A method for characterizing full-field mechanical property dispersion of a turbine blade thermal barrier coating

Abstract

The application discloses a kind of turbine blade thermal barrier coating full-field mechanical property dispersity characterization method, including the pretreatment of turbine blade thermal barrier coating sample;Obtain the mechanical property data of turbine blade thermal barrier coating sample, and mechanical property data include: thermal barrier coating section porosity, thermal barrier coating thickness, thermal barrier coating section density, thermal barrier coating elastic modulus and thermal barrier coating hardness;Mechanical property data is imported into Matlab, and based on two-dimensional interpolation method or linear interpolation method, the three-dimensional model of turbine blade thermal barrier coating is established, to characterize the overall mechanical property of turbine blade thermal barrier coating and the mechanical property of local area position.The three-dimensional model of turbine blade thermal barrier coating is established by Matlab, and two-dimensional interpolation or linear interpolation method is used, combined with contour line, so that the mechanical property dispersity of turbine blade thermal barrier coating whole or local area can be well characterized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material micro-nano processing and characterization, and particularly relates to a method for characterizing full-field mechanical property dispersion of a turbine blade thermal barrier coating. BACKGROUND

[0002] Thermal barrier coatings (TBCs) are ceramic coatings with excellent high-temperature oxidation resistance and very low thermal conductivity, which are deposited on the surface of high-temperature-resistant metals or superalloys through a bonding layer, can effectively reduce the service temperature of the protected substrate, reduce the thermal shock load, reduce the demand for cooling air, and improve the thermal efficiency of the device, and are widely used in aerospace, chemical industry, metallurgy and energy fields.

[0003] The service life of thermal barrier coatings has always been a key research content in the research of thermal barrier coatings. Since the mechanical properties and service environment of turbine blade thermal barrier coatings are dispersed, the service life is also dispersed, that is, the service life of some positions of the blade is the short board of the service life of the blade. The existing research also lacks reliable characterization of the full-field mechanical property dispersion of turbine blade thermal barrier coatings.

[0004] In the prior art, Weibull distribution is used to characterize the full-field mechanical property dispersion of turbine blade thermal barrier coatings, and the Weibull cumulative distribution probability is:

[0005] P i =1-[-(X i X0) m ]

[0006] Wherein, P i represents the cumulative distribution probability; i represents the serial number; X0 represents the intrinsic value of Weibull distribution of a certain property; m represents the Weibull modulus, the larger m is, the smaller the dispersion of the test results is; X i represents the i-th value in ascending order.

[0007] The Weibull cumulative distribution probability can be rewritten as:

[0008] ln ln[1 / (1-P i )]=m ln X i -m ln X0

[0009] Take ln ln[1 / (1-P i )] as the y-axis, and ln H iFor x axis, -m ln H0 is the intercept, the formula is a linear function expression, the slope of the function expression is the modulus m of Weibull distribution, therefore, the size parameter X0 of linear fitting Weibull distribution can be obtained by using the measured X value, the N values measured by experiment are arranged in the order from small to large, and the probability that the value is not higher than the i-th value (X)i is P i , P i is:

[0010] P i = i / (N+1)

[0011] In the formula, N is the capacity of the sample, and the equation can be obtained by combining the above formula:

[0012]

[0013] Through linear regression analysis, m and X0 are obtained by least square method.

[0014] The defects of the above Weibull distribution: only the overall dispersion of the mechanical properties of the thermal barrier coating on the turbine blade can be analyzed and presented, and the dispersion and variation trend of the mechanical properties of a local area at different positions of the thermal barrier coating cannot be analyzed and presented. Most importantly, the dispersion of the mechanical properties of the thermal barrier coating obtained by using the Weibull distribution is independent of the size of the thermal barrier coating, that is, when the dispersion of the mechanical properties of the thermal barrier coating is characterized, the size of the thermal barrier coating cannot be considered, which leads to the conclusion that the dispersion of the mechanical properties of the thermal barrier coating of turbine blades of different sizes is basically the same when the Weibull distribution is used to analyze the dispersion of the mechanical properties of the thermal barrier coating. But in fact, the mechanical properties of the thermal barrier coating on the turbine blade with larger size change less, that is, when the same size area is taken for Weibull distribution analysis, the conclusion that the dispersion of the mechanical properties of the thermal barrier coating on the turbine blade with larger size is smaller is obtained, which brings great inconvenience to the characterization of the dispersion of the thermal barrier coating.

