CN114230345B - High-strength porous silicon carbide ceramic for molten metal filtration and preparation method thereof - Google Patents
High-strength porous silicon carbide ceramic for molten metal filtration and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a high-strength porous silicon carbide ceramic for molten metal filtration and a preparation method thereof, belongs to the technical field of porous ceramic filtration, and aims to solve the problems that a ceramic skeleton prepared by a slurry dipping method is low in density, and the filtering effect of small-size non-metallic inclusions can be obviously reduced through a traditional skeleton surface densification processing process. The porous silicon carbide ceramic matrix formed by surrounding the unit body of the high-porosity ceramic filtering center by the low-porosity ceramic supporting layer and coating the ceramic protective layer on the outer side of the supporting layer jointly form the high-strength porous silicon carbide ceramic for molten metal filtering.
Description
Technical Field
The invention belongs to the technical field of porous ceramic filtration, and particularly relates to a high-strength porous silicon carbide ceramic for molten metal filtration and a preparation method thereof.
Background
Non-metallic inclusions in molten metal solution (molten aluminum, molten steel, etc.) not only seriously reduce mechanical properties of metal material such as strength, hardness, toughness, etc., but also adversely affect technological properties such as castability, machinability, etc. Therefore, how to reduce the content of non-metallic inclusions in molten metal is a key to improve the quality of metal materials and is an urgent problem in the technical field of manufacturing high-quality castings.
At present, porous silicon carbide ceramics with a three-dimensional network structure are one of the main approaches for filtering out molten metal impurities. The preparation method of the porous silicon carbide ceramic material comprises a slurry dipping method, a foaming method, a pore-forming agent adding method and the like, wherein the slurry dipping method is to burn off organic foam dipped in ceramic slurry at high temperature to obtain a ceramic body with higher porosity and larger pore diameter, and is mainly applied to the field of metal melt filters.
However, organic foams burnt out in the slurry dipping method can form a hollow hole structure in the ceramic framework, so that the compactness of the material is limited, and the main problems of reduced mechanical strength and poor thermal shock resistance exist. The traditional processing technology (such as a secondary slurry coating method) for densifying the surface of the framework can improve the strength of the ceramic, but can obviously reduce the filtering effect on small-size nonmetallic inclusions. And secondly, the porous silicon carbide ceramic is a sintered product, the edge is brittle and irregular, the thermal shock resistance is poor, and the porous silicon carbide ceramic is easy to crack in the molten metal filtering process to cause secondary slag inclusion.
Disclosure of Invention
In order to overcome the defects of the conventional porous silicon carbide ceramic filter, the invention aims to provide a porous silicon carbide ceramic matrix formed by surrounding a unit body of a high-porosity ceramic filtering center by a low-porosity ceramic supporting layer, and coating a ceramic protective layer on the outer side of the supporting layer, so that the high-strength porous silicon carbide ceramic for molten metal filtration is formed together.
The method comprises the following specific steps:
step 1: soaking polyurethane sponge in the shapes required by the ceramic filtering center and the ceramic supporting layer in 10-30 wt% sodium hydroxide solution for 2-3 hours;
and 2, step: soaking the polyurethane sponge processed in the step 1 into the slurry A, and extruding the redundant slurry out, wherein the thickness of the slurry attached to the surface of the sponge wire mesh is 0.3-0.6mm;
and 3, step 3: soaking the polyurethane sponge of the ceramic support layer treated in the step (1) into the slurry B, and extruding out the redundant slurry, wherein the thickness of the slurry attached to the surface of the sponge silk screen is 0.5-0.8mm;
and 4, step 4: putting the polyurethane sponge of the ceramic filter center processed in the step 2 into the polyurethane sponge of the ceramic support layer processed in the step 3, and tightly surrounding the polyurethane sponge to obtain a porous silicon carbide ceramic unit body;
and 5: tightly attaching the porous silicon carbide ceramic unit bodies obtained in the step (4) to form a required filter shape, standing and drying for 24 hours, and shaping to obtain a porous silicon carbide ceramic matrix;
and 6: coating a ceramic protective layer on each surface of the outer side of the porous silicon carbide ceramic matrix obtained in the step (5), namely respectively immersing each surface of the outer side into the ceramic slurry B for 2-5mm;
and 7: and (3) placing the porous silicon carbide ceramic matrix with the ceramic protective layer in a high-temperature furnace, and sintering for 4 hours at 1600-1900 ℃ to obtain the high-strength porous silicon carbide ceramic for molten metal filtration.
