Abstract: The inventive titanium alloy comprises, expressed in mass %: aluminium 4.0-6.0; vanadium 4.5-5.0; molybdenum 4.5-5.0; 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 total aluminum and zirconium content does not exceed 7.2. The inventive method for heat treatment consists in heating to t&bgr;<>&agr;+&bgr;−(30-70)° C., conditioning during 2-5 hrs. at that temperature, 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: This invention relates to a high temperature melting composition and a method of using the composition for brazing high temperature niobium-based substrates, such as niobium-based refractory metal-intermetallic compositions (RMIC), including but not restricted to niobium-silicide composite alloys. The high temperature melting composition can include one or more alloys. The alloys include a base element selected from titanium, tantalum, niobium, hafnium, silicon, and germanium. The alloys also include at least one secondary element that is different from the base element. The secondary element can be selected from chromium, aluminum, niobium, boron, silicon, germanium and mixtures thereof. When two or more alloys are included in the composition, it is preferable, but not required, to select at least one lower melting alloy and at least one higher melting alloy. The composition is preferably a homogeneous mixture of the two or more alloys combined in powder form.

Abstract: A muffler of a muffler made of a titanium alloy wherein advantages of lightness and corrosion-resistance that the titanium alloy originally has are used, and heat-resistance and oxidization-resistance are heightened without damaging costs or workability so that the span of life and flexibility for design are improved. A muffler made of a titanium alloy, wherein the titanium alloy comprises 0.5-2.3% by mass of Al and optionally one or more other alloying elements. The metal texture may comprise more than 90% by volume of the &agr; phase and 20% or less of the &bgr; phase. This muffler is superior in heat-resistance, oxidization-resistance, weldability and so on.

Abstract: In an alloy on the basis of titanium aluminides niobium is included in the alloy of titanium and aluminum.

Abstract: In order to improve castability of a titanium alloy, 0.1-5 wt %, preferably 0.5-3 wt %, of bismuth is doped, based on the weight of bismuth and the titanium alloy. The titanium alloy is for making a dental casting or a medical implant.

Abstract: A process of preparing aligned, in-situ, two-phase single crystal alloys of titanium, aluminum and niobium which comprises growing the alloys at rates of about 3.0 mm. to about 6.0 mm. per hour by rotating a seed rod alloy consisting essentially of Ti-43 to 45 Al-10 to 12 Nb+0.5 Si, in atomic percent, at about 7.75 to 8.25 RPM while in contact with a rotating feed rod alloy consisting essentially of Ti-43 to 45 Al-10 to 12 Nb, in atomic-percent, rotating at about 5.75 to 6.25 RPM in an atmosphere of substantially pure argon at melt temperatures ranging from about 1650° C. to 1750° C. to obtain two-phase single crystal alloys of Ti-43 to 45Al-10 to 12 Nb characterized as having improved ductility, excellent oxidation resistance, and high-temperature creep strength. These alloys are particularly useful for manufacturing high-temperature material components for internal combustion engines, gas turbines, and advanced aircraft engines.

Abstract: A creep resistant titanium aluminide alloy having fine particles such as boride particles at colony boundaries and/or grain boundary equiaxed structures. The alloy can include alloying additions such as ≦10 at % W, Nb and/or Mo. The alloy can be free of Cr, V, Mn, Cu and/or Ni and can include, in atomic %, 45 to 55% Ti, 40 to 50% Al, 1 to 10% Nb, 0.1 to 2% W, up to 1% Mo and 0.1 to 0.8% B or the alloy can include, in weight %, 50 to 65% Ti, 25 to 35% Al, 2 to 20% Nb, up to 5% Mo, 0.5 to 10% W and 0.01 to 0.5% B.

