Abstract: To provide a method of producing a strengthened alloy capable of shortening the time necessary for aging treatment and obtaining a strengthened alloy with enhanced tensile strength. The method of producing a strengthened alloy comprises a solution treatment step S1 of immersing an alloy material into molten lithium held at a solution treatment temperature higher than solution temperature of solute metal of the alloy material, a solution stop step S2 of immersing the alloy material into molten lithium held at a cooling temperature lower than the solution treatment temperature after the solution treatment step S1, an aging treatment step S3 of immersing the alloy material into molten lithium held at an aging treatment temperature lower than the solution temperature after the solution stop step S2, and an aging stop step S4 of immersing the alloy material into molten lithium held at an aging stop temperature lower than the aging treatment temperature after the aging treatment step S3.

Abstract: The present disclosure describes methods of heat treating Ti-based alloys and various improvements that can be realized using such heat treatments. In one exemplary implementation, the invention provides a method of forming a metal member that involves forming an alloy into a utile shape and cooling the alloy from a first temperature above a beta transus temperature of the alloy to a second temperature below the beta transus temperature at a cooling rate of no more than about 30° F./minute. If so desired, the alloy my be treated for a period of about 1-12 hours at about 700-1100° F. Titanium alloys treated according to aspects of the invention may have higher tensile strengths and higher fracture toughness than conventional wrought, mill-annealed Ti 64 alloy.

Abstract: The present disclosure describes methods of heat treating Ti-based alloys and various improvements that can be realized using such heat treatments. In one exemplary implementation, the invention provides a method of forming a metal member that involves forming an alloy into a utile shape and cooling the alloy from a first temperature above a beta transus temperature of the alloy to a second temperature below the beta transus temperature at a cooling rate of no more than about 30° F./minute. If so desired, the alloy my be treated for a period of about 1-12 hours at about 700-1100° F. Titanium alloys treated according to aspects of the invention may have higher tensile strengths and higher fracture toughness than conventional wrought, mill-annealed Ti 64 alloy.

Abstract: Ti 5-5-5-3 titanium alloy heat treatment process having, in weighted percentages, the following composition: between 4.4 and 5.7% aluminum, between 4.0 and 5.5% vanadium, between 0.30 and 0.50% iron, between 4.0 and 5.5% molybdenum, between 2.5 and 3.5% chromium, between 0.08 and 0.18% oxygen, 0.10% traces of carbon, 0.05% traces of nitrogen, 0.30% traces of zirconium, 0.15% traces of silicon, the residual percentage being titanium and impurities, characterised in that the heat treatment of said alloy is carried out by: heating to a first stage of between 810 and 840?° C. and below the ?-transus temperature of the alloy; maintaining at the first stage for one to three hours; cooling to a second stage of between 760° C. and 800° C. without intermediate reheating; maintaining at the second stage for two to five hours; cooling to ambient temperature; heating to a third stage of between 540° C. and 650° C.; maintaining at the third stage for four to twenty hours, then cooling to ambient temperature.

Abstract: The invention relates to a method of brazing a Ti—Al alloy. According to the invention, a layer of nickel (2) is disposed between a part (1) which is made from titanium aluminide and a brazing sheet (3), such as to enable: the aforementioned part (1) to be brazed to another metallic material (4) without the aluminium diffusing from one to the other; and a stable link with good mechanical strength to be produced. The invention can be used for the assembly of aircraft engine parts which are made from titanium aluminide and nickel-based superalloy.

Abstract: A gamma titanium aluminide alloy consisting of 46 at % aluminium, 8 at % tantalum and the balance titanium plus incidental impurities has an alpha transus temperature T? between 1310° C. and 1320° C. The gamma titanium aluminide alloy was heated to a temperature T1=1330° C. and was held at T1=1330° C. for 1 hour or longer. The gamma titanium aluminide alloy was air cooled to ambient temperature to allow the massive transformation to go to completion. The gamma titanium aluminide alloy was heated to a temperature T2=1250° C. to 1290° C. and was held at T2 for 4 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix. The heat treatment reduces quenching stresses and allows larger castings to be grain refined.

