Aero-engine hollow guide vane calibration test block and nondestructive testing method

Abstract

A calibration test block for a hollow guide vane of an aero-engine comprises a plurality of sub-parts which have the same structure and bonding mode with the hollow guide vane of the aero-engine, and a plurality of bonding interfaces are formed among the sub-parts; according to different structural characteristics, the aero-engine hollow guide vane calibration test block is provided with a plurality of detection structure partitions, each detection structure partition at least comprises a section of bonding interface, at least one prefabricated defect is arranged on the bonding interface at least one end, and the prefabricated defect is configured to be one or more sound attenuation layers. The calibration test block for the hollow guide vane of the aero-engine can eliminate the influence of the surface curvature, the wall body thickness and the internal structure of the guide vane on an ultrasonic detection result, and the defect detection precision on a bonding interface is improved. The invention further provides a nondestructive testing method for the hollow guide vane of the aero-engine.

Description

Technical Field

[0001] The invention belongs to the field of aeroengines, and in particular relates to an aeroengine hollow guide vane calibration test block and a nondestructive testing method. Background Art

[0002] In order to further reduce the structural weight, improve the thrust-to-weight ratio and fuel efficiency, the cold end parts of aircraft engines, such as the intermediate casing unit, are sampled with hollow structures to replace solid structural parts under the premise of full strength requirements to further reduce the structural weight. Among them, the outlet guide vane adopts a fusion design with the intermediate casing support plate, and a hollow structure is formed by bonding the guide vane base with the cover plate, metal honeycomb and other sub-components. According to the simulation analysis and test verification results, the bonding interface is the weak link of the guide vane, and the bonding quality of the bonding surface directly determines the reliability of the part. Therefore, the bonding interface must be 100% fully inspected by ultrasonic testing. However, the hollow guide vane has a complex structure. Not only does the shape have a certain curvature, but the wall at different positions also has asymmetric thickness changes. The internal hollow structure also includes various complex structures such as cavities and metal honeycombs. There are many interfaces, complex structures, and lack of regularity. The conventional metal material pulse ultrasonic reflection method cannot meet the 100% structural full detection requirements, and it is difficult to accurately identify and evaluate the defect state in the hollow guide vane. Therefore, providing a calibration test block suitable for ultrasonic testing of hollow guide vanes of aircraft engines has high practical value for improving the accuracy of quality testing of the bonding interface of the hollow guide vanes. Summary of the invention

[0003] The purpose of the present invention is to provide a calibration test block for hollow guide vanes of an aero-engine to improve the accuracy of ultrasonic testing of the bonding interface of the hollow guide vanes. The present invention also provides a non-destructive testing method for hollow guide vanes of an aero-engine.

[0004] According to an embodiment of one aspect of the present invention, there is provided an aircraft engine hollow guide vane calibration test block, the test block comprising a plurality of sub-components, the plurality of sub-components having the same structure as the corresponding sub-components of the aircraft engine hollow guide vane, the plurality of sub-components being bonded and connected in the same manner as the sub-components of the aircraft engine hollow guide vane and forming a plurality of bonding interfaces; the aircraft engine hollow guide vane calibration test block comprising a plurality of detection structure partitions, each of the detection structure partitions comprising at least one section of the bonding interface, each of the detection structure partitions comprising different structural features, the structural features comprising one or more of the number of the bonding interfaces, the types of the sub-components on both sides of the bonding interface and the thickness of the glue layer of the bonding interface; at least one prefabricated defect is arranged in the bonding interface of each of the detection structure partitions, and the prefabricated defect is arranged as one or more layers of sound attenuation layers.

[0005] The calibration block can reflect the influence of the curvature change, thickness change and internal structure change of different areas of the hollow guide vane of the aircraft engine on the ultrasonic echo signal, and accurately covers the structural characteristics of the parts. Before ultrasonic measurement of the hollow guide vane of the aircraft engine, the calibration block is used for pre-calibration, which can effectively improve the accuracy of ultrasonic testing.

