Fiber-reinforced max phase ceramic matrix composite and sintering method

Abstract

The application discloses a fiber-reinforced MAX phase ceramic matrix composite material and a sintering method. The fiber-reinforced MAX phase ceramic matrix composite material comprises a matrix and a fiber-reinforced phase, and the matrix is a pure phase Ti2AlC powder. The preparation process of the MAX phase ceramic matrix composite material is simple, the sintering temperature is low, the holding time is short, the obtained composite material has high density and excellent performance, the thermal expansion coefficient of Al2O3 fiber is similar to that of the matrix, the mechanical properties of the 10vol.% fiber-reinforced MAX phase ceramic matrix composite material can be greatly improved, the room temperature bending strength can reach 698 MPa, and the fracture toughness can reach 9.83 MPa*m 1 / 2 .

Description

Technical Field

[0001] This invention belongs to the field of ceramic matrix composite technology, and more specifically, relates to a fiber-reinforced MAX phase ceramic matrix composite and a sintering method thereof. Background Technology

[0002] Ternary layered ceramics (M n+1 AX n The M-phase (or MAX-phase) is a layered hexagonal structure of carbides or nitrides of pre-transition metals. "M" represents a pre-transition metal element, "A" represents a main group element (mostly Group IIIA and IVA elements), and "X" represents C or N. In the crystal structure of this type of material, near-close-packed M layers are alternated with pure A element layers, and X atoms fill the octahedral positions between the M layers. This structure consists of transition metal carbonitrides M-phases. n+1 X n The MAX phase compounds are composed of alternating stacked nanosheets and group A atomic layers. Due to their unique structural characteristics, these compounds exhibit excellent overall performance, possessing not only the superior thermal, electrical, and mechanical properties of their respective binary metal carbides or nitrides, but also, in some aspects, superior performance. In transition metal carbonitrides (M... n+1 X n In the octahedral structure, the MX bonds are mainly covalent or ionic, thus giving the material the characteristics of traditional ceramics such as low density, high melting point, high elastic modulus, and high yield strength. The octahedral layers are separated by A-atom layers, and the MA bonds exhibit very obvious metallic bonding characteristics, giving the material the electrical and thermal conductivity, good microscopic plasticity, ease of machining, and high damage tolerance of metallic materials. The weak metallic bonds between the layered structures provide the MAX phase compound with self-lubricating properties superior to graphite. Therefore, the MAX phase compound can be used as a bonding material between metals and ceramics, a high-temperature precision structural material, an electrode material, or an anti-corrosion coating, and is thus called a novel type of functional structural ceramic.

[0003] Although MAX phase materials have many unique and superior properties compared with traditional ceramics and alloy structural components, their compressive strength, flexural strength, and hardness are slightly insufficient compared with currently used traditional ceramics and structural components. Therefore, various strengthening methods are needed to improve the mechanical properties of MAX phase ceramics.

[0004] Ceramic matrix composites refer to composites in which a second-phase reinforcement (particles, whiskers, continuous fibers, etc.) is introduced into a ceramic matrix, thereby improving its strength and toughness. Compared with pure-phase ceramics, particle-reinforced ceramics require higher stress to fracture and have a larger slope; under the same conditions, greater stress is needed to deform particle-reinforced ceramics. However, particle-reinforced ceramics still exhibit brittle fracture, breaking directly after reaching the stress limit without a yield plateau to provide a buffer region. In contrast, fiber-reinforced ceramics exhibit pseudo-plastic fracture; even after exceeding their yield strength, a certain external load is still required to cause fracture. Therefore, fiber reinforcement has the most significant toughening effect.

[0005] However, existing fiber toughening methods have problems such as weak bonding between fibers and the matrix and numerous internal defects in composite materials. Therefore, how to solve these problems has become a current research hotspot. Summary of the Invention

[0006] The present invention aims to provide a fiber-reinforced MAX phase ceramic matrix composite material and its preparation method. The preparation process of the ceramic matrix composite material is simple, the sintering temperature is low, the holding time is short, and the resulting composite material has high density and excellent performance.

[0007] To achieve the above objectives, according to one aspect of the present invention, a fiber-reinforced MAX phase ceramic matrix composite material is provided, comprising a matrix and a fiber-reinforced phase, wherein the matrix is ​​pure phase Ti2AlC powder.

