A silicon-based ceramic core that is resistant to cold and heat shock, high temperature creep and easy to remove and its preparation process

A technology of anti-cold and thermal shock, ceramic core, applied in cores, manufacturing tools, casting and molding equipment, etc., can solve the problem of difficulty in ensuring the uniformity of cristobalite, achieve excellent easy removal performance, high temperature creep resistance Effects of performance, high strength and chemical stability

Active Publication Date: 2021-10-29
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When the silicon-based ceramic core is sintered, the amount of cristobalite precipitation must be controlled to ensure that the ceramic core has good overall performance, but it is difficult to ensure the uniformity of cristobalite precipitation only by adjusting the process parameters

Method used

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  • A silicon-based ceramic core that is resistant to cold and heat shock, high temperature creep and easy to remove and its preparation process
  • A silicon-based ceramic core that is resistant to cold and heat shock, high temperature creep and easy to remove and its preparation process

Examples

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Effect test

preparation example Construction

[0034] The preparation process of the ceramic core is as follows:

[0035] (1) Quartz glass, alumina and cristobalite are put into a pot mill according to the proportioning ratio, and the pot mill is used at 80r / min for 24 hours, and the obtained powder is used for subsequent use;

[0036] (2) Heat the plasticizer to 85°C, and when it melts completely, add the powder obtained in step (1) into the plasticizer in 4 batches, and the amount of each batch accounts for 25% of the total powder. Stir to ensure that there is no dry powder. After all the powders are added, a slurry is obtained. In the slurry, the ceramic powder accounts for 82%, and the plasticizer accounts for 18%. The composition of the plasticizer is (wt.%): paraffin wax 86%, stearic acid 3%, PVC 11%. The resulting slurry is poured into a slurry ingot for preservation;

[0037] (3) heating the slurry ingot prepared in step (2) to 90-110° C., keeping it warm for 12-24 hours, and preparing a ceramic core blank after ...

Embodiment 1

[0040] Ceramic core composition: quartz glass (100 mesh to 200 mesh): 76%, cristobalite (1000 mesh to 3000 mesh): 4%, alumina (600 mesh to 1000 mesh): 20%; the quartz glass, square The purity of quartz and alumina is 99.9%; after adding plasticizer, press it into a plate-shaped ceramic core blank with a size of 12cm*1cm*0.4cm;

[0041] Use alumina powder with a purity of ≥99.9% and a particle size of 150-200 mesh as a filler, embed the ceramic core blank in the filler powder, raise the temperature to 500°C at a heating rate of 5°C / min and keep it for 5 hours, then heat it at 15°C Raise the temperature to 1220°C at a heating rate of / min, and keep it warm for 2 hours. After sintering the ceramic core, by analyzing the X-ray spectrum, it is calculated that the relative content of cristobalite in the ceramic core is about 10%, and the ceramic core continues to heat up to 1550°C , heat preservation for 1 hour, at this time the high temperature creep performance of the ceramic core...

Embodiment 2

[0045] Ceramic core composition: quartz glass (100 mesh to 200 mesh): 74%, cristobalite (1000 mesh to 3000 mesh): 6%, alumina (600 mesh to 1000 mesh): 20%; the quartz glass, square The purity of quartz and alumina is 99.9%; after adding plasticizer, press it into a plate-shaped ceramic core blank with a size of 12cm*1cm*0.4cm;

[0046]Use alumina powder with a purity of ≥99.9% and a particle size of 150-200 mesh as a filler, embed the ceramic core blank in the filler powder, raise the temperature to 500°C at a heating rate of 5°C / min and keep it for 5 hours, then heat it at 15°C Raise the temperature to 1220°C at a heating rate of / min, and keep it warm for 2 hours. After sintering the ceramic core, by analyzing the X-ray spectrum, calculate that the relative content of cristobalite in the ceramic core is about 15%, and continue to heat the ceramic core to 1550°C , heat preservation for 1 hour, at this time the high temperature creep performance of the ceramic core was measure...

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Abstract

The invention discloses a ceramic core with high resistance to cold and heat shock, high temperature creep resistance and easy removal and a preparation process thereof, belonging to the technical field of high temperature alloys. Quartz glass powder with a certain particle size is used to form the matrix skeleton of the ceramic core to ensure that the ceramic core has good thermal shock resistance; crystal cristobalite and alumina powder with a particle size of micron or below increase the sintering density of the ceramic core and thus increase the high temperature. Creep resistance; during the directional solidification process, cristobalite acts as a seed crystal to make the large-grained quartz glass easy to crystallize and form cracks during the cooling process. When the core is removed, the lye is easy to soak into the crack, which improves the removal of the ceramic core. performance.

Description

technical field [0001] The invention relates to the technical field of high-temperature alloys, and in particular provides a silicon-based ceramic core for large-size single crystal / directional hollow guide vanes that is resistant to cold and heat shock, high temperature creep and easy to remove, and a preparation process thereof. Background technique [0002] Single crystal / directional turbine blades are the most critical hot-end components of gas turbines. With the development of gas turbines, the power and thermal efficiency continue to increase, and the requirements for the temperature bearing capacity of turbine blades are also getting higher and higher. In order to improve the temperature bearing capacity, the cooling structure of the blade is becoming more and more complicated, and the difficulty of its preparation is obviously increased or decreased. [0003] Single crystal / directional turbine blade cooling cavity structures are typically formed using ceramic cores....

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B22C9/10B22C1/00
CPCB22C1/00B22C9/10
Inventor 李凯文姜卫国肖久寒董加胜楼琅洪
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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