals of this project included the scale-up of the titanium hydride production process to a production rate of 50 kg/hr at a purity level of 99+%. This goal was to be achieved by incrementally increasing the production capability of a series of reactor systems. This methodic approach was designed to allow Idaho Titanium Technologies to systematically address the engineering issues associated with plasma system performance, and powder collection system design and performance. With quality powder available, actual fabrication with the titanium hydride was to be pursued. Finally, with a successful titanium production system in place, the production of titanium aluminide was to be pursued by the simultaneously injection of titanium and aluminum precursors into the reactor system. Some significant accomplishments of the project are: A unique and revolutionary torch/reactor capable of withstanding temperatures up to 5000 C with high thermal efficiency has been operated. The dissociation of titanium tetrachloride into titanium powder and HC1 has been demonstrated, and a one-megawatt reactor potentially capable of producing 100 pounds per hour has been built, but not yet operated at the powder level. The removal of residual subchlorides and adsorbed HC1 and the sintering of powder to form solid bodies have been demonstrated. The production system has been operated at production rates up to 40 pounds per hour. Subsequent to the end of the project, Idaho Titanium Technologies demonstrated that titanium hydride powder can indeed be sintered into solid titanium metal at 1500 C without sintering aids.
Date: September 1, 2000
Creator: Cordes, R. A. & Donaldson, A.
Partner: UNT Libraries Government Documents Department
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An Assessment of Uncommon Titanium Binary Systems: Ti-Zn, Ti-Cu, and Ti-Sb

Description: The current study focuses on phase stability and evolution in the titanium-zinc titanium-copper and titanium-antimony systems. The study utilized the Laser Engineering Net Shaping (LENS™) processing technique to deposit compositionally graded samples of three binary system in order to allow the assessment of phase stability and evolution as a function of composition and temperature the material is subjected to. Through LENS™ processing it was possible to create graded samples from Ti-xSb (up to 13wt%) and Ti-xCu (up to 16wt%). The LENS™ deposited gradient were solutionized, and step quenched to specific aging temperature, and the resulting microstructures and phase were characterized utilizing XRD, EDS, SEM, FIB and TEM. The Ti-Zn system proved incapable of being LENS™ deposited due to the low vaporization temperature of Zn; however, a novel processing approach was developed to drip liquid Zn onto Ti powder at temperatures above β transus temperature of Ti (882 ◦C) and below the vaporization temperature of Zn (907 ◦C). The product of this processing technique was characterized in a similar way as the graded LENS™ depositions. From measurements performed on Ti-Sb it seems that Sb could be a potential α stabilizer in Ti due to the presence of a mostly homogeneous α grains throughout the gradient; however, from XRD it can be understood that a titanium antimonide phase is present. From results obtained from the Ti-Zn samples, it can be surmised that the eutectoid reaction seems to be active, i.e. The eutectoid reaction is kinetically fast, as concluded by the presence of pearlitic structures. Finally, for the Ti-Cu system this work has been attempted to prove or disprove the existence of the Ti3Cu through the use of XRD and TEM SAD patterns. From XRD spectra collected there are peaks belonging to the Ti3Cu orthorhombic phase along with Ti2Cu and α-Ti phase. In …
Date: May 2015
Creator: Brice, David
Partner: UNT Libraries
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Titanium metal: extraction to application

Description: In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium. In this paper, we discuss all aspects of the titanium industry from ore deposits through extraction to present and future applications. The methods of both primary (mining of ore, extraction, and purification) and secondary (forming and machining) operations will be analyzed. The chemical and physical properties of titanium metal will be briefly examined. Present and future applications for titanium will be discussed. Finally, the economics of titanium metal production also are analyzed as well as the advantages and disadvantages of various alternative extraction methods.
Date: September 1, 2002
Creator: Gambogi, Joseph & Gerdemann, Stephen J.
Partner: UNT Libraries Government Documents Department
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Plasma quench production of titanium from titanium tetrachloride

Description: This project, Plasma Quench Production of Titanium from Titanium Tetrachloride, centers on developing a technique for rapidly quenching the high temperature metal species and preventing back reactions with the halide. The quenching technique chosen uses the temperature drop produced in a converging/diverging supersonic nozzle. The rapid quench provided by this nozzle prevents the back reaction of the halide and metal. The nature of the process produces nanosized particles (10 to 100 nm). The powders are collected by cyclone separators, the hydrogen flared, and the acid scrubbed. Aluminum and titanium powders have been produced in the laboratory-scale device at 1 gram per hour. Efforts to date to scale up this process have not been successful.
Date: October 1, 1994
Creator: Sears, J. W.
Partner: UNT Libraries Government Documents Department
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Fatigue Testing of Abrasive Water Jet Cut Titanium

