High-strength quartz sand ceramic material as well as preparation method and application thereof

Abstract

The invention relates to a high-strength quartz sand ceramic material as well as a preparation method and application thereof. The quartz fibers and the silicon carbide fibers are proportioned according to the gradient, a multi-scale enhanced network is constructed, grain boundary slippage is inhibited, meanwhile, nanoscale micropores are formed in the surfaces of the fibers through HF acid etching, and the interface shear strength is improved by combining bridging of a silane coupling agent. In addition, the Al2O3-ZrO2 solid solution is subjected to staged gradient sintering, namely, first-stage degumming, second-stage nucleation and third-stage densification, so that abnormal growth of crystal grains is inhibited, nano-crystal grains are subjected to high-density dislocation entanglement and a solid solution crystal boundary pinning effect, the crystal boundary slippage resistance is improved by 3 times, meanwhile, Si-O-A l bonds are formed between excessive Al2O3 and the modified fibers, and the mechanical property of the modified fibers is improved. The interface thermal resistance is reduced, the heat resistance of the material is improved, and thermal stress concentration is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of lightweight building materials, and in particular to a high-strength quartz sand ceramic material and a preparation method thereof. Background Art

[0002] Quartz ceramics are widely used in aerospace, semiconductors, and other fields due to their high-temperature resistance and low dielectric loss. However, traditional materials suffer from low strength, with flexural strength generally less than 50 MPa, fracture toughness ≤ 0.8 MPa·m¹ / ², and poor thermal shock stability (cracking after ≤ three rapid cooling and heating cycles). Furthermore, existing molding processes (such as dry pressing and gel casting) struggle to control porosity, resulting in a yield of only 75%. Fiber reinforcement also suffers from poor dispersion (content ≤ 6 wt.%), and the use of grain growth agents can easily reduce grain boundary strength, limiting their application in complex working conditions. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems of low strength and poor thermal stability of quartz sand ceramic materials in the prior art, and thus provide a method of constructing a three-dimensional interpenetrating network structure by synergizing high-purity quartz sand + modified fiber + Al2O3-ZrO2 grain growth agent, multi-stage ball milling dispersion, vacuum impregnation molding and gradient sintering process, so that the bending strength of the material can be increased to 92MPa, and there is no cracking after water cooling ≥10 times after thermal shock cycle at 1200℃.

[0004] In order to solve the above technical problems, the present invention is achieved through the following technical solutions.

[0005] The first aspect of the present invention provides a high-strength quartz sand ceramic material, which is made from the following raw materials in parts by weight: 85-90 parts of high-purity quartz sand, 5-8 parts of modified fiber, 1-3 parts of grain growth agent, 0.5-1.5 parts of dispersant, and 2-4 parts of binder; the modified fiber is a mixture of quartz fiber and silicon carbide fiber, and the grain growth agent is a composite powder of Al2O3 and ZrO2; the material is prepared by multi-stage ball milling dispersion, vacuum impregnation molding and gradient sintering process.

[0006] By using a mixture of quartz fiber and silicon carbide fiber as the modified fiber, the high-temperature stability of the material is improved while improving high-temperature resistance. The quartz fibers are arranged along the molding direction, and the silicon carbide fibers are cross-arranged at 45 degrees to form a multi-level reinforcement network. The composite powder of Al2O3 and ZrO2, which is a grain growth agent, can form a solid solution during the sintering process, inhibiting abnormal grain growth and controlling the grain size within 100 nanometers. It works synergistically with the reinforcement network to improve the yield strength of the material.

[0007] Furthermore, the particle size D50 of the quartz sand is 5-10 μm, and the SiO2 purity is ≥99.9%.

[0008] Furthermore, the mass ratio of quartz fiber to silicon carbide fiber in the modified fiber is 4:1-1.5:1, and the average aspect ratio of the modified fiber is ≥50:1.

