Metallographic mounting method for metal strips

Abstract

The present invention discloses a metallographic mounting method for metal strips, comprising the following steps: sample preparation: obtaining a section of metal strip to be tested from a raw metal strip; bending: bending the metal strip to be tested into a corrugated shape, wherein the bent metal strip comprises at least three connecting edges and at least two connecting portions, with two adjacent connecting edges connected by corresponding connecting portions; and inlay molding: inlay molding the bent metal strip to produce a metallographic specimen. The invention provides a metallographic mounting method for metal strips that ensures metallographic continuity when the inlaid metal strip is greater than the diameter of the metallographic specimen and is easy to measure.

Description

Technical Field

[0001] The invention relates to the technical field of metallographic sample preparation, in particular to a metallographic inlay method of a metal strip. Background Art

[0002] With the continuous deep processing of metal materials, metal strips are gradually developing in the direction of becoming thinner and lighter. Especially for battery materials, achieving ultra-thinness and lightweight has become a trend. In the field of battery materials, the metal strips involved are usually metal composite materials. Whether it is from the analysis of composite metal composition, processing performance, or analysis of internal structural changes of metal materials, it is necessary to use metallographic analysis methods. That is, a strip of composite material needs to be made into a metallographic specimen. The inlay molding step of making the metallographic specimen usually includes placing the strip to be tested into the inner chamber of the inlaying machine, filling the inner chamber with inlay powder, heating and melting the inlay powder, and cooling and solidifying it, thereby obtaining a metallographic specimen with the strip embedded inside. At present, there are two main inlay molding methods for metal strips whose length exceeds the diameter of the metallographic specimen. The first method is linear sampling, which is to cut the long metal strip into multiple short metal strips that are basically straight and then place them in the inlay machine for inlay molding. The first method requires a sample clamp or other fixing device to clamp and fix each short metal strip, and the metallographic structure of the resulting metallographic specimen is discontinuous; the second method is winding sampling, which is to wind the long metal strip into a roll and then place it in the inlay machine for inlay molding. Since the gaps between the layers of the rolled metal strip are small, it is difficult to fill them with inlay powder, resulting in incomplete filling of the inlay powder, making it easy for the obtained metallographic specimen to produce bubbles, and the gaps between the metal strip layers in the metallographic specimen are small or even stuck together, which makes it difficult to distinguish the layers of metal strips during metallographic testing, affecting the detection. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a metallographic mounting method for metal strips, which can ensure that the mounted metal strips are metallographically continuous when the length is greater than the diameter of the metallographic specimen and can be easily measured.

[0004] According to an embodiment of the present invention, the metallographic inlay method of a metal strip includes the following steps: sample preparation: obtaining a section of the metal strip to be tested from the metal strip raw material; bending: bending the metal strip to be tested into a corrugated shape, wherein the bent metal strip includes at least three connecting edges and at least two connecting parts, and two adjacent connecting edges are connected by corresponding connecting parts; inlay molding: inlay molding the bent metal strip to produce a metallographic specimen.

[0005] The metallographic inlay method for metal strips according to the embodiment of the present invention has at least the following beneficial effects: through the above-mentioned arrangement, the length of the inlaid metal strip can be greater than the diameter of the metallographic sample, and the distance between two adjacent connecting edges can be easily adjusted and controlled to ensure that the distance between the two adjacent connecting edges is large enough. Compared with the existing linear sample preparation, the metallographic inlay method provided by the embodiment of the present invention can ensure the metallographic continuity of the inlaid metal strip, and the detection results are more representative of the sample, and no fixing device is required. Compared with the existing winding sample preparation method, the metallographic inlay method provided by the embodiment of the present invention is easier to fill with inlay powder and reduce the bubbles generated by the metallographic sample. The two adjacent connecting edges will not be too close to affect the detection, and are easy to measure.

[0006] According to some embodiments of the present invention, the connecting portion is arc-shaped.

[0007] According to some embodiments of the present invention, in the bending step, the metal strip is bent around the round rod so that the connecting portion is arc-shaped.

[0008] According to some embodiments of the present invention, two adjacent connecting edges are parallel to each other or arranged at an angle.

[0009] According to some embodiments of the present invention, the metal strip is straight in its width direction without side bending.

[0010] According to some embodiments of the present invention, the metal strip has a thickness s, wherein 0.06 mm ≤ s ≤ 0.50 mm.

