Showing papers on "Titanium published in 1978"

Pillared interlayered clay materials useful as catalysts and sorbents

Abstract: Stable pillared interlayered clay compositions are prepared by reacting smectite type clays with polymeric cationic hydroxy metal complexes of metals such as aluminum, zirconium, and/or titanium. These novel interlayered clay compositions which possess substantial surface area in pores of less than 30 A in diameter are used as catalysts, catalytic supports, and sorbents.

The wetting of alumina and vitreous carbon by copper-tin-titanium alloys

Abstract: The wetting behaviour of copper-rich copper-tin-titanium alloys on alumina and vitreous carbon substrates at 1050 to 1150° C has been determined using the sessile drop technique. Substantial additions of titanium induce copper to wet, but tin has no significant effect. However, the simultaneous addition of tin and titanium is markedly beneficial, particularly with vitreous carbon. Metallographic and EPMA studies showed that titanium-rich reaction products were formed at the interfaces. The wetting and reactivity data are interpreted in terms of surface enrichment of the alloys by tin and of a disproportionately greater activity of titanium in tin.

C-V characteristics of metal-titanium dioxide-silicon capacitors

Abstract: Titanium dioxide capacitors were fabricated on silicon wafers using electron-beam evaporation. The TiO2 films varied in thickness from 500 to 2000 A. Post-deposition oxidation at 1000°C in dry O2 was used to promote stoichiometric conversion of the films to the rutile phase. Capacitive densities of greater than 2 pf/sq. mil were obtained (dielectric constants ranged from 4 to 40). For long oxidation times, significant silicon dioxide grows under the TiO2 as a result of oxygen diffusing through the TiO2 film. Titanium was also shown to diffuse into the silicon during the oxidation cycle resulting in an n-type diffusion. Surface state densities ranging from 1011 to 5 × 1011 cm−2 eV−1 at midgap were obtained for good devices. Longer oxidation times result in lower capacitance, leakage current and surface state density.

Effects of compositional variation on absorption spectra of lunar pyroxenes

Abstract: Polarized absorption spectra of lunar pyroxenes with a range of iron, calcium, magnesium, titanium and chromium contents were measured on polished, oriented single crystals; spectral data on pure synthetic FeSiO3 were also recorded. The bands at 1 and 2 microns were found to vary significantly in position with composition within the pyroxene quadrilateral; wavelengths increased with increasing calcium and iron. In the visible region, a weak band at 640 nm correlates in intensity with Cr2O3, but not with titanium as had been previously suggested. The 505-nm ferrous iron peak is a sharp doublet in most low-calcium pyroxenes but a singlet in augites. A peak at 475 nm and an intense absorption edge below 700 nm correlated with titanium content.

A study on titanium diffusion into LiNbO3 waveguides by electron probe analysis and X-ray diffraction methods

Abstract: The diffusion of titanium into lithium niobate has been studied by X-ray rocking curve and topographic methods as well as electron probe microanalysis in an attempt to determine the diffusion mechanism and evaluate the crystallinity of the diffused layer. It was found that the titanium concentration along the depth in the diffused layer approximates to a Gaussian distribution, the activation energy for diffusion being 2.18 eV. We also found that the diffusion of titanium caused a marked lattice contraction along the a-axis (Δa/a ≈ −10−3) resulting in the generation of misfit dislocations and cracks in the diffused layer. The high activation energy and the lattice contraction suggest that the titanium ions diffuse substitutionally into the lithium niobate crystal. Mechanisms causing refractive index changes in the diffused layer are also discussed.

Temperature programmed desorption study of water adsorbed on metal oxides. I. Anatase and rutile.

