NICKEL BASED MONOCRYSTALLINE SUPERALLOY, METHOD OF HEAT TREATING SAID ALLOY, AND PARTS MADE THEREFROM

摘要

A NICKEL BASED MONOCRYSTALLINE SUPERALLOY, METHOD OF HEAT TREATING SAID ALLOY, AND PARTS MADE THEREFROM. A monocrystalline superalloy with a nickel based matrix and particularly intended for the manufacture of turbine blades, has the following composition, by weight: Al = 5.4% to 602%; Co = 4% to 7%; Cr = 6% to 9%; Mo = 0% to 2.5%; Ta = 5.5% to 8%; Ti = 0% to 1%; W = 7% to 9%; and Ni = balance to 100%. The invention also provides a method of improving the alloy's resistance to creep, in which the Ni3Al type ?' phase is put completely into solution at a first temperature, and then the ?' phase is precipitated into the ? solid solution at a temperature greater than 1000.degree.C. This treatment considerably increases the alloy's resistance to creep over a wide range of temperatures.