A water soluble ceramic core removal method

Abstract

The application provides a water-soluble ceramic core removal method, which comprises the following steps: S1, placing a water-soluble ceramic core in multiple acid tanks in sequence for reaction, and the total reaction time is 2-4 h; S2, placing the water-soluble ceramic core after acid pickling in the step S1 in multiple water tanks in sequence for cleaning, and the cleaning time is 15-30 min; S3, placing the water-soluble ceramic core after the treatment in the step S2 in a plasma cleaning machine for dry cleaning, and the cleaning time is 2-5 min; and S4, placing the water-soluble ceramic core after the treatment in the step S3 in an alcohol tank, and the cleaning time is 2-5 min. The water-soluble ceramic core removal method avoids the abrasion of the core in the manual cleaning process, sets multiple acid tanks with different concentration gradients, increases the overflow of the acid liquid and water, accelerates the dissolution and collapse of the water-soluble ceramic core, effectively reduces the soaking time of the ceramic core, and improves the core removal efficiency and core removal quality.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine manufacturing, and in particular relates to a method for removing water-soluble ceramic cores. Background Technology

[0002] Hollow blades, as the most critical component of aero-engines, directly affect their performance. With the continuous increase in turbine inlet temperature, simple optimization of traditional hollow blade cooling structures is no longer sufficient to meet this requirement, necessitating new blade cooling structures or methods. In recent years, based on film cooling, multi-layered film cooling structures have emerged, such as double-walled film cooling structures and porous plate cooling structures. Allison and GE in the United States are among the world's leading companies in double-walled blade cooling technology. In my country, double-walled cooling structures are transitioning from theoretical research to engineering application; however, the fabrication methods for these structures remain in the exploratory stage of engineering applications.

[0003] Water-soluble ceramic cores, due to their ease of dissolution, can be used in conjunction with silicon-based or aluminum-based ceramic cores to prepare hollow ceramic cores with complex structures. These hollow ceramic cores can be used in the fabrication of hollow blades with double-walled structures. The key to improving the efficiency of double-walled ceramic core fabrication and ensuring quality stability lies in rapidly removing the water-soluble core.

[0004] Existing methods for removing water-soluble cores mostly involve immersing them in water or a weak acid solution. This requires manual cleaning of the core, which is inconvenient and inefficient. Furthermore, the core may be damaged during handling. If the immersion time in the acid solution is too short, the core may not be completely removed, while if the immersion time is too long, the core may deform. Summary of the Invention

[0005] In view of this, the present invention aims to overcome the defects in the prior art and propose a method for removing water-soluble ceramic cores.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A method for removing water-soluble ceramic cores includes the following steps:

[0008] S1: The water-soluble ceramic core is placed in multiple acid tanks for reaction, with a total reaction time of 2-4 hours;

[0009] S2: Place the water-soluble ceramic core that has been acid-washed in the acid bath in step S1 into multiple water baths for cleaning, with a cleaning time of 15-30 minutes.

[0010] S3: Place the water-soluble ceramic core treated in step S2 into a plasma cleaner for dry cleaning for 2-5 minutes.

[0011] S4: Place the water-soluble ceramic core treated in step S3 into an alcohol bath and clean it for 2-5 minutes.

[0012] Preferably, step S1 includes three acid tanks: acid tank 1, acid tank 2, and acid tank 3. In acid tank 1, the acid concentration is 5-10%, the acid temperature is 20-25°C, and the reaction time is 0.5-1.5 hours. In acid tank 2, the acid concentration is 5-10%, the acid temperature is 20-25°C, and the reaction time is 1-1.5 hours. In acid tank 3, the acid concentration is 3-5%, the acid temperature is 20-25°C, and the reaction time is 0.5-1 hour.

[0013] Preferably, in step S1, the acid tank is an overflow tank, and the overflow flow rate of acid tank No. 1, acid tank No. 2, and acid tank No. 3 is 50-500cc / min.

[0014] Preferably, step S2 includes two water tanks, namely water tank 1 and water tank 2. The temperature of water tank 1 is 20-25℃ and the cleaning time is 10-20 minutes; the temperature of water tank 2 is 20-25℃ and the cleaning time is 5-10 minutes.