[0009] Furthermore, the average aspect ratio of the modified fiber is 50-80:1, ensuring both dispersibility and material toughness.

[0010] Furthermore, the average aspect ratio of the modified fiber is 50:1. At this time, the thermal expansion coefficient of the modified fiber is close to the thermal expansion coefficient of the Al2O3-ZrO2 interface, thereby improving the thermal management capability of the material.

[0011] Furthermore, the mass ratio of quartz fiber to silicon carbide fiber in the modified fiber is 7:3, which can ensure low thermal conductivity while ensuring high-temperature mechanical strength.

[0012] Furthermore, the grain growth agent has a mass ratio of Al2O3 to ZrO2 of 2:1-3:2, and a particle size of ≤1 μm. During sintering, the Al2O3 and ZrO2 form an Al2Zr2O5 solid solution, inhibiting grain growth. Furthermore, excess Al2O3 forms Si-O-Al bonds with the modified fiber, reducing interfacial thermal resistance, improving material heat resistance, and preventing thermal stress concentration.

[0013] Furthermore, the dispersant is a polycarboxylate ammonium salt with an HLB value of 12-15.

[0014] Furthermore, the dispersant includes one or more of ammonium polyacrylate, ammonium salt of maleic acid-acrylic acid copolymer, ammonium polymethacrylate, and graft copolymerized polycarboxylate ammonium salt.

[0015] Furthermore, the binder is acrylamide-acrylic acid copolymer.

[0016] Furthermore, the acrylamide-acrylic acid copolymer is one or more of a standard acrylamide-acrylic acid copolymer and a functionalized acrylamide-acrylic acid copolymer.

[0017] The present invention also provides a method for preparing a quartz sand ceramic material, comprising the following steps:

[0018] (1) Preparation of modified fiber: quartz fiber and silicon carbide fiber were mixed, immersed in ethanol for ultrasonic treatment, dried, immersed in HF acid solution, stirred for reaction, filtered, washed with water, and dried to obtain modified fiber;

[0019] (2) mixing quartz sand and a grain growth agent to obtain a mixture;

[0020] (3) adding the modified fiber and the dispersant into water, mixing with the binder after ultrasonic treatment and ball milling to form a slurry;

[0021] (4) adding the mixture of step (2) to the slurry of step (3), mixing, impregnating, and drying to obtain a quartz sand ceramic matrix;

[0022] (5) Gradient sintering the quartz sand ceramic matrix to obtain the quartz sand ceramic material.

[0023] Furthermore, (1) modified fiber preparation: quartz fiber and silicon carbide fiber are mixed in a mass ratio of 4:1-1.5:1, immersed in anhydrous ethanol, ultrasonically treated at 50-60°C for 1-2 hours, vacuum dried, immersed in 30-60% HF acid solution, stirred for reaction for 0.5-1 hour, filtered, washed with water until neutral, and then dried to obtain the modified fiber.

[0024] Further, (2) quartz sand and a grain growth agent are added into a solvent and ball milled and mixed.

[0025] Furthermore, the solvent is anhydrous ethanol.

[0026] Further, (3) the modified fiber and dispersant in step (1) are added to deionized water, ultrasonically treated, mixed with a binder, and subjected to multi-stage ball milling to form a high solid content slurry.

[0027] Further, (4) the mixture in step (2) is added to step (3) and mixed evenly, and then vacuum impregnation and drying are performed in sequence to obtain a quartz sand ceramic matrix.

[0028] Further, (5) the quartz sand ceramic matrix in step (4) is subjected to gradient sintering:

[0029] The first stage: heating to 50-200℃ at a heating rate of 5-10℃ / min to remove volatile water;

[0030] The second stage: heating to 200-800℃ at a heating rate of 3-5℃ / min and keeping at that temperature for 1-5 hours;

[0031] The third stage: heating the temperature to 800-1250° C. at a heating rate of 10-15° C. / min and keeping the temperature for 1.5-5 hours to obtain the quartz sand ceramic material.

