Bevel production method for laser cladding crack repair

Abstract

The present application relates to the technical field of aircraft engine parts maintenance, and specifically discloses a method for making a groove for laser cladding crack repair, including performing fluorescent flaw detection on the engine turbine rotor blade to mark the tip crack position; grinding the blade basin surface and end surface at the tip crack position until a metallic luster is visible; under a bright light source, opening a U-shaped groove at the outer wall of the blade at the tip crack position, with the opening of the U-shaped groove facing the blade end surface; under a black light, eliminating the intersection crack between the blade cover plate and the blade basin surface by grinding; after confirming that the intersection crack has been eliminated under the black light, under a bright light source, grinding the bottom of the U-shaped groove into a hole to obtain a groove for laser cladding crack repair. Thus, the small groove laser cladding technology can be applied to the repair of turbine rotor blade tip cracks, extending the life of engine parts and reducing engine maintenance costs.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft engine component maintenance, and in particular to a method for making a groove for laser cladding crack repair. Background Art

[0002] With the development of laser additive technology, more and more parts are repaired by laser cladding, but in general, laser cladding is still limited to the lengthening, size, pit repair on the plane. Laser cladding repairs cracks mostly use large grooves of more than 120°. The reason for this situation is that laser cladding technology is highly automated and is affected by laser nozzles, etc., so the accessibility is poor. The groove angle must be increased to achieve additive. This large groove method also causes great damage to the matrix, affecting the structural strength of the parts. At the same time, laser additive materials are powders. If all cracks are discharged, there is no matrix material support, resulting in direct collapse of the cladding and failure to form.

[0003] One of the main failure modes of aircraft engine turbine rotor blade service inspection is cracks, accounting for about 90%. The length of the blade tip crack is to the cover plate, and the location is distributed at the boss. Affected by the structural mutations of the cover plate, boss, etc., the blade tip wall thickness changes suddenly within a short distance (within 3mm). The conventional variable power method cannot be used during laser cladding. Therefore, the conventional crack repair groove forms I-shaped, U-shaped, V-shaped, Y-shaped, and double V-shaped are not suitable for laser cladding repair of parts with structural mutations. Summary of the invention

[0004] The purpose of the present application is to provide a method for producing a groove for laser cladding crack repair, so as to solve the problem in the prior art that the length of the crack at the tip of the turbine rotor blade of an aircraft engine is as long as the cover plate, and the position is distributed at the boss. Due to the influence of structural mutations such as the cover plate and the boss, the tip wall thickness size suddenly changes within a short distance, and the conventional variable power method cannot be used during laser cladding. Therefore, the conventional crack repair groove form is not suitable for laser cladding repair of parts with structural mutations.

[0005] To achieve the above-mentioned purpose, the embodiment of the present application provides a method for making a groove for repairing cracks by laser cladding, comprising: Step 1) Perform fluorescent flaw detection on the engine turbine rotor blades to mark the tip crack position; Step 2) grinding the blade basin surface and the end surface at the blade tip crack position until a metallic luster is visible; Step 3) Under a bright light source, a U-shaped groove is formed on the outer wall of the blade at the position of the blade tip crack, with the opening of the U-shaped groove facing the blade end surface; Step 4) Under a black light, remove the cracks at the intersection of the blade cover and the blade basin by grinding; Step 5) After confirming that the intersection cracks have been eliminated under a black light, the bottom of the U-shaped groove is polished and penetrated into a hole under a bright light source to obtain the groove for laser cladding crack repair.

[0006] Optionally, the step 3) includes: The blade is placed horizontally, and a A1.0 or A1.5 carbide grinding head is used to open the U-shaped groove on the outer wall of the blade at the position of the blade tip crack.

[0007] Optionally, it also includes: when the distance between the tip crack and a boss arranged on the inner side of the tip of the engine turbine rotor blade is less than or equal to a preset value, grinding the end surface of the boss close to the tip crack until the distance between the tip crack and the boss is greater than the preset value.

[0008] Optionally, the step 3) includes: A support layer of preset thickness is reserved at the bottom of the U-shaped groove.

[0009] Optionally, the diameter of the hole does not exceed Φ1.5 mm.

[0010] Optionally, the step 5) includes: A fluorescent inspection is performed to check whether there is a crack defect at the position of the U-shaped groove. If there is a crack defect, the groove making method for repairing the crack by laser cladding is re-executed to make a groove for repairing the crack by laser cladding at the crack defect.

[0011] Optionally, after step 5), the following steps are included: The blade is placed at an angle and repaired by laser cladding.

