A debinding method for ceramic green body

Abstract

The present invention relates to the field of ceramic processing technology, and discloses a method for removing binder from a ceramic blank, comprising the following steps: S1, removing dust from the ceramic blank and a first substrate; S2, the upper and lower end surfaces of the first substrate are provided with criss-cross through grooves, the criss-crossed positions of the through grooves are provided with through holes, and a gas flow channel is formed between the through grooves, the through holes and the ceramic blank; S3, placing the first substrate and the ceramic blank into a debinding furnace; S4, vacuuming the debinding furnace and introducing reducing gas; S5, heating the debinding furnace to a preset heating temperature; S6, taking out the ceramic blank after the temperature in the debinding furnace drops to a cooling temperature. The beneficial effects of the present invention are as follows: before placing the ceramic blank on the substrate, the ceramic blank and the substrate are subjected to dust removal treatment, and at the same time, the reducing gas can flow between the substrate and the ceramic blank, thereby reducing the residual carbon impurities, improving the debinding effect, and improving the yield rate of the ceramic blank.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic processing, in particular to a debinding method for a ceramic blank. Background Art

[0002] A lot of organic binders and plasticizers are added to the ceramic body during its forming, such as paraffin wax in hot die casting and polyvinyl alcohol in film rolling and cast film. During firing, a large amount of organic matter in the body melts, decomposes, and volatilizes, which will cause the body to deform and crack. At the same time, the organic matter contains a lot of carbon. When there is insufficient oxygen to form a reducing atmosphere, it will affect the sintering quality. Therefore, it is necessary to remove the organic matter in the body before firing to ensure the shape, size and quality requirements of the product. This process is called debinding.

[0003] In the prior art, the ceramic body is generally placed on a substrate and heat treated in a reducing atmosphere. Before the ceramic body is placed on the substrate, the substrate and the ceramic body are not cleaned, and foreign impurities are easily attached to the substrate and the ceramic body, affecting the subsequent debinding effect. In addition, since the substrate and the surface of the ceramic body are completely fitted during debinding without any gap, the reducing gas cannot flow between the substrate and the ceramic body, resulting in uneven temperature distribution of the body during debinding, which easily leads to residual carbon impurities, poor debinding effect, and reduced yield rate of the ceramic body. Summary of the invention

[0004] The purpose of the present invention is to provide a method for debinding a ceramic body, wherein the ceramic body and the substrate are subjected to dust removal treatment before the ceramic body is placed on a substrate, and at the same time, reducing gas can flow between the substrate and the ceramic body to reduce residual carbon impurities, improve the debinding effect, and increase the yield rate of the ceramic body.

[0005] In order to achieve the above object, the present invention provides a method for debinding a ceramic body, comprising the following steps:

[0006] S1, performing dust removal on the ceramic body and the first substrate;

[0007] S2, placing the ceramic body on the first substrate, wherein the upper and lower end surfaces of the first substrate are both provided with crisscross through grooves, through holes are provided at the crisscrossing positions of the through grooves, and gas flow channels are formed between the through grooves, the through holes and the ceramic body;

[0008] S3, placing the first substrate and the ceramic body as a whole into a binder removal furnace;

[0009] S4, performing a vacuum treatment on the debinding furnace, and when the pressure in the debinding furnace reaches a preset value, introducing a reducing gas into the debinding furnace, and the reducing gas can move along the path of the gas flow channel;

[0010] S5, heating the debinding furnace to a preset heating temperature, and performing a heating treatment on the ceramic body for a preset time;

[0011] S6. After the ceramic body is heated to the preset time, the binder removal furnace stops heating, and the ceramic body is taken out after the temperature in the binder removal furnace drops to the cooling temperature.

[0012] Furthermore, in the step S2, the ceramic body is placed on a first substrate, and a second substrate is provided on the ceramic body, wherein the second substrate has the same structure as the first substrate.

[0013] Furthermore, the width of the gas flow channel ranges from 0.1 mm to 2 mm.

[0014] Furthermore, the debinding furnace is heated to the preset heating temperature at a heating rate of 1-10°C / min.

[0015] Furthermore, the preset duration is 4-6 hours.

[0016] Furthermore, the cooling temperature ranges from 30°C to 50°C.

[0017] Furthermore, the preset value of the pressure in the debinding furnace is less than 3000Pa.

[0018] Furthermore, the gas outlet passage of the reducing gas entering the debinding furnace is directly opposite to the gas flow passage.

[0019] Furthermore, in the step S1, an ion dust collector is used to perform dust removal on the first substrate and the ceramic body.

[0020] Furthermore, the flow rate of the reducing gas is 15-20 L / min.

