Method of testing the microstructure of a bulk sample and apparatus for testing the microstructure of a bulk sample

Abstract

The application relates to the technical field of material testing, and provides a method for testing the microstructure of a block sample and a device for testing the microstructure of the block sample. The method for testing the microstructure of the block sample is characterized in that the thickness of each polishing and the flatness of the testing surface of the block sample are accurately controlled by using a gauze for fine polishing and by accurate measurement, and milligram-level micro powder is obtained; the block sample after layered polishing is accurately installed on an XRD tester through a sample frame and a fixing support for testing, the main crystal phase content in the layer of the block sample can be calculated by analyzing XRD testing data, the milligram-level micro powder is tested by using IR, the main organic group content in the layer of the block sample is obtained, and the block sample can be accurately tested in a micron-level layer by using the method, and the micron-level spatial distribution of the main crystal mineral phase and the organic polymer of the block sample can be obtained.

Description

Technical Field

[0001] This invention relates to the field of materials testing technology, and in particular to a method and apparatus for testing the microstructure of bulk samples. Background Technology

[0002] XRD is an abbreviation for X-ray diffraction. XRD testing is a powerful and widely used non-destructive analytical technique, primarily used for phase identification and crystal structure analysis of materials. By analyzing the X-ray diffraction patterns of a material, its internal atomic arrangement can be revealed.

[0003] When X-rays irradiate a crystal, constructive interference occurs between atomic planes when the optical path difference is an integer multiple of the wavelength. By measuring the diffraction intensity at different θ angles, the d-value can be deduced, thus identifying the substance. Powder X-ray diffraction (PXRD) is the most commonly used method. It uses ground polycrystalline or powder samples, employing randomly oriented grains to ensure the Bragg condition is met, generating diffraction cones, and thus obtaining spectra. It is suitable for phase identification, quantitative analysis, etc., and sample preparation is simple. However, for XRD testing of bulk samples, although the principle is the same as PXRD, the uneven surface of bulk samples can lead to peak shifts and intensity distortion, resulting in high precision requirements for grinding bulk samples.

[0004] The principle of testing block samples using XRD technology is the same as that of testing powder samples, but the specific test methods differ significantly. Testing block samples using XRD technology generally involves using a precision cutting machine (such as a low-speed saw or wire cutting machine) to obtain appropriately sized small pieces from a large sample; then, the pieces are successively polished using metallographic sandpaper of progressively finer grits (e.g., from 400 grit to 2000 grit), followed by polishing and surface cleaning.

[0005] However, for large-sized (50*50*10mm or 50*50*15mm) block samples requiring μm-level layered grinding and the collection of mg-level micropowder for other tests, the conventional method of grinding with metallographic sandpaper (e.g., from 60 to 2000 grit) is unsuitable. With 60-400 grit sandpaper, the thickness achieved in a single grinding operation is too large or cannot be precisely controlled, making micron-level, precise layered grinding and testing impossible. While 400-2000 grit sandpaper can perform micron-level layered grinding, the resulting micropowder adheres to the sandpaper. Methods such as tapping, alcohol washing, ultrasonic vibration, and liquid nitrogen freezing cannot collect the milligram-level micropowder adhering to the sandpaper. Therefore, the milligram-level micropowder required for IR testing cannot be obtained, making it impossible to simultaneously test the content of crystalline phases and organic groups in the same sample and the same micron-level structural layer.

[0006] When performing μm-level stratification tests on large-sized (50*50*10mm or 50*50*15mm) block samples, the current methods for fixing block samples are not suitable in order to ensure that the surface of the block sample is aligned with the reference plane of the sample stage. Summary of the Invention

[0007] This application aims to at least solve one of the technical problems existing in the related art. To this end, this application proposes a method for testing the microstructure of bulk samples. Using the method of this application, the bulk sample can be polished in micron-level layers. XRD and IR tests can be performed on the polished bulk sample and the micro powder, respectively, to obtain the micron-level spatial distribution of the main crystalline mineral phases and organic polymers of the bulk sample.

[0008] This application also proposes a device for measuring the microstructure of bulk samples.

[0009] A method for testing the microstructure of a block sample according to an embodiment of the first aspect of this application includes the following steps: The block sample was polished in micron-level layers using a mesh screen. The thickness of each polishing and the flatness of the test surface of the block sample were measured using a micrometer and a steel ruler. The milligram-level micro powder produced during polishing was collected. If the grinding thickness and surface flatness of the block sample meet the requirements, the block sample is fixed using a sample frame. The sample frame containing the block sample is mounted on an XRD analyzer using a fixed bracket, and the block sample is subjected to XRD testing and analysis to obtain XRD test data. The milligram-level micro powder obtained by grinding block samples was subjected to IR testing and analysis to obtain IR test data; The mineral phase content in the layer of the block sample is obtained by analyzing the XRD test data, and the organic group content in the layer of the block sample is obtained by analyzing the IR test data.

[0010] The method for testing the microstructure of block samples according to embodiments of this application controls the thickness of each grinding step by using a mesh screen and measures the surface flatness of each grinding step, thereby obtaining block samples with grinding precision down to the micrometer level. Using this block sample for testing effectively increases the accuracy of XRD testing. Furthermore, the mesh screen grinding process also yields milligram-level micropowder. IR analysis of this milligram-level micropowder allows for the determination of the content of major organic groups in that layer of the block sample, thus revealing the micrometer-level spatial distribution of the main crystalline mineral phases and organic polymers. Through the series of measures provided by this invention, simultaneous and accurate testing of the crystalline phase and organic group content in the same sample and the same micrometer-level structural layer is achieved.

[0011] According to one embodiment of this application, the mesh is an 80-mesh to 1000-mesh Al2O3 mesh or SiC mesh.

