Secondary two-way mold pressing mold for densification forming of active reaction material

Abstract

The invention provides a secondary two-way mold pressing mold for densification forming of an active reaction material, which comprises a base, a central shaft is vertically, integrally and coaxially arranged in the center of the base, one end of a female mold is coaxially sleeved on the central shaft, and the other end of the female mold is matched with a forward pressure head; the center shaft is coaxially sleeved with a reverse mold pressing space retaining gasket, and the reverse mold pressing space retaining gasket is located between the base and the female mold; the device further comprises a reverse pressing head. Compared with a traditional one-way mold pressing mold, the secondary two-way mold pressing mold has the advantages that secondary reverse pressurization can be achieved only by adding a reverse mold pressing space retaining gasket and a reverse pressing head, the internal density of an active reaction material in the direction away from a forward pressing head is further improved, and the density uniformity of the active reaction material is improved; further, the mechanical property of the sintered active reaction material is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of reactive materials, and relates to densification molding, and particularly relates to a secondary bidirectional molding die for densification molding of reactive materials. Background Art

[0002] Reactive materials refer to materials that can release energy externally through exothermic reactions occurring between internal components or with the ambient medium under specific conditions. The metal / polymer system is the most common and widely studied reactive material system. The metal / polymer system consists of a metal component and a polymer. The metal component includes Al, Ni, and W; the polymer typically includes fluoropolymers such as polytetrafluoroethylene and polyvinylidene fluoride. Among them, polytetrafluoroethylene is widely used due to its high energy density, large fluorine content (more than 75%), stable properties, and resistance to deterioration and aging.

[0003] Metal / polymer reactive materials are usually stable under normal conditions, but can rapidly initiate and release a large amount of energy under high-speed impact conditions. Taking the most common aluminum / polytetrafluoroethylene system as an example. Under high-temperature conditions, polytetrafluoroethylene decomposes to generate small-molecular-weight gases, which can undergo redox reactions with aluminum to form C and AlF 3 , and release a large amount of energy. In the presence of oxygen in the surrounding environment, C can further undergo an oxidation reaction to form CO 2 and release energy.

[0004] Metal / polymer reactive materials are often prepared by a single pressing and sintering method, but it is easy to have problems such as low density and uneven density distribution, which in turn affect the performance of the reactive materials after sintering. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a secondary bidirectional molding die for densification molding of reactive materials, so as to solve the technical problem that the density and density uniformity of reactive materials need to be further improved when preparing metal / polymer reactive materials by a single pressing die in the existing technology.

[0006] To solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0007] A secondary bidirectional molding die for densification molding of reactive materials includes a base, a central shaft is vertically and integrally coaxially arranged at the center of the base, one end of a female die is coaxially sleeved on the central shaft, and the other end of the female die is cooperatively installed with a positive punch.

[0008] A reverse molding space retaining washer is also coaxially sleeved on the central axis, and the reverse molding space retaining washer is located between the base and the female mold.

[0009] It also includes a reverse punch.

[0010] The present invention also has the following technical features:

[0011] Specifically, the secondary two-way molding includes forward molding and reverse molding; in the forward molding state, with the base as the base and the reverse molding space retaining washer as the reverse molding retaining molding space, the forward punch is used to press down the active reaction material; in the reverse molding state, with the forward punch as the base, the base, the central axis, and the reverse molding space retaining washer are removed, and the reverse punch is used to press down the active reaction material.

[0012] Specifically, a first installation cavity is coaxially arranged in the female mold, the first installation cavity penetrates through one end close to the bottom in the female mold, and the central axis and one end of the lower pressing pad are coaxially arranged in the first installation cavity from bottom to top in sequence.

[0013] A second installation cavity is also coaxially arranged in the female mold, the second installation cavity penetrates through one end close to the top in the female mold, the bottom of the second installation cavity is communicated with the top of the first installation cavity, and the other end of the lower pressing pad, the active reaction material forming cavity, and the upper pressing pad are coaxially arranged in the second installation cavity from bottom to top in sequence.

