Laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference

Abstract

This invention discloses a laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point differences. Step S1 calculates the comprehensive influence of the cladding combination, enabling the prediction of the actual crack shape characteristics of the scene to be generated by the laser cladding combination under the laser cladding experimental parameters. In step S3, based on the type and magnitude of the predicted actual crack shape characteristics of the scene for the cladding combination, a corresponding first laser parameter adjustment set and / or second laser parameter adjustment set are matched. Then, the laser parameter values ​​in the first or second laser parameter adjustment set, or the smaller change value of the common laser parameters in the first and second laser parameter adjustment sets, are used to update the parameter values ​​of the same type of laser cladding experimental parameters. This achieves rapid and accurate adjustment of the laser cladding experimental parameter values ​​that can resist the predicted actual crack shape characteristics of the scene.

Description

Technical Field

[0001] This invention relates to the field of laser cladding technology, and more specifically to a laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point differences. Background Technology

[0002] Cladding is a surface treatment technology that improves the performance of a substrate by melting and coating it with a material. Common cladding processes include laser cladding, plasma cladding, and arc cladding. During the cladding process, cracks may appear on the cladding layer and the substrate surface. These cracks can affect the bonding strength between the cladding layer and the substrate, thus affecting the substrate's performance. The causes and types of cracks are diverse, with different causes typically resulting in different types of cracks. Crack types include longitudinal cracks, transverse cracks, intergranular cracks, periodically propagating cracks, radial cracks, boundary cracks, and internal cracks. These different crack shapes arise under corresponding scene factors. For example, during laser cladding of YSZ@Ni coatings, due to the cooling and contraction of the molten pool material, the stress at both ends of the cladding layer is relatively high. The tensile stress is greatest in the X-direction at the bonding layer between the substrate and the YSZ coating, making it prone to transverse cracks perpendicular to the scanning direction. However, regardless of the type of crack, if the physical properties of the cladding material and the substrate, such as the coefficient of thermal expansion and melting point, are significantly different, the characteristics of the crack under the corresponding scenario factors (ignoring the differences in the coefficient of thermal expansion and melting point) may be significantly altered. Consequently, it becomes difficult to use the characteristics of the crack under the scenario factors as feedback to adjust the relevant control parameters in the laser cladding process.

[0003] Inevitably, the coefficients of thermal expansion and melting points of the cladding material and the substrate differ at different life stages. Even if the differences are all under constrained conditions (within the preset difference threshold range), these differences may further lead to significant changes in the crack shape characteristics formed under corresponding scenario factors. How to quantify the ability of the different differences in the coefficients of thermal expansion and melting points at different life stages to change the crack shape characteristics formed under corresponding scenario factors (ignoring the differences in the coefficients of thermal expansion and melting points) is the first technical problem that this application aims to solve.

[0004] Most importantly, the second technical problem this application aims to solve is how to use the changed crack shape characteristics as feedback to adjust the relevant control parameters in the laser cladding process after the cracks formed under the corresponding scenario factors change due to dynamic changes (dynamic changes due to the different life stages of the cladding material and the substrate). Summary of the Invention

[0005] This invention aims to reduce the probability of cladding cracks and improve cladding quality under the constraint of thermal expansion and melting point differences between the cladding material and the substrate at their respective life stages. It provides a laser cladding method based on feedback adjustment under the constraint of thermal expansion and melting point differences.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A laser cladding method based on feedback adjustment is provided under the constraints of thermal expansion and melting point difference, including the following steps:

[0008] S1, obtain the difference in thermal expansion coefficient and melting point between the cladding material and the substrate constituting the cladding assembly at the current life stage, and calculate the comprehensive influence of the comprehensive difference in thermal expansion coefficient and melting point on the initial characteristic value of the scene experimental crack shape formed under the experimental environment of changing the scene factors currently present in the cladding assembly through the difference point matching method.

[0009] S2, based on the comprehensive influence calculated in step S1, predict the actual crack shape characteristics of the scene expected to be generated by the laser cladding combination based on the laser cladding experimental parameters.

[0010] S3. Based on the type and size of the predicted value of the actual crack shape characteristics of the scene predicted in step S2, after adjusting the laser cladding experimental parameters with the corresponding strategy, laser cladding is started on the cladding combination.

[0011] Preferably, step S1, the method for calculating the combined influence of the combined difference between the thermal expansion coefficient and the melting point on the initial characteristic value of the scene experimental crack shape formed under the experimental environment of the scene factors currently present in the cladding combination, includes the following steps:

[0012] S11, the difference in thermal expansion coefficient and the difference in melting point between the cladding material and the substrate at the current life stage are substituted into the first fitting function and the second fitting function respectively as independent variables, and the y values ​​of the first fitting function and the second fitting function are solved.

[0013] S12, calculate the absolute value of the difference between the y-value of the first fitting function and the initial characteristic value of the crack shape in the scenario experiment, as the first influence of the difference in the coefficient of thermal expansion in the current life stage on changing the initial characteristic value of the crack shape in the scenario experiment; calculate the absolute value of the difference between the y-value of the second fitting function and the initial characteristic value of the crack shape in the scenario experiment, as the second influence of the difference in the melting point in the current life stage on changing the initial characteristic value of the crack shape in the scenario experiment.

[0014] S13, obtain the piecewise compensation function corresponding to the cladding combination having the first influence amount and the second influence amount, and use the y value obtained by solving the obtained piecewise compensation function as the comprehensive influence amount of the comprehensive difference on changing the initial characteristic value of the crack shape in the scenario experiment.

[0015] Preferably, the first fitting function and / or the second fitting function are univariate higher-order functions, and the method for constructing the univariate higher-order function includes the following steps:

[0016] A1, in the experimental environment where the cladding combination currently has the aforementioned scenario factors, laser cladding is performed on the cladding experimental material and experimental substrate in the initial stage of life using the aforementioned laser cladding experimental parameters to obtain the initial characteristic value of the scenario experimental crack shape.

[0017] A2, In the same real environment with the aforementioned scenario factors, laser cladding is performed on each sample combination with different lifespan stages using the same laser cladding experimental parameters to obtain the scenario experimental crack shape change characteristic value associated with each sample combination; at least one of the cladding sample material and sample substrate in each sample combination has a different lifespan stage.

[0018] A3, compare the similarity between the feature values ​​of the crack shape change in each scenario experiment and the initial feature values ​​of the crack shape in the scenario experiment, so as to filter out the feature values ​​of the crack shape change in the scenario experiment with similarity less than the similarity threshold.

[0019] A4. Classify the remaining sample combinations after filtering in step A3 to obtain fitting sample combinations for fitting the first curve and the second curve, respectively.

[0020] A5, fit the first curve or the second curve with the corresponding combination of fitting samples to solve for the term coefficients of the first fitting function associated with the first curve and the term coefficients of the second fitting function associated with the second curve.

[0021] The cladding experimental material and the cladding sample material are of the same type as the cladding material; the experimental substrate and the sample substrate are of the same type as the substrate.

[0022] As a preferred embodiment, in step A4, the method for classifying the remaining sample combinations after filtering in step A3 is as follows:

[0023] Each sample combination whose absolute value of the difference in thermal expansion coefficient is less than a first difference threshold is classified as a first fitted sample combination, and the first fitted sample combination is used to construct the second fitted function; each sample combination whose absolute value of the difference in melting point is less than a second difference threshold is classified as a second fitted sample combination, and the second fitted sample combination is used to construct the first fitted function.

[0024] Preferably, the absolute value of the difference in melting point between any two pairs of the first fitted sample combinations is greater than the second difference threshold; and the absolute value of the difference in thermal expansion coefficient between any two pairs of the second fitted sample combinations is greater than the first difference threshold.