Abstract: The invention relates to TiAl-base alloys with excellent oxidation resistance, and a method for producing the same. The TiAl-base alloy of the invention comprises a substrate and a surface part formed on the substrate, the surface part comprising at least one element of Cr, Nb, Ta and W and having a surface condition capable of forming a dense film of an oxide of the element or Al2O3 in high-temperature oxidizing atmospheres. The method of the invention comprises heating a TiAl-base alloy material having an Al content of from 15 at. % to 55 at. % in the presence of an oxide having a smaller negative value of standard free energy of formation than that of alumina. The method of the invention provides TiAl-base alloys with excellent oxidation resistance. The TiAl-base alloys of the invention have significantly improved oxidation resistance and are resistant to heat at high temperatures of 900° C. or higher.

Abstract: A muffler of a muffler made of a titanium alloy wherein advantages of lightness and corrosion-resistance that the titanium alloy originally has are used, and heat-resistance and oxidization-resistance are heightened without damaging costs or workability so that the span of life and flexibility for design are improved. A muffler made of a titanium alloy, wherein the titanium alloy comprises 0.5-2.3% by mass of Al and optionally one or more other alloying elements. The metal texture may comprise more than 90% by volume of the &agr; phase and 20% or less of the &bgr; phase. This muffler is superior in heat-resistance, oxidization-resistance, weldability and so on.

Abstract: This invention relates to a TiAl intermetallic compound-based alloy exhibiting excellent heat resistance, oxidation resistance and resonance resistance and having a cast structure composed of fine equiaxed grains. Specifically, it relates to a TiAl intermetallic compound-based alloy comprising of 45 to 48 atomic percent of Al, 5 to 9 atomic percent of Nb, 1 to 2 atomic percent of Cr, 0.2 to 0.5 atomic percent of Si, 0.3 to 2 atomic percent of Ni, 0.01 to 0.05 atomic percent of Y, and the balance being Ti and incidental impurities, the alloy exhibiting excellent heat resistance, oxidation resistance and resonance resistance and having a cast structure formed of fine equiaxed grains.

Abstract: A TiAl based alloy having excellent strength as well as an improvement in toughness at room temperature, in particular an improvement in impact properties at room temperature, and a production method thereof, and a blade using the same are provided. This TiAl based alloy has a microstructure in which lamellar grains having a mean grain diameter of from 1 to 50 &mgr;m are closely arranged. The alloy composition is Ti-(42-48)Al-(5-10) (Cr and/or V) or Ti-(38-43)Al-(4-10)Mn. The alloy can be obtained by subjecting the alloy to high-speed plastic working in the cooling process, after the alloy has been held in an equilibrium temperature range of the &agr; phase or the (&agr;+&bgr;) phase.

Abstract: The disclosed &bgr; titanium alloys contain alloying elements of molybdenum between 10.0 and 12.0 weight percent, aluminum between 2.8 and 4.0 weight percent, chromium and vanadium between 0.0 and 2.0 weight percent, and niobium between 0.0 and 4.0 weight percent. Orthodontic arch wires and appliances of nickel-free &bgr; titanium alloys having pseudo-elastic properties associated with stress-induced martensitic transformation. These arch wires and appliances were found to possess a high strain recovery up to 3.5% strain of deformation, a lower stiffness yielding relatively constant force for tooth movement and improved formability over that of pseudo-elastic nitinol. Eyeglasses having parts made of such materials can be welded. Stents made of this material avoid problems which a certain percentage of the population have when nickel is included within alloys used in the human body. Other medical devices which are used in the body also have this benefit.

Abstract: A two-phase titanic aluminide alloy having a lamellar microstructure with little intercolony structures. The alloy can include fine particles such as boride particles at colony boundaries and/or grain boundary equiaxed structures. The alloy can include alloying additions such as ≦10 at % W, Nb and/or Mo. The alloy can be free of Cr, V, Mn, Cu and/or Ni and can include, in atomic %, 45 to 55% Ti, 40 to 50% Al, 1 to 5% Nb, 0.3 to 2% W, up to 1% Mo and 0.1 to 0.3% B. In weight %, the alloy can include 57 to 60% Ti, 30 to 32% Al, 4 to 9% Nb, up to 2% Mo, 2 to 8% W and 0.02 to 0.08% B.

