81 results about "Laser ultrasonics" patented technology

The invention relates to the technical field of ultrasonic signal processing, in particular to a wavelet and MAD adaptive threshold combined laser ultrasonic signal denoising method. The method comprises the following steps: firstly, preprocessing an acquired trigger channel signal and an ultrasonic channel signal, determining a signal starting point through differential positioning, and intercepting an effective signal segment; carrying out multilayer wavelet decomposition on the effective signal segment to obtain a wavelet coefficient of each layer; extracting a detail coefficient of the highest decomposition layer, and adaptively estimating a noise standard deviation based on a median absolute deviation criterion; calculating an adaptive threshold according to the noise standard deviation and the signal length, and processing each layer of wavelet coefficient by adopting a hard threshold function; and finally, carrying out wavelet inverse transformation reconstruction to obtain a denoised signal. According to the method, prior noise information is not needed, the noise level can be adaptively estimated, the optimal threshold value can be determined, the signal features are reserved while noise is effectively suppressed, and the signal-to-noise ratio is remarkably improved.

The invention relates to the field of welding seam detection, and discloses a welding seam center line real-time tracking method and device, computer equipment and a storage medium, and the method comprises the steps: obtaining a laser tracking evaluation speed, an ultrasonic tracking evaluation speed and a tracking speed threshold value of a to-be-detected weldment; if the laser tracking evaluation speed and the ultrasonic tracking evaluation speed are both larger than the tracking speed threshold value, the weld joint center line of the to-be-detected weldment is tracked according to a laser and ultrasonic simultaneous inspection strategy; and if the laser tracking evaluation speed or the ultrasonic tracking evaluation speed is smaller than or equal to the tracking speed threshold value, the welding seam center line of the to-be-detected weldment is tracked according to a main laser and auxiliary ultrasonic strategy. According to the invention, the obvious limitation of a single laser tracking technology under the conditions of a complex surface and strong illumination is overcome, and high-precision and high-robustness real-time tracking is realized through acousto-optic fusion.

The invention belongs to the field of nondestructive testing, and relates to an all-optical non-contact ultrasonic nondestructive testing device, which utilizes a laser ultrasonic technology to excite a material to generate an ultrasonic signal, and is combined with a displacement table and a high-sensitivity optical microphone to realize detection and imaging of defects of a composite material plate. The whole system has the comprehensive advantages of no contact, no damage, high sensitivity, rapid signal response, strong environmental adaptability and the like, and can be widely applied to high-quality nondestructive detection requirements of various materials such as metal and nonmetal in the production, manufacturing, use and maintenance processes.

The invention relates to the technical field of nondestructive testing, in particular to a nondestructive testing method based on fusion of laser ultrasound and piezoelectric guided wave, which comprises the following steps: respectively carrying out preliminary detection by adopting a piezoelectric guided wave technology and a laser ultrasound technology; calculating the comprehensive credibility of the single-source model and inputting a multi-source model decision; constructing a basic probability distribution function based on a DS evidence theory to integrate detection results; and high-precision detection parameters are generated by using a weighted Dempster fusion algorithm. According to the method, the piezoelectric guided wave deep positioning capacity and the laser ultrasonic high-precision surface detection capacity are combined, the DS evidence theory and the weighted fusion algorithm are used for reducing the influence of environmental noise, the detection precision and efficiency are remarkably improved, and the method is suitable for defect detection of carbon fiber composite materials and other high-performance composite materials and has wide application prospects. And reliable technical support is provided for industrial application.

A laser ultrasonic inspection apparatus includes a first laser light source, and a laser interferometer configured to use a second laser beam to detect a vibration of the target, wherein the laser interferometer includes a second laser light source configured to irradiate the target with the second laser beam, a light modulator configured use a vibrator to modulate a frequency of the second laser beam, a photodetector configured to receive the second laser beam from the light modulator and the second laser beam from the target to output a light reception signal, and a signal processor configured to detect the vibration based on the light reception signal and a reference signal, and measure, based on the reference signal, an elapsed time from the first laser light source emits the first laser beam to the vibration is detected, and the vibrator is a signal source of the reference signal.

This invention relates to the field of laser ultrasonic nondestructive testing technology, specifically a method for optimizing laser source parameters during laser-induced ultrasound based on FEA (Feature-Enhanced Amplification). The invention obtains the geometric dimensions and material parameters of the insulator under test, constructs a geometric model, adds solid heat transfer and mechanical fields, and establishes a finite element model through thermal expansion coupling. Multiple laser pulse width and laser spot radius values ​​are determined and combined to obtain multiple parameter schemes. Each parameter scheme is applied to the finite element model as the time and spatial distribution parameters of the laser heat source, and transient calculations are performed. Displacement time-domain data of monitoring points are extracted and subjected to Fast Fourier Transform (FFT) to obtain frequency-domain data. The ultrasonic signal characteristics of each parameter scheme are compared and analyzed, and the parameter combination that meets the testing requirements is selected as the optimization result. This invention significantly reduces parameter optimization costs and improves testing efficiency through simulation-guided experiments.

The invention provides a cross-domain transfer learning laser ultrasonic layering defect detection method suitable for a composite material and application thereof.The method comprises the steps that firstly, multi-channel input containing a frequency domain, a time-frequency domain and Koopman operator characteristics is constructed for the problem of data distribution deviation caused by the batch difference of the composite material; secondly, extracting and fusing high-dimensional spatial-temporal features through a multi-channel attention mechanism and a graph convolutional network; and finally, migrating the defect features of the source domain to the target domain in combination with dynamic distribution self-adaption and domain adversarial training strategies. The method can effectively overcome model performance reduction caused by material attribute change, realizes high-precision layering defect identification and imaging under the condition of no target domain label, and is suitable for composite material detection in a complex industrial scene.

The application belongs to the technical field of ultrasonic detection, and discloses a subsurface defect detection method, device, equipment and storage medium. The method comprises the following steps: acquiring surface roughness and surface material corresponding to a metal sample to be detected; searching for corresponding optimal laser detection power from a database according to the surface roughness and the surface material; and performing laser ultrasonic detection on the metal sample to be detected based on the optimal laser detection power, so as to obtain a subsurface defect detection result corresponding to the metal sample to be detected. In the above manner, the optimal laser detection power is selected according to the roughness and material of the metal sample for laser ultrasonic detection, so that the laser ultrasonic detection precision and efficiency are effectively improved, and the accuracy of metal subsurface defect detection is further improved.

The application relates to a laser ultrasonic microscopic imaging system, method and device, wherein the laser ultrasonic microscopic imaging system comprises an excitation light source for emitting excitation light, a detection light source for emitting detection light, a first modulation module for modulating the deflection angle of the excitation light and reflecting the excitation light, a second modulation module for modulating the deflection angle of the detection light and reflecting the detection light, and an optical path converter, wherein the excitation light and the detection light form laser spots and detection spots on a sample surface, and a detection module and a data processing module are used to receive and process the detection light reflected from the sample surface to obtain an ultrasonic wave velocity image of the sample surface. The first modulation module and the second modulation module are used to high-speed modulate the excitation light and the detection light, so that the effect of rapidly measuring and imaging the ultrasonic wave velocity of the sample surface is achieved.

The invention discloses a laser ultrasonic detection system and a laser processing quality detection method, and belongs to the technical field of laser processing quality detection.The laser ultrasonic detection system comprises a first laser transmitter, a spectroscope, a scanning lens, a second laser transmitter, a detection lens, a laser ultrasonic receiver, a third laser transmitter and a mobile platform; the first laser emitter emits a first laser beam, the first laser beam passes through the spectroscope and the scanning lens and then irradiates a workpiece, the second laser emitter emits a second laser beam, and the second laser beam passes through the detection lens and irradiates the workpiece. Reflected light beams, irradiated to the workpiece, of the second laser beam and the third laser beam are received by the laser ultrasonic receiver, defect detection is conducted on the workpiece in a non-contact detection mode, online detection can be achieved, ultrasonic signals are transmitted through laser, and the anti-interference capacity is high.

The invention provides a surface crack laser ultrasonic quantitative detection method, device, equipment and medium, and relates to the technical field of nondestructive detection.The method comprises the steps that laser ultrasonic B-scanning data are obtained through synchronous scanning, a multi-modal characteristic wave propagation mechanism is analyzed, a flight time analysis model is established, and the flight time analysis model is analyzed; and a theoretical and experimental multi-modal characteristic mode is constructed, and discretization similarity matching is carried out, so that the depth and the inclination angle of the surface crack are stably inverted in a full-parameter space, and quantitative detection is realized. According to the method, instability caused by dependence of a single mode or a single characteristic can be avoided, synchronous and high-precision quantitative detection on the surface crack depth and the crack inclination angle under the condition of complex multi-mode wave aliasing is realized, and the problems of insufficient characterization accuracy and robustness of geometric parameters of cracks in the prior art are solved.

The utility model discloses a laser ultrasonic nondestructive detector for metal welding residual stress, which relates to the technical field of residual stress detection equipment and comprises a box body, a mounting groove is formed in the box body, and a plurality of first rotating shafts are rotatably connected in the mounting groove. The spring winding device has the advantages that the rotating roller and the first rotating shaft are driven to rotate when the two ends of a connecting wire are pulled, so that a spring is wound, meanwhile, through mutual cooperation of the first rotating shaft, a ratchet wheel, a second rotating shaft and a pawl, the connecting wire is wound, and the connecting wire is wound. After use, a push plate is pushed to slide towards the interior of a push groove, then a push rod and a second connecting plate are pushed, and then a first connecting plate and a second rotating shaft are driven to rotate, so that a pawl is driven to rotate, limiting of the pawl to a ratchet wheel is relieved, and the spring rebounds; and therefore, the first rotating shaft and the rotating roller can be driven to wind the connecting wire.

The application provides a gradient material thickness measurement method and system based on laser ultrasonic dispersion spectrum, and relates to the technical field of laser measurement, and comprises the following steps: modulating excitation laser through an optical mask to form a transient grating with periodic intensity distribution, exciting ultrasonic waves with specific frequencies in a material to be measured by using the transient grating, and receiving Lamb wave signals generated by the structure of the material to be measured by using a laser interferometer for line scanning; performing two-dimensional Fourier transform on the Lamb wave signals to obtain a target dispersion curve; the target dispersion curve comprises a mapping relationship between signal frequencies and wave numbers; a sample pair composed of multiple groups of material thickness parameters and dispersion curve parameters is generated by using a transfer matrix algorithm, and a preset deep neural network is trained based on the sample pair until a loss function reaches a preset threshold range, so that a target neural network is obtained; and the target dispersion curve is input into the target neural network to obtain thickness parameters of the material to be measured.

1. The name of the design product: multifunctional laser ultrasonic atomizer. 2. The use of the design product: the design product is used in the field of physiotherapy, and is used for the physiotherapy or post-fogging drug delivery of the vagina. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

The invention relates to the technical field of optical detection, in particular to a buried structure detection device based on laser-induced ultrasonic waves, which comprises a laser, a light splitting element, a light modulation module, a beam combining element, a light sensitive element and a lock-in amplifier, and is characterized in that pulse laser generated by the laser is divided into pump light and detection light; after the light modulation module periodically modulates the pump light, the pump light and the probe light are confocal on the surface of a to-be-detected sample through the beam combining element; the pump light excites ultrasonic waves, and the ultrasonic waves are reflected by the metal grating in the sample to form a sound wave induction interface grating; the detection light is received by the photosensitive element after being diffracted and is converted into an electric signal; a lock-in amplifier extracts a synchronized diffracted signal from the signal using the modulation frequency. The method can effectively penetrate through the opaque material layer to detect the completely buried alignment mark, overcomes the limitation of the traditional optics and the existing laser ultrasonic technology, and improves the detection precision and reliability of the deep structure.

The invention provides a laser ultrasonic testing device which has a small number of components and is easy to miniaturize. A laser ultrasonic inspection device is characterized by being provided with: a first laser light source that irradiates a subject with a pulsed first laser light; and a laser interferometer that detects vibration of the subject caused by ultrasonic waves induced in the subject by irradiation of the first laser light using the second laser light, the laser interferometer including: a second laser light source that irradiates the subject with the second laser light; a vibrator-type optical modulator that modulates the frequency of the second laser light using a vibration element; a light receiving element that receives the second laser beam that has passed through the oscillator-type optical modulator and the second laser beam that has passed through the subject, and outputs a light receiving signal; and a signal processing unit that detects vibration on the basis of the light reception signal and a reference signal, and that measures the elapsed time from the emission of the first laser light from the first laser light source until the detection of vibration on the basis of the reference signal, the vibration element being a signal source of the reference signal.

The application discloses a kind of hot metal component laser ultrasonic defect detection device and detection method, detection device includes high temperature heating module, laser excitation module, laser detection module, mobile scanning automatic focusing module and signal acquisition and control module;Laser excitation module and laser detection module excite laser, and by mobile scanning automatic focusing module will excitation laser and detection laser be incident to the different positions of the metal component to be measured, and reflected detection laser is transferred to signal acquisition and control analysis module by optical probe and interferometer and is handled and imaging.The detection device of the application has the functions of metal component high temperature heating simulation, detection laser automatic focusing, fast mobile scanning, defect automatic imaging, can efficiently realize the accurate detection and imaging of hot metal component surface, internal defect, is suitable for dynamic defect detection simulation in high temperature extreme environment, and makes up the deficiency that conventional ultrasonic detection method is difficult to realize non-contact high temperature nondestructive testing.

The invention relates to the technical field of material analysis and detection, and discloses a laser ultrasonic detection device for a crack prefabricated sample of a fatigue testing machine, which comprises a crack prefabrication control module, a laser ultrasonic detection module, a feature fusion reconstruction module and a modeling and visual output module, according to the method, femtosecond laser-liquid nitrogen collaborative cutting, quantum dot acoustic calibration, laser ultrasonic detection and deep learning reconstruction methods are systematically integrated, so that the technical problems of high probability of thermal damage, uncontrollable initial crack and high discreteness of a detection result in the machining process of a traditional crack prefabricated sample are solved; non-contact and nondestructive detection is achieved, multi-dimensional information such as crack space distribution, acoustic response change and expansion trend is synchronously output, and the detection result can be directly used for crack prefabrication quality evaluation of a fatigue testing machine and optimization and adjustment of material process parameters. The whole scheme is high in detection precision, good in repeatability, high in automation degree and suitable for fatigue test crack prefabrication and detection scenes with high consistency and high reliability.

The invention discloses a laser ultrasonic inspection device for an end socket bolt of a reactor pressure vessel. The laser ultrasonic inspection device comprises a rack, a guide transmission mechanism, a pair of detection rotating mechanisms, a clamping mechanism, a horizontal turnover mechanism and a detection action mechanism. According to the laser ultrasonic inspection device for the end socket bolt of the reactor pressure vessel, clamping and posture adjustment of the end socket bolt and excitation and reception of ultrasonic signals are realized through cooperation of the rack, the guide transmission mechanism, the detection rotating mechanism, the clamping mechanism, the horizontal turnover mechanism and the detection action mechanism. Compared with a traditional detection device, the device is high in integration level and capable of achieving comprehensive detection of the end socket bolt, a laser ultrasonic detection mode is adopted, direct contact with the surface of the end socket bolt is not needed, and damage to the surface of the end socket bolt is avoided. The pair of detection rotating mechanisms is provided with an ultrasonic detection probe and a pulse laser respectively, the relative position and angle of the ultrasonic detection probe and the pulse laser can be flexibly adjusted, and the accuracy and flexibility of detection are ensured.

The invention discloses a concrete defect intelligent imaging system based on an acoustic array, which is applied to the field of chemical or physical analysis, and comprises a hybrid probe layer, and through the cooperative cooperation of an intelligent imaging regulation and control processing unit and a self-adaptive full contact layer, on one hand, the dynamic cooperative control of laser ultrasound and an acousto-optic array is realized, and on the other hand, the dynamic cooperative control of the laser ultrasound and the acousto-optic array is realized; full-waveform signals of a concrete base material can be comprehensively received and analyzed, cross-size defects in a thick and large concrete structure can be accurately recognized and quantitatively analyzed, full-scale detection from the superficial layer to the deep layer and from macroscopic defects to microscopic cracks is achieved, intelligent detection is carried out with high resolution and high detection depth, and the detection efficiency is improved. And on the other hand, during contact type detection, the system can effectively adapt to concrete base materials with different surface states, so that the adaptability of the concrete defect intelligent imaging system is improved, and the precision during contact type detection is improved.

This application relates to a laser ultrasonic residual stress detection system and method based on orthogonal thermal gratings, belonging to the field of stress detection technology. The system includes: a laser excitation and detection module for exciting and detecting laser ultrasonic waves on the component under test; a laser modulation module for modulating laser ultrasonic waves at different incident depths and simultaneously generating laser ultrasonic waves in the X and Y directions; a mechanical processing module for controlling the receiving positions of the X and Y direction laser ultrasonic wave signals; and a signal processing module for calculating the residual stress distribution of the component under test based on the X and Y direction laser ultrasonic waves at different incident depths and acoustoelastic theoretical stress. The laser excitation and detection module, laser modulation module, and mechanical processing module are all electrically connected to the signal processing module. This application achieves rapid, effective, and accurate detection of residual stress on the inner edges of the component under test.

The invention provides an ellipsometer measurement system and a measurement method. The system comprises an ultrasonic excitation unit, an ellipsometer detection unit, a focusing unit and a processing unit. A first light beam emitted by the ultrasonic excitation unit and a second light beam emitted by the ellipsometry detection unit are focused on the same area of the surface of the to-be-detected sample through the focusing unit; the reflected light of the to-be-detected sample reflecting the light beams is received by the ellipsometry detection unit and converted into an electric signal, and the processing unit determines the thickness of the to-be-detected sample according to the first light beam, the second light beam and the electric signal. The system utilizes pulse laser to excite high-frequency ultrasonic waves on the surface of a thin film, so that the polarization state of reflected probe light is influenced, and micro modulation synchronous with the ultrasonic frequency is formed. The thickness and the optical constant of the thin film are measured in a lossless manner; by combining the laser ultrasonic technology and the ellipsometer, the application range of the ellipsometer is remarkably expanded, and the ellipsometer can meet the requirements for online detection of light-proof films in the fields of semiconductors, precision optical processing and the like.

The invention relates to an integrated infrared ray ultrasonic nondestructive testing system and method, and belongs to the technical field of nondestructive testing. The system comprises an infrared detection module, a ray detection module, a laser ultrasonic detection module, a three-dimensional dynamic vision imaging module, a mechanical motion module and a multi-layer multi-interface three-dimensional imaging module. According to the invention, the infrared detection module, the ray detection module and the laser ultrasonic detection module are combined, so that the detection can face a multi-layer multi-interface aircraft structure, and the obtained multi-source detection data can help detection personnel to judge the relationship among various defects from the overall perspective. By analyzing relevance of various types of defects in different structures, traceability analysis of damage of complex structures composed of various structures by detection personnel is facilitated.

The application provides a lithium battery lithium precipitation detection method and system based on laser ultrasonic multi-feature fusion, and relates to the field of battery detection. The detection method comprises the following steps: controlling a laser generating device to irradiate a lithium battery sample with laser and obtaining time domain data of ultrasonic signals from the lithium battery sample; converting the time domain data into frequency domain data, fusing the time domain data and the frequency domain data through a cross attention mechanism to obtain ultrasonic fusion features; and inputting the ultrasonic fusion features into a trained lithium precipitation prediction model to obtain the lithium precipitation probability of the lithium battery sample. This detection method can realize non-contact nondestructive detection while improving the detection accuracy.

The application discloses a kind of laser shock peening and ultrasonic gradient stress detection integrated system and method, belong to high-end equipment manufacturing and surface engineering technical field.System includes multi-axis industrial robot, composite end effector, strengthening laser output head, laser ultrasonic excitation probe and control unit, laser ultrasonic excitation probe and laser ultrasonic receiving probe follow strengthening laser output head rear; Trigger strengthening and detection in the robot step gap, utilize the dispersion characteristics of wideband surface acoustic wave to retrieve the residual stress distribution of five characteristic gradient layers in surface layer to 1.5 mm Depth, and adjust laser energy or back sweep compensation with stress value of gradient layer as criterion to realize closed-loop regulation and control;Solve the problem of process and detection procedure fragmentation, deep stress unknown and unable to real-time closed-loop, realize in-situ detection, gradient stress quantitative analysis, adaptive compensation, full-optical non-contact adaptive complex surface and quality data traceability.

The invention discloses a laser ultrasonic inspection device, a display device, an electronic apparatus, and a moving object, and provides a laser ultrasonic inspection device which has a small number of components, is easy to miniaturize, and has good portability, and a display device, an electronic apparatus, and a moving object which are provided with the laser ultrasonic inspection device. The laser ultrasonic inspection apparatus includes: a first laser light source that emits a pulsed first laser; the laser interferometer is used for detecting the vibration of the measured object by using second laser; an imaging unit for imaging the irradiation position of the first laser light and the object to be measured; and a housing, the laser interferometer having: a resonator-type optical modulator that modulates the frequency of the second laser light using a resonator element; and a light receiving element that receives interference light of the second laser light passing through the object to be measured and the second laser light passing through the oscillator-type light modulator, the oscillator element being a signal source of the reference signal, the first laser light source emitting the first laser light on the basis of the reference signal, and the imaging unit performing imaging on the basis of the reference signal.

The invention relates to the technical field of nondestructive testing of microelectronic devices, in particular to a laser ultrasonic non-contact detection method and system based on polarity characteristics, and the method comprises the following steps: carrying out two-dimensional scanning on the surface of a sample, and collecting a time domain diffraction signal of each scanning point; respectively extracting the polarity of a first diffraction peak in a preset time window from the time domain diffraction signal of each scanning point; calculating polarity space statistical characteristics based on the polarity of each scanning point; and generating a defect probability heat map based on the polar space statistical characteristics. According to the method, the polarity fluctuation characteristic of the first diffraction peak in the laser ultrasonic time domain diffraction signal is extracted and utilized and is converted into the polarity space statistical characteristic, and the defect probability heat map is calculated and generated, so that the limitation that the traditional detection dependent on signal amplitude is easily interfered by laser power fluctuation and mechanical vibration is effectively overcome; and the detection signal-to-noise ratio and the positioning precision for the nano-scale defect of the subsurface layer are obviously improved.

The application discloses a system for laser ultrasonic detection of surface damage of carbon fiber composite materials, which comprises an excitation module, an interference detection module and a signal processing unit; the excitation module is used for vertically incident laser on the sample surface; the interference detection module is used for capturing vibration information in the sample and propagation information of ultrasonic waves; the signal processing unit carries out noise reduction processing on the received signal to obtain smooth and interference-free ultrasonic wave information; the application adopts a full non-contact laser galvanometer, a laser interference defect detection system, a nanosecond pulse laser as an excitation source and a laser Doppler vibrometer as a receiver; the distance between the excitation module, the detection module and the carbon fiber composite material sample is changed according to the actual working environment within the working distance; and the sample is rapidly scanned in a non-contact and non-damage manner by using the propagation of low-order mode Lamb waves in the sample.

Non-contact and non-destructive systems and Methods for crack detection that can accurately detect even the smallest cracks and defects such as SCCs in thick materials and structures are disclosed. The systems and methods described herein include a laser ultrasonic inspection system that utilizes guided ultrasonic waves (GUW) for crack inspection and quantification on materials and structures. The systems and methods described herein may include, but are not limited to, a pulsed laser emitter that emits a pulsed laser beam for exciting ultrasonic guided waves propagated into the material or structure to be tested and a scanning Doppler vibrometer take non-contact vibration measurements (i.e., wave motion measurements) of the excited waves within material or structure to be tested. In embodiments, the systems and methods described herein may also include a thin metal material adhered to, attached to, or positioned on the surface of the area of the material or structure to be tested. The systems and methods described herein generate wave images for both area scans and line scans of the test structure and based on the wave images also generate energy map images to identify the presence of cracks and / or defects in the structure / material to be tested.

The invention relates to a coating structure thickness measuring method based on a laser ultrasonic zero-group velocity Lamb wave technology, which comprises the following steps: acquiring a frequency domain waveform of a simulation signal in a zero-group velocity Lamb wave of a simulation model, extracting a resonance frequency corresponding to a formant in the frequency domain waveform for calculating a zero-group velocity Lamb wave frequency-thickness product, and establishing a multiple linear regression fitting model; and the resonant frequency of the coating structure sample is collected, the resonant frequency and the total thickness are input into the multiple linear regression fitting model, and the coating thickness and the substrate thickness are obtained. According to the method, key parameters of ZGV Lamb waves are extracted, multiple linear regression and a least square method are combined, linear relations between different coating structure thicknesses and corresponding resonant frequencies and multiple linear models between frequency-thickness products and the thicknesses of all the layers are established, and therefore synchronous quantitative measurement of the thicknesses of all the layers of the coatings is achieved; therefore, the overall quality characteristics of the coating structure are reflected.