CN-115890131-B - Repair method of aeroengine hollow blade

Abstract

The invention discloses a repair method of a hollow blade of an aeroengine, which comprises the following steps of determining an area of a hollow blade, which needs to be restored, of determining processing parameters of the air film hole, setting femtosecond laser processing parameters, mounting the hollow blade to be repaired on a machine tool for positioning, processing the air film hole to be repaired by adopting a femtosecond laser processing technology, performing quality inspection on the repaired air film hole by referring to the processing parameters of the air film hole, and testing water flow of the repaired hollow blade. The invention irradiates the air film hole blocked by the hollow blade by using ultra-short pulse laser processed by the femtosecond laser, ablates and gasifies the non-conductive material blocked at the air film hole due to welding and material-increasing repair by the ultra-high energy density of the femtosecond laser, thereby achieving the effects of recovering the size of the air film hole or adjusting the size of the air film hole, and detects the aperture of the air film hole by water flow test, so that the water flow of the repaired hollow blade can completely meet the technical standard requirement.

Inventors

• XU LIANGHUI
• ZHOU QUN
• LUO KUILIN
• CHEN TAILI
• WANG BINGXUE
• CHEN LINGHAN
• SUN JIANG
• HOU XIAOWEI

Assignees

• 国营川西机器厂

Dates

Publication Date

20260505

Application Date

20221229

Claims (8)

1. 1. The repairing method of the hollow blade of the aero-engine is characterized by comprising the following steps of: Comparing a hollow blade to be repaired, which is subjected to welding, material-increasing repair, spraying and self-adaptive machining, with a design drawing, and determining an area of a gas film hole on the hollow blade, which needs to be restored to be machined; determining processing parameters of the air film hole according to the design drawing; Step three, setting femtosecond laser processing parameters according to the processing parameters determined in the step two; Step four, mounting the hollow blade to be repaired on a machine tool, and positioning the hollow blade; Fifthly, processing the air film hole to be repaired by adopting a femtosecond laser processing technology, and removing the non-conductive material covered on the air film hole or blocked in the air film hole by utilizing the ultra-high energy density of the ultra-short pulse in the femtosecond laser processing technology; Step six, referring to the technological parameters of the air film hole, and performing quality inspection on the repaired air film hole; step seven, mounting the repaired hollow blade into water flow test equipment to test the water flow of the hollow blade, judging that the hollow blade is repaired to be qualified if the water flow test value accords with a specified range, sequentially executing the steps three to seven after the processing aperture of the air film hole is increased within a range specified by a design drawing if the water flow test value is smaller than the lower limit of the specified range, re-plugging the unqualified air film hole on the hollow blade if the water flow test value is larger than the upper limit of the specified range, and sequentially executing the steps one to seven after the processing aperture of the air film hole is reduced within the range specified by the design drawing.
2. 2. The method for repairing a hollow vane of an aeroengine as claimed in claim 1, wherein in the second step, the processing parameters of the air film hole comprise parameters of pore diameter, hole position degree, hole surface roughness, pore opening and hole wall recast layer.
3. 3. The method for repairing a hollow blade of an aircraft engine according to claim 1, wherein in the third step, the machining parameters of the femtosecond laser include parameters of a laser beam type, a lens focal length, a distance from a front cassette hole, a final lens to a workpiece surface, an auxiliary gas type, an auxiliary gas flow rate, a pulse width, a pulse speed, laser energy, laser power, a laser beam movement mode, a laser beam movement angle and a feed rate.
4. 4. The method for repairing the hollow blade of the aeroengine as claimed in claim 3, wherein in the third step, the processing parameters of the femtosecond laser are that the pulse width is 10 fs-200 fs, the pulse speed is 100KHz, the laser power is 10W, the feeding rate is 10 μm and the processing layer number is 50.
5. 5. The method for repairing a hollow blade of an aeroengine as claimed in claim 1, wherein in the fourth step, the hollow blade to be repaired is mounted on a machine tool by a fixture, and the hollow blade is positioned by a machine tool positioning test sensor.
6. 6. The method for repairing a hollow blade of an aeroengine as claimed in claim 1, wherein in the fifth step, the energy density of the ultrashort pulse in the femtosecond laser processing technology is 10 18 J/cm 2 or more.
7. 7. The method for repairing a hollow blade of an aircraft engine according to claim 1, wherein in the fifth step, the non-conductive material covered on or blocked in the air film hole is a ceramic thermal barrier coating.
8. 8. The method for repairing a hollow blade of an aircraft engine according to claim 1, wherein in the sixth step, the quality inspection parameters of the repaired air film hole comprise parameters of hole diameter, hole position degree, hole surface roughness, hole opening and hole wall recasting layers.

