Manufacturing method of sample grinding clamp for phase change instrument

Abstract

The invention relates to a manufacturing method of a sample grinding clamp for a phase change instrument. The manufacturing method comprises the following steps: 1) manufacturing an embedded positioning plate; 2) manufacturing a to-be-inlaid body; (3) placing a to-be-inlaid body on a mold base, and placing a mold on the periphery of the to-be-inlaid body; 4) adding the inlay powder into the mold; (5) the powder adding and pressurizing processes are repeated, and the filling height of the inlaid powder reaches h; (6) the filling height of the inlaid powder reaches 1.5 h; (7) the filling height of the inlaid powder exceeds 2 h; 8) placing a mold cover on the top of the mold; (9) pressurizing, heating and keeping for a period of time to obtain an embedded block; 10) cooling the mold and removing the pressure; and 11) taking out the inlaying block and corroding to obtain the sample grinding fixture composed of the fixture body and the fixture cover.The sample grinding fixture is manufactured by adopting an inlaying method, the manufacturing process is simple, and the sample grinding fixture has the advantages of being high in positioning precision and convenient to use, can be repeatedly used, and is beneficial to improving the experiment efficiency and reducing the experiment cost.

Description

A method for manufacturing a sample grinding fixture for a phase change instrument Technical Field

[0001] This invention relates to the field of materials testing and analysis technology, and in particular to a method for manufacturing a sample grinding fixture for a phase change instrument. Background Technology

[0002] A fully automated phase transition analyzer is an experimental device used to heat, hold, cool, and even deform small, standard cylindrical metal samples (typically 3–5 mm in diameter and 10 mm in length) to reveal the changes in microstructure and properties of materials during hot working. Typical experiments using a fully automated phase transition analyzer include: determination of critical points, determination of static continuous cooling transformation curves, and simulation of heat treatment processes.

[0003] The samples used in phase transition analyzers require grinding to obtain a smooth, scratch-free, undisturbed, and chipped cross-section—the metallographic observation surface—containing complete information from the edge to the core. However, the small sample size makes grinding or polishing difficult. Currently, the commonly used method is mounting (including hot-press mounting or cold mounting), where small samples are made into larger mounting blocks for clamping during grinding or polishing. After rough grinding, fine grinding, and polishing, the sample is prepared for subsequent metallographic observation. However, traditional mounting methods have a relatively long production cycle, and the mounting blocks cannot be reused, increasing costs; this drawback is particularly pronounced when the experimental volume is large. Therefore, it is essential to develop a reusable sample grinding fixture.

[0004] Chinese patent application No. 201320837786.3 discloses a reusable "clamp for phase change instrument samples." The clamp is mounted on the worktable of a grinding machine and is flat. It has multiple through holes, any one of which connects the top and bottom surfaces of the clamp and is perpendicular to both. The thickness of the clamp is less than the cylindrical height of the phase change instrument sample, and the sample is cylindrical. The difference between the clamp's thickness and the sample's cylindrical height is 0.5 mm. This clamp is used for grinding samples on a surface grinder, improving the consistency of multiple phase change instrument samples. The through holes are formed by drilling the clamp perpendicular to the top or bottom surface using a twist drill. While its structure and manufacturing process are simple, it requires high machining accuracy and has poor adjustability.

[0005] Chinese patent application No. 201320365991.4 discloses a reusable fixture for grinding metallographic specimens. The fixture is made of stainless steel and has dimensions of ø40–60 mm × 15–25 mm. Ten to sixteen through-holes with a diameter of ø3–5 mm are drilled evenly on the circumference of the upper surface, 4–8 mm from the circumference (i.e., ø32–44 mm in diameter). At a depth of 5.5 mm in each hole, a through-hole of M4 × 4–8 mm is drilled perpendicular to the circular wall. Each hole is fitted with an M4 × 10 mm bolt for tightening and securing the specimen. This method, also using drilling, requires a good fit between the drilled holes and the specimen, high machining precision, and is difficult to manufacture. To ensure the quality and efficiency of grinding the specimens, at least two specimens must be installed at a time, symmetrically, with their upper surfaces aligned. This requires high installation precision and is inconvenient to use. Summary of the Invention

[0006] This invention provides a method for manufacturing a sample grinding fixture for a phase change instrument. The sample grinding fixture is made by an inlay method, which is simple to manufacture. The sample grinding fixture has the advantages of high positioning accuracy and convenient use, and can be reused, which helps to improve experimental efficiency and reduce experimental costs.