[0006] Furthermore, in some embodiments, the sound attenuation layer is configured as an air layer. The air layer can simulate the defect of debonding of the adhesive layer.

[0007] Furthermore, in some embodiments, the air layer is formed by confining air on the bonding interface through an airtight film layer. The position, shape and size of the prefabrication defect can be accurately limited by providing the airtight film layer.

[0008] Furthermore, in some embodiments, the plurality of sub-components are connected by bonding via one or more layers of adhesive films, and the locations where the prefabricated defects are arranged include: between the adhesive film and the sub-components and / or between two adjacent layers of adhesive films.

[0009] Furthermore, in some embodiments, the sub-component includes a hollow guide vane substrate, a cover plate and a metal honeycomb body, the hollow guide vane substrate and the cover plate define a guide vane cavity, the metal honeycomb body is filled in the guide vane cavity and forms a first bonding surface and a second bonding surface on both sides in the thickness direction, respectively, the gap between the hollow guide vane substrate, the cover plate and the metal honeycomb body is set as a glue filling area, and the detection structure partition includes: the bonding surface between the hollow guide vane substrate and the cover plate, the glue filling area and the filling area of ​​the metal honeycomb body.

[0010] Furthermore, in some embodiments, the prefabricated defects are respectively arranged on the bonding surface between the hollow guide vane base and the cover plate, the glue filling area, the first bonding surface and the second bonding surface, wherein the prefabricated defects arranged on the first bonding surface and the second bonding surface have overlapping areas and non-overlapping areas along the thickness direction.

[0011] Furthermore, in some embodiments, the maximum width of the prefabricated defect is 5 mm-15 mm.

[0012] According to another embodiment of the present invention, a method for nondestructive testing of hollow guide vanes of an aircraft engine is provided, the method comprising the following steps:

[0013] A hollow guide vane calibration block for an aeroengine is provided. The hollow guide vane calibration block for an aeroengine includes a plurality of sub-components. The plurality of sub-components have the same structure as the sub-components of the hollow guide vane for an aeroengine and are bonded together using the same bonding material. The bonding connection position forms a bonding interface. When bonding the plurality of sub-components, a prefabricated defect is set on the bonding interface. The prefabricated defect is set as one or more layers of sound attenuation layers. According to the structural characteristics of the bonding connection position of the hollow guide vane for an aeroengine, a plurality of detection structure partitions are divided on the hollow guide vane calibration block for an aeroengine. Each of the detection structure partitions includes at least one section of the bonding interface. The structural characteristics include one or more of the number of the bonding interfaces, the types of the sub-components on both sides of the bonding interface, and the thickness of the adhesive layer of the bonding interface. At least one prefabricated defect is set in each of the detection structure partitions. Ultrasonic detection is performed on the hollow guide vane calibration block for an aeroengine using an ultrasonic detection device, and the ultrasonic detection signals of different detection structure partitions are calibrated according to the size of the prefabricated defect to obtain calibration parameters. Ultrasonic testing is performed on the finished parts of the hollow guide vanes of an aero-engine, and the test results are corrected using the calibration parameters. This method can effectively correct the influence of the variable curvature, variable thickness and hollow structure of the hollow guide vanes of an aero-engine on the accuracy of ultrasonic testing, and improve the detection accuracy of bonding interface defects.

[0014] Furthermore, in some embodiments, before ultrasonic testing is performed on the aircraft engine hollow guide vane calibration test block, a calibration test step is also included for the prefabricated defect, wherein the calibration test uses industrial CT or ultrasonic C-scanning to calibrate and measure the actual size of the prefabricated defect. Calibration measurement of the size of the prefabricated defect after bonding can further improve the test accuracy and avoid calibration errors caused by changes in shape or size of the prefabricated defect during heating and curing.

[0015] Furthermore, in some embodiments, the method for setting the prefabricated defect is to adhere an airtight film layer on the bonding interface and fill the airtight film layer with air. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of a hollow guide vane calibration test block for an aircraft engine in one embodiment;

[0017] Figure 2 It is a schematic diagram of the cross-sectional structure of a hollow guide vane calibration test block for an aircraft engine in one embodiment;

[0018] Figure 3a Schematic diagram of the locations of the first and third types of prefabricated defects of a hollow guide vane calibration test block for an aircraft engine in one embodiment;

[0019] Figure 3bSchematic diagram of the location of the second type of prefabricated defects in an aircraft engine hollow guide vane calibration test block in one embodiment.

[0020] The purpose of the above drawings is to explain the present invention in detail so that those skilled in the art can understand the technical concept of the present invention, but it is not intended to limit the present invention. For the sake of simplicity, the above drawings only schematically illustrate the structures related to the technical features of the present invention, and do not strictly follow the actual proportions to draw the complete structure and all details. DETAILED DESCRIPTION

[0021] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The phrase appearing in various locations in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments herein may be combined with other embodiments without causing structural conflicts.

[0022] In the description of this article, unless otherwise clearly specified and limited, the technical terms "installed", "connected", "connected" and the like should be understood in a broad sense, which can be a movable connection, a fixed connection or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0023] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to have a specific orientation, be installed or operate in a specific orientation, and should not be construed as a limitation on the embodiments in this document.

[0024] In the description of this article, the terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order or primary and secondary relationship of the described technical features. In the description of this article, the meaning of "plurality" is at least two.

[0025] At present, the calibration test block used for ultrasonic testing is usually a standard test block with a flat-bottom hole defect. By measuring the test block with a known size defect, the calibration parameters are obtained, and the ultrasonic echo signal in the actual test is corrected, thereby realizing non-destructive testing of internal defects in the material. However, the hollow guide vane used in the aircraft engine has a complex structure. The external structure is the aerodynamic structure of a typical stator blade, which has a certain curvature. The thickness of the hollow guide vane varies at different positions and there are many non-parallel walls. The hollow guide vane is provided with different structures such as cavities, glue filling areas, and metal honeycombs. The number of bonding interfaces is large, the structure is complex and irregular, and the echo signal generated by the hollow guide vane's own structure is complex. The commonly used pulse ultrasonic reflection method cannot meet the safety requirements of 100% structural full detection of the bonding interface of the hollow guide vane of the aircraft engine.

[0026] In order to solve the above problems, an embodiment of one aspect of the present invention provides an aircraft engine hollow guide vane calibration test block. The structure of the test block is as follows Figure 1 , Figure 2As shown, the test block is formed by bonding multiple sub-components, and the structure of each sub-component is the same as that of the sub-component of the hollow guide vane of the aircraft engine. The bonding position and bonding material between each sub-component are also the same as those of the finished parts of the hollow guide vane of the aircraft engine; specifically, in some embodiments, each sub-component is bonded and connected by a thermosetting adhesive layer. Each sub-component specifically includes: a hollow guide vane substrate 1, a cover plate 2, a metal honeycomb 3 and an aluminum foil 4. Among them, a groove body with a single-side opening along the thickness direction is provided on the hollow guide vane substrate 1, and together with the cover plate 2, the inner cavity of the hollow guide vane is defined. A step surface 5 is provided on the peripheral side of the groove body of the hollow guide vane substrate 1, and the cover plate 2 is bonded and connected to the hollow guide vane substrate 1 through the step surface 5. The area where the step surface 5 is located along the thickness direction of the hollow guide vane substrate 1 is the first detection structure partition A. Ultrasonic detection is performed along the thickness direction of the hollow guide vane substrate 1. In the detection direction, there are the cover plate 2, the adhesive layer on the step surface 5 and the hollow guide vane substrate 1. The metal honeycomb body 3 is filled in the inner cavity surrounded by the hollow guide vane substrate 1 and the cover plate 2. Along the thickness direction, one side of the metal honeycomb body 3 forms a first bonding surface 7 with the bottom of the groove body of the hollow guide vane substrate 1, and the other side forms a second bonding surface 8 with the aluminum foil 4. The aluminum foil 4 is arranged between the metal honeycomb body 3 and the cover plate 2 to avoid wear between the metal honeycomb body 3 and the cover plate 2. Along the thickness direction of the hollow guide vane substrate 1, there are two bonding interfaces in the distribution area of ​​the metal honeycomb body 3, and the ultrasonic signal passes through the metal honeycomb body 3. This area is the second detection structure partition B. On the peripheral side of the metal honeycomb body 3, a glue filling area 6 is provided at the gap position between the metal honeycomb body 3 and the hollow guide vane substrate 1 and the cover plate 2. The adhesive material filled in the glue filling area 6 has a greater thickness, and the bonding strength requirement is relatively low. Along the thickness direction of the hollow guide vane substrate 1, the area where the glue filling area 6 is located is the third detection structure partition C. Ultrasonic detection is performed along the thickness direction of the hollow guide vane substrate 1, and the cover plate 2, the glue filling area 6 and the hollow guide vane substrate 1 exist in the detection direction.

