Metal surface microstructure machining method based on biological liquid microjet

Abstract

The invention relates to a metal surface microstructure processing method based on biological liquid microjet. The metal surface microstructure processing method comprises the following steps: (1) carrying out enlarged culture on microorganisms; (2) clamping the metal element; and (3) processing a surface microstructure: pressurizing the supernatant of the culture solution, spraying the pressurized supernatant to the surface of the material by a fine nozzle at a certain speed, reacting metal in a jet flow field with the high-oxidability supernatant, converting the metal into ions, and dissolving the ions into the supernatant to remove the material, and the preparation of the textured surface is completed through the relative movement of the biological liquid micro jet flow and the surface to be machined and selective etching. And (4) re-oxidizing the culture solution. According to the method, a culture solution rich in high-oxidability ions is continuously converted by utilizing the metabolic characteristic of microorganisms, the high-oxidability culture solution is sprayed out through a micro-jet after being accelerated and pressurized and etches a metal surface material, and a flow field of high-energy micro-jet and the culture solution with the etching characteristic cooperate to directly machine a microstructure on the surface. The relative movement of the nozzle and the surface of the workpiece can realize the processing of large-area plane and curved surface microstructures.

Description

Technical Field

[0001] The invention belongs to the technical field of biological removal processing, and in particular relates to a metal surface microstructure processing method based on biological fluid microjet. Background Art

[0002] Metals are widely used in basic components, fuel cells and medical implants due to their plasticity, conductivity and corrosion resistance. However, the harsh service environment places higher demands on the surface performance of metal components. Surface texturing is a technology that uses processing technology to produce functional micro-nano structures with certain arrangement rules on the surface of materials. These micro-nano structures are beneficial to improving the physical, chemical and biological properties of the surface of materials. The preparation of functional microstructures on the contact surface is expected to further improve the surface performance of components, making them more stable, reliable and have a longer service life.

[0003] There are many ways to process textured surfaces, which are mainly divided into traditional processing and special processing. Traditional processing mainly includes micro-milling and micro-drilling. However, traditional processing often produces a heat-affected zone on the surface of the material during the processing, which directly affects the mechanical properties of the material. In addition, the high-precision microstructure puts higher requirements on processing equipment and tools, which is the main reason for the surge in processing costs. Special processing such as laser processing and electrospark processing are also widely used in the preparation of textured surfaces. Although the processing efficiency of special processing is relatively high, when using special processing to prepare microstructures, heat damage layers and remelting layers will be generated, which directly affect the micromorphology of the functional microstructure and the performance improvement of the textured surface. Under the background of the green, low-consumption and environmentally friendly development of the manufacturing industry, the demand for a processing microstructure with low resource consumption, green processing process and precision forming is becoming more and more urgent. Summary of the invention

[0004] The main technical problem to be solved by the present invention is to provide a metal surface microstructure processing method based on biological fluid microjet, which achieves low resource consumption, green processing and precise forming of microstructure.

[0005] In order to solve the above technical problems, the present invention provides a method for metal surface microstructure processing based on biological fluid microjet, comprising the following steps:

[0006] (1) Microbial expansion: Providing a culture environment to promote the growth and reproduction of microorganisms, while increasing the activity of microorganisms and the concentration of highly oxidizing ions in the culture medium;

[0007] (2) Clamping of components to be processed;

[0008] (3) Processing of surface microstructure: The supernatant of the culture fluid is pressurized by a high-pressure generator and then sprayed onto the material surface through a micro nozzle. The metal in the jet field of the processing part reacts with the highly oxidizing supernatant and is converted into ions that dissolve into the supernatant to achieve material removal. The relative movement of the micro jet of biological fluid and the surface to be processed and selective etching complete the preparation of the textured surface.

[0009] (4) Reoxidation of the culture medium: The supernatant involved in material removal produces low-oxidizing ions that are transformed by highly active microorganisms and then regain high oxidizing properties, continuing to participate in the processing of the textured surface, ensuring that the supernatant is always highly oxidizing.

