Abstract: An extension is formed directly on an article by melting a portion or end of the article having an attached integral mandrel within a ceramic mold, followed by cooling of the end under controlled conditions sufficient to cause an integral extension to solidify on the article. A ceramic mold is attached on the end of the article over the integral mandrel with a mold cavity that generally defines the shape of the extension to be formed. The mold may be formed in situ on the mandrel, or preformed and attached to the subject article over the mandrel. Extensions formed by the method of this invention have a microstructure that is continuous and compatible with that of the article. Such microstructures may include epitaxial growth of the extension from the microstructure of the article. The method establishes a temperature gradient within the article during solidification that may be further controlled by auxiliary heating and/or cooling of the article and/or extension during the practice of the method.

Abstract: An extension is formed directly on an article by melting a compatible alloy preform within a ceramic mold, followed by cooling of the end under controlled conditions sufficient to cause an integral extension to solidify on the article. A ceramic mold is attached on the end of the article with a mold cavity that generally defines the shape of the extension to be formed. The mold may be formed in situ on a removable mandrel, or preformed and attached to the subject article. Extensions formed by the method of this invention have a microstructure that is continuous and compatible with that of the article. Such microstructures may include epitaxial growth of the extension from the microstructure of the article. The method establishes a temperature gradient within the article during solidification that may be further controlled by auxiliary heating and/or cooling of the article and/or extension during the practice of the method.

Abstract: Single crystal superalloy castings are described which have excellent oxidation resistance. The oxidation resistance is due to the presence of small but effective amounts of magnesium in the casting. Single crystal castings containing magnesium in the range of 5-200 parts per million, by weight, are described.

Abstract: A gas-turbine moving blade made of a Ni-base superalloy containing less grain boundary strengthening elements, in which a blade portion is formed of a single crystal and the rest is formed of columnar crystals, and a gas turbine including the moving blade. A thermal efficiency of the gas turbine can be improved to 35% or more, and a thermal efficiency of complex power generation with a steam turbine can be improved to 45% or more.

Abstract: The aluminum conductor having increase of its electric resistivity kept small at ultra low temperature of 30.degree. K. or lower even after cyclic strain is given at ultra low temperature, by controlling the crystal structure of the high purity aluminum conductor with purity of 99.9-99.9999 wt %. The crystal structure consist of (i) a veritable single or a substantially single crystal consisting of a bundle of sub-grains which have their crystal axes in the same direction or in the directions within a couple of degrees of deviation as a whole which has a specific crystal axis of <111> or <100> or the crystal axes close thereto in the longitudinal direction of the aluminum conductor, or (ii) a polycrystal most of which grains have respective specific crystal axes of <111> and/or <100>, or the crystal axes close thereto with respect to each grain in the longitudinal direction of the aluminum conductor, and have specific grain size of 0.01 mm to 3.0 mm.

Abstract: A nickel base superalloy composition consisting essentially of, in weight %, 9.3-10.0% Co, 6.4-6.8% Cr, 0.5-0.7% Mo, 6.2-6.6% W, 6.3-6.7% Ta, 5.45-5.75% Al, 0.8-1.2% Ti, 0.07-0.12% Hf, 2.8-3.2% Re, and balance essentially Ni wherein a carbon concentration of about 0.01 to about 0.08 weight % is provided for improving the cleanliness of a single crystal investment casting produced therefrom.

Abstract: Single crystal superalloy castings are described which have excellent oxidation resistance. The oxidation resistance is due to the presence of small but effective amounts of magnesium in the casting. Single crystal castings containing magnesium in the range of 5-200 parts per million, by weight, are described.

Abstract: A NiAl intermetallic alloy and article is provided with improved high temperature strength, particularly stress rupture strength, through the generation of a multiphase microstructure comprising a beta matrix and at least one precipitate phase. The strength properties and microstructure are the result of alloying with at least two elements selected from Ga, Hf, and optionally Ti, Zr, Ta, Nb, and V, in defined ranges. Preferred are at least two of the elements Ga, Hf, and Ti, and specifically preferred are all three. A specifically preferred form of the invention, in atomic percent, is about 45-59% Ni, about 0.02-0.5% Ga, about 0.2 to less than 1% Hf, about 0.1-10% Ti, with the balance A1 and incidental impurities.