[0025] Preferably, in step A5, the method for solving the term coefficients of the second fitting function is as follows:

[0026] The characteristic value of the crack shape change in the scenario experiment associated with each of the first fitting sample combinations is used as the dependent variable of the second fitting function, and the difference in melting point between the cladding sample material and the sample substrate in the first fitting sample combination that forms the characteristic value of the crack shape change in the scenario experiment is used as the independent variable. The coefficients of the second fitting function are then calculated in reverse.

[0027] The method for solving the term coefficients of the first fitted function is as follows:

[0028] Using the characteristic value of the change in crack shape in the scenario experiment associated with each of the second fitted sample combinations as the dependent variable of the first fitted function, and using the difference in the coefficient of thermal expansion between the cladding sample material and the sample substrate in the corresponding second fitted sample combination that forms the characteristic value of the change in crack shape in the scenario experiment as the independent variable, the term coefficients of the first fitted function are calculated by reverse deduction.

[0029] Preferably, the piecewise compensation function in step S13 is a quadratic function, and the method for constructing the piecewise compensation function includes the following steps:

[0030] B1. Obtain the first influence quantity and the second influence quantity of each sample combination. Use the maximum value of each first influence quantity as the upper limit of the interval and the minimum value as the lower limit of the interval to obtain the first influence quantity value interval. Use the maximum value of each second influence quantity as the upper limit of the interval and the minimum value as the lower limit of the interval to obtain the second influence quantity value interval.

[0031] B2, the first influence value interval and the second influence value interval are divided into several interval segments according to their respective corresponding numerical intervals;

[0032] B3. Classify the remaining sample combinations after filtering in step A3 to obtain the first segmented compensation sample group set and the second segmented compensation sample group set.

[0033] B4, each sample combination in the first segmented compensation sample group set is aggregated into the first segmented compensation sample group subset bound to the first interval segment into which the first influence quantity of the sample combination falls, and each sample combination in the second segmented compensation sample group set is aggregated into the second segmented compensation sample group subset bound to the second interval segment into which the second influence quantity of the sample combination falls.

[0034] B5, using the second unit influence and the first crack shape characteristic value deviation of each sample combination in the first segmented compensation sample group subset as the dependent and independent variables of the first segmented compensation function bound to the first segmented compensation sample group subset, and using the first unit influence and the second crack shape characteristic value deviation of each sample combination in the second segmented compensation sample group subset as the dependent and independent variables of the second segmented compensation function bound to the second segmented compensation sample group subset, the term coefficients of the first segmented compensation function and / or the second segmented compensation function are obtained by curve fitting.

[0035] As a preferred embodiment, in step B3, the method for classifying the remaining sample combinations after filtering in step A3 is as follows:

[0036] The sample combinations in which the y-value of the first fitting function is greater than the y-value of the second fitting function are added to the first segmented compensation sample set; the sample combinations in which the y-value of the first fitting function is less than or equal to the y-value of the second fitting function are added to the second segmented compensation sample set.

[0037] The second unit influence in step B5 is: the ratio of the absolute value of the difference between the y-value of each sample combination in the first segmented compensation sample group subset and the scene real crack shape feature value of the sample combination in the second fitting function to the melting point difference of the sample combination.

[0038] The deviation of the first crack shape feature value in step B5 is: the absolute value of the difference between the scene real crack shape feature value of the sample combination with the second unit influence in the first segmented compensation sample group subset and the y value in the first fitting function;

[0039] The first unit influence in step B5 is: the ratio of the absolute value of the difference between the y-value of each sample combination in the second segmented compensation sample group subset in the first fitting function and the scene real crack shape feature value of the sample combination, to the difference in the thermal expansion coefficient of the sample combination.

[0040] The deviation of the second crack shape feature value in step B5 is: the absolute value of the difference between the scene's true crack shape feature value of the sample combination with the first unit influence in the second segmented compensation sample group subset and the y value in the second fitting function.

[0041] Preferably, in step S13, the method for obtaining the corresponding piecewise compensation function for the cladding combination is as follows:

[0042] Determine whether the y-value of the cladding combination in the first piecewise compensation function associated with the first influence amount is greater than the y-value of the cladding combination in the second piecewise compensation function associated with the second influence amount.

[0043] If so, then the first piecewise compensation function is used as the obtained piecewise compensation function;

[0044] If not, then the second piecewise compensation function is used as the obtained piecewise compensation function.

[0045] Preferably, in step S13, the method for calculating the comprehensive influence quantity associated with the cladding combination is as follows:

[0046] The first average value of the scene real crack shape feature value of each sample combination in the first segmented compensation sample group subset bound to the first interval segment into which the first influence quantity of the cladding combination falls is calculated. The difference in the thermal expansion coefficient of the cladding combination is used as the independent variable of the constructed first fitting function, and the y value of the first fitting function is solved. Then, the absolute value of the difference between the first average value and the y value of the solved first fitting function is used as the independent variable of the first segmented compensation function, and the y value of the first segmented compensation function is solved as the first comprehensive influence quantity associated with the cladding combination.

[0047] The second average value of the scene real crack shape feature value of each sample combination in the second segmented compensation sample group subset bound to the second interval segment into which the second influence quantity of the cladding combination falls is calculated. The melting point difference of the cladding combination is used as the independent variable of the constructed second fitting function, and the y value of the second fitting function is solved. Then, the absolute value of the difference between the second average value and the solved y value of the second fitting function is used as the independent variable of the second segmented compensation function, and the y value of the second segmented compensation function is solved as the second comprehensive influence quantity associated with the cladding combination.

[0048] The predicted value of the scene's true crack shape features in step S2 is: the first comprehensive influence value, the first sum of the y-value of the cladding combination in the first fitting function and the initial feature value of the scene's experimental crack shape, and / or the second comprehensive influence value, the second sum of the y-value of the cladding combination in the second fitting function and the initial feature value of the scene's experimental crack shape;

[0049] The first type associated with the first sum is bound to a first laser parameter adjustment set that has the ability to resist changing the initial feature value of the crack shape in the scene experiment to the first sum; the second type associated with the second sum is bound to a second laser parameter adjustment set that has the ability to resist changing the initial feature value of the crack shape in the scene experiment to the second sum.

[0050] In step S3, the corresponding first laser parameter adjustment set and / or second laser parameter adjustment set are matched according to the type and magnitude of the first sum and / or the second sum. Then, the laser parameter values ​​of the same type are updated by comparing the parameter values ​​of each laser parameter in the first laser parameter adjustment set or the second laser parameter adjustment set, or the parameter values ​​of the common laser parameters in the first laser parameter adjustment set and the second laser parameter adjustment set with the parameter values ​​of the common laser parameters that have the smallest change in the parameter values ​​of the same type of laser cladding experimental parameters.

[0051] The present invention has the following beneficial effects:

[0052] 1. By establishing a mapping relationship between the coefficient of thermal expansion, melting point, and different life stages of the cladding material and substrate, the coefficient of thermal expansion and melting point of the cladding material and substrate can be directly read after identifying the current life stage, thus realizing non-destructive testing of the coefficient of thermal expansion and melting point of the cladding material and substrate at different life stages.

[0053] 2. The fluctuations of the first curve fitted by the first fitting function and the second curve fitted by the second fitting function reflect the changes in the characteristic of "the greater the difference in thermal expansion coefficient and melting point, the easier it is to generate cracks" by sample combinations of the same type but at different life stages under the same scenario factors. This makes the first and second curves better characterize the influence of sample combinations with different thermal expansion coefficients and / or melting points at different life stages on the initial characteristics of the scene experimental crack shape formed in the experimental environment with the same scenario factors. That is, it considers the mutual influence between scenario factors and the characteristic of "the greater the difference in thermal expansion coefficient and melting point, the easier it is to generate cracks" on the change in the initial characteristics of the scene experimental crack shape formed in the experimental environment without considering the difference in thermal expansion coefficient and melting point at different life stages. This makes the comprehensive influence calculated in step S13 more accurate, which is conducive to improving the accuracy of subsequent laser cladding parameter adjustments and thus greatly improving the quality of laser cladding.