Abstract: A creep resistant titianium aluminide alloy composition consisting essentially of, in atomic percent, about 44 to about 49 Al, about 0.5 to about 4.0 Nb, about 0.0 to about 3.0 Mn, about 1.0 to about 1.5 W, about 0.1 to about 1.0 Mo, about 0.4 to about 0.75 Si, and the balance Ti.

Abstract: A titanium aluminide having the following chemical composition:Al: 33.5-34.5 wt %,Fe: 1.5-2.0 wt %,V: 1.5-2.0 wt %, andB: 0.05-0.10 wt %, with the remainder being Ti and inevitable impurities. Greatly decreased is a ratio of .alpha..sub.2 phase (Ti.sub.3 Al) precipitatable in a TiAl matrix. Accordingly, it is possible to deposit a trace amount (2-5%) of thin line-like .alpha..sub.2 phase in the TiAl matrix. This titanium aluminide is particularly suitable for precision casting.

Abstract: A titanium-based intermetallic alloy having a high yield stress, a high creep resistance and sufficient ductility at ambient temperature has the following chemical composition as measured in atomic percentages:Al, from 16 to 26; Nb, from 18 to 28; Mo, from 0 to 2; Si, from 0 to 0.8; Ta, from 0 to 2; Zr, from 0 to 2; and Ti as the balance to 100; with the condition that Mo+Si+Zr+Ta>0.4%.Production, working and heat-treatment ranges adapted to the intended use of the material are also defined.

Abstract: TiAl intermetallic compound-based alloys comprising Ti, Al, Nb and Cr and, if necessary, further comprising Ni and Co, which have excellent plastic workability, good resistance to oxidation at high temperatures, high strength or good creep resistance.

Abstract: The methods of the present invention provide efficient mechanical milling or alloying of stock materials of titanium and aluminum in order to increase yield of the titanium stock and reduce cost in connection with the production of a titanium-aluminum-based alloy sinter. Sponge titanium, which has a particle size of 1 to 20 mm and which contains hydrogen at 3.5 mass % or more, is used as the titanium stock. The sponge titanium is ball-milled with an aluminum stock in an argon atmosphere to produce a hydrogen-containing titanium-aluminum-based alloy powder. Furthermore, this powder may be sintered, as required.

Abstract: A joined tubular body comprises a titanium alloy pipe of which crystal grain is hard to coarsen at the time of welding or hot-extruding, which consists by weight percentage of at least one element selected from 0.01.about.10% of S, 0.01.about.10% of Se and 0.01.about.10% of Te (the total sum does not exceed 10%), one or both of 0.01.about.10% REM and 0.01.about.10% of Ca (the total sum does not exceed 10%), and the above pipe is joined to a titanium alloy pipe consisting of the above elements and also at least one element selected from Al.ltoreq.10%, V.ltoreq.25%, Sn.ltoreq.15%, Co.ltoreq.10%, Cu.ltoreq.10%, Ta.ltoreq.15%, Mn.ltoreq.10%, Hf.ltoreq.10%, W.ltoreq.10%, Si.ltoreq.0.5%, Nb.ltoreq.20%, Zr.ltoreq.10%, Mo.ltoreq.15%, and 0.ltoreq.0.1% (the total sum does not exceed 30%).

Abstract: Method and apparatus for melting reactive metallic materials, such as for example titanium base alloys and other reactive alloys, by selective and sequential induction heating of a plurality of solid alloy charge components segregated in a refractory melting vessel in a manner to effect rapid top-to-bottom melting that avoids harmful reaction of the melt with refractory melting vessel material and contamination of the melt.