The porosity of the polyurethane sponge in the ceramic filtering center in the step 1 is higher than that of the polyurethane sponge in the ceramic supporting layer, and preferably, the pore density of the polyurethane sponge in the ceramic filtering center ranges from 20PPI to 30PPI, and the pore density of the polyurethane sponge in the ceramic supporting layer ranges from 10PPI to 20PPI.
The slurry A in the step 2 comprises the following components: 50-65wt% of silicon carbide powder, 2000-3500 mesh particle size, 5-10 wt% of sintering aid, 5-10 wt% of adhesive, 0.5-1wt% of dispersant and 14-39.5 wt% of deionized water.
The slurry B comprises the following components: 40-55wt% of silicon carbide powder, 4000-5000 meshes of particle size, 5-10 wt% of sintering aid, 10-15 wt% of adhesive, 5-10 wt% of amorphous silicon powder, 4000-5000 meshes of particle size, 0.5-1wt% of dispersant and 9-39.5 wt% of deionized water.
Preferably, the sintering aid is alumina and/or kaolin, the binder is sodium carboxymethyl cellulose, and the dispersant is sodium polyacrylate.
The ceramic support layer polyurethane sponge in the step 4 needs to tightly surround the ceramic filter center polyurethane sponge, so that the size of the ceramic filter center polyurethane sponge can be properly larger than the reserved size of the center of the ceramic support layer polyurethane sponge.
The shape of the filter formed by the porous silicon carbide ceramic unit bodies in the step 5 is preferably a cuboid, a cylinder or a polygon.
The three-dimensional structure of the porous silicon carbide ceramic for filtering the high-strength molten metal in the step 7 is the same as that of polyurethane foam, the pore diameter of a ceramic filtering center is 0.8-1.5mm, the pore diameter of a ceramic supporting layer is 1-3mm, the thickness of a protective layer is 2-5mm, and the surface of a ceramic framework is provided with micro-nano holes with the pore diameter of 0.8-20 mu m.
The invention has the beneficial effects that:
the invention provides a high-strength porous silicon carbide ceramic for molten metal filtration, which is formed by a ceramic supporting layer and a unit body of a ceramic filtration center and coated by a ceramic protective layer, and a preparation method thereof. The ceramic supporting layer with low porosity has high pressure resistance and plays a role in bearing the heat flow scouring of high-temperature molten metal; the ceramic filtering center with high porosity has the functionality of porous ceramic, and the three-dimensional reticular macro-pore structure of the formed porous silicon carbide ceramic unit body can effectively intercept and adsorb non-metallic inclusions without influencing the over-flow of molten metal; the ceramic protective layer coats the outer side surface of the ceramic supporting layer, so that the direct impact of molten metal on the irregular brittle edges of the supporting layer is avoided, the problem of secondary slag inclusion caused by easy falling of the edges is solved, and the overall thermal shock resistance of the filter ceramic is further improved. Secondly, the particle size of the silicon carbide powder in the slurry A used in the ceramic filtering center is required to be larger (the mesh number is smaller), the gaps among the formed ceramic powder particles are larger, and the capability of deeply adsorbing micro inclusions in molten metal can be improved to a greater extent by forming a large number of micro-nano pore structures on the surface of a ceramic framework; the size of the silicon carbide powder in the slurry B used for the ceramic support layer is smaller (the mesh number is larger), the gaps among the formed ceramic powder particles are smaller, the ceramic framework is more densified, and the strength is improved.
On the other hand, the adhesive content of the slurry B soaked in the ceramic supporting layer polyurethane sponge is higher than that of the slurry A, so that the viscosity of the slurry B can be improved, the phenomenon that the slurry is too much soaked in gaps of the ceramic filtering center polyurethane sponge to cause blockage is avoided, and meanwhile, the bonding strength of the supporting layer and the filtering center area can also be enhanced. In addition, a small amount of amorphous silicon powder is added into the slurry B, so that the thermal expansion coefficient of the slurry B is slightly lower than that of the slurry A, after sintering, the ceramic supporting layer generates compressive stress, the strength of the porous silicon carbide ceramic can be effectively improved, and the oxidation resistance of the ceramic supporting layer is also improved. The ceramic protective layer slurry on the outermost side is consistent with the ceramic supporting layer slurry, has the same thermal expansion coefficient, and prevents the problems of cracking and falling.
Therefore, the high-strength porous silicon carbide ceramic structure prepared by the invention has high mechanical strength and thermal shock resistance while ensuring the functions of filtering, separating, adsorbing nonmetallic inclusions and the like, is suitable for the field of filtering high-temperature molten metals such as aluminum liquid, molten steel and the like, and can obviously improve the casting quality and the subsequent cutting and processing quality. The preparation method is simple and convenient to operate, does not need additional processes such as secondary sintering and the like, has low requirements on equipment, and is suitable for mass production of different sizes.
Drawings
FIG. 1 is a flow chart illustrating the steps of the method of the present invention
FIG. 2 is a schematic view of a porous silicon carbide ceramic in example 1
FIG. 3 is a photograph of a porous silicon carbide ceramic cell body in example 1
FIG. 4 is a photograph of the porous silicon carbide ceramic substrate in example 1
FIG. 5 is a photograph of the porous silicon carbide ceramic in example 1
FIG. 6 is a schematic view of a porous silicon carbide ceramic in example 2
Detailed Description
The technical solution of the invention is further explained and illustrated in the form of specific embodiments.
Example 1
Firstly soaking the polyurethane sponge of the cuboid ceramic filtering center and the hollow cuboid ceramic supporting layer in 15wt% of sodium hydroxide solution for 3 hours for pretreatment, then soaking the treated polyurethane sponge of the ceramic filtering center into slurry A, soaking the polyurethane sponge of the ceramic supporting layer into slurry B, and extruding redundant slurry. Secondly, putting the polyurethane sponge at the center of the cuboid ceramic filter into the polyurethane sponge at the hollow cuboid ceramic support layer to be tightly surrounded, and obtaining the porous silicon carbide ceramic unit body in a shape of Chinese character 'hui'. And tightly attaching the four porous silicon carbide ceramic unit bodies to form a rectangular filter, standing and drying for 24 hours, and shaping to obtain the 'field' -shaped porous silicon carbide ceramic matrix. Then, the four outer sides of the porous silicon carbide ceramic matrix are respectively immersed into the slurry B for 4mm to obtain the ceramic protective layer coated on each outer side. And finally, placing the porous silicon carbide ceramic substrate with the ceramic protective layer in a high-temperature furnace, and sintering at 1700 ℃ for 4 hours to obtain the high-strength porous silicon carbide ceramic for filtering the molten metal.
Wherein the pore density of the polyurethane sponge in the ceramic filter center is 30PPI, and the pore density of the polyurethane sponge in the ceramic support layer is 10PPI. The slurry A comprises the following components: 60wt% of silicon carbide powder, 5wt% of alumina and 5wt% of kaolin, 5wt% of sodium carboxymethyl cellulose, 1wt% of sodium polyacrylate and 29wt% of deionized water, wherein the particle size of the silicon carbide powder is 2500 meshes. The slurry B comprises the following components: 50wt% of silicon carbide powder, 50% of each of 4000 meshes and 5000 meshes, 4wt% of each of alumina and kaolin, 10wt% of sodium carboxymethyl cellulose, 10wt% of amorphous silicon powder, 1wt% of sodium polyacrylate and 21wt% of deionized water, wherein the particle size of the amorphous silicon powder is 4000 meshes. And mechanically stirred at the rotating speed of 1500r/min for 1 hour respectively.
As shown in fig. 2, fig. 3 is a photograph of a unit body of the porous silicon carbide ceramic, fig. 4 is a photograph of a unit body of the porous silicon carbide ceramic, and fig. 5 is a photograph of the prepared porous silicon carbide ceramic, it can be seen that the high-strength porous silicon carbide ceramic formed by the unit body of the ceramic support layer and the ceramic filter center and coated by the ceramic protective layer has high mechanical strength and thermal shock resistance while ensuring to filter out non-metallic inclusions, and is suitable for filtering high-temperature molten metal.