Description: Battelle Memorial Institute as part of its U.S. Department of Energy (USDOE) Contract No. DE-AC05-76RL01830 to operate the Pacific Northwest National Laboratory (PNNL) provides technology assistance to qualifying small businesses in association with a Technology Assistance Program (TAP). Qualifying companies are eligible to receive a set quantity of labor associated with specific technical assistance. Having applied for a TAP agreement to assist with fatigue characterization of Abrasive Water Jet (AWJ) cut titanium specimens, the OMAX Corporation was awarded TAP agreement 09-02. This program was specified to cover dynamic testing and analysis of fatigue specimens cut from titanium alloy Ti-6%Al-4%V via AWJ technologies. In association with the TAP agreement, a best effort agreement was made to characterize fatigue specimens based on test conditions supplied by OMAX.
Date: June 8, 2009
Creator: Hovanski, Yuri; Dahl, Michael E. & Williford, Ralph E.
Partner: UNT Libraries Government Documents Department
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Titanium Boride Formation and Its Subsequent Influence on Morphology and Crystallography of Alpha Precipitates in Titanium Alloys

Description: Over the last two decades there has been an increased interest in understanding the influence of trace boron additions in Ti alloys. These additions refine the prior β grain size in as-cast Ti alloys along with increasing their modulus and yield strength due to the precipitation of TiB. TiB also acts as a heterogeneous nucleation site for α precipitation and has been shown to influence the α phase morphology. B is completely soluble in liquid Ti but has a negligible solubility in both body centered cubic β and hexagonal close packed α phases of Ti. Thus, during solidification of hypoeutectic B containing alloys, B is rejected from β into the liquid where it reacts with Ti to form pristine single crystal whiskers of TiB. Despite a substantial amount of reported experimental work on the characterization of TiB precipitates, its formation mechanism and influence on α phase precipitation are still not clear. The current work is divided into two parts – (i) understanding the mechanism of TiB formation using first principles based density functional theory (DFT) calculations and (ii) elucidating how TiB influences the α phase morphology and crystallography in titanium alloys using electron microscopy techniques. TiB exhibits anisotropic growth morphology with [010] direction as its predominant growth direction and displays a hexagonal cross section with (100), (101), and (10) as the bounding planes. A high density of stacking faults has been experimentally observed on the (100) plane. The present study, by using DFT based nudged elastic band (NEB) calculations, elucidates for the first time that the diffusion of B through TiB is via an interstitial-assisted mechanism as opposed to vacancy-assisted mechanism hypothesized in literature. This one dimensional interstitial-assisted diffusion results in the anisotropic growth of TiB. In addition, the energetics of TiB- α interfaces was calculated to understand the hexagonal …
Date: December 2013
Creator: Nandwana, Peeyush
Partner: UNT Libraries
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Compressive Properties of Titanium Sheet at Elevated Temperatures

Description: "Results are presented of compressive stress-strain tests of titanium sheet at temperatures from room temperature up to 800 degrees Fahrenheit, exposure times of 1/2 to 2 hours, and strain rates of 0.002 to 0.006 per minute. The results show that titanium has favorable compressive properties, comparable to those in tension, up through 800 degrees Fahrenheit. Marked anisotropy in compression was also noted" (p. 1).
Date: February 1950
Creator: Barrett, Paul F.
Partner: UNT Libraries Government Documents Department
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The Polarographic Determination of Titanium in Plutonium Solutions

Description: A polarographic method for the determination of titanium in the presence of plutonium has been devised. Hydrochloric acid solutions of plutonium and titanium are reduced with zinc, made one molar in tartaric acid, and further reduced in the polarographic cell with liquid zine amalgam. Plutonium is thus reduced to the non-interfering (III) oxidation state and a well defined anodic wave for the oxidation of titanium (III) to titanium (IV) is obtained. The height of this wave is directly proportional to the titanium concentration for plutonium-titanium solutions containing 20 grams plutonium per liter. The precision for the analyses of duplicate samples has been calculated at the 95 percent confidence level to be 2.9 percent for those containing 0.025 to 0.050 gm titanium per liter and 1.1 percent for those containing 0.089 to 0.51 gm titanium per liter.
Date: December 20, 1951
Creator: Smith, Maynard E. (Maynard Elliott)
Partner: UNT Libraries Government Documents Department
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RESUME OF INFORMATION ON HYDROGEN IN TITANIUM ALLOYS AND ITS IMPLICATIONS TO HRP