[0012] According to one embodiment of this application, the process of using a mesh screen to perform micron-level layered grinding of a block sample, measuring the thickness of each grinding step and the flatness of the test surface of the block sample using a micrometer and a steel ruler, and collecting milligram-level micro powder generated during grinding includes: Mark the test direction and the location of the thickness test points on the back of the block sample; lay weighing paper flat on a horizontally placed glass plate, and lay the mesh of the specified mesh size on the weighing paper; polish the test surface of the block sample on the mesh in the specified direction to a specified number of times; use a micrometer to measure the thickness of the thickness test points of the block sample to an accuracy of 1 μm, and record the thickness of each test point; place a steel ruler on the polished surface of the block sample, and compare the surface flatness of the test surface of the block sample with the light, and control the surface flatness and polishing thickness of the test surface of the block sample together with the number of polishing times and the test data of the micrometer. Collect the milligram-level micropowder on the weighing paper and seal it for subsequent IR testing.

[0013] According to one embodiment of this application, the sample frame includes a main panel, an upright panel, stiffening ribs, an end panel, and a cover plate. The end plate is connected to a first end of the upright panel, the main panel is connected to a second end of the upright panel, and the stiffening ribs are connected to the upright panel, the end panel, and the main panel. The cover plate is detachably connected to the end panel.

[0014] According to one embodiment of this application, the step of fixing the block sample using a sample frame includes: Place the polished large-sized block sample with the test surface facing down on a clean glass plate. Remove the cover plate of the sample frame and attach the sample frame to the outer periphery of the block sample on the glass plate, so that the main panel faces down and is close to the designated position of the block sample, and ensure that the main panel (6) and the test surface of the block sample are in the same plane. Use clay strips to fix the sides of the block sample to the sample frame; Fix a strip of modeling clay to the back of the block sample, making the modeling clay strip protrude above the plane of the end plate; use the cover plate to flatten the modeling clay strip until it is flush with the end plate; Secure the cover plate to the end plate using anti-slip screws; Observe the block sample fixed in the sample frame and ensure that the test surface of the block sample is on the same plane as the main panel and is tightly fixed.

[0015] According to one embodiment of this application, the step of mounting the sample frame containing the block sample onto an XRD analyzer and performing testing and analysis on the block sample includes: The mounting bracket is fixedly installed on the crossbeam of the XRD tester; The sample frame containing the block sample is mounted in the sample holder of the XRD tester; The main panel of the sample frame is connected to the fixed bracket using cotton thread of a specified length, wherein the first end of the cotton thread is connected to the connection hole on the main panel, and the second end of the cotton thread is fixedly connected to a pre-set groove on the fixed bracket. The width and depth of the groove are both approximately 1 mm.

[0016] According to one embodiment of this application, the IR testing and analysis of the milligram-level micro powder obtained by grinding the block sample includes: Place a clean agate mortar in an electronic balance with an accuracy of 0.01 mg, and weigh 150 mg of KBr, accurate to 0.01 mg. Place the weighing paper in an electronic balance with an accuracy of 0.01 mg, and weigh 1.5 mg of the milligram-level micro powder obtained from the mesh polishing, accurate to 0.01 mg; The weighed milligram-level micro powder and the weighed KBr are ground together in an agate mortar and ground clockwise for 100 revolutions. The powder is scraped to the center of the mortar with a stainless steel spoon. Then, the powder is ground counterclockwise for 100 revolutions. The powder is scraped to the center of the mortar with a stainless steel spoon. This process is repeated until 1000 revolutions are completed. The ground and mixed powder is evenly spread in the sample preparation container and pressed into an IR test piece; Place the IR test piece in the IR instrument for IR testing.

[0017] According to one embodiment of this application, before performing micron-level layered grinding of the block sample using a mesh screen, measuring the thickness of each grinding step and the flatness of the test surface of the block sample using a micrometer and a steel ruler, and collecting the milligram-level micro powder generated during grinding, the process includes: The extruded polystyrene board is cut to obtain the first strip, and the first strip is used to form the first mold with a specification of 50*50*5mm. The first mold is filled with standard mortar made of reference cement, standard sand and drinking tap water, and then vibrated and cured to form a standard mortar substrate. Extruded polystyrene (XPS) boards are cut to obtain second strips. These second strips are then bonded together to form a second mold with dimensions of 50*50*10mm and 50*50*15mm respectively. Using the 50*50*10mm second mold, a standard mortar substrate and polymer cement slurry are vibrated and molded together to form a large-format 50*50*10mm polymer cement block sample of the standard mortar substrate. Similarly, using the same 50*50*10mm second mold, a 50*50*5mm standard brick is vibrated and molded together with polymer cement slurry to form a large-format 50*50*10mm polymer cement block sample of the standard brick substrate. Finally, the 50*50*15mm second mold is used to vibrate and mold the same 50*50*10mm standard brick with polymer cement slurry to form a large-format 50*50*15mm polymer cement block sample of the standard brick substrate. Standard curing is then performed to form the large-format polymer cement block sample. According to one embodiment of this application, the step of analyzing the XRD test data to obtain the mineral phase content of the blocky sample in the current layer and analyzing the IR test data to obtain the organic group content of the blocky sample in the current layer includes: Integrate the area of ​​the characteristic peak of a typical mineral phase in the curve obtained by the XRD analyzer; compare the integrated value with the integrated area of ​​the corresponding characteristic peak of the same specification block sample of the mineral phase standard to calculate the content of the mineral phase in a certain layer of the block sample. Integrate the area of ​​the characteristic peak of a typical group in the curve obtained by the IR analyzer; compare the obtained integral value with the regression curve of the integral area of ​​the corresponding characteristic peak of the standard organic polymer corresponding to the group, and calculate the content of the organic polymer in a certain layer of the block sample. The mineral phase content and organic group content of each layer of the block sample were analyzed to obtain the micron-scale spatial distribution of the main crystalline mineral phase and organic polymers of the block sample.

