A controllable couplant thickness device for phased array ultrasonic testing and a testing method thereof

Abstract

The application discloses a controllable couplant thickness device for phased array ultrasonic detection and a detection method thereof, and relates to the technical field of nondestructive testing. The device comprises the following steps: obtaining a detection frequency of phased array ultrasonic detection and a sound velocity parameter in a couplant, calculating a propagation wavelength of ultrasonic waves in the couplant, and determining a corresponding target thickness parameter; selecting a preset positive integer and combining the propagation wavelength to obtain a spacing value between a probe detection surface and a surface of a measured workpiece, the spacing value being an integer multiple of a half wavelength of the propagation wavelength. The application controls the thickness of the coupling layer to be an integer multiple of a half wavelength, improves the sound pressure transmission efficiency, increases the detection sensitivity by about 6 dB to 10 dB, reduces the echo amplitude deviation from more than 6 dB to within 1 dB, and thus improves the detection consistency and repeatability. Meanwhile, the application can be adapted to curved surface detection through roller or profiling adjustment to avoid decoupling problems, and can be integrated with automatic equipment to realize digital detection and stable operation.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, specifically to a controllable coupling agent thickness device and its testing method for phased array ultrasonic testing. Background Technology

[0002] Phased array ultrasonic testing is an advanced non-destructive testing technology that uses electronically controlled multi-element probes to achieve sound beam deflection, focusing, and dynamic scanning. It is widely used for defect detection in critical structures such as pressure vessels, pipelines, and turbine blades. During this testing process, a coupling agent is typically filled between the probe and the workpiece to eliminate air and ensure that ultrasonic waves can effectively penetrate the workpiece. According to acoustic transmission theory, when the coupling layer thickness is equal to an integer multiple of half the wavelength of the ultrasonic wave propagating in the coupling agent, multiple reflections from the interface can undergo phase superposition, achieving a sound pressure transmission rate close to the theoretical maximum, thus improving detection sensitivity and signal stability. Therefore, the coupling layer thickness has a decisive influence on the test results and is one of the key factors affecting the quality of phased array ultrasonic testing.

[0003] However, current technologies commonly employ manual application of coupling agent and handheld probe testing. The coupling layer thickness relies heavily on operator experience, making it difficult to maintain precise measurements as an integer multiple of half the wavelength. This leads to random fluctuations in sound pressure transmittance, compromising detection sensitivity and result consistency. Furthermore, the repeatability of test results is poor under different operators or at different testing times, with significant variations in defect echo amplitude, affecting the reliability of quantitative evaluation. In addition, for curved or complex workpieces, traditional coupling methods struggle to maintain a uniform and stable coupling layer, easily generating local gaps or air bubbles, resulting in false positives or false negatives. Moreover, existing methods fail to meet the requirements of automated testing systems for the stability and controllability of the coupling state.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a controllable coupling agent thickness device and its detection method for phased array ultrasonic testing, so as to solve the problems in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for detecting the thickness of a controllable coupling agent for phased array ultrasonic testing, comprising the following steps: The detection frequency and sound velocity parameters in the couplant of the phased array ultrasonic testing are obtained, and the propagation wavelength of the ultrasonic wave in the couplant is calculated. At the same time, the corresponding target thickness parameters are determined. A preset positive integer is selected and calculated in conjunction with the propagation wavelength to obtain the distance value between the probe detection surface and the surface of the workpiece being measured. This distance value is an integer multiple of half the propagation wavelength. The actual gap between the probe detection surface and the surface of the workpiece is adjusted by using a spacing adjustment structure set on the outer periphery of the probe, and the gap is kept within the range corresponding to the spacing value. The probe detects that the sealing structure on the outer periphery of the probe forms a closed space with the surface of the workpiece being tested, and then a coupling agent is injected into the closed space until it is full and there are no air bubbles left. Phased array ultrasonic scanning is performed based on a stable coupling agent thin layer formed in a closed space to acquire the detection signal data of the workpiece under test.

[0007] Preferably, to address the issue of how changes in the sound velocity of the coupling agent affect the accuracy of propagation wavelength calculation, an adaptive correction process for acoustic parameters is constructed, with the following steps: Data on the change of sound velocity of the coupling agent under different temperature conditions and different working states were collected, and a mapping relationship model between temperature and sound velocity was established. Obtain the real-time temperature information of the current detection environment, and match the corresponding sound velocity parameters according to the mapping relationship; The matched sound velocity parameters are calculated with the detection frequency to recalculate the propagation wavelength of the ultrasonic wave in the coupling agent; The updated propagation wavelength is output to the subsequent spacing calculation process, and the thickness parameter is updated simultaneously to ensure that the coupling layer thickness is consistent with the actual acoustic environment.

[0008] Preferably, regarding the impact of coupling layer thickness selection on detection results, a thickness parameter optimization and determination process is established, with the following steps: Establish a model relating the coupling layer thickness to acoustic wave transmission efficiency for different positive integers; Analyze the influence trend of coupling layer thickness variation on acoustic energy attenuation, signal amplitude, and penetration capability; The range of positive integer values ​​is screened and constrained based on the detection target, workpiece thickness, and defect detection accuracy requirements. The output is a matching positive integer and is used in the spacing calculation to balance the transmission efficiency and sound energy attenuation, thereby improving the stability of the detection signal.

