CN112174678A

CN112174678A - High-strength two-dimensional ceramic silk screen material and preparation method thereof

Info

Publication number: CN112174678A
Application number: CN202011009601.0A
Authority: CN
Inventors: 张劲松; 田冲; 杨振明; 高勇; 徐奕辰
Original assignee: Institute of Metal Research of CAS
Current assignee: Institute of Metal Research of CAS
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2021-01-05
Anticipated expiration: 2040-09-23
Also published as: CN112174678B

Abstract

The invention mainly relates to the field of porous ceramics, in particular to a high-strength two-dimensional ceramic silk screen material and a preparation method thereof. Based on the structural design of the screen mesh (A) with adjustable composition material and/or structure and/or the screen mesh (B) with adjustable hole type structure, the material is a flat thin sheet or a corrugated sheet structure with one or more layers macroscopically, the screen mesh is a solid or hollow structure, the aperture of the screen mesh surrounded by the screen mesh is 2-60 meshes, the area ratio of the screen mesh is 50-95%, the composition material is preferably but not limited to silicon carbide and/or silicon nitride ceramic, and the preparation method is preferably but not limited to reaction sintering. The high-strength two-dimensional ceramic wire mesh material has the characteristics of high strength, high temperature resistance, corrosion resistance, oxidation resistance and the like, and solves the problems of low mechanical strength, non-corrosion resistance, non-high temperature resistance and the like of a wire mesh structure base material required by manufacturing industrial devices or parts serving in harsh environments.

Description

High-strength two-dimensional ceramic silk screen material and preparation method thereof

The technical field is as follows:

the invention mainly relates to the field of porous ceramics, in particular to a high-strength two-dimensional ceramic silk screen material and a preparation method thereof, which are suitable for construction and manufacture of equipment required by various harsh industrial operation processes, and are particularly suitable for service environments requiring high strength, high temperature resistance, chemical corrosion resistance, organic swelling resistance and the like.

Background art:

the silk screen material is a mesh material manufactured by the processes of weaving, welding, rolling, punching and the like, exists in a two-dimensional flat sheet or two-dimensional corrugated sheet mode, and is typically characterized in that the thickness is far less than the length and the width, and the main functions are as follows: screening, filtering, printing, fixing, and providing a high geometric surface area. According to different materials, there are several kinds of silk screens made of natural materials, metal wire screens, synthetic polymer wire screens, glass fiber wire screens, ceramic wire screens, etc. As an important basic material or structural unit, screen materials have been widely used in many fields of social production and life, such as aviation, aerospace, printing and dyeing, electronics, mining, pharmacy, grain, food processing, chemical industry, and the like.

During the application of screen materials, certain performance limitations are also gradually highlighted: (1) the metal wire mesh, no matter the wire mesh, the stainless steel wire mesh or the corrosion-resistant alloy (hastelloy) wire mesh, can not solve the chemical corrosion problem under the acidic working condition well; (2) the natural material silk screen and the artificial synthetic polymer silk screen can not be used in high temperature environment, and the swelling resistance is also common; (3) the service performance of the glass fiber silk screen is limited by the polymer coating on the surface of the glass fiber silk screen; (4) the ceramic silk screen has low strength and poor performance, which leads to the current situation that the product has patent application but does not meet the practical requirement. Besides the brittle fracture of the ceramic, the unreasonable selection of the mesh structure design, the material of the silk screen and the preparation method (especially the sintering method) is the main reason for the problem. The mesh structure of the silk screen is unreasonable in design, so that mesh nodes can easily become stress concentration points of external mechanical load and thermal stress generated in the preparation process; the unreasonable selection of the material of the silk screen directly leads to the low mechanical property of the ceramic silk screen; the common sintering method is accompanied by larger or even larger shrinkage rate, and the characteristic and the thermal stress caused by the superposition of the thermal conductivity coefficient of the silk screen which is lower than that of homogeneous compact materials can amplify the problems caused by the two factors.

For example: utility model patent (publication No. CN2445806Y) discloses porcelain matter silk screen ripple packs, but its net silk only has horizontal bar and vertical retort to interweave and forms, and this kind of silk screen simple structure, net silk node stress concentration is serious, can't further improve the intensity of silk screen material. The patent (publication No. CN111389340A) discloses a structural design method for improving the service performance of a ceramic screen by using a reinforced steel bar, but the structural design method does not solve the problem of poor mechanical property of the ceramic screen, and the introduction of a metal steel bar restricts the exertion of the corrosion resistance of the ceramic. The invention patent (publication number CN104072179B) discloses a technique for preparing a ceramic coating on the surface of a wire mesh material to improve the strength of the whole wire mesh material, but the technique has the problem that the ceramic layer falls off due to thermal expansion mismatch of metal and ceramic layer, and the wire mesh is exposed and not corrosion-resistant. Therefore, the method faces to a harsh service environment, improves the intrinsic performance of the screen material, promotes the expansion of the operating condition range of downstream industrial equipment, develops a new application range, improves the service life and the service stability, and has important industrial application value.