[0012] The embodiments of the present application have the following advantages: Compared with the prior art, the above technical solution provides a method for making a groove for laser cladding crack repair, which applies small groove laser cladding technology to the repair of cracks on the tip of aircraft engine turbine rotors, extending the life of aircraft engine parts, reducing engine maintenance costs, and shortening maintenance cycles. The shape of the groove for laser cladding crack repair is based on the U-shaped groove, with the cover plate polished and penetrated, and a thin layer of crack bottoming is reserved on the upper part of the U-shaped groove. Compared with the conventional U-shaped groove, the damage to the substrate is less, and the bottom of the groove for laser cladding crack repair is polished and penetrated, the molten pool has small flow resistance, and the laser cladding forming is fuller. In addition, the upper part is reserved for support, and the cladding will not collapse. This solves the problem in the prior art that the crack at the tip of the turbine rotor blade of an aero-engine extends to the cover plate and is located at the boss. Due to the sudden structural changes of the cover plate, the boss, etc., the wall thickness of the tip suddenly changes within a short distance, and the conventional variable power method cannot be used during laser cladding. Therefore, the conventional crack repair groove forms are not suitable for laser cladding repair of parts with sudden structural changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0014] Figure 1 A flowchart of the steps of a method for making a groove for repairing cracks by laser cladding is provided for at least one embodiment of the present application. DETAILED DESCRIPTION

[0015] The following is a description of the implementation of the present application by specific specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0016] In the description of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Unless otherwise clearly specified and limited, the terms "set", "install", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0017] It should also be noted that the terms "step 1)", "step 2)", "step 3)", etc. in the claims and specification of the present application are used to distinguish different steps rather than to describe a specific order or sequence. It should be understood that these steps can be executed substantially in parallel or in reverse order under appropriate circumstances, depending on the functions involved.

[0018] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0019] The present application embodiment provides a method for making a groove for repairing cracks by laser cladding, referring to Figure 1 ,include: Step 1) Perform fluorescent flaw detection on the engine turbine rotor blades to mark the tip crack position; Step 2) grinding the blade basin surface and the end surface at the blade tip crack position until a metallic luster is visible; Step 3) Under a bright light source, a U-shaped groove is formed on the outer wall of the blade at the position of the blade tip crack, with the opening of the U-shaped groove facing the blade end surface; Step 4) Under a black light, remove the cracks at the intersection of the blade cover and the blade basin by grinding; Step 5) After confirming that the intersection cracks have been eliminated under a black light, the bottom of the U-shaped groove is polished and penetrated into a hole under a bright light source to obtain the groove for laser cladding crack repair.

[0020] Specifically, after the fluorescent flaw detection, the inner wall and end surface of the blade at the position of the blade tip crack can be polished with diamond until a metallic luster is visible.

[0021] Specifically, the method of eliminating the intersection cracks between the blade cover plate and the blade basin surface by grinding includes: Stand the leaf up and place it under a black light with the end facing up. Use a polishing pen to polish the joint cracks until they are eliminated.

[0022] In some embodiments, the step of opening a U-shaped groove on the outer wall of the blade at the tip crack position includes: The blade is placed horizontally, and a A1.0 or A1.5 carbide grinding head is used to open the U-shaped groove on the outer wall of the blade at the position of the blade tip crack.

[0023] Specifically, placing the blade horizontally means placing the blade with the crack side of the blade tip facing upward and the end surface of the blade pointing in the horizontal direction.

[0024] In some embodiments, it also includes: when the distance between the tip crack and a boss arranged on the inner side of the tip of the engine turbine rotor blade is less than or equal to a preset value, the end surface of the boss close to the tip crack is polished until the distance between the tip crack and the boss is greater than the preset value.

[0025] Specifically, the preset value may be 0.4 mm-0.6 mm.

[0026] In some embodiments, after a U-shaped groove is formed on the outer wall of the blade at the tip crack position, the method further includes: reserving a support layer of a preset thickness at the bottom of the U-shaped groove.

[0027] Specifically, when a U-shaped groove is opened on the outer wall of the blade at the tip crack position, grinding cannot penetrate, and the preset thickness of the support layer reserved at the bottom can be 0.04mm-0.06mm.

[0028] In some embodiments, the diameter of the hole does not exceed Φ1.5 mm.

[0029] Specifically, the hole is an irregular circle, and the diameter of the hole may be Φ1.2 mm or Φ1.1 mm.

[0030] In some embodiments, after grinding and penetrating the bottom of the U-shaped groove into a hole, the method further includes: A fluorescent inspection is performed to check whether there is a crack defect at the position of the U-shaped groove. If there is a crack defect, the groove making method for repairing the crack by laser cladding is re-executed to make a groove for repairing the crack by laser cladding at the crack defect.

[0031] In some embodiments, after obtaining the groove for repairing cracks by laser cladding, the method further comprises: The blade is placed at an angle (for example, the tip crack is tilted upward and the blade as a whole is tilted at 45°) and laser cladding repair is performed.

[0032] The method provided in the present application is mainly applicable to blade tip cracks with a width not greater than 2.5 mm.

[0033] In summary, compared with the prior art, the above technical solution provides a method for making a groove for laser cladding crack repair, which applies small groove laser cladding technology to the repair of cracks on the tip of aircraft engine turbine rotors, extending the life of aircraft engine parts, reducing engine maintenance costs, and shortening maintenance cycles. The shape of the groove for laser cladding crack repair is based on the U-shaped groove, with the cover plate polished and penetrated, and a thin layer of crack bottoming is reserved on the upper part of the U-shaped groove. Compared with the conventional U-shaped groove, the damage to the substrate is less, and the bottom of the groove for laser cladding crack repair is polished and penetrated, the molten pool has small flow resistance, and the laser cladding forming is fuller. In addition, the upper part is reserved for support, and the cladding will not collapse. This solves the problem in the prior art that the crack at the tip of the turbine rotor blade of an aero-engine extends to the cover plate and is located at the boss. Due to the sudden structural changes of the cover plate, the boss, etc., the wall thickness of the tip suddenly changes within a short distance, and the conventional variable power method cannot be used during laser cladding. Therefore, the conventional crack repair groove forms are not suitable for laser cladding repair of parts with sudden structural changes.

[0034] Note that, unless otherwise directly stated, all features disclosed in this specification (including any attached claims, abstracts and drawings) may be replaced by alternative features for achieving the same, equivalent or similar purposes. Therefore, unless otherwise explicitly stated, each feature disclosed is only an example of a group of equivalent or similar features. Where used, further, preferably, further and more preferably are simple beginnings for elaborating another embodiment based on the aforementioned embodiment, and the content of further, preferably, further or more preferably followed by the aforementioned embodiment is combined with the complete composition of another embodiment. Several further, preferably, further or more preferably settings following the same embodiment can be arbitrarily combined to form another embodiment.

[0035] In the implementation of functions and steps, the corresponding functions and steps in various embodiments may also occur in a different order than shown. For example, two consecutive functions and steps may actually be performed or implemented substantially in parallel, and they may sometimes be performed or implemented in the opposite order, depending on the functions involved.

[0036] Although the present application has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application all fall within the scope of protection claimed in the present application.

Claims

1. A method for making a groove for repairing cracks by laser cladding, characterized in that: include: Step 1) Perform fluorescent flaw detection on the engine turbine rotor blades to mark the tip crack position; Step 2) grinding the blade basin surface and the end surface at the blade tip crack position until a metallic luster is visible; Step 3) Under a bright light source, a U-shaped groove is formed on the outer wall of the blade at the position of the blade tip crack, with the opening of the U-shaped groove facing the blade end surface; Step 4) Under a black light, remove the cracks at the intersection of the blade cover and the blade basin by grinding; Step 5) After confirming that the intersection cracks have been eliminated under a black light, the bottom of the U-shaped groove is polished and penetrated into a hole under a bright light source to obtain the groove for laser cladding crack repair.

2. The method for making a groove for repairing cracks by laser cladding according to claim 1, characterized in that: The step 3) comprises: The blade is placed horizontally, and the U-shaped groove is opened on the outer wall of the blade at the position of the blade tip crack using an A1.0 or A1.5 hard alloy grinding head.

3. The method for making a groove for repairing cracks by laser cladding according to claim 1, characterized in that: include: When the distance between the tip crack and a boss arranged on the inner side of the tip of the engine turbine rotor blade is less than or equal to a preset value, the end surface of the boss close to the tip crack is polished until the distance between the tip crack and the boss is greater than the preset value.

4. The method for making a groove for repairing cracks by laser cladding according to claim 1 or 2, characterized in that: The step 3) comprises: A support layer of preset thickness is reserved at the bottom of the U-shaped groove.

5. The method for making a groove for repairing cracks by laser cladding according to claim 1, characterized in that: The diameter of the hole does not exceed Φ1.5mm.

6. The method for making a groove for repairing cracks by laser cladding according to claim 1, characterized in that: The step 5) comprises: A fluorescent inspection is performed to check whether there is a crack defect at the position of the U-shaped groove. If there is a crack defect, the groove making method for repairing the crack by laser cladding is re-executed to make a groove for repairing the crack by laser cladding at the crack defect.

7. The method for making a groove for repairing cracks by laser cladding according to claim 1, characterized in that: After step 5), the following steps are included: The blade is placed at an angle and repaired by laser cladding.

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