A sintering stacking fixture for bent metal foil and a hot pressing sintering process

Abstract

This invention discloses a sintering stacking fixture and hot-pressing sintering process for bent metal foil sheets. The fixture includes a base plate with multiple side plates separated from its upper side, forming a stacking space. Side plate slots are evenly arranged along the vertical direction on at least one edge of each side plate. Removable horizontally inserted constraint pieces are inserted into these slots. A lower graphite clamping block and an upper graphite clamping block, matching the shape of the stacking space, are removably disposed within the stacking space. These clamping blocks are used to clamp and fix the stacked bent metal foil sheets. This invention solves the problems of existing fixtures, such as difficulty in stacking large quantities of bent metal foil sheets leading to misalignment and deformation, difficulty in fixture disassembly, and the high radiant heat consumption and prolonged cooling time during sintering.

Description

Technical Field

[0001] This invention relates to the field of metal foil stacking and sintering technology, specifically to a sintering stacking fixture for bent metal foils and a hot pressing sintering process. Background Technology

[0002] Currently, vacuum hot pressing sintering mostly uses two or more layers of components for sintering, requiring no fixtures or using simple fixtures; there are no fixtures for stacking thousands of bent metal foil sheets. For metal foil sheets without bending stress, barrel-shaped graphite fixtures can be used for hot pressing sintering. The typical structure consists of several bow-shaped sheets surrounding a hollow cylinder, with the sintering material placed in the hollow. An additional ring of hollow cylindrical blocks is added around the outside for fixation, and graphite pressure pads of the same shape as the hollow are added on the top and bottom. This method provides all-around wrapping of the sintering material and has a strong restraining effect. However, due to the assembly gaps between the components, the material expands and "squeezes in" during hot pressing sintering, which not only affects the disassembly of the fixture after sintering but also causes localized deformation of the sintered material.

[0003] Furthermore, for metal foils with bending stress, during the stacking of thousands of foils, as the number of stacked foils gradually increases, the bending stress accumulates to a point where it becomes uncontrollable by the operator, potentially leading to misalignment and deformation of some foils, affecting the final sintering result. In addition, the addition of numerous graphite clamps around the material for perimeter constraint increases the amount of heating material during sintering, generating unnecessary energy consumption and prolonging cooling time, thus reducing production efficiency and economic benefits. Summary of the Invention

[0004] This invention provides a sintering stacking fixture and hot pressing sintering process for bent metal foil sheets, which can solve the problems of existing methods such as difficulty in stacking large quantities of bent metal foil sheets, easy misalignment and deformation, difficulty in disassembling the fixture, and the fixture occupying a lot of radiant heat energy and prolonging the cooling time during sintering.

[0005] To achieve the above objectives, in a first aspect, the present invention provides the following technical solution: a sintering and stacking fixture for bent metal foil, comprising a base plate, wherein multiple side plates are separately disposed on the upper side of the base plate, the side plates forming a stacking space, and side plate slots are uniformly arranged along the vertical direction on at least one edge of each side plate, wherein constraint inserts are detachably and horizontally inserted into the side plate slots, and graphite lower clamping blocks and graphite upper clamping blocks with shapes matching the stacking space are detachably disposed within the stacking space, wherein the graphite lower clamping blocks and graphite upper clamping blocks are used to clamp and fix the stacked bent metal foil. The flexible arrangement of the side plates can form a suitable stacking space, allowing for a clearer view of the actual stacking situation. The constraint inserts can be used to separate and stack the bent metal foil to correct the position of the foil at any time. The side plates do not need to constrain the bent metal foil during the sintering process, reducing sintering energy consumption and avoiding deformation caused by expansion during the sintering process.

[0006] Preferably, a connecting plate is installed on the lower outer side of the side plate, and a rib plate connected to the side plate is installed on the upper side of the connecting plate. The connecting plate facilitates the fixing of the side plate to the bottom plate, while the rib plate can improve the support strength of the side plate.

[0007] Preferably, the upper ends of the side plates are connected by a connecting piece, which can increase the stability of the stacking space.

[0008] Preferably, the lower end of the side plate is connected to the base plate by a fastener passing through the first elongated adjustment groove on the base plate. The connecting piece is provided with a second elongated adjustment groove at the position where it connects to the side plate. By providing the first and second elongated adjustment grooves, it is possible to accommodate bent metal foil sheets of different sizes, thus giving the fixture better adaptability.

[0009] Preferably, the end faces of the lower graphite clamping block and the upper graphite clamping block are respectively provided with strap positioning grooves, which facilitates the use of straps to tighten the lower graphite clamping block, the upper graphite clamping block and the bent metal foil.