Abstract: This invention relates to a hot corrosion resistant nickel-based superalloy comprising the following elements in percent by weight: from about 11.5 to about 13.5 percent chromium, from about 5.5 to about 8.5 percent cobalt, from about 0.40 to about 0.55 percent molybdenum, from about 4.5 to about 5.5 percent tungsten, from about 4.5 to about 5.8 percent tantalum, from about 0.05 to about 0.25 percent columbium, from about 3.4 to about 3.8 percent aluminum, from about 4.0 to about 4.4 percent titanium, from about 0.01 to about 0.06 percent hafnium, and the balance nickel plus incidental impurities, the superalloy having a phasial stability number N.sub.V3B less than about 2.45. Single crystal articles can be suitably made from the superalloy of this invention. The article can be a component for a gas turbine engine and, more particularly, the component can be a gas turbine blade or gas turbine vane.

Abstract: The present invention provides a nickel base superalloy having an improved combination of stress rupture life and microstructural stability with respect to the formation of TCP phases. A unique feature is the specific combination of the content of elements consisting of Al, Ti and W in a second range defined by their sum in a nickel base superalloy having high contents of rhenium, in excess of 1.3 atomic percent (about 4.0 weight percent) to lower the propensity for TCP phase formation and thus render the alloy more stable at high temperatures. The interaction of Ru with the remaining elements to modify the refractory element phase partitioning provides unique capabilities, causing elements to partition to the gamma phase or the gamma prime phase in a reverse direction than normally experienced in Ni-base superalloys. These Ni-base superalloys are termed Ru-containing Reverse Partitioning Ni-base Superalloys.

Abstract: A nickel base superalloy capable of being made into a single crystal article is provided with high temperature strength and improved stability by limiting the presence of an undesirable SRZ constituent. Significant to the control of formation of such undesirable constituents is the control of the amount of Re in the alloy in combination with elements such as Al, Cr, Ta, Mo, Co and W. A solution heat treatment is provided for additional control.

Abstract: An improved nickel-based single crystal superalloy has both an extremely low sulphur content and a very low lanthanum, cerium, or lanthanum plus yttrium, or cerium plus yttrium, or content, whereby the amount while very low, is sufficient to react with the remaining available sulphur in the alloy and with sulphur from the fuel used in engine operation, such that the very thin, protective scale layer of aluminum oxide formed on the surfaces of the nickel-based alloy parts exposed to the very high temperatures incident in high efficiency turbine engines, will afford effective, long-life protection for the surfaces of these engine components, through the virtual elimination of spalling of the aluminum oxide scale during cyclic engine operations.

Abstract: There is provided by the present invention nickel-base superalloys for producing single crystal articles having improved tolerance to low angle grain boundaries and an improved balance between cyclic oxidation and hot corrosion resistance. The improved tolerance arises from the discovery that nickel-base superalloys suitable for casting as single crystal articles can be improved by the addition of small, but controlled, amounts of boron and carbon, and optionally hafnium, and is manifested principally by improved grain boundary strength. As one result of this increased grain boundary strength, grain boundary mismatches far greater than the 6.degree. limit for prior art single crystal superalloys can be tolerated in single crystal articles made from the nickel-base superalloys of this invention. This translates, for example, into lower inspection costs and higher casting yields as grain boundaries over a broader range can be accepted by visual inspection techniques without resort to expensive X-ray techniques.

Abstract: A process is provided for welding a gamma-prime precipitation-strengthened nickel base superalloy by heating the weld area and adjacent region to a ductile temperature, welding while maintaining the entire weld area and adjacent region at the ductile temperature and holding the weldment, weld area and adjacent region at the ductile temperature until the entire weld has solidified. The ductile temperature is above the aging temperature but below the incipient melting temperature of the superalloy.

Abstract: This invention relates to a nickel-based superalloy comprising the following elements in percent by weight: from about 5.0 to about 7.0 percent rhenium, from about 1.8 to about 4.0 percent chromium, from about 1.5 to about 9.0 percent cobalt, from about 7.0 to about 10.0 percent tantalum, from about 3.5 to about 7.5 percent tungsten, from about 5.0 to about 7.0 percent aluminum, from about 0.1 to about 1.2 percent titanium, from about 0 to about 0.5 percent columbium, from about 0.25 to about 2.0 percent molybdenum, from about 0 to about 0.15 percent hafnium, and the balance nickel+incidental impurities, the superalloy having a phasial stability number N.sub.v3B less than about 2.10.

Abstract: Disclosed is a method of making moldless/coreless single crystal castings of NiAl(.beta.') alloys. Drops of molten NiAl(.beta.') alloy is deposited on a starter seed block of single crystal alloy and casting structures are epitaxially grown to predetermined configurations and shapes by repeatedly dropping and solidifying molten NiAl(.beta.') materials.

Abstract: An extension is provided on an end of an article having a directionally oriented microstructure by using the article end as a growth seed in a molten material compatible with material from which the article end is made. The extension is directionally solidified as integral with and as an extension of the article end and with a microstructure compatible with that of the article end.

Abstract: A turbine rotor is formed from a turbine disk having a rim with a circumferential direction, and a plurality of turbine blade segments each fixed to the turbine disk around a circumference of the rim of the turbine disk. The turbine blade segments are oriented such that the elastic modulus of the turbine blade segments parallel to the circumferential direction is less than that of the rim of the turbine disk parallel to the circumferential direction. This arrangement is preferably achieved using single crystal turbine blade segments made of an an alloy having a cubic crystal structure, such as a nickel-based superalloy, with a <010> direction oriented radially and a <001> direction oriented circumferentially.

Abstract: A nickel base superalloy capable of being made into a single crystal article is provided with high temperature strength and improved stability by limiting the Presence of an undesirable SRZ constituent. Significant to the control of formation of such undesirable constituents is the control of the amount of Re in the alloy in combination with elements such as Al, Cr, Ta, Mo, Co and W. A solution heat treatment is provided for additional control.

Abstract: A uniform composite of hypermonotectic composition and a method for producing the same wherein the composition has a plurality of aligned and constrained fibers therein. These fibers serve to uniformly distribute L.sub.11 from the reaction L.sub.I .fwdarw.S.sub.I +L.sub.II.

Abstract: A single crystal shroud, preferably used around the high pressure turbine section of a gas turbine engine, has a composition, in weight percent, of from about 5 to about 10 percent chromium, from about 5 to about 10 percent cobalt, from 0 to about 2 percent molybdenum, from about 3 to about 10 percent tungsten, from about 3 to about 8 percent tantalum, from 0 to about 2 percent titanium, from about 5 to about 7 percent aluminum, from 0 to about 6 percent rhenium, from 0 to about 0.50 percent hafnium, from 0 to about 0.07 percent carbon, from 0 to about 0.015 percent boron, and from 0 to about 0.075 percent yttrium, balance nickel. The environmentally- resistant shroud preferably is used in the as-cast condition without any oxidation and corrosion resistant flowpath coating.

Abstract: A beta phase nickel aluminide microalloyed with iron having improved ductility. Nickel aluminide intermetallics alloyed with no more than about 0.5 atomic percent iron have significantly improved room temperature ductility over conventional unalloyed beta phase nickel aluminides or beta phase nickel aluminides alloyed with higher percentages of iron.

Abstract: An austenitic steel comprising Ni of 9-30%, Cr of 10-23%, and Fe of at least 45%, is characterized in comprising enough Cr and Ni to form whole austenitic structure in the equilibrium diagram at 700.degree. C., having austenitic phase at room temperature, and the austenitic phase is a single crystal, and has superior resistance against stress. The austenitic steel preferably comprises C.ltoreq.0.1%, Si.ltoreq.1%, Mn.ltoreq.2%, Ni 9-15%, Cr 16-18.5%, and at least one of elements selected from the group of Mo 1-3%, Ti 0.05-1%, and Nb 0.1-1.5%. The alloy is useful as a material for members of a reactor core of a nuclear reactor.

Abstract: Nickel aluminide single crystal alloys having improved strength and ductility at elevated temperatures, produced by major elemental additions to strengthen the Ni.sub.3 Al phase by solid solutioning and/or secondary phase formation. The major elemental additions comprise (by weight) 7-20% Al, 0.5-9% molybedenum, 0.5-10% tungsten and 2-15% titanium. Optional minor elemental additions of boron, manganese, silcon and/or hafnium are preferred.

Abstract: A method of improving the low temperature ductility of an iron-aluminide is taught. The aluminide for which the method is applicable is one having between 30 and 50 atom percent of aluminum. The aluminide may also have substituents for part of the iron and for the aluminum. The alloy may contain up to 10 atom percent of substituents for the iron selected from the group of metals comprising nickel cobalt chromium and manganese. The alloy may also contain substituents for the aluminum of up to 5 atom percent of a metal selected from the group comprising titanium, niobium, tantalum, hafnium, zirconium, vanadium, and silicon. The alloy has a B2 crystal structure. The first step of the process is to select the metal to be processed. The next step is to directionally solidify the selected metal. The next step is to determine the Ductile Brittle Transition Temperature (DBTT). The metal is then heated to above the DBTT and is deformed while above the DBTT temperature.

Abstract: A nickel-base superalloy, particularly adapted for use in gas turbine engine single crystal blades and vanes is provided with a specific composition and heat treated in a particular manner to exhibit an improved balance of critical high temperature mechanical properties and resistance to oxidation and hot corrosion significantly superior to presently available alloys. In its broad form, the alloy composition comprises, by weight, 7-12% Cr, 1-5% Mo, 3-5% Ti, 3-5% Al, 5-15% Co, 3-12% W, up to 10% Re, 2-6% Ta, up to 2% Cb, up to 3% V, up to 2% Hf, the balance being essentially nickel and incidental impurities. Nickel-base superalloy single crystal articles formed of the alloy are described, as is the method, including heat treatment, employed to make the article.

Abstract: A nickel-based superalloy consisting essentially of, in weight percent, from about 4 to about 5 percent chromium, from about 11 to about 14 percent cobalt, from about 4 to about 8 percent tungsten, from about 6 to about 10 percent tantalum, from about 5 to about 7 percent aluminum, from about 5.5 to about 8 percent rhenium, from about 0 to about 0.50 percent hafnium, from about 0 to about 0.07 percent carbon, from 0 to about 0.01 percent boron, from 0 to about 0.030 percent yttrium, from 0 to about 6 percent ruthenium, from 0 to about 1 percent molybdenum, from 0 to about 1 percent niobium, and the balance essentially nickel. Articles made from the superalloy of the invention are especially useful when cast as single crystal airfoils for use in advanced gas turbine engines.

Abstract: A precipitation strengthening type nickel base single crystal alloy, which consists essentially of, on a weight percent basis,10-30% chromium,0.1-5% niobium,0.1-8% titanium,0.1-8% aluminum,optionally one or more components selected from the group consisting of 0.1-3% tantalum, 0.05-0.5% copper, 0.05-3% hafnium, 0.05-3% rhenium, 0.05-3% molybdenum, 0.05-3% tungsten, 0.05-0.5% boron, 0.05-0.5% zirconium, andthe remainder being nickel and incidental impurities, and exhibits a narrow solidification temperature range.

Abstract: A NiAl nickel aluminide alloyed with yttrium, optionally gallium, and an element selected from the group consisting of chromium, molybdenum and combinations thereof, having improved room temperature ductility and plastic strain. NiAl nickel aluminide intermetallics alloyed with no more than about 5 atomic percent of additional elements have significantly improved room temperature ductility over conventional unalloyed beta phase nickel aluminides or beta phase nickel aluminides alloyed with higher percentages of additional elements. The NiAl nickel aluminide comprises, in atomic percent, at least 50% nickel, about 0.01% to about 0.25% yttrium, about 0 to about 0.15% gallium, about 0.05% to about 4% of an element selected from the group consisting of chromium, molybdenum and combinations thereof, and balance from about 40% to about 49.85% aluminum and trace impurities.

Abstract: A beta phase nickel aluminide microalloyed with gallium having improved ductility. Nickel aluminide intermetallics alloyed with up to about 0.25 atomic percent gallium have significantly improved room temperature ductility over conventional unalloyed beta phase nickel aluminides or beta phase nickel aluminides alloyed with higher percentages of gallium.

Abstract: The present invention is directed to a heat treatment for nickel-base superalloys used to make single crystal parts and components for gas turbine engines. The heat treatment is conducted in a vacuum or inert atmosphere and includes the steps of solutionizing in a temperature range sufficient to achieve solution of at least 95% of the .gamma.' phase, preferably 2385.degree.-2395.degree. F., for 2 hours; cooling to 2000.degree. F. at 100.degree. F./min minimum, furnace cooling to 1200.degree. F. in 60 min. or less and thereafter cooling to room temperature; heating to 2050.degree..+-.25.degree. F. for 4 hours; furnace cooling to below 1200.degree. F. in 6 min. or less and thereafter to room temperature; and heating to 1650.degree..+-.25.degree. F. for 4 hours and thereafter furnace cooling to room temperature.

Abstract: A method is provided for obtaining an alloy having an ordered microstructure which comprises the steps of heating the central portion of the alloy under uniform temperature so that it enters a liquid phase while the outer portions remain solid, applying a constant electric current through the alloy during the heating step, and solidifying the liquid central portion of the alloy by subjecting it to a temperature-gradient zone so that cooling occurs in a directional manner and at a given rate of speed while maintaining the application of the constant electric current through the alloy. The method is particularly suitable for use with nickel-based superalloys. The method of the present invention produces an alloy having superior characteristics such as reduced segregation. After subsequent precipitation by heat-treatment, the alloys produced by the present invention will have excellent strength and high-temperature resistance.

Abstract: Disclosed are novel nickel base single crystal alloy compositions consisting essentially of, by weight, about 4.0-10.0% chromium, 1.5-6.0% cobalt, 1.0-12.0% molybdenum, 3.0-10.0% tungsten, 2.5-7.0% titanium, 2.5-7.0% aluminum, 3.0-10.0% tantalum, about 0.02%-1.5% of hafnium and/or about 0.02%-1.0% silicon, from about 0.02%-1.0% each of yttrium and/or lanthanum, from about 0.3% to about 8.0% rhenium; from about 0.2% to about 4.0% vanadium and/or from about 0.2% to about 4.0% niobium; from about 0.02% to about 3% platinum; from about 0 to about 1.0% boron, the balance nickel, and the balance nickel.Methods of thermal treatment and coating of the novel alloys to enhance their mechanical properties are also disclosed, as are articles produced by such methods.

Abstract: A single crystal nickel-base superalloy is disclosed having an improved incipient melting temperature and oxidation resistance. The single crystal nickel-base alloy of this invention is characterized by specific addition of chromium, tungsten, aluminum and tantalum to produce an alloy having moderate high temperature strength and improved oxidation resistance and incipient melting temperature. The nominal composition of our new single crystal alloy (in weight percent) is 10-15% Cr, 0-4% Co, 6-8.5% W, 6-7% Al, 0-1% Ti, 2-6% Ta, and the balance nickel.

Abstract: A thermomechanical method for fabricating net shape single crystal airfoils is disclosed. A cast single crystal superalloy workpiece is solution heat treated to provide a homogeneous gamma prime distrubition. The single crystal sheet stock is then warm worked, generally forged or rolled, at a working temperature of gamma prime solvus minus about 50.degree.-300.degree. F. with a maximum six percent deformation per pass. Following the first warm working, the single crystal sheet stock is cyclic annealed in a temperature range of gamma prime solvus minus about 50.degree.-125.degree. F. to prevent recrystallization of the single crystal sheet stock. The cyclic annealing is preferably cycled three to ten times between the low and high ends of the temperature range at a rate of change of temperature between about 1.degree. F. per minute to about 10.degree. F. per minute.

Abstract: A nickel base superalloy for columnar grain, directional solidification which contains Re for strength and creep resistance, and substantially eliminates the use of Zr and minimizes Si to prevent DS grain boundary cracking. The creep- and stress-rupture properties, which approach nickel base superalloy single crystal performance, are achieved without the use of high temperature gamma prime solution treatment.

Abstract: A method for manufacturing an alloy rod having giant magnetostriction, which comprises the steps of: supplying a granular or flaky alloy material, which comprises at least two rare earth metals including terbium and dysprosium and at least one transition metal, into a tubular crucible in an inert gas atmosphere kept under a pressure of from 0.2 to 10 atm., arranged in a vertical cylindrical heating furnace; totally melting the alloy material in the crucible in the heating furnace; and then vertically moving any one of the crucible and the heating furnace at a speed of from 0.1 to 5.0 mm/minute in a temperature region of from 1,270.degree. to 1,180.degree. C. of the heating furnace, in which a temperature decreases at a temperature gradient of from 10.degree. to 100.degree. C.

Abstract: An oxidation- and corrosion-resistant high-temperature alloy of high toughness at room temperature for directional solidification, based on an intermetallic compound of the nickel aluminide type and having the following composition:Al=10-20 atom %Si=0.5-8 atom %Nb=2-10 atom %B=0.1-2 atom %Ni=remainder,the total of Al, Si, Nb and B amounting at most to a value of 25 atom %. The alloy contains at least 90% by volume of the intermetallic phases Ni.sub.3 Al, Ni.sub.3 Si and Ni.sub.3 Nb.

Abstract: Fibers of Bi(2212) have been produce by pendant drop melt extraction. This technique involves the end of a rod of Bi(2212) melted with a hydrogen-oxygen torch, followed by lowering onto the edge of a spinning wheel. The fibers are up to 15 cm in length with the usual lateral dimensions, ranging from 20 um to 30 um. The fibers require a heat treatment to make them superconducting.

Abstract: A monocrystalline superalloy with a nickel based matrix and particularly intended for the manufacture of turbine blades, has the following composition, by weight: Al=5.4% to 6.2%; Co=4% to 7%; Cr=6% to 9%; Mo=0% to 2.5%; Ta=5.5% to 8%; Ti=O% to 1%; W=7% to 9%; and Ni=balance to 100%.The invention also provides a method of improving the alloy's resistance to creep, in which the Ni.sub.3 Al type .gamma.' phase is put completely into solution at a first temperature, and then the .gamma.' phase is precipitated into the .gamma. solid solution at a temperature greater than 1000.degree. C. This treatment considerably increases the alloy's resistance to creep over a wide range of temperatures.

Abstract: The addition of small amounts of rhenium, technitium and their mixtures and, optionally erbium, to a nickel-based superalloy in which the ratio of nickel to chromium is approximately 3-4 to 1, provides enhanced mechanical properties particularly suitable for applications in the manufacture of gas turbine engine components, airframe skins and combustion chambers.

Abstract: An electric conductor for video and audio appliances and a method of manufacturing the electric conductor. The electric conductor is constituted by a linear member made of copper or silver, which is composed of an assembly of segments each regarded substantially as single crystal having a length not less than twice a diameter of the single crystal. The method includes the steps of curing molten copper or molten silver into an ingot in a single direction along a longitudinal direction of the ingot and subjecting the ingot to cold working or warm working.

