Method for extracting a foreign body lodged in a high-pressure distributor blade
A method for extracting at least one foreign body lodged within a blade of a high-pressure distributor of a turbojet engine, the high-pressure distributor including hollow fixed blades between two annular shrouds forming a gas flow path, each blade being coated with a thermal barrier and provided with at least one recess at least partially obstructed by a first soldered closing plate, includes the following operations: cutting off the first closing plate, extracting the foreign body from the recess, carrying out an endoscopic inspection of an internal space of the recess in order to verify that no foreign body remains, positioning a second closing plate on the recess, and soldering the second closing plate directly onto the distributor with the blades coated with the thermal barrier.
1. A method for extracting at least one foreign body lodged within a blade of a high-pressure distributor of a turbojet engine, said high-pressure distributor including fixed hollow blades between two annular shrouds forming a gas flow stream, each blade being coated with a thermal barrier and drilled with at least one cavity at least partially obstructed by a first brazed closing plate, the method comprising:
cutting the first brazed closing plate,
extracting the foreign body out of the cavity,
endoscopically inspecting an internal space of the cavity to check that no foreign bodies remain,
positioning a second closing plate on the cavity, and
brazing the second closing plate directly to the distributor with the blades coated with the thermal barrier.
2. The extraction method according to claim 1 , wherein cutting the first brazed closing plate is performed by grinding said plate.
3. The extraction method according to claim 1 , wherein positioning the second closing plate is performed by jig boring on the high-pressure distributor.
4. The extraction method according to claim 1 , wherein the second closing plate is pre-sintered.
5. The extraction method according to claim 1 , wherein brazing the second closing plate is performed in a vacuum furnace at a temperature below 1200° C.
6. The extraction method according to claim 5 , wherein brazing the second closing plate includes a thermal cycle performed at a temperature of between approximately 1160° C. and 1200° C. for 10 to 20 minutes, and then a diffusion cycle at a temperature of between approximately 1150° C. and 1200° C. for 2 to 4 hours.
7. The extraction method according to claim 1 , further comprising, after brazing the second closing plate, an operation of X-ray inspecting the high-pressure distributor.