[0027] In the first detection structure partition A, the second detection structure partition B and the third detection structure partition C, the thickness direction of the hollow guide vane substrate 1 is taken as the detection direction, and there is at least one bonding interface in each detection structure partition. The bonding interfaces in the same detection structure partition have the same structural characteristics, where the structural characteristics include the types of sub-components on both sides of the bonding interface, the number of bonding interfaces in the detection direction, and the thickness of the adhesive layer of the bonding interface. Figure 3a , Figure 3bAs shown, in each detection structure partition, multiple prefabricated defects are arranged as evenly as possible, wherein 8 prefabricated defects (A-1 to A-8) are arranged in the first detection structure partition A; in the second detection structure partition B, 5 prefabricated defects (B1-1 to B1-5) are arranged on the first bonding surface 7, and 4 prefabricated defects (B2-1 to B2-4) are arranged on the second bonding surface 8, wherein the prefabricated defects B1-5 and B2-2 overlap in the detection direction; and 6 prefabricated defects (C-1 to C-6) are arranged in the third detection structure partition C.

[0028] Each detection defect is configured as a sound attenuation layer with a certain size and thickness. In a preferred embodiment, the sound attenuation layer is arranged as an air layer between the glue layer and the part or between the glue layers when there are multiple glue layers.

[0029] In a further preferred embodiment, the prefabricated defect is formed by adhering an airtight film layer, such as a polytetrafluoroethylene layer, to the adhesive layer and filling it with a certain amount of air.

[0030] In a preferred embodiment, the prefabricated defects have different sizes according to different detection sensitivity requirements of different detection structure partitions. In the first detection structure partition A, the prefabricated defects are set to 6mm×6mm; in the second detection structure partition B, the prefabricated defects are set to 12mm×12mm; in the third detection structure partition C, the prefabricated defects are set to 6mm×6mm.

[0031] By using the aircraft engine hollow guide vane calibration test block provided by the above embodiment, the sensitivity of ultrasonic detection can be effectively improved, and the detection accuracy of defects on the bonding interface can be improved.

[0032] According to another embodiment of the present invention, there is provided a method for nondestructive testing of hollow guide vanes of an aircraft engine, the method comprising the following steps:

[0033] First, manufacture sub-components with the same structure as the actual parts, and bond and mold them in the same way as the actual parts to obtain calibration test blocks. Before bonding, it is necessary to divide different detection structure partitions according to the structural characteristics of the bonding positions of different sub-components, so that each detection structure partition includes at least one bonding interface, and set prefabricated defects of a certain size on each bonding interface by pasting polytetrafluoroethylene and filling it with air. The setting positions of the prefabricated defects should be as uniform as possible, and ensure that there is at least one prefabricated defect in each detection structure partition. The division criteria of the detection structure partitions are that the two sides of the bonding interface have the same sub-component type, the adhesive layer thickness of the bonding interface is the same, and the number of bonding interfaces along the ultrasonic detection direction is the same.

