[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

CN110981528B - Directional porous aluminum nitride ceramic and rapid preparation method thereof - Google Patents

Directional porous aluminum nitride ceramic and rapid preparation method thereof Download PDF

Info

Publication number
CN110981528B
CN110981528B CN201911243222.5A CN201911243222A CN110981528B CN 110981528 B CN110981528 B CN 110981528B CN 201911243222 A CN201911243222 A CN 201911243222A CN 110981528 B CN110981528 B CN 110981528B
Authority
CN
China
Prior art keywords
aluminum nitride
porous aluminum
powder
nitride ceramic
ceramic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201911243222.5A
Other languages
Chinese (zh)
Other versions
CN110981528A (en
Inventor
史忠旗
魏智磊
袁媛
谢文琦
张哲健
夏鸿雁
王波
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xianyang Gazelle Valley New Material Technology Co ltd
Original Assignee
Xian Jiaotong University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xian Jiaotong University filed Critical Xian Jiaotong University
Priority to CN201911243222.5A priority Critical patent/CN110981528B/en
Publication of CN110981528A publication Critical patent/CN110981528A/en
Application granted granted Critical
Publication of CN110981528B publication Critical patent/CN110981528B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/581Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on aluminium nitride
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632Organic additives
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64Burning or sintering processes
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • C04B38/0006Honeycomb structures
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • C04B38/0051Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof characterised by the pore size, pore shape or kind of porosity
    • C04B38/0054Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof characterised by the pore size, pore shape or kind of porosity the pores being microsized or nanosized
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3224Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
    • C04B2235/3225Yttrium oxide or oxide-forming salts thereof
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30Constituents and secondary phases not being of a fibrous nature
    • C04B2235/44Metal salt constituents or additives chosen for the nature of the anions, e.g. hydrides or acetylacetonate
    • C04B2235/444Halide containing anions, e.g. bromide, iodate, chlorite
    • C04B2235/445Fluoride containing anions, e.g. fluosilicate
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/66Specific sintering techniques, e.g. centrifugal sintering
    • C04B2235/666Applying a current during sintering, e.g. plasma sintering [SPS], electrical resistance heating or pulse electric current sintering [PECS]

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Ceramic Products (AREA)

Abstract

本发明公开了一种定向多孔氮化铝陶瓷及其快速制备方法,采用叔丁醇为溶剂,柠檬酸为分散剂对氮化铝粉和烧结助剂进行冷冻干燥,并将干燥后的生坯放入放电等离子烧结炉中进行无压快速烧结后,可以得到气孔率和抗压强度较高的定向多孔氮化铝陶瓷。本发明制备定向多孔氮化铝陶瓷的方法具有工艺简单、周期短、重复性好、成本低等特点。制备出的定向多孔氮化铝陶瓷在金属过滤、催化剂载体、聚合物增强相、汽车工业、太阳能发电等领域具有广泛的应用前景。

Figure 201911243222

The invention discloses a directional porous aluminum nitride ceramic and a rapid preparation method thereof. The aluminum nitride powder and a sintering aid are freeze-dried by using tert-butanol as a solvent and citric acid as a dispersant, and the dried green body is dried. After being placed in a spark plasma sintering furnace for pressureless rapid sintering, the oriented porous aluminum nitride ceramics with high porosity and compressive strength can be obtained. The method for preparing the oriented porous aluminum nitride ceramics of the invention has the characteristics of simple process, short period, good repeatability, low cost and the like. The prepared oriented porous aluminum nitride ceramics have broad application prospects in the fields of metal filtration, catalyst carrier, polymer reinforcement phase, automobile industry, solar power generation and so on.