[0007] To achieve the above objectives, the present invention employs the following technical solution: a method for manufacturing a sample grinding fixture for a phase change instrument, comprising the following steps: 1) fabricating an inlay positioning plate, wherein inlay positioning holes are formed on the inlay positioning plate; 2) joining two cylindrical samples for the phase change instrument together to form a sample column, wrapping one end of the sample column with a separating material tape, the wrapping length being not less than 3 / 4 of the total length of the sample column; inserting the wrapped sample column into the inlay positioning hole to obtain the object to be inlaid; 3) placing the object to be inlaid on a mold base, and placing a cylindrical mold around the object to be inlaid; 4) adding inlay powder into the mold, making it flush with the bottom surface of the inlay positioning plate; 5) applying pressure to the inlay powder in the mold through a pressure plate, compacting the inlay powder, removing the inlay positioning plate, and repeating the powder adding and pressurizing process to achieve a high filling height of the inlay powder. 6) Replace the pressure plate with an isolation plate, and repeat the powder filling and pressurization process to make the filling height of the embedded powder reach 1.5h; 7) Replace the pressure plate with another isolation plate, and repeat the powder filling and pressurization process to make the filling height of the embedded powder exceed 2h; 8) Remove the pressure plate and place the mold cover on top of the mold; 9) Move the mold cover down to apply pressure to the inside of the mold, heat the mold and hold it for a period of time to obtain the embedded block; 10) After the heat preservation is completed, cool the mold and remove the pressure; 11) Open the mold cover, remove the embedded block from the mold and then etch it; The embedded block is divided into three parts: bottom embedded block, middle embedded block and top embedded block; The bottom embedded block is used as the fixture body, the middle embedded block is discarded, and the top embedded block is used as the fixture cover. The fixture body and the fixture cover together form the sample grinding fixture.

[0008] A method for manufacturing a sample grinding fixture for a phase change instrument includes the following steps: 1) Take a circular hard plate, and attach pads with the same radius to both sides of the hard plate to form an inlay positioning plate; drill n circular through holes on the inlay positioning plate as inlay positioning holes, the radius of the circular through holes being the same as the radius of the cylindrical sample for the phase change instrument; 2) Take 2n cylindrical samples for the phase change instrument, each cylindrical sample having a height h of 10mm; group every two cylindrical samples, and coaxially connect the two cylindrical samples in the same group to form a sample column; The isolation tape wraps around 3 / 4 of the total length of the sample column at one end, i.e., the wrapping length is 1.5h, and the exposed length at the other end is 0.5h. The wrapped sample columns, with the exposed ends facing upwards, are inserted one by one into the corresponding mounting holes of the mounting positioning plate. The position of the mounting positioning plate is adjusted so that it is in the middle position of the lower cylindrical sample in each sample column. After adjustment, the bottom surfaces of each sample column are on the same horizontal plane, and this horizontal plane is parallel to the mounting positioning plate, thus obtaining the object to be mounted. 3) The object to be mounted is placed on the mold base, and the cylindrical... 4) Place the mold around the body to be inlaid, making the mold coaxial with the inlay positioning plate, and the inner diameter of the mold is larger than the inner diameter of the inlay positioning plate; 5) Add the inlay powder into the mold through the annular gap between the mold and the inlay positioning plate. During the addition process, gently tap the outer wall of the mold to make the inlay powder evenly distributed. After the inlay powder fills the space below the inlay positioning plate, continue to add until it is flush with the bottom surface of the inlay positioning plate. At this time, the filling height of the inlay powder is 0.5h; 6) Take another circular pressure plate with the same radius as the inner diameter of the mold. Make circular through holes on the pressure plate corresponding to the position and radius of each sample column. Place the pressure plate on top of the inlay positioning plate, and then apply a pressure of 15-40MPa to compact the inlay powder downwards; then take out the inlay positioning plate, add inlay powder again, and make the filling height of the inlay powder reach h. Repeat the powder adding and pressurizing process until the height of the inlay powder no longer decreases after pressurization; 7) Take a separation material plate with the same shape and size as the pressure plate except for the thickness. Replace the pressure plate with the separation material plate and continue to add inlay powder until the filling height of the inlay powder reaches 1.5h; Press with a pressure plate and repeat the powder adding and pressing process until the height of the embedded powder no longer decreases after pressing; 7) Take another isolation plate with the same shape and size as the pressure plate except for the thickness, add the embedded powder again, so that the filling height of the embedded powder exceeds 2h; Press with a pressure plate and repeat the powder adding and pressing process until the height of the embedded powder no longer decreases after pressing; 8) Remove the pressure plate, place the mold cover on the top of the mold, so that the mold cavity containing the embedded body and embedded powder is in a completely closed state; 9) Move the mold cover down, apply a pressure of 15-40MPa to the inside of the mold, then heat the mold to 130-180℃, and maintain this pressure and temperature for 6-15min, so that the thermosetting embedded powder undergoes a cross-linking reaction, melts, flows and solidifies to form an embedded block; 10) After the heat preservation is completed, stop heating and cool the mold to 6 Below 0℃, slowly remove pressure during cooling; 11) Open the mold cover, remove the insert from the mold and place it in the etching solution. The etching solution corrodes the isolation plate and enters the interior of the insert through the corrosion gaps to contact the sample column, causing the sample column to shrink in volume after corrosion; the two isolation plates divide the insert into three parts: bottom insert, middle insert, and top insert; the bottom insert acts as a clamping body, and after the lower cylindrical sample is removed, it has multiple through holes with a height of h, which are used for positioning holes during cylindrical sample grinding; the middle insert is discarded; the top insert acts as a clamping cover, and the upper cylindrical sample is embedded in it, that is, the top insert has multiple positioning pins with an exposed length of 0.5h, which are used to push the cylindrical sample to be ground out from the corresponding positioning holes of the clamping body during cylindrical sample grinding; the clamping body and the clamping cover together form the sample grinding fixture.