[0014] Specifically, a forward punch with a T-shaped cross-section is coaxially arranged on the top of the upper pressing pad, the bottom of the central axis of the forward punch is located in the second installation cavity, and the base of the forward punch is located on the top of the female mold.

[0015] Specifically, one end of the reverse punch is located inside the first installation cavity, and the diameter of the reverse punch is equal to the diameter of the first installation cavity.

[0016] Specifically, the diameter of the chassis of the base is greater than or equal to the outer diameter of the female mold.

[0017] Preferably, the diameter of the central axis is equal to the inner diameter of the reverse molding space retaining washer.

[0018] Specifically, the diameter of the base of the forward punch is greater than the diameter of the second installation cavity.

[0019] Specifically, the diameter of the central axis of the forward punch is equal to the diameter of the second installation cavity.

[0020] Specifically, the material of the reverse molding space retaining washer is an incompressible material.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] (Ⅰ) In the secondary bidirectional molding die of the present invention, compared with the traditional unidirectional molding die, only a reverse molding space retaining washer and a reverse punch need to be added to achieve secondary reverse pressurization, further improving the internal density of the reactive material away from the direction of the forward punch, increasing the density uniformity of the reactive material, and thus enhancing the mechanical properties of the reactive material after sintering. Description of the Drawings

[0023] Figure 1 It is a front molding cross-sectional schematic view of the secondary bidirectional molding die for densification molding of reactive materials in the embodiment of the present invention.

[0024] Figure 2 It is a reverse molding cross-sectional schematic view of the secondary bidirectional molding die for densification molding of reactive materials in the embodiment of the present invention.

[0025] The meanings of the various reference numerals in the figure are as follows: 1 - base, 2 - reverse molding space retaining washer, 3 - lower pressing pad, 4 - female die, 5 - forward punch, 6 - reverse punch, 7 - central axis.

[0026] 401 - first installation cavity, 402 - second installation cavity.

[0027] 40201 - reactive material forming cavity, 40202 - upper pressing pad.

[0028] The following further details the specific content of the present invention in conjunction with the drawings and embodiments. Specific Embodiments

[0029] It should be noted that all components and materials in the present invention, unless otherwise specified, are all components and materials known in the prior art. For example, the forward punch uses a known forward punch, SKD61 die steel uses known SKD61 die steel, and polytetrafluoroethylene uses known polytetrafluoroethylene.

[0030] In the present invention, polytetrafluoroethylene is widely used due to its high energy density, large fluorine content (more than 75%), stable properties, and resistance to deterioration and aging. Specific applications are, for example: Huang Caimin. Research on the Microstructure Regulation and Mechanical and Thermal Properties of Metal-Type Energetic Structural Materials [D]. Changsha: National University of Defense Technology, 2020.

[0031] Following the above technical solutions, the following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solutions of this application fall within the protection scope of the present invention.

[0032] Embodiment:

[0033] This embodiment provides a secondary two-way molding die for densifying and forming reactive materials, as follows Figure 1 As shown in the figure, it includes a base 1. A central shaft 7 is vertically and integrally coaxially arranged at the center of the base 1. One end of a female mold 4 is coaxially sleeved on the central shaft 7, and the other end of the female mold 4 is cooperatively installed with a forward punch 5.

[0034] As follows Figure 1 As shown in the figure, a reverse molding space retaining washer 2 is also coaxially sleeved on the central shaft 7. The reverse molding space retaining washer 2 is located between the base 1 and the female mold 4.

[0035] As follows Figure 2 As shown in the figure, it also includes a reverse punch 6.

[0036] As a preferred solution of this embodiment, as follows Figure 1 and Figure 2 As shown in the figure, the secondary two-way molding includes forward molding and reverse molding; in the forward molding state, with the base 1 as the base, the reverse molding space retaining washer 2 as the reverse molding retaining space, the forward punch 5 is used to press down the reactive material; in the reverse molding state, with the forward punch 5 as the base, removing the base 1, the central shaft 7 and the reverse molding space retaining washer 2, the reverse punch 6 is used to press down the reactive material.