Figure 201911243222

Description

Directional porous aluminum nitride ceramic and rapid preparation method thereof
Technical Field
The invention belongs to the technical field of preparation of inorganic non-metallic materials, and relates to directional porous aluminum nitride ceramic and a rapid preparation method thereof.
Background
The porous AlN ceramic has a series of excellent characteristics of high thermal conductivity, low thermal expansion coefficient, excellent mechanical property, high chemical stability and the like, so the porous AlN ceramic is widely applied to the fields of molten metal filtration, catalyst carriers, polymer reinforced phases, heat exchange components and the like. The key to improving the thermal physical property and the mechanical property of the porous AlN ceramic is to regulate and control the relationship among the porosity, the pore morphology and the pore structure.
At present, the method for preparing the porous ceramic mainly comprises the following steps: organic foam impregnation, foaming, sol-gel, extrusion, and the like. However, these methods have problems of high energy consumption, long preparation period, low strength, uncontrollable pore structure, etc. For example, the preparation method of the porous aluminum nitride ceramic material disclosed in the patent publication No. CN105503236B requires not only many high-temperature sintering processes but also a complicated preparation process, which results in high energy consumption and long preparation period. The invention patent with publication number CN105489714B 'a porous AlN composite substrate and application thereof in epitaxial growth of high-quality gallium nitride films', the porous AlN layer is grown on the substrate by an MOCVD system, and the defects of complex preparation process, low yield of porous AlN ceramics, difficult control of pore structure and the like exist.
Disclosure of Invention
The invention aims to provide a directional porous aluminum nitride ceramic and a rapid preparation method thereof, which can overcome the defects of long preparation period, low production efficiency, difficult control of a pore structure and the like of the porous AlN ceramic prepared by the traditional method.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
the invention discloses a directional porous aluminum nitride ceramic and a rapid preparation method thereof, which comprises the following steps:
1) taking aluminum nitride powder, yttrium oxide powder, calcium fluoride powder and citric acid as raw materials, taking tert-butyl alcohol as a solvent, and fully and uniformly mixing to prepare slurry;
2) freezing the slurry, and then carrying out vacuum freeze drying to obtain a green body;
3) and placing the green body in a discharge plasma pressureless rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1100-1400 ℃ from room temperature at the heating rate of 100-300 ℃/min, preserving the temperature for 3-7min, stopping heating, naturally cooling the temperature in the furnace to below 100 ℃, and taking out a white block in the furnace, namely the directional porous aluminum nitride ceramic.
Preferably, in step 1), the aluminum nitride powder and the tert-butyl alcohol are mixed according to the following volume percentages: 10% -35%: 65-90 percent of the total weight of the aluminum nitride powder, 1-3 percent of the weight of yttrium oxide powder, 3-5 percent of the weight of calcium fluoride powder and 1-5 percent of the weight of aluminum nitride powder.
Preferably, in the step 1), aluminum nitride powder, yttrium oxide powder, calcium fluoride powder, citric acid and tert-butyl alcohol are placed into a ball milling tank for mixing, the ball milling time is 2-12 hours, the material-ball ratio is 4:1, and the rotating speed is 400 r/min.
Preferably, in the step 2), the freezing temperature is-100 to-25 ℃, and the vacuum freeze-drying temperature is-100 to-20 ℃.
Preferably, in step 2), the slurry is poured into a cylindrical silicon rubber mold for freezing, and the bottom of the silicon rubber mold is a copper column partially immersed in liquid nitrogen.
The invention discloses oriented porous aluminum nitride ceramic prepared by the rapid preparation method, which is of a honeycomb structure, wherein the pore diameter of a honeycomb is 12-50 mu m, the wall thickness is 10-20 mu m, the porosity is 60-87%, and the compressive strength is 0.1-10 MPa.
Compared with the prior art, the invention has the following beneficial effects:
the invention adopts a method combining freeze drying and spark plasma non-pressure sintering (SPS) to rapidly prepare the oriented porous AlN ceramic, adopts tert-butyl alcohol as a freeze drying solvent, citric acid as a dispersing agent and yttrium oxide and calcium fluoride as sintering aids, uniformly mixes the four raw materials and AlN powder by ball milling, performs freeze drying, and puts a dried sample into an SPS rapid sintering furnace for rapid sintering under a vacuum condition to prepare the oriented porous AlN ceramic. Compared with the traditional preparation process, the preparation method has the advantages of low energy consumption, short preparation period, controllable pore structure and the like, does not need high-energy-consumption processes such as high-temperature long-time heat preservation and the like, and can effectively improve the strength and the production efficiency of the porous AlN ceramic.