[0010] In a second aspect, the present invention also provides a hot pressing sintering process using a sintering stacking fixture for bent metal foils as described in the first aspect, comprising the following steps:

[0011] S1. Select the appropriate number of side plates according to the size and shape of the metal foil to be sintered and install them on the base plate. Place the corresponding straps on the base plate using the gaps between the side plates and place the graphite clamping block into the stacking space.

[0012] S2. After arranging the bent metal foil, place the bent metal foil layer by layer on the graphite clamping block. Observe the distance between the height of the bent metal foil and the nearest side plate slot. When the height of the bent metal foil is close to the side plate slot, insert the constraint insert into the corresponding side plate slot. The inserted constraint insert constrains the bent metal foil in the height direction. Then, based on this, perform the next layer stacking operation.

[0013] S3. After stacking the bent metal foil to a suitable height, place the upper graphite clamping block on top of the bent metal foil. Wrap the upper graphite clamping block, the bent metal foil, and the lower graphite clamping block around the straps placed on the base plate and tighten them. During the tightening process, gradually remove the constraint inserts until all the constraint inserts are removed and then tighten the straps.

[0014] S4. The sintered assembly consisting of the upper graphite clamping block, the bent metal foil, and the lower graphite clamping block is moved into the hot pressing sintering furnace. After the assembly is sintered using the furnace pressure head fixing column, the binding straps are removed and hot pressing sintering is performed.

[0015] Preferably, in steps S2 and S3, graphite paper is provided between the upper graphite clamping block and the bent metal foil, and between the lower graphite clamping block and the bent metal foil.

[0016] Preferably, the strap is a ratchet strap.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The flexible side plates can be arranged to form a suitable stacking space, allowing for a clearer view of the actual stacking situation. The constraint inserts can be used to separate and stack the bent metal foils to correct their position at any time. The side plates of the fixture do not need to constrain the bent metal foils during sintering, avoiding foil deformation caused by thermal expansion and surrounding constraints, reducing sintering energy consumption, and preventing deformation caused by expansion during sintering. The heating power of the hot-press sintering furnace is reduced from 140KW to 70KW. The reduced heating element shortens the sintering time and improves production efficiency. The traditional sintering process takes 23 hours from entering the furnace to cooling to room temperature. With the fixture and sintering process of this invention, the entire sintering time is shortened to 12 hours. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the sintering stacking fixture of the present invention;

[0020] Figure 2 This is a top view of the sintering stacking fixture of the present invention;

[0021] Figure 3 This is a bottom view of the sintering stacking fixture of the present invention;

[0022] Figure 4 for Figure 2 AA-direction sectional view of the structure;

[0023] Figure 5 This is a perspective view of the sintered whole of the present invention;

[0024] Figure 6 This is a cross-sectional view of the sintered integral and the sintering stacking fixture of the present invention.

[0025] Figure label:

[0026] 1. Base plate, 2. Side plate, 3. Connecting piece, 4. Constraint insert, 5. Side plate slot, 6. Connecting plate, 7. Rib plate, 8. Upper graphite clamping block, 9. Strap positioning slot, 10. Lower graphite clamping block, 11. Connecting hole, 12. Second long strip adjustment slot, 13. First long strip adjustment slot, A. Bending metal foil, B. Stacking space. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] Traditional clamp-constrained hot pressing sintering of metal has the following problems when stacking 4000-6000 bent metal foil sheets: First, stacking is difficult, and the accumulation of bending stress can lead to misalignment and deformation of the foil sheets during operation. Second, gaps in the clamp assembly can cause material defects during sintering and increase the difficulty of subsequent disassembly. Finally, it is a waste of resources, as the presence of a large amount of clamp material consumes the radiated heat energy during sintering and prolongs the cooling time during the cooling stage after sintering. Therefore, in order to solve the above problems, this embodiment provides the following technical solution: Figure 1-6 As shown, a sintering and stacking fixture for bent metal foil includes a base plate 1. Multiple side plates 2 are separately disposed on the upper side of the base plate 1, forming a stacking space B. Side plate slots 5 are evenly arranged along the vertical direction on at least one edge of each side plate 2. Constraint inserts 4 are detachably and horizontally inserted into the side plate slots 5. A graphite lower clamping block 10 and a graphite upper clamping block 8, matching the shape of the stacking space B, are detachably disposed within the stacking space B. The graphite lower clamping block 10 and the graphite upper clamping block 8 are used to clamp and fix the stacked bent metal foil A. The flexibly arranged side plates 2 can form a suitable stacking space B, which can more clearly reflect the actual stacking situation. The constraint inserts 4 can be used to separate and stack the bent metal foil A to correct its position at any time. The side plates do not need to constrain the bent metal foil A during the sintering process, reducing sintering energy consumption and avoiding deformation caused by expansion during sintering.