[0018] According to the apparatus for testing the microstructure of a bulk sample mentioned in the second aspect of this application, the method for performing the above-described method for testing the microstructure of a bulk sample includes: An XRD analyzer is used to analyze bulk samples and obtain XRD test data. An IR analyzer is used to analyze milligram-level micro powders and obtain IR test data. Extruded polystyrene board mold, used to form polymer cement block samples with substrate; Mesh screen is used to grind blocky samples into layers and obtain milligram-level micro powder; Sample frame, used to support block-shaped samples; A mounting bracket is used to mount the sample frame with the block sample onto the crossbeam of the XRD tester.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram illustrating the steps of a micron-level layering test method using XRD and IR provided in an embodiment of this application.

[0022] Figure 2 This is a schematic diagram of the structure of the first mold cavity and the second mold cavity provided in the embodiments of this application.

[0023] Figure 3 This is the main view of the sample frame provided in the embodiment of this application.

[0024] Figure 4 This is a left view of the sample frame provided in the embodiment of this application.

[0025] Figure 5 This is a top view of the sample frame provided in the embodiments of this application.

[0026] Figure 6 This is a schematic diagram of the T-beam structure provided in the embodiments of this application.

[0027] Figure 7 Spatial distribution diagram of C3S and C4AF in block samples when the base layer is V1 ceramic tile.

[0028] Figure 8 Spatial distribution diagram of C3S and C4AF in block samples when the base layer is a standard mortar substrate.

[0029] Figure 9 Spatial distribution diagram of CH and AFt in block samples when the base layer is V1 ceramic tile.

[0030] Figure 10 Spatial distribution diagram of CH and AFt in block samples when the base layer is a standard mortar substrate.

[0031] Figure 11 Spatial distribution diagram of VAE in block samples when the base layer is V1 ceramic tile.

[0032] Figure 12 Spatial distribution diagram of VAE in block samples when the base layer is a standard mortar substrate.

[0033] Figure label: 1. First XPS strip; 2. Second XPS strip; 3. Third XPS strip; 4. First mold cavity; 5. Second mold cavity; 6. Main panel; 7. Vertical plate; 8. Rib plate; 9. End plate; 10. Cover plate. Detailed Implementation

[0034] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0035] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application 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, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections, wherein a fixed connection can include an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0037] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] XRD is an abbreviation for X-ray diffraction. XRD testing is a widely used non-destructive analytical technique, primarily used for phase identification and crystal structure analysis of materials. By analyzing the X-ray diffraction patterns of a material, its internal atomic arrangement can be revealed.

[0040] The physical basis of XRD testing technology is Bragg's Law: nλ = 2dsinθ, where n is the diffraction order (a positive integer, usually 1); λ is the wavelength of the incident X-rays (known, for example, λ = 0.15406 nm for Kα radiation from a Cu target); d is the interplanar spacing (the value to be solved, representing the interplanar spacing of atoms in the crystal); and θ is the diffraction angle (the angle between the incident / diffracted X-rays and the crystal planes, which can be measured experimentally). When X-rays irradiate a crystal, the regularly arranged atomic planes inside the crystal act like a series of reflective gratings. Only when the optical path difference (2dsinθ) is equal to an integer multiple of the X-ray wavelength will constructive interference (i.e., signal enhancement) occur, thus being received by the detector. By measuring the diffraction intensity at different angles θ, the interplanar spacing d can be deduced. Different substances have characteristic d values, which can be used to identify the type of substance being tested.

[0041] Powder X-ray diffraction (PXRD) is the most commonly used method. Samples are typically polycrystalline or powdered materials ground into fine powder. The numerous randomly oriented small grains ensure that some grains will always satisfy the Bragg condition, thus producing diffraction cones at all possible θ angles. A detector scans these cones to obtain the diffraction pattern. Powder sample preparation is simple, and its applications are very wide, mainly for phase identification, quantitative analysis, and grain size calculation.

[0042] The principle of XRD testing of block samples is the same as that of testing powder samples, but the specific test methods are quite different. XRD testing of block samples generally uses a precision cutting machine (such as a low-speed saw or wire cutting machine) to obtain small pieces of appropriate size from a large sample; then, it is polished with metallographic sandpaper of progressively finer grit (such as from 400 grit to 2000 grit), followed by polishing and surface cleaning.

[0043] However, when performing μm-level layered grinding on large-sized (50*50*10mm or 50*50*15mm) block samples and collecting mg-level samples for subsequent IR and other tests, the conventional method of grinding with metallographic sandpaper (e.g., from 400 grit to 2000 grit) is not suitable. Experiments have shown that fine powder adheres to the metallographic sandpaper, and methods such as tapping, alcohol washing, ultrasonic vibration, and liquid nitrogen freezing cannot collect the mg-level fine powder adhering to the metallographic sandpaper in its entirety.

[0044] When performing μm-level stratification tests on large-sized (50*50*10mm or 50*50*15mm) block samples, the current methods for fixing block samples are not suitable in order to ensure that the surface of the block sample is aligned with the reference plane of the sample stage.

[0045] The following is combined with Figures 1-12 The present invention describes a method and apparatus for testing the microstructure of bulk samples.

[0046] A method for testing the microstructure of a block sample according to an embodiment of the first aspect of this application includes the following steps: The block sample was polished in micron-level layers using a mesh screen. The thickness of each polishing and the flatness of the test surface of the block sample were measured using a micrometer and a steel ruler. The milligram-level micro powder produced during polishing was collected. If the grinding thickness and surface flatness of the block sample meet the requirements, the block sample is fixed by a sample frame. The sample frame containing the block sample is mounted on the XRD analyzer using a fixed bracket, and the block sample is subjected to XRD test analysis to obtain XRD test data. The milligram-level micro powder obtained by grinding block samples was subjected to IR testing and analysis to obtain IR test data; The mineral phase content in this layer of the block sample is obtained by analyzing the XRD test data, and the organic group content in this layer of the block sample is obtained by analyzing the IR test data.

