Demolding method for MAX phase gel casting green body with large size and complex shape

Abstract

The invention provides a demolding method of a large-size complex-shape MAX phase gel casting green body, and belongs to the field of ceramic part preparation. The method comprises the steps that S1, the inner surface of a mold for injection molding is washed clean with clear water, then the inner surface of the mold is wiped with an organic solvent, the cleaned mold is naturally aired or dried, and a dry mold is obtained; s2, uniformly spraying a polytetrafluoroethylene emulsion on the inner surface of a dry mold, or dipping the dry mold in the polytetrafluoroethylene emulsion, removing the redundant polytetrafluoroethylene emulsion to form a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and airing or drying to obtain a mold adhered with a polytetrafluoroethylene coating; s3, the mold adhered with the polytetrafluoroethylene coating is placed in a sintering furnace to be baked, the mold is taken out after cooling, and an injection mold is obtained; and S4, injecting the MAX-phase gel injection molding slurry into an injection molding mold, opening the injection molding mold after the injection molding slurry is polymerized and cured, and taking out an injection molding green body.

Description

Technical Field

[0001] The invention relates to the field of ceramic parts preparation, and in particular to a demoulding method for a large-size and complex-shaped MAX phase gel injection molding green body. Background Art

[0002] MAX phase ceramics are a type of ternary layered compounds, usually n+1 AX n It is represented by , where n is 1 to 3. Structurally, M is a transition metal, A is a main group element, and X is carbon or nitrogen. This type of material has the dual characteristics of metallic bonds and covalent bonds, showing the high electrical conductivity, high thermal conductivity and good thermal shock resistance of metals; it also has the typical characteristics of ceramics, such as high hardness, wear resistance, corrosion resistance, radiation resistance and oxidation resistance, and can maintain excellent mechanical properties even in high temperature environments. These characteristics make MAX phase ceramics show obvious advantages under extreme conditions, especially as high-temperature structural materials in the core of reactors.

[0003] Gel injection molding technology is an efficient molding method suitable for making large-sized and complex-shaped ceramic parts, and can also be used to mold MAX phase ceramics. However, in water-based slurries, as ternary ceramics, MAX phase ceramic powder particles have complex hydrated groups on their surfaces, such as ≡Ti–OH, -OTi–(OH)2, ≡Ti–OH2 + ,≡Ti–O - ,=Ti + ,=Ti–O - ,-TiO + ,-TiO–OH,-TiO–O - ,=Al–OH2 + ,=Al–OH,=Al–O - , -CH2 and C=O, etc. The presence of these hydrated functional groups makes the MAX phase gel-casting green body very chemically active, and it is very easy to react chemically with the mold to form an adhesion layer, causing the MAX phase green body to crack when demolded. Summary of the invention

[0004] The present invention is made to solve the above problems and aims to provide a demoulding method for large-sized and complex-shaped MAX phase gel casting green bodies.

[0005] The invention provides a demoulding method for a large-sized and complex-shaped MAX phase gel injection molding green body, which has the following characteristics and comprises the following steps: S1: firstly, the inner surface of the injection molding mold is rinsed clean with clean water, and then the inner surface of the mold is wiped with an organic solvent to remove organic pollutants that may adhere to the inner surface of the mold, and finally the cleaned mold is naturally dried or baked to obtain a dry mold; S2: polytetrafluoroethylene emulsion is evenly sprayed on the inner surface of the dry mold, or the dry mold is immersed in polytetrafluoroethylene emulsion, and then the excess polytetrafluoroethylene emulsion is removed to form a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and then the mold is dried or baked to obtain a mold with a polytetrafluoroethylene coating adhered thereto; S3: the mold with the polytetrafluoroethylene coating adhered thereto is placed in a sintering furnace for baking, and after the furnace temperature is cooled to room temperature, the mold is taken out to obtain an injection molding mold; S4: MAX phase gel injection molding slurry is injected into the injection molding mold, and after the injection molding slurry is polymerized and solidified, the injection molding mold is opened to take out the large-sized and complex-shaped MAX phase gel injection molding green body.