Description: A summary is presented of available information on the nature of H embrittlement in Ti, its control, and effects on other Ti properties. Most data also apply to Zr. Types of embrittlement are discussed, along with H sources and effects on mechanical properties. Also, the effects of H on forming heat treatment, and joining are discussed as well as Ti production and processing and methods of H removal. Finally, H in-service pickup is considered, and methods for establishing the extent of this reaction are discussed. (J.R.D.)
Date: February 12, 1958
Creator: Hammond, J.P.
Partner: UNT Libraries Government Documents Department
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Special Developments Project Progress Report 2: February 1, 1954 to November 1, 1954

Description: Abstract: Further work has been done towards developing a high-output hydrogen ion source using the principle of the Ti ion source, the release of ions from hydrogenated titanium. It is concluded that previous efforts had resulted in the production of large quantities of low-energy ions but had failed in the attempt to accelerate a significant fraction of these. A new approach is undertaken that involves an entirely different geometry. Successfully accelerated and focused beams are obtained. Performance data and mass-analysis distributions are given. The problems of extraction and scaling are discussed. Future subjects of investigation are outlined.
Date: November 1954
Creator: Ruby, Lawrence
Partner: UNT Libraries Government Documents Department
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Passive films and blistering of titanium

Description: Coupons of titanium alloys under consideration as components of the Engineered Barrier System in the proposed repository at Yucca Mountain have been evaluated for their passive film composition and stability. Oxide depths and compositions on specimens exposed in long-term corrosion testing for one year were determined with x-ray photoemission spectroscopy. The specimens removed from long-term testing, as well as separate coupons polarized cathodically in an electrochemical cell, exhibited blistering associated with hydride formation in both scanning electron microscopy and atomic force microscopy.
Date: December 1, 1998
Creator: Bedrossian, P. J.; Estill, J. C.; Farmer, J. C.; McCright, R. D. & Phinney, D. L.
Partner: UNT Libraries Government Documents Department
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Swelling and Structure of Vanadium-Base Alloys Irradiated in the Dynamic Helium Charging Experiment

Description: Combined effects of dynamically charged helium and neutron damage on density change, void distribution, and microstructural evolution of V-4Cr-4Ti alloy have been determined after irradiation to 18--31 dpa at 425--600 C in the Dynamic Helium Charging Experiment (DHCE), and the results were compared with those from a non-DHCE in which helium generation and negligible. For specimens irradiated to {approx}18-31 dpa at 500--600 with a helium generation rate of 0.4--4.2 appm He/dpa, only a few helium bubbles were observed at the interface of grain matrices and some of the Ti(O,N,C) precipitates, and no microvoids or helium bubbles were observed either in grain matrices or near grain boundaries. Under these conditions, dynamically produced helium atoms seem to be trapped in the grain matrix without significant bubble nucleation or growth, and in accordance with this, density changes from DHCE and non-DHCE (negligible helium generation) were similar for comparable fluence and irradiation temperature. Only for specimens irradiated to {approx}31 dpa at 425 C, when helium was generated at a rage of 0.4--0.8 appm helium/dpa, were diffuse helium bubbles observed in limited regions of grain matrices and near {approx}15% of the grain boundaries in densities significantly lower than those in the extensive coalescences of helium bubbles typical of other alloys irradiated in tritium-trick experiments. Density changes of specimens irradiated at 425 C in the DHCE were significantly higher than those from non-DHCE irradiation. Microstructural evolution in V-4Cr-4Ti was similar for DHCE and non-DHCE except for helium bubble number density and distribution. As in non-DHCE, the irradiation-induced precipitation of ultrafine Ti{sub 5}Si{sub 3} was observed for DHCE at >500 C but not at 425 C.
Date: August 1994
Creator: Chung, H. M.; Loomis, B. A. & Smith, D. L.
Partner: UNT Libraries Government Documents Department
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Titanium Minerals in the Heavy Sand Deposits of Assateague Island, Maryland

Description: Report issued by the Bureau of Mines over titanium deposits of Assateague Island, Maryland. As stated in the introduction, "the purpose of this project was to study a typical coastal deposit of beach sands in the Middle Atlantic States, particularly in the area surrounding the Delmarva Peninsula" (p. 1). This report includes tables, maps, and illustrations.
Date: 1959
Creator: Kuster, W. V.
Partner: UNT Libraries Government Documents Department
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Thermochemistry of gas-phase species relevant to titanium nitride CVD

