A method for preparing an article including a nickel-based superalloy is presented. The method includes heat-treating a workpiece including a nickel-based superalloy at a temperature above a gamma-prime solvus temperature of the nickel-based superalloy and cooling the heat-treated workpiece with a cooling rate less than 50 degrees Fahrenheit/minute from the temperature above the gamma-prime solvus temperature of the nickel-based superalloy so as to obtain a cooled workpiece. The cooled workpiece includes a gamma-prime precipitate phase having an average particle size less than 250 nanometers at a concentration of at least 10 percent by volume, and is substantially free of a gamma-double-prime phase. An article having a minimum dimension greater than 6 inches is also presented. The article includes a material that has a gamma-prime precipitate phase having an average particle size less than 250 nanometers, and is substantially free of a gamma-double-prime phase.

A method for preparing an article including a nickel-based superalloy is presented. The method includes heat-treating a workpiece including a nickel-based superalloy at a temperature above a gamma-prime solvus temperature of the nickel-based superalloy and cooling the heat-treated workpiece with a cooling rate less than 50 degrees Fahrenheit/minute from the temperature above the gamma-prime solvus temperature of the nickel-based superalloy so as to obtain a cooled workpiece. The cooled workpiece includes a gamma-prime precipitate phase having an average particle size less than 250 nanometers at a concentration of at least 10 percent by volume, and is substantially free of a gamma-double-prime phase. An article having a minimum dimension greater than 6 inches is also presented. The article includes a material that has a gamma-prime precipitate phase having an average particle size less than 250 nanometers, and is substantially free of a gamma-double-prime phase.

The present concepts include a zero-porosity structure having a plurality of structural elements arranged to provide a negative Poisson's ratio and, further, a new mechanism to generate negative Poisson's ratio is single material, zero-porosity structure.

The present invention relates to a nickel-based superalloy for diffusion bonding, which includes a surface depletion layer in a state in which an aluminum (Al) or titanium (Ti) content is depleted, the surface depletion layer being formed to a depth of 50 μm or less from a surface for diffusion bonding, and a method for diffusion bonding using the same.

A nickel-chromium-iron-aluminum alloy contains (in wt. %)>17 to 33% chromium, 1.8 to <4.0% aluminum, 0.10 to 15.0% iron, 0.001 to 0.50% silicon, 0.001 to 2.0% manganese, 0.00 to 0.60% titanium, 0.0002 to 0.05% each of magnesium and/or calcium, 0.005 to 0.12% carbon, 0.001 to 0.050% nitrogen, 0.0001 to 0.020% oxygen, 0.001 to 0.030% phosphorus, not more than 0.010% sulfur, not more than 2.0% molybdenum, not more than 2.0% tungsten, the remainder nickel with nickel ≥50% and the usual process-related impurities, for use in solar power tower plants using nitrate salt melts as the heat transfer medium, wherein the following relations must be satisfied: Fp≤39.9 (2a) with Fp=Cr+0.272*Fe+2.36*Al+2.22*Si+2.48*Ti+0.374*Mo+0.538*W−11.8*C (3a), wherein Cr, Fe, Al, Si, Ti, Mo, W and C is the concentration of the respective elements in % by weight.

A coating-substrate combination includes: a Ni-based superalloy substrate comprising, by weight percent: 2.0-5.1 Cr; 0.9-3.3 Mo; 3.9-9.8 W; 2.2-6.8 Ta; 5.4-6.5 Al; 1.8-12.8 Co; 2.8-5.8 Re; 2.8-7.2 Ru; and a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 5.8-9.3 Al; 4.4-25 Cr; 3.0-13.5 Co; up to 6.0 Ta, if any; up to 6.2 W, if any; up to 2.4 Mo, if any; 0.3-0.6 Hf; 0.1-0.4 Si; up to 0.6 Y, if any; up to 0.4 Zr, if any; up to 1.0 Re, if any.

A coating-substrate combination includes: a Ni-based superalloy substrate comprising, by weight percent: 2.0-5.1 Cr; 0.9-3.3 Mo; 3.9-9.8 W; 2.2-6.8 Ta; 5.4-6.5 Al; 1.8-12.8 Co; 2.8-5.8 Re; 2.8-7.2 Ru; and a coating comprising, exclusive of Pt group elements, by weight percent: Ni as a largest content; 5.8-9.3 Al; 4.4-25 Cr; 3.0-13.5 Co; up to 6.0 Ta, if any; up to 6.2 W, if any; up to 2.4 Mo, if any; 0.3-0.6 Hf; 0.1-0.4 Si; up to 0.6 Y, if any; up to 0.4 Zr, if any; up to 1.0 Re, if any.

Provided is a method for manufacturing an Ni-based alloy member in which the equilibrium amount of γ′ phase precipitation at 700° C. is from 30 to 70 volume %. The method includes the steps of preparing an Ni-based alloy powder having a predetermined chemical composition; forming a precursor body wherein an average grain diameter of the γ phase grains is 50 μm or less, by using the Ni-based alloy powder; and heating the precursor body to a temperature at least the γ′ phase solvus temperature and subsequently slow-cooling the heated precursor body from the temperature to a temperature at least 100° C. lower than the γ′ phase solvus temperature at a cooling rate of 100° C./h or lower. There is obtained a softened body in that the γ′ phase particles of at least 20 volume % precipitate between/among the γ phase grains having an average grain diameter of 50 μm or less.

Provided is a method for manufacturing an Ni-based alloy member in which the equilibrium amount of γ′ phase precipitation at 700° C. is from 30 to 70 volume %. The method includes the steps of preparing an Ni-based alloy powder having a predetermined chemical composition; forming a precursor body wherein an average grain diameter of the γ phase grains is 50 μm or less, by using the Ni-based alloy powder; and heating the precursor body to a temperature at least the γ′ phase solvus temperature and subsequently slow-cooling the heated precursor body from the temperature to a temperature at least 100° C. lower than the γ′ phase solvus temperature at a cooling rate of 100° C./h or lower. There is obtained a softened body in that the γ′ phase particles of at least 20 volume % precipitate between/among the γ phase grains having an average grain diameter of 50 μm or less.

This blade repair method has: a first welding step in which overlay welding in which a first welding material is used is performed to form a notched part and a bury a first region positioned on a blade-body side with a first welding material; and a second welding step in which, after the first welding step, overlay welding in which a second welding material is used is performed to form a notched part and bury a second region positioned on a front-surface side of a platform with the second welding material. The high-temperature strength of the second welding material is higher than the high-temperature strength of the first welding material, the weldability of the first welding material is higher than the weldability of the second welding material, and the second region is located in a range from 1.0 mm to 3.0 mm (inclusive) from the front surface of the platform toward the blade body.