A cleaning method for an a sandwich structure ceramic 3D printing product

Abstract

The present application relates to the technical field of aerospace material surface cleaning, and particularly relates to a cleaning method of A sandwich structure ceramic 3D printing product. The cleaning method of the A sandwich structure ceramic 3D printing product provided by the present application realizes effective cleaning of the A sandwich structure product without damaging the product structure and material by means of a combined cleaning scheme of ultrasonic cavitation cleaning, pulse airflow blowing and negative pressure flash drying, and in combination with the design of technical parameters such as ultrasonic frequency, pulse frequency, nano-bubble core particle size, gas core component, fluid Reynolds number and negative pressure drying pressure, so as to be beneficial to guarantee the performance and reliability of the A sandwich structure missile head cover body, and also provide a solution for effective cleaning of other complex honeycomb structure products.

Description

Technical Field

[0001] This invention relates to the field of aerospace material surface cleaning technology, and in particular to a cleaning method for A-layered ceramic 3D printed products. Background Technology

[0002] As a crucial component of the missile system, the performance of the missile's nose cone directly impacts its overall combat effectiveness. The nose cone needs to possess high wave transparency to ensure unimpeded radar guidance and communication signal transmission during flight. Simultaneously, it must exhibit excellent high-temperature resistance and high structural strength to guarantee structural integrity and functional stability under extreme temperature variations and various mechanical loads.

[0003] To meet these stringent performance requirements, missile nose cones are often designed as A-type sandwich structures, including inner and outer skins and interconnected honeycomb core layers, which have advantages such as being lightweight, high-strength, heat-resistant, and having good wave transmission and load-bearing performance.

[0004] However, cleaning the honeycomb core structure has always been a technical challenge in the manufacturing and maintenance of missile nose cones. Due to the numerous tiny pores and interconnected channels within, traditional cleaning methods struggle to effectively remove dirt, debris, and residues from these pores. Incomplete cleaning can affect the cone's wave transmission and structural performance. Furthermore, damage to the cone material must be avoided during cleaning to prevent compromising its high-temperature resistance and structural strength. Therefore, developing a cleaning method that can effectively clean A-layer structures without damaging the product's structure and materials is crucial for ensuring the performance and reliability of missile nose cones. Summary of the Invention

[0005] To address the technical challenge of effectively cleaning A-layer sandwich structure products without damaging their structure or materials, this invention provides a cleaning method for A-layer sandwich structure ceramic 3D printed products, comprising the following steps: S1. Immerse the workpiece in a cleaning solution containing nano-bubble cores and apply phase-modulated ultrasonic waves with matching frequencies to perform ultrasonic cavitation cleaning. S2. Use pulsed airflow to blow the inner wall of the workpiece from multiple angles; S3. Use a flash dryer to perform negative pressure flash drying on the workpiece.

[0006] In one embodiment, in step S1, the particle size distribution of the nanobubble core is D50≤250 nm.

[0007] In one embodiment, in step S1, the core of the nanobubble is a mixture of argon and ozone, with a volume ratio of argon to ozone of (8~9.5):(0.5~2).

[0008] In one embodiment, in step S1, ultrasonic waves are generated by an array of three ultrasonic transducers with a phase difference of 120° to perform ultrasonic cavitation cleaning.

[0009] In one embodiment, the frequency in step S1 satisfies the following formula:

[0010] In the formula, F is the ultrasonic frequency (Hz); c is the sound velocity in the cleaning fluid (m / s); d is the equivalent diameter of the core pore (m); and D is the depth of the core pore (m).

[0011] In one embodiment, in step S2, the Reynolds number of the pulsed airflow satisfies 4000≤Re≤8000.

[0012] In one embodiment, in step S2, the pulse frequency is 10 Hz ~ 50 Hz, the pulse width is 0.5 ms ~ 3 ms, and the pressure is 0.6 MPa ~ 5 MPa.

[0013] In one embodiment, in step S2, the purging trajectory of the pulsed airflow is a spiral retreat pattern.

[0014] In one embodiment, the helical lead angle of the purging trajectory is 30°~55°.

[0015] In one embodiment, the negative pressure of the negative pressure flash drying in step S3 is -60 kPa to -80 kPa, the temperature is 40°C to 70°C, and the drying time is 5 min to 10 min.

[0016] In summary, compared with the prior art, the invention has the following beneficial effects: The cleaning method for A-layer structure ceramic 3D printed products provided by this invention, through steps such as ultrasonic cavitation cleaning, pulsed airflow purging and negative pressure flash drying, can effectively clean A-layer structure ceramic 3D printed products without damaging the product structure and materials. It also provides an effective cleaning solution for other complex honeycomb structure products. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of a 3D-printed ceramic product with a sandwich structure (A) in the prior art. Figure 2 This is a cross-sectional view of the side wall of the shell of a 3D-printed ceramic product with a sandwich structure (A) in the prior art.

[0019] Figure label: 10-Outer skin; 20-Core layer; 21-Honeycomb unit; 30-Inner skin; 31-Through hole. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] This invention Figure 1 This is a type of A-layered ceramic 3D printed product, with an overall conical shell structure. The shell sidewalls are A-layered structures, including an outer skin 10, a core layer 20, and an inner skin 30. The inner skin 30 has through holes 31, and the core layer 20 has a honeycomb structure. (See reference...) Figure 2 As shown, each cellular unit 21 is interconnected and communicates with the through hole 31.

