Showing papers on "Titanium published in 1969"

The formation of omega phase in titanium and zirconium alloys: A review

Abstract: The omega phase is a metastable phase which forms in alloys of titanium and zirconium with most transition metals. In this paper the available data from both alloy systems on the occurrence, the structure, the mechanism of formation, and the morphology of the phase are reviewed and compared. The effect of omega phase on the mechanical behaviour and on the superconducting properties is then discussed. It is concluded that uncertainties still exist on the mechanism of the omega transformation during quenching and on the mechanism of the effect of omega on the mechanical properties.

Preparation of High-Purity Submicron Barium Titanate Powders

Abstract: Simultaneous hydrolytic decomposition of barium bis isopropoxide and titanium tetrakis tertiary amyloxide was used to produce stoichiometric BaTiO3. The particle size range was 50 to 150 A. The purity was 99.98+%, the major contaminant being silicon from the glass apparatus. The homogeneity and stoichiometry of the powder were demonstrated by electron microscopy and wet chemical analysis. X-ray and infrared analyses indicate that the material, as-prepared and helium-dried at 5O°C, has the titanate crystal structure. The powder sinters at 1300°C to a high density, translucent body with a uniform microstructure. The experiments suggest that the alkoxy-based preparation of oxides may provide a broad base for improving the quality and reproducibility of electrical and structural ceramics.

Implants of titanium or a titanium alloy for the surgical treatment of bones

Abstract: A titanium or titanium implant with the novel feature of the surface layer formed as an oxide, nitride, carbide and carbonitride. The surface layer is applied to prevent abrasion and corrosion of the implant and to prevent fretting between contacting implants as well as to improve the appearance thereof.

Electrodes for electrochemical processes

Abstract: A method for the manufacture of an electrode for use in electrochemical processes, which comprises forming on the surface of a support of film-forming metal of the group of titanium, zirconium, niobium, tantalum and tungsten or an alloy principally of one of these metals, a layer of an operative electrode material, applying over the said layer a coating comprising a thermally decomposable organo-compound of a film-forming metal of the group of alkoxides and alkoxy-halides of titanium, zirconium, niobium, tantalum and tungsten wherein the halogen is chlorine, bromine or fluorine in a liquid vehicle and heating the coating to convert the organo-compound of the film-forming metal to an oxide.

Metallo-organic compounds containing metal–nitrogen bonds. Part VI. Infrared and nuclear magnetic resonance of dialkylamidoderivatives of titanium, vanadium, zirconium, niobium, hafnium, tantalum, and thorium

Abstract: I.r. and n.m.r. spectra have been measured on solutions of a number of dialkylamido-compounds M(NR2)x of titanium, vanadium, zirconium, niobium, hafnium, tantalum, and thorium and on the alkylimido-trisdialkylamidotantalums RNTa(NR2)3. Assignments of characteristic bands are made and the metal–nitrogen stretching frequencies are discussed in terms of a significant contribution of nitrogen → metal pπ–dπ bonding. The variable temperature n.m.r. studies on Zr(NMe2)4 confirmed the presence of polymeric species in solution.

Metallic and non-metallic behaviour in compounds of transition metals

Abstract: The condition for metallic or non-metallic behaviour in compounds of transition metals is examined, with particular reference to titanates, vanadium and titanium oxides, and to Fe3O4

Crystallography and defect chemistry of solid solutions of vanadium and titanium oxides.

Abstract: Ti and V sesquioxides and TiO-VO solid solutions crystallography and defect chemistry over entire range of compositions

Wetting of Binary Aluminum Alloys in Contact with Be, B4C, and Graphite

Abstract: Sessile drop contact angles between liquid aluminum alloys and solid beryllium, boron carbide, and graphite were measured to 840°C under vacuum and in helium. Little wetting occurred between most of the combinations, but at 20% magnesium the contact angle on beryllium decreased to 68°. Low contact angles were noted for the binary aluminum alloys on graphite coated with titanium.