The invention content is as follows:

in order to solve the defect of low mechanical strength of the conventional ceramic wire mesh material, the invention aims to provide a high-strength two-dimensional ceramic wire mesh material and a preparation method thereof, so as to solve the problems of low mechanical strength, non-corrosion resistance, non-high temperature resistance and the like of a wire mesh structure base material required by manufacturing industrial devices or parts in service in a severe environment.

The technical scheme of the invention is as follows:

the utility model provides a two-dimentional ceramic silk screen material of high strength, this two-dimentional ceramic silk screen material macroscopically is the two-dimentional thin slice structure of one deck or more than two-layer, and two-dimentional thin slice structure is flat thin slice or ripple piece structure, and two-dimentional thin slice itself contains ceramic material and the adjustable silk screen net silk of structure, and the silk screen net silk forms the mesh hole of pass structure adjustable, and the silk screen hole aperture that the silk screen net silk enclosed is 2 ~ 60 meshes, and the silk screen hole area accounts for the ratio 50% ~ 95%.

The high-strength two-dimensional ceramic wire mesh material is characterized in that the wire mesh contained in the two-dimensional ceramic wire mesh material is of a solid or hollow structure.

The screen hole type structure of the high-strength two-dimensional ceramic screen material is one or more than two of a circular structure, an oval structure, a conventional polygon structure, a variant polygon structure, a hierarchical polygon structure, a chiral structure or an anti-chiral structure.

In the high-strength two-dimensional ceramic silk screen material, the corrugated shape S of the corrugated sheet is one or more than two of the following shapes: triangular, vertex-smooth triangular, square wave, vertex-smooth square wave, trapezoidal wave, vertex-smooth trapezoidal wave, sinusoidal wave.

The high-strength two-dimensional ceramic wire mesh material is characterized in that the ceramic material, the wire mesh structure and the wire mesh hole type structure of different two-dimensional ceramic wire mesh materials are the same or different.

The high-strength two-dimensional ceramic silk screen material is characterized in that the ceramic material comprises silicon carbide, silicon nitride, silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, zirconium oxide, yttrium oxide and mullite 3Al₂O₃·2SiO₂One or more of SiAlON (SiAlON), AlN and BN.

The preparation method of the high-strength two-dimensional ceramic silk screen material adopts solid phase sintering or liquid phase sintering.

The preparation method of the high-strength two-dimensional ceramic wire mesh material adopts a reaction sintering process aiming at the silicon carbide or silicon nitride two-dimensional ceramic wire mesh material; aiming at the two-dimensional ceramic silk screen material compounded by silicon carbide and silicon nitride, a sintering process combining silicon nitride and silicon carbide is adopted.

The preparation method of the high-strength two-dimensional ceramic silk screen material comprises the following specific steps:

(1) template selection: adopting a single-layer or more than two-layer flat-sheet or corrugated-sheet organic silk screen material, metal or alloy silk screen material or glass fiber silk screen material as a template, wherein the material of the silk screen material template comprises but is not limited to polyethylene, polystyrene, polyurethane, nylon, polypropylene, terylene, polyvinyl chloride, polyvinyl alcohol or polyether; the material of the metal or alloy wire mesh material includes but is not limited to iron, steel, copper, titanium, aluminum, nickel, zinc, magnesium or alloy containing the above elements;

(2) preparing ceramic slurry: mixing ceramic solid powder, an organic dispersant or organic polymer resin, a curing agent and a solvent according to the proportion of 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the organic dispersant or organic polymer resin: 1000mL, and preparing ceramic slurry by fully ball-milling and mixing;

(3) the construction of the two-dimensional ceramic silk screen material precursor adopts one or the combination of more than two of the following steps:

the method comprises the following steps: coating, namely repeatedly coating the ceramic slurry in the step (2) on the silk screen material template in the step (1) by adopting a gas spraying, airless spraying or slurry dipping process, drying by hot air between two adjacent spraying or dipping processes, measuring the area ratio of silk screen holes to be between 20 and 30 percent, and specifically designing and setting according to different pore diameters and strength requirements to obtain a two-dimensional ceramic silk screen material precursor;

step two: chemical vapor deposition of a ceramic layer;