[0029] Specifically, the size and shape of side plate 2 can be set according to the shape of the bent metal foil A, such as... Figure 1-6 As shown, the bent metal foil A is square in shape, so four side plates 2 can be used to form a square stacking space B. The side plates 2 are separated with gaps between them. The side plates 2 and the base plate 1 are detachably connected by fasteners. Both sides of the side plates 2 have side plate slots 5. The side plate slots 5 on each side plate 2 must be precisely aligned to maintain consistency. In order to ensure the consistency of the slots on the four side plates 2, the four side plates 2 can be stacked and fixed and then processed by wire cutting. Each side plate slot 5 has a slot width of 0.5mm and a slot depth of 60mm.

[0030] The thickness and width of the constraint insert 4 match the size of the side plate slot 5. It can be made of stainless steel and has sufficient strength to support the bent metal foil A. The thickness can be 0.3mm, so that a large gap will not be generated inside the bent metal foil A.

[0031] In this embodiment, as Figure 1 As shown, a connecting plate 6 is installed on the lower outer side of the side plate 2, and a rib plate 7 connected to the side plate 2 is installed on the upper side of the connecting plate 6. The connecting plate 6 facilitates the fixing of the side plate 2 to the base plate 1, while the rib plate 7 improves the support strength of the side plate 2. Simultaneously, to improve the strength of the stacking fixture, the upper ends of the side plates 2 are connected by a connecting piece 3. The connecting piece 3 increases the stability of the stacking space B, and its shape is determined according to the relative position between the side plates 2. Figure 1-2 As shown, the four side plates 2 are connected by L-shaped connecting pieces, and the two ends of the L-shaped connecting pieces are connected to the side plates 2 by at least two screws.

[0032] Meanwhile, the lower end of the side plate 2 is connected to the base plate 1 by a fastener passing through the first elongated adjustment groove 13 on the base plate 1. A second elongated adjustment groove 12 is provided on the connecting piece 3 at the position where it connects to the side plate 2. By providing the first elongated adjustment groove 13 and the second elongated adjustment groove 12, it is possible to accommodate bent metal foil sheets A of different sizes, giving the clamp better adaptability. In this embodiment, such as... Figure 2-3 As shown, a first elongated adjustment groove 13 can be provided on the base plate 1 corresponding to the side plate 2. Similarly, a second elongated adjustment groove 12 can be provided at the end of the connecting piece 3 corresponding to the side plate 2, so that the distance between the two side plates 2 can be adjusted.

[0033] In this embodiment, as Figure 5 As shown, the graphite lower clamping block 10 and the graphite upper clamping block 8 are respectively provided with strap positioning grooves 9 on their end faces, which facilitates the use of straps to tighten the graphite lower clamping block 10, the graphite upper clamping block 8 and the bent metal foil A.

[0034] This embodiment also provides a hot pressing sintering process using the above-mentioned sintering stacking fixture for bent metal foil, including the following steps:

[0035] S1. Fix the four side plates 2 onto the base plate 1. Place the corresponding straps on the base plate 1 using the gaps between the side plates 2. The straps can be ratchet straps, which can effectively tighten the straps. Place the graphite lower clamping block 10 into the stacking space B. After the graphite lower clamping block 10 is placed, the distance between its height and the bottommost side plate groove 5 on the side plate 2 is less than 10mm. Then place a layer of graphite paper on the upper side of the graphite lower clamping block 10 to prevent the sintered bent metal foil A from sticking to the graphite lower clamping block 10.

[0036] S2. After arranging the bent metal foil A, place the bent metal foil A layer by layer on the graphite clamping block 10. Observe the distance between the height of the bent metal foil A and the nearest side plate slot 5. The height of the bent metal foil A placed each time should not be greater than the slot spacing between the side plate slots 5. For example, if the slot spacing is 10mm, the height of the bent metal foil A placed each time should not exceed 10mm. When the height of the bent metal foil A is close to the side plate slot 5, insert the constraint insert 4 into the corresponding side plate slot 5. The inserted constraint insert 4 constrains the bent metal foil A in the height direction, making its bending degree tend to be even. Then, based on this, carry out the next layer stacking operation.

[0037] S3. After stacking the bent metal foil A to a suitable height, place a piece of graphite paper of the same area on its upper surface. Place the upper graphite clamping block 8 on the upper end of the bent metal foil A. Wrap the upper graphite clamping block 8, the bent metal foil A and the lower graphite clamping block 10 around the binding strap placed on the base plate 1 and tighten them. During the tightening process, gradually remove the constraint insert 4 until all the constraint insert 4 are removed and then tighten the binding strap.