[0006] The demolding method of large-sized complex-shaped MAX phase gel-casting green body provided by the present invention may also have the following characteristics: wherein, in step S1, the material of the mold is metal or epoxy resin, the organic solvent is a small molecule liquid phase organic solvent, and the organic solvent is selected from any one or more of butanone, acetone, ethanol, propanol, glycerol, tetrahydrofuran, methanol, and butanol.

[0007] The demoulding method of the large-sized and complex-shaped MAX phase gel-casting green body provided by the present invention may also have the following characteristics: wherein the metal is metallic aluminum and the organic solvent is anhydrous ethanol.

[0008] In the demolding method of large-sized complex-shaped MAX phase gel injection molding green body provided by the present invention, it can also have the following characteristics: wherein, the mold is a detachable mold, including upper and lower modules or upper, middle and lower modules, and the roughness of the inner surface of the mold is Ra <100, step S3 also includes: after taking out the mold, completing the assembly of the mold to obtain an injection mold, in step S4, each module is removed in turn when the injection mold is opened.

[0009] The demoulding method of the large-sized complex-shaped MAX phase gel-casting green body provided by the present invention may also have the following characteristics: wherein, in step S2, the polytetrafluoroethylene emulsion is a water-based emulsion, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 15wt.%-95wt.%, the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 0.01-100μm, the pH value of the polytetrafluoroethylene emulsion is 5-13, the viscosity is 1-1000mPa·s, and the density is 1.1-1.8g / cm 3 , the thickness of the polytetrafluoroethylene emulsion adhesion layer is 0.01-4mm.

[0010] The demolding method of large-sized complex-shaped MAX phase gel-casting green body provided by the present invention may also have the following characteristics: wherein, in step S2, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 65wt.%, the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 0.5μm, the pH value of the polytetrafluoroethylene emulsion is 8.5, the viscosity is 50mPa·s, and the thickness of the polytetrafluoroethylene emulsion adhesion layer is 0.5mm.

[0011] The demolding method of large-sized complex-shaped MAX phase gel-casting green body provided by the present invention may also have the following characteristics: wherein, in step S2, air-drying is performed in a cool place indoors for 0.2-20 hours, and oven-drying is performed for 0.1-10 hours, and the drying temperature is 30-100°C.

[0012] The demolding method of large-sized complex-shaped MAX phase gel-casting green body provided by the present invention may also have the following characteristics: wherein, in step S2, air drying is performed in a cool indoor place for 6 hours, preferably in a cool indoor place for 2 hours, and the drying temperature is 60°C.

[0013] The demolding method of large-sized complex-shaped MAX phase gel-casting green body provided by the present invention may also have the following characteristics: wherein, in step S3, the baking temperature is 150-500°C, the time is 0.01-10h, the heating rate is 1-20°C / min, and the thickness of the polytetrafluoroethylene coating is 10-500μm.

[0014] The demolding method of large-sized complex-shaped MAX phase gel-molding green body provided by the present invention may also have the following characteristics: wherein, in step S3, the baking temperature is 380°C, the time is 0.5h, the heating rate is 8°C / min, and the molding mold meets the molding requirements of the MAX phase gel-molding slurry.

[0015] Functions and Effects of the Invention

[0016] According to the demoulding method of large-sized and complex-shaped MAX phase gel injection molding green body involved in the present invention, because polytetrafluoroethylene emulsion is used as a demoulding agent, the demoulding agent can be evenly and efficiently applied to the inner surface of the large-sized and complex-shaped mold with the help of the flow of the liquid phase; a layer of polytetrafluoroethylene coating is formed on the inner surface of the mold by high-temperature baking, which can increase the adhesion of the polytetrafluoroethylene coating to the inner surface of the mold, prevent the polytetrafluoroethylene coating from falling off, increase the number of mold uses, reduce production costs, and improve efficiency; polytetrafluoroethylene can effectively isolate the chemical reaction between the complex hydrated groups on the surface of the MAX phase ceramic powder particles and the mold, thereby avoiding demoulding adhesion and obtaining a defect-free large-sized and complex-shaped MAX phase ceramic gel injection molding green body.

