Calculation and testing methods for adhesion and internal polymerization of polymer functional coatings

Abstract

This invention discloses a method for calculating and testing the adhesion and internal polymerization force of polymer functional coatings, belonging to the field of coating performance testing technology. This invention abandons the traditional model of testing and calculating these two properties separately, instead utilizing an existing universal testing machine with simple modifications to form an integrated, linked testing device. It eliminates the need for high-end specialized equipment, enabling bidirectional synchronous acquisition of mechanical data and deformation image data in a single test, simultaneously obtaining experimental parameters related to coating interface adhesion and internal polymerization force. This invention combines experimentally acquired data with coating peeling and fracture morphology to achieve visual scoring, and uses simplified calculation formulas to replace complex mechanical models for numerical calculations, effectively reducing operational and computational difficulty. Furthermore, by comparing and linking performance parameters, it intuitively clarifies the intrinsic relationship between the two properties and quickly determines the coating failure type.

Description

Technical Field

[0001] This invention relates to the field of coating performance testing technology, specifically to a method for calculating and testing the adhesion and internal polymerization force of polymer functional coatings. Background Technology

[0002] Polymer functional coatings are widely used in many fields such as metal protection, building material decoration, and industrial corrosion prevention. The interfacial adhesion between the coating and the substrate, as well as the internal polymerization force of the coating itself, are two core key performance indicators that determine the service life and stability of the coating.

[0003] Currently, mainstream testing methods in the industry have significant shortcomings. Firstly, the testing process is fragmented. Traditional methods test coating adhesion and internal cohesion separately, requiring different testing fixtures and adjustments to multiple test parameters. This results in a cumbersome testing process, long testing cycles, and high labor and equipment costs. Secondly, data acquisition is often inconsistent. Slight differences in environmental conditions between two independent tests can cause systematic deviations in the two sets of test data, failing to accurately reflect the true matching relationship between the two properties of the same sample.

[0004] Thirdly, the computational logic is complex. Most existing performance numerical calculations rely on professional finite element models and multi-level mechanical fitting formulas, which require a high level of professional knowledge from operators. On-site testing personnel find it difficult to quickly master and apply these methods, resulting in poor practical application. Fourthly, the performance correlation is lacking. Existing testing systems can only output adhesion and internal cohesion values ​​separately, failing to intuitively reflect the linkage and change between the two properties. This makes it difficult to quickly determine the dominant failure mode of the coating, hindering coating formulation optimization and construction process adjustment.

[0005] Meanwhile, the cost of existing dedicated integrated testing equipment is high, and most small and medium-sized testing institutions and manufacturers cannot configure it in batches. Relying solely on conventional mechanical testing machines makes it difficult to simultaneously test both indicators, further limiting the development of rapid batch testing of coating performance. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing traditional testing methods, such as separate testing and independent calculation, complex experimental procedures, poor data consistency, complex calculation models, and inability to intuitively reflect performance correlations. This invention provides a method for calculating and testing the adhesion and internal polymerization force of polymer functional coatings. This method utilizes existing conventional universal testing machines and can be easily modified to build an integrated testing device, eliminating the need for high-end specialized testing equipment. It achieves simultaneous bidirectional mechanical data acquisition in a single test, simultaneously obtaining the corresponding test parameters for coating interface adhesion and coating internal polymerization force.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a method for calculating and testing the adhesion and internal polymerization force of a polymer functional coating, comprising the following steps: S1 sample preparation: Select a standard substrate and complete the surface pretreatment of the substrate. Coat the substrate surface with a uniformly molded polymer functional coating. After curing and shaping, arrange and paste multiple sets of parallel rigid test strips at equal intervals on the coating surface to complete the preparation of standardized test samples. The S2 integrated linkage testing device is built by modifying the structure of the existing general universal material testing machine, adding a bidirectional force sensor to the transmission end of the testing machine, and setting up a synchronous image acquisition device. The prepared test sample is fixedly installed in the lower clamping position of the testing machine, and the rigid test strip is stably connected to the upper clamping position of the testing machine. The S3 test involves bidirectional data acquisition. The tensile operating parameters of the testing machine are set and the testing machine is started to carry out a uniform tensile test. During the test, the bidirectional force sensor synchronously acquires the mechanical data of the peeling of the coating substrate interface and the mechanical data of the internal fracture of the coating. At the same time, the synchronous image acquisition device continuously captures and records the image data of the complete deformation process of coating peeling and internal fracture. S4 Visual Morphology Scoring: Retrieve image data collected throughout the experiment, and according to a pre-set unified scoring standard, complete the visual scoring of coating interface peeling morphology and coating internal fracture morphology respectively. The S5 simplified formula is used to calculate the peel force data, fracture force data and two visual morphology scores obtained from the test into the preset simplified adhesion force calculation formula and internal cohesion calculation formula respectively, so as to accurately calculate the adhesion force value and internal cohesion value of the sample coating. S6 comparative analysis compares the calculated adhesion value with the internal cohesion value, defines the coating failure judgment range corresponding to different ratios, determines the actual failure mode of the coating, and simultaneously sorts out the linkage relationship between the two performance parameters. The S7 test data integration output summarizes all original test data, morphological scoring results, performance calculation values, and failure judgment conclusions, and automatically generates a standardized and complete test report.