The directional porous AlN ceramic prepared by the method has uniform internal pore structure, controllable appearance and high repeatability, and has wide application prospect in the fields of metal filtration, catalyst carriers, polymer reinforced phases, automobile industry, solar power generation and the like.
Drawings
FIG. 1 is a schematic view of a freeze-drying process;
FIG. 2 is a schematic view of a discharge plasma pressureless rapid sintering apparatus;
FIG. 3 is an XRD pattern of an oriented porous AlN ceramic;
FIG. 4 is an SEM image of an oriented porous AlN ceramic; wherein, (a) is an SEM image parallel to the freezing direction, and (b) is an SEM image perpendicular to the freezing direction.
Wherein: 1-slurry; 2-a silicon rubber mold; 3-copper columns; 4-green body; 5-oriented porous AlN ceramic; 6-graphite cushion blocks; 7-pressure head; 8-graphite mold; 9-sample; 10-electrode.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, which is a freeze-drying process diagram in the rapid preparation method of the directional porous aluminum nitride ceramic disclosed by the invention, after raw materials are prepared into slurry, the uniformly mixed slurry 1 is poured into a cylindrical silicon rubber mold 2 for freezing, the bottom of the mold is a copper column 3 partially immersed in liquid nitrogen, a frozen sample is placed in a freeze dryer for vacuum freeze-drying, a green blank 4 is obtained, and the directional porous aluminum nitride ceramic 5 is obtained through sintering treatment. Referring to fig. 2, which is a schematic view of a discharge plasma pressureless rapid sintering furnace (SPS) used in the process of the present invention, in the figure, 6 is a graphite pad, 7-pressure head; 8-graphite mold; 9-sample; 10-electrode. Example 1
Mixing AlN powder 18g, yttrium oxide powder 0.18g, calcium fluoride powder 0.72g, citric acid 0.9g and 50mL of tert-butyl alcohol, and putting the mixture into a sealed alumina ball milling tank for ball milling for 4 hours, wherein the ball-material ratio is 4:1, the rotating speed is 400 r/min. Then, the slurry after ball milling is poured into a silicon rubber mold for freezing, the bottom of the mold is a copper column precooled in liquid nitrogen, the freezing temperature is controlled at-25 ℃, and the frozen sample is placed in a freeze dryer for vacuum freeze drying at-50 ℃. And finally, placing the dried green body into an SPS rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1250 ℃ from room temperature at the heating rate of 200 ℃/min, preserving the temperature for 5min, stopping heating, and taking out a sample after the temperature in the furnace is naturally cooled to be below 100 ℃ to obtain the oriented porous AlN ceramic with the compressive strength of 0.1 MPa.
The resulting product was characterized by X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM). FIG. 3 is an XRD spectrum of a product containing hexagonal AlN phase as a main component, a sintering aid and Al2O3CaAl produced by the reaction12O19、Ca3Al12O6、CaAlF5And Y3Al5O12And waiting for the second phase. FIG. 4 is an FESEM photograph of the product, and it can be found that the oriented porous AlN ceramic has a honeycomb structure, has oriented pores vertically arranged inside, a porosity of 87%, a honeycomb pore diameter of 50 μm, and a wall thickness of 10 μm.
Example 2
30g of AlN powder, 0.6g of yttrium oxide powder, 1.5g of calcium fluoride powder, 0.9g of citric acid and 50mL of tert-butyl alcohol are mixed and then put into a sealed alumina ball-milling tank for ball-milling for 2 hours, wherein the ball-material ratio is 4:1, the rotating speed is 400 r/min. Then, the slurry after ball milling is poured into a silicon rubber mold for freezing, the bottom of the mold is a copper column precooled in liquid nitrogen, the freezing temperature is controlled at-100 ℃, and the frozen sample is placed in a freeze dryer for vacuum freeze drying at-50 ℃. And finally, placing the dried green body into an SPS rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1200 ℃ from room temperature at the heating rate of 150 ℃/min, preserving the temperature for 3min, stopping heating, and taking out a sample after the temperature in the furnace is naturally cooled to be below 100 ℃ to obtain the oriented porous AlN ceramic with the compressive strength of 0.2 MPa.
The resulting product was characterized by X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM). It can be found that the oriented porous AlN ceramic has a honeycomb structure, has oriented pores vertically arranged inside, has a porosity of 82%, a honeycomb pore diameter of 35 μm and a wall thickness of 12 μm. Other results were the same as in example 1.
Example 3
Mixing 40g of AlN powder, 1.2g of yttrium oxide powder, 1.2g of calcium fluoride powder, 0.8g of citric acid and 50mL of tert-butyl alcohol, and putting the mixture into a sealed alumina ball milling tank for ball milling for 6 hours, wherein the ball-material ratio is 4:1, the rotating speed is 400 r/min. Then, the slurry after ball milling is poured into a silicon rubber mold for freezing, the bottom of the mold is a copper column precooled in liquid nitrogen, the freezing temperature is controlled at minus 50 ℃, and the frozen sample is placed in a freeze dryer for vacuum freeze drying at minus 20 ℃. And finally, placing the dried green body into an SPS rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1200 ℃ from room temperature at the heating rate of 100 ℃/min, keeping the temperature for 6min, stopping heating, and taking out a sample after the temperature in the furnace is naturally cooled to be below 100 ℃ to obtain the oriented porous AlN ceramic with the compressive strength of 1.5 MPa.