[0009] Preferably, the thickness parameter matching process is further strengthened by refining the constraints around the range of positive integer values. By introducing material acoustic property parameters and detection sensitivity evaluation indicators, the coupling layer thickness corresponding to positive integers is graded and screened. A judgment criterion is established by combining sound pressure transmission efficiency and echo amplitude stability, limiting the value range that meets the stable transmission condition, thereby improving the matching degree between the spacing calculation result and the detection signal.

[0010] Preferably, to address the issue of fluctuations in the gap between the probe and the workpiece during movement, a multi-point support stabilization control process is constructed, with the following steps: Multiple support points are arranged circumferentially around the outer periphery of the probe to form a stable support structure. An initial gap state is established by adjusting the relative height of each support point, thus forming a stable contact relationship; Acquire the actual gap data between the probe detection surface and the workpiece surface, and compare it with the target spacing in real time; By finely adjusting each support point in a coordinated manner, the gap deviation is controlled within the allowable range, thereby maintaining gap stability during probe movement.

[0011] Preferably, to address gap variations caused by curved surfaces or irregular structures, a dynamic feedback adjustment mechanism is introduced, with the following steps: A distance detection unit is set up to continuously measure the gap between the probe detection surface and the workpiece surface; The measurement results are compared with the target spacing to obtain the gap deviation data; Adjustment signals are generated based on deviation data using a control algorithm; The drive actuator dynamically compensates and adjusts the probe position, ensuring that the gap remains within the set range during the detection process.

[0012] Preferably, to address the issues of residual and unevenly distributed air bubbles during the coupling agent filling process, a synergistic process of sealing and venting is constructed, with the following steps: The probe detection surface, workpiece surface, and sealing structure enclose a closed or semi-closed space; The coupling agent is continuously injected into the space through the supply channel, so that the coupling agent gradually expands to cover the entire space area; During the filling process, air is guided out by setting an exhaust path, and air bubbles are prevented from remaining inside the space. The coupling agent is continuously replenished until a uniform and continuous liquid layer is formed inside the space, thereby ensuring a stable and consistent coupling layer thickness.

[0013] Preferably, the supply channel is arranged along one side of the enclosed space to form a directional flow path, and the exhaust path is set at a relative position to form a through flow line. The coupling agent is advanced along a preset direction and drives the internal gas to migrate synchronously, forming a continuous unidirectional flow state in the enclosed space, thereby achieving bubble-free filling and maintaining a uniform distribution of the liquid layer.

[0014] Preferably, in conjunction with the requirements of automated testing, the testing process is controlled in an integrated manner, with the following steps: The gap adjustment process is linked with the probe motion control system to achieve synchronous control; The gap adjustment operation is performed in real time as the probe moves along the workpiece surface; Maintain a stable coupling layer thickness throughout the entire detection path to ensure consistent detection conditions; It continuously acquires and outputs detection signal data, realizing automated operation of the detection process and data consistency control.

[0015] A controllable coupling agent thickness device for phased array ultrasonic testing includes a parameter acquisition and wavelength calculation module, a thickness calculation and determination module, a gap adjustment and control module, a coupling cavity construction and filling module, and an ultrasonic scanning and testing module. The parameter acquisition and wavelength calculation module acquires the detection frequency and sound velocity parameters in the couplant of the phased array ultrasonic detection, calculates the propagation wavelength of the ultrasonic wave in the couplant, and determines the corresponding target thickness parameters. The thickness calculation and determination module selects a preset positive integer and calculates the distance value between the probe detection surface and the surface of the workpiece to be measured by combining it with the propagation wavelength. This distance value is an integer multiple of half the wavelength of the propagation wavelength. The gap adjustment control module uses a gap adjustment structure set on the outer periphery of the probe to adjust the actual gap between the probe detection surface and the surface of the workpiece being measured, and keeps the gap within the range corresponding to the gap value. The coupling cavity is constructed and filled by a sealing structure on the outer periphery of the probe detection surface, which forms a closed space with the surface of the workpiece being tested. Coupling agent is injected into the closed space until it is filled and no air bubbles remain. The ultrasonic scanning and testing module performs phased array ultrasonic scanning and testing based on a stable coupling agent thin layer formed in a closed space, and acquires the detection signal data of the workpiece under test.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention precisely controls the coupling layer thickness to an integer multiple of half the wavelength, enabling a stable phase superposition effect of ultrasonic waves at the interface. This improves sound pressure transmission efficiency, achieving a stable and higher level compared to the large transmittance fluctuations in traditional manual application methods. Consequently, defect echo signals are clearer and more stable, and detection sensitivity is increased by approximately 6-10 dB. Furthermore, since the coupling layer thickness is determined by both structure and parameters, it no longer relies on manual experience. This significantly reduces the differences in results between different operators or different testing batches, lowering the echo amplitude deviation from over 6 dB to less than 1 dB. This improves the consistency and comparability of test results and addresses the repeatability issues in phased array testing.

[0017] This invention demonstrates excellent adaptability to complex working conditions. Through roller support or automatic contour adjustment, the probe maintains a stable gap during the inspection of curved workpieces, ensuring the coupling layer thickness remains optimized and avoiding local decoupling or bubble problems common in traditional methods. This solves the problem of unstable coupling during curved surface inspection. Furthermore, this solution can be integrated with automated scanning equipment. By standardizing parameter calculation and gap control processes, it achieves digital and automated operation of the inspection process, reducing uncertainties caused by human intervention and thus improving inspection efficiency and overall reliability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a diagram of the array probe, coupling agent cavity, distance controller, and coupling agent supply pipeline of the present invention.

[0020] Figure 2 The roller protrusion of this invention is calibrated at the micrometer level to ensure that the gap between the probe and the workpiece is strictly equal to an integer multiple of half the wavelength.

[0021] Figure 3 The bolt insertion depth of this invention can be precisely adjusted to adapt to different detection frequencies and n values.

[0022] Figure 4 This invention relates to a distance sensor and a motor drive.

[0023] Figure 5 To prevent coupling agent leakage, the sealing ring of this invention ensures that the cavity thickness is entirely determined by the distance control component.

[0024] Figure 6 This is a flowchart of the detection process of the present invention. Detailed Implementation

[0025] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0026] This invention provides, for example Figures 1-6 The method for detecting controllable coupling agent thickness for phased array ultrasonic testing is shown below, with the following specific steps: By precisely setting and maintaining the thickness of the coupling layer between the probe and the workpiece under inspection, the detection process is always under optimal acoustic transmission conditions.

[0027] In practical applications, the detection frequency used in phased array ultrasonic testing and the sound velocity parameters in the coupling agent are first obtained, and the propagation wavelength of the ultrasonic wave in the coupling agent is calculated based on the acoustic propagation relationship. ,in , The speed of sound in the coupling agent. The detection frequency is used. The above calculations yield the acoustic characteristic parameters under the current detection conditions, providing a basis for subsequent gap control.

[0028] After obtaining the propagation wavelength λ, a positive integer is further selected. Based on the expected transmission efficiency and actual testing requirements, To configure, you usually select... The value should be an integer between 1 and 3 to avoid excessively thick coupling layers that could lead to increased acoustic attenuation. Based on this positive integer... With propagation wavelength The target gap between the probe detection surface and the surface of the workpiece to be inspected is calculated. It satisfies the relation By defining the thickness of the coupling layer using this formula, multiple reflections of ultrasound waves within the coupling layer can produce a phase superposition effect, thereby increasing the sound pressure transmission rate.

[0029] Determine the target gap Next, the actual gap between the probe's detection surface and the surface of the workpiece is adjusted. Specifically, this gap can be controlled by a spacing adjustment structure located on the outer periphery of the probe, ensuring a stable support relationship between the probe and the workpiece during contact, thereby limiting the actual gap to the target gap. Within a nearby area. During the inspection process, as the probe moves along the workpiece surface, the spacing adjustment structure maintains continuous contact with the workpiece surface, thereby maintaining the consistency and stability of the gap throughout the scanning path.

[0030] After gap adjustment, a closed coupling space is further formed between the probe detection surface and the surface of the workpiece to be inspected. This coupling space is jointly enclosed by the probe detection surface, the surface of the workpiece to be inspected, and a sealing structure set on the outer periphery of the probe. The sealing structure undergoes a certain elastic deformation when in contact with the workpiece surface, thereby achieving circumferential sealing, preventing outside air from entering, and providing space conditions for the stable existence of the coupling agent.

[0031] Subsequently, coupling agent is injected into the aforementioned enclosed space through the coupling agent supply path. During the injection process, the coupling agent gradually fills the entire space while expelling existing air to avoid residual air bubbles adversely affecting sound wave propagation. Once the space is filled with coupling agent, a uniform liquid layer is formed between the probe detection surface and the workpiece surface; the thickness of this liquid layer is the aforementioned determined gap. Thus satisfying Acoustic conditions.

[0032] After the coupling agent thin layer has stabilized and formed, phased array ultrasonic testing is performed. Ultrasonic waves are emitted by the probe and reflected signals are received to detect and analyze internal defects in the workpiece. During the testing process, the coupling layer thickness remains constant. Within a certain range, the transmission efficiency of sound waves at the interface is close to the optimal state, thereby improving the amplitude stability and consistency of the detection signal.

[0033] During operation, as the probe continuously scans the workpiece surface, the spacing adjustment structure maintains a stable gap between the probe's detection surface and the workpiece surface. Simultaneously, the sealing structure prevents coupling agent leakage, and the coupling agent supply path can be replenished as needed to maintain the continuity of the coupling agent layer. Because the gap is determined by structural parameters rather than controlled by human experience throughout the process, the impact of human factors on the detection results is significantly reduced.

[0034] Furthermore, when the workpiece to be inspected has a curved surface structure, a stable gap d can still be maintained in local areas through the multi-point contact spacing adjustment method and the flexible adaptability of the sealing structure, ensuring the continuity of the coupling agent thin layer under curved surface conditions and thus guaranteeing the reliability of the inspection process. Using the above method, the gap can be adjusted under different inspection frequencies. as well as The parameters in the parameters are used to adapt to different detection tasks.

[0035] In summary, by analyzing the propagation wavelength By calculating the coefficients, selecting the positive integer n, and determining the target gap d, and combining this with gap adjustment, sealing, and coupling agent filling processes, precise control and stable maintenance of the coupling layer thickness were achieved, ensuring that the detection process always met the requirements. and This condition effectively improves the sensitivity, repeatability, and consistency of phased array ultrasonic testing, and has good engineering application value.

[0036] To achieve stable control of the gap between the probe's detection surface and the workpiece surface, the distance control process was refined, and different gap adjustment methods were adopted in different application scenarios to ensure that the gap always meets the requirements. The requirements are met, and it must remain continuous and stable during dynamic detection.

[0037] Multiple rolling contact units are evenly distributed around the outer periphery of the probe housing. Each rolling contact unit is preferably a roller or a support ball structure, and is formed to a fixed size through precision machining. The protrusion height of each rolling contact unit relative to the probe detection surface is calibrated during the manufacturing stage to ensure that this protrusion height matches the target gap d. When the probe approaches the workpiece surface and performs a scanning motion, each rolling contact unit forms rolling contact with the workpiece surface, thereby creating a stable gap between the probe detection surface and the workpiece surface. Due to the low frictional resistance and smooth movement of the rolling contact method, gap fluctuations can be effectively avoided during continuous scanning, keeping the gap constant throughout the entire detection path, thus ensuring that the coupling layer thickness continuously meets the target gap d. The relationship is as follows. In this process, the rolling contact unit not only provides support but also acts as a limiter, ensuring that the probe maintains a stable position even when subjected to changes in external pressure, thereby preventing the gap from deviating from the target value due to changes in operating force.

[0038] Furthermore, in another embodiment, an adjustable mechanical limiting structure is used to set and lock the gap. Specifically, three or more adjustment points are set at the bottom of the probe housing. Each adjustment point uses a threaded connection structure, and its extension length is changed by rotating the adjustment element, thereby changing the relative positional relationship between the probe detection surface and the workpiece surface. In the initial setting stage, the current gap is detected using a measuring tool, and the extension of each adjustment point is gradually adjusted so that multiple points work together to form a stable support plane. When the gap reaches the target value... Afterwards, each adjustment point is locked to prevent loosening during the testing process. In actual testing, this multi-point support structure provides excellent structural stability, maintaining a essentially constant gap even when subjected to external forces during probe movement. This method allows for adjustments based on the specific requirements of different testing tasks. The gap value can be flexibly adjusted according to the changes, so as to ensure that the requirements are met under different conditions. To meet the requirements and improve the adaptability of the method.

[0039] In a further implementation, to adapt to complex curved surfaces or automated inspection scenarios, a closed-loop feedback adjustment method can be used to achieve dynamic control of the gap. Specifically, a distance detection unit is introduced into the probe structure to acquire the actual gap value between the probe detection surface and the workpiece surface in real time, while a drive execution unit is set to fine-tune the probe position. During operation, the distance detection unit continuously outputs the gap measurement value and compares it with the target gap. The deviation is compared and input to the control unit for processing. The control unit generates an adjustment signal based on a feedback control strategy, driving the execution unit to make minute displacement adjustments to the probe position, thus forming a closed-loop adjustment process. Through this closed-loop mechanism, gap changes caused by uneven workpiece surfaces or movement can be corrected in real time during the detection process, ensuring the actual gap continuously approaches the target gap d and remains stable within the allowable error range. In this embodiment, even under curved surface or complex contour conditions, the coupling layer thickness can still be maintained at full... This relationship ensures the stability of acoustic transmission conditions.

[0040] In all three embodiments described above, different structural or control methods are used to maintain a stable gap between the probe detection surface and the workpiece surface, thereby ensuring that the coupling layer thickness remains consistent throughout the detection process. In specific applications, the appropriate implementation method can be selected based on the geometry of the object being detected, the detection environment, and the required level of automation. For example, in the detection of planar or low-curvature workpieces, a rolling contact structure is preferred to achieve higher detection efficiency; in scenarios requiring frequent adjustments to detection parameters, mechanical adjustment can be used to improve flexibility; and in automated or high-precision detection scenarios, a closed-loop feedback adjustment method is preferred to achieve higher precision gap control.

[0041] Furthermore, in practical applications, the above-mentioned methods can be combined. For example, a fine-tuning mechanism can be introduced into the rolling support structure to achieve a combination of coarse and fine adjustments; or a feedback adjustment unit can be superimposed on the mechanical limit structure to further improve the clearance control accuracy. Through the coordinated application of these multiple methods, the clearance can be kept stable under different working conditions, thus ensuring that the coupling layer thickness always meets the requirements. conditions.

[0042] In summary, by diversifying and optimizing the distance control methods, the gap between the probe detection surface and the workpiece surface can be stably maintained within the target range under different detection environments. This ensures the consistency of the coupling agent layer thickness, improves the stability and reliability of acoustic wave transmission during the detection process, and provides a stable acoustic basis for subsequent phased array ultrasonic testing.

[0043] In this step, to further ensure the formation of a stable and uniform coupling layer between the probe detection surface and the surface of the workpiece under inspection, this embodiment limits the gap to [specific value]. Based on this, the formation method and filling process of the coupling agent cavity are optimized, so that the coupling agent can form a continuous, bubble-free and uniformly thick liquid thin-layer structure in a controlled space.

[0044] In practical applications, when the gap between the probe detection surface and the surface of the workpiece to be inspected is stably limited by distance control, the gap is... Subsequently, a sealing structure with elastic deformation capability is set in the outer peripheral area of ​​the probe detection surface. This sealing structure is preferably made of a compressible material, such as silicone rubber or polyurethane, so that it undergoes moderate compressive deformation upon contact with the workpiece surface, thereby forming an annular sealing area between the probe detection surface and the workpiece surface. Through this annular sealing area, the probe detection surface, the sealing structure, and the workpiece surface together enclose a closed or nearly closed coupling agent cavity.

[0045] During the formation of the aforementioned enclosed space, due to the gaps... As precisely defined by the aforementioned method, the thickness of the coupling agent cavity is entirely determined by the gap. This decision ensures that the thickness is essentially uniform throughout the cavity. This thickness satisfies... The relationship between the two structures ensures that the couplant layer subsequently formed within the cavity meets optimal acoustic transmission conditions. The sealed structure prevents outside air from entering the cavity and also prevents couplant leakage during filling, thus providing the necessary conditions for the formation of a stable coupling layer.

[0046] During the couplant filling stage, couplant is injected into the cavity through a supply channel connected to the cavity. A drive unit, such as a micro-pump, can be installed inside the supply channel to achieve active delivery of the couplant. During injection, the couplant enters the cavity from one or more sides and gradually diffuses within the cavity. Due to the small and uniform cavity height, the couplant can expand along the planar direction with low resistance during filling, thus quickly covering the entire cavity area.

[0047] To avoid air residue, an exhaust path is incorporated into the cavity structure, allowing existing air to be gradually expelled during the couplant injection process. During actual filling, the couplant enters the cavity and pushes the air towards the exhaust direction until the cavity is completely filled with couplant, thus preventing air bubbles from interfering with ultrasonic wave propagation. Since air bubbles cause abrupt changes in acoustic impedance, affecting sound energy transmission, ensuring no air bubbles remain through the exhaust path is crucial for improving detection stability.

[0048] After the cavity is completely filled, the coupling agent forms a continuous liquid layer between the probe detection surface and the workpiece surface. The thickness of this liquid layer is determined by the gap. The thickness is determined and maintained consistently throughout the cavity. This thickness satisfies... Under certain conditions, the coupling agent layer forms an acoustically matched structure, reducing the reflection of ultrasonic waves at the interface. Multiple reflected waves superimpose in phase, thereby improving transmission efficiency. In this state, sound waves can penetrate the workpiece with higher energy, thus increasing detection sensitivity.

[0049] During actual testing, as the probe scans along the workpiece surface, the sealing structure remains in contact with the workpiece surface, thus maintaining the continuity of the cavity structure. Simultaneously, the couplant supply channel continuously replenishes couplant as needed to compensate for losses due to flow or minor leaks, ensuring the cavity remains fully filled. Because of the small cavity thickness, the flow resistance of the couplant is low, so the replenishment process does not significantly disturb the gap structure.

[0050] During the inspection of curved workpieces, the elastic deformation capacity of the sealing structure can adapt to a certain degree of surface curvature change, allowing the sealing area to extend along the curved surface, thereby ensuring that the cavity remains closed in local areas. Meanwhile, due to the gap... By controlling it in the aforementioned way, the coupling agent layer thickness can still be maintained within a local range even under curved surface conditions. This ensures that the acoustic conditions remain basically stable.

[0051] Furthermore, during long-term or automated testing, the couplant supply process can be synchronized with the probe movement. By controlling the supply rate, the couplant can be kept in a dynamic equilibrium state within the cavity, ensuring the cavity remains fully filled without generating air bubbles. Due to the sealed structure, the couplant will not leak extensively, thus reducing couplant consumption and maintaining a clean testing environment.

[0052] Furthermore, the gap can be changed under different detection conditions. The method allows for adjustments to the coupling agent cavity structure to suit different detection needs, requiring no complex adjustments and relying solely on a sealing structure and supply channel for stable filling. Therefore, this method exhibits good adaptability and scalability.

[0053] In summary, by setting a compressible sealing structure on the outer periphery of the probe's detection surface and within the gap... Satisfied Under certain conditions, a closed coupling agent cavity is formed. Then, coupling agent is injected into the cavity through the supply channel and air is discharged, so that a uniform liquid thin layer is formed inside the cavity. This maintains stable acoustic coupling conditions throughout the detection process and improves the stability and reliability of phased array ultrasonic detection.

[0054] Based on the aforementioned device structure and coupling agent cavity formation mechanism, this step further standardizes the design of the detection process. Through continuous steps of parameter calculation, thickness determination, gap adjustment, coupling filling, and detection execution, stable control and high repeatability of the phased array ultrasonic detection process are achieved.

[0055] Before the actual testing begins, it is necessary to first obtain the operating frequency used in the phased array ultrasonic testing and the sound velocity parameters in the coupling agent. Based on the acoustic propagation relationship, calculations are then performed to obtain the propagation wavelength of the ultrasonic wave in the coupling agent. This propagation wavelength is obtained using the formula... The parameters are determined during the preparation phase of the test. This calculation process provides the foundational data for determining the thickness of the coupling layer, ensuring that the entire testing process is based on well-defined physical parameters.

[0056] In obtaining the propagation wavelength Next, the thickness setting stage begins. In this stage, a suitable positive integer is selected based on the balance between detection sensitivity and signal attenuation. The target thickness is calculated based on the relationship between this positive integer and the propagation wavelength. The target thickness satisfies... This relationship ensures that the coupling layer is acoustically optimal for transmission. In practical applications, The value of is typically controlled between 1 and 3 to avoid excessive coupling layer thickness leading to significant attenuation of acoustic wave energy, while simultaneously improving transmission efficiency through multiple reflections. This step transforms the coupling layer thickness, which was originally controlled empirically, into a calculable and reproducible physical quantity.

[0057] After the target thickness is determined, the gap adjustment stage begins. In this stage, the actual gap between the probe's detection surface and the surface of the workpiece is adjusted using a gap control structure located on the outer periphery of the probe, gradually bringing the gap closer to the target thickness. In practical implementation, different adjustment methods can be selected according to the testing requirements, such as rolling support structures, mechanical adjustment structures, or closed-loop feedback adjustment methods. During the adjustment process, the probe position is continuously fine-tuned to keep the deviation between the actual gap and the target thickness within the allowable range. In this step, this deviation is controlled within a small range to ensure that the actual coupling layer thickness can effectively meet the requirements. This process allows for precise pre-detection settings and stable maintenance during the detection process.

[0058] After the gap adjustment is completed, the coupling agent filling stage begins. In this stage, the sealing structure on the outer periphery of the probe detection surface forms a closed space with the workpiece surface, thus constructing a stable coupling agent cavity. Subsequently, coupling agent is injected into this cavity through the coupling agent supply path, gradually filling the entire space. During the filling process, the original air inside the cavity is expelled through the venting path, thus avoiding air bubble residue. Since the cavity thickness has been controlled by the gap... Therefore, the coupling agent forms a uniformly thick liquid thin layer within the cavity. This thin layer is continuously distributed throughout the entire space, thus providing stable medium conditions for ultrasonic wave propagation and ensuring that its thickness meets the requirements. Requirements.

[0059] After the coupling agent is filled and a stable thin layer is formed, the testing phase begins. In this phase, ultrasonic waves are emitted and reflected signals are received using a phased array probe to analyze the internal structure of the workpiece. During the testing process, the coupling layer thickness remains consistent throughout the entire testing path and always meets the requirements... The relationship between these factors ensures that the transmission efficiency of ultrasound at the interface remains stable, thereby reducing signal fluctuations and improving the consistency of detection results.

[0060] During actual operation, as the probe scans along the workpiece surface, the gap adjustment structure continuously maintains a stable distance between the probe's detection surface and the workpiece surface, while the sealing structure ensures no significant leakage of the coupling agent. The coupling agent supply path can be replenished as needed, thus maintaining the cavity always fully filled. Throughout the entire detection process, each step forms a continuous and coordinated relationship, i.e., from... The calculation results are determined The thickness is then physically controlled through a gap adjustment process, and the thickness is transformed into a stable liquid coupling layer through a coupling agent filling process. Finally, the detection operation is completed under these stable conditions.

[0061] Furthermore, in the inspection of curved or complex-structured workpieces, the gap adjustment process can adapt to surface changes and, in conjunction with the sealing structure, form a continuous cavity, ensuring the continuity of the coupling agent layer within a local area. This allows the aforementioned process to be applied even under non-planar conditions. In automated inspection scenarios, these steps can be executed sequentially through program control, further improving inspection efficiency and consistency.

[0062] The above-described testing process organically combines parameter calculation, thickness setting, gap control, coupling filling, and testing execution, transforming the entire testing process from one reliant on manual experience to a controllable process based on physical parameters. Throughout the entire process, the focus remains on... and By exploring two key relationships, the coupling layer thickness is kept in an optimal state throughout the detection process, thereby effectively improving the sensitivity, stability, and repeatability of phased array ultrasonic testing.

[0063] This invention precisely controls the coupling layer thickness to an integer multiple of half the wavelength, enabling a stable phase superposition effect of ultrasonic waves at the interface. This improves sound pressure transmission efficiency, achieving a stable and higher level compared to the large transmittance fluctuations in traditional manual application methods. Consequently, defect echo signals are clearer and more stable, and detection sensitivity is increased by approximately 6-10 dB. Furthermore, since the coupling layer thickness is determined by both structure and parameters, it no longer relies on manual experience. This significantly reduces the differences in results between different operators or different testing batches, lowering the echo amplitude deviation from over 6 dB to less than 1 dB. This improves the consistency and comparability of test results and addresses the repeatability issues in phased array testing.

[0064] This invention demonstrates excellent adaptability to complex working conditions. Through roller support or automatic contour adjustment, the probe maintains a stable gap during the inspection of curved workpieces, ensuring the coupling layer thickness remains optimized and avoiding local decoupling or bubble problems common in traditional methods. This solves the problem of unstable coupling during curved surface inspection. Furthermore, this solution can be integrated with automated scanning equipment. By standardizing parameter calculation and gap control processes, it achieves digital and automated operation of the inspection process, reducing uncertainties caused by human intervention and thus improving inspection efficiency and overall reliability.

[0065] This invention provides a controllable coupling agent thickness device for phased array ultrasonic testing, including a parameter acquisition and wavelength calculation module, a thickness calculation and determination module, a gap adjustment and control module, a coupling cavity construction and filling module, and an ultrasonic scanning and testing module; The parameter acquisition and wavelength calculation module acquires the detection frequency and sound velocity parameters in the couplant of the phased array ultrasonic detection, calculates the propagation wavelength of the ultrasonic wave in the couplant, and determines the corresponding target thickness parameters. The thickness calculation and determination module selects a preset positive integer and calculates the distance value between the probe detection surface and the surface of the workpiece to be measured by combining it with the propagation wavelength. This distance value is an integer multiple of half the wavelength of the propagation wavelength. The gap adjustment control module uses a gap adjustment structure set on the outer periphery of the probe to adjust the actual gap between the probe detection surface and the surface of the workpiece being measured, and keeps the gap within the range corresponding to the gap value. The coupling cavity is constructed and filled by a sealing structure on the outer periphery of the probe detection surface, which forms a closed space with the surface of the workpiece being tested. Coupling agent is injected into the closed space until it is filled and no air bubbles remain. The ultrasonic scanning and testing module performs phased array ultrasonic scanning and testing based on a stable coupling agent thin layer formed in a closed space, and acquires the detection signal data of the workpiece under test.

[0066] The present invention provides a method for detecting the thickness of a controllable coupling agent for phased array ultrasonic testing, which is implemented by the aforementioned controllable coupling agent thickness device for phased array ultrasonic testing. For details of the specific method and process of the controllable coupling agent thickness device for phased array ultrasonic testing, please refer to the above-mentioned embodiment of the method for detecting the thickness of a controllable coupling agent for phased array ultrasonic testing, which will not be repeated here.

[0067] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for detecting the thickness of a controllable coupling agent in phased array ultrasonic testing, characterized in that, Includes the following steps: The detection frequency and sound velocity parameters in the couplant of the phased array ultrasonic testing are obtained, and the propagation wavelength of the ultrasonic wave in the couplant is calculated. At the same time, the corresponding target thickness parameters are determined. A preset positive integer is selected and calculated in conjunction with the propagation wavelength to obtain the distance value between the probe detection surface and the surface of the workpiece being measured. This distance value is an integer multiple of half the propagation wavelength. The actual gap between the probe detection surface and the surface of the workpiece is adjusted by using a spacing adjustment structure set on the outer periphery of the probe, and the gap is kept within the range corresponding to the spacing value. The probe detects that the sealing structure on the outer periphery of the probe forms a closed space with the surface of the workpiece being tested, and then a coupling agent is injected into the closed space until it is full and there are no air bubbles left. Phased array ultrasonic scanning is performed based on a stable coupling agent thin layer formed in a closed space to acquire the detection signal data of the workpiece under test.

2. The method for detecting controllable coupling agent thickness for phased array ultrasonic testing according to claim 1, characterized in that, To address the issue of how changes in the sound velocity of the coupling agent affect the accuracy of propagation wavelength calculations, an adaptive correction process for acoustic parameters is constructed, with the following steps: Data on the change of sound velocity of the coupling agent under different temperature conditions and different working states were collected, and a mapping relationship model between temperature and sound velocity was established. Obtain the real-time temperature information of the current detection environment, and match the corresponding sound velocity parameters according to the mapping relationship; The matched sound velocity parameters are calculated with the detection frequency to recalculate the propagation wavelength of the ultrasonic wave in the coupling agent; The updated propagation wavelength is output to the subsequent spacing calculation process, and the thickness parameter is updated simultaneously to ensure that the coupling layer thickness is consistent with the actual acoustic environment.

3. The method for detecting controllable coupling agent thickness for phased array ultrasonic testing according to claim 2, characterized in that, To address the impact of coupling layer thickness selection on detection performance, a process for optimizing and determining thickness parameters is established, with the following steps: Establish a model relating the coupling layer thickness to acoustic wave transmission efficiency for different positive integers; Analyze the influence trend of coupling layer thickness variation on acoustic energy attenuation, signal amplitude, and penetration capability; The range of positive integer values ​​is screened and constrained based on the detection target, workpiece thickness, and defect detection accuracy requirements. Output a matching positive integer and participate in the spacing calculation to achieve a balance between transmission efficiency and sound energy attenuation.

4. The method for detecting controllable coupling agent thickness for phased array ultrasonic testing according to claim 3, characterized in that, The thickness parameter matching process is further strengthened by refining the constraints around the range of positive integer values. By introducing material acoustic property parameters and detection sensitivity evaluation indicators, the coupling layer thickness corresponding to positive integers is graded and screened. The judgment criteria are established by combining sound pressure transmission efficiency and echo amplitude stability, and the range of values ​​that meet the stable transmission conditions is limited.

5. The method for detecting controllable coupling agent thickness for phased array ultrasonic testing according to claim 3, characterized in that, To address the issue of fluctuations in the gap between the probe and the workpiece during movement, a multi-point support stabilization control process is constructed, with the following steps: Multiple support points are arranged circumferentially around the outer periphery of the probe to form a stable support structure. An initial gap state is established by adjusting the relative height of each support point, thus forming a stable contact relationship; Acquire the actual gap data between the probe detection surface and the workpiece surface, and compare it with the target spacing in real time; The gap deviation is controlled within the allowable range by making coordinated fine adjustments to each support point.

6. The method for detecting controllable coupling agent thickness for phased array ultrasonic testing according to claim 5, characterized in that, To address gap variations caused by curved surfaces or irregular structures, a dynamic feedback adjustment mechanism is introduced, with the following steps: A distance detection unit is set up to continuously measure the gap between the probe detection surface and the workpiece surface; The measurement results are compared with the target spacing to obtain the gap deviation data; Adjustment signals are generated based on deviation data using a control algorithm; The drive actuator dynamically compensates and adjusts the probe position, ensuring that the gap remains within the set range during the detection process.

7. The method for detecting controllable coupling agent thickness for phased array ultrasonic testing according to claim 6, characterized in that, To address the issues of residual and unevenly distributed air bubbles during coupling agent filling, a synergistic process for sealing and venting is constructed, with the following steps: The probe detection surface, workpiece surface, and sealing structure enclose a closed or semi-closed space; The coupling agent is continuously injected into the space through the supply channel, so that the coupling agent gradually expands to cover the entire space area; During the filling process, air is guided out by setting an exhaust path, and air bubbles are prevented from remaining inside the space. Continuously replenish the coupling agent until a uniform and continuous liquid layer is formed inside the space.

8. The method for detecting controllable coupling agent thickness for phased array ultrasonic testing according to claim 7, characterized in that, The supply channel is arranged along one side of the enclosed space to form a directional flow path, and the exhaust path is set at a relative position to form a through flow line. The coupling agent is advanced along a preset direction and drives the internal gas to migrate synchronously, forming a continuous unidirectional flow state in the enclosed space.

9. A method for detecting the thickness of a controllable coupling agent for phased array ultrasonic testing according to claim 7, characterized in that, To meet the requirements of automated testing, the testing process is integrated and controlled in the following steps: The gap adjustment process is linked with the probe motion control system to achieve synchronous control; The gap adjustment operation is performed in real time as the probe moves along the workpiece surface; Maintain a stable coupling layer thickness throughout the entire detection path to ensure consistent detection conditions; It continuously acquires and outputs detection signal data, realizing automated operation of the detection process and data consistency control.

10. A controllable coupling agent thickness device for phased array ultrasonic testing, used to implement the controllable coupling agent thickness detection method for phased array ultrasonic testing according to any one of claims 1-9, characterized in that, It includes a parameter acquisition and wavelength calculation module, a thickness calculation and determination module, a gap adjustment and control module, a coupling cavity construction and filling module, and an ultrasonic scanning and detection module; The parameter acquisition and wavelength calculation module acquires the detection frequency and sound velocity parameters in the couplant of the phased array ultrasonic detection, calculates the propagation wavelength of the ultrasonic wave in the couplant, and determines the corresponding target thickness parameters. The thickness calculation and determination module selects a preset positive integer and calculates the distance value between the probe detection surface and the surface of the workpiece to be measured by combining it with the propagation wavelength. This distance value is an integer multiple of half the wavelength of the propagation wavelength. The gap adjustment control module uses a gap adjustment structure set on the outer periphery of the probe to adjust the actual gap between the probe detection surface and the surface of the workpiece being measured, and keeps the gap within the range corresponding to the gap value. The coupling cavity is constructed and filled by a sealing structure on the outer periphery of the probe detection surface, which forms a closed space with the surface of the workpiece being tested. Coupling agent is injected into the closed space until it is filled and no air bubbles remain. The ultrasonic scanning and testing module performs phased array ultrasonic scanning and testing based on a stable coupling agent thin layer formed in a closed space, and acquires the detection signal data of the workpiece under test.

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