Ceramic core for high-generation single crystal high-temperature alloy blade and preparation method of ceramic core

Abstract

The invention relates to the field of ceramic cores, and particularly discloses a ceramic core for a high-generation single-crystal high-temperature alloy blade and a preparation method of the ceramic core. The ceramic core comprises the following raw materials in percentage by weight: 55-75% of quartz glass powder, 5-15% of fused corundum powder, 5-15% of zirconium silicate powder, 1-10% of a high-temperature-resistant material and 10-25% of a plasticizer, wherein the high-temperature-resistant material comprises a barium material and a nickel material in a weight ratio of 1: (0.1-10). The ceramic core has high high-temperature creep strength and high-temperature chemical stability, meanwhile, the high-temperature deflection is low, the apparent porosity is high, the phenomenon of deformation or breakage is not prone to occurring when the single-crystal high-temperature alloy blade is poured, and the casting qualification rate of the single-crystal high-temperature alloy blade is greatly increased.

Description

Technical Field

[0001] The present application relates to the field of ceramic cores, and more specifically, to a ceramic core for high-generation single-crystal superalloy blades and a preparation method thereof. Background Art

[0002] The performance of aero-engines is the main factor restricting the development of aviation. The thrust-to-weight ratio, which affects the key performance of aero-engines, is closely related to the temperature-bearing capacity of the hot-end component turbine blades. At present, improving the temperature-bearing capacity of turbine blades through the hollow air-cooled structure of turbine blades has become an important means to improve engine performance. The ceramic core is the key to realizing the hollow inner cavity structure of engine blades. With the development of cooling technology, the inner cavity structure of blades is becoming increasingly complex, which puts higher requirements on the structure and performance of ceramic cores.

[0003] At present, the most widely used ceramic core is the silicon-based ceramic core, which uses quartz glass as the main raw material, has excellent high-temperature physical and chemical stability, and excellent removability. However, as the requirements for the structural complexity of silicon-based ceramic cores for single-crystal superalloy blades are getting higher and higher, the high-temperature stability of existing silicon-based ceramic cores is difficult to meet actual applications. For example, when actually casting single-crystal superalloy blades, due to the long-term action of the alloy liquid and the silicon-based ceramic core at high temperature (above 1450°C for more than 1 hour), the silicon-based ceramic core will deform or break, thus affecting the overall manufacturing of the blades.

[0004] Although there are currently various studies on improving the high-temperature performance of ceramic cores, there are still certain problems. For example, the Chinese patent with the publication number CN 105669198A discloses a preparation process of a ceramic core mainly made of lanthanum oxide, which can improve the temperature resistance limit of the ceramic core. However, the content of lanthanum oxide is between 80% and 90%, the cost of the core is too high, and it needs to be stored in an airtight manner or filled with inert gas before casting, making it difficult to be used in production. Another example is the Chinese patent with the publication number CN108178637A, which discloses a preparation process of a ceramic core mainly made of yttrium oxide, and the maximum working temperature can reach 1700°C. However, the content of yttrium oxide is between 70% and 80%, and there is also the problem of too high core cost. Another example is the Chinese patent with the publication number CN 110256077A, which discloses a production process of a ceramic core using yttrium oxide as the raw material and cerium oxide, lanthanum oxide and europium oxide as additives. The content of yttrium oxide is above 80%, and the sintering temperature needs to reach above 1400°C. Both the raw material cost and the sintering cost are relatively high, and it is not suitable for large-scale production. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a ceramic core for high-generation single-crystal superalloy blades and a preparation method thereof.

[0006] In a first aspect, a ceramic core for high-generation single-crystal superalloy blades provided by the present application adopts the following technical solution: A ceramic core for high-generation single-crystal superalloy blades, calculated by weight percentage, the raw materials used for the ceramic core include the following components: Quartz glass powder 55 - 75%; Fused alumina powder 5 - 15%; Zirconium silicate powder 5 - 15%; High-temperature resistant material 1 - 10%; Plasticizer 10 - 25%; The high-temperature resistant material includes barium-based material and nickel-based material with a weight ratio of 1:(0.1 - 10).