Abstract: An improved high-modulus, low-cost, castable, weldable titanium alloy and a process for making such an alloy is provided. In general, titanium is alloyed with about 0.75 weight percent iron and about 8 weight percent aluminum to result in an alloy with a modulus of over 21.times.10.sup.6 psi. This modulus is above the modulus for conventional castable titanium alloys, such as the commercially-available castable titanium alloy containing 6 weight percent aluminum and 4 weight percent vanadium.Applications for this alloy include golf club heads, which can be fabricated by casting a golf club head body from the above alloy and welding a sole plate onto the cast golf club head body. This provides a golf club head with superior energy transfer characteristics for hitting a golf ball.

Abstract: A titanium aluminide based alloy consisting of 42-48 at % aluminium, 2-5 at % niobium, 3-8 at % zirconium, 0-1 at % boron, 0-0.4 at % silicon and the balance, apart from incidental impurities, is titanium. The titanium aluminize alloy composition has a satisfactory combination of high tensile strength, acceptable ductility at room temperature and low secondary creep rate at elevated temperature, so as to be suitable for use in high temperature applications for example aero-engines and automobile engines. It is suitable for compressor discs and compressor blades of aero-engines.

Abstract: An alloy on the basis of .gamma.-TiAl with an addition of the elements Re and Pd, which have a low oxygen affinity and/or one of elements X consisting of Ag, Cu, and Au, which are capable of forming compounds of the type AlX.sub.4 with aluminum and, if present, are present in the amounts of 2.5-20 At- % Re, 5-20 At- % Cu, or 5-20 At- % Ag, such an alloy having excellent oxidation resistance in combination with low density and high strength.

Abstract: This invention is a Titanium Aluminum alloy consisting essentially of the formula in atomic percent; Ti.sub.Bal. Al.sub.45-48 B.sub.0.01-0.75 Cr.sub.0-2 W .sub.0.25-2.25 Si.sub.0.1-0.7. The Boron is present in an atom. % of 0.01-0.75. The desired range is 0.1-0.5. The preferred range is 0.25+/-0.05. The optimum range is 0.25. The Chromium is present in an atom. % of 0-2. The desired range is 1.3-1.6. The preferred range is 1.5+/-0.1. The optimum range is 1.5. The Tungsten is present in an atom. % of 0.25-2.25. The desired range is 0.3-2.11. The preferred range is 0.75+/-0.05. The optimum range is 0.75. The Silicon is present in an atom. % of 0.1-0.7. The desired range is 0.4-0.6. The preferred range is 0.5+/-0.05. The optimum range is 0.5. The atom. % ratio of Cr/W is 0-5. The desired range is 1.33-2.69. The preferred range is 1.8-2.6. The optimum range is 1.85-2.5. The preferred alloy is a Titanium Aluminum alloy consisting essentially of the formula in atomic percent; Ti.sub.Bal. Al.sub.45.82 B.sub.0.25 Cr.

Abstract: The invention is a process for simultaneously improving at least two mechanical properties of mill-processed (.alpha.+.beta.) titanium alloy, which may or may not contain silicon, which includes steps of heat treating the mill-processed titanium alloy such that the (.alpha.+.beta.) microstructure of said alloy is transformed into an (.alpha.+.alpha..sub.2 +.beta.) microstructure, preferably containing no silicides. The heat treating steps involve subjecting the mill-processed titanium alloy to a sequence of thermomechanical process steps, and the mechanical properties which are simultaneously improved include (a) tensile strength at room, cryogenic, and elevated temperatures; (b) fracture toughness; (c) creep resistance; (d) elastic stiffness; (e) thermal stability; (f) hydrogen embrittlement resistance; (g) fatigue; and (h) cryogenic temperature embrittlement resistance. As a consequence of the process, the (.alpha.+.alpha..sub.2 +.beta.) microstructure contains equiaxed alpha phase strengthened with .alpha.