[0021] Compared with the prior art, a debinding method for a ceramic green body in an embodiment of the present invention has the following beneficial effects: before placing the ceramic green body on the first substrate, the ceramic green body and the first substrate are respectively subjected to dust removal treatment to avoid introducing external impurities into the debinding furnace and affecting the debinding effect of the ceramic green body; in addition, the end surface of the first substrate that is bonded to the ceramic green body is evenly distributed with criss-cross through grooves, and through holes are provided at the criss-crossing locations of the through grooves, and gas flow channels are formed between the through grooves, the through holes and the ceramic green body, and the reducing gas can circulate in the gas flow channel and fully contact the surface of the ceramic green body. At the same time, the surface temperature of the ceramic green body is evenly distributed, the residual carbon impurities are reduced, the debinding effect is improved, and the yield rate of the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1is a process flow chart of a debinding method for a ceramic green body according to an embodiment of the present invention;

[0023] Figure 2 It is a structural schematic diagram of a first substrate and a second substrate in a debinding method for a ceramic green body according to an embodiment of the present invention;

[0024] Figure 3 2 is a first structural schematic diagram of a first substrate of a method for debinding a ceramic green body according to an embodiment of the present invention;

[0025] Figure 4 is a second structural schematic diagram of the first substrate of the debinding method for a ceramic green body according to an embodiment of the present invention;

[0026] Figure 5 3 is a schematic diagram of the structure of the first substrate of the method for debinding a ceramic green body according to an embodiment of the present invention;

[0027] Figure 6 It is a fourth structural schematic diagram of the first substrate of the debinding method for a ceramic green body according to an embodiment of the present invention.

[0028] In the figure, 1, first substrate; 2, second substrate; 11, through groove; 12, through hole; 13, supporting part; a, ceramic body. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "inside", "outside", etc. used in the present invention to indicate the orientation or positional relationship are based on the positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred devices and elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In the description of the present invention, it should be understood that the present invention uses the terms "first", "second", etc. to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0032] like Figure 1 As shown, a debinding method for a ceramic body according to a preferred embodiment of the present invention comprises the following steps:

[0033] S1, performing dust removal treatment on the ceramic body a and the first substrate 1;

[0034] S2, placing the ceramic body on the first substrate 1, wherein the upper and lower end surfaces of the first substrate 1 are both provided with crisscross through grooves 11, and through holes 12 are provided at the crisscross positions of the through grooves 11, and gas flow channels are formed between the through grooves 11, the through holes 12 and the ceramic body;

[0035] S3, placing the first substrate 1 and the ceramic body a as a whole into a binder removal furnace;

[0036] S4, performing a vacuum treatment on the debinding furnace, and when the pressure in the debinding furnace reaches a preset value, introducing a reducing gas into the debinding furnace, and the reducing gas can move along the path of the gas flow channel;

[0037] S5, heating the debinding furnace to a preset heating temperature, and performing a heating treatment on the ceramic body a for a preset time;

[0038] S6. After the ceramic body a is heated to the preset time, the binder removal furnace stops heating up, and when the temperature in the binder removal furnace drops to the cooling temperature, the ceramic body a is taken out.

[0039] Among them, in step S1, in order to facilitate the dust removal treatment of the first substrate 1 and the ceramic body a, in the present invention, an ion dust collector is used to remove the dust from the first substrate 1 and the ceramic body a, and the first substrate 1 and the ceramic body a are respectively placed in the dust removal area of ​​the ion dust collector, and the end faces of the first substrate 1 and the ceramic body a are dusted to avoid introducing external impurities into the debinding furnace and affecting the debinding effect.

[0040] In step S2, in order to allow the reducing gas to flow between the first substrate 1 and the ceramic body a and fully contact the ceramic body a to remove carbon impurities, Figure 2 The upper and lower end surfaces of the first substrate 1 are provided with crisscross through grooves 11, and through holes 12 are provided at the crisscross positions of the through grooves 11. A gas flow channel is formed between the through grooves 11, the through holes 12 and the ceramic body. The through grooves 11 divide the end surface of the first substrate 1 into a plurality of support portions 13. The support portions 13 are in contact with the ceramic body a. In order to reduce the contact area between the first substrate 1 and the ceramic body a and increase the contact area between the ceramic body a and the reducing gas, the shape of the support portion 13 is designed. When the support portion 13 is in contact with the surface of the ceramic body a, refer to Figure 3 , Figure 5 , the support portion 13 can be set as a cylinder or a cube, which is set vertically; when the support portion 13 is in line contact with the ceramic body a, refer to Figure 4The shape of the support portion 13 can be set to be a semi-cylinder, which is set horizontally, and the lower end surface of the ceramic body a is tangent to the side wall of the semi-cylinder; when the support portion 13 is in point contact with the ceramic body a, refer to Figure 6 The support portion 13 is set to be a hemisphere. It can be seen that the support portion 13 can also be set to other shapes and can be adjusted according to the actual gas flow conditions, and is not limited to the solution described in the present invention. Furthermore, the shape of the through hole 12 can also be set. The shape of the through hole 12 can be polygonal, circular, elliptical, etc. In this embodiment, in order to facilitate processing, it is preferably circular.