[0007] By adopting the above technical solution, the present application uses quartz glass powder as the main raw material to provide good high-temperature stability and removal performance for the ceramic core. The synergistic effect of fused alumina powder and zirconium silicate powder further improves the mechanical strength and thermal shock resistance of the ceramic core. Both the barium-based material and nickel-based material in the high-temperature resistant material have high high-temperature strength and chemical stability. Their synergistic effect can significantly improve the high-temperature creep strength of the ceramic core, and at the same time enhance the high-temperature chemical stability of the ceramic core, reducing the possibility of deformation or fracture of the ceramic core when casting single-crystal superalloy blades, and greatly improving the casting qualification rate of single-crystal superalloy blades. In addition, the addition of the plasticizer ensures excellent processing performance of the ceramic core during the forming process.

[0008] Preferably, the weight ratio of the barium-based material to the nickel-based material is 1:(1 - 2).

[0009] By adopting the above technical solution, the present application further optimizes the ratio between the barium-based material and the nickel-based material in the high-temperature resistant material, enabling them to give full play to their synergistic effect with each other, thereby further improving the high-temperature performance of the ceramic core, reducing the possibility of deformation or fracture of the ceramic core when casting single-crystal superalloy blades, and greatly improving the casting qualification rate of single-crystal superalloy blades.

[0010] Optionally, the barium-based material includes one of barium titanate, barium strontium titanate, barium zirconate, and barium carbonate.

[0011] Preferably, the barium-based material includes barium titanate.

[0012] Optionally, the nickel-based material includes one of nickel oxide, nickel sesquioxide, nickel hydroxide, and pure nickel powder.

[0013] Preferably, the nickel-based material includes nickel oxide.

[0014] By adopting the above technical solution, the present application uses one of barium titanate, barium strontium titanate, barium zirconate and barium carbonate as the barium-based material, and uses one of nickel oxide, nickel sesquioxide, nickel hydroxide and pure nickel powder as the nickel-based material. By utilizing the mutual cooperation of the barium-based material and the nickel-based material and giving full play to the synergistic effect between the two, the high-temperature performance of the ceramic core is significantly improved. Experimental results show that the synergistic effect between barium titanate and nickel oxide is the strongest, and it has the strongest effect on improving the high-temperature performance of the ceramic core.

[0015] Preferably, by weight percentage, the fused silica powder includes 20-40% of 200-mesh fused silica powder, 20-40% of 400-mesh fused silica powder, 10-20% of 800-mesh fused silica powder, and 10-20% of 1250-mesh fused silica powder.

[0016] By adopting the above technical solution, the present application optimizes the particle size distribution of the fused silica powder. Specifically, the proportions of both 200-mesh fused silica powder and 400-mesh fused silica powder are 20-40%, which ensures that the framework structure of the ceramic core has good strength and support performance, and at the same time improves the filling density of the material; the proportions of 800-mesh fused silica powder and 1250-mesh fused silica powder are 10-20% respectively, which further optimizes the microstructure inside the ceramic core and enhances its high-temperature performance. This reasonable combination of multi-level particle sizes significantly improves the overall performance of the ceramic core. While meeting the requirements of complex internal cavity structures, it effectively reduces the problem of thermal stress concentration under high-temperature conditions, thereby enhancing the applicability of the ceramic core in the manufacturing of high-generation single-crystal superalloy blades.

[0017] Preferably, both the electrofused corundum powder and the zirconium silicate powder are materials passing through a 325-mesh sieve, and both the barium-based material and the nickel-based material are materials passing through a 500-mesh sieve.

[0018] By adopting the above technical solution, the fact that both the electrofused corundum powder and the zirconium silicate powder are materials passing through a 325-mesh sieve can ensure uniform distribution of powder particles, improve the density and surface finish of the ceramic core, thereby enhancing the high-temperature stability and mechanical strength of the ceramic core. The fact that both the barium-based material and the nickel-based material are materials passing through a 500-mesh sieve is conducive to uniform dispersion in the raw materials, thereby further enhancing the high-temperature stability and mechanical strength of the ceramic core, and at the same time reducing the possibility of local stress concentration problems caused by over-sized particles, and improving the casting qualification rate of single-crystal superalloy blades.

