阅读说明：本技术 一种晶粒编织复相陶瓷材料及其制备方法 (Grain-woven complex-phase ceramic material and preparation method thereof ) 是由 黄毅华 江东亮 黄政仁 陈忠明 张辉 于 2019-09-25 设计创作，主要内容包括：本发明涉及一种晶粒编织复相陶瓷材料及其制备方法,所述晶粒编织复相陶瓷材料包括两种以上长棒状陶瓷晶粒沿不同方向取向排列的方式编织而成；所述陶瓷晶粒选自长棒状AlN晶粒和长棒状Si-3N-4晶粒中至少一种,以及长棒状SiC晶粒。(The invention relates to a grain-woven complex-phase ceramic material and a preparation method thereof, wherein the grain-woven complex-phase ceramic material is woven by more than two long rod-shaped ceramic grains which are oriented and arranged along different directions; the ceramic crystal grains are selected from long rod-shaped AlN crystal grains and long rod-shaped Si 3 N 4 At least one of crystal grains, and long rod-shaped SiC crystal grains.)

1. the grain-woven complex-phase ceramic material is characterized by comprising more than two long rod-shaped ceramic grains which are woven in a mode of oriented arrangement along different directions; the ceramic crystal grains are selected from long rod-shaped AlN crystal grains and long rod-shaped Si₃N₄At least one of crystal grains, and long rod-shaped SiC crystal grains.

2. The grain-woven complex phase ceramic material as claimed in claim 1, wherein the length of the ceramic grains is 1-30 μm.

3. The grain-woven complex phase ceramic material as claimed in claim 1 or 2, wherein the grain orientation difference of more than two kinds of long rod-like ceramic grains oriented and arranged in different directions is: long rod shaped SiC crystal grain parallel to magnetic field direction, long rod shaped AlN crystal grain and long rod shaped Si₃N₄The grains are parallel to the magnetic field direction.

4. A method for preparing a grain-knitted complex phase ceramic material according to any one of claims 1 to 3, comprising: mixing raw material powder comprising at least one of silicon carbide powder, silicon nitride and aluminum nitride to prepare slurry, performing slurry injection molding in a magnetic field, and drying to obtain a blank; calcining the obtained blank to obtain the grain-woven complex-phase ceramic material; the silicon carbide powder and at least one of silicon nitride and aluminum nitride are magnetic powder, and have a difference in magnetic susceptibility in each direction of a crystal axis.

5. The method according to claim 4, wherein the particle size of the raw material powder is 0.3 to 10 μm, preferably 0.5 to 5 μm.

6. The preparation method according to claim 4 or 5, characterized in that a sintering aid and a dispersant are added to the raw material powder to prepare slurry; the sintering aid is aluminum oxide or/and yttrium oxide, and the addition amount is 1-10 wt% of the mass of the raw material powder; the dispersing agent is at least one of polyethyleneimine, tetramethylammonium hydroxide, methylcellulose and polyvinylpyrrolidone, and the addition amount of the dispersing agent is 0.2-3.0 wt% of the raw material powder.

7. The method according to any one of claims 4 to 6, wherein the slurry has a solid content of 10 to 50 vol%.

8. The method according to any one of claims 4 to 7, wherein the slip casting time is 1 to 8 hours.

9. The production method according to any one of claims 4 to 8, wherein, after slip casting, drying and isostatic pressing are performed to obtain a green body; preferably, the drying temperature is 60-120 ℃, the drying time is 4-20 hours, and the cold isostatic pressing treatment pressure is 100-200MPa, and the drying time is 5-20 minutes.

10. The method according to any one of claims 4 to 9, wherein the calcination is carried out in an inert atmosphere at 1400 to 2000 ℃ for 0.5 to 3 hours; preferably, the inert atmosphere is an argon atmosphere.

Technical Field

The invention relates to a grain-woven complex-phase ceramic material and a preparation method thereof, belonging to the field of complex-phase ceramic materials.

Background

The ceramic material has the advantages of small density, high strength and the like. However, ceramic materials are generally brittle and have poor reliability and do not effectively exploit their potential advantages. The toughness and strength of ceramics can be improved by compounding different ceramic phases. Aiming at some special requirements, the composite structure and the proportion of the ceramic can be effectively controlled, so that the optimal performance of the material is realized. The simpler compounding is that the toughness of the ceramic is increased by the dispersed phase of the particles, and the multiphase ceramic material is prepared by casting, carbonization of plant fiber and other methods.