[0011] According to some embodiments of the present invention, the minimum distance between two adjacent connecting edges is h, where h≥8s.

[0012] According to some embodiments of the present invention, the diameter of the metallographic sample is d, and the total length of the metal strip is L, wherein d≤L≤5d.

[0013] According to some embodiments of the present invention, the inlay molding includes the following steps: inlaying: placing the bent metal strip in the inner bin of the inlay machine, then filling the inner bin with inlay powder, and then covering and sealing it; heating: heating the inner bin to a temperature of 155°C-160°C; pressurizing and keeping warm to melt the inlay powder to form a metallographic sample; and cooling the metallographic sample.

[0014] According to some embodiments of the present invention, the heat preservation time after pressurization is 15 to 20 minutes.

[0015] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0017] Figure 1 Flowchart of a metallographic inlay method for a metal strip according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A flow chart of the inlay molding of the metallographic inlay method of the metal strip is shown;

[0019] Figure 3 Schematic diagram of a metal strip (two adjacent connecting edges form an angle) bent according to the metallographic inlay method of a metal strip according to an embodiment of the present invention;

[0020] Figure 4 Schematic diagram of a metal strip (two adjacent connecting edges are parallel to each other) bent according to the metallographic inlay method of a metal strip according to an embodiment of the present invention;

[0021] Figure 5 A top view of a metal strip bent according to the metallographic inlay method of a metal strip according to an embodiment of the present invention;

[0022] Figure 6 is a schematic diagram of a bending process of a metallographic inlay method for a metal strip according to an embodiment of the present invention;

[0023] Figure 7 This is a physical picture of a metallographic sample produced by the metallographic mounting method of a metal strip according to an embodiment of the present invention.

[0024] Reference numerals:

[0025] Metal strip 100 , connecting edge 110 , connecting portion 120 , and round rod 200 . DETAILED DESCRIPTION

[0026] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0027] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0028] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0029] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0030] Existing linear sample preparation methods require cutting multiple short metal strips, then using sample clamps or other fixtures to clamp and secure the short metal strips, ensuring that the multiple short metal strips are spaced apart. The metallographic specimens obtained using linear sample preparation methods are discontinuous, and in practice, the order of the short metal strips can easily be mixed up, resulting in test results that fail to accurately reflect the metallographic changes in the metal strip 100. Existing coiled sample preparation methods typically require the use of a machine to coil the metal strip. The resulting metallographic specimens have small gaps between the layers of metal strip 100, or even have them adhered to each other. This makes it difficult to distinguish the individual metal strips during metallographic testing, and it is also difficult to determine the location of the test point (or test area) on the entire metal strip 100.

[0031] Reference Figure 1 、 Figure 2 、 Figure 3 and Figure 7 The metallographic inlay method of a metal strip according to an embodiment of the present invention includes the following steps: sample preparation: obtaining a section of metal strip 100 to be tested from the metal strip raw material; bending: bending the metal strip 100 to be tested into a corrugated shape, wherein the bent metal strip 100 includes at least three connecting edges 110 and at least two connecting portions 120, and two adjacent connecting edges 110 are connected by corresponding connecting portions 120; and inlay molding: inlay molding the bent metal strip 100 to produce a metallographic sample.

[0032] Reference Figure 3 and Figure 7Through the above arrangement, the length of the inlaid metal strip 100 can be greater than the diameter of the metallographic sample, and the distance between two adjacent connecting edges 110 can also be easily adjusted and controlled to ensure that the distance between the two adjacent connecting edges 110 is large enough. Compared with the existing linear sample preparation, the metallographic inlay method provided by the embodiment of the present invention can ensure the metallographic continuity of the inlaid metal strip 100, and the test results are more representative of the sample, and no fixing device is required. Compared with the existing winding sample preparation method, the metallographic inlay method provided by the embodiment of the present invention is easier to fill with inlay powder and reduce the bubbles generated by the metallographic sample. The two adjacent connecting edges 110 will not be too close to affect the detection, and are easy to measure.