(4) and (3) removing the template by adopting one or the combination of more than two of the following steps:

the method comprises the following steps: carrying out chemical corrosion or electrochemical corrosion treatment on the two-dimensional ceramic silk screen material precursor obtained in the step (3) in an acid solution or an alkali solution to remove the silk screen material template;

step two: carrying out heat treatment on the two-dimensional ceramic silk screen material precursor obtained in the step (3) under the protection of inert gas or under a vacuum condition, so that a silk screen material template is heated and decomposed;

(5) and (3) sintering: and (3) carrying out high-temperature sintering on the two-dimensional ceramic silk screen material precursor without the template under the protection of inert gas or under a vacuum condition, wherein the temperature is 900-2500 ℃, and the heat preservation time is 10 min-6 h.

The preparation method of the high-strength two-dimensional ceramic silk screen material comprises the following steps of (5): performing one or more than two methods of the following operations: acid solution cleaning, alkali solution cleaning, organic solvent cleaning, deionized water cleaning, roasting in air and calcining under the protection of inert atmosphere.

The design idea of the invention is as follows:

aiming at the problems of easy brittle failure of ceramics, low overall mechanical strength, large shrinkage, easy deformation, poor mechanical property of the silk screen and the like existing in the traditional ceramic silk screen material. The invention starts from designing a wire mesh structure with low stress concentration degree, preferably selects a ceramic system with excellent comprehensive performance and capable of realizing low shrinkage rate preparation, and realizes the preparation and application of the high-strength two-dimensional ceramic wire mesh. The design idea is just the innovation of the invention.

After the structure of the wire mesh and the wire mesh holes is regulated, when the wire mesh bears mechanical load, the stress concentration phenomenon at the wire mesh nodes is reduced, and the overall strength of the two-dimensional ceramic wire mesh material is improved. After the material composition or the preparation process of the silk screen mesh is regulated and controlled, the bonding strength between the crystal grains in the silk screen mesh is increased, the mechanical property of the silk screen is improved, and the overall mechanical strength of the two-dimensional ceramic silk screen material is improved. In the thickness direction of the two-dimensional ceramic silk screen material, one or more than two of the composition material, the silk screen mesh structure and the silk screen hole-pattern structure of the two-dimensional ceramic silk screen material are superposed or combined, and the effect is that the overall mechanical strength of the two-dimensional ceramic silk screen material is improved, and the specific surface area of the silk screen can be improved while the mechanical property of the silk screen is ensured.

The invention has the following advantages and beneficial effects:

1. the invention designs the structure and the composition of the two-dimensional ceramic silk screen material based on the silk screen mesh (A) with adjustable composition material and/or structure and/or the silk screen mesh (B) with adjustable hole type structure, reduces the stress concentration phenomenon in the interior of the mesh and/or at the node of the mesh and the mesh, and improves the overall mechanical strength of the two-dimensional ceramic silk screen material.

2. The high-strength two-dimensional ceramic screen material has the characteristics of high strength, high temperature resistance, corrosion resistance, oxidation resistance and the like, and is suitable for manufacturing industrial devices or parts under severe environmental conditions.

3. The high-strength two-dimensional ceramic silk screen material has the advantages that the structure of the silk screen (A) and/or the hole type structure of the silk screen holes (B) can be adjusted and controlled, and the structural design is favorably carried out according to specific service conditions.

Description of the drawings:

fig. 1 is a schematic structural diagram of a high-strength two-dimensional ceramic wire mesh material according to the present invention. 1-P1 is a structural schematic diagram of a two-dimensional ceramic silk screen material with a flat sheet structure; 1-P2 is a structural schematic diagram of a two-dimensional ceramic wire mesh material with a corrugated sheet structure; a is a silk screen mesh; b is a wire mesh hole, and S is the wave shape of a wave plate.

Fig. 2(a) -2 (b) show the hole pattern structure of the high-strength two-dimensional ceramic screen material of the present invention. Wherein: FIG. 2(a) is a circle; fig. 2(b) is an oval shape.

Fig. 3(a) -3 (c) are screen hole pattern structures of the high strength two-dimensional ceramic screen material of the present invention-conventional polygonal structures: FIG. 3(a) is a trilateral; FIG. 3(b) is a quadrilateral; FIG. 3(c) is a regular hexagon; wherein a and b represent the respective feature sizes, and α represents the angle between the feature sizes.

