Patent ID: 7896986

Claim:
A method of locally repairing a Ni 3 (Al,Ti) superalloy component, the method comprising: locally heating, in a heat zone, only the portion of the component that requires repair at a temperature close to, at, or above the Ni 3 (Al,Ti) solution temperature with a hold temperature of the portion of the superalloy component that requires repair in the range of 1,850° F. to 2,400° F., with a sufficiently high hold temperature to prevent strainage cracking; while the remainder of the component, not being in the heat zone, does not undergo any separate heating and retains its original microstructure devoid of any recrystallization; performing a repair, selected from the group consisting of welding and brazing, upon the locally heated portion of the superalloy component that requires repair; and then cooling the locally heated portion of the component that requires repair from the hold temperature at two rates over a time period totaling three to ten hours, to prevent diffusion of molecules and to resist recrystallization in locations where repair is not necessary, and to resist cracking in the heat affected zone, said cooling, at a first rate, where upon reaching a cooling temperature of about 1,200° F. to 1,700° F., the portion of the component that requires repair is cooled at a second rate more rapidly than at the first rate; where at the slower first rate continued diffusion of molecules is permitted while at the more rapid second rate further diffusion of the molecules is limited, wherein the superalloy component is an equiaxed material, a directionally solidified material, or a single crystal material, cooling is by a gas cooling medium directed immediately adjacent the heat zone, to carry away heat, and the superalloy component is a blade of a combustion turbine.