[0019] In a second aspect, the present application provides a preparation method for a ceramic core for high-generation single-crystal superalloy blades, adopting the following technical solution: A preparation method for a ceramic core for high-generation single-crystal superalloy blades includes the following steps: S1. Heat the plasticizer to melting at a temperature of 100 - 150°C, then add other raw materials and mix them evenly. After cooling to room temperature, a material block is obtained. S2. Obtain a core blank by hot - press injection molding of the material block. S3. Obtain a ceramic core by step - by - step high - temperature sintering of the core blank.

[0020] By adopting the above - mentioned technical solution, in this application, the plasticizer is first heated to melting at a certain temperature and mixed evenly with other raw materials, which can effectively improve the bonding performance between the raw materials, ensure the uniformity and stability of the material block, and provide a good foundation for subsequent molding and sintering. Then, using the hot - press injection molding process, the core blank can be accurately molded to meet the requirements of the complex - structure turbine blade cavity, while improving production efficiency and product yield. After that, the step - by - step high - temperature sintering process is adopted. Through multi - stage temperature - controlled heat preservation treatment, the internal stress is effectively released, reducing the phenomenon of deformation or cracking of the ceramic core at high temperature, and significantly improving the high - temperature stability and mechanical strength of the ceramic core.

[0021] Preferably, the process steps of the step - by - step high - temperature sintering are specifically as follows: First, increase the temperature from room temperature to 200 - 300°C at a heating rate of 5 - 10°C / min, keep it warm for 2 - 6 h, then increase the temperature to 600 - 700°C at a heating rate of 0.1 - 7°C / min, keep it warm for 2 - 6 h, then increase the temperature to 900 - 1100°C at a heating rate of 0.1 - 5°C / min, keep it warm for 2 - 6 h, then increase the temperature to 1200 - 1350°C at a heating rate of 0.1 - 3°C / min, keep it warm for 2 - 6 h, and then cool to room temperature.

[0022] By adopting the above - mentioned technical solution, in the initial stage of this application, the temperature is first increased from room temperature to 200 - 300°C at a heating rate of 5 - 10°C / min and kept warm for 2 - 6 h, which helps to remove moisture and organic impurities in the raw materials, reducing the possibility of generating pores or cracks during subsequent high - temperature treatment; then the temperature is increased to 600 - 700°C at a heating rate of 0.1 - 7°C / min and kept warm for 2 - 6 h, promoting the initial sintering of raw material particles and grain growth, and enhancing the densification of the material; then the temperature is increased to 900 - 1100°C at a heating rate of 0.1 - 5°C / min and kept warm for 2 - 6 h, further strengthening the bonding force between particles and improving the overall strength and heat - resistant performance of the material; then the temperature is increased to 1200 - 1350°C at a heating rate of 0.1 - 3°C / min and kept warm for 2 - 6 h, ensuring the full sintering of the ceramic core and forming a stable microstructure, so as to maintain good mechanical properties and anti - deformation ability in a high - temperature environment. The preparation method of this application can effectively control thermal stress, reduce the risk of cracking through the design of gradual heating and segmented heat preservation, while optimizing sintering efficiency and energy consumption, and is suitable for large - scale production applications.

[0023] In summary, the present application has the following beneficial technical effects: 1. The ceramic core of the present application has strong high-temperature creep strength, high-temperature chemical stability, low high-temperature deflection, and high apparent porosity, and is not prone to deformation or fracture during the casting of single-crystal superalloy blades, greatly improving the casting qualification rate of single-crystal superalloy blades; 2. The preparation method of the ceramic core of the present application can effectively control thermal stress through the design of stepwise heating and segmented heat preservation, reduce the risk of cracking, and at the same time optimize the sintering efficiency and energy consumption, making it suitable for large-scale production applications. Specific Embodiments

[0024] The present application will be further described in detail below in conjunction with embodiments.

[0025] All raw materials used in the present application are commercially available products. The plasticizer is wax for precision casting, with a melting point of 86°C, purchased from Shenyang Yicheng Corrosion-Resistant Alloy Equipment Co., Ltd.

