Preparation method of high-purity corundum crucible for high-temperature alloy smelting

Abstract

The invention discloses a preparation method of a high-purity corundum crucible for high-temperature alloy smelting, belongs to the technical field of precision casting refractory material forming preparation, and aims to solve the problems that an Al2O3 crucible is easily eroded by high-temperature alloy, impurities are generated during high-temperature alloy smelting, and the Al2O3 crucible is difficult to be suitable for high-temperature alloy smelting. According to the technical key points, 60%-70% by mass of aluminum oxide Al2O3 powder and 30%-40% by mass of silicon oxide SiO2 powder are added into a ball milling tank to be subjected to ball milling treatment, the aluminum oxide Al2O3 powder comprises fine powder mixed powder with the particle size being 5-50 micrometers, medium powder mixed powder with the particle size being 50-300 micrometers and coarse powder mixed powder with the particle size being 0.4-0.5 mm, and the coarse powder mixed powder is mixed with the medium powder mixed powder with the particle size being 2-5 micrometers. A binder polyvinyl alcohol (PVA) solution is added into the mixed powder for granulation operation, after the mixed material is aged, the mixed material is pressed in a cold isostatic pressing mode, a crucible preformed blank is obtained and sintered at different temperatures after being dried, and the crucible is obtained. The method has the effect that the sintered high-purity corundum crucible has excellent high temperature resistance and thermal stability at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of precision casting refractory material molding preparation, and more specifically, relates to a preparation method of a high-purity corundum crucible for melting high-temperature alloys. Background Art

[0002] High-temperature alloys have excellent high-temperature strength, good oxidation resistance and thermal corrosion resistance, good fatigue performance and fracture toughness and other comprehensive properties. They have become key materials for high-temperature components such as aircraft engine turbine blades, guide vanes, and turbine disks. Especially in aircraft engines, the proportion of nickel-based high-temperature alloys is as high as 55% to 65%. Due to the complex composition of high-temperature alloys, a small amount of impurities will significantly reduce their performance. For example, O, N, and S can be converted into non-metallic inclusions, which are usually the initiation sites and expansion channels of fatigue cracks. At the same time, they will become crystallization cores and develop into grain defects during the solidification process. Therefore, it is necessary to accurately control the composition and impurity content of high-temperature alloys, improve the purity of high-temperature alloys, and further develop the application potential of this material.

[0003] When high-temperature alloys are melted in a vacuum induction furnace, the temperature is usually higher than the directional solidification temperature. During the melting process, the alloy melt is in contact with the inner surface of the crucible for a long time. Since the alloy usually contains a certain amount of active elements such as Al, C, Cr, etc., these elements are prone to interface reaction with SiO2 in the crucible, and the reaction products enter the melt and reduce the purity of the melt. As a result, the performance of the high-temperature alloy is reduced due to the generation of impurities during melting.

[0004] The prior art usually uses crucibles made of Y2O3, CaO and MgO to melt high-temperature alloys, which is useful for improving the purity of the melt, but has disadvantages such as high cost, difficulty in storage, and difficulty in forming. It has not yet been applied on a large scale. When the commonly used Al2O3 crucible is used to melt high-temperature alloys, the crucible will be corroded by the high-temperature alloy, and the particles will fall off and enter the molten alloy, forming Al2O3 inclusions with larger particles. In addition, when melting high-temperature alloys, the trace element Ca in the molten high-temperature alloy will reduce the corrosion resistance of the Al2O3 material, resulting in more obvious physical corrosion of the Al2O3 crucible. Therefore, the Al2O3 crucible is easy to produce impurities when melting high-temperature alloys, which reduces the performance of the high-temperature alloy, and is also easily corroded by the high-temperature alloy, resulting in reduced availability and difficult to be used in melting high-temperature alloys. Summary of the invention

[0005] In order to solve the problem that Al2O3 crucible is easily corroded by high-temperature alloys, impurities are generated when smelting high-temperature alloys, and it is difficult to be used for smelting high-temperature alloys, and further solve the problem that the microstructure of the crucible prepared by this material combination is uneven and non-dense, which leads to its reduced strength and sintering deformation.

[0006] In a first aspect, a method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to an embodiment of the present application comprises the following steps:

[0007] S1: Add 60% to 70% by weight of aluminum oxide Al2O3 powder and 30% to 40% by weight of silicon oxide SiO2 powder into a ball mill for ball milling at a ball milling speed of 120 to 150 r / min for 20 to 24 h, wherein the aluminum oxide Al2O3 powder includes a fine powder mixed powder with a particle size of 5 to 50 μm, a medium powder mixed powder with a particle size of 50 to 300 μm, and a coarse powder mixed powder with a particle size of 0.4 to 0.5 mm, and the silicon oxide SiO2 powder includes a mixed powder with a particle size of 50 to 300 μm;

[0008] S2: adding a binder polyvinyl alcohol (PVA) solution to the mixed powder after ball milling, mixing and grinding, granulating, and then sieving and aging;

[0009] S3: The mixture obtained after aging treatment is formed by cold isostatic pressing to obtain a crucible preform;

[0010] S4: drying the crucible preform to obtain a crucible green body;

[0011] S5: the green crucible is sintered at 1200° C. to 1320° C. and cooled to room temperature to obtain the high-purity corundum crucible for high-temperature alloy smelting.

[0012] According to a method for preparing a high-purity corundum crucible for high-temperature alloy smelting in an embodiment of the present application, the crucible green body is sintered at 1260°C.

[0013] According to a method for preparing a high-purity corundum crucible for high-temperature alloy smelting in an embodiment of the present application, by mass, the ratio of fine powder mixed powder with a particle size of 5 to 50 μm in alumina Al2O3 powder: medium powder mixed powder with a particle size of 50 to 300 μm: coarse powder mixed powder with a particle size of 0.4 to 0.5 mm: silicon oxide SiO2 powder mixed powder with a particle size of 50 to 300 μm = 2:2:2:3 or 1:3:3:3.

[0014] According to a method for preparing a high-purity corundum crucible for high-temperature alloy smelting in an embodiment of the present application, in step S2, the mass of polyvinyl alcohol PVA is 2% to 4% of the total mass of the mixed powder, and the concentration of the binder polyvinyl alcohol PVA solution is 8%. The mixed powder and the binder polyvinyl alcohol PVA are fully mixed and ground to make the coarse, medium and fine particles evenly distributed, and then passed through a 20-mesh sieve, and the mixture is aged for 24 hours.

[0015] According to a method for preparing a high-purity corundum crucible for high-temperature alloy smelting in an embodiment of the present application, in step S3, the aging treated mixed material is loaded into the crucible model cavity, and the filling operation is performed on a vibrating operating platform for 3 to 5 minutes. After the mold is sealed, it is placed in the high-pressure oil chamber of a cold isostatic press for cold isostatic pressing. The cold isostatic pressing pressure is 100 to 200 MPa, and the pressing time is 3 to 10 minutes. It is then taken out and demolded to obtain a crucible preform.

[0016] According to a method for preparing a high-purity corundum crucible for high-temperature alloy smelting in an embodiment of the present application, in step S4, the crucible preform is naturally shade-dried for 24 to 48 hours, and then placed in an oven for drying at a drying temperature of 100 to 150° C. for 12 to 18 hours to obtain a crucible green body.

[0017] According to a method for preparing a high-purity corundum crucible for high-temperature alloy smelting in an embodiment of the present application, in step S5, the crucible green body is placed in a sintering furnace for sintering treatment, the sintering temperature is 1200-1400°C, the sintering time is 15-20h, the heating rate is 80°C / h, the insulation time is 2-4h, and then the crucible is cooled to room temperature with the furnace to obtain the high-purity corundum crucible for high-temperature alloy smelting.

[0018] According to a method for preparing a high-purity corundum crucible for high-temperature alloy smelting in an embodiment of the present application, in step S1, the aluminum oxide Al2O3 powder is an electric-melted aluminum oxide Al2O3 powder, and the silicon oxide SiO2 powder is an electric-melted silicon oxide SiO2 powder, and the powder purity is ≥99.9%.

[0019] In a second aspect, a high-purity corundum crucible for high-temperature alloy smelting according to the embodiments of the present application is prepared by any one of the preparation methods described.

[0020] In a third aspect, the high-purity corundum crucible for high-temperature alloy melting according to the embodiment of the present application is used in the preparation of nickel-based high-temperature alloy remelting casting.

[0021] Beneficial effects:

[0022] 1. In order to improve the sintering density of the high-purity corundum ceramic crucible and obtain excellent high temperature resistance and high temperature stability, the present invention is based on the principle of activated sintering and adds silicon oxide SiO2. Silicon oxide SiO2 has a low thermal expansion coefficient and excellent thermal stability, and can reduce the sintering temperature and form a liquid phase during the sintering process. Aluminum oxide Al2O3 does not react with high-temperature alloys when molten alloy, and has excellent high temperature resistance. After aluminum oxide Al2O3 and silicon oxide SiO2 are evenly mixed, the sintered high-purity corundum crucible has excellent high temperature resistance and thermal stability.

[0023] 2. In the process of mixing aluminum oxide Al2O3 and silicon oxide SiO2 of different particle sizes, the experimental results show that the mass ratio of aluminum oxide Al2O3 and silicon oxide SiO2 using the present invention, especially the particle size classification and the specific particle size value range selection and distribution of the present invention, can be distinguished from other schemes without doping coarse particles or using other ranges of particle size selection and distribution, and no agglomerates are formed, so that the medium and coarse powders are the skeleton, and the fine powders are evenly distributed between the large skeletons to form a dense structure, which can improve the uniformity and density of the microstructure and high strength. The prepared high-purity corundum ceramic crucible has excellent density, and, when combined with a sintering temperature of 1200°C to 1320°C, especially 1260°C, can achieve a sintering shrinkage rate of at least 5.5%, which greatly reduces the deformation of the material during sintering, and has a high balance between porosity and strength.

[0024] 3. The method of the present invention has simple and easy operation steps, short process flow and low production cost. In general, the prepared ceramic crucible has the characteristics of high density and low manufacturing cost, which can meet the industrial production needs in the field of high-temperature alloy smelting. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a real photo of a high-purity corundum crucible made by the process of the present invention.

[0026] Figure 2 This is a photo of the inner surface of a high-temperature alloy melted in a high-purity corundum crucible using vacuum induction melting.

[0027] Figure 3 It is the microstructure morphology of high purity corundum crucible.

[0028] Figure 4 This is a comparison of the microstructure morphology of different crucibles in the experimental example.

[0029] Figure 5 This is a comparison chart of the porosity and strength of different crucibles in the experimental example.

[0030] Figure 6 This is a comparison chart of the shrinkage rates of different crucibles at different sintering temperatures in the experimental example.

[0031] Figure 7 This is a graph showing the trend of porosity and strength of different crucibles at different temperatures in the experimental example. DETAILED DESCRIPTION

[0032] The scheme of the present invention is further described below in conjunction with embodiments:

[0033] The present invention aims to provide a refractory material for melting high-temperature alloys that has high chemical stability and excellent thermal shock resistance and can be put into large-scale production for preparing crucibles. Al2O3 doped with SiO2 to prepare crucibles can form a corundum phase, so that aluminum oxide Al2O3 does not react with high-temperature alloys when molten alloy, and has excellent high temperature resistance. Silicon oxide SiO2 has a low thermal expansion coefficient and excellent thermal stability. In addition, Al2O3 and SiO2 have low costs and can be put into large-scale production.

[0034] However, the powder of Al2O3 doped SiO2 material is easy to form agglomerates, which makes the prepared crucible have uneven microstructure, resulting in low strength and large deformation of the material during sintering.

[0035] The present invention further prepares a crucible with excellent thermal shock resistance and thermal stability, and has uniform microstructure, high density, high strength, and small deformation of the material during sintering. To achieve the above purpose, according to one aspect of the present invention, the present invention provides a method for preparing a high-purity corundum crucible for high-temperature alloy smelting, the method comprising:

[0036] S1: The fused alumina Al2O3 powder, wherein the fine powder particle size is 5-50μm, the medium powder particle size is 50-300μm, the coarse powder particle size is 0.4mm-0.5mm, and the fused silicon oxide SiO2 powder with a particle size of 50-300μm, is proportioned according to the proportion of 60%-70% of the fused alumina Al2O3 powder and 30%-40% of the fused silicon oxide SiO2 powder. The powders are added to the ball mill in order from large to small in mass, and zirconium oxide balls are added in advance. The ball milling speed is 120-150r / min, and the ball milling time is 20-24h. Among them, the purpose of adding the powders to the ball mill in order from large to small in mass is to improve the mixing uniformity, and the mixed powder is ball milled for a long time to ensure that the powders are fully and evenly mixed. Preferably, the powder purity is ≥99.9%.

[0037] Alumina Al2O3 does not react with high-temperature alloys when molten alloy, and has excellent high temperature resistance. Silicon oxide SiO2 has a low thermal expansion coefficient and has excellent thermal stability. During the mixing process of aluminum oxide Al2O3 and silicon oxide SiO2 of different particle sizes, medium and coarse powders are used as aggregates, and fine powders are evenly distributed between large skeletons to form a dense structure, so that the sintered high-purity corundum crucible has excellent high temperature resistance and thermal stability.

[0038] S2: pour out the mixed powder after ball milling, add the binder polyvinyl alcohol PVA, the mass of the polyvinyl alcohol PVA is 2% to 4% of the total mass of the mixed powder, and the concentration of the binder polyvinyl alcohol PVA solution is 8%. Grind the mixed powder and the binder polyvinyl alcohol PVA thoroughly to make them uniform, then pass through a 20-mesh sieve (about 1mm), and age the mixture for 24 hours.

[0039] S3: The aging mixture is loaded into the crucible model cavity, and the filling operation is performed on a vibrating operating platform for 3 to 5 minutes. After the mold is sealed, the model cavity is placed in the high-pressure oil chamber of the cold isostatic press for cold isostatic pressing. The cold isostatic pressing pressure is 100 to 200 MPa, and the pressing time is 3 to 10 minutes. Then, the preform is taken out and demolded to obtain a crucible preform.

[0040] S4: The crucible preform obtained in step 3 is naturally dried in the shade for 24 to 48 hours, and then placed in an oven for drying at a drying temperature of 100 to 150° C. for 12 to 18 hours.

[0041] S5: placing the green crucible obtained in step 4 in a sintering furnace for sintering at a sintering temperature of 1200-1400°C for 15-20 hours, ensuring a heating rate of 80°C / h, a holding time of 2-4 hours, and then cooling to room temperature with the furnace to obtain the high-purity corundum crucible for high-temperature alloy smelting. The high-purity corundum crucible obtained by the above preparation method of the present invention has a high melting point and can be used to smelt most types of high-temperature alloys on the market.

[0042] Example 1: A high-purity corundum crucible for high-temperature alloy smelting is prepared by cold isostatic pressing technology, and the specific steps are as follows:

[0043] S1: Mix fused alumina Al2O3 powder, including fine powder with a particle size of 5-50μm, medium powder with a particle size of 50-300μm, coarse powder with a particle size of 0.5mm, and fused silicon oxide SiO2 powder with a particle size of 50-300μm, in a mass ratio of 2:2:2:3, add the powders into a ball mill in descending order of particle size, add zirconium oxide balls in advance, and the ball mill speed is 120r / min. The ball mill time is 20h to obtain a mixed powder.

[0044] S2: Add binder polyvinyl alcohol (PVA) to the mixed powder for granulation. The mass of the added binder PVA is 2% of the mixed powder, and the concentration of the binder polyvinyl alcohol (PVA) solution is 8%. Grind the mixed powder and the binder polyvinyl alcohol (PVA) thoroughly to make them evenly mixed, then pass through a 20-mesh sieve, and age the powder for 24 hours.

[0045] S3: The aging mixture is loaded into the crucible model cavity, and the filling operation is performed on a vibrating operating platform for 5 minutes. After the mold is sealed, the crucible model cavity is placed in the high-pressure oil chamber of the cold isostatic press for cold isostatic pressing. The cold isostatic pressing pressure is 150 MPa, and the pressing time is 5 minutes. Then, the preform is taken out and demolded to obtain a crucible preform.

[0046] S4: The crucible preform obtained in step 3 is naturally dried in the shade for 24 hours, and then placed in an oven for drying at a drying temperature of 100° C. for 12 hours.

[0047] S5: placing the crucible green body obtained in step 4 in a sintering furnace for sintering, ensuring a heating rate of 80°C / h, sintering to 1260°C, keeping the temperature for 2h, and then cooling to room temperature with the furnace to obtain the high-purity corundum crucible for high-temperature alloy smelting.

[0048] Example 2: A high-purity corundum crucible for high-temperature alloys prepared by cold isostatic pressing, the specific steps are as follows:

[0049] S1: Mix fused alumina Al2O3 powder, including fine powder with a particle size of 5-50μm, medium powder with a particle size of 50-300μm, coarse powder with a particle size of 0.5mm, and fused silicon oxide SiO2 powder with a particle size of 50-300μm, in a mass ratio of 1:3:3:3, add the powders into a ball mill in descending order of particle size, add zirconium oxide balls in advance, and the ball mill speed is 120r / min. The ball mill time is 24h to obtain a mixed powder.

[0050] S2: Add binder polyvinyl alcohol (PVA) to the mixed powder for granulation. The mass of the added binder polyvinyl alcohol (PVA) is 3% of the mixed powder, and the concentration of the binder polyvinyl alcohol (PVA) solution is 8%. Grind the mixed powder and the binder polyvinyl alcohol (PVA) thoroughly to make them evenly mixed, then pass through a 20-mesh sieve, and age the powder for 24 hours.

[0051] S3: The aging powder is loaded into the crucible model cavity, and the filling operation is performed on a vibrating operating platform for 5 minutes. After the mold is sealed, the crucible model cavity is placed in the high-pressure oil chamber of the cold isostatic press for cold isostatic pressing. The cold isostatic pressing pressure is 180 MPa, and the pressing time is 5 minutes. Then, the preform is taken out and demolded to obtain a crucible preform.

[0052] S4: The crucible preform obtained in step 3 is naturally dried in the shade for 24 hours, and then placed in an oven for drying at a drying temperature of 100° C. for 12 hours.

[0053] S5: placing the crucible green body obtained in step 4 in a sintering furnace for sintering, ensuring a heating rate of 80°C / h, sintering to 1280°C, keeping the temperature for 2h, and then cooling to room temperature with the furnace to obtain the high-purity corundum crucible for high-temperature alloy smelting.

[0054] Experimental Example: Table 1 shows the ratio of fine powder mixed powder: medium powder mixed powder: coarse powder mixed powder: silicon oxide SiO2 powder by mass, where 2# is the relevant data of Example 1. 3# and 4# do not contain coarse powder mixed powder. It can be found from Table 1 that from 1# to 4#, the particle size distribution of aluminum oxide Al2O3 powder is divided into fine powder, medium powder and coarse powder. Among them: 1# fine powder particle size <5μm, medium powder particle size 50-300μm, coarse powder particle size 0.5-1mm; 2# fine powder particle size 5-50μm, medium powder particle size 50-300μm, coarse powder particle size 0.4-0.5mm; 3# fine powder particle size <5μm, medium powder particle size 50-300μm, no coarse powder particle size; 4# fine powder particle size 5-50μm, medium powder particle size 50-300μm, no coarse powder particle size.

[0055] Table 1

[0056]

[0057] according to Figure 4 Corresponding to the microscopic images of crucibles 1# to 4#, according to Figure 5 Corresponding to the porosity and strength of 1# to 4#, 1#, 3#, and 4# have coarse particles and agglomerates formed by the agglomeration of fine powder, and the microstructure is uneven, resulting in low strength. The microstructure of 2# is uniform and dense, and the strength is higher.

[0058] according to Figure 6 Corresponding to the shrinkage rates at different sintering temperatures under the particle size ratios of 2# and 3#, it can be found that the shrinkage rate of 2# sintered at 1260°C is the lowest at 5.5%, that is, its green body molding density is the highest, the bonding degree of coarse, medium and fine particles is the best, and the deformation of the material during sintering is the smallest. The high green body molding density of the material and the small deformation of the material during sintering indicate that the material has high performance uniformity.

[0059] according to Figure 7 Corresponding to the changing trend of porosity and strength of crucibles 1# to 4# at different temperatures, the porosity and strength changes of samples at different sintering temperatures all show a basic trend, that is, the porosity gradually decreases and the strength gradually increases. Since the crucible requires a certain porosity and strength, the balance between the two is more consistent at 1200-1320℃ for 2#, and the porosity is too low at 1380℃.

[0060] As described above, the present invention records a high-purity corundum refractory material and a crucible preparation method for high-temperature alloy smelting. Using fused aluminum oxide Al2O3 powder and fused silicon oxide SiO2 powder as raw materials, according to the reaction between the raw materials, a refractory material composed of 60% to 70% aluminum oxide Al2O3 powder and 30% to 40% silicon oxide SiO2 powder is determined, wherein aluminum oxide Al2O3 uses three powders with different particle sizes, and silicon oxide SiO2 uses one powder size. The mixed powder that has been fully ball-milled is granulated, and the binder polyvinyl alcohol PVA is added with a mass of 2% to 4% of the mass of the mixed powder, and the mixed powder is ground and sieved. The high-purity corundum crucible is formed by cold isostatic pressing the above-mentioned treated powder, drying the green body after obtaining it, and sintering it at 1200℃ to 1400℃. The method of the invention can effectively improve the purity of the corundum crucible, is suitable for smelting high-temperature alloys, and the crucible does not react with the high-temperature alloy, and has the advantages of low production cost, high production efficiency, and the like.

[0061] The terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0062] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a high-purity corundum crucible for high-temperature alloy smelting, characterized in that: The steps include: S1: Add 60% to 70% by weight of aluminum oxide Al2O3 powder and 30% to 40% by weight of silicon oxide SiO2 powder into a ball mill for ball milling at a ball milling speed of 120 to 150 r / min for 20 to 24 h, wherein the aluminum oxide Al2O3 powder includes a fine powder mixed powder with a particle size of 5 to 50 μm, a medium powder mixed powder with a particle size of 50 to 300 μm, and a coarse powder mixed powder with a particle size of 0.4 to 0.5 mm, and the silicon oxide SiO2 powder includes a mixed powder with a particle size of 50 to 300 μm; S2: adding a binder polyvinyl alcohol (PVA) solution to the mixed powder after ball milling, mixing and grinding, granulating, and then sieving and aging; S3: The mixture obtained after aging treatment is formed by cold isostatic pressing to obtain a crucible preform; S4: drying the crucible preform to obtain a crucible green body; S5: the green crucible is sintered at 1200° C. to 1400° C. and cooled to room temperature to obtain the high-purity corundum crucible for high-temperature alloy smelting.

2. The method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to claim 1, characterized in that: The green crucible was sintered at 1260°C.

3. The method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to claim 1 or 2, characterized in that: By mass, the ratio of fine powder mixed powder with particle size of 5-50μm in aluminum oxide Al2O3 powder: medium powder mixed powder with particle size of 50-300μm: coarse powder mixed powder with particle size of 0.4-0.5mm: silicon oxide SiO2 powder mixed powder with particle size of 50-300μm = 2:2:2:3 or 1:3:3:

3.

4. The method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to claim 1, characterized in that: In step S2, the mass of polyvinyl alcohol PVA is 2% to 4% of the total mass of the mixed powder, and the concentration of the binder polyvinyl alcohol PVA solution is 8%. The mixed powder and the binder polyvinyl alcohol PVA are fully mixed and ground to make the coarse, medium and fine particles evenly distributed, and then passed through a 20-mesh sieve and the mixture is aged for 24 hours.

5. The method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to claim 1, characterized in that: In step S3, the aged mixed material is loaded into the crucible model cavity, and the filling operation is performed on a vibrating operating platform for 3 to 5 minutes. After the mold is sealed, it is placed in the high-pressure oil chamber of a cold isostatic press for cold isostatic pressing. The cold isostatic pressing pressure is 100 to 200 MPa, and the pressing time is 3 to 10 minutes. Then it is taken out and demolded to obtain a crucible preform.

6. The method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to claim 1, characterized in that: In step S4, the crucible preform is naturally shade-dried for 24 to 48 hours, and then placed in an oven for drying at a temperature of 100 to 150° C. for 12 to 18 hours to obtain a crucible green body.

7. The method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to claim 1, characterized in that: In step S5, the crucible green body is placed in a sintering furnace for sintering treatment, the sintering temperature is 1200-1400°C, the sintering time is 15-20h, the heating rate is 80°C / h, the holding time is 2-4h, and then cooled to room temperature with the furnace to obtain the high-purity corundum crucible for high-temperature alloy smelting.

8. The method for preparing a high-purity corundum crucible for high-temperature alloy smelting according to claim 1, characterized in that: In step S1, the aluminum oxide Al2O3 powder is fused aluminum oxide Al2O3 powder, and the silicon oxide SiO2 powder is fused silicon oxide SiO2 powder, and the purity of the powders is ≥99.9%.

9. A high-purity corundum crucible for high-temperature alloy smelting, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

10. Use of the high-purity corundum crucible for high-temperature alloy smelting according to claim 9 in preparing remelting and pouring of nickel-based high-temperature alloy.

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