Abstract: In an alloy having a Ti/Al ratio close to 52/48, good castability, by virtue of initial solidification in the .beta. phase, together with a sufficiently low density and a good oxidation resistance are obtained by introducing approximately 2 atom. % of rhenium and/or tungsten. These alloys can be used especially for the production of aeronautical turbomachine components.

Abstract: A coating for protecting titanium aluminide alloys, including the TiAl .gamma.+Ti.sub.3 Al (.alpha..sub.2) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000.degree. C. is disclosed. This protective coating consists essentially of titanium, aluminum, and chromium in the following approximate atomic ratio:Ti(41.5-34.5)Al(49-53)Cr(9.5-12.

Abstract: A diffusion barrier to help protect titanium aluminide alloys, including the coated alloys of the TiAl.gamma.+Ti.sub.3 Al (.alpha..sub.2) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000.degree. C. is disclosed. The coating may comprise FeCrAlX alloys. The diffusion barrier comprises titanium, aluminum, and iron in the following approximate atomic percent:Ti-(50-55)Al-(9-20)Fe.This alloy is also suitable as an oxidative or structural coating for such substrates.

Abstract: This invention relates to a titanium alloy anode for the electrolytic production of manganese dioxide, wherein the alloy anode is made of titanium as a base metal, and comprises at least three other metals selected from the group consisting of manganese, chromium, iron, silicon, aluminum, cerium, neodymium and mischmetal; the addition of which may be within the range of 8 to 20 weight percent based on the weight of the total composition. The alloy anode, being easy to manufacture and having irregular sectional profiles, is free from severe passivation during electrolytic production using high current density due to its combined properties. The alloy anode, being highly resistant to corrosion by the electrolysis solution, requires no activation treatment during the electrolytic process. The purposefully-designed shapes of the anode permit good attachment of the deposited product layer and prevent the deposition from cracking and peeling-off.

Abstract: In a process for the production of alloys from at least two alloy components (A, B, C, D, . . . ) with different melting points by melting in an inductively heated cold-walled crucible (1) with a cooled crucible base (3), in order to obtain an exact and homogeneous alloy composition at least a part of the alloy components (A, B, C, D, . . . ) are introduced into the cold-walled crucible (1) consecutively and in stacked fashion where eithera) the alloy component (a) in each case with the lower melting point is introduced first orb) the alloy component in each case with the lower density is introduced firstand following the introduction at least one of further alloy component the heating energy is switched on. The process serves preferably for the production of the intermetallic phase TiAl, where firstly the aluminium and then the titanium are stacked in the cold-walled crucible (1).

Abstract: Creep resistant gamma titanium alumninide comprising titanium in the range of about 55 to about 71 weight % and aluminum in the range of 29 to about 35 weight % by virtue of including oxygen intentionally in the composition in an effective amount to significantly increase the high temperature creep resistance of the alloy. The composition can include greater than about 800 ppm up to about 1500 ppm oxygen to this end.

Abstract: TiAl-based intermetallic compound alloys contain chromium and consist essentially of a dual-phase microstructure of .gamma. and .beta. phases, with the .beta. phase precipitating at .gamma. grain boundaries. The .beta. phase precipitating at .gamma. grain boundaries is 2% to 25% by volume fraction. A process for preparing TiAl-based intermetallic compound alloys comprises the steps of preparing a molten TiAl-based intermetallic compound alloy of a desired composition, solidifying the molten alloy, homogenizing the solidified alloy by heat treatment, and thermomechanically working the homogenized alloy.

Abstract: A titanium matrix composite having eutectically formed titanium-ceramic reinforcement containing at least two of the elements of silicon, aluminum, zirconium, manganese, chromium, molybdenum, carbon, iron, boron, cobalt, nickel, germanium and copper.

Abstract: A titanium matrix composite having eutectically formed titanium alloy reinforcement containing at least two of the elements of silicon, aluminum, zirconium, manganese, chromium, molybdenum, carbon, iron, boron, cobalt, nickel, germanium and copper.

