An aluminum-magnesium based ceramic crucible for melting superalloys and a method for manufacturing the same

Abstract

The application discloses an aluminum-magnesium-based ceramic crucible for smelting high-temperature alloy and a preparation method thereof. According to weight fractions, the aluminum-magnesium-based ceramic crucible comprises the following components: 20-40 parts of high-purity white corundum powder particles, 15-35 parts of high-purity white corundum particles, 13-20 parts of high-purity white corundum fine powder particles, 0-10 parts of aluminum-magnesium spinel, 9-13 parts of alpha-alumina powder, 5-9 parts of magnesium lactate, 4-8 parts of a binding agent, 0.2 parts of a dispersing agent, and 5-10 parts of deionized water; wherein the diameter of the high-purity white corundum powder particles is 3-5 mm, the diameter of the high-purity white corundum particles is 1-3 mm, and the diameter of the high-purity white corundum fine powder is less than 1 mm. The ceramic crucible prepared by the application is chemically stable, cannot react with high-temperature alloy during use, and cannot precipitate harmful substances, so that the smooth casting is ensured on the basis of meeting the use strength, and the performance and production efficiency of high-temperature alloy precision castings are greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of precision casting, and particularly relates to an aluminum-magnesium-based ceramic crucible for smelting high-temperature alloy and a preparation method thereof. BACKGROUND

[0002] High-temperature alloy is an indispensable part in the development of aero-engines and gas turbines. Precision casting is a process method for manufacturing high-temperature alloy castings. Since the working condition has high temperature, high vacuum degree and continuous temperature rise and fall, and the high-temperature alloy contains active metal elements, the crucible for casting has very high requirements. At present, the traditional aluminum-silicon-based crucible has a certain degree of refractory inclusion problem in the precision casting working condition of high-temperature alloy. SUMMARY

[0003] In view of this, the application discloses an aluminum-magnesium-based ceramic crucible for smelting high-temperature alloy and a preparation method thereof, so as to prepare an aluminum-magnesium-based refractory crucible with high melting point, low thermal conductivity, excellent heat insulation performance, good thermal stability and excellent slag erosion resistance.

[0004] The technical scheme provided by the application is specifically a kind of aluminum-magnesium-based ceramic crucible for smelting high-temperature alloy, by weight fraction, comprising: high-purity white corundum powder particles 20-40 parts, high-purity white corundum particles 15-35 parts, high-purity white corundum fine powder particles 13-20 parts, aluminum-magnesium spinel 0-10 parts, alpha-alumina powder 9-13 parts, magnesium lactate 5-9 parts, binder 4-8 parts, dispersing agent 0.2 parts, deionized water 5-10 parts;The diameter of the high-purity white corundum powder particles is 3-5mm, the diameter of the high-purity white corundum particles is 1-3mm, and the diameter of the high-purity white corundum fine powder is less than 1mm.

[0005] The application also provides a preparation method of the aluminum-magnesium-based ceramic crucible for smelting high-temperature alloy, comprising:

[0006] Step 1: preparing aggregate: according to weight fraction, high-purity white corundum powder particles 20-40 parts, high-purity white corundum particles 15-35 parts, high-purity white corundum fine powder particles 13-20 parts, and aluminum-magnesium spinel powder 2 parts are mixed uniformly in a mixing device to obtain the aggregate;

[0007] Step 2: preparing powder; according to weight fraction, alpha-alumina powder 9-13 parts, magnesium lactate 5-9 parts, binder 4-8 parts, and dispersing agent 0.2 parts are mixed uniformly in a stirrer to obtain the powder;

[0008] Step 3: preparing slurry; the aggregate is sent into the stirrer, the powder is slowly added during stirring, deionized water 5-10 parts is gradually added after uniform mixing, and the slurry is fully stirred to form a uniform slurry;

[0009] Step 4: adjust the pH of the slurry to weakly acidic pH 5-7;

[0010] Step 5: the slurry obtained in step 4 is sent to a vacuum stirrer, after removing the air bubbles generated by stirring, it is sealed and stored for use;

[0011] Step 6: Pour the defoamed slurry into the silica gel mold cavity treated with silicone methyl branched silicone oil, and place the poured silica gel mold on a vibration platform to remove air from the silica gel mold, so that the slurry is fully filled in the silica gel mold and the surface is slurry-like;

[0012] Step 7: demolding and drying: place the poured mold and slurry in a constant temperature and humidity box for curing and hardening, then take out the hardened slurry, remove the silica gel mold, and obtain the crucible embryo, which is then placed in an oven for drying to remove excess moisture inside the crucible embryo;

[0013] Step 8: sintering of the crucible embryo: place the dried crucible embryo in a push plate kiln to obtain an aluminum-magnesium-based ceramic crucible after sintering.

[0014] Further, the particle size of the aluminum-magnesium spinel powder in step 1 is 325 mesh; the mixing time of the aggregate in the mixing device is 5-10 min.

[0015] Further, the particle size of the α-alumina powder in step 2 is 5 μm; the binder is hydrated alumina; the dispersing agent is sodium tripolyphosphate; and the mixing time of the powder in the stirrer is 10-15 min.

[0016] Further, in step 3, the aggregate is added and mixed for 3 min, then the powder is added; the powder is mixed for 10-20 min, then deionized water is added, and the stirring time is 10-15 min.

[0017] Further, in step 4, lactic acid is added to adjust the pH of the system to weakly acidic; the mixing time is 5 min.

[0018] Further, in step 5, the vacuum degree during the defoaming process in the vacuum stirrer is -0.09 Mpa, and the vacuum defoaming time is 15-30 min.

[0019] Further, in step 6, the vibration platform is first used for high-frequency vibration, and the vibration time is 1-2 min, then it is converted to low-frequency vibration, and the vibration time is 3-5 min.

[0020] Further, in step 7, the temperature and humidity of the constant temperature and humidity box during the hardening of the slurry are 25℃ and 45% respectively; after the crucible embryo is demolded, the drying temperature is 110℃, and the drying time is 18-24 h.

[0021] Further, the sintering temperature of the crucible in step 8 is 900-1200℃.

[0022] The application provides an aluminum-magnesium-based ceramic crucible for smelting high-temperature alloy and a preparation method thereof.

[0023] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory and are not restrictive of the disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0026] Figure 1 An XRD pattern of the aluminum-magnesium-based ceramic crucible provided by the disclosed embodiment of the present application;

[0027] Figure 2 A micro-morphology diagram of the aluminum-magnesium-based ceramic crucible provided by the disclosed embodiment of the present application. DETAILED DESCRIPTION

[0028] The exemplary embodiments will be described in detail herein below with reference to the drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they only represent examples of systems consistent with some aspects of the present application, as detailed in the appended claims.

[0029] In order to solve the problems of the existing ceramic crucible in the process of use, such as easy to react with the molten alloy, precipitate harmful substances and poor resistance to extreme cold and heat, the embodiment provides an aluminum-magnesium-based ceramic crucible for smelting high-temperature alloy. The aluminum-magnesium-based ceramic crucible is prepared from the following raw materials by weight: 20-40 parts of high-purity white corundum powder particles with a particle size of 3-5 mm, 15-35 parts of high-purity white corundum particles with a particle size of 1-3 mm, 13-20 parts of high-purity white corundum fine powder with a particle size of less than 1 mm, 0-10 parts of aluminum-magnesium spinel, 9-13 parts of alpha-alumina powder, 5-9 parts of magnesium lactate, 4-8 parts of binder, and 0.2 parts of dispersant, in addition to 5-10 parts of deionized water.

[0030] The manufacturing steps of the ceramic crucible are as follows:

[0031] Step 1: aggregate mixing: by weight, take 20-40 parts of high-purity white corundum powder particles, 15-35 parts of high-purity white corundum particles, 13-20 parts of high-purity white corundum fine powder, and 0-10 parts of aluminum-magnesium spinel, and send them into a mixing device. After the aggregates are uniformly mixed, they are ready for use; preferably, in step 1, the particle size of the magnesium-aluminum spinel powder is 325 mesh, and the mixing time of the mixing device is 5-100 min;

[0032] Step 2: powder mixing: by weight, take 9-13 parts of alpha-alumina powder, 5-9 parts of magnesium lactate, 4-8 parts of binder, and 0.2 parts of dispersant, and send them into a blender. After they are thoroughly mixed and uniformly distributed, they are ready for use; further preferably, in step 2, the particle size of the alpha-alumina is 5 μm; the binder is hydrated alumina; the dispersant is sodium tripolyphosphate; and the mixing time is 10-15 min;

[0033] Step 3: thorough mixing of aggregates and powder: send the uniformly mixed aggregates into a blender, slowly add the powder during the stirring process, and after the mixing is uniform, gradually add 5-13 parts of deionized water. After the uniform slurry is formed by thorough stirring, it is ready for use; further preferably, in step 3, the aggregates are added and mixed for 3 min after the powder is added; the powder is added and mixed for 10-20 min; the deionized water is added and stirred for 10-15 min;

[0034] Step 4: adjustment of the pH value of the system: test the pH value of the slurry in step 3. If the pH value is too high, add a small amount of lactic acid to adjust the slurry to weak acidity. After the uniform mixing, it is ready for use; further preferably, in step 4, the pH value of the system is adjusted to weak acidity (pH value between 5 and 7) by adding lactic acid; and the mixing time is 5 min;

[0035] Step 5: vacuum degassing: send the slurry in step 4 into a vacuum blender, remove the air bubbles in the slurry caused by stirring, and then seal and store it for later use; further preferably, in step 5, the vacuum degree needs to reach -0.09 Mpa during the vacuum degassing process, and the vacuum degassing time is 15-30 min.

[0036] Step 6: Crystallizer casting: take the slurry after degassing in step 5 and pour it into the cavity of the silica gel mold treated with methyl silicone oil, at the same time, place the poured silica gel mold on the vibration platform, and remove the air in the silica gel mold by vibration to make the slurry fully fill the inside of the silica gel mold and the surface be slurry-like; further preferably, in step 6, first use high-frequency vibration, the vibration time is 1-2 min, then change to low-frequency vibration, the vibration time is 3-5 min, after vibration, seal the pouring port of the mold with plastic wrap and store it;

[0037] Step 7: demolding and drying: place the poured mold and slurry in a constant temperature and humidity box for curing and hardening, take it out after the slurry is hardened, remove the silica gel mold, and get the crystallizer embryo, then place it in an oven for drying to remove excess water in the inside of the crystallizer embryo; further preferably, in step 7, the temperature and humidity of the constant temperature and humidity box during the hardening of the slurry are 25℃ and 45% respectively; after the crystallizer embryo is demolded, the drying temperature is 110℃ and the drying time is 18-24h;

[0038] Step 8: sintering of the crystallizer embryo: place the dried crystallizer embryo in a push plate kiln to get the aluminum-magnesium-based ceramic crystallizer of the present application after sintering. In step 8, the sintering temperature of the crystallizer is 900-1200℃.

[0039] The present embodiment provides a preparation method of an aluminum-magnesium-based ceramic crystallizer for melting and refining of high-temperature alloy. The prepared ceramic crystallizer has stable chemical properties and will not react with high-temperature alloy during the melting process, and will not precipitate harmful substances, which can effectively avoid the introduction of inclusions in the precision casting process, greatly improving the quality of high-temperature alloy castings. In addition, the main components of the present embodiment are alumina and magnesium lactate, in which magnesium ions can be uniformly distributed in the system after magnesium lactate is dissolved in water, and magnesium aluminate spinel is generated by reaction with alumina under high-temperature sintering, which can effectively avoid the generation of internal defects caused by the generation of magnesium aluminate spinel. Figure 1 The characteristic peak of aluminum magnesium spinel appears in the XRD pattern of the present embodiment, indicating that magnesium aluminate spinel is generated in the system; and the lactate ion can improve the fluidity of the system and reduce the water demand of the system due to the charge effect. Moreover, the conversion of magnesium aluminate spinel is accompanied by volume expansion, and due to the uniform distribution of magnesium ions, this part of the volume expansion is shared by the whole system, avoiding internal defects caused by the generation of magnesium aluminate spinel. In addition, this part of the volume expansion can also fill the internal defects of the system to reduce the porosity of the crystallizer. Figure 2 The microstructure of the present embodiment can be seen from the microstructure figure that the microstructure is dense, which improves the corrosion resistance and thermal shock resistance of the aluminum-magnesium-based ceramic crystallizer. On the basis of meeting the use strength, the smooth progress of casting is ensured, so the method of the present embodiment can greatly improve the performance and production efficiency of high-temperature alloy precision castings.

[0040] Example 1

[0041] An aluminum magnesium-based ceramic crucible for high-temperature alloy melting and refining is prepared according to the following steps:

[0042] 1) aggregate mixing: take 20 parts of 3-5 mm high-purity white corundum powder particles, 35 parts of 1-3 mm high-purity white corundum particles, and 13 parts of 0-1 high-purity white corundum fine powder by weight, add 10 parts of aluminum magnesium spinel into a mixing device, mix for 7 min, mix the aggregate uniformly, and reserve;

[0043] 2) powder mixing: take 9 parts of α-alumina powder, 9 parts of magnesium lactate, and 4 parts of hydrated alumina by weight, additionally add 0.2 parts of sodium tripolyphosphate into a stirrer, mix for 12 min, mix uniformly, and reserve;

[0044] 3) aggregate and powder mixing: put the mixed aggregate into a stirrer, slowly add the powder during stirring, mix for 13 min, gradually add 5 parts of deionized water after uniform mixing, fully stir for 10 min, form a uniform slurry, and reserve;

[0045] 4) system pH adjustment: test the system pH and add a small amount of lactic acid to make the system pH weakly acidic, mix for 5 min, and reserve;

[0046] 5) vacuum degassing: put the slurry in step 4) into a vacuum stirrer, when the vacuum degree reaches -0.09 Mpa, stir for 20 min, remove the air bubbles generated during stirring, seal and store, and reserve;

[0047] 6) crucible casting: pour the slurry after degassing in step 5) into a silica gel mold cavity treated with silicone methyl branched silicone oil, at the same time, place the poured silica gel mold on a vibration platform, first perform high-frequency vibration for 2 min, then switch to low-frequency vibration for 4 min, to remove air in the silica gel mold, make the slurry fully fill in the silica gel mold, and make the surface of the slurry;

[0048] 7) demolding and drying: place the poured mold and slurry in a constant temperature and humidity box with a temperature of 25℃ and a humidity of 45%, and cure and harden, take out after the slurry is hardened, remove the silica gel mold, obtain the crucible blank, and place it in an oven to dry for 20 h to remove excess water in the crucible blank;

[0049] 8) crucible blank sintering: place the dried crucible blank in a push plate kiln, sinter at 950℃, and obtain the aluminum magnesium-based ceramic crucible of the application.

[0050] Example 2

[0051] An aluminum magnesium-based ceramic crucible for high-temperature alloy melting and refining is prepared according to the following steps:

[0052] 1) aggregate mixing: take 25 parts of 3-5mm high-purity white corundum powder particles, 30 parts of 1-3mm high-purity white corundum particles, 16 parts of 0-1 high-purity white corundum fine powder, and 6 parts of aluminum-magnesium spinel by weight, and send them into a mixing device for mixing for 5 minutes, then mix the aggregate uniformly, and reserve it for use;

[0053] 2) powder mixing: take 10 parts of α-alumina powder, 8 parts of magnesium lactate, 5 parts of a binder, and additionally add 0.2 parts of a dispersing agent by weight, and send them into a stirrer for mixing for 13 minutes, then mix them uniformly, and reserve it for use;

[0054] 3) aggregate and powder mixing: send the uniformly mixed aggregate into a stirrer, slowly add the powder during stirring, mix for 15 minutes, then gradually add 7 parts of deionized water, and stir for 13 minutes, then form a uniform slurry, and reserve it for use;

[0055] 4) system pH adjustment: test the system pH and add a small amount of lactic acid to make the system weakly acidic, mix for 5 minutes, and reserve it for use;

[0056] 5) vacuum degassing: send the slurry in step 4) into a vacuum stirrer, and when the vacuum degree reaches -0.09 Mpa, stir for 17 minutes, then remove the air bubbles generated during stirring, seal and store, and reserve it for use;

[0057] 6) crucible casting: take the slurry after degassing in step 5) and pour it into a silicone mold cavity treated with a silicone resin methyl branched silicone oil, at the same time, place the poured silicone mold on a vibration platform, first perform high-frequency vibration for 1 minute, then switch to low-frequency vibration for 5 minutes, to remove the air in the silicone mold, so that the slurry is fully filled in the silicone mold and the surface is slurry-like;

[0058] 7) demolding and drying: place the poured mold and slurry in a constant temperature and humidity box with a temperature of 25℃ and a humidity of 45%, and cure and harden, then take it out after the slurry is hardened, remove the silicone mold, get the crucible blank, and place it in an oven for drying for 19 hours to remove the excess water in the crucible blank;

[0059] 8) crucible blank sintering: place the dried crucible blank in a push plate kiln, and sinter it at 1050℃ to obtain the aluminum-magnesium-based ceramic crucible for high-temperature alloy melting and refining.

[0060] Example 3

[0061] An aluminum-magnesium-based ceramic crucible for high-temperature alloy melting and refining is prepared according to the following steps:

[0062] 1) aggregate mixing: take 30 parts of 3-5mm high-purity white corundum powder particles, 25 parts of 1-3mm high-purity white corundum particles, 19 parts of 0-1 high-purity white corundum fine powder, and 2 parts of aluminum-magnesium spinel by weight, and send them into a mixing device for mixing for 9 minutes. After the aggregate is uniformly mixed, it is ready for use;

[0063] 2) powder mixing: take 11 parts of α-alumina powder, 7 parts of magnesium lactate, and 6 parts of a binder by weight, and additionally add 0.2 parts of a dispersing agent, and send them into a stirrer for mixing for 10 minutes. After they are uniformly mixed, they are ready for use;

[0064] 3) aggregate and powder mixing: send the uniformly mixed aggregate into a stirrer, slowly add the powder during stirring, mix for 17 minutes, and then gradually add 5 parts of deionized water. After the mixture is uniformly mixed, it is stirred for 14 minutes. After a uniform slurry is formed, it is ready for use;

[0065] 4) adjustment of the acidity and alkalinity of the system: test the acidity and alkalinity of the system, and add a small amount of lactic acid to make the system weakly acidic. After mixing for 5 minutes, it is ready for use;

[0066] 5) vacuum degassing: send the slurry in step 4) into a vacuum stirrer, and after the vacuum degree reaches -0.09 Mpa, stir for 25 minutes. After the air bubbles generated during stirring are removed from the slurry, it is sealed and stored for later use;

[0067] 6) crucible casting: pour the slurry after degassing in step 5) into a silica gel mold cavity that has been treated with a methyl branched silicone oil. At the same time, place the poured silica gel mold on a vibration platform, and first perform high-frequency vibration for 2 minutes, and then low-frequency vibration for 4 minutes, to remove the air in the silica gel mold, so that the slurry is fully filled in the silica gel mold and the surface is slurry-like;

[0068] 7) demolding and drying: place the poured mold and slurry in a constant temperature and humidity box with a temperature of 25℃ and a humidity of 45%, and cure and harden the slurry. After the slurry is hardened, remove the silica gel mold to obtain a crucible blank, and then place the crucible blank in an oven for drying for 22 hours to remove excess water in the crucible blank;

[0069] 8) sintering of the crucible blank: place the dried crucible blank in a push plate kiln, and sinter it at 1100℃ to obtain the aluminum-magnesium-based ceramic crucible for melting and refining of high-temperature alloys.

[0070] Example 4

[0071] An aluminum-magnesium-based ceramic crucible for melting and refining of high-temperature alloys is prepared according to the following steps:

[0072] 1) aggregate mixing: take 35 parts of 3-5mm high-purity white corundum powder particles, 20 parts of 1-3mm high-purity white corundum particles, 20 parts of 0-1 high-purity white corundum fine powder, and 0 parts of aluminum-magnesium spinel by weight, and send them into a mixing device, mix for 8 minutes, mix the aggregate uniformly, and reserve;

[0073] 2) powder mixing: take 12 parts of α-alumina powder, 6 parts of magnesium lactate, 7 parts of a binder, and 0.2 parts of a dispersant by weight, and send them into a mixer, mix for 11 minutes, mix them uniformly, and reserve;

[0074] 3) aggregate and powder mixing: send the mixed aggregate into a mixer, slowly add the powder during the mixing process, mix for 19 minutes, gradually add 5 parts of deionized water after uniform mixing, mix for 11 minutes, form a uniform slurry, and reserve;

[0075] 4) system pH adjustment: test the system pH and add a small amount of lactic acid to make the system weakly acidic, mix for 5 minutes, and reserve;

[0076] 5) vacuum degassing: send the slurry in step 4) into a vacuum mixer, reach a vacuum degree of -0.09 Mpa, mix for 15 minutes, remove the air bubbles generated during the mixing process, seal and reserve, and reserve;

[0077] 6) crucible casting: pour the slurry after degassing in step 5) into a silica gel mold cavity treated with a methyl branched silicone oil, and place the poured silica gel mold on a vibration platform, first perform high-frequency vibration for 2 minutes, and then perform low-frequency vibration for 3 minutes, to remove the air in the silica gel mold, so that the slurry is fully filled in the silica gel mold and the surface is slurry-like;

[0078] 7) demolding and drying: place the poured mold and slurry in a constant temperature and humidity box with a temperature of 25°C and a humidity of 45%, and harden, take out the hardened slurry, remove the silica gel mold, obtain the crucible blank, and dry in an oven for 18 hours to remove excess water in the crucible blank;

[0079] 8) crucible blank sintering: place the dried crucible blank in a push plate kiln, sinter at 1150°C, and obtain the aluminum-magnesium-based ceramic crucible of the application.

[0080] Example 5

[0081] An aluminum-magnesium-based ceramic crucible for melting and refining of high-temperature alloys is prepared according to the following steps:

[0082] 1) aggregate mixing: take 40 parts of 3-5mm high-purity white corundum powder particles, 15 parts of 1-3mm high-purity white corundum particles, 19 parts of 0-1 high-purity white corundum fine powder, 0 parts of aluminum magnesium spinel by weight, and send them into the mixing equipment, mix for 10 minutes, mix the aggregate uniformly, and reserve;

[0083] 2) powder mixing: take 13 parts of α-alumina powder, 5 parts of magnesium lactate, 8 parts of binder, and additionally add 0.2 parts of dispersant by weight, send them into the stirrer, mix for 15 minutes, mix uniformly, and reserve;

[0084] 3) aggregate powder mixing: send the mixed aggregate into the stirrer, slowly add the powder during stirring, mix for 12 minutes, add 5 parts of deionized water gradually after mixing uniformly, stir for 15 minutes, form a uniform slurry, and reserve;

[0085] 4) system pH adjustment: test the system pH and add a small amount of lactic acid to make the system weakly acidic, mix for 5 minutes, and reserve;

[0086] 5) vacuum degassing: send the slurry in step 4) into a vacuum stirrer, when the vacuum degree reaches-0.09Mpa, stir for 30 minutes, remove the air bubbles generated during stirring, seal and store, and reserve;

[0087] 6) crucible casting: take the slurry after degassing in step 5) and pour it into a silicone mold cavity treated with silicone resin methyl branched silicone oil, at the same time, place the poured silicone mold on a vibration platform, first high-frequency vibration for 1 minute, then low-frequency vibration for 5 minutes, to remove the air in the silicone mold, so that the slurry is fully filled in the silicone mold and the surface is slurry-like;

[0088] 7) demolding and drying: place the poured mold and slurry in a constant temperature and humidity box with a temperature of 25℃ and a humidity of 45%, harden, take out after the slurry hardens, remove the silicone mold, get the crucible blank, and place it in an oven to dry for 24 hours to remove excess water in the crucible blank;

[0089] 8) crucible blank sintering: place the dried crucible blank in a push plate kiln, sinter at 1150℃, and get the aluminum magnesium-based ceramic crucible of the application.

[0090] The performance of the aluminum magnesium-based ceramic crucible prepared according to the formula and process of the application is compared with that of the existing product, and the results are as follows:

[0091] Table 1: performance test table

[0092]

[0093] The preparation method of the aluminum-magnesium-based ceramic crucible for melting and refining of superalloy provided in the embodiment, the prepared ceramic crucible has stable chemical properties, the main component is Al2O3 and MgO, and the ceramic crucible will not react with the superalloy in the melting process and will not precipitate harmful substances, so that the problem of introducing inclusions in the precision casting process can be effectively avoided, and the quality of the superalloy castings is greatly improved. In addition, combined with the above preparation process, the generation of aluminum-magnesium spinel in the sintering process is accompanied by appropriate volume expansion to fill the internal defects, reduce the porosity of the crucible, and improve the corrosion resistance and thermal shock resistance of the crucible. On the basis of meeting the use strength, the smooth progress of casting is ensured, so the above method can greatly improve the performance and production efficiency of the superalloy precision castings.

[0094] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

Claims

1. A method for the production of an alumina-magnesia based ceramic crucible for the smelting of superalloys, characterized in that, The aluminum-magnesium-based ceramic crucible comprises, in parts by weight, 20-40 parts of high-purity white corundum powder particles, 15-35 parts of high-purity white corundum particles, 13-20 parts of high-purity white corundum fine powder particles, 2-10 parts of aluminum-magnesium spinel, 9-13 parts of α-alumina powder, 5-9 parts of magnesium lactate, 4-8 parts of a binding agent, 0.2 parts of a dispersing agent, and 5-10 parts of deionized water; wherein the high-purity white corundum powder particles have a diameter of 3-5 mm, the high-purity white corundum particles have a diameter of 1-3 mm, and the high-purity white corundum fine powder has a diameter of less than 1 mm. The preparation method comprises: Step 1: preparing aggregate: obtaining, in parts by weight, 20-40 parts of high-purity white corundum powder particles, 15-35 parts of high-purity white corundum particles, 13-20 parts of high-purity white corundum fine powder particles, and 2-10 parts of aluminum-magnesium spinel powder, mixing them uniformly in a mixing device to obtain the aggregate; Step 2: preparing powder: obtaining, in parts by weight, 9-13 parts of α-alumina powder, 5-9 parts of magnesium lactate, 4-8 parts of a binding agent, and 0.2 parts of a dispersing agent, mixing them uniformly in a stirrer to obtain the powder; Step 3: preparing slurry: feeding the aggregate into the stirrer, slowly adding the powder during stirring, adding deionized water, 5-10 parts, gradually after uniform mixing, and fully stirring to form uniform slurry; Step 4: adjusting the slurry to weak acidity with a pH value of 5-7; Step 5: feeding the slurry obtained in Step 4 into a vacuum stirrer, removing the air bubbles generated during stirring, and sealing and storing for later use; Step 6: pouring the slurry after bubble removal into a silicone mold cavity treated with methyl branched silicone oil, placing the poured silicone mold on a vibration platform, vibrating to remove air in the silicone mold, and making the slurry fully fill the silicone mold and have a slurry surface; Step 7: demolding and drying: placing the poured mold and slurry in a constant temperature and humidity box for curing and hardening, taking out the slurry after hardening, removing the silicone mold, obtaining a crucible embryo, and drying the crucible embryo in an oven to remove excess water in the crucible embryo; Step 8: sintering the crucible embryo: placing the dried crucible embryo in a push plate kiln, sintering to obtain an aluminum-magnesium-based ceramic crucible.

2. A method of producing an alumina-magnesia based ceramic crucible for smelting of superalloys according to claim 1, characterized in that, In Step 1, the particle size of the aluminum-magnesium spinel powder is 325 mesh, and the mixing time of the aggregate in the mixing device is 5-10 min.

3. A method of producing an alumina-magnesia based ceramic crucible for melting superalloys according to claim 1, characterized in that, In Step 2, the particle size of the α-alumina powder is 5 μm, the binding agent is hydrated alumina, the dispersing agent is sodium tripolyphosphate, and the mixing time of the powder in the stirrer is 10-15 min.

4. The method of claim 1, wherein the aluminum-magnesium based ceramic crucible for melting superalloys is prepared by the steps of: In Step 3, the aggregate is added and mixed for 3 min after the powder is added, the powder is added and mixed for 10-20 min, the deionized water is added, and the stirring time is 10-15 min.

5. The method of claim 1, wherein the aluminum-magnesium based ceramic crucible for melting superalloys is prepared by the steps of: In Step 4, lactic acid is added to adjust the pH value of the system to weak acidity, and the mixing time is 5 min.

6. The method of claim 1, wherein the aluminum-magnesium based ceramic crucible for melting superalloys is prepared by the steps of: In Step 5, the vacuum degree during bubble removal in the vacuum stirrer is -0.09 Mpa, and the vacuum bubble removal time is 15-30 min.

7. The method for preparing an aluminum-magnesium-based ceramic crucible for high-temperature alloy melting according to claim 1, characterized in that, In Step 6, the vibration platform is first used for high-frequency vibration for 1-2 min, and then for low-frequency vibration for 3-5 min.

8. The method for preparing an aluminum-magnesium-based ceramic crucible for high-temperature alloy melting according to claim 1, characterized in that, The temperature and humidity of the constant temperature and humidity box during the hardening of the slurry in Step 7 are 25°C and 45%, respectively; after the crucible body is demolded, the drying temperature is 110°C, and the drying time is 18-24h.

9. A method for preparing an aluminum-magnesium-based ceramic crucible for high-temperature alloy melting according to claim 1, characterized in that, The sintering temperature of the crucible in Step 8 is 900-1200°C.

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