Method and system for identifying bond boundaries between sound bonds and weak bonds in multilayer article

Abstract

A method of identifying bond boundaries between sound bonds and weak bonds in a multi-layer article may include determining a plurality of locations on a surface of the article; for each of the plurality of locations, obtaining a full-wave time-domain waveform of ultrasonic waves reflected from the article; and for each pair of adjacent positions of the plurality of positions, generating a waveform based on a comparison of a waveform characteristic of a first waveform generated at a first position of the pair of adjacent positions and a waveform characteristic of a second waveform generated at a second position of the pair of adjacent positions, determining whether a bonding boundary exists between the first position and the second position; and in response to determining that there is a bonding boundary between the first position and the second position, determining a boundary position based on the first position and the second position, and recording the boundary position.

Description

[0001] This application is a divisional application. The application number of the original application is 202080029656.X, the international application number is PCT / US2020 / 028713, the application date is April 17, 2020, and the name of the invention is "Method and system for identifying bonding boundaries between sound bonds and weak bonds in multi-layer products."

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 834,987, filed on April 17, 2019, the entire contents of which are incorporated herein by reference. Background Art

[0004] Many articles used in industry and commerce may include multi-layer components or materials, such as plastic coatings on metals, rubber coatings on metals, epoxy coatings on metals, plastic coatings on glass, or clad metal components. An important consideration in the quality of a multi-layer component or material is the strength of the bonds between the layers in the multi-layer component or material. For example, in the field of clad metal products such as explosively welded metals, a common standard is that the welded product should have a shear strength of at least 20 kilopounds per square inch (ksi).

[0005] Bond failure, i.e., lack of bonding between layers, or weak bonding between layers, can affect the safety or utility of articles made from multi-layer components or materials. For example, weak or defective bonds can cause components to wear out more quickly, resulting in increased maintenance and replacement costs for the user. In addition, weak or defective bonds in multi-layer components or articles can lead to catastrophic failure, resulting in mechanical damage or injury to the user.

[0006] Therefore, it is helpful to test the bond quality of multi-layer parts or materials before using them. Nondestructive testing methods such as ultrasonic testing can be used for quality control in the manufacture of multi-layer parts or materials. By analyzing the waveforms from ultrasonic testing, the boundaries between sound bond areas and defective bond areas can be identified and marked. The defective bond areas can then be repaired if possible, or cut away from the article and discarded.

[0007] While conventional nondestructive testing techniques may be able to identify areas of bond failure or lack of bonding between layers, conventional techniques may have difficulty identifying weak bond areas. Therefore, it may be desirable to develop methods and systems that can more reliably identify bond boundaries between sound bonds and weak bonds in multilayer articles. Summary of the invention

[0008] An exemplary embodiment of a method for identifying a bond boundary between a sound bond and a weak bond in an article having a first layer and a second layer may include determining a plurality of locations on a surface of the article. The method may also include, for each of the plurality of locations, obtaining a full-wave time domain waveform of an ultrasonic wave reflected from the article. The method may also include, for each pair of adjacent locations in the plurality of locations, determining whether there is a bond boundary between the first location and the second location based on a comparison of a waveform characteristic of a first waveform generated at a first location in the pair of adjacent locations with a waveform characteristic of a second waveform generated at a second location in the pair of adjacent locations. The method may also include, for each pair of adjacent locations in the plurality of locations, in response to determining that there is a bond boundary between the first location and the second location, determining a boundary location based on one or both of the first location and the second location, and recording the boundary location.

[0009] An exemplary embodiment of a system for identifying a bond boundary between a sound bond and a weak bond in an article having a first layer and a second layer may include: a tool head; an ultrasonic transducer mounted on the tool head in a fixed position; a motor system operably coupled to the tool head and configured to move the tool head along a two-dimensional plane parallel to the surface of the article; a position sensor configured to output a position signal indicating the position of the tool head; and a controller operably coupled to the ultrasonic transducer, the motor system, and the position sensor. The controller may be configured to control the motor system to move the transducer to a plurality of positions along the surface of the article. The controller may also be configured to, for each of the plurality of positions, identify the coordinates of the position based on the position signal, control the transducer to transmit an ultrasonic wave through the article, and generate a full-wave time domain waveform based on the reflected ultrasonic wave received by the transducer. The controller may also be configured to, for each pair of adjacent positions in the plurality of positions, determine whether a bond boundary exists between the first position and the second position based on a comparison of a waveform characteristic of a first waveform generated at a first position in the pair of adjacent positions with a waveform characteristic of a second waveform generated at a second position in the pair of adjacent positions. The controller may be further configured to, for each pair of adjacent positions in the plurality of positions, determine boundary coordinates based on one or both of the first position and the second position in response to determining that a joined boundary exists.

[0010] An exemplary embodiment of a non-transitory computer-readable storage medium may include computer-executable instructions that, when executed by a computer, cause the computer to acquire a first waveform associated with a first position on a surface of an article including a first layer and a second layer. The first waveform may be generated by transmitting an ultrasonic wave through the article via a transducer and generating a full-wave time-domain waveform based on the reflected ultrasonic wave received at the transducer. The computer-executable instructions may also cause the computer to acquire a second waveform associated with a second position on the surface of the article. The second waveform may be generated by transmitting an ultrasonic wave through the article via the transducer and generating a full-wave time-domain waveform based on the reflected ultrasonic wave received at the transducer. The computer-executable instructions may also cause the computer to determine whether there is a joint boundary between a first position in a pair of adjacent positions and a second position in the pair of adjacent positions based on a comparison of waveform characteristics of the first waveform generated at the first position and waveform characteristics of the second waveform generated at the second position; and in response to determining that there is a joint boundary between the first position and the second position, determine a boundary position based on one or both of the first position and the second position, and record the boundary position. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more specific description will be given by referring to the exemplary embodiments shown in the accompanying drawings. It should be understood that these drawings depict exemplary embodiments and do not limit the scope of the present disclosure, and the exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0012] Figure 1 is a schematic diagram of a multilayer article according to an exemplary embodiment;

[0013] Figure 2 is an exploded schematic diagram of a multilayer article according to an exemplary embodiment;

[0014] Figure 3 is a flow chart of a method of identifying a bond boundary between a sound bond and a weak bond according to an exemplary embodiment;

[0015] Figure 4 is a flow chart of a method of identifying a bond boundary between a sound bond and a weak bond according to an exemplary embodiment;

[0016] Figure 5 is a flow chart of a method of comparing characteristics of waveforms and determining whether a joining boundary exists between two points according to an exemplary embodiment;

[0017] Figure 6 is a flow chart of a method of comparing characteristics of waveforms and determining whether a joining boundary exists between two points according to an exemplary embodiment;

[0018] Figure 7 is a schematic diagram of a surface of a multilayer article according to an exemplary embodiment;

[0019] Figure 8 is a schematic diagram of an ultrasonic waveform of a multilayer article according to an exemplary embodiment;

[0020] Fig. 9 is a schematic diagram of an ultrasonic waveform of a multilayer article according to an exemplary embodiment;

[0021] Fig.10 is a schematic diagram of a surface of a multilayer article according to an exemplary embodiment;

[0022] Fig.11 is a schematic diagram of a system for identifying bond boundaries between strong bonds and weak bonds in a multi-layer article according to an exemplary embodiment;

[0023] Fig.12 is a schematic block diagram of a system for identifying bond boundaries between strong bonds and weak bonds in a multi-layer article according to an exemplary embodiment;

[0024] Fig.13 is a schematic diagram of a surface of a multilayer article according to an exemplary embodiment;

[0025] Fig.14 is a low magnification optical micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0026] Fig.15 is a low magnification optical micrograph of a bonding surface of a base layer of a clad article according to an exemplary embodiment;

[0027] Fig.16 is a low magnification optical micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0028] Fig.17 is a low magnification optical micrograph of a bonding surface of a base layer of a clad article according to an exemplary embodiment;

[0029] Fig.18 is a high magnification optical micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0030] Fig.19 is a high magnification optical micrograph of a bonding surface of a base layer of a clad article according to an exemplary embodiment;

[0031] Fig. 20 is a high magnification optical micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0032] Fig.21is a high magnification optical micrograph of a bonding surface of a base layer of a clad article according to an exemplary embodiment;

[0033] Fig. 22 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0034] Fig.23 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0035] Fig.24 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0036] Fig.25 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0037] Fig.26 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0038] Fig. 27 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0039] Fig.28 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0040] Fig.29 is a scanning electron microscope micrograph of a bonding surface of a cladding layer of a cladding article according to an exemplary embodiment;

[0041] Fig.30 is a flow chart of a method of comparing characteristics of waveforms and determining whether a joining boundary exists between two points according to an exemplary embodiment; and

[0042] Fig.31 is a graph of fast Fourier transforms of ultrasonic waveforms of comparative clad articles according to exemplary embodiments.

[0043] The various features, aspects and advantages of the exemplary embodiments will become more apparent through the following detailed description and the accompanying drawings, in which the same reference numerals represent the same components throughout the drawings and the detailed description. The various features described are not necessarily drawn to scale in the drawings, but are drawn to emphasize specific features relevant to some embodiments.

[0044] The headings used herein are for organizational purposes only and are not meant to limit the scope of the disclosure or the claims.To facilitate understanding, reference numerals have been used, where possible, to designate identical elements that are common to the figures. DETAILED DESCRIPTION

[0045] Reference will now be made in detail to various embodiments. The examples are provided by way of explanation and are not meant to be limiting and do not constitute a definition of all possible embodiments.

[0046] Figure 1 An exemplary embodiment of an article 100 having multiple layers is shown. The article 100 may include a base layer 110 and a cladding layer 120 bonded to the base layer 110. The article may include an interface 105 between the base layer 110 and the cladding layer 120, which may correspond to a bond between the base layer 110 and the cladding layer 120.

[0047] In an exemplary embodiment, the article 100 may be a clad metal article. The base layer 110 may be formed of a material such as stainless steel, carbon steel, titanium, nickel, aluminum, or an alloy comprising any of these materials. In an exemplary embodiment, the cladding 120 may be formed of a material such as aluminum, steel, titanium, zirconium, copper, silver, tantalum, or an alloy comprising any of these materials. However, it should be understood that the base layer 110 and the cladding 120 are not limited to these materials and other materials may be used according to the requirements of a specific application. The cladding 120 may be bonded to the base layer 110 by a solid state welding method, thereby forming an interface 105 between the cladding 120 and the first metal layer 110. The interface 105 may be a region between the cladding 120 and the base layer 110, where atoms from each of the cladding 120 and the base layer 110 diffuse into each other.

[0048] Solid-state welding may include a group of welding processes that produce a bond / weld between structural elements at a temperature below the melting point of the substrates being joined, without the addition of a brazing filler metal. In exemplary embodiments, solid-state welding may be described as a bonding / welding process that (i) does not subject a portion of the structural element to a liquid or vapor phase, (ii) uses pressure, and (iii) is performed with or without the aid of temperature. Solid-state welding is performed over a wide range of pressures and temperatures, with significant deformation and solid-state diffusion of the substrates. Solid-state welding processes include cold welding, diffusion welding, explosion welding, forging welding, friction welding, hot pressure welding, roller welding, and ultrasonic welding.

[0049] In an exemplary embodiment, the solid state weld between the base layer 110 and the cladding layer 120 may be an explosion weld. Explosive welding ("EXW") is a solid state welding technique that uses a controlled explosion to force dissimilar metals into a high quality metallurgical bond joint. The transition joint between the dissimilar metals has high mechanical strength, is ultra-high vacuum tight and can withstand severe thermal excursions. EXW is a solid phase process that welds or clads two metals together by using an explosive to accelerate one of the components at an extremely high velocity. The process is solid phase because both components are in the solid state of matter at all times.

[0050] Although the article 100 is described above as a solid-state welded article, and more specifically as an explosively welded article, it should be understood that the embodiments described herein may also be applied to other types of articles, such as conventional welded metals, articles having a metallic layer and a non-metallic layer, and articles having two non-metallic layers.

[0051] Figure 2 An exploded view of the article 100 is shown. Figure 2 As shown, the base layer 110 may include a base layer bonding surface 112 and a base layer outer surface 114. Additionally, the cladding layer 120 may include a cladding bonding surface 122 and a cladding outer surface 124. When the base layer 110 and the cladding layer 120 are bonded together, either the base layer outer surface 114 or the cladding outer surface 124 may be considered a surface of the article 100 for the purposes of the embodiments described herein.

[0052] Figure 3 An exemplary embodiment of a method 300 is shown for identifying a boundary between a sound bond between a base layer 110 and a cladding layer 120 and a weak bond between a base layer 110 and a cladding layer 120 in an article 100, such as Figure 1-Figure 2 The term "boundary" may refer to a location in the xy plane (see Figure 7 ), where the interface between the cladding 120 and the base layer 110 changes from a sound bond to a weak bond. In block 302, a total of n locations are identified on the surface of the article 100, where n is an integer greater than or equal to 2. Figure 7 An exemplary embodiment is shown in which a plurality of locations 162 have been identified within a test area 160 on the outer surface 124 of the cladding of the article 100. Figure 7 The locations 162 are shown arranged on the cladding outer surface 124, but in alternative exemplary embodiments, the locations 162 may be identified on the base layer outer surface 114. The locations 162 may be arranged with a constant spacing between each location 162, or there may be different spacings between the locations 162. Additionally, in exemplary embodiments, only a sub-area of ​​the article 100 may need to be tested, and the locations 162 may be identified only in the test area 160, such as Figure 7In another exemplary embodiment, it may be desirable to test the entirety of the article 100 , and the locations 162 may be identified on the entire outer surface 124 of the cladding.

[0053] return Figure 3 , in block 304, parameter i is set equal to 1. In block 306, an i-th waveform corresponding to the i-th position 162 of the plurality of positions 162 is obtained. The i-th waveform may be a time domain waveform of the intensity of the reflected ultrasonic wave at the i-th position. In an exemplary embodiment, the i-th waveform may be a full-wave waveform. The full-wave waveform is an unrectified waveform of the reflected ultrasonic wave, showing positive and negative amplitudes. Figure 8 The first waveform 700 and Fig. 9 The second waveform 800 shown is an exemplary embodiment of a full-wave time domain waveform. Obtaining the i-th waveform may include retrieving a waveform from a digital memory, or obtaining a real-time waveform using an ultrasonic transducer. The transducer may be handheld or may be mounted on an automated system. Table 1 below identifies exemplary embodiments of transducer types that may be used and exemplary embodiments of parameters associated with the transducer.

[0054]

[0055] It should be understood that the transducers and parameters listed in Table 1 are exemplary only, and other types of transducers and / or values ​​of the parameters may be used.

[0056] exist Figure 3 In block 308, the (i+1)th waveform is obtained. Similar to the i-th waveform, obtaining the (i+1)th waveform may include retrieving a waveform from a digital memory, or obtaining a real-time waveform using an ultrasonic transducer. In an exemplary embodiment, the same transducer may be used to obtain the i-th waveform and the (i+1)th waveform. For example, the transducer may move to the i-th position and obtain the i-th waveform, and then move to the (i+1)th position and obtain the (i+1)th waveform. The transducer may be moved discretely to each position, or may be moved continuously through each position and obtain waveforms while moving.

[0057] In block 310, the i-th waveform is compared to the (i+1)-th waveform, and in block 312, it is determined whether the comparison performed in block 310 indicates a boundary between a sound bond between the base layer 110 and the cladding layer 120 and a weak bond between the base layer 110 and the cladding layer 120 (see Figure 1-Figure 2 ). Further details regarding the comparison in block 310 and the determination in block 312 will be explained in detail herein. If the comparison does indicate a joined boundary (i.e., "yes" at block 312), the method 300 proceeds to block 314. If the comparison does not indicate a joined boundary (i.e., "no" at block 312), the method 300 proceeds to block 316.

[0058] In block 314, the position of the joining boundary is determined based on one or both of the i-th position and the (i+1)-th position. Fig.10 shows a graph with coordinate x 1 ,y 1 The first position 170 and has coordinates x 2 ,y 2 The boundary position 174 between the first position 170 and the second position 172 may have a coordinate x b ,y b The x coordinate of the boundary position 174 is b can fall within the range [x 1 、x 2 ] (including the endpoints), and the y coordinate y of the boundary position 174 b Can fall within the range [y 1 ,y 2 ] (including the endpoints). In an exemplary embodiment, the coordinates of the boundary position 174 may be set to the midpoint between the first position 170 and the second position 172. Alternatively, depending on the user's preference and needs, the coordinates of the boundary position 174 may be set to any position between and including the first position 170 and the second position 172.

[0059] In block 315, the boundary location is recorded. In an exemplary embodiment, the recording may be manual. For example, when the comparison of the waveforms indicates a bond boundary, the article 100 is inspected using a transducer (see Figure 1 - Figure) can mark the outer surface 124 of the envelope with a writing instrument, a portable surface printer, or another suitable marking tool. Alternatively, if an automated system is used, the system may include a writing instrument, a surface printer, a laser etcher, or other suitable marking tool to physically mark the boundary location on the article 100. Alternatively, the recording of the boundary location may include electronically storing the coordinates of the boundary location as data in a storage medium.

[0060] In block 316, it is determined whether parameter i is equal to value n-1. If i is equal to n-1 ("yes" in block 316), method 300 proceeds to block 320, where the method ends. If i is not equal to n-1 ("no" in block 316), method 300 proceeds to block 318, where i is incremented by 1. Method 300 then returns to block 306.

[0061] Figure 4 Another exemplary embodiment of a method 400 is shown, the method 300 identifying a boundary between a sound bond between a base layer 110 and a cladding layer 120 in an article 100 and a weak bond between the base layer 110 and the cladding layer 120, such as Figure 1-Figure 2 As will be explained in detail herein, method 400 obtains waveforms at all locations 162 and then loops through these waveforms to compare them. This can be beneficial when using an automated system that can electronically store waveforms in a storage medium because the boundary locations can later be calculated and linked to identification information (such as a serial number or batch number) of the tested article. This will contribute to higher throughput of the automated system by eliminating the time required to compare waveforms and physically mark the boundary locations on the article.

[0062] In box 402, a total of n positions are identified on the surface of the article 100, where n is an integer greater than or equal to 2. In box 404, a parameter i is set equal to 1. In box 406, a transducer (e.g., one of the transducers described in Table 1 or another suitable transducer) is moved to the i-th position of the n positions. In box 408, an ultrasonic wave is transmitted through the article 100 via the transducer. In box 410, the reflected ultrasonic wave is received at the transducer at the i-th position. In box 412, an i-th waveform corresponding to the i-th position is obtained. The i-th waveform can be a time domain waveform of the intensity of the reflected ultrasonic wave at the i-th position. As part of generating the i-th waveform in box 412, the i-th waveform can be electronically stored as data in a storage medium.

[0063] In block 414, it is determined whether parameter i is equal to n. If parameter i is not equal to n ("no" in block 414), method 400 proceeds to block 416. In block 416, parameter i is incremented by 1, and method 400 returns to block 406. If parameter i is equal to n ("yes" in block 414), method 400 proceeds to block 418.

[0064] In block 418, parameter i is reset to 1. In block 420, the i-th waveform is compared to the (i+1)-th waveform. As part of block 420, the i-th waveform and the (i+1)-th waveform may need to be retrieved from electronic storage. In block 422, a determination is made as to whether the comparison performed in block 420 indicates a joined boundary. Further details regarding the comparison in block 420 and the determination in block 422 will be explained in detail herein. If the comparison does indicate a joined boundary (i.e., "yes" at block 422), the method 400 proceeds to block 424. If the comparison does not indicate a joined boundary (i.e., "no" at block 422), the method 400 proceeds to block 426.

[0065] In block 424, the boundary position of the joining boundary is determined. The determination of the joining boundary is similar to the above description of Figure 3 In block 425, the boundary position is recorded. The recording of the combined boundary is similar to the above description of Figure 3 The method described in block 315 of .

[0066] In block 426, it is determined whether parameter i is equal to value n-1. If i is equal to n-1 ("yes" in block 426), method 400 proceeds to block 430, where method 400 ends. If i is not equal to n-1 ("no" in block 426), method 400 proceeds to block 428, where i is incremented by 1. Method 400 then returns to block 420, where the next pair of waveforms are compared.

[0067] Figure 5 An exemplary embodiment of a method 500 for comparing characteristics of waveforms and determining whether a joining boundary exists between two points is shown. The method 500 may include corresponding to Figure 3 Boxes 310 and 312 or Figure 4 In describing method 500, reference will also be made to the elements of box 420 and box 422. Figure 8 The first waveform 700 and Fig. 9 A second waveform 800 is shown.

[0068] return Figure 5 , in block 502, a first waveform 700 is obtained. The first waveform 700 may be obtained by using an ultrasound transducer as described in detail above. Alternatively, the first waveform 700 may be retrieved as electronic data from a storage medium.

[0069] In block 504, the peaks in the first waveform 700 are counted (ie, Figure 8 The first number p of peaks 710) shown in 1 In an exemplary embodiment, a first number p of peaks in a subset of the first waveform 700 corresponding to a predetermined range 706 of values ​​along an x-axis of the first waveform 700 may be counted. 1The predetermined range 706 may correspond to values ​​in the time domain in which one would expect to see ultrasonic waves reflected from the interface between the cladding 120 and the base layer 110. For example, in an exemplary embodiment, it may be assumed that a transducer is placed on the cladding 120. Knowing the thickness of the cladding 120 and the speed of sound in the material of the cladding 120, it may be calculated how long it takes for the ultrasonic wave to propagate from the transducer to the interface between the cladding 120 and the base layer 110 and back to the transducer. This time period may be used to calculate the midpoint of the predetermined range 706. The width of the predetermined range 706 may be calculated based on manufacturing tolerances for the thickness of the cladding 120 and / or an estimated thickness of the interface between the cladding 120 and the base layer 110, and then these distance values ​​are converted to corresponding values ​​in the time domain of the waveform based on the speed of sound in the material of the cladding 120. Other factors that may affect the calculation of the midpoint and / or width of the predetermined range may include the type of transducer used (i.e., single element, dual element, delayed tip, etc.) and / or the type of ultrasound used (i.e., contact, immersion, water column, etc.). Alternatively or additionally, the user may perform a calibration procedure on the article being tested or a known sample prior to testing to determine or confirm an appropriate value for the predetermined range 706. For example, the interface between the cladding 120 and the base layer 110 may be visually identified on the ultrasonic waveform to set the predetermined range 706. For the first waveform 700, the predetermined range 706 is used. Figure 8 The peak (at Figure 8 The first number p (denoted as 710) 1 Equals 2.

[0070] In another exemplary embodiment, the first number p of peaks 1 y value of the first waveform 700. The predetermined first threshold 702 may be based on the power level of the transducer used, the specific materials forming the base layer 110 and the cladding layer 120 (see Figure 1-Figure 2 ), the thickness of the base layer 110 and the cladding layer 120, and / or other factors that may affect the propagation of ultrasonic waves. In an exemplary embodiment, the user may perform a calibration procedure on the tested article or a known sample before testing to determine the appropriate level of the first threshold 702. For the first waveform 700, using the first threshold 702, Figure 8 The first number p of peaks is shown 1 Equals 2.

[0071] return Figure 5 In block 506, count the valleys in the first waveform 700 (in Figure 8 The first number t (denoted as 712 in FIG. 1 In an exemplary embodiment, a first number t of valleys in a subset of the first waveform 700 corresponding to a predetermined range 706 of values ​​along the x-axis of the first waveform 700 may be counted. 1For the first waveform 700, a predetermined range 706 is used, Figure 8 Shows the valley (in Figure 8 The first number t (denoted as 712 in FIG. 1 is equal to 1. Alternatively, the first number of valleys t 1 704. In an exemplary embodiment, the second threshold value may be the negative value of the first threshold value 702. Alternatively, the second threshold value 704 may be based on the power level of the transducer used, the specific materials forming the base layer 110 and the cladding layer 120 (see Figure 1-Figure 2 ), the thickness of the base layer 110 and the cladding layer 120, and / or other factors that may affect the propagation of ultrasonic waves. In an exemplary embodiment, the user may perform a calibration procedure on the tested article or a known sample before testing to determine the appropriate level of the second threshold 704. For the first waveform 700, the second threshold 704 is used, Figure 8 It is shown that the first number t1 of valleys is equal to 1.

[0072] In box 508, a second waveform 800 corresponding to a different position is obtained in a similar manner as in box 502. In box 510, the peaks of the second waveform 800 are counted in a similar manner as in box 504. Fig. 9 The second number p of the peak marked as 810 in 2 . In counting the second number of peaks p 2 When the first number p for counting peaks can be used 1 The first threshold 702 or the predetermined range 706 of the second waveform 800 is counted in a similar manner as in the block 506. Fig. 9 The second number t of the valley marked as 812 in 2 . In counting the second number of valleys t 2 When the first number t for counting valleys can be used 1 A second threshold 704 or a predetermined range 706 is defined.

[0073] In block 514, a first number of peaks p is determined. 1 Is it equal to the second number of peaks p 2 And the first number of valleys t 1 Is it equal to the second number of valleys t 2 If both equations are true ("yes" in block 514), the method 500 proceeds to block 516 where it is determined that a join boundary does not exist. If either equation is not true ("no" in block 514), the method 500 proceeds to block 518 where it is determined that a join boundary does exist.

[0074] Figure 6An exemplary embodiment of a method 600 for comparing characteristics of waveforms and determining whether a joining boundary exists between two points is shown. Figure 6 In the example, blocks 602 to 612 are related to Figure 5 The same is true for blocks 502 to 512 in FIG. Figure 6 In block 614, a first number p of peaks is determined. 1 and whether the first total number of valleys t1 is equal to the second number of peaks p 2 and the second number of valleys t 2 If the equation in block 614 is true ("yes" in block 614), the method 600 proceeds to block 616, where it is determined that a join boundary does not exist. If the equation in block 614 is not true ("no" in block 614), the method 600 proceeds to block 618, where it is determined that a join boundary does exist.

[0075] Fig.30 An exemplary embodiment of a method 900 for comparing characteristics of waveforms and determining whether a joining boundary exists between two points is shown. In the above-described methods 500 and 600, waveforms 700 and 800 are characterized by the number of peaks and valleys. In contrast, Fig.30 The characteristics compared in the illustrated method 900 are the component frequencies of the waveforms as determined by a Fast Fourier Transform (FFT).

[0076] In block 902, a first waveform 700 is obtained. The acquisition of the first waveform 700 in block 902 may be performed in the same manner as Figure 5 Box 502 or Figure 6 In block 904, the first waveform FFT 750 of the first waveform 700 is calculated, such as Fig.31 The first waveform FFT 750 can be generated by a known FFT algorithm.

[0077] In block 906, a first peak a is identified. 1 The first peak a 1 The amplitude at the first maximum peak 752 of the first waveform FFT 750 may correspond to (see Fig.31 ).Although Fig.31 It may appear that two maximum peaks are shown for the first waveform FFT 750, it being understood that many FFT algorithms will generate symmetrical curves when operating on real data sets, as opposed to operating on complex data sets. Therefore, it is sufficient to identify only the single first maximum peak 752 of the first waveform FFT 750. Fig.31 In the specific example shown, the first peak value a of the first maximum peak 752 is 1 Calculated to be 9.04.

[0078] In block 908, a second waveform 800 is obtained. The acquisition of the second waveform 800 in block 908 may be performed in the same manner as Figure 5 Box 508 or Figure 6 In block 910, a second waveform FFT 850 of the second waveform 800 is calculated, such as Fig.31 The second waveform FFT 850 can be generated by a known FFT algorithm.

[0079] In block 912, a second peak a is identified. 2 The second peak a 2 The amplitude at the second maximum peak 852 of the second waveform FFT 850 may correspond to (see Fig.31 ).exist Fig.31 In the specific example shown, the second peak value a of the second maximum peak 852 is 2 Calculated to be 14.08.

[0080] In block 914, a first peak value a is determined. 1 and the second peak a 2 The predetermined FFT threshold may be based on the average change in the peak value in the known sound combined samples. For example, if the calibration process determines that the known sound combined samples have an FFT peak change of 5%, the predetermined FFT threshold may be a multiple of that change. For example, in an exemplary embodiment, the predetermined FFT threshold may be 10%, 15%, or 20% or more of the peak value. In an exemplary embodiment, the difference b may be calculated as only the first peak a 1 and the second peak a 2 The straight-line difference between , as given by equation (1):

[0081] b= |a 1 - a 2 | (1)

[0082] In an alternative exemplary embodiment, the difference b can be expressed as 1 or the second peak a 2 For example, the difference b can be given by equation (2):

[0083]

[0084] It should be noted that the denominator in equation (2) can be obtained by the second peak value a 2 Instead, or alternatively, the first peak a 1 and the second peak a 2 The average value is used instead.

[0085] Returning to block 914, if the first peak a is determined1 and the second peak a 2 If the difference b between is greater than a predetermined FFT threshold ("yes" in block 914), the method 900 proceeds to block 918, where it is determined that a combined boundary exists. If it is determined that the difference b is not greater than a predetermined FFT threshold ("no" in block 914), the method 900 proceeds to block 916, where it is determined that no combined boundary exists. Fig.31 In the specific example shown, the difference b is 5.04, or the first peak a 1 Assuming the predetermined FFT threshold is 20%, this would indicate that there is a joining boundary between the position corresponding to the first waveform 700 and the position corresponding to the second waveform 800.

[0086] In the above method 900, the peak values ​​of the FFT waveforms are compared. However, it should be understood that other characteristics of the FFT waveforms may also be compared. For example, in an exemplary embodiment, the values ​​at predetermined bins of the FFT waveforms may be compared, rather than the values ​​at the peaks. Alternatively, in an exemplary embodiment, the x-axis values ​​(i.e., peak positions) of the peaks of the FFT waveforms may be compared. If the peak positions of the two FFT waveforms vary by more than a predetermined number of bins, it may be determined that a join boundary exists between the points corresponding to the two FFT waveforms.

[0087] Figure 11 to Figure 12 An exemplary embodiment of a system 200 for identifying a bond boundary between a strong bond and a weak bond in an article 100 having a first layer and a second layer is shown. Fig.11 As shown, the system may include a first rail 210, a first rail mount 212, a second rail 220, a tool head 222, an ultrasonic transducer 232, and a controller 240. In an exemplary embodiment, the system 200 may also include a marking device 234.

[0088] The second track 220 can be mounted on the first track 210 via the first track mount 212. The system can also include one or more first track mounted motors 214 (see Fig.12 ), the first rail mounting motor 214 is configured to move the first rail mounting member 212 in the y direction along the first rail 210, thereby moving the second rail 220 in the y direction due to the second rail 220 being mounted on the first rail 210 via the first rail mounting member 212. The system 200 may also include one or more position sensors, such as a first rail mounting member encoder 216 (see Fig.12 ). The first rail mount encoder 216 may be configured to output an encoder signal indicating a position of the first rail mount 212 along the first rail 210 in the y-direction.

[0089] The system 200 may further include a tool head motor 224 (see Fig.12 ), the tool head motor 224 is configured to move the tool head 222 in the x-direction along the second track 220. The system 200 may further include a position sensor, such as a tool head encoder 226 operably coupled to the tool head motor 224 (see Fig.12 The tool head encoder 226 may be configured to output an encoder signal indicative of a position of the tool head 222 in the x-direction along the second track 220 .

[0090] In other words, the first rail mount motor 214 and the tool head motor 224 may be part of a motor system operably coupled to the tool head 222 and configured to move the tool head 222 along a two-dimensional plane parallel to the surface of the article 100. The first rail mount encoder 216 and the tool head encoder 226 are exemplary embodiments of encoders operably coupled to the motor system and configured to output encoder signals indicative of the position of the tool head 222.

[0091] The ultrasonic transducer 232 may be mounted on the tool head 222 at a fixed position relative to the tool head 222. Thus, the position of the ultrasonic transducer 232 may be calculated based on the position of the tool head 222 calculated based on the encoder signal. Additionally, the marking device 234 may be mounted on the tool head 222 at a fixed position relative to the tool head 222. Thus, the position of the marking device 234 may be calculated based on the position of the tool head 222 calculated based on the encoder signal. The marking device 234 may be any device suitable for marking the surface of the article being tested. Non-limiting examples of the marking device 234 may include a pen, a surface printer, a laser etcher, or another suitable marking tool for physically marking a boundary position on the article 100.

[0092] like Fig.12 As shown, the controller 240 may be operably coupled to the ultrasonic transducer 232, the first rail mount motor 214, the first rail mount encoder 216, the tool head motor 214, the tool head encoder 226, and the marking device 234 via a bus 250. Alternatively, the controller may be configured to wirelessly communicate with the ultrasonic transducer 232, the first rail mount motor 214, the first rail mount encoder 216, the tool head motor 214, the tool head encoder 226, and the marking device 234 via radio signals, Bluetooth, wireless LAN, or other suitable wireless communication methods.

[0093] As in Fig.12As further seen in , the controller 240 may include a processor 240a and a memory 240b. The controller 240 may also be operably coupled to an external storage medium 242. In addition, for the purposes of this disclosure, the controller 240 may also be considered to be operably coupled to the memory 240b. The memory 240b and the external storage medium 242 may be non-transitory computer-readable storage media. The processor 240a of the controller 240 may be configured to execute computer-executable instructions stored on either the memory 240b and / or the external storage medium 242.

[0094] Memory 240b and external storage medium 242 are examples of computer-readable media. Computer-readable media can be any available media that can be accessed by a computer, and include volatile and non-volatile media, removable and non-removable media. As an example, rather than by limitation, computer-readable media can include computer storage media and communication media. Computer storage media can include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable read-only memory (EEPROM), flash memory or other storage technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical disk storage, cassettes, tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store the required information and can be accessed by a computer. Communication media contain one or more of computer-readable instructions, data structures, program modules, etc., and / or other data in modulated data signals such as carrier waves or other transmission mechanisms, and can include any known information transfer media consistent with the present disclosure. The term "modulated data signal" refers to a signal whose one or more characteristics are set or changed in such a manner as to encode information in the signal. By way of example and not limitation, communication media include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio frequency (RF), infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer-readable media.

[0095] In an exemplary embodiment, the controller 240 may be configured to control the first rail mount motor 214 and the tool head motor 224 to move the transducer 232 to a plurality of positions 162 along the surface of the article 100 (see Figure 7 ).Although Fig.11 While the transducer 232 is shown moving along the outer cladding surface 124 of the article 100 , it will be understood that the transducer 232 may move along the base layer outer surface 114 of the article 100 .

[0096] The controller 240 may also be configured to, for each position 162 in the plurality of positions 162, identify coordinates of the position based on encoder signals from the first rail mount encoder 216 and encoder signals from the tool head encoder 226 based on a fixed relationship between the transducer 232 and the tool head 222. In an exemplary embodiment, the coordinates may be calculated relative to a coordinate system inherent to the system 200. In another exemplary embodiment, the controller 240 may be configured to calculate the coordinates relative to an index mark 190 disposed on a surface of the article 100.

[0097] The controller 240 may also be configured to control the transducer 232 to transmit ultrasonic waves through the article 100. The transducer 232 may be configured to receive reflected ultrasonic waves, such as waves reflected from the cladding outer surface 124, waves reflected from the interface between the cladding 120 and the base layer 110, and / or waves reflected from the base layer outer surface 114 (i.e., the back wall). The controller 240 may also be configured to generate a full-wave time domain waveform based on the reflected ultrasonic waves received by the transducer 232, such as Figure 8 The first waveform 700 or Fig. 9 A second waveform 800 is shown. In an exemplary embodiment, controller 240 may store the waveform in memory 240b or storage medium 242 as waveform data associated with the location on the surface of article 100 where the waveform was recorded.

[0098] The controller 240 may also be configured to determine, for each pair of adjacent positions in the plurality of positions 162, whether a joining boundary exists between a first position in the pair and a second position in the pair. Fig.10 An exemplary embodiment of a pair of adjacent positions including a first position 170 and a second position 172 is shown, and the controller 240 can be configured to determine whether a joining boundary exists between the first position 170 and the second position 172. The controller 240 can do this by comparing the waveform characteristics of the first waveform 700 recorded at the first position 170 and the waveform characteristics of the second waveform 800 recorded at the second position 172. In an exemplary embodiment, the controller can implement the following Figure 5 The method 500 described, Figure 6 Method 600 as described in or as Fig.30 Any of the methods 900 described in to determine whether a joining boundary exists between the first location 170 and the second location 172.

[0099] The controller 240 may also be configured to determine boundary coordinates based on one or both of the first position and the second position in response to determining that a combined boundary exists between the first position 170 and the second position 172. For example, the controller 240 may be configured to set the coordinates of the boundary position to the coordinates of the first position 170, the coordinates of the second position 172, or the coordinates calculated from both the first position 170 and the second position 172. Fig.10 In the exemplary embodiment shown, the coordinates of boundary location 174 are calculated as the midpoint between first location 170 and second location 172 .

[0100] In an exemplary embodiment, once the coordinates of the boundary location 174 are determined by the controller 240, the user can manually mark the coordinates of the boundary location 174 on the surface of the tested article 100. The area around the coordinates of the boundary location 174 can be tested in further detail by hand to determine the full extent of the weak bond area in the article 100. Alternatively, in an exemplary embodiment, the controller 240 can be configured to record the coordinates of the boundary location 174. For example, the controller 240 can be configured to control the marking tool 234 to mark the surface of the article 100 at a point corresponding to the boundary coordinates. Regardless of whether the marking is performed manually by the user or automatically by the system 200 via the marking tool 234, once the testing is completed, the collection of marks 125 can indicate the weak bond area (see Fig.13 ). In an exemplary embodiment, it may be assumed that the smaller area indicated by marking 125 may be a weak bond area, while the larger remaining area corresponds to a sound bond.

[0101] In an exemplary embodiment, as an alternative to marking the article 100 or in addition to marking, the controller 240 may also be configured to record the boundary coordinates by storing the boundary coordinates as electronic data in the memory 240b or storage medium 242. The stored boundary coordinates may be used for subsequent processing of the article, for example, a machine tool may be programmed to cut away the portion of the article 100 defined by the boundary coordinates, thereby cutting away the weak bond area. In addition, storing the boundary coordinates as electronic data may allow the boundary location to be mapped onto an image of the article 100 on a computer display. In another exemplary embodiment, the area of ​​the article 100 identified as having a weak bond may be repaired if possible.

[0102] Although the system 200 is described above as employing the first rail encoder 216 and the tool head encoder 226, it should be understood that the system 200 is not limited to encoders for determining the position of the tool head 222. For example, other position detection sensors such as photogrammetric sensors or laser sensors may be used. Alternatively, a retroreflector may be positioned on the tool head 222 for use with a laser metrology system.

[0103] In addition, the system 200 is described above with reference to the tool head 222 moving along the first track 220 and the second track 220. However, the system 200 is not limited to this embodiment. For example, in an alternative embodiment, the tool head 222 can be mounted on an articulated arm with multiple degrees of freedom to move the tool head to each desired position on the surface of the article 100.

[0104] Figures 14 to 29 is an image showing portions of a cladding article identified as soundly bonded and portions identified as weakly bonded using one or more of the methods 300, 400, 500, 600, and 900 described above. Figures 14 to 29 In the embodiment, the article 100 has a base layer 110 composed of stainless steel and a cladding layer 120 composed of babbitt metal. The cladding layer 120 is bonded to the base layer 110 by explosion welding.

[0105] Figures 14 to 17 is a low magnification optical micrograph of the substrate bonding surface 112 and the cladding bonding surface 122. Fig.14 In FIG. 1 , a coherent cladding bonding wave 126 is shown corresponding to the cladding bonding surface 122 in the healthy bonding region. Fig.15 In FIG. 1 , a continuous base bonding wave 116 is shown corresponding to the base bonding surface 112 in the healthy bonding area. In contrast, in FIG. Fig.16 In FIG. 1 , a non-coherent cladding bonding wave 128 is shown corresponding to the cladding bonding surface 122 in the weak bonding region, and in FIG. Fig.17 , a non-coherent base layer bonding wave 118 is shown corresponding to the base layer bonding surface 112 in the weak bonding area. The non-coherent bonding waves 118, 128 indicate the weak bonding area.

[0106] Figures 18 to 21 is a low magnification optical micrograph of the substrate bonding surface 112 and the cladding bonding surface 122. Fig.18 and corresponding to the base bonding surface 112 in the sound bonding area Fig.19 In contrast, there are no visible defects in the cladding bonding surface 122 corresponding to the weak bonding area. Fig. 20 and corresponding to the base bonding surface 112 in the weak bonding area Fig.21 , a circular defect 130 is shown indicating a weak bonding area.

[0107] Figure 22 to Figure 25 1 is a scanning electron microscope (SEM) micrograph of a region of the cladding bonding surface 122 in the healthy bonding region. Figure 22 to Figure 25 The fuzzy appearance of the surface and limited microcracks in the sintered state indicate a sound bond. Figure 26 to Figure 29is a SEM micrograph of a region of the cladding bonding surface 112 in the weak bonding region. Figure 26 to Figure 29 As can be seen in FIG. 1 , there is significant microporosity indicated by voids 140, significant cracks 142, rounded and / or oval structures 144, and severe angular features 146, all of which are indicative of areas of weak bonding.

[0108] Therefore, in Figures 14 to 29 In the 3D image, the method described in this article successfully non-destructively identified areas of strong and weak bonding, which was subsequently confirmed by detailed inspection of the bonding surface.

[0109] In various embodiments, configurations, and aspects, the present disclosure includes components, methods, processes, systems, and / or devices as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. In various embodiments, configurations, and aspects, the present disclosure contemplates actual or optional use or inclusion of components or processes, such as those known or understood in the art and consistent with the present disclosure, although not shown and / or described herein.

[0110] Embodiments of the present disclosure may operate with many other general or special computing system environments or configurations. Examples of computing systems, environments, and / or configurations that may be suitable for use with the systems and methods described herein include, but are not limited to, personal computers, server computers, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and the like.

[0111] Embodiments of the present disclosure may be described in the general context of computer executable instructions (such as program modules) executed by a computer. Typically, a program module may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The systems and methods described herein may also be practiced in a distributed computing environment, where tasks are performed by remote processing devices linked through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media including memory storage devices. The tasks performed by programs and modules are described below with the aid of the accompanying drawings. A person skilled in the art may implement the exemplary embodiments as processor executable instructions that may be written on any form of computer readable media in a corresponding computing environment according to the present invention.

[0112] The phrases "at least one," "one or more," and "and / or" are open-ended expressions that are conjunctions and disjunctions in operation. For example, each of "at least one of A, B, and C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C," and "A, B, and / or C" means only A, only B, only C, A and B, A and C, B and C, or A, B, and C.

[0113] In this specification and the appended claims, reference will be made to a plurality of terms with the following meanings. The terms "one" (or "an") and "the" refer to one or more of the entity, and therefore include plural references, unless the context clearly specifies otherwise. Therefore, the terms "one" (or "an"), "one or more" and "at least one" are used interchangeably herein. In addition, references to "one embodiment", "some embodiments", "embodiments", etc. are not intended to be interpreted as excluding the existence of additional embodiments that also include the features. The approximate language used throughout the specification and claims can be applied to modify any quantitative representation, which can vary within the allowed range without causing changes in the basic functions associated with it. Therefore, the values ​​modified by terms such as "approximately" are not limited to the specified exact values. In some cases, approximate language may correspond to the accuracy of the instrument used to measure the value. Terms such as "first", "second", "upper", "lower", etc. are used to distinguish one element from another, and unless otherwise specified, these terms are not meant to refer to elements of a specific order or quantity.

[0114] As used herein, the terms "may" and "may be" indicate the possibility of occurring under a set of circumstances; possessing a particular property, characteristic, or function; and / or qualifying another verb by expressing one or more of the ability, property, or possibility associated with the qualifying verb. Thus, the use of "may" and "may be" indicates that the modified term is clearly appropriate, capable, or suitable for the indicated capacity, function, or use, while taking into account that in some circumstances the modified term may sometimes be inappropriate, unable, or unsuitable. For example, in some circumstances, an event or capacity can be expected, while in other circumstances it cannot occur, and this distinction is reflected in the terms "may" and "may be".

[0115] As used in the claims, the word "comprising" and its grammatical variants logically also include different and varying degrees of phrases, such as, but not limited to, "consisting substantially of" and "consisting of. Where necessary, ranges have been provided and these ranges include all sub-ranges therebetween. It is intended that the appended claims should cover variations in scope unless the disclosure explicitly uses specific ranges in certain embodiments.

[0116] As used herein, the terms "determine," "calculate," and "compute" and variations thereof are used interchangeably and include any type of methodology, process, mathematical operation or technique.

[0117] The present disclosure is given for the purpose of illustration and description. The present disclosure is not limited to one or more forms disclosed herein. In the specific embodiments of the present disclosure, for example, various features of some exemplary embodiments are grouped together to representatively describe these and other expected embodiments, configurations and aspects, and it is not feasible to include a description of each potential embodiment, variant and combination of features in the present disclosure. Therefore, the features of the disclosed embodiments, configurations and aspects can be combined in alternative embodiments, configurations and aspects that are not explicitly discussed above. For example, the features listed in the attached claims are less than all the features in a single disclosed embodiment, configuration or aspect. Therefore, the attached claims are hereby incorporated into the present specific embodiments, and each claim independently serves as a separate embodiment of the present disclosure.

[0118] The advancement of science and technology may provide changes not necessarily expressed in the terms of the present disclosure, but the claims do not necessarily exclude such changes.

Claims

1. A method for identifying a bond boundary between a strong bond and a weak bond in an article having a first layer and a second layer, the method comprising: determining a plurality of locations on a surface of the article; For each of the plurality of positions, obtaining a full-wave time-domain waveform of the ultrasonic wave reflected from the article; For each pair of adjacent positions in the plurality of positions: determining whether a joining boundary exists between a first position and a second position based on a comparison of a waveform characteristic of a first waveform generated at a first position in the pair of adjacent positions and a waveform characteristic of a second waveform generated at a second position in the pair of adjacent positions; as well as In response to determining that a joining boundary exists between the first position and the second position, determining a boundary position based on one or both of the first position and the second position, and recording the boundary position; Wherein the determining whether there is a junction boundary between the first position and the second position comprises: counting a first number of peaks of the first waveform; counting a second number of peaks of the second waveform; In response to the first peak number being not equal to the second peak number, it is determined that a binding boundary exists between the first position and the second position.

2. The method according to claim 1, wherein obtaining a full-wave time domain waveform comprises: transmitting ultrasonic waves through the article via a transducer; receiving the reflected ultrasonic wave by the transducer; as well as The full-wave time domain waveform is generated based on the reflected ultrasonic wave.

3. The method according to claim 1, wherein obtaining a full-wave time domain waveform comprises: Waveform data corresponding to the full-wave time-domain waveform is acquired from a storage medium.

4. The method according to claim 1, wherein: evaluating the waveform characteristics for a predetermined x-axis range of the first waveform and the second waveform; and The predetermined x-axis range is based on a speed of sound waves traveling through the material of the first layer and a thickness of the first layer.

5. The method of claim 1, wherein said recording said boundary location comprises marking a surface of said article at a location corresponding to said boundary location. The method according to claim 1 , wherein the recording the boundary position comprises storing the coordinates of the boundary position in a storage medium.

7. The method according to claim 1, wherein: The product is a cladding product; The first layer includes a first metal or a first metal alloy; and The second layer includes a second metal or a second metal alloy. The method of claim 7 , wherein the first layer is solid state welded to the second layer.

9. The method of claim 8, wherein the first layer is explosion welded to the second layer.

10. A method of identifying a bond boundary between a strong bond and a weak bond in an article having a first layer and a second layer, the method comprising: determining a plurality of locations on a surface of the article; For each of the plurality of positions, obtaining a full-wave time-domain waveform of the ultrasonic wave reflected from the article; For each pair of adjacent positions in the plurality of positions: determining whether a joining boundary exists between a first position and a second position based on a comparison of a waveform characteristic of a first waveform generated at a first position in the pair of adjacent positions and a waveform characteristic of a second waveform generated at a second position in the pair of adjacent positions; as well as In response to determining that a joining boundary exists between the first position and the second position, determining a boundary position based on one or both of the first position and the second position, and recording the boundary position; Wherein the determining whether there is a junction boundary between the first position and the second position comprises: counting a first number of valleys of the first waveform; counting a second number of valleys of the second waveform; In response to the first valley number not being equal to the second valley number, it is determined that a bonding boundary exists between the first position and the second position.

11. The method according to claim 10, wherein obtaining a full-wave time domain waveform comprises: transmitting ultrasonic waves through the article via a transducer; receiving the reflected ultrasonic wave by the transducer; as well as The full-wave time domain waveform is generated based on the reflected ultrasonic wave.

12. The method according to claim 11, wherein obtaining a full-wave time domain waveform comprises: Waveform data corresponding to the full-wave time-domain waveform is acquired from a storage medium.

13. The method of claim 10, wherein: evaluating the waveform characteristics for a predetermined x-axis range of the first waveform and the second waveform; and The predetermined x-axis range is based on a speed of sound waves traveling through the material of the first layer and a thickness of the first layer.

14. The method of claim 10, wherein said recording said boundary location comprises marking a surface of said article at a location corresponding to said boundary location.

15. The method of claim 10, wherein the recording the boundary position comprises storing the coordinates of the boundary position in a storage medium.

16. The method of claim 10, wherein: The product is a cladding product; The first layer includes a first metal or a first metal alloy; and The second layer includes a second metal or a second metal alloy.

17. The method of claim 16, wherein the first layer is solid state welded to the second layer.

18. The method of claim 17, wherein the first layer is explosion welded to the second layer.

19. A method of identifying a bond boundary between a strong bond and a weak bond in an article having a first layer and a second layer, the method comprising: determining a plurality of locations on a surface of the article; For each of the plurality of positions, obtaining a full-wave time-domain waveform of the ultrasonic wave reflected from the article; For each pair of adjacent positions in the plurality of positions: determining whether a joining boundary exists between a first position and a second position based on a comparison of a waveform characteristic of a first waveform generated at a first position in the pair of adjacent positions and a waveform characteristic of a second waveform generated at a second position in the pair of adjacent positions; as well as In response to determining that a joining boundary exists between the first position and the second position, determining a boundary position based on one or both of the first position and the second position, and recording the boundary position; Wherein the determining whether there is a junction boundary between the first position and the second position comprises: counting a first number of peaks of the first waveform; counting a first number of valleys of the first waveform; counting a second number of peaks of the second waveform; counting a second number of valleys of the second waveform; calculating a first sum of the first number of peaks and the first number of valleys and a second sum of the second number of peaks and the second number of valleys; and In response to the first sum not being equal to the second sum, it is determined that a bonding boundary exists between the first position and the second position.

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