Modified gadolinium oxide material, and preparation method and application thereof

Abstract

The application provides a modified gadolinium oxide material formula used as a silicon-based ceramic core tracer and a modified gadolinium oxide doped silicon-based ceramic core preparation process, and mainly applies to the field of precision casting of directional or single crystal nickel-based superalloy hollow turbine blade. The material is composed of the following raw materials in percentage by weight: gadolinium oxide powder: quartz glass powder is 1:(1-3), distilled water is 40-60% of the total amount of gadolinium oxide powder and quartz glass powder, and ammonium citrate is 0.5-1% of the solid content. In the application, the shrinkage, high-temperature deflection and the like of the gadolinium-containing silicon-based ceramic core are improved by adding the modified gadolinium oxide material, the casting problems such as pouring core leakage, small inner cavity and poor collapsibility caused by the conventional gadolinium-doped silicon-based core can be avoided, the cost and period of the hollow blade precision casting are effectively reduced, and the casting qualified rate of the hollow turbine blade is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gadolinium oxide, and particularly relates to a modified gadolinium oxide material, a preparation method and application thereof, in particular to a core-shell structure modified gadolinium oxide material used as a neutron detection tracer for a silicon-based ceramic core, and particularly relates to a core-shell structure modified gadolinium oxide material doped in a silicon-based ceramic core, and mainly applied to the field of precision casting of nickel-based high-temperature alloy hollow turbine blades. BACKGROUND

[0002] The nickel-based high-temperature alloy hollow turbine blade is a core component of an aero-engine and a gas turbine. The complex inner cavity shape and the inner cavity air cooling channel of the hollow turbine blade are mainly realized by a ceramic core forming. With the continuous improvement of the pursuit of high efficiency, integration, weight reduction and cost and other indexes of an aero-turbine engine, the requirements of the air cooling channel, size precision and the like of the turbine blade inner cavity are also increasingly complex and strict. The continuous increase of the complexity of the turbine blade inner cavity leads to gradually increasing difficulty in ceramic core stripping, and the residual core of the blade blind cavity is difficult to be completely detected. SUMMARY

[0003] Therefore, the purpose of the application is to provide a modified gadolinium oxide material, a preparation method and application thereof. The modified gadolinium oxide material provided by the application is used as a neutron detection tracer for a silicon-based ceramic core, and after being doped in the silicon-based ceramic core, the shrinkage rate, deflection and collapse performance of the ceramic core meet the casting use requirements, and the modified gadolinium oxide material is mainly applied to a complex inner cavity structure hollow turbine blade which needs to be detected by a neutron ray.

[0004] The application provides a modified gadolinium oxide material prepared from materials including the following raw materials:

[0005] Gadolinium oxide, quartz glass, water and ammonium citrate.

[0006] Preferably, the mass ratio of the gadolinium oxide and the quartz glass is 1:(1-3);

[0007] The mass of the water is 40-60% of the total mass of the gadolinium oxide and the quartz glass;

[0008] The mass of the ammonium citrate is 0.5-1% of the total mass of the gadolinium oxide and the quartz glass.

[0009] The application provides a preparation method of the modified gadolinium oxide material.

[0010] The gadolinium oxide, the water and the ammonium citrate are first mixed to obtain a mixture;

[0011] The mixture and the quartz glass are secondly mixed to obtain a slurry;

[0012] The slurry is reacted to obtain the modified gadolinium oxide material.

[0013] Preferably, the first mixing is ball milling.

[0014] The rotation speed of the ball milling is 300-500 r / min.

[0015] The ball milling time is 3-5 h.

[0016] Preferably, the second mixing is ball milling.

[0017] The rotation speed of the ball milling is 300-500 r / min.

[0018] The ball milling time is 20-40 min.

[0019] Preferably, the reaction temperature is 800-1000℃, and the reaction time is 0.5-1.5 h.

[0020] Preferably, the reaction further comprises:

[0021] The obtained reaction product is crushed and sieved.

[0022] The mesh number of the sieve is 80-120 mesh.

[0023] The application provides a silicon-based ceramic core material, comprising the modified gadolinium oxide material in the above technical solution or the modified gadolinium oxide material prepared by the method in the above technical solution.

[0024] The application provides a preparation method of the silicon-based ceramic core material in the above technical solution, comprising:

[0025] The ceramic powder and the modified gadolinium oxide material are thirdly mixed to obtain a mixture.

[0026] The plasticizer and the mixture are fourthly mixed to obtain the silicon-based ceramic core material.

[0027] Preferably, the mass of the modified gadolinium oxide material is 3-8% of the mass of the ceramic powder.

[0028] The third mixing time is 0.5-1.5 h.

[0029] The fourth mixing temperature is 120-140℃.

[0030] The fourth mixing is performed under vacuum.

[0031] The application finds that, by adding a proper amount of gadolinium oxide as a tracer for residual core detection in a ceramic core, the residual core which is not easy to be identified by visual inspection in the inner cavity of a hollow turbine blade can be detected by using a neutron imaging method. However, the silicon oxide-based core doped with gadolinium oxide has certain gaps in performance compared with conventional silicon-based ceramic cores when applied to the actual casting process of a nickel-based superalloy hollow turbine blade, especially a small-size blade with a cantilever structure U-shaped end inner cavity, which is specifically shown in the following aspects: first, the silicon-based ceramic core containing gadolinium has large shrinkage at high temperature, resulting in the reduction of the size of the inner cavity of the blade; second, the silicon-based ceramic core containing gadolinium has poor deflection and serious softening at high temperature, resulting in a high core leakage rate of the blade after pouring; third, the silicon-based ceramic core containing gadolinium has poor collapsibility, resulting in low core removal efficiency of the blade after pouring, and poor inner cavity quality of the blade after frequent core removal. Therefore, the application develops a modified gadolinium oxide material suitable for a silicon-based ceramic core, meets the application and repair of the silicon-based ceramic core containing gadolinium, and improves the casting qualification rate of the blade.

[0032] The application improves the deterioration of the ceramic core caused by the doping of gadolinium by doping the modified gadolinium oxide material in the silicon-based ceramic core: on the one hand, the gadolinium oxide is mixed with quartz powder at high temperature in advance by the modified gadolinium oxide powder to realize coating and agglomeration, reduces the contact between the gadolinium oxide and the quartz glass powder raw material in the ceramic core, and reduces the influence of the existence of the gadolinium oxide on the performance of the silicon-based core; on the other hand, the quartz glass powder raw material of the modified gadolinium oxide is crystallized into cristobalite after high-temperature treatment in the preparation process, which can promote the crystallization of the silicon-based ceramic core at high temperature as a seed crystal for the ceramic core. Finally, the characteristics of large shrinkage, poor deflection and poor collapsibility of the conventional silicon-based ceramic core containing gadolinium are improved, the core packing rate, wall thickness qualification rate and core removal efficiency of the blade are improved, and the manufacturing cost and processing cycle are reduced. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the application.

[0034] The application provides a modified gadolinium oxide material prepared from a material including the following raw materials:

[0035] Gadolinium oxide, quartz glass, water and ammonium citrate.

[0036] In the application, the gadolinium oxide is preferably gadolinium oxide powder; and the quartz glass is preferably quartz glass powder.

[0037] In the present application, the mass ratio of gadolinium oxide and quartz glass is preferably 1:(1-3), more preferably 1:(1.5-2.5), and most preferably 1:2.

[0038] In the present application, the water is preferably distilled water.

[0039] In the present application, the mass of the water is preferably 40-60% of the total mass of gadolinium oxide and quartz glass, more preferably 45-55%, and most preferably 50%.

[0040] In the present application, the mass of the ammonium citrate is preferably 0.5-1% of the total mass of gadolinium oxide and quartz glass, more preferably 0.6-0.9%, and most preferably 0.7-0.8%.

[0041] The present application provides a preparation method of the modified gadolinium oxide material as described in the above technical solution, comprising:

[0042] The gadolinium oxide, water, and ammonium citrate are first mixed to obtain a mixture;

[0043] The mixture and the quartz glass are second mixed to obtain a slurry;

[0044] The slurry is reacted to obtain a modified gadolinium oxide material.

[0045] In the present application, the first mixing is preferably carried out in a ball mill tank; the first mixing is preferably ball milling; the rotation speed of the ball milling is preferably 300-500 r / min, more preferably 350-450 r / min, and most preferably 400 r / min; and the ball milling time is preferably 3-5 h, more preferably 3.5-4.5 h, and most preferably 4 h.

[0046] In the present application, the second mixing is preferably ball milling; the rotation speed of the ball milling is preferably 300-500 r / min, more preferably 350-450 r / min, and most preferably 400 r / min; and the ball milling time is preferably 20-40 min, more preferably 25-35 min, and most preferably 30 min.

[0047] In the present application, the reaction is preferably carried out in a reaction kettle; the reaction temperature is preferably 800-1000℃, more preferably 850-950℃, and most preferably 900℃; and the reaction time is preferably 0.5-1.5 h, more preferably 0.8-1.2 h, and most preferably 1.0 h.

[0048] In the present application, after the reaction is completed, preferably further comprising:

[0049] The obtained reaction product is crushed and sieved through a screen, and the obtained powder is used as a modified gadolinium oxide material.

[0050] In the present application, the mesh number of the screen is preferably 80-120 mesh, more preferably 90-110 mesh, and most preferably 100 mesh.

[0051] In the present application, the preparation method of the modified gadolinium oxide material preferably comprises:

[0052] A certain amount of gadolinium oxide powder, distilled water and ammonium citrate are weighed according to the proportion and placed in a ball mill tank;

[0053] The above materials are ball milled together, the ball milling speed is 400 r / min, and the ball milling time is 4 h, and a uniform slurry is prepared;

[0054] Mix a certain proportion of quartz glass powder with the above slurry, uniformly stir for 30 min at a ball milling speed of 400 r / min, so that they are uniformly mixed;

[0055] Put the uniformly mixed slurry into a reaction kettle and react at 900 DEG C for 1 h;

[0056] After cooling, the block material is crushed and passed through a 100 mesh screen, and the obtained powder is ready for use.

[0057] The present application provides a silicon-based ceramic core material, comprising: the modified gadolinium oxide material described in the above technical solution, or the modified gadolinium oxide material prepared by the method described in the above technical solution.

[0058] The present application provides a preparation method of the silicon-based ceramic core material described in the above technical solution, comprising:

[0059] Mixing the ceramic powder and the modified gadolinium oxide material to obtain a mixture;

[0060] Mixing the plasticizer and the mixture to obtain the silicon-based ceramic core material.

[0061] In the present application, the ceramic powder preferably comprises: quartz powder.

[0062] In the present application, the mass content of the quartz powder in the ceramic powder is preferably ≥80%.

[0063] In the present application, the ceramic powder preferably further comprises: a mineralizer.

[0064] In the present application, the mass content of the quartz powder in the ceramic powder is preferably 80-90%, more preferably 83-87%, and most preferably 85%; the mass content of the mineralizer in the ceramic powder is preferably 10-20%, more preferably 13-17%, and most preferably 15%.

[0065] In the present application, the mass of the modified gadolinium oxide is preferably 3-8% of the mass of the ceramic powder, more preferably 4-7%, and most preferably 5-6%.

[0066] In the present application, the third mixing is preferably performed in a V-shaped mixing barrel; the time of the third mixing is preferably 0.5-1.5h, more preferably 0.8-1.2h, and most preferably 1.0h.

[0067] In the present application, the plasticizer preferably comprises:

[0068] Paraffin wax, beeswax, and polyethylene.

[0069] In the present application, the mass content of the paraffin wax in the plasticizer is preferably 90-95%, more preferably 91-94%, and most preferably 92-93%; the mass content of the beeswax in the plasticizer is preferably 3-7%, more preferably 4-6%, and most preferably 5%; and the mass content of the polyethylene in the plasticizer is preferably 1-3%, more preferably 1.5-2.5%, and most preferably 2%.

[0070] In the present application, the mass of the plasticizer is preferably 10-25% of the mass of the ceramic powder, more preferably 15-20%, and most preferably 16-18%.

[0071] In the present application, the fourth mixing preferably comprises:

[0072] The plasticizer is added to the blender, and after the plasticizer is completely melted, the blender is started; the mixture is added to the plasticizer, and the blender is continued; vacuum is then drawn, and the blender is continued; after the blender, the vacuum is broken, and the slurry is obtained, which is cooled to obtain the silicon-based ceramic core material.

[0073] In the present application, the temperature of the fourth mixing (the temperature at which the plasticizer is melted) is preferably 120-140℃, more preferably 125-135℃, and most preferably 130℃; the fourth mixing is preferably performed under stirring; the stirring speed is preferably 25-45r / min, more preferably 30-40r / min, and most preferably 35r / min; the time of the continued stirring is preferably 6-10h, more preferably 7-9h, and most preferably 8h; the fourth mixing is preferably performed under vacuum; the time of the vacuum stirring is preferably 0.5-1.5h, more preferably 0.8-1.2h, and most preferably 1.0h; and the vacuum degree of the vacuum is preferably below 0.05MPa.

[0074] In the present application, the silicon-based ceramic core material is preferably a silicon-based ceramic core material ingot; and preferably further comprises:

[0075] The silicon-based ceramic core material ingot is melted and hot-pressed to obtain a ceramic core green body;

[0076] The ceramic core green body is fired to obtain a ceramic core.

[0077] In the present application, the hot pressing is preferably performed in a ceramic core hot pressing injection machine; the material temperature during the hot pressing is preferably 90-110 DEG C, more preferably 95-105 DEG C, and most preferably 100 DEG C; the pressure is preferably 3-9 MPa, more preferably 4-7 MPa, and most preferably 5 MPa; the injection time is preferably 5-20 s, more preferably 10-15 s, and most preferably 12-13 s; and the pressure maintaining time is preferably 10-60 s, more preferably 20-50 s, and most preferably 30-40 s.

[0078] In the present application, the firing is preferably performed by embedding the ceramic core green body in mullite fillers; the temperature of the firing is preferably 1150-1250 DEG C, more preferably 1180-1220 DEG C, and most preferably 1200 DEG C; and the time is preferably 2-6 h, more preferably 3-5 h, and most preferably 4 h.

[0079] In the present application, the preparation method of the silicon-based ceramic core material preferably comprises:

[0080] The core-shell structure modified gadolinium oxide powder prepared above is weighed at 3-8% of the mass fraction of the ceramic powder, and the powder is added into a V-shaped mixing barrel and mixed for 1 h.

[0081] The plasticizer material is added into a stirring machine, the temperature is set to 130 DEG C, after the plasticizer material is completely melted, the stirring is started at 35 r / min, the ceramic powder mixed uniformly in the V-shaped mixing barrel is gradually added, after the powder is completely added, the stirring is continued for 8 h, vacuum stirring is performed for 1 h, the vacuum degree is below 0.05 MPa, after the stirring, the vacuum is broken, the slurry is poured out, and the core-shell structure modified gadolinium oxide doped silicon-based ceramic core material is prepared after cooling.

[0082] The present application improves the deterioration of the ceramic core after the gadolinium element is doped by doping the modified gadolinium oxide material in the silicon-based ceramic core: on the one hand, the quartz powder and the gadolinium oxide are mixed at high temperature in advance to realize coating and agglomeration, the contact between the gadolinium oxide and the quartz glass powder raw material in the ceramic core is reduced, and the influence of the existence of the gadolinium oxide on the performance of the silicon-based core is reduced; on the other hand, the modified gadolinium oxide quartz glass powder raw material is crystallized into cristobalite after high-temperature treatment in the preparation process, which can promote the crystallization of the silicon-based ceramic core at high temperature as a seed crystal for the ceramic core; finally, the characteristics of large shrinkage, poor deflection and poor collapsibility of the conventional gadolinium-containing silicon-based ceramic core are improved, the blade core injection rate, the wall thickness qualification rate and the core removal efficiency are improved, and the manufacturing cost and the processing cycle are reduced.

[0083] Example 1

[0084] The gadolinium oxide powder and the quartz glass powder are weighed according to the mass ratio, and the mass ratio is 1:1, distilled water is weighed, and the mass of the distilled water is 40% of the total mass of the gadolinium oxide powder and the quartz glass powder; the ammonium citrate is weighed, and the mass of the ammonium citrate is 1% of the total mass of the gadolinium oxide powder and the quartz glass powder;

[0085] The gadolinium oxide powder, the distilled water and the ammonium citrate material are added into a ball mill tank for ball milling together, the ball milling speed is 400 r / min, and the ball milling time is 4 h, so that the uniform slurry is prepared;

[0086] The weighed quartz glass powder is mixed with the above slurry, and the slurry is uniformly stirred at a ball milling speed of 400 r / min for 30 min, so that the mixture is uniformly mixed;

[0087] The uniformly mixed slurry is placed in a reaction kettle and reacted at 900 DEG C for 1 h;

[0088] After the reaction is cooled, the bulk material is crushed and sieved through a 100-mesh sieve, and the powder obtained through the sieving is reserved;

[0089] The modified gadolinium oxide powder prepared above is weighed according to 4% of the mass of the ceramic powder (quartz powder 85wt%, mineralizer 15wt%), and the powder is added into a V-shaped mixing barrel and mixed for 1 h;

[0090] The plasticizer material (93wt% paraffin, 5wt% beeswax, 2wt% polyethylene) is added into a stirrer, and the amount of the plasticizer material is 15% of the mass of the ceramic powder, and the temperature is set to 130 DEG C; after the plasticizer material is completely melted, the stirring is started at 35 r / min, and the ceramic powder mixed with the modified gadolinium oxide in the V-shaped mixing barrel is gradually added; after the powder is completely added, the stirring is continued for 8 h, and the vacuum degree is below 0.05 MPa after vacuum stirring for 1 h; after the stirring, the vacuum is broken, and the slurry is poured out; after cooling, the core-shell structure modified gadolinium oxide doped silicon-based ceramic core material ingot is obtained;

[0091] The above ingot is melted, and the ceramic core green body is prepared according to the following technical parameters using a ceramic core hot-pressing injection machine according to a mold, the material temperature is 95 DEG C, the pressure is 4.5 MPa, the injection time is 5 s, and the pressure maintaining time is 35 s;

[0092] The obtained ceramic core green body is buried in mullite filler and fired at a final firing temperature of 1210 DEG C for 4 h, so that a silicon oxide-based ceramic core is prepared.

[0093] The shrinkage, deflection and collapse rate of the silicon oxide-based ceramic core prepared in Example 1 are detected according to AETM181A "High-temperature Alloy Investment Casting Ceramic Core Performance Detection Method", and the detection results are that the shrinkage of the silicon oxide-based ceramic core prepared in Example 1 is 0.15%, the deflection is 0.2 mm, and the collapse rate is 0.015 g / min.

[0094] Example 2

[0095] Gd2O3 powder and quartz glass powder were weighed according to the mass ratio of 1:2, distilled water was weighed, and the mass of the distilled water was 50% of the total mass of the Gd2O3 powder and the quartz glass powder; ammonium citrate was weighed, and the mass of the ammonium citrate was 1% of the total mass of the Gd2O3 powder and the quartz glass powder;

[0096] The Gd2O3 powder, distilled water, and ammonium citrate material were added to a ball mill tank for ball milling together, the ball milling speed was 400 r / min, and the ball milling time was 4 h, to prepare a uniform slurry;

[0097] The weighed quartz glass powder was mixed with the above slurry, and uniform stirring was performed at a ball milling speed of 400 r / min for 30 min to make the mixture uniform;

[0098] The uniformly mixed slurry was placed in a reaction kettle and reacted at 900℃ for 1 h;

[0099] After the reaction was cooled, the bulk material was crushed and passed through a 100-mesh sieve, and the powder obtained from the sieve was reserved;

[0100] The modified Gd2O3 powder prepared above was weighed at 6% of the mass of the ceramic powder (quartz powder 85wt%, mineralizer 15wt%), and the powder was added to a V-shaped mixing barrel and mixed for 1 h;

[0101] A plasticizer material (93wt% paraffin, 5wt% beeswax, 2wt% polyethylene) was added to a blender, and the amount added was 15% of the mass of the ceramic powder, and the temperature was set to 130℃. After the plasticizer material was completely melted, stirring was started at 35 r / min, and the ceramic powder with modified Gd2O3 mixed uniformly in the V-shaped mixing barrel was gradually added. After all the powder was added, stirring was continued for 8 h, and vacuum stirring was performed for 1 h at a vacuum degree of 0.05 MPa or below. After stirring, the vacuum was broken, and the slurry was poured out. After cooling, a core-shell structure modified Gd2O3 doped silicon-based ceramic core material ingot was prepared;

[0102] The above ingot was melted, and a ceramic core green body was prepared according to the following technical parameters using a ceramic core hot-pressing injection machine: material temperature 98℃, pressure 5 MPa, injection time 5 s, and pressure holding time 35 s;

[0103] The obtained ceramic core green body was buried in mullite filler and fired at a final firing temperature of 1210℃ for 4 h to prepare a silicon oxide-based ceramic core.

[0104] The silicon oxide-based ceramic core prepared in Example 2 was detected according to the method of Example 1, and the detection results were: shrinkage rate 0.18%, deflection 0.18 mm, and collapse rate 0.012 g / min.

[0105] Example 3

[0106] Gd2O3 powder and quartz glass powder were weighed according to the mass ratio of 1:3; distilled water was weighed, and the mass of the distilled water was 60% of the total mass of the Gd2O3 powder and the quartz glass powder; ammonium citrate was weighed, and the mass of the ammonium citrate was 1% of the total mass of the Gd2O3 powder and the quartz glass powder;

[0107] The Gd2O3 powder, distilled water, and ammonium citrate materials were added to a ball mill tank and ball milled together, with a ball milling speed of 400 r / min and a ball milling time of 4 h, to prepare a uniform slurry;

[0108] The weighed quartz glass powder was mixed with the above slurry, and uniform stirring was performed at a ball milling speed of 400 r / min for 30 min to make the mixture uniform;

[0109] The uniformly mixed slurry was placed in a reaction kettle and reacted at 900℃ for 1 h;

[0110] After the reaction was cooled, the bulk material was crushed and passed through a 100-mesh sieve, and the undersize powder obtained was reserved;

[0111] The modified Gd2O3 powder prepared above was weighed at 6% of the mass of the ceramic powder (quartz powder 85wt%, mineralizer 15wt%), and the powder was added to a V-shaped mixing barrel and mixed for 1 h;

[0112] A plasticizer material (93wt% paraffin, 5wt% beeswax, 2wt% polyethylene) was added to a blender, and the amount added was 15% of the mass of the ceramic powder, with the temperature set to 130℃. After the plasticizer material was completely melted, stirring was turned on at 35 r / min, and the ceramic powder mixed uniformly in the V-shaped mixing barrel was gradually added. After all the powder was added, stirring was continued for 8 h, and vacuum stirring was performed for 1 h at a vacuum degree of 0.05 MPa or less. After stirring, the vacuum was broken, and the slurry was poured out. After cooling, a core-shell structure modified Gd2O3 doped silicon-based ceramic core material ingot was prepared;

[0113] The above ingot was melted, and a ceramic core green body was prepared according to the following technical parameters using a ceramic core hot-pressing injection machine: material temperature 95℃, pressure 4.5 MPa, injection time 5 s, and holding time 35 s;

[0114] The obtained ceramic core green body was buried in mullite filler and fired at a final firing temperature of 1210℃ for 4 h to prepare a silicon oxide-based ceramic core.

[0115] The silicon oxide-based ceramic core prepared in Example 3 was detected according to the method of Example 1, and the detection results were: shrinkage rate 0.2%, deflection 0.15 mm, and collapse rate 0.012 g / min.

[0116] The embodiment results show that the modified gadolinium oxide material for nuclear shell structure prepared by controlling the modified gadolinium oxide material formula and process of the gadolinium-containing silicon-based ceramic core is used as a neutron detection tracer, and the material doped in the silicon-based ceramic core has excellent comprehensive performance, can be applied to ceramic cores of different sizes and structures, and has the characteristics of small shrinkage, low deflection, good collapsibility and the like.

[0117] While the application has been described and illustrated with reference to specific embodiments thereof, these descriptions and illustrations are not intended to limit the application. Those skilled in the art can clearly understand that various changes can be made to specific conditions, materials, compositions, substances, methods or processes to adapt them to the objects, spirit and scope of the present application without departing from the true spirit and scope of the application as defined by the appended claims. All such modifications are intended to be within the scope of the appended claims. Although the methods disclosed herein have been described with reference to specific operations performed in a particular order, it will be understood that these operations can be combined, subdivided or reordered to create equivalent methods without departing from the teachings of the present application. Therefore, unless specifically indicated otherwise, the order and grouping of operations are not a limitation of the present application.

Claims

1. A method for preparing a silicon-based ceramic core material, comprising: mixing a ceramic powder and a modified gadolinium oxide material to obtain a mixture; mixing a plasticizer and the mixture to obtain the silicon-based ceramic core material; the modified gadolinium oxide material has a mass of 3-8% of the mass of the ceramic powder; the ceramic powder comprises quartz powder and a mineralizer, wherein the mass content of the quartz powder in the ceramic powder is ≥80%, and the mass content of the mineralizer in the ceramic powder is 10-20%; the third mixing is performed for 0.5-1.5 hours; the fourth mixing comprises: adding the plasticizer into a stirrer, starting stirring after the plasticizer is completely melted, continuously stirring after the mixture is added into the plasticizer, vacuum stirring, breaking the vacuum after stirring, obtaining a slurry, and obtaining the silicon-based ceramic core material after cooling; wherein, the modified gadolinium oxide material is prepared from a material comprising gadolinium oxide, quartz glass, water, and ammonium citrate; the modified gadolinium oxide material is prepared by the following method: mixing the gadolinium oxide, water, and ammonium citrate to obtain a mixture; mixing the mixture and the quartz glass to obtain a slurry; reacting the slurry to obtain the modified gadolinium oxide material; during the preparation of the modified gadolinium oxide material: the mass ratio of the gadolinium oxide to the quartz glass is 1: (1-3) ; the mass of the water is 40-60% of the total mass of the gadolinium oxide and the quartz glass; the mass of the ammonium citrate is 0.5-1% of the total mass of the gadolinium oxide and the quartz glass; the first mixing is ball milling, the rotation speed of the ball milling is 300-500 r / min, and the ball milling is performed for 3-5 hours; the second mixing is ball milling, the rotation speed of the ball milling is 300-500 r / min, and the ball milling is performed for 20-40 minutes; the reaction is performed at a temperature of 800-1000 ℃ for 0.5-1.5 hours.

2. The method of claim 1, wherein, the temperature of the fourth mixing is 120-140 ℃.

3. The method of claim 1, wherein, during the preparation of the modified gadolinium oxide material: after the reaction, the obtained reaction product is broken and sieved through a mesh; the mesh has a mesh number of 80-120. 4.A silicon-based ceramic core material prepared by the method of any one of claims 1-3. ​