[0023] Example 1 This embodiment provides a cleaning method for A-layered ceramic 3D printed products, including the following steps: S1. Immerse the workpiece in a cleaning solution containing nano-bubble cores and apply phase-modulated ultrasonic waves with matching frequencies to perform ultrasonic cavitation cleaning. S2. Use pulsed airflow to blow the inner wall of the workpiece from multiple angles; S3. Use a flash dryer to perform negative pressure flash drying on the workpiece.

[0024] Specifically, in this embodiment, in step S1, the particle size distribution of the nanobubble core is D50≤250 nm; in actual operation, the cavitation effect is stronger and more uniform, and at the same time, the small bubbles can penetrate into micron-level gaps and blind holes, resulting in fewer cleaning dead angles and better micro-area cleaning effect.

[0025] Preferably, in this embodiment, the nanobubble core is a mixed gas obtained by mixing argon and ozone in a volume ratio of 9:1; in specific operation, the inert gas argon carries ozone as the gas core, and the ozone can decompose organic pollutants, thereby obtaining a synergistic ultrasonic chemical effect.

[0026] Specifically, in this embodiment, in step S1, three sets of ultrasonic transducer arrays with a phase difference of 120° are used to generate ultrasonic waves for ultrasonic cavitation cleaning. Simultaneously, the frequency satisfies the following formula:

[0027] In the formula, F is the ultrasonic frequency (Hz); c is the sound velocity in the cleaning fluid (m / s); d is the equivalent diameter of the core layer pore (m); and D is the depth of the core layer pore (m). The sound velocity in the cleaning fluid can be directly measured by a sound velocity measuring instrument, and the equivalent diameter of the pore is the diameter of the circumscribed circle.

[0028] Furthermore, in this embodiment, in step S2, the pulsed airflow is a pulsed Taylor vortex airflow with a Reynolds number satisfying 4000≤Re≤8000. Preferably, the pulse frequency is 10 Hz, the pulse width is 1 ms, and the pressure is 1.2 MPa. In actual operation, a spiral-receding purging trajectory is used to purge from the top of the cone to the bottom of the cone inside the shell, blowing out the residual liquid from the ultrasonic cavitation cleaning; preferably, the spiral lead angle of the purging trajectory is 45°.

[0029] Furthermore, in this embodiment, in step S3, the negative pressure of the negative pressure flash drying is -60 kPa, the temperature is 40℃, and the drying time is 8 min.

[0030] Although this paper frequently uses terms such as A-layer, A-type layer, nanobubble core, phase-modulated ultrasound, ultrasonic cavitation cleaning, pulsed airflow, negative pressure flash drying, ultrasonic transducer array, core layer channel, equivalent diameter, spiral receding type, spiral lead angle, missile nose cone, high wave transmittance, high temperature resistance, high structural strength, lightweight, high strength, core layer, honeycomb core layer, inner skin, outer skin, conical shell, shell sidewall, cone apex, rounded rectangular through-hole, honeycomb structure, and honeycomb cell, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cleaning method for A-layered ceramic 3D printed products, characterized in that, Includes the following steps: S1. Immerse the workpiece in a cleaning solution containing nano-bubble cores and apply phase-modulated ultrasonic waves with matching frequencies to perform ultrasonic cavitation cleaning. S2. Use pulsed airflow to blow the inner wall of the workpiece from multiple angles; S3. Use a flash dryer to perform negative pressure flash drying on the workpiece; In step S1, ultrasonic waves are generated using an array of three ultrasonic transducers with a phase difference of 120° to perform ultrasonic cavitation cleaning; the frequency satisfies the following formula: In the formula, F is the ultrasonic frequency (Hz); c is the sound velocity in the cleaning fluid (m / s); d is the equivalent diameter of the core pore (m); and D is the depth of the core pore (m). In step S2, the Reynolds number of the pulsed airflow satisfies 4000≤Re≤8000; the pulse frequency is 10 Hz ~ 50 Hz, the pulse width is 0.5 ms ~ 3 ms, and the pressure is 0.6 MPa ~ 5 MPa; the purging trajectory of the pulsed airflow is a spiral receding type; and the spiral lead angle of the purging trajectory is 30°~55°. The A-layer structure ceramic 3D printed product has an overall conical shell structure. The shell sidewall is an A-layer structure, including an outer skin (10), a core layer (20) and an inner skin (30). The inner skin (30) has through holes (31). The core layer (20) has a honeycomb structure. Each honeycomb unit (21) is interconnected and communicates with the through holes (31).

2. The cleaning method for A-layered ceramic 3D printed products according to claim 1, characterized in that: In step S1, the particle size distribution of the nanobubble core is D50≤250 nm.

3. The cleaning method for A-layered ceramic 3D printed products according to claim 2, characterized in that: In step S1, the core of the nanobubble is a mixture of argon and ozone, with a volume ratio of argon to ozone of (8~9.5):(0.5~2).

4. The cleaning method for A-layered ceramic 3D printed products according to claim 3, characterized in that: In step S3, the negative pressure of the negative pressure flash drying is -60 kPa to -80 kPa, the temperature is 40℃ to 70℃, and the drying time is 5 min to 10 min.

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