Blade Tip Repair
Publication Date: 2009-Oct-01
The IP.com Prior Art Database
A tip repair method for gas turbine engine blades that restores the life of a blade. The method, for blades with damaged tips, provides an alternative to the replacement of damaged blades with new blades. The method includes removing portions of the damaged tip so as to expose ribs and/or webs at the blade end and then fitting to the tip, tip plates that each separately span openings formed between the ribs and /or webs. The fitting of the tip plates includes welding all outer edges of each tip plate to the blade end, including the exposed ribs and/or webs.
Blade Tip Repair
Base material: Nickel base super alloy material
Weld Filler: Nickel base weld filler/similar to base material
Plate: Nickel base weld filler/similar to base material
Background: Turbine Blade suffers from extensive damage at the tip during high temperature turbine operation. The following are the damages and not limited to:
· Tip oxidation
· Tip radial cracks
· Tip rubbing
· Foreign object damage
· Brazed tip liberation
· Tip plate cracks and damaged
These damages are being repaired during reconditioning to restore the lifetime of the component or increase the tip durability for it to be able to perform another cycle rather than replacing it with a new blade thus being a cost effective solution for the turbine operator.
This document describes the damages seen on the blade tip, steps and methods to repair these damages and the design of the new tip feature.
State of the art:
The repair method as in the state of the art, the tip of the blade is removed (squealer tip, tip plate, and tip crack repaired) and one single replacement cap is attached by welding.
Repair approach for tip repair of a rotor blade on a gas turbine engine.
The blade coating shall be stripped and then heat-treated to improve weld ability of the base material. The tip shall then be removed by automated grinding while maintaining the ribs or webs where the initial blade tip plate was placed.
In order to improve the tip plate durability, sever...