Abstract: A gamma titanium aluminide alloy is provided, based on the intermetallic compound TiAl, in which the resulting alloy is characterized by high creep strength and environmental resistance at elevated temperatures in excess of about 650.degree. C., and as high as about 850.degree. C. The alloy achieves these desirable properties through limited and interrelated additions of chromium, niobium and tantalum, whose combined amount is established by a minimum amount necessary to achieve a desired level of oxidation resistance.

Abstract: A TiAl base alloy containing 46 to 54 mol % of Ti and 46 to 52 mol % of Al in which Sb is added within a range of 0.1 to 1 mol %, at least one element of Hf and/or Zr is further added within a range of 0 to 3 mol %, and three phases of a .gamma. phase, an .alpha..sub.2 phase and Sb-rich phase coexist.

Abstract: A titanium aluminide component is disclosed based on intermetallic phases of the system titanium-aluminum and having an aluminum content between 42 at. Percent and 53 at. Percent. The titanium aluminide component has on its surface a lamellar, eutectoid Ti.sub.3 Al/TiAl structure. Also disclosed is a process for preparing the titanium aluminide component.

Abstract: TiAl-besed intermetallic compound alloys contain chromium and consist essentially of a dual-phase microstructure of .gamma. and .beta. phases, with the .beta. phase precipitating at .gamma. grain boundaries. The .beta. phase precipitating at .gamma. grain boundaries is 2% to 25% by volume fraction. A process for preparing TiAl-based intermetallic compound alloys comprises the steps of preparing a molten TiAl-based intermetallic compound alloy of a desired composition, solidifying the molten alloy, homogenizing the solidified alloy by heat treatment, and thermomechanically working the homogenized alloy.

Abstract: A high strength and high ductility TiAl-based intermetallic compound includes a content of aluminum in a range represented by 42.0 atom %.ltoreq.Al.ltoreq.50.0 atom %, a content of vanadium in a range represented by 1.0 atom %.ltoreq.V.ltoreq.3.0 atom %, a content of niobium in a range represented by 1.0 atom %.ltoreq.Nb.ltoreq.10.0 atom %, a content of boron in a range represented by 0.03 atom %.ltoreq.B.ltoreq.2.2 atom %, and the balance of titanium and unavoidable impurities. A product of the TiAl-based intermetallic compound is formed by only casting or casting followed by a homogenizing thermal treatment.

Abstract: A multiphase, high-temperature material contains an intermetallic base alloy of the Ti.sub.3 Al type, which is intended especially for use in heat engines such as internal combustion engines, gas turbines and aircraft engines. The material contains from 44 to 73 atom % titanium, from 19 to 35 atom % aluminum, from 2 to 6 atom % silicon, and from 5 to 15 atom % niobium. The desired microstructure is attained by heat treating the alloy at between 800.degree. and 1100.degree. C.

Abstract: The present invention comprises a plurality of single phase gamma TiAl alloys modified by Ta. These alloys comprise Ti.sub.(45-46) Al.sub.(50-51) Ta.sub.4 in atomic percent, and exhibit significant room temperature ductility, in the range of 1.3-2.1% tensile elongation. The alloys may be made by the use of cast and forging techniques.

Abstract: A method of heat treating Ti/Al-base alloys to improve tensile ductility and reduce the likelihood of in-service embrittlement is disclosed. The method comprises: selecting a Ti/Al-base alloy that contains a mixture of .alpha. and .alpha.2 phases, heat treating the alloy so as to form a controlled amount of .alpha.2 particles, and then cooling the alloy so as to primarily promote the growth of additional .alpha.2 on the previously formed particles, rather than the nucleation of new .alpha.2 particles. This method may be used with Ti/Al-base alloys that also comprise Sn, Ga and In as alloy constituents, and is believed to be useful for a number of Ti/Al-base engineering alloys. Alloys made by this method have been observed to maintain significant tensile ductility, even after aging at elevated temperatures under load (e.g. creep conditions).