In recent years, fiber weaving complex phase materials become a research hotspot in the field. The long fibers can be woven by a conventional and macroscopic weaving method, and then the materials are compounded by impregnation, siliconizing and the like. However, it is difficult to achieve two-dimensional weaving for short fiber or whisker materials. Thus, although silicon carbide ceramics have superior mechanical and thermal properties, there is room for improvement in toughness and strength.

Disclosure of Invention

The invention aims to provide a grain-woven complex-phase ceramic material formed by weaving and compounding silicon carbide ceramic and other ceramics and a preparation method thereof.

On one hand, the invention provides a grain-woven complex-phase ceramic material which is woven by more than two long rod-shaped ceramic grains in different direction orientation arrangement modes; the ceramic crystal grains are selected from long rod-shaped AlN crystal grains and long rod-shaped Si₃N₄At least one of crystal grains, and long rod-shaped SiC crystal grains.

In the present disclosure, the grain-woven complex phase ceramic material is woven by more than two kinds of long rod-shaped ceramic grains arranged along different directions. The toughness and strength of the obtained grain-woven complex-phase ceramic material are further improved.

Preferably, the length of the ceramic crystal grain is 1 to 30 μm.

In a preferred scheme, the difference of the orientation factors of more than two long rod-shaped ceramic crystal grains which are oriented and arranged in different directions is that one is arranged in parallel to a magnetic field and the other is arranged in perpendicular to the magnetic field; for example, long rod-like SiC crystal grains are parallel to the magnetic field direction, long rod-like AlN crystal grains and long rod-like Si₃N₄The grains are parallel to the magnetic field direction. Preferably, the complex phase ceramic grains are vertically oriented.

On the other hand, the invention provides a preparation method of the grain-woven complex phase ceramic material, which comprises the following steps: mixing raw material powder comprising at least one of silicon carbide powder, silicon nitride and aluminum nitride to prepare slurry, performing slurry injection molding in a magnetic field, and drying to obtain a blank; calcining the obtained blank to obtain the grain-woven complex-phase ceramic material; the silicon carbide powder and at least one of the silicon nitride and the aluminum nitride are magnetic powder, and have magnetic susceptibility difference in each direction of a crystal axis.

The invention provides a grain-woven silicon carbide composite ceramic. The complex phase ceramic is prepared by adopting magnetic field orientation and taking silicon carbide, silicon nitride or silicon carbide and aluminum nitride powder as the crystal orientation of particles in slurry of raw materials. In the disclosure, the crystal grain braided silicon carbide composite ceramic is prepared by adding magnetic powder into raw materials, enabling the magnetic powder to have magnetic anisotropy between at least one of silicon nitride powder and aluminum nitride powder and silicon carbide powder, and then orienting through a magnetic field. The magnetic powder can be unmagnetized powder or magnetized powder. Preferably, the raw materials are prepared into slurry, and the slurry is injected and molded under the magnetic field intensity of 1-20T. Countless raw material powder in the slurry with good dispersibility and stability can be orderly arranged in a medium-intensity magnetic field according to the direction with the lowest self energy to obtain a blank. And de-bonding and sintering the obtained blank to finally enable the crystal grain orientation to occur.

Preferably, the particle size of the raw material powder is 0.3 to 10 μm, preferably 0.5 to 5 μm.

Preferably, the sintering aid is aluminum oxide or/and yttrium oxide, and the addition amount is 1-10 wt% of the mass of the raw material powder; the dispersing agent is at least one of polyethyleneimine, tetramethylammonium hydroxide, methylcellulose and polyvinylpyrrolidone, and the addition amount of the dispersing agent is 0.2-3.0 wt% of the raw material powder.

Preferably, the solid content of the slurry is 10-50 vol%; the solvent is selected from at least one of alcohol, water, methanol and acetone.

Preferably, the slip casting time is 1-8 hours; preferably, after slip casting, drying and isostatic pressing treatment are carried out to obtain a blank; more preferably, the drying temperature is 60 to 120 ℃, the drying time is 4 to 20 hours, and the cold isostatic pressing treatment pressure is 100 to 200MPa, and the drying time is 5 to 20 minutes.

