Showing papers on "Titanium published in 1974"

Alloy for metallization and brazing of abrasive materials

Abstract: The herein-proposed alloy is characterized in that it contains apart from such known components as copper, tin, aluminium, cadmium, zinc, titanium, chromium, zirconium, manganese, molybdenum, tungsten, iron, cobalt and nickel also vanadium, niobium, tantalum and boron taken either separately or in combination, in an amount of 0.001 to 80 weight percent of the total weight of all the components thereof. The alloy is advantageous in possessing good technological characteristics, being resistant to oxidation at elevated temperatures, featuring good adhesion to all kinds of abrasive materials and giving strong brazing alloys and metallization coatings.

A combined metallurgical and histological study of tissue-prosthesis interactions in orthopedic patients.

Abstract: Metallurgical and histological examinations of implants and adjacent tissue removed from orthopedic patients have been performed in a series of 190 cases. The results have been correlated with clinical findings where possible. The two major factors to emerge from this study were that many stainless steel implants corrode in the body and that titanium implants release titanium into the local tissue, which may become discolored. Severe cases of corrosion in stainless steel implants were attributed to faulty manufacturing technique and poor implant usage. This corrosion was frequently associated with crystal-like “microplates” in the tissue and lead to clinically significant effects in some cases. Less severe cases of corrosion were almost invariably associated with interfaces between components. Susceptibility to this corrosion may be minimised by improvements in design and materials specification. Titanium levels in excess of 2,000 ppm were found in the tissue in 3 cases out of 19 analysed, no specimen of a control series showing greater than 100 ppm. Histological sections showed accumulations of intracellular particles of exogenous origin. The evidence that such titanium release and particle accumulation causes clinically significant effects is only minimal but it is possible that systemic distribution of titanium and remote hypersensitivity effects could arise.

Coated steel product and process of producing the same

Abstract: A coated steel product, namely, a cutting instrument such as a band saw blade, in which the body of the blade is of steel, the tooth tip is of impulse hardened steel and the tip is covered with a coating of titanium carbide or refractory metal carbide, the coating metal or compound having been deposited by ion plating onto the surface of the tip. The process through which the cutting tool is produced includes preshaping and sharpening the tool, then ion cleaning the tips, bombarding the tips with ions of the titanium or refractory metal followed by reacting the titanium or refractory metal with a carbon containing chemical or their carbides and then simultaneously subjecting both the coating and the steel tip to a magnetic flux for impulse hardening primarily the steel tip. Other coatings of metal carbides, nitrides, borides and metal compounds are described.

Electrical feed-through assembly suitable for electronic devices implantable in a human body

Abstract: An electrical feed-through assembly suitable for electronic devices to be implanted in a human body consisting of a titanium coupler provided with a flange into which is fitted an the alumina sleeve. A titanium coupler is fitted over the other end of alumina sleeve and compression joints are formed between the alumina sleeve and the two titanium parts. A platinum wire is sealed in the titanium coupler and extends through the sleeve and titanium coupler. A nickel coating is sputtered onto the inner surface of the titanium coupler to provide a solderable surface. The flange is used to weld the feed-through assembly onto a housing containing such an electronic device.

Communication: improvement of the natural flame-resistance of wool. part i: metal-complex applications

Abstract: Negatively charged titanium and zirconium complexes with α-hydroxy carboxylic acids and fluorides can be exhausted on the positively charged wool fibre in acid conditions, the result being a significant improvement in the natural flame-resistance of wool that is fast to washing and dry-cleaning. The complexes with carboxylic acids are exhausted on the wool fibre at the boil, whereas the fluoride complexes can be effectively exhausted at lower temperatures. The fluoride complexes can also be applied by a pad-batch-rinse-dry technique. Titanium complexes are more effective than the zirconium ones, probably because of better penetration of the fibre with the smaller titanium complexes. However, titanium complexes cause yellowing of wool, which increases with light exposure. Zirconium complexes do not affect the shade of wool and are fast to light.

