Vacuum hot pressing die

Abstract

The utility model relates to the technical field of target material production, in particular to a vacuum hot pressing die. Comprising a female die, the female die is provided with a die hole penetrating through the upper surface and the lower surface of the female die, the lower pressing head can be inserted into the die hole from the lower portion, the diameter of the lower pressing head is equal to the diameter of the die hole, the cylindrical cushion cylinder is used for being placed in the die hole, the outer diameter of the cushion cylinder is equal to the inner diameter of the die hole, and the cushion cylinder is made of flexible graphite paper. And the upper pressing head can be inserted into the cushion cylinder from the upper part. The service life of the female die is longer.

Description

Technical Field

[0001] The utility model relates to the technical field of target material production, in particular to a vacuum hot pressing mold. Background Art

[0002] The vacuum hot pressing process is a commonly used process in the target material production industry. It is a process in which powder is pressed through a mold in a vacuum hot pressing furnace that can heat and provide a vacuum environment, so that the powder becomes a dense solid under the action of high temperature and high pressure. Titanium boride, niobium oxide, lithium phosphate and other ceramic target materials can be produced using the vacuum hot pressing process. In the prior art, the structure of the vacuum hot pressing mold is relatively simple, including a female mold and two pressing heads. In order to be resistant to high temperatures, the female mold and the pressing heads are generally made of high-density graphite. A mold hole is provided in the center of the female mold, which passes through its upper and lower surfaces. The cross-section of the mold hole is generally circular. The two pressing heads are inserted into the mold hole from the top and bottom respectively, and apply pressure to the powder in the mold hole, so that the powder becomes a dense solid under the action of high temperature (high temperature provided by the vacuum hot pressing furnace) and high pressure. However, when the powder is about to become a dense solid (called a semi-dense solid, which has a certain hardness at this time), the pressing continues, and the semi-dense solid continues to shorten, thereby rubbing against the mold hole wall, causing the mold hole wall to wear. After becoming a dense solid (with a higher hardness), it will also rub against the mold hole wall during demolding, causing the hole wall to wear, thereby reducing the service life of the female mold. Utility Model Content

[0003] The technical problem to be solved by the present invention is to provide a vacuum hot pressing mold in view of the above-mentioned technical deficiencies.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is: a vacuum hot pressing mold, including a female mold, which is provided with mold holes running through its upper and lower surfaces, and also includes a lower pressure head that can be inserted into the mold hole from below, the diameter of the lower pressure head is equal to the diameter of the mold hole, and also includes a cylindrical gasket for placing into the mold hole, the outer diameter of the gasket is equal to the inner diameter of the mold hole, the gasket is made of flexible graphite paper, and also includes an upper pressure head that can be inserted into the gasket from above.

[0005] To further optimize the technical solution, a base plate is provided at the bottom of the cushion cylinder.

[0006] To further optimize the technical solution, a cap ring is provided on the outer side of the top of the gasket tube, and the outer diameter of the cap ring is larger than the diameter of the die hole.

[0007] Compared with the prior art, the utility model has the following advantages: because a gasket tube that can be inserted into the die hole of the female mold is added, the gasket tube is made of flexible graphite paper. During vacuum hot pressing, the powder and the pressed target material blank are located inside the gasket tube. Since the gasket tube has good lubricity and low hardness, it causes less wear on the die hole wall, thereby improving the service life of the female mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural schematic diagram of a vacuum hot pressing mold.

[0009] Figure 2 It is a structural diagram of the gasket.

[0010] In the figure: 1, female mold; 2, lower pressure head; 3, cushion cylinder; 31, bottom plate; 32, cap ring; 4, upper pressure head. DETAILED DESCRIPTION

[0011] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. Furthermore, descriptions of known structures and technologies are omitted in the following description to avoid unnecessary confusion regarding the concepts of the present invention.