[0033] like Figures 3 to 5 As shown, the metal strip 100 to be tested is bent into a corrugated shape, and the connecting edges 110 of the bent metal strip 100 are arranged in sequence along the left-right direction. The distance between two adjacent connecting edges 110 is sufficient, and it is easy to distinguish between each connecting edge 110 and the connecting portion 120. The position of the testing point on the entire metal strip 100 can also be easily seen. In addition, the upper surface of each connecting edge 110 is relatively flush with the upper surface of each connecting portion 120, and the lower surface of each connecting edge 110 is relatively flush with the lower surface of each connecting portion 120, that is, the bent metal strip 100 is relatively flat as a whole. Through the above arrangement, the metallographic sample produced by the metallographic mounting method provided by the present invention is convenient for metallographic testing.

[0034] Reference Figure 2 It is conceivable that in some embodiments, the inlay molding process includes the following steps: inlaying: placing the bent metal strip 100 in the inner chamber of the inlay molding machine, then filling the inner chamber with inlay powder and sealing the chamber with a cover; heating: heating the inner chamber to 155°C-160°C; applying pressure and maintaining the temperature to melt the inlay powder to form a metallographic specimen; and cooling the metallographic specimen. With the above-described arrangement, the metallographic specimen produced through the inlay molding process exhibits excellent transparency, fully melted inlay powder, and minimal or no bubbles, facilitating metallographic specimen testing.

[0035] It is conceivable that in some embodiments, the heat preservation time after pressurization is 15 to 20 minutes, so that the inlay powder can be completely melted. The inlay powder melted under pressure can be better filled into the space between two adjacent connecting edges 110 of the metal strip 100, so that the metallographic sample is in good transparency with no bubbles or very few bubbles.

[0036] It is conceivable that, in the specific implementation process, the metallographic specimen can be taken out of the mounting machine and then cooled by standing at room temperature. The cooling time should be no less than the holding time, that is, the cooling time is greater than or equal to 20 minutes, so that the interior of the metallographic specimen is completely solidified.

[0037] Reference Figure 2 It is conceivable that, in some embodiments, the mosaic molding further comprises the following steps: surface treatment, grinding and polishing the surface of the metallographic sample to make the surface of the metallographic sample smoother, which is conducive to detection.

[0038] Reference Figures 3 to 5 It is conceivable that, in some embodiments, the thickness of the metal strip 100 is s, where 0.06 mm ≤ s ≤ 0.50 mm, and the metal strip 100 is easy to bend. In the bending step, the metal strip 100 can be bent into a corrugated shape by a bending device or manually.

[0039] Reference Figures 3 to 5 It is conceivable that, in some embodiments, the minimum distance between two adjacent connecting edges 110 is h, where h≥8s, so that the distance between two adjacent connecting edges 110 is sufficient to avoid affecting the filling of the inlay powder.

[0040] Reference Figures 3 to 5 It is conceivable that, in some embodiments, the connecting portion 120 is arc-shaped, and the connecting portion 120 and the corresponding connecting edge 110 transition naturally. In addition, the connecting portion 120 can ensure that the distance between two adjacent connecting edges 110 is large enough.

[0041] The metallographic specimens obtained by the existing linear sample preparation method or the winding sample preparation method can only detect the metallographic structure in a single situation. However, the metallographic specimens obtained by the metallographic inlay method provided by the present invention have a bent metal strip 100, and each connecting edge 110 is basically a straight line, while the connecting portion 120 is an arc. Therefore, the metallographic specimens obtained by the metallographic inlay method provided by the present invention can detect the metallographic structure of the metal strip 100 when it is bent, and can also detect the metallographic structure of the metal strip 100 when it is straight. In this way, richer detection results can be obtained, which is conducive to a more comprehensive analysis of the metal strip 100.

[0042] Reference Figure 6 It is conceivable that, in some embodiments, in the bending step, when manually bending the metal strip 100, a round rod 200 can be used to assist in the bending, wherein the metal strip 100 is bent around the round rod 200 so that the connecting portion 120 is arc-shaped, avoiding the formation of an acute angle at the connecting portion 120, thereby avoiding a significant impact on the metallographic structure of the connecting portion 120, and the round rod 200 can be used to control the distance between two adjacent connecting edges 110.

[0043] It is conceivable that in some embodiments, during the bending step, the metal strip 100 may be bent into a corrugated shape using a bending device. Specifically, the bending device includes two bending rollers, each having a plurality of bending teeth disposed on its outer circumference. The bending teeth of one roller are inserted between two bending teeth of the other roller. The bending teeth on the two rollers cooperate with each other to bend the metal strip 100 passing between the two rollers into a corrugated shape.

