A method for preparing an article, comprising: heat-treating a workpiece comprising 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 27.8 degrees Celsius/minute (50 degrees Fahrenheit/minute) from the temperature above the gamma-prime solvus temperature of the nickel-based superalloy to a temperature below the gamma-prime solvus temperature of the nickel-based superalloy so as to obtain a cooled workpiece comprising a coprecipitate of a gamma-prime phase and a gamma-double-prime phase at a concentration of at least 10 percent by volume of a material of the cooled workpiece, wherein the gamma-prime phase has an average particle size less than 250 nanometers, wherein the nickel-based superalloy comprises: from 0.1 weight percent to 6 weight percent tantalum or from 0.1 weight percent to 6 weight percent of a combination of both titanium and tantalum; from 0.1 weight percent to 6 weight percent aluminum; and from 0.5 weight percent to 9 weight percent niobium, wherein an atomic ratio of tantalum to aluminum or an atomic ratio of a combination of both titanium and tantalum to aluminum is in a range from 0.1 to 4, wherein the nickel-based superalloy further comprises from 10 weight percent to 30 weight percent chromium, from 0 weight percent to about 45 weight percent cobalt, from 0 weight percent to 40 weight percent iron, from 0 weight percent to 4 weight percent molybdenum, from 0 weight percent to 4 weight percent tungsten, from 0 weight percent to 2 weight percent of hafnium, from 0 weight percent to 0.1 weight percent of zirconium, from 0 weight percent to 0.2 weight percent of carbon, from 0 weight percent to 0.1 weight percent of boron, the balance being Nickel and wherein there is at least 30 weight percent nickel. heat-treating a workpiece comprising 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 27.8 degrees Celsius/minute (50 degrees Fahrenheit/minute) from the temperature above the gamma-prime solvus temperature of the nickel-based superalloy to a temperature below the gamma-prime solvus temperature of the nickel-based superalloy so as to obtain a cooled workpiece comprising a coprecipitate of a gamma-prime phase and a gamma-double-prime phase at a concentration of at least 10 percent by volume of a material of the cooled workpiece, wherein the gamma-prime phase has an average particle size less than 250 nanometers, wherein the nickel-based superalloy comprises: from 0.1 weight percent to 6 weight percent tantalum or from 0.1 weight percent to 6 weight percent of a combination of both titanium and tantalum; from 0.1 weight percent to 6 weight percent aluminum; and from 0.5 weight percent to 9 weight percent niobium, from 0.1 weight percent to 6 weight percent tantalum or from 0.1 weight percent to 6 weight percent of a combination of both titanium and tantalum; from 0.1 weight percent to 6 weight percent aluminum; and from 0.5 weight percent to 9 weight percent niobium, wherein an atomic ratio of tantalum to aluminum or an atomic ratio of a combination of both titanium and tantalum to aluminum is in a range from 0.1 to 4, wherein the nickel-based superalloy further comprises from 10 weight percent to 30 weight percent chromium, from 0 weight percent to about 45 weight percent cobalt, from 0 weight percent to 40 weight percent iron, from 0 weight percent to 4 weight percent molybdenum, from 0 weight percent to 4 weight percent tungsten, from 0 weight percent to 2 weight percent of hafnium, from 0 weight percent to 0.1 weight percent of zirconium, from 0 weight percent to 0.2 weight percent of carbon, from 0 weight percent to 0.1 weight percent of boron, the balance being Nickel and wherein there is at least 30 weight percent nickel. <EOS>