The resulting product was characterized by X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM). It was found that the oriented porous AlN ceramic had a honeycomb structure with oriented pores vertically arranged inside, a porosity of 75%, a honeycomb pore diameter of 25 μm and a wall thickness of 14 μm. Other results were the same as in example 1.
Example 4
55g of AlN powder, 0.55g of yttrium oxide powder, 2.2g of calcium fluoride powder, 1.1g of citric acid and 50mL of tert-butyl alcohol are mixed and then put into a sealed alumina ball-milling tank for ball-milling for 10 hours, wherein the ball-material ratio is 4:1, the rotating speed is 400 r/min. Then, the slurry after ball milling is poured into a silicon rubber mold for freezing, the bottom of the mold is a copper column precooled in liquid nitrogen, the freezing temperature is controlled to be-75 ℃, and the frozen sample is placed in a freeze dryer for vacuum freeze drying at-100 ℃. And finally, placing the dried green body into an SPS rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1400 ℃ from room temperature at the heating rate of 300 ℃/min, keeping the temperature for 3min, stopping heating, and taking out a sample after the temperature in the furnace is naturally cooled to be below 100 ℃ to obtain the directional porous AlN ceramic with the compressive strength of 4 MPa.
The resulting product was characterized by X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM). It can be found that the directional porous AlN ceramic has a honeycomb structure, the interior of the ceramic is vertically arranged directional holes, the porosity is 70%, the pore diameter of the honeycomb is 18 μm, and the wall thickness is 16 μm. Other results were the same as in example 1.
Example 5
70g of AlN powder, 1.05g of yttrium oxide powder, 2.45g of calcium fluoride powder, 1.4g of citric acid and 50mL of tert-butyl alcohol are mixed and then put into a sealed alumina ball-milling tank for ball-milling for 8 hours, wherein the ball-material ratio is 4:1, the rotating speed is 400 r/min. Then, the slurry after ball milling is poured into a silicon rubber mold for freezing, the bottom of the mold is a copper column precooled in liquid nitrogen, the freezing temperature is controlled at-100 ℃, and the frozen sample is placed in a freeze dryer for vacuum freeze drying at-75 ℃. And finally, placing the dried green body into an SPS rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1300 ℃ from room temperature at the heating rate of 250 ℃/min, preserving the temperature for 4min, stopping heating, and taking out a sample after the temperature in the furnace is naturally cooled to be below 100 ℃ to obtain the directional porous AlN ceramic with the compressive strength of 6 MPa.
The resulting product was characterized by X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM). It can be found that the directional porous AlN ceramic has a honeycomb structure, the interior of the ceramic is provided with directional holes which are vertically arranged, the porosity is 65%, the pore diameter of the honeycomb is 14 μm, and the wall thickness is 18 μm. Other results were the same as in example 1.
Example 6
Mixing 88g of AlN powder, 2.64g of yttrium oxide powder, 4.4g of calcium fluoride powder, 0.88g of citric acid and 50mL of tert-butyl alcohol, and putting the mixture into a sealed alumina ball-milling tank for ball milling for 12 hours, wherein the ball-material ratio is 4:1, the rotating speed is 400 r/min. Then, the slurry after ball milling is poured into a silicon rubber mold for freezing, the bottom of the mold is a copper column precooled in liquid nitrogen, the freezing temperature is controlled to be-75 ℃, and the frozen sample is placed in a freeze dryer for vacuum freeze drying at-50 ℃. And finally, placing the dried green body into an SPS rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1100 ℃ from room temperature at the heating rate of 150 ℃/min, keeping the temperature for 7min, stopping heating, and taking out a sample after the temperature in the furnace is naturally cooled to be below 100 ℃ to obtain the oriented porous AlN ceramic with the compressive strength of 10 MPa.
The resulting product was characterized by X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM). It can be found that the oriented porous AlN ceramic has a honeycomb structure, the interior of the AlN ceramic is provided with oriented pores which are vertically arranged, the porosity is 60%, the pore diameter of the honeycomb is 12 mu m, and the wall thickness is 20 mu m. Other results were the same as in example 1.
In conclusion, the method adopts tert-butyl alcohol as a solvent and citric acid as a dispersing agent to freeze-dry the aluminum nitride powder and the sintering aid, and the dried green body is placed into a discharge plasma sintering furnace to be rapidly sintered under no pressure, so that the oriented porous aluminum nitride ceramic with high porosity and compressive strength can be obtained. The method for preparing the directional porous aluminum nitride ceramic has the characteristics of simple process, short period, good repeatability, low cost and the like. The prepared directional porous aluminum nitride ceramic has wide application prospect in the fields of metal filtration, catalyst carriers, polymer reinforced phases, automobile industry, solar power generation and the like.
The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims (3)

1. A rapid preparation method of directional porous aluminum nitride ceramics is characterized by comprising the following steps:
1) taking aluminum nitride powder, yttrium oxide powder, calcium fluoride powder and citric acid as raw materials, taking tert-butyl alcohol as a solvent, and fully and uniformly mixing to prepare slurry;
wherein the aluminum nitride powder and the tertiary butanol are mixed according to the following volume percentage: 10% -35%: 65-90 percent of the total weight of the aluminum nitride powder, 1-3 percent of yttrium oxide powder, 3-5 percent of calcium fluoride powder and 1-5 percent of citric acid;
fully mixing the aluminum nitride powder, the yttrium oxide powder, the calcium fluoride powder, the citric acid and the tertiary butanol in a ball milling tank for 2-12 hours at a material-ball ratio of 4:1 and a rotation speed of 400 r/min;
2) freezing the slurry, and then carrying out vacuum freeze drying to obtain a green body;
wherein the freezing temperature is-100 to-25 ℃, and the vacuum freeze drying temperature is-100 to-20 ℃;
3) placing the green body in a discharge plasma pressureless rapid sintering furnace, vacuumizing until the air pressure is less than 10Pa, heating to 1100-1400 ℃ from room temperature at the heating rate of 100-300 ℃/min, preserving the heat for 3-7min, stopping heating, naturally cooling the temperature in the furnace to be below 100 ℃, and taking out a white block in the furnace to be directional porous aluminum nitride ceramic, wherein the directional porous aluminum nitride ceramic is of a honeycomb structure, the pore diameter of the honeycomb is 12-50 mu m, the wall thickness is 10-20 mu m, the porosity is 60-87%, and the compressive strength is 0.1-10 MPa.
2. The rapid preparation method of directional porous aluminum nitride ceramic according to claim 1, wherein in step 2), the slurry is poured into a cylindrical silicon rubber mold for freezing, and the bottom of the silicon rubber mold is a copper column partially immersed in liquid nitrogen.
3. The oriented porous aluminum nitride ceramic prepared by the rapid preparation method according to any one of claims 1 to 2 is characterized in that the oriented porous aluminum nitride ceramic is of a honeycomb structure, the honeycomb pore diameter is 12-50 μm, the wall thickness is 10-20 μm, the porosity is 60-87%, and the compressive strength is 0.1-10 MPa.
CN201911243222.5A 2019-12-06 2019-12-06 Directional porous aluminum nitride ceramic and rapid preparation method thereof Active CN110981528B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911243222.5A CN110981528B (en) 2019-12-06 2019-12-06 Directional porous aluminum nitride ceramic and rapid preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911243222.5A CN110981528B (en) 2019-12-06 2019-12-06 Directional porous aluminum nitride ceramic and rapid preparation method thereof