[0008] Furthermore, in step S1, the standard substrate used is a metal sheet of fixed specifications, and the surface of the substrate is uniformly roughened by sandblasting to a roughness Ra of 3.2μm~6.3μm; the thickness of the polymer functional coating is strictly controlled to be between 50μm and 500μm, and the thickness deviation range does not exceed ±10μm; the rigid test strips are made of stainless steel rods of uniform specifications, and the size of a single test strip is controlled to be 15mm in width and 1mm in thickness, and the spacing between test strips in the same group is 20mm.

[0009] Furthermore, in step S2, the bidirectional force sensor has the function of synchronous detection of normal force and tangential force, and the fixed mechanical detection accuracy is set to be no less than 0.1N. The synchronous image acquisition device is set to a fixed shooting resolution of no less than 1920×1080 pixels, a shooting frame rate of no less than 30fps, and the distance between the shooting device and the sample surface is 30cm~50cm, and the shooting angle is 45° to the sample surface.

[0010] Furthermore, in step S3, the uniform tensile speed of the testing machine is strictly limited to 1 mm / min to 5 mm / min, and a stop judgment condition for sudden force change is set. The ambient temperature and humidity are monitored synchronously throughout the test to ensure that the test environment conditions are uniform and stable, and to accurately extract the core data of average peel force and average breaking force during the test.

[0011] Furthermore, step S4 employs a unified scoring system with a ten-point scale. Adhesion morphology is graded based on the residual state of the coating interface, and internal cohesion morphology is graded based on the integrity of the internal fracture surfaces of the coating, thus unifying the scoring criteria across the entire process. Specifically: Adhesion morphology scoring: The state of the coating peeling interface is scored based on the image data acquired by the synchronous image acquisition device. A completely clean interface with no coating residue is 10 points, a coating residue area of ​​less than 10% is 8 points, 10%~30% is 6 points, 30%~50% is 4 points, and more than 50% is 2 points. Its core function is to quantify and correct the effective stress area. By standardizing the scoring of the failure interface morphology, it corrects the test error caused by the non-ideal stress section and calibrates the measured average peel force and average breaking force.