Process for making linings for friction operated apparatus

Abstract: A friction lining according to the invention is formed of bounded solidified previously molten particles formed on its support by plasma deposition; the base planes 0001 of a major proportion of the crytals in said lining are oriented in directions substantially parallel to the friction surfaces; the materials of which said linings are formed contain metals, metallic oxides or carbides having high melting points; they include cobalt, magnesium, neodymium, titanium, tungsten under its hexagonal form, yttrium, nickel under its hexagonal form, MoC, Mo 2 C, NbC, Nb 2 C, Ta 2 C, WC, W 2 C, V 2 C, Cr 2 O 3 , TiO 2 ; they may contain under an alloyed form proportions of non hexagonal materials, including molybdenum, chromium, aluminum, copper, iron, the non hexagonal nickel, niobium, B 4 C, TaC, TiC, Cr 3 C 2 , VC, ZrC, ZrO 2 , Al 2 O 3 , which do not affect the hexagonal structure of the alloys obtained.

Recovery of titanium dioxide from ores

Abstract: Titanium dioxide is recovered from ilmenite in high purity and high yield. The ore is leached with concentrated hydrochloric acid at room temperature to dissolve at least 80% of the titanium and iron values of the ore and to leave gangue material substantially undissolved. After separation from solid gangue material and conversion of ferric iron to ferrous iron, the titanium chlorides are hydrolyzed and titanium oxyhydrate is precipitated. A substantial proportion of the ferrous chloride may be removed from the solution by crystallization prior to the hydrolysis of the titanium chlorides. The titanium oxyhydrate, after separation from the mother liquor, and purified, if necessary to remove traces of ferric materials, is dried and converted into substantially pure pigment grade titanium dioxide. The iron values may be recovered from the mother liquor and a closed hydrochloric acid cycle may be established.

Reactions and Kinetics of Newly Generated Titanium Surfaces and Relevance to Stress Corrosion Cracking

Abstract: Instrumentation is described for obtaining current-time curves for new metal surfaces produced by fast fracture in electrolytes under potentiostatic conditions. Measured anodic current densities for titanium specimens in acid solutions decayed about a million fold in a time of 10−4 to 103 seconds at which steady state was approached. Analysis of the experimental data indicate the actual initial current density for anodic dissolution is more than 10 A/cm2 in 3M HCl and may be orders of magnitude greater. Thus stress corrosion crack propagation by an anodic process in titanium cannot be ruled out. Formation of metal salt films would be predicted at high anodic current densities in cracks. Calculations show that formation and growth of a salt film in the tip region would give a rapidly decaying current density moving away from the tip which would keep the tip sharp. This phenomenon may be called the electrochemical knife.

Mother alloy of aluminum, titanium and boron and process for fabrication

Abstract: An aluminum-titanium-boron mother alloy having a boron content of 0.2 to 0.8% by weight and a titanium content such that Ti - 2.2 B ≧ 3.9%, in which the matrix has a preponderant proportion of grains of less than 30 microns in size, and contains fine TiB2 crystals having an average size of about 1 micron primarily dispersed along the grain boundaries, and the method for the preparation of same by the formation of titanium diboride by the action of liquid aluminum on titanium oxide and boron oxide in solution in molten cryolite, mixing the reactants in a manner to utilize the starting materials, and then quenching the formed alloy rapidly to cool and solidify the mother alloy, preferably by pouring the liquid alloy in water to produce the alloy in the form of granules or fine powder.

Production of graphite fiber reinforced metal matrix composites

Abstract: A graphite fiber reinforced metal matrix composite prepared by hot-pressing, comprising layers of a matrix metal selected from the group consisting of magnesium and magnesium based alloys; in combination with alternate layers of a graphite fiber. The improvement consists of small additions of a metal selected from the group consisting of titanium, chromium, nickel, zirconium, hafnium and silicon in order to promote wetting and bonding between the graphite fibers and the matrix metal.

