Metallographic mounting method for ultrathin metal strip

Abstract

The invention discloses a metallographic sample mounting method for an ultrathin metal strip, which comprises the following steps of: 1, bending the edge of the ultrathin metal strip inwards along a plurality of directions to obtain a sample with a horizontal top surface and a plurality of bending angles at the bottom end; step 2, adhering the top surface of the sample to the inner bottom surface of a mold of a hot sample mounting machine, and then carrying out hot sample mounting; and 3, grinding and polishing the sample subjected to hot mounting. According to the sample mounting method, the ultra-thin metal strip is bent inwards, so that the bending angle of the ultra-thin metal strip is embedded into the resin block at a certain angle, the contact area of the ultra-thin metal strip and the resin block is increased, and the situation that the ultra-thin metal strip cannot be firmly attached to the resin block and is prone to falling off is avoided. The method is suitable for the technical field of metal material metallographic sample preparation.

Description

Technical Field

[0001] The invention belongs to the technical field of metallographic sample preparation of metal materials, and in particular relates to a metallographic sample mounting method for ultra-thin metal strips. Background Art

[0002] Ultrathin metal strips (approximately tens of microns thick) have become key materials in modern science and industry due to their lightweight, high strength, excellent electrical and thermal conductivity, and flexible processing capabilities. Their application has penetrated nearly every high-tech field, from consumer electronics to defense and military applications. Their core value lies in achieving functional integration and performance breakthroughs unattainable with their extremely thin thickness, unmatched by traditional materials. With the convergence of materials science, precision machining, and interdisciplinary technologies, their potential for application in fields such as quantum technology and biomedicine will be further unleashed.

[0003] When ultra-thin metal strips are used in various fields, the properties of the material itself become the focus of research. Observing the metallographic structure has become an indispensable test method for analyzing its microscopic morphology. The first step in metallographic sample preparation for traditional specimens is mounting, which is divided into cold mounting and hot mounting. It can be used to prepare small specimens or sharp specimens with irregular shapes, and can achieve perfect edge protection. Among them, the hot mounting method has the characteristics of high quality, uniform size and shape, and short preparation time. However, when using a hot mounting machine to mount ultra-thin metal strips, it cannot fit firmly with the resin block, resulting in the ultra-thin metal strip falling off; and conventional hot mounting parameters will cause damage to the ultra-thin metal strip. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art by providing a metallographic mounting method for ultrathin metal strips. This method bends the ultrathin metal strip inward, embedding the bent corner of the ultrathin metal strip into a resin block at a certain angle. This increases the contact area between the ultrathin metal strip and the resin block, solving the problem of the ultrathin metal strip not being able to securely adhere to the resin block and being prone to falling off.

[0005] To achieve the above object, the present invention adopts a technical solution: a metallographic mounting method for ultra-thin metal strips, characterized in that the mounting method comprises the following steps: Step 1: bend the edge of the ultra-thin metal strip inward in several directions to obtain a sample with a horizontal top surface and a plurality of bending angles at the bottom end; Step 2: stick the top surface of the sample obtained in step 1 to the bottom surface of the hot mounting mold, and then perform hot mounting; Step 3: Grind and polish the sample hot-mounted in step 2.

[0006] The above-mentioned metallographic mounting method for an ultra-thin metal strip is characterized in that the ultra-thin metal strip is cleaned with acetone or anhydrous ethanol before being bent inward in step 1.

[0007] The invention adopts acetone or anhydrous ethanol to clean the ultra-thin metal strip, so as to avoid surface deformation of the ultra-thin metal strip caused by wiping.

[0008] The above-mentioned metallographic mounting method of an ultra-thin metal strip is characterized in that, when the flat surface of the ultra-thin metal strip before being bent inward in step one is a rectangle, the four corners are bent inward respectively, and the right-angled sides of the bending angles are all less than 1 / 2 of the length of the sides of the rectangle to which they belong; when the flat surface of the ultra-thin metal strip before being bent inward is a circle or an irregular shape, it is bent inward along the four directions of east, south, west and north respectively, and the height of the bending angles in each direction is less than 1 / 4 of the diameter or long axis of the ultra-thin metal strip.

