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Method for removing ceramic mold core of hollow blade of aeroengine

An aero-engine and hollow blade technology, which is applied in the field of aero-engine hollow blade removal, can solve the problems that salts cannot flow out quickly, hinder the lye reaction, and reduce the safety of parts, so as to improve the core removal efficiency and core removal. The effect of mass, increased reaction interface, and shortened de-cored time

Inactive Publication Date: 2018-04-03
SINO EURO MATERIALS TECH OF XIAN CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The speed of the chemical reaction is related to the temperature, concentration and pressure of the lye. The traditional core removal process increases the concentration of the lye to increase the speed of the core removal. The core process is not easy to operate. On the other hand, when the concentration of alkali is high, it will form a gel-like substance in the cavity because it cannot quickly dissolve and react to form a salt solution. Salt substances cannot flow out quickly
The sticky substance left on the surface of the core further hinders the reaction between the lye and the core, which greatly increases the difficulty and cycle of core removal

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] 1) One-time stripping

[0022] Put the tenon of the hollow leaf upwards and place it in a KOH solution with a concentration of 30%. The temperature of the lye is 150°C, the pressure of the lye is 0.2MPa, and the pressure fluctuation period is 9 minutes. After 20 hours of reaction, the leaves are taken out and rinsed with water for 2 minutes.

[0023] 2) Secondary stripping

[0024] Turn the hollow leaves that have been removed from the core once by step 1) upside down 180°, and place them in a KOH solution with a concentration of 35%. The leaves were taken out and rinsed with clean water for 2 minutes.

[0025] 3) Acid neutralization

[0026] The hollow blades that have been cored twice in step 2) are placed in citric acid stirred with compressed air for neutralization for 30 minutes.

[0027] 4) cleaning

[0028] Place the hollow leaves soaked in citric acid in step 3) in clear water stirred with compressed air and rinse for 15 minutes.

Embodiment 2

[0030] 1) One-time stripping

[0031] Put the tenon of the hollow leaf upwards and place it in a KOH solution with a concentration of 30%. The temperature of the lye is 150°C, the pressure of the lye is 0.4MPa, and the pressure fluctuation period is 9min. After 20 hours of reaction, the leaves are taken out and rinsed with clean water for 2 minutes;

[0032] 2) Secondary stripping

[0033] Turn the hollow leaf that has been removed from the core once by step (1) upside down 180°, and place it in a KOH solution with a concentration of 30%. Take out the leaves and rinse them with clean water for 2 minutes;

[0034] 3) Acid neutralization

[0035] Place the hollow blade that has been cored twice in step 2) in citric acid stirred with compressed air for neutralization for 30 minutes;

[0036] 4) cleaning

[0037] Place the hollow leaves soaked in citric acid in step 3) in clear water stirred with compressed air and rinse for 15 minutes.

Embodiment 3

[0039] 1) One-time stripping

[0040] Put the tenon of the hollow leaf upwards and place it in a KOH solution with a concentration of 40%. The temperature of the lye is 150°C, the pressure of the lye is 0.7MPa, and the pressure fluctuation period is 9 minutes. After 20 hours of reaction, the leaves are taken out and rinsed with water for 2 minutes;

[0041] 2) Secondary stripping

[0042] Turn the hollow leaf that has been removed from the core once by step 1) upside down 180°, and place it in a KOH solution with a concentration of 40%. Take out the leaves and rinse them with clean water for 2 minutes;

[0043] 3) Acid neutralization

[0044] Place the hollow blade that has been cored twice in step 2) in citric acid stirred with compressed air for neutralization for 30 minutes;

[0045] 4) cleaning

[0046] Place the hollow leaves soaked in citric acid in step 3) in clear water stirred with compressed air and rinse for 15 minutes.

[0047] After the cold light source and ...

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PUM

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Abstract

A method for removing a ceramic mold core of a hollow blade of an aeroengine comprises the three steps of primary core-removing, secondary core-removing and acid liquid neutralizing and cleaning, wherein the concentration of KOH alkaline liquid used for core-removing is 30%-40%, the temperature of the alkaline liquid for core-removing of each time is 150 DEG C, the core-removing pressure is 0.2-0.7 MPa, and the core-removing time of each time is 20 h. According to the method, the method that the concentration of the alkaline liquid is decreased, pressurizing and depressurizing are conducted atintervals in the process is adopted, so that the alkaline liquid is boiled and makes full contact with the mold core, thus, the scouring action is achieved, and the full core-removing effect is achieved; and the temperature of the alkaline liquid is increased by increasing the pressure instead of increasing the concentration of the KOH alkaline liquid, therefore, core-removing is facilitated, corrosion to a casting can be relieved, the core-removing time is shortened to two days, and the qualification rate of one-time core-removing reaches 98% or above.

Description

technical field [0001] The invention relates to the technical field of removing hollow blades of aero-engines, and in particular relates to a method for removing ceramic cores of hollow blades of aero-engines. Background technique [0002] The core removal technology formed by investment casting of hollow blades has received widespread attention. In order to meet the requirements of complex cavity and thin wall of engine blades, the technology of using high-strength cores to achieve high-precision casting has become increasingly mature, but It is still very difficult to remove this high-strength core from the casting, and the difficulty of removing the core is positively related to the complexity of the blade, which is one of the bottlenecks restricting the production of blades. [0003] Because of the chemical reaction between the ceramic core and the KOH solution, SiO 2 +KOH=K 2 SiO 3 +H 2 O, silicon-based ceramic cores generally use KOH for core removal. [0004] The...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22D29/00
CPCB22D29/002
Inventor 宋嘉明刘海浪张鹏王庆相梁书锦张平祥
Owner SINO EURO MATERIALS TECH OF XIAN CO LTD
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