H-rich sintering device and method for MAX phase gel casting green body

Abstract

The invention relates to an H-rich sintering device and method for MAX phase gel casting green bodies. The H-rich sintering device comprises an outer protective cover, a sintering table arranged in the outer protective cover and an inner protective cover arranged on the sintering table, and a to-be-sintered MAX-phase green body is arranged in the inner protective cover; an air inlet and an air outlet are formed in the outer protective cover; and a gap for a sintering atmosphere to enter is reserved in the inner protective cover. The sintering method comprises the following steps that an H-rich sintering device is placed in a sintering furnace, an MAX-phase green body is placed in an inner protective cover, and the sintering furnace is vacuumized; introducing inert gas into the sintering furnace until the sintering furnace is full of inert gas atmosphere; and the sintering furnace is heated, the MAX-phase green body is sintered, and mixed gas containing hydrogen and inert gas is continuously introduced in the sintering process. Compared with the prior art, sintering decomposition caused by A-site element loss in the MAX phase gel casting green body sintering process can be inhibited.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic processing and preparation, in particular to a H-rich sintering device and a sintering method for a MAX phase gel injection molding green body. Background Art

[0002] MAX phase ceramics belong to ternary layered compounds, usually represented by M n+1 AX n (n can be 1 to 3), where M is a transition metal, A is a main group element, and X can be carbon or nitrogen. This material combines the properties of covalent bonds and metallic bonds, giving it metal-like high electrical and thermal conductivity and excellent thermal shock resistance. At the same time, they also exhibit typical qualities of ceramics, such as high hardness, wear resistance, corrosion resistance, radiation resistance and oxidation resistance, and can maintain excellent mechanical properties even under high temperature conditions. These characteristics make MAX phase ceramics an ideal choice for extremely harsh environments, especially as high-temperature structural materials for reactor cores.

[0003] Structurally, MAX phase ceramics show special chemical bond characteristics through their unique crystal structure. Studies on its electronic structure show that MX bonding exhibits strong covalent and ionic bonding characteristics, MA bonds are weaker, mainly covalent bonds and metallic bonds, and MM is completely connected by metallic bonds. The strong covalent bonds between M and A atoms form chains such as Ti-C-Ti-C-Ti, which enhances the strength and elastic modulus of the material. In the MAX phase, the weaker covalent bonds between the MX sheets and the A atomic planes make it easier for A atoms to detach from the MX sheets, leaving behind MX nanosheets with high structural stability.

[0004] Gel injection molding technology is an effective molding method for manufacturing large-sized and complex-shaped ceramic parts, and the process is also applicable to the molding of MAX phase ceramics. However, due to the special valence bond structure of the MAX phase, the "A-position elements" in the gel injection molding green body are easily decomposed and lost during the high-temperature sintering process, which will eventually lead to unstable mechanical properties of the MAX phase ceramic sintered body and reduce the safety of the main structure of the MAX phase parts. In order to solve the sintering problem of MAX phase colloid molding green body, the academic community has made some efforts and attempts. For example, molten Si is placed near the MAX phase colloid molding green body to form a sintering protection of Si atmosphere to inhibit sintering decomposition, but there is still Si element loss in an open environment, and the protective effect is limited. In addition, the C element volatilized in the graphite resistance furnace in the open environment promotes the loss of Si element (generating SiC). The sintering atmosphere described in Chinese patent CN 108046806A is an inert atmosphere or vacuum, which cannot avoid the loss of "A-position" elements and the decomposition of MAX phase gel injection molding green body. Chinese patent CN 110028326 A proposes to sinter in a closed environment through an A-rich protective atmosphere and use a protective cover to isolate the buried powder, so as to avoid the escape of the A-site element and the decomposition of the MAX phase gel injection molding green body. However, the A-site element molten at the sintering temperature is extremely corrosive and can easily corrode the protective cover and crucible, which is not conducive to long-term sintering; and buried powder sintering has very high requirements on powder purity and chemical stability. During the sintering process, the powder cannot release impurity elements, otherwise the impurity elements will react with the A-site element, resulting in the decomposition of the green body, which undoubtedly greatly increases the sintering cost.

