Preparation method of low-cost and high-efficiency alumina fiber reinforced alumina composite material
阅读说明：本技术 一种低成本、高效氧化铝纤维增强氧化铝复合材料制备方法 (Preparation method of low-cost and high-efficiency alumina fiber reinforced alumina composite material ) 是由 刘海韬 姜如 黄文质 于 2019-10-25 设计创作，主要内容包括：本发明涉及连续纤维增强陶瓷基复合材料制备技术领域,具体公开了一种低成本、高效氧化铝纤维增强氧化铝复合材料制备方法。该方法的具体步骤是,首先配制稳定的氧化铝浆料,然后将氧化铝浆料刷涂在去胶后的氧化铝纤维布上,经模压后成型,经干燥后得到氧化铝纤维增强氧化铝复合材料粗坯,最后经过烧结得到氧化铝纤维增强氧化铝复合材料。本发明提供的制备方法具有工艺简单、制备周期短的特点,制备得到的氧化铝纤维增强氧化铝复合材料具有优异的高温力学性能和热稳定性能。(The invention relates to the technical field of preparation of continuous fiber reinforced ceramic matrix composites, and particularly discloses a preparation method of a low-cost and high-efficiency alumina fiber reinforced alumina composite. The method comprises the specific steps of firstly preparing stable alumina slurry, then brushing the alumina slurry on the alumina fiber cloth after removing the glue, molding after mould pressing, drying to obtain an alumina fiber reinforced alumina composite material rough blank, and finally sintering to obtain the alumina fiber reinforced alumina composite material. The preparation method provided by the invention has the characteristics of simple process and short preparation period, and the prepared alumina fiber reinforced alumina composite material has excellent high-temperature mechanical property and thermal stability.)
1. A preparation method of a low-cost and high-efficiency alumina fiber reinforced alumina composite material is characterized by comprising the following steps:
(1) dispersing alumina powder into deionized water, adding an acidic solution or an alkaline solution to regulate the viscosity and the Zeta potential value of the slurry, and performing ball milling to obtain stable alumina slurry;
(2) cutting the alumina fiber cloth into a specification size, and then removing glue from the alumina fiber cloth;
(3) laying the alumina fiber cloth obtained in the step (2) in a mould, uniformly coating the alumina slurry obtained in the step (1) on the surface of each layer of alumina fiber cloth, carrying out mould closing and mould pressing, forming, and then drying to obtain an alumina fiber reinforced alumina composite material rough blank;
(4) and (4) performing primary sintering on the composite material rough blank obtained in the step (3), cooling along with a furnace, demolding, and then performing high-temperature sintering to obtain the alumina fiber reinforced alumina composite material.
2. The process of claim 1, wherein the alumina slurry has an alumina solids content of 45vol% ~ 60vol%, a viscosity of 80mPa marked as s ~ 400mPa marked as s, and a Zeta potential of 45mV ~ 75mV or-50 mV ~ mV-30 mV.
3. The method according to claim 1, wherein the acidic solution is nitric acid or hydrochloric acid, and the basic solution is aqueous ammonia.
4. The preparation method according to claim 1, wherein in the step (1), the average particle size of the alumina powder is 0.1 μm ~ 0.4.4 μm, the ball milling speed is 300 r/min ~ 500 r/min, and the ball milling time is 2h ~ 4 h.
5. The preparation method according to claim 1, wherein the step (2) of removing the photoresist comprises the steps of placing the alumina fiber cloth in a muffle furnace, heating the alumina fiber cloth in air to 600 ℃ ~ 700 ℃ for 700 ℃, keeping the temperature for 1h ~ 3h, cooling the alumina fiber cloth with the furnace to room temperature, and taking out the alumina fiber cloth.
6. The preparation method according to claim 1, wherein in the step (3), the drying process comprises heating to 90 ℃ and ~ 120 ℃ in air and keeping the temperature for 2h and ~ 4 h.