[0017] The method of the present invention effectively solves the problems of cracking of green body of MAX phase ceramic parts and sticking to molds that may occur during demolding. In addition, the MAX phase ceramic parts manufactured by this method not only have the advantages of large size (greater than 200mm) and complex shape, but also can ensure the performance requirements of the material in extreme working environments such as high temperature, high corrosion, high wear and high radiation such as nuclear power reactors, and ensure the stability and reliability of the material under harsh conditions. Through the application of this technology, the potential of MAX phase ceramics in high pressure, high irradiation and other applications has been fully utilized, greatly expanding its application prospects in the field of advanced manufacturing. DETAILED DESCRIPTION

[0018] The present invention provides a demoulding method for a large-sized and complex-shaped MAX phase gel casting green body, the method comprising the following steps:

[0019] S1: First, rinse the inner surface of the injection mold with clean water, then wipe the inner surface of the mold with an organic solvent to remove organic pollutants that may adhere to the inner surface of the mold, and finally dry the cleaned mold naturally or bake it to obtain a dry mold.

[0020] Wherein, in step S1, the material of the mold is metal or epoxy resin, preferably metal aluminum; the organic solvent is a small molecule liquid phase organic solvent, and the organic solvent is selected from any one or more of butanone, acetone, ethanol, propanol, glycerol, tetrahydrofuran, methanol, butanol, preferably anhydrous ethanol. The mold is a detachable mold, including upper and lower modules or upper, middle and lower modules, preferably including upper, middle and lower modules, and the inner surface roughness of the mold is Ra<100.

[0021] S2: spraying polytetrafluoroethylene emulsion evenly on the inner surface of the dry mold, or immersing the dry mold in polytetrafluoroethylene emulsion, then removing excess polytetrafluoroethylene emulsion to form a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and drying or baking to obtain a mold with polytetrafluoroethylene coating.

[0022] Wherein, in step S2, the polytetrafluoroethylene emulsion is a water-based emulsion, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 15wt.%-95wt.%, preferably 65wt.%; the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 0.01-100μm, preferably 0.5μm; the pH value of the polytetrafluoroethylene emulsion is 5-13, preferably 0.5μm; the viscosity of the polytetrafluoroethylene emulsion is 1-1000mPa·s, preferably 50mPa·s; the density of the polytetrafluoroethylene emulsion is 1.1-1.8g / cm 3 ; The thickness of the polytetrafluoroethylene emulsion adhesion layer is 0.01-4mm, preferably 0.5mm.

[0023] In step S2, air drying is air drying in a cool place indoors for 0.2-20 hours, preferably 6 hours. Drying is oven drying for 0.1-10 hours, preferably 2 hours; the drying temperature is 30-100°C, preferably 60°C.

[0024] S3: placing the mold with the polytetrafluoroethylene coating in a sintering furnace for baking, and after the furnace temperature cools to room temperature, taking out the mold, completing the assembly of the mold, and obtaining an injection mold. The injection mold meets the injection molding requirements of the MAX phase gel injection molding slurry.

[0025] In step S3, the baking temperature is 150-500°C, preferably 380°C; the baking time is 0.01-10h, preferably 0.5h; the baking heating rate is 1-20°C / min, preferably 8°C / min; and the thickness of the polytetrafluoroethylene coating is 10-500μm.

[0026] S4: Inject the MAX phase gel injection molding slurry into the injection molding mold. After the injection molding slurry is polymerized and solidified, open the injection molding mold (remove each module in sequence, for example, remove the upper, middle and lower modules in sequence), and take out the large-sized and complex-shaped MAX phase gel injection molding green body.