Description: In this work, three different ab initio methods are used to predict bond dissociation enthalpies (BDE) and atomization energies for TiCl{sub n} (n = 1-4) and Ti(NH{sub 2})n (n = 1-4) compounds, as well as for the complex TiCl{sub 4}:NH{sub 3}. There is considerable variation in the predicted BDES, even for highly electron-correlated methods. However, bond-additivity corrections applied to coupled-cluster calculations at the CCSD(T) level, expected to be the most reliable of the three methods, yield Ti-Cl BDEs in good agreement with experimental results. An experimental estimate of the TiCl{sub 4} BDE is also reported that is consistent with the ab initio results and recent experiments by others indicating that the TiCl{sub 3} heat of formation reported in the JANAF Tables is too low. Finally, the predicted BDEs indicate that the gas-phase reaction of TiCl{sub 4} and NH{sub 3} to form the complex Cl{sub 4}Ti:NH{sub 3} is exothermic by 17 kcal mol{sub {minus}1}. In addition, decomposition of the complex to form Cl{sub 3}TiNH{sub 2} and HCl is endothermic by 20 kcal mol{sup {minus}1}.
Date: June 1, 1995
Creator: Allendorf, M. D.; Janssen, C. L.; Colvin, M. E.; Melius, C. F.; Nielsen, I. M. B.; Osterheld, T. H. et al.
Partner: UNT Libraries Government Documents Department
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Advanced titanium processing

Description: The Albany Research Center of the U.S. Department of Energy has been investigating a means to form useful wrought products by direct and continuous casting of titanium bars using cold-wall induction melting rather than current batch practices such as vacuum arc remelting. Continuous ingots produced by cold-wall induction melting, utilizing a bottomless water-cooled copper crucible, without slag (CaF2) additions had minor defects in the surface such as ''hot tears''. Slag additions as low as 0.5 weight percent were used to improve the surface finish. Therefore, a slag melted experimental Ti-6Al-4V alloy ingot was compared to a commercial Ti-6Al-4V alloy ingot in the areas of physical, chemical, mechanical, and corrosion attributes to address the question, ''Are any detrimental effects caused by slag addition''?
Date: January 1, 2001
Creator: Hartman, Alan D.; Gerdemann, Stephen J.; Schrems, Karol K.; Holcomb, Gordon R.; Argetsinger, Edward R.; Hansen, Jeffrey S. et al.
Partner: UNT Libraries Government Documents Department
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Scaling up the 454 Titanium Library Construction and Pooling of Barcoded Libraries

Description: We have been developing a high throughput 454 library construction process at the Joint Genome Institute to meet the needs of de novo sequencing a large number of microbial and eukaryote genomes, EST, and metagenome projects. We have been focusing efforts in three areas: (1) modifying the current process to allow the construction of 454 standard libraries on a 96-well format; (2) developing a robotic platform to perform the 454 library construction; and (3) designing molecular barcodes to allow pooling and sorting of many different samples. In the development of a high throughput process to scale up the number of libraries by adapting the process to a 96-well plate format, the key process change involves the replacement of gel electrophoresis for size selection with Solid Phase Reversible Immobilization (SPRI) beads. Although the standard deviation of the insert sizes increases, the overall quality sequence and distribution of the reads in the genome has not changed. The manual process of constructing 454 shotgun libraries on 96-well plates is a time-consuming, labor-intensive, and ergonomically hazardous process; we have been experimenting to program a BioMek robot to perform the library construction. This will not only enable library construction to be completed in a single day, but will also minimize any ergonomic risk. In addition, we have implemented a set of molecular barcodes (AKA Multiple Identifiers or MID) and a pooling process that allows us to sequence many targets simultaneously. Here we will present the testing of pooling a set of selected fosmids derived from the endomycorrhizal fungus Glomus intraradices. By combining the robotic library construction process and the use of molecular barcodes, it is now possible to sequence hundreds of fosmids that represent a minimal tiling path of this genome. Here we present the progress and the challenges of developing these scaled-up processes.
Date: March 23, 2009
Creator: Phung, Wilson; Hack, Christopher; Shapiro, Harris; Lucas, Susan & Cheng, Jan-Fang
Partner: UNT Libraries Government Documents Department
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