[0012] Internal Cohesion Morphology Scoring: The state of the coating fracture surface is scored based on image data acquired by the synchronous image acquisition device. A smooth fracture surface without obvious cracks scores 10 points; a fracture surface with a few micro-cracks scores 8 points; obvious cracks but not penetrating scores 6 points; penetrating cracks with a few fragments scores 4 points; and a large amount of fragments falling off scores 2 points. Its core function is to provide a quantitative correction coefficient for the effective stress area. By standardizing the scoring of the failure interface morphology, it corrects the test errors caused by non-ideal stress sections and calibrates the measured average peel force and average fracture force. Furthermore, in step S5, based on the measured dimensions of the test strip, the measured thickness of the coating, and the effective test length, combined with mechanical data and morphology scoring, a linear simplified calculation formula is constructed to complete the quantitative calculation of the two performance indicators.

[0013] The formula for calculating adhesion force is: F_a = (F_p × S_a) / (W × L) Where F_a is the adhesion value of the coating, in MPa; F_p is the average peel force, in N; S_a is the adhesion morphology score; W is the width of the rigid test strip, in mm; and L is the peel length of the coating, in mm.

[0014] The formula for calculating the internal cohesion is: F_c = (F_b × S_c) / (W × T) Where F_c is the internal cohesive force of the coating, in MPa; F_b is the average breaking force, in N; S_c is the internal cohesive force morphology score; W is the width of the rigid test strip, in mm; and T is the coating thickness, in mm.

[0015] Furthermore, in step S6, by calculating the ratio of adhesion force to internal cohesion force, three failure modes—cohesive failure, mixed failure, and interface failure—are classified. Simultaneously, by combining different coating preparation process parameters, a curve showing the interrelationship between these two performance characteristics can be plotted. Specifically, this includes: Calculate the ratio of adhesion strength to internal cohesion strength: R = F_a / F_c; When R>1.2, the interfacial adhesion of the coating is significantly higher than its internal cohesive force, that is, the interfacial bonding strength is greater than the coating's own strength. When the coating is under stress, failure will preferentially occur inside the coating, and the failure mode of the coating is determined to be cohesive failure. When 0.8≤R≤1.2, the adhesion and cohesion values ​​are basically equal, the interfacial bonding strength and the coating strength are on the same order of magnitude, and when under stress, interfacial peeling and internal fracture will occur simultaneously or together, and the failure mode of the coating is determined to be mixed failure. When R < 0.8, the interfacial adhesion of the coating is significantly lower than the internal cohesive force, that is, the interfacial bonding strength is weaker than the coating's own strength. When under stress, failure will preferentially occur at the interface between the coating and the substrate, and the failure mode of the coating is determined to be interfacial failure. Adhesion-internal cohesion correlation curves were plotted under different coating thicknesses and curing conditions to analyze the influence of process parameters on the two properties.

[0016] One or more technical solutions provided in this application embodiment have at least the following technical effects or advantages compared with the prior art: 1. Construct an integrated and interconnected testing system. The testing platform can be built by simply modifying a conventional universal testing machine. There is no need to purchase new high-end special testing equipment. The equipment modification cost is low and the application is easy to popularize.

[0017] 2. A single tensile test can simultaneously obtain mechanical parameters related to interfacial adhesion and internal coating cohesion, effectively reducing the number of tests, greatly simplifying the testing process, shortening the overall test cycle, avoiding data errors caused by differences in multiple test environments, and improving the overall consistency of test data.

[0018] 3. It uses simple linear calculation formulas to replace traditional complex and cumbersome professional mechanical calculation models. Operators do not need to master advanced mechanical theory knowledge. The calculation logic is simple and intuitive, balancing detection accuracy and on-site operation convenience, and is suitable for daily operation by grassroots testing personnel.

[0019] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structural layout of the integrated linkage testing device of the present invention; Figure 2 This is a schematic diagram of the overall execution timing of the method for calculating and testing the adhesion and internal polymerization force of the polymer functional coating of the present invention; Figure 3 This is a schematic diagram of the runtime sequence for bidirectional synchronous data acquisition during a single test of the present invention; Figure 4 This is a schematic diagram of the numerical calculation logic for adhesion and internal cohesion of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] The following is in conjunction with the appendix Figure 1 To be continued Figure 4 This invention provides a complete and detailed description of the calculation and testing method for the adhesion and internal polymerization force of a polymer functional coating. Equivalent embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are all within the protection scope of this invention.