[0047] According to the method for testing the microstructure of block samples according to the embodiments of this application, the thickness of each grinding is controlled by using a mesh, and the surface flatness of each grinding is controlled by measurement, thereby obtaining a block sample with grinding precision at the micrometer level. Using this block sample for testing can effectively increase the accuracy of XRD testing of the block sample. Furthermore, milligram-level micro powder can also be obtained through the grinding of the mesh. Using the milligram-level micro powder obtained by the mesh grinding for IR testing analysis, the content of the main organic groups in this layer of the block sample can be obtained, thereby obtaining the micrometer-level spatial distribution of the main crystalline mineral phases and organic polymers of the block sample.

[0048] It should be noted that the main advantage of this application is that, through the series of measures provided by this invention, the content of crystal phases and organic groups in the same micron-level structural layer of the same sample can be tested simultaneously and accurately.

[0049] Provided that the grinding thickness and surface flatness of the block sample meet the preset requirements, the block sample is fixed using a sample frame. These preset requirements may include thickness and flatness requirements for the block sample.

[0050] Analyze the XRD test data. Professional XRD analysis software, such as Jade or MDI Jade, can be used to determine the types of mineral phases in the sample by comparing the diffraction patterns with those of standard materials. Then, based on the area integral value of the characteristic diffraction peaks of each mineral phase, compare the integral area of ​​the corresponding characteristic peaks in the same size block sample of the standard material to calculate the mineral phase content in that layer of the block sample.

[0051] The IR test data are analyzed. Based on the position and intensity of the characteristic absorption peaks of organic groups, the content of organic groups in that layer of the bulk sample is determined. By comparing the IR test data of different layers of micronized powder, the distribution of organic groups in the bulk sample can also be analyzed.

[0052] Understandably, by controlling the thickness of each grinding pass using a mesh screen and measuring the thickness and surface flatness of the block sample using a micrometer and a steel ruler, block samples with grinding precision down to the micrometer level can be obtained. Using these block samples for XRD testing can effectively reduce testing errors caused by uneven sample surfaces and inaccurate delamination, thereby improving the accuracy of XRD testing.

[0053] By polishing with a mesh screen, not only can block samples meeting XRD testing requirements be obtained, but milligram-level micro-powders can also be collected simultaneously. Using these micro-powders for IR analysis, the content of major organic groups in that layer of the block sample can be determined. Combined with the mineral phase content information obtained from XRD testing, a comprehensive understanding of the micron-level spatial distribution of the main crystalline mineral phases and organic polymers in the block sample can be achieved, providing richer information for material performance research and application development.

[0054] According to one embodiment of this application, the mesh is an 80-1000 mesh Al2O3 mesh or an 80-1000 mesh SiC mesh.

[0055] According to one embodiment of this application, a mesh screen is used to perform micron-level layered polishing on a block sample. A micrometer and a steel ruler are used to measure the thickness of each polishing pass and the flatness of the test surface of the block sample. Milligram-level micropowder generated during polishing is collected. The process includes: marking the test direction and the location of thickness test points on the back of the block sample; laying weighing paper flat on a horizontally placed glass plate, placing a mesh screen of a specified mesh size on the weighing paper, and polishing the test surface of the block sample on the mesh screen in a specified direction for a specified number of times; measuring the thickness of each thickness test point of the block sample using a micrometer, accurate to 1 μm, and recording the thickness of each test point; placing a steel ruler on the polished surface of the block sample and comparing the surface flatness of the test surface against light, controlling the surface flatness and polishing thickness of the block sample test surface together with the number of polishing passes and the test data from the micrometer; collecting and storing the milligram-level micropowder on the weighing paper for subsequent IR testing.

[0056] Understandably, by precisely marking the test direction and test points, and using a micrometer and steel ruler to measure and control the thickness and surface flatness, it is possible to obtain block samples with grinding precision down to the micrometer level. Using these block samples for XRD testing can effectively reduce testing errors caused by uneven sample surfaces and inaccurate delamination, thereby improving the accuracy of XRD testing.

[0057] In one embodiment, the sample frame includes a main panel 6, an upright plate 7, a stiffener 8, an end plate 9, and a cover plate 10. The end plate 9 is connected to the first end of the upright plate 7, the main panel 6 is connected to the second end of the upright plate 7, and the stiffener 8 is connected to the upright plate 7, the end plate 9, and the main panel 6. The cover plate 10 is detachably connected to the end plate 9.

[0058] In one embodiment, the main panel 6 is perforated with holes, the end plate 9 has screw holes, and the cover plate 10 has holes.

[0059] During XRD measurements of bulk samples, it is crucial to ensure maximum coplanarity between the flat test surface and the main panel. This application uses modeling clay and specialized fixtures to fix the sample, ensuring the test surface of the bulk sample is coplanar with the main panel. The XRD instrument can be set to the standard θ / 2θ simultaneous measurement mode (Bragg-Brentano geometry). However, it is important to note that this mode requires the sample surface to maintain the correct geometric relationship with both the incident and diffracted beams; surface unevenness will severely disrupt this relationship, leading to peak shift and intensity distortion. Parameter settings: The scanning speed can be appropriately slowed down to increase the counting statistics and improve the signal-to-noise ratio.

[0060] According to one embodiment of this application, a block sample is fixed using a sample frame, including: Place the polished block sample with the test surface facing down on a clean glass plate; remove the cover plate 10 of the sample frame, and place the sample frame on the outer perimeter of the block sample on the glass plate, so that the main panel 6 faces down and is close to the designated position of the block sample, and ensure that the main panel 6 and the test surface of the block sample are in the same plane. Use clay strips to fix the sides of the block sample to the sample frame; Fix a strip of modeling clay to the back of the block sample, so that the modeling clay strip is higher than the plane of end plate 9; Press the clay strip flat with the cover plate 10 until it is flush with the end plate; fix the cover plate 10 to the end plate 9 with anti-slip screws; Use a steel ruler to compare the block sample fixed in the sample frame with the light, ensuring that the test surface of the block sample is on the same plane as the main panel 6 and is tightly fixed.

[0061] According to one embodiment of this application, mounting a sample frame containing a block sample on an XRD analyzer and performing testing and analysis on the block sample includes: The mounting bracket is fixedly installed on the crossbeam of the XRD tester; The sample frame containing the block sample is installed in the sample holder of the XRD tester. Connect the main panel of the sample frame to the fixed bracket using cotton thread of a specified length. The first end of the cotton thread is connected to the connection hole on the main panel, and the second end of the cotton thread is fixedly connected to the groove on the fixed bracket. The width and depth of the trench are both approximately 1 mm.

[0062] According to one embodiment of this application, IR testing and analysis of milligram-level micro powder obtained by grinding block samples includes: Place a clean agate mortar in an electronic balance with an accuracy of 0.01 mg, and weigh 150 mg of KBr, accurate to 0.01 mg. Place the weighing paper in an electronic balance with an accuracy of 0.01 mg, and weigh 1.5 mg of milligram-level micro powder obtained by grinding the mesh, accurate to 0.01 mg. Grind the weighed milligram-level micro powder together with the weighed KBr in an agate mortar clockwise for 100 revolutions. Use a stainless steel spoon to scrape the powder into the center of the mortar. Then grind counterclockwise for 100 revolutions and use a stainless steel spoon to scrape the powder into the center of the mortar. Repeat this process until you have ground 1000 times. The ground and mixed powder is evenly spread in the sample preparation container and pressed into an IR test piece; Place the IR test piece in the IR instrument for IR testing.

[0063] According to one embodiment of this application, a block sample is subjected to micron-level layered grinding using a mesh screen. Before measuring the thickness of each grinding pass and the surface flatness of the block sample using a micrometer and a steel ruler, and collecting the milligram-level micro powder generated during grinding, the process includes: The first strip is obtained by cutting the extruded polystyrene board. The first strip is then bonded together to form the first mold with a size of 50*50*5mm. The first mold is filled with standard mortar made of reference cement, standard sand and drinking tap water. The mortar is then vibrated and molded and cured according to standard to form a standard mortar substrate. The extruded polystyrene board is cut to obtain a second strip. The second strip is then bonded together to form a second mold with specifications of 50*50*10mm and 50*50*15mm respectively. Using the 50*50*10mm second mold, a standard mortar substrate and polymer cement slurry are vibrated together to form a large-size polymer cement block sample of 50*50*10mm standard mortar substrate. Using the 50*50*10mm second mold, a 50*50*5mm standard brick is vibrated together with polymer cement slurry to form a large-size polymer cement block sample of 50*50*10mm standard brick substrate. Using the 50*50*15mm second mold, a 50*50*10mm standard brick is vibrated together with polymer cement slurry to form a large-size polymer cement block sample of 50*50*15mm standard brick substrate. Standard curing is then performed to form the large-size polymer cement block sample.

[0064] The method for testing the microstructure of a block sample according to the embodiments of this application includes the following steps: The extruded polystyrene board is cut to obtain the first strip. The first strip is used to bond together to form the first mold. The first mold is used to form the standard mortar made of reference cement, standard sand and drinking tap water. The standard mortar is then cured according to standard to form the standard mortar substrate.

[0065] The extruded polystyrene board is cut to obtain a second strip. The second strip is used to bond together to form a second mold. The standard mortar substrate, standard brick substrate and polymer cement slurry are molded together using the second mold and then cured according to standard to form a large-size polymer cement block sample with substrate.

[0066] According to one embodiment of this application, cutting extruded polystyrene board to obtain a first strip, and using the first strip to form a first mold includes: spreading a PE film on a glass plate; placing the formed first mold cavity 4 and second mold cavity 5 on the PE film; preparing standard mortar according to the ratio of reference cement: standard sand: water = 450: 1350: 225; filling the mixed mortar into the formed first mold cavity 4 and the formed second mold cavity 5; tamping with a tamper and then vibrating and smoothing; curing in a standard curing box under the first preset conditions for 1 day and then demolding; continuing to cure for another 21 days; curing in a standard curing room under the second preset conditions for more than 7 days to obtain a standard mortar substrate.

[0067] In some embodiments, the first preset conditions for the standard curing chamber are a temperature of 20±1℃ and a humidity of 95% or higher.

[0068] In some embodiments, the second preset conditions for the standard curing chamber are a temperature of 23±2℃ and a humidity of 50±10%.

[0069] According to one embodiment of this application, cutting extruded polystyrene board to obtain a second strip includes: placing a 50*50*5mm standard mortar substrate or a 50*50*5mm ceramic tile block conforming to JC / T547 in a third mold cavity; placing a 15*10*5mm standard mortar substrate or a 15*10*5mm ceramic tile block conforming to JC / T547 in a fourth mold cavity; preparing a polymer cement slurry according to the ratio of reference cement:VAE adhesive powder:cellulose ether:water = 1000:100:10:720; filling the mixed polymer cement slurry into the third and fourth mold cavities where the standard mortar substrate or ceramic tile substrate has been placed, tamping it with a trowel, vibrating it, smoothing it, curing it in a standard curing room under the third preset conditions for 2 days, demolding it, and then continuing to cure it under the third preset conditions for 28 days to obtain a block-shaped polymer cement sample with a substrate.

