C / c-sic composite material and method for manufacturing the same

Abstract

This invention belongs to the field of carbon-ceramic composite material technology, specifically relating to a C / C-SiC composite material and its preparation method. Adding a mixed powder comprising Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder to the melt-infiltrating powder can lower the melt-infiltrating temperature and simultaneously modify the ceramic matrix material. Using microwave heating for rapid heating can shorten the melt-infiltrating time, improve the product density, and enhance mechanical properties. Applying ultrasonic waves during the melt-infiltrating process can achieve even better infiltration results. The density of the C / C-SiC composite material described in this invention is ≥2.3 g / cm³. 3 Compressive strength ≥300MPa, flexural strength ≥305MPa, fracture toughness ≥34MPa·m 1 / 2 .

Description

Technical Field

[0001] This invention belongs to the field of carbon-ceramic composite material technology, specifically a C / C-SiC composite material and its preparation method. Background Technology

[0002] Currently, C / C-SiC composites possess excellent properties such as low density, high specific strength, high specific modulus, high temperature resistance, oxidation resistance, and corrosion resistance, making them promising for applications in aerospace, defense, and brake materials. At present, the main methods for preparing C / C-SiC composites include precursor impregnation pyrolysis (PIP), reactive melt infiltration (RMI), and chemical vapor infiltration (CVI). Among these, PIP faces difficulties in densifying the fine pores within the material, limiting its application; CVI-prepared thick components are difficult to densify internally. RMI, with its advantages of short preparation cycle and low cost, has become a research hotspot. However, the high temperature of the RMI process (far exceeding the melting point of silicon, 1410℃) can easily damage carbon fibers, leading to a decrease in the mechanical properties of C / C-SiC composites. Therefore, the RMI process requires further improvement and optimization. Summary of the Invention

[0003] To address the problems existing in the prior art, the main objective of this invention is to propose a C / C-SiC composite material and its preparation method.

[0004] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0005] A method for preparing a C / C-SiC composite material includes the following steps:

[0006] S1. Spread the mixed powder evenly on the bottom of the crucible and compact it;

[0007] S2. Place the low-density C / C composite material on top of the mixed powder, and cover the top of the low-density C / C composite material with the mixed powder;

[0008] S3. Microwave heating is used to rapidly heat the mixed powder and low-density C / C composite material until the mixed powder melts.

[0009] S4. During the reaction melting and infiltration process after the mixed powder is melted, ultrasonic-assisted reaction melting and infiltration is activated to obtain C / C-SiC composite material.

[0010] In a preferred embodiment of the preparation method of C / C-SiC composite material according to the present invention, in steps S1 and S2, the mixed powder includes Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder; the mixed powder, by mass percentage, includes: 2.5-20 wt% Al2O3 powder, 0.5-10 wt% SiC powder, 1-20 wt% AlSi alloy powder, 0.5-5.0 wt% rare earth oxide powder, with the balance being Si powder; the rare earth oxide powder is one or more of Eu2O3, Er2O3, Lu2O3, Yb2O3, Y2O3, Gd2O3, La2O3, and CeO2.

[0011] In a preferred embodiment of the preparation method of C / C-SiC composite material according to the present invention, in step S1, the compaction degree of the mixed powder is greater than 80%.

[0012] In a preferred embodiment of the preparation method of C / C-SiC composite material according to the present invention, in step S2, the open porosity of the low-density C / C composite material is greater than 20%, and the through porosity is greater than 18%.

[0013] In a preferred embodiment of the preparation method of the C / C-SiC composite material of the present invention, in step S2, the volume ratio of carbon fiber to carbon matrix of the low-density C / C composite material is 1:(1~1.5).

[0014] In a preferred embodiment of the preparation method of C / C-SiC composite material according to the present invention, in step S2, the mass of the mixed powder covering the upper part of the low-density C / C composite material is 10-30% of the mass of the mixed powder in step S1.

[0015] In a preferred embodiment of the preparation method of C / C-SiC composite material according to the present invention, in step S3, the heating power during microwave heating is 10-150kW; the heating rate during microwave heating is 15-80℃ / min.

[0016] In a preferred embodiment of the preparation method of C / C-SiC composite material according to the present invention, in step S4, the ultrasonic wave is turned on at 1100-1300℃; the power of the ultrasonic wave is 10-200kW.

[0017] To solve the above-mentioned technical problems, according to another aspect of the present invention, the present invention provides the following technical solution:

[0018] A C / C-SiC composite material is prepared using the above-described method for preparing C / C-SiC composite materials.

