Quality detection method and system for superhard protective coating on surface of watch glass

Abstract

The invention belongs to the technical field of surface engineering analysis, and provides a method and a system for detecting the quality of a superhard protective coating on the surface of watch glass, in a high-low cycle test process, temperature data of a substrate coating and an outer coating in a high-low temperature switching stage are acquired in real time, temperature difference analysis is performed, and the superhard protective coating on the surface of the watch glass is obtained. The temperature matching degree of the substrate coating and the outer coating is detected, the temperature change rate difference between the substrate coating and the outer coating is obtained in the dynamic temperature difference analysis process of temperature data, obtained in real time, of the substrate coating and the outer coating, and correlation analysis is conducted on the temperature change rate difference and the corresponding temperature change matching difference. And whether the temperature change rate difference and the temperature change matching difference have relevance or not is evaluated, so that the internal stress distribution and change condition of the coating in the temperature change process can be deeply known, and the potential cracking phenomenon of the coating is prevented and found in time.

Description

Technical Field

[0001] This invention belongs to the field of surface engineering analysis technology, specifically a method and system for quality testing of ultra-hard protective coatings on watch glass surfaces. Background Technology

[0002] As a common timekeeping tool in people's daily lives, the protective performance of the glass surface of a watch is of paramount importance. Due to its excellent properties such as high hardness, wear resistance, and corrosion resistance, ultra-hard protective coatings are widely used on the surface of watch glass to enhance its scratch resistance and impact resistance, and extend the life of the watch.

[0003] In the existing technology, the performance of coatings under temperature change environment is not considered in a comprehensive and in-depth manner. On the one hand, in the high and low temperature cycle test, the existing technology often does not pay enough attention to the temperature difference analysis between the base coating and the outer coating during the high and low temperature switching stage. Due to the different material properties of the base coating and the outer coating, their expansion or contraction degree is different when the temperature changes, which will lead to stress inside the coating. On the other hand, when analyzing the temperature data of the base coating and the outer coating, the existing technology does not delve into the correlation between the difference in temperature change rate and the difference in temperature change matching between the base coating and the outer coating. In the actual temperature change process, the difference in temperature change rate and the difference in temperature change matching affect each other and work together to affect the stress state of the coating. Furthermore, even when the temperature difference between the base coating and the outer coating is recognized, existing technologies lack effective methods to analyze whether this difference is cumulative. The cumulative effect of temperature differences further exacerbates stress concentration within the coating, increasing the risk of cracking. However, existing technologies cannot accurately determine the cumulative effect of these differences, precisely locate stress concentration areas, or detect potential stress concentration points within the coating in advance. This makes the coating more susceptible to quality problems under complex temperature variations, affecting the overall performance and reliability of the watch.

[0004] Therefore, the present invention provides a method and system for quality testing of ultra-hard protective coatings on watch glass surfaces. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0006] The technical solution adopted by this invention to solve its technical problem is: Firstly, a quality testing method for an ultra-hard protective coating on a watch glass surface includes: During the high and low temperature cycle test, the temperature difference between the base coating and the outer coating during the high and low temperature switching phase was analyzed, and the temperature matching degree between the base coating and the outer coating was detected. In the process of dynamic temperature difference analysis of the temperature data of the base coating and the outer coating acquired in real time, the difference in temperature change rate between the base coating and the outer coating is obtained, and correlation analysis is performed with the corresponding temperature change matching difference to evaluate whether there is a correlation between the temperature change rate difference and the temperature change matching difference. If there is a strong correlation, then based on the assessed high temperature matching degree, analyze whether there is an overlap of temperature change differences between the base coating and the outer coating during the high and low temperature switching phase. If there is a case of overlapping differences, obtain the correlation coefficient of the overlapping differences, and adjust the preheating temperature of the substrate according to the correlation coefficient of the overlapping differences.

[0007] As a preferred approach, the process for detecting the temperature matching degree between the base coating and the outer coating is as follows: A high-low temperature switching cycle is set, and the high-low temperature switching cycle is equally divided into several high-low temperature switching nodes. The temperature values ​​of the base coating and the outer coating at the same high-low switching node are obtained to obtain the unit base temperature value and the unit outer layer temperature value. The unit base temperature value and the unit outer layer temperature value at each high-low switching node are combined to obtain the temperature matching analysis group. The Euclidean distance formula is used for processing to output the internal and external temperature matching degree. If the internal and external temperature matching degree is greater than the internal and external temperature matching threshold, it will be displayed as a low temperature matching degree; If the internal and external temperature matching degree is less than or equal to the internal and external temperature matching threshold, it will be displayed as a high temperature matching degree.