Example 2
Firstly soaking polyurethane sponges of the triangular prism ceramic filtering center and the hollow triangular prism ceramic supporting layer in 15wt% of sodium hydroxide solution for 3 hours for pretreatment, then soaking the treated polyurethane sponges of the ceramic filtering center into the slurry A, soaking the polyurethane sponges of the ceramic supporting layer into the slurry B, and extruding redundant slurry. And secondly, putting the polyurethane sponge in the triangular prism ceramic filtering center into the polyurethane sponge in the hollow triangular prism ceramic supporting layer to tightly surround the polyurethane sponge so as to obtain the triangular prism-shaped porous silicon carbide ceramic unit body. And tightly attaching the six porous silicon carbide ceramic unit bodies to form a hexagonal prism filter, standing and drying for 24 hours, and shaping to obtain the porous silicon carbide ceramic matrix. Then, the six outer sides of the porous silicon carbide ceramic matrix are respectively immersed into the slurry B for 4mm to obtain the ceramic protective layer coated on each outer side. And finally, placing the porous silicon carbide ceramic substrate with the ceramic protective layer in a high-temperature furnace, and sintering at 1700 ℃ for 4 hours to obtain the high-strength porous silicon carbide ceramic for filtering the molten metal.
Wherein the pore density of the polyurethane sponge in the ceramic filter center is 25PPI, and the pore density of the polyurethane sponge in the ceramic support layer is 15PPI. The slurry A comprises the following components: 55wt% of silicon carbide powder, 3000-mesh particle size, 8wt% of each of alumina and kaolin, 5wt% of sodium carboxymethyl cellulose, 1wt% of sodium polyacrylate and 23wt% of deionized water. The slurry B comprises the following components: 45wt% of silicon carbide powder, 50% of each of 4500-mesh and 5000-mesh particle sizes, 5wt% of each of alumina and kaolin, 15wt% of sodium carboxymethyl cellulose, 10wt% of amorphous silicon powder, 1wt% of sodium polyacrylate and 19wt% of deionized water, wherein the particle size of the amorphous silicon powder is 5000-mesh. And mechanically stirred at the rotating speed of 1500r/min for 1 hour respectively. Fig. 6 is a schematic structural view of the porous silicon carbide ceramic in this embodiment.
Claims (7)
1. A preparation method of high-strength porous silicon carbide ceramic for molten metal filtration is characterized by comprising the following specific steps:
step 1: soaking polyurethane sponge in the shapes required by the ceramic filter center and the ceramic support layer for 2-3 hours in a sodium hydroxide solution with the concentration of 10-30wt%;
step 2: soaking the polyurethane sponge processed in the step 1 into the slurry A, and extruding the redundant slurry out, wherein the thickness of the slurry attached to the surface of the sponge wire mesh is 0.3-0.6mm;
and step 3: soaking the polyurethane sponge of the ceramic support layer treated in the step (1) into the slurry B, and extruding out the redundant slurry, wherein the thickness of the slurry attached to the surface of the sponge silk screen is 0.5-0.8mm;
and 4, step 4: putting the polyurethane sponge of the ceramic filter center treated in the step 2 into the polyurethane sponge of the ceramic support layer treated in the step 3, and tightly surrounding the polyurethane sponge to obtain a porous silicon carbide ceramic unit body;
and 5: tightly attaching the porous silicon carbide ceramic unit bodies obtained in the step (4) to form a required filter shape, standing and drying for 24 hours, and shaping to obtain a porous silicon carbide ceramic matrix;
step 6: coating a ceramic protective layer on each outer side surface of the porous silicon carbide ceramic matrix obtained in the step (5), namely respectively immersing each outer side surface into the ceramic slurry B for 2-5mm;
and 7: placing the porous silicon carbide ceramic matrix with the ceramic protection layer in a high-temperature furnace, and sintering for 4 hours at 1600-1900 ℃ to obtain the high-strength porous silicon carbide ceramic for molten metal filtration;
the porosity of the polyurethane sponge in the ceramic filtering center in the step 1 is higher than that of the polyurethane sponge in the ceramic supporting layer;
the slurry A in the step 2 comprises the following components: 50-65wt% of silicon carbide powder, 5-10wt% of sintering aid, 5-10wt% of adhesive, 0.5-1wt% of dispersing agent and 14-39.5 wt% of deionized water; the particle size of the silicon carbide powder is 2000 to 3500 meshes;
the slurry B comprises the following components: 40-55wt% of silicon carbide powder, 5-10wt% of a sintering aid, 10-15wt% of an adhesive, 5-10wt% of amorphous silicon powder, 0.5-1wt% of a dispersing agent and 9-39.5wt% of deionized water; wherein the particle size of the silicon carbide powder is 4000 to 5000 meshes, and the particle size of the amorphous silicon powder is 4000 to 5000 meshes.
2. The method for preparing the high-strength porous silicon carbide ceramic for molten metal filtration according to claim 1, wherein the pore density of the polyurethane sponge in the ceramic filtration center ranges from 20 to 30PPI, and the pore density of the polyurethane sponge in the ceramic support layer ranges from 10 to 20PPI.
