Die for preparing boron carbide workpiece with holes
By compacting the boron carbide raw material in the mold and performing hot press sintering, the problem of sintering aid in the pressurized boron carbide workpiece is solved, the acid and alkali resistance and physical properties of the boron carbide workpiece are improved, and the product quality is ensured.
Patent Information
- Application Number
- CN202421033025.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-13
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-05-13
AI Technical Summary
In the prior art, when preparing boron carbide products with special pore positions, dry-press molding is used to make boron carbide pelletizing, resulting in the inclusion of sintering agents that affect the physical properties and acid and alkali resistance of boron carbide ceramics.
Design a mold, including the mold body and pressed assembly parts, and compact boron carbide raw materials between the upper template and the lower template, prefabricated hole positions, and form boron carbide workpieces with holes during hot pressing and sintering, avoiding pollution problems. Improved workpiece quality.
It effectively improves the acid and alkali resistance and physical properties of boron carbide workpieces, ensures product quality, and avoids the performance reduction caused by sintering aids.
Smart Images
Figure CN222222972U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of boron carbide ceramic processing and relates to a mold for preparing a boron carbide workpiece with a hole. Background Art
[0002] Boron carbide is the second hardest material in the world, with a Mohs hardness second only to diamond and a low density. Boron carbide ceramic materials have excellent physical properties, and their bending strength, elastic modulus and fracture toughness are better than those of ceramic materials such as alumina and silicon carbide. Boron carbide ceramic materials also have the advantages of good chemical stability and acid and alkali resistance, and are widely used in bulletproof armor ceramics, ceramic parts, nuclear industry, grinding and other industries.
[0003] At present, for boron carbide products with special pores, pressureless boron carbide granules are generally dry pressed. According to the requirements of the product drawings, the cold pressed parts are precisely processed, the processing allowance of the subsequent process is designed, and then pressureless sintering is performed. The general sintering temperature is 1900-2100℃, and the densification sintering of pressureless boron carbide is completed by sintering aids. However, pressureless boron carbide contains sintering aid substances, which will affect the physical properties of boron carbide ceramics, such as Vickers hardness, elastic modulus, toughness, etc., and the acid and alkali resistance of boron carbide ceramics will also be greatly reduced.
[0004] Therefore, it is very necessary to reduce the adverse effects in the production process of perforated products. Utility Model Content
[0005] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a mold for preparing a boron carbide workpiece with holes, which realizes the prefabrication of holes on the boron carbide workpiece and can be used for hot pressing and sintering, thereby avoiding contamination of the boron carbide workpiece and improving the quality of the workpiece.
[0006] To achieve this purpose, the utility model adopts the following technical solutions:
[0007] The utility model provides a mold for preparing a boron carbide workpiece with a hole, comprising a mold main body and at least one pressing assembly component, wherein a hollow mold cavity is arranged in the mold main body, and the pressing assembly component is located in the hollow mold cavity; the pressing assembly component comprises an upper template and a lower template which are buckled with each other, wherein the upper template and the lower template are respectively provided with a first assembly hole and a second assembly hole, wherein the first assembly hole and the second assembly hole are arranged opposite to each other, an upper pad is movably arranged in the first assembly hole, and a lower pad is movably arranged in the second assembly hole, and the space between the upper template and the lower template is used for filling boron carbide raw material.
[0008] The utility model assembles an upper template and an upper pad, and a lower template and a lower pad respectively, and compacts the boron carbide raw material between the upper template and the lower template, preforms holes on the surface of the boron carbide raw material under the compaction effect of the upper pad and the lower pad, and then installs the pressed assembly components into the hollow mold cavity of the mold body, and then transfers them to a sintering furnace for hot pressing and sintering to form a boron carbide workpiece with holes, thereby avoiding product pollution problems, effectively improving product quality, and ensuring that the acid and alkali resistance and physical properties of the boron carbide workpiece meet the requirements.
[0009] As a preferred technical solution of the utility model, the thickness of the upper pad is greater than the thickness of the upper template; the thickness of the lower pad is less than the thickness of the lower template, and after the upper template and the lower template are buckled together, the upper pad is partially located in the second assembly hole.
