145 results about "Titanium aluminide" patented technology

(a) The metal matrix composite is suitable for the manufacture of flat or shaped titanium aluminide, zirconium aluminide, or niobium aluminide articles and layered metal composites having improved mechanical properties such as lightweight plates and sheets for aircraft and automotive applications, thin cross-section vanes and airfoils, heat-sinking lightweight electronic substrates, bulletproof structures for vests, partition walls and doors, as well as sporting goods such as helmets, golf clubs, sole plates, crown plates, etc. The composite material consists of a metal (e.g., Ti, Zr, or Nb-based alloy) matrix at least partially intercalated with a three-dimensional skeletal metal aluminide structure, whereby ductility of the matrix metal is higher than that of the metal aluminide skeleton. The method for manufacturing includes the following steps: (a) providing an aluminum skeleton structure having open porosity of 50-95 vol. %, (b) filling said skeleton structure with the powder of a reactive matrix metal, (c) compacting the aluminum skeleton / matrix powder composite preform by cold rolling, cold die pressing, cold isostatic pressing, and / or hot rolling, (d) consolidating the initial or compacted composite preform by sintering, hot pressing, hot rolling, hot isostatic pressing, and / or hot extrusion to provide, at least partially, a reaction between aluminum skeleton and matrix metal powder, and (e) diffusion annealing followed by any type of heat treatment needed to provide predetermined mechanical and surface properties of the resulting metal matrix composite. The combination of ductile matrix and metal aluminide skeletal structure results in significant improvement of mechanical properties of the composite material, especially hot strength. This high-strength aluminide-based material can also be used as a core component in multilayer metal matrix composites.

The method is suitable for the manufacture of flat or shaped titanium aluminide articles and layered metal matrix composites such as lightweight plates and sheets for aircraft and automotive applications, thin cross-section vanes and blades, composite electrodes, heat-sinking lightweight electronic substrates, bulletproof structures for vests, partition walls and doors, as well as for sporting goods such as helmets, golf clubs, sole plates, crown plates, etc. The method includes the following steps: (a) forming a porous preform of the reactive powder alloy or a porous multi-layer composite preform consisting of reactive powder metals and alloys by consolidation using at least one method selected from low-temperature loose sintering in vacuum, high-temperature loose sintering in vacuum, low-pressure sintering in an inert gas, cold pressing, direct powder rolling, isostatic or die pressing, and other means of room temperature and warm temperature consolidation, and / or combination thereof, to provide the density not less than 25% from the theoretical density of said reactive alloy; (b) hot consolidating by hot pressing said preform, hot rolling, hot isostatic pressing, or hot extrusion to obtain the density of 98-100% from the theoretical density of said reactive alloy; (c) additional sintering and / or annealing at the temperature being at least 900° C. to decrease the residual porosity, control the microstructure, and improve the mechanical properties, especially ductility and / or plasticity of the resulting metal sheets or layered composites. The hot pressing is carried out at the temperature ranging 950-1700° C., preferably at 1250-1450° C., and at pressure ranging 50-350 kg / cm<2>. The HIP is carried out at the temperature ranging 1250-1350° C. and at pressure ranging 15000-40000 psi. The layered composite preform is manufactured by individual loose sintering, one layer of the composite at a time, and assembling them in the desired order. The composite consists of layers of titanium and / or titanium hydride, Ti-6Al-4V alloy, alpha-titanium aluminide alloy, beta-titanium aluminide alloy, and gamma-titanium aluminide alloy in any combinations.

Methods for making various titanium base alloys and titanium aluminides into engineering components such as rings, tubes and pipes by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent centrifugal casting of the melt in the graphite molds rotating along its own axis under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding, the said molds either revolving around its own horizontal or vertical axis or centrifuging around a vertical axis of rotation.

Electronics packages having a primary metallic material, such as a titanium metallic material, metallurgically bonded to one or more secondary regions within the primary metallic material, the composite regions having desirable thermal conductivity properties and having a coefficient of thermal expansion ("CTE") that generally matches the CTE of the primary metallic material are provided. Electronics packages comprising titanium having heat sinks comprising a metal matrix material such as aluminum silicon carbide or a composite metallic structure such as titanium aluminide / copper, are described. Methods for manufacturing electronics packages having a composite structure are also disclosed.

Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with a refractory metal such as W or Re or a refractory metal carbide such as TaC or HfC. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with titanium carbide via either chemical deposition or plasma assisted chemical vapor deposition, magnetron sputtering or sputtering. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

A thermal actuator for a micro-electromechanical device, especially a liquid drop emitter for ink jet printing, is disclosed. The thermal actuator comprises a base element and a movable element extending from the base element and residing at a first position. The movable element includes a barrier layer constructed of a barrier material having low thermal conductivity material, bonded between a first layer and a second layer; wherein the first layer is constructed of a first material having a high coefficient of thermal expansion and the second layer is constructed of a second material having a high thermal conductivity and a high Young's modulus. An apparatus is provided adapted to apply a heat pulse directly to the first layer, causing a thermal expansion of the first layer relative to the second layer and deflection of the movable element to a second position, followed by relaxation of the movable element towards the first position as heat diffuses through the barrier layer to the second layer. Configurations of the movable element as a cantilever, doubly-anchored beam and clamped plate are disclosed. Diamond and silicon carbide materials are well suited for use as the second material. Titanium aluminide is a preferred material for the first material.

A filter such as a cigarette filter having a metal reagent which selectively binds with a gaseous component of a gas stream such as tobacco smoke. The metal reagent comprises nanometer or micrometer size clusters of a transition metal or alloy containing a transition metal. The transition metal can be incorporated in an intermetallic compound such as titanium aluminide or iron aluminide. The metal clusters can be incorporated in or on a support material such as silica gel, porous carbon or a zeolite. The metal reagent can remove the gaseous component by selectively binding to unsaturated hydrocarbons such as 1,3-butadiene. The binding can occur by insertion of a metal atom of the metal reagent into a C—H bond or a C—C bond of the gaseous component.

A titanium-aluminide turbine wheel (120, 220, 320, 420) is joined to the end of a shaft (110, 210, 310, 410) by utilizing a titanium surface on the end of the shaft to be joined to the wheel, and electron-beam welding the wheel onto the titanium surface on the shaft. A steel shaft (110, 310, 410) can have a titanium-containing end piece (130, 330, 430) mechanically joined (by brazing, bonding, or welding) to the end of the shaft, and the end piece can be directly electron-beam welded to the wheel. Alternatively, the shaft (210) can be formed as a titanium member and the end (212) of the shaft can be directly electron-beam welded to the wheel (220). In another embodiment, a ferrous end piece (330) is mechanically joined to the titanium-aluminide turbine wheel (320) and then the end piece is directly electron-beam welded to the end of a steel shaft (310). Alternatively, a silver-titanium alloy member (430) is sandwiched between the wheel (420) and a steel shaft (410) and is melted to join the parts together.

Titanium aluminide (TiAl) rotor shaft assembly (10) of a type used in a turbocharger has a TiAl rotor (20) with an axially protruded portion (40) that is fixedly joined to a recessed portion (50) of a metal shaft (30) by the synergistic combination of an interference fit, such as a heat shrinkage fit, further supported by a brazed joint (60) in which a thin layer of a brazing material (110) is interposed between the surface of the protruded portion (120) and the recessed surface (130). Optionally, one or both of the jointed surfaces have braze channels (90) to facilitate braze flow within the joint. Methods for producing the rotor shaft assembly (10) and a turbocharger having the rotor shaft assembly (10) are provided.

A rotor shaft assembly (101) of a type used in a turbocharger, manufactured by mounting a powder compact of a titanium aluminide rotor (203) to a powder compact of a steel shaft (207), with a metal powder admixed with a binder (211) interposed between the rotor and shaft, and debinding and sintering the mounted compact combination. Sintering produces a strong metallurgical bond between the shaft and rotor, providing a near-net rotor shaft assembly (101) and also an inexpensive and efficient method for the manufacture of an assembly capable of withstanding the high forces and temperatures within a turbocharger.

Lightweight metal matrix composites containing a skeleton structure of titanium, titanium aluminide, or Ti-based alloy are manufactured by low temperature infiltration with molten Mg-based alloy or Mg-Al alloy at 450-750° C., with molten In, Pb, or Sn at 300-450° C., or with molten Ag and Cu at 900-1100° C. The skeleton structure with a density of 25-35% is produced by loose sintering of Ti or Ti-based alloy powders. A primary deformation of the Ti skeleton structure before the infiltration is carried out by cold or hot rolling or forging to obtain a porous flat or shaped preform with a porosity <50% and pores drawn out in one direction such as the direction of future rolling of the composite plate. A secondary deformation of the infiltrated preform is carried out by multistage cold, or especially hot rolling, to refine the microstructure of the infiltrated skeleton structure and transform it into the textured microstructure strengthened by intermetallic phases such as TiAl, Ti3Al, and TiAl3. Subsequent re-sintering or diffusion annealing form a fully dense final structure of the resulting material having improved mechanical properties. The molten Mg-based infiltrate is alloyed with Al, Si, Zr, Nb, and / or V with the addition of TiB2, SiC, and Si3N4 sub-micron particles as infiltration promoters. The molten Ag- or Cu-based infiltrate can be alloyed with elements depressing its melting point. The method allows for control of the microstructure of composite materials by changing parameters of deformation, infiltration, and heat treatment. The method is suitable for the manufacture of flat or shaped metal matrix composites having improved ductility, such as lightweight bulletproof plates and sheets for aircraft and automotive applications, composite electrodes, heat-sinking lightweight electronic substrates, sporting goods such as helmets, golf clubs, sole plates, crown plates, etc.

The lightweight bulletproof metal matrix macrocomposites (MMMC) contain (a) 10-99 vol. % of permeable skeleton structure of titanium, titanium aluminide, Ti-based alloys, and / or mixtures thereof infiltrated with low-melting metal selected from Al, Mg, or their alloys, and (b) 1-90 vol. % of ceramic and / or metal inserts positioned within said skeleton, whereby a normal projection area of each of said inserts is equal to or larger than the cross-section area of a bullet or a projectile body. The MMMC are manufactured as flat or solid-shaped, double-layer, or multi-layer articles containing the same inserts or different inserts in each layer, whereby insert projections of each layer cover spaces between inserts of the underlying layer. The infiltrated metal contains 1-70 wt. % of Al and Mg in the balance, optionally, alloyed with Ti, Si, Zr, Nb, V, as well as with 0-3 wt. % of TiB2, SiC, or Si3N4 sub-micron powders, to promote infiltrating and wetting by Al-containing alloys. The manufacture includes (a) forming the permeable metal powder and inserts into the skeleton-structured preform by positioning inserts in the powder followed by loose sintering in vacuum to provide the average porosity of 20-70%, (b) heating and infiltrating the porous preform with molten infiltrating metal for 10-40 min at 450-750° C., (c) hot isostatic pressing of the infiltrated composite, and (d) re-sintering or diffusion annealing. The positioning of the ceramic inserts in Ti-based powder is carried out by using a metal grid aiding the placement of inserts in a predetermined geometric pattern, and said grid becomes the integral part of the macrocomposite material. The technology is suitable for the manufacture of flat or shaped metal matrix macrocomposites having improved ductility and impact energy absorption such as lightweight bulletproof plates and sheets for airplane, helicopter, and automotive applications.

Methods for making various metallic alloys such as nickel, cobalt and / or iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent casting of the melt in the graphite molds under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding.

A process for producing sheets of γ-TiAl includes the steps of forming a melt of a γ-TiAl alloy; casting the γ-TiAl alloy to form an as-cast γ-TiAl alloy; encapsulating the as-cast γ-TiAl alloy to form an as-cast γ-TiAl alloy preform; and rolling the as-cast γ-TiAl alloy preform to form a sheet comprising γ-TiAl.

The present disclosure includes a turbocharger. The turbocharger may include a titanium-aluminide turbine and a shaft. A single joint connects the turbine to the shaft. The joint may include an alloy comprising at least 80 atomic percent nickel and palladium.

Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with titanium carbide. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with titanium carbide via either chemical deposition or plasma assisted chemical vapor deposition, magnetron sputtering or sputtering. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

The present disclosure includes a turbocharger. The turbocharger may include a turbine that includes titanium-aluminide and a shaft that includes titanium. A single joint connects the turbine to the shaft.

An intermetallic composite and method of making an intermetallic composite is disclosed comprising a porous titanate preform of the formula εxTiyOz, where ε represents an element reduceable by molten aluminum to form an aluminate of the formula εiAjOk. Adding aluminum and heating the preform sufficient to melt the aluminum results in formation of a post-combustion intermetallic composite comprising both titanium aluminide and 68 -aluminate.

The present invention relates to the manufacture of fully dense strips, plates, sheets, and foils of titanium alloys, titanium metal matrix composites, titanium aluminides, and flat multilayer composites of said materials manufactured by direct rolling and sintering of blended powders. The resulting titanium alloy flat products are suitable in the aerospace, automotive, sporting goods, and other industries. The process includes the following steps: (a) providing a C.P. titanium matrix powder and at least one powder of alloying components such as elemental alloying powder, pre-alloyed master alloy powders, and / or hard reinforcing particles, (b) mechanical activation by attrition of all alloying components, whereby the particle size of attrited alloying powders is at least ten times smaller than the particle size of the matrix titanium powder, (c) blending titanium powder as a ductile matrix material with attrited alloying powders obtained in step (b), (d) cold direct powder rolling of the blend in a mill with horizontally-positioned rolls to achieve density of the rolled strip of 60±20% of the theoretical value, whereby diameters of rolls are different, so that the green strip is bent for the subsequent densification by a second horizontal re-rolling mill staying in line with the first powder rolling mill, and rotations of edging pair of rolls of at least one of the said mills differ in the rate by 5-15% to promote densification of the green strip by shear deformation, the diameter of the rolls of the direct powder rolling mill is 40-250 times larger than thickness of the rolled strip, (e) densification by cold re-rolling of the green strip in a horizontal rolling mill, whereby diameter of the rolls of the densification mill is 1.1-5 times larger than the diameter of rolls of the direct powder rolling mill to provide compressive action and avoid shearing action of the green strip and achieve density of the rolled strip in the range of 90±10%, (f) multiple cold re-rolling of the strip in vertically-positioned rolls at equal rotation rate of the edging rolls to achieve density of the green rolled strip about 100% of the theoretical value, and (g) sintering of near fully-dense green rolled strip in vacuum, or in protective atmosphere batch furnace, or in continuous belt furnace in protective atmosphere. Typical mechanical properties of fully-dense Ti-6Al-4V alloy strips manufactured by the process of the present invention are: tensile strength is 130-140 ksi (897-966 MPa), yield strength is 120-130 ksi (828-897 MPa), and elongation is over 10%.

A frictional welding process for joining a titanium aluminide turbine to a titanium alloy shaft is disclosed. The disclosed process includes preheating the turbine to a designated temperature, providing a specially-designed joining interface geometry at the distal end of the shaft and optimizing the frictional welding parameters. The frictional welding is carried out in multiple steps but, while the shaft is being spun by a rotating chuck, two different pressures and two different time periods are used until the narrower portions of the distal end of the shaft have been fused onto the welding surface of the turbine. Then, an additional forging step with yet another engagement pressure between the shaft and the turbine is carried out without rotation of the shaft.

Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with pyrolytic graphite. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with pyrolytic graphite via a chemical deposition process. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.