[0026] Example 1.1 A preparation method of a ceramic core for high-generation single-crystal superalloy blades includes the following steps: S1. At a temperature of 100°C, 19 kg of wax for precision casting is heated to melting, and then 55 kg of quartz glass powder (200 mesh), 10 kg of fused corundum powder (sieved under 325 mesh), 15 kg of zirconium silicate powder (sieved under 325 mesh), and 1 kg of high-temperature resistant material (sieved under 500 mesh) are added and mixed evenly. After cooling to room temperature, a material block is obtained; the high-temperature resistant material includes barium-based material and nickel-based material with a weight ratio of 1:0.1, specifically 0.91 kg of barium-based material and 0.09 kg of nickel-based material. The barium-based material is barium titanate, and the nickel-based material is nickel oxide; S2. The material block is hot-press injection molded under the conditions of an injection temperature of 100°C, a mold temperature of 30°C, an injection pressure of 2.5 MPa, and a holding pressure of 60 s to obtain a core blank; S3. The core blank is subjected to stepwise high-temperature sintering. Specifically, it is first heated from room temperature to 200°C at a heating rate of 5°C / min and held for 2 h, then heated to 600°C at a heating rate of 0.1°C / min and held for 2 h, then heated to 900°C at a heating rate of 0.1°C / min and held for 2 h, then heated to 1200°C at a heating rate of 0.1°C / min and held for 2 h, and then cooled to room temperature to obtain a ceramic core.

[0027] Example 1.2 A preparation method of a ceramic core for high-generation single-crystal superalloy blades includes the following steps: S1. At a temperature of 110 °C, heat 15 kg of wax for precision casting until it melts, then add 60 kg of quartz glass powder (200 mesh), 5 kg of fused alumina powder (undersize of 325 mesh), 10 kg of zirconium silicate powder (undersize of 325 mesh), and 10 kg of high-temperature resistant material (undersize of 500 mesh), mix evenly, and obtain a block after cooling to room temperature; the high-temperature resistant material includes barium-based material and nickel-based material with a weight ratio of 1:0.1, specifically 9.09 kg of barium-based material and 0.91 kg of nickel-based material, where the barium-based material is barium titanate and the nickel-based material is nickel oxide; S2. Under the conditions of an injection temperature of 100 °C, a mold temperature of 30 °C, an injection pressure of 2.5 MPa, and a holding pressure of 60 s, obtain a core blank after hot-press injection molding; S3. Subject the core blank to step-by-step high-temperature sintering. Specifically, first increase the temperature from room temperature to 220 °C at a heating rate of 6 °C / min, hold for 3 h, then increase the temperature to 610 °C at a heating rate of 1 °C / min, hold for 3 h, then increase the temperature to 950 °C at a heating rate of 1 °C / min, hold for 3 h, then increase the temperature to 1230 °C at a heating rate of 0.8 °C / min, hold for 3 h, and then cool to room temperature to obtain a ceramic core.

[0028] Example 1.3 A preparation method of a ceramic core for high-generation single-crystal superalloy blades includes the following steps: S1. At a temperature of 120 °C, heat 25 kg of wax for precision casting until it melts, then add 60 kg of quartz glass powder (200 mesh), 8 kg of fused alumina powder (undersize of 325 mesh), 5 kg of zirconium silicate powder (undersize of 325 mesh), and 2 kg of high-temperature resistant material (undersize of 500 mesh), mix evenly, and obtain a block after cooling to room temperature; the high-temperature resistant material includes barium-based material and nickel-based material with a weight ratio of 1:0.1, specifically 1.82 kg of barium-based material and 0.18 kg of nickel-based material, where the barium-based material is barium titanate and the nickel-based material is nickel oxide; S2. Under the conditions of an injection temperature of 100 °C, a mold temperature of 30 °C, an injection pressure of 2.5 MPa, and a holding pressure of 60 s, obtain a core blank after hot-press injection molding; S3. Subject the core blank to step-by-step high-temperature sintering. Specifically, first increase the temperature from room temperature to 250 °C at a heating rate of 7 °C / min, hold for 4 h, then increase the temperature to 640 °C at a heating rate of 3 °C / min, hold for 4 h, then increase the temperature to 980 °C at a heating rate of 2 °C / min, hold for 4 h, then increase the temperature to 1260 °C at a heating rate of 1.5 °C / min, hold for 4 h, and then cool to room temperature to obtain a ceramic core.