7. The preparation method according to claim 1, wherein in the step (4), the primary sintering process comprises the steps of putting the composite material rough blank obtained in the step (3) into a muffle furnace, raising the temperature to 700 ℃ ~ 900 ℃ and 900 ℃ at a heating rate of 5 ℃ per minute ~ 10 ℃ per minute in the air, preserving the temperature for 0.5h ~ 2h, and naturally cooling to room temperature, and the high-temperature sintering process comprises the steps of putting the composite material rough blank obtained after the primary sintering and demolding into the muffle furnace, raising the temperature to 1100 ℃ ~ 1300 ℃ at a heating rate of 5 ℃ per minute ~ 10 ℃ per minute in the air, preserving the temperature for 0.5h ~ 2h, and naturally cooling to room temperature.
8. The method of claim 1, wherein the alumina fiber reinforced alumina composite has a fiber volume fraction of 40% ~ 60%.
Technical Field
The invention belongs to the technical field of preparation of continuous fiber reinforced ceramic matrix composite materials, and particularly relates to a preparation method of a low-cost and high-efficiency alumina fiber reinforced alumina composite material.
Background
Continuous alumina fiber reinforced alumina composite (Al)2O3/Al2O3Composite material) has excellent characteristics of high temperature resistance, oxidation resistance, high strength, high toughness, corrosion resistance, abrasion resistance and the like, and is an important candidate material for high-temperature parts of equipment such as future aircraft engines and the like. However, limited by the mechanical properties of alumina fibers and the preparation level of composite materials, Al is currently available in China2O3/Al2O3The mechanical properties of the composite materials are generally lower than those of non-oxide composite materials, such as C/SiC and SiC/SiC composite materials, which greatly limits Al2O3/Al2O3The engineering application of the composite material cannot fully embody the advantage of high-temperature oxidation resistance of the composite material. To further develop Al2O3/Al2O3Application potential of composite material, stress improvement of Al2O3/Al2O3Mechanical properties of the composite material.
For example, chinese patent publication No. CN105254320A discloses a method for preparing a continuous alumina fiber reinforced alumina ceramic matrix composite, which comprises preparing an interface phase on the surface of a fiber by PIP process, preparing a porous alumina matrix blank skeleton by freeze-drying process, repeatedly impregnating the porous alumina matrix blank skeleton with an alumina inorganic precursor to obtain a dense matrix blank, and finally sintering to obtain a high-performance composite. Chinese patent publication No. CN106904952A discloses a high temperature resistant and high strength alumina fiber reinforced composite material and a preparation method thereof, wherein a continuous alumina fiber preform is impregnated with a double nano composite impregnation solution in which silica and alumina are uniformly mixed, and the alumina fiber reinforced oxide composite material is finally obtained through steps of vacuum pressure impregnation, high temperature heat treatment and the like. The tensile strength of the composite material at room temperature is 300MPa, but the tensile strength of the composite material is obviously reduced at high temperature due to the silicon oxide contained in the matrix component, the tensile strength is reduced to 135MPa at 1100 ℃, and the tensile strength is reduced to 90MPa at 1200 ℃.
The two alumina fiber reinforced oxide composite materials disclosed above have excellent normal temperature mechanical properties, but still have the following disadvantages: 1) in the preparation process, an organic precursor solution is introduced into a matrix, and the organic precursor solution faces complicated chemical processes in the drying and high-temperature heat treatment processes and is easy to damage fibers; 2) the preparation period is long, the thermal damage of the alumina fiber is easily aggravated by repeated dipping-high temperature heat treatment, and the mechanical property of the composite material is not favorably improved.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide the preparation method of the alumina fiber reinforced alumina composite material, which has the advantages of simple process, low cost, short preparation period and stable quality and is suitable for batch and large-scale production.
In order to realize the aim, the invention provides a preparation method of a low-cost and high-efficiency alumina fiber reinforced alumina composite material, which comprises the following steps:
(1) dispersing alumina powder into deionized water, adding an acidic solution or an alkaline solution to regulate the viscosity and the Zeta potential value of the slurry, and performing ball milling to obtain stable alumina slurry;
(2) cutting the alumina fiber cloth into a specification size, and then removing glue from the alumina fiber cloth;
(3) laying the alumina fiber cloth obtained in the step (2) in a mould, uniformly coating the alumina slurry obtained in the step (1) on the surface of each layer of alumina fiber cloth, carrying out mould closing and mould pressing, forming, and then drying to obtain an alumina fiber reinforced alumina composite material rough blank;
(4) and (4) performing primary sintering on the composite material rough blank obtained in the step (3), cooling along with a furnace, demolding, and then performing high-temperature sintering to obtain the alumina fiber reinforced alumina composite material.