[0015] In summary, the dispersion characterization of the full-field mechanical properties of the thermal barrier coating of the turbine blade in the prior art has the following problems: the dispersion of the mechanical properties of a local area at different positions of the thermal barrier coating cannot be analyzed and presented; the dispersion of the performance obtained by characterization is not related to the size of the sample. SUMMARY

[0016] The present application is aimed at providing a method for characterizing the dispersion of the full-field mechanical properties of a turbine blade thermal barrier coating, which can characterize the dispersion of the mechanical properties of the whole or local area of the turbine blade thermal barrier coating well by establishing a three-dimensional model of the turbine blade thermal barrier coating through Matlab, using two-dimensional interpolation or linear interpolation method, and combining with contour lines.

[0017] The object of the present application is achieved by the following technical solutions:

[0018] A method for characterizing the dispersion of the full-field mechanical properties of a turbine blade thermal barrier coating, comprising the following steps:

[0019] S1. Pre-treating a turbine blade thermal barrier coating sample, comprising:

[0020] S11. Cutting the turbine blade thermal barrier coating to obtain a plurality of cross-section samples;

[0021] S12. Embedding the cross-section samples to obtain solidified cross-section samples;

[0022] S13. Polishing the solidified cross-section samples;

[0023] S14. Ultrasonic cleaning and blow-drying the polished cross-section samples;

[0024] S2. Obtaining mechanical property data of the turbine blade thermal barrier coating sample, which includes: thermal barrier coating cross-section porosity, thermal barrier coating thickness, thermal barrier coating cross-section density, thermal barrier coating elastic modulus and thermal barrier coating hardness;

[0025] The thermal barrier coating elastic modulus and thermal barrier coating hardness of the turbine blade thermal barrier coating sample are obtained according to the following formula:

[0026] M=M0exp(-BP) (1)

[0027] 1=P+D (2)

[0028] M=M0(e B ) D-1 (3)

[0029] E eq =E0(e B ) D-1 (4)

[0030] H=H0(e B ) D-1(5)

[0031] wherein M and M0 represent the elastic modulus and the hardness respectively, P represents the porosity, D represents the density, and M0 and B are both constants;

[0032] S3, importing the mechanical property data obtained in the above step into Matlab, and establishing a three-dimensional model of the turbine blade thermal barrier coating based on a two-dimensional interpolation method or a linear interpolation method to represent the overall mechanical property and the mechanical property of the local area position of the turbine blade thermal barrier coating, including:

[0033] importing the two-dimensional position coordinates of the turbine blade thermal barrier coating in Matalab;

[0034] selecting n points on the turbine blade thermal barrier coating, and performing position assignment on the coordinates of the n points;

[0035] sorting the n points, and importing the mechanical property data;

[0036] adopting the two-dimensional interpolation method or the linear interpolation method to perform interpolation, and dividing the Z-axis range;

[0037] constructing a three-dimensional surface graph of the turbine blade thermal barrier coating according to the two-dimensional position coordinates and the Z-axis range to obtain a three-dimensional model.

[0038] In the present application:

[0039] Further, step S11 is to fix the prepared turbine blade thermal barrier coating sample on a linear cutting machine, and cut a plurality of cross-section samples.

[0040] Further, step S12 is to use epoxy resin glue to perform sample inlaying treatment on the cross-section sample to obtain a cured cross-section sample, specifically, placing the cross-section sample with the cross-section downward into a mold; then mixing and stirring the epoxy resin A glue and B glue in a weight ratio of 2:1 uniformly, and pouring into the mold; finally, placing the mold into a 60℃ incubator for incubation for 50 min, so that the sample inlaying glue is cured.

[0041] Further, step S13 is to fix the cured cross-section sample on a sample grinder, and perform grinding and polishing treatment on the cross-section of the cross-section sample, specifically, using 180-mesh, 300-mesh, 600-mesh and 1200-mesh water sandpaper to grind the cross-section sample in sequence, and the grinding time is 5 min; then using the same force, using 7μm, 2.5μm, 1μm and 0.5μm diamond polishing powder to polish the cross-section sample in sequence, and the polishing time is 5 min, until the surface of the cross-section sample is smooth and has no obvious scratches.

[0042] Further, step S14 is to put the polished cross-section sample into a beaker containing alcohol, and put the beaker into an ultrasonic cleaning instrument to clean the cross-section sample, the cleaning time is 5 minutes, and the surface of the cross-section sample is blown dry by a hair dryer after cleaning.

[0043] Further, the two-dimensional position coordinates of the turbine blade thermal barrier coating introduced in the Matalab in the step S3 include: when the two-dimensional interpolation method is used, the introduced two-dimensional position coordinates start from the second original coordinate, and simultaneously serve as the last position coordinate, and the remaining position coordinates become the n-1th in turn; or when the linear interpolation is used, the two-dimensional position coordinates introduced correspond to the original number of coordinates.

[0044] Further, the n points selected on the turbine blade thermal barrier coating and the position assignment of the coordinates of the n points in the step S3 include: when the two-dimensional interpolation method is used, the first point is assigned twice, and serves as the position 1 and the position n+1 respectively, and the remaining points are assigned once; when the linear interpolation method is used, the coordinates of the n points are assigned in turn, and the assignment is performed n times.

[0045] Further, the three-dimensional curved surface graph of the turbine blade thermal barrier coating is constructed according to the two-dimensional position coordinates and the Z-axis range in the step S3, and a three-dimensional model is obtained, which includes: constructing a curved surface graph in the Matalab according to the two-dimensional position coordinates and the Z-axis range; the grid lines in the Matalab are closed, and the background is set to white; a color table is introduced, and the contour lines are drawn, and the mechanical properties of the turbine blade thermal barrier coating are represented by the change of color and the width of the contour lines.

[0046] Compared with the prior art, the present application has the following advantages:

[0047] 1. The turbine blade thermal barrier coating full-field mechanical property dispersion characterization method can well characterize the mechanical property dispersion of the turbine blade thermal barrier coating as a whole or in each local region by establishing a three-dimensional model of the turbine blade thermal barrier coating by using the Matalab and using the two-dimensional interpolation method or the linear interpolation method.

[0048] 2. The turbine blade thermal barrier coating full-field mechanical property dispersion characterization method can clearly know the mechanical property dispersion degree of each position on the turbine blade thermal barrier coating by simultaneously combining the contour lines and analyzing the density of the contour lines, because the width of the contour line represents the change rate of the performance, that is, the wider the contour line size, the lower the data change rate of the position.

[0049] The method can associate the dispersion of the mechanical properties of the turbine blade thermal barrier coating with the size, and even if the overall dispersion is the same for different sizes of the blade, the mechanical dispersion of the same area size can be analyzed; and even if the mechanical dispersion of the same area size is the same for different sizes of the blade, the overall dispersion can be analyzed according to the model and contour line.

[0050] 3, The method for characterizing the dispersion of the full-field mechanical properties of the turbine blade thermal barrier coating can clearly and clearly characterize the dispersion of the full-field mechanical properties of the turbine blade thermal barrier coating from the whole to the local, and the distribution of the mechanical properties of the turbine blade thermal barrier coating and the change of the mechanical properties with the position can be clearly and clearly seen.

[0051] The dispersion and change trend of the mechanical properties of a local area at different positions on the thermal barrier coating can be clearly seen.

[0052] The dispersion of the performance obtained by characterization is associated with the size of the sample, and can be used to analyze thermal barrier coating blades of different sizes and compare the dispersion thereof. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 is a graph of blade profile measurement points in the embodiment of the present application.