Fig. 4(a) -fig. 4(f) are screen hole type structures of the high strength two-dimensional ceramic screen material of the present invention-special (variant) polygonal structures: FIG. 4(a) is a four-bladed polygon; FIG. 4(b) is a hexagon; FIG. 4(c) is a double reentrant hexagonal shape; FIG. 4(d) is a regular hexagon + double reentrant corner hexagon; FIG. 4(e) is a single reentrant hexagonal shape; FIG. 4(f) is a regular triangle + regular hexagon; wherein a, b, c represent the respective feature sizes, and α represents the included angle between the feature sizes.

Fig. 5(a) -5 (c) are screen hole type structures-hierarchical polygonal structures of the high strength two-dimensional ceramic screen material of the present invention: FIG. 5(a) is a graded hexagon; FIG. 5(b) is a hierarchical quadrilateral; FIG. 5(c) is a hierarchical trilateral; wherein a, b, c represent the respective characteristic dimensions.

Fig. 6(a) -6 (e) are screen hole type structures-special (variant) polygonal structures of the high strength two-dimensional ceramic screen material of the present invention: FIG. 6(a) is a third-order chiral structure; FIG. 6(b) is a fourth-order chiral structure; FIG. 6(c) is a sixth-order chiral structure; FIG. 6(d) is a third order anti-chiral structure; FIG. 6(e) is a fourth order anti-chiral structure; wherein a and r represent the respective characteristic dimensions.

Fig. 7(a) -7 (g) show the kind of the corrugated shape S of the corrugated sheet in the high-strength two-dimensional ceramic mesh material according to the present invention. Wherein, fig. 7(a) is a triangular corrugation, and H, l and alpha are characteristic parameters; FIG. 7(b) is a triangle with rounded vertices, and H, l and α are characteristic parameters; FIG. 7(c) is a square waveform; FIG. 7(d) is a top rounded square waveform; FIG. 7(e) is a trapezoidal waveform; FIG. 7(f) is a top rounded trapezoidal waveform; fig. 7(g) shows a sine wave waveform.

Fig. 8 is a physical diagram of a high-strength two-dimensional silicon carbide graded hexagonal screen material in the invention.

The specific implementation mode is as follows:

in a specific implementation process, the preparation method of the high-strength two-dimensional ceramic wire mesh material comprises the following general flow:

(1) template selection: as shown in fig. 1, a single-layer or multi-layer flat sheet or corrugated sheet organic silk screen material, a metal or alloy silk screen material, and a glass fiber silk screen material are used as templates, and the mesh structure of the template are designed as required, wherein the organic silk screen template is made of materials including but not limited to polyethylene, polystyrene, polyurethane, nylon, polypropylene, terylene, and polyvinyl chloride; the material of the metal or alloy wire mesh material includes, but is not limited to, iron, steel, copper, titanium, aluminum, nickel, zinc, magnesium, and other metals or alloys containing the above elements.

(2) Preparing ceramic slurry: mixing ceramic solid powder, an organic dispersant or organic polymer resin, a curing agent and a solvent according to the proportion of 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the organic dispersant or organic polymer resin: 1000mL, and preparing slurry by fully ball-milling and mixing. The organic dispersant includes, but is not limited to, sodium phosphate, sodium silicate, sodium citrate, sodium ethylene diamine tetracetate, sodium diacetate, polyacrylamide, polyacrylic acid or sodium salt thereof, hydroxymethyl cellulose, polyvinyl alcohol or polyvinyl butyral, and the organic polymer resin includes, but is not limited to, melamine resin, furfural resin, epoxy resin, phenolic resin, furan resin, polyurethane, polyester or polyether.

(3) The silk screen precursor is constructed by adopting one or the combination of more than two of the following steps:

the method comprises the following steps: coating, namely repeatedly coating the slurry in the step (2) on the silk screen sheet in the step (1) by adopting a gas spraying, airless spraying or slurry dipping process, drying the slurry by hot air between two adjacent spraying or dipping processes, measuring the area ratio of the silk screen holes to be between 20 and 30 percent, and specifically designing and setting according to different hole diameters and strength requirements to obtain a silk screen material precursor;

step two: chemical vapor deposition of ceramics;

the method comprises the following steps: carrying out chemical corrosion or electrochemical corrosion treatment on the silk screen precursor obtained in the step (3) in an acid solution or an alkali solution to remove the silk screen template;

step two: carrying out heat treatment on the silk screen precursor obtained in the step (3) under the protection of inert gas or under a vacuum condition to ensure that the silk screen template is heated and decomposed;

(5) and (3) sintering: and (3) sintering the silk screen material precursor at high temperature under the protection of inert gas or under vacuum condition, wherein the temperature is 900-2500 ℃, and the heat preservation time is 10 min-6 h.