[0027] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments specifically describe the demoulding method of the large-sized and complex-shaped MAX phase gel-casting green body of the present invention.

[0028] Example 1

[0029] S1: First, rinse the inner surface of the injection mold with deionized water, then wipe the inner surface of the mold with anhydrous ethanol to remove organic pollutants that may adhere to the inner surface of the mold, and finally dry the cleaned mold naturally to obtain a dry mold.

[0030] Wherein, in step S1, the material of the mold is metal aluminum; the mold is a detachable mold, including upper, middle and lower modules, and the roughness of the inner surface of the mold is Ra<10.

[0031] S2: spraying polytetrafluoroethylene emulsion evenly on the inner surface of the dry mold, removing excess polytetrafluoroethylene emulsion, forming a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and drying naturally to obtain a mold with polytetrafluoroethylene coating adhered thereto.

[0032] Wherein, in step S2, the polytetrafluoroethylene emulsion is a water-based emulsion, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 40wt.%, the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 3μm, the pH value of the polytetrafluoroethylene emulsion is 8.5, and the viscosity of the polytetrafluoroethylene emulsion is 50s -1 The density of polytetrafluoroethylene emulsion is 1.2 g / cm3 , the thickness of the tetrafluoroethylene emulsion adhesion layer is 0.1 mm.

[0033] In step S2, natural drying is air drying in a cool place indoors for 18 hours.

[0034] S3: placing the mold with the polytetrafluoroethylene coating in a sintering furnace for baking, and after the furnace temperature cools to room temperature, taking out the mold, completing the assembly of the mold, and obtaining an injection mold. The injection mold meets the injection molding requirements of the MAX phase gel injection molding slurry.

[0035] In step S3, the baking temperature is 330° C., the baking time is 10 min, the baking heating rate is 5° C. / min, and the thickness of the polytetrafluoroethylene coating is 90 μm.

[0036] S4: Inject the Ti3SiC2 gel injection molding slurry into the injection molding mold. After the injection molding slurry completes polymerization and solidification, open the injection molding mold (remove the upper, middle and lower modules in turn), and take out the large-sized and complex-shaped MAX phase gel injection molding green body, which is recorded as the Ti3SiC2 ceramic impeller (open) demolding green body.

[0037] The Ti3SiC2 ceramic impeller (open type) obtained in this embodiment is demoulded without adhesion to the inner surface of the mold, and there are no macroscopic defects such as cracks and cracks on the surface and inside of the green body. The microstructure of the green body is dense and uniform. After sintering, the relative density is 97.1%, the bending strength is 350MPa, and the fracture toughness is higher than 5.0MPa·m 0.5 The diameter of the parts (centrifugal pump impellers) is 210mm, with good corrosion resistance, which meets the service performance requirements of Ti3SiC2 ceramic impellers for nuclear reactor core structural materials.

[0038] Example 2

[0039] S1: First, rinse the inner surface of the injection mold with tap water, then wipe the inner surface of the mold with methanol to remove organic pollutants that may adhere to the inner surface of the mold, and finally dry the cleaned mold naturally to obtain a dry mold.

[0040] In step S1, the mold is made of stainless steel; the mold is a detachable mold, including an upper module and a lower module, and the inner surface roughness of the mold is Ra<15

[0041] S2: Immerse the dry mold in polytetrafluoroethylene emulsion, then remove excess polytetrafluoroethylene emulsion to form a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and dry it to obtain a mold with a polytetrafluoroethylene coating.

[0042] Wherein, in step S2, the polytetrafluoroethylene emulsion is a water-based emulsion, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 55wt.%, the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 8μm, the pH value of the polytetrafluoroethylene emulsion is 9, and the viscosity of the polytetrafluoroethylene emulsion is 50s -1 is 50mPa·s, and the density of polytetrafluoroethylene emulsion is 1.3g / cm 3 , the thickness of the tetrafluoroethylene emulsion adhesion layer is 0.5 mm.

[0043] In step S2, the drying is performed in an oven for 2 hours at a drying temperature of 80°C.

[0044] S3: placing the mold with the polytetrafluoroethylene coating in a sintering furnace for baking, and after the furnace temperature cools to room temperature, taking out the mold, completing the assembly of the mold, and obtaining an injection mold. The injection mold meets the injection molding requirements of the MAX phase gel injection molding slurry.

[0045] In step S3, the baking temperature is 350° C., the baking time is 15 min, the baking heating rate is 8° C. / min, and the thickness of the polytetrafluoroethylene coating is 130 μm.

[0046] S4: Inject the Ti3SiC2 gel injection molding slurry into the injection molding mold. After the injection molding slurry completes polymerization and solidification, open the injection molding mold (remove the upper and lower modules in turn), and take out the large-sized and complex-shaped MAX phase gel injection molding green body, which is recorded as the Ti3SiC2 ceramic impeller (open) demolding green body.

[0047] The Ti3SiC2 ceramic impeller (open type) obtained in this embodiment is demoulded without adhesion to the inner surface of the mold, and there are no macroscopic defects such as cracks and cracks on the surface and inside of the green body. The microstructure of the green body is dense and uniform. After sintering, the relative density is 98.3%, the bending strength is 330MPa, and the fracture toughness is higher than 5.3MPa·m 0.5 The diameter of the parts (centrifugal pump impellers) is 230mm, with good corrosion resistance, which meets the service performance requirements of Ti3AlC2 ceramic impellers for nuclear reactor core structural materials.

[0048] Example 3

[0049] S1: First, rinse the inner surface of the injection mold with distilled water, then wipe the inner surface of the mold with acetone to remove organic pollutants that may adhere to the inner surface of the mold, and finally place the cleaned mold in an oven to dry to obtain a dry mold.

[0050] Wherein, in step S1, the material of the mold is metal aluminum; the mold is a detachable mold, including upper, middle and lower modules, and the roughness of the inner surface of the mold is Ra<5.

[0051] S2: spraying polytetrafluoroethylene emulsion evenly on the inner surface of the dry mold, removing excess polytetrafluoroethylene emulsion, forming a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and drying naturally to obtain a mold with polytetrafluoroethylene coating adhered thereto.

[0052] Wherein, in step S2, the polytetrafluoroethylene emulsion is a water-based emulsion, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 70 t.%, the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 2 μm, the pH value of the polytetrafluoroethylene emulsion is 9.5, and the viscosity of the polytetrafluoroethylene emulsion is 50s -1 is 350mPa·s, and the density of polytetrafluoroethylene emulsion is 1.4g / cm 3 , the thickness of the tetrafluoroethylene emulsion adhesion layer is 1 mm.

[0053] In step S2, natural drying is air drying in a cool place indoors for 20 hours.

[0054] S3: placing the mold with the polytetrafluoroethylene coating in a sintering furnace for baking, and after the furnace temperature cools to room temperature, taking out the mold, completing the assembly of the mold, and obtaining an injection mold. The injection mold meets the injection molding requirements of the MAX phase gel injection molding slurry.

[0055] In step S3, the baking temperature is 380° C., the baking time is 30 min, the baking heating rate is 10° C. / min, and the thickness of the polytetrafluoroethylene coating is 300 μm.

[0056] S4: Inject the Ti3SiC2 gel injection molding slurry into the injection molding mold. After the injection molding slurry completes polymerization and solidification, open the injection molding mold (remove the upper, middle and lower modules in turn), and take out the large-sized and complex-shaped MAX phase gel injection molding green body, which is recorded as the Ti3SiC2 ceramic impeller (open) demolding green body.

[0057] The Ti3SiC2 ceramic impeller (open type) obtained in this embodiment is demoulded without adhesion to the inner surface of the mold, and there are no macroscopic defects such as cracks and cracks on the surface and inside of the green body. The microstructure of the green body is dense and uniform. After sintering, the relative density is 96.8%, the bending strength is 290MPa, and the fracture toughness is higher than 5.5MPa·m 0.5 The diameter of the parts (centrifugal pump impellers) is 200mm, with good corrosion resistance, which meets the service performance requirements of Ti2AlC ceramic impellers for nuclear reactor core structural materials.