Abstract: An alloy having from about 5 to about 15 wt % Ta, from 0 to about 5 wt % Nb, from about 0.5 to about 15 wt % Zr, and the balance Ti is disclosed. The alloy is particularly intended for medical devices, such as implants for the body.

Abstract: A method of forming titanium structures, and more specifically, a method of superplastically continuous roll forming titanium structures are disclosed herein. In one embodiment, a method of forming a shape in an article comprising titanium, the method including, among other things, providing first and second rolling members, the first rolling members being conductive and the second rolling members being continuous roll shaping members; contacting the article with the first rolling members to transfer a current to the article to heat the article to a temperature suitable for superplastic forming; and with the article being in a superplastic state, contacting the article with the second rolling members to form the shape in the article.

Abstract: A method of heat treating a thermomechanical part made of a TA6Zr4DE titanium alloy. A solution-annealing is performed at a temperature lying in the range beta transus ?20° C. and beta transus ?15° C. for a duration lying in the range four hours to eight hours. The method is applicable to fabricating high pressure compressor disks.

Abstract: Embodiments of the present invention provide methods of processing nickel-titanium alloys including from greater than 50 up to 55 atomic percent nickel to provide a desired austenite transformation temperature and/or austenite transformation temperature range. In one embodiment, the method comprises selecting a desired austenite transformation temperature, and thermally processing the nickel-titanium alloy to adjust an amount of nickel in solid solution in a TiNi phase of the alloy such that a stable austenite transformation temperature is reached, wherein the stable austenite transformation temperature is essentially equal to the desired austenite transformation temperature.

Abstract: Titanium material less susceptible to discoloration and method for thereof are provided. Titanium materials less susceptible to discoloration in the atmosphere are obtainable by controlling the fluorine and carbon contents in the oxide film on the surface thereof and the thickness of the oxide film. Such titanium materials are obtainable by dissolving the surface thereof in an aqueous fluonitric acid solution with a nitric acid concentration of not higher than 80 g/l or heat-treating at between 300 and 900° C. in a vacuum or in an inert gas atmosphere of argon or helium after dissolving in the aqueous fluonitric acid solution.

Abstract: A method for producing a substrate having a carbon-doped titanium oxide layer, which is excellent in durability (high hardness, scratch resistance, wear resistance, chemical resistance, heat resistance) and functions as a visible light responding photocatalyst, is provided. The surface of a substrate, which has at least a surface layer comprising titanium, a titanium alloy, a titanium alloy oxide, or titanium oxide, is heat-treated in a combustion gas atmosphere of a gas consisting essentially of a hydrocarbon, or in a gas atmosphere consisting essentially of a hydrocarbon, such that the surface temperature of the substrate is 900 to 1,500° C.; or a combustion flame of a gas consisting essentially of a hydrocarbon, is directly struck against the surface of the substrate for heat treatment such that the surface temperature of the substrate is 900 to 1,500° C., thereby forming a carbon-doped titanium oxide layer, whereby the substrate having the carbon-doped titanium oxide layer is obtained.

Abstract: A damage tolerant microstructure for a lamellar alloy, such as a lamellar ?TiAl alloy, is provided in accordance with the present invention. The alloy comprises a matrix and a plurality of grains or lamellar colonies, a portion of which exhibit a nonplanar morphology within said matrix. Each of the lamellar colonies contains a multitude of lamella with irregularly repeating order. The ?TiAl platelets have a triangular (octahedral) unit cell and stack with ? twins. The ?2Ti3Al platelets are irregularly interspersed. The unit cell for ?2Ti3Al is hexagonal. Each of the layers has a curved, nonplanar structure for resisting crack formation and growth.