[0054] 3. Step A3 filters out invalid shape samples that further alter the initial characteristic value of the scene experiment crack shape caused by sample combinations at different life stages under the same scene factors. This makes the constructed univariate high-order function more accurately characterize the degree of influence of each sample combination at different life stages on changing the characteristic value of the scene experiment crack shape, and quantifies this degree of influence. This makes it possible to control and adjust the process parameters of laser cladding based on the feedback adjustment of these quantified data.

[0055] 4. By calculating the comprehensive influence of the cladding combination in step S1, the prediction of the actual crack shape characteristics of the scene expected to be generated by laser cladding of the cladding combination based on the laser cladding experimental parameters is realized. In step S3, the corresponding first laser parameter adjustment set and / or second laser parameter adjustment set are matched according to the type and magnitude of the predicted actual crack shape characteristics of the scene for the cladding combination. Then, the laser parameter values ​​of the same type are updated with the smaller change value of each laser parameter value in the first laser parameter adjustment set or the second laser parameter adjustment set, or the common laser parameter in the first laser parameter adjustment set and the second laser parameter adjustment set. This realizes the rapid and accurate adjustment of the laser cladding experimental parameter values ​​that can resist the predicted actual crack shape characteristics of the scene.

[0056] 5. After calculating the first and second influence quantities of the cladding combination, the piecewise compensation function corresponding to the cladding combination is obtained. The y-value obtained by solving the piecewise compensation function is used as the comprehensive influence quantity required for step S2 to predict the predicted value of the actual crack shape characteristics of the scene to be generated by the laser cladding combination under the laser cladding experimental parameters. When calculating the comprehensive influence quantity, it is only necessary to calculate the absolute value of the difference between the first average value of the cladding combination and the y-value in the first fitting function, or the absolute value of the difference between the second average value of the cladding combination and the y-value in the second fitting function, as the independent variable and substitute it into the obtained piecewise compensation function. This realizes the rapid calculation of the comprehensive influence quantity required in step S2. The piecewise compensation function is associated with the corresponding influence quantity value interval segment. The fine-grained characterization of the piecewise compensation function represents the different changes in the initial characteristic value of the crack shape of the scene experiment by different comprehensive influence quantities, making the calculated comprehensive influence quantity more accurate. This is conducive to improving the response speed and accuracy of subsequent updates and adjustments to the laser cladding experimental parameters, thereby improving the quality of laser cladding. Attached Figure Description

[0057] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0058] Figure 1 This is a diagram illustrating the implementation steps of the laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point differences provided in this embodiment of the invention. Detailed Implementation

[0059] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0060] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0061] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0062] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating a connection between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0063] This invention provides a laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point differences, such as... Figure 1 As shown, the steps include:

[0064] S1, obtain the difference in thermal expansion coefficient and melting point between the cladding material and the substrate in the current life stage, and calculate the comprehensive influence of the comprehensive difference in thermal expansion coefficient and melting point on the initial characteristic value of the scene experimental crack shape formed under the experimental environment of the current scene factors (ignoring the difference in thermal expansion coefficient and melting point) of the cladding assembly.

[0065] The cladding assembly consists of a cladding material and a substrate. For example, the cladding material may be yttrium-stabilized zirconia (YSZ), and the substrate may be Ni. The current lifespan stage of the cladding material and the substrate is identified using existing methods, and since the methods for identifying the current lifespan stage of the cladding material and the substrate are not within the scope of the claims made in this application, they are not specifically described here.

[0066] After identifying the current lifespan stage of the cladding material and the substrate, the thermal expansion coefficient and melting point of the cladding material and the substrate at the current lifespan stage are obtained directly by looking up a table through a mapping relationship between the lifespan stage and the thermal expansion coefficient and melting point. Then, the difference in thermal expansion coefficient and the difference in melting point between the two are calculated. The difference in thermal expansion coefficient is the absolute value of the difference between the thermal expansion coefficient of the cladding material and the thermal expansion coefficient of the substrate, and the difference in melting point is the absolute value of the difference between the melting point of the cladding material and the melting point of the substrate.

[0067] Currently, the methods for calculating the coefficient of thermal expansion and melting point of cladding materials and substrates are complex and lack accuracy. For example, existing methods for calculating the coefficient of thermal expansion include the expansion method, X-ray diffraction method, laser interferometry, and double-line method. These methods are either highly accurate but costly, or inexpensive but inaccurate, and none can achieve non-destructive detection of the coefficient of thermal expansion and melting point of cladding materials and substrates. Therefore, this application establishes a mapping relationship between the coefficient of thermal expansion, melting point, and the lifespan stages of the cladding material and substrate. After identifying the current lifespan stage, the coefficient of thermal expansion and melting point of the cladding material and substrate can be directly read, achieving non-destructive detection of the coefficient of thermal expansion and melting point of the cladding material and substrate at different lifespan stages.

[0068] After obtaining the difference in thermal expansion coefficient and melting point between the cladding material and the substrate at the current life stage, in step S1, the comprehensive influence of the combined difference in thermal expansion coefficient and melting point on the initial characteristic value of the scene experimental crack shape formed under the experimental environment of changing the scene factors currently present in the cladding combination is calculated by the difference point matching method.

[0069] It should be noted that the current scenario factors of the cladding material do not ignore the influence of differences in thermal expansion coefficients and melting points on the characteristic values ​​of the formed scenario crack shape. However, when forming the initial characteristic values ​​of the scenario crack shape under the experimental environment of this cladding combination with these scenario factors, the differences in thermal expansion coefficients and melting points in these scenario factors are ignored. The method of ignoring is as follows:

[0070] For example, yttrium-stabilized zirconium oxide as the cladding material and Ni as the substrate are considered to be in the initial lifespan stage immediately after leaving the factory or within one month thereafter. For both the cladding material and substrate in the initial lifespan stage, the difference in their coefficients of thermal expansion and melting points can be ignored by default, because before laser cladding, cladding materials and substrates with similar coefficients of thermal expansion and melting points are usually selected to form the cladding combination. Factors that typically ignore differences in coefficients of thermal expansion and melting points include the dimensional characteristics of the cladding material and / or substrate, the cooling characteristics of the molten pool, such as the cooling shrinkage characteristics of the molten pool material and the stress characteristics at both ends of the cladding layer, as explained in the background art.

[0071] However, the differences in thermal expansion coefficients and melting points between the cladding material and the substrate can change significantly at different life stages. Even if these changes are within a controllable range (under constraints), they can still cause significant alterations to the initial characteristic values ​​of the crack shape in the scenario experiment. Therefore, assuming the selected types of cladding material and substrate remain constant, the impact of the differences in thermal expansion coefficients and melting points at different life stages on crack formation cannot be ignored. Thus, it is necessary to quantify the combined impact of the differences in thermal expansion coefficients and melting points on the initial characteristic values ​​of the crack shape in the scenario experiment. This is crucial for making precise parameter adjustments based on quantified data during subsequent adjustments to the cladding parameters, thereby improving cladding quality.

[0072] In this embodiment, the method for calculating the combined influence of the difference in the coefficient of thermal expansion and melting point of the cladding material and the substrate at the current life stage on the initial characteristic value of the experimental crack shape formed under the experimental environment (ignoring the influence of the difference in coefficient of thermal expansion and melting point) of the current scenario factors of the cladding combination specifically includes the following steps:

[0073] S11, the difference in thermal expansion coefficient and melting point between the cladding material and the substrate at the current life stage are used as independent variables and substituted into the first fitting function and the second fitting function respectively to solve for the y values ​​of the first fitting function and the second fitting function.

