Tungsten filament toughened silicon carbide ceramic-based composite material and preparation method thereof

Abstract

The invention belongs to the technical field of silicon carbide ceramic-based composite materials, and particularly relates to a tungsten filament toughened silicon carbide ceramic-based composite material and a preparation method thereof.The preparation method comprises the following steps that S1, tungsten filaments are woven into a first tungsten filament prefabricated body; s2, performing chemical vapor deposition on the first tungsten filament preform by adopting process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on the surface of the second tungsten filament preform; s3, the second tungsten filament prefabricated body is impregnated with silicon carbide slurry and sintered to obtain a third tungsten filament prefabricated body, and the third tungsten filament prefabricated body is filled with a silicon carbide matrix; and S4, the step S3 is repeated, and the tungsten filament toughened silicon carbide ceramic-based composite material is obtained. The tungsten filament is adopted as a toughening phase of the silicon carbide ceramic composite material, and the mechanical property of the silicon carbide ceramic composite material can be remarkably improved by optimizing the preparation process of the silicon carbide ceramic-based composite material.

Description

Technical Field

[0001] The present application relates to the technical field of silicon carbide ceramic-based composite materials. Specifically, the present application relates to a tungsten filament toughened silicon carbide ceramic-based composite material and a preparation method thereof. Background Art

[0002] Silicon carbide ceramics offer advantages such as low density, high hardness, high stiffness, wear resistance, oxidation resistance, thermal shock resistance, high thermal conductivity, low expansion coefficient, and low neutron absorption cross-section. They are widely used in precision bearings, compression cylinders, wear-resistant seals, gas rotors, and nuclear reactors. However, because silicon carbide is a brittle ceramic material, cracks inevitably cause catastrophic failure, making it crucial to improve its fracture toughness.

[0003] There are several methods to improve the fracture toughness of silicon carbide ceramics: particle toughening, pore toughening, whisker toughening and continuous fiber toughening. Toughening methods such as particle toughening, pore toughening and whisker toughening can cause cracks inside silicon carbide ceramics to deflect and bifurcate during diffusion, which can improve its fracture toughness to a certain extent, but the degree of improvement in fracture toughness is limited. Continuous fiber toughened silicon carbide ceramic-based composites have good toughening effects and mature preparation technology. The invention patent with announcement number CN102249721B discloses a method for carbon fiber reinforced silicon carbide, which adopts the method of precursor impregnation and high-temperature pyrolysis to prepare carbon fiber reinforced silicon carbide composite materials. The invention patent with announcement number CN102276279B discloses a method for silicon carbide fiber reinforced silicon carbide, which adopts the method of precursor impregnation, hot molding and high-temperature pyrolysis to prepare silicon carbide fiber reinforced silicon carbide composite materials. The above patents all effectively improve the fracture toughness of silicon carbide ceramics.

[0004] Tungsten wire has excellent mechanical properties, high temperature resistance, and a thermal expansion coefficient that matches well with silicon carbide (the thermal expansion coefficient of tungsten wire is 4.5×10 -6 / K, the thermal expansion coefficient of silicon carbide is 4.0-4.5×10 -6 / K) and other advantages. Therefore, there is an urgent need for a preparation method that can utilize the excellent properties of tungsten wire and apply it to silicon carbide ceramic-based composites. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a preparation method of a tungsten wire toughened silicon carbide ceramic-based composite material, which is characterized in that it includes the following steps: S1, weaving tungsten wire into a first tungsten wire preform; S2, using process gas to perform chemical vapor deposition on the first tungsten wire preform to obtain a second tungsten wire preform, and a silicon carbide coating is formed on the surface of the second tungsten wire preform; S3, using silicon carbide slurry to impregnate the second tungsten wire preform and sintering to obtain a third tungsten wire preform, and the third tungsten wire preform is filled with a silicon carbide matrix; S4, repeating step S3 to obtain a tungsten wire toughened silicon carbide ceramic-based composite material.

[0006] As a preferred embodiment of the method for preparing a tungsten wire toughened silicon carbide ceramic matrix composite material described in the present application, in step S1, the specific structure of the first tungsten wire preform includes: a 2.5D structure, a three-dimensional four-directional structure, a three-dimensional five-directional structure or a three-dimensional six-directional structure.