Abstract: The adsorbed state of water on TiO2 was studied by temperature programmed desorption (TPD) in the range 0–1000 °C. Pure anatase and rutile samples, the TPD spectra of water from which were not affected by any contaminant, could be obtained by the hydrolysis of titanium oxalate and tetrachloride solutions, respectively. Two desorption peaks were observed for anatase with the peak maxima at 69–127 (I) and 191–256 °C (II), and three for rutile at 32–90 (I), 188–265 (II), and 310–356 °C (III). The sum of adsorbed amounts for peaks II, and III are within a monolayer coverage, that of peak I exceeding it. The enthalpies of adsorption were evaluated to be 36 and 55–69kJ·mol−1 for peaks I and II of anatase, and 36, 64, and 104 kj·mol−1 for peaks I, II, and III of rutile, respectively. From these results, the corresponding adsorbed species of peak I was tentatively assigned to physical adsorption, that of peak II to chemisorption on surface oxygen ion by hydrogen bond, and that of peak III to chemisortpion on Ti4+...

Microstructural investigations on mixed RuO2-TiO2 coatings

Abstract: Mixed oxide coatings consisting of varying proportions of RuO2 and TiO2 have been prepared on titanium and silica substrates. Development of the microstructure was examined by X-ray diffraction and also monitored by resistivity measurements. The X-ray results suggest that the mixed oxide coatings prepared at 400° C are best described as a metastable solid solution of the two components. The resistivity-composition relationship however is more indicative of a finely interdispersed mixture of conducting and insulating particles. Coatings fired at higher temperatures (700–800° C) exhibit separate X-ray diffraction peaks corresponding to almost pure RuO2 and TiO2 phases with no evidence of significant solid solubility.

Process for the polymerisation of alpha-olefins and method for preparing solid catalytic complexes for use in this polymerisation process

Abstract: not available for EP0000007Abstract of corresponding document: US4617360Catalyst systems for the polymerization of alpha -olefins, as well as process for making and using the same, which comprises an organometallic compound, like an organoaluminum compound, and a solid catalyst complex formed by reacting together at least one compound selected from organic oxygen-containing and halogen-containing compounds of each of the metals of magnesium and titanium and at least one aluminum halide selected from organoaluminum chlorides of formula AlRnCl3-n wherein R is an alkyl radical featuring at least 4 carbon atoms and 1

Reversible Optical Changes Within Anodic Oxide Films on Titanium and Niobium

Abstract: During passage of cathodic current, large and reversible changes in ellipsometric parameters are interpreted in terms of changes in absorption and/or refractive index of surface anodic oxide films on Nb and Ti without significant change in thickness A model based on dissolution and ionization of deposited hydrogen satisfactorily accounts for the slow reversible change in the optical absorption of films on Nb and for the impedance changes previously reported More rapidly reversible changes in both absorption and refractive index occur in films on Ti The decrease in refractive index is consistent with the reversible formation of TiOOH at negative potentials 11 figures, 2 tables

The Oxygen Electrode Reaction in Alkaline Solutions on Oxide Electrodes Prepared by the Thermal Decomposition Method

Abstract: The irreversibility of the oxygen electrode reaction is the main cause of efficiency losses in water electrolysis cells, fuel cells, and some battery systems. At conditions typical for water electrolysis, the effectiveness of various metal oxide electrodes toward oxygen evolution decreased in the order. Poor activities were observed on V, Cr, Mo, W, Mn, and Re oxide electrodes. When mixed with 70 mole percent (m/o) , all metal oxides tested except ruthenium oxide were ineffective in catalyzing the oxygen evolution reaction. A catalyst‐loading study showed that films on Ti require about to mask the effect of the titanium substrate. Either a chemical step or a second electron transfer step appears to be rate determining for the oxygen evolution reaction on oxide electrodes with good electrocatalytic properties. Studies of the oxygen reduction reaction indicate that the activity of oxide electrodes in the cathodic direction is considerably less than in the anodic direction.