[0005] Therefore, in order to solve the problems in the sintering process of MAX phase colloid-molded green bodies, it is urgent to develop a new type of MAX phase ceramic sintering device and method. Summary of the invention

[0006] The purpose of the present invention is to provide a H-rich sintering device and method for MAX phase gel casting green body in order to overcome the defects of the existing MAX phase gel casting green body technology that the A-site elements are easily lost and corrosive.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] The present invention first provides a H-rich sintering device for MAX phase gel casting green body, comprising an outer protective cover, a sintering table arranged in the outer protective cover, and an inner protective cover arranged on the sintering table, wherein the MAX phase green body to be sintered is placed in the inner protective cover;

[0009] The outer protective cover is provided with an air inlet and an air outlet for continuously introducing a sintering atmosphere including hydrogen and an inert gas during the sintering process;

[0010] The inner protective cover has a gap for the sintering atmosphere to enter.

[0011] Furthermore, the sintering table is located at the center of the outer protective cover, and the MAX phase green body is placed at the center of the inner protective cover.

[0012] Furthermore, the placement width of the inner protective cover does not exceed the width of the table top of the sintering table.

[0013] Furthermore, the width of the sintering table does not exceed 3 / 4 of the width of the outer protective cover, and the sum of the heights of the sintering table and the inner protective cover does not exceed 3 / 4 of the height of the outer protective cover.

[0014] Furthermore, the air inlet and the air outlet are at the same height, and the outer protective cover is completely sealed except for the air inlet and the air outlet.

[0015] Furthermore, the material of the outer protective cover and the inner protective cover is one or more of zirconium, molybdenum, tantalum, niobium, tungsten, high-purity aluminum oxide, silicon carbide or silicon nitride.

[0016] Furthermore, the inner protective cover is composed of two nested parts, and there is a gap at the nested part for the sintering atmosphere to enter, and the width of the gap is less than 1 mm. During the high-temperature sintering process, the sintering atmosphere can pass through the gap into the inner protective cover to remove the impurity oxygen in the MAX phase powder and inhibit the surface decomposition of the MAX phase green body.

[0017] The present invention also provides a sintering method using the above H-rich sintering device, comprising the following steps:

[0018] S1: placing the H-rich sintering device in a sintering furnace, placing the MAX phase green body in an inner protective cover, and evacuating the sintering furnace to a vacuum;

[0019] S2: Introducing inert gas into the sintering furnace until both the outer protective cover and the inner protective cover are filled with inert gas atmosphere;

[0020] S3: The sintering furnace is heated to raise the temperature, and the MAX phase green body is sintered. During the sintering process, a mixed gas including hydrogen and an inert gas is continuously introduced.

[0021] Furthermore, in step S1, the sintering furnace is evacuated to below 10-1000Pa.

[0022] Furthermore, in step S2, the inert gas is one or both of argon and helium.

[0023] Furthermore, steps S1 and S2 are repeated 2-3 times to ensure that the oxygen and nitrogen in the sintering device are exhausted and the inner protective cover and the outer protective cover are filled with inert gas.

[0024] Furthermore, in step S3, the content of hydrogen in the mixed gas is 5-85 vol.%, preferably 10%-30%.

[0025] Furthermore, in step S3, the flow rate of the mixed gas is 50-5000 ml / min, and more preferably 200-500 ml / min.

[0026] Furthermore, in step S3, the sintering temperature is 1300-1800°C.

[0027] Furthermore, in step S3, the heating rate of the sintering is 2-20°C / min, preferably 5-10°C / min.

[0028] Furthermore, in step S3, the constant temperature time of sintering is 0.5-10 hours, preferably 2.5-4 hours.

[0029] The present invention also provides a MAX phase gel injection molding ceramic component sintered by the sintering method, wherein the density of the ceramic component is greater than 97%.

[0030] Furthermore, MAX phase gel-molded ceramic parts have large size (>200 mm), complex shape and have technical characteristics such as radiation resistance, high temperature resistance, oxidation resistance, corrosion resistance and erosion resistance.

[0031] The MAX phase ceramic parts prepared by the invention can meet the service requirements of nuclear reactor core structural materials for Ti3SiC2 ceramic parts.

[0032] The MAX phase ceramics described in the present invention include all known MAX phase ceramics, including but not limited to Ti3SiC2 ceramics, Ti3AlC2 ceramics and Ti2AlC ceramics.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The sintering method of the present invention adopts H-rich atmosphere sintering, which can also suppress the sintering decomposition caused by the loss of A-site elements during the sintering process of the MAX phase gel casting green body.

[0035] (2) The present invention adopts H-rich atmosphere sintering to avoid the corrosion of the protective cover and the crucible by the molten A-site elements in the Al-rich sintering, which can prolong the sintering densification time and reduce the replacement frequency of the protective cover and the crucible, thereby improving the sintering quality and reducing the sintering cost.

[0036] (3) The present invention adopts H-rich atmosphere sintering and uses an outer protective cover instead of buried powder, thereby avoiding the requirement of high purity and high chemical stability of buried powder, and can also reduce production costs and improve production efficiency.

[0037] (4) The present invention adopts H-rich atmosphere sintering to avoid the reaction between oxygen elements contained in the MAX phase powder and the A-site elements, thereby promoting sintering densification.

[0038] (5) The present invention adopts H-rich atmosphere sintering, and the density of the prepared MAX phase gel injection molding ceramic parts can reach more than 97%, and the surface of the parts does not decompose, which can meet the relevant requirements for the performance of MAX phase materials under high temperature, high corrosion, high abrasion, and high radiation environmental conditions such as nuclear power reactors. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of the H-rich sintering device of the present invention.

[0040] Description of the markings in the figure:

[0041] 1-outer protective cover, 2-sintering table, 3-inner protective cover, 4-air inlet, 5-air outlet, 6-MAX phase green body. DETAILED DESCRIPTION

[0042] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0043] In the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 invention; in addition, unless otherwise clearly specified and limited, the terms "installed", "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 a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The sintering methods in the following embodiments are all implemented based on the following H-rich sintering device of MAX phase gel casting green body. Figure 1 As shown, the H-rich sintering device comprises an outer protective cover 1, a sintering table 2 arranged in the outer protective cover 1, and an inner protective cover 3 arranged on the sintering table 2, and the MAX phase green body 6 to be sintered is placed in the inner protective cover 3. The outer protective cover 1 is provided with an air inlet 4 and an air outlet 5 for continuously introducing a sintering atmosphere including hydrogen and an inert gas during the sintering process. The inner protective cover 3 has a gap for the sintering atmosphere to enter.

[0045] In some specific embodiments, the sintering table 2 is located at the center of the outer protective cover, and the MAX phase green body 6 is placed at the center of the inner protective cover 3 .

[0046] In some specific implementations, the placement width of the inner protective cover 3 does not exceed the width of the table surface of the sintering table 2 .

[0047] In some specific embodiments, the width of the sintering table 2 does not exceed 3 / 4 of the width of the outer protective cover 1 , and the sum of the heights of the sintering table 2 and the inner protective cover 3 does not exceed 3 / 4 of the height of the outer protective cover 1 .

[0048] In some specific embodiments, the axial heights of the air inlet 4 and the air outlet 5 are flush, and the outer protective cover 1 is completely sealed except for the air inlet 4 and the air outlet 5 .

[0049] In some specific embodiments, the outer protective cover 1 and the inner protective cover 3 are made of one or more of zirconium, molybdenum, tantalum, niobium, tungsten, high-purity aluminum oxide, silicon carbide or silicon nitride. Among them, zirconium, molybdenum, tantalum, niobium, tungsten, etc. are refractory metals or alloys that are non-volatile at high temperatures, and high-purity aluminum oxide, silicon carbide, silicon nitride, etc. are structural ceramics with low volatility at high temperatures.

[0050] In some specific implementations, the inner protective cover 3 is composed of two nested parts, an upper part and a lower part, and a gap exists at the nested part for the sintering atmosphere to enter, and the width of the gap is less than 1 mm.

[0051] The present invention also provides a sintering method using the above H-rich sintering device, comprising the following steps:

[0052] S1: placing the H-rich sintering device in a sintering furnace, placing the MAX phase green body in an inner protective cover, and evacuating the sintering furnace to a vacuum;

[0053] S2: Introducing inert gas into the sintering furnace until both the outer protective cover and the inner protective cover are filled with inert gas atmosphere;

[0054] S3: The sintering furnace is heated to raise the temperature, and the MAX phase green body is sintered. During the sintering process, a mixed gas including hydrogen and an inert gas is continuously introduced.