Publications (2)

Publication Number Publication Date
CN110981528A CN110981528A (en) 2020-04-10
CN110981528B true CN110981528B (en) 2021-02-26

Family

ID=70091003

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911243222.5A Active CN110981528B (en) 2019-12-06 2019-12-06 Directional porous aluminum nitride ceramic and rapid preparation method thereof

Country Status (1)

Country Link
CN (1) CN110981528B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111807842B (en) * 2020-07-07 2021-09-21 山东大学 Porous silicon carbide ceramic material and preparation method thereof
CN111908906A (en) * 2020-07-20 2020-11-10 中国科学院上海硅酸盐研究所 High-porosity porous fused quartz with oriented pore structure and preparation method thereof
CN113480828B (en) * 2021-03-02 2022-06-14 海南大学 Aluminum nitride nanoflower/polymer composite material and preparation method thereof
CN116410000B (en) * 2021-12-31 2024-06-14 江苏博睿光电股份有限公司 A substrate, preparation method and application
CN117069510A (en) * 2023-05-26 2023-11-17 东莞市钧杰陶瓷科技有限公司 Preparation method of processable aluminum nitride ceramic

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19741332A1 (en) * 1997-09-19 1999-03-25 Ceramtec Ag High density sintered silicon nitride ceramic
CN101597177A (en) * 2009-07-10 2009-12-09 清华大学 Preparation method of a highly oriented tubular through-hole porous ceramic
CN101935220A (en) * 2010-08-31 2011-01-05 西安交通大学 Carbon nanofiber reinforced aluminum nitride composite ceramics and preparation method thereof
CN105801092A (en) * 2016-03-04 2016-07-27 广东工业大学 Raw materials of transparent ceramic as well as preparation method and application
CN108046828A (en) * 2017-12-14 2018-05-18 西安交通大学 A kind of tubular porous ceramic with radial structure and preparation method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19741332A1 (en) * 1997-09-19 1999-03-25 Ceramtec Ag High density sintered silicon nitride ceramic
CN101597177A (en) * 2009-07-10 2009-12-09 清华大学 Preparation method of a highly oriented tubular through-hole porous ceramic
CN101935220A (en) * 2010-08-31 2011-01-05 西安交通大学 Carbon nanofiber reinforced aluminum nitride composite ceramics and preparation method thereof
CN105801092A (en) * 2016-03-04 2016-07-27 广东工业大学 Raw materials of transparent ceramic as well as preparation method and application
CN108046828A (en) * 2017-12-14 2018-05-18 西安交通大学 A kind of tubular porous ceramic with radial structure and preparation method thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Freeze-Casting of Porous Ceramics:A Review of Current Achievements and Issues;Sylvain Deville;《ADVANCED ENGINEERING MATERIALS》;20081231;155-169 *
Implementing continuous freeze-casting by separated control of thermal gradient and solidification rate;Tao Zheng et al.;《International Journal of Heat and Mass Transfer》;20190107;986-993 *
莰烯为溶剂制备多孔氮化硅陶瓷的研究;于方丽 等;《人工晶体学报》;20190831;1511-1515,1521 *