[0015] Preferably, in step S2, the water tank is an overflow tank, and the overflow flow rate of the No. 1 water tank and the No. 2 water tank is 50-500cc / min.

[0016] Preferably, in step S4, the alcohol tank is an overflow tank, and the overflow flow rate of the alcohol tank is 50-500cc / min.

[0017] Preferably, the acid solution in the acid tank in step S1 is a solution of citric acid and / or acetic acid.

[0018] Preferably, the acid in the acid tank in step S1 and the water in the water tank in step S2 are both filtered and recycled, and the overflow of alcohol in step S4 is recycled.

[0019] It should be noted that the transfer of water-soluble cores during the removal process is carried out using a porous basket and a robotic arm.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] This invention saves manpower and time compared to manual operation, avoids wear and tear on the cores during manual cleaning, and accelerates the dissolution and disintegration of water-soluble ceramic cores by setting up multiple acid tanks with different concentration gradients, thereby reducing the soaking time of the ceramic cores, improving core removal efficiency and quality, and preventing core deformation. Plasma cleaning removes excess moisture or chemical residues from the core surface, and alcohol forms a protective film on the core surface to further remove residues. Simultaneously, the recycling of acid, water, and alcohol reduces energy consumption, saves costs, and improves overall production efficiency. In practice, using this method for core removal can shorten the core removal time to within 5 hours, with a first-pass yield rate of over 95%. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process flow of the present invention;

[0023] Figure 2 and Figure 3 Photograph of the ceramic core after processing in Example 3;

[0024] Figure 4 This is a photograph of the ceramic core after processing, as shown in Comparative Example 1.

[0025] Figure 5 This is a photograph of the ceramic core after processing, as shown in Comparative Example 2.

[0026] Figure 6 This is a photograph of the ceramic core after processing, as shown in Comparative Example 3.

[0027] Figure 7 This is a photograph of a ceramic core after being soaked in acid for 12 hours, as described in the prior art. Detailed Implementation

[0028] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0029] The present invention will be described in detail below with reference to the embodiments.

[0030] Example 1

[0031] A method for removing water-soluble ceramic cores includes the following steps:

[0032] (1) One-time core removal: The water-soluble ceramic core is placed in acid tank No. 1 with an acid concentration of 8%, an acid temperature of 20℃, and an overflow flow rate of 80cc / min. The reaction time is 0.5h.

[0033] (2) Secondary core removal: The water-soluble ceramic core after the first core removal process is placed in acid tank No. 2 with an acid concentration of 8%, an acid temperature of 20℃, and an overflow flow rate of 80cc / min. The reaction time is 1.5h.

[0034] (3) Three-stage core removal: The water-soluble ceramic core after two-stage core removal is placed in acid tank No. 3 with an acid concentration of 5%, an acid temperature of 20℃, and an overflow flow rate of 80 / min, and the reaction time is 0.5h.

[0035] (4) First cleaning: The water-soluble ceramic core after three core removal processes is placed in water tank No. 1 at a temperature of 20℃ and an overflow flow rate of 80cc / min for 20 minutes.

[0036] (5) Second cleaning: The water-soluble ceramic core after the first cleaning is placed in water tank No. 2 at a temperature of 20℃ and an overflow flow rate of 80cc / min for 10 minutes.

[0037] (6) Three cleanings: The water-soluble ceramic core after two cleanings is placed in a plasma cleaner for 5 minutes.

[0038] (7) Four cleanings: The water-soluble ceramic core after three cleanings is placed in an alcohol bath at a temperature of 20°C and an overflow flow rate of 80cc / min for 5 minutes.

[0039] Example 2

[0040] A method for removing water-soluble ceramic cores includes the following steps:

[0041] (1) Core removal in one step: The water-soluble ceramic core is placed in acid tank No. 1 with an acid concentration of 10%, an acid temperature of 20℃, and an overflow flow rate of 150cc / min. The reaction time is 1h.

[0042] (2) Secondary core removal: The water-soluble ceramic core after the first core removal process is placed in acid tank No. 2 with an acid concentration of 8%, an acid temperature of 20℃, and an overflow flow rate of 150cc / min. The reaction time is 1h.