3. The method of claim 1, wherein the sintering aid is alumina and/or kaolin, the binder is sodium carboxymethylcellulose, and the dispersant is sodium polyacrylate.
4. The method of claim 1, wherein the dimension of the ceramic filter center polyurethane sponge is greater than the center dimension of the ceramic support layer polyurethane sponge, such that an interference fit is formed between the ceramic support layer polyurethane sponge and the ceramic filter center polyurethane sponge.
5. The method of preparing a high-strength porous silicon carbide ceramic for molten metal filtration according to claim 1, wherein the filter composed of the porous silicon carbide ceramic unit bodies of step 5 has a shape of a rectangular parallelepiped, a cylinder, or a polygon.
6. The method for preparing a high-strength porous silicon carbide ceramic for molten metal filtration according to claim 1, wherein the porous silicon carbide ceramic for molten metal filtration of step 7 has the same three-dimensional structure as the polyurethane foam, the pore diameter of the ceramic filtration core is 0.8 to 1.5mm, the pore diameter of the ceramic support layer is 1 to 3mm, the thickness of the protective layer is 2 to 5mm, and the surface of the ceramic skeleton has micro-nano pores with a pore diameter of 0.8 to 20 μm.
7. A high-strength porous silicon carbide ceramic for molten metal filtration, which is prepared by the preparation method according to any one of claims 1 to 6.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101224361A (en) * | 2007-10-25 | 2008-07-23 | 晶锐瓷业（北京）有限公司 | Spumy ceramic filter capable of high slag resistance and thermal stability, and fabricating method thereof |
| CN102350134A (en) * | 2011-07-29 | 2012-02-15 | 王建忠 | Multilayer casting filter |
| CN105131934A (en) * | 2015-10-08 | 2015-12-09 | 河南天祥新材料股份有限公司 | Double-layer high-strength fracturing propping agent and preparing method thereof |
| EP3392034A1 (en) * | 2017-04-19 | 2018-10-24 | Rolls-Royce High Temperature Composites Inc | Method to process a ceramic matrix composite (cmc) with a protective ceramic coating |
| CN209998316U (en) * | 2019-04-18 | 2020-01-31 | 孙中民 | Filter disc bracket for casting |
| CN111905461A (en) * | 2020-07-29 | 2020-11-10 | 高博集团有限公司 | PM2.5 vehicle-mounted air filter material and preparation method thereof |
| CN112745135A (en) * | 2021-01-08 | 2021-05-04 | 武汉科技大学 | Magnesium oxide-silicon carbide-carbon porous ceramic filter and preparation method thereof |
| CN113651634A (en) * | 2021-08-11 | 2021-11-16 | 吉林大学 | Preparation method of leakage-proof composite heat storage material |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20210331096A1 (en) * | 2018-07-09 | 2021-10-28 | Kabushikigaisya Prozeal | Ceramic Filter And Manufacturing Method Therefor |
-
2021
- 2021-11-24 CN CN202111404168.5A patent/CN114230345B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101224361A (en) * | 2007-10-25 | 2008-07-23 | 晶锐瓷业（北京）有限公司 | Spumy ceramic filter capable of high slag resistance and thermal stability, and fabricating method thereof |
| CN102350134A (en) * | 2011-07-29 | 2012-02-15 | 王建忠 | Multilayer casting filter |
| CN105131934A (en) * | 2015-10-08 | 2015-12-09 | 河南天祥新材料股份有限公司 | Double-layer high-strength fracturing propping agent and preparing method thereof |
| EP3392034A1 (en) * | 2017-04-19 | 2018-10-24 | Rolls-Royce High Temperature Composites Inc | Method to process a ceramic matrix composite (cmc) with a protective ceramic coating |
| CN209998316U (en) * | 2019-04-18 | 2020-01-31 | 孙中民 | Filter disc bracket for casting |
| CN111905461A (en) * | 2020-07-29 | 2020-11-10 | 高博集团有限公司 | PM2.5 vehicle-mounted air filter material and preparation method thereof |
| CN112745135A (en) * | 2021-01-08 | 2021-05-04 | 武汉科技大学 | Magnesium oxide-silicon carbide-carbon porous ceramic filter and preparation method thereof |
| CN113651634A (en) * | 2021-08-11 | 2021-11-16 | 吉林大学 | Preparation method of leakage-proof composite heat storage material |
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