Methods for preparing superalloy articles and related articles

A method for preparing an article, comprising:

• heat-treating a workpiece comprising a nickel-based superalloy at a temperature higher than a gamma-prime solvus temperature of the nickel-based superalloy, wherein the nickel-based superalloy comprises:
• at least 30 weight percent nickel;
• from about 0.5 weight percent to about 4 weight percent aluminum;
• from about 1.5 weight percent to about 7 weight percent niobium, and
• less than 2 weight percent titanium, less than 2 weight percent tantalum or less than 2 weight percent of a combination of titanium and tantalum,
• wherein an atomic ratio of titanium to aluminum, an atomic ratio of tantalum to aluminum or an atomic ratio of the combination of titanium and tantalum to aluminum is less than 1;
• and
• cooling the heat-treated workpiece with a cooling rate less than 10 degrees Fahrenheit/minute from the temperature above the gamma-prime solvus temperature of the nickel-based superalloy so as to obtain a cooled workpiece comprising a gamma-prime precipitate phase at a concentration of at least 20 percent by volume of a material of the cooled workpiece and having an average particle size less than 100 nanometers,
• wherein the cooled workpiece is substantially free of a gamma-double-prime phase.

An article comprising:

• a material comprising:
• at least 30 weight percent nickel;
• from about 0.25 weight percent to about 6 weight percent aluminum;
• from about 0.5 weight percent to about 9 weight percent niobium, and
• less than 4 weight percent titanium, less than 4 weight percent tantalum or less than 4 weight percent of a combination of titanium and tantalum,
• wherein an atomic ratio of titanium to aluminum, an atomic ratio of tantalum to aluminum or an atomic ratio of the combination of titanium and tantalum to aluminum is less than 2;
• wherein the material further comprises a gamma-prime precipitate phase having an average particle size less than 250 nanometers dispersed within the material at a concentration of at least 10 percent by volume of the material, and wherein the material is substantially free of a gamma-double-prime phase, and
• wherein the article has a minimum dimension greater than 6 inches.