[0054] Figure 2 is a graph of thermal barrier coating cross-sectional porosity, thickness, and density in the embodiment of the present application.

[0055] Figure 3 is a graph of thermal barrier coating Young's modulus data fitting in the embodiment of the present application.

[0056] Figure 4 is a graph of thermal barrier coating hardness value data fitting in the embodiment of the present application.

[0057] Figure 5 is a graph of the three-dimensional model of the mechanical property dispersion of the thermal barrier coating in the embodiment of the present application. DETAILED DESCRIPTION

[0058] To make the purpose, technical scheme and advantages of the present application clearer and more intelligible, the present application will be further described in detail below with reference to the specific embodiments and the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of well-known structures and techniques is omitted to avoid unnecessary confusion of the concept of the present application.

[0059] The present application will be described in detail below with reference to the accompanying drawings and embodiments.

[0060] Figure 1 is a graph of blade profile measurement points.

[0061] Embodiment:

[0062] A method for characterizing the full-field mechanical property dispersion of a turbine blade thermal barrier coating, comprising the following steps:

[0063] Step S1: pretreating the turbine blade thermal barrier coating sample;

[0064] Step S2: obtaining the thermal barrier coating cross-sectional porosity, thermal barrier coating thickness, thermal barrier coating cross-sectional density, thermal barrier coating elastic modulus, and thermal barrier coating hardness of the turbine blade thermal barrier coating sample;

[0065] Step S3: establishing a three-dimensional model of the turbine blade thermal barrier coating using Matlab to characterize the overall mechanical properties and the mechanical properties of the local area position of the turbine blade thermal barrier coating;

[0066] In the step S1, the turbine blade thermal barrier coating sample is fixed on a linear cutting machine, and a plurality of cross-section samples are cut.

[0067] Step S11: fixing the prepared turbine blade thermal barrier coating sample on a linear cutting machine and cutting a plurality of cross-section samples;

[0068] Step S12: embedding the cross-section samples using epoxy resin glue to obtain the cured cross-section samples;

[0069] Specifically, the cross-section of the cross-section sample is placed downward into a mold; then the epoxy resin A glue and B glue are mixed and stirred uniformly at a weight ratio of 2:1, and then poured into the mold; finally, the mold is placed in a 60℃ incubator for 50min to allow the embedding glue to cure;

[0070] Step S13: fixing the cured cross-section sample on a sample grinder and grinding and polishing the cross-section of the cross-section sample;

[0071] Specifically, the cross-section sample is ground with 180-mesh, 300-mesh, 600-mesh, and 1200-mesh water sandpaper in sequence, and the grinding time is 5 minutes; then the cross-section sample is polished with 7μm, 2.5μm, 1μm, and 0.5μm diamond polishing powder in sequence with the same force, and the polishing time is 5 minutes, until the surface of the cross-section sample is smooth without obvious scratches;

[0072] Step S14: placing the cross-section sample obtained after grinding and polishing into a beaker containing alcohol, and placing the beaker into an ultrasonic cleaning instrument to clean the cross-section sample, and the cleaning time is 5 minutes, and then the surface is blown dry with a hair dryer after cleaning;

[0073] Step S2 includes:

[0074] Step S21: obtaining the two-dimensional coordinates of the cross-section of the pretreated cross-section sample through a scanner;

[0075] Step S22: measuring the thermal barrier coating cross-section porosity and the thermal barrier coating thickness of the cross-section sample;

[0076] Specifically, when measuring the thermal barrier coating thickness of the cross-section sample, the thermal barrier coating thickness and the bond coating thickness at multiple points of the cross-section sample are directly measured by using SEM (scanning electron microscope);

[0077] When measuring the thermal barrier coating cross-section porosity at multiple points of the cross-section sample, the thermal barrier coating cross-section morphology of the cross-section sample is observed by using SEM combined with BSE (electron back scattered diffraction) detector to obtain an image representing chemical composition by gray scale change; then the obtained digital micrograph is analyzed on Matrox-II program, different values are set on the micrograph of the thermal barrier coating according to different gray scales, and the black area (i.e. the porosity area) existing in the thermal barrier coating is marked according to different numerical values, and the porosity of the thermal barrier coating is calculated according to the proportion of the black area in the whole thermal barrier coating structure;