[0010] In a preferred embodiment, the microorganisms described in step (1) include Thiobacillus ferrooxidans and Thiobacillus thiooxidans.

[0011] In a preferred embodiment, the culture environment in step (1) includes a carbon source, a nitrogen source, nutrients, water, oxygen supply, culture temperature, pH, and shaking speed of a shaker.

[0012] In a preferred embodiment, during the clamping process of the component to be processed in step (2), the normal projection area of ​​the micro-jet flow field does not interfere with the non-processing area of ​​the component to be processed.

[0013] In a preferred embodiment, the supernatant of step (3) is obtained by filtering the culture fluid through a microporous filter membrane smaller than the diameter of the microorganisms, and the microorganisms in the culture fluid are placed in a microbial transformation part to maintain their activity.

[0014] In a preferred embodiment, the high voltage generator in step (3) can generate pulsed or continuous high voltage micro jets.

[0015] In a preferred embodiment, the diameter of the micro nozzle in step (3) is smaller than the main dimension of the surface microstructure, including but not limited to micrometer level.

[0016] In a preferred embodiment, the shape and number of the micro nozzles in step (3) are designed according to the arrangement and shape of the microstructure of the surface to be processed, and the increase in the number of nozzles should not affect the pressure and velocity distribution of the jet flow field.

[0017] In a preferred embodiment, the micro-nozzle posture in step (3) cooperates with the workpiece posture to achieve relative position control between the high-pressure micro-fluid and the microstructure on the surface to be processed.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention utilizes the metabolic characteristics of microorganisms to generate highly oxidizing ions that react with metal particles, and introduces micro jets to directly process surface microstructures. This method has the characteristics of small environmental impact, strong sustainability, and controllable microstructure morphology;

[0020] 2. In the process of surface microstructure processing, the present invention integrates the etching characteristics of microbial products and micro-beams to realize the processing of metal surface microstructures, eliminates the redundant mask process in traditional processing, and realizes low-cost, high-efficiency, and localized processing of surface microstructures.

[0021] 3. The microbial transformation area and the microfluidic processing area of ​​the present invention are separated by a microporous filter, and the microorganisms are not directly involved in harsh environments such as high pressure. The number and activity of microorganisms in the culture medium are maintained at a high level, ensuring the sustainability of material removal processing.

[0022] 4. The morphology of the metal surface microstructure in the present invention is closely related to the pressure distribution and velocity distribution of the microjet flow field, which improves the microstructure forming accuracy and the controllability of the micromorphology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of a metal surface microstructure processing method based on biological fluid microjet in Example 1;

[0024] Figure 2 Schematic diagram of the textured surface processing of the curved micro-pit array in Example 1;

[0025] Figure 3 This is a schematic diagram of the processing of the plane cross microstructure in Example 2;

[0026] Figure 4 Schematic diagram of the processing of planar circular array sinusoidal microstructures in Example 3.

[0027] In the figure, 1-air pump, 2-microorganism reactor, 3-ion exchange pump, 4-microorganism filter, 5-ion exchange pipeline, 6-liquid storage tank, 7-high pressure generator, 8-high pressure pipeline, 9-micro nozzle, 9'-another position of the micro nozzle, 10-micro jet, 10'-another position of the micro jet, 11-component to be processed, 12-clamping device, 13-displacement platform, 14-nozzle movement trajectory. DETAILED DESCRIPTION

[0028] In order to make the technical solutions and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0029] Example 1

[0030] A method for processing metal surface microstructure based on biological fluid microjet, comprising the following steps:

[0031] 1. Microbial expansion culture: The microorganism used in this example is Acidithiobacillus ferrooxidans, which can directly convert low-oxidizing Fe 2+ Convert highly oxidizing Fe 3+ .like Figure 1 As shown, during the microbial expansion culture process, (NH4)2SO4, MgSO4·7H2O, K2HPO4, KCl, Ca(NO3)2, FeSO4·7H2O, water, and the previous generation of bacteria are added to the microbial reactor 2 to promote the growth and reproduction of acidophilic ferrothiobacillus ferrooxidans, the pH of the culture solution is adjusted to 1.8, the culture temperature T=30°C, the shaking speed of the shaker is 160rpm, and the air pump 1 is used to continuously supply air to the microbial reactor 2 to promote the growth of microorganisms. In addition, since the activity of refrigerated bacteria is low, the activity of the microorganisms is further improved by culturing from generation to generation. After the microbial expansion culture, the Fe in the culture solution 3+ The concentration was increased to 5 g / L.

[0032] 2. Clamping of components to be processed: Figure 1 and Figure 2 As shown, the component 11 to be processed is fixed by a clamping device 12, and the surface of the component 11 to be processed does not interfere with the micro nozzle 9 and the micro jet 10. The material of the component 11 to be processed is brass, and the shape is an irregular curved surface.

[0033] 3. Processing of surface microstructure: such as Figure 1 and Figure 2 As shown, the culture solution is added from the microbial reactor 2, and the supernatant is obtained through the ion exchange pump 3 and the microbial filter 4, and then stored in the liquid storage tank 6 through the ion exchange pipeline 5. The microbial filter 4 isolates the acidophilic ferrothiobacillus in the microbial culture area to prevent the microorganisms from entering the high-pressure environment and causing the microbial conversion efficiency to decrease. The highly oxidizing supernatant in the liquid storage tank 6 forms a micro jet 10 through the high-pressure generator 7, the high-pressure pipeline 8, and the micro nozzle 9. The micro nozzle 9 adjusts the relative position of the micro jet 10 and the element to be processed 11 under the drive of the displacement platform 13. The other position 10' of the micro jet generated by the other position 9' of the micro nozzle can react with the material to prepare micro pits, and the micro jet 10 reacts with the surface material of the element to be processed 11 to remove the surface material. Among them, the outlet cross-section of the micro nozzle 9 is circular, the diameter is 800μm, a single nozzle is used, and the jet flow rate is 14.53m / s. The high-pressure generator 7 uses a pulse jet mode to complete the processing of the array micro pits.

[0034] 4. Reoxygenation of culture medium: Figure 1 As shown, the high-pressure micro jet 10 reacts with the element to be processed 11 to generate a low-oxidizing supernatant and refluxes into the liquid storage tank 6. The low-oxidizing ions in the liquid storage tank 6 reach the microbial reactor 2 via the ion exchange pipeline 5, the microbial filter 4, and the ion exchange pump 3. The highly active microorganisms use their own metabolic characteristics to quickly convert the low-oxidizing ions into high-oxidizing ions. After the oxidizing property in the culture medium is restored, it returns to the liquid storage tank 6 to participate in the processing of the microstructure.

[0035] Example 2

[0036] A method for processing metal surface microstructure based on biological fluid microjet, comprising the following steps:

[0037] 1. Microbial expansion culture: The microorganism used in this example is Acidithiobacillus ferrooxidans, which can directly convert low-oxidizing Fe 2+ Convert highly oxidizing Fe 3+ .like Figure 1 As shown, during the microbial expansion culture process, (NH4)2SO4, MgSO4·7H2O, K2HPO4, KCl, Ca(NO3)2, FeSO4·7H2O, water, and the previous generation of bacteria are added to the microbial reactor 2 to promote the growth and reproduction of acidophilic ferrothiobacillus ferrooxidans, the pH of the culture solution is adjusted to 1.8, the culture temperature T=30°C, the shaking speed of the shaker is 160rpm, and the air pump 1 is used to continuously supply air to the microbial reactor 2 to promote the growth of microorganisms. In addition, since the activity of refrigerated bacteria is low, the activity of the microorganisms is further improved by culturing from generation to generation. After the microbial expansion culture, the Fe in the culture solution 3+ The concentration was increased to 5 g / L.

[0038] 2. Clamping of components to be processed: Figure 1 and Figure 3 As shown, the component 11 to be processed is fixed by a clamping device 12, and the surface of the component 11 to be processed does not interfere with the micro nozzle 9 and the micro jet 10. The material of the component 11 to be processed is brass, and the shape is a rectangular plate.

[0039] 3. Processing of surface microstructure: such as Figure 1 and Figure 3As shown, the culture liquid is added from the microbial reactor 2, and the supernatant is obtained through the ion exchange pump 3 and the microbial filter 4, and then stored in the liquid storage tank 6 through the ion exchange pipeline 5. The microbial filter 4 isolates the acidophilic ferrothiobacillus in the microbial culture area to prevent the microorganisms from entering the high-pressure environment and causing the microbial conversion efficiency to decrease. The supernatant in the liquid storage tank 6 forms a micro jet 10 of highly oxidizing supernatant through the high-pressure generator 7, the high-pressure pipeline 8, and the micro nozzle 9. The micro jet 10 reacts with the surface material of the component to be processed 11 to remove the surface material. The micro nozzle 9 is driven by the displacement platform 13 to process the plane cross microstructure on the surface of the rectangular plate according to the nozzle movement trajectory 14. Among them, the outlet cross section of the micro nozzle 9 is circular, the diameter is 800μm, a single nozzle is used, the jet flow rate is 14.53m / s, and the high-pressure generator 7 uses a continuous injection mode.

[0040] 4. Reoxygenation of culture medium: Figure 1 As shown, the high-pressure micro jet 10 reacts with the element to be processed 11 to generate a low-oxidizing culture solution and refluxes into the liquid storage tank 6. The low-oxidizing ions in the liquid storage tank 6 reach the microbial reactor 2 via the ion exchange pipeline 5, the microbial filter 4, and the ion exchange pump 3. The highly active microorganisms use their own metabolic characteristics to rapidly convert the low-oxidizing ions into high-oxidizing ions. After the oxidizing property in the culture solution is restored, it returns to the liquid storage tank 6 to participate in the processing of the functional microstructure.

[0041] Example 3

[0042] A method for processing metal surface microstructure based on biological fluid microjet, comprising the following steps:

[0043] 1. Microbial expansion culture: The microorganism used in this example is Acidithiobacillus ferrooxidans, which can directly convert low-oxidizing Fe 2+ Convert highly oxidizing Fe 3+ .like Figure 1 As shown, during the microbial expansion culture process, (NH4)2SO4, MgSO4·7H2O, K2HPO4, KCl, Ca(NO3)2, FeSO4·7H2O, water, and the previous generation of bacteria are added to the microbial reactor 2 to promote the growth and reproduction of acidophilic ferrothiobacillus ferrooxidans, the pH of the culture solution is adjusted to 1.8, the culture temperature T=30°C, the shaking speed of the shaker is 160rpm, and the air pump 1 is used to continuously supply air to the microbial reactor 2 to promote the growth of microorganisms. In addition, since the activity of refrigerated bacteria is low, the activity of the microorganisms is further improved by culturing from generation to generation. After the microbial expansion culture, the Fe in the culture solution 3+ The concentration was increased to 5 g / L.

[0044] 2. Clamping of components to be processed: Figure 1 and Figure 4 As shown, the component 11 to be processed is fixed by a clamping device 12, and the surface of the component 11 to be processed does not interfere with the micro nozzle 9 and the micro jet 10. The material of the component 11 to be processed is brass, and the shape is a round plate.

[0045] 3. Processing of surface microstructure: such as Figure 1 and Figure 4 As shown, the culture liquid is added from the microbial reactor 2, and the supernatant is obtained through the ion exchange pump 3 and the microbial filter 4, and then stored in the liquid storage tank 6 through the ion exchange pipeline 5. The microbial filter 4 isolates the acidophilic ferrothiobacillus in the microbial culture area to prevent the microorganisms from entering the high-pressure environment and causing the microbial conversion efficiency to decrease. The supernatant in the liquid storage tank 6 forms a micro jet 10 of highly oxidizing supernatant through the high-pressure generator 7, the high-pressure pipeline 8, and the micro nozzle 9. The micro jet 10 reacts with the surface material of the component to be processed 11 to remove the surface material. The micro nozzle 9 is driven by the displacement platform 13 to process the plane circumferential array sinusoidal microstructure on the surface of the circular plate according to the nozzle movement trajectory 14. Among them, the outlet cross section of the micro nozzle 9 is circular, the diameter is 800μm, a single nozzle is used, the jet flow rate is 14.53m / s, and the high-pressure generator 7 uses a continuous injection mode.

[0046] 4. Reoxygenation of culture medium: Figure 1 As shown, the high-pressure micro jet 10 reacts with the element to be processed 11 to generate a low-oxidizing culture solution and refluxes into the liquid storage tank 6. The low-oxidizing ions in the liquid storage tank 6 reach the microbial reactor 2 via the ion exchange pipeline 5, the microbial filter 4, and the ion exchange pump 3. The highly active microorganisms use their own metabolic characteristics to rapidly convert the low-oxidizing ions into high-oxidizing ions. After the oxidizing property in the culture solution is restored, it returns to the liquid storage tank 6 to participate in the processing of the functional microstructure.

[0047] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited to this. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A method for metal surface microstructure processing based on biological fluid microjet, comprising the following steps: (1) Microbial expansion: Providing a culture environment to promote the growth and reproduction of microorganisms, while increasing the activity of microorganisms and the concentration of highly oxidizing ions in the culture medium; (2) Clamping of components to be processed; (3) Processing of surface microstructure: The supernatant of the culture fluid is pressurized by a high-pressure generator and then sprayed onto the material surface through a micro-nozzle. The metal in the jet field of the processing part reacts with the highly oxidizing supernatant and is converted into ions that dissolve into the supernatant to achieve material removal. The relative movement of the micro-jet of the biological fluid and the surface to be processed and selective etching complete the preparation of the textured surface. (4) Reoxidation of the culture medium: The supernatant involved in material removal produces low-oxidizing ions, which are transformed by highly active microorganisms and then restored to high oxidizing properties. The ions continue to participate in the processing of the textured surface, ensuring that the supernatant is always highly oxidizing.

2. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: The microorganisms described in step (1) include Thiobacillus ferrooxidans and Thiobacillus thiooxidans.

3. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: The culture environment in step (1) includes a carbon source, a nitrogen source, nutrients, water, oxygen supply, culture temperature, pH, and shaking speed of a shaker.

4. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: During the clamping process of the component to be processed in step (2), the normal projection area of ​​the micro-jet flow field has no interference with the non-processing area of ​​the component to be processed.

5. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: The supernatant in step (3) is obtained by filtering the culture solution through a microporous filter membrane smaller than the diameter of the microorganisms, and the microorganisms in the culture solution are placed in a microbial transformation part to maintain their activity.

6. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: The high voltage generator in step (3) can generate pulsed or continuous high voltage micro jets.

7. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: The diameter of the micro nozzle in step (3) is smaller than the main dimension of the surface microstructure, including but not limited to micrometer level.

8. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: The shape and number of the micro nozzles in step (3) are designed according to the arrangement and shape of the microstructures on the surface to be processed, and the increase in the number of nozzles should not affect the pressure and velocity distribution of the jet flow field.

9. The method for metal surface microstructure processing based on biological fluid microjet according to claim 1, characterized in that: The coordination of the micro-nozzle posture and the workpiece posture in step (3) realizes the relative position control of the high-pressure micro-fluid and the microstructure of the surface to be processed.

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