Preferably, the calcination is carried out in an inert atmosphere at 1400-2000 ℃ for 0.5-3 hours; preferably, the inert atmosphere is an argon atmosphere.

Preferably, before calcining, the obtained blank is heated to 600-1200 ℃ at a speed of 3-30 ℃/min; preferably, the temperature is raised to 600-1200 ℃ at the speed of 3-30 ℃/min in a vacuum atmosphere, and the temperature is preserved for 20-120 min.

Has the advantages that:

due to the magnetic anisotropy of the ceramic powder, countless small particles in the slurry with good dispersibility and stability can be orderly arranged in a medium-strength magnetic field according to the direction with the lowest self energy, and the crystal grain orientation is generated. Furthermore, due to the difference in magnetic susceptibility of the magnetic silicon carbide powder in each direction of the crystal axis, the ceramic crystal grains are aligned in a fixed <006> direction with the lowest energy, and aluminum nitride and silicon nitride are aligned in a direction perpendicular to the <006> direction. In addition, the process is controlled in the sintering process, so that grains are not rearranged. The preparation method has simple process and low cost, and is beneficial to large-scale production.

Detailed Description

The present invention is further illustrated by the following examples, which are to be understood as merely illustrative and not restrictive.

In the present disclosure, the grain-woven complex phase ceramic material is formed by complex-phase weaving (i.e., arranging in a vertical orientation) of two long rod-shaped ceramic grains, wherein the two long rod-shaped ceramic grains can be SiC and Si₃N₄Alternatively, SiC and AlN may be combined. Wherein the content of SiC can be 20-80 wt%. In an alternative embodiment, the two long rod-shaped ceramic crystal grains are vertically grown, and the length of the crystal grains is between 1 and 30 mu m.

In an embodiment of the present inventionIn the implementation mode, powder with silicon carbide and silicon nitride or silicon carbide and aluminum nitride and the like is used as raw material powder to prepare slurry, particles in the silicon carbide slurry are oriented by utilizing a medium-intensity magnetic field, and then the crystal grain woven complex phase ceramic is prepared by sintering (or calcining). Specifically, silicon carbide powder and other ceramic powder (Si) are used₃N₄Or AlN) in each direction of the crystal axis, and adopting a medium-intensity magnetic field to enable the crystal grains to be highly directionally woven in the slurry along the same direction to prepare the silicon carbide complex phase ceramic. The preparation method has simple process and low cost, is beneficial to large-scale production, and the relative density of the prepared grain-woven complex-phase ceramic is more than 90 percent.

The method for preparing the grain-woven complex phase ceramic in the medium-intensity magnetic field is specifically described below.

And (4) preparing slurry. Mixing silicon carbide powder and silicon nitride or aluminum nitride powder according to stoichiometric ratio to prepare slurry. Specifically, a raw material powder (SiC powder, silicon nitride powder, AlN powder, or the like), a sintering aid, a dispersant, and a solvent are mixed and ground to prepare a slurry. The raw material powder may be unmagnetized powder or magnetized powder. The method for mixing the slurry in the present invention is not particularly limited, and a known method such as ball-milling can be used. As one example, the process of hybrid milling may include, for example: mixing the raw material powder, the sintering aid, the dispersing agent and the solvent, and then carrying out ball milling and mixing for 1-4 hours at the rotating speed of 200-400 rpm. The ball milling medium can adopt silicon carbide balls or zirconia balls and the like. In addition, the solvent can be water or alcohol, and the using amount of the solvent is configured according to the solid content requirement. Wherein the SiC powder accounts for 20-80 wt% of the total mass of the raw material powder.

In an alternative embodiment, a treated, magnetic silicon carbide powder may be used as the raw material powder. The magnetic silicon carbide powder may have a saturation magnetic moment of 10^-4～10^-5emu/g. In addition, the purity of the magnetic silicon carbide powder can be more than 98%.

In an alternative embodiment, the particle morphology of the raw material powder is not specifically limited, and needs to satisfy the requirement of configuring good dispersion in a medium-high magnetic fieldIn the case of a slurry of properties and stability, numerous small particles can be arranged in an ordered manner in the direction of lowest self-energy. The particle size of the magnetic silicon carbide powder may be 0.3 to 10 μm, preferably 0.5 to 5 μm. Si₃N₄Or AlN has a purity of more than 98% and a particle diameter of 0.3 to 10 μm, preferably 0.5 to 5 μm.

In alternative embodiments, the magnetic silicon carbide powder may be prepared from silicon carbide powder by neutron bombardment or elemental doping. Neutron bombardment causes vacancies to be created in the silicon carbide crystal, thereby inducing magnetism. As an example, the procedure of neutron bombardment treatment is exemplified by (Liu Y, Wang G, Wang S, Yang J, Chen L, Qin X2011 phys. Alternatively, when the magnetic silicon carbide powder is prepared by doping an element, the doping element may be, for example, Al, B, Fe, Mn, or the like. The doping amount of the doping element can be 0.3 to 2 wt%. When the doping amount is 0.3 to 1 wt%, the crystal grains are fully dissolved in the solution. As an example, the step of the element doping process may include, for example: mixing 1 wt% of alumina powder and a silicon carbide powder doping source, heating to 800-1000 ℃ under a vacuum condition, keeping for 0.5-2h, heating to 1500-2100 ℃ under an argon atmosphere, and calcining for 1-2h to obtain the doped magnetic silicon carbide powder.

In alternative embodiments, alumina and/or yttria may be used as the sintering aid. The purity of the alumina is more than 98 percent, and the particle size is 0.1-5 mu m. The purity of the yttrium oxide is more than 98%, and the particle size is 0.5-10 mu m. The content of alumina and/or yttria is preferably 1 to 10wt% based on the weight of the raw material powder.

In alternative embodiments, the dispersant is polyethyleneimine or tetramethylammonium hydroxide. The amount of the dispersant is preferably 0.2 to 3.0wt% of the raw material powder. When the amount of the dispersant is 0.2 to 3.0wt%, a slurry having good dispersibility can be prepared, and when a slurry having good dispersibility and stability is prepared in a medium-high magnetic field, countless small particles can be arranged in an ordered manner in a direction in which their own energy is the lowest.

In alternative embodiments, the solvent may be water or alcohol, or the like. The solid content of the prepared slurry is 10-50 vol%, and the solid content of the slurry can be controlled by controlling the adding amount of the powder and the solvent. When the solid content of the slurry is 10-50 vol%, the slurry has the advantages of suspension maintenance and easy magnetic field grouting solidification. Preferably, the weaving degree of the grain weaving complex phase ceramic material is controlled by a magnetic field and the solid content of slurry.

Further preferably, the slurry obtained can be subjected to vacuum defoaming or defoaming by adding a defoaming agent. As an example, for example, 0.2ml of an antifoaming agent is added to the slurry, and then vacuum is applied while stirring, thereby removing air bubbles from the slurry.

Further preferably, the pH value of the prepared aqueous slurry solution can be adjusted to 8.0-10 so as to improve the activity of the dispersing agent and prevent the slurry from rapidly settling along with gravity. As an example, the pH of the prepared aqueous slurry solution may also be adjusted to 8.0 by NaOH to increase the activity of the dispersant, thereby reducing slurry settling. Therefore, the invention can prepare the slurry with good dispersibility and stability by controlling the pH value, the content of the dispersant and the solid content of the slurry.

And (4) grouting the slurry in a magnetic field to form a blank. The invention adopts a magnetic field to pre-weave crystal grains, and the magnetic field intensity is within the range of 1-20T, preferably 1-10T, and more preferably 4-10T on the premise of ensuring the orientation of the crystal grains. The orientation of crystal grains can be realized by combining a medium-strength magnetic field with the magnetism of slurry, while the orientation of common non-magnetic powder needs a magnetic field of more than 10T, and the strength can be generated only by a superconducting magnetic field. The magnetic field intensity required by the invention can be determined according to the difference of the anisotropy magnetization rates of the slurry powder. Specifically, slip casting may include injecting the above slurry into a mold (the mold may be a plaster mold), and standing in a magnetic field of 4-10T (e.g., 6T). The time for the slip casting may be 1 to 8 hours, preferably 2 to 4 hours. In addition, both slurry preparation and slip casting can be performed at room temperature. In the slip casting process, due to the difference of the magnetic susceptibility of the magnetic silicon carbide powder in each direction of the crystal axis, the energy is minimum when the crystal grains are arranged along the <006> direction, and the silicon nitride and the aluminum nitride ceramic are vertical to the <006> direction.

In an alternative embodiment, after the slip casting is solidified, the blank is taken out and dried, and then is subjected to cold isostatic pressing treatment to further improve the density of the biscuit. The drying condition can be that the mixture is placed at 60-120 ℃ for 4-20 hours. The pressure of the cold isostatic pressing can be 100-200MPa, and the time can be 5-20 minutes.

And sintering (or calcining) the blank to densify the ceramic to obtain the grain-woven complex-phase ceramic material. Wherein, the sintering can adopt a pressureless sintering (calcining) process, the sintering condition can be 1400-2000 ℃ (preferably 1900-2000 ℃), and the time is 0.5-3 hours. Preferably, the sintering regime comprises: heating to 600-1200 ℃ under a vacuum condition; and then heating to 1200-2000 ℃ in an argon atmosphere for calcining to obtain the grain-woven complex-phase ceramic material. More preferably, the temperature is raised to 600-1200 ℃ at the speed of 3-30 ℃/min, and the heat preservation time is 20-120 min. The purity of the argon gas is more than 99%.

In the invention, the relative density of the obtained grain-woven complex-phase ceramic material is more than 90 percent by adopting a drainage method. Silicon carbide ceramic grain edge<006>The orientation is arranged in a directional orientation mode, and the orientation factor of the orientation is 0.8-1 by XRD. Silicon nitride and aluminum nitride ceramics perpendicular to<006>Direction, measured with xrd along<006>The directional orientation factor can be 0.8 to 1. The toughness of the grain-woven complex-phase ceramic material measured by a grooving method is 6-10 MPa m^1/2. The strength of the grain-woven complex-phase ceramic material is 300-1000 MPa measured by adopting three-point bending resistance.

The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that certain insubstantial modifications and adaptations of the invention by those skilled in the art may be made in light of the above teachings. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below.

Example 1:

preparing Al-doped magnetic silicon carbide powder: mixing 1 wt% of alumina powder and a silicon carbide powder doping source, heating to 800-1000 ℃ under a vacuum condition, keeping for 0.5-2h, heating to 1500-2100 ℃ under an argon atmosphere, and calcining for 1-2h to obtain doped magnetic silicon carbide powder;

adding 1.0 wt% of tetramethylammonium hydroxide and 5 wt% of alumina powder into silicon carbide and silicon nitride powder (the total mass is 100g, the mass ratio is 3: 7), adding a defoaming agent to remove bubbles, ball-milling and mixing for 4h in 93ml of water medium at the rotating speed of 300rpm to prepare slurry with the solid content of 25 vol%, adjusting the pH value of the slurry water solution to be 8.0, grouting and molding for 6 hours in a 10T magnetic field, drying, carrying out cold isostatic pressing treatment for 5min at 200MPa, carrying out high-temperature sintering for 1h at 1850 ℃, and finally realizing the prepared crystal grain weaving to obtain the crystal grain weaving multiphase ceramic material. By xrd testing, the silicon carbide orientation factor in the <006> direction was found to be 0.87 and the silicon nitride orientation factor in the <006> direction was found to be only 0.20.

Example 2:

preparing Al-doped magnetic silicon carbide powder, which comprises the following specific steps of example 1;

adding 1.0 wt% of tetramethylammonium hydroxide and 5 wt% of alumina powder into Al-doped magnetic silicon carbide powder and silicon nitride powder (the total mass is 100g, the mass ratio is 5: 5), removing bubbles in vacuum, ball-milling and mixing for 4h in 93ml of alcohol medium at the rotating speed of 300rpm to prepare slurry with the solid content of 25 vol%, adjusting the pH value of the slurry aqueous solution to 8.0, carrying out slurry injection molding for 6 hours in a 9T magnetic field, drying, carrying out cold isostatic pressing treatment for 5min at 200MPa, carrying out high-temperature sintering for 1h at 1750 ℃, finally realizing grain weaving, and testing through xrd to obtain that the silicon carbide orientation factor along the <006> direction is 0.92 and the silicon nitride orientation factor along the <006> direction is only 0.17.