[0010] During the application process, after the lower template and the lower pad are assembled, the boron carbide raw material is laid, and then the upper template is buckled. The upper pad protrudes from the upper template and extends into the second assembly hole, cooperating with the lower pad to form prefabricated hole positions at the corresponding positions of the boron carbide raw material.
[0011] As a preferred technical solution of the utility model, the first assembly hole and the second assembly hole have the same hole diameter, and the outer diameters of the surfaces of the upper and lower cushion blocks on one side close to each other are the same.
[0012] As a preferred technical solution of the utility model, the outer peripheral surface of the upper pad is a smooth surface or a threaded surface.
[0013] The utility model can realize the production of prefabricated holes with different inner walls by adjusting the outer peripheral surface of the upper pad. When the outer peripheral surface of the upper pad is a smooth surface, the inner wall of the prefabricated hole of the boron carbide workpiece is smooth, and when the outer peripheral surface of the upper pad is a threaded surface, the inner wall of the prefabricated hole of the boron carbide workpiece has threads.
[0014] It should be noted that the outer peripheral surface mentioned in the present invention refers to the connecting surface of the upper pad or the lower pad for connecting the upper end surface and the lower end surface thereof.
[0015] The outer diameter of the upper pad increases from the side surface away from the lower template to the direction close to the lower pad. The outer diameter of the lower pad increases from the side surface away from the upper template to the direction close to the upper pad.
[0016] The utility model optimizes the structures of the upper pad and the lower pad to facilitate the assembly and disassembly of the pressed assembly parts, thereby avoiding damage to the workpiece during operation and affecting the overall performance.
[0017] As a preferred technical solution of the utility model, a first cushion layer is provided between the upper template and the boron carbide raw material, and a second cushion layer is provided between the lower template and the boron carbide raw material.
[0018] As a preferred technical solution of the present invention, the first cushion layer and the second cushion layer independently include graphite paper.
[0019] The first cushion layer and the second cushion layer of the utility model can prevent the upper cushion block or the lower cushion block from adhering to the boron carbide raw material during high-temperature sintering, thereby making it impossible to remove the pure boron carbide workpiece, resulting in product damage or scrapping.
[0020] As a preferred technical solution of the utility model, the diameters of the upper template and the lower template are independently 300-500 mm, for example, 300 mm, 320 mm, 350 mm, 380 mm, 400 mm, 420 mm, 430 mm, 450 mm, 460 mm, 480 mm or 500 mm, but are not limited to the listed values, and other unlisted values within the numerical range are also applicable.
[0021] The hole diameters of the first assembly hole and the second assembly hole are independently 100-200 mm, for example, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm or 200 mm, but are not limited to the listed values, and other unlisted values within the numerical range are also applicable.
[0022] The thickness difference between the upper template and the upper pad is 5 to 15 mm, for example, it can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm or 15 mm, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
[0023] As a preferred technical solution of the utility model, the number of the pressing and assembling components is at least two, and at least two of the pressing and assembling components are sequentially stacked and arranged in the hollow mold cavity.
[0024] In the mold filling process, the utility model sequentially places the lower mold plate, the second cushion layer, the boron carbide raw material, the first cushion layer and the upper mold plate in the hollow mold cavity of the mold body from bottom to top, and stacks them in this order until the entire hollow mold cavity is filled.
[0025] The combination of the upper template and the lower template in the pressing assembly provided by the utility model can also be used alone to form a through hole on a boron carbide workpiece. During the application process, the boron carbide raw material is laid on the surface of the lower template, so that a hole is left in the middle of the boron carbide raw material, and then the upper template is buckled, and then loaded into the mold body for hot pressing and sintering to form a boron carbide workpiece with a through hole.
[0026] As a preferred technical solution of the utility model, the mold body includes a graphite guard plate and a protective jacket which are nested in sequence, the hollow mold cavity is opened in the graphite guard plate, and a support tray is also arranged at the bottom of the mold body.
[0027] As a preferred technical solution of the utility model, the graphite guard plate is composed of at least two graphite plates, and at least two of the graphite plates are spliced to form the hollow mold cavity.
[0028] The numerical range described in the present invention not only includes the point values listed above, but also includes any point values between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.