[0055] In some specific embodiments, in step S1, the sintering furnace is evacuated to below 10-1000 Pa.

[0056] In some specific embodiments, in step S2, the inert gas is one or both of argon and helium.

[0057] In some specific embodiments, steps S1 and S2 are repeated 2-3 times to ensure that the oxygen and nitrogen in the sintering device are exhausted and the inner protective cover and the outer protective cover are filled with inert gas.

[0058] In some specific embodiments, in step S3, the content of hydrogen in the mixed gas is 5-85 vol.%, preferably 10%-30%.

[0059] In some specific embodiments, in step S3, the flow rate of the mixed gas is 50-5000 ml / min.

[0060] In some specific embodiments, in step S3, the sintering temperature is 1300-1800°C.

[0061] In some specific embodiments, in step S3, the heating rate of the sintering is 2-20°C / min, preferably 8°C / min.

[0062] In some specific embodiments, in step S3, the constant temperature time of sintering is 0.5-10 hours, preferably 3 hours.

[0063] The above embodiments can be implemented individually or in any combination of two or more. The above embodiments are described in more detail below with reference to specific examples.

[0064] Embodiment 1:

[0065] This embodiment provides a sintering device and a sintering method for sintering Ti3SiC2 gel casting green body, which are as follows:

[0066] (1) Place the debonded Ti3SiC2 gel casting green body in the inner protective cover and Figure 1 As shown, the sintering device is assembled. The sintering table is located in the center of the outer protective cover, the inner protective cover is placed on the sintering table, the Ti3SiC2 green body is located in the center of the inner protective cover, the placement width of the inner protective cover does not exceed the table width of the sintering table, the width of the sintering table does not exceed three-quarters of the width of the outer protective cover, and the sum of the heights of the sintering table and the inner protective cover does not exceed three-quarters of the height of the outer protective cover; the left and right sides of the outer protective cover are respectively provided with an outlet and an inlet, and a mixture of hydrogen and argon is continuously introduced during the sintering process. The inner and outer protective covers are made of metal molybdenum; the outer protective cover is completely sealed except for the inlet and outlet; the inner protective cover is composed of two nested parts, and there is a gap in the nested part, with a gap width of 0.5mm; during the high-temperature sintering process, the sintering atmosphere can pass through the gap into the inner protective cover to remove the impurity oxygen in the Ti3SiC2 green body and inhibit the sintering and decomposition of the Ti3SiC2 green body.

[0067] (2) Place the assembled sintering device into the sintering furnace, seal the sintering furnace, evacuate to below 10Pa, and then fill argon into the sintering device until the pressure inside the sintering device returns to atmospheric pressure. Repeat the above evacuation and argon filling steps two or three times to exhaust the oxygen and nitrogen in the sintering device and fill the inner and outer protective covers with argon. During the evacuation and argon filling process, other gases in the inner protective cover can be replaced with argon through the gaps in the inner protective cover.

[0068] (3) The sintering furnace is heated and the mixed gas of hydrogen and argon is continuously introduced during the heating process until the sintering of the Ti3SiC2 gel injection molded green body is completed to obtain large-sized and complex-shaped Ti3SiC2 ceramic parts. The mixed gas is a mixture of high-purity argon and high-purity hydrogen, the volume ratio of hydrogen is 10 vol.%, and the mixed gas flow rate is 200 ml / min. The sintering temperature is 1600°C, the constant temperature time is 3 hours, and the heating rate is 8°C / min.

[0069] Finally, the Ti3SiC2 ceramic parts obtained in this embodiment have no signs of decomposition on the surface and inside, and the microstructure is dense and uniform, with a relative density of 97.5%, a flexural strength of 441 MPa, and a fracture toughness of 6.7 MPa·m 0.5 The diameter of the parts (centrifugal pump parts) is 225mm, with good corrosion resistance, which meets the service requirements of nuclear reactor core structural materials for Ti3SiC2 ceramic parts.

