Method for fabricating microtextured metal surfaces by biojet and thermal transfer.

Abstract

This invention provides a method for fabricating microtextured metal surfaces using biojet and thermal transfer, belonging to the field of surface engineering, and aims to efficiently and inexpensively produce textured metal surfaces with functional microstructures. [Solution] A method for producing a microtextured metal surface by biojet and thermal transfer includes the steps of: step S1. improving the strong oxidizing properties of the culture medium by expanding the cultivation of microorganisms; step S2. removing dust and contaminant layers from the metal surface; step S3. creating a mask pattern on the metal surface by thermal transfer technology; and step S4. processing a microstructure on the metal surface by biojet technology to obtain the microtextured surface. This method for producing a metal microtextured surface is environmentally friendly, consumes little energy, has a simple processing process, and has good processing sustainability.

Description

Technical Field

[0001] The present invention relates to the technical field of surface texturing, and particularly to a method for fabricating a micro-textured metal surface by biojet and thermal transfer.

Background Art

[0002] A micro-textured metal surface refers to changing the physicochemical properties of the surface of a metal material by constructing micron- or nano-sized texture structures, such as grooves, columnar arrays, holes, etc. on the surface of the metal material. These micro-textures endow the metal material with unique properties, such as controllable wettability, and can achieve superhydrophobicity or superhydrophilicity; in terms of heat dissipation performance, heat exchange can be enhanced; in terms of tribological properties, friction reduction and resistance reduction can be achieved; also, biocompatibility improvement, antibacterial property improvement, etc. can be achieved. Due to these excellent properties, micro-textured metal surfaces show great potential in the fields of microfluidics, biomedicine, heat dissipation of electronic devices, mechanical manufacturing, and antibacterial materials.

[0003] Many attempts have been made regarding the fabrication of micro-textured metal surfaces. For example, Patent Document CN112140452A discloses a method for fabricating an anti-icing coating surface with a concave micro-nano bipolar structure that fabricates concave micro-textures on a metal surface using micro-milling technology, but its processing process may cause damage and stress concentration on the metal surface. Also, for example, Patent Document CN110408977A discloses a multi-scale enhanced boiling surface and its composite fabrication method for fabricating a honeycomb-like microstructure on a metal surface using an electrochemical method, but this method has a complex processing process and is prone to generating chemical waste liquid during the processing process, which may affect the environment. Also, Patent Document CN118218774A discloses a method for fabricating a superhydrophobic silver surface using nanosecond laser technology, which fabricates a fine pore structure array on the metal surface using laser technology, but this method has expensive equipment and too high energy consumption in the processing process.

[0004] As described above, in order to overcome the shortcomings of conventional technology and meet the needs of actual applications, it is necessary to develop a method for producing microtextured metal surfaces that have low surface residual stress, low energy consumption during processing, are environmentally friendly, have a simple and convenient process, and are low cost. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The main technical problem that this invention aims to solve is to provide a method for producing microtextured metal surfaces by biojet and thermal transfer that has low surface residual stress, low energy consumption during the processing process, is environmentally friendly, is a simple and convenient process, and is low cost. [Means for solving the problem]

[0006] To solve the above technical problems, the present invention provides a method for producing a microtextured metal surface by biojet and thermal transfer, comprising the following steps. Step S1. Improve microbial activity and oxidative properties of the culture medium through large-scale cultivation of microorganisms; Step S2. Remove dust and contaminant layers from the metal surface; Step S3. Design a pattern with a regular arrangement, transfer it to heat transfer paper, and use heat transfer technology to transfer the textured pattern on the transfer paper to the metal surface processed in Step S2 to generate a mask surface; Step S4. The metal material having the mask surface treated in step S3 is subjected to microstructure processing by biojet machining.

[0007] In preferred embodiments, the microorganisms in step S1 include Thiobacillus ferrooxydans and Thiobacillus thiooxydans.

[0008] In preferred embodiments, the culture medium components in step S1 include the number of microorganisms and the concentration of metabolites.

[0009] In a preferred embodiment, the removal method in step S2 includes grinding, polishing, washing, and drying.

[0010] In preferred embodiments, the metallic material on the metal surface in step S2 is a pure metal material, a metal alloy material, or a metal sintered material in which the oxidative properties of the partial or overall components are lower than those of the microbial conversion product.

[0011] In preferred embodiments, the components of the metallic material include, but are not limited to, iron, cobalt, copper, and tin.

[0012] In a preferred embodiment, the pattern on the mask surface in step S3 is a combination of figures having regular microstructure shapes and arrangements; The aforementioned figures include, but are not limited to, circles and rectangles, and the aforementioned patterns include, but are not limited to, rectangles, sines, and hexagons. In preferred embodiments, the pattern transfer device used includes a laser printer and an inkjet printer. In a preferred embodiment, the masking material used in step S3 does not react with the oxidizing substance and adheres closely to the metal substrate; The mask material includes carbon powder, resin powder, and toner. In preferred embodiments, the weakly oxidizing substance generated in the solution after the reaction in step S4 is converted back into a strongly oxidizing substance by biochemical reactions within the microorganism. Compared to conventional technologies, the technical form of the present invention has the following beneficial effects. [Effects of the Invention]

[0013] Compared to conventional masking methods, the thermal transfer texture masking method used in the present invention does not require complex processes such as photolithography and development, and allows surface masking to be applied to metal surfaces by simple heating and pressurization, resulting in a simple manufacturing process.

[0014] Compared with the conventional microtexture processing method, the present invention utilizes the reaction between the strongly oxidizing substance generated by microorganisms and metal to achieve material removal, and has the characteristics of simple process, low cost, low energy consumption, and low damage.

[0015] By introducing jet technology, the contact frequency between the strongly oxidizing substance and the metal surface is increased, the processing efficiency of the textured surface is improved, and the weakly oxidizing substance generated in the solution after the reaction is converted into a strongly oxidizing substance by biochemical reactions within the microorganisms, enabling the realization of the processing cycle.

Brief Description of the Drawings

[0016] [Figure 1] It is a flowchart of the method for fabricating a microtexture metal surface by biojet and thermal transfer of the present invention. [Figure 2] It is a diagram showing the dimensions and arrangements of the mask patterns designed in Example 1 and Example 2 of the present invention. [Figure 3] It is a three-dimensional topography diagram of the brass microbump surface in Example 1 of the present invention. [Figure 4] It is a cross-sectional view of the three-dimensional topography of the microbump in FIG. 3. [Figure 5] It is a three-dimensional topography diagram of the brass microbump surface in Example 2 of the present invention. [Figure 6] It is a cross-sectional view of the three-dimensional topography of the microbump in FIG. 5.

Modes for Carrying Out the Invention

[0017] In the following, in order to make the technical forms and features of the present invention clearer, the present invention will be described in more detail while referring to the attached drawings and specific examples. However, these examples are only for explaining the present invention and do not limit the scope of the present invention. After reading the present invention, any various equivalent modifications made to the present invention by those skilled in the art are all included in the scope limited by the attached patent claims.

Example

[0018] This example provides a method for fabricating a superhydrophobic metal surface by biojet and thermal transfer, which includes the following steps.

[0019] Step S1. The microorganism adopted in the example is Thiobacillus ferrooxidans. Since the activity of the primary strain was low, it was necessary to perform an enlarged culture to improve its biological activity. Different volume gradients of 100 ml, 500 ml, 2000 ml, and 10000 ml were provided to gradually increase the microbial activity. The components of the microbial culture solution include 30 g / L ammonium sulfate, 5 g / L magnesium sulfate heptahydrate, 5 g / L dipotassium hydrogen phosphate, 1 g / L potassium chloride, 0.144 g / L calcium nitrate tetradecahydrate, and 248.2 g / L ferrous sulfate heptahydrate. The pH of the culture solution was adjusted to 1.8 with dilute sulfuric acid. The Thiobacillus ferrooxidans strain was inoculated into the culture solution and cultured in a constant temperature shaker for 20 h while ventilating. The temperature was 30 °C, the rotation speed of the shaker was 180 rpm, and the total iron ion concentration in the finally obtained bacterial solution was 5.5 g / L. It is necessary to ensure that Fe 2+ is almost converted to Fe 3+ . Based on the color development characteristics of Fe 2+ and Fe 3+ in different solutions, it was determined whether it had completely changed by titration.

[0020] Step S2. For the metal, H62 brass with a diameter of φ=25 and a height of h=10mm was used. Oil and grease on the surface were polished off using metal sandpaper of 400, 1000, and 2000 grit in sequence. Then, the metal material was ultrasonically cleaned using experimental pure water and anhydrous ethanol in sequence, and a clean metal surface was obtained after drying.