[0032] Furthermore, the modified fiber in step (1) is prepared by mixing quartz fiber and silicon carbide fiber in a mass ratio of 4:1-1.5:1, immersing in anhydrous ethanol, ultrasonically treating at 50-60°C for 1-2 hours, vacuum drying, immersing in a 30-60% HF acid solution, stirring and reacting for 0.5-1 hour, filtering and washing with water until neutral, and then drying, and then placing in an organic silicon coupling agent solution, standing and vacuum drying to obtain the modified fiber. By immersing in ethanol for cleaning and then immersing in the HF acid solution, micropores are formed on the reaction surface, thereby improving the interfacial bonding strength.

[0033] Furthermore, the multi-stage ball milling time in step (3) is 6-12 hours, and the multi-stage ball milling includes coarse grinding and fine grinding. During the coarse grinding process, steel balls with a diameter of 10-15 mm are used for particle crushing, and during the fine grinding process, steel balls with a diameter of 3-5 mm are used for particle refinement.

[0034] Furthermore, the vacuum impregnation step is first performed with 5-10 MPa for pre-pressing and shaping, and then cold isostatic pressing is performed at 180-220 MPa.

[0035] The quartz sand ceramic material of the present invention is widely used in the fields of construction, machinery and aviation.

[0036] The present invention has the following beneficial effects compared to the prior art:

[0037] The present invention achieves a leap-forward improvement in the performance of quartz sand ceramic materials through the synergistic effect of raw material system innovation, process optimization and interface design;

[0038] Quartz fibers (low-temperature elastic phase) and silicon carbide fibers (high-temperature rigid phase) are mixed in a gradient ratio to create a multi-scale reinforcement network. At low temperatures, the quartz fibers provide plastic deformation and absorb energy; at high temperatures, the silicon carbide fibers form a rigid framework. The SiO2 glass phase, generated by oxidation of SiC, chemically bonds with the matrix, inhibiting grain boundary slip.

[0039] The fiber surface is etched with HF acid to form nanoscale micropores, which are then bridged with a silane coupling agent to enhance interfacial shear strength. Simultaneously, the Al2O3-ZrO2 solid solution undergoes a phased gradient sintering process: debonding in the first stage, nucleation in the second, and densification in the third. This suppresses abnormal grain growth, keeping the grain size within 50-100nm, a 62.5% reduction compared to conventional processes. The nanocrystals enhance grain boundary slip resistance through high-density dislocation entanglement and the solid solution grain boundary pinning effect.

[0040] HF acid etching combined with silane coupling agent treatment increases the fiber-matrix interface strength to 25 MPa. The mixed solvent effectively extracts alkali metal impurities from quartz sand, and combined with the chemical adsorption of alkali metals by Al2O3-ZrO2, the resistivity is increased. The gradient sintering process achieves a material density of 98.5%, a pore size of <1 μm, and a 60% reduction in thermal stress.

[0041] Process synergy: Multi-stage ball milling reduces particle uniformity to a CV value of ≤5%. Vacuum impregnation combined with staged heating significantly improves green body densification efficiency. The final material achieves a flexural strength of 92 MPa and survives 12 thermal shock cycles without cracking, surpassing existing technical bottlenecks in overall performance.

[0042] This invention provides a new paradigm for the research and development of high-performance ceramic materials for extreme environments through the innovative coupling of microstructure design and macroscopic process control. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the following examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] Example 1

[0045] Example 1 of the present invention, based on the fact that high-strength quartz sand ceramic materials belong to lightweight building materials, the present invention provides a high-strength quartz sand ceramic material, which includes the following raw materials, by weight: 85 parts of high-purity quartz sand (D50 = 8 μm, SiO2 purity of 99.9%), 6 parts of modified fiber, 1 part of a composite powder of Al2O3 and ZrO2, 1 part of polycarboxylate ammonium salt (ZH-6010, Huangshan Zhonghao), and 2 parts of acrylamide-acrylic acid copolymer (CAS 9003-06-9, Hubei Gaide Chemical).