[0019] As a preferred embodiment of the C / C-SiC composite material described in this invention, the density of the C / C-SiC composite material is ≥2.3 g / cm³. 3 Compressive strength ≥300MPa, flexural strength ≥305MPa, fracture toughness ≥34MPa·m 1 / 2 .

[0020] The beneficial effects of this invention are as follows:

[0021] This invention proposes a C / C-SiC composite material and its preparation method. Adding a mixed powder comprising Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder to the melt-infiltrating powder can lower the melt-infiltrating temperature and simultaneously modify the ceramic matrix material. Using microwave heating for rapid heating can shorten the melt-infiltrating time, improve the product density, and enhance mechanical properties. Applying ultrasonic waves during the melt-infiltrating process can achieve even better infiltration results. The density of the C / C-SiC composite material of this invention is ≥2.3 g / cm³. 3 Compressive strength ≥300MPa, flexural strength ≥305MPa, fracture toughness ≥34MPa·m 1 / 2 . Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a cross-sectional scanning electron microscope image of the C / C-SiC composite material prepared in Example 1 of the present invention.

[0024] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] According to one aspect of the present invention, the present invention provides the following technical solution:

[0027] A method for preparing a C / C-SiC composite material includes the following steps:

[0028] S1. Spread the mixed powder evenly on the bottom of the crucible and compact it;

[0029] S2. Place the low-density C / C composite material on top of the mixed powder, and cover the top of the low-density C / C composite material with the mixed powder;

[0030] S3. Microwave heating is used to rapidly heat the mixed powder and low-density C / C composite material until the mixed powder melts.

[0031] S4. During the reaction melting and infiltration process after the mixed powder is melted, ultrasonic-assisted reaction melting and infiltration is activated to obtain C / C-SiC composite material.

[0032] Preferably, in steps S1 and S2, the mixed powder comprises Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder; the mixed powder, by mass percentage, comprises: 2.5-20 wt% Al2O3 powder, 0.5-10 wt% SiC powder, 1-20 wt% AlSi alloy powder, 0.5-5.0 wt% rare earth oxide powder, with the balance being Si powder; the rare earth oxide powder is one or more of Eu2O3, Er2O3, Lu2O3, Yb2O3, Y2O3, Gd2O3, La2O3, and CeO2.

[0033] Preferably, in step S1, the compaction degree of the mixed powder is greater than 80%.

[0034] Preferably, in step S2, the open porosity of the low-density C / C composite material is greater than 20%, and the through porosity is greater than 18%.

[0035] Preferably, in step S2, the volume ratio of carbon fiber to carbon matrix in the low-density C / C composite material is 1:(1~1.5).

[0036] Preferably, in step S2, the mass of the mixed powder covering the upper part of the low-density C / C composite material is 10-30% of the mass of the mixed powder in step S1.

[0037] Preferably, in step S3, the heating power during microwave heating is 10 to 150 kW; the heating rate during microwave heating is 15 to 80 °C / min.

[0038] Preferably, in step S4, the ultrasonic wave is turned on at 1100–1300°C; the power of the ultrasonic wave is 10–200 kW.

[0039] According to another aspect of the present invention, the present invention provides the following technical solution:

[0040] A C / C-SiC composite material is prepared using the above-described method for preparing C / C-SiC composite materials, wherein the density of the C / C-SiC composite material is ≥2.3 g / cm³. 3 Compressive strength ≥300MPa, flexural strength ≥305MPa, fracture toughness ≥34MPa·m 1 / 2 .

[0041] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0042] Example 1

[0043] A method for preparing a C / C-SiC composite material includes the following steps:

[0044] S1. The mixed powder is evenly spread on the bottom of the crucible and compacted; the mixed powder includes Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder; the mixed powder, by mass percentage, includes: 2.5wt% Al2O3 powder, 6.8wt% SiC powder, 2.6wt% AlSi alloy powder, 0.5% rare earth oxide powder, with the balance being Si powder; the rare earth oxide powder is one or more of Er2O3, Y2O3, Gd2O3, La2O3, and CeO2; the compaction degree of the mixed powder is 90%.

[0045] S2. Place the low-density C / C composite material on top of the mixed powder, and cover the top of the low-density C / C composite material with the mixed powder; the open porosity of the low-density C / C composite material is 40%, and the through porosity is 38%; the volume ratio of carbon fiber to carbon matrix in the low-density C / C composite material is 1:1.5, and the mass of the mixed powder covering the top of the low-density C / C composite material is 10% of the mass of the mixed powder in step S1;

[0046] S3. Microwave heating is used to rapidly heat the mixed powder and low-density C / C composite material until the mixed powder melts; the heating power during microwave heating is 150kW; the heating rate of microwave heating is 80℃ / min.