[0070] In some embodiments, the third preset conditions for the standard curing chamber are a temperature of 23±2℃ and a humidity of 50±10%.

[0071] According to one embodiment of this application, XRD test data is analyzed to obtain the mineral phase content of the blocky sample at the current layer, and IR test data is analyzed to obtain the organic group content of the blocky sample at the current layer, including: Integrate the area of ​​the characteristic peak of a typical mineral phase in the curve obtained by the XRD analyzer; compare the integrated value with the integrated area of ​​the corresponding characteristic peak of the same specification block sample of the mineral phase standard to calculate the content of the mineral phase in a certain layer of the block sample. Integrate the area of ​​the characteristic peak of a typical group in the curve obtained by the IR analyzer; compare the obtained integral value with the regression curve of the integral area of ​​the corresponding characteristic peak of the standard organic polymer corresponding to the group, and calculate the content of the organic polymer in a certain layer of the block sample. The mineral phase content and organic group content of each layer of the block sample were analyzed to obtain the micron-scale spatial distribution of the main crystalline mineral phase and organic polymers of the block sample.

[0072] According to the second aspect of this application, the apparatus for testing the microstructure of a block sample includes a method for performing the aforementioned method for testing the microstructure of a block sample, comprising: an XRD analyzer for analyzing the block sample and obtaining XRD test data; an IR analyzer for analyzing milligram-level micropowder and obtaining IR test data; an extruded polystyrene board mold for forming a polymer cement block sample with a substrate; a mesh screen for layering and grinding the block sample to obtain milligram-level micropowder; a sample frame for supporting the block sample; and a fixing bracket for mounting the sample frame with the block sample onto the crossbeam of the XRD analyzer.

[0073] In one embodiment, the fixing bracket is a T-beam.

[0074] The present application describes a method for micron-level layering testing using XRD and IR, with reference to a specific embodiment.

[0075] First, using a heating wire, three XPS strips, each 5mm thick, were cut: a first XPS strip 1, a second XPS strip 2, and a third XPS strip 3. These were then bonded together with adhesive to create a first mold cavity 4 (50×50×5mm) and a second mold cavity 5 (15×10×5mm). Next, the first mold cavity 4 and the second mold cavity 5 were placed on a glass plate covered with a smooth PE film. Standard mortar was prepared according to a ratio of cement:standard sand:water = 450:1350:225 and filled into the mold cavity. After tamping, vibrating, and smoothing, the mold cavity is cured in a standard curing chamber (temperature 20±1℃, humidity ≥95%) for 1 day before demolding. After curing for another 21 days, it is transferred to a standard curing room (temperature 23±2℃, humidity 50±10%) for more than 7 days to obtain standard mortar substrates of 50×50×5mm and 15×10×5mm for later use. At the same time, V1 ceramic tiles that meet the requirements of JC / T547 are cut into small pieces of 15×10×5mm.

[0076] Next, polymer cement stone composite block samples were prepared: fourth, fifth, and sixth XPS strips, each 10mm thick, were cut using a heating wire and bonded together to form a 50×50×10mm third mold cavity and a 15×10×10mm fourth mold cavity; the third and fourth mold cavities were placed behind a glass plate, and the aforementioned standard mortar substrate or V1 ceramic tile pieces (smooth side up) were placed in them respectively; then, polymer cement slurry was prepared according to the ratio of reference cement: VAE adhesive powder: cellulose ether (HPMC 40,000): water = 1000:10:720, and filled into the mold cavity. After tamping, vibration, and smoothing, the samples were cured in a standard curing room for 2 days before demolding, and then cured for more than 28 days to obtain block polymer cement samples with substrates of 50×50×10mm and 15×10×10mm for later use.

[0077] XRD testing and stratification analysis were then performed: First, the back of the standard mortar substrate or V1 ceramic tile substrate of the 50×50×10mm large block sample was smoothed with P60 metallographic sandpaper. The test direction and thickness measurement points were marked. The thickness of the four sides and the center was measured with a micrometer (accuracy 1μm) and recorded. The polymer cement test surface of the block sample was placed face down on a clean horizontal glass plate. The sample frame was attached (without the cover plate 10) and placed close to one corner and two sides of the block sample. The sides of the block sample were fixed with clay strips. The clay strips were fixed on the back of the block sample and made to extend above the end plate plane. The cover plate 10 was used to flatten the clay strips on the back of the block sample so that they were flush with the end plate. The cover plate 10 was installed with anti-slip screws to ensure that the test surface of the block sample was coplanar with the main panel 6 of the frame and was firmly fixed. The self-made T-beam was installed on the XRD tester (Rigaku Ultima). On the crossbeam (Ⅳ, 40kV, 40mA), insert the sample frame with the block sample into the test block holder, connect the main panel of the frame to the groove of the T-beam with cotton thread of fixed length, set the scanning parameters of the XRD tester (2θ is 5°~65°, DS is 1mm, speed is 5deg / min, step is 0.01°) and then turn on the test. After the XRD tester has completed the test, save the data.

[0078] After the first test, remove the block sample and remove the modeling clay. Lay weighing paper flat on a horizontal glass plate, and then lay a mesh (not metallographic sandpaper) flat on the weighing paper. Grind the surface of the polymer cement block sample in four directions (1-100 times). Collect the milligram-level micro powder on the weighing paper with a brush and seal it. Measure the thickness at five points and check the flatness with a steel ruler. Control the overall surface condition by controlling the number of grindings, thickness measurement, and flatness observation. Practice shows that grinding twice in each of the four directions with fine mesh can achieve a thickness of 4μm (i.e., each grinding thickness is about 0.5μm). By controlling the number of grindings and thickness monitoring, the grinding thickness of each batch can be controlled at the micrometer level, and the amount of micro powder can reach the milligram level (for subsequent IR measurement). When grinding a thickness of 200μm or more is required, coarse sandpaper can be used to save time. After grinding, the block sample is fixed in the same way and subjected to the next XRD test, and the operation is repeated.