Abstract: An article comprises a Cr-bearing, predominantly gamma titanium aluminide matrix including second phase dispersoids, such as TiB.sub.2, in an amount effective to increase both the strength and the ductility of the matrix.

Abstract: A Ti--Al system intermetallic compound comprised of 25 at. % to 75 at. % of aluminum and the remainder of titanium. The compound includes 0.004 at. % to 1.0 at. % each of at least one halogen element selected from the group consisting of fluorine, chlorine, bromine and iodine. Alternatively, to provide a Ti--Al system intermetallic compound with oxidation resistance, the surface of the Ti--Al system intermetallic compound is heated to 800.degree. C. to 1125.degree. C. in a mixture of gas including 2 ppm to 1% by volume of at least one halogen element selected from the group consisting of fluorine, chlorine, bromine and iodine, and also including 0.1% by volume or more of oxygen. Thus, a dense aluminum oxide film is formed on the surface of the intermetallic compound. Alternatively, to form the dense aluminum oxide film, at least one halogen element is first disposed on the part providing the oxidation resistance of the intermetallic compound, and heated for 0.2 hour or longer at 800.degree. C. to 1125.degree.

Abstract: An article comprises a Cr-bearing, predominantly gamma titanium aluminide matrix including second phase dispersoids, such as TiB.sub.2, in an amount effective to increase both the strength and the ductility of the matrix.

Abstract: Titanium alloys containing aluminum, hafnium, tantalum, and silicon are found to have improved tensile strengths as well as ductility and oxidation resistance at temperatures up to and above 750.degree. C. without embrittlement.

Abstract: A TiAl alloy base melt including at least one of Cr, C, Ga, Mo, Mn, Nb, Ni Si, Ta, V and W and at least about 0.5 volume % boride dispersoids is investment cast to form a crack-free, net or near-net shape article having a gamma TiAl intermetallic-containing matrix with a grain size of about 10 to about 250 microns as a result of the presence of the boride dispersoids in the melt. As hot isostatically pressed and heat treated to provide an equiaxed grain structure, the article exhibits improved strength.

Abstract: Gamma titanium aluminide alloy articles having improved properties are produced by the following methods:The first of these methods comprises the steps of: (a) heat treating an alloy billet or preform at a temperature in the approximate range of T.sub..alpha. to T.sub..alpha. +100.degree. C. for about 0.5 to 8 hours, (b) shaping the billet at a temperature between T.sub..alpha. -30.degree. C. and T.sub..alpha. to produce a shaped article, and (c) aging the thus-shaped article at a temperature between about 750.degree. and 1050.degree. C. for about 2 to 24 hours.The second method comprises (a) rapidly preheating an alloy preform to a temperature in the approximate range of T.sub..alpha. to T.sub..alpha. +100.degree. C., (b) shaping the billet at a temperature between T.sub..alpha. and T.sub..alpha. +100.degree. C. to produce a shaped article, and (c) aging the thus-shaped article at a temperature between about 750.degree. and 1050.degree. C. for about 2 to 24 hours.

Abstract: Powder metallurgy techniques are disclosed for fabricating gamma titanium alloy articles (TiAl type alloys) from mixture of powder wherein one species is based on Al.sub.3 Ti and the other Ti.sub.3 Al. Mixtures of these powders in the proper ratio can be compacted, worked, and heat treated to form the desired gamma TiAl alloy.

Abstract: A TiAl intermetallic compound source and a boride which is less stable than TiB.sub.2 are mixed and melted, followed by solidification to form a TiB.sub.2 -dispersed TiAl-based composite material in which the TiB.sub.2 is contained in an amount of 0.3 to 10% by volume. In this process, the dispersed TiB.sub.2 particles become very fine, so that the hardness as well as the elongation and bending strength of the TiAl material are improved by the finely dispersed TiB.sub.2 particles.