Abstract: High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus <111> crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded <111> single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular <111> texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.

Abstract: A method for casting comprising: providing a seed, the seed characterized by: an arcuate form and a crystalline orientation progressively varying along an arc of the form; providing molten material; and cooling and solidifying the molten material so that a crystalline structure of the seed propagates into the solidifying material.

Abstract: A method for casting comprising: providing a seed, the seed characterized by: an arcuate form and a crystalline orientation progressively varying along an arc of the form; providing molten material; and cooling and solidifying the molten material so that a crystalline structure of the seed propagates into the solidifying material.

Abstract: A method for casting comprising: providing a seed, the seed characterized by: an arcuate form and a crystalline orientation progressively varying along an arc of the form; providing molten material; and cooling and solidifying the molten material so that a crystalline structure of the seed propagates into the solidifying material.

Abstract: High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus <111> crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded <111> single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular <111> texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.

Abstract: High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus <111> crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded <111> single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular <111> texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.

Abstract: A method is disclosed for manufacturing a tie shaft for aero or land based gas turbine engine. The method includes flow forming a tie shaft preform to produce a tie shaft. In one example, the tie shaft includes a nickel alloy cylindrical wall having a length to diameter ratio of at least 6:1, wherein the diameter is an average outer diameter. The wall includes a minimum effective strain of 0.3 in/in (7.6 mm/mm), and a grain size is in the range of G4 to G16 per ASTM E112. The wall includes a roll formed threaded surface having a thread roughness of less than 1260 ?in (32 microns).

Abstract: A method for casting comprising: providing a seed, the seed characterized by: an arcuate form and a crystalline orientation progressively varying along an arc of the form; providing molten material; and cooling and solidifying the molten material so that a crystalline structure of the seed propagates into the solidifying material.

Abstract: High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus <111> crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded <111> single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular <111> texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.

Abstract: A method is disclosed for manufacturing a tie shaft for aero or land based gas turbine engine. The method includes flow forming a tie shaft preform to produce a tie shaft. In one example, the tie shaft includes a nickel alloy cylindrical wall having a length to diameter ratio of at least 6:1, wherein the diameter is an average outer diameter. The wall includes a minimum effective strain of 0.3 in/in (7.6 mm/mm), and a grain size is in the range of G4 to G16 per ASTM E112. The wall includes a roll formed threaded surface having a thread roughness of less than 1260 ?in (32 microns).

Abstract: A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15% Cr, 13.6% Co, 4.1% Mo, 4.6% Ti, 2.2% Al, 0.01% C, 0.007% B, 0.07% Zr, balance Ni. This material is forged at a temperature above the gamma prime solvus and at a true strain of at least 0.5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.

Abstract: A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15% Cr, 13.6% Co, 4.1% Mo, 4.6% Ti, 2.2% Al, 0.01% C, 0.007% B, 0.07% Zr, balance Ni. This material is forged at a temperature above the gamma prime solvus and at a true strain of at least 0.5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.

Abstract: A process is described for converting a fine grain superalloy casting into a forging having mechanical properties equivalent to those resulting from powder metallurgy processing. Cast material is extruded and forged. A HIP treatment is employed to close porosity.

Abstract: Methods for increasing the forgeability of cast superalloy materials are described. An extremely overaged microstructure is developed by solutionizing the material and slow cooling in the vicinity of the solvus temperature to cause a precipitation of extremely coarse gamma prime material. Subsequently the material can be isothermally forged.