[0079] Experiments show that the main components are relatively uniformly distributed within the block samples (500μm-4500μm thickness). However, the component distribution on the surface of the block samples and at the interface between the polymer cement and the substrate differs significantly from that in the matrix. Therefore, the layer thickness after grinding is in the micrometer range at the surface, with intervals of tens of micrometers, while the layer thickness in the matrix is ​​several hundred micrometers, decreasing to tens or a few micrometers at the interface. Finally, the test results were qualitatively and quantitatively analyzed (integration, peak division) using XRD tape cards and EXCEL to determine the crystal types (C3S, C4AF, CH, CaCO3, AFt, SiO2, etc.) and their content variations in each layer.

[0080] The collected micro powder was subjected to IR testing. 1.5 mg was weighed at a time and ground 1000 times with 150 mg KBr. The powder was then evenly spread and pressed into a test piece. During the test, the resolution was changed from the conventional 16 to 2, and four points around the test piece and one point in the middle were tested at the same time. The VAE content in the layer was calculated based on the average value of the five test points.

[0081] Figures 7 to 12 This is a partial test result.

[0082] Figure 7 Spatial distribution diagram of C3S and C4AF in block samples when the base layer is V1 ceramic tile.

[0083] Figure 8 Spatial distribution diagram of C3S and C4AF in block samples when the base layer is a standard mortar substrate.

[0084] Figure 9 Spatial distribution diagram of CH and AFt in block samples when the base layer is V1 ceramic tile.

[0085] Figure 10 Spatial distribution diagram of CH and AFt in block samples when the base layer is a standard mortar substrate.

[0086] Figure 11 Spatial distribution diagram of VAE in block samples when the base layer is V1 ceramic tile.

[0087] Figure 12 Spatial distribution diagram of VAE in block samples when the base layer is a standard mortar substrate.

[0088] The micron-level layering test method using XRD and IR in this application has the following advantages: Given the high viscosity of polymer cement slurry, a release agent must be used when molding with conventional steel or wooden molds. However, release agents (such as machine oil or other organic products) easily contaminate the blocky sample, thus adversely affecting subsequent microstructure testing. To address this issue, this application proposes using extruded polystyrene (XPS) boards to create a self-made mold. Utilizing the extremely poor adhesion properties of XPS, demolding can be easily achieved without any release agent, effectively avoiding release agent contamination and potential material phase changes during cutting, while significantly reducing manufacturing costs.

[0089] In the grinding and collection stage, for micron-level stratified sampling of large-sized block samples, this method uses a mesh screen instead of traditional metallographic sandpaper. When grinding with conventional metallographic sandpaper (e.g., 400-2000 grit), the resulting trace amounts of powder adhere severely to the sandpaper surface. Even with methods such as tapping, alcohol washing, ultrasonic vibration, or liquid nitrogen freezing, it is impossible to completely collect milligram-level powder, and the grinding thickness is difficult to precisely control to the micron level. However, when using a mesh screen, the powder can easily pass through the mesh and fall onto the weighing paper below, thus easily achieving complete collection. This method not only precisely controls the grinding thickness to the micron level but also stably collects sufficient amounts of powder (e.g., ≥1.5 mg) to meet the needs of subsequent single or repeated IR tests. Simultaneously, by combining a micrometer and a steel ruler for optical comparison, the thickness, surface flatness, and uniformity of the block sample can be ensured to achieve micron-level precision.

[0090] Regarding sample fixation, existing technologies typically employ mechanical clamps to secure large, blocky samples, which struggles to meet the stringent positional accuracy requirements of micron-level layered testing. This method achieves precise fixation through a self-designed combination system of a sample frame and a T-beam fixing bracket. Utilizing the plasticity of modeling clay and the adjustability of screws, the test surface remains flush with the main panel of the frame even as the thickness of the blocky sample changes during grinding. The T-beam effectively transfers the weight of the blocky sample to the crossbeam of the XRD analyzer, preventing damage to the sample clamp; the pre-designed grooves in the fixing bracket, combined with a fixed-length cotton thread, further ensure consistency of the measurement surface for each test.

[0091] In XRD testing, detection accuracy can be improved by slowing down the scanning speed and reducing the scanning step size.

[0092] In IR testing, using a balance with an accuracy of 0.01 mg can reduce weighing errors; thorough grinding and mixing of the micro powder and KBr can reduce mixing errors; improving IR resolution can improve testing accuracy; and measuring and comprehensively calculating different positions on the same sample can reduce errors at different positions on the sample.