[0029] Compared with the prior art, the beneficial effects of the utility model are:
[0030] The utility model provides a mold for preparing a boron carbide workpiece with holes. The boron carbide raw material is compacted between an upper mold plate and a lower mold plate, a hole is preformed under the compaction of an upper cushion block and a lower cushion block, and then a pressed assembly component is loaded into a hollow mold cavity of a mold body, and then the mold is transferred to a sintering furnace for hot pressing and sintering to form a boron carbide workpiece with holes, thereby avoiding product contamination problems, effectively improving product quality, and ensuring that the acid and alkali resistance and physical properties of the boron carbide workpiece meet the requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 A schematic diagram of the structure of a pressing assembly component provided for a specific embodiment of the utility model;
[0032] Figure 2 A schematic diagram of the combination of an upper template and an upper pad provided for a specific embodiment of the utility model;
[0033] Figure 3 A schematic diagram of the combination of a lower template and a lower pad provided for a specific implementation of the utility model.
[0034] Among them, 100-pressed assembly component; 1-upper template; 2-lower template; 3-first assembly hole; 4-second assembly hole; 5-upper cushion block; 6-lower cushion block. DETAILED DESCRIPTION
[0035] It should be understood that, in the description of the present utility model, the terms "center", "upper", "lower", "top", "bottom", "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.
[0036] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.
[0037] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.
[0038] The utility model provides a mold for preparing a boron carbide workpiece with a hole, comprising a mold body and at least one pressing assembly component 100, wherein a hollow mold cavity is arranged in the mold body, and the pressing assembly component 100 is located in the hollow mold cavity. Figure 1 As shown, the pressing assembly component 100 includes an upper mold plate 1 and a lower mold plate 2 that are engaged with each other. Figure 2 and Figure 3 As shown, the upper template 1 and the lower template 2 are respectively provided with a first assembly hole 3 and a second assembly hole 4, the first assembly hole 3 and the second assembly hole 4 are arranged opposite to each other, an upper pad 5 is movably arranged in the first assembly hole 3, and a lower pad 6 is movably arranged in the second assembly hole 4, and the space between the upper template 1 and the lower template 2 is used to fill the boron carbide raw material.
[0039] The thickness of the upper pad 5 is greater than that of the upper template 1; the thickness of the lower pad 6 is less than that of the lower template 2. After the upper template 1 and the lower template 2 are buckled, the upper pad 5 is partially located in the second assembly hole 4. In the application process, after the lower template 2 and the lower pad 6 are assembled, the boron carbide raw material is laid, and then the upper template 1 is buckled. The upper pad 5 protrudes from the upper template 1 and extends into the second assembly hole 4, and cooperates with the lower pad 6, so that the corresponding position of the boron carbide raw material forms a prefabricated hole position.
[0040] In some embodiments, the first assembly hole 3 and the second assembly hole 4 have the same hole diameter, and the outer diameters of the surfaces of the upper cushion block 5 and the lower cushion block 6 on one side close to each other are the same.
[0041] In some embodiments, the outer peripheral surface of the upper pad 5 is a smooth surface or a threaded surface. When the outer peripheral surface of the upper pad 5 is a smooth surface, the inner wall of the prefabricated hole of the boron carbide workpiece is smooth, and when the outer peripheral surface of the upper pad 5 is a threaded surface, the inner wall of the prefabricated hole of the boron carbide workpiece has threads.
[0042] In some embodiments, the outer diameter of the upper pad 5 increases from the side surface away from the lower mold plate 2 to the direction close to the lower pad 6. The outer diameter of the lower pad 6 increases from the side surface away from the upper mold plate 1 to the direction close to the upper pad 5. The utility model optimizes the structure of the upper pad 5 and the lower pad 6 to facilitate the assembly and disassembly of the pressed assembly component 100, avoiding damage to the workpiece during operation and affecting the overall performance.
[0043] In some embodiments, a first cushion layer is provided between the upper template 1 and the boron carbide raw material, and a second cushion layer is provided between the lower template 2 and the boron carbide raw material. Specifically, the first cushion layer and the second cushion layer independently include graphite paper. The first cushion layer and the second cushion layer can prevent the upper cushion block 5 or the lower cushion block 6 from adhering to the boron carbide raw material during the high-temperature sintering process, thereby making it impossible to remove the pure boron carbide workpiece, resulting in product damage or scrapping.
