A brazed construction ultrasonic scanning device and method of detection

Abstract

The application provides a kind of brazing ultrasonic scanning device for the ultrasonic detection of the part with offset annular brazing structure, including ultrasonic probe for the ultrasonic detection of the part with offset annular brazing structure.The device includes an automatic scanning mechanism with a reflection module for detecting inside the annular brazing structure, and the ultrasonic probe is movably arranged in the housing of the automatic scanning mechanism, and the water distance of the ultrasonic detection can be adjusted by adjusting the distance between the mirror at the bottom of the housing.The device can effectively detect the complex structure of the annular brazing structure, improve the detection accuracy and efficiency.The application also provides an ultrasonic detection method.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic testing, specifically relating to an ultrasonic scanning device and testing method for brazed structures. Background Technology

[0002] Ultrasonic testing is one of the most commonly used techniques in industrial non-destructive testing, widely applied in manufacturing fields such as metallurgy, automotive, and aerospace. It can effectively detect defects such as porosity, cracks, and inclusions inside parts. For example, when calculating the brazing rate of brazed structures, ultrasonic immersion C-scan can be used to calculate the brazing area using the echo images. For ring-shaped parts commonly used in the aerospace field, existing conventional testing systems such as Scanmaster or GE USM can use ultrasonic probes to perform circumferential testing on the parts, thus providing overall scan results.

[0003] However, for complex parts with biased annular brazed structures, such as parts with multiple tubular brazed structures distributed along their edges, the ultrasonic signal, when using conventional equipment for surround scanning, needs to pass through multiple reflecting surfaces and is subject to interference from asymmetrical structures, making it difficult to effectively assess the welding quality of the brazed structure. Therefore, designing an ultrasonic testing device capable of effectively detecting complex welded structures is crucial for improving the efficiency of part inspection. Summary of the Invention

[0004] This invention provides an ultrasonic scanning device for brazed structures, enabling effective detection of the brazed microstructure of complex parts from within an offset annular brazed structure. This invention also provides an ultrasonic testing method for brazed structures.

[0005] According to one aspect of the present invention, an ultrasonic scanning device for brazed structures is provided for ultrasonic testing of parts with biased annular brazed structures. The ultrasonic scanning device includes an automatic scanning mechanism for extending into the interior of the annular brazed structure for testing. The automatic scanning mechanism is provided with a reflection module, which includes a housing and a reflector. The housing includes a transmission window disposed on a side wall, and the reflector is mounted at the bottom of the housing. An ultrasonic probe is movably mounted inside the housing. The ultrasonic probe is movable relative to the housing along a first rotation axis to adjust the distance between it and the reflector, thereby adjusting the ultrasonic testing distance.

[0006] This ultrasonic scanning device for brazed structures can scan and inspect circumferential welds from the inside by rotating the automatic scanning mechanism around an axis, avoiding interference from complex, especially asymmetrical, external structures. The reflection module allows the ultrasonic probe to move along the first rotation axis to adjust the water distance, enabling inspection even in confined spaces.

[0007] Optionally, the housing is configured as a cylinder to facilitate testing within the tubular structure and avoid interference.

[0008] Optionally, the reflector is a concave reflector. A concave reflector can converge ultrasonic signals, further reducing the detection distance.

[0009] Optionally, the automatic scanning mechanism further includes a first rotating axis arranged along the emission direction of the ultrasonic probe, and a second and third rotating axis arranged on the top of the automatic scanning mechanism perpendicular to the first rotating axis and mutually perpendicular, to allow the automatic scanning mechanism to rotate 360° around the first rotating axis and to oscillate around the second and third rotating axes. The second and third rotating axes allow the automatic scanning mechanism to perform ultrasonic scanning on inclined tubular structures, improving the degree of freedom of detection.

[0010] According to another aspect of the present invention, an ultrasonic testing method is provided for ultrasonic testing of parts with an offset annular brazed structure, employing a water immersion testing process, comprising the following steps: 1) preparing and testing a first comparative sample; 2) preparing and testing a second comparative sample; 3) testing the test piece, and comparing the test data with the first and second comparative samples to obtain a test result. The test piece includes a first part and a second part, which are connected together by at least one annular brazed structure, the annular brazed structure being offset from the center of the first part. The first comparative sample is a substrate defect sample, comprising a substrate and brazed structure with the same structure as the test area of ​​the test piece, and further comprising flat-bottomed holes of different positions and sizes disposed in the substrate to simulate substrate defects; the second comparative sample is a brazing rate sample, comprising a substrate and brazed structure with the same structure as the test area of ​​the test piece, and further comprising weld gaps disposed in the brazed structure to simulate missing solder or incomplete welding defects.

[0011] By comparing the detection signals with those of the first and second comparative samples, the true condition of the brazing structure in the sample to be tested can be analyzed and determined, eliminating the interference of inherent defects in the substrate, and thus enabling targeted process optimization.

[0012] Furthermore, the ultrasonic inspection method involves inserting an ultrasonic probe into the center of the annular brazed structure and rotating it 360° to scan the surrounding surface of the part. This internal scanning method eliminates interference from complex structures, especially asymmetrical external structures, resulting in more accurate inspection results.

[0013] Further, the preparation of the second comparative sample includes the following steps: a) coating a flow-blocking agent on a nickel foil with the same wall thickness as the annular brazed structure; b) inserting the nickel foil between the first part and the second part to be welded, at different depths in the area to be welded; c) brazing the substrate to be welded of the second comparative sample, and then removing the nickel foil to obtain the second sample.

[0014] Furthermore, in step b), the preset depth range of the nickel foil is 25% to 100% of the total depth of the annular brazing structure. Simulating different degrees of weld defects helps to accurately assess the brazing adhesion rate of the brazing structure.

[0015] Furthermore, the ultrasonic detection method employs ultrasonic C-scan. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an ultrasonic scanning system for a brazed structure in one embodiment;

[0017] Figure 2a and Figure 2b This is a schematic diagram of the automatic scanning mechanism and its surrounding structure in one embodiment;

[0018] Figure 3a This is a schematic diagram of the structure of the test piece in one embodiment;

[0019] Figure 3b This is a partial schematic diagram of the test piece in one embodiment;

[0020] Figure 3c for Figure 3b Partial cross-sectional view of the test specimen;

[0021] Figure 4 This is a schematic diagram of the structure of the first comparative sample in one embodiment;

[0022] Figure 5 This is a schematic diagram of the structure of the second comparative sample in one embodiment;

[0023] Figures 6a to 6d These are schematic diagrams of the pre-set defects 25a to 25d of the second comparative sample in one embodiment;

[0024] Figure 7 This is a schematic diagram of the ultrasonic testing signal of a brazed structure in one embodiment.

[0025] The purpose of the above figures is to provide a detailed description of the present invention so that those skilled in the art can understand the technical concept of the invention, and not to limit the invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the meanings commonly understood by those skilled in the art; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having” and their synonyms in the specification, claims and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0028] In this document, the terms "first," "second," etc., are used only to distinguish different counterparts and do not indicate the number, specific order, or primary / secondary relationship of the technical features referred to. In the description herein, "multiple" means two or more, unless otherwise explicitly specified.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The use of the term "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments herein, terms such as “center,” “edge,” “horizontal,” “vertical,” “lateral,” “longitudinal,” “length,” “width,” “depth,” “thickness,” “radial,” “axial,” “up,” and “down” indicate orientation or positional relationships only for the purpose of facilitating the description of the embodiments and simplifying the description, and are not intended to indicate or limit that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and are therefore not intended to limit the embodiments of the present invention.

[0031] In the description of the embodiments herein, unless otherwise explicitly specified or delimited, the terms "installation," "connection," "linking," etc., should be interpreted broadly, such as referring to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or connections through an intermediate medium. Those skilled in the art should be able to understand the specific meaning of the above terms in the embodiments herein according to the specific circumstances.

[0032] For some complex components in aero-engines, the brazed structure is annular and off-center, and may contain multiple adjacent weld seams. Using conventional equipment for external ultrasonic scanning presents challenges. The ultrasonic signal must penetrate the complex external contours, and reflected signals are obstructed by various interfaces, making accurate detection of the weld structure difficult. Therefore, specialized inspection equipment is needed for components with such offset annular brazed structures.

[0033] According to one aspect of the present invention, an ultrasonic scanning device for brazed structures is provided, such as... Figure 1 As shown, this device is used for ultrasonic testing of parts with biased annular brazed structures. The device is computer-controlled, transmitting and receiving ultrasonic signals via a pulse transceiver. The returned data is acquired by a data acquisition system and displayed on an oscilloscope. The controller of the device controls an automatic scanning mechanism 1 to perform water immersion ultrasonic testing. During testing, the automatic scanning mechanism 1 is immersed in a coupling agent 3 to scan the test piece 2, where the coupling agent 3 is typically pure water. The automatic scanning mechanism 1 optionally includes a vertically arranged first rotating axis 11. Under the action of the control mechanism, the automatic scanning mechanism can rotate 360° around the first rotating axis 11 in the XY plane and move up and down along the first rotating axis 11 in the Z direction. A reflection module 12 is provided at the end of the automatic scanning mechanism 1, combined with… Figure 2a and Figure 2b The reflection module 12 includes a housing 121, a reflector 122, and a transmission window 123 disposed on the side wall of the housing 121. The reflector 122 is mounted at the bottom of the housing 121, forming a 45° angle with the first rotation axis 11. An ultrasonic probe 13 is movably mounted inside the housing 121, with its transmission direction coaxial with the first rotation axis 11. The reflector 122 is positioned in the transmission direction of the ultrasonic probe 13, allowing the ultrasonic signal 131 to be reflected by the reflector 122 and emitted perpendicularly to the first rotation axis 11 through the transmission window 123, thus scanning the sample 2. The reflected signal 132 can also return through the transmission window 123, be reflected by the reflector 122, and be received by the ultrasonic probe 13. The ultrasonic probe can move relative to the housing 121 along the Z-axis to adjust its distance from the reflector 122, thereby adjusting the ultrasonic detection distance to adapt to different measurement environments.

[0034] For a typical ring-shaped sample to be tested, such as Figure 3a As shown, the overall structure is ring-shaped and consists of multiple identical, repeating part modules 20 connected together. Figure 3b Each component module 20 is composed of a first component 21 and a second component 22 connected by an annular brazing structure 23. Figure 3c for Figure 3bA cross-sectional structural diagram is shown. The repeating part module 20 is composed of a first part 21 and a second part 22 stacked on top of each other. The first part 21 is formed by a roughly U-shaped groove structure, with a circular through hole in the middle. The second part includes a lower conical surface and an upper cylindrical surface. The upper cylindrical surface of the second part abuts against the inner surface of the through hole of the first part and is connected together by an annular brazing structure 23. The part as a whole includes multiple such part modules 20, where none of the brazing structures 23 is located at the center of the part under test, and the overall structure of the part is relatively complex. If scanning from the outside, there are too many reflective surfaces involved in the ultrasonic signal, and the echo signal is messy, making it difficult to effectively evaluate the welding quality of the brazing structure 23. At this time, the automatic scanning mechanism 1 can be inserted into the hole at the center of the brazing structure 23 and rotate 360° around the first rotation axis 11 to complete the complete scan of the inner surface of the hole, so as to realize the detection of the brazing structure 23. According to the different sizes of the brazing structure 23, the position of the ultrasonic probe 13 in the housing 121 is adjusted to obtain the water distance that meets the detection requirements.

[0035] To facilitate the detection of porous structures, the housing 121 may optionally be cylindrical to reduce the risk of collisions and interference in confined spaces. The reflector 122 may optionally be a concave reflector to better focus ultrasonic signals. In some embodiments, the device may also have a second and a third rotation axis perpendicular to the first rotation axis 11 and mutually perpendicular to each other on the top of the automatic scanning mechanism 1, allowing the automatic scanning mechanism 1 to swing around the second and third rotation axes in the XZ and YZ planes respectively, thereby increasing the degrees of freedom of the detection device and enabling it to detect samples with a certain tilt angle.

[0036] According to another aspect of the present invention, an ultrasonic testing method is provided for ultrasonic testing of parts with biased annular brazed structures, employing a water immersion ultrasonic testing process. The method includes the following steps:

[0037] 1) Prepare and test the first control sample;

[0038] 2) Prepare and test the second control sample;

[0039] 3) Test the test piece and compare the test data with the first and second comparative samples to obtain the test results.

[0040] In one embodiment, the test piece is circular in shape, such as... Figure 3a As shown, it includes multiple repeating part modules 20, such as Figure 3b As shown, combined with Figure 3cEach component module 20 is formed by stacking a first component 21 and a second component 22 and brazing them together at the through-hole location. The first components 21 in adjacent component modules 20 are interconnected to connect the test piece into a whole. The first component 21 is made of GH3536 nickel-based alloy, and the whole formed by connecting the first components 21 has an outer diameter of 580 mm, an inner diameter of 360 mm, and a weld area wall thickness of 4 mm. The second component 22 is made of DD6 nickel-based single crystal alloy, with a diameter of 40 mm and a weld area wall thickness of 3 mm. The brazing structure 23 is obtained by welding with BNi-2 brazing filler metal, with a weld thickness of 0.5 mm. The welding process is shown in Table 1.

[0041]

[0042]

[0043] Table 1 Brazing process parameters

[0044] The first comparative sample is a substrate defect sample, such as... Figure 4 As shown, the sample is made by welding a first part 21 and a second part 22, which are identical to the individual part module 20 of the part under test, using the same brazing process, and separately cutting out the annular brazed structure 23 and the surrounding structure. Multiple flat-bottomed holes 24a-24i are provided on the outer surface of the first comparative sample to simulate defects in the substrate of the test sample. The typical parameters for setting the size of the flat-bottomed holes are shown in Table 2; the hole diameter can be set from 0.4mm to 2.0mm depending on the actual part condition or test requirements. Specifically, in this embodiment, the size parameters of the flat-bottomed holes are shown in Table 3.

[0045] Flat bottom hole number Aperture (mm) Drilling depth (mm) 24a 0.4-2.0 R4-R2 24b 0.4-2.0 R4-R3+(R3-R2) / 2 24c 0.4-2.0 R4-R3 24d 0.4-2.0 R4-R3-1.52mm 24e 0.4-2.0 (R4-R3) / 2 24f 0.4-2.0 1.52mm 24g 0.4-2.0 R4-R1-1.52mm 24h 0.4-2.0 R4-R1-(R2-R1) / 2 24i 0.4-2.0 R4-R2+1.52mm

[0046] Table 2. Common Calculation Method for Flat Bottom Hole Dimensions of the First Comparative Sample

[0047]

[0048]

[0049] Table 3 shows the flat-bottom hole dimensions of the first comparative sample in one embodiment.

[0050] The second comparative sample is the solder adhesion rate comparative sample, such as... Figure 5 As shown, the second comparative specimen is made by welding a first part 21 and a second part 22, identical to the part under test, using the same brazing process, and separately cutting out the annular brazed structure 23 and its surrounding structure. The brazed structure area of ​​the second comparative specimen has multiple weld gaps 25a-25d to simulate defects such as insufficient filler metal or incomplete welding. Its preparation method includes the following steps:

[0051] a) Coat a flow-blocking agent such as Nicrobraze STOP-OFFTYLL white onto a nickel foil with the same wall thickness h as the annular brazed structure 23. In this embodiment, the nickel foil thickness is 0.5 mm, and the width k can be set to different values ​​according to experimental requirements.

[0052] b) Arrange the first part 21 and the second part 22 according to their welding positions, and insert the nickel foil along the axial direction of the gap to be welded to different depths, ranging from 25%w to 100%w, where w is the total axial depth of the annular brazing structure. In this embodiment, the depths 25a to 25d are respectively as follows: Figures 6a to 6d As shown, 25a has a depth of 25% w, 25b has a depth of 50% w, 25c has a depth of 75% w, and 25d has a depth of 100% w.

[0053] c) Powdered brazing filler metal such as BNi-2 and adhesive such as Nicrobraze S-Binder were mixed in a certain proportion and filled into the gap to be welded between the first part 21 and the second part 22. The parts were then placed in a drying oven and dried at 130°C for 1.5 hours, and welded according to the parameters shown in Table 1. After welding, the nickel foil was removed to obtain the second comparative sample.

[0054] Due to the complex structure of the test piece, which includes multiple annular brazed structures, it is difficult for ordinary ultrasonic scanning devices to effectively detect the brazed structures from the outside. Ultrasonic scanning from inside the annular weld is required. However, the internal space of the second part 22 is small, and it is difficult to adjust and set a reasonable scanning distance with ordinary ultrasonic scanning devices.

[0055] Therefore, this detection method employs the ultrasonic scanning device for the brazed structure described in the aforementioned embodiment. First, water immersion ultrasonic testing is performed on the first and second comparison samples, respectively. The automatic scanning mechanism 12 is inserted into the inner surface of the second part 22 of the comparison sample to inspect its wall. The position of the ultrasonic probe 13 within the housing 121 is adjusted to obtain a water distance that meets the testing requirements. An ultrasonic scan is performed on the wall surface to obtain the ultrasonic reflection amplitude. The reflection amplitude is adjusted to 80% of the full screen height, and the automatic scanning mechanism 12 is rotated 360° around the first rotation axis 11. The gain corresponding to the ultrasonic reflection signals of each prefabricated defect 24a-24i and 25a-25d is recorded, and a DAC curve is plotted, as shown below. Figure 7 As shown, this is the data for comparison.

[0056] Next, the test piece is scanned and inspected. The inner wall of each component module 20 is scanned with the same parameters to complete the ultrasonic scan of the entire component, preferably a C-scan. The detected discontinuous signals are compared with the prefabricated defects in the first and second comparative samples to determine the type, location, and size of the reflectors, calculate the brazing rate, and thus complete the evaluation of the brazing structural defects of the test piece. Optionally, the data signals collected by the first and second comparative samples can be fitted using interpolation methods to achieve an accurate correspondence with the actual test results of the test sample.

[0057] This ultrasonic testing method for brazed structures can effectively distinguish between signals from substrate defects such as internal bubbles and signals from missing or incomplete brazing of the filler metal during the welding process by preparing two different comparative samples. This allows for accurate assessment of welding quality and provides direction for targeted improvement of welding process parameters.

[0058] It should be understood that the purpose of the above embodiments is to provide a more detailed description of the present invention in conjunction with the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention, and not to limit the scope of protection of the present invention. Within the scope of the claims of the present invention, improvements or equivalent substitutions of the involved parts, structures or method steps, as well as combinations of different embodiments without causing structural or principle conflicts, all fall within the protection scope of the present invention.

Claims

1. An ultrasonic testing method for brazed structures, used for ultrasonic testing of parts with offset annular brazed structures, employing water immersion ultrasonic testing technology, characterized in that... The test piece includes a first part and a second part, which are connected together by at least one annular brazing structure, which is offset from the center of the first part. The detection method employs a brazing ultrasonic scanning device, which includes an ultrasonic probe and an automatic scanning mechanism for extending into the annular brazed structure for detection. The automatic scanning mechanism is equipped with a reflection module, which includes a housing and a reflector. The housing includes a transmission window on its side wall, and the reflector is mounted at the bottom of the housing. The ultrasonic probe is movably mounted inside the housing. The automatic scanning mechanism also includes a first rotation axis arranged along the transmission direction of the ultrasonic probe. The ultrasonic probe can move relative to the housing along the first rotation axis to adjust the distance between it and the reflector, thereby adjusting the ultrasonic detection distance. The ultrasonic testing method for brazed structures includes the following steps: 1) Prepare and test the first control sample; 2) Prepare and test the second control sample; 3) To test the test piece, insert the ultrasonic probe into the center of the annular brazed structure and rotate it 360° to scan the surrounding part wall. Compare the test data with the first and second comparative samples to obtain the test results. The first comparative specimen is a substrate defect specimen, which includes a substrate and brazing structure with the same structure as the test area of ​​the test piece, and also includes flat-bottomed holes of different positions and sizes in the substrate to simulate substrate defects. The second comparative specimen is a brazing rate specimen, which includes a substrate and brazing structure with the same structure as the test area of ​​the test piece, and also includes a weld gap set in the brazing structure to simulate defects such as lack of solder or incomplete welding. The preparation of the second comparative sample includes the following steps: a) Coating a flow-blocking agent onto a nickel foil with the same wall thickness as the annular brazed structure; b) Insert the nickel foil between the first part and the second part to be welded, at different depths preset in the area to be welded; c) Brazing the substrate to be welded in the second comparative sample and removing the nickel foil to obtain the second comparative sample.

2. The ultrasonic testing method for brazed structures according to claim 1, characterized in that, The preset depth range of the nickel foil in step b) is 25% to 100% of the total depth of the annular brazing structure.

3. The ultrasonic testing method for brazed structures according to claim 1, characterized in that, The ultrasonic testing method uses ultrasonic C-scan.

4. The ultrasonic testing method for brazed structures according to claim 1, characterized in that, The casing is configured as a cylinder.

5. The ultrasonic testing method for brazed structures according to claim 2, characterized in that, The reflector is configured as a concave reflector.

6. The ultrasonic testing method for brazed structures according to claim 1, 4, or 5, characterized in that, The automatic scanning mechanism further includes a second rotating axis and a third rotating axis disposed on the top of the automatic scanning mechanism, perpendicular to the first rotating axis and perpendicular to each other, so as to allow the automatic scanning mechanism to rotate 360° around the first rotating axis and to swing around the second rotating axis and the third rotating axis.

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