[0093] Through the series of measures provided by this invention, the synchronous and accurate testing of the crystalline phase and organic group content in the same polymer cement sample and the same micron-level structural layer is achieved.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the microstructure of a bulk sample, characterized in that, Includes the following steps: The block sample was polished in micron-level layers using a mesh screen. The thickness of each polishing and the flatness of the test surface of the block sample were measured using a micrometer and a steel ruler. The milligram-level micro powder produced during polishing was collected. If the grinding thickness and surface flatness of the block sample meet the requirements, the block sample is fixed using a sample frame. The sample frame containing the block sample is mounted on an XRD analyzer using a fixed bracket, and the block sample is subjected to XRD testing and analysis to obtain XRD test data. The milligram-level micro powder obtained by grinding block samples was subjected to IR testing and analysis to obtain IR test data; The mineral phase content in the layer of the block sample is obtained by analyzing the XRD test data, and the organic group content in the layer of the block sample is obtained by analyzing the IR test data. The mesh is an 80-1000 mesh Al2O3 mesh or an 80-1000 mesh SiC mesh; The process of using a mesh screen to perform micron-level layered polishing of the block sample includes: Mark the test direction and the location of the thickness test points on the back of the block sample; lay weighing paper flat on a horizontally placed glass plate, and lay the mesh of the specified size on the weighing paper; polish the test surface of the block sample on the mesh in the specified direction to a specified number of times; use a micrometer to measure the thickness of the thickness test points of the block sample to an accuracy of 1 μm, and record the thickness of each test point; place a steel ruler on the polished surface of the block sample, and compare the surface flatness of the test surface of the block sample with the light, and control the surface flatness and polishing thickness of the test surface of the block sample together with the number of polishing times and the test data of the micrometer; collect the milligram-level micro powder on the weighing paper and seal it for subsequent IR testing; The sample frame includes a main panel (6), a vertical plate (7), a stiffening plate (8), an end plate (9), and a cover plate (10). The end plate (9) is connected to the first end of the vertical plate (7), the main panel (6) is connected to the second end of the vertical plate (7), and the stiffening plate (8) is connected to the vertical plate (7), the end plate (9), and the main panel (6). The cover plate (10) is detachably connected to the end plate (9). The method of fixing the block sample using a sample frame includes: Place the polished block sample with the test surface facing down on a clean glass plate; remove the cover plate (10) of the sample frame, and place the sample frame on the outer periphery of the block sample on the glass plate, so that the main panel (6) faces down and is close to the designated position of the block sample, and ensure that the main panel (6) and the test surface of the block sample are in the same plane. Use clay strips to fix the sides of the block sample to the sample frame; A clay strip is fixed to the back of the block sample, so that the clay strip is higher than the plane of the end plate (9); Press the clay strip flat with the cover plate (10) until it is flush with the end plate (9); fix the cover plate (10) and the end plate (9) with anti-slip screws; Use a steel ruler to compare the light with the block sample fixed in the sample frame to ensure that the test surface of the block sample and the main panel (6) are on the same plane and tightly fixed.

2. The method for testing the microstructure of a block sample according to claim 1, characterized in that, The step of mounting the sample frame containing the block sample onto an XRD analyzer and performing testing and analysis on the block sample includes: The mounting bracket is fixedly installed on the crossbeam of the XRD tester; The sample frame containing the block sample is mounted in the sample holder of the XRD tester; The main panel of the sample frame is connected to the fixed bracket using cotton thread of a specified length, wherein the first end of the cotton thread is connected to the connection hole on the main panel, and the second end of the cotton thread is fixedly connected to a pre-set groove on the fixed bracket. The width and depth of the groove are both 1 mm.

3. The method for testing the microstructure of a block sample according to claim 1, characterized in that, The IR testing and analysis of the milligram-level micro powder obtained from grinding the block sample includes: Place a clean agate mortar in an electronic balance with an accuracy of 0.01 mg, and weigh 150 mg of KBr, accurate to 0.01 mg. Place the weighing paper in an electronic balance with an accuracy of 0.01 mg, and weigh 1.5 mg of the milligram-level micro powder obtained from the mesh polishing, accurate to 0.01 mg; The weighed milligram-level micro powder and the weighed KBr are ground together in an agate mortar and ground clockwise for 100 revolutions. The powder is scraped to the center of the mortar with a stainless steel spoon. Then, the powder is ground counterclockwise for 100 revolutions. The powder is scraped to the center of the mortar with a stainless steel spoon. This process is repeated until 1000 revolutions are completed. The ground and mixed powder is evenly spread in the sample preparation container and pressed into an IR test piece; Place the IR test piece in the IR instrument for IR testing.

4. The method for testing the microstructure of a block sample according to any one of claims 1 to 3, characterized in that, Before using a mesh screen to perform micron-level layered grinding of the block sample, measuring the thickness of each grinding step and the flatness of the test surface of the block sample using a micrometer and a steel ruler, and collecting the milligram-level micro powder generated during grinding, the process includes: The extruded polystyrene board is cut to obtain the first strip, and the first strip is used to form the first mold with a specification of 50*50*5mm. The first mold is filled with standard mortar made of reference cement, standard sand and drinking tap water, and then vibrated and cured to form a standard mortar substrate. Extruded polystyrene boards are cut to obtain second strips. These second strips are then bonded together to form a second mold with dimensions of 50*50*10mm and 50*50*15mm respectively. Using the 50*50*10mm second mold, a standard mortar substrate and polymer cement slurry are vibrated together to form a large-format 50*50*10mm polymer cement block sample of the standard mortar substrate. Using the same 50*50*10mm mold, a 50*50*5mm standard brick is vibrated together with polymer cement slurry to form a large-format 50*50*10mm polymer cement block sample of the standard brick substrate. Similarly, using the same 50*50*15mm mold, a 50*50*10mm standard brick is vibrated together with polymer cement slurry to form a large-format 50*50*15mm polymer cement block sample of the standard brick substrate. Standard curing is then performed to form the large-format polymer cement block sample.

5. The method for testing the microstructure of a block sample according to any one of claims 1 to 4, characterized in that, The step of analyzing the XRD test data to obtain the mineral phase content of the blocky sample at the current layer and analyzing the IR test data to obtain the organic group content of the blocky sample at the current layer includes: Integrate the area of ​​the characteristic peak of a typical mineral phase in the curve obtained by the XRD analyzer; compare the integrated value with the integrated area of ​​the corresponding characteristic peak of the same specification block sample of the mineral phase standard to calculate the content of the mineral phase in a certain layer of the block sample. Integrate the area of ​​the characteristic peak of a typical group in the curve obtained by the IR analyzer; compare the obtained integral value with the regression curve of the integral area of ​​the corresponding characteristic peak of the standard organic polymer corresponding to the group, and calculate the content of the organic polymer in a certain layer of the block sample. The mineral phase content and organic group content of each layer of the block sample were analyzed to obtain the micron-scale spatial distribution of the main crystalline mineral phase and organic polymers in the block sample.

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