[0044] In some embodiments, the diameters of the upper template 1 and the lower template 2 are independently 300-500 mm.
[0045] The diameters of the first assembly hole 3 and the second assembly hole 4 are independently 100-200 mm.
[0046] The thickness difference between the upper template 1 and the upper cushion block 5 is 5 to 15 mm.
[0047] In some embodiments, the number of the pressing assembly components 100 is at least two, and at least two pressing assembly components 100 are sequentially stacked in the hollow mold cavity. In the mold filling process of the utility model, the lower mold plate 2-the second cushion layer-the boron carbide raw material-the first cushion layer-the upper mold plate 1 are sequentially placed in the hollow mold cavity of the mold body from bottom to top, and stacked in this order until the entire hollow mold cavity is filled.
[0048] In some embodiments, the mold body includes a graphite guard plate and a protective jacket that are nested in sequence, the hollow mold cavity is provided in the graphite guard plate, and a support tray is further provided at the bottom of the mold body. Specifically, the graphite guard plate is composed of at least two graphite plates, and at least two of the graphite plates are spliced to form the hollow mold cavity.
[0049] Example 1
[0050] This embodiment provides a mold for preparing a boron carbide workpiece with a hole, including a mold body and ten sets of pressing assembly parts. The mold body includes a graphite guard plate and a protective jacket that are nested in sequence, a hollow mold cavity with an inner diameter of 400 mm is opened in the graphite guard plate, and a support tray is also provided at the bottom of the mold body.
[0051] The pressing assembly component includes an upper template and a lower template that are interlocked, the diameter of the upper template and the lower template are both 400mm, the upper template and the lower template are respectively provided with a first assembly hole and a second assembly hole, the aperture of the first assembly hole and the second assembly hole are both 150mm.
[0052] The first assembly hole and the second assembly hole are arranged opposite to each other. An upper pad is movably arranged in the first assembly hole. The thickness of the upper pad is greater than that of the upper template, and the thickness difference is 10mm. A lower pad is movably arranged in the second assembly hole. The thickness of the lower pad is less than that of the lower template. After the upper template and the lower template are buckled, the upper pad extends into the second assembly hole. The outer diameter of the upper pad increases from the side surface away from the lower template to the direction close to the lower pad, and the outer diameter of the lower pad increases from the side surface away from the upper template to the direction close to the upper pad. The space between the upper template and the lower template is used to fill the boron carbide raw material. A first cushion layer is arranged between the upper template and the boron carbide raw material, and a second cushion layer is arranged between the lower template and the boron carbide raw material. Both the first cushion layer and the second cushion layer are graphite paper.
[0053] Application Example 1
[0054] This application example uses the mold provided in Example 1 to manufacture a pure boron carbide workpiece with a blind hole, specifically comprising the following steps:
[0055] (1) Assemble the upper template and the lower template separately, place the upper pad in the first assembly hole of the upper template, and place the lower pad in the second assembly hole of the lower template for standby use;
[0056] (2) placing the assembled lower mold plate at the bottom of the hollow mold cavity and laying a second cushion layer;
[0057] (3) compacting the boron carbide raw material powder on the upper surface of the second cushion layer, and then laying the first cushion layer on the upper surface of the boron carbide raw material;
[0058] (4) placing the assembled upper template on the upper surface of the first cushion layer, with the upper cushion block protruding from the upper template and extending into the second assembly hole of the lower template to extrude the boron carbide raw material;
[0059] (5) According to the order of steps (1) to (4), ten sets of pressed assembly parts are stacked in sequence to fill the hollow mold cavity, and then the mold body is transferred to a sintering furnace for hot pressing and sintering;
[0060] (6) After the hot pressing sintering is completed, the mold body is taken out, and the pressed assembly parts are disassembled to obtain ten boron carbide workpieces. A blind hole with a depth of 10 mm is formed in the center of the boron carbide workpiece.