[0008] According to one embodiment of the present invention, the coefficients of thermal expansion of the fiber reinforcing phase and the matrix are similar, and the difference between the coefficients of thermal expansion of the fiber reinforcing phase and the matrix is ​​no more than 30%, preferably no more than 20%, and more preferably no more than 10%.

[0009] According to one embodiment of the present invention, the fiber reinforcing phase is one or more of SiC fiber, Al2O3 fiber, and basalt fiber.

[0010] According to another aspect of the present invention, a sintering method for fiber-reinforced MAX phase ceramic matrix composite material is also provided, which is obtained by SPS discharge plasma sintering of reinforcing fibers and pure phase Ti2AlC powder.

[0011] Preferably, the sintering temperature of the SPS discharge plasma sintering is 1100℃~1400℃, the pressure is 25~50MPa, and the holding time is 2~15min.

[0012] According to one embodiment of the present invention, the SPS discharge plasma sintering process is as follows: the heating rate before 800°C is 90-110°C / min, the heating rate between 800-1000°C is 45-55°C / min, the heating rate from 1000°C to the sintering temperature of 1100-1400°C is 220-280°C / min, then the temperature is held for 2-15 minutes, followed by cooling, and the pressure during the sintering process is 25-50 MPa.

[0013] Preferably, the SPS discharge plasma sintering process is as follows: the heating rate before 800℃ is 100-105℃ / min, the heating rate between 800-1000℃ is 48-52℃ / min, and after 1000℃, the temperature is increased to the sintering temperature of 1300-1400℃ at a rate of 240-260℃ / min, then held for 8-12 minutes, followed by cooling. The pressure during the sintering process is 40-50 MPa.

[0014] More preferably, the sintering temperature is 1300℃, the sintering pressure is 40MPa, and the holding time is 10min.

[0015] According to one embodiment of the invention, the amount of reinforcing fiber added is 0.01-30 vol.% of the total amount, preferably 10-30 vol.% of the total amount. For example, 10 vol.%, 15 vol.%, 20 vol.%, 25 vol.%, 30 vol.%, or any range between the above values.

[0016] According to one embodiment of the present invention, the reinforcing fiber is one or more selected from SiC fiber, Al2O3 fiber, and basalt fiber. Preferably, the SiC fiber has a length of 50-100 μm and an aspect ratio of 5-1000; the Al2O3 fiber has a length of 5-10 μm and an aspect ratio of 5-20.

[0017] Preferably, the pure phase Ti2AlC powder has a particle size of -325 mesh and a particle size distribution D50 of 5-15 μm.

[0018] According to one embodiment of the present invention, the sintering method further includes the step of uniformly mixing pure phase Ti2AlC powder with reinforcing fibers:

[0019] 1) Weigh the pure phase Ti2AlC powder and reinforcing fiber, and put all the raw materials into the ball mill jar in the order of ball milling beads, pure phase Ti2AlC powder and reinforcing fiber. Measure out alcohol and pour it into the ball mill jar. Mix it manually with a glass rod and add alcohol dropwise to make the ball mill jars of the same size have the same mass.

[0020] 2) Set the ball mill speed to 700-900 r / min and the ball milling time to 2-8 h, with a forward and reverse rotation time ratio of 1:1, and turn on the up-and-down rotation.

[0021] 3) After ball milling, separate the grinding balls from the slurry using a large-size sieve. Take out the powder-alcohol mixture and place it in a beaker. Rinse the walls of the ball mill jar and the grinding balls with alcohol to remove any remaining slurry.

[0022] 4) Cover the beaker with a layer of aluminum foil and poke some small holes to facilitate alcohol evaporation. Place the beaker in an oven to dry. After the powder is dried, use a large-size filter to separate large clumps of powder. Collect and sieve the powder to obtain composite powder.

[0023] According to one embodiment of the present invention, the grinding jar is a polytetrafluoroethylene grinding jar; the grinding balls are selected from three sizes: large, medium and small, with the large size being 8-10 mm, the medium size being 4-7 mm and the small size being 2-3 mm, and the mass ratio of the large grinding balls, medium grinding balls and small grinding balls being 2:5:3.

[0024] Preferably, the mass ratio of the grinding beads, composite powder, and alcohol is 1:1:(1-2).