[0074] In this embodiment, the first fitting function and the second fitting function are preferably univariate high-order equations, and the method for constructing the univariate high-order equations specifically includes the following steps:

[0075] A1. Under the experimental environment of this cladding assembly and the current scenario factors, laser cladding is performed on the experimental material and substrate in the initial stage of their lifespan using laser cladding experimental parameters to obtain the initial characteristic values ​​of the crack shape in the scenario experiment. The laser cladding parameters include laser power, scanning speed, preheating temperature, powder feed rate, and powder feed speed. The experimental values ​​of the laser cladding parameters (laser cladding experimental parameters) can be set, for example, with specified laser power, specified scanning speed, specified preheating temperature, specified powder feed rate, and specified powder feed speed. The specified values ​​of the laser cladding parameters are empirical values, representing the empirical values ​​that minimize the probability of crack formation.

[0076] A2. In a real environment with this scenario factor (the difference in thermal expansion coefficient and melting point cannot be ignored), laser cladding is performed on each sample combination with different life stages using the same laser cladding experimental parameters to obtain the characteristic value of crack shape change associated with each sample combination in the scenario experiment.

[0077] It is important to clarify that "different lifetime stages" for each sample combination means that at least one of the cladding sample materials and the sample substrate in each sample combination is currently in a different lifetime stage. For example, the same type of cladding sample materials in two sample combinations are currently in the same lifetime stage, but the same type of sample substrates are currently in different lifetime stages; or the same type of cladding sample materials in two sample combinations are currently in different lifetime stages, but the same type of sample substrates are currently in the same lifetime stage; or both the cladding sample materials and the sample substrates in two sample combinations are currently in different lifetime stages. Furthermore, the cladding experimental material, the cladding sample material, and the cladding material constituting the cladding combination are of the same type, such as yttrium-stabilized zirconia; and the experimental substrate, the sample substrate, and the substrate constituting the cladding combination are also of the same type, such as Ni.

[0078] A3. Compare the similarity between the feature values ​​of the crack shape change in each scenario obtained in step A2 and the initial feature values ​​of the crack shape in the scenario obtained in step A1, so as to filter out the feature values ​​of the crack shape change in the scenario that have a similarity less than the similarity threshold.

[0079] It should be noted that the differences in thermal expansion coefficients and melting points at different life stages have a relatively minor impact on the initial characteristic values ​​of the scene experimental crack shape formed by the same type of cladding material and substrate under the same experimental environment with the same laser cladding experimental parameters. Theoretically, the change in the scene experimental crack shape characteristic value should not differ significantly from the initial characteristic value. Therefore, step A3 filters out invalid shape samples, allowing the constructed univariate high-order function to more accurately characterize the degree of influence of various sample combinations at different life stages on the change in the scene experimental crack shape characteristic value.

[0080] It should also be noted that the initial feature value of the crack shape in the scene experiment is a numerical representation of the initially formed crack shape; the change feature value of the crack shape in the scene experiment is a numerical representation of the changed crack shape. For example, the shape of the crack can be represented by parameters such as the crack length, width, and bending angle. To facilitate calculation, this embodiment converts the crack shape features expressed in image form into feature values ​​that represent the shape numerically. There are many such conversion methods available. The core is to establish a conversion relationship between the numerical value and the shape. Since the conversion process is not within the scope of the claims of this application, it will not be described in detail.

[0081] Similarly, in step A3, there are many methods to compare the similarity between the feature value of the change in the shape of the crack in the scene experiment and the initial feature value of the crack shape in the scene experiment. For example, the absolute value of the difference between the two feature values ​​can be calculated. If the absolute value of the difference is greater than the preset absolute value threshold, it is determined that the two are not similar, and then the feature value of the change in the shape of the crack in the scene experiment is filtered out.

[0082] After completing the filtering in step A3, the method for constructing a univariate higher-order function proceeds to the next step:

[0083] A4. Classify the remaining sample combinations after filtering in step A3 to obtain fitting sample combinations for fitting the first curve and the second curve, respectively. The specific classification method is as follows:

[0084] The sample combinations whose absolute difference in thermal expansion coefficients is less than a first difference threshold are classified as the first fitted sample combination, and the first fitted sample combination is used to construct the second fitted function; the sample combinations whose absolute difference in melting point is less than a second difference threshold are classified as the second fitted sample combination, and the second fitted sample combination is used to construct the first fitted function.

[0085] For example, suppose the remaining sample combinations after filtering include combinations c1, c2, c3, and c4, where the differences in thermal expansion coefficients and melting points between the cladding sample material and the sample substrate in combination c1 are assumed to be t1 and m1, respectively; and the differences in thermal expansion coefficients and melting points between the cladding sample material and the sample substrate in combination c2 are assumed to be t2 and m2, respectively. Furthermore, the absolute value of the difference between t1 and t2 is less than a first difference threshold. Then, combinations c1 and c2 are classified as first fitting sample combinations for constructing a second fitting function and added to the first fitting sample combination set. Similarly, suppose the differences in melting points between the cladding sample material and the sample substrate in combinations c3 and c4 are m3 and m4, respectively. Furthermore, the absolute value of the difference between m3 and m4 is less than a second difference threshold. Then, combinations c3 and c4 are classified as second fitting sample combinations for constructing a first fitting function and added to the second fitting sample combination set. To improve the feature distinguishability among the first fitting samples in the first fitting sample combination set, preferably, the absolute value of the difference in melting point differences between each pair of first fitting sample combinations is greater than the second difference threshold. Similarly, in order to improve the feature differentiation between each second fitted sample in the second fitted sample combination, preferably, the absolute value of the difference in the coefficient of thermal expansion between each pair of the second fitted sample combinations is greater than the first difference threshold.

[0086] A5, fit the first curve or the second curve with the corresponding combination of fitted samples, and solve for the term coefficients of the first fitted function associated with the first curve and the term coefficients of the second fitted function associated with the second curve;

[0087] Specifically, the method for solving the coefficients of the second fitted function is as follows:

[0088] The characteristic value of the crack shape change in the scenario experiment associated with each first fitting sample combination is used as the dependent variable of the second fitting function, and the difference in melting point between the cladding sample material and the sample substrate in the corresponding first fitting sample combination that forms the characteristic value of the crack shape change in the scenario experiment is used as the independent variable. The coefficients of the terms of the second fitting function are calculated in reverse, thereby completing the construction of the second fitting function.

[0089] The method for solving the coefficients of the first fitted function is as follows:

[0090] The characteristic value of the crack shape change in the scenario experiment associated with each second fitting sample combination is used as the dependent variable of the first fitting function. The difference in the coefficient of thermal expansion between the cladding material and the sample substrate in the corresponding second fitting sample combination that forms the characteristic value of the crack shape change in the scenario experiment is used as the independent variable. The term coefficients of the first fitting function are then calculated in reverse, thereby completing the construction of the first fitting function.

[0091] It should be noted here that the fluctuations of the first curve fitted by the first fitting function and the second curve fitted by the second fitting function reflect the changing characteristics of the feature "the greater the difference in thermal expansion coefficient and melting point, the easier it is to generate cracks" when sample combinations of the same type but at different life stages under the same scenario factors. That is, when the type of scenario factors and / or sample combination changes, the fluctuations of the first and second curves correspondingly change the characteristic of "the greater the difference in thermal expansion coefficient and melting point, the easier it is to generate cracks." This makes the first and second curves better characterize the characteristics of the same type of cladding material and substrate but at different life stages, with varying thermal expansion coefficients. The influence of various sample combinations of differences in coefficient of thermal expansion and / or melting point on the initial characteristics of the crack shape formed in an experimental environment with the same scene factors is considered. That is, the interaction between scene factors and the characteristic that "the greater the difference in coefficient of thermal expansion and melting point, the easier it is to generate cracks" is considered. This is to change the initial characteristics of the crack shape formed in an experimental environment with the same scene factors without considering the differences in coefficient of thermal expansion and melting point at different life stages. This makes the comprehensive influence calculated in step S13 more accurate, which is conducive to improving the accuracy of subsequent laser cladding parameter adjustments and thus greatly improving the quality of laser cladding.

[0092] In step S11, considering the differences in thermal expansion coefficients and melting points between the cladding material and the substrate at the current life stage, the y-values ​​of the first and second fitting functions are obtained. This yields the characteristic values ​​of how the current differences in thermal expansion coefficients and melting points affect the initial characteristic values ​​of the crack shape in the experimental scenario. Then, in step S1, the method for calculating the comprehensive influence of the combined differences in thermal expansion coefficients and melting points on changing the initial characteristic values ​​of the crack shape formed under the experimental environment of the current scenario factors of the cladding material is transferred to the following step:

[0093] S12, calculate the absolute value of the difference between the y-value of the first fitting function and the initial characteristic value of the crack shape in the scenario experiment, as the first influence of the difference in the thermal expansion coefficient of the current life stage on changing the initial characteristic value of the crack shape in the scenario experiment; calculate the absolute value of the difference between the y-value of the second fitting function and the initial characteristic value of the crack shape in the scenario experiment, as the second influence of the difference in the melting point of the current life stage on changing the initial characteristic value of the crack shape in the scenario experiment.

[0094] S13, obtain the piecewise compensation function corresponding to the cladding combination with the first and second influence quantities, and use the y value obtained by solving the obtained piecewise compensation function as the comprehensive influence quantity of the comprehensive difference between the thermal expansion coefficient and the melting point on the initial characteristic value of the crack shape in the scene experiment.

[0095] In this embodiment, the piecewise compensation function is preferably a quadratic function, and the method for constructing the piecewise compensation function includes the following steps:

[0096] B1. Obtain the first and second influence values ​​of each sample combination. Use the maximum value of each first influence value as the upper limit of the interval and the minimum value as the lower limit of the interval to obtain the numerical range of the first influence value. Use the maximum value of each second influence value as the upper limit of the interval and the minimum value as the lower limit of the interval to obtain the numerical range of the second influence value.

[0097] For example, suppose that in a combination of n samples, the minimum value of the first influence is minc2 and the maximum value is maxc8, then the range of the first influence is [minc2, maxc8]. Similarly, suppose that in a combination of n samples, the minimum value of the second influence is minc5 and the maximum value is maxc29, then the range of the second influence is [minc5, maxc29].

[0098] B2, the numerical ranges of the first and second influence quantities are divided into several interval segments by corresponding numerical intervals;

[0099] For example, assuming the numerical range of the first influence quantity is divided into 10 interval segments, the corresponding numerical intervals are: Assuming the numerical range of the second influencing factor is divided into 8 segments, the corresponding numerical intervals are:

[0100]

[0101] B3. Classify the remaining sample combinations after filtering in step A3 to obtain the first segmented compensation sample group set and the second segmented compensation sample group set.

[0102] In step B3, the method for classifying the remaining sample combinations after filtering in step A3 is as follows:

[0103] The sample groups whose y-values ​​of the first fitting function are greater than those of the second fitting function are added to the first segmented compensation sample group set; the sample groups whose y-values ​​of the first fitting function are less than or equal to those of the second fitting function are added to the second segmented compensation sample group set.

[0104] For example, for sample combination c1, if the difference in thermal expansion coefficients between the cladding sample material and the sample substrate in c1 is substituted into the first fitting function and the resulting y value is greater than the y value obtained by substituting the difference in melting points between the cladding sample material and the sample substrate in c1 into the second fitting function, then sample combination c1 is added to the first segmented compensation sample group set; otherwise, it is added to the second segmented compensation sample group set.

[0105] B4, each sample combination in the first segmented compensation sample group set is aggregated into the first segmented compensation sample group subset bound to the first interval segment in which the first influence quantity of the sample combination falls, and each sample combination in the second segmented compensation sample group set is aggregated into the second segmented compensation sample group subset bound to the second interval segment in which the second influence quantity of the sample combination falls.

[0106] Taking the aggregation of the first segment of the compensated sample group as an example, the subset aggregation method is explained:

[0107] For example, for sample combination c1 in the first segmented compensation sample group set, assume that the first influence quantity associated with c1 falls into the category represented as If the first interval segment is bound to the first segment compensation sample group subset numbered "001", then the sample combination c1 is added to the first segment compensation sample group subset numbered "001".

[0108] B5, using the second unit influence and the first crack shape characteristic value deviation of each sample combination in the first segmented compensation sample group subset as the dependent and independent variables of the first segmented compensation function bound to the first segmented compensation sample group subset, and using the first unit influence and the second crack shape characteristic value deviation of each sample combination in the second segmented compensation sample group subset as the dependent and independent variables of the second segmented compensation function bound to the second segmented compensation sample group subset, the term coefficients of the first segmented compensation function and / or the second segmented compensation function are obtained by curve fitting.

[0109] The second unit influence is: the ratio of the absolute value of the difference between the y-value of each sample combination in the second fitting function and the scene real crack shape feature value of the sample combination in the first segmented compensation sample group subset, to the melting point difference of the sample combination.

[0110] For example, suppose the first segmented compensation sample subset contains sample combinations c1, c2, c3, ..., cn, where n is the number of sample combinations in the first segmented compensation sample subset. The melting point difference c1dm of sample combination c1 has a y-value of c1b2 in the second fitting function, and the thermal expansion coefficient difference c1dt has a y-value of c1b1 in the first fitting function. The crack shape characteristic value (defined as the true crack shape characteristic value of the scene) formed by sample combination c1 under the aforementioned scene factors is assumed to be v1. Then, the second unit influence of sample combination c1 is:

[0111] The first crack shape feature value deviation is: the absolute value of the difference between the scene's true crack shape feature value and the y-value in the first fitting function of the sample combination with the second unit influence in the first segmented compensation sample subset. For example, the sample combination c1 in the first segmented compensation sample subset mentioned above has a second unit influence of... Furthermore, the actual crack shape feature value of the sample combination c1 is v1, and the difference in thermal expansion coefficient of the sample combination c1 in the first fitting function is y-value c1b1. Therefore, the deviation of the first crack shape feature value is |c1b1-v1|.

[0112] The second unit influence of the sample combination c1 mentioned above. As the dependent variable of the first piecewise compensation function, the deviation of the first crack shape characteristic value |c1b1-v1| is used as the independent variable of the first piecewise compensation function. At the same time, the data points consisting of all sample combinations in the subset of the first piecewise compensation sample group, including sample combination c1, are fitted to form the first piecewise compensation curve. Then, the coefficients of the first piecewise compensation function are calculated by back-calculating based on the first piecewise compensation curve, thereby completing the construction of the first piecewise compensation function in step B5.

[0113] The method for constructing the second segmented compensation function corresponding to the second segmented compensation sample subset is the same as the method for constructing the first segmented compensation function, so it will not be described again.

[0114] As can be seen from steps B1-B5, in step S13, there are two piecewise compensation functions obtained based on the first and second influence quantities of the cladding combination. These are the first piecewise compensation function associated with the first interval segment into which the first influence quantity of the cladding combination falls, and the second piecewise compensation function associated with the second interval segment into which the second influence quantity falls. Therefore, in step S13, there are two comprehensive influence quantities, using the y-value of the piecewise compensation function as the combined influence quantity of the difference in thermal expansion coefficient and melting point of the cladding combination on changing the initial characteristic value of the crack shape in the scenario experiment.