Also Published As

Publication number Publication date
CN110981528A (en) 2020-04-10

Similar Documents

Publication Publication Date Title
CN110981528B (en) Directional porous aluminum nitride ceramic and rapid preparation method thereof
CN101037345B (en) Method for preparing mullite porous ceramic by gel refrigeration drying process
CN110922191B (en) A kind of silicon carbide polymer precursor ceramic defect healing method
CN108863394B (en) A method for preparing porous ceramics by gel casting combined with freeze-drying
CN101182233A (en) Gradient porous ceramic membrane and its preparation method
CN108706978A (en) The method that mist projection granulating combination 3DP and CVI prepare carbon/silicon carbide ceramic matrix composite
CN103274693A (en) Porous silicon carbide ceramic provided with novel pore wall structure and preparation method thereof
CN110937920A (en) A kind of ultra-light and high-strength anorthite porous ceramic and preparation method thereof
CN107082628A (en) Preparation method of porous ceramic support based on molecular sieve membrane synthesis residual liquid
CN108147835B (en) A method for preparing ceramic blocks with hierarchical porous structure using bacterial cellulose as a biological template
CN105084878A (en) Preparation method of acicular mullite porous ceramic block material with superhigh amount of porosity
CN111056846B (en) A kind of oriented porous aluminum nitride honeycomb ceramics rapidly prepared by freeze-drying and combustion synthesis method and method thereof
CN115448719A (en) A high-entropy bulk ceramic airgel with high temperature stability and its preparation method and application
CN101844934A (en) Preparation method of porous Al2O3 ceramic
CN107265416A (en) The preparation method of pyrolytic boron nitride material
CN111484330A (en) Diamond-enhanced silicon carbide substrate, preparation method thereof and electronic product
CN113860875B (en) Preparation method of in-situ synthesized silicon carbide nanowire network modified carbon/carbon composite material
CN110483061A (en) A kind of high porosity and high-intensitive silicon nitride ceramics and its preparation method and application
CN113149014B (en) Method for preparing boron carbide powder using organic carbon source
CN111116209B (en) A kind of oriented porous silicon nitride honeycomb ceramic and rapid preparation method thereof
CN103979979A (en) Method for preparing barium zirconate crucible by slip casting
CN114349516B (en) Method for synthesizing high-density SiC ceramic at low temperature
CN117735994A (en) Preparation method of AlN porous ceramic with honeycomb directional structure
CN116179169A (en) A wood chip-derived porous ceramic-based heat storage material based on waste utilization and its preparation method
CN111410540A (en) A kind of preparation method of directional pore structure porous silicon nitride ceramics

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20221129

Address after: 712046 Floor 2, Building 7, Incubation Park, Gaoke Second Road, Xianyang Hi tech Industrial Development Zone, Shaanxi Province

Patentee after: Xianyang Gazelle Valley New Material Technology Co.,Ltd.

Address before: 710049 No. 28 West Xianning Road, Shaanxi, Xi'an

Patentee before: XI'AN JIAOTONG University

TR01 Transfer of patent right