Preferably, in the above preparation method, the alumina solid content in the alumina slurry is 45vol% to 60vol%, the viscosity of the alumina slurry is 80mPa · s to 400mPa · s, and the Zeta potential of the alumina slurry is 45mV to 75mV or-50 mV to-30 mV. The solid content of the alumina slurry is favorable for improving the yield of slurry ceramics, reducing volume shrinkage and matrix cracks, the proper viscosity is favorable for slurry brush coating, the proper Zeta potential is regulated and controlled, the powder in the slurry is uniformly distributed and is not easy to settle, and the slurry stability is good.
Preferably, in the above preparation method, the acidic solution is nitric acid or hydrochloric acid, and the basic solution is ammonia water.
Preferably, in the preparation method, in the step (1), the average particle size of the alumina powder is 0.1 to 0.4 μm, the ball milling speed is 300 to 500 revolutions per minute, and the ball milling time is 2 to 4 hours.
Preferably, in the above preparation method, the step (2) of removing the photoresist specifically comprises: placing the alumina fiber cloth in a muffle furnace, heating the alumina fiber cloth to 600-700 ℃ in the air, preserving the heat for 1-3 h, cooling the alumina fiber cloth along with the furnace to room temperature, and taking out the alumina fiber cloth.
Preferably, in the above preparation method, in the step (3), the drying process is: heating to 90-120 ℃ in the air, and keeping the temperature for 2-4 h.
Preferably, in the above preparation method, in the step (4), the primary sintering process is: al obtained in the step (3)2O3/Al2O3Putting the composite material rough blank into a muffle furnace, heating to 700-900 ℃ at a heating rate of 5-10 ℃/min in the air, preserving the heat for 0.5-2 h, and naturally cooling to room temperature; the high-temperature sintering process comprises the following steps: the Al obtained by demoulding after primary sintering2O3/Al2O3Putting the composite material rough blank into a muffle furnace, heating to 1100-1300 ℃ in air at a heating rate of 5-10 ℃/min, preserving the heat for 0.5-2 h, and naturally cooling to room temperature.
Preferably, in the above preparation method, the volume fraction of the fibers in the alumina fiber reinforced alumina composite material is 40% to 60%.
Compared with the prior art, the invention has the following beneficial effects:
1. the alumina slurry only contains deionized water and alumina powder, and only has a physical process of sintering and compacting alumina powder in the drying-high-temperature heat treatment process, and no other chemical reaction exists, so that the chemical damage of alumina fibers is reduced, and the excellent mechanical property of the alumina fibers is ensured; in addition, other chemical solvents are not adopted in the process of preparing the slurry, and the slurry has the characteristic of good environmental protection.
2. The preparation method is suitable for preparing the two-dimensional fiber cloth reinforced Al2O3/Al2O3The composite material has short preparation period, does not need repeated high-temperature heat treatment, reduces the heat damage to the alumina fiber, has high mechanical property, and improves the interlaminar shear strength of the composite material on the basis of ensuring the excellent bending strength of the composite material; al prepared by the method2O3/Al2O3The mechanical property of the composite material is stable at high temperature and after long-term thermal examination at high temperature, and the composite material has excellent high-temperature mechanical property and thermal stability.
3. The preparation method has the advantages of simple process, short preparation period, simple equipment conditions, cost saving and contribution to batch and large-scale production. The method also has the advantage of near net shape, and is beneficial to preparing components with complex shapes.
Drawings
FIG. 1 is a photograph showing an optical photograph of an alumina fiber-reinforced alumina composite in example 1 of the present invention.
FIG. 2 is a cross-sectional view of an alumina fiber reinforced alumina composite in example 1 of the present invention.
FIG. 3 is a typical load-displacement curve for an alumina fiber reinforced alumina composite of example 1 of the present invention.
FIG. 4 is a microstructure diagram of a fracture of an alumina fiber reinforced alumina composite in example 1 of the present invention.
Detailed Description
The following detailed description of specific embodiments of the invention is provided, but it should be understood that the scope of the invention is not limited to the specific embodiments. Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention. Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.