[0025] Preferably, during ball milling, in order to ensure uniform stress on the ball mill jars and stable operation of the ball mill, two or four ball mill jars of the same size and weight are symmetrically distributed and placed simultaneously for ball milling each time.

[0026] According to one embodiment of the present invention, the sintering method further includes:

[0027] 1) Line the inside of the graphite mold with graphite paper to prevent the sample from sticking to the mold at high temperatures;

[0028] 2) Load the composite powder of pure phase Ti2AlC and reinforcing fiber into the mold, press the head, blow off the surface powder, and cover it with graphite insulation felt for later use.

[0029] 3) Place the prepared mold into the SPS sintering chamber, set the sintering parameters, and start the sintering process.

[0030] Beneficial effects of the present invention

[0031] The MAX phase ceramic matrix composite material provided by this invention has a simple preparation process, low sintering temperature, short holding time, and the resulting composite material has high density and excellent performance. The Al2O3 fibers and the matrix have similar coefficients of thermal expansion, resulting in good thermal matching during sintering. The mechanical properties of the MAX phase ceramic matrix composite material reinforced with 10 vol.% fibers can be significantly improved, with a room temperature flexural strength reaching 698 MPa and a fracture toughness reaching 9.83 MPa·m. 1 / 2 . Attached Figure Description

[0032] Figure 1 The image shows the backscattered electron morphology and elemental distribution of the ceramic matrix composite material obtained by sintering in Comparative Example 1.

[0033] Figure 2 The image shows the backscattered electron morphology and elemental distribution of the ceramic matrix composite material obtained by sintering in Example 1.

[0034] Figure 3 Figure 1 shows the fracture morphology of the ceramic matrix composite material obtained by sintering in Example 1, where Figure a is magnified by 200 times and Figure b is magnified by 1000 times.

[0035] Figure 4 The image shows the backscattered electron morphology of the ceramic matrix composite material obtained by sintering in Example 2.

[0036] Figure 5 The fracture morphology of Example 2 is shown in Figure a, which is magnified by 200 times and Figure b is magnified by 1000 times. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be emphasized that the specific embodiments described herein are only for better illustrating the invention and represent some, not all, embodiments, and therefore are not intended to limit the invention. Furthermore, the technical features involved in the embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

[0038] Comparative Example 1

[0039] This invention uses Ti2AlC powder provided by Forsmann Technology (Beijing) Co., Ltd. as the raw material for sintering. The powder has a particle size of -325 mesh and a particle size distribution of D10 = 2.874 μm, D50 = 9.533 μm, and D90 = 33.96 μm.

[0040] The SPS equipment used in this invention is a third-generation SPS discharge plasma sintering furnace manufactured by Shanghai Chenhua Technology Co., Ltd.

[0041] This invention uses ball milling to grind Ti2AlC powder to a suitable size, employing a TJQ-450 omnidirectional planetary ball mill manufactured by Dongfang Tianjing Company.

[0042] The preparation method of the material is as follows:

[0043] (1) Weigh 36.87g of Ti2AlC powder, put the raw materials into the ball mill jar in the order of ball milling beads and powder, and pour 150ml of alcohol into the ball mill jar. Mix them manually with a glass rod, and add alcohol dropwise to make the ball mill jars of the same size have the same mass.

[0044] In ball milling, a 500ml polytetrafluoroethylene (PTFE) ball mill jar is used. Three sizes of grinding balls are selected: large (8-10mm), medium (4-7mm), and small (2-3mm), with a mass ratio of 2:5:3. Laboratory-grade 99.9% anhydrous ethanol with a density of 0.79g / ml is used. The mass ratio of grinding balls, Ti2AlC and fiber composite powder, and ethanol is 1:1:(1-2). To ensure uniform stress distribution and stable operation of the ball mill, two or four ball mill jars of equal size and weight are symmetrically distributed and used simultaneously for each milling process.

[0045] (2) Set the ball mill speed to 800 r / min and the ball milling time to 6 h, with the forward and reverse rotation time being 1:1, and start the up and down rotation.

[0046] (3) After ball milling, the grinding beads are separated from the slurry through a large-size sieve. The powder-alcohol mixture is taken out and placed in a 500ml beaker. The walls of the ball milling jar and the residual slurry on the grinding beads are rinsed with alcohol.

[0047] (4) Cover the beaker with a layer of aluminum foil and poke some small holes to facilitate alcohol evaporation. Place the beaker in an oven and dry it at 70°C for 12 hours.

[0048] (5) After the powder is dried, use a large-size filter screen to separate the large clumps of powder and collect the sieved composite powder for later use.

[0049] (6) Place graphite paper inside the graphite mold (inner diameter φ45mm, outer diameter φ70mm, height 50mm) to prevent the sample from sticking to the mold at high temperature.

[0050] (7) Weigh 36.5g of the composite powder obtained in step (5), put the weighed composite powder into the mold, press the press head and blow off the surface powder, and cover it with graphite insulation felt for later use.

[0051] (8) Place the prepared mold into the SPS sintering chamber and sinter the composite powder into blocks: the heating rate is 100℃ / min before 800℃, the heating rate is 50℃ / min between 800-1000℃, and the heating rate is 250℃ / min after 1000℃. The cooling method is water cooling. Set the sintering temperature to 1300℃, the sintering pressure to 40MPa, and the holding time to 10min.

[0052] (9) Remove the sample from the mold, grind off the graphite paper adhering to the surface, cut it into a standard sample using wire cutting process, and grind off the surface cutting marks for later use.

[0053] According to the national standards GB / T 4711-1999 "Test Method for Bending Strength of Ceramic Materials" and GB / T 6569-2006 "Test Method for Bending Strength of Fine Ceramics", the bending strength of composite materials was measured using the three-point bending method. The test was conducted on a WDW-100 electronic universal testing machine. The three-point bending sample was a cuboid with dimensions of 3mm × 4mm × 30mm, where the sample length s was 30mm, width b was 3mm, thickness h was 4mm, span L was 24mm, and the loading condition was 0.5mm / min. The average value of 5 samples was taken for each test. The formula for calculating the bending strength of the material is shown below:

[0054]

[0055] In the formula, σ represents the bending strength of the material, with units of MPa; F m The maximum load on the sample is in N; L, b, and h are the span, sample width, and sample thickness, respectively, in mm.

[0056] The fracture toughness of the composite material was tested using the single-sided notched beam method (SENB) according to standard ASTM E399-2012e3. The test was conducted on a WDW-100 electronic universal testing machine. The material was cut into specimens with dimensions of 6mm × 3mm × 30mm, and a notch of appropriate depth was cut in the middle of the specimen using a diamond wire cutter with a diameter of approximately 0.2mm. The test was then performed on the electronic universal testing machine. The span L was 24mm, the specimen width b was 6mm, the thickness h was 3mm, the pre-made notch c had a depth of 1.2mm and a width of 0.2mm, and the loading condition was 0.05mm / min. The average value of 5 specimens was taken for each test. The fracture toughness K of the material was determined. ⅠC The calculation formula is as follows:

[0057]

[0058] In the formula K ⅠC The fracture toughness of the material is expressed in MPa·m. 1 / 2 Y is the stress intensity factor; F m The maximum load on the sample is in N; L, b, and h are the span, sample width, and sample thickness, respectively, in mm; c is the slit depth, in mm.

[0059] The obtained sample had a flexural strength of 412 MPa and a fracture toughness of 5.54 MPa·m1 / 2.

[0060] Example 1

[0061] This invention uses Ti2AlC powder provided by Forsmann Technology (Beijing) Co., Ltd. as the raw material for sintering. The powder has a particle size of -325 mesh and a particle size distribution of D10 = 2.874 μm, D50 = 9.533 μm, and D90 = 33.96 μm.

[0062] This invention uses SiC fibers provided by Qinhuangdao Yinuo High-tech Materials Development Co., Ltd. as the reinforcing phase of the composite material. The fiber length is 50-100μm and the aspect ratio is 5-1000.

[0063] The SPS equipment used in this invention is a third-generation SPS discharge plasma sintering furnace manufactured by Shanghai Chenhua Technology Co., Ltd.

[0064] In the MAX phase ceramic matrix composite material prepared in this experiment, the fiber addition amount was 30 vol.%.

[0065] This invention selects ball milling to uniformly mix Ti2AlC powder and fiber, using the TJQ-450 omnidirectional planetary ball mill manufactured by Dongfang Tianjing Company.

