Rene 80 Cast Nickel Base Alloy filed in 1968 by Ross 

Abstract: An improved cast nickel base alloy has a combination of stability, high-temperature stress rupture strength and hot corrosion resistance primarily through control of such phases as sigma, eta, and the carbides. Control is achieved through the balance of the elements Al, Ti, Mo, W, Co, Cr and C in the proper relationships with a Ni base in the substantial absence of Fe. 

 INCO IN939  Alloys of Nickel, Chromium And Cobalt filed in 1976 by Shaw 

Abstract: The high temperature properties of a nickel-base alloy containing correlated percentages of chromium, cobalt, tungsten, molybdenum, titanium, aluminum, carbon, tantalum, niobium, zirconium, hafnium, boron, yttrium and lanthanum are substantially maintained or improved by further correlation of the percentages of chromium, carbon and boron in the alloy.

 Rene 150 Cast nickel-base alloy article filed in 1977 by Wukusick 

Abstract: A cast nickel-base alloy article having a complex internal passage and a columnar grain structure is provided with an improved combination of castability and mechanical properties through a control of the amount of gamma prime phase and its related phase formers, a careful control of Co and Al along with Hf and a control of the gamma solution strengtheners, particularly Mo and W. 

 PWA 1480 Heat Treated Superalloy Single Crystal Article And Process filed in 1978 by Duhl 

Abstract: Nickel base superalloy single crystal articles formed of a particular composition and heat treated are described as is the process employed. The resultant articles are substantially free from the grain boundary strengtheners such as carbon, boron, and zirconium and contain only a limited amount of cobalt. As a result of the alloy composition, the alloys have a high incipient melting temperature. The heat treatment process homogenizes the micro-structure, and refines the gamma prime morphology. The alloy is a nickel base alloy containing from about 8 to about 12% chromium, from about 4.5 to about 5. 5% aluminum, from about 1 to 2% titanium, from 3 to 5% tungsten, and from 10 to 14% tantalum. The cobalt content is controlled to fall within the range of 3-7%, and the balance is essentially nickel. The alloy employed in the present invention is free from intentional additions of carbon, boron and zirconium, although obviously these elements may be present as unintentional impurities. 

 CMSX-4 Single Crystal Alloy Technology
filed in 1984 by Harris 

Abstract: Single crystal nickel-base superalloy having very fine gamma prime after heat treatment in a temperature range permitting total gamma prime solutioning without incipient melting. Component of the heat treated alloy has exceptional resistance to creep under high temperature and stress, particularly in that part of the creep curve representing one percent or less elongation. The alloy exhibits exceptionally low steady-state creep rate.

 PWA 1484 Advanced High Strength Single Crystal Superalloy Compositions filed in 1985 by Duhl 

Abstract: A superalloy composition and single crystal articles of the composition are described. The broad range is 3-12% Cr, 0-3% Mo, 3-10% W, 0-5% Re, 6-12% Ta, 4-7% Al, 0-15% Co, 0-0.045% C, 0-0.02% B, 0-0.1% Zr, 0-0.8% Hf, 0-2% Nb, 0-1% V, 0-0.7% Ti, 0-10% (Ru+Rh+Pd+Os+Ir+Pt), balance essentially Ni. An equation is presented to select the most useful specific compositions from within this range. An exemplary preferred composition is 5.0% Cr, 10.0% Co, 2.0% Mo, 6.0% W, 3.1% Re, 5.6% Al, 9.0% Ta, 0.1% Hf, balance essentially Ni. 

 DS Rene 142 Cast Columnar Grain Hollow Nickel Base Alloy Articles filed in 1991 by Ross 

Abstract: One form of an improved cast, hollow, columnar grain nickel base alloy article is provided with outstanding elevated temperature stability as represented by oxidation resistance, an improved combination of longitudinal and transverse stress rupture properties, and a thin wall of less than about 0.035 inch, substantially free of cracks. Described is a heat treatment in combination with an alloy for providing such an article. 

 CMSX-10 Single Crystal Nickel-based Superalloy filed in 1992 by Erickson 

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. 

 Rene N4 Nickel-based Superalloys For Producing Single Crystal Articles Having Improved Tolerance To Low Angle Grain Boundaries filed in 1992 by Ross 

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° 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. These alloys are especially useful when directionally solidified as hot-section components of aircraft gas turbine engines, particularly rotating blades and stationary vanes. The superalloy contains by weight percent, 7-12 Cr, 5-15 Co, 0.5-5 Mo, 3-12 W, 2-6 Ta, 2-5 Ti, 3-5 Al, 0-2 Cb, 0.1-0.2 Hf, 0. 05-0.07 C, 0.002-0.05 B, and nickel. 