High efficiency catalyst for polymerizing olefins

Abstract: Compositions exhibiting high catalytic activity in the polymerization of α-olefins are prepared by reacting a mixture of a tetrahydrocarbyloxy titanium compound such as tetraisopropyl titanate and/or a titanium tetrahalide such as titanium tetrachloride and a titaniumoxydihalide such as titaniumoxydichloride, an organomagnesium component such as a hydrocarbon soluble complex of dialkyl magnesium and an organoaluminum compound such as triethyl aluminum and a halide source such as ethyl aluminum dichloride. Polymerization processes employing this catalyst composition do not require conventional catalyst removal steps in order to provide polymers having suitable color and other physical characteristics and these catalysts provide higher efficiencies and a broader molecular weight distribution than those catalysts employing either of the titanium compounds alone.

Method of recycling aluminum scrap into sheet material for aluminum containers

Abstract: A composition and method whereby aluminum scrap, including consumer scrap, is recycled into aluminum sheet and aluminum containers. Aluminum scrap is melted in a heated furnace to form a melt composition. The melt is adjusted to form the present composition, consisting essentially of silicon, 0.1-1.0%; iron 0.1-0.9%; manganese 0.4-1.0%; magnesium 1.3-2.5%; copper 0.05-0.4%; and titanium, 0-0.2%, the balance being essentially aluminum. Aluminum scrap comprising consumer scrap, plant scrap, and can making scrap is heated to form the melt composition, which requires a minimum amount of adjustment to arrive at the present alloy composition. The composition is then cast and fabricated into sheet having strength and formability properties making it suitable for container manufacture. Container manufacture according to the process and composition of the present invention comprises drawn-and-ironed can body manufacture and easy-opening end manufacture. Sheet fabrication according to the present invention comprises direct chill casting, scalping, preheating, hot breakdown rolling, continuous hot rolling, annealing, cold rolling and shearing. Sheet manufacture may also comprise continuous strip casting and solution heat treatment.

Electropolishing of Titanium in Perchloric Acid‐Acetic Acid Solution: I . Auger Electron Spectroscopy Study of Anodic Films

Abstract: Anodic films on titanium formed in a perchloric acid‐acetic acid electropolishing electrolyte were investigated by Auger electron spectroscopy (AES) depth profile analysis. Films formed in at different potentials were used as standards for determining sputter rate and stoichiometry. Obtained results show linear film growth to occur up to the onset of electropolishing when film thickness abruptly decreases and becomes independent of potential. The electropolishing film observed by AES contains chloride ions, the concentration of which exhibits a maximum at the metal‐film interface.

Nitrogen fixation via photoenhanced reduction on p-GaP electrodes

Abstract: A system is reported here which produces nitrogen fixation at room temperature and atmospheric pressure by a photoenhanced reduction process. The system is a photoelectrochemical cell which contains a p-GaP electrode cathode and an aluminum metal anode immersed in a nonaqueous electrolyte of titanium tetraisopropoxide and aluminum chloride dissolved in glyme. When nitrogen is passed through the electrolyte and the p-GaP electrode is illuminated with band-gap light, the nitrogen is reduced and is recovered as ammonia; aluminum is consumed in the process and acts as the reducing agent. The activation energy for the process is provided by light absorbed in the p-GaP electrode; hence, this system is an example of photocatalysis in a photoelectrochemical cell. The cell has been successfully operated in both flow and static modes. It is postulated that the aluminum anode undergoes a direct redox reaction with the electrolyte in addition to the redox reaction which is coupled to the p-GaP cathode. It is believed that the direct redox reaction of the aluminum anode is with titanium(IV) isopropoxide to produce aluminum(III) isopropoxide and titanium(III) and/or titanium(II) isopropoxide. The authors note that the significance of this work is not that nitrogen can be fixed by reducing metals andmore » metal complexes, but that interesting photocatalytic effects can be achieved on semiconducting electrodes, and that these effects appear to involve hot carrier injection processes. 1 figure.« less