[0029] Example 1.4 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, comprising the following steps: S1. At a temperature of 135 °C, 10 kg of precision casting wax is heated to melting, and then 65 kg of quartz glass powder (200 mesh), 15 kg of fused corundum powder (undersize of 325 mesh), 5 kg of zirconium silicate powder (undersize of 325 mesh), and 5 kg of high-temperature resistant material (undersize of 500 mesh) are added and mixed evenly. After cooling to room temperature, a material block is obtained; the high-temperature resistant material includes barium-based material and nickel-based material with a weight ratio of 1:0.1, specifically 4.55 kg of barium-based material and 0.45 kg of nickel-based material, wherein the barium-based material is barium titanate and the nickel-based material is nickel oxide; S2. The material block is subjected to hot-press injection molding under the conditions of an injection temperature of 100 °C, a mold temperature of 30 °C, an injection pressure of 2.5 MPa, and a pressure holding time of 60 s to obtain a core blank; S3. The core blank is subjected to stepwise high-temperature sintering. Specifically, it is first heated from room temperature to 280 °C at a heating rate of 8 °C / min and held for 5 h, then heated to 680 °C at a heating rate of 5 °C / min and held for 5 h, then heated to 1050 °C at a heating rate of 3.5 °C / min and held for 5 h, and then heated to 1290 °C at a heating rate of 2.2 °C / min and held for 5 h, and then cooled to room temperature to obtain a ceramic core.

[0030] Example 1.5 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, comprising the following steps: S1. At a temperature of 150 °C, 12 kg of precision casting wax is heated to melting, and then 75 kg of quartz glass powder (200 mesh), 5 kg of fused corundum powder (undersize of 325 mesh), 6 kg of zirconium silicate powder (undersize of 325 mesh), and 2 kg of high-temperature resistant material (undersize of 500 mesh) are added and mixed evenly. After cooling to room temperature, a material block is obtained; the high-temperature resistant material includes barium-based material and nickel-based material with a weight ratio of 1:0.1, specifically 1.82 kg of barium-based material and 0.18 kg of nickel-based material, wherein the barium-based material is barium titanate and the nickel-based material is nickel oxide; S2. The material block is subjected to hot-press injection molding under the conditions of an injection temperature of 100 °C, a mold temperature of 30 °C, an injection pressure of 2.5 MPa, and a pressure holding time of 60 s to obtain a core blank; S3. The core blank is subjected to stepwise high-temperature sintering. Specifically, it is first heated from room temperature to 300 °C at a heating rate of 10 °C / min and held for 6 h, then heated to 700 °C at a heating rate of 7 °C / min and held for 6 h, then heated to 1100 °C at a heating rate of 5 °C / min and held for 6 h, and then heated to 1350 °C at a heating rate of 3 °C / min and held for 65 h, and then cooled to room temperature to obtain a ceramic core.

[0031] Example 2.1 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the weight ratio of barium titanate to nickel oxide is 1:1, specifically 1 kg of barium titanate and 1 kg of nickel oxide, and the rest are the same as in Example 1.3.

[0032] Example 2.2 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the weight ratio of barium titanate to nickel oxide is 1:2, specifically 0.67 kg of barium titanate and 1.33 kg of nickel oxide, and the rest are the same as in Example 1.3.

[0033] Example 2.3 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the weight ratio of barium titanate to nickel oxide is 1:5, specifically 0.33 kg of barium titanate and 1.67 kg of nickel oxide, and the rest are the same as in Example 1.3.

[0034] Example 2.4 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the weight ratio of barium titanate to nickel oxide is 1:10, specifically 0.18 kg of barium titanate and 1.82 kg of nickel oxide, and the rest are the same as in Example 1.3.

[0035] Example 3.1 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the barium-based material is barium zirconate, and the rest are the same as in Example 1.3.

[0036] Example 3.2 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the barium-based material is barium strontium titanate, and the rest are the same as in Example 1.3.

[0037] Example 3.3 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the barium-based material is barium carbonate, and the rest are the same as in Example 1.3.

[0038] Example 4.1 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the nickel-based material is nickel sesquioxide, and the rest is the same as Example 1.3.

[0039] Example 4.2 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the nickel-based material is pure nickel powder, and the rest is the same as Example 1.3.

[0040] Example 4.3 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the nickel-based material is nickel hydroxide, and the rest is the same as Example 1.3.

[0041] Example 5.1 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the barium-based material is barium zirconate and the nickel-based material is nickel sesquioxide, and the rest is the same as Example 1.3.