Sulfidation resistant nickel-iron base alloy

Abstract: A sulfidation-resistant alloy having high stress-rupture strength at about 1350°-1500°F, containing about 0.02-0.08% carbon, 21-26% chromium, 52-58% nickel, 1-3.5% molybdenum, 1.75-3.25% titanium, 0.75- 2.25% aluminum, 0.50-2.00% columbium, up to 0.02% boron and the balance iron.

The wear resistance of pure and silicon-alloyed isotropic carbons.

Abstract: Comparative evaluations of the wear resistance of isotropic pyrolytic carbons deposited in fluidized beds (Pyrolite carbons) were carried out at room temperature in distilled water. The test procedure employed a polished, rotating disk bearing on a polished flat specimen. Couples of pure and silicon-alloyed Pyrolite carbons, glassy carbon, titanium, and Stellite 21 were studied. All combinations exhibited a time-independent volume wear rate. For a given disk the wear resistance of pure carbons increased with increasing density. A further reduction in wear rate was achieved by alloying the pyrolytic carbon with silicon. Under comparable conditions the wear resistance of glassy carbon was found to be inferior to that of either high-density, pure Pyrolite carbon or the alloyed Pyrolite carbons. Metal plates were worn by carbon at rates comparable to high-density pure and alloyed isotropic carbon plates. However, as disks bearing on carbon flats, metals caused high wear rates that decreased by increasing the ...

Effect of titanium on the ductility of 26% chromium, lovv interstitial ferritic stainless steel

Abstract: The effect of titanium additions on the ductility of a 26%Cr steel containing about 0·005%C and 0·025%N was investigated. The microstructural changes which occurred during slow cooling werefollowed by means of chemical analysis, optical microscopy, X-ray diffraction and microprobe analyses performed on specimens water quenched from various temperatures within the range 2400°–600° F (1316°–316°C). The results were correlated with changes in room-temperature tensile properties and it was found that the low ductility of coarse-grained 26%Cr territic stainless steel was caused by the formation of a grain-boundary carbide or carbonitride phase at a temperature of about 1650°F(900°C). A titanium addition of 5(C+N) improved the ductility by preventing grain-boundary precipitation. TiN formed in the molten steel and, upon solidification, the random distribution of TiN particles served as nuclei for precipitation of chromium carbides within the grains. Increasing the titanium addition to 9·4(C+N) resulted ...

High strength corrosion resistant nickel-base alloy

Abstract: Alloys containing controlled percentages of chromium, aluminum, titanium, molybdenum, tungsten, tantalum, zirconium, boron, carbon and a dispersoid such as yttria afford good stress rupture properties at intermediate temperatures, eg, 1400*F, and at more elevated temperatures, eg, 1900*F, together with good oxidation and/or control of nitrogen important for enhancing sulfidation resistance

Process for producing a sintered article of a titanium alloy

Abstract: A sintered article of a titanium alloy is produced by powder metallurgy techniques, the alloy having uniform structure, and improved mechanical properties, machinability and weldability. The process comprises; partially sintering a powder mixture of (a) at least one selected from the group consisting of powdered titanium and titanium hydride having a particle size of minus 60 mesh and (b) at least one powdered additive selected from the group consisting of powdered Ni, Al, Cu, Sn, Pd, Co, Fe, Cr, Mn, and Si having a particle size of minus 60 mesh, to partially alloy the titanium with one or more additives employed; after furnace cooling the partially sintered mass to room temperature, pulverizing it to powder of minus 60 mesh in particle size to prepare mother alloy powder; mixing (a) the mother alloy powder having a particle size of minus 60 mesh, (b) at least one selected from the group consisting of powdered titanium and titanium hydride having a particle size of minus 60 mesh, and (c), if necessary, at least one additional element selected from the group consisting of powdered V, Mo, Zr and Al-V alloy, which are added for the purpose of avoiding excess formation of a liquid phase during the subsequent sintering; compacting the thus formed powder mixture into a compact having a predetermined shape; and sintering the compact at a temperature ranging from 1000°C to 1500°C in a non-oxidizing and non-nitriding atmosphere for from 30 minutes to 2 hours.