Coated cemented carbide body and method of making such a body

Abstract: COATED CEMENTED CARBIDE BODY AND METHOD OF MAKING SUCH A BODY Abstract of the Disclosure There is disclosed a sintered cemented carbide body containing at least one carbide besides binder metal, on which body there is applied at least one thin, wear resistant surface layer essentially consisting of aluminium oxide. The aluminium oxide to at least 85% consists of the kappa modification, the remainder, which mainly constitutes the alpha modification, being formed as surface portions or spots having a size of at the most 10 µm, the relationship between the size and the occurrence of the alpha form aluminium oxide spots being within the area AOBC in Fig. 1 of the attached drawing. The body is made by a method wherein a cemented carbide substrate is contacted with a gas containing an aluminium halide and a re-ducing agent at high temperature, characterized in that a dopant addition of tetravalent titanium, zirconium and/or hafnium ions is added to the gas in an amount of 0.03 to 0.5% of the totally supplied amount of gas.

Ornamental part for watches and method of producing the same

Abstract: An ornamental part for watches such as a watch case having a composite coating layer consisting essentially of titanium and titanium nitride, the ratio of the two components being varied in the direction of the thickness of the layer. The composite coating may be formed by the physical vapor deposition method in which the titanium in the vapor phase is reacted with nitrogen under a glow-discharge condition. The coating thus formed has a gold color and excellent physical and chemical properties.

Structure and Electrical Properties of Titanium Nitride Films

Abstract: Metallic titanium, in nitrogen atmosphere with specified pressures (pN) ranging from 10-6 to 10-4 Torr, was evaporated on glass substrates heated at temperatures (Ts) between 300 to 500°C. X-ray analysis revealed that the films were composed of α-titanium, distorted titanium phase, amorphous phase, and TiN. The distorted titanium phase was found to extend to a high concentration of nitrogen (x=0.5). In particular, the specimens evaporated at pN=2.0×10-5 Torr and Ts=500°C had maximum resistivity of 270 µΩ-cm and a very small negative value of the temperature coefficient of resistance (0 to -20 ppm/°C) for an extended range of temperatures (-190 to 200°C). The excess resistivity of the distorted titanium phase can be mainly interpreted in terms of two kinds of carrier scattering, one due to nitrogen atoms randomly distributed at vacant interstitials, another attributable to grain boundaries involved.

Transparent, electrically conductive laminated structure and process for production thereof

Abstract: OF THE DISCLOSURE The invention provides a transparent, electrically conductive laminated structure composed of (A) a transparent solid substrate of a film-forming synthetic resin layer, (B) a thin layer of an oxide of titanium, derived from a layer of an organic titanium compound and containing organic residual moieties of the said organic titanium compound in contact with the said substrate (A), (C) a thin layer of an electrically conductive metal in contact with the said layer (B), (D) a thin layer of an oxide of titanium in contact with the said layer (C), and (E) a transparent top layer in contact with the said layer (D). The structure displays good optical transparency and electrical conductivity and is useful, for instance, in solar energy collectors, greenhouses, windows of buildings and the like.

Olefine polymerization process

Abstract: A titanium trihalide is ground with an organic Lewis Base compound which contains at least one phosphorus atom, and optionally at least one nitrogen atom, and a titanium tetrahalide, the Lewis Base and the titanium tetrahalide being used in amounts of 5 to 75, preferably 5 to 50%, molar and 1 to 50, preferably 5 to 30% molar respectively relative to the titanium trihalide. The materials are conveniently milled together and the milled product can be used as a component of an olefine polymerization catalyst and when such catalysts are used to polymerize propylene a high activity is achieved together with satisfactory stereospecificity.

Catalyst for preparing polyalkenes

Abstract: An improved process for polymerizing α-alkenes and using Ziegler-type catalyst compositions is described. The Ziegler-type catalyst composition comprises a component consisting of an organoaluminum compound, an organomagnesium compound and a titanium compound or their reaction products on an inorganic porous solid particulate carrier material, wherein the aluminum/magnesium/titanium components are distributed and absorbed onto the inorganic carrier material, in separate steps, with removal of solvent or diluent therein between whereby the final catalyst/carrier composition when used in the polymerization process produces solid particulate polymer products with narrow particle size distributions.