Ultrasonic vibration assisted chemical polishing method and device for inner wall of metal capillary tube

Abstract

The invention discloses an ultrasonic vibration assisted chemical polishing method and device for the inner wall of a metal capillary tube, and the device comprises a chemical polishing solution supply system which is used for conveying a chemical polishing solution into the metal capillary tube; the ultrasonic vibration system is used for connecting the metal capillary tube and applying high-frequency vibration; the metal capillary tube fixing device is used for clamping the metal capillary tube; the temperature control system is used for maintaining the temperature of the chemical polishing solution. Through ultrasonic vibration-assisted chemical polishing, the polishing effect of the inner wall of the metal capillary tube is improved, the surface roughness is reduced, and the laser-assisted electrochemical machining performance is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser electrolytic combined machining, and particularly relates to a method and device for ultrasonic vibration assisted chemical polishing of the inner wall of a metal capillary. BACKGROUND

[0002] With the rapid development of manufacturing industry, micro-porous structures are widely used in the fields of aerospace, medicine and electronics. For example, the gas film cooling hole of a turbine blade cannot have a recast layer, micro-cracks and a heat affected zone on the inner surface due to the harsh working environment, and the hole opening is smooth and free of burrs. Metal tube electrode electrolytic machining is a machining technology based on the principle of electrochemical anodic dissolution, which has the advantages of no electrode loss, no recast layer and no heat affected zone, but the machining efficiency is not high. Laser electrolytic combined machining can combine electrolytic machining with laser machining to improve the surface quality and machining efficiency of electrolytic machining. Some scholars use glass tubes or polytetrafluoroethylene tubes to cover the inside of the metal capillary, which limits the size of the metal capillary, making it difficult to machine holes with a diameter of less than 0.8 mm, and affecting the flushing effect of the electrolyte. It has been found by researchers of Nanhang that a larger inner diameter tube electrode can effectively improve the cleaning conditions and promote the discharge of machining by-products. However, the rough inner wall of the metal capillary on the market will increase the transmission loss, which seriously affects the performance of laser-assisted electrolytic machining. The current polishing of the inner wall of the capillary, such as magnetorheological polishing, electrochemical polishing, abrasive flow polishing and ultrasonic vibration polishing, has its own shortcomings and cannot be well applied to the polishing of the inner wall of the capillary with a diameter of 1.0 mm or less. SUMMARY

[0003] To solve the above technical problems, the application provides an ultrasonic vibration assisted chemical polishing method and device for the inner wall of a metal capillary, which improves the polishing effect of the inner wall of the metal capillary, reduces the surface roughness and improves the performance of laser-assisted electrolytic machining through ultrasonic vibration assisted chemical polishing.

[0004] In one aspect, to achieve the above-mentioned purpose, the application provides an ultrasonic vibration assisted chemical polishing method for the inner wall of a metal capillary, which comprises the following steps:

[0005] chemically removing oil from the metal capillary;

[0006] removing the oxide layer on the inner wall of the metal capillary;

[0007] pumping a chemical polishing solution containing an oxidizing agent, a complexing agent and an acid into the metal capillary at a set flow rate;

[0008] applying ultrasonic vibration to the metal capillary at the same time;

[0009] cleaning and drying the metal capillary after polishing.

[0010] Optionally, the chemical oil removal treatment uses an oil removal solution containing 40 g / L Na2CO3, 40 g / L NaOH, 40 g / L Na3PO4·12H2O, 10 g / L C 18 H 29 NaO3S, which is circulated at a flow rate of 100 mL / min at 60-70°C for 30 minutes, and then washed with distilled water.

[0011] Optionally, the oxide layer is removed by sequentially treating with a 180 g / L NaOH solution and an 80 g / L NaNO3 solution at 90°C for 10 minutes, and then washing with 10% H2SO4 at room temperature for 10 minutes.

[0012] Optionally, the chemical polishing solution contains 0.15 wt% K2S2O8 as an oxidizing agent, 0.15 wt% lactic acid as a complexing agent, 120 mL / L H3PO4, and 60 mL / L HCl.

[0013] Optionally, the flow rate is set to 120 mL / min, the ultrasonic vibration frequency is 40 kHz, and the polishing time is 150 seconds.

[0014] Optionally, the chemical polishing solution supply system includes a liquid storage tank, a pump, a flow meter, and a pipeline for controlling the delivery flow rate of the polishing solution.

[0015] Optionally, a metal capillary tube fixing device is used to clamp the capillary tube and connect the hose interface of the ultrasonic vibration head.

[0016] In another aspect to achieve the above-mentioned object, the present application also provides an ultrasonic vibration-assisted metal capillary tube inner wall chemical polishing device, comprising:

[0017] a chemical polishing solution supply system for delivering chemical polishing solution to the metal capillary tube;

[0018] an ultrasonic vibration system for connecting the metal capillary tube and applying high-frequency vibration;

[0019] a metal capillary tube fixing device for clamping the metal capillary tube;

[0020] a temperature control system for maintaining the temperature of the chemical polishing solution.