[0008] The preferred approach is as follows: The correlation analysis process is as follows: The duration between adjacent high and low temperature switching nodes is taken as the adjacent switching period, and the duration corresponding to each adjacent switching period is obtained as the unit temperature change duration. The temperature difference between the unit base temperature value and the unit outer layer temperature value of adjacent high and low temperature switching nodes is calculated, and the absolute value is taken to obtain the unit base temperature change value and the unit outer layer temperature change value. The ratio of these values ​​to the unit temperature change duration is calculated to output the unit base temperature change rate and the unit outer layer temperature change rate. The temperature change rate of the unit substrate and the temperature change rate of the unit outer layer are subtracted, and the absolute value is taken to output the unit temperature rate difference value. The temperature difference between adjacent base layers and outer layers is calculated by subtracting the temperature values ​​of adjacent base layers and outer layers at adjacent high-low switching nodes, and the absolute value is taken to obtain the temperature difference between adjacent base layers and outer layers. The absolute value of the difference is then taken to obtain the temperature difference between adjacent layers. The ratio of the adjacent temperature change difference value to the unit temperature rate difference value within each adjacent switching time period is calculated to obtain the adjacent temperature change time difference value. The standard deviation is then calculated to obtain the difference correlation value.

[0009] A preferred approach is to assess whether there is a correlation between the difference in temperature change rate and the difference in temperature change matching, as follows: If the difference correlation value is greater than the difference correlation threshold, it is displayed as a weak difference correlation signal; If the difference correlation value is less than or equal to the difference correlation threshold, it is displayed as a strong difference correlation signal.

[0010] As a preferred approach, the specific process for obtaining the amplitude-velocity coupling value based on the evaluated temperature high matching degree is as follows: The ratio of the unit temperature rate difference value to the unit temperature change rate threshold is calculated, and the unit temperature change difference ratio is output. The ratio of adjacent temperature change difference values ​​to adjacent temperature change difference thresholds is calculated and output as the adjacent temperature change difference ratio. The amplitude-velocity coupling value is obtained by multiplying the unit temperature-velocity difference value within the same adjacent switching time period with the adjacent temperature change difference value.

[0011] As a preferred approach, the superposition analysis process for the temperature change differences between the base coating and the outer coating is as follows: Input the amplitude-velocity coupling value corresponding to each adjacent switching time period into a two-dimensional coordinate system to construct an amplitude-velocity coupling change curve. Extract the coordinates of all peak points and trough points on the amplitude-velocity coupling change curve. Take the curves corresponding to the coordinates of adjacent trough points and the coordinates of the peak points between adjacent trough points as a coupling change analysis curve to obtain multiple coupling change analysis curves. Obtain the distance between the X coordinate of each trough point and the X coordinate of each crest point to obtain the first neighbor horizontal distance and the last neighbor horizontal distance. Obtain the distance between the Y coordinate of each trough point and the Y coordinate of each crest point to obtain the first adjacent peak-trough distance and the last adjacent peak-trough distance; The product of the first neighbor's horizontal distance and the first neighbor's peak-valley distance is calculated to obtain the first neighbor's change value. The product of the last neighbor's horizontal distance and the last neighbor's peak-valley distance is calculated to obtain the last neighbor's change value. The difference between the first neighbor's change value and the last neighbor's change value is calculated, and the absolute value is taken to obtain the first and last neighbor difference value.

[0012] The preferred approach is to assess whether there are overlapping differences, as follows: If the difference between the first and last adjacent values ​​is greater than the threshold for the difference between the first and last adjacent values, it is displayed as a trend fluctuation signal. Then, the coupling change analysis curves corresponding to the continuously displayed trend fluctuation signals are merged, and the duration corresponding to the coupling change analysis curves of the merged multiple continuously displayed trend fluctuation signals is extracted to obtain the number of adjacent switching time periods contained within the duration, which is recorded as the moving average time. If the curve stability value is less than or equal to the curve stability threshold, it is displayed as a trend stability signal. Then, the time corresponding to the analyzed coupling change analysis curve is extracted to obtain the number of adjacent switching time periods within the time corresponding to the coupling change analysis curve, which is recorded as the moving average time. Based on the moving average, the amplitude-velocity coupling value corresponding to the same adjacent switching time period of the continuous moving average is calculated as a moving average to obtain the coupling moving average value. The difference between adjacent coupling moving average values ​​is obtained to obtain the coupling moving average difference value. The number of coupling moving average differences with positive signs is counted and the ratio is calculated with the total number of coupling moving average differences to obtain the growth ratio. If the growth ratio is greater than or equal to the growth ratio threshold, it will be displayed as a difference superposition signal; If the growth ratio is less than the growth ratio threshold, it is displayed as a non-additive difference.