[0037] In this embodiment, after the reverse molding space retaining washer 2 is assembled with the base 1, forward molding is carried out. The function of the reverse molding space retaining washer 2 is to leave space for reverse molding the reactive material; after forward molding, the reverse punch 6 is used for reverse molding to further improve the density and uniformity of the reactive material.

[0038] In this embodiment, the shape of the reactive material molded by the secondary two-way molding die for densifying and forming reactive materials in this embodiment is a cylinder with a diameter of 15 mm.

[0039] As a preferred solution of this embodiment, as follows Figure 1 As shown in the figure, a first installation cavity 401 is coaxially arranged inside the female mold 4. The first installation cavity 401 penetrates one end near the bottom inside the female mold 4. One end of the central shaft 7 and a lower pressing pad 3 are coaxially arranged in the first installation cavity 401 from bottom to top in sequence.

[0040] As follows Figure 1 As shown in the figure, a second installation cavity 402 is also coaxially arranged inside the female mold 4. The second installation cavity 402 penetrates one end near the top inside the female mold 4. The bottom of the second installation cavity 402 is communicated with the top of the first installation cavity 401. The other end of the lower pressing pad 3, a reactive material forming cavity 40201 and an upper pressing pad 40202 are coaxially arranged in the second installation cavity 402 from bottom to top in sequence.

[0041] As a preferred solution of this embodiment, as Figure 1 shown, a forward punch 5 with a T-shaped cross-section is coaxially arranged at the top of the upper pressure pad 40202. The bottom of the central axis of the forward punch 5 is located in the second installation cavity 402, and the base of the forward punch 5 is located at the top of the female die 4.

[0042] As a preferred solution of this embodiment, as Figure 2 shown, one end of the reverse punch 6 is located inside the first installation cavity 401, and the diameter of the reverse punch 6 is equal to the diameter of the first installation cavity 401.

[0043] In this embodiment, the diameter of the reverse punch 6 is 40 mm.

[0044] As a preferred solution of this embodiment, as Figure 1 shown, the diameter of the chassis of the base 1 is greater than or equal to the outer diameter of the female die 4.

[0045] In this embodiment, the chassis of the base 1 is a cylindrical chassis with a diameter of 60 mm.

[0046] In this embodiment, the outer diameter of the female die 4 is 60 mm.

[0047] As a preferred solution of this embodiment, as Figure 1 shown, the diameter of the central axis 7 is equal to the inner diameter of the reverse molding space retaining washer 2.

[0048] In this embodiment, the central axis 7 is a cylinder with a diameter of 40 mm.

[0049] In this embodiment, the inner diameter of the reverse molding space retaining washer 2 is 40 mm, and the outer diameter of the reverse molding space retaining washer 2 is 60 mm, which is adapted to the base 1.

[0050] As a preferred solution of this embodiment, as Figure 1 shown, the diameter of the base of the forward punch 5 is greater than the diameter of the second installation cavity 402.

[0051] In this embodiment, the base of the forward punch 5 is a cylindrical base with a diameter of 60 mm.

[0052] As a preferred solution of this embodiment, as Figure 1 shown, the diameter of the central axis of the forward punch 5 is equal to the diameter of the second installation cavity 402.

[0053] In this embodiment, the central axis of the forward punch 5 is a cylinder with a diameter of 15 mm.

[0054] As a preferred solution of this embodiment, the material of the reverse molding space retaining washer 2 is an incompressible material.

[0055] In this embodiment, the material of all components is SKD61 die steel.

[0056] When the secondary two-way die for densification molding of reactive materials in this embodiment is in use, it specifically includes the following steps:

[0057] Step 1: Put 2 sets of reverse die pressing space retaining washers on the base 1, and assemble them with the female die 4 and the lower pressing pad 3. Then, weigh an appropriate amount of physically mixed and uniform aluminum powder / polytetrafluoroethylene powder and place it in the reactive material forming cavity 40201. Then, in the second installation cavity 402 and on the reactive material forming cavity 40201, sequentially place the upper pressing pad 40202 and the forward punch 5 to complete the preparation work required for forward die pressing. Use a powder press to pre-press the forward punch 5 to preliminarily densify the aluminum powder / polytetrafluoroethylene powder, then apply a preset pressure, keep the pressure for a certain time, and then release the pressure to complete the forward die pressing.

[0058] Step 2: Flip the entire secondary two-way die, remove the base 1 and the reverse die pressing space retaining washers, assemble the reverse punch 6, and use the powder press to pressurize the reverse punch 6 again. Keep the pressure for a certain time and then release the pressure to complete the reverse die pressing.

[0059] Step 3: Demold and take out the cylindrical blank of the die-pressed aluminum powder / polytetrafluoroethylene reactive material.

Claims

1. A secondary bidirectional molding die for densification molding of active reaction materials, comprising a base (1), a central axis (7) being coaxially arranged in a vertically integrated manner at the center of the base (1), one end of a female mold (4) being coaxially mounted on the central axis (7), and the other end of the female mold (4) being mounted in cooperation with a positive pressure head (5); Features: A reverse molded space retaining gasket (2) is coaxially mounted on the central axis (7), and the reverse molded space retaining gasket (2) is located between the base (1) and the female mold (4); A reverse pressure head (6) is also included.

2. The secondary bidirectional compression mold for densification of active reaction materials according to claim 1, characterized in that: The secondary bidirectional molding includes forward molding and reverse molding; in the forward molding state, the base (1) is used as the base, the reverse molding space retaining gasket (2) is used as the reverse molding space retaining molding space, and the forward pressure head (5) is used to press down the active reaction material; in the reverse molding state, the forward pressure head (5) is used as the base, the base (1), the central axis (7) and the reverse molding space retaining gasket (2) are removed, and the reverse pressure head (6) is used to press down the active reaction material.

3. The secondary bidirectional compression mold for densification of active reaction materials according to claim 1, characterized in that: A first installation cavity (401) is coaxially arranged in the female mold (4), the first installation cavity (401) passes through one end of the female mold (4) close to the bottom, and the central axis (7) and one end of the lower pressure pad (3) are coaxially arranged in the first installation cavity (401) from bottom to top; A second installation cavity (402) is also coaxially arranged in the female mold (4), and the second installation cavity (402) passes through one end of the female mold (4) close to the top, and the bottom of the second installation cavity (402) is connected to the top of the first installation cavity (401). The other end of the lower pressure pad (3), the active reaction material molding cavity (40201) and the upper pressure pad (40202) are coaxially arranged in the second installation cavity (402) from bottom to top.

4. The secondary bidirectional compression molding die for densification of active reaction materials according to claim 3, characterized in that: A forward pressure head (5) with a T-shaped cross section is coaxially arranged on the top of the upper pressure pad (40202), the bottom of the central axis of the forward pressure head (5) is located in the second installation cavity (402), and the base of the forward pressure head (5) is located on the top of the female mold (4).

5. The secondary bidirectional compression molding die for densification of active reaction materials according to claim 3, characterized in that: One end of the reverse pressure head (6) is located inside the first installation cavity (401), and the diameter of the reverse pressure head (6) is equal to the diameter of the first installation cavity (401).

6. The secondary bidirectional compression mold for densification molding of active reaction materials according to claim 1, characterized in that: The diameter of the bottom plate of the base (1) is greater than or equal to the outer diameter of the female mold (4).

7. The secondary bidirectional compression mold for densification of active reaction materials according to claim 1, characterized in that: The diameter of the central axis (7) is equal to the inner diameter of the reverse molded space retaining gasket (2).

8. The secondary bidirectional compression mold for densification molding of active reaction materials according to claim 1, characterized in that: The diameter of the base of the forward pressure head (5) is greater than the diameter of the second installation cavity (402).

9. The secondary bidirectional compression molding die for densification of active reaction materials according to claim 1, characterized in that: The diameter of the central axis of the forward pressure head (5) is equal to the diameter of the second installation cavity (402).

10. The secondary bidirectional compression mold for densification molding of active reaction materials according to claim 1, characterized in that: The material of the reverse molded space retaining gasket (2) is an incompressible material.

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