[0078] Figure 2 the graph of the thermal barrier coating cross-section porosity, thickness and density;

[0079] Step S23: determining the thermal barrier coating elastic modulus and the thermal barrier coating hardness;

[0080] Specifically, first, the Vickers indenter is calibrated, the cross-section sample after pretreatment is fixed on the sample table, a smooth area on the surface of the cross-section sample is selected, and then the Vickers indenter is used to perform indentation test on the cross-section sample after pretreatment to obtain experimental data required for calculating the thermal barrier coating elastic modulus and the thermal barrier coating hardness;

[0081] The experimental data required for calculating the thermal barrier coating elastic modulus and the thermal barrier coating hardness include: the indenter area on the cross-section sample during indentation test, the load increment, the increment of indentation depth in the range of 60-95% of the maximum load after unloading, the Poisson's ratio of the coating, the Young's modulus of the indenter, the Poisson's ratio of the indenter, the maximum load, and the depth value corresponding to the maximum load;

[0082] In order to ensure the accuracy of the data, six different positions are selected on the cross section for indentation experiment, five indentation points are selected at each position, and the spacing of each indentation point should be appropriate (at least 5 times the indentation size above), so as not to affect each other; The indentation process includes: loading, holding and unloading, the whole indentation process adopts constant loading rate, the loading and unloading rate is 10mN / s, and the peak load is set to 8mN; The loading, holding and unloading time is 10s, 5s and 10s respectively;

[0083] Finally, the experimental data is substituted into the following formula to calculate the elastic modulus of the thermal barrier coating and the hardness of the thermal barrier coating;

[0084]

[0085] In the above formula, A is the area of the indenter, dP is the load increment, and dh is the increment of the indentation depth in the range of 60-95% of the maximum load after loading and unloading;

[0086]

[0087] In the above formula, E c is the Young's modulus of the coating, v c is the Poisson's ratio of the coating, E i and v i are the Young's modulus and Poisson's ratio of the indenter respectively;

[0088]

[0089] In the above formula, P max is the maximum load, and h is the depth corresponding to the maximum load;

[0090] According to the above three formulas, the elastic modulus of the thermal barrier coating and the hardness of the thermal barrier coating can be calculated;

[0091] Since the cross section sample is polished after being polished, the columnar crystals are damaged, and the elastic modulus and hardness of the thermal barrier coating are directly measured by using the nanoindentation method, which will cause inaccurate experimental results, and the error range of multiple measurements is too large; Therefore, the elastic modulus of the thermal barrier coating and the hardness of the thermal barrier coating are determined by the following method:

[0092] The expression of the elastic modulus of the thermal barrier coating and the hardness of the thermal barrier coating is as follows:

[0093] M=M0exp(-BP) (1)

[0094] In formula (1), M and M0 represent the Young's modulus and hardness of the dense material and the porous material respectively, and P represents the porosity;

[0095] According to the following formula:

[0096] 1 = P + D (2)

[0097] D represents the density, so combined with equation (1) and equation (2) can be written as:

[0098] M = M0(e B ) D-1 (3)

[0099] In equation (3), e B > 1, 0 < D < 1, only the composition and phase structure of the material can affect the values of B and M0, and the APS coating and the EB-PVD YSZ coating are both t' phase in ideal case, so M0 and B in equation (3) above are both constants; the value of M0 can be determined by the exhaustion method, that is, by multi-point fitting through nanoindentation method, so that M0 and e B in the selected coating can be determined; therefore we only need to measure the value of the density D in equation (3) above to obtain the Young's modulus and hardness of the corresponding point;

[0100] The Young's modulus and hardness are respectively written as:

[0101] E eq = E0(e B ) D-1 (4)

[0102] H = H0(e B ) D-1 (5)

[0103] Determination of E0 and H0: using the data obtained in the experiment, the Young's modulus value and the hardness value are fitted respectively;

[0104] Specifically, five-point fitting of the Young's modulus, the determination coefficient is 0.9842, E0 = 251.1, e B = 5.261; five-point fitting of the hardness, the determination coefficient is 0.9688, H0 = 10.71, e B = 5.344; the porosity measured in step S22 is combined with equation (3) to obtain the density D;

[0105] Figure 3 The fitting graph of the Young's modulus data of the thermal barrier coating;

[0106] Step S3 comprises:

[0107] Step S31: importing the two-dimensional position coordinates of the turbine blade thermal barrier coating in Matalab;

[0108] Step S32: assigning the position to the coordinates of the n points measured in step S2;

[0109] Step S33: sorting the n points measured and importing the mechanical property data;

[0110] Step S34: Perform interpolation using two-dimensional interpolation or linear interpolation, and divide the Z-axis range;

[0111] Step S35: Construct a three-dimensional surface diagram of the thermal barrier coating of the turbine blade based on the two-dimensional position coordinates and the Z-axis range. At the same time, adjust the format, import the color table, set the viewpoint, and obtain a complete three-dimensional model.

[0112] Specifically, in step S31, if the subsequent step S34 uses two-dimensional interpolation, the imported position coordinates start from the second of the original coordinates and are used as the last position coordinates, while the remaining position coordinates become the (n-1)th coordinates in sequence.

[0113] If the subsequent step S34 uses linear interpolation, the imported position coordinates correspond to the original number of coordinates.

[0114] In step S32, if the subsequent step S34 uses two-dimensional interpolation, in order for the surfaces to coincide, the first point is assigned twice, as position 1 and position n+1 respectively, so it is assigned a total of n+1 times.

[0115] If the subsequent step S34 uses linear interpolation, the coordinates of the n points are assigned sequentially, for a total of n assignments;

[0116] In step S33, sorting all measurement points on the sample cross-section includes the following steps:

[0117] Specifically, when using linear interpolation:

[0118] kx = zeros(7,1);

[0119] for i = 1:40

[0120] if XX(i,1)==x1(1)

[0121] kx(1) = i;

[0122] elseif XX(i,1)==x1(2)

[0123] kx(2) = i;

[0124] elseif XX(i,1)==x1(3)

[0125] kx(3) = i;

[0126] elseif XX(i,1)==x1(4)

[0127] kx(4) = i;

[0128] elseif XX(i,1) == x1(5)

[0129] kx(5) = i;

[0130] elseif XX(i,1) == x1(6)

[0131] kx(6) = i;

[0132] end

[0133] end

[0134] for i = 41:79

[0135] if XX(i,1) == x1(2)

[0136] kx(2) = i;

[0137] elseif XX(i,1) == x1(3)

[0138] kx(3) = i;

[0139] elseif XX(i,1) == x(4)

[0140] kx(4) = i;[[ID=3​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0154] kx(2) = i;

[0155] elseif XX(i,1) == x1(3)

[0156] kx(3) = i;

[0157] elseif XX(i,1) == x1(4)

[0158] kx(4) = i;

[0159] elseif XX(i,1) == x1(5)

[0160] kx(5) = i;

[0161] elseif XX(i,1) == x1(6)

[0162] kx(6) = i;

[0163] end

[0164] end

[0165] ky = zeros(6,1);

[0166] for i = 1:79

[0167] if XX(i,2) == y1(1)

[0168] ky(1) = i;

[0169] elseif XX(i,2) == y1(2)

[0170] ky(2) = i;

[0171] elseif XX(i,2) == y1(3)

[0172] ky(3) = i;

[0173] elseif XX(i,2) == y1(4)

[0174] ky(4) = i;

[0175] elseif XX(i,2) == y1(5)

[0176] ky(5) = i;

[0177] elseif XX(i,2) == y1(6)

[0178] ky(6) = i;

[0179] end

[0180] end

[0181] In step S34, interpolation is performed on one circle of the sample cross section and between the cross sections according to the serial number;

[0182] Two-dimensional interpolation method (cubic spline interpolation, bilinear interpolation) : the x and y axis coordinates of the points on the curved surface are replaced by the arranged serial numbers, so that the entire curved surface is unfolded and flattened, then two-dimensional interpolation is performed, and finally it is restored;

[0183] Linear interpolation: linear interpolation is first performed on the cross section, and then linear interpolation is performed between each cross section;

[0184] The divided Z-axis range includes: setting the height on the Z-axis to 20-70, and dividing it into 79 parts;

[0185] In step S35, a curved surface graph is first constructed in Matlab according to the two-dimensional position coordinates and the Z-axis range, then the grid line display is closed and the background is set to white; finally, the color table is imported, and the change of color is used to represent the change of the mechanical property of the blade thermal barrier coating;

[0186] Figure 4 The graph fitted for the hardness value data of the thermal barrier coating;

[0187] The mechanical property here refers to the density of the blade thermal barrier coating;

[0188] When the change of color is used to represent the mechanical property of the blade thermal barrier coating, contour lines are drawn, and the width of the contour lines represents the change rate of the mechanical property; the wider the contour line size, the lower the data change rate at that position;

[0189] Specifically, the entire data is divided into 256 colors for representation, and the color scale is divided into 17 parts by a black line; the black line is the contour line, and the data range represented by the width of the contour line is ± (maximum value-minimum value) / 512, which means that the wider the contour line size, the lower the data change rate at that position; at the same time, we can clearly and intuitively know the degree of dispersion of the mechanical property at each position by analyzing the density of the contour line; the greater the contour line density, the greater the dispersion;

[0190] At the same time, the format is adjusted, specifically, the color scale is changed to be consistent with the line, and the font size is set; the window size is adjusted; the XY axis coordinate range is set; and the coordinate axis scale is set;

[0191] The viewing angle is set, and in the embodiment of the application, a viewing angle graph from 135° to 30° is set, and finally a complete three-dimensional model is obtained.

[0192] Figure 5 The graph of the three-dimensional model of the dispersion of the mechanical property of the thermal barrier coating.

[0193] Results and Discussion:

[0194] The present application aims to protect a kind of turbine blade thermal barrier coating full-field mechanical property dispersion characterization method, including the pretreatment of turbine blade thermal barrier coating sample;Obtain the mechanical property data of turbine blade thermal barrier coating sample, and mechanical property data includes: thermal barrier coating section porosity, thermal barrier coating thickness, thermal barrier coating section density, thermal barrier coating elastic modulus and thermal barrier coating hardness;Mechanical property data is imported into Matlab, and three-dimensional model of turbine blade thermal barrier coating is established based on two-dimensional interpolation method or linear interpolation method, to characterize the overall mechanical property of turbine blade thermal barrier coating and the mechanical property of local area position.The three-dimensional model of turbine blade thermal barrier coating is established by Matlab, and two-dimensional interpolation or linear interpolation method is used, combined with contour line, so that the mechanical property dispersion of turbine blade thermal barrier coating as a whole or local area can be well characterized.

[0195] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes of the principles of the present application, and do not constitute a limitation of the present application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. In addition, the appended claims of the present application are intended to cover all variations and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.