[0013] The preferred approach is as follows: The process for obtaining the differential superposition correlation coefficient is as follows: Extract the amplitude-velocity coupling change curve and combine the coordinates of adjacent peak points and trough points into a coupling analysis group; The coordinates of adjacent peaks and troughs within each coupling analysis group are calculated using the slope calculation formula, and the coupling analysis coefficients are output. If the signal is displayed as a stable trend, the coupling analysis coefficients will be averaged to calculate the difference superposition correlation coefficient. If the signal is displayed as a trend fluctuation, the maximum and minimum coupling analysis coefficients are selected and averaged to calculate the difference superposition correlation coefficient.

[0014] The preferred solution is as follows: The procedure for adjusting the substrate preheating temperature is as follows: The current substrate preheating temperature is obtained by multiplying it with the differential superposition correlation coefficient, and then summing the product with the current substrate preheating temperature to obtain the substrate preheating temperature to be adjusted, thus completing the adjustment operation of the substrate preheating temperature.

[0015] Secondly, a quality inspection system for an ultra-hard protective coating on the surface of watch glass includes: Internal and external matching analysis module: During high and low temperature cycle testing, analyze the temperature difference between the base coating and the outer coating during the high and low temperature switching phase, and detect the temperature matching degree between the base coating and the outer coating. Difference Correlation Analysis Module: During the dynamic temperature difference analysis of the real-time acquired temperature data of the base coating and the outer coating, the difference in temperature change rate between the base coating and the outer coating is obtained, and correlation analysis is performed with the corresponding temperature change matching difference to evaluate whether there is a correlation between the temperature change rate difference and the temperature change matching difference. Difference Overlap Assessment Module: If there is a strong correlation, the module analyzes whether there is an overlap of temperature changes between the base coating and the outer coating during the high and low temperature switching phase, based on the assessed high temperature matching degree. Substrate preheating adjustment module: If there is a difference superposition, the difference superposition correlation coefficient is obtained, and the substrate preheating temperature is adjusted according to the difference superposition correlation coefficient.

[0016] The beneficial effects of this invention are as follows: This invention acquires real-time temperature data of the base coating and outer coating during high and low temperature switching phases during high and low temperature cycle testing, performs temperature difference analysis, and detects the temperature matching degree between the base coating and outer coating. In the process of dynamic temperature difference analysis of the real-time acquired temperature data of the base coating and outer coating, the difference in temperature change rate between the base coating and outer coating is obtained and correlated with the corresponding temperature change matching difference. The correlation between the temperature change rate difference and the temperature change matching difference is evaluated. This is not only helpful for a deeper understanding of the internal stress distribution and changes of the coating during temperature changes, preventing and timely detection of potential coating cracking, but also reflects the different degrees of expansion or contraction of the base coating and outer coating, indirectly reflecting the fatigue degree of the coating under long-term temperature cycling, which can be used to predict the service life of the coating. If a strong correlation exists, this invention analyzes whether there is a superposition of temperature changes between the base coating and the outer coating during the high-low temperature switching phase, based on the evaluated high temperature matching degree. If a superposition of differences exists, a correlation coefficient is obtained, and the preheating temperature of the base is adjusted according to the correlation coefficient. This not only changes the stress state of the coating during temperature changes, accurately locates stress concentration areas, and reduces potential stress concentration points inside the coating, but also changes the temperature change pattern of the coating, making the temperature changes of the base coating and the outer coating more coordinated during the high-low temperature switching process, reducing the generation of thermal stress, and ensuring that the ultra-hard protective coating on the watch glass surface can effectively play a protective role for a long time, improving the service life and quality of the watch. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a flowchart of the steps in the quality inspection method of an ultra-hard protective coating on the surface of watch glass according to the present invention; Figure 2 This is a flowchart illustrating the quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to the present invention. Figure 3 This is a schematic diagram of a module of a quality inspection system for an ultra-hard protective coating on the surface of watch glass according to the present invention. Detailed Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments. Example 1