[0070] Embodiment 2:

[0071] This embodiment provides a sintering device and a sintering method for sintering Ti3AlC2 gel casting green body, which are as follows:

[0072] (1) Place the debonded Ti3AlC2 gel casting green body in the inner protective cover and Figure 1 As shown, the sintering device is assembled. The sintering table is located in the center of the outer protective cover, the inner protective cover is placed on the sintering table, the Ti3AlC2 green body is located in the center of the inner protective cover, the placement width of the inner protective cover does not exceed the table width of the sintering table, the width of the sintering table does not exceed three-quarters of the width of the outer protective cover, and the sum of the heights of the sintering table and the inner protective cover does not exceed three-quarters of the height of the outer protective cover; the outer protective cover has an outlet and an inlet on the left and right sides, respectively, and a mixture of hydrogen and helium is continuously introduced during the sintering process. The inner and outer protective covers are made of metal molybdenum; the outer protective cover is completely sealed except for the inlet and outlet; the inner protective cover is composed of two nested parts, and there is a gap in the nested part, with a gap width of 0.2mm; during the high-temperature sintering process, the sintering atmosphere can pass through the gap into the inner protective cover to remove the impurity oxygen in the Ti3AlC2 green body and inhibit the sintering and decomposition of the Ti3AlC2 green body.

[0073] (2) Place the assembled sintering device into the sintering furnace, seal the sintering furnace, evacuate to below 20Pa, and then fill helium into the sintering device until the pressure inside the sintering device returns to atmospheric pressure. Repeat the above evacuation and helium filling steps two or three times to exhaust the oxygen and nitrogen in the sintering device and fill the inner and outer protective covers with helium. During the evacuation and helium filling process, other gases in the inner protective cover can be replaced with helium through the gaps in the inner protective cover.

[0074] (3) The sintering furnace is heated and the mixed gas of hydrogen and helium is continuously introduced during the heating process until the sintering of the Ti3AlC2 gel injection molded green body is completed to obtain large-sized and complex-shaped Ti3AlC2 ceramic parts. The mixed gas is a mixture of high-purity helium and high-purity hydrogen, the volume ratio of hydrogen is 20 vol.%, and the mixed gas flow rate is 500 ml / min. The sintering temperature is 1500°C, the constant temperature time is 2.5 h, and the heating rate is 10°C / min.

[0075] Finally, the Ti3AlC2 ceramic parts obtained in this embodiment have no signs of decomposition on the surface and inside, the microstructure is dense and uniform, the relative density is 98.3%, the bending strength is 394MPa, and the fracture toughness is 6.1MPa·m 0.5 The diameter of the parts (centrifugal pump parts) is 210mm, with good corrosion resistance, which meets the service requirements of nuclear reactor core structural materials for Ti3AlC2 ceramic parts.

[0076] Embodiment 3:

[0077] This embodiment provides a sintering device and a sintering method for sintering a Ti2AlC gel casting green body, as follows:

[0078] (1) Place the debonded Ti2AlC gel casting green body in the inner protective cover and Figure 1 As shown, the sintering device is assembled. The sintering table is located in the center of the outer protective cover, the inner protective cover is placed on the sintering table, the Ti2AlC green body is located in the center of the inner protective cover, the placement width of the inner protective cover does not exceed the table width of the sintering table, the width of the sintering table does not exceed three-quarters of the width of the outer protective cover, and the sum of the heights of the sintering table and the inner protective cover does not exceed three-quarters of the height of the outer protective cover; the outer protective cover has an outlet and an inlet on the left and right sides, respectively, and a mixture of hydrogen and argon is continuously introduced during the sintering process. The inner and outer protective covers are made of metal molybdenum; the outer protective cover is completely sealed except for the inlet and outlet; the inner protective cover is composed of two nested parts, and there is a gap in the nested part, with a gap width of 0.2mm; during the high-temperature sintering process, the sintering atmosphere can pass through the gap into the inner protective cover to remove the impurity oxygen in the Ti2AlC green body and inhibit the sintering and decomposition of the Ti2AlC green body.

[0079] (2) Place the assembled sintering device into the sintering furnace, seal the sintering furnace, evacuate to below 15Pa, and then fill argon into the sintering device until the pressure inside the sintering device returns to atmospheric pressure. Repeat the above evacuation and argon filling steps two or three times to exhaust the oxygen and nitrogen in the sintering device and fill the inner and outer protective covers with argon. During the evacuation and argon filling process, other gases in the inner protective cover can be replaced with argon through the gaps in the inner protective cover.