[0009] The radius r of the cylindrical sample is 1.5 to 2.5 mm.

[0010] The pad is a rubber sheet.

[0011] The insulating material tape is a polytetrafluoroethylene tape film, a polyethylene film, a polypropylene film, or an aluminum foil.

[0012] Instead of wrapping with release tape, use a paste-like release agent or a release spray.

[0013] The insulating material plate is made of aluminum foil or white cardboard.

[0014] In step 10), cooling is performed using either water cooling or air cooling.

[0015] The corrosive liquid is a nitric acid corrosive liquid.

[0016] Compared with the prior art, the beneficial effects of the present invention are: the sample grinding fixture is made by using an inlay method, the manufacturing process is simple, the sample grinding fixture has the advantages of high positioning accuracy and convenient use, and it can be reused, which helps to improve experimental efficiency and reduce experimental costs. Attached Figure Description

[0017] Figure 1a is a schematic diagram of the manufacturing process of a sample grinding fixture for a phase change instrument according to the present invention.

[0018] Figure 1b is a top view of Figure 1a.

[0019] Figure 2a is a schematic diagram of the manufacturing process of a sample grinding fixture for a phase change instrument according to the present invention.

[0020] Figure 2b is a top view of Figure 2a.

[0021] Figure 3a is a schematic diagram of the manufacturing process of a sample grinding fixture for a phase change instrument according to the present invention.

[0022] Figure 3b is a top view of Figure 3a.

[0023] Figure 4a is a front sectional view of the clamp cover of the present invention.

[0024] Figure 4b is a top view of Figure 4a.

[0025] Figure 5a is a front cross-sectional view of the clamping body described in this invention.

[0026] Figure 5b is a top view of Figure 5a.

[0027] Figure 6 is a schematic diagram of a cylindrical sample to be ground being held in the sample grinding fixture described in this invention.

[0028] In the diagram: 1. Mold 2. Mold base 3. Hard plate 4. Pad 5. Sample column 6. Separating strip 7. Embedding powder 8. Pressure plate 9. Separating plate 10. Mold cover 11. Fixture cover 12. Positioning pin 13. Fixture body 14. Positioning hole 15. Cylindrical sample to be ground Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: The manufacturing method of the sample grinding fixture for a phase change instrument according to the present invention includes the following steps: 1) Making an inlay positioning plate, with inlay positioning holes opened on the inlay positioning plate; 2) As shown in Figures 1a and 1b, two cylindrical samples for phase change instruments are joined together to form a sample column 5, and one end of the sample column 5 is wrapped with a separating material strip 6, the wrapping length being not less than 3 / 4 of the total length of the sample column 5; the wrapped sample column 5 is inserted into the inlay positioning hole to obtain the object to be inlaid; 3) As shown in Figures 1a and 1b, the object to be inlaid is placed on the mold base 2, and the cylindrical mold 1 is placed around the object to be inlaid; 4) Inlay powder 7 is added into the mold 1, making it flush with the bottom surface of the inlay positioning plate; 5) As shown in Figures 2a and 2b, pressure is applied to the inlay powder 7 in the mold 1 through the pressure plate 8, and after the inlay powder 7 is compacted, the inlay positioning plate is removed, and the powder adding and pressing process is repeated until the filling height of the inlay powder 7 reaches h. 6) After replacing the pressure plate 8 with an isolation plate 9, repeat the powder filling and pressurization process to make the filling height of the embedded powder 7 reach 1.5h; 7) As shown in Figures 3a and 3b, after replacing the pressure plate 8 with another isolation plate 9, repeat the powder filling and pressurization process to make the filling height of the embedded powder 7 exceed 2h; 8) Remove the pressure plate 8 and place the mold cover 10 on top of the mold 1; 9) Move the mold cover 10 down to apply pressure to the inside of the mold 1, heat the mold 1 and keep it for a period of time to obtain the embedded block; 10) After the heat preservation is completed, cool the mold 1 and remove the pressure; 11) Open the mold cover 10, take the embedded block out of the mold 1 and then etch it; The embedded block is divided into three parts: bottom embedded block, middle embedded block and top embedded block; The bottom embedded block serves as the fixture body 13 (as shown in Figures 5a and 5b), the middle embedded block is discarded, and the top embedded block serves as the fixture cover 11 (as shown in Figures 4a and 4b). The fixture body 13 and the fixture cover 11 together form the sample grinding fixture.

[0030] As a preferred embodiment, the manufacturing method of the sample grinding fixture for a phase change instrument according to the present invention specifically includes the following steps: 1) As shown in Figures 1a and 1b, take a circular hard plate 3, and attach pads 4 (preferably rubber plates) with the same radius to both sides of the hard plate 3 to form an inlay positioning plate; drill n circular through holes on the inlay positioning plate as inlay positioning holes, the radius of the circular through holes being the same as the radius of the cylindrical sample for the phase change instrument; the radius r of the cylindrical sample is 1.5 to 2.5 mm.

[0031] 2) Take 2n cylindrical specimens for the phase change instrument, each with a height h of 10 mm; group every two cylindrical specimens together, and coaxially connect the two specimens in the same group to form a specimen column 5; wrap 3 / 4 of the total length of the specimen column 5 with a release tape 6 at one end, i.e., the wrapped length is 1.5h, and the exposed length at the other end is 0.5h; the release tape 6 is preferably made of polytetrafluoroethylene (PTFE) film, polyethylene (PE) film, polypropylene (PP) film, or aluminum foil. Alternatively, a paste-like release agent (such as silicone grease or petroleum jelly) or a release spray (such as silicone-based release spray) can be used instead of wrapping with the release tape 6.Insert the wrapped sample columns 5, with their exposed ends facing upwards, into the corresponding mounting holes of the mounting positioning plate. Adjust the position of the mounting positioning plate so that it is in the middle of the lower cylindrical sample of each sample column 5. After adjustment, the bottom surfaces of each sample column 5 are on the same horizontal plane, and this horizontal plane is parallel to the mounting positioning plate, thus obtaining the object to be mounted; 3) As shown in Figures 1a and 1b, place the object to be mounted on the mold base 2, and place the cylindrical mold 1 around the object to be mounted, so that the mold 1 is coaxial with the mounting positioning plate, and the inner diameter of the mold 1 is larger than the inner diameter of the mounting positioning plate; 4) Add the mounting powder 7 into the mold 1 through the annular gap between the mold 1 and the mounting positioning plate. During the addition process... Gently tap the outer wall of mold 1 to distribute the embedding powder 7 evenly. After the embedding powder 7 fills the space below the embedding positioning plate, continue adding powder until it is flush with the bottom surface of the embedding positioning plate. At this time, the filling height of the embedding powder 7 is 0.5h. 5) As shown in Figures 2a and 2b, take another circular pressure plate 8. The radius of the pressure plate 8 is the same as the inner diameter of mold 1. Circular through holes corresponding to the positions and radii of each sample column 5 are opened on the pressure plate 8. Place the pressure plate 8 on top of the embedding positioning plate, and then apply a pressure of 15-40 MPa to compact the embedding powder 7 downwards. Then remove the embedding positioning plate, add embedding powder 7 again, and make the filling height of the embedding powder 7 reach h. Repeat the powder adding and pressurizing process. 6) Take a separating material plate 9 (preferably aluminum foil or white cardboard) with the same shape and size as the pressure plate except for thickness. Replace the pressure plate with the separating material plate and continue to add the inserting powder until the filling height of the inserting powder reaches 1.5h. Press with the pressure plate and repeat the powder adding and pressing process until the height of the inserting powder no longer decreases after pressing. 7) As shown in Figures 3a and 3b, take another separating material plate 9 with the same shape and size as the pressure plate except for thickness. Add inserting powder again until the filling height of the inserting powder exceeds 2h. Press with the pressure plate and repeat the powder adding and pressing process until the height of the inserting powder no longer decreases after pressing. 8) Take 8) Remove the pressure plate and place the mold cover 10 on top of the mold 1, ensuring it is placed correctly and level, so that the cavity of the mold 1 containing the insert and insert powder 7 is completely sealed; 9) Move the mold cover 10 down and apply a pressure of 15-40 MPa to the inside of the mold 1, then heat the mold 1 to 130-180°C and maintain this pressure and temperature for 6-15 minutes, so that the thermosetting insert powder 7 undergoes a cross-linking reaction, melts, flows and solidifies to form an insert block; 10) After the heat preservation is completed, stop heating and cool the mold 1 to below 60°C (using water cooling or air cooling). During the cooling process, slowly remove the pressure to prevent pores or cracks from being generated due to the shrinkage of the insert material.