[0020] Please see Figure 1 - Figure 2 As shown in the embodiment of the present invention, a quality inspection method for an ultra-hard protective coating on a watch glass surface includes the following steps: Step 1: During the high and low temperature cycle test, acquire the temperature data of the base coating and the outer coating in real time during the high and low temperature switching phase, and perform temperature difference analysis to detect the temperature matching degree between the base coating and the outer coating. In a preferred embodiment, a high-low temperature switching cycle is set, and the high-low temperature switching cycle is equally divided into several high-low temperature switching nodes; Among them, the time interval between adjacent high and low temperature switching nodes is equal; The temperature values ​​of the substrate coating and the outer coating are obtained at the same high-low switching node to obtain the unit substrate temperature value and the unit outer layer temperature value. The temperature matching analysis group is obtained by combining the unit base temperature value and the unit outer layer temperature value at each high-low switching node. Input the temperature matching analysis group into the Euclidean distance formula, and the output will be the internal and external temperature matching degree. ; Specifically, ,in, This represents the total number of high and low temperature switching nodes. Represented as the first The unit substrate temperature value at each high / low switching node. Represented as the first The outer layer temperature value of the cell at each high / low switching node; The internal and external temperature matching degree is compared with the internal and external temperature matching threshold, as follows: If the internal and external temperature matching degree is greater than the internal and external temperature matching threshold, it indicates that the temperature matching degree between the base coating and the outer coating is low at each high and low temperature switching node during the high and low temperature switching cycle, which is displayed as low temperature matching degree. If the internal and external temperature matching degree is less than or equal to the internal and external temperature matching threshold, it indicates that the temperature matching degree between the base coating and the outer coating is high at each high and low temperature switching node during the high and low temperature switching cycle, which is displayed as a high temperature matching degree. Step 2: During the dynamic temperature difference analysis of the real-time acquired temperature data of the base coating and the outer coating, the temperature change rate difference between the base coating and the outer coating is obtained, and a correlation analysis is performed with the corresponding temperature change matching difference to evaluate whether there is a correlation between the temperature change rate difference and the temperature change matching difference. In a preferred embodiment, the duration between adjacent high and low temperature switching nodes is taken as the adjacent switching time period, and the duration corresponding to each adjacent switching time period is obtained as the unit temperature change duration. The difference between the unit substrate temperature values ​​of adjacent high and low temperature switching nodes is calculated, and the absolute value is taken to output the unit substrate temperature change value. The ratio of the temperature change value of the unit substrate to the unit temperature change time is calculated to output the temperature change rate of the unit substrate. Similarly, the outer layer temperature values ​​of adjacent high and low temperature switching nodes are subtracted, and the absolute value is taken to output the outer layer temperature change value of the unit. The ratio of the temperature change value of the outer layer of the unit to the temperature change duration of the unit is calculated, and the temperature change rate of the outer layer of the unit is output. The temperature change rate of the unit substrate and the temperature change rate of the unit outer layer are subtracted, and the absolute value is taken to output the unit temperature rate difference value. The difference between the unit base temperature values ​​at adjacent high and low switching nodes is calculated, and the absolute value is taken to output the temperature change difference value between adjacent bases. The difference between the outer layer temperature values ​​of adjacent high and low switching nodes is calculated, and the absolute value is taken to output the temperature change difference value between adjacent outer layers. The difference between the adjacent base temperature change difference value and the adjacent outer layer temperature change difference value within the same adjacent switching time period is taken as the absolute value to obtain the adjacent temperature change difference value. The ratio of the adjacent temperature change difference value within the same adjacent switching time period to the unit temperature rate difference value is calculated, and the adjacent temperature change time difference value is output. The standard deviation of adjacent temperature change time difference values ​​is calculated, and the difference correlation value is output. It should be noted that the difference correlation coefficient is used to measure the degree of correlation between the difference in temperature change rate and the difference in temperature change matching. Specifically, on the one hand, the correlation between the difference in temperature change rate and the difference in temperature change matching reflects the consistency of the coating during different temperature changes, which helps to evaluate the stability of the overall performance of the coating and assess the probability of different coatings cracking due to high and low temperature changes, and even further determine the high and low temperature change range that leads to cracking of different coatings. On the other hand, it reflects the bonding quality between the base coating and the outer coating. The difference correlation value is compared with the difference correlation threshold, as follows: If the difference correlation value is greater than the difference correlation threshold, it indicates that the correlation between the temperature change rate difference and the temperature change matching difference is not strong, and it is displayed as a weak difference correlation signal. If the difference correlation value is less than or equal to the difference correlation threshold, it indicates that there is a relatively close correlation between the temperature rate difference and the temperature change matching difference, which is a strong difference correlation signal. Specifically, the purpose of assessing whether there is a correlation between differences in temperature change rates and differences in temperature change matching is: Objective 1: To gain a deeper understanding of the internal stress distribution and changes of the coating during temperature changes. If the difference between the two is weakly correlated, it means that the layers of the coating cannot work together when the temperature changes, which can easily lead to internal stress concentration and increase the risk of coating cracking. If the difference between the two is strongly correlated, it means that the potential cracking of the coating can be prevented and detected in time based on the temperature change difference or temperature change rate difference between the base coating and the outer coating. Objective 2: The correlation between the difference in temperature change rate and the difference in temperature change matching will affect the stability of coating performance. If the correlation between the two is not good, the expansion or contraction of the base coating and the outer coating will be different when the temperature changes rapidly, which may lead to micro-cracks on the coating surface, thereby affecting its hardness and wear resistance. This helps to ensure that the coating can perform stably under various temperature conditions. Objective 3: The correlation between the difference in temperature change rate and the difference in temperature change matching can reflect the fatigue degree of the coating under long-term temperature cycling, and can be used to predict the service life of the coating, providing a basis for the maintenance and replacement of watches. The specific solution in this embodiment is as follows: During the high and low temperature cycle test, the temperature data of the base coating and the outer coating are acquired in real time during the high and low temperature switching phase, and temperature difference analysis is performed to detect the temperature matching degree of the base coating and the outer coating. In the process of dynamic temperature difference analysis of the temperature data of the base coating and the outer coating acquired in real time, the temperature change rate difference between the base coating and the outer coating is obtained, and correlation analysis is performed with the corresponding temperature change matching difference to evaluate whether there is a correlation between the temperature change rate difference and the temperature change matching difference. This is not only helpful for a deeper understanding of the internal stress distribution and changes of the coating during temperature changes, preventing and timely detection of potential cracking phenomena in the coating, but also reflects the different degrees of expansion or contraction of the base coating and the outer coating, which indirectly reflects the fatigue degree of the coating under long-term temperature cycling, and can be used to predict the service life of the coating. Example 2