(6) And (3) post-treatment: subjecting the sample obtained in step (5) to one or more of the following operations: acid solution cleaning, alkali solution cleaning, organic solvent (including but not limited to acetone and absolute ethyl alcohol) cleaning, deionized water cleaning, roasting in air and roasting under the protection of inert atmosphere.

As shown in fig. 2(a) -2 (b), the screen hole type structure of the high strength two-dimensional ceramic screen material of the present invention. Wherein: FIG. 2(a) is a circle, which has the effect of achieving close packing of circular meshes; FIG. 2(b) is an oval shape, which functions to achieve close packing or oriented packing of oval shaped meshes.

As shown in fig. 3(a) -3 (c), the screen hole type structure of the high-strength two-dimensional ceramic screen material of the present invention, the conventional polygonal structure: FIG. 3(a) is a trilateral shape, which functions to achieve triangular mesh and its close packing; FIG. 3(b) is a quadrilateral shape, the purpose of which is to achieve rectangular meshes and their close packing; fig. 3(c) is a regular hexagon, which functions to achieve a regular hexagonal mesh and its close packing.

As shown in fig. 4(a) -4 (f), the screen hole type structure of the high-strength two-dimensional ceramic screen material of the present invention, a special (variant) polygonal structure: FIG. 4(a) is a four-bladed polygon, whose function is to achieve anisotropic mesh and close packing; FIG. 4(b) is a hexagon, which functions to realize a regular hexagonal mesh; FIG. 4(c) is a double reentrant hexagonal pattern which functions to achieve a double reentrant hexagonal mesh; FIG. 4(d) is a regular hexagon + double reentrant hexagon, which functions to realize the combination of regular hexagonal meshes and double reentrant hexagonal meshes; FIG. 4(e) is a single reentrant hexagonal pattern which functions to achieve a single reentrant hexagonal mesh; fig. 4(f) is a regular triangle + a regular hexagon, and the function of the mesh is to realize the combination of the regular triangle mesh and the regular hexagon mesh.

As shown in fig. 5(a) -5 (c), the screen hole type structure of the high-strength two-dimensional ceramic screen material of the present invention, a hierarchical polygonal structure: FIG. 5(a) is a stepped hexagon, which functions to achieve two-level hexagonal meshes and reduce node stress; FIG. 5(b) is a hierarchical quadrilateral whose role is to realize two-level quadrilateral meshes and reduce node stress; fig. 5(c) is a stepped trilateral shape, which functions to achieve two-level triangular meshes and reduce nodal stress.

As shown in fig. 6(a) -6 (e), the screen hole type structure of the high-strength two-dimensional ceramic screen material of the present invention, a special (variant) polygonal structure: FIG. 6(a) is a third-order chiral structure, which functions to achieve a third-order chiral mesh and reduce nodal stress; FIG. 6(b) is a fourth-order chiral structure, which is used to realize a fourth-order chiral mesh and reduce node stress; FIG. 6(c) is a sixth-order chiral structure, which functions to achieve a sixth-order chiral mesh and reduce nodal stress; FIG. 6(d) is a third-order anti-chiral structure, which functions to achieve a third-order anti-chiral mesh and reduce nodal stress; FIG. 6(e) is a fourth-order anti-chiral structure, which functions to achieve a fourth-order anti-chiral mesh and reduce nodal stress.

As shown in fig. 7(a) -7 (g), the kind of the corrugated shape S of the corrugated sheet in the high-strength two-dimensional ceramic mesh material of the present invention. Wherein, FIG. 7(a) is a triangular corrugation, which has the function of increasing the resistance to mechanical load; FIG. 7(b) is a triangle with smooth vertices, which is used to reduce the stress concentration at the vertices of the triangle corrugation; fig. 7(c) is a square wave waveform, which functions to realize a square wave type corrugated plate; FIG. 7(d) is a top-rounded square waveform for reducing stress concentration at the top of the square-wave corrugated board; fig. 7(e) is a trapezoidal wave shape, which functions to realize a trapezoidal wave type corrugated plate; FIG. 7(f) is a top-rounded trapezoidal waveform for reducing the stress concentration at the top of the corrugated board; fig. 7(g) is a sine wave waveform, and functions to realize a sine wave type corrugated plate.