[0009] The present invention can maximize the adhesion between the ultra-thin metal strip with a bending angle and the resin powder by controlling the length of the bending angle to be no greater than 1 / 2 of the side length of the rectangle to which it belongs and the height of the bending angle to be less than 1 / 4 of the diameter or long axis of the ultra-thin metal strip.

[0010] The above-mentioned metallographic mounting method of an ultra-thin metal strip is characterized in that when the flat surface of the ultra-thin metal strip before being bent inward in step one is rectangular, the length and width are both 5mm~15mm; when the flat surface of the ultra-thin metal strip before being bent inward is circular, the diameter is 5mm~15mm; when the flat surface of the ultra-thin metal strip before being bent inward is irregular, the major axis and minor axis are both 5mm~15mm.

[0011] The present invention controls the size of the ultra-thin metal strip to 5mm-15mm. Since the mounting hole of the mounting machine is a circle with a diameter of 30mm, the length and width of the ultra-thin metal strip exceed 15mm. During the hot mounting process, gaps will appear on the inside of the ultra-thin metal strip, resulting in unstable contact and easy falling off.

[0012] The above-mentioned metallographic mounting method for an ultra-thin metal strip is characterized in that the inner angle of the bending angle in step 1 is 30°~90°.

[0013] The present invention sets the inner angle of the bending angle to 30°-90°, thereby preventing the bending angle from being flattened during the hot mounting process, thereby reducing the firmness between the ultra-thin metal strip and the resin block.

[0014] The above-mentioned metallographic mounting method for an ultra-thin metal strip is characterized in that the hot mounting method described in step 2 is: lowering the bottom surface of the mold by 8 mm to 12 mm, adding resin powder around the sample, and then adding resin powder to the middle of the sample. When the resin powder completely covers the sample, lowering the bottom surface of the mold to the lowest point and continuing to add resin powder until the height of the resin powder in the mold does not exceed 1 / 2 of the mold height, and then keeping it warm at 120°C to 140°C and 5MPa to 10MPa for 3min to 5min.

[0015] The present invention lowers the bottom surface of the mold by 8mm to 12mm at first, so that resin powder can be added at this height and the resin powder can be ensured to completely cover the sample. Then, the bottom surface of the mold is lowered to the lowest point and the resin powder is filled. The sample hot-mounted by this method has a high-quality resin block, is convenient for subsequent polishing, and does not waste resin powder. By adopting the method of first adding the resin powder around the sample and then adding it to the middle of the sample, it is avoided that the bending angle will be crushed by adding it to the middle of the sample first. Since the strength of the ultra-thin metal strip is low, in order to maximize the adhesion between the bending angle and the resin powder, the bending angle is used as the maximum inward force, so the resin powder is first added around the sample and then to the middle of the sample. By controlling the hot mounting temperature and pressure, it is suitable for ultra-thin metal strips of different materials, different melting points and different temperature sensitivity ranges, and can avoid bubbles or melting on the inside of the ultra-thin metal strip. By controlling the height of the resin powder in the mold not to exceed 1 / 2 of the mold height, it is ensured that the sample is easy to take out while reducing the waste of resin powder caused by the sample being too high.

[0016] The above-mentioned metallographic mounting method for an ultra-thin metal strip is characterized in that the polishing in step three is performed using 2000-mesh metallographic wet sandpaper.

[0017] The present invention adopts 2000 mesh metallographic water sandpaper for grinding, so as to avoid the ultra-thin metal strip being damaged due to excessive grinding.

[0018] Compared with the prior art, the present invention has the following advantages: 1. The present invention bends the ultra-thin metal strip inward so that the bending angle of the ultra-thin metal strip is embedded in the resin block at a certain angle, thereby increasing the contact area between the ultra-thin metal strip and the resin block, improving the firmness of the combination of the ultra-thin metal strip and the resin block, and avoiding the phenomenon of the ultra-thin metal strip falling or loosening.

[0019] 2. The mounting method of the present invention is easy to operate, non-toxic, and can quickly perform longitudinal metallographic hot mounting of ultra-thin metal strips, greatly improving the sample preparation quality and efficiency. It does not require additional special equipment and is easy to promote.

[0020] 3. The present invention can avoid the formation of bubbles or melting inside the ultra-thin metal strip, which would cause damage to the ultra-thin metal strip sample, by properly controlling the temperature and pressure of the hot mounting.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the rectangular ultra-thin metal strip after being bent inwards according to the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of the circular ultra-thin metal strip after being bent inwards according to the present invention. DETAILED DESCRIPTION

[0024] Example 1 The mounting method of this embodiment comprises the following steps: Step 1: Take a rectangular ultra-thin metal strip with a length and width of 5mm, clean it with acetone or anhydrous ethanol, and bend the four corners of the ultra-thin metal strip inward to obtain Figure 1 The sample shown has a horizontal top surface and four bent angles at the bottom; the inner angles of the right angles of the bent angles are all 30°, and the lengths of the right angles of the bent angles are all less than 1 / 2 of the length of the side of the rectangle to which they belong; Step 2: Use double-sided tape to adhere the top surface of the sample obtained in Step 1 to the inner bottom surface of the hot mounting mold. Then lower the bottom of the mold by 10 mm, add resin powder around the sample, and then add resin powder to the middle of the sample. When the resin powder completely covers the sample, lower the bottom of the mold to the lowest point and continue adding resin powder until the height of the resin powder in the mold does not exceed 1 / 2 of the mold height. Then, heat it at 120°C and 5 MPa for 3 minutes before hot mounting. Step 3: Grind and polish the sample hot-mounted in step 2 using 2000-grit metallographic water sandpaper.

[0025] The surface of the sample prepared in this embodiment is mirror-like, in preparation for subsequent metallographic structure observation.

[0026] Example 2 The mounting method of this embodiment comprises the following steps: Step 1: Take a 10mm diameter round ultra-thin metal strip, clean it with acetone or anhydrous ethanol, and bend the edges of the ultra-thin metal strip inward along the four directions of east, south, west and north to obtain the following: Figure 1 The sample shown has a horizontal top surface and four bending angles at the bottom; the inner angle of the bending angles is 60°, and the height of the bending angles in each direction is less than 1 / 4 of the long axis of the ultra-thin metal strip; Step 2: Use double-sided tape to adhere the top surface of the sample obtained in Step 1 to the inner bottom surface of the hot mounting mold. Then lower the mold bottom by 8 mm, add resin powder around the sample, and then add resin powder to the center of the sample. When the resin powder completely covers the sample, lower the mold bottom to the lowest point and continue adding resin powder until the height of the resin powder in the mold does not exceed 1 / 2 of the mold height. Then, heat it at 130°C and 7 MPa for 4 minutes before hot mounting. Step 3: Grind and polish the sample hot-mounted in step 2 using 2000-grit metallographic water sandpaper.

[0027] The surface of the sample prepared in this embodiment is mirror-like, in preparation for subsequent metallographic structure observation.

[0028] Example 3 The mounting method of this embodiment comprises the following steps: Step 1: Take an irregularly shaped ultra-thin metal strip with a major axis and a minor axis of 15 mm, clean it with acetone or anhydrous ethanol, and bend the edges of the ultra-thin metal strip inward in the four directions of east, south, west and north to obtain a sample with a horizontal top surface and four bending angles at the bottom; the inner angle of the bending angles is 90°, and the height of the bending angle in each direction is less than 1 / 4 of the major axis of the ultra-thin metal strip; Step 2: Use double-sided tape to adhere the top surface of the sample obtained in Step 1 to the inner bottom surface of the hot mounting mold. Then lower the mold bottom by 12 mm, add resin powder around the sample, and then add resin powder to the center of the sample. When the resin powder completely covers the sample, lower the mold bottom to the lowest point and continue adding resin powder until the height of the resin powder in the mold does not exceed 1 / 2 of the mold height. Then, heat it at 140°C and 10 MPa for 5 minutes before hot mounting. Step 3: Grind and polish the sample hot-mounted in step 2 using 2000-grit metallographic water sandpaper.

[0029] The surface of the sample prepared in this embodiment is mirror-like, in preparation for subsequent metallographic structure observation.

[0030] Example 4 The difference between this embodiment and embodiment 1 is that in step 1, the length of the rectangular ultra-thin metal strip is 10 mm and the width is 15 mm.

[0031] The surface of the sample prepared in this embodiment is mirror-like, in preparation for subsequent metallographic structure observation.

[0032] Example 5 The difference between this embodiment and embodiment 2 is that the diameter of the circular ultra-thin metal strip in step 1 is 5 mm.

[0033] The surface of the sample prepared in this embodiment is mirror-like, in preparation for subsequent metallographic structure observation.

[0034] Example 6 The difference between this embodiment and embodiment 2 is that the diameter of the circular ultra-thin metal strip in step 1 is 15 mm.

[0035] The surface of the sample prepared in this embodiment is mirror-like, in preparation for subsequent metallographic structure observation.

[0036] Example 7 The difference between this embodiment and embodiment 3 is that in step 1, the long axis of the irregularly shaped ultra-thin metal strip is 8 mm and the short axis is 5 mm.

[0037] The surface of the sample prepared in this embodiment is mirror-like, in preparation for subsequent metallographic structure observation.

[0038] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A metallographic mounting method for ultra-thin metal strips, characterized in that: The mounting method includes the following steps: Step 1: bend the edge of the ultra-thin metal strip inward in several directions to obtain a sample with a horizontal top surface and a plurality of bending angles at the bottom end; Step 2: stick the top surface of the sample obtained in step 1 to the bottom surface of the hot mounting mold, and then perform hot mounting; Step 3: Grind and polish the sample hot-mounted in step 2.

2. The metallographic mounting method of an ultra-thin metal strip according to claim 1, characterized in that: The ultra-thin metal strip described in step 1 is cleaned with acetone or anhydrous ethanol before being bent inward.

3. The metallographic mounting method of an ultra-thin metal strip according to claim 1, characterized in that: When the flat surface of the ultra-thin metal strip before being bent inward in step one is a rectangle, the four corners are bent inward respectively, and the right-angled sides of the bending angles are all less than 1 / 2 of the length of the sides of the rectangle to which they belong; when the flat surface of the ultra-thin metal strip before being bent inward is a circle or an irregular shape, it is bent inward along the four directions of east, south, west and north, and the height of the bending angles in each direction is less than 1 / 4 of the diameter or long axis of the ultra-thin metal strip.

4. The metallographic mounting method of an ultra-thin metal strip according to claim 1, characterized in that: When the flat surface of the ultra-thin metal strip before being bent inward in step one is rectangular, the length and width are both 5mm~15mm; when the flat surface of the ultra-thin metal strip before being bent inward is circular, the diameter is 5mm~15mm; when the flat surface of the ultra-thin metal strip before being bent inward is irregular, the major axis and minor axis are both 5mm~15mm.

5. The metallographic mounting method of an ultra-thin metal strip according to claim 1, characterized in that: The inner angle of the bending angle in step 1 is 30°~90°.

6. The metallographic mounting method of an ultra-thin metal strip according to claim 1, characterized in that: The hot mounting method described in step 2 is as follows: lower the bottom of the mold by 8mm~12mm, add resin powder around the edges of the sample, and then add resin powder to the middle of the sample. When the resin powder completely covers the sample, lower the bottom of the mold to the lowest point and continue adding resin powder until the height of the resin powder in the mold does not exceed 1 / 2 of the mold height, then keep warm at 120℃~140℃ and 5MPa~10MPa for 3min~5min.

7. The metallographic mounting method of an ultra-thin metal strip according to claim 1, characterized in that: The polishing described in step 3 is performed using 2000-grit metallographic water sandpaper.

Images