Abstract: A method for manufacturing a high-strength titanium alloy golf club head part includes making at least one golf club head part with a titanium alloy. The golf club head part is then heated to a temperature higher than a critical temperature of generating martensite and maintained above the critical temperature not more than thirty minutes. The golf club head part is then cooled to a temperature below the critical temperature at a cooling rate higher than 10° C./s. Next, the golf club head part is heated to a heat-treatment temperature higher than 450° C. and maintained at the heat-treatment temperature at least one hour. The golf club head part is then cooled to room temperature. The mechanical characteristics of a golf club head formed by the golf club head part are enhanced.

Abstract: A titanium alloy includes at least one alloying element whose molybdenum equivalent “Moeq” is from 3 to 11% by mass, at least one interstitial solution element selected from the group consisting of O, N and C in an amount of from 0.3 to 3% by mass, and the balance of Ti, when the entirety is taken as 100% by mass. Its content of Al is controlled to 1.8% by mass or less, and it is ? single phase at room temperature at least.

Abstract: A method is provided for welding two gamma titanium aluminide articles together. The method includes preheating the two articles to a welding temperature of from about 1700° F. to about 2100° F., thereafter electron beam welding the two articles together at the welding temperature and in a welding vacuum to form a welded structure, and thereafter annealing the welded structure at an annealing temperature of from about 1800° F. to about 2200° F., to form a joined structure.

Abstract: A method of treating an article including a titanium alloy having 5-6.5% aluminum by weight; 1.5-2.5% tin by weight; 1.5-2.5% chromium by weight; 1.5-2.5% molybdenum by weight; 1.5-2.5% zirconium by weight; and titanium. The method includes heat treating the titanium alloy without exposing the titanium alloy to a beta anneal process. There is also an article that has been subjected to a heat treatment process that does not include a beta anneal.

Abstract: A metallic structure having a graded microstructure is provided. The metallic structure comprises a graded region comprising a plurality of grains having a gradient in grain size varying as a function of position between a first median grain size at an outer region and a second median grain size at an inner region and a plurality of dispersoids dispersed within the microstructure. The first median grain size is different from the second median grain size. A method of forming a metallic structure having a graded microstructure is also provided. The method comprises: providing a metallic structure comprising at least one reactive species; diffusing at least one reactant at a controlled rate from an outer region of the metallic structure towards an inner region of the metallic structure to form a gradient in reactant activity; reacting the reactant with the reactive species to form a plurality of dispersoids; and heat treating the metallic structure to achieve grain growth so as to form a graded microstructure.

Abstract: A method is provided for improving the machinability of a titanium alloy includes heating the alloy at a temperature and time period that imparts to the alloy a microstructure having between about 10 and 15 vol. % alpha phase in a beta phase matrix. According to one embodiment, the alloy is thereafter annealed at a temperature lower than the temperature for the initial heating step, and for a duration that is longer than the time period for the initial heating step.

Abstract: A gamma titanium aluminide alloy consisting of 46 at % aluminium, 8 at % tantalum and the balance titanium plus incidental impurities has an alpha transus temperature T? between 1310° C. and 1320° C. The gamma titanium aluminide alloy was heated to a temperature T1=1330° C. and was held at T1=1330° C. for 1 hour or longer. The gamma titanium aluminide alloy was air cooled to ambient temperature to allow the massive transformation to go to completion. The gamma titanium aluminide alloy was heated to a temperature T2=1250° C. to 1290° C. and was held at T2 for 4 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix. The heat treatment reduces quenching stresses and allows larger castings to be grain refined.

Abstract: An article of titanium or a titanium-based alloy, or of zirconium or a zirconium-based alloy is case hardened by heat treatment for at least 12 hours at one or more temperatures in the range of 850° C. to 900° C. and at a pressure in the order of atmospheric pressure in an oxygen diffusion atmosphere. The oxygen diffusion atmosphere comprises a carrier gas such as argon which does not react chemically with the article the said temperature range and molecular oxygen. The concentration of oxygen as the oxygen diffusion atmosphere is in the range of 10 volumes per million to 400 volumes per million.

Abstract: Embodiments of the present invention provide methods of processing nickel-titanium alloys including from greater than 50 up to 55 atomic percent nickel to provide a desired austenite transformation temperature and/or austenite transformation temperature range. In one embodiment, the method comprises selecting a desired austenite transformation temperature, and thermally processing the nickel-titanium alloy to adjust an amount of nickel in solid solution in a TiNi phase of the alloy such that a stable austenite transformation temperature is reached, wherein the stable austenite transformation temperature is essentially equal to the desired austenite transformation temperature.

Abstract: The invention relates to a method for producing high-performance Cr—Ti—V hydrogen storage alloys utilizing a thermit process, whereby residence of adversely affecting impurities is inhibited, addition of not less than 10 at % of Ti as an alloy component is realized, and thermal burden on the crucible used in the method is reduced. The method includes the steps of: (A) providing an alloy material (1) comprising a Cr oxide, a V oxide, and a reducing agent Al, and an alloy material (2) comprising Ti; (B) placing the alloy materials in a crucible for thermit reduction so that the alloy material (1) is placed above the alloy material (2); (C) igniting the alloy material (1) placed in step (B) and melting all metal elements contained in the alloy materials the with heat of the thermit reaction of the alloy material (1); and (D) making the alloy melt obtained in step (C) into an alloy.

Abstract: A method for absorbing and releasing hydrogen comprises applying repeatedly hydrogen pressurization and depressurization to a hydrogen storage metal alloy of a body-centered cubic structure-type phase exerting a two-stage or inclined plateau characteristic in a hydrogen storage amount vs hydrogen pressure relation in an appropriate fashion to absorb and release hydrogen. At least at one stage during the release of hydrogen, the temperature (T2) of the above-mentioned hydrogen storage metal alloy is made higher than the temperature (T1) of the hydrogen storage metal alloy during the hydrogen absorption process (T2>T1). This enables the release and utilization of occluded hydrogen at a low-pressure plateau region or an inclined plateau lower region.

Abstract: The purpose is to provide a cathode electrode for manufacturing an electrodeposited copper foil which is possible to be continuously and stably usable for a long duration of 3000 hours or longer to subsequently lessen the frequency of maintenance work execution as low as possible and to contribute to lower the running cost of the electrodeposited copper foil manufacture. As the means for achieving the purpose, a cathode electrode made of a titanium material is employed for obtaining an electrodeposited copper foil using an electrolytic copper solution and the titanium material having 7.0 or higher crystal grain size number and 35 ppm or lower initial hydrogen content is used for manufacturing the cathode electrode for manufacturing an electrodeposited copper foil. Further, also provided is a manufacturing method of the titanium material to be employed for the cathode electrode made of a titanium material.

Abstract: The invention relates to a method for producing components with a high load capacity from ?+? TiAl alloys, especially for producing components for aircraft engines or stationary gas turbines. According to this method, enclosed TiAl blanks of globular structure are preformed by isothermal primary forming in the ?+?? or ? phase area. The preforms are then shaped out into components with a predeterminable contour by means of at least one isothermal secondary forming process, with dynamic recrystallization in the ?+?? or ? phase area. The microstructure is adjusted by solution annealing the components in the ? phase area and then cooling them off rapidly.

Abstract: A titanium material for a target has a microstructure in which the grain size is small and uniform and also has a macrostructure of the surface of the titanium material which is non-patterned and is excellent in surface property. A titanium ingot in which Vacuum Arc Remelting or Electron Beam Melting is performed is roughly forged at a temperature from 700° C. up to the ? transformation temperature, and is then forged for finishing at room temperature to 350° C., and is finally annealed.

Abstract: A damage tolerant microstructure for a lamellar alloy, such as a lamellar ?TiAl alloy, is provided in accordance with the present invention. The alloy comprises a matrix and a plurality of grains or lamellar colonies, a portion of which exhibit a nonplanar morphology within said matrix. Each of the lamellar colonies contains a multitude of lamella with irregularly repeating order. The ?TiAl platelets have a triangular (octahedral) unit cell and stack with ? twins. The ?2Ti3Al platelets are irregularly interspersed. The unit cell for ?2Ti3Al is hexagonal. Each of the layers has a curved, nonplanar structure for resisting crack formation and growth.

Abstract: The invention relates to plastic metal working, more specifically to methods for producing parts of the disk- or shell-type having conical, hemispherical, and also combined parts, such as disk-and-shaft ones. The invention is instrumental in producing large axially symmetric parts from hard-to-work multiphase alloys. The method consists in that the billet is heated in a temperature range above 0.4 m.p. but below the temperature at which a total content of precipitates or an allotropic modification of the matrix of a multiphase alloy is not below 7%. Then the preheated billet is rolled, while controlling its temperature and the tool load, as well as the rolling speed. Once rolled the billet is heat-treated at a temperature depending on the microstructure of the billet material resulting from rolling. Prerolling preparing of a specified microstructure of the billet material is also described.

Abstract: Titanium resistant to discoloration in an atmospheric environment characterized by having an average carbon concentration of 14 at % or less in a range to a depth of 100 nm from the surface and having an oxide film of a thickness of 12 to 40 nm at its surface. Titanium resistant to discoloration in an atmospheric environment characterized in that, in X-ray diffraction of its surface, a ratio (X1/X2) of a (200) peak intensity X1 of TiC to a (110) peak intensity X2 of titanium is not more than 0.18 and by having an oxide film of a thickness of 12 to 40 nm at its surface.

Abstract: A method for absorbing and releasing hydrogen comprises applying repeatedly hydrogen pressurization and depressurization to a hydrogen storage metal alloy of a body-centered cubic structure-type phase exerting a two-stage or inclined plateau characteristic in a hydrogen storage amount vs hydrogen pressure relation in an appropriate fashion to absorb and release hydrogen. At least at one stage during the release of hydrogen, the temperature (T2) of the above-mentioned hydrogen storage metal alloy is made higher than the temperature (T1) of the hydrogen storage metal alloy during the hydrogen absorption process (T2>T1). This enables the release and utilization of occluded hydrogen at a low-pressure plateau region or an inclined plateau lower region.

Abstract: A stranded wire having improved fatigue characteristics and made of a shape memory and/or superelastic material, such as Ni/Ti or alloys thereof. Further, the stranded wire may be coiled along the entire length of the wire or only a portion thereof to form one or more coil springs. The stranded and optionally coiled wire is heat treated to set the wire in the twisted configuration.

Abstract: A method for heat treating titanium-alloy articles in a vacuum furnace includes a step of first determining, for a first set of titanium articles in a first vacuum furnace and for a first set of heat treatment conditions, a minimum surface area of the first set of titanium articles associated with an acceptable alpha case formation for the first set of titanium articles. There is a second determining, for a second set of titanium articles in a second vacuum furnace and for a second set of heat treatment conditions, of a minimum surface area of a second set of titanium articles associated with an acceptable alpha case formation for the second set of titanium articles, responsive to the value of the minimum surface area of the first set of titanium articles.

Abstract: A shaped part or article of manufacture is formed of a selected gamma titanium aluminide alloy with outstanding mechanical properties which can be produced particularly economically. First, a semi-finished article is formed in a hot forming process with a degree of deformation of greater than 65%. Then the semi-finished article is shaped with the alloy being in a solid-liquid phase by applying mechanical forming forces during at least part of the shaping process.

Abstract: To provide a hydrogen absorbing alloy having a BCC (body-centered cubic structure) as a crystal structure, and particularly a hydrogen-absorbing alloy for a nickel-hydride cell having excellent discharge capacity and durability (cycle characteristics), said hydrogen-absorbing alloy having a composition expressed by the general formula Ti(100-a-b-c-d)CraVbNicXd, where X is at least one member selected from the group consisting of Y (yttrium), lanthanoids, Pd and Pt, and each of a, b, c and d is represented, in terms of at %, by the relations 8≦a≦50, 30<b≦60, 5≦c≦15, 2≦d≦10 and 40≦a+b+c+d≦90, wherein the crystal structure of a principal phase is a body-centered cubic structure, and further, the alloy contains at least one of Mo and W in place of V and at least one member selected from the group consisting of Y (yttrium), lanthanoids, Pd and Pt, and its crystal structure is converted to the body-centered cubic structure by heat-treatment.

Abstract: A method for heat treating titanium-alloy articles in a vacuum furnace includes a step of first determining, for a first set of titanium articles in a first vacuum furnace and for a first set of heat treatment conditions, a minimum surface area of the first set of titanium articles associated with an acceptable alpha case formation for the first set of titanium articles. There is a second determining, for a second set of titanium articles in a second vacuum furnace and for a second set of heat treatment conditions, of a minimum surface area of a second set of titanium articles associated with an acceptable alpha case formation for the second set of titanium articles, responsive to the value of the minimum surface area of the first set of titanium articles.

Abstract: A high strength and ductility &agr;+&bgr; type titanium alloy, comprising at least one is isomorphous &bgr; stabilizing element in a Mo equivalence of 2.0-4.5 mass %, at least one eutectic &bgr; stabilizing element in an Fe equivalence of 0.3-2.0 mass %, Si in an amount of 0.1-1.5 mass %, and C in an amount of 0.01-0.15% mass, and has a &bgr; transformation temperature no lower than 940° C.

Abstract: Quenching a work piece made of a titanium alloy having a temperature higher than 800° C. to a temperature lower than 500° C. at a cooling rate greater than 10° C./second between 800° C. and 500° C. is used to render the cooled work piece containing &agr;″ phase as a major phase. The titanium alloy composition contains at least one isomorphous beta stabilizing element selected from Mo, Nb, Ta and W; and the balance Ti, wherein said composition has a Mo equivalent value from about 6 to about 9. The work piece is preferably a medical device.

Abstract: Quenching a work piece made of a titanium alloy having a temperature higher than 800° C. to a temperature lower than 500° C. at a cooling rate greater than 10° C./second between 800° C. and 500° C. is used to render the cooled work piece containing &agr;″ phase as a major phase. The work piece is preferably a medical implant.

Abstract: A titanium alloy includes at least one alloying element whose molybdenum equivalent “Moeq” is from 3 to 11% by mass, at least one interstitial solution element selected from the group consisting of O, N and C in an amount of from 0.3 to 3% by mass, and the balance of Ti, when the entirety is taken as 100% by mass. Its content of Al is controlled to 1.8% by mass or less, and it is &bgr; single phase at room temperature at least.

Abstract: Medical devices, medical device components, and methods of making the same. For example, one embodiment provides a method of shaping a reinforcing member through annealing. Another exemplary embodiment includes a method of making a medical device that includes such a shaped reinforcement member incorporated therein. Yet another exemplary embodiment provides a medical device including such a shaped reinforcing member therein.

Abstract: The invention relates to a component produced in one piece from an intermetallic &ggr;-TiAl-based alloy with graduated microstructure transition between spatially adjacent areas each of different microstructure structure, which has a lamellar cast microstructure composed of &agr;2/&ggr; lamellae in at least one area, and a near-&ggr; microstructure, duplex microstructure or fine-lamellar microstructure in at least one other area, and a transition zone with graduated microstructure, in which the lamellar cast microstructure gradually changes into the other named microstructure, is present between these areas, as well as to a process for its production.

Abstract: A gamma titanium aluminide alloy consisting of 48 at % aluminium, 2 at % chromium, 2 at % niobium and the balance titanium plus incidental impurities was heat treated according to the present invention. The gamma titanium aluminide alloy has an alpha transus temperature T&agr;=1360° C. The gamma titanium aluminide alloy was heated to a temperature T1=1380° C. and was held at T2=1380° C. for 1 hour. The gamma titanium aluminide alloy was oil cooled. The gamma titanium aluminide alloy was heated to a temperature T2=1320° C. and was held at T2=1320° C. for 2 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix.