Abstract: This invention relates to a heat resistant single-crystal nickel-base super alloy that possesses microstructural stability and excellent creep rupture strength and oxidation resistance. This alloy is composed of 4-9% chromium, 4-6.5% aluminum, 5-8.5% wolfram, 5-8.5% tantalum, 3-6% molybdenum, 0.01-0.30% hafnium, 0.02-4% cobalt by weight, and the balance of nickel and incidental elements and meets the conditional expression wolfram+tantalum<16%. The preferable chemcial composition of this alloy is approximately 6.4% chromium, approximately 5.1% aluminum, approximately 7.3% wolfram, 7.3% tantalum, approximately 4.3% molybdenum, approximately 0.1% hafnium, approximately 1% cobalt by weight, and the balance of nickel and incidental elements.

Abstract: Fibers of YBa.sub.2 Cu.sub.3 O.sub.x have been produce by pendant drop melt extraction. This technique involves the end of a rod of YBa.sub.2 Cu.sub.3 O.sub.x melted with a hydrogen-oxygen torch, followed by lowering onto the edge of a spinning wheel. The fibers are up to 10 cm in length with the usual lateral dimensions, ranging from 20 .mu.m to 125 .mu.m. The fibers require a heat treatment to make them superconducting.

Abstract: Nickel base superalloy single crystal articles, preferably aircraft gas turbine blades and vanes, and a process for preparation thereof, wherein phase stability after extended elevated temperature exposure is enhanced by controlling the content of heavy refractory elements and gamma prime phase forming elements. The nominal alloy composition range in weight percent is 4-6 percent chromium, 8-12 percent cobalt, 1-2.5 percent molybdenum, 3-6 percent tungsten, 1.8-3.2 percent rhenium, 0-2.5 percent ruthenium, 5-6 percent aluminum, 0.5-1.5 percent titanium, 7-10 percent tantalum, 0.08-0.12 percent hafnium, balance nickel. The sum of the heavy refractory elements molybdenum plus tungsten plus rhenium is 8.4-10.4 percent, and the sum of the gamma prime forming elements aluminum plus titanium plus tantalum is 13.8-15.7 percent.

Abstract: A monocrystalline superalloy with a nickel based matrix and particularly intended for the manufacture of turbine blades, has the following composition, by weight: Al=5.4% to 6.2%; Co=4% to 7%; Cr=6% to 9%; Mo=0% to 2.5%; Ta=5.5% to 8%; Ti=0% to 1%; Wt32 7% to 9%; and Ni=balance to 100%.The invention also provides a method of improving the alloy's resistance to creep, in which the Ni.sub.3 Al type .gamma.' phase is put completely into solution at a first temperature, and then the .gamma.' phase is precipitated into the .gamma. solid solution at a temperature greater than 1000.degree. C. This treatment considerably increases the alloy's resistance to creep over a wide range of temperatures.

Abstract: A method for producing a single crystal of chromium is disclosed, comprising sintering a chromium molding to thereby apply thereto a thermal strain and heat treating the resulting thermally strained chromium molding. The method achieves high efficiency of crystal growth and produces a single-crystal chromium molding of complicated shape.

Abstract: The anisotropy typically observed in single crystal nickel base superalloys is reduced by intentionally adding certain small amounts of carbon, boron, zirconium or hafnium, either individually or in combination, to the alloy composition.

Abstract: Nickel base superalloys having properties equal to or better than alloys currently used in gas turbine engines are described. Preferably, the alloys of the present invention are cast into single crystals.

Abstract: A low density superalloy having good resistance to oxidation has the following composition by weight:Co: 5.0 to 6.0%W: 4.8 to 5.2%Cr: 7.8 to 8.3%Al: 5.8 to 6.1%Ta: 3.3 to 3.7%Mo: 2.1 to 2.4%Ti: 1.8 to 2.2%B: .ltoreq.10 ppmZr: .ltoreq.50 ppmNi: balance to 100%.