[0021] Technical effects of the present application:

[0022] Improved polishing efficiency: through ultrasonic vibration assistance, the chemical polishing solution and the metal capillary tube inner wall are fully reacted, significantly improving the polishing efficiency.

[0023] Reduced surface roughness: the chemical polishing solution composition and process parameters are optimized, reducing the metal capillary tube inner wall surface roughness to Ra0.26 μm.

[0024] Corrosion resistance is improved: the corrosion resistance of the polished stainless steel surface is better than that of untreated stainless steel, with a positive shift of about 0.71V in corrosion potential and a nearly one order of magnitude decrease in corrosion current density.

[0025] Wide application range: suitable for polishing the inner wall of metal capillary with a diameter of 1.0mm or less to improve the performance of laser-assisted electrolytic processing. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings constituting a part of this application are used to provide a further understanding of the application, the illustrative embodiments of the application and their descriptions are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0027] Figure 1 It is a structural schematic diagram of the ultrasonic vibration assisted metal capillary inner wall chemical polishing device of the embodiment of the application;

[0028] Figure 2 It is a chemical polishing process schematic diagram, wherein (a) is an initial stainless steel capillary, (b) is chemical oil removal, (c) is oxide layer removal, (d) is chemical polishing-etching stage, (e) is chemical polishing-bright stage, and (f) is chemical polishing-over etching stage. DETAILED DESCRIPTION

[0029] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict. The application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0030] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in a different order.

[0031] In this embodiment, an ultrasonic vibration assisted metal capillary inner wall chemical polishing method is provided, which comprises:

[0032] Chemical oil removal treatment is performed on the metal capillary;

[0033] The oxide layer on the inner wall of the metal capillary is removed;

[0034] A chemical polishing solution containing an oxidizing agent, a complexing agent and an acid is pumped into the metal capillary at a set flow rate;

[0035] At the same time, ultrasonic vibration is applied to the metal capillary;

[0036] After polishing, the metal capillary is cleaned and dried.

[0037] Specifically, the pretreatment is as follows: Figure 2As shown in the figure, (a) is the initial stainless steel capillary, (b) is the chemical degreasing, (c) is the removal of the oxide layer, (d) is the chemical polishing-etching stage, (e) is the chemical polishing-bright stage, and (f) is the chemical polishing-over-etching stage.

[0038] Chemical degreasing: use a degreasing solution composed of 40 g / L Na2CO3, 40 g / L NaOH, 40 g / L Na3PO4·12H2O, 10 g / L C 18 H 29 NaO3S, heated to 60-70°C, pump flow rate is 100 mL / min, and the inner surface is cleaned with distilled water after 30 minutes of degreasing.

[0039] Removal of the oxide layer: use a hot solution of 180 g / L NaOH and 80 g / L NaNO3 at 90°C for 10 minutes to loosen the oxide layer, and then use 10% H2SO4 at room temperature 20°C for 10 minutes for acid pickling to easily remove the oxide layer.

[0040] Chemical polishing: the chemical polishing solution is composed of 0.15wt% potassium persulfate (K2S2O8) as the oxidizing agent, 0.15wt% lactic acid as the complexing agent, 120 mL / L of phosphoric acid, and 60 mL / L of hydrochloric acid.

[0041] Polishing process: the chemical polishing solution is pumped into the metal capillary at a pump flow rate of 120 mL / min, and the chemical polishing time is 150 seconds. The metal capillary is connected by a hose to an ultrasonic vibration device, and the ultrasonic frequency is 40 kHz, so that the chemical polishing solution and the inner wall of the metal capillary fully react to achieve polishing of the inner wall.

[0042] Post-processing: cleaning: a large amount of deionized water is needed before each next step to prevent contamination. Drying: use a drying device to dry the metal capillary.

[0043] As Figure 1 shown in the figure, the embodiment also provides an ultrasonic vibration assisted metal capillary inner wall chemical polishing device, which comprises:

[0044] Chemical polishing solution supply system: including a liquid storage tank, a pump, a flow meter and a pipeline, for delivering the chemical polishing solution into the metal capillary.

[0045] Ultrasonic vibration system: including an ultrasonic generator, a transducer and a vibration head, for generating high frequency vibration and transmitting it to the metal capillary.

[0046] Metal capillary fixing device: for fixing the metal capillary to ensure its stability during polishing.

[0047] Temperature control system: used to control the temperature of the chemical polishing solution, ensuring that the polishing is carried out at room temperature.

[0048] Control system: used to control parameters such as pump flow, ultrasonic vibration frequency and chemical polishing time.

[0049] The implementation process of this embodiment includes the following steps:

[0050] Taking an aviation parts manufacturing enterprise as an example, the application of the ultrasonic vibration assisted metal capillary inner wall chemical polishing device of the present application is introduced. The enterprise produces a turbine blade air film cooling hole with an inner diameter of 0.4mm, an outer diameter of 0.5mm and a length of 50mm. The device of the present application is used for inner wall polishing, which significantly improves the surface quality of the inner wall of the hole, reduces the transmission loss and improves the performance of laser assisted electrolytic machining.

[0051] Specifically includes:

[0052] 1. Installation

[0053] The chemical polishing solution supply system, ultrasonic vibration system, metal capillary fixing device and control system are installed according to the instructions to ensure that the components are connected correctly and stably.

[0054] The metal capillary is fixed on the fixing device to ensure its stability during polishing.

[0055] 2. Commissioning

[0056] Set the pump flow to 120mL / min, the ultrasonic vibration frequency to 40kHz and the chemical polishing time to 150 seconds through the control system.

[0057] Start the chemical polishing solution supply system and check whether the chemical polishing solution is delivered smoothly and the flow is stable.

[0058] Start the ultrasonic vibration system and check whether the vibration frequency meets the set value and whether the vibration is uniform.

[0059] 3. Operation

[0060] Start the chemical polishing solution supply system and deliver the chemical polishing solution to the metal capillary.

[0061] Start the ultrasonic vibration system to make the chemical polishing solution fully react with the inner wall of the metal capillary and achieve inner wall polishing.

[0062] Monitor the parameters during the chemical polishing process through the control system to ensure that the polishing process is stable.

[0063] 4. Maintenance

[0064] Regularly check the operation of the chemical polishing solution supply system and ultrasonic vibration system and replace the wear parts in time.

[0065] Periodically clean the metal capillary fixture to prevent corrosion from residual chemical polishing solution.

[0066] Periodically calibrate the control system to ensure accurate and reliable parameters.

[0067] The above merely provides the preferred embodiment of the present application, and the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of the changes or replacements within the technical scope disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An ultrasonic vibration-assisted metal capillary inner wall chemical polishing method, characterized by, The method comprises: chemically deoiling the metal capillary tube; removing the oxide layer on the inner wall of the metal capillary tube; pumping a chemical polishing solution containing an oxidizing agent, a complexing agent and an acid into the metal capillary tube at a set flow rate; applying ultrasonic vibration to the metal capillary tube at the same time; cleaning and drying the metal capillary tube after polishing.

2. The ultrasonic vibration-assisted metal capillary inner wall chemical polishing method according to claim 1, wherein Chemical degreasing treatment was carried out with degreasing solution containing 40 g / L Na2CO3, 40 g / L NaOH, 40 g / L Na3PO4-12H2O, 10 g / L C 18 H 29 NaO3S at 60-70 °C with a flow rate of 100 mL / min for 30 minutes, and then washed with distilled water.

3. The ultrasonic vibration-assisted metal capillary inner wall chemical polishing method according to claim 1, wherein The oxide layer is removed by treating the metal capillary tube with a solution of 180 g / L NaOH and 80 g / L NaNO3 at 90°C for 10 minutes, and then with 10% H2SO4 at room temperature for 10 minutes.

4. The ultrasonic vibration-assisted metal capillary inner wall chemical polishing method according to claim 1, wherein The chemical polishing solution contains 0.15 wt% K2S2O8 as an oxidizing agent, 0.15 wt% lactic acid as a complexing agent, 120 mL / L H3PO4 and 60 mL / L HCl.

5. The ultrasonic vibration-assisted metal capillary inner wall chemical polishing method according to claim 1, wherein The set flow rate is 120 mL / min, the ultrasonic vibration frequency is 40 kHz, and the polishing time is 150 seconds.

6. The ultrasonic vibration-assisted metal capillary inner wall chemical polishing method according to claim 1, wherein The chemical polishing solution supply system comprises a solution tank, a pump, a flow meter and a pipeline for controlling the flow rate of the polishing solution.

7. The ultrasonic vibration-assisted metal capillary inner wall chemical polishing method according to claim 1, wherein The metal capillary tube fixing device is used to clamp the capillary tube and connect the hose interface of the ultrasonic vibration head.

8. An ultrasonic vibration-assisted chemical polishing device for the inner wall of a metal capillary, characterized in that, The device for implementing the ultrasonic vibration assisted chemical polishing method of the inner wall of a metal capillary tube as claimed in any one of claims 1-7 comprises: a chemical polishing solution supply system for delivering the chemical polishing solution to the metal capillary tube; an ultrasonic vibration system for connecting the metal capillary tube and applying high-frequency vibration; a metal capillary tube fixing device for clamping the metal capillary tube; a temperature control system for maintaining the temperature of the chemical polishing solution.

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