[0032] 11) Open the mold cover 10, remove the insert from the mold 1 and place it in the etching solution (preferably nitric acid etching solution). The etching solution etches the isolation plate 9 and enters the interior of the insert through the etched gaps to contact the sample column 5, causing the sample column 5 to shrink in volume after etching. The two isolation plates 9 divide the insert into three parts: bottom insert, middle insert and top insert. The bottom insert serves as the fixture body 13, as shown in Figures 5a and 5b. After the lower cylindrical sample is removed, it has multiple through holes with a height of h, which are used for positioning holes 14 during cylindrical sample grinding. The middle insert is discarded. The top insert serves as the fixture cover 11, as shown in Figures 4a and 4b. The upper cylindrical sample is embedded in it. That is, the top insert has multiple positioning posts 12 with an exposed length of 0.5h, which are used to push the cylindrical sample 15 to be ground out from the corresponding positioning holes 14 of the fixture body 13 during cylindrical sample grinding. The fixture body 13 and the fixture cover 11 together form the sample grinding fixture.

[0033] The sample grinding fixture for phase change instrument prepared by the present invention is used for hand-held grinding. When in use, the cylindrical sample 15 to be ground is placed in the positioning hole 14 of the fixture body 13, and the non-grinding end of the cylindrical sample 15 to be ground is axially positioned by the positioning pin 12 on the fixture cover 11. The part of the cylindrical sample 15 to be ground that protrudes outside the fixture body 13 is ground and polished until the experimental requirements are met.

[0034] To more intuitively illustrate the present invention, the embodiments of the present invention will be further described in conjunction with the examples. The following examples are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention, including simple variations or equivalent substitutions, are all within the scope of protection of the present invention.

[0035]

Example 1

[0036] 2) Take 8 cylindrical specimens for phase change instrument, each cylindrical specimen with a height h of 10 mm; take 4 groups of 2 cylindrical specimens in each group and connect the 2 cylindrical specimens in the same group coaxially to form a specimen column (height 20 mm); wrap 3 / 4 of the total length of the specimen column with a separating material tape at one end, i.e., wrapping length of 15 mm, and leave the other end exposed length of 5 mm; insert the wrapped specimen columns with the exposed ends facing up into the corresponding mounting positioning holes of the mounting positioning plate, adjust the position of the mounting positioning plate so that it is in the middle position of the lower cylindrical specimens of each specimen column, i.e., 5 mm away from the bottom surface of the specimen column. After adjustment, the bottom surfaces of each specimen column are on the same horizontal plane, and this horizontal plane is parallel to the mounting positioning plate, thus obtaining the object to be mounted.

[0037] 3) Place the object to be inlaid on the mold base, and place the cylindrical mold with an inner diameter of 30mm around the object to be inlaid, so that the mold is coaxial with the inlay positioning plate.