 Rene N5 Property Balanced Nickel-base
Superalloys For Producing Single
Crystal Articles  Originally filed in 1985 by
Wukusick , re-filed in 1994 issued in 2000 

Abstract: The present invention is directed to the achievement of increased gas turbine engine efficiencies through further improvements in nickel-base superalloys used to make parts and components for gas turbine engines. The present invention comprises nickel-base superalloys for producing single crystal articles having a significant increase in temperature capability, based on stress rupture strength and low and high cycle fatigue properties, over single crystal articles made from current production nickel-base superalloys. Further, because of their superior resistance to degradation by cyclic oxidation, and their resistance to hot corrosion, the superalloys of this invention possess a balance in mechanical and environmental properties which is unique and has not heretofore been obtained.

 Nickel Base Superalloy With Improved
Machinability And Method Of Making Thereof
(Rene 80 Mod. For IGT) filed in 1999 by Vogt 

Abstract: Machineable nickel base alloy casting, consisting essentially of, in weight %, about 12.5% to 15% Cr, about 9.00% to 10.00% Co, about 3.70% to 4.30% Mo, about 3.70% to 4.30% W, about 2.80% to 3.20% Al, about 4.80% to 5.20% Ti, about 0.005% to 0.02% B, up to about 0.10% Zr, and balance essentially Ni and carbon below about 0.08 weight % to improve machinability while retaining alloy strength properties after appropriate heat treatment. 

 Directional Solidification (DS) Casting Process filed in 1964 by VerSnyder 

Abstract: The blades of the present invention have an elongated, columnar macro-grain structure with substantially unidirectional crystals aligned substantially parallel to the axis of the cast blade; that is, with a columnar structure in the alloy of the blade. The grain boundaries of the alloy of the cast blade are oriented so as to be substantially parallel to the principal stress axis of the blade, and there is an almost complete elimination of grain boundaries normal to this stress axis. 

 Single Crystal Casting Process filed in 1964 by Piearcey 

Abstract: A cast metallic alloy part for a gas turbine power plant is formed as an elongated single crystal of a strong, heat resistant and corrosion-resistant alloy having a face-centered cubic crystal structure, said crystal being oriented with its <001> direction being less than 20 degrees from the elongated axis of the crystal, said single crystal part having an air-foil portion and a laterally enlarged integral base portion, the whole being a single integral crystal.The present invention relates to a novel and improved process and mold for the formation of elongated shaped objects comprising a single crystal oriented in a particularly desirable direction and to an apparatus useful in carrying out the process, as well as to novel and such improved single-crystal blades and vanes for a gas turbine engine, especially those blades and vanes formed from certain nickel-based alloys. 

 Liquid Metal Cooling Apparatus for Casting of Directionally Solidified Articles filed in 1971 by Tschinkel 

Abstract: Apparatus for casting directionally solidified articles either columnar grained or single crystal in which the rate of solidification is controlled by gradual immersion or submergence by a liquid coolant.One of the principal features of the present invention is the very rapid heat removal from the mold in conjunction with a sharp transition between the hot and cold surroundings in order to maintain a high thermal gradient and also a high growth rate for making the cast article. Another feature is the use of a liquid coolant into which the mold is immersed or in which the mold is submerged gradually for the rapid extraction of heat from the mold, thereby obtaining the desired grain growth within the mold. Another feature is the use of this liquid coolant to circulate around all of the several molds in a multiple mold casting so that the heat removal from the several molds will be the same and, accordingly, the desired grain growth will be obtained within all of the molds. A particular feature of the invention is the control of the dendritic growth within the casting in such a way as to significantly reduce the distance between the dendrites and thereby minimize the segregation of the microconstituents in the interdendritic regions. 

 Gas Jet Process For Producing A Directionally Solidified Casting filed in 1997 by Kats 

Abstract: The process serves to produce a directionally solidified casting (20) and uses an alloy located in a casting mold (12). The casting mold (12) is guided from a heating chamber (4) into a cooling chamber (5). The heating chamber (4) is here at a temperature above the liquidus temperature of the alloy, and the cooling chamber (5) is at a temperature below the solidus temperature of the alloy. The heating chamber (4) and the cooling chamber (5) are separated from one another by a baffle (3), aligned transversely to the guidance direction, having an opening (7) for the casting mold (12). When carrying out the process, a solidification front (19) is formed, beneath which the directionally solidified casting (20) is formed. The part of the casting mold (12) which is guided into the cooling chamber (5) is cooled with a flow of inert gas. As a result, castings (20) which are practically free of defects are achieved with high throughput times. 

 Some Examples of Solid Particle Erosion in the Gas Turbine & Steam Turbine Industry 

High-Temperature Erosion Testing Standard and
Round Robin Testing