[0080] (3) The sintering furnace is heated and the mixed gas of hydrogen and argon is continuously introduced during the heating process until the sintering of the Ti2AlC gel injection molded green body is completed to obtain large-sized and complex-shaped Ti2AlC ceramic parts. The mixed gas is a mixture of high-purity argon and high-purity hydrogen, the volume ratio of hydrogen is 30 vol.%, and the mixed gas flow rate is 300 ml / min. The sintering temperature is 1450°C, the constant temperature time is 4 hours, and the heating rate is 5°C / min.

[0081] Finally, the Ti2AlC ceramic parts obtained in this embodiment have no signs of decomposition on the surface and inside, and the microstructure is dense and uniform, with a relative density of 97.1%, a flexural strength of 351 MPa, and a fracture toughness of 5.7 MPa·m 0.5 The diameter of the parts (centrifugal pump parts) is 205mm, with good corrosion resistance, which meets the service requirements of nuclear reactor core structural materials for Ti2AlC ceramic parts.

[0082] The H-rich sintering device and method of MAX phase gel casting green body described in the present invention cover all known MAX phase ceramics, including but not limited to Ti3SiC2 ceramics, Ti3AlC2 ceramics and Ti2AlC ceramics. The above shows and describes the basic principles, main features and advantages of the present invention.

[0083] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A H-rich sintering device for MAX phase gel casting green body, characterized in that: It comprises an outer protective cover (1), a sintering table (2) arranged in the outer protective cover (1), and an inner protective cover (3) arranged on the sintering table (2), wherein the MAX phase green body (6) to be sintered is placed in the inner protective cover (3); The outer protective cover (1) is provided with an air inlet (4) and an air outlet (5) for continuously introducing a sintering atmosphere including hydrogen and an inert gas during the sintering process; The inner protective cover (3) has a gap for the sintering atmosphere to enter.

2. The H-rich sintering device for MAX phase gel casting green body according to claim 1, characterized in that: The sintering table (2) is located at the central position inside the outer protective cover (1), and the MAX phase green body (6) is placed at the central position inside the inner protective cover (3).

3. The H-rich sintering device for MAX phase gel casting green body according to claim 1, characterized in that: The placement width of the inner protective cover (3) does not exceed the width of the tabletop of the sintering table (2); The width of the sintering table (2) does not exceed 3 / 4 of the width of the outer protective cover (1), and the sum of the heights of the sintering table (2) and the inner protective cover (3) does not exceed 3 / 4 of the height of the outer protective cover (1).

4. The H-rich sintering device for MAX phase gel casting green body according to claim 1, characterized in that: The air inlet (4) and the air outlet (5) are at the same height, and the area of ​​the outer protective cover (1) other than the air inlet (4) and the air outlet (5) is completely sealed.

5. The H-rich sintering device for MAX phase gel casting green body according to claim 1, characterized in that: The material of the outer protective cover (1) and the inner protective cover (3) is one or more of zirconium, molybdenum, tantalum, niobium, tungsten, high-purity aluminum oxide, silicon carbide or silicon nitride.

6. The H-rich sintering device for MAX phase gel casting green body according to claim 1, characterized in that: The inner protective cover (3) is composed of two nested parts, an upper part and an lower part, and a gap is present at the nested part for the sintering atmosphere to enter, and the width of the gap is less than 1 mm.

7. A sintering method using the H-rich sintering device according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: placing the H-rich sintering device in a sintering furnace, placing the MAX phase green body (6) in an inner protective cover (3), and evacuating the sintering furnace to a vacuum; S2: introducing an inert gas into the sintering furnace until both the outer protective cover (1) and the inner protective cover (3) are filled with an inert gas atmosphere; S3: heating the sintering furnace to raise the temperature, sintering the MAX phase green body (6), and continuously introducing a mixed gas including hydrogen and an inert gas during the sintering process.

8. A sintering method according to claim 7, characterized in that: In step S2, the inert gas is one or both of argon and helium; In step S3, the content of hydrogen in the mixed gas is 5-85 vol.%, and the flow rate of the mixed gas is 50-5000 ml / min.

9. A sintering method according to claim 7, characterized in that: In step S3, the sintering temperature is 1300-1800°C, the heating rate is 2-20°C / min, and the sintering constant temperature time is 0.5-10h.

10. A MAX phase gel-casting ceramic component sintered by the sintering method of claim 7, characterized in that: The density of the ceramic component is greater than 97%.

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