The following description will be made of a flat-sheet type high-strength two-dimensional reaction-sintered silicon carbide mesh ceramic material as an example, in which the specific embodiment is as follows:

example 1

In this embodiment, the main process of the specific implementation of the flat-sheet type high-strength two-dimensional reaction sintering silicon carbide wire mesh ceramic material includes:

(1) template selection: adopting a single-layer flat sheet organic silk screen material as a template, wherein the template silk screen is of a hollow structure; as shown in fig. 3(b), the screen hole pattern has a quadrangular structure.

(2) Preparing ceramic slurry: mixing silicon carbide powder (with an average particle size of 5 mu m), phenolic resin, a phenolic resin curing agent and ethanol according to a ratio of 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of phenolic resin: 1000mL, and preparing slurry by fully ball-milling and mixing.

(3) Constructing a silk screen precursor, namely repeatedly coating the slurry in the step (2) on the silk screen template in the step (1) by airless spraying, drying by hot air between each coating, and measuring the area percentage of silk screen holes to be between 50 and 60 percent to obtain the silk screen material precursor;

(4) removing the template: carrying out heat treatment on the silk screen precursor obtained in the step (3) under the protection of inert gas or under a vacuum condition to ensure that the silk screen template is heated and decomposed;

(5) and (3) sintering: and (3) carrying out high-temperature liquid silicon infiltration reaction sintering on the silk screen material precursor without the template under the vacuum condition, wherein the temperature is 1600-2000 ℃, and the heat preservation time is 10 min-6 h.

(6) And (3) post-treatment: and (4) washing the sample obtained in the step (5) with an alkali solution and deionized water.

The obtained flat-sheet type high-strength two-dimensional reaction sintering silicon carbide silk screen material is composed of silicon carbide and silicon. The mesh is of a solid structure, and the mesh hole type is the same as the template material and is of a quadrilateral mesh hole structure. The aperture of the mesh screen is 30 meshes, and the area of the mesh screen accounts for 50 percent. The apparent compressive strength was 20 MPa. The test method comprises the following steps: after a plurality of pieces of silk screen materials are stacked, a mechanical load is applied in the direction perpendicular to the thickness direction of the silk screen pieces, and the apparent compressive strength of the unit area is obtained.

The present invention is illustrated by the following examples, which are not intended to limit the scope of the invention.

Example 2

The embodiment is an implementation process of a corrugated sheet type high-strength two-dimensional reaction sintering silicon carbide screen ceramic material, and is different from embodiment 1 in that: selecting a corrugated organic silk screen material as a template for the template material in the step (1), wherein the corrugation is in a smooth-vertex triangle shape, and the template silk screen is in a hollow structure; as shown in fig. 3(c), the screen hole patterns are regular hexagons.

As shown in fig. 7, the obtained corrugated sheet type high-strength two-dimensional reaction-sintered silicon carbide wire mesh ceramic material is composed of silicon carbide and silicon. The mesh is of a solid structure, and the hole pattern of the mesh is the same as that of a template material and is of a regular hexagon structure. The aperture of the mesh is 20 meshes, and the area of the mesh accounts for 50 percent. The apparent compressive strength was 25 MPa. The test method comprises the following steps: after a plurality of pieces of silk screen materials are stacked, a mechanical load is applied in the direction perpendicular to the thickness direction of the silk screen pieces, and the apparent compressive strength of the unit area is obtained.

Example 3

The present embodiment is an implementation process of a flat-sheet type high-strength two-dimensional silicon nitride mesh ceramic material, and is different from embodiment 1 in that: selecting a flat sheet organic silk screen material as a template for the template material in the step (1), wherein the template silk screen is of a hollow structure; as shown in fig. 4(a), the screen hole pattern is a four-bladed polygonal structure.

In the step (2), silicon carbide powder of the same mass is replaced by mixed powder (mass ratio is 80: 10: 5: 3: 2) of silicon nitride powder (average particle size is 2 μm), silicon powder (average particle size is 3 μm), aluminum oxide, yttrium oxide, magnesium oxide and the like. And (5) replacing vacuum conditions with high-purity nitrogen protection conditions, wherein the sintering temperature is 1700 ℃, and the heat preservation time is 6 hours. The obtained flat-sheet type high-strength two-dimensional silicon nitride silk screen ceramic material is made of silicon nitride and silicon. The mesh is of a hollow structure, and the mesh hole pattern of the mesh is the same as that of a template material and is of a four-paddle polygonal mesh structure. The aperture of the mesh is 20 meshes, and the area of the mesh accounts for 50 percent. The apparent compressive strength was 45 MPa. The test method comprises the following steps: after a plurality of pieces of silk screen materials are stacked, a mechanical load is applied in the direction perpendicular to the thickness direction of the silk screen pieces, and the apparent compressive strength of the unit area is obtained.

