Showing papers on "Titanium powder published in 1990"

Effect of Nitrogen Pressure and Diluent Content on the Combustion Synthesis of Titanium Nitride

Abstract: This paper reports the effects of gas pressure and diluent content on the combustion synthesis of titanium nitride was investigated. Combustion of titanium powder samples containing TiN as a diluent in the concentration range 0 to 60 wt% was carried out in a nitrogen atmosphere at pressures in the range 0.1 to 1.4 MPA. Analysis of the dependence of combustion wave velocity on temperature gave an activation energy of 342 {plus minus} 50 kJ {circle dot}mol{sup {minus}1}, which is in good agreement with reported values for the diffusion of nitrogen in titanium nitride.

Method for manufacturing titanium powder or titanium composite powder

Abstract: A method for manufacturing a titanium powder, which comprises the steps of: causing a molten reducing agent comprising molten magnesium at a temperature of 650° to 900° C. or molten sodium at a temperature of 100° to 900° C. to fall into a reaction vessel; ejecting a titanium tetrachloride gas at a temperature of 650° to 900° C. toward the falling flow of the molten reducing agent in the reaction vessel to atomize the molten reducing agent, and producing titanium particles containing molten reaction product which comprises molten magnesium chloride or molten sodium chloride, through a reducing reaction between the atomized molten reducing agent and the titanium tetrachloride gas; and removing the reaction product from the titanium particles containing the reaction product to manufacture a titanium powder.

Production of Titanium Powders by the Calciothermic Reduction of TiO2

Abstract: Synopsis : According to the measurements of equilibrium oxygen concentration in Ti under Ca-CaO co-existence, the deoxidation limit is 500 ppm at 1 273 K. On the basis of these data, preparation of Ti powders have been carried out by reduction of TiO2 using saturated Ca vapors, liquid Ca and CaH2 powders at 1 273 K and subsequent rinsing of CaO in the aqueous solution of HCl, CH3COOH or NH4Cl. The oxygen and calcium levels in the Ti powders reduced by the saturated Ca vapors and the liquid Ca were not below 2 000 and 1 000 ppm, respectively. This was attributed to the CaO which were confined inside the sintered Ti particles and could not be exposed to the rinsing solution. Reduction of the TiO2-CaO mixtures has led to the residual oxygen with the range of 1 000-2 000 ppm, thus the presence of CaO in the starting oxide was effective to control the sintering between reduced Ti powders. The particle size of the reduced Ti was 1-10 Reduction of TiO2 by mixing with excess amount of CaH2 powders could eliminate oxygen below 700 ppm which is close to the deoxidation limit for Ti by Ca of activity of unity.

Interaction of Si3N4 with titanium powder

Abstract: On etudie la reaction de Si 3 N 4 polycristallin avec de la poudre de titane a des temperatures de 1173 a 1323 o K. On examine la structure des films formes a l'interface

Producing titanium particulates from in situ titanium-zinc intermetallic

Abstract: A process for producing salt free titanium powder by reacting zinc and a titanium halide in the presence of a reducing agent to form a solid zinc titanium product. Titanium halide vapor is introduced into a liquid alloy of zinc and the reducing agent at a temperature between 650°-907° C. The titanium halide is introduced beyond the titanium solubility limit in zinc to precipitate a zinc titanium intermetallic compound and also produce a liquid halide salt. The intermetallic compound forms and accumulates at an interface between the salt and liquid alloy. The compound is periodically removed from the interface, crushed into a powder, and the zinc is evaporatively separated from the titanium to produce pure titanium powder. The process preferably occurs above the peritectic decomposition temperature of Zn3 Ti, and most preferably above the peritectic decomposition temperature of Zn2 Ti, to maximize the titanium content of the resulting product.

