Sample preparation method of small EBSD sample

Abstract

The invention provides a sample preparation method of a small EBSD sample, and relates to the technical field of sample preparation of EBSD samples. The preparation method of the small EBSD sample comprises the following steps: S1, cleaning a metal sample with alcohol, putting the metal sample into a mold with the observation surface facing downwards, and selecting a screw with the diameter of 5mm and the length of 30mm; s2, a medium is poured into the mold, and the metal sample is coated with the medium; s3, taking out the cured medium from the mold, and rotating the screw to enable the sample to fall off from the cured medium; s4, repairing the hole site of the metal sample on the cured medium carrier, polishing the metal sample by using polishing equipment, and cleaning the polished surface by using cleaning liquid after polishing is finished, so as to obtain a mirror observation surface of the EBSD; and S5, screwing a screw into the medium after grinding, and ejecting out the sample to obtain the EBSD sample. Through combination of the screw and the resin medium, the screw is flexibly adopted to extrude the metal sample from the medium, the sample is not difficult to take out due to small size, and the device is efficient and convenient.

Description

Technical Field

[0001] The invention relates to the technical field of EBSD sample preparation, in particular to a small EBSD sample preparation method. Background Art

[0002] EBSD is the backscattered electron diffraction technique, which is a technique that uses a diffracted electron beam to identify the crystallographic orientation of a sample. Mounted in a scanning electron microscope, the tilt angle is about 70 degrees. The accelerated electron beam is shot into the sample, generating rebounded backscattered electrons, which are diffracted by the surface crystal structure and carry the information of the grain orientation on the surface of the sample. They enter the detector to determine the directionality of each grain. After knowing the orientation of each grain, it can be used in the analysis method of determining grain boundaries, phase identification, grain orientation, texture and strain. People use calibrated EBSD to observe the organization and structural information of metal samples. Before observation, the metal sample needs to be prepared for EBSD.

[0003] In daily EBSD testing, the observation surface of the sample needs to be ground and polished until there are no tiny scratches, then electrolytically polished or ion polished, and then placed in an electron microscope for EBSD testing. When the sample size is very small (less than or equal to 5 square millimeters), it is impossible to grind the sample directly by hand. The sample can only be resin-mounted first, then ground and polished, and then the embedded resin is knocked off or dissolved. After taking out the sample, electrolytic polishing is performed, or the mounted sample is directly ion polished, and finally a sample that can be tested by EBSD is obtained.

[0004] However, this method makes the process of removing the sample after embedding more troublesome and is easy to damage the sample. If the resin is knocked off by external force, it is easy to scratch the polished surface; or the sample is subjected to external force and its structure is changed. If the resin is dissolved by solvent, it may cause corrosion to the sample surface.

[0005] Therefore, in view of the above defects, this application proposes a method for preparing small EBSD samples. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a method for preparing a small EBSD sample, comprising the following steps: S1. Based on the test requirements, the sample size and test parameters are verified, and the sample production steps are formulated. The metal sample is cleaned with alcohol, the geometric structure of the sample is carefully observed, and the size of the sample is measured to obtain the basic data of the sample. The metal sample is placed in the mold with the largest geometric surface facing down, and a screw with a diameter of 5 mm and a length of 30 mm is selected; S2. Calculate the optimal curing position of the sample using a linear programming model based on the test parameters and sample basic data in step S1, adjust the sample placement position, pour the medium into the mold so that it covers the metal sample, and at the same time make the screw hang on the top of the metal sample, adjust the height of the bracket to support the screw, and the lower end of the screw extends into the medium to just support the top of the metal sample, and wait for the medium to solidify; S3. After the medium is cured into a rubber state, the cured medium is taken out of the mold, the screw is turned to make the sample fall off from the cured medium, and then the screw is taken out; S4, repairing the metal sample holes on the medium carrier after curing, removing the burrs on the sample holes, and then inserting the metal sample into the sample hole of the medium again, and then using a polishing device to polish the metal sample. After polishing, wash the polished surface with a practical cleaning liquid to obtain an EBSD mirror observation surface. The mirror observation surface is inspected by using an interference method, which magnifies the surface microscopic roughness through the principle of light wave interference to determine whether the sample grinding surface is easy to observe. If the section does not meet the observation requirements, repeat steps S1-S4 until the section roughness meets the requirements and proceed to the next step; S5. Use the medium as a carrier to grind the metal sample to achieve a smooth cross-section for observation. After grinding, screw the screw into the medium to eject the sample to obtain an EBSD sample, and then directly use EBSD to analyze the cross-section of the sample.

