Nickel alloy and articles

Articles suitable for use in high temperature applications, such as turbomachinery components, and methods for making such articles, are provided. The article comprises a material comprising a plurality of L12-structured gamma-prime phase precipitates distributed within a matrix phase at a concentration of at least 20% by volume, wherein the gamma-prime phase precipitates are less than 1 micrometer in size, and a plurality of A3-structured eta phase precipitates distributed within the matrix phase at a concentration in the range from about 1% to about 25% by volume. The solvus temperature of the eta phase is higher than the solvus temperature of the gamma-prime phase. Moreover, the material has a median grain size less than 10 micrometers. The method comprises providing a workpiece, the workpiece comprising at least about 40% nickel, from about 1.5% to about 8% titanium, and from about 1.5% to about 4.5% aluminum. A weight ratio of titanium to aluminum is in the range from about 1 to about 4, and the workpiece further comprises a plurality of A3-structured ordered eta phase precipitates distributed within the matrix phase at a concentration in the range from about 1% to about 25% by volume. The method further comprises mechanically working the workpiece at a temperature below a solvus temperature of the eta phase; and heat treating the workpiece at a temperature sufficiently high to dissolve any gamma prime phase present in the workpiece but below the solvus temperature of the eta phase.