[0046] On the other hand, embodiment 1 of the present invention provides a method for preparing high-strength quartz sand ceramic material, comprising the following steps: mixing the raw materials according to the above ratios.

[0047] (1) Preparation of modified fiber: Quartz fiber (domestic QF-300, average length 300 μm, average diameter 6 μm) and silicon carbide fiber (domestic SCS-6, average length 350 μm, average diameter 7 μm) were mixed in a mass ratio of 7:3, immersed in anhydrous ethanol, ultrasonically treated at 50°C (frequency 40 kHz, power 200 W) for 1 hour, vacuum-dried at 60°C for 2 hours, immersed in 30% HF acid solution, stirred for 0.6 hours, filtered, washed with water until neutral, and placed in an organic silicon coupling agent solution (KH-570, weight concentration 2%, solvent is anhydrous ethanol) for 2 hours, and vacuum-dried at 80°C for 3 hours to obtain the modified fiber;

[0048] (2) High-purity quartz sand (D50 = 8 μm, SiO2 purity of 99.9%) and a grain growth agent (Al2O3: ZrO2 = 2:1, average particle size of 0.5 μm) were added to anhydrous ethanol and ball-milled. The mixture was first coarsely ground with a 10 mm steel ball at 200 rpm for 6 h, and then finely ground with a 5 mm steel ball at 300 rpm for 6 h to obtain a 62 vol.% mixture slurry (D50 = 8.2 μm, CV = 5%).

[0049] (3) adding the modified fiber in step (1) to deionized water and ultrasonically treating it at a power of 300 W for 20 minutes to obtain an ammonia polyacrylic acid solution (0.5 wt.%), mixing it with an acrylamide-acrylic acid copolymer, and first coarse grinding it with an 8 mm steel ball at 200 rpm for 3 hours, and then fine grinding it with a 5 mm steel ball at 300 rpm for 3 hours to form a slurry;

[0050] (4) adding the mixture slurry in step (2) to step (3), placing the mixture slurry and the slurry in step (3) into a stirring kettle and stirring at 50 rpm for 3 h to mix evenly, and then vacuum impregnation (first 5 MPa pre-pressing for 5 min, then 180 MPa cold isostatic pressing for 10 min), demolding, and drying in sequence to obtain a quartz sand ceramic matrix;

[0051] (5) Gradient sintering of the quartz sand ceramic matrix in step (4):

[0052] The first stage: heating to 200℃ at a heating rate of 5℃ / min to remove volatile water;

[0053] The second stage: heating to 800℃ at a heating rate of 3℃ / min and keeping at that temperature for 3 hours;

[0054] The third stage: heating the material to 1250°C at a heating rate of 15°C / min and keeping the temperature for 3 hours to obtain quartz sand ceramic material.

[0055] Example 2

[0056] The difference between Example 2 and Example 1 is that no organosilicon coupling agent is added in step (1).

[0057] Example 3

[0058] The difference between Example 3 and Example 1 is that the mass ratio of quartz fiber to silicon carbide fiber is 4:1.

[0059] Example 4

[0060] The difference between Example 4 and Example 1 is that the mass ratio of quartz fiber to silicon carbide fiber is 3:2.

[0061] Example 5

[0062] The difference from Example 1 is that the mass ratio of Al2O3 to ZrO2 is 3:2

[0063] Example 6

[0064] The difference from Example 1 is that in step (5)

[0065] The first stage: heating to 200℃ at a heating rate of 10℃ / min to remove volatile water;

[0066] The second stage: heating to 800℃ at a heating rate of 3℃ / min and keeping at that temperature for 3 hours;

[0067] The third stage: heating the material to 1250°C at a heating rate of 15°C / min and keeping the temperature for 3 hours to obtain quartz sand ceramic material.