Example 4

The embodiment is an implementation process of a corrugated sheet type high-strength two-dimensional silicon nitride screen ceramic material, and is different from embodiment 1 in that: selecting a corrugated organic silk screen material as a template for the template material in the step (1), wherein the corrugation is in a smooth-vertex triangle shape, and the template silk screen is in a hollow structure; as shown in fig. 4(b), the screen hole pattern is a deformed hexagonal structure.

In the step (2), silicon carbide powder of the same mass is replaced by mixed powder (mass ratio is 80: 10: 5: 3: 2) of silicon nitride powder (average particle size is 2 μm), silicon powder (average particle size is 3 μm), aluminum oxide, yttrium oxide, magnesium oxide and the like. And (5) replacing vacuum conditions with high-purity nitrogen protection conditions, wherein the sintering temperature is 1700 ℃, and the heat preservation time is 6 hours. The obtained flat-sheet type high-strength two-dimensional silicon nitride silk screen ceramic material is made of silicon nitride and silicon. The mesh is of a hollow structure, and the mesh hole pattern of the mesh is the same as that of a template material and is of a deformed hexagonal mesh structure. The aperture of the mesh hole is 35 meshes, and the area of the mesh hole accounts for 55 percent. The apparent compressive strength was 50 MPa. The test method comprises the following steps: after a plurality of pieces of silk screen materials are stacked, a mechanical load is applied in the direction perpendicular to the thickness direction of the silk screen pieces, and the apparent compressive strength of the unit area is obtained.

Example 5

The present embodiment is an implementation process of a flat-sheet type high-strength two-dimensional reaction-sintered silicon carbide multilayer wire mesh ceramic material, and is different from embodiment 1 in that: the template material in the step (1) is a flat sheet 2-layer organic silk screen material as a template, and the template silk screen is of a solid structure; as shown in fig. 5(a), the screen hole patterns have a stepped hexagonal structure.

The obtained flat-sheet type high-strength two-dimensional reaction sintering silicon carbide multilayer silk screen ceramic material is composed of silicon carbide and silicon. The mesh is a solid structure, and the mesh hole pattern of the mesh is the same as that of a template material and is a graded hexagonal mesh hole structure. The aperture of the mesh screen is 25 meshes, and the area of the mesh screen accounts for 52 percent. The apparent compressive strength was 65 MPa. The test method comprises the following steps: after a plurality of pieces of silk screen materials are stacked, a mechanical load is applied in the direction perpendicular to the thickness direction of the silk screen pieces, and the apparent compressive strength of the unit area is obtained.

As shown in fig. 8, a physical diagram of the high-strength two-dimensional silicon carbide graded hexagonal screen material in the invention can be seen from fig. 8: compared with the conventional regular hexagon mesh, the mesh structure of the wire mesh material is characterized in that the stress at the node of the mesh structure is concentrated, and the regular hexagon with the secondary scale is used for replacing the same position in the mesh structure, so that the stress concentration phenomenon is reduced, the structural stability is improved, and the higher mechanical compression resistance of the material is realized.

Example 6

The embodiment is an implementation process of a corrugated sheet type high-strength two-dimensional silicon nitride multilayer silk screen ceramic material, and is different from embodiment 3 in that: the template material in the step (1) selects 3 layers of organic silk screen materials of corrugated sheets as templates, the corrugated shape is sine wave shape, and the template silk screen is solid structure; as shown in fig. 6(a), the screen hole patterns are all three-order chiral structures.

The obtained corrugated sheet type high-strength two-dimensional silicon nitride multilayer silk screen ceramic material is composed of silicon nitride and silicon. The mesh is of a hollow structure, the mesh hole pattern of the mesh is the same as that of a template material, and 3 layers are of three-order chiral structures. The aperture of the mesh is 20 meshes, and the area of the mesh accounts for 53 percent. The apparent compressive strength was 78 MPa. The test method comprises the following steps: after a plurality of pieces of silk screen materials are stacked, a mechanical load is applied in the direction perpendicular to the thickness direction of the silk screen pieces, and the apparent compressive strength of the unit area is obtained.

Example 7

The embodiment is an implementation process of a corrugated sheet type high-strength two-dimensional silicon nitride multilayer silk screen ceramic material, and is different from embodiment 3 in that: in the step (1), the template material is a corrugated sheet 3-layer organic silk screen material as a template, the corrugation is in a smooth trapezoidal wave shape with smooth top points, and the template silk screen is in a solid structure. As shown in FIG. 6(a), the mesh hole pattern of layer 1 is a third-order chiral structure. As shown in FIG. 3(b), the mesh hole pattern of the layer 2 is a quadrangle. As shown in FIG. 6(a), the 3 rd layer of the silk screen hole pattern is a three-order chiral structure.