[0007] Preferably, the medium preparation method in step S2 is: selecting a resin and a curing agent; The resin and the curing agent are mixed in a mass ratio of 1:1 to obtain a medium. The selected amount is calculated according to the size of the sample and measured according to the data calculation in step S1.

[0008] Preferably, the medium solidification time in step S2 is 1-3 hours.

[0009] Preferably, in S4, during polishing, sandpaper is first used, followed by polishing with a diamond solution, and finally the cross section is cleaned with a solution.

[0010] Preferably, the measurement of the geometric structure in step S1 is performed by a three-dimensional scanner, and then a regression analysis is performed to obtain the applicable surface. The size of the sample in step S1 is measured by an infrared measuring device, and then the parameters are compared to adjust the polishing process. Preferably, a sample preparation mold for a small EBSD sample, the EBSD sample is the sample described above, comprising a mold, one side of the mold is fixedly connected to a side arm, the upper part of the side arm is slidably provided with a bracket, the bracket is threadedly connected to a threaded rod, the threaded rod is rotatably connected in the side arm, and the top end of the threaded rod passes through the side arm and is fixedly connected to a knob; The steps for using the sample preparation mold are: placing the sample into the mold (1), then selecting an optimal geometric position to place the sample, then pouring a medium into the mold (1), and executing steps S1 to S5.

[0011] The present invention provides a method for preparing a small EBSD sample, which has the following beneficial effects: The present invention combines screws and resin media. When preparing metal samples, the screws are flexibly used to extrude the metal samples from the media. The resin media is then used as a carrier to grind the metal samples. After grinding and polishing, the screws are further used to extrude the metal samples. This convenient and quick setting enables the metal samples to be completely and well polished. At the same time, the samples will not be difficult to remove due to being too small. This is very efficient and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a step diagram of the present invention; Figure 2 It is a structural diagram of the mold of the present invention; Figure 3 This is a roughness determination system diagram of the present invention.

[0013] Among them, 1. mold; 2. side arm; 3. bracket; 4. threaded rod; 5. knob. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] Embodiment 1:

[0016] like Figure 1-3 As shown, an embodiment of the present invention provides a method for preparing a small EBSD sample, comprising the following steps: S1. Based on the test requirements, the sample size and test parameters are verified, and the sample production steps are formulated. The metal sample is cleaned with alcohol, the geometric structure of the sample is carefully observed, and the size of the sample is measured to obtain the basic data of the sample. The metal sample is placed in the mold with the largest geometric surface facing down, and a screw with a diameter of 5 mm and a length of 30 mm is selected; S2. Calculate the optimal curing position of the sample using a linear programming model based on the test parameters and sample basic data in step S1, adjust the sample placement position, pour the medium into the mold so that it covers the metal sample, and at the same time make the screw hang on the top of the metal sample, adjust the height of the bracket to support the screw, and the lower end of the screw extends into the medium to just support the top of the metal sample, and wait for the medium to solidify; S3. After the medium is cured into a rubber state, the cured medium is taken out of the mold, the screw is turned to make the sample fall off from the cured medium, and then the screw is taken out; S4, such as Figure 3 As shown, the metal sample hole on the medium carrier after curing is repaired and the burrs on the sample hole are removed, and then the metal sample is inserted into the sample hole of the medium again, and then the metal sample is polished using a polishing device. After polishing, the polished surface is cleaned with a cleaning liquid to obtain an EBSD mirror observation surface. The mirror observation surface is inspected using an interference method, which uses the principle of light wave interference to magnify the surface microscopic roughness to determine whether the sample grinding surface is easy to observe. If the section does not meet the observation requirements, repeat steps S1-S4 until the section roughness meets the requirements and proceed to the next step; S5. Use the medium as a carrier to grind the metal sample to achieve a smooth cross-section for observation. After grinding, screw the screw into the medium to eject the sample to obtain an EBSD sample, and then directly use EBSD to analyze the cross-section of the sample.

[0017] The medium preparation method in step S2 is: selecting resin and curing agent; The resin and the curing agent are mixed in a mass ratio of 1:1 to obtain a medium. The selected amount is calculated according to the size of the sample and measured according to the data calculation in step S1.

[0018] The medium curing time in step S2 is 1-3 hours.

[0019] In S4, when polishing, sandpaper is used first, followed by diamond solution polishing, and finally the cross section is cleaned with solution.