[0068] Example 7

[0069] The difference from Example 1 is that in step (5)

[0070] The first stage: heating to 200℃ at a heating rate of 5℃ / min to remove volatile water;

[0071] The second stage: heating to 500℃ at a heating rate of 3℃ / min and keeping it at that temperature for 3 hours;

[0072] The third stage: heating to 800°C at a heating rate of 15°C / min and keeping the temperature for 3 hours to obtain quartz sand ceramic material.

[0073] Example 8

[0074] The difference from Example 1 is that the mass ratio of quartz fiber to silicon carbide fiber is 5:1.

[0075] Comparative Example 1

[0076] A high-strength quartz sand ceramic material comprises the following raw materials, measured by weight: 85 parts of high-purity quartz sand (D50=8μm, SiO2 purity of 99.9%), 6 parts of quartz fiber, 1 part of composite powder of Al2O3 and ZrO2, 1 part of polycarboxylic acid ammonium salt, and 2 parts of acrylamide-acrylic acid copolymer.

[0077] On the other hand, embodiment 1 of the present invention provides a method for preparing a high-strength quartz sand ceramic material, comprising the following preparation steps:

[0078] (1) Preparation of quartz fiber: Quartz fiber (domestic QF-300, average length 300 μm, average diameter 6 μm) was immersed in anhydrous ethanol, ultrasonically treated (frequency 40 kHz, power 200 W) at 50°C for 1 hour, vacuum dried at 60°C for 2 hours, immersed in 30% HF acid solution, stirred for 0.6 hours, filtered, washed with water until neutral, and then placed in an organic silicon coupling agent solution (KH-570, weight concentration 2%, solvent is anhydrous ethanol) for 2 hours, and vacuum dried at 80°C for 3 hours to obtain modified quartz fiber;

[0079] (2) High-purity quartz sand (D50 = 8 μm, SiO2 purity of 99.9%) and a grain growth agent (Al2O3: ZrO2 = 2:1, particle size 0.5 μm) were ball-milled. The mixture was first coarsely ground with a 10 mm steel ball at 200 rpm for 6 h, and then finely ground with a 5 mm steel ball at 300 rpm for 6 h to obtain a 62 vol.% composite powder slurry (D50 = 8.2 μm, CV = 5%).

[0080] (3) adding the modified fiber in step (1) to deionized water and ultrasonically treating it at a power of 300 W for 20 minutes to obtain an ammonia polyacrylic acid solution (0.5 wt.%), mixing it with an acrylamide-acrylic acid copolymer, and first coarse grinding it with an 8 mm steel ball at 200 rpm for 3 hours, and then fine grinding it with a 5 mm steel ball at 300 rpm for 3 hours to form a slurry;

[0081] (4) adding the mixture slurry in step (2) to step (3), placing the mixture slurry and the slurry in step (3) into a stirring kettle and stirring at 50 rpm for 3 h to mix evenly, and then vacuum impregnation (first 5 MPa pre-pressing for 5 min, then 180 MPa cold isostatic pressing for 10 min), demolding, and drying in sequence to obtain a quartz sand ceramic matrix;

[0082] (5) Gradient sintering of the quartz sand ceramic matrix in step (4):

[0083] The first stage: heating to 200℃ at a heating rate of 5℃ / min to remove volatile water;

[0084] The second stage: heating to 800℃ at a heating rate of 3℃ / min and keeping at that temperature for 3 hours;

[0085] The third stage: heating the material to 1250°C at a heating rate of 15°C / min and keeping the temperature for 3 hours to obtain quartz sand ceramic material.

[0086] Comparative Example 2

[0087] The difference from Comparative Example 1 is that the quartz fiber is replaced by silicon carbide fiber (domestic SCS-6, average length 350 μm, average diameter 7 μm).

[0088] Comparative Example 3

[0089] The difference from Example 1 is that the grain growth agent is only ZrO2.

[0090] Comparative Example 4

[0091] The difference from Example 1 is that the grain growth agent is only Al2O3.

[0092] Comparative Example 5

[0093] The difference from implementation 1 is that in step (5), the quartz sand ceramic matrix in step (4) is sintered once: the temperature is raised to 1250° C. at a heating rate of 15° C. / min and kept at this temperature for 6 hours.

[0094] Comparative Example 6

[0095] The difference from Example 1 is that low-purity quartz sand is used, and the SiO2 content is 98%.

[0096] Performance testing:

[0097] The flexural strength was tested according to the ASTM C1161 standard; the dielectric constant and loss tangent were tested according to the ASTM D2520-95 standard; the fracture toughness was tested according to the ASTM E1820-21 standard; and the thermal shock stability was tested using the water quenching method according to the ASTM C1171-21 standard (heating to 1200°C, holding for 20 minutes, quickly quenching to room temperature to check for cracking, and cyclic testing until cracking occurs, and the number of cycles until cracking occurs is recorded). The test data are shown in Table 1.

[0098] Table 1 Performance test results of Examples 1-8 and Comparative Examples 1-6

[0099]

[0100] According to the experimental results of Example 1, the gradient ratio of quartz fiber and silicon carbide fiber and the synergy of nano-grains greatly improve the flexural strength and fracture toughness, and the Al2O3-ZrO2 solid solution inhibits grain growth, improves the interface performance of the material, and thus improves the thermal stability of the material; while in Comparative Example 1, due to the lack of high-temperature support of silicon carbide fiber, the strength drops sharply at high temperature, and cracking occurs only twice in the thermal shock cycle; Comparative Example 2 has low toughness due to the addition of only silicon carbide fiber; Example 8 has excessive quartz fiber content, and the flexural strength and fracture toughness are improved compared with Comparative Example 2, but the grain size grows, the interface performance decreases, and the dielectric constant and thermal stability are reduced; Comparative Example 3 has no ZrO2 synergy, resulting in grain coarsening; Comparative Example 4 has no Al2O3 synergy, the solid solution is not fully formed, and the dielectric properties deteriorate; Comparative Example 5 adopts one-time sintering, resulting in excessive porosity and reduced comprehensive performance; Comparative Example 6 uses low-purity quartz sand, which leads to grain boundary defects. In summary, the present invention creatively gradient-mixes quartz fiber and silicon carbide fiber, controls the ratio and dosage, and utilizes multi-stage ball milling, Al2O3-ZrO2 solid solution, and gradient sintering technology to achieve a leapfrog improvement in the performance of quartz sand ceramic materials.

[0101] The analytical methods involved in the present invention are described in detail. It should be noted that the above description is intended solely to help those skilled in the art better understand the methods and concepts of the present invention and is not intended to limit the relevant content. Those skilled in the art may make appropriate adjustments or modifications to the present invention without departing from the principles of the present invention, and such adjustments and modifications shall also fall within the scope of protection of the present invention.

Claims

1. A high-strength quartz sand ceramic material, characterized in that: The invention is made of the following raw materials in parts by weight: 85-90 parts of high-purity quartz sand, 5-8 parts of modified fiber, 1-3 parts of grain growth agent, 0.5-1.5 parts of dispersant, and 2-4 parts of binder; the modified fiber is a mixture of quartz fiber and silicon carbide fiber, and the grain growth agent is a composite powder of Al2O3 and ZrO2; the material is prepared by multi-stage ball milling dispersion, vacuum impregnation molding and gradient sintering process.

2. The quartz sand ceramic material according to claim 1, characterized in that The particle size D50 of the quartz sand is 5-10 μm, and the SiO2 purity is ≥99.9%.

3. The quartz sand ceramic material according to claim 1, characterized in that The mass ratio of the quartz fiber to the silicon carbide fiber in the modified fiber is 4:1-1.5:1, and the average aspect ratio of the modified fiber is ≥50:

1.

4. The quartz sand ceramic material according to claim 1, characterized in that The mass ratio of Al2O3 to ZrO2 in the grain growth agent is 2:1-3:2, and the particle size is ≤1 μm.

5. The high-strength quartz sand ceramic material according to claim 1, characterized in that: The dispersant is polycarboxylate ammonium salt with an HLB value of 12-15.

6. The quartz sand ceramic material according to claim 1, characterized in that The binder is acrylamide-acrylic acid copolymer.

7. The method for preparing the quartz sand ceramic material according to any one of claims 1 to 6, characterized in that: The steps include: (1) Preparation of modified fiber: quartz fiber and silicon carbide fiber were mixed, immersed in ethanol for ultrasonic treatment, dried, immersed in HF acid solution, stirred for reaction, filtered, washed with water, and dried to obtain modified fiber; (2) mixing quartz sand and a grain growth agent to obtain a mixture; (3) adding the modified fiber and the dispersant into water, mixing with the binder after ultrasonic treatment and ball milling to form a slurry; (4) adding the mixture of step (2) to the slurry of step (3), mixing, impregnating, and drying to obtain a quartz sand ceramic matrix; (5) Gradient sintering the quartz sand ceramic matrix to obtain the quartz sand ceramic material.

8. The preparation method according to claim 7, characterized in that (1) Preparation of modified fiber: quartz fiber and silicon carbide fiber are mixed in a mass ratio of 4:1-1.5:1, immersed in anhydrous ethanol, ultrasonically treated at 50-60°C for 1-2 hours, vacuum dried, immersed in 30-60% HF acid solution, stirred for reaction for 0.5-1 hour, filtered, washed with water until neutral, and then dried to obtain the modified fiber; and / or, in (2), adding quartz sand and a grain growth agent into a solvent and ball milling and mixing them to obtain a mixture slurry; and / or, in (3), the modified fiber and dispersant in step (1) are added to deionized water, ultrasonically treated, mixed with a binder, and subjected to multi-stage ball milling to form a high solid content slurry; and / or, in (4), adding the mixture in step (2) to step (3), mixing them uniformly, and then vacuum impregnating and drying them in sequence to obtain a quartz sand ceramic matrix; And / or, in (5), the quartz sand ceramic matrix in step (4) is subjected to gradient sintering: the first stage: heating to 50-200°C at a heating rate of 5-10°C / min to remove volatile water; the second stage: heating to 200-800°C at a heating rate of 3-5°C / min and keeping warm for 1-5 hours; the third stage: heating to 800-1250°C at a heating rate of 10-15°C / min and keeping warm for 1.5-5 hours to obtain the quartz sand ceramic material.

9. The preparation method according to claim 7, characterized in that Preparation of the modified fiber in step (1): quartz fiber and silicon carbide fiber are mixed in a mass ratio of 4:1-1.5:1, immersed in anhydrous ethanol, ultrasonically treated at 50-60°C for 1-2 hours, vacuum dried, immersed in 30-60% HF acid solution, stirred for reaction for 0.5-1 hour, filtered, washed with water until neutral, and then dried, and then placed in an organic silicon coupling agent solution, allowed to stand, and vacuum dried to obtain the modified fiber. And / or, the multi-stage ball milling time in step (3) is 6-12 hours, and the multi-stage ball milling includes coarse grinding and fine grinding, the coarse grinding process uses steel balls with a diameter of 10-15 mm for particle crushing, and the fine grinding process uses 3-5 mm steel balls for particle refinement.

10. Application of the quartz sand ceramic material according to any one of claims 1 to 6 or the quartz sand ceramic material prepared by the preparation method according to any one of claims 7 to 9 in the fields of construction, machinery, and aviation.

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