[0025] First, combine Figure 1 The schematic diagram of the integrated testing device shows the overall structural layout, completing the assembly of the testing equipment and the sample clamping operation. This device is based on a universal testing machine, requiring no replacement of the entire machine; only accessories need to be added to the existing structure for modification. A bidirectional force sensor is fixedly installed below the fixture on the universal testing machine, with its lower end connected to a rigid test strip group. This bidirectional force sensor can simultaneously collect two independent loads: orthogonal normal force and tangential force. The normal force corresponds to the peeling force at the coating-substrate interface, while the tangential force corresponds to the internal shear fracture force of the coating between two rigid test strips in the same group. The two force values ​​are output independently through separate channels and do not interfere with each other. The rigid test strip group is adhered and fixed to the surface of the polymer functional coating, which is attached to the top surface of a standard substrate. The standard substrate is securely clamped and fixed inside the lower fixture of the universal testing machine. A synchronous image acquisition device is independently set up to the side of the sample testing area, facing the tensile deformation area of ​​the coating, recording the stress changes of the sample throughout the entire process. The operator first completes the standardized sample preparation, applies a coating to the pretreated standard substrate and attaches the rigidity test strips, and then proceeds according to... Figure 1 The structure shown completes the connection of the upper and lower clamps, the wiring of the sensors, and the alignment of the image acquisition equipment in sequence, ensuring that the overall clamping is secure and the connection is free from misalignment, thus completing the hardware setup work in the early stage of the experiment.

[0026] After the device is set up, according to Figure 2 The overall execution sequence diagram shows the sequential progression of the entire testing process. The entire process begins according to personnel operation instructions, first completing two preparatory tasks: sample preparation and device setup. Then, the operator inputs all test parameters into the testing machine system, including tensile rate, shutdown threshold, and environmental control standards. After parameter settings are complete, the official test start command is issued. Once the test starts, two main working modules are activated simultaneously and in parallel: a mechanical data acquisition module, which continuously collects mechanical signals using a bidirectional force sensor; and an image data acquisition module, which continuously captures the test process using a synchronous image acquisition device. The data acquired from both types of acquisitions are uniformly transmitted and aggregated to the data processing terminal. The terminal sequentially completes background calculations such as visual morphological scoring, dual-performance numerical calculation, and linked comparative analysis. Finally, all test results and judgment conclusions are integrated and summarized, and a standardized test report is output to the operator, strictly adhering to… Figure 2Sequential logic ensures that the entire process operates in a standardized and error-free sequence.

[0027] Specifically, the sample preparation includes: preparing a polymer functional coating sample with uniform thickness on the surface of a standard substrate; attaching multiple sets of parallel rigid test strips at equal intervals to the coating surface, each set of test strips containing at least two parallel rigid strips with a fixed spacing. The surface of the standard substrate is sandblasted to a roughness Ra of 3.2μm~6.3μm; the thickness of the polymer functional coating is controlled between 50μm and 500μm, with a thickness deviation not exceeding ±10μm; the rigid test strips are stainless steel strips with a width of 15mm and a thickness of 1mm, and the spacing between the two rigid strips in each set of test strips is 20mm.

[0028] The setup includes: modifying an existing universal testing machine, installing a bidirectional force sensor and a synchronous image acquisition device on the machine, fixing the prepared sample on the lower clamp of the machine, and connecting the rigid test strip to the upper clamp of the machine. The bidirectional force sensor simultaneously measures the normal force perpendicular to the coating surface and the tangential force parallel to the coating surface, with a measurement accuracy of not less than 0.1N; the synchronous image acquisition device has a resolution of not less than 1920×1080 pixels, a frame rate of not less than 30fps, a lens distance of 30cm~50cm from the sample surface, and an image capture angle of 45° to the sample surface.

