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Corrosion Properties of Titanium and its Alloys

Description: From Introduction: "The objective in preparing this Bulletin is to collect as much as possible of the published corrosion data on titanium and its alloys in aqueous and organic solutions, to correlate and summarize it, and to present it in convenient form."
Date: unknown
Creator: Schlain, David
Partner: UNT Libraries Government Documents Department

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

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

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

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

Electrochemical Reduction of Titanium in Nonaqueous Solvents

Description: Abstract: Electrorefining of Ti in nonaqueous solvents has been studied by the U.S. Bureau of Mines as a method for recycling impure scrap Ti. Electrochemical behavior of Ti species was investigated using cyclic voltammetry. Research results showed that Ti metal can be dissolved in polar solvents such as dimethylformamide or dimethyl sulfoxide. However, deposition of Ti from these solvents was not successful. Several solvent systems were investigated for electrodepos.tion of Ti but no deposits were obtained. Reduction of Ti' complexes to Ti" proved to be straightforward, but reduction to lower oxidation states could not be confirmed. In dimethylformamide solutions, cyclic voltammetry results demonstrated the reduction of Ti to an oxidation state of less than three, but no Ti metal was identified. In dimethyl sulfoxide solutions containing LiCl, it was possible to deposit Li metal. After adding Ti salts to the solution, electrolysis quickly passivated the electrode. Deposition of Ti was also investigated in solutions of dimethoxyethane and propylene carbonate but, again, no reduction of Ti to oxidation states of less than three occurred. Therefore, the prospects for a nonaqueous electrorefining system for Ti metal do not appear promising.
Date: 1995
Creator: Sibrell, P. L.
Partner: UNT Libraries Government Documents Department

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

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

Oxidation behavior and microstructural decomposition of Ti-6Al-4V and Ti-6Al-4V-1B sheet

Description: This article conducts a direct comparison between the oxidation behavior of Ti-6Al-4V and Ti-6Al-4V + 1B to elucidate whether the addition of boron to Ti-^Al-4V impacts the oxidation behavior.
Date: August 1, 2016
Creator: Brice, David. A.; Samimi, P.; Ghamarian, I.; Liu, Yue; Brice, R. M.; Reidy, Richard F. et al.
Partner: UNT College of Engineering

Phototoxic Effects of Titanium Dioxide Nanoparticles on Daphnia Magna

Description: Titanium dioxide nanoparticles (TiO2-NP) are one of the most abundantly utilized nanomaterials in the world. Studies have demonstrated the mechanism of acute toxicity in TiO2-NP to be the production of reactive oxygen species (ROS) leading to oxidative stress and mortality in exposed organisms. It has also been demonstrated that the anatase crystalline conformation is capable of catalyzing the cleavage of water molecules to further increase the concentration of ROS in the presence of ultraviolet radiation. This photoenhanced toxicity significantly lowers the toxicity threshold of TiO2-NP to environmentally relevant concentrations (ppb). The goal of this study was to determine whether dietary uptake and accumulation of TiO2-NP in the aquatic filter feeder Daphnia magna resulted in photoenhanced toxicity. D. magna and S. caprincornatum were exposed to aqueous solutions of 20ppm and 200ppm TiO2-NP for 24hrs and then transferred to clean moderately hard water. Samples were taken at various time points, dried, and TiO2 quantified using ICP-MS. Toxicity assays were run on D. magna using three TiO2-NP (20ppm, 200ppm) exposure protocols and two ultraviolet radiation treatments. The first exposure group was exposed to aqueous solutions of TiO2-NP for the duration of the test. The second exposure group was exposed to TiO2-NP for an hour and then transferred to clean water. The third exposure group was fed S. capricornatum that had been allowed to adsorb TiO2-NP. All samples were then placed in an outdoor UV exposure system and exposed to either full spectrum sunlight (with UV) or filtered sunlight (no UV). Here we show that TiO2 uptake peaked at one hour of exposure likely due to sedimentation of the particles out of suspension, thus decreasing bioavailability for the duration of the test. Interetsingly, when D. magna were moved to clean water, aqueous concentrations of TiO2 increase as a result of depuration from the gut ...
Date: December 2013
Creator: Mansfield, Charles M.
Partner: UNT Libraries

The Uranium-Titanium Alloy System

Description: Abstract: "A uranium-titanium constitution diagram is presented. There is complete solid solubility between titanium and gamma uranium above about 2100 F. Only one compound exists in the system. It has a hexagonal structure based on U2Ti. It has a fairly wide range of stability, particularly on the titanium side. Beta-titanium solid solution decomposes eutectoidally into alpha titanium and compound at 1150 F. Eutectoid composition is about 72 atomic per cent titanium. Gamma-uranium solid solution decomposes eutectoidally at 1325 F into beta uranium and compound. Eutectoid composition is about 6 atomic per cent titanium. Beta uranium and compound react peritectoidally at 1233 F to give alpha uranium. Solubility of titanium in alpha and beta uranium is low as is the solubility or uranium in alpha titanium."
Date: November 5, 1952
Creator: Udy, Murray C. & Boulger, Francis W.
Partner: UNT Libraries Government Documents Department

Preparation, Cladding, and Evaluation of Titanium-boron Dispersions

Description: This report discusses tests on the preparation and cladding of hot-pressed and pressure-bonded titanium-boron. It explores the properties of titanium-boron as a control material in reactors.
Date: June 9, 1957
Creator: Paprocki, Stan J.; Keller, Donald L.; Hodge, Edwin S.; Cunningham, George W.; Gedwill, Michael A. & Lozier, Donald E.
Partner: UNT Libraries Government Documents Department

Further investigation of the feasibility of the freeze-casting method for forming full-size infiltrated titanium carbide turbine blades

Description: Report presenting an investigation of a method of casting full-size cermet turbine blades from titanium carbide. An extremely thick piece of titanium carbide was prepared with a small amount of binder, cast into a mold by vibration, centrifuged, and frozen to retain the shape of the mold. Densities and radiographs of the blade prior to infiltration were used as criteria for soundness.
Date: October 1956
Creator: Grala, E. M.
Partner: UNT Libraries Government Documents Department

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

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

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

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

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