[0066] The preparation method of fiber-reinforced MAX phase ceramic matrix composites is as follows:

[0067] (1) Weigh 36.61g of powder and 12.29g of fiber (the amount of fiber added is 30 vol.%). Put all the raw materials into the ball mill jar in the order of ball milling beads, powder and fiber. Measure 150ml of alcohol and pour it into the ball mill jar. Mix it manually with a glass rod and add alcohol dropwise to make the ball mill jars of the same size have the same mass.

[0068] In ball milling, a 500ml polytetrafluoroethylene (PTFE) ball mill jar is used. Three sizes of grinding balls are selected: large (8-10mm), medium (4-7mm), and small (2-3mm), with a mass ratio of 2:5:3. Laboratory-grade 99.9% anhydrous ethanol with a density of 0.79g / ml is used; the mass ratio of grinding balls, composite powder, and alcohol is 1:1:(1-2). To ensure uniform stress distribution and stable operation of the ball mill, two or four ball mill jars of equal size and weight are symmetrically distributed and used simultaneously for each milling process.

[0069] (2) Set the ball mill speed to 800 r / min and the ball milling time to 6 h, with the forward and reverse rotation time being 1:1, and start the up and down rotation.

[0070] (3) After ball milling, the grinding beads are separated from the slurry through a large-size sieve. The powder-alcohol mixture is taken out and placed in a 500ml beaker. The walls of the ball milling jar and the residual slurry on the grinding beads are rinsed with alcohol.

[0071] (4) Cover the beaker with a layer of aluminum foil and poke some small holes to facilitate alcohol evaporation. Place the beaker in an oven and dry it at 70°C for 12 hours.

[0072] (5) After the powder is dried, use a large-size filter screen to separate the large clumps of powder and collect the sieved composite powder for later use.

[0073] (6) Place graphite paper inside the graphite mold (inner diameter φ45mm, outer diameter φ70mm, height 50mm) to prevent the sample from sticking to the mold at high temperature.

[0074] (7) Weigh 40g of the composite powder obtained in step (5), put the weighed composite powder into the mold, press the press head and blow off the surface powder, and cover it with graphite insulation felt for later use.

[0075] (8) Place the prepared mold into the SPS sintering chamber and sinter the composite powder into blocks: the heating rate is 100℃ / min before 800℃, the heating rate is 50℃ / min between 800-1000℃, and the heating rate is 250℃ / min after 1000℃. The cooling method is water cooling. Set the sintering temperature to 1300℃, the sintering pressure to 40MPa, and the holding time to 10min.

[0076] (9) Remove the sample from the mold, grind off the graphite paper adhering to the surface, cut it into a standard sample using wire cutting process, and grind off the surface cutting marks for later use.

[0077] According to the national standards GBT4711-1999 "Test Method for Bending Strength of Ceramic Materials" and GBT6569-2006 "Test Method for Bending Strength of Fine Ceramics", the bending strength of composite materials was measured by the three-point bending method, and the test was carried out on a WDW-100 electronic universal testing machine.

[0078] The fracture toughness of composite materials was tested using the single-sided notched beam method (SENB) according to standard ASTM E399-2012e3.

[0079] The obtained sample had a flexural strength of 485 MPa and a fracture toughness of 5.7 MPa·m. 1 / 2 Compared to the pure-phase Ti2AlC sample, the flexural strength increased by 73 MPa and the fracture toughness increased by 0.16 MPa·m1. / 2 .

[0080] Example 2

[0081] This invention uses Ti2AlC powder provided by Forsmann Technology (Beijing) Co., Ltd. as the raw material for sintering. The powder has a particle size of -325 mesh and a particle size distribution of D10 = 2.874 μm, D50 = 9.533 μm, and D90 = 33.96 μm.

[0082] Al2O3 fibers provided by Qinhuangdao Yinuo High-tech Materials Development Co., Ltd. were selected as the reinforcing phase of the composite material. The fiber length was 50-100μm and the aspect ratio was 5-20.

[0083] The SPS equipment used is a third-generation SPS discharge plasma sintering furnace manufactured by Shanghai Chenhua Technology Co., Ltd.

[0084] In the MAX phase ceramic matrix composite material prepared by this invention, the amount of fiber added is 10 vol.%.

[0085] This invention selects ball milling to uniformly mix Ti2AlC powder and fiber, using the TJQ-450 omnidirectional planetary ball mill manufactured by Dongfang Tianjing Company.

[0086] The preparation method of fiber-reinforced MAX phase ceramic matrix composites is as follows:

[0087] (1) Weigh 47.06g of powder and 5.04g of Al2O3 fiber (the fiber addition amount is 10 vol.%). Place all raw materials into the grinding jar in the order of grinding beads, powder, and fiber. Measure 150ml of alcohol and pour it into the grinding jar. Mix it manually with a glass rod and add alcohol dropwise to ensure that the grinding jars are of the same mass. In the grinding process, a 500ml polytetrafluoroethylene grinding jar is used. Three sizes of grinding beads are selected: large (8-10mm), medium (4-7mm), and small (2-3mm). The mass ratio of large, medium, and small grinding beads is 2:5:3. The alcohol used is laboratory-grade 99.9% anhydrous ethanol with a density of 0.79g / ml. The mass ratio of grinding beads, composite powder, and alcohol is 1:1:(1-2). In order to ensure uniform stress on the grinding jars and stable operation of the ball mill during ball milling, two or four grinding jars of the same size and weight are symmetrically distributed and placed simultaneously for each ball milling process.

[0088] (2) Set the ball mill speed to 800 r / min and the ball milling time to 6 h, with the forward and reverse rotation time being 1:1, and turn on the up and down rotation.

[0089] (3) After ball milling, the grinding beads are separated from the slurry through a large-size sieve. The powder-alcohol mixture is taken out and placed in a 500ml beaker. The walls of the ball milling jar and the residual slurry on the grinding beads are rinsed with alcohol.

[0090] (4) Cover the beaker with a layer of aluminum foil and poke some small holes to facilitate alcohol evaporation. Place the beaker in an oven and dry it at 70°C for 12 hours.

[0091] (5) After the powder is dried, use a large-size filter screen to separate the large clumps of powder and collect the sieved composite powder for later use.

[0092] (6) Place graphite paper inside the graphite mold (inner diameter φ45mm, outer diameter φ70mm, height 50mm) to prevent the sample from sticking to the mold at high temperature.

[0093] (7) Weigh 40g of the composite powder obtained in step (5), put the weighed composite powder into the mold, press the press head and blow off the surface powder, and cover it with graphite insulation felt for later use.

[0094] (8) Place the prepared mold into the SPS sintering chamber and sinter the composite powder into blocks: the heating rate is 100℃ / min before 800℃, the heating rate is 50℃ / min between 800-1000℃, and the heating rate is 250℃ / min after 1000℃. The cooling method is water cooling. Set the sintering temperature to 1300℃, the sintering pressure to 40MPa, and the holding time to 10min.

[0095] (9) Remove the sample from the mold, grind off the graphite paper adhering to the surface, cut it into a standard sample using wire cutting process, and grind off the surface cutting marks for later use.

[0096] According to the national standards GBT4711-1999 "Test Method for Bending Strength of Ceramic Materials" and GBT6569-2006 "Test Method for Bending Strength of Fine Ceramics", the bending strength of composite materials was measured by the three-point bending method, and the test was carried out on a WDW-100 electronic universal testing machine.

[0097] The fracture toughness of composite materials was tested using the single-sided notched beam method (SENB) according to standard ASTM E399-2012e3.

[0098] The obtained sample had a flexural strength of 698 MPa and a fracture toughness of 9.83 MPa·m. 1 / 2 Compared to the pure-phase Ti2AlC sample, the flexural strength increased by 286 MPa and the fracture toughness increased by 4.29 MPa·m. 1 / 2 .

[0099] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A sintering method for fiber-reinforced MAX phase ceramic matrix composites, characterized in that, It was obtained by SPS discharge plasma sintering of reinforcing fibers and pure-phase Ti2AlC powder; The reinforcing fiber is Al2O3 fiber; the difference in the coefficient of thermal expansion between the reinforcing fiber and the matrix does not exceed 10%. The sintering temperature of the SPS discharge plasma sintering is 1100℃~1400℃, the pressure is 25~50Mpa, and the holding time is 2~15min. The SPS discharge plasma sintering process is as follows: the heating rate is 90~110℃ / min before 800℃, the heating rate is 45~55℃ / min between 800-1000℃, the heating rate is 220-280℃ / min after 1000℃ to the sintering temperature of 1100-1400℃, then the temperature is held for 2~15min, followed by cooling. The pressure during the sintering process is 25~50MPa.

2. The sintering method according to claim 1, characterized in that, The SPS discharge plasma sintering process is as follows: the heating rate is 100~105℃ / min before 800℃, the heating rate is 48~52℃ / min between 800-1000℃, and after 1000℃, the temperature is increased to the sintering temperature of 1300-1400℃ at a rate of 240~260℃ / min, then held for 8~12min, followed by cooling. The pressure during the sintering process is 40-50MPa.

3. The sintering method according to claim 1, characterized in that, The sintering temperature is 1300℃, the sintering pressure is 40MPa, and the holding time is 10min.

4. The sintering method according to claim 1, characterized in that, The amount of the reinforcing fiber added is 0.01-30 vol.% of the total amount.

5. The sintering method according to claim 4, characterized in that, The amount of reinforcing fiber added accounts for 10-30 vol.% of the total amount.

6. The sintering method according to claim 5, characterized in that, The amount of the reinforcing fiber added is 10 vol.%, 15 vol.%, 20 vol.%, 25 vol.%, or 30 vol.% of the total amount.

7. The sintering method according to claim 1, characterized in that, The Al2O3 fibers have a length of 5-10 μm and an aspect ratio of 5-20.

8. The sintering method according to claim 1, characterized in that, The pure phase Ti2AlC powder has a particle size of -325 mesh and a particle size D50 of 5-15µm.

9. The sintering method according to claim 1, characterized in that, It also includes the step of uniformly mixing the pure phase Ti2AlC powder with the reinforcing fibers: 1) Weigh the pure phase Ti2AlC powder and reinforcing fiber, and put all the raw materials into the ball mill jar in the order of ball milling beads, pure phase Ti2AlC powder and reinforcing fiber. Measure out alcohol and pour it into the ball mill jar. Mix it manually with a glass rod and add alcohol dropwise to make the ball mill jars of the same size have the same mass. 2) Set the ball mill speed to 700~900 r / min and the ball milling time to 5-7 h, with a forward and reverse rotation time ratio of 1:1, and turn on the up-and-down rotation. 3) After ball milling, separate the grinding balls from the slurry using a large-size sieve. Take out the powder-alcohol mixture and place it in a beaker. Rinse the walls of the ball mill jar and the grinding balls with alcohol to remove any remaining slurry. 4) Cover the beaker with a layer of aluminum foil and poke some small holes to facilitate alcohol evaporation. Place the beaker in an oven to dry. After the powder is dried, use a large-size filter to separate large clumps of powder. Collect and sieve the powder to obtain composite powder.

10. The sintering method according to claim 9, characterized in that, The grinding jar is a polytetrafluoroethylene (PTFE) grinding jar; the grinding balls are selected in three sizes: large (8-10mm), medium (4-7mm), and small (2-3mm), with a mass ratio of 2:5:3 for large, medium, and small grinding balls.

11. The sintering method according to claim 9, characterized in that, The mass ratio of the grinding beads, composite powder, and alcohol is 1:1:(1-2).

12. The sintering method according to claim 9, characterized in that, When performing ball milling, two or four ball milling jars of the same size and weight are placed symmetrically and simultaneously for each ball milling process.

13. The sintering method according to claim 1, characterized in that, The sintering method further includes: 1) Line the inside of the graphite mold with graphite paper to prevent the sample from sticking to the mold at high temperatures; 2) Load the composite powder of pure phase Ti2AlC and reinforcing fiber into the mold, press the head, blow off the surface powder, and cover it with graphite insulation felt for later use. 3) Place the prepared mold into the SPS sintering chamber, set the sintering parameters, and start the sintering process.

14. A fiber-reinforced MAX phase ceramic matrix composite material, characterized in that, The fiber-reinforced MAX phase ceramic matrix composite material is prepared by the sintering method according to any one of claims 1 to 13, wherein the matrix is ​​pure phase Ti2AlC powder and the fiber reinforcement phase is Al2O3 fiber; The difference in the coefficients of thermal expansion between the fiber-reinforcing phase and the matrix does not exceed 10%.

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