Single crystal nickel-base superalloy article and method for making

This patent describes an improved nickel-base superalloy capable of being cast as a single crystal by directional solidification, having an improved balance of high temperature strength and high temperature oxidation and corrosion resistance consisting essentially of, by weight: 7-12% Cr, 1-5% Mo, 3-5% Ti, 3-5% Al, 5-15% Co, 3-12% W, 2-6% Ta, up to 10% Re, up to 2% Cb, up to 3% V, up to 2% Hf, balance Ni and incidental impurities, further characterized wherein the superalloy has no added C, B, and Zr and, if present, the elements, are at impurity levels, the alloy having an Al:Ti ratio from about 0.5 to about 1 while maintaining the Cr:Al ratio from about 1.5-4