[0034] After the prefabrication defect setting is completed, the calibration test block is heated and cured using the same curing parameters as the actual part.

[0035] In a preferred embodiment, after the curing is completed, the prefabricated defects can also be calibrated and measured to check whether the size, shape and position of the prefabricated defects change during the curing process. Specifically, the calibration measurement can be implemented by industrial CT or ultrasonic C-scanning or other non-destructive testing means that can perform three-dimensional measurement of the pores inside the material.

[0036] After completing the calibration measurement, the calibration test block is measured using ultrasonic testing equipment used for quality inspection of finished aircraft engine hollow guide vanes. The signal characteristics of each prefabricated defect position are measured separately to obtain the calibration parameters.

[0037] Finally, the ultrasonic testing equipment was used to carry out ultrasonic testing on the hollow guide vanes of finished aircraft engines, and the test results were corrected using the corresponding calibration parameters to achieve accurate detection of bonding interface defects of hollow blades of aircraft engines.

[0038] In a preferred embodiment, Figure 1 , Figure 2 The process of ultrasonic testing of hollow guide vanes of aircraft engines shown is as follows:

[0039] First, prepare the sub-components of hollow guide vane substrate 1, cover plate 2, metal honeycomb 3 and aluminum foil 4; then divide the detection structure into A, B, C according to the structural characteristics of the bonding interface between each sub-component and set prefabricated defects in the glue layer to obtain the calibration test block. The calibration test block is heated and cured using the heating and curing parameters used in actual production. Subsequently, the calibration test block is scanned using industrial CT to check whether the size, shape, and position of each prefabricated defect meet the preset conditions. If there is a large deviation, the calibration test block needs to be re-prepared. Next, the calibration block is tested using ultrasonic testing equipment to record the signals of prefabricated defects of different positions, sizes and defect characteristics, such as the echo signal characteristics of the prefabricated defects set on the side of the glue layer close to the cover plate 2, the prefabricated defects set on the side of the glue layer away from the cover plate 2, and the echo signal characteristics of the prefabricated defects set between the two glue layers, as well as the echo signal characteristics of a single prefabricated defect on the first bonding surface 7, a single prefabricated defect on the second bonding surface 8, and two overlapping prefabricated defects (B1-5, B2-2) located on the first bonding surface 7 and the second bonding surface 8, respectively, to obtain calibration parameters. Ultrasonic testing is performed on the finished parts of the hollow guide vanes of aircraft engines using ultrasonic testing equipment. According to different testing positions, the corresponding calibration parameters are used to correct the test results to achieve accurate measurement of bonding interface defects.

[0040] The purpose of the above embodiments is to further explain the present invention in detail in conjunction with the accompanying drawings so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, the optimization or equivalent replacement of the part structures and method steps involved, as well as the combination of implementation methods in different embodiments without conflict of structure and principle, all fall within the protection scope of the present invention.

Claims

1. A hollow guide vane calibration test block for an aircraft engine. It is characterized in that The invention comprises a plurality of sub-components, wherein the plurality of sub-components have the same structure as the corresponding sub-components of the hollow guide vane of the aircraft engine, and the plurality of sub-components are bonded and connected in the same manner as the sub-components of the hollow guide vane of the aircraft engine to form a plurality of bonding interfaces; The aircraft engine hollow guide vane calibration test block includes a plurality of detection structure partitions, each of the detection structure partitions includes at least one section of the bonding interface, and each of the detection structure partitions includes different structural features, and the structural features include one or more of the number of the bonding interfaces, the types of the sub-components on both sides of the bonding interface, and the thickness of the glue layer of the bonding interface; At least one prefabricated defect is arranged in the bonding interface of each detection structure partition, and the prefabricated defect is arranged as one or more sound attenuation layers.