The obtained corrugated sheet type high-strength two-dimensional silicon nitride multilayer silk screen ceramic material is composed of silicon nitride and silicon. The mesh is of a hollow structure, and the hole pattern of the mesh is the same as that of a template material. The aperture of the mesh is 20 meshes, and the area of the mesh accounts for 52 percent. The apparent compressive strength was 67 MPa. The test method comprises the following steps: after a plurality of pieces of silk screen materials are stacked, a mechanical load is applied in the direction perpendicular to the thickness direction of the silk screen pieces, and the apparent compressive strength of the unit area is obtained.

The above examples show that, based on the structural design of the component material and/or the structure-adjustable wire mesh (a) and/or the hole-type structure-adjustable wire mesh (B), the high-strength two-dimensional ceramic wire mesh material of the present invention combines with the preferable material system and the preparation method, and the overall mechanical strength of the two-dimensional ceramic wire mesh material is significantly improved, so as to solve the problem that the ceramic wire mesh material has poor overall mechanical properties and restricts the production and practical application. The structure of the silk screen (A) and/or the hole type structure of the silk screen (B) can be highly regulated and controlled, and the structural design is favorably carried out according to specific service conditions. Meanwhile, the material has the characteristics of high strength, high temperature resistance, corrosion resistance, oxidation resistance and the like, is suitable for manufacturing industrial devices or parts under severe environment conditions, and has a good application prospect.

Claims

1. The utility model provides a high strength two-dimentional ceramic silk screen material, its characterized in that, this two-dimentional ceramic silk screen material macroscopically is the two-dimentional thin slice structure of one deck or more than two-layer, and two-dimentional thin slice structure is flat thin slice or corrugated plate structure, and two-dimentional thin slice self contains ceramic material and the adjustable silk screen net of structure, and the silk screen net forms the adjustable silk screen hole of pass structure, and the silk screen hole aperture that the silk screen net encloses is 2 ~ 60 meshes, and the silk screen hole area accounts for the ratio 50% -95%.

2. The high strength two-dimensional ceramic wire mesh material according to claim 1, wherein the two-dimensional ceramic wire mesh material comprises wires which are of a solid or hollow structure.

3. The high strength two dimensional ceramic wire mesh material of claim 1, wherein the wire mesh type structure of the two dimensional ceramic wire mesh material is one or more of circular, elliptical, regular polygonal, modified polygonal, graded polygonal, chiral or anti-chiral structures.

4. The high strength two-dimensional ceramic wire mesh material according to claim 1, wherein the corrugated shape S of the corrugated sheet is one or two or more of the following shapes: triangular, vertex-smooth triangular, square wave, vertex-smooth square wave, trapezoidal wave, vertex-smooth trapezoidal wave, sinusoidal wave.

5. The high strength two dimensional ceramic screen material of claim 1, wherein the ceramic material, screen mesh structure, screen pore type structure of different two dimensional ceramic screen materials are the same or different.

6. The high-strength two-dimensional ceramic screen material according to claim 1, wherein the ceramic material comprises silicon carbide, silicon nitride, silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, zirconium oxide, yttrium oxide, mullite 3Al₂O₃·2SiO₂One or more of SiAlON (SiAlON), AlN and BN.

7. A method of producing a high strength two dimensional ceramic mesh material according to any one of claims 1 to 6, wherein solid phase sintering or liquid phase sintering is used.

8. The method for preparing the high-strength two-dimensional ceramic wire mesh material according to claim 7, wherein a reaction sintering process is adopted for the silicon carbide or silicon nitride two-dimensional ceramic wire mesh material; aiming at the two-dimensional ceramic silk screen material compounded by silicon carbide and silicon nitride, a sintering process combining silicon nitride and silicon carbide is adopted.

9. The preparation method of the high-strength two-dimensional ceramic wire mesh material according to claim 7, comprising the following steps:

step two: chemical vapor deposition of a ceramic layer;

10. The method of preparing a high strength two dimensional ceramic screen material of claim 9, wherein step (5) is followed by a post-treatment: performing one or more than two methods of the following operations: acid solution cleaning, alkali solution cleaning, organic solvent cleaning, deionized water cleaning, roasting in air and calcining under the protection of inert atmosphere.