[0044] The metal strip 100 is bent into a corrugated shape using a bending device. The bent metal strip 100 has a regular shape and flat upper and lower surfaces, making it easier to measure, but the corresponding cost is higher. Manually bending the metal strip 100 into a corrugated shape allows inspectors to perform the operation at any time, making it more convenient. However, the shape of the bent metal strip 100 is easily affected by the inspector's experience, and the manually bent metal strip 100 may not be as regular as the metal strip 100 bent by the bending device. Therefore, bending the metal strip 100 using a bending device and manually bending the metal strip 100 each have their advantages and disadvantages, and those skilled in the art can choose the method according to their needs.

[0045] Reference Figures 3 to 5 It is conceivable that, in some embodiments, two adjacent connecting edges 110 are parallel to each other or arranged at an angle.

[0046] Reference Figure 3 and Figure 4 It is conceivable that in some embodiments, the metal strip 100 is Figure 3 Specifically, Figure 3 As shown, the metal strip 100 is straight along the vertical direction, with no bends at either the upper or lower ends, i.e., no lateral bend. The upper end surface of the metal strip 100 is substantially horizontal, facilitating measurement. In a specific implementation, if the original metal strip is straight along its width and free of lateral bend, and the metal strip 100 obtained from the original metal strip is also straight along its width and free of lateral bend, the metal strip 100 can be bent directly. If the metal strip 100 obtained from the original metal strip has lateral bend, the metal strip 100 needs to be flattened before bending to ensure that the metal strip 100 is straight along its width and free of lateral bend.

[0047] Reference Figure 7It is conceivable that in some embodiments, the diameter of the metallographic specimen is d, and the total length of the metal strip 100 is L. Specifically, during the sample preparation step, a length of metal strip 100 of L is obtained from the original metal strip, where d ≤ L ≤ 5d. With this arrangement, the total length of the metal strip 100 can exceed the diameter of the metallographic specimen, and the total length of the metal strip 100 can reach up to five times the diameter of the metallographic specimen. Thus, the metallographic mounting method provided by the present invention can fully preserve the length of the metal strip 100 being inspected, ensure the metallographic continuity of the metal strip 100, and provide more representative inspection results.

[0048] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the scope of the present invention.

Claims

1. A metallographic inlay method for a metal strip, characterized in that: The following steps are involved: Sample preparation: obtaining a section of metal strip to be tested (100) from the metal strip raw material; Bending: bending the metal strip (100) to be tested into a corrugated shape, wherein the bent metal strip (100) comprises at least three connecting edges (110) and at least two connecting portions (120), and two adjacent connecting edges (110) are connected by corresponding connecting portions (120); Inlay molding: The bent metal strip (100) is subjected to inlay molding to produce a metallographic specimen.

2. The metallographic inlay method of a metal strip according to claim 1, characterized in that: The connecting portion (120) is arc-shaped.

3. The metallographic inlay method of a metal strip according to claim 2, characterized in that: In the bending step, the metal strip (100) is bent around the round rod (200) so that the connecting portion (120) is arc-shaped.

4. The metallographic inlay method of a metal strip according to claim 1, characterized in that: Two adjacent connecting edges (110) are parallel to each other or arranged at an angle.

5. The metallographic inlay method of a metal strip according to claim 1, characterized in that: The metal strip (100) is straight in its width direction without side bending.

6. The metallographic inlay method of a metal strip according to any one of claims 1 to 5, characterized in that: The metal strip (100) has a thickness of s, wherein 0.06 mm ≤ s ≤ 0.50 mm.

7. The metallographic inlay method of a metal strip according to claim 6, characterized in that: The minimum distance between two adjacent connecting edges (110) is h, where h≥8s.

8. The metallographic mounting method of a metal strip according to any one of claims 1 to 5, characterized in that: The diameter of the metallographic sample is d, and the total length of the metal strip (100) is L, wherein d≤L≤5d.

9. The metallographic inlay method of a metal strip according to claim 1, characterized in that: The inlay molding comprises the following steps: Inlaying: placing the bent metal strip (100) in an inner chamber of an inlaying machine, then filling the inner chamber with inlay powder, and then covering and sealing; Heating: The temperature of the inner chamber is heated to 155°C-160°C; Pressurizing and maintaining heat to melt the inlay powder to form a metallographic specimen; Cool the metallographic specimen.

10. The metallographic inlay method of a metal strip according to claim 9, characterized in that: After pressurization, keep warm for 15 to 20 minutes.

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