2. The hollow guide vane calibration block for an aircraft engine according to claim 1, It is characterized in that The sound attenuation layer is configured as an air layer.

3. The hollow guide vane calibration block for an aircraft engine according to claim 2, It is characterized in that The air layer is formed by the air-impermeable film layer confining air on the bonding interface.

4. The hollow guide vane calibration test block for an aero-engine according to claim 1, 2 or 3, It is characterized in that The plurality of sub-components are connected by bonding via one or more layers of adhesive films, and the locations where the prefabricated defects are arranged include: between the adhesive film and the sub-components and / or between two adjacent layers of adhesive films.

5. The hollow guide vane calibration test block for an aero-engine according to claim 1, 2 or 3, It is characterized in that The sub-component includes a hollow guide vane substrate, a cover plate and a metal honeycomb body, the hollow guide vane substrate and the cover plate define a guide vane cavity, the metal honeycomb body is filled in the guide vane cavity and forms a first bonding surface and a second bonding surface on both sides in the thickness direction, respectively, the gap between the hollow guide vane substrate, the cover plate and the metal honeycomb body is set as a glue filling area, and the detection structure partition includes: the bonding surface between the hollow guide vane substrate and the cover plate, the glue filling area and the filling area of ​​the metal honeycomb body.

6. The hollow guide vane calibration block for an aircraft engine according to claim 5, It is characterized in that The prefabricated defects are respectively arranged on the bonding surface of the hollow guide vane base and the cover plate, the glue filling area, the first bonding surface and the second bonding surface, wherein the prefabricated defects arranged on the first bonding surface and the second bonding surface have overlapping areas and non-overlapping areas along the thickness direction.

7. The hollow guide vane calibration test block for an aero-engine according to claim 1, 2 or 3, It is characterized in that The maximum width of the prefabricated defect is 5mm-15mm.

8. A nondestructive testing method for hollow guide vanes of aircraft engines. It is characterized in that The following steps are involved: Provided is an aircraft engine hollow guide vane calibration test block, the aircraft engine hollow guide vane calibration test block comprising a plurality of sub-components, the plurality of sub-components having the same structure as the sub-components of the aircraft engine hollow guide vane, and being bonded together using the same bonding material, the bonding positions forming a bonding interface, and when bonding the plurality of sub-components, prefabricated defects are arranged on the bonding interface, the prefabricated defects being arranged as one or more sound attenuation layers; According to the structural characteristics of the bonding connection position of the hollow guide vane of the aircraft engine, a plurality of detection structure partitions are divided on the calibration test block of the hollow guide vane of the aircraft engine, each of the detection structure partitions includes at least one section of the bonding interface, and the structural characteristics include one or more of the number of the bonding interfaces, the types of the sub-components on both sides of the bonding interface, and the thickness of the glue layer of the bonding interface; each of the detection structure partitions is provided with at least one of the prefabrication defects; Using ultrasonic testing equipment to perform ultrasonic testing on the hollow guide vane calibration test block of the aircraft engine, and calibrating the ultrasonic testing signals of different detection structure partitions according to the size of the prefabricated defects to obtain calibration parameters; Ultrasonic testing is performed on the finished parts of the hollow guide vanes of an aero-engine, and the testing results are corrected using the calibration parameters.

9. The nondestructive testing method for hollow guide vanes of an aircraft engine according to claim 8, It is characterized in that Before ultrasonic testing is performed on the aero-engine hollow guide vane calibration test block, a step of calibrating the prefabricated defect is also included. The calibration test uses industrial CT or ultrasonic C-scanning to calibrate and measure the actual size of the prefabricated defect.

10. The nondestructive testing method for hollow guide vanes of an aircraft engine according to claim 8 or 9, It is characterized in that The method for setting the prefabricated defect is to stick an airtight film layer on the bonding interface and fill the airtight film layer with air.

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