[0061] Application Example 2
[0062] This application example uses the mold provided in Example 1 to manufacture a pure boron carbide workpiece with a through hole, which specifically includes the following steps:
[0063] (1) placing the lower template at the bottom of the hollow mold cavity and laying the second cushion layer;
[0064] (2) compacting the boron carbide raw material powder on the upper surface of the second cushion layer, leaving a hole in the center of the boron carbide raw material;
[0065] (3) subsequently laying a first cushion layer on the upper surface of the boron carbide raw material, and placing an upper template on the upper surface of the first cushion layer;
[0066] (4) according to the order of steps (1) to (3), ten sets of pressed assembly parts are stacked in sequence to fill the hollow mold cavity, and then the mold body is transferred to a sintering furnace for hot pressing and sintering;
[0067] (5) After the hot pressing sintering is completed, the mold body is taken out and the pressed assembly parts are disassembled to obtain ten boron carbide workpieces with through holes with a depth of 10 mm.
[0068] The applicant declares that the above is only a specific implementation method of the present utility model, but the protection scope of the present utility model is not limited thereto. The technicians in the relevant technical field should understand that any changes or substitutions that can be easily thought of by the technicians in the relevant technical field within the technical scope disclosed in the present utility model fall within the protection scope and disclosure scope of the present utility model.
Claims
1. A mold for preparing a boron carbide workpiece with a hole, characterized in that: It comprises a mould body and at least one pressing assembly component, wherein a hollow mould cavity is arranged in the mould body, and the pressing assembly component is located in the hollow mould cavity; the pressing assembly component comprises an upper mould plate and a lower mould plate which are interlocked with each other, wherein the upper mould plate and the lower mould plate are respectively provided with a first assembly hole and a second assembly hole, wherein the first assembly hole and the second assembly hole are arranged opposite to each other, an upper pad is movably arranged in the first assembly hole, and a lower pad is movably arranged in the second assembly hole, and the space between the upper mould plate and the lower mould plate is used for filling boron carbide raw material.
2. The mold for preparing a boron carbide workpiece with a hole according to claim 1, characterized in that: The thickness of the upper pad is greater than the thickness of the upper template; the thickness of the lower pad is less than the thickness of the lower template. After the upper template is buckled with the lower template, the upper pad is partially located in the second assembly hole.
3. The mold for preparing a boron carbide workpiece with a hole according to claim 1, characterized in that: The first assembly hole and the second assembly hole have the same hole diameter, and the outer diameters of the surfaces of the upper cushion block and the lower cushion block on one side close to each other are the same.
4. The mold for preparing a boron carbide workpiece with a hole according to claim 3, characterized in that: The outer peripheral surface of the upper pad is a smooth surface or a threaded surface; The outer diameter of the upper pad increases gradually from the side surface away from the lower template to the direction close to the lower pad; The outer diameter of the lower pad increases gradually from a side surface away from the upper template toward a direction close to the upper pad.
5. The mold for preparing a boron carbide workpiece with a hole according to claim 1, characterized in that: A first cushion layer is arranged between the upper template and the boron carbide raw material, and a second cushion layer is arranged between the lower template and the boron carbide raw material.
6. The mold for preparing a boron carbide workpiece with a hole according to claim 5, characterized in that: The first cushion layer and the second cushion layer independently include graphite paper.
7. The mold for preparing a boron carbide workpiece with a hole according to claim 2, characterized in that: The diameters of the upper and lower templates are independently 300 to 500 mm; The diameters of the first assembly hole and the second assembly hole are independently 100 to 200 mm; The thickness difference between the upper template and the upper pad is 5 to 15 mm.
8. The mold for preparing a boron carbide workpiece with a hole according to claim 1, characterized in that: The number of the press-fit components is at least two, and at least two of the press-fit components are sequentially stacked and arranged in the hollow mold cavity.
9. The mold for preparing a boron carbide workpiece with a hole according to claim 1, characterized in that: The mold body comprises a graphite guard plate and a protective jacket which are nested in sequence, the hollow mold cavity is provided in the graphite guard plate, and a supporting tray is also provided at the bottom of the mold body.
10. The mold for preparing a boron carbide workpiece with a hole according to claim 9, characterized in that: The graphite guard plate is composed of at least two graphite plates, and at least two of the graphite plates are spliced to form the hollow mold cavity.