Synthesis of Ti-Al Intermetallic Compounds by HIP-reaction Sintering

Abstract: TiAl intermetallic compounds were fabricated by HIP-reaction sintering. Elemental powder mixtures of titanium and aluminum with composition Ti-45 to 55 at%A1 were HIP treated after encapsulation with pyrex glass tube. At 1473K treatment, duplex phase of Ti3A1 and TiAl was detected in all compositions, but there was no lamellar structure typical for TiAl intermetallics. And as HI Ping temperature rises, Ti3A1/TiAl laminated structure was observed in the specimens of Ti-rich composition, which were almost fully densified and had a fine grain structure with mean size about 30μm. The DTA analysis showed exothermic peak at 923K, which indicates that the self propagating reaction takes place at the melting temperature of aluminum. It was considered that several compounds of Ti-Al system were synthesized by self propargating reaction at the first stage and densified by subsequent hot isostatic pressure and finally transformed to laminated structure by the effect of heat treatment.

Frameless, coreless porous intrabony implant

Abstract: PURPOSE:To form the intrabony implant with which the infiltration of biobony structure is vigorous by constituting a porous sintered metal layer having a relatively small pore size range and porous sintered metal layers which are respectively laminated and integrated by sintering to both sides thereof and have a relatively large pore size range. CONSTITUTION:The main implant body I consists of the three layers. The sintered metal layers 1, 1 which have the relatively small pore size range (30-50mum) and have about 80% porosity are disposed on both the front and rear surfaces of the above-mentioned layers and the sintered metal layer 2 having the relatively small pore size range (50-200mum) is disposed to the middle. These three layers 1, 2, 1 are laminated and integrated by sintering to the flameless and coreless form. Tube holes 3... are bored at random through the thickness of this body by an electrobeam method to allow the infiltration and permeation of the bony structure. Pure titanium powder grains (50-100mum) are used for the metal powder grains of the layer 1 and the same pure titanium powder grains (100-200mum) are used for the layer 2, respectively. The main implant body I and a post 4 made of a titanium alloy are subjected to argon arc welding by using a welding rod of titanium.

DTA studies on the corrosion behavior of titanium powder in NaCl and Na2SO4

Abstract: The corrosion/oxidation behavior of titanium powder in air and in the presence of corrodents NaCl and Na2SO4 was investigated by employing the DTA technique.

Method for removing chlorine from metallic titanium powder

Abstract: PURPOSE: To obtain metallic Ti powder usable for powder metallurgy and enabling the production of a metallic Ti ingot having a low Cl content by remelting by bringing powdery metallic Ti into contact with a fluid in a supercritical state in a vessel and dissolving Cl contained in the Ti in the fluid. CONSTITUTION: Powdery metallic Ti is brought into contact with a fluid in a supercritical state in a vessel and Cl contained in the metallic Ti powder is dissolved in the fluid. At this time, a batch process in which both the powder and fluid are sealed in the same vessel and a circulating process in which the fluid is circulated produce the same effect. Water, CO or methanol is desirably used as the fluid in a supercritical state. Metallic Ti having a low Cl content is obtd. and a high purity ingot can be obtd. by remelting the Ti once when the Ti is remelted to produce an ingot. COPYRIGHT: (C)1991,JPO&Japio

Production of titanium disulfide

Abstract: PURPOSE:To obtain titanium disulfide capable of exhibiting battery characteristics suitable as positive pole active substance in Li secondary batteries at a low cost with excellent productivity by thermally reacting metallic Ti in sulfur vapor containing a very small amount of an alkali metal halide added thereto CONSTITUTION:A metallic titanium material 8 (eg, titanium powder) is placed in a titanium charging part 5 of a quartz tube 1 and distilled sulfur 9 containing a very small amount of an alkali metal halide (eg, LiCl) added thereto is placed in a sulfur charging part 6 to vacuum seal the quartz tube 1 The metallic titanium material 8 is then heated in an electric furnace 3 for heating the titanium and the distilled sulfur 9 is simultaneously heated in an electric furnace 4 for controlling the sulfur vapor pressure to produce vapor of the sulfur The metallic titanium material 8 is then thermally reacted in the vapor of the sulfur to form titanium disulfide on the surface of the metallic titanium material 8 Even the interior thereof is further reacted by accelerating action with the alkali metal halide contained in the sulfur 9 to produce the titanium disulfide