Abstract: A method for preparing ultra-fine grain titanium or titanium-alloy articles used for adjoining or assembling of detail components. Coarse-grained titanium or titanium-alloy materials typically are heated and forced under constant pressure through a friction stir processing tooling device containing a stirring chamber and a stirring rod. As the material is passed through the stirring chamber, the stirring rod solutionizes the titanium or titanium-alloy material and stirs the material to obtain a homogeneous or uniform material condition. As the processed material exits the stirring chamber of the friction stir process tooling device, it reconsolidates as an extremely homogeneous structure possessing ultra-fine grain structure. Titanium or titanium-alloy materials having been processed to achieve such ultra-fine grain material structure may then be manufactured into aerospace structural articles or components such as fasteners or articles that do not require a subsequent thermal or heat-treatment steps.

Abstract: A Ti—Ni shape memory alloy with ductility, including Ti of 50˜66 atomic % in a composition, and in which precipitation of Ti2Ni phases at grain boundaries is suppressed.

Abstract: Titanium material less susceptible to discoloration and method for thereof are provided. Titanium materials less susceptible to discoloration in the atmosphere are obtainable by controlling the fluorine and carbon contents in the oxide film on the surface thereof and the thickness of the oxide film. Such titanium materials are obtainable by dissolving the surface thereof in an aqueous fluonitric acid solution with a nitric acid concentration of not higher than 80 g/l or heat-treating at between 300 and 900° C. in a vacuum or in an inert gas atmosphere of argon or helium after dissolving in the aqueous fluonitric acid solution.

Abstract: A Ti alloy poppet valve consists of a valve stem and a valve head, and is employed as intake or exhaust valve in an internal combustion engine of an automobile. O2 is put into the valve in a furnace at very slight amount and heated to introduce oxygen atoms into titanium of the valve to form a Ti—O interstitial solid solution without making titanium oxides. The valve is strengthened to increase hardness and wear resistance.

Abstract: The inventive titanium alloy comprises, expressed in mass %: aluminium 4.0-6.3; vanadium 4.5-5.9; molybdenum 4.5-5.9; chromium 2.0-3.6; ferrum 0.2-0.5; the rest being titanium. An equivalent molybdenum content is determined as corresponding to Moequiv≧13.8. The inventive method for heat treatment consists in heating to t&bgr;⇄&agr;+&bgr;−(30-70)° C., conditioning during 2-5 hrs, air or water cooling and age-hardening at a temperature ranging from 540° C. to 600° C. during 8-16 hrs. Said alloy has a high volumetric deformability and is used for manufacturing massive large-sized forged and pressed pieces having a high strength level, satisfactory characteristics of plasticity and fracture toughness.

Abstract: The present invention comprises a method of making a golf club head by casting a molten titanium alloy and thereafter removing the alpha case that is formed on the surface of the titanium by means of a conformal milling process. The conformal milling process uniformly dissolves the alpha case without distorting the underlying metal. The reduction in wall thickness caused by the conformal milling results in a concomitant reduction in the weight of the part without any loss in the critical impact strength of the part. In fact, impact strength is increased. This weight can then be redistributed as a supplemental weight member, which can be used to lower the center of mass of the club. The weight member can further be positioned on the sole plate or club body in such a way so as to permit fine tuning of the location of the center of mass of the club, as well as shaped so as to increase the polar moment of inertia of the club head about the golf club shaft.

Abstract: A high strength and ductility &agr;+&bgr; type titanium alloy, comprising at least one isomorphous &bgr; stabilizing element in a Mo equivalence of 2.0-4.5 mass %, at least one eutectic &bgr; stabilizing element in an Fe equivalence of 0.3-2.0 mass %, and Si in an amount of 0.1-1.5 mass %, and optionally comprising C in an amount of 0.01-0.15% mass.