[0115] The following is a detailed explanation of the method for calculating the comprehensive impact of the cladding combination in step S13:

[0116] The first average value of the scene real crack shape feature value of each sample combination in the first segmented compensation sample group subset bound to the first interval segment into which the first influence quantity of the cladding combination falls is calculated. The difference in the thermal expansion coefficient of the cladding combination is used as the independent variable of the constructed first fitting function. The y value of the first fitting function is solved. Then, the absolute value of the difference between the first average value and the y value of the solved first fitting function is used as the independent variable of the first segmented compensation function. The y value of the first segmented compensation function is solved as the first comprehensive influence quantity associated with the cladding combination.

[0117] For example, the first segmented compensation sample subset bound to the first interval segment where the first influence of the cladding combination falls includes sample combinations c1, c2, and c3. Let the actual crack shape feature values ​​of sample combinations c1, c2, and c3 be denoted as v1, v2, and v3, respectively. Then the first average value is... Assuming the difference in thermal expansion coefficients of the cladding assembly is represented by t1, then t1 is substituted as the independent variable into the constructed first fitting function to solve for the y-value of the first fitting function, and then... The absolute value of the difference between the y-value and the first fitting function is the independent variable of the first piecewise compensation function associated with the first piecewise compensation sample group subset. The y-value of the first piecewise compensation function is solved as the first comprehensive influence of the cladding combination.

[0118] The solution method for the second comprehensive influence of this cladding combination is as follows:

[0119] The second average value of the scene real crack shape feature value of each sample combination in the second segmented compensation sample group subset bound to the second interval segment into which the second influence quantity of the cladding combination falls is calculated. The melting point difference of the cladding combination is used as the independent variable of the constructed second fitting function, and the y value of the second fitting function is solved. Then, the absolute value of the difference between the second average value and the y value of the solved second fitting function is used as the independent variable of the second segmented compensation function associated with the second segmented compensation sample group subset, and the y value of the second segmented compensation function is solved as the second comprehensive influence quantity associated with the cladding combination.

[0120] Preferably, in this embodiment, the y-value of the piecewise compensation function with a larger y-value is used as the comprehensive influence quantity for predicting the actual crack shape characteristics of the cladding combination in the scenario in step S2 below. The larger y-value among the two piecewise compensation functions represents the maximum change in crack shape characteristics of the y-value of the first fitting function or the second fitting function under the above-mentioned scenario factors by laser cladding with laser cladding experimental parameters for the cladding combination at the current life stage. This means that in step S3 below, it is more necessary to adjust the laser cladding experimental parameters to resist the larger y-value of the piecewise compensation function, so as to reduce the probability of the deviation of the first crack shape characteristic value or the second crack shape characteristic value represented by the larger y-value. Therefore, in this embodiment, the y-value of the piecewise compensation function with a larger y-value is preferably used as the comprehensive influence quantity.

[0121] However, in reality, assuming the y-value of the first piecewise compensation function is greater than the y-value of the second piecewise compensation function, for the same cladding combination, there is a certain probability that either a deviation in the first crack shape characteristic value or a deviation in the second crack shape characteristic value will occur when cladding the combination with the laser cladding experimental parameters. Since the y-values ​​of the first and second piecewise compensation functions are both predicted values, theoretically, one can choose to adjust the laser cladding parameters (such as laser power, laser cladding speed, etc.) that can resist the deviation in the first crack shape characteristic value represented by the y-value of the first piecewise compensation function, or one can choose to adjust the laser cladding parameters (such as powder feed rate, powder feed speed, etc.) that can resist the deviation in the second crack shape characteristic value represented by the y-value of the second piecewise compensation function, or one can choose to adjust the laser cladding parameters (such as laser power, laser cladding parameters, powder feed rate, powder feed speed, etc.) that can resist the deviations in the first and second crack shape characteristic values ​​represented by the y-values ​​of the first and second piecewise compensation functions, respectively. Therefore, after calculating the combined influence of the thermal expansion coefficient and melting point difference of the cladding combination on the initial characteristic value of the crack shape in the scenario experiment through the above step S1, the laser cladding experiment parameters are adjusted by any one of the following three strategies, and then the cladding combination is laser cladding is started.

[0122] The three adjustment strategies are as follows:

[0123] After calculating the comprehensive influence of the cladding combination on the initial characteristic value of the crack shape in the scene experiment through step S1, the process is first transferred to... Figure 1 The steps shown are as follows:

[0124] S2, based on the comprehensive impact calculated in step S1, predict the actual crack shape characteristics of the scene expected to be generated by the laser cladding combination under the laser cladding experimental parameters.

[0125] S3. Based on the type and size of the predicted value of the actual crack shape characteristics in the scene predicted in step S2, the laser cladding experimental parameters are adjusted using the corresponding strategy, and then the laser cladding combination is started.

[0126] The prediction method in step S2 is as follows:

[0127] The first comprehensive influence value, the sum of the y-value of the cladding combination in the first fitting function and the initial feature value of the crack shape in the scene experiment (defined as the first sum value), and / or the second comprehensive influence value, the sum of the y-value of the cladding combination in the second fitting function and the initial feature value of the crack shape in the scene experiment (defined as the second sum value) are calculated as the predicted value of the scene real crack shape feature of the cladding combination.

[0128] The first sum is associated with a first type, and the second sum is associated with a second type. The first type is bound to a first laser parameter adjustment set that has the ability to resist changing the initial characteristic values ​​of the scene experiment crack shape to the first sum; the second type is bound to a second laser parameter adjustment set that has the ability to resist changing the initial characteristic values ​​of the scene experiment crack shape to the second sum.

[0129] For example, for a cladding assembly using yttrium-stabilized zirconium oxide as the cladding material and Ni as the substrate, under the scenario of "cooling and shrinking of the molten pool material, high stress at both ends of the cladding layer, and maximum tensile stress in the X direction at the bonding layer between the substrate and the YSZ coating," laser cladding is to be performed using experimental parameters determined by empirical values ​​summarized from repeated experiments. It is assumed that the laser cladding experimental parameters include laser power, scanning speed, preheating temperature, powder feed rate, and powder feed speed, each with corresponding empirical initial parameter values.

[0130] After step S2 predicts the predicted value of the actual crack shape feature of the scene to be generated by laser cladding of the cladding combination with the laser cladding experimental parameters, if the predicted value of the actual crack shape feature corresponds to the first sum value, then the first laser parameter adjustment set associated with the first sum value is matched. If the predicted value of the actual crack shape feature corresponds to the second sum value, then the second laser parameter adjustment set associated with the second sum value is matched.

[0131] For example, if the first sum is assumed to be v11, and the initial characteristic value of the crack shape in the scenario experiment is assumed to be v0, then the resistance to changing v0 to v11 is v11-v0. Therefore, the amount of change of each laser cladding parameter value in the first laser parameter adjustment set relative to the empirical initial parameter value of the same type of experimental parameter in the laser cladding experiment parameters can resist the occurrence of v11-v0. For example, the laser cladding experiment parameters include laser power p1, scanning speed p2, preheating temperature p3, powder feeding amount p4, and powder feeding speed p5, and the parameter values ​​of experimental parameters p1, p2, p3, p4, and p5 are represented as vp1, vp2, vp3, vp4, and vp5, respectively. Assuming that adjusting the laser power from vp1 to vp11 and the scanning speed from vp2 to vp22 is sufficient to resist the resistance of v11-v0, then the laser cladding parameter values ​​in the first laser parameter adjustment set are as follows: the parameter value of laser power is vp11, the parameter value of scanning speed is vp22, the parameter value of preheating temperature is maintained at vp3, the parameter value of powder feeding amount is maintained at vp4, and the parameter value of powder feeding speed is maintained at vp5.

[0132] It should be noted that the ability of each parameter in the first laser parameter adjustment set to resist changes in v11-v0 compared to the empirical initial parameter values ​​of similar experimental parameters is derived from repeated experiments. For example, it can also be obtained through a curve fitting function and prediction. For instance, for each combination of cladding samples predicted to undergo v11-v0 changes at a corresponding lifespan stage using laser cladding experimental parameters, one of the laser cladding experimental parameters is extracted as the parameter to be adjusted, while the values ​​of other parameters remain unchanged. Using the parameter value of each adjustment to the extracted parameter as the independent variable, and the actual crack shape characteristics of the cladding sample combination within a specified time under the adjusted parameter value as the dependent variable, a quadratic function is fitted. The parameter value corresponding to the valley value in the fitted curve represented by this quadratic function is taken as the parameter value capable of resisting changes in v11-v0. Using the same method, the corresponding parameter values ​​capable of resisting changes in v11-v0 for each parameter in the laser cladding experimental parameters are obtained. Since the calculation method for the ability of the parameter values ​​in the first laser parameter adjustment set to resist changes in v11-v0 compared with the empirical initial parameter values ​​of similar experimental parameters is not within the scope of the rights claimed in this application, it will not be specifically explained.

[0133] The specific setting methods for each parameter value in the second laser parameter adjustment set are the same as those in the first laser parameter adjustment set, and will not be repeated here.

[0134] Additionally, it should be noted that after step S2 predicts the actual crack shape characteristics of two scenarios for the same cladding combination using the first comprehensive influence amount and the second comprehensive influence amount respectively, the parameter values ​​of the common laser parameters in the first laser parameter adjustment set and the second laser parameter adjustment set are compared with the parameter values ​​of the common laser parameters of the same type of laser cladding experiment parameters, and the parameter values ​​of the common laser parameters with the smallest change are updated for the same type of laser cladding experiment parameters.

[0135] For example, the first laser cladding parameter adjustment set includes laser power, scanning speed, and powder feeding amount; the second laser cladding parameter adjustment set includes scanning speed, powder feeding amount, and powder feeding speed. Assuming that the absolute value of the difference between the scanning speed in the first laser cladding parameter adjustment set and the scanning speed in the laser cladding experimental parameters is smaller than the absolute value of the difference between the scanning speed in the second laser cladding parameter adjustment set and the scanning speed in the laser cladding experimental parameters, then the scanning speed in the laser cladding experimental parameters is updated using the scanning speed in the first laser cladding parameter adjustment set. Similarly, assuming that the absolute value of the difference between the powder feeding amount in the first laser cladding parameter adjustment set and the powder feeding amount in the laser cladding experimental parameters is larger than the absolute value of the difference between the powder feeding amount in the second laser cladding parameter adjustment set and the powder feeding amount in the laser cladding experimental parameters, then the powder feeding amount in the laser cladding experimental parameters is updated using the powder feeding amount in the second laser cladding parameter adjustment set. The parameters of the same type of laser cladding experiment are updated with the parameter values ​​of the common laser parameters with the smallest change, so that the laser cladding process is smoother and the probability of crack formation is reduced.

[0136] In summary, this application, through the comprehensive influence quantity calculated in step S1 for the cladding combination, achieves the prediction of the actual crack shape characteristic value of the scene expected to be generated by laser cladding of the cladding combination based on the laser cladding experimental parameters. In step S3, based on the type and magnitude of the predicted actual crack shape characteristic value of the scene for the cladding combination, a corresponding first laser parameter adjustment set and / or second laser parameter adjustment set are matched. Then, the laser parameter values ​​of the same type are updated with the smaller change value among the laser parameter values ​​in the first laser parameter adjustment set or the second laser parameter adjustment set, or the common laser parameters in the first laser parameter adjustment set and the second laser parameter adjustment set. This achieves rapid and accurate adjustment of the laser cladding experimental parameter values ​​that can resist the predicted actual crack shape characteristic value of the scene.

[0137] It should be stated that the above-described specific embodiments are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art should understand that various modifications, equivalent substitutions, and variations can be made to the present invention. However, such variations, as long as they do not depart from the spirit of the present invention, should be within the scope of protection of the present invention. Furthermore, some terminology used in this specification and claims is not limiting, but merely for ease of description.

Claims

1. A laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference, characterized in that, Including the following steps: S1, obtain the difference in thermal expansion coefficient and melting point between the cladding material and the substrate constituting the cladding assembly at the current life stage, and calculate the comprehensive influence of the comprehensive difference in thermal expansion coefficient and melting point on the initial characteristic value of the scene experimental crack shape formed under the experimental environment of changing the scene factors currently present in the cladding assembly through the difference point matching method. S2, based on the comprehensive influence calculated in step S1, predict the actual crack shape characteristics of the scene expected to be generated by the laser cladding combination based on the laser cladding experimental parameters. S3, based on the type and size of the predicted value of the actual crack shape characteristics of the scene predicted in step S2, after adjusting the laser cladding experimental parameters with the corresponding strategy, laser cladding is started on the cladding combination; Step S1, the method for calculating the combined influence of the combined difference between the thermal expansion coefficient and the melting point on the initial characteristic value of the scene experimental crack shape formed under the experimental environment of the scene factors currently present in the cladding combination, includes the following steps: S11, the difference in thermal expansion coefficient and the difference in melting point between the cladding material and the substrate at the current life stage are substituted into the first fitting function and the second fitting function respectively as independent variables, and the y values ​​of the first fitting function and the second fitting function are solved. S12, calculate the absolute value of the difference between the y-value of the first fitting function and the initial characteristic value of the crack shape in the scenario experiment, as the first influence of the difference in the coefficient of thermal expansion in the current life stage on changing the initial characteristic value of the crack shape in the scenario experiment; calculate the absolute value of the difference between the y-value of the second fitting function and the initial characteristic value of the crack shape in the scenario experiment, as the second influence of the difference in the melting point in the current life stage on changing the initial characteristic value of the crack shape in the scenario experiment. S13, obtain the piecewise compensation function corresponding to the cladding combination having the first influence amount and the second influence amount, and use the y value obtained by solving the obtained piecewise compensation function as the comprehensive influence amount of the comprehensive difference on changing the initial characteristic value of the crack shape in the scenario experiment; The first fitting function and / or the second fitting function are univariate higher-order functions, and the method for constructing the univariate higher-order function includes the following steps: A1, in the experimental environment where the cladding combination currently has the aforementioned scenario factors, laser cladding is performed on the cladding experimental material and experimental substrate in the initial stage of life using the aforementioned laser cladding experimental parameters to obtain the initial characteristic value of the scenario experimental crack shape. A2, In the same real environment with the aforementioned scenario factors, laser cladding is performed on each sample combination with different life stages using the same laser cladding experimental parameters to obtain the scenario experimental crack shape change characteristic value associated with each sample combination. The lifespan stages of at least one of the cladding sample material and sample substrate in each of the aforementioned sample combinations are different; A3, compare the similarity between the feature values ​​of the crack shape change in each scenario experiment and the initial feature values ​​of the crack shape in the scenario experiment, so as to filter out the feature values ​​of the crack shape change in the scenario experiment with similarity less than the similarity threshold. A4. Classify the remaining sample combinations after filtering in step A3 to obtain fitting sample combinations for fitting the first curve and the second curve, respectively. A5, fit the first curve or the second curve with the corresponding combination of fitting samples to solve for the term coefficients of the first fitting function associated with the first curve and the term coefficients of the second fitting function associated with the second curve. The cladding experimental material and the cladding sample material are of the same type as the cladding material; the experimental substrate and the sample substrate are of the same type as the substrate.