Epitaxial Growth of Titanium Thin Films

Abstract: Single crystal thin films of titanium have been epitaxially grown on NaCl substrates of three different orientations [(001), (110), (111)]. At thicknesses above 500 A, the normal hexagonal close-packed structure is obtained. Below approximately 350 A, the metal is seen to grow in a previously unreported face-centered cubic structure with the lattice parameter, ao = 4.33 A. This structure is thought to result from pseudomorphic type growth on the NaCl substrate in keeping with proposed misfit theories. At a critical thickness (∼200–300 A), there is a transformation from the fcc phase to the normal hcp phase in deposits on the (001) and (111) substrate surfaces. The deposit on the (110) NaCl surface demonstrated a coexistence of fcc and hcp material at all thicknesses.

Liquidus Curves and Corrosion of Fe, Ti, Zr, and Cu in Liquid Bi-Pb Alloys

Abstract: Liquidus curves were measured of Fe in Pb, Fe in Pb-Bi alloys ranging from 39.3 to 93.5% Bi, Cu in Pb-Bi alloys around the eutectic composition, and Ti and Zr in Pb-Bi alloys of approximat...

Transparent conductive coating and process therefor

Abstract: THE TRANSPARENT ELECTRICALLY-CONDUCTIVE COATING IS A COMPOSITE LAYER COMPRISING A FIRST LAYER DEPOSITED AS TITANIUM MONOXIDE, A SECOND LAYER OF NOBLE METAL AND A THIRD LAYER DEPOSITED AS TITANIUM MONOXIDE, ON A TRANSPARENT SUBSTRATE. EACH OF THE LAYERS IS SUFFICIENTLY THIN TO HAVE A SUBSTANTIAL TRANSMISSIVITY TO OPTICAL RADIATION. THE PROCESS COMPRISES SUCCESSIVE IN-VACUO DEPOSITIONS OF THE LAYERS. THE LAYERS PROVIDE A CONDUCTIVE COATING ON GLASS OR FLEXIBLE POLYMER COMPOSITION SUBSTRATE WHICH IS HIGHLY TRANSPARENT IN THE VISIBLE, ULTRAVIOLET AND INFRARED SPECTRUM.

Induction melting of metals in cold, self-lined crucibles

Abstract: Metals such as titanium and zirconium are melted and formed by induction heating within a cold segmented metal crucible having a self-generating and self-renewing insulating lining.

Thermal expansivities, thermal conductivities, and densities of vanadium, titanium, chromium and some vanadium-base alloys: A comparison with austenitic stainless steel

Abstract: Computer-fitted polynomial expressions are presented that define the linear thermal-expansion behavior of vanadium, titanium, chromium, certain VTi and VTiCr alloys, and AISI Types 304 and 316 stainless steels between 0 ° and 1000 °C. The mean expansion coefficients for the vanadium-base alloys differ only slightly from those for unalloyed vanadium (plus or minus 6%), and are 65% to 80% lower than the mean expansion coefficients for the austenitic stainless steels. Densities of the vanadium-base alloys and the austenitic stainless steels were determined at 25 °C by liquid displacement. The VTi alloys show a non-linear decrease in density with increasing titanium for titanium contents greater than 30 wt.%. The VTiCr alloys also exhibit a non-linear change in density for compositions containing greater than 15 wt.% titanium, and greater than 5 wt.% chromium. A comparison of the mechanical and thermal properties of two vanadium-base alloys and two austenitic stainless steels was made to determine their relative usefulness as reactor fuel jackets for service between 500 ° and 700 °C. This comparison shows that vanadium alloy fuel jackets would be subjected to only one-third the thermal stresses generated in austenitic stainless steel jackets during reactor excursions between 500 ° and 700 °C under conditions where the fuel is not in intimate contact with the jacket. This difference in thermal stresses in the two jacket materials is the result of the 37% higher tensile strength, 40% higher thermal conductivity, and 70% lower thermal expansivity exhibited by the vanadium alloys as compared with austenitic stainless steel.