[0047] S4. During the reaction melting and infiltration process after the mixed powder is melted, ultrasonic-assisted reaction melting and infiltration is turned on. The ultrasonic waves are turned on at 1100℃ and the power of the ultrasonic waves is 200kW to obtain C / C-SiC composite material.

[0048] The cross-sectional scanning electron microscope image of the C / C-SiC composite material prepared in this embodiment is shown below. Figure 1 As shown, the C / C-SiC composite material exhibits ductile fracture with a large number of carbon fibers pulled out, and its density is 2.41 g / cm³. 3The compressive strength is 313.65 MPa, the flexural strength is 308.31 MPa, and the fracture toughness is 39.58 MPa·m. 1 / 2 .

[0049] Example 2

[0050] A method for preparing a C / C-SiC composite material includes the following steps:

[0051] S1. The mixed powder is evenly spread at the bottom of the crucible and compacted; the mixed powder includes Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder; the mixed powder, by mass percentage, includes: 20wt% Al2O3 powder, 0.5wt% SiC powder, 20wt% AlSi alloy powder, 3.5% rare earth oxide powder, with the balance being Si powder; the rare earth oxide powder is one or more of Er2O3, Lu2O3, Y2O3, and CeO2; the compaction degree of the mixed powder is 92%.

[0052] S2. Place the low-density C / C composite material on top of the mixed powder, and cover the top of the low-density C / C composite material with the mixed powder; the open porosity of the low-density C / C composite material is 35%, and the through porosity is 31%; the volume ratio of carbon fiber to carbon matrix of the low-density C / C composite material is 1:1.2, and the mass of the mixed powder covering the top of the low-density C / C composite material is 16% of the mass of the mixed powder in step S1;

[0053] S3. Microwave heating is used to rapidly heat the mixed powder and low-density C / C composite material until the mixed powder melts; the heating power during microwave heating is 50kW; the heating rate of microwave heating is 40℃ / min.

[0054] S4. During the reaction melting and infiltration process after the mixed powder is melted, ultrasonic-assisted reaction melting and infiltration is turned on. The ultrasonic waves are turned on at 1140℃ and the power of the ultrasonic waves is 100kW to obtain C / C-SiC composite material.

[0055] The density of the C / C-SiC composite material prepared in this embodiment is ≥ 2.32 g / cm³. 3 The compressive strength is 310.27 MPa, the flexural strength is 311.75 MPa, and the fracture toughness is 34.09 MPa·m. 1 / 2 .

[0056] Example 3

[0057] A method for preparing a C / C-SiC composite material includes the following steps:

[0058] S1. The mixed powder is evenly spread on the bottom of the crucible and compacted; the mixed powder includes Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder; the mixed powder, by mass percentage, includes: 15.0 wt% Al2O3 powder, 10 wt% SiC powder, 1 wt% AlSi alloy powder, 5.0% rare earth oxide powder, with the balance being Si powder; the rare earth oxide powder is one or more of Y2O3, Gd2O3, and La2O3; the compaction degree of the mixed powder is 87%.

[0059] S2. Place the low-density C / C composite material on top of the mixed powder, and cover the top of the low-density C / C composite material with the mixed powder; the open porosity of the low-density C / C composite material is 39%, and the through porosity is 36%; the volume ratio of carbon fiber to carbon matrix of the low-density C / C composite material is 1:1.4, and the mass of the mixed powder covering the top of the low-density C / C composite material is 25% of the mass of the mixed powder in step S1;

[0060] S3. Microwave heating is used to rapidly heat the mixed powder and low-density C / C composite material until the mixed powder melts; the heating power during microwave heating is 110kW; the heating rate of microwave heating is 61℃ / min.

[0061] S4. During the reaction infiltration process after the mixed powder is melted, ultrasonic-assisted reaction infiltration is turned on. The ultrasonic waves are turned on at 1220℃ and the power of the ultrasonic waves is 160kW to obtain C / C-SiC composite material.

[0062] The density of the C / C-SiC composite material prepared in this embodiment is 2.35 g / cm³. 3 The compressive strength is 301.63 MPa, the flexural strength is 318.71 MPa, and the fracture toughness is 38.17 MPa·m. 1 / 2 .

[0063] Comparative Example 1

[0064] The difference from Example 1 is that Si powder is used instead of the mixed powder.

[0065] The density of the C / C-SiC composite material prepared in this comparative example is 2.16 g / cm³. 3 The compressive strength is 265.72 MPa, the flexural strength is 260.89 MPa, and the fracture toughness is 28.65 MPa·m. 1 / 2 .