Example 3:

preparing Al-doped magnetic silicon carbide powder, which comprises the following specific steps of example 1;

adding 1.0 wt% of tetramethylammonium hydroxide and 5 wt% of alumina powder into Al-doped magnetic silicon carbide powder and aluminum nitride powder (the total mass is 100g, the mass ratio is 5: 5), ball-milling and mixing for 4h in an alcohol medium, rotating at the speed of 300rpm to prepare slurry with the solid content of 40 vol%, slip casting for 3 hours in a 6T magnetic field, drying, performing cold isostatic pressing treatment at 200MPa, performing high-temperature sintering at 1850 ℃, and finally realizing the prepared grain weaving to obtain the grain weaving multiphase ceramic material. By xrd testing, the silicon carbide orientation factor in the <006> direction was found to be 0.90 and the aluminum nitride orientation factor in the <006> direction was found to be only 0.23.

Example 4:

preparing Mn-doped magnetic silicon carbide powder: and (2) mixing the following components in percentage by mass as 100: 1-2, mixing silicon carbide powder and a Mn element doping source, heating to 800-1000 ℃ under a vacuum condition, keeping for 0.5-2h, heating to 1200-1400 ℃ under an argon atmosphere, and calcining for 0.5-3h to obtain Al-doped magnetic silicon carbide powder;

adding 1.0 wt% of tetramethylammonium hydroxide and 5 wt% of alumina powder into Mn-doped magnetic silicon carbide powder and silicon nitride powder (the total mass is 100g, the mass ratio is 4: 6), adding a defoaming agent to remove bubbles, ball-milling and mixing for 4h in 93ml of water medium at the rotating speed of 300rpm to prepare slurry with the solid content of 25 vol%, adjusting the pH value of the slurry water solution to 8.5, grouting and molding for 6 hours in a 9T magnetic field, drying, performing cold isostatic pressing treatment at 200MPa for 10min, performing high-temperature sintering at 1850 ℃ for 2h, and finally realizing grain weaving to obtain the prepared grain-woven complex-phase ceramic material. By xrd testing, it was found that the silicon carbide orientation factor in the <006> direction was 0.92 and the silicon nitride orientation factor in the <006> direction was only 0.15.

Example 5:

preparing Al-doped magnetic silicon carbide powder, which comprises the following specific steps of example 1;

adding 1.0 wt% of tetramethylammonium hydroxide, 5 wt% of alumina powder and 5 wt% of yttrium oxide powder into Al-doped magnetic silicon carbide powder (the total mass is 100g, the mass ratio is 5: 5), ball-milling and mixing for 4h in an alcohol medium at the rotating speed of 300rpm to prepare slurry with the solid content of 40 vol%, slip casting for 3h in a 6T magnetic field, drying, carrying out cold isostatic pressing treatment at 200MPa, carrying out high-temperature sintering at 1850 ℃, and finally realizing the prepared crystal grain weaving to obtain the crystal grain weaving multiphase ceramic material. By xrd testing, it was found that the silicon carbide orientation factor in the <006> direction was 0.95 and the aluminum nitride orientation factor in the <006> direction was only 0.17.

Example 6:

preparing B-doped magnetic silicon carbide powder: and (2) mixing the following components in percentage by mass as 100: 1-2, mixing the silicon carbide powder with an element B doping source, heating to 800-1000 ℃ under a vacuum condition, keeping for 0.5-2h, heating to 1800-2000 ℃ under an argon atmosphere, and calcining for 1-2h to obtain B-doped magnetic silicon carbide powder;

adding 1.0 wt% of tetramethylammonium hydroxide and 5 wt% of alumina powder into B-doped magnetic silicon carbide powder and silicon nitride powder (the total mass is 100g, the mass ratio is 5: 5), adding a defoaming agent to remove bubbles, ball-milling and mixing for 4h in 46.5ml of alcohol medium at the rotating speed of 300rpm to prepare slurry with the solid content of 40 vol%, adjusting the pH value of the slurry aqueous solution to 9.0, performing slip casting for 3 hours in a 6T magnetic field, drying, performing cold isostatic pressing treatment at 200MPa for 15min, performing high-temperature sintering at 1750 ℃ for 2h, and finally realizing the prepared grain weaving to obtain the grain woven complex-phase ceramic material. By xrd testing, it was found that the silicon carbide orientation factor in the <006> direction was 0.93 and the silicon nitride orientation factor in the <006> direction was only 0.14.

Comparative example 1

The preparation method of the grain-woven complex phase ceramic material in the comparative example 1 is basically the same as that of the example 1, and the difference is that: the magnetic field is not intensified.

Table 1 shows the composition and performance parameters of the multiphase materials prepared according to the present invention: