CN110776322B - Carbon-free composite ceramic submersed nozzle material and preparation method thereof - Google Patents
Carbon-free composite ceramic submersed nozzle material and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a carbon-free composite ceramic submerged nozzle material and a preparation method thereof, and belongs to the technical field of composite ceramics. The invention takes hafnium boride, zirconium oxide fiber, niobium silicide and silicon nitride as raw materials, adopts the processes of ball milling and mixing in sequence, drying, hot-pressing sintering and the like to prepare the material of the hafnium boride-zirconium oxide fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle, ensures the reliability of the material of the zirconium oxide fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle by ball milling in sequence, coating hexagonal boron nitride on graphite paper and the inner wall of a mould for lubrication and adding a sintering aid niobium silicide, and the nozzle has the functions of anti-clogging and liquid steel cleaning. The hafnium boride-zirconium oxide fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle has the advantages of high material density, molten steel erosion resistance, oxidation resistance, excellent mechanical strength, difficult fracture in the installation and use process and high use reliability. The method has simple process and short production period, and is suitable for industrial production.
Description
Technical Field
The invention belongs to the field of composite ceramic materials, and particularly relates to a carbon-free hafnium boride-zirconia fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle material and a preparation method thereof.
Background
Hafnium boride (HfB)2) The hafnium boride has a two-dimensional network structure formed by alternating boron atom planes and hafnium atom planes in the crystal structure, and the ionic bond between the boron atom planes and the hafnium atom planes and the strong bond property of a boron-boron covalent bond determine the high temperature resistance (the melting point is 3380 ℃) of the hafnium boride, so that the hafnium boride has high strength at normal temperature and high temperature, good thermal shock resistance, oxidation resistance at high temperature, good chemical stability and almost no acid-base corrosion (except hydrofluoric acid).
CN201410234517.7 provides a preparation method of a tungsten-aluminum nitride-hafnium boride composite material, which comprises the following steps: firstly, mixing and ball-milling mixed powder of tungsten powder, aluminum nitride powder and hafnium boride powder with absolute ethyl alcohol according to a proportion to obtain slurry; drying and grinding the slurry to obtain a blank; thirdly, carrying out hot-pressing sintering on the blank to obtain the tungsten-aluminum nitride-hafnium boride composite material. According to the invention, the aluminum nitride is introduced into the composite system of tungsten and hafnium boride, so that the room temperature fracture toughness of the composite material can be improved, the sintering temperature can be reduced, the sintering temperature of the composite material can be further reduced through mechanical alloying, and the separation between a ceramic phase and a metal can be avoided. The tungsten-aluminum nitride-hafnium boride composite material prepared by the method has good matching performance of room temperature fracture toughness and high temperature tensile strength.
The application numbers are: 201811177542.0, a carbon fiber reinforced hafnium boride-tantalum boride-carbon ceramic matrix composite and a method for preparing the same are provided. The method comprises the following steps: (1) dipping a carbon fiber preform by using a hafnium-tantalum precursor solution containing a hafnium-tantalum precursor copolymer, a boron source precursor, a carbon source precursor and an organic solvent, and then sequentially carrying out curing and cracking on the dipped carbon fiber preform; and (2) repeating the step (1) for a plurality of times to prepare the carbon fiber reinforced hafnium boride-tantalum boride-carbon ceramic matrix composite material. The preparation method has the advantages of simple process, no need of any additive, low preparation temperature, short preparation period, easy industrial implementation and the like. The carbon fiber reinforced hafnium boride-tantalum boride-carbon ceramic-based composite material prepared by the method has the advantages of good toughness, ultrahigh temperature resistance, excellent oxidation resistance, excellent ablation resistance and the like.
Submerged entry nozzle (submerged nozzle) is a refractory casing for pouring in a continuous casting plant installed at the bottom of a tundish and inserted below the level of the steel in a crystallizer. The main function of the submerged nozzle is to prevent secondary oxidation of the pouring flow of the tundish and molten steel splashing; the covering slag of the crystallizer is prevented from being involved into the molten steel; the flow state and heat flow distribution of the injection flow in the crystallizer are improved, so that the uniform growth of a billet shell in the crystallizer is promoted, and the elimination of gas and inclusions in steel is facilitated. The submerged nozzles have remarkable effects on improving the quality of casting blanks, improving labor conditions, stabilizing continuous casting operation, preventing surface defects of the casting blanks and the like, so that the submerged nozzles are adopted for casting in slab continuous casting and bloom continuous casting in various countries in the world.
The basic requirements of the submerged nozzle material are good molten steel melting loss resistance, strong slag erosion resistance and good thermal shock resistance. The commonly used materials are fused silica and Al2O3-two species C. The submerged nozzle is made of fused quartz as raw material and is formed by slurry casting and high-temperature sintering. The nozzle has small heat conductivity coefficient (1000 deg.C)2W/m.K), good thermal stability and low thermal expansion rate (e.g. containing 99% SiO)2The expansion rate of the quartz at 1000 ℃ is 0.05-0.06%), the quartz is not easy to form nodules, and the quartz can be used without preheating. The fused quartz nozzle is not suitable for casting steel with manganese content more than 0.5 percent because of SiO in the Mn nozzle2Reaction to generate MnO.SiO with the melting point of only 1300 DEG C2The glass reduces the viscosity of the glass layer on the surface of the water gap and accelerates the melting loss of the water gap.
Al2O3the-C submerged nozzle is formed by taking corundum and graphite as basic raw materials, adding metal silicon, silicon carbide and the like, forming in an isostatic press and then performing protective sintering, and is suitable for pouring most steel grades.
Al2O3Before the-C nozzle is used, graphite burning loss (decarburization) occurs in the preheating process, so that the porosity of the surface layer of the nozzle is increased, and the corrosion resistance of the surface layer of the nozzle is reduced. Al in casting special steels and Al or Al-Si killed steels2O3-C immersion nozzle tends to produce Al2O3The accretion phenomenon causes unstable flow state of molten steel, even the nozzle is blocked, which damages normal casting flow and affects the quality of steel billets. In Al2O3ZrB developed on the basis of-C2-Al2O3The oxidation resistance of the-C nozzle material is greatly improved, but the problem of nozzle blockage is still not solved. Al (Al)2O3-C nozzle Al2O3One of the main causes of clogging is the presence of carbon in the nozzle material, and SiO therein2Reduction reaction is carried out, and the reduced SiO and CO further react with Al in the molten steel to produce Al2O3Al adhered to the inner wall surface of the nozzle2O3On the aggregate, Al on the inner wall of the nozzle2O3And (6) depositing. Therefore, the non-carbonization of the material of the submerged nozzle is one of the methods for solving the problem of nozzle blockage, and the literature, "research and application of non-carbon raw materials in steelmaking process" indicates that the material of the submerged nozzle has various advantages of non-carbonization.
The hafnium boride can be used as a high-speed cosmic arrow material and can be used in the atmosphere of 2000-2200 ℃, and the oxidation resistance of the boron compound containing much hafnium is 10 times higher than that of zirconium boride. The hafnium boride has high strength at normal temperature and high temperature, good thermal shock resistance, oxidation resistance at high temperature, good chemical stability and almost no acid-base corrosion, and meets the requirements of good molten steel corrosion resistance, strong slag corrosion resistance and good thermal shock resistance of the submerged nozzle material.
The submerged nozzle material has excellent thermal shock resistance, high fracture toughness and thermal shock resistance, which means more use times, long service life and excellent use reliability. Therefore, the hafnium boride ceramic used as a submerged entry nozzle must be further improved in thermal shock resistance, fracture toughness and thermal shock resistance to increase its competitive advantage. In addition, the carbon-free hafnium boride ceramic nozzle material has the functions of preventing blockage and cleaning molten steel.
Single hafnium boride ceramic (bending strength less than or equal to 400MPa, compressive strength about 1555.3 MPa, elastic modulus about 343GPa, fracture toughness less than or equal to 3.5 MPa.m1/2) The thermal shock resistance, the erosion resistance, the thermal shock resistance and the fracture toughness of the hafnium boride ceramic are limited, and the comprehensive mechanical strength of the hafnium boride ceramic is difficult to meet the mechanical strength requirement required by a nozzle brick, so that the preparation process and the formula of the hafnium boride ceramic must be improved, and the hafnium boride ceramic can be used as an immersion nozzle. At present, most scholars at home and abroad introduce a second phase into a ceramic matrix to improve the heat shock resistance, the fracture toughness and the thermal shock resistance. However, experiments show that simply adding the second phase does not effectively improve the performance, but rather reduces the performance if the design is not reasonable.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a carbon-free hafnium boride-zirconia fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle material and a preparation method thereof.
The invention provides a carbon-free composite ceramic submerged nozzle material which is prepared by compositely firing hafnium boride, zirconium oxide fiber, niobium silicide and silicon nitride, wherein the hafnium boride accounts for 70-87 vol%, the zirconium oxide fiber accounts for 5-15 vol%, the niobium silicide accounts for 4.5-5 vol%, and the silicon nitride accounts for 3.5-10 vol%.
The preparation method of the carbon-free composite ceramic submerged nozzle material comprises the following steps:
firstly, using mixed powder of hafnium boride, niobium silicide and silicon nitride as ball-milling material, mixing the ball-milling material with absolute ethyl alcohol, adding ZrO2Ball milling is carried out for 3-4 hours under the condition that the rotating speed is 150-180 r/min;
secondly, adding zirconia fiber, continuing secondary ball milling and mixing for 4-5 hours, and obtaining mixed slurry after ball milling is finished;
thirdly, drying the mixed slurry to obtain sintered powder;
and fourthly, sintering: coating hexagonal boron nitride on the inner wall of the mold and the contact part of the sintering powder before loading, loading the sintering powder into a graphite mold, and putting the graphite mold into a vacuum hot-pressing furnace for hot-pressing sintering;
wherein the sintering conditions are as follows: heating to 1800-1900 ℃ at a temperature rise speed of 5-20 ℃/min, sintering, keeping the temperature for 60 +/-5 min, and keeping the vacuum degree in the furnace less than or equal to 10 in the whole sintering process-2And Pa, filling argon protective atmosphere, and applying sintering pressure of 20-25 MPa in the sintering process.
Further, the mixing ratio of the ball-milling material to the absolute ethyl alcohol is 1: 1-1: 2.
Further, the ZrO2The ball-material ratio of the grinding balls to the ball-milling material is 4: 1.
Further, the drying conditions of the dry mixed slurry are as follows: the drying speed is 30-50 r/min, and the temperature is 40-75 ℃.
Advantageous effects
The hafnium boride is of a hexagonal structure, a two-dimensional network structure is formed by the alternate appearance of boron atom surfaces and hafnium atom surfaces in the crystal structure, the ionic bond between the boron atom surfaces and the hafnium atom surfaces and the strong bond property of a boron-boron covalent bond determine the high temperature resistance (the melting point is 3380 ℃) of the hafnium boride, the strength of the hafnium boride is very high at normal temperature and high temperature, the hafnium boride is good in thermal shock resistance and oxidation resistance at high temperature, the hafnium boride has good chemical stability and is hardly corroded by acid and alkali, and the requirements of good molten steel corrosion resistance, strong slag corrosion resistance and good thermal shock resistance of a submerged nozzle material are met. In addition, the material does not contain carbon and SiO2Thereby preventing blockageThe plug and the molten steel cleaning function. However, the related use of the hafnium boride-based submerged nozzle is not reported in China.
The denser the material of the water gap, the more excellent the erosion resistance and the erosion resistance in the continuous casting process. The hafnium boride grains are connected by strong covalent bonds, atoms diffuse slowly during sintering, and are difficult to sinter and densify, so that the hafnium boride is not suitable for being produced by adopting the traditional nozzle preparation process technology of slurry casting molding. The hot-pressing sintering method can reduce the porosity and improve the density and the mechanical property of the material, thereby being an ideal method for preparing the hafnium boride ceramic for the submerged nozzle.
Although hafnium boride having a large hafnium content is excellent in oxidation resistance, it is necessary to add a small amount of additives in order to further improve its high-temperature oxidation resistance. At present, adding silicide is one of the methods for improving the oxidation resistance of hafnium boride. At high temperature, a hafnium oxide and borosilicate glass dense oxide film layer is generated on the surface of the hafnium boride material added with silicide, so that external oxygen can be prevented from entering the material to be further oxidized.
Zirconium oxide (ZrO)2) The fiber can be used for a long time in an ultrahigh temperature oxidizing atmosphere of more than 1500 ℃, the maximum using temperature can reach 2200 ℃ and even 2500 ℃, the fiber can still keep a complete fiber shape and has a tetragonal phase (t-ZrO)2) To monoclinic phase (m-ZrO)2) The martensitic transformation effect of (2). Thus, the introduction of the second phase ZrO in the hafnium boride ceramic2The fiber can simultaneously achieve the effects of fiber toughening and phase change toughening. In addition, the normal temperature thermal conductivity of the zirconia is 4.0W/m.K, and the thermal conductivity of the material of the nozzle is slightly reduced by introducing the zirconia at 1000 ℃ of 2.09W/m.K.
When hot-pressing sintering is adopted, the length of the zirconia fiber can be partially damaged due to overlarge pressure, and the toughening mechanism of fiber debonding, pulling-out and bridging is weakened, so that a small amount of sintering aid needs to be added to reduce the sintering temperature and pressure. The melting point of niobium silicide is 1940 ℃, and the niobium silicide can generate a borosilicate glass compact oxide film layer with hafnium boride to improve the oxidation resistance of the borosilicate glass compact oxide film layer, so the niobium silicide is the best sintering aid for preparing the zirconium oxide fiber toughened hafnium boride-based ceramic by a hot pressing method.
The friction factor of the silicon nitride is 0.02-0.35, and the silicon nitride is equivalent to the surface of the oiled metal, so that the silicon nitride has excellent self-lubricating capability. It has excellent chemical stability, and can resist all inorganic acids except hydrofluoric acid and most non-metal solution. In addition, it can resist cold and hot impact, and can be heated to above 1000 deg.C in air, and can be cooled rapidly and heated rapidly, and will not be broken. Therefore, when the hafnium boride ceramic is added into the hafnium boride ceramic, the friction coefficient can be reduced, the molten steel scouring resistance is improved, and the thermal shock resistance are improved.
The hexagonal boron nitride has a melting point of 3000 ℃, has a layered structure similar to graphite, has good lubricity, is coated on the inner wall of the grinding tool to reduce the friction force between particles and the inner wall of the grinding tool, is beneficial to uniform distribution of pressure in a blank so as to reduce density difference of each part, ensures that the material has reliable mechanical property, and simultaneously reduces diffusion of carbon elements in the graphite into the blank.
The drying of the invention adopts a rotary evaporation drying method, the rotating speed and the temperature of the rotary evaporation dryer are properly controlled, and if the rotating speed is too low and the drying is not sufficient, the centrifugal force is too high to cause the gravity segregation.
The invention relates to a hafnium boride-zirconia fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle material and a preparation method thereof, wherein the prepared hafnium boride-zirconia fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle material has the apparent porosity of less than or equal to 8%, the bending strength of more than or equal to 450MPa, and the fracture toughness of more than or equal to 6.28 MPa.m1/2The maximum thermal shock resistance temperature delta T can reach 1400 ℃, the molten steel erosion resistance is less than or equal to 0.62mm/h, the thermal shock resistance frequency is more than or equal to 50 (1100 ℃, water cooling), the spalling resistance is less than or equal to 18.7 percent, and the thermal expansion coefficient is less than or equal to 6.67 multiplied by 10-5K-1. The invention adopts the process method, takes hafnium boride, zirconia fiber, niobium silicide and silicon nitride as raw materials, and adopts the processes of ball milling, mixing, drying, hot-pressing sintering and the like to prepare the hafnium boride-zirconia fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle.
The carbon-free composite ceramic submerged nozzle prepared by the process has the advantages of high material density, molten steel erosion resistance, oxidation resistance, excellent mechanical strength, difficult fracture in the installation and use process and high material use reliability. The method has simple process and short production period, and is suitable for industrial production.
Detailed Description
The present invention will be described in detail with reference to specific examples.
In the embodiment of the invention, the average grain diameter of the hafnium boride powder is less than or equal to 5 mu m, and the purity is more than or equal to 99 percent; ZrO (ZrO)2The diameter of the fiber is 5-10 μm, and the length is 100-500 μm; the average grain diameter of the niobium silicide powder is less than or equal to 10 mu m, and the purity is more than or equal to 99 percent; the average grain diameter of the silicon nitride powder is less than or equal to 5 mu m, and the purity is more than or equal to 99 percent. The average grain diameter of the hexagonal boron nitride for lubrication is respectively less than or equal to 20 mu m, and the purity is more than or equal to 99 percent;
example 1:
the embodiment provides a carbon-free composite ceramic submerged nozzle material, which is formed by compositely firing hafnium boride, zirconium oxide fibers, niobium silicide and silicon nitride, wherein the hafnium boride accounts for 87vol%, the zirconium oxide fibers account for 5vol%, the niobium silicide accounts for 4.5vol%, and the silicon nitride accounts for 3.5 vol%.
1. Taking mixed powder of 87vol% hafnium boride, 4.5vol% niobium silicide and 3.5vol% silicon nitride as ball milling material, adding the ball milling material and absolute ethyl alcohol into a polyurethane ball milling tank according to the volume ratio of 1:2, and adding ZrO according to the ball-to-material ratio of 4:12Grinding balls, wherein the rotating speed of the ball mill is 180r/min, and the ball milling time is 3 hours.
2. And (4) suspending the ball mill, opening the ball milling tank, adding 5vol% of zirconia fiber, continuing ball milling and mixing for 5 hours, and performing total ball milling for 8 hours to obtain mixed slurry.
3. And drying the mixed slurry by using a mixing dryer to obtain the sintered powder, wherein the rotating speed of the mixing dryer is 50r/min, and the temperature is 40 ℃.
4. And (3) sintering: before loading, coating a lubricating isolation layer on the inner wall of the mold, loading sintering powder into the graphite mold, separating the sintering powder and the upper and lower graphite gaskets by coating hexagonal boron nitride graphite paper, and then putting the mold into a vacuum hot-pressing furnace for hot-pressing sintering. Heating to 1900 deg.C at a temperature raising rate of 20 deg.C/min, sintering, maintaining the vacuum degree in the furnace at 10 deg.C or less for 60min-2Pa, filling argon protective atmosphere, and applying in the sintering processAnd adding 20MPa of sintering pressure.
According to the embodiment, the mixing and grinding process is improved according to the requirement of the submerged nozzle material, the hardness and brittleness of the composite ceramic can reach the requirement of the submerged nozzle material under the condition of not adding carbon by the improved process, and if the composite ceramic is mixed in advance or together according to the traditional process, the cracking phenomenon is easy to occur under the cold and hot impact of later-stage molten steel.
Example 2:
the embodiment provides a carbon-free composite ceramic submerged nozzle material, which is formed by compositely firing hafnium boride, zirconium oxide fibers, niobium silicide and silicon nitride, wherein the hafnium boride accounts for 78vol%, the zirconium oxide fibers account for 10vol%, the niobium silicide accounts for 4.5vol%, and the silicon nitride accounts for 7.5 vol%.
1. Taking mixed powder of 78vol% hafnium boride, 4.5vol% niobium silicide and 7.5vol% silicon nitride as ball milling material, adding the ball milling material and absolute ethyl alcohol into a polyurethane ball milling tank according to the volume ratio of 1:1.5, and adding ZrO according to the ball-to-material ratio of 4:12And grinding balls, wherein the rotating speed of the ball mill is 160r/min, and the ball milling time is 3 hours.
2. And (4) suspending the ball mill, opening the ball milling tank, adding 10vol% of zirconia fiber, continuing ball milling and mixing for 4.5 hours, and performing ball milling for 7.5 hours to obtain mixed slurry.
3. And drying the mixed slurry by adopting a mixing dryer, wherein the rotating speed of the mixing dryer is 40r/min, the temperature is 50 ℃, and the sintered powder is obtained after the drying is finished.
4. And (3) sintering: coating hexagonal boron nitride on the inner wall of the mold before loading, loading sintering powder into a graphite mold, separating the sintering powder from the upper graphite gasket and the lower graphite gasket by coating hexagonal boron nitride graphite paper, and then placing the mold into a vacuum hot-pressing furnace for hot-pressing sintering. Heating to 1850 ℃ at a temperature rise rate of 15 ℃/min, sintering, keeping the temperature for 55min, and keeping the vacuum degree in the furnace to be less than or equal to 10 in the whole sintering process-2Pa, filling argon protective atmosphere, and applying sintering pressure of 23MPa in the sintering process.
Example 3:
the embodiment provides a carbon-free composite ceramic submerged nozzle material, which is formed by compositely firing hafnium boride, zirconium oxide fibers, niobium silicide and silicon nitride, wherein the hafnium boride accounts for 70vol%, the zirconium oxide fibers account for 15vol%, the niobium silicide accounts for 5vol%, and the silicon nitride accounts for 10 vol%.
1. Taking mixed powder of 70vol% hafnium boride, 5vol% niobium silicide and 10vol% silicon nitride as ball milling material, adding the ball milling material and absolute ethyl alcohol into a polyurethane ball milling tank according to the volume ratio of 1:1, and adding ZrO according to the ball-to-material ratio of 4:12Grinding balls, wherein the rotating speed of the ball mill is 150r/min, and the ball milling time is 4 hours.
2. And (4) suspending the ball mill, opening the ball milling tank, adding 15vol% of zirconia fiber, continuing ball milling and mixing for 4 hours, and performing total ball milling for 8 hours to obtain mixed slurry.
3. And drying the mixed slurry by using a mixing dryer, wherein the rotating speed of the mixing dryer is 30r/min, the temperature is 75 ℃, and the sintered powder is obtained after drying.
4. And (3) sintering: coating hexagonal boron nitride on the inner wall of the mold before loading, loading sintering powder into a graphite mold, separating the sintering powder from the upper graphite gasket and the lower graphite gasket by coating hexagonal boron nitride graphite paper, and then placing the mold into a vacuum hot-pressing furnace for hot-pressing sintering. Heating to 1800 ℃ at a temperature rise rate of 5 ℃/min for sintering, keeping the temperature for 65min, and keeping the vacuum degree in the furnace to be less than or equal to 10 in the whole sintering process-2And Pa, filling argon protective atmosphere, and applying 25MPa of sintering pressure in the sintering process.
Experiments show that if the four raw materials of the embodiment are ball-milled together, the maximum thermal shock resistance temperature of the zirconia fiber is lower than 600 ℃ after the zirconia fiber is excessively short-milled, and the requirements of the nozzle material cannot be met. If the hexagonal boron nitride is not coated inside during sintering, the finished product is easy to crack and cannot be used as a nozzle material.
The detection results of the material of the hafnium boride-zirconia fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle prepared in the embodiments 1 to 3 of the present invention are as follows:
| item | Example 1 | Example 2 | Example 3 |
| Apparent porosity (%) | 6.5 | 7.2 | 8 |
| Bending strength (Mpa) | 532.8±28.6 | 517.4±26.7 | 496.2±20.3 |
| Breaking wilting (MPa. m 1/2) | 6.28±0.23 | 8.15±0.25 | 7.61±0.20 |
| Maximum thermal shock resistance temperature Delta T | 1400 | 1400 | 1400 |
| Molten steel erosion resistance (mm/h) | 0.62 | 0.28 | 0.31 |
| Thermal shock resistance times (1100 ℃, water cooling) | 63 | 72 | 65 |
| Resistance to peeling (100%) | 12.3 | 15.6 | 16.2 |
| Coefficient of thermal expansion (10-5K-1) | 5.32 | 5.17 | 5.89 |
The finally prepared hafnium boride-zirconia fiber-niobium silicide-silicon nitride composite ceramic submerged nozzle material has the following technical parameters: apparent porosity is less than or equal to 8 percent, bending strength is more than or equal to 450MPa, and fracture toughness is more than or equal to 6.28 MPa.m1/2The maximum thermal shock resistance temperature delta T can reach 1400 ℃, the molten steel erosion resistance is less than or equal to 0.62mm/h, the thermal shock resistance frequency is more than or equal to 50 (1100 ℃, water cooling), the spalling resistance is less than or equal to 18.7 percent, and the thermal expansion coefficient is less than or equal to 6.67 multiplied by 10-5K-1。
Claims (4)
1. A preparation method of a carbon-free composite ceramic submerged nozzle material is characterized by comprising the following steps: the preparation method of the carbon-free composite ceramic submerged nozzle material comprises the following steps:
firstly, using mixed powder of hafnium boride, niobium silicide and silicon nitride as ball-milling material, mixing the ball-milling material with absolute ethyl alcohol, adding ZrO2Ball milling is carried out for 3-4 hours under the condition that the rotating speed is 150-180 r/min;
secondly, adding zirconia fiber, continuing secondary ball milling and mixing for 4-5 hours, and obtaining mixed slurry after ball milling is finished;
thirdly, drying the mixed slurry to obtain sintered powder;
and fourthly, sintering: coating hexagonal boron nitride on the inner wall of the mold and the contact part of the sintering powder before loading, loading the sintering powder into a graphite mold, and putting the graphite mold into a vacuum hot-pressing furnace for hot-pressing sintering;
wherein, the hafnium boride accounts for 70-87 vol%, the zirconia fiber accounts for 5-15 vol%, the niobium silicide accounts for 4.5-5 vol%, and the silicon nitride accounts for 3.5-10 vol%;
wherein the sintering conditions are as follows: the temperature rise speed is 5-20 ℃ min, the mixture is heated to 1800-1900 ℃ for sintering, the temperature is kept for 60 +/-5 min, and the vacuum degree in the furnace is kept less than or equal to 10 in the whole sintering process-2And Pa, filling argon protective atmosphere, and applying sintering pressure of 20-25 MPa in the sintering process.
2. The method for preparing a carbon-free composite ceramic submerged nozzle material according to claim 1, wherein the method comprises the following steps: the mixing ratio of the ball-milling material to the absolute ethyl alcohol is 1: 1-1: 2.
3. The method for preparing a carbon-free composite ceramic submerged nozzle material according to claim 1, wherein the method comprises the following steps: the ZrO2The ball-material ratio of the grinding balls to the ball-milling material is 4: 1.
4. The method for preparing a carbon-free composite ceramic submerged nozzle material according to claim 1, wherein the method comprises the following steps: the drying conditions of the dry mixed slurry are as follows: the drying speed is 30-50 r/min, and the temperature is 40-75 ℃.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101265108A (en) * | 2008-04-16 | 2008-09-17 | 哈尔滨工业大学 | Boride-silicon carbide-boron carbide ternary ceramic-base composite material and preparation method thereof |
| CN101417880A (en) * | 2008-11-21 | 2009-04-29 | 哈尔滨工业大学 | Low temperature sintered boride base ceramic materials and preparation method thereof |
| CN102060554A (en) * | 2010-11-30 | 2011-05-18 | 哈尔滨工业大学 | High-strength high-toughness zirconium diboride-silicon carbide-zirconia ceramic-based composite material and preparation method thereof |
| CN102728827A (en) * | 2012-07-23 | 2012-10-17 | 武汉钢铁(集团)公司 | Continuous casting tundish capable of improving molten steel cleanliness |
| CN103286306A (en) * | 2012-02-29 | 2013-09-11 | 宝山钢铁股份有限公司 | Non-oxide enhanced material for slag line of submersed nozzle |
| CN104311139A (en) * | 2014-10-22 | 2015-01-28 | 山东理工大学 | Preparation method of silicon nitride and silicon carbide combined hafnium boride foamed ceramic |
-
2019
- 2019-11-26 CN CN201911172579.9A patent/CN110776322B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101265108A (en) * | 2008-04-16 | 2008-09-17 | 哈尔滨工业大学 | Boride-silicon carbide-boron carbide ternary ceramic-base composite material and preparation method thereof |
| CN101417880A (en) * | 2008-11-21 | 2009-04-29 | 哈尔滨工业大学 | Low temperature sintered boride base ceramic materials and preparation method thereof |
| CN102060554A (en) * | 2010-11-30 | 2011-05-18 | 哈尔滨工业大学 | High-strength high-toughness zirconium diboride-silicon carbide-zirconia ceramic-based composite material and preparation method thereof |
| CN103286306A (en) * | 2012-02-29 | 2013-09-11 | 宝山钢铁股份有限公司 | Non-oxide enhanced material for slag line of submersed nozzle |
| CN102728827A (en) * | 2012-07-23 | 2012-10-17 | 武汉钢铁(集团)公司 | Continuous casting tundish capable of improving molten steel cleanliness |
| CN104311139A (en) * | 2014-10-22 | 2015-01-28 | 山东理工大学 | Preparation method of silicon nitride and silicon carbide combined hafnium boride foamed ceramic |
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