[0041] Furthermore, during the debinding process, carbon impurities are discharged and flow with the reducing gas. To prevent impurities from adhering to the upper surface of the product, in step S2, after the ceramic body a is placed on the first substrate 1, a second substrate 2 is provided on top of the ceramic body a. The second substrate 2 has the same structure as the first substrate 1, and its structure will not be described in detail. In the present invention, preferably, the width of the gas flow channel is in the range of 0.1 mm to 2 mm. The width of the gas flow channel can also be adaptively adjusted according to actual conditions, and can be greater than 2 mm or less than 0.1 mm.

[0042] In step S4, in order to avoid excessive pressure in the debinding furnace and affect the operation of components in the debinding furnace, the preset value of the pressure in the debinding furnace is less than 3000Pa. Furthermore, in order to enable the reducing gas to fully contact with the ceramic body a, the outlet channel of the reducing gas entering the debinding furnace is directly opposite to the gas flow channel, ensuring that the reducing gas quickly enters the gas flow channel. In order to facilitate the control of the flow rate of the reducing gas, the flow rate of the reducing gas is controlled between 15-20L / min.

[0043] In step S5, in order to enable the debinding furnace to reach the preset heating temperature more quickly, the temperature rise speed of the debinding furnace is between 1-10°C / min, and can be adaptively adjusted according to the actual working conditions of the debinding furnace. Furthermore, in order to ensure that carbon impurities can be fully discharged, it is necessary to maintain the preset heating temperature and heat to a preset time. Preferably, in this embodiment, the preset time is 4-6h.

[0044] In step S6, in order to facilitate manual removal of the first substrate 1 and the ceramic body a after binder removal to avoid burns, the cooling temperature is in the range of 30°C-50°C, and the temperature can be adjusted accordingly according to actual needs.

[0045] In summary, an embodiment of the present invention provides a method for debinding a ceramic green body. Before placing the ceramic green body a on the first substrate 1, the ceramic green body a and the first substrate 1 are respectively subjected to dust removal treatment to avoid introducing external impurities into the debinding furnace and affecting the debinding effect of the ceramic green body a. In addition, the end surface of the first substrate 1 that is bonded to the ceramic green body a is evenly distributed with criss-cross through grooves 11, and the criss-crossing parts of the through grooves 11 are provided with through holes 12. Gas flow channels are formed between the through grooves 11, the through holes 12 and the ceramic green body, and the reducing gas can flow in the gas flow channel and fully contact the surface of the ceramic green body a. At the same time, the surface temperature of the ceramic green body a is evenly distributed, the residual carbon impurities are reduced, the debinding effect is improved, and the yield rate of the product is improved.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for debinding a ceramic body, characterized in that: The following steps are involved: S1, performing dust removal on the ceramic body and the first substrate; S2, placing the ceramic body on the first substrate, wherein the upper and lower end surfaces of the first substrate are both provided with crisscross through grooves, through holes are provided at the crisscrossing positions of the through grooves, and gas flow channels are formed between the through grooves, the through holes and the ceramic body, and a second substrate is provided on top of the ceramic body, and the second substrate has the same structure as the first substrate; S3, placing the first substrate and the ceramic body as a whole into a binder removal furnace; S4, performing a vacuum treatment on the debinding furnace, and when the pressure in the debinding furnace reaches a preset value, introducing a reducing gas into the debinding furnace, and the reducing gas can move along the path of the gas flow channel; S5, heating the debinding furnace to a preset heating temperature, and performing a heating treatment on the ceramic body for a preset time; S6. After the ceramic body is heated to the preset time, the binder removal furnace stops heating, and the ceramic body is taken out after the temperature in the binder removal furnace drops to the cooling temperature.

2. The method for debinding a ceramic body according to claim 1, characterized in that: The width of the gas flow channel ranges from 0.1 mm to 2 mm.

3. The debinding method for a ceramic body according to claim 1, characterized in that: The debinding furnace is heated to the preset heating temperature at a heating rate of 1-10°C / min.

4. The method for debinding a ceramic body according to claim 1, characterized in that: The preset duration is 4-6 hours.

5. The method for debinding a ceramic body according to claim 1, characterized in that: The cooling temperature ranges from 30°C to 50°C.

6. The method for debinding a ceramic body according to claim 1, characterized in that: The preset value of the pressure in the debinding furnace is less than 3000Pa.

7. The method for debinding a ceramic body according to claim 1, characterized in that: The gas outlet passage of the reducing gas entering the debinding furnace is directly opposite to the gas flow passage.

8. The method for debinding a ceramic body according to claim 1, characterized in that: In the step S1, an ion dust collector is used to perform dust removal on the first substrate and the ceramic body.

9. The method for debinding a ceramic body according to claim 1, characterized in that: The flow rate of the reducing gas is 15-20 L / min.

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