Continuous carbon fiber toughened wc ceramic composite material and method of making same

Abstract

The application belongs to the technical field of composite materials, and particularly relates to a preparation method of continuous carbon fiber toughened WC ceramic composite material, wherein WC is uniformly dispersed in a solvent to obtain a WC suspension; a surface modified continuous carbon fiber braid is fixed on an electrode of an electrophoresis device, and WC is uniformly deposited on the surface of the continuous carbon fiber braid after electrification to obtain a process product; the process product is dried, and then a discharge plasma sintering or hot-pressing sintering process is adopted to obtain the continuous carbon fiber toughened WC ceramic composite material. The continuous carbon fiber toughened WC ceramic composite material has a density of greater than or equal to 13.5 g / cm 3 , a hardness of greater than or equal to 20.5 GPa, and a bending strength of greater than or equal to 1830 MPa and a fracture toughness of greater than or equal to 19.5 MPa.m 1 / 2 .

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically a continuous carbon fiber toughened WC ceramic composite material and its preparation method. Background Technology

[0002] WC ceramics, due to their high hardness, high strength, high density, and high wear resistance, are widely used in aerospace, defense, and transportation. Like other ceramic materials, WC ceramics have relatively low fracture toughness and are prone to brittle fracture, limiting their applications. Therefore, improving the fracture toughness of WC ceramics while maintaining its advantages has attracted widespread attention from researchers worldwide. Several methods have been used to improve the fracture toughness of WC ceramics: particle toughening, porosity toughening, and whisker toughening. These toughening methods can deflect and branch cracks within the WC ceramic during propagation, increasing fracture toughness to some extent, but the degree of improvement is limited. Summary of the Invention

[0003] To address the problems existing in the prior art, the main objective of this invention is to propose a continuous carbon fiber toughened WC ceramic composite material and its preparation method, which utilizes electrophoretic deposition and spark plasma sintering / hot pressing sintering methods to achieve the preparation of the continuous carbon fiber toughened WC ceramic composite material.

[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 continuous carbon fiber toughened WC ceramic composite material includes the following steps:

[0006] S1. Disperse WC uniformly in a solvent to obtain a WC suspension;

[0007] S2. The surface-modified continuous carbon fiber braid is fixed at the electrode of the electrophoresis equipment. After energizing, WC is uniformly deposited on the surface of the continuous carbon fiber braid to obtain the process product.

[0008] S3. The process product is dried, and then continuous carbon fiber toughened WC ceramic composite material is obtained by spark plasma sintering or hot pressing sintering process.

[0009] In a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material of the present invention, in step S1, the WC suspension is composed of WC powder, solvent, dispersant and defoamer.

[0010] As a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material of the present invention, in step S1, the particle size of WC powder in the WC suspension is 40nm~400μm; the solvent is deionized water or anhydrous ethanol; the dispersant is polyvinylpyrrolidone or tetramethylammonium hydroxide; and the defoamer is amine citrate or polyethyleneimine.

[0011] In a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material of the present invention, in step S1, the content of solid matter in the WC suspension is 30-70 wt%.

[0012] In a preferred embodiment of the preparation method of continuous carbon fiber toughened WC ceramic composite material according to the present invention, in step S1, the mass ratio of solvent, dispersant and defoamer in WC suspension is (80.5~95.9):(20.9~3.1):(16.4~0.1).

[0013] As a preferred embodiment of the preparation method of continuous carbon fiber toughened WC ceramic composite material according to the present invention, in step S2, the continuous carbon fiber woven part is plain weave fabric, twill weave fabric, non-woven fabric, or mesh fabric.

[0014] As a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material of the present invention, in step S2, the method for modifying the surface of the continuous carbon fiber cloth is to use laser technology for modification, and the laser power is 5-150W.

[0015] In a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material according to the present invention, in step S2, the current density of electrophoretic deposition is 10-200 mA / cm². 2 Electrophoretic deposition time is 30–100 min.

[0016] In a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material of the present invention, in step S2, the weight gain of the continuous carbon fiber braid after electrophoretic deposition is 200-1200 wt%.

[0017] As a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material of the present invention, wherein: in step S3, the density of the continuous carbon fiber braid in the products of spark plasma sintering and hot pressing sintering is 5 to 20 layers / cm.

[0018] As a preferred embodiment of the preparation method of the continuous carbon fiber toughened WC ceramic composite material of the present invention, in step S3, the temperature of spark plasma sintering and hot pressing sintering is 1300-2100℃, and the sintering time is 5-120min.

[0019] To solve the above-mentioned technical problems, according to another aspect of the present invention, the present invention provides the following technical solution:

[0020] A continuous carbon fiber toughened WC ceramic composite material is prepared by the above-described preparation method for continuous carbon fiber toughened WC ceramic composite materials.

[0021] As a preferred embodiment of the continuous carbon fiber toughened WC ceramic composite material of the present invention, the density of the continuous carbon fiber toughened WC ceramic composite material is ≥13.5 g / cm³. 3 Hardness ≥ 20.5 GPa, flexural strength ≥ 1830 MPa, fracture toughness ≥ 19.5 MPa·m 1 / 2 .

[0022] The beneficial effects of this invention are as follows:

[0023] This invention proposes a method for preparing continuous carbon fiber toughened WC ceramic composites. WC is uniformly dispersed in a solvent to obtain a WC suspension. A surface-modified continuous carbon fiber braid is fixed to the electrode of an electrophoresis apparatus. After applying an electric current, WC is uniformly deposited onto the surface of the continuous carbon fiber braid to obtain the process product. The process product is dried, and then subjected to spark plasma sintering or hot pressing sintering processes to obtain the continuous carbon fiber toughened WC ceramic composite. The density of the continuous carbon fiber toughened WC ceramic composite of this invention is ≥13.5 g / cm³. 3 Hardness ≥ 20.5 GPa, flexural strength ≥ 1830 MPa, fracture toughness ≥ 19.5 MPa·m 1 / 2 . Detailed Implementation

[0024] 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.

[0025] According to one aspect of the present invention, the present invention provides the following technical solution:

[0026] A method for preparing a continuous carbon fiber toughened WC ceramic composite material includes the following steps:

[0027] S1. Disperse WC uniformly in a solvent to obtain a WC suspension;

[0028] S2. The surface-modified continuous carbon fiber braid is fixed at the electrode of the electrophoresis equipment. After energizing, WC is uniformly deposited on the surface of the continuous carbon fiber braid to obtain the process product.

[0029] S3. The process product is dried, and then continuous carbon fiber toughened WC ceramic composite material is obtained by spark plasma sintering or hot pressing sintering process.

[0030] Through in-depth research, the inventors of this invention discovered that continuous carbon fibers have a significant toughening effect on ceramic materials, and therefore introduced them into WC ceramic materials. After preparing a suspension of WC powder, an electrophoretic deposition process is used to uniformly attach WC particles to the surface of the continuous carbon fiber woven part. Using spark plasma sintering or hot pressing sintering techniques, the WC ceramic can be sintered to achieve density, ultimately obtaining the desired continuous carbon fiber-toughened WC ceramic composite material.

[0031] Preferably, in step S1, the WC suspension is composed of WC powder, solvent, dispersant, and defoamer; the particle size of the WC powder in the WC suspension is 40nm to 400μm; the solvent is deionized water or anhydrous ethanol; the dispersant is polyvinylpyrrolidone or tetramethylammonium hydroxide; and the defoamer is amine citrate or polyethyleneimine.

[0032] Preferably, in step S1, the content of solid matter in the WC suspension is 30-70 wt%; the mass ratio of solvent, dispersant and defoamer in the WC suspension is (80.5-95.9):(20.9-3.1):(16.4-0.1).

[0033] Preferably, in step S2, the continuous carbon fiber woven fabric is plain weave, twill weave, non-woven fabric, or mesh fabric.

[0034] Preferably, in step S2, the method for modifying the surface of the continuous carbon fiber cloth is to use a laser process for modification, with a laser power of 5 to 150 W.

[0035] Preferably, in step S2, the current density for electrophoretic deposition is 10–200 mA / cm². 2 Electrophoretic deposition time is 30–100 min.

[0036] Preferably, in step S2, the weight gain of the continuous carbon fiber braid after electrophoretic deposition is 200–1200 wt%.

[0037] Preferably, in step S3, the density of the continuous carbon fiber braid in the products of spark plasma sintering and hot pressing sintering is 5 to 20 layers / cm.

[0038] Preferably, in step S3, the temperature of spark plasma sintering and hot pressing sintering is 1300-2100℃, and the sintering time is 5-120 min.

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

[0040] A continuous carbon fiber toughened WC ceramic composite material is prepared by the above-described preparation method for continuous carbon fiber toughened WC ceramic composite materials.

[0041] Preferably, the density of the continuous carbon fiber toughened WC ceramic composite material is ≥13.5 g / cm³. 3 Hardness ≥ 20.5 GPa, flexural strength ≥ 1830 MPa, fracture toughness ≥ 19.5 MPa·m 1 / 2 .

[0042] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0043] Example 1

[0044] A method for preparing a continuous carbon fiber toughened WC ceramic composite material includes the following steps:

[0045] S1. WC is uniformly dispersed in a solvent to obtain a WC suspension. The WC suspension consists of WC powder, solvent, dispersant, and defoamer. The particle size of the WC powder in the WC suspension is 40 nm. The solvent is deionized water. The dispersant is polyvinylpyrrolidone. The defoamer is ammonium citrate. The solid content of the WC suspension is 30 wt%. The mass ratio of solvent, dispersant, and defoamer in the WC suspension is 80.5:10.8:9.7.

[0046] S2. The surface-modified continuous carbon fiber woven fabric is fixed at the electrode of the electrophoresis equipment. After energizing, WC is uniformly deposited on the surface of the continuous carbon fiber woven fabric to obtain the process product. The continuous carbon fiber woven fabric is a plain weave fabric. The surface modification method of the continuous carbon fiber fabric is laser modification with a laser power of 5W. The current density of electrophoretic deposition is 10mA / cm². 2 The electrophoretic deposition time was 30 min; the weight gain of the continuous carbon fiber braid after electrophoretic deposition was 200 wt%.

[0047] S3. The process product is dried and then subjected to spark plasma sintering at a temperature of 2100℃ for 5 minutes to obtain a continuous carbon fiber toughened WC ceramic composite material with a plain weave fabric density of 20 layers / cm.

[0048] The properties of the continuous carbon fiber toughened WC ceramic composite material prepared in this embodiment are as follows: density is 13.65 g / cm³. 3 The hardness is 20.94 GPa, the flexural strength is 1859.35 MPa, and the fracture toughness is 20.67 MPa·m. 1 / 2 .

[0049] Example 2

[0050] A method for preparing a continuous carbon fiber toughened WC ceramic composite material includes the following steps:

[0051] S1. WC is uniformly dispersed in a solvent to obtain a WC suspension. The WC suspension consists of WC powder, solvent, dispersant, and defoamer. The particle size of the WC powder in the WC suspension is 400 μm. The solvent is anhydrous ethanol. The dispersant is tetramethylammonium hydroxide. The defoamer is polyethyleneimine. The solid content of the WC suspension is 70 wt%. The mass ratio of solvent, dispersant, and defoamer in the WC suspension is 88.8:9.5:1.7.

[0052] S2. The surface-modified continuous carbon fiber woven fabric is fixed at the electrode of the electrophoresis equipment. After energizing, WC is uniformly deposited on the surface of the continuous carbon fiber woven fabric to obtain the process product. The continuous carbon fiber woven fabric is a twill fabric. The surface modification method of the continuous carbon fiber fabric is laser modification with a laser power of 150W. The current density of electrophoretic deposition is 200mA / cm². 2 The electrophoretic deposition time was 100 min; the weight gain of the continuous carbon fiber braided part after electrophoretic deposition was 1200 wt%.

[0053] S3. The process product is dried, and then hot pressing sintering process is adopted. The temperature of spark plasma sintering and hot pressing sintering is 1800℃ and the sintering time is 100min to obtain continuous carbon fiber toughened WC ceramic composite material, wherein the density of twill cloth is 5 layers / cm.

[0054] The properties of the continuous carbon fiber toughened WC ceramic composite material prepared in this embodiment are as follows: density is 14.65 g / cm³. 3 The hardness is 21.57 GPa, the flexural strength is 1895.42 MPa, and the fracture toughness is 19.95 MPa·m. 1 / 2 .

[0055] Example 3

[0056] A method for preparing a continuous carbon fiber toughened WC ceramic composite material includes the following steps:

[0057] S1. WC is uniformly dispersed in a solvent to obtain a WC suspension. The WC suspension consists of WC powder, solvent, dispersant, and defoamer. The particle size of the WC powder in the WC suspension is 50 μm. The solvent is anhydrous ethanol. The dispersant is polyvinylpyrrolidone. The defoamer is polyethyleneimine. The solid content of the WC suspension is 45 wt%. The mass ratio of solvent, dispersant, and defoamer in the WC suspension is 93.8:5.6:0.6.

[0058] S2. The surface-modified continuous carbon fiber braid is fixed at the electrode of the electrophoresis equipment. After energizing, WC is uniformly deposited on the surface of the continuous carbon fiber braid to obtain the process product. The continuous carbon fiber braid is a non-woven fabric. The surface modification method of the continuous carbon fiber fabric is laser modification with a laser power of 108W. The current density of electrophoretic deposition is 150mA / cm². 2 The electrophoretic deposition time was 60 min; the weight gain of the continuous carbon fiber braided part after electrophoretic deposition was 1050 wt%.

[0059] S3. The process product is dried, and then a spark plasma sintering process is adopted. The spark plasma sintering and hot pressing sintering temperature is 1300℃ and the sintering time is 120min to obtain a continuous carbon fiber toughened WC ceramic composite material, wherein the density of the non-woven fabric is 12 layers / cm.

[0060] The properties of the continuous carbon fiber toughened WC ceramic composite material prepared in this embodiment are as follows: density is 14.59 g / cm³. 3 The hardness is 22.01 GPa, the flexural strength is 1832.98 MPa, and the fracture toughness is 19.56 MPa·m. 1 / 2 .

[0061] Example 4

[0062] A method for preparing a continuous carbon fiber toughened WC ceramic composite material includes the following steps:

[0063] S1. WC is uniformly dispersed in a solvent to obtain a WC suspension. The WC suspension consists of WC powder, solvent, dispersant, and defoamer. The particle size of the WC powder in the WC suspension is 260 μm. The solvent is deionized water. The dispersant is tetramethylammonium hydroxide. The defoamer is ammonium citrate. The solid content of the WC suspension is 59 wt%. The mass ratio of solvent, dispersant, and defoamer in the WC suspension is 95.9:3.1:1.0.

[0064] S2. The surface-modified continuous carbon fiber woven fabric is fixed at the electrode of the electrophoresis equipment. After energizing, WC is uniformly deposited on the surface of the continuous carbon fiber woven fabric to obtain the process product. The continuous carbon fiber woven fabric is a mesh fabric. The surface modification method of the continuous carbon fiber fabric is laser modification with a laser power of 135W. The current density of electrophoretic deposition is 80mA / cm². 2 The electrophoretic deposition time was 85 min; the weight gain of the continuous carbon fiber braid after electrophoretic deposition was 850 wt%.

[0065] S3. The process product is dried, and then hot pressing sintering process is adopted. The temperature of spark plasma sintering and hot pressing sintering is 1650℃ and the sintering time is 50min to obtain continuous carbon fiber toughened WC ceramic composite material, wherein the density of the mesh fabric is 16 layers / cm.

[0066] The properties of the continuous carbon fiber toughened WC ceramic composite material prepared in this embodiment are as follows: density is 14.37 g / cm³. 3 The hardness is 21.15 GPa, the flexural strength is 1909.58 MPa, and the fracture toughness is 21.09 MPa·m. 1 / 2 .

[0067] Comparative Example 1

[0068] The difference from Example 4 is that no dispersant or defoamer was added in step S1.

[0069] The properties of the continuous carbon fiber toughened WC ceramic composite material prepared in this comparative example are as follows: density is 14.23 g / cm³. 3 The hardness is 18.62 GPa, the flexural strength is 1653.91 MPa, and the fracture toughness is 10.56 MPa·m. 1 / 2 It can be seen that the WC distribution in the WC suspension without dispersant and defoamer is uneven, which in turn leads to uneven distribution of WC particles in the carbon fiber mesh fabric, resulting in a decrease in the performance of the final sample.

[0070] Comparative Example 2

[0071] The difference from Example 4 is that, instead of using an electrophoretic deposition process, WC powder and carbon fiber mesh were alternately layered and then hot-pressed and sintered to finally obtain a continuous carbon fiber toughened WC ceramic composite material.

[0072] The properties of the continuous carbon fiber reinforced WC ceramic composite material prepared in this comparative example are as follows: density is 13.72 g / cm³. 3 The hardness is 15.61 GPa, the flexural strength is 1236.17 MPa, and the fracture toughness is 11.32 MPa·m. 1 / 2 It can be seen that the absence of an electrophoretic deposition method will result in uneven distribution of WC particles in the carbon fiber mesh, leading to a decrease in the performance of the final sample.

[0073] Comparative Example 3

[0074] The difference from Example 4 is that instead of continuous carbon fibers and electrophoretic deposition process, carbon nanotubes and WC powder were mixed and then hot-pressed and sintered to finally obtain whisker-toughened WC ceramic composite material.

[0075] The properties of the continuous carbon fiber reinforced WC ceramic composite material prepared in this comparative example are as follows: density is 14.56 g / cm³. 3 The hardness is 20.95 GPa, the flexural strength is 1956.21 MPa, and the fracture toughness is 6.53 MPa·m. 1 / 2 It can be seen that the fracture toughness of WC ceramic composites without continuous fiber toughening is significantly different, resulting in a reduction in the performance of the final sample.

[0076] As can be seen from the above embodiments and comparative examples, the present invention uses an electrophoretic deposition process to uniformly distribute WC particles on the surface of a continuous carbon fiber braid, so that the carbon fibers are uniformly distributed in the subsequent composite material. The continuous carbon fiber toughened WC ceramic composite material can significantly increase its fracture toughness while ensuring its hardness and flexural strength, thus meeting the requirements of special service conditions.

[0077] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any 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 continuous carbon fiber toughened WC ceramic composite material, characterized in that, Includes the following steps: S1. Disperse WC uniformly in a solvent to obtain a WC suspension; S2. The surface-modified continuous carbon fiber braid is fixed at the electrode of the electrophoresis equipment. After energizing, WC is uniformly deposited on the surface of the continuous carbon fiber braid to obtain the process product. S3. The process product is dried and then obtained by spark plasma sintering or hot pressing sintering process to obtain continuous carbon fiber toughened WC ceramic composite material. In step S1, the WC suspension is composed of WC powder, solvent, dispersant, and defoamer; the content of solid matter in the WC suspension is 30~70wt%; the mass ratio of solvent, dispersant, and defoamer in the WC suspension is (80.5~95.9):(20.9~3.1):(16.4~0.1); The density of the continuous carbon fiber toughened WC ceramic composite material is ≥13.5 g / cm³. 3 Hardness ≥ 20.5 GPa, flexural strength ≥ 1830 MPa, fracture toughness ≥ 19.5 MPa·m 1 / 2 .

2. The method for preparing continuous carbon fiber toughened WC ceramic composite material according to claim 1, characterized in that, In step S1, the WC powder in the WC suspension has a particle size of 40nm~400μm; the solvent is deionized water or anhydrous ethanol; the dispersant is polyvinylpyrrolidone or tetramethylammonium hydroxide; and the defoamer is citrate amine or polyethyleneimine.

3. The method for preparing continuous carbon fiber toughened WC ceramic composite material according to claim 1, characterized in that, In step S2, the continuous carbon fiber woven fabric is plain weave, twill weave, non-woven fabric, or mesh fabric.

4. The method for preparing continuous carbon fiber toughened WC ceramic composite material according to claim 1, characterized in that, In step S2, the method for modifying the surface of the continuous carbon fiber cloth is to use a laser process for modification, with a laser power of 5~150W.

5. The method for preparing continuous carbon fiber toughened WC ceramic composite material according to claim 1, characterized in that, In step S2, the current density for electrophoretic deposition is 10~200 mA / cm². 2 The electrophoretic deposition time is 30~100min; the weight gain of continuous carbon fiber braided parts after electrophoretic deposition is 200~1200wt%.

6. The method for preparing continuous carbon fiber toughened WC ceramic composite material according to claim 1, characterized in that, In step S3, the density of the continuous carbon fiber braided parts in the products of spark plasma sintering and hot pressing sintering is 5~20 layers / cm.

7. The method for preparing continuous carbon fiber toughened WC ceramic composite material according to claim 1, characterized in that, In step S3, the temperature of spark plasma sintering and hot pressing sintering is 1300~2100℃, and the sintering time is 5~120min.

8. A continuous carbon fiber reinforced WC ceramic composite material, characterized in that, The WC ceramic composite material was prepared using the method described in any one of claims 1-7.