[0021] Please see Figure 1 - Figure 2 The quality inspection method for an ultra-hard protective coating on a watch glass surface according to an embodiment of the present invention further includes the following steps: Step 3: If there is a strong correlation, then based on the assessed high temperature matching degree, analyze whether there is an overlap of temperature change differences between the base coating and the outer coating during the high and low temperature switching phase. In a preferred embodiment, the temperature change matching degree includes a low temperature matching degree and a high temperature matching degree; For example, regarding high temperature matching, whether there is an additive effect of temperature change differences between the base coating and the outer coating is discussed in the following process: Extract the unit temperature rate difference value and the adjacent temperature change difference value within the same adjacent switching time period; The ratio of the unit temperature rate difference value to the unit temperature change rate threshold is calculated, and the unit temperature change difference ratio is output. The ratio of adjacent temperature change difference values ​​to adjacent temperature change difference thresholds is calculated and output as the adjacent temperature change difference ratio. It should be noted that the unit temperature change rate threshold and the adjacent temperature change difference threshold are set by those skilled in the art; The amplitude-velocity coupling value is calculated by multiplying the unit temperature rate difference value within the same adjacent switching time period with the adjacent temperature change difference value. It is understandable that the amplitude-rate coupling value means that it is calculated by multiplying the unit temperature rate difference value within the same adjacent switching period with the adjacent temperature change difference value. The unit temperature rate difference value reflects the difference in temperature change rate between the base coating and the outer coating at adjacent high and low temperature switching nodes, while the adjacent temperature change difference value reflects the difference in the amplitude of temperature change between the base coating and the outer coating within the same adjacent switching period, reflecting the dynamic characteristics of the coating at different temperature change stages. On the one hand, it can indirectly reflect the uneven stress distribution between different layers of the coating. On the other hand, it can serve as an indicator to predict the cracking phenomenon of the coating during the high and low temperature switching process, which helps to detect potential cracking problems in the coating in advance. Input the amplitude-velocity coupling value corresponding to each adjacent switching time period into a two-dimensional coordinate system, with the X-axis representing time and the Y-axis representing the amplitude-velocity coupling value, and construct an amplitude-velocity coupling change curve. Find the coordinates of all peaks and troughs on the amplitude-velocity coupling change curve. For example, the curves corresponding to the coordinates of adjacent trough points and the coordinates of the peak points between adjacent trough points are used as a single coupled change analysis curve to obtain multiple coupled change analysis curves. Obtain the distance between the X coordinate of one of the adjacent valley points and the X coordinate of the peak point within the coordinates of the adjacent valley points to obtain the first nearest horizontal distance; Similarly, by obtaining the distance between the X coordinate of another trough point and the X coordinate of the crest point within the coordinates of an adjacent trough point, the tail-nearest horizontal distance can be obtained. Input the Y coordinate of one of the adjacent valley points and the Y coordinate of the peak point into the coordinate distance formula, and the output will be the first nearest peak-valley distance. Input the Y coordinates of another trough point and the Y coordinates of the peak point within the coordinates of the adjacent trough point into the coordinate distance formula, and the output will be the tail adjacent peak-trough distance. The product of the first neighbor horizontal distance and the first neighbor peak-valley distance is calculated, and the first neighbor change value is output. The tail neighbor horizontal distance and the tail neighbor peak-valley distance are multiplied to calculate the tail neighbor variation value. The difference between the first and last neighboring changes is calculated, and the absolute value is taken to output the first and last neighboring difference value. If the difference between the first and last adjacent values ​​is greater than the threshold for the difference between the first and last adjacent values, it indicates that the trend change of the analyzed coupling change analysis curve is relatively volatile and is displayed as a trend fluctuation signal. Then, the coupling change analysis curves corresponding to the continuously displayed trend fluctuation signals are merged, and the duration corresponding to the multiple continuously displayed trend fluctuation signals of the merged coupling change analysis curves is extracted to obtain the number of adjacent switching time periods contained in the duration, which is recorded as the moving average time. If the difference between the first and last adjacent values ​​is less than or equal to the threshold of the difference between the first and last adjacent values, it indicates that the trend change of the analyzed coupling change analysis