2. The laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference as described in claim 1, characterized in that, In step A4, the method for classifying the remaining sample combinations after filtering in step A3 is as follows: Each sample combination whose absolute value of the difference in thermal expansion coefficient is less than a first difference threshold is classified as a first fitted sample combination, and the first fitted sample combination is used to construct the second fitted function; each sample combination whose absolute value of the difference in melting point is less than a second difference threshold is classified as a second fitted sample combination, and the second fitted sample combination is used to construct the first fitted function. The absolute value of the difference in melting point between any two pairs of the first fitted sample combinations is greater than the second difference threshold; the absolute value of the difference in thermal expansion coefficient between any two pairs of the second fitted sample combinations is greater than the first difference threshold.

3. The laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference as described in claim 2, characterized in that, In step A5, the method for solving the coefficients of the second fitted function is as follows: The characteristic value of the crack shape change in the scenario experiment associated with each of the first fitting sample combinations is used as the dependent variable of the second fitting function, and the difference in melting point between the cladding sample material and the sample substrate in the first fitting sample combination that forms the characteristic value of the crack shape change in the scenario experiment is used as the independent variable. The coefficients of the second fitting function are then calculated in reverse. The method for solving the term coefficients of the first fitted function is as follows: Using the characteristic value of the change in crack shape in the scenario experiment associated with each of the second fitted sample combinations as the dependent variable of the first fitted function, and using the difference in the coefficient of thermal expansion between the cladding sample material and the sample substrate in the corresponding second fitted sample combination that forms the characteristic value of the change in crack shape in the scenario experiment as the independent variable, the term coefficients of the first fitted function are calculated by reverse deduction.

4. The laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference as described in claim 1, characterized in that, The piecewise compensation function in step S13 is a quadratic function in one variable. The method for constructing the piecewise compensation function includes the following steps: B1. Obtain the first influence quantity and the second influence quantity of each sample combination. Use the maximum value of each first influence quantity as the upper limit of the interval and the minimum value as the lower limit of the interval to obtain the first influence quantity value interval. Use the maximum value of each second influence quantity as the upper limit of the interval and the minimum value as the lower limit of the interval to obtain the second influence quantity value interval. B2, the first influence value interval and the second influence value interval are divided into several interval segments according to their respective corresponding numerical intervals; B3. Classify the remaining sample combinations after filtering in step A3 to obtain the first segmented compensation sample group set and the second segmented compensation sample group set. B4, each sample combination in the first segmented compensation sample group set is aggregated into the first segmented compensation sample group subset bound to the first interval segment into which the first influence quantity of the sample combination falls, and each sample combination in the second segmented compensation sample group set is aggregated into the second segmented compensation sample group subset bound to the second interval segment into which the second influence quantity of the sample combination falls. B5, using the second unit influence and the first crack shape characteristic value deviation of each sample combination in the first segmented compensation sample group subset as the dependent and independent variables of the first segmented compensation function bound to the first segmented compensation sample group subset, and using the first unit influence and the second crack shape characteristic value deviation of each sample combination in the second segmented compensation sample group subset as the dependent and independent variables of the second segmented compensation function bound to the second segmented compensation sample group subset, the term coefficients of the first segmented compensation function and / or the second segmented compensation function are obtained by curve fitting.

5. The laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference according to claim 4, characterized in that, In step B3, the method for classifying the remaining sample combinations after filtering in step A3 is as follows: The sample combinations in which the y-value of the first fitting function is greater than the y-value of the second fitting function are added to the first segmented compensation sample set; the sample combinations in which the y-value of the first fitting function is less than or equal to the y-value of the second fitting function are added to the second segmented compensation sample set. The second unit influence in step B5 is: the ratio of the absolute value of the difference between the y-value of each sample combination in the first segmented compensation sample group subset and the scene real crack shape feature value of the sample combination in the second fitting function to the melting point difference of the sample combination. The deviation of the first crack shape feature value in step B5 is: the absolute value of the difference between the scene real crack shape feature value of the sample combination with the second unit influence in the first segmented compensation sample group subset and the y value in the first fitting function; The first unit influence in step B5 is: the ratio of the absolute value of the difference between the y-value of each sample combination in the second segmented compensation sample group subset in the first fitting function and the scene real crack shape feature value of the sample combination, to the difference in the thermal expansion coefficient of the sample combination. The deviation of the second crack shape feature value in step B5 is: the absolute value of the difference between the scene's true crack shape feature value of the sample combination with the first unit influence in the second segmented compensation sample group subset and the y value in the second fitting function.

6. The laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference as described in claim 4, characterized in that, In step S13, the method for obtaining the corresponding piecewise compensation function for the cladding combination is as follows: Determine whether the y-value of the cladding combination in the first piecewise compensation function associated with the first influence amount is greater than the y-value of the cladding combination in the second piecewise compensation function associated with the second influence amount. If so, then the first piecewise compensation function is used as the obtained piecewise compensation function; If not, then the second piecewise compensation function is used as the obtained piecewise compensation function.

7. The laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference as described in claim 4, characterized in that, In step S13, the method for calculating the comprehensive impact quantity associated with the cladding combination is as follows: The first average value of the scene real crack shape feature value of each sample combination in the first segmented compensation sample group subset bound to the first interval segment into which the first influence quantity of the cladding combination falls is calculated. The difference in the thermal expansion coefficient of the cladding combination is used as the independent variable of the constructed first fitting function, and the y value of the first fitting function is solved. Then, the absolute value of the difference between the first average value and the y value of the solved first fitting function is used as the independent variable of the first segmented compensation function, and the y value of the first segmented compensation function is solved as the first comprehensive influence quantity associated with the cladding combination. The second average value of the scene real crack shape feature value of each sample combination in the second segmented compensation sample group subset bound to the second interval segment into which the second influence quantity of the cladding combination falls is calculated. The melting point difference of the cladding combination is used as the independent variable of the constructed second fitting function, and the y value of the second fitting function is solved. Then, the absolute value of the difference between the second average value and the solved y value of the second fitting function is used as the independent variable of the second segmented compensation function, and the y value of the second segmented compensation function is solved as the second comprehensive influence quantity associated with the cladding combination.

8. The laser cladding method based on feedback adjustment under the constraints of thermal expansion and melting point difference according to claim 4, characterized in that, The predicted value of the scene's true crack shape features in step S2 is: the first comprehensive influence value, the first sum of the y-value of the cladding combination in the first fitting function and the initial feature value of the scene's experimental crack shape, and / or the second comprehensive influence value, the second sum of the y-value of the cladding combination in the second fitting function and the initial feature value of the scene's experimental crack shape; The first type associated with the first sum is bound to a first laser parameter adjustment set that has the ability to resist changing the initial feature value of the crack shape in the scene experiment to the first sum; the second type associated with the second sum is bound to a second laser parameter adjustment set that has the ability to resist changing the initial feature value of the crack shape in the scene experiment to the second sum. In step S3, the corresponding first laser parameter adjustment set and / or second laser parameter adjustment set are matched according to the type and magnitude of the first sum and / or the second sum. Then, the laser parameter values ​​of the same type are updated by comparing the parameter values ​​of each laser parameter in the first laser parameter adjustment set or the second laser parameter adjustment set, or the parameter values ​​of the common laser parameters in the first laser parameter adjustment set and the second laser parameter adjustment set with the parameter values ​​of the common laser parameters that have the smallest change in the parameter values ​​of the same type of laser cladding experimental parameters.

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