[0012] Specific implementation method: Figure 1-2 As shown, a vacuum hot pressing mold includes a female mold 1, and the female mold 1 is provided with a mold hole penetrating the upper and lower surfaces thereof, the cross-section of the mold hole is circular, and also includes a lower pressure head 2 that can be inserted into the mold hole from below, the lower pressure head 2 is cylindrical, and the diameter of the lower pressure head 2 is equal to the diameter of the mold hole, so that after the lower pressure head 2 is inserted into the mold hole, there is basically no gap between the two, and powder is not easy to leak downward from between the two, and also includes a cylindrical gasket 3 for placing in the mold hole, the outer diameter of the gasket 3 is equal to the inner diameter of the mold hole, and the gasket 3 is made of flexible graphite paper, and also includes an upper pressure head 4 that can be inserted into the gasket 3 from above, the upper pressure head 4 is cylindrical and its diameter is slightly smaller than the inner diameter of the gasket 3. During use, the female mold 1 is fixed in a vacuum hot-pressing furnace. The upper and lower rams 4 and 2 are connected to the piston rods of hydraulic cylinders located on the upper and lower sides of the vacuum hot-pressing furnace, respectively. The lower ram 2 is slightly inserted into the die hole. When producing target materials by vacuum hot-pressing, a backing tube 3 is placed into the die hole, with the bottom of the backing tube 3 in contact with the top of the lower ram 2. A prescribed amount of powder is then added to the backing tube 3. After vacuum is drawn and heated to a certain temperature, the lower ram 2 is inserted downward into the backing tube 3 to pressurize the powder (the lower ram 2 also moves upward to apply pressure during this process, and the backing tube 3 moves upward a certain distance during the pressurization process). Because the backing tube 3 is made of flexible graphite paper with good lubricity and low hardness, it minimizes wear on the die hole wall, thereby extending the service life of the female mold 1. The backing tube 3 is disposable and can be used one at a time.

[0013] Furthermore, a bottom plate 31 is provided at the bottom of the cushion tube 3. At this time, the lower part of the cushion tube 3 is closed. In this case, a specified amount of powder can be added to the cushion tube 3 first, and the cushion tube 3 can be vibrated by a vibration device to make the powder therein more evenly distributed (the loose density is more consistent, so that the density consistency of the target material after hot pressing is also better), and then it can be placed in the mold hole.

[0014] Furthermore, a cap ring 32 is provided on the outer side of the top of the gasket tube 3. The outer diameter of the cap ring 32 is larger than the diameter of the die hole. Because the material of the gasket tube 3 is flexible, the existence of the cap ring 32 can make the top of the gasket tube 3 less likely to deform, that is, it is not easy to become elliptical (if the ellipticity is large, the upper pressure head 4 cannot be inserted into the gasket tube 3 and the gasket tube 3 is crushed), so that the upper pressure head 4 can be easily inserted into the gasket tube 3.

[0015] It should be understood that the above-described specific embodiments of the present invention are merely illustrative of or explanation of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the scope of protection of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. A vacuum hot pressing mold, comprising a female mold (1), wherein the female mold (1) is provided with mold holes penetrating the upper and lower surfaces thereof, and further comprising a lower pressure head (2) capable of being inserted into the mold hole from below, wherein the diameter of the lower pressure head (2) is equal to the diameter of the mold hole, and wherein: It also includes a cylindrical cushion tube (3) for placing in the die hole, the outer diameter of the cushion tube (3) is equal to the inner diameter of the die hole, the cushion tube (3) is made of flexible graphite paper, and also includes an upper pressure head (4) that can be inserted into the cushion tube (3) from above.

2. The vacuum hot pressing mold according to claim 1, characterized in that: A bottom plate (31) is provided at the bottom of the cushion cylinder (3).

3. A vacuum hot pressing mold according to any one of claims 1-2, characterized in that: A cap ring (32) is provided on the outer side of the top of the gasket cylinder (3), and the outer diameter of the cap ring (32) is larger than the diameter of the die hole.

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