Claims

1. A method for characterizing the dispersion of the full-field mechanical properties of a thermal barrier coating on turbine blades, characterized in that, Comprising the following steps: S1. Pre-treating the turbine blade thermal barrier coating sample, comprising: S11. Cutting the turbine blade thermal barrier coating to obtain a plurality of cross-section samples; S12. Embedding the cross-section samples to obtain cured cross-section samples; S13. Polishing the cured cross-section samples; S14. Ultrasonic cleaning and blowing dry the polished cross-section samples; S2. Obtaining the mechanical property data of the turbine blade thermal barrier coating sample, the mechanical property data comprising: thermal barrier coating cross-section porosity, thermal barrier coating thickness, thermal barrier coating cross-section density, thermal barrier coating elastic modulus and thermal barrier coating hardness; According to the following formula to obtain the turbine blade thermal barrier coating elastic modulus and thermal barrier coating hardness: （1） （2） （3） （4） （5） where M and respectively represent the elastic modulus and the hardness, P represents the porosity, D represents the density, and B are constants; E eq represents the Young's modulus; H represents the hardness; and Determination: using the data obtained in the experiment, the Young's modulus values and the hardness values are fitted, respectively; S3, the mechanical property data obtained in the above step is imported into Matlab, and a three-dimensional model of the turbine blade thermal barrier coating is established based on two-dimensional interpolation method or linear interpolation method to represent the overall mechanical properties and local area position mechanical properties of the turbine blade thermal barrier coating, comprising: Importing the two-dimensional position coordinates of the turbine blade thermal barrier coating in Matlab; Selecting n points on the turbine blade thermal barrier coating and assigning position values to the coordinates of the n points; Sorting the n points and importing the mechanical property data; Interpolating by two-dimensional interpolation method or linear interpolation method and dividing the Z-axis range; According to the two-dimensional position coordinates and the Z-axis range, a three-dimensional surface graph of the turbine blade thermal barrier coating is constructed to obtain a three-dimensional model.

2. The method of claim 1, wherein the method is characterized in that: Step S11 is to fix the prepared turbine blade thermal barrier coating sample on a linear cutting machine to cut a plurality of cross-section samples.

3. The method of claim 1, wherein the method is characterized in that: Step S12 is to embed the cross-section samples with epoxy resin glue to obtain cured cross-section samples, specifically, the cross-section of the cross-section sample is placed downward into a mold; then the epoxy resin A glue and B glue are mixed and stirred uniformly by weight ratio of 2:1, poured into the mold; finally, the mold is placed in a 60℃ incubator for 50min to allow the embedding glue to cure.

4. The method of claim 1, wherein the method is characterized in that: Step S13 is to fix the cured cross-section sample on a sample grinder to polish and polish the cross-section of the cross-section sample, specifically, 180 mesh, 300 mesh, 600 mesh and 1200 mesh water sandpaper are used in turn to polish the cross-section sample for 5 minutes; then the same force is used to polish the cross-section sample with 7μm, 2.5μm, 1μm and 0.5μm diamond polishing powder in turn for 5 minutes, until the surface of the cross-section sample is smooth without obvious scratches.

5. The method of claim 1, wherein: Step S14 is to place the cross-section sample obtained after polishing into a beaker containing alcohol, and place the beaker in an ultrasonic cleaner to clean the cross-section sample, the cleaning time is 5 minutes, and the surface is blown dry after cleaning.

6. The method of claim 1, wherein: The two-dimensional position coordinates of the turbine blade thermal barrier coating imported in the step S3 include: when the two-dimensional interpolation method is used, the imported two-dimensional position coordinates start from the second original coordinate and are taken as the last position coordinate, and the remaining position coordinates are sequentially taken as the n-1th position coordinate; or when the linear interpolation method is used, the imported two-dimensional position coordinates are taken as the original number of coordinates corresponding to the original coordinates.

7. The method of claim 1, wherein the method is characterized in that: The n points selected on the turbine blade thermal barrier coating and the position assignment of the coordinates of the n points in the step S3 include: when the two-dimensional interpolation method is used, the first point is assigned twice and is taken as the position 1 and the position n+1 respectively, and the remaining points are assigned once; when the linear interpolation method is used, the coordinates of the n points are sequentially assigned, and the assignment is performed n times in total.

8. The method of claim 1, wherein the method is characterized in that: The three-dimensional curved surface graph of the turbine blade thermal barrier coating constructed according to the two-dimensional position coordinates and the Z-axis range in the step S3 to obtain a three-dimensional model includes: constructing a curved surface graph according to the two-dimensional position coordinates and the Z-axis range in Matlab; closing the grid lines in Matlab, setting the background to white; importing a color table and drawing contour lines, and using the change of color and the width of the contour lines to represent the mechanical properties of the turbine blade thermal barrier coating.

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