[0038] 4) Add the embedding powder into the mold through the annular gap between the mold and the embedding positioning plate. During addition, gently tap the outer wall of the mold to ensure even distribution of the embedding powder. After the embedding powder fills the space below the embedding positioning plate, continue adding until it is flush with the bottom surface of the embedding positioning plate. At this point, the filling height of the embedding powder is 5mm. 5) Take another circular pressure plate with a thickness of 2mm (a steel plate is used in this embodiment). The radius of the pressure plate is the same as the inner diameter of the mold (30mm). Circular through holes corresponding to the positions and radii of each sample column are made on the pressure plate. Place the pressure plate on top of the embedding positioning plate and apply a pressure of 28MPa to compact the embedding powder downwards. Then remove the embedding positioning plate and add embedding powder again. 6) Take a separating material plate (30mm in diameter, with holes) that has the same shape and size as the pressure plate except for its thickness. Replace the pressure plate with the separating material plate and continue adding insert powder until the insert powder reaches a filling height of 15mm. Press with the pressure plate and repeat the process of adding powder and pressing until the insert powder no longer decreases after pressing. 7) Take another separating material plate that has the same shape and size as the pressure plate except for its thickness. Add insert powder again until the insert powder reaches a filling height of 21mm. Press with the pressure plate and repeat the process of adding powder and pressing until the insert powder no longer decreases after pressing. 8) Remove the pressure plate and place the mold cover on top of the mold to completely seal the mold cavity containing the insert and insert powder; 9) Lower the mold cover and apply a pressure of 28 MPa to the inside of the mold. Then heat the mold to 150°C and maintain this pressure and temperature for 8 minutes to allow the thermosetting insert powder to undergo a cross-linking reaction, melt, flow, and solidify to form an insert block; 10) After the heat preservation is completed, stop heating and cool the mold to 50°C using water cooling. During the cooling process, slowly remove the pressure; 11) Open the mold cover, remove the insert block from the mold, and place it in a nitric acid etching solution for 1 minute. The nitric acid etching solution will corrode the release agent. The plate enters the insert through the corrosion-induced gaps and contacts the sample column, causing the sample column's volume to shrink after corrosion. Two layers of isolation plates divide the insert into three parts: a bottom insert, a middle insert, and a top insert. The bottom insert acts as a clamping body, with four 10mm high through holes for positioning during cylindrical sample grinding after the lower cylindrical sample is removed. The middle insert is discarded. The top insert acts as a clamping cover, with the upper cylindrical sample embedded within it. The top insert has four 5mm exposed positioning pins for ejecting the cylindrical sample from the corresponding positioning holes in the clamping body for grinding. The clamping body and the clamping cover together form the sample grinding fixture. The length of the cylindrical sample to be ground is (10mm + grinding amount), and the length of the cylindrical sample after grinding is 10mm.

[0039] The sample grinding fixture prepared in this embodiment can grind four cylindrical samples to be ground simultaneously.

[0040] [Example 2] In this example, the manufacturing process of the sample grinding fixture for the phase change instrument is as follows: 1) Take a circular hard plate with a diameter of 30 mm and a thickness of 2 mm. Attach pads with a diameter of 30 mm and a thickness of 2 mm to both sides of the hard plate to form an inlay positioning plate. The pads are made of rubber and have a certain degree of elasticity. Drill 11 circular through holes on the inlay positioning plate as inlay positioning holes. The radius of the circular through holes is the same as the radius of the cylindrical sample used in the phase change instrument, i.e., r = 1.5 mm.

[0041] 2) Take 22 cylindrical specimens for phase change instrument, each with a height h of 10 mm; two cylindrical specimens are grouped together, for a total of 11 groups. After coaxially connecting the two cylindrical specimens in the same group, a specimen column (height 20 mm) is formed. Use a separating material tape to wrap 3 / 4 of the total length of the specimen column at one end, i.e., the wrapping length is 15 mm, and the exposed length at the other end is 5 mm. Insert the wrapped specimen columns with the exposed ends facing up into the corresponding mounting positioning holes of the mounting positioning plate. Adjust the position of the mounting positioning plate so that it is in the middle position of the lower cylindrical specimens of each specimen column, i.e., 5 mm away from the bottom surface of the specimen column. After adjustment, the bottom surfaces of each specimen column are on the same horizontal plane, and this horizontal plane is parallel to the mounting positioning plate, thus obtaining the object to be mounted.

[0042] 3) Place the object to be inlaid on the mold base, and place the cylindrical mold with an inner diameter of 40mm around the object to be inlaid, so that the mold is coaxial with the inlay positioning plate.

[0043] 4) Add the embedding powder into the mold through the annular gap between the mold and the embedding positioning plate. During addition, gently tap the outer wall of the mold to ensure even distribution of the embedding powder. After the embedding powder fills the space below the embedding positioning plate, continue adding until it is flush with the bottom surface of the embedding positioning plate. At this point, the filling height of the embedding powder is 5mm. 5) Take another circular pressure plate with a thickness of 2mm (a steel plate is used in this embodiment). The radius of the pressure plate is the same as the inner diameter of the mold (40mm). Circular through holes corresponding to the positions and radii of each sample column are made on the pressure plate. Place the pressure plate on top of the embedding positioning plate and apply a pressure of 35MPa to compact the embedding powder downwards. Then remove the embedding positioning plate and add embedding powder again. 6) Take a separator plate (40mm in diameter, with holes) that has the same shape and size as the pressure plate except for its thickness. Replace the pressure plate with the separator plate and continue adding separator powder until the filling height reaches 15mm. Press down with the pressure plate and repeat the process of adding powder and pressing until the filling height of the separator powder no longer decreases. 7) Take another separator plate that has the same shape and size as the pressure plate except for its thickness. Add separator powder again until the filling height reaches 21mm. Press down with the pressure plate and repeat the process of adding powder and pressing until the filling height of the separator powder no longer decreases. 8) Remove the pressure plate and place the mold cover on top of the mold to completely seal the mold cavity containing the insert and the insert powder; 9) Lower the mold cover and apply a pressure of 32 MPa to the inside of the mold. Then heat the mold to 160°C and maintain this pressure and temperature for 12 minutes to allow the thermosetting insert powder to undergo a cross-linking reaction, melt, flow, and solidify to form an insert block; 10) After the heat preservation is completed, stop heating and cool the mold to 40°C using air cooling. During the cooling process, slowly remove the pressure; 11) Open the mold cover, remove the insert block from the mold, and place it in a nitric acid etching solution for 1 minute. The nitric acid etching solution will then corrode the isolation plate. The sample enters the insert through the corrosion-induced gaps and contacts the sample column, causing the sample column's volume to shrink after corrosion. Two layers of isolation plates divide the insert into three parts: a bottom insert, a middle insert, and a top insert. The bottom insert acts as a clamping body, with 11 through holes, each 10mm high, for positioning during cylindrical sample grinding after the lower cylindrical sample is removed. The middle insert is discarded. The top insert acts as a clamping cover, with the upper cylindrical sample embedded within it. The top insert has 11 exposed positioning pins, each 5mm long, used to push the cylindrical sample to be ground out from the corresponding positioning holes in the clamping body for grinding. The clamping body and the clamping cover together form the sample grinding fixture. The length of the cylindrical sample to be ground is (10mm + grinding amount), and the length of the cylindrical sample after grinding is 10mm.

[0044] The sample grinding fixture prepared in this embodiment can grind 11 cylindrical samples to be ground at the same time.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a sample grinding fixture for a phase change instrument, characterized in that, The process includes the following steps: 1) Fabricating an inlay positioning plate with inlay positioning holes; 2) Connecting two phase change instruments with cylindrical samples to form a sample column, wrapping one end of the sample column with a separating material tape, the wrapping length being no less than 3 / 4 of the total length of the sample column; inserting the wrapped sample column into the inlay positioning hole to obtain the inlay body; 3) Placing the inlay body on the mold base, and placing the cylindrical mold around the inlay body; 4) Adding inlay powder into the mold, making it flush with the bottom surface of the inlay positioning plate; 5) Applying pressure to the inlay powder in the mold using a pressure plate, compacting the inlay powder, removing the inlay positioning plate, and repeating the powder adding and pressurizing process until the filling height of the inlay powder reaches h; 6) Replacing the pressure plate with a separating material plate and then... 7) After replacing the pressure plate with another isolation plate, repeat the powder filling and pressurization process to make the powder filling height exceed 2h; 8) Remove the pressure plate and place the mold cover on top of the mold; 9) Move the mold cover down to apply pressure to the inside of the mold, heat the mold and hold it for a period of time to obtain the insert; 10) After the heat preservation is completed, cool the mold and remove the pressure; 11) Open the mold cover, take the insert out of the mold and then etch it; The insert is divided into three parts: bottom insert, middle insert and top insert; The bottom insert serves as the fixture body, the middle insert is discarded, and the top insert serves as the fixture cover. The fixture body and the fixture cover together form the sample grinding fixture.

2. The method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1, characterized in that, The specific steps are as follows: 1) Take a circular rigid plate and attach pads with the same radius to both sides of the rigid plate to form an inlay positioning plate; drill n circular through holes on the inlay positioning plate as inlay positioning holes, the radius of the circular through holes being the same as the radius of the cylindrical sample used for the phase change instrument; 2) Take 2n cylindrical samples for the phase change instrument, each cylindrical sample having a height h of 10mm; group every two cylindrical samples together, and coaxially connect the two cylindrical samples in the same group to form a sample column; use a separating material tape to secure the sample column at one end. The sample column is wrapped with 3 / 4 of its total length, i.e., the wrapped length is 1.5h, and the other end is exposed with a length of 0.5h. The wrapped sample columns are inserted one by one into the mounting positioning holes of the mounting positioning plate with the exposed ends facing upwards. The position of the mounting positioning plate is adjusted so that it is in the middle position of the lower cylindrical sample of each sample column. After adjustment, the bottom surface of each sample column is on the same horizontal plane, and this horizontal plane is parallel to the mounting positioning plate, thus obtaining the object to be mounted; 3) The object to be mounted is placed on the mold base, and the cylindrical mold is placed on the object to be mounted. 4) Add the inlay powder into the mold through the annular gap between the mold and the inlay positioning plate. During the addition process, gently tap the outer wall of the mold to distribute the inlay powder evenly. After the inlay powder fills the space below the inlay positioning plate, continue adding until it is flush with the bottom surface of the inlay positioning plate. At this time, the filling height of the inlay powder is 0.5h. 5) Take another circular pressure plate with the same radius as the inner diameter of the mold. Make circular through holes on the pressure plate corresponding to the position and radius of each sample column. Place the pressure plate on top of the inlay positioning plate and then apply a pressure of 15-40MPa to compact the inlay powder downwards. Then remove the inlay positioning plate and add inlay powder again until the filling height of the inlay powder reaches h. Repeat the powder adding and pressurizing process until the height of the inlay powder no longer decreases after pressurization. 6) Take a separation material plate with the same shape and size as the pressure plate except for the thickness. Replace the pressure plate with the separation material plate and continue adding inlay powder until the filling height of the inlay powder reaches 1.5h; Press with a pressure plate and repeat the powder adding and pressing process until the height of the embedded powder no longer decreases after pressing; 7) Take another isolation plate with the same shape and size as the pressure plate except for the thickness, add the embedded powder again, so that the filling height of the embedded powder exceeds 2h; Press with a pressure plate and repeat the powder adding and pressing process until the height of the embedded powder no longer decreases after pressing; 8) Remove the pressure plate, place the mold cover on the top of the mold, so that the mold cavity containing the embedded body and embedded powder is in a completely closed state; 9) Move the mold cover down, apply a pressure of 15-40MPa to the inside of the mold, then heat the mold to 130-180℃, and maintain this pressure and temperature for 6-15min, so that the thermosetting embedded powder undergoes a cross-linking reaction, melts, flows and solidifies to form an embedded block; 10) After the heat preservation is completed, stop heating and cool the mold to 6 Below 0℃, slowly remove pressure during cooling; 11) Open the mold cover, remove the insert from the mold and place it in the etching solution. The etching solution corrodes the isolation plate and enters the interior of the insert through the corrosion gaps to contact the sample column, causing the sample column to shrink in volume after corrosion; the two isolation plates divide the insert into three parts: bottom insert, middle insert, and top insert; the bottom insert acts as a clamping body, and after the lower cylindrical sample is removed, it has multiple through holes with a height of h, which are used for positioning holes during cylindrical sample grinding; the middle insert is discarded; the top insert acts as a clamping cover, and the upper cylindrical sample is embedded in it, that is, the top insert has multiple positioning pins with an exposed length of 0.5h, which are used to push the cylindrical sample to be ground out from the corresponding positioning holes of the clamping body during cylindrical sample grinding; the clamping body and the clamping cover together form the sample grinding fixture.

3. A method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1 or 2, characterized in that, The radius r of the cylindrical sample is 1.5 to 2.5 mm.

4. A method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1 or 2, characterized in that, The pad is a rubber sheet.

5. A method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1 or 2, characterized in that, The insulating material tape is a polytetrafluoroethylene tape film, a polyethylene film, a polypropylene film, or an aluminum foil.

6. A method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1 or 2, characterized in that, Instead of wrapping with release tape, use a paste-like release agent or a release spray.

7. A method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1 or 2, characterized in that, The insulating material plate is made of aluminum foil or white cardboard.

8. A method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1 or 2, characterized in that, In step 10), cooling is performed using either water cooling or air cooling.

9. A method for manufacturing a sample grinding fixture for a phase change instrument according to claim 1 or 2, characterized in that, The corrosive liquid is a nitric acid corrosive liquid.

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