[0029] In the formal tensile testing process, strict adherence to... Figure 3 A schematic diagram of the bidirectional synchronous data acquisition operation is shown for the synchronous data acquisition process. The tensile actuator pulls the rigid test bar upwards at a preset constant rate. After the test enters the continuous testing phase, it enters a cyclic acquisition state. The bidirectional force sensor continuously transmits real-time data of normal and tangential forces to the data buffer module. The normal force data fully reflects the force value change pattern during the coating interface peeling process, from which the average peeling force can be extracted. The tangential force data fully reflects the force value change pattern during the internal fracture process of the coating, from which the average fracture force can be extracted. These two types of data are two independent sets of test results, not a single comprehensive destructive force value. The synchronous image acquisition unit continuously captures images of coating deformation at a set fixed frame rate. All raw data are temporarily stored in the data buffer module. During the operation of the tensile actuator, the bidirectional force sensor monitors force value fluctuations in real time. Once a failure characteristic signal of a significant drop in force value is detected, a stop command is immediately sent to the tensile actuator, and the tensile action is immediately terminated. After the shutdown is completed, the data caching module stops data entry and completely transmits all the original mechanical data and image data stored throughout the test to the backend data processing module, realizing the simultaneous retention of two types of core data in a single test and completely abandoning the traditional work mode of collecting data in stages.

[0030] Specifically, the bidirectional data acquisition for a single test includes: starting the universal testing machine and stretching the rigid test strip upwards at a constant rate. During the stretching process, a bidirectional force sensor simultaneously acquires peel force data at the coating-substrate interface and fracture force data within the coating. Simultaneously, a synchronous image acquisition device continuously records images of the entire process of coating peeling and fracture. The constant stretching rate is 1 mm / min to 5 mm / min. Stretching is stopped when the force value detected by the bidirectional force sensor drops sharply and the drop exceeds 50% of the peak value. The peel force data is the average force value when the coating peels off from the substrate interface during stretching, and the fracture force data is the average force value when the coating fractures internally during stretching. During the stretching process, ambient temperature and humidity data are simultaneously acquired, with the ambient temperature controlled at 23±2℃ and the relative humidity controlled at 50±5%.

[0031] After all data collection work is completed, relying on Figure 4 The schematic diagram of the numerical calculation logic for adhesion and internal cohesion completes the accurate calculation of performance parameters. First, all available raw input data is compiled, mainly including two types of mechanical fundamental data: average peel force and average fracture force obtained from experimental measurements, and two types of visual evaluation data: adhesion morphology score and internal cohesion morphology score obtained through manual evaluation. The core function of the two morphology scores is as an effective force-bearing area correction coefficient: under actual test conditions, the coating peel interface and internal fracture surface are not ideal uniform planes. Interface residues, cracks, and debris can cause a deviation between the actual effective force-bearing area and the nominal theoretical force-bearing area of ​​the sample. Standardized morphology scores are used to calibrate and correct the measured force values, eliminating systematic errors caused by the test morphology, and calculating the interface adhesion strength and internal cohesion strength that conform to the true intrinsic properties of the coating material. The average peel force and adhesion morphology score are jointly imported into the adhesion calculation formula, and the final adhesion value is calculated by combining the sample size parameters. Similarly, the average fracture force and internal cohesion morphology score are jointly imported into the internal cohesion calculation formula, and the final internal cohesion value is calculated by matching the coating thickness parameters. After all two types of performance values ​​have been calculated, they are aggregated and output to the performance results output terminal, thus completing the determination of quantitative indicators. The entire process is carried out in accordance with... Figure 4 The established calculation logic is deduced sequentially, with a clear operational hierarchy and no redundant calculation steps, simplifying the difficulty of manual verification while ensuring accurate and reliable calculation results.

[0032] Specifically, the visualization scoring includes: based on the collected images of the entire process, visually scoring the peeling and fracture morphologies of the coating according to a preset scoring standard to obtain an adhesion morphology score and an internal cohesion morphology score. The preset scoring standard uses a 10-point scale, specifically: Adhesion morphology scoring: The state of the coating peeling interface is scored based on the image data acquired by the synchronous image acquisition device. A completely clean interface with no coating residue is 10 points, a coating residue area of ​​less than 10% is 8 points, 10%~30% is 6 points, 30%~50% is 4 points, and more than 50% is 2 points. Its core function is to quantify and correct the effective stress area. By standardizing the scoring of the failure interface morphology, it corrects the test error caused by the non-ideal stress section and calibrates the measured average peel force and average breaking force.

[0033] Internal Cohesion Morphology Scoring: The state of the coating fracture surface is scored based on image data acquired by a synchronous image acquisition device. A smooth fracture surface without obvious cracks scores 10 points; a fracture surface with a few micro-cracks scores 8 points; obvious cracks but not penetrating scores 6 points; penetrating cracks with a few debris scores 4 points; and a large amount of debris falling off scores 2 points. Its core function is to provide a quantitative correction coefficient for the effective stress area. By standardizing the scoring of the failure interface morphology, it corrects the test errors caused by non-ideal stress sections and calibrates the measured average peel force and average fracture force.

[0034] The simplified formula calculation includes: based on the collected peel force data, fracture force data and corresponding visual scores, substituting them into the preset adhesion calculation formula and internal cohesion calculation formula respectively, to calculate the adhesion value and internal cohesion value of the coating.

[0035] The formula for calculating adhesion force is: F_a = (F_p × S_a) / (W × L) Where F_a is the adhesion value of the coating, in MPa; F_p is the average peel force, in N; S_a is the adhesion morphology score; W is the width of the rigid test strip, in mm; and L is the peel length of the coating, in mm.

[0036] The formula for calculating the internal cohesion is: F_c = (F_b × S_c) / (W × T) Where F_c is the internal cohesive force of the coating, in MPa; F_b is the average breaking force, in N; S_c is the internal cohesive force morphology score; W is the width of the rigid test strip, in mm; and T is the coating thickness, in mm.

[0037] After completing the numerical calculations, the operators conducted a comparative analysis of the two sets of performance values. The failure modes of the coating were determined by calculating the ratio of the two values. This ratio, R=Fa / Fc, is a dimensionless ratio of adhesion strength to internal cohesion strength, used to visually characterize the relative strength difference between interfacial adhesion and coating cohesive strength. 0.8 and 1.2 are commonly used engineering experience thresholds in the field of coating mechanical testing, primarily used to define the difference level between two sets of mechanical parameters of the same dimension. Specifically, a difference within 20% indicates roughly equal performance, while a difference exceeding 20% ​​indicates a significant performance difference. This is a standard used in the field to determine the degree of difference between two sets of mechanical parameters of the same magnitude and has universal applicability. The morphology scoring and failure mode determination are completely independent technical logic dimensions and do not have a circular reasoning relationship: morphology scoring is a quantitative correction method for the morphology of local failure sections, used to optimize the accuracy of mechanical calculations; failure mode determination is a macroscopic failure mechanism judgment conclusion based on the corrected true strength parameters. The two are logically progressive, each performing its own function, without causal circular contradictions. Three types of failure were identified—cohesive failure, mixed failure, and interface failure—by using fixed threshold ranges: When R > 1.2, the interfacial adhesion is significantly higher than the internal cohesion, and stress failure of the coating preferentially occurs within the coating, which is classified as cohesive failure; when 0.8 ≤ R ≤ 1.2, the adhesion and cohesion values ​​are basically equal, and interfacial peeling and internal fracture occur simultaneously, which is classified as mixed failure; when R < 0.8, the interfacial adhesion is significantly lower than the internal cohesion, and stress failure preferentially occurs at the interface between the coating and the substrate, which is classified as interface failure. These three types of failures were thus clearly distinguished. Throughout the experiment, ambient temperature and humidity were strictly controlled to ensure consistent and stable external conditions, further improving the repeatability of the test results.

[0038] Specifically, the comparative linkage analysis includes: comparing and analyzing the calculated adhesion value and internal cohesion value, plotting the adhesion-internal cohesion correlation curve, and determining the quantitative relationship between the two properties. The comparative linkage analysis specifically includes: Calculate the ratio of adhesion strength to internal cohesion strength: R = F_a / F_c; When R>1.2, the interfacial adhesion of the coating is significantly higher than its internal cohesive force, that is, the interfacial bonding strength is greater than the coating's own strength. When the coating is under stress, failure will preferentially occur inside the coating, and the failure mode of the coating is determined to be cohesive failure. When 0.8≤R≤1.2, the adhesion and cohesion values ​​are basically equal, the interfacial bonding strength and the coating strength are on the same order of magnitude, and when under stress, interfacial peeling and internal fracture will occur simultaneously or together, and the failure mode of the coating is determined to be mixed failure. When R < 0.8, the interfacial adhesion of the coating is significantly lower than the internal cohesive force, that is, the interfacial bonding strength is weaker than the coating's own strength. When under stress, failure will preferentially occur at the interface between the coating and the substrate, and the failure mode of the coating is determined to be interfacial failure. The test results for typical test samples are shown in Tables 1 and 2 below: Table 1. Adhesion and Cohesion Morphology Scores of Typical Test Samples

[0039] Table 2 Failure Mode Determination for Typical Test Samples

[0040] Adhesion-internal cohesion correlation curves were plotted under different coating thicknesses and curing conditions to analyze the influence of process parameters on the two properties.

[0041] Finally, by integrating the basic information of the sample, the operating parameters of the device, the original collected data, the visual scoring results, the calculated values ​​of the two performance parameters, and the failure mode determination conclusions, the calculated adhesion value, internal cohesion value, failure mode determination results, and adhesion-internal cohesion correlation curve are automatically generated into a test report. The test report includes sample information, test conditions, original data, calculation results, and analysis conclusions, and is compiled into a complete and standardized test report. This completes all the procedures for the simultaneous testing and calculation of the adhesion and internal cohesion of the polymer functional coating.

[0042] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for calculating and testing the adhesion and internal polymerization force of a polymer functional coating, characterized in that, Includes the following steps: S1 Sample Preparation: Prepare a polymer functional coating sample with uniform thickness on the surface of a standard substrate. Paste multiple sets of parallel rigid test strips at equal intervals on the coating surface. Each set of test strips contains at least two parallel rigid strips with a fixed spacing. S2 Integrated Linkage Testing Device Construction: Based on the existing universal material testing machine, a bidirectional force sensor and a synchronous image acquisition device are installed on the testing machine. The prepared sample is fixed on the lower clamp of the testing machine, and the rigid test strip is connected to the upper clamp of the testing machine. S3 One-time test with bidirectional data acquisition: Start the universal material testing machine and stretch the rigid test strip upward at a constant rate. During the stretching process, the peel force data of the coating and substrate interface and the fracture force data inside the coating are collected simultaneously through the bidirectional force sensor. At the same time, the entire process of coating peeling and fracture is continuously recorded by the synchronous image acquisition device. S4 Visual Scoring: Based on the collected images of the entire process, the peeling and fracture patterns of the coating are visually scored according to the preset scoring criteria to obtain the adhesion pattern score and the internal cohesion pattern score. S5 Simplified Formula Calculation: Based on the collected peel force data, fracture force data, and corresponding visual scores, substitute them into the preset adhesion calculation formula and internal cohesion calculation formula to calculate the adhesion value and internal cohesion value of the coating. S6 Comparative Linkage Analysis: The calculated adhesion value and internal cohesion value are compared and linked to form an adhesion-internal cohesion correlation curve, which determines the quantitative relationship between the two properties.

2. The calculation and testing method according to claim 1, characterized in that, In step S1, the surface of the standard substrate is sandblasted to a roughness Ra of 3.2μm~6.3μm; the thickness of the polymer functional coating is controlled between 50μm and 500μm, with a thickness deviation of no more than ±10μm; the rigid test strip is a stainless steel strip with a width of 15mm and a thickness of 1mm, and the spacing between the two rigid strips in each set of test strips is 20mm.

3. The calculation and testing method according to claim 1, characterized in that, In step S2, the bidirectional force sensor simultaneously measures the normal force perpendicular to the coating surface and the tangential force parallel to the coating surface, with a measurement accuracy of not less than 0.1N; the resolution of the synchronous image acquisition device is not less than 1920×1080 pixels, the acquisition frame rate is not less than 30fps, the distance between the lens and the sample surface is 30cm~50cm, and the shooting angle is at a 45° angle to the sample surface.

4. The calculation and testing method according to claim 1, characterized in that, In step S3, the constant stretching rate is 1 mm / min to 5 mm / min; when the force value detected by the bidirectional force sensor drops sharply and the drop exceeds 50% of the peak value, the stretching is stopped; the peel force data is the average force value when the coating and substrate interface peels apart during the stretching process, and the fracture force data is the average force value when the coating breaks inside during the stretching process.

5. The calculation and testing method according to claim 1, characterized in that, In step S4, the preset scoring standard adopts a 10-point system, specifically as follows: Adhesion morphology rating: The state of the coating peeling interface is rated based on the image data collected by the synchronous image acquisition device. A completely clean interface with no coating residue is 10 points. The area of ​​coating residue on the interface is less than 10% and 8 points. 10%~30% is 6 points. 30%~50% is 4 points. More than 50% is 2 points. Internal cohesion morphology score: The state of the coating fracture surface is scored based on the image data collected by the synchronous image acquisition device. A smooth fracture surface without obvious cracks is 10 points, a fracture surface with a few micro-cracks is 8 points, obvious cracks but not penetrating is 6 points, cracks penetrating and a few debris are 4 points, and a large amount of debris falling off is 2 points.

6. The calculation and testing method according to claim 1, characterized in that, In step S5, the adhesion calculation formula is as follows: F_a = (F_p × S_a) / (W × L) Where F_a is the adhesion value of the coating, in MPa; F_p is the average peel force, in N; S_a is the adhesion morphology score; W is the width of the rigid test strip, in mm; and L is the peel length of the coating, in mm.

7. The calculation and testing method according to claim 1, characterized in that, In step S5, the formula for calculating the internal cohesion is: F_c = (F_b × S_c) / (W × T) Where F_c is the internal cohesive force of the coating, in MPa; F_b is the average breaking force, in N; S_c is the internal cohesive force morphology score; W is the width of the rigid test strip, in mm; and T is the coating thickness, in mm.

8. The calculation and testing method according to claim 1, characterized in that, In step S6, the comparative linkage analysis specifically includes: Calculate the ratio of adhesion strength to internal cohesion strength: R = F_a / F_c; When R > 1.2, the failure mode of the coating is determined to be cohesive failure; When 0.8 ≤ R ≤ 1.2, the failure mode of the coating is determined to be mixed failure; When R < 0.8, the failure mode of the coating is determined to be interface failure; Adhesion-internal cohesion correlation curves were plotted under different coating thicknesses and curing conditions to analyze the influence of process parameters on the two properties.

9. The calculation and testing method according to claim 1, characterized in that, In step S3, during the stretching process, ambient temperature and humidity data are collected simultaneously. The ambient temperature is controlled at 23±2℃ and the relative humidity is controlled at 50±5%.

10. The calculation and testing method according to claim 1, characterized in that, It also includes step S7: automatically generating a test report from the calculated adhesion value, internal cohesion value, failure mode determination result, and adhesion-internal cohesion correlation curve. The test report includes sample information, test conditions, raw data, calculation results, and analysis conclusions.

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