[0043] (3) Three-stage core removal: The water-soluble ceramic core after the second core removal process is placed in acid tank No. 3 with an acid concentration of 5%, an acid temperature of 20℃, and an overflow flow rate of 150cc / min. The reaction time is 1h.

[0044] (4) First cleaning: The water-soluble ceramic core after three core removal processes is placed in water tank No. 1 at a temperature of 20℃ and an overflow flow rate of 150cc / min for 20 minutes.

[0045] (5) Second cleaning; The water-soluble ceramic core after the first cleaning is placed in water tank No. 2 at a temperature of 20℃ and an overflow flow rate of 150cc / min for 10 minutes.

[0046] (6) Three cleanings: The water-soluble ceramic core after two cleanings is placed in a plasma cleaner for 3 minutes.

[0047] (7) Four cleanings: The water-soluble ceramic core after three cleanings is placed in an alcohol bath at a temperature of 20°C and an overflow flow rate of 150cc / min for 3 minutes.

[0048] Example 3

[0049] A method for removing water-soluble ceramic cores includes the following steps:

[0050] (1) Core removal in one step; The water-soluble ceramic core is placed in acid tank No. 1 with an acid concentration of 8%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 1.5h;

[0051] (2) Secondary core removal; The water-soluble ceramic core after the first core removal process is placed in acid tank No. 2 with an acid concentration of 5%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 1.5h.

[0052] (3) Three-stage core removal: The water-soluble ceramic core after the second core removal process is placed in acid tank No. 3 with an acid concentration of 5%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min. The reaction time is 1h.

[0053] (4) First cleaning; The water-soluble ceramic core after three core removal processes is placed in water tank No. 1 at a temperature of 20℃ and an overflow flow rate of 200cc / min for 15 minutes.

[0054] (5) Second cleaning; The water-soluble ceramic core after the first cleaning is placed in water tank No. 2 at a temperature of 20℃ and an overflow flow rate of 200cc / min for 5 minutes.

[0055] (6) Three cleanings: The water-soluble ceramic core after two cleanings is placed in a plasma cleaner for 5 minutes.

[0056] (7) Four cleanings: The water-soluble ceramic core after three cleanings is placed in an alcohol bath at a temperature of 20°C and an overflow flow rate of 200cc / min for 5 minutes.

[0057] Comparative Example 1

[0058] A method for removing water-soluble ceramic cores includes the following steps:

[0059] (1) Core removal in one step; The water-soluble ceramic core is placed in acid tank No. 1 with an acid concentration of 8%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 2h;

[0060] (2) Secondary core removal; The water-soluble ceramic core after the first core removal process is placed in acid tank No. 2 with an acid concentration of 5%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 2h.

[0061] (3) First cleaning; The water-soluble ceramic core after the second core removal process is placed in water tank No. 1 at a temperature of 20℃ and an overflow flow rate of 200cc / min for 15 minutes.

[0062] (4) Second cleaning; The water-soluble ceramic core after the first cleaning is placed in water tank No. 2 at a temperature of 20℃ and an overflow flow rate of 200cc / min for 5 minutes.

[0063] (5) Three cleanings: The water-soluble ceramic core after two cleanings is placed in a plasma cleaner for 5 minutes.

[0064] (6) Four cleanings: The water-soluble ceramic core after three cleanings is placed in an alcohol bath at a temperature of 20°C and an overflow flow rate of 200cc / min for 5 minutes.

[0065] Comparative Example 2

[0066] A method for removing water-soluble ceramic cores includes the following steps:

[0067] (1) Core removal in one step; The water-soluble ceramic core is placed in acid tank No. 1 with an acid concentration of 8%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 1.5h;

[0068] (2) Secondary core removal; The water-soluble ceramic core after the first core removal process is placed in acid tank No. 2 with an acid concentration of 5%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 1.5h.

[0069] (3) Three-stage core removal: The water-soluble ceramic core after the second core removal process is placed in acid tank No. 3 with an acid concentration of 5%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min. The reaction time is 1h.

[0070] (4) Plasma cleaning: After the water-soluble ceramic core has been washed with water after three core removal cleaning treatments, it is placed in a plasma cleaner for 5 minutes.

[0071] (5) Four cleanings: The water-soluble ceramic core after plasma cleaning is placed in an alcohol bath at a temperature of 20°C and an overflow flow rate of 200cc / min for 5 minutes.

[0072] Comparative Example 3

[0073] A method for removing water-soluble ceramic cores includes the following steps:

[0074] (1) Core removal in one step; The water-soluble ceramic core is placed in acid tank No. 1 with an acid concentration of 8%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 1.5h;

[0075] (2) Secondary core removal; The water-soluble ceramic core after the first core removal process is placed in acid tank No. 2 with an acid concentration of 5%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min, and the reaction time is 1.5h.

[0076] (3) Three-stage core removal: The water-soluble ceramic core after the second core removal process is placed in acid tank No. 3 with an acid concentration of 5%, an acid temperature of 25℃, and an overflow flow rate of 200cc / min. The reaction time is 1h.

[0077] (4) First cleaning; The water-soluble ceramic core after three core removal processes is placed in water tank No. 1 at a temperature of 20℃ and an overflow flow rate of 200cc / min for 15 minutes.

[0078] (5) Second cleaning; The water-soluble ceramic core after the first cleaning is placed in water tank No. 2 at a temperature of 20℃ and an overflow flow rate of 200cc / min for 5 minutes.

[0079] (6) Four cleanings: The water-soluble ceramic core after three cleanings is placed in an alcohol bath at a temperature of 20°C and an overflow flow rate of 200cc / min for 5 minutes.

[0080] The ceramic core after cleaning in Example 3, and the ceramic cores after cleaning in Comparative Examples 1-3 are shown in the photographs. Figures 2-7 As shown, it is clear that the ceramic core surface treated by the method of the present invention is clean and free of adhesions, and the surface is smooth and free of wear. Removing any step in the method of the present invention would not achieve the above-mentioned effect.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water soluble ceramic core removal process characterized by: It comprises the following steps: S1: the water-soluble ceramic core is placed in multiple acid tanks in sequence for reaction, and the total reaction time is 2-4h; S2: the water-soluble ceramic core after acid pickling in step S1 is placed in multiple water tanks in sequence for cleaning, and the cleaning time is 15-30min; S3: the water-soluble ceramic core after step S2 is placed in a plasma cleaning machine for dry cleaning, and the cleaning time is 2-5min; S4: the water-soluble ceramic core after step S3 is placed in an alcohol tank for cleaning, and the cleaning time is 2-5min; The step S1 is provided with three acid tanks, which are No. 1 acid tank, No. 2 acid tank and No. 3 acid tank. The acid concentration in the No. 1 acid tank is 5-10%, the acid temperature is 20-25℃, and the reaction time is 0.5-1.5h; the acid concentration in the No. 2 acid tank is 5-10%, the acid temperature is 20-25℃, and the reaction time is 1-1.5h; the acid concentration in the No. 3 acid tank is 3-5%, the acid temperature is 20-25℃, and the reaction time is 0.5-1h; the acid tank in step S1 is an overflow tank, and the overflow flow of the No. 1 acid tank, the No. 2 acid tank and the No. 3 acid tank is 50-500cc / min; The step S2 is provided with two water tanks, which are No. 1 water tank and No. 2 water tank. The temperature of the No. 1 water tank is 20-25℃, and the cleaning time is 10-20min; the temperature of the No. 2 water tank is 20-25℃, and the cleaning time is 5-10min; The water tank in step S2 is an overflow tank, and the overflow flow of the No. 1 water tank and the No. 2 water tank is 50-500cc / min.

2. The water soluble ceramic core removal process of claim 1, wherein: The alcohol tank in step S4 is an overflow tank, and the overflow flow of the alcohol tank is 50-500cc / min.

3. The water soluble ceramic core removal method of claim 1, wherein: The acid solution in the acid tank in step S1 is a solution of citric acid and / or acetic acid.

4. The water soluble ceramic core removal method of claim 1, wherein: The acid solution in the acid tank in step S1 and the water in the water tank in step S2 are all recycled after filtration, and the alcohol overflow in step S4 is recycled.

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