curve is relatively stable and shows a trend stable signal. Then, the time corresponding to the analyzed coupling change analysis curve is extracted to obtain the number of adjacent switching time periods within the time corresponding to the coupling change analysis curve, which is recorded as the moving average time. Based on the moving average, the amplitude-velocity coupling value corresponding to the adjacent switching time period of the continuous moving average is calculated by moving average to obtain the coupling moving average value; The difference between adjacent coupling mean values ​​is obtained by subtracting them. The number of coupled mean shift differences with positive statistical signs is counted, and the ratio of this ratio to the total number of coupled mean shift differences is calculated to output the growth ratio. It should be noted that the total number of coupled mean shift differences is odd; The growth ratio is compared with a growth ratio threshold, as follows: If the growth ratio is greater than or equal to the growth ratio threshold, it indicates that the amplitude-velocity coupling value shows an increasing trend, and there is an overlap of temperature change differences between the base coating and the outer coating. If the growth ratio is less than the growth ratio threshold, it indicates that the amplitude-velocity coupling value does not show an increasing trend and there is no superposition of temperature change differences between the base coating and the outer coating. In detail, the purpose of analyzing whether there is an overlap of temperature changes between the base coating and the outer coating is as follows: From the perspective of internal stress analysis, since the overlap of temperature changes is closely related to the distribution and changes of internal stress in the coating, analyzing whether there is overlap can accurately locate stress concentration areas, helping to identify potential stress concentration points within the coating in advance; from the perspective of coating cracking risk prediction, since the overlap of temperature changes significantly increases the risk of coating cracking, and the different rates and magnitudes of temperature changes between different coatings increase the probability of the coating being subjected to excessive thermal stress in local areas after overlap, therefore, analyzing whether there is overlap can assess the complexity of thermal stress the coating is subjected to during high and low temperature transitions, improving the accuracy of cracking risk prediction; from the perspective of coating performance stability, since the overlap of temperature changes can lead to changes in the internal structure of the coating, affecting the crystal structure and chemical bond state of the coating material, and thus changing the physical properties of the coating, analyzing whether there is overlap can help understand the performance change patterns of the coating at different temperature stages and assess the performance stability of the coating under long-term temperature cycling. Step 4: If there is a case of overlapping differences, obtain the correlation coefficient of the overlapping differences, and adjust the preheating temperature of the substrate according to the correlation coefficient of the overlapping differences. In a preferred embodiment, the process for obtaining the differential superposition correlation coefficient is as follows: Extract the amplitude-velocity coupling change curve and combine the coordinates of adjacent peak points and trough points into a coupling analysis group; The coordinates of adjacent peaks and troughs within each coupling analysis group are calculated using the slope calculation formula, and the coupling analysis coefficients are output. If the signal is displayed as a stable trend, the coupling analysis coefficients will be averaged to calculate the difference superposition correlation coefficient. If the signal is a trend fluctuation, the maximum and minimum coupling analysis coefficients are selected and averaged to calculate the difference superposition correlation coefficient. The procedure for adjusting the substrate preheating temperature is as follows: The current substrate preheating temperature is obtained by multiplying the product with the differential superposition correlation coefficient and then summing the product with the current substrate preheating temperature to obtain the substrate preheating temperature to be adjusted, thus completing the adjustment operation of the substrate preheating temperature. The specific solution in this embodiment is as follows: If a strong correlation exists, based on the assessed high temperature matching degree, analyze whether there is a superposition of temperature change differences between the base coating and the outer coating during the high and low temperature switching phase. If there is a superposition of differences, obtain the superposition correlation coefficient and adjust the base preheating temperature according to the superposition correlation coefficient. This not only changes the stress state of the coating during temperature change, accurately locates stress concentration areas, and reduces potential stress concentration points inside the coating, but also changes the temperature change pattern of the coating, making the temperature changes of the base coating and the outer coating more coordinated during the high and low temperature switching process, reducing the generation of thermal stress, ensuring that the ultra-hard protective coating on the watch glass surface can effectively play a protective role for a long time, and improving the service life and quality of the watch. Example 3

