Abstract: Airfoil outer wall thickness of a gas turbine engine blade is increased in the zone that is proximate the trailing edge and blade hub by forty to sixty percent (40-60%) greater than comparable greatest wall thickness anywhere else along the trailing edge from outboard that zone all the way to the blade tip. The increased thickness zone includes a transition zone that bridges the respective airfoil outer wall thicknesses proximate the hub and tip of the blade. Some embodiments also incorporate pedestals with compound curve fillets in the increased wall thickness zone. The increased thickness zone reduces blade cracking propensity and enhances service life.

Abstract: A pre-weld heat treatment of the nickel based superalloy including heating a nickel based superalloy (e.g., IN939) casting to 2120° F. at a rate of 2° F. per minute, and then soaking the casing for one hour at 2120° F. The casting is then cooled in stages including slowly cooling the casting at a rate of 1° F. per minute to about 1900° F. and holding at that temperature for about 10 minutes. Then the casting is further slowly cooled at a rate of 1° F. per minute to about 1800° F. and holding at that temperature for about 10 minutes, and further slowly cooled to a temperature range of 1650° F. to 1450° F., and then fast cooled to room temperature. The pre-weld heat treatment may optionally include a step of heating the casting to about 1850° F. at a rate of 50° F. per minute before slowly heating to 2120° F.

Abstract: A pre-weld heat treatment of the nickel based superalloy including heating a nickel based superalloy (e.g., IN939) casting to 2120° F. at a rate of 2° F. per minute, and then soaking the casing for one hour at 2120° F. The casting is then cooled in stages including slowly cooling the casting at a rate of 1° F. per minute to about 1900° F. and holding at that temperature for about 10 minutes. Then the casting is further slowly cooled at a rate of 1° F. per minute to about 1800° F. and holding at that temperature for about 10 minutes, and further slowly cooled to a temperature range of 1650° F. to 1450° F., and then fast cooled to room temperature. The pre-weld heat treatment may optionally include a step of heating the casting to about 1850° F. at a rate of 50° F. per minute before slowly heating to 2120° F.