[0058] The demolding method of a large-sized complex-shaped MAX phase gel-casting green body described in the present invention covers all known MAX phase ceramics. The basic principles, main features and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only illustrative of the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A demoulding method for a large-sized and complex-shaped MAX phase gel casting green body, characterized in that: The following steps are involved: S1: First, rinse the inner surface of the injection mold with clean water, then wipe the inner surface of the mold with an organic solvent to remove organic pollutants that may adhere to the inner surface of the mold, and finally dry the cleaned mold naturally or in an oven to obtain a dry mold; S2: spraying polytetrafluoroethylene emulsion uniformly on the inner surface of the dry mold, or dipping the dry mold into polytetrafluoroethylene emulsion, then removing excess polytetrafluoroethylene emulsion to form a uniform polytetrafluoroethylene emulsion adhesion layer on the inner surface of the mold, and drying or baking to obtain a mold with a polytetrafluoroethylene coating; S3: placing the mold with the polytetrafluoroethylene coating in a sintering furnace for baking, and after the furnace temperature is cooled to room temperature, taking out the mold to obtain an injection mold; S4: injecting MAX phase gel injection molding slurry into the injection molding mold, and after the injection molding slurry is polymerized and solidified, opening the injection molding mold to take out the large-sized and complex-shaped MAX phase gel injection molding green body.

2. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 1, characterized in that: in, In step S1, the mold is made of metal or epoxy resin. The organic solvent is a small molecule liquid phase organic solvent, and the organic solvent is selected from any one or more of butanone, acetone, ethanol, propanol, glycerol, tetrahydrofuran, methanol, and butanol.

3. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 2, characterized in that: in, The metal is aluminum. The organic solvent is anhydrous ethanol.

4. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 1, characterized in that: in, The mold is a detachable mold, including an upper and lower module or an upper, middle and lower module, and the inner surface roughness of the mold is Ra<100. Step S3 also includes: after taking out the mold, completing the assembly of the mold to obtain the injection mold, In step S4, each module is removed in sequence when the injection mold is opened.

5. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 1, characterized in that: in, In step S2, the polytetrafluoroethylene emulsion is a water-based emulsion, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 15wt.%-95wt.%, and the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 0.01-100μm, The polytetrafluoroethylene emulsion has a pH value of 5-13, a viscosity of 1-1000 mPa·s, and a density of 1.1-1.8 g / cm 3 , The thickness of the polytetrafluoroethylene emulsion adhesion layer is 0.01-4 mm.

6. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 5, characterized in that: in, In step S2, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 65wt.%, and the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 0.5μm. The pH value of the polytetrafluoroethylene emulsion is 8.5, and the viscosity is 50 mPa·s. The thickness of the polytetrafluoroethylene emulsion adhesion layer is 0.5 mm.

7. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 1, characterized in that: in, In step S2, the drying is air drying in a cool place indoors for 0.2-20 hours. The drying is oven drying for 0.1-10h, and the drying temperature is 30-100°C.

8. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 1, characterized in that: in, In step S2, the drying is air drying in a cool place indoors for 6 hours. The drying is preferably air drying in a cool place indoors for 2 hours, and the drying temperature is 60°C.

9. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 1, characterized in that: in, In step S3, the baking temperature is 150-500°C, the time is 0.01-10h, the heating rate is 1-20°C / min, and the thickness of the polytetrafluoroethylene coating is 10-500μm.

10. The demoulding method of large-size and complex-shaped MAX phase gel casting green body according to claim 9, characterized in that: in, In step S3, the baking temperature is 380°C, the time is 0.5h, and the heating rate is 8°C / min. The injection molding mold meets the injection molding requirements of MAX phase gel casting slurry.