Gamma-prime precipitation hardening nickel-base yttria particle- dispersion-strengthened superalloy

摘要

A gamma-prime precipitation hardening nickel-base yttria particle- dispersion-strengthened superalloy having a composition consisting essentially of, by weight, 3.0 to 6.0% of Al, 8.5 to 10.9% of Co, 3.9 to 7.5% of Cr, 0.5 to 1.2% of Ti, 3.6 to 6.3% of Ta, 11.4 to 13. 3% of W, 0. 02 to 0.2% of Zr, 1.3 to 2.6% of Mo, 0.001 to 0.1% of C, 0. 001 to 0.02% of B, 0.5 to 1.7% of yttria (Y.sub.2 O.sub.3), not more than 0.8% of O and the balance being Ni and having a structure composed of coarse recrystallized grains with a GAR of at least 20 and a short axis diameter of at least 0.5 mm, said alloy being produced by mechanically mixing a nickel carbonyl powder, element powders of Co, Cr, Ta, W and Mo, alloy powders of Ni--Al, Ni--Ti--Al, Ni--Zr and Ni--B, and a fine yttria powder in amounts to provide said composition, sealing the mixed powder into an extrusion can, extruding it, and subjecting the extruded material to zone annealing heat-treatment while its maximum temperature is within the range from its hardness softening temperature to its solidus temperature.