Anodic Polarization of Titanium and Titanium Alloys in Hydrochloric Acid

Abstract: : Commercially pure titanium and the alloys studied exhibited active to passive transitions in HCl. Increasing the acid concentration increased the critical current for passivity and shifted the critical potential for passivity in the noble direction. Increasing the temperature served only to increase the critical current for passivity. Activation energies for the anodic polarization process were the right order of magnitude for a reaction controlled by reactivity at the metal surface. For the alpha-beta alloy 6Al-6V-2Sn the critical current for passivity increased as the ratio of amounts of beta-to-alpha phase decreased with increasing strength level. The addition of Fe(3+) and Cu(2+) (0.03 M) to the HCl facilitated passivation of the metal and its alloys. The maximum dissolution current densities for the metal and alloys in HCl were double those in H2SO4. Pitting of several of the alloys occurred in HCl but not in H2SO4. (Author)

Process for coating titanium dioxide on solid materials

Abstract: A PROCESS FOR THE PRODUCTION OF COATING BASED ON TITANIUM DIOXIDE, WHICH PROCESS COMPRISES FEEDING TWO SOLUTIONS CONCURRENTLY TO AN AQUEOUS SUSPENSION OF MATERIAL TO TO COATED HAVING A TEMPERATURE OF ABOUT 50-100*C. AND A PH BETWEEN 0.5 AND 3.5, SAID TWO SOLUTIONS BEING (A) AN AQUEOUS 0.001 TO 0.2 MOLAR SOLUTION OF A TITANIUM SALT HAVING A CONTENT IN FREE ACID CORRESPONDING TO A NORMALITY OF 0.002 TO 1.5; AND (B) AN AQUEOUS 0.025 TO 8 NORMAL ALKALI METAL BASE WITH THE PROVISION THAT THE FEEDING OF THE ALKALI METAL BASE IS MAINTAINED SO THAT IT IS JUST CAPABLE OF NEUTRALIZING THE ACID CONTAINED IN THE TITANIUM SALT SOLUTION AS WELL AS THE ACID PRODUCED DURING THE REACTION, AND THAT THE QUANTITY OF TITANIUM SALT ADDED PER MINUTE IS KEPT WITHIN THE ORDER OF MAGNITUDE OF ABOUT 0.01 TO 20X10**-5 MOLES PER SQUARE METER OF SURFACE TO BE COATED.

Hot forming of titanium and titanium alloys

Abstract: A method for bulk deformation of titanium and titanium alloys employing elevated temperatures for the billet and the dies. The method permits single step forging from a billet or preform to a final shape without the necessity of further machining.

A method for removing titanium dioxide impurities from kaolin

Abstract: The removal of titanium minerals from kaolin can be accomplished by treatment with dispersing agents in an amount in excess of that required to produce maximum deflocculation of the kaolinite particles. In this reflocculated state the kaolinite particles attain a high degree of suspensional stability, and the titanium mineral particles, primarily anatase, are liberated and can be separated by sedimentation. Substantial removal of anatase impurities can be achieved by this method.

Method and electrolytes for anodizing titanium and its alloys

Abstract: Titanium and its alloys are anodized by making the metal the anode in an electrolytic system which utilizes carbon as the cathode and an electrolyte consisting of water, both a silicate and a perborate of an alkali metal, the hydroxide of an alkali metal, and the alkali metal salt of an acid selected from the group consisting of ethylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid, and mixtures thereof. Direct current applied to the system may be varied between 10 and 50 amperes per square foot of anode surface, with EMF pressures not exceeding a rate of 8 volts per minute until the current threshold is obtained.

Process for the production of colored coatings

Abstract: A process for the production of colored surfaces on zinc, tin and lead-tin coatings by the provision of oxide films having light interference effects; zinc, tin and lead-tin alloys for use in the process; and alloy coating compositions and colored articles produced thereby. A molten alloy of zinc, tin or leadtin with a minor amount of an oxygen-avid element such as titanium, manganese or vanadium is oxidized by exposure to a free oxygen-containing gas under controlled time and temperature conditions for the provision of a surface film of an oxide of the oxygen-avid addition element having light interference color characteristics.

Effect of “Pure” Methanol on the Cracking of Titanium

Abstract: Methanol-water-chloride solutions effect on titanium alloys failure time, noting effect of changing water volume on cracking

Effect of metal–oxygen bond on the sensitivity of atomic-absorption spectroscopic technique

Abstract: Studies on sensitivity in atomic absorption spectroscopy of nickel, tin, titanium, zirconium, hafnium, niobium, and tantalum, as metallocenes and as simple salts or oxy-salts, have shown that the m...