[0066] Comparative Example 2

[0067] The difference from Example 1 is that in step S3, a conventional heating method is used with a heating rate of 5°C / min; and in step S4, ultrasonic-assisted reaction melting is not used.

[0068] The density of the C / C-SiC composite material prepared in this comparative example is 2.20 g / cm³. 3 The compressive strength is 281.06 MPa, the flexural strength is 249.81 MPa, and the fracture toughness is 30.28 MPa·m. 1 / 2 .

[0069] Comparative Example 3

[0070] The difference from Example 1 is that ultrasonic-assisted reactive melting is not used in step S4.

[0071] The density of the C / C-SiC composite material prepared in this comparative example is 2.25 g / cm³. 3 The compressive strength is 289.29 MPa, the flexural strength is 253.05 MPa, and the fracture toughness is 32.93 MPa·m. 1 / 2 .

[0072] Comparative Example 4

[0073] The difference from Example 1 is that Si powder is used instead of mixed powder, and a conventional heating method is used in step S3 with a heating rate of 5°C / min.

[0074] The density of the C / C-SiC composite material prepared in this comparative example is 2.19 g / cm³. 3 The compressive strength is 291.26 MPa, the flexural strength is 248.25 MPa, and the fracture toughness is 31.05 MPa·m. 1 / 2 .

[0075] As can be seen from the above embodiments and comparative examples, the addition of a mixed powder comprising Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder to the melt-infiltrating powder in this invention can lower the melt-infiltrating temperature and simultaneously modify the ceramic matrix material. Using microwave heating for rapid temperature rise can shorten the melt-infiltrating time, improve product density, and enhance mechanical properties. Applying ultrasonic waves during the melt-infiltrating process can achieve even better infiltration results. The density of the C / C-SiC composite material described in this invention is ≥2.3 g / cm³. 3 Compressive strength ≥300MPa, flexural strength ≥305MPa, fracture toughness ≥34MPa·m 1 / 2 .

[0076] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for preparing a C / C-SiC composite material, characterized in that, Includes the following steps: S1. Spread the mixed powder evenly on the bottom of the crucible and compact it; S2. Place the low-density C / C composite material on top of the mixed powder, and cover the top of the low-density C / C composite material with the mixed powder; S3. Microwave heating is used to rapidly heat the mixed powder and low-density C / C composite material until the mixed powder melts. S4. During the reaction melting and infiltration process after the mixed powder is melted, ultrasonic-assisted reaction melting and infiltration is activated to obtain C / C-SiC composite material. In steps S1 and S2, the mixed powder comprises Si powder, Al2O3 powder, SiC powder, AlSi alloy powder, and rare earth oxide powder; the mixed powder, by mass percentage, comprises: 2.5~20wt% Al2O3 powder, 0.5~10wt% SiC powder, 1~20wt% AlSi alloy powder, 0.5~5.0wt% rare earth oxide powder, with the balance being Si powder; the rare earth oxide powder is one or more of Eu2O3, Er2O3, Lu2O3, Yb2O3, Y2O3, Gd2O3, La2O3, and CeO2; Density of the C / C-SiC composite material ≥ 2.3 g / cm 3 Compressive strength ≥ 300 MPa, bending strength ≥ 305 MPa, and fracture toughness ≥ 34 MPa·m 1 / 2 .

2. The method for preparing the C / C-SiC composite material according to claim 1, characterized in that, In step S1, the compaction degree of the mixed powder is greater than 80%.

3. The method for preparing the C / C-SiC composite material according to claim 1, characterized in that, In step S2, the open porosity of the low-density C / C composite material is greater than 20%, and the through porosity is greater than 18%.

4. The method for preparing the C / C-SiC composite material according to claim 1, characterized in that, In step S2, the volume ratio of carbon fiber to carbon matrix in the low-density C / C composite material is 1:(1~1.5).

5. The method for preparing the C / C-SiC composite material according to claim 1, characterized in that, In step S2, the mass of the mixed powder covering the upper part of the low-density C / C composite material is 10-30% of the mass of the mixed powder in step S1.

6. The method for preparing the C / C-SiC composite material according to claim 1, characterized in that, In step S3, the heating power during microwave heating is 10~150kW; the heating rate during microwave heating is 15~80℃ / min.

7. The method for preparing the C / C-SiC composite material according to claim 1, characterized in that, In step S4, the ultrasonic wave is turned on at 1100~1300℃; the power of the ultrasonic wave is 10~200kW.

8. A C / C-SiC composite material, characterized in that, The C / C-SiC composite material was prepared using the preparation method described in any one of claims 1-7.

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