[0021] Step S3. A textured transfer toner mask was generated on the metal surface processed in Step S2 using thermal transfer technology. First, a pattern of circular protrusions arranged in a regular hexagon was designed using computer graphics software, with a circular diameter φ of 300 μm, a center-to-center distance of 500 μm, and each circle being arranged to form a regular hexagon. A schematic diagram of the dimensions of the processed microstructure is shown in Figure 2. Next, the pattern was printed onto thermal transfer paper using a laser printer to form a toner layer, and the textured toner on the thermal transfer paper was transferred to the metal surface by heating and pressurizing to complete the textured transfer toner mask.

[0022] Step S4. A supernatant liquid containing a strong oxidizing substance was sprayed onto the metal surface having the textured transfer toner mask obtained in Step S3 using jet technology, processing the metal surface to have a functional microstructure. The jet speed was 2 m / s and the processing time was 30 min. [Examples]

[0023] Step S1. The microorganism used in the example was Thiobacillus ferrooxydans. Since the activity of the primary strain was low, it was necessary to expand the culture to improve its biological activity. A volume gradient of 100 ml, 500 ml, 2000 ml, and 10000 ml was established to gradually increase the microbial activity. The microbial culture solution contained 30 g / L ammonium sulfate, 5 g / L magnesium sulfate heptahydrate, 5 g / L dipotassium hydrogen phosphate, 1 g / L potassium chloride, 0.144 g / L calcium nitrate tetrahydrate, and 248.2 g / L ferrous sulfate heptahydrate. The pH of the culture solution was adjusted to 1.8 with dilute sulfuric acid. The Thiobacillus ferrooxydans strain was inoculated into the culture solution and cultured for 20 hours in a constant temperature shaker with aeration at a temperature of 30°C and a shaker rotation speed of 180 rpm. The total iron ion concentration in the final bacterial solution was 5.5 g / L. 2+ is almost Fe 3+ It is necessary to ensure that it has been converted to Fe 2+ and Fe 3+ Based on the color development characteristics in different solutions, it was determined by titration whether the color had completely changed.

[0024] Step S2. For the metal, H62 brass with a diameter of φ=25 and a height of h=10mm was used. Oil and grease on the surface were polished off using metal sandpaper of 400, 1000, and 2000 grit in sequence. Then, the metal material was ultrasonically cleaned using experimental pure water and anhydrous ethanol in sequence, and a clean metal surface was obtained after drying.

[0025] Step S3. A textured transfer toner mask was generated on the metal surface processed in Step S2 using thermal transfer technology. First, a pattern of circular protrusions arranged in a regular hexagon was designed using computer graphics software, with a circular diameter φ of 300 μm, a center-to-center distance of 500 μm, and each circle being arranged to form a regular hexagon. A schematic diagram of the dimensions of the processed microstructure is shown in Figure 2. Next, the pattern was printed onto thermal transfer paper using a laser printer to form a toner layer, and the textured toner on the thermal transfer paper was transferred to the metal surface by heating and pressurizing to complete the textured transfer toner mask.

[0026] Step S4. A supernatant liquid containing a strong oxidizing substance was sprayed onto the metal surface having the textured transfer toner mask obtained in Step S3 using jet technology, processing the metal surface to have a functional microstructure. The jet speed was 3 m / s and the processing time was 30 min.

[0027] The above-described embodiment is merely one specific example of the present invention, and the design concept of the present invention is not limited thereto. Making any substantial changes to the present invention using this design concept will be deemed to infringe the scope of protection of the present invention.

Claims

1. Step S1. Improve microbial activity and the oxidative properties of the culture medium by expanding the culture of microorganisms; Step S2. Remove dust and contaminant layers from the metal surface; Step S3. Design a pattern with a regular arrangement, transfer it to heat transfer paper, and use heat transfer technology to transfer the textured pattern on the transfer paper to the metal surface processed in Step S2 to generate a mask surface; Step S4. The metal material having the mask surface treated in step S3 is subjected to microstructure processing by biojet machining; A method for producing a microtextured metal surface by biojet and thermal transfer, characterized by including [a specific element].

2. The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the microorganism in step S1 includes Thiobacillus ferrooxydans and Thiobacillus thiooxydans.

3. The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the components of the culture medium in step S1 include the number of microorganisms and the concentration of metabolