Device and method for measuring thickness uniformity of functional coating

Abstract

The invention discloses functional coating thickness uniformity measuring equipment and a functional coating thickness uniformity measuring method. The equipment comprises a measurement module, an automatic control module, a display module and a calculation module. The measurement method comprises the following steps: 1, the measurement module collects a microwave frequency domain complex reflection coefficient at a certain point of a sample to be measured; 2, transmitting a measured frequency domain signal to a calculation module; 3, the calculation module processes the frequency domain signal to obtain a time domain signal and obtain the thickness of each coating; 4, the automatic control module adjusts a sample measurement point position, and the steps are repeated; and 5, the calculation module carries out average calculation on the coating thickness of each point position and transmits the thickness and thickness uniformity data to the display module for visualization. The functional coating thickness uniformity measuring equipment is simple in composition and convenient to use, the measuring method is high in automation degree, the coating uniformity measuring efficiency and precision can be remarkably improved, and the practical engineering significance is achieved.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology for coatings, and in particular to a device and method for measuring the uniformity of thickness of functional coatings. Background Technology

[0002] Coating thickness and its uniformity are important indicators of coating quality, playing a crucial role in product quality, process control, and cost control. Coating thickness uniformity significantly impacts product reliability and usability. By inspecting coating thickness and uniformity, in addition to assessing the reasonableness of workpieces with tolerance requirements or repair dimensional requirements, it is also possible to directly or indirectly evaluate the coating's corrosion resistance, abrasion resistance, and other properties. Therefore, it is widely used in coating quality inspection and process research.

[0003] During the production process, it is essential to accurately measure the coating thickness to ensure that the coating reaches the specified thickness. This prevents coating failure due to inappropriate thickness or excessive coating thickness leading to excessive paint loss and increased costs. Microwaves, with their non-contact and deep-penetrating capabilities, offer advantages such as fast detection speed, high sensitivity, and low cost when used to measure coating thickness and uniformity. Summary of the Invention

[0004] This invention provides a functional coating thickness uniformity measurement device and method for measuring coating thickness and thickness uniformity. The functional coating thickness uniformity measurement device proposed in this invention is simple in composition and easy to use. The measurement method is highly automated, fast, and accurate, significantly improving the efficiency and accuracy of coating thickness and thickness uniformity measurement, and has practical engineering significance.

[0005] The specific technical solutions provided by the embodiments of the present invention are as follows:

[0006] In a first aspect, a functional coating thickness uniformity measuring device includes: a measuring module, an automatic control module, a display module, and a calculation module;

[0007] The measurement module mainly includes:

[0008] Three-dimensional adjustable support, vector network analyzer, sample stage, waveguide probe;

[0009] Vector network analyzers and waveguide probes are primarily responsible for the generation and reception of microwave frequency domain signals.

[0010] The three-dimensional adjustable bracket is used to support the waveguide probe and is connected to the automatic control module, which can adjust the position of the sample measurement point through the automatic control module;

[0011] The automated control module is mainly used for:

[0012] The three-dimensional adjustable support of the control and measurement module enables automated measurement of multiple points on the sample;

[0013] The calculation module is mainly used for:

[0014] The microwave frequency domain complex reflection coefficient signal measured by the measurement module is processed to obtain the microwave time domain complex reflection coefficient signal. The peak value of the time domain signal is calibrated, the time difference between each peak value is read, and the actual thickness of each coating of the sample is calculated according to the standard time and thickness.

[0015] Based on the measurement results at each point on the sample, the calculation module provides the average thickness and thickness uniformity of each coating on the sample.

[0016] The display module is mainly used for:

[0017] Display of the final measurement results of the coating thickness of each sample.

[0018] Secondly, a method for measuring the thickness uniformity of a functional coating mainly includes the following five main steps:

[0019] 1. The measurement module acquires the microwave frequency domain complex reflection coefficient at a certain point of the sample under test;

[0020] 2. The measured frequency domain signal is transmitted to the calculation module;

[0021] 3. The calculation module processes the frequency domain signal to obtain the time domain signal and calculates the thickness of each coating.

[0022] IV. The automated control module adjusts the sample measurement points and repeats the above steps;

[0023] 5. The calculation module calculates the average coating thickness at each point and transmits the thickness and thickness uniformity data to the display module for visualization.

[0024] Therefore, the method provided by this invention can accurately measure the coating thickness and calculate the thickness uniformity. This method eliminates the need for manually reading the time values ​​corresponding to the maximum and minimum values ​​of the complex reflection coefficient curve to determine the coating thickness, thus avoiding errors caused by human intervention. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a coating thickness measurement method based on microwave time domain.

[0026] Figure 2 This is a schematic diagram of time-domain signal calibration in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of a functional coating thickness uniformity measuring device disclosed in this invention.

[0028] Figure 4 This is a schematic diagram of a method for measuring the uniformity of the thickness of a functional coating disclosed in this invention.

[0029] Figure 5 This is a schematic diagram of the nine-point measurement method in an embodiment of the present invention. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. Obviously, the described embodiments are merely one preferred embodiment of the present invention, and not all embodiments. For example, the waveguide probe in this application can refer to a waveguide of any form and bandwidth. In the preferred embodiment shown in the present invention, the waveguide probe uses a rectangular waveguide of 26.5 GHz to 40 GHz.

[0031] This invention provides a functional coating thickness uniformity measurement device and method for measuring coating thickness and thickness uniformity. The method and device are based on the same inventive concept. Since the principles by which the method and device solve the problem are similar, their implementations can be referred to interchangeably, and repeated details will not be repeated.

[0032] The principle of the coating thickness measurement method based on microwave time domain is introduced below, such as... Figure 1 As shown, the vector network analyzer and waveguide probe can acquire the frequency domain curves of the incident coating and the microwaves reflected at the coating interface, denoted as a(ω) and b(ω), respectively. The ratio of the reflected wave to the incident wave is called the complex reflection coefficient, denoted as Γ(ω):

[0033]

[0034] This signal is a frequency domain signal, which is usually difficult and complex to analyze. However, by using the inverse Fourier transform:

[0035]

[0036] This frequency domain signal can be converted into a time domain signal Γ(t), such as Figure 2 As shown, peak calibration is performed on the time-domain signal, the time corresponding to each peak is read, and the difference between the times corresponding to each peak is calculated. This value is the propagation time of the microwave signal within the coating. Based on the relationship that the propagation distance and time of the microwave signal in the same coating medium are proportional, the unknown thickness of the currently measured sample can be determined from the known thickness of the standard sample and the propagation time of the microwave within its coating.

[0037]

[0038] Where d is the thickness of the sample being measured. refThe known thickness of the standard sample is given, and t is the time it takes for the microwave to propagate through the coating of the sample being measured. ref This represents the time it takes for microwaves to propagate through the coating of the standard sample.

[0039] Measuring the thickness of a sample coating using the microwave time domain method has advantages such as ease of operation, simple calculation, and accurate results.

[0040] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. (See attached drawings) Figure 3 As shown, this embodiment of the invention provides a functional coating thickness uniformity measuring device, which includes: a measuring module, an automatic control module, a display module, and a calculation module;

[0041] The measurement module mainly includes:

[0042] Three-dimensional adjustable support, vector network analyzer, sample stage, waveguide probe;

[0043] Vector network analyzers and waveguide probes are primarily responsible for the generation and reception of microwave frequency domain signals.

[0044] The three-dimensional adjustable bracket is used to support the waveguide probe and is connected to the automatic control module, which can adjust the position of the sample measurement point through the automatic control module;

[0045] The automated control module is mainly used for:

[0046] The three-dimensional adjustable support of the control and measurement module enables automated measurement of multiple points on the sample;

[0047] The calculation module is mainly used for:

[0048] The microwave frequency domain complex reflection coefficient signal measured by the measurement module is processed to obtain the microwave time domain complex reflection coefficient signal. The peak value of the time domain signal is calibrated, the time difference between each peak value is read, and the actual thickness of each coating of the sample is calculated according to the standard time and thickness.

[0049] Based on the measurement results at each point on the sample, the calculation module provides the average thickness and thickness uniformity of each coating on the sample.

[0050] The display module is mainly used for:

[0051] Display of the final measurement results of the coating thickness of each sample.

[0052] like Figure 4 As shown, this embodiment of the invention provides a method for measuring the uniformity of functional coating thickness. The implementation process of this embodiment is described in detail below with reference to a specific example. The method includes:

[0053] Step S01: The measurement module acquires the microwave frequency domain complex reflection coefficient curve at a certain point of the sample to be tested.

[0054] Optionally, the measurement module can employ rectangular waveguides, circular waveguides, elliptical waveguides, single-ridge waveguides, double-ridge waveguides, etc.

[0055] Optionally, the bandwidth of the waveguide can be selected as needed. The larger the waveguide bandwidth, the smaller the minimum resolution of the corresponding time-domain signal, the larger the amount of data to be calculated, the longer the measurement time, and the more accurate the experimental results.

[0056] Step S02: The measured frequency domain signal is transmitted to the calculation module.

[0057] Step S03: The calculation module processes the frequency domain signal to obtain the time domain signal and calculates the thickness of each coating.

[0058] Optionally, the processing of the frequency domain signal can be inverse Fourier transform or inverse discrete Fourier transform. Inverse discrete Fourier transform requires less data and has a shorter computation time.

[0059] The calculation module can automatically calibrate the peak value and corresponding time of the time domain signal, and calculate the time difference between each peak value. Based on the known thickness and propagation time of the standard sample, the coating thickness at that point of the measured sample is obtained.

[0060] Step S04: The automated control module adjusts the sample measurement points and repeats the above steps.

[0061] Optionally, the automated control module can adjust the sample measurement points using a nine-point measurement method. For example... Figure 5 As shown, the nine-point measurement method involves taking the midpoint of the sample diagonal as the central sampling point, then selecting four points on the diagonal that are equidistant from the central sampling point as sampling points, and finally taking the four endpoints of the sample as sampling points, and measuring the sample coating thickness at each of the nine points.

[0062] Step S05: The calculation module calculates the average coating thickness at each point and transmits the thickness and thickness uniformity data to the display module for visualization.

[0063] The formula for thickness uniformity is as follows:

[0064]

[0065] Where V represents the uniformity of the sample coating thickness, n represents the number of sampling points, and d i The coating thickness at a certain point. This represents the average coating thickness.

[0066] In this embodiment, the average coating thickness of the sample was measured to be 520 μm, consistent with the 500 μm coating thickness of the standard sample, with an error of only 4%, demonstrating high measurement accuracy. The measured coating uniformity was 90%, indicating good uniformity, and the measurement operation was simple.

[0067] In summary, the method provided by the embodiments of the present invention can measure the thickness and uniformity of the sample coating. Furthermore, the method provided by the embodiments of the present invention is applicable to the thickness measurement of all coatings based on metal substrates. It is simple to operate and has a small error, and can accurately measure the coating thickness and uniformity of devices.

[0068] It should be noted that the module division in the embodiments of this invention is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0069] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0070] Therefore, although the present invention has been shown above with reference to preferred embodiments, these preferred embodiments are not intended to limit the present invention. Those skilled in the art can still modify the technical solutions described in the foregoing embodiments. Any modifications, refinements, and equivalent substitutions made without departing from the spirit and scope of the present invention should fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention is determined by the scope defined in the claims.

Claims

1. A functional coating thickness uniformity measurement apparatus, characterized by, Comprise: Measurement module, automation control module, display module and calculation module; The measurement module mainly contains: Three-dimensional adjustable support, vector network analyzer, sample stage, waveguide probe; Vector network analyzer and waveguide probe are mainly responsible for the generation and reception of microwave frequency domain signal; Three-dimensional adjustable support is used for the support of waveguide probe and is connected with automation control module, which can adjust the sample measurement point through automation control module; The automation control module is mainly used for: Control the three-dimensional adjustable support of the measurement module to realize the automatic measurement of multiple points of the sample; The calculation module is mainly used for: Processing the microwave frequency domain complex reflection coefficient signal measured by the measurement module to obtain the microwave time domain complex reflection coefficient signal, and peak value calibration is carried out on the time domain signal, the corresponding time difference between each peak value is read, and the actual thickness of each coating of the sample is calculated according to the standard time and thickness; According to the measurement results of each point of the sample, the calculation module gives the average thickness and thickness uniformity of each coating of the sample; The display module is mainly used for: The final measurement results of the thickness of each coating of the sample.

2. A method of measuring functional coating thickness uniformity, characterized by, Comprise the following five main steps: I. The measurement module collects the microwave frequency domain complex reflection coefficient of the sample at a certain point; Two, the measured frequency domain signal is transmitted to the calculation module; Three, the calculation module processes the frequency domain signal to obtain the time domain signal and the thickness of each coating; Four, the automation control module adjusts the sample measurement point, and repeats the above steps; Five, the calculation module calculates the average thickness of each point coating and transmits the thickness and thickness uniformity data to the display module for visualization.

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