[0020] The geometric structure in step S1 is measured by a 3D scanner, and then regression analysis is performed to obtain the applicable surface. The size of the sample in step S1 is measured by an infrared measuring device, and then the parameters are compared to adjust the polishing process. A sample preparation mold for a small EBSD sample comprises a mold 1, a side arm 2 is fixedly connected to one side of the mold 1, a bracket 3 is slidably arranged on the upper part of the side arm 2, a threaded rod 4 is threadedly connected to the bracket 3, the threaded rod 4 is rotatably connected in the side arm 2, and the top end of the threaded rod 4 passes through the side arm 2 and is fixedly connected to a knob 5; The steps for using the sample preparation mold are: put the sample into the mold 1, then place the sample in the optimal geometric position, then pour the medium into the mold 1, and execute steps S1-S5.

[0021] Embodiment 2:

[0022] Reference Figure 1-Figure 2 As shown, an embodiment of the present invention provides a method for preparing a small EBSD sample, characterized in that it includes the following steps: S1. Clean the metal sample with alcohol, then put the metal sample into mold 1 with the observation surface facing down, and select a screw with a diameter of 5 mm and a length of 30 mm. Alcohol can clean the metal sample well without corroding it. The length and size of the screw can be selected according to the size of the metal sample. Here, it is best to use a 5 mm diameter screw for small samples, which is easy to operate and can flexibly eject the metal sample; S2, pour the medium into the mold 1 so that it covers the metal sample, and at the same time, make the screw hang on the top of the metal sample, adjust the height of the bracket 3 to support the screw, and the lower end of the screw extends into the medium to just support the top of the metal sample, and wait for the medium to solidify. The combination of resin and curing agent makes it easy to trim after solidification, and can also support the grinding of the metal sample, which is convenient for sample processing operations. When embedding the sample, embed an upright screw next to the sample. When the resin is cured into a rubber state, turn the screw to push the metal sample out of the resin, and screw out the screw at the same time, leaving the thread hole and the sample outline; trim the outline and thread hole to facilitate the metal sample and the screw to be re-embedded in the resin, and use the screw to push the polished metal sample out along the thread hole, which overcomes the difficult process of removing the metal sample from the embedded resin, and will not cause any damage to the surface of the polished metal sample; S3. After the medium solidifies into a rubber state, the solidified medium is taken out from the mold 1, and the screw is turned to make the sample fall off from the solidified medium, and then the screw is taken out. The rubber medium can hold the metal sample, and is also convenient for subsequent trimming and is conducive to the support of subsequent polishing and grinding of the metal sample; S4. Repair the metal sample holes on the medium carrier after curing, remove the burrs on the sample holes, and then insert the metal sample into the sample hole of the medium again, and then use the polishing equipment to polish the metal sample. After the polishing is completed, the polished surface is cleaned with a practical cleaning liquid to obtain the mirror observation surface of EBSD. The polishing method and tools are selected according to the actual use. EBSD is mainly scanned by a scanning electron microscope, which is an electron microscope that generates an image of the sample surface by scanning the surface of the sample with a focused electron beam. Electrons interact with atoms in the sample to generate various signals containing information about the surface mapping morphology and composition of the sample. The electron beam is usually scanned in a raster scanning pattern, and the position of the beam is combined with the detected signal to produce an image. Scanning electron microscopes can achieve a resolution better than 1 nanometer. Samples can be observed under high vacuum, low vacuum, wet conditions with an environmental scanning electron microscope, and a wide range of low or high temperatures. The most common scanning electron microscope mode is to detect secondary electrons emitted by atoms excited by an electron beam. The number of secondary electrons that can be detected depends on the sample mapping morphology, as well as other factors. By scanning the sample and collecting the emitted secondary electrons using a special detector, an image is created showing the topography of the surface. It is also possible to produce high-resolution images of the sample surface in three dimensions, identifying the surface structure of the sample; S5. Use the medium as a carrier to grind the metal sample to achieve a smooth cross-section for observation. After grinding, screw the screw into the medium to eject the sample to obtain an EBSD sample, and then directly use EBSD to analyze the cross-section of the sample.

[0023] The medium preparation method in step S2 is: selecting resin and curing agent; The resin and the curing agent are mixed in a mass ratio of 2.4:1 to obtain a medium. The ratio of the resin and the curing agent is selected according to the actual sample to be prepared, which is more suitable for flexible preparation of metal sample sections.