[0042] Example 5.2 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the barium-based material is strontium barium titanate and the nickel-based material is pure nickel powder, and the rest is the same as Example 1.3.

[0043] Example 5.3 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, the barium-based material is barium carbonate and the nickel-based material is nickel hydroxide, and the rest is the same as Example 1.3.

[0044] Example 6.1 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, 60 kg of quartz glass powder includes 20% of 200-mesh quartz glass powder, 40% of 400-mesh quartz glass powder, 20% of 800-mesh quartz glass powder, and 20% of 1250-mesh quartz glass powder, and the rest is the same as Example 1.3.

[0045] Example 6.2 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, 60 kg of quartz glass powder includes 40% of 200-mesh quartz glass powder, 30% of 400-mesh quartz glass powder, 10% of 800-mesh quartz glass powder, and 20% of 1250-mesh quartz glass powder, and the rest is the same as in Example 1.3.

[0046] Example 6.3 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, 60 kg of quartz glass powder includes 40% of 200-mesh quartz glass powder, 20% of 400-mesh quartz glass powder, 20% of 800-mesh quartz glass powder, and 20% of 1250-mesh quartz glass powder, and the rest is the same as in Example 1.3.

[0047] Example 6.4 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, 60 kg of quartz glass powder is all 400-mesh quartz glass powder, and the rest is the same as in Example 1.3.

[0048] Example 6.5 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, 60 kg of quartz glass powder is all 800-mesh quartz glass powder, and the rest is the same as in Example 1.3.

[0049] Example 6.6 A preparation method of a ceramic core for high-generation single-crystal superalloy blades, which is different from Example 1.3 in that in step S1, 60 kg of quartz glass powder is all 1250-mesh quartz glass powder, and the rest is the same as in Example 1.3.

[0050] Comparative Example 1.1 It is different from Example 1.3 in that in step S1, the high-temperature resistant material is all barium titanate, and the rest is the same as in Example 1.3.

[0051] Comparative Example 1.2 It is different from Example 1.3 in that in step S1, the high-temperature resistant material is all nickel oxide, and the rest is the same as in Example 1.3.

[0052] Comparative Example 1.3 It is different from Example 1.3 in that in step S1, the high-temperature resistant material includes yttrium oxide and lanthanum oxide with a weight ratio of 1:1, specifically 1 kg of yttrium oxide and 1 kg of lanthanum oxide, and the rest is the same as in Example 1.3.

[0053] Comparative Example 1.4 It is different from Example 1.3 in that in step S1, nickel oxide in the high-temperature resistant material is replaced with yttrium oxide, and the rest is the same as that in Example 1.3.

[0054] Comparative Example 1.5 It is different from Example 1.3 in that in step S1, nickel oxide in the high-temperature resistant material is replaced with lanthanum oxide, and the rest is the same as that in Example 1.3.

[0055] Comparative Example 2.1 It is different from Example 1.3 in that in step S1, the high-temperature resistant material includes barium titanate and nickel oxide with a weight ratio of 1:0.05, specifically 1.9 kg of barium titanate and 0.1 kg of nickel oxide, and the rest is the same as that in Example 1.3.

[0056] Comparative Example 2.2 It is different from Example 1.3 in that in step S1, the high-temperature resistant material includes barium titanate and nickel oxide with a weight ratio of 1:15, specifically 0.125 kg of barium titanate and 1.875 kg of nickel oxide, and the rest is the same as that in Example 1.3.

[0057] Comparative Example 3.1 It is different from Example 1.3 in that in the stepwise high-temperature sintering of step S3, first, the temperature is raised from room temperature to 250 °C at a heating rate of 7 °C / min and held for 4 h, then the temperature is raised to 980 °C at a heating rate of 3 °C / min and held for 8 h, and then the temperature is raised to 1260 °C at a heating rate of 1.5 °C / min and held for 4 h, and the rest is the same as that in Example 1.3.

[0058] Comparative Example 3.2 It is different from Example 1.3 in that in the stepwise high-temperature sintering of step S3, first, the temperature is raised from room temperature to 250 °C at a heating rate of 7 °C / min and held for 4 h, then the temperature is raised to 640 °C at a heating rate of 3 °C / min and held for 4 h, and then the temperature is raised to 1260 °C at a heating rate of 2 °C / min and held for 8 h, and the rest is the same as that in Example 1.3.

[0059] Performance Detection 1. Referring to HB 5353.3-2004, the high-temperature flexural strength of the ceramic cores prepared in the above examples and comparative examples was measured. The test temperature was 1600 °C, and the temperature was raised to 1600 °C at a heating rate of 300 - 400 °C / h, held at the test temperature for 30 min, and then loaded at a speed of 6 - 8 mm / min until the specimen broke. Record the load value when the specimen broke and calculate the flexural strength. The size of the specimen was 60 mm × 10 mm × 4 mm.

[0060] 2. The apparent porosity of the ceramic cores obtained from the above-mentioned examples and comparative examples was measured with reference to HB 5353.1-2004. The test piece was a cylindrical test piece with a volume of 1.5-2.0 cm 3 .

[0061] 3. The high-temperature deflection of the ceramic cores obtained from the above-mentioned examples and comparative examples was measured with reference to HB 5353.4-2004. The test temperature was 1600 °C, and the temperature was raised to 1600 °C at a heating rate of 300-400 °C / h. After holding for more than 10 min to eliminate the thermal gradient, the load was applied at a speed of 0.5 mm / min, and the maximum deflection value was recorded through the load-displacement curve. The specimen size was 2 mm×6 mm×120 mm.

[0062] The above performance test results were all recorded in Table 1.

[0063] Table 1 Performance Test Results Table Data Analysis: As can be seen from Table 1, the ceramic cores prepared in Examples 1.1-1.5 of the present application had a flexural strength of 27.5-35.8 MPa, a high-temperature deflection of 0.18-0.25 mm, and an apparent porosity of 15.3-22.5% at a temperature of 1600 °C. They obviously had strong high-temperature creep strength, high-temperature chemical stability, low high-temperature deflection, and high apparent porosity, and were not prone to deformation or fracture during the casting of single-crystal superalloy blades, greatly improving the casting qualification rate of single-crystal superalloy blades.

[0064] The ceramic cores prepared in Examples 2.1-2.4 had a flexural strength higher than that of Example 1.3 at 1600 °C, a high-temperature deflection lower than that of Example 1.3 at 1600 °C, and an apparent porosity higher than that of Example 1.3. This shows that further optimizing the ratio between barium titanate and nickel oxide can further improve the high-temperature resistance of the ceramic core. Among them, when the weight ratio between barium titanate and nickel oxide was further optimized to 1:(1-2) in Examples 2.1-2.2, the obtained ceramic core had the best high-temperature resistance.

[0065] The ceramic cores prepared in Examples 3.1-5.3 had a flexural strength lower than that of Example 1.3 at 1600 °C, a high-temperature deflection higher than that of Example 1.3 at 1600 °C, and an apparent porosity lower than that of Example 1.3. This shows that mixing and matching barium titanate and nickel oxide can give full play to the synergistic effect between the two, thereby greatly enhancing the high-temperature resistance of the ceramic core. Replacing any one of the barium-based material and the nickel-based material, or adopting other combination forms, will significantly reduce the high-temperature resistance of the ceramic core.

[0066] The flexural strength of the ceramic cores prepared in Examples 6.1 - 6.3 at 1600 °C is higher than that of Example 1.3, the high-temperature deflection at 1600 °C is lower than that of Example 1.3, and the apparent porosity is higher than that of Example 1.3. The flexural strength of the ceramic cores prepared in Examples 6.4 - 6.5 at 1600 °C is lower than that of Example 1.3, the high-temperature deflection at 1600 °C is higher than that of Example 1.3, and the apparent porosity is lower than that of Example 1.3. This shows that using a mixture of quartz glass powders with multiple particle sizes can improve the overall performance of the ceramic core. While meeting the requirements of complex internal cavity structures, it effectively reduces the problem of thermal stress concentration under high-temperature conditions, thereby enhancing the applicability of the ceramic core in the manufacturing of high-generation single-crystal superalloy blades.

[0067] The flexural strength of the ceramic cores prepared in Comparative Examples 1.1 - 1.5 at 1600 °C is lower than that of Example 1.3, the high-temperature deflection at 1600 °C is higher than that of Example 1.3, and the apparent porosity is lower than that of Example 1.3. This shows that compared with other high-temperature resistant materials, using a mixture of barium titanate and nickel oxide in this application can give full play to the synergistic effect between the two, thereby improving the high-temperature resistance of the ceramic core.

[0068] The flexural strength of the ceramic cores prepared in Comparative Examples 2.1 - 2.2 at 1600 °C is lower than that of Example 1.3, the high-temperature deflection at 1600 °C is higher than that of Example 1.3, and the apparent porosity is lower than that of Example 1.3. This shows that optimizing the ratio between barium titanate and nickel oxide can enable the two to exert the best synergistic effect, thereby improving the high-temperature resistance of the ceramic core.

[0069] The flexural strength of the ceramic cores prepared in Comparative Examples 3.1 - 3.2 at 1600 °C is lower than that of Example 1.3, the high-temperature deflection at 1600 °C is higher than that of Example 1.3, and the apparent porosity is lower than that of Example 1.3. This shows that the preparation method of this application can effectively control thermal stress, reduce the risk of cracking, and improve the high-temperature stability and mechanical strength of the ceramic core through the design of stepwise heating and segmented heat preservation.

[0070] The examples of this specific implementation manner are all preferred examples of this application, and do not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A ceramic core for high-generation single-crystal superalloy blades, characterized in that, By weight percentage, the raw materials used for the ceramic core include the following components: Quartz glass powder 55 - 75%; Fused corundum powder 5 - 15%; Zirconium silicate powder 5 - 15%; High-temperature resistant material 1 - 10%; Plasticizer 10 - 25%; The high-temperature resistant material includes barium-based material and nickel-based material with a weight ratio of 1:(0.1 - 10).

2. The ceramic core for a high-generation single-crystal superalloy blade according to claim 1, wherein The weight ratio of the barium-based material to the nickel-based material is 1:(1 - 2).

3. A ceramic core for a high-generation single-crystal superalloy blade according to claim 1 or 2, characterized in that The barium-based material includes one of barium titanate, barium strontium titanate, barium zirconate, and barium carbonate.

4. A ceramic core for a high-generation single-crystal superalloy blade according to claim 3, characterized in that The barium-based material includes barium titanate.

5. A ceramic core for a high-generation single-crystal superalloy blade according to claim 1 or 2, characterized in that, The nickel-based material includes one of nickel oxide, nickel sesquioxide, nickel hydroxide, and pure nickel powder.

6. A ceramic core for a high-generation single-crystal superalloy blade according to claim 5, characterized in that, The nickel-based material includes nickel oxide.

7. A ceramic core for a high-generation single-crystal superalloy blade according to claim 1, characterized in that, By weight percentage, the quartz glass powder includes 20 - 40% of 200-mesh quartz glass powder, 20 - 40% of 400-mesh quartz glass powder, 10 - 20% of 800-mesh quartz glass powder, and 10 - 20% of 1250-mesh quartz glass powder.

8. A ceramic core for a high-generation single-crystal superalloy blade according to claim 1, characterized in that The fused corundum powder and zirconium silicate powder are both materials passing through a 325-mesh sieve, and the barium-based material and nickel-based material are both materials passing through a 500-mesh sieve.

9. A method for preparing a ceramic core for a high-generation single-crystal superalloy blade according to claim 1, characterized in that, It includes the following steps: S1. At a temperature of 100 - 150 °C, heat the plasticizer to melting, then add other raw materials and mix evenly. After cooling to room temperature, a material block is obtained. S2. The material block is hot-pressed and injection-molded to obtain a core blank. S3. The core blank is subjected to step-by-step high-temperature sintering to obtain a ceramic core.

10. The preparation method of a ceramic core for a high-generation single-crystal superalloy blade according to claim 9, characterized in that, The process steps of the step-by-step high-temperature sintering are specifically as follows: First, at a heating rate of 5 - 10 °C / min, heat from room temperature to 200 - 300 °C and hold for 2 - 6 h. Then, at a heating rate of 0.1 - 7 °C / min, heat to 600 - 700 °C and hold for 2 - 6 h. Then, at a heating rate of 0.1 - 5 °C / min, heat to 900 - 1100 °C and hold for 2 - 6 h. After that, at a heating rate of 0.1 - 3 °C / min, heat to 1200 - 1350 °C and hold for 2 - 6 h. Subsequently, cool to room temperature.

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