Description

Repair method of aeroengine hollow blade Technical Field The invention relates to the technical field of maintenance of aero-engine parts, in particular to a method for repairing hollow blades of an aero-engine. Background The service life of the aeroengine prolonged by maintenance is more than 80% of the whole life cycle of the aeroengine, wherein the maintenance of the hollow blade of the aeroengine is an important link. The hollow blade of the aeroengine generally has faults such as cracks, ablation, material reduction and the like, the defect of the hollow blade material is mainly repaired by means of welding, laser material increase and the like in maintenance work, and then the shape of the hollow blade is recovered by self-adaptive machining. As shown in fig. 1, in the welding and laser additive repairing process, partial or complete blockage of part of the air film holes on the hollow blade 100 is inevitably caused to form air film holes 200 with unqualified aperture, and the blocked air film holes must be repaired. At present, the mode of electric spark machining is generally adopted in the industry to repair and machine the air film hole blocked on the hollow blade, for example, chinese patent application with publication number of CN114289808A discloses a turbine blade special-shaped air film hole electric spark machining method, the technical scheme adopts a numerical control electric spark small hole machine to carry out distributed electric spark machining on the air film hole on the turbine blade, the numerical control electric spark small hole machine adopts a thin copper pipe electrode wire to carry out electric spark machining, the electric spark machining method of the turbine blade special-shaped air film hole designed by the scheme utilizes a simple electric spark copper pipe electrode wire to replace a cutter, the cutter cannot machine special-shaped holes on materials, the special-shaped air film hole on the high-temperature alloy blade is milled at a high speed according to a machining track, the whole turbine blade special-shaped air film hole machining is only required to be clamped once, the full-automatic completion is realized, the machining efficiency is high, and the actual machining track is redetermined by analyzing the real-time loss amount of the electrode wire during machining, thereby effectively improving the machining precision. However, in the above patent application, electric spark processing is adopted for repairing the gas film hole, and in the electric spark processing, redundant metal is removed through the electric corrosion phenomenon of pulse spark discharge between an electrode and a workpiece, the processed material is required to have conductivity, so that only a conductive metal matrix can be processed, but a non-conductive material on the gas film hole cannot be removed, and in addition, as shown in fig. 2, when the electric spark processing is carried out on the metal material, the electric corrosion is caused on the surface layer of the metal matrix 300 due to high temperature generated by pulse discharge, part of molten metal is re-solidified on the surface of the gas film hole to form a remelting layer 400 with the thickness of 10-40 μm, and the hollow blade of the aeroengine works in a severe environment with high temperature, the existence of the remelting layer can cause the uneven texture of the surface layer of the hollow blade, the performance of the hollow blade is reduced, and the microcrack in the remelting layer can cause fatigue crack expansion of the hollow blade under the action of long-term alternating heat stress, so that the hollow blade is damaged, and the hollow blade is damaged, so that an accident is caused, and serious potential safety hazard exists. Disclosure of Invention The invention aims to solve the technical problem of providing a repairing method for hollow blades of an aeroengine, which can effectively improve the repairing effect on blocked air film holes on the hollow blades. The technical scheme adopted for solving the technical problems is that the repairing method of the hollow blade of the aero-engine comprises the following steps: Comparing a hollow blade to be repaired, which is subjected to welding, material-increasing repair, spraying and self-adaptive machining, with a design drawing, and determining an area of a gas film hole on the hollow blade, which needs to be restored to be machined; determining processing parameters of the air film hole according to the design drawing; Step three, setting femtosecond laser processing parameters according to the processing parameters determined in the step two; Step four, mounting the hollow blade to be repaired on a machine tool, and positioning the hollow blade; Fifthly, processing the air film hole to be repaired by adopting a femtosecond laser processing technology, and removing the non-conductive material covered on the air film hole or blocked in the air film hole