[0038] S4. Remove the sintered assembly consisting of the upper graphite clamping block 8, the bent metal foil A, and the lower graphite clamping block 10 from the stacking space B. The sintered assembly can be removed by hoisting. For example, multiple connecting holes 11 can be provided on the upper graphite clamping block 8 to facilitate the transfer of the sintered assembly. Alternatively, the side plate 2 can be removed and the sintered assembly can be transferred to the hot pressing sintering furnace. After the sintered assembly is fixed by the furnace pressure head, the binding straps can be removed and hot pressing sintering can be performed.

[0039] After sintering, the upper graphite clamping block 8 and the lower graphite clamping block 10 are separated from the bent metal foil A to obtain the desired sintered material block. Throughout the sintering process, the bent metal foil A is unconstrained externally, thus avoiding foil deformation caused by thermal expansion and surrounding constraints, reducing sintering energy consumption, and preventing deformation due to expansion during sintering. The heating power of the hot-pressing sintering furnace is reduced from 140KW to 70KW, and the reduced heating element shortens the sintering time.

[0040] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0041] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A hot press sintering process of a sintering stack fixture of a curved metal foil, characterized by, The sintering stacking fixture includes: A base plate (1) is provided with multiple side plates (2) on its upper side. The side plates (2) form a stacking space (B). Side plate slots (5) are evenly arranged along the vertical direction on at least one edge of the side plates (2). Constraint inserts (4) are detachably and horizontally inserted into the side plate slots (5). Graphite lower clamping blocks (10) and graphite upper clamping blocks (8) with shapes matching the stacking space (B) are detachably provided in the stacking space (B). The graphite lower clamping blocks (10) and graphite upper clamping blocks (8) are used to clamp and fix the stacked curved metal foils (A). The hot pressing sintering process includes the following steps: S1. Select the appropriate number of side plates (2) according to the size and shape of the metal foil to be sintered and install them on the base plate (1). Place the corresponding straps on the base plate (1) using the gap between the side plates (2) and place the graphite lower clamping block (10) into the stacking space (B). S2. After arranging the bent metal foil (A), place the bent metal foil (A) layer by layer on the graphite clamping block (10). Observe the distance between the height of the bent metal foil (A) and the nearest side plate slot (5). When the height of the bent metal foil (A) is close to the side plate slot (5), insert the constraint insert (4) into the corresponding side plate slot (5). The inserted constraint insert (4) constrains the bent metal foil (A) in the height direction. Then, based on this, perform the next layer stacking operation. S3. After stacking the bent metal foil (A) to a suitable height, place the graphite upper clamping block (8) on the upper end of the bent metal foil (A), and use the straps placed on the base plate (1) to wrap around and tighten the graphite upper clamping block (8), the bent metal foil (A) and the graphite lower clamping block (10). During the tightening process, gradually remove the constraint inserts (4) until all the constraint inserts (4) are removed and then tighten the straps. S4. Move the sintered whole consisting of the upper graphite clamping block (8), the bent metal foil (A) and the lower graphite clamping block (10) into the hot pressing sintering furnace. After fixing the sintered whole with the furnace pressure head, release the binding strap and then perform hot pressing sintering.

2. The hot press sintering process of a sintered stack of bent metal foils of claim 1, wherein: A connecting plate (6) is installed on the lower outer side of the side plate (2), and a rib plate (7) connected to the side plate (2) is installed on the upper side of the connecting plate (6).

3. The hot press sintering process of a sintered stack of bent metal foils of claim 1, wherein: The upper ends of the side plates (2) are connected by connecting pieces (3).

4. The hot pressing sintering process for the sintering stacking fixture of bent metal foils according to claim 3, characterized in that: The lower end of the side plate (2) is connected to the bottom plate (1) by a fastener passing through the first elongated adjustment groove (13) on the bottom plate (1), and the connecting piece (3) is provided with a second elongated adjustment groove (12) at the position where it is connected to the side plate (2).

5. The hot pressing sintering process for the sintering stacking fixture of bent metal foils according to claim 1, characterized in that: The graphite lower clamping block (10) and the graphite upper clamping block (8) are respectively provided with strap positioning grooves (9) on their end faces.

6. The hot pressing sintering process for the sintering stacking fixture of bent metal foils according to claim 1, characterized in that: In steps S2 and S3, graphite paper is provided between the upper graphite clamping block (8) and the bent metal foil (A), and between the lower graphite clamping block (10) and the bent metal foil (A).

7. The hot pressing sintering process for the sintering stacking fixture of bent metal foils according to claim 1, characterized in that: The strap mentioned is a ratchet strap.

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