[0007] As a preferred embodiment of the method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material described in the present application, in step S2, the process gas includes methylsilane or tetrachloromethylsilane, the temperature of the chemical vapor deposition is 900-1200° C., the pressure of the chemical vapor deposition is 500-9000 Pa, and the thickness of the silicon carbide coating on the surface of the second tungsten filament preform is 50-500 nm;

[0008] Furthermore, the thickness of the silicon carbide coating on the surface of the second tungsten filament preform is any one of 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, or a range between two of them.

[0009] As a preferred embodiment of the method for preparing a tungsten filament toughened silicon carbide ceramic-based composite material described in the present application, in step S3, the silicon carbide slurry is composed of silicon carbide powder, solvent, dispersant, and defoaming agent, and the content of solid matter in the silicon carbide slurry is 15wt%-60wt%.

[0010] As a preferred embodiment of the method for preparing a tungsten wire-toughened silicon carbide ceramic-based composite material described in the present application, the particle size of the silicon carbide powder is 50 nm-10 μm; the solvent includes liquid polycarbosilane; the dispersant includes sodium polyacrylate or polycarboxylate; and the defoamer includes a polyether defoamer or a polyoxyethylene-polyoxypropylene block copolymer defoamer.

[0011] As a preferred embodiment of the method for preparing a tungsten filament toughened silicon carbide ceramic-based composite material described in the present application, the mass ratio of the solvent, the dispersant, and the defoaming agent is (81.9-94.4): (15.6-5.5): (2.5-0.1).

[0012] As a preferred embodiment of the method for preparing a tungsten wire-toughened silicon carbide ceramic-based composite material described in the present application, in step S3, the immersion pressure is less than 20 Pa, and the immersion time is 5-50 hours.

[0013] As a preferred embodiment of the method for preparing a tungsten wire-toughened silicon carbide ceramic-based composite material described in the present application, in step S3, the sintering temperature is 900-1400°C, the sintering time is 1-3 hours, and the sintering is carried out in a vacuum, nitrogen or argon environment.

[0014] As a preferred embodiment of the method for preparing a tungsten wire toughened silicon carbide ceramic matrix composite material described in the present application, in step S4, step S3 is repeated 6-13 times.

[0015] The present application also provides a tungsten wire toughened silicon carbide ceramic matrix composite material, which is prepared using the above-mentioned preparation method of the tungsten wire toughened silicon carbide ceramic matrix composite material. The density of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 95%, the compressive strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 680 MPa, the flexural strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 825 MPa, the tensile strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 595 MPa, and the fracture toughness of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 25 MPa·m 1 / 2 , the volume fraction of the tungsten wire is 40%-65%.

[0016] The beneficial effects of this application are as follows:

[0017] The present application provides a method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material, which uses tungsten filament as the toughening phase of the silicon carbide ceramic composite material and optimizes the preparation process of the silicon carbide ceramic matrix composite material to significantly improve the mechanical properties of the silicon carbide ceramic composite material;

[0018] The present application also provides a tungsten wire toughened silicon carbide ceramic matrix composite material, which uses tungsten wire as the toughening phase of the silicon carbide ceramic composite material and has excellent mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0020] Figure 1 Schematic diagram of the preparation process of tungsten wire toughened silicon carbide ceramic matrix composite material in this application;

[0021] Figure 2 This is a photo of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 1 of this application.

[0022] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] The following will be a clear and complete description of the technical solutions in the embodiments. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] The present application provides a preparation method of a tungsten filament toughened silicon carbide ceramic-based composite material, which is characterized by comprising the following steps: S1, weaving tungsten filaments into a first tungsten filament preform; S2, using a process gas to perform chemical vapor deposition on the first tungsten filament preform to obtain a second tungsten filament preform, and a silicon carbide coating is formed on the surface of the second tungsten filament preform; S3, using silicon carbide slurry to impregnate the second tungsten filament preform and sintering to obtain a third tungsten filament preform, and the third tungsten filament preform is filled with a silicon carbide matrix; S4, repeating step S3 to obtain a tungsten filament toughened silicon carbide ceramic-based composite material.

[0025] As a preferred embodiment of the method for preparing a tungsten wire toughened silicon carbide ceramic matrix composite material described in the present application, in step S1, the specific structure of the first tungsten wire preform includes: a 2.5D structure, a three-dimensional four-directional structure, a three-dimensional five-directional structure or a three-dimensional six-directional structure.

[0026] As a preferred embodiment of the method for preparing a tungsten wire toughened silicon carbide ceramic-based composite material described in the present application, in step S2, the process gas includes methylsilane or tetrachloromethylsilane, the temperature of the chemical vapor deposition is 900-1200°C, the pressure of the chemical vapor deposition is 500-9000 Pa, and the thickness of the silicon carbide coating on the surface of the second tungsten wire preform is 50-500 nm.

[0027] As a preferred embodiment of the method for preparing a tungsten filament toughened silicon carbide ceramic-based composite material described in the present application, in step S3, the silicon carbide slurry is composed of silicon carbide powder, solvent, dispersant, and defoaming agent, and the content of solid matter in the silicon carbide slurry is 15wt%-60wt%.

[0028] As a preferred embodiment of the method for preparing a tungsten wire-toughened silicon carbide ceramic-based composite material described in the present application, the particle size of the silicon carbide powder is 50 nm-10 μm; the solvent includes liquid polycarbosilane; the dispersant includes sodium polyacrylate or polycarboxylate; and the defoamer includes a polyether defoamer or a polyoxyethylene-polyoxypropylene block copolymer defoamer.

[0029] As a preferred embodiment of the method for preparing a tungsten filament toughened silicon carbide ceramic-based composite material described in the present application, the mass ratio of the solvent, the dispersant, and the defoaming agent is (81.9-94.4): (15.6-5.5): (2.5-0.1).

[0030] As a preferred embodiment of the method for preparing a tungsten wire-toughened silicon carbide ceramic-based composite material described in the present application, in step S3, the immersion pressure is less than 20 Pa, and the immersion time is 5-50 hours.

[0031] As a preferred embodiment of the method for preparing a tungsten wire-toughened silicon carbide ceramic-based composite material described in the present application, in step S3, the sintering temperature is 900-1400°C, the sintering time is 1-3 hours, and the sintering is carried out in a vacuum, nitrogen or argon environment.

[0032] As a preferred embodiment of the method for preparing a tungsten wire toughened silicon carbide ceramic matrix composite material described in the present application, in step S4, step S3 is repeated 6-13 times.

[0033] The present application also provides a tungsten wire toughened silicon carbide ceramic matrix composite material, which is prepared using the above-mentioned preparation method of the tungsten wire toughened silicon carbide ceramic matrix composite material. The density of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 95%, the compressive strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 680 MPa, the flexural strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 825 MPa, the tensile strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 595 MPa, and the fracture toughness of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 25 MPa·m 1 / 2 , the volume fraction of the tungsten wire is 40%-65%.

[0034] The technical solution of this application is further described below with reference to specific embodiments.

[0035] See also Figure 1 , Figure 1This is a schematic diagram of the preparation process of the tungsten filament toughened silicon carbide ceramic-based composite material of the present application. Tungsten filaments are braided to obtain a first tungsten filament preform, the first tungsten filament preform is subjected to chemical vapor deposition to obtain a second tungsten filament preform, the second tungsten filament preform is impregnated with silicon carbide slurry and sintered to obtain a third tungsten filament preform, and the steps of impregnating and sintering the third tungsten filament preform are repeated to obtain a tungsten filament toughened silicon carbide ceramic-based composite material.

[0036] Example 1

[0037] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0038] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a 2.5D structure;

[0039] Step S2: chemical vapor deposition is performed on the first tungsten filament preform using a process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on the surface of the second tungsten filament preform, wherein: the process gas is methylsilane, the chemical vapor deposition temperature is 900° C., the pressure is 500 Pa, and the thickness of the silicon carbide coating on the second tungsten filament preform is 50 nm;

[0040] Step S3: Adding silicon carbide powder, a dispersant, and a defoamer to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 50 nm, the dispersant is sodium polyacrylate, the defoamer is a polyether defoamer, the solvent is liquid polycarbosilane, the solid matter content in the silicon carbide slurry is 41 wt %; and the mass ratio of the solvent, the dispersant, and the defoamer is 81.9:15.6:2.5;

[0041] Step S4: impregnating the second tungsten filament preform in step S2 with the silicon carbide slurry in step S3 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 10 Pa, the impregnation time is 5 hours, the sintering temperature is 900° C., the sintering time is 1 hour, and the sintering is performed in a vacuum environment;

[0042] Step S5: Repeat step S4 six times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0043] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 1 are as follows: density of 95.32%, compressive strength of 689.63 MPa, flexural strength of 834.51 MPa, tensile strength of 601.79 MPa, fracture toughness of 28.43 MPa·m 1 / 2 , where the volume fraction of tungsten wire is 41%.

[0044] See also Figure 2 , Figure 2 This is a photo of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 1 of this application.

[0045] Example 2

[0046] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0047] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a three-dimensional four-directional structure;

[0048] Step S2: chemical vapor deposition is performed on the first tungsten filament preform using a process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on the surface of the second tungsten filament preform, wherein: the process gas is tetrachloromethylsilane, the chemical vapor deposition temperature is 1200° C., the pressure is 9000 Pa, and the thickness of the silicon carbide coating on the second tungsten filament preform is 500 nm;

[0049] Step S3: Adding silicon carbide powder, a dispersant, and a defoamer to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 900 nm, the dispersant is sodium polyacrylate, the defoamer is a polyoxyethylene-polyoxypropylene segmented copolymer defoamer, the solvent is liquid polycarbosilane, the solid matter content in the silicon carbide slurry is 15 wt %; and the mass ratio of the solvent, dispersant, and defoamer is 89.6:8.7:1.7;

[0050] Step S4: impregnating the second tungsten filament preform in step S2 with the silicon carbide slurry in step S3 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 5 Pa, the impregnation time is 50 h, the sintering temperature is 1400° C., the sintering time is 2 h, and the sintering is performed in a nitrogen environment;

[0051] Step S5: Repeat step S4 9 times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0052] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 2 are as follows: density of 96.43%, compressive strength of 712.56 MPa, flexural strength of 903.42 MPa, tensile strength of 789.54 MPa, fracture toughness of 35.41 MPa·m 1 / 2 , of which the volume fraction of tungsten wire is 53%.

[0053] Example 3

[0054] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0055] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a three-dimensional five-directional structure;

[0056] Step S2: chemical vapor deposition is performed on the first tungsten filament preform using a process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on the surface of the second tungsten filament preform, wherein: the process gas is methylsilane, the chemical vapor deposition temperature is 1100° C., the pressure is 6000 Pa, and the thickness of the silicon carbide coating on the second tungsten filament preform is 370 nm;

[0057] Step S3: adding silicon carbide powder, a dispersant, and a defoamer to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 10 μm, the dispersant is a polycarboxylate, the defoamer is a polyether defoamer, the solvent is liquid polycarbosilane, the solid matter content in the silicon carbide slurry is 60 wt %; and the mass ratio of the solvent, the dispersant, and the defoamer is 94.4:5.5:0.1;

[0058] Step S4: impregnating the second tungsten filament preform in step S2 with the silicon carbide slurry in step S3 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 8 Pa, the impregnation time is 30 h, the sintering temperature is 1200° C., the sintering time is 3 h, and the sintering is performed in an argon environment;

[0059] Step S5: Repeat step S4 13 times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0060] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 3 are as follows: density of 98.21%, compressive strength of 733.97 MPa, flexural strength of 878.46 MPa, tensile strength of 803.65 MPa, fracture toughness of 40.19 MPa·m 1 / 2 , where the volume fraction of tungsten wire is 65%.

[0061] Example 4

[0062] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0063] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a three-dimensional six-directional structure;

[0064] Step S2: chemical vapor deposition is performed on the first tungsten filament preform using a process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on the surface of the second tungsten filament preform, wherein: the process gas is tetrachloromethylsilane, the chemical vapor deposition temperature is 1150° C., the pressure is 2000 Pa, and the thickness of the silicon carbide coating on the second tungsten filament preform is 200 nm;

[0065] Step S3: Adding silicon carbide powder, a dispersant, and a defoamer to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 4 μm, the dispersant is a polycarboxylate, the defoamer is a polyoxyethylene-polyoxypropylene segmented copolymer defoamer, the solvent is liquid polycarbosilane, the solid matter content in the silicon carbide slurry is 29 wt %; and the mass ratio of the solvent, dispersant, and defoamer is 87.5:11.6:0.9;

[0066] Step S4: impregnating the second tungsten filament preform in step S2 with the silicon carbide slurry in step S3 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 19 Pa, the impregnation time is 24 hours, the sintering temperature is 1300° C., the sintering time is 2.5 hours, and the sintering is performed in a nitrogen environment;

[0067] Step S5: Repeat step S4 11 times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0068] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 4 are as follows: density of 97.21%, compressive strength of 696.78 MPa, flexural strength of 921.37 MPa, tensile strength of 776.33 MPa, fracture toughness of 37.96 MPa·m 1 / 2 , of which the volume fraction of tungsten wire is 58%.

[0069] Comparative Example 1

[0070] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0071] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a three-dimensional six-directional structure;

[0072] Step S2: chemical vapor deposition is performed on the first tungsten filament preform using a process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on the surface of the second tungsten filament preform, wherein: the process gas is tetrachloromethylsilane, the chemical vapor deposition temperature is 1150° C., the pressure is 2000 Pa, and the thickness of the silicon carbide coating on the second tungsten filament preform is 200 nm;

[0073] Step S3: adding silicon carbide powder to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 4 μm, the solvent is liquid polycarbosilane, and the solid content in the silicon carbide slurry is 29 wt%;

[0074] Step S4: impregnating the second tungsten filament preform in step S2 with the silicon carbide slurry in step S3 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 19 Pa, the impregnation time is 24 hours, the sintering temperature is 1300° C., the sintering time is 2.5 hours, and the sintering is performed in a nitrogen environment;

[0075] Step S5: Repeat step S4 11 times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0076] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Comparative Example 1 are as follows: density of 90.56%, compressive strength of 453.44 MPa, flexural strength of 567.31 MPa, tensile strength of 221.49 MPa, fracture toughness of 15.21 MPa·m 1 / 2 , of which the volume fraction of tungsten wire is 58%.

[0077] Comparative Example 2

[0078] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0079] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a three-dimensional six-directional structure;

[0080] Step S2: Adding silicon carbide powder, a dispersant, and a defoamer to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 4 μm, the dispersant is a polycarboxylate, the defoamer is a polyoxyethylene-polyoxypropylene segmented copolymer defoamer, the solvent is liquid polycarbosilane, the solid matter content in the silicon carbide slurry is 29 wt %; and the mass ratio of the solvent, dispersant, and defoamer is 87.5:11.6:0.9;

[0081] Step S3: impregnating the second tungsten filament preform in step S1 with the silicon carbide slurry in step S2 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 19 Pa, the impregnation time is 24 hours, the sintering temperature is 1300° C., the sintering time is 2.5 hours, and the sintering is performed in a nitrogen environment;

[0082] Step S4: repeat step S3 11 times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0083] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Comparative Example 2 are as follows: density of 96.30%, compressive strength of 489.31 MPa, flexural strength of 498.78 MPa, tensile strength of 289.54 MPa, fracture toughness of 10.34 MPa·m 1 / 2 , of which the volume fraction of tungsten wire is 58%.

[0084] Comparative Example 3

[0085] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0086] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a three-dimensional six-directional structure;

[0087] Step S2: chemical vapor deposition is performed on the first tungsten filament preform using a process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on the surface of the second tungsten filament preform, wherein: the process gas is tetrachloromethylsilane, the chemical vapor deposition temperature is 1150° C., the pressure is 2000 Pa, and the thickness of the silicon carbide coating on the second tungsten filament preform is 200 nm;

[0088] Step S3: Adding silicon carbide powder, a dispersant, and a defoamer to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 4 μm, the dispersant is a polycarboxylate, the defoamer is a polyoxyethylene-polyoxypropylene segmented copolymer defoamer, the solvent is liquid polycarbosilane, the solid matter content in the silicon carbide slurry is 29 wt %; and the mass ratio of the solvent, dispersant, and defoamer is 87.5:11.6:0.9;

[0089] Step S4: impregnating the second tungsten filament preform in step S2 with the silicon carbide slurry in step S3 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 50 Pa, the impregnation time is 24 hours, the sintering temperature is 1300° C., the sintering time is 2.5 hours, and the sintering is performed in a nitrogen environment;

[0090] Step S5: Repeat step S4 11 times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0091] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 4 are as follows: density of 89.53%, compressive strength of 397.72 MPa, flexural strength of 334.55 MPa, tensile strength of 187.35 MPa, fracture toughness of 8.48 MPa·m 1 / 2 , of which the volume fraction of tungsten wire is 58%.

[0092] Comparative Example 4

[0093] A tungsten filament toughened silicon carbide ceramic matrix composite material and a preparation method thereof, wherein the specific preparation method comprises the following steps:

[0094] Step S1: weaving tungsten wires into a first tungsten wire preform, wherein the structure of the first tungsten wire preform is a three-dimensional six-directional structure;

[0095] Step S2: adding silicon carbide powder to a solvent to prepare a silicon carbide slurry, wherein: the particle size of the silicon carbide powder is 4 μm, the solvent is liquid polycarbosilane, and the solid content in the silicon carbide slurry is 29 wt%;

[0096] Step S3: impregnating the second tungsten filament preform in step S1 with the silicon carbide slurry in step S2 and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix, wherein: the impregnation pressure is 50 Pa, the impregnation time is 24 hours, the sintering temperature is 1300° C., the sintering time is 2.5 hours, and the sintering is performed in a nitrogen environment;

[0097] Step S4: repeat step S3 11 times to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

[0098] The properties of the tungsten wire toughened silicon carbide ceramic matrix composite material prepared in Example 4 are as follows: density of 85.63%, compressive strength of 333.18 MPa, flexural strength of 275.28 MPa, tensile strength of 123.91 MPa, fracture toughness of 6.58 MPa·m 1 / 2 , of which the volume fraction of tungsten wire is 58%.

[0099] Comparative Example 5

[0100] Comparative Example 5 refers to a carbon fiber reinforced silicon carbide composite material sample prepared by the process in the invention patent application number 200810030556.X.

[0101] The carbon fiber reinforced silicon carbide composite material prepared in this embodiment has the following properties: compressive strength of 212.34 MPa, flexural strength of 449.76 MPa, tensile strength of 102.81 MPa, and fracture toughness of 10.27 MPa·m 1 / 2 .

[0102] Comparative Example 6

[0103] Comparative Example 6 refers to a carbon fiber reinforced silicon carbide composite material sample prepared by the process in the invention patent application number 201110154829.3.

[0104] The properties of the silicon carbide fiber reinforced silicon carbide composite material prepared in this embodiment are as follows: compressive strength of 367.59 MPa, flexural strength of 639.68 MPa, tensile strength of 189.11 MPa, and fracture toughness of 25.72 MPa·m 1 / 2 .

[0105] It can be seen from the above embodiments and comparative examples that: Example 4 combined with comparative example 1 shows that the presence or absence of a dispersant and a defoaming agent in the silicon carbide slurry described in step S3 will affect the performance of the final sample. The absence of a dispersant and a defoaming agent will cause the silicon carbide powder to be unevenly distributed in the silicon carbide slurry, thereby causing the silicon carbide powder to be poorly impregnated in the second tungsten wire preform, resulting in a decrease in the performance of the final sample; Example 4 combined with comparative example 2 shows that the presence or absence of the chemical vapor deposition step in step S2 in Example 4 will affect the performance of the final sample. The absence of a chemical vapor deposition silicon carbide interface coating on the surface of the first tungsten wire preform will cause a hard connection between the tungsten wire and the silicon carbide substrate, thereby causing a decrease in the performance of the final sample; Example 4 combined with comparative example 3 shows that Example The impregnation pressure in step S4 described in Example 4 will affect the performance of the final sample. A higher impregnation pressure will lead to poor impregnation effect and low sample density, which will in turn cause the performance of the final sample to be reduced. Example 4 combined with Comparative Example 4 shows that the dispersant, defoaming agent, chemical vapor deposition, and impregnation pressure have a synergistic effect and have a synergistic effect on the performance of the final sample. Combining Example 1, Example 2, Example 3, Example 4, Comparative Example 5 and Comparative Example 6, it can be seen that the mechanical properties of tungsten wire toughened silicon carbide ceramic matrix composite materials are better than those of carbon fiber reinforced silicon carbide composite materials. This method uses tungsten wire as the toughening phase. The tungsten wire toughened silicon carbide ceramic matrix composite material prepared by optimizing the preparation process has excellent mechanical properties and meets the requirements of special service conditions.

[0106] The present application provides a method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material, which uses tungsten filament as the toughening phase of the silicon carbide ceramic composite material and optimizes the preparation process of the silicon carbide ceramic matrix composite material to significantly improve the mechanical properties of the silicon carbide ceramic composite material;

[0107] The present application also provides a tungsten wire toughened silicon carbide ceramic matrix composite material, which uses tungsten wire as the toughening phase of the silicon carbide ceramic composite material and has excellent mechanical properties.

[0108] The above description is only a preferred embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for preparing a tungsten wire toughened silicon carbide ceramic matrix composite material, characterized in that: The following steps are involved: S1, weaving tungsten wire into a first tungsten wire preform; S2. Performing chemical vapor deposition on the first tungsten filament preform using a process gas to obtain a second tungsten filament preform, wherein a silicon carbide coating is formed on a surface of the second tungsten filament preform; S3, impregnating the second tungsten filament preform with silicon carbide slurry and sintering to obtain a third tungsten filament preform, wherein the third tungsten filament preform is filled with a silicon carbide matrix; S4. Repeat step S3 to obtain a tungsten wire toughened silicon carbide ceramic matrix composite material.

2. The method for preparing a tungsten wire toughened silicon carbide ceramic matrix composite material according to claim 1, characterized in that: In the step S1, the specific structure of the first tungsten filament preform includes: a 2.5D structure, a three-dimensional four-directional structure, a three-dimensional five-directional structure or a three-dimensional six-directional structure.

3. The method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material according to claim 1, characterized in that: In step S2, the process gas includes methylsilane or tetrachloromethylsilane, the temperature of the chemical vapor deposition is 900-1200°C, the pressure of the chemical vapor deposition is 500-9000 Pa, and the thickness of the silicon carbide coating on the surface of the second tungsten filament preform is 50-500 nm.

4. The method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material according to claim 1, characterized in that: In step S3, the silicon carbide slurry is composed of silicon carbide powder, a solvent, a dispersant, and a defoaming agent, and the content of solid matter in the silicon carbide slurry is 15 wt % to 60 wt %.

5. The method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material according to claim 4, characterized in that: The particle size of the silicon carbide powder is 50 nm-10 μm; the solvent includes liquid polycarbosilane; the dispersant includes sodium polyacrylate or polycarboxylate; and the defoamer includes a polyether defoamer or a polyoxyethylene-polyoxypropylene block copolymer defoamer.

6. The method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material according to claim 4, characterized in that: The mass ratio of the solvent, the dispersant and the defoaming agent is (81.9-94.4): (15.6-5.5): (2.5-0.1).

7. The method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material according to claim 1, characterized in that: In step S3, the immersion pressure is less than 20 Pa, and the immersion time is 5-50 hours.

8. The method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material according to claim 1, characterized in that: In the step S3, the sintering temperature is 900-1400° C., the sintering time is 1-3 hours, and the sintering is performed in a vacuum, nitrogen or argon environment.

9. The method for preparing a tungsten filament toughened silicon carbide ceramic matrix composite material according to claim 1, characterized in that: In step S4, step S3 is repeated 6-13 times.

10. A tungsten wire toughened silicon carbide ceramic matrix composite material, characterized in that: The tungsten wire toughened silicon carbide ceramic matrix composite material is prepared by the preparation method of any one of claims 1 to 9, wherein the density of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 95%, the compressive strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 680 MPa, the flexural strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 825 MPa, the tensile strength of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 595 MPa, and the fracture toughness of the tungsten wire toughened silicon carbide ceramic matrix composite material is greater than or equal to 25 MPa·m 1 / 2 , the volume fraction of the tungsten wire is 40%-65%.

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