[0024] The medium curing time in step S2 is 1-3 hours, and sufficient time is conducive to the curing of the resin to a hardness and elasticity suitable for processing.

[0025] In S4, when polishing, sandpaper is used first, followed by diamond solution polishing, and finally the cross section is cleaned with solution, which is conducive to showing the texture and structure of the cross section of the metal sample.

[0026] Embodiment three:

[0027] Reference Figure 1-Figure 2The embodiment of the present invention proposes a sample preparation mold for a small EBSD sample, including a mold 1, a side arm 2 is fixedly connected to one side of the mold, a bracket 3 is slidably provided on the upper part of the side arm 2, the bracket 3 is threadedly connected to a threaded rod 4, the threaded rod 4 is rotatably connected to the side arm 2, the top of the threaded rod 4 passes through the side arm 2 and is fixedly connected to a knob 5, the bracket 3 can be adjusted to a height at the top of the mold through the threaded rod 4, so that samples of different sizes are conveniently combined and cured together with screws, and at the same time, the bracket 3 supports the screws to make pouring resin more convenient, and the screws can just hit the top of the metal sample.

[0028] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a small EBSD sample, characterized in that: The following steps are involved: S1. Based on the test requirements, the sample size and test parameters are verified, and the sample production steps are formulated. The metal sample is cleaned with alcohol, the geometric structure of the sample is carefully observed, and the size of the sample is measured to obtain the basic data of the sample. The metal sample is placed in the mold with the largest geometric surface facing down, and a screw with a diameter of 5 mm and a length of 30 mm is selected; S2. Calculate the optimal curing position of the sample using a linear programming model based on the test parameters and sample basic data in step S1, adjust the sample placement position, pour the medium into the mold so that it covers the metal sample, and at the same time make the screw hang on the top of the metal sample, adjust the height of the bracket to support the screw, and the lower end of the screw extends into the medium to just support the top of the metal sample, and wait for the medium to solidify; S3. After the medium is cured into a rubber state, the cured medium is taken out of the mold, the screw is turned to make the sample fall off from the cured medium, and then the screw is taken out; S4, repairing the metal sample holes on the medium carrier after curing, removing the burrs on the sample holes, and then inserting the metal sample into the sample hole of the medium again, and then using a polishing device to polish the metal sample. After polishing, wash the polished surface with a practical cleaning liquid to obtain an EBSD mirror observation surface. The mirror observation surface is inspected by using an interference method, which magnifies the surface microscopic roughness through the principle of light wave interference to determine whether the sample grinding surface is easy to observe. If the section does not meet the observation requirements, repeat steps S1-S4 until the section roughness meets the requirements and proceed to the next step; S5. Use the medium as a carrier to grind the metal sample to achieve a smooth cross-section for observation. After grinding, screw the screw into the medium to eject the sample to obtain an EBSD sample, and then directly use EBSD to analyze the cross-section of the sample.

2. The method for preparing a small EBSD sample according to claim 1, characterized in that: The medium preparation method in step S2 is: selecting resin and curing agent; The resin and the curing agent are mixed in a mass ratio of 1:1 to obtain a medium. The selected amount is calculated according to the size of the sample and measured according to the data calculation in step S1.

3. The method for preparing a small EBSD sample according to claim 1, characterized in that: The medium solidification time in step S2 is 1-3 hours.

4. The method for preparing a small EBSD sample according to claim 1, characterized in that: In S4, during polishing, sandpaper is first used, followed by polishing with a diamond solution, and finally the cross section is cleaned with a solution.

5. The method for preparing a small EBSD sample according to claim 1, characterized in that: The geometric structure in step S1 is measured by a three-dimensional scanner, and then a regression analysis is performed to obtain the applicable surface. The size of the sample in step S1 is measured by an infrared measuring device, and then the polishing process is adjusted by comparing the parameters.

6. A sample preparation mold for a small EBSD sample, wherein the EBSD sample is a sample as described in claims 1 to 5, characterized in that: The mold (1) comprises a side arm (2) fixedly connected to one side of the mold (1); a bracket (3) is slidably provided on the upper part of the side arm (2); a threaded rod (4) is threadedly connected to the bracket (3); the threaded rod (4) is rotatably connected to the side arm (2); the top end of the threaded rod (4) passes through the side arm (2) and is fixedly connected to a knob (5); The steps for using the sample preparation mold are: placing the sample into the mold (1), then selecting an optimal geometric position to place the sample, then pouring a medium into the mold (1), and executing steps S1 to S5.

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