[0022] Please see Figure 3 The quality inspection system for an ultra-hard protective coating on the surface of watch glass, as described in this embodiment of the invention, includes the following modules: Internal and external matching analysis module: During high and low temperature cycle testing, analyze the temperature difference between the base coating and the outer coating during the high and low temperature switching phase, and detect the temperature matching degree between the base coating and the outer coating. Difference Correlation Analysis Module: During the dynamic temperature difference analysis of the real-time acquired temperature data of the base coating and the outer coating, the difference in temperature change rate between the base coating and the outer coating is obtained, and correlation analysis is performed with the corresponding temperature change matching difference to evaluate whether there is a correlation between the temperature change rate difference and the temperature change matching difference. Difference Overlap Assessment Module: If there is a strong correlation, the module analyzes whether there is an overlap of temperature changes between the base coating and the outer coating during the high and low temperature switching phase, based on the assessed high temperature matching degree. Substrate preheating adjustment module: If there is a difference superposition, the difference superposition correlation coefficient is obtained, and the substrate preheating temperature is adjusted according to the difference superposition correlation coefficient.

[0023] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for quality inspection of an ultra-hard protective coating on the surface of watch glass, characterized in that: include: During the high and low temperature cycle test, the temperature difference between the base coating and the outer coating during the high and low temperature switching phase was analyzed, and the temperature matching degree between the base coating and the outer coating was detected. In the process of dynamic temperature difference analysis of the temperature data of the base coating and the outer coating acquired in real time, the difference in temperature change rate between the base coating and the outer coating is obtained, and correlation analysis is performed with the corresponding temperature change matching difference to evaluate whether there is a correlation between the temperature change rate difference and the temperature change matching difference. If there is a strong correlation, then based on the assessed high temperature matching degree, analyze whether there is an overlap of temperature change differences between the base coating and the outer coating during the high and low temperature switching phase. If there is a case of overlapping differences, obtain the correlation coefficient of the overlapping differences, and adjust the preheating temperature of the substrate according to the correlation coefficient of the overlapping differences.

2. The quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to claim 1, characterized in that: The process for testing the temperature matching degree between the base coating and the outer coating is as follows: A high-low temperature switching cycle is set, and the high-low temperature switching cycle is equally divided into several high-low temperature switching nodes. The temperature values ​​of the base coating and the outer coating at the same high-low switching node are obtained to obtain the unit base temperature value and the unit outer layer temperature value. The unit base temperature value and the unit outer layer temperature value at each high-low switching node are combined to obtain the temperature matching analysis group. The Euclidean distance formula is used for processing to output the internal and external temperature matching degree. If the internal and external temperature matching degree is greater than the internal and external temperature matching threshold, it will be displayed as a low temperature matching degree; If the internal and external temperature matching degree is less than or equal to the internal and external temperature matching threshold, it will be displayed as a high temperature matching degree.

3. The quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to claim 1, characterized in that: The process of association analysis is as follows: The duration between adjacent high and low temperature switching nodes is taken as the adjacent switching period, and the duration corresponding to each adjacent switching period is obtained as the unit temperature change duration. The temperature difference between the unit base temperature value and the unit outer layer temperature value of adjacent high and low temperature switching nodes is calculated, and the absolute value is taken to obtain the unit base temperature change value and the unit outer layer temperature change value. The ratio of these values ​​to the unit temperature change duration is calculated to output the unit base temperature change rate and the unit outer layer temperature change rate. The temperature change rate of the unit substrate and the temperature change rate of the unit outer layer are subtracted, and the absolute value is taken to output the unit temperature rate difference value. The temperature difference between adjacent base layers and outer layers is calculated by subtracting the temperature values ​​of adjacent base layers and outer layers at adjacent high-low switching nodes, and the absolute value is taken to obtain the temperature difference between adjacent base layers and outer layers. The absolute value of the difference is then taken to obtain the temperature difference between adjacent layers. The ratio of the adjacent temperature change difference value to the unit temperature rate difference value within each adjacent switching time period is calculated to obtain the adjacent temperature change time difference value. The standard deviation is then calculated to obtain the difference correlation value.

4. The quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to claim 3, characterized in that: The process for assessing whether there is a correlation between differences in temperature change rates and differences in temperature change matching is as follows: If the difference correlation value is greater than the difference correlation threshold, it is displayed as a weak difference correlation signal; If the difference correlation value is less than or equal to the difference correlation threshold, it is displayed as a strong difference correlation signal.

5. The quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to claim 1, characterized in that: Based on the evaluated high temperature matching degree, the specific process for obtaining the amplitude-velocity coupling value is as follows: The ratio of the unit temperature rate difference value to the unit temperature change rate threshold is calculated, and the unit temperature change difference ratio is output. The ratio of adjacent temperature change difference values ​​to adjacent temperature change difference thresholds is calculated and output as the adjacent temperature change difference ratio. The amplitude-velocity coupling value is obtained by multiplying the unit temperature-velocity difference value within the same adjacent switching time period with the adjacent temperature change difference value.

6. The quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to claim 5, characterized in that: The superposition analysis process of temperature change differences between the base coating and the outer coating is as follows: Input the amplitude-velocity coupling value corresponding to each adjacent switching time period into a two-dimensional coordinate system to construct an amplitude-velocity coupling change curve. Extract the coordinates of all peak points and trough points on the amplitude-velocity coupling change curve. Take the curves corresponding to the coordinates of adjacent trough points and the coordinates of the peak points between adjacent trough points as a coupling change analysis curve to obtain multiple coupling change analysis curves. Obtain the distance between the X coordinate of each trough point and the X coordinate of each crest point to get the first neighbor horizontal distance and the last neighbor horizontal distance; Obtain the distance between the Y coordinate of each trough point and the Y coordinate of each crest point to obtain the first adjacent peak-trough distance and the last adjacent peak-trough distance; The product of the first neighbor's horizontal distance and the first neighbor's peak-valley distance is calculated to obtain the first neighbor's change value. The product of the last neighbor's horizontal distance and the last neighbor's peak-valley distance is calculated to obtain the last neighbor's change value. The difference between the first neighbor's change value and the last neighbor's change value is calculated, and the absolute value is taken to obtain the first and last neighbor difference value.

7. The quality inspection method for an ultra-hard protective coating on a watch glass surface according to claim 1, characterized in that: The process for assessing whether there is an overlap of differences is as follows: If the difference between the first and last adjacent values ​​is greater than the threshold for the difference between the first and last adjacent values, it is displayed as a trend fluctuation signal. Then, the coupling change analysis curves corresponding to the continuously displayed trend fluctuation signals are merged, and the duration corresponding to the coupling change analysis curves of the merged multiple continuously displayed trend fluctuation signals is extracted to obtain the number of adjacent switching time periods contained within the duration, which is recorded as the moving average time. If the curve stability value is less than or equal to the curve stability threshold, it is displayed as a trend stability signal. Then, the time corresponding to the analyzed coupling change analysis curve is extracted to obtain the number of adjacent switching time periods within the time corresponding to the coupling change analysis curve, which is recorded as the moving average time. Based on the moving average, the amplitude-velocity coupling value corresponding to the same adjacent switching time period of the continuous moving average is calculated as a moving average to obtain the coupling moving average value. The difference between adjacent coupling moving average values ​​is obtained to obtain the coupling moving average difference value. The number of coupling moving average differences with positive signs is counted and the ratio is calculated with the total number of coupling moving average differences to obtain the growth ratio. If the growth ratio is greater than or equal to the growth ratio threshold, it will be displayed as a difference superposition signal; If the growth ratio is less than the growth ratio threshold, it is displayed as a non-overlapping difference signal.

8. The quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to claim 1, characterized in that: The process of obtaining the differential superposition correlation coefficient is as follows: Extract the amplitude-velocity coupling change curve and combine the coordinates of adjacent peak points and trough points into a coupling analysis group; The coordinates of adjacent peaks and troughs within each coupling analysis group are calculated using the slope calculation formula, and the coupling analysis coefficients are output. If the signal is displayed as a stable trend, the coupling analysis coefficients will be averaged to calculate the difference superposition correlation coefficient. If the signal is displayed as a trend fluctuation, the maximum and minimum coupling analysis coefficients are selected and averaged to calculate the difference superposition correlation coefficient.

9. The quality inspection method for an ultra-hard protective coating on the surface of a watch glass according to claim 1, characterized in that: The procedure for adjusting the substrate preheating temperature is as follows: The current substrate preheating temperature is obtained by multiplying it with the differential superposition correlation coefficient, and then summing the product with the current substrate preheating temperature to obtain the substrate preheating temperature to be adjusted, thus completing the adjustment operation of the substrate preheating temperature.

10. A quality inspection system for an ultra-hard protective coating on the surface of watch glass, characterized in that: Includes the following modules: Internal and external matching analysis module: During high and low temperature cycle testing, analyze the temperature difference between the base coating and the outer coating during the high and low temperature switching phase, and detect the temperature matching degree between the base coating and the outer coating. Difference Correlation Analysis Module: During the dynamic temperature difference analysis of the real-time acquired temperature data of the base coating and the outer coating, the difference in temperature change rate between the base coating and the outer coating is obtained, and correlation analysis is performed with the corresponding temperature change matching difference to evaluate whether there is a correlation between the temperature change rate difference and the temperature change matching difference. Difference Overlap Assessment Module: If there is a strong correlation, the module analyzes whether there is an overlap of temperature changes between the base coating and the outer coating during the high and low temperature switching phase, based on the assessed high temperature matching degree. Substrate preheating adjustment module: If there is a difference superposition, the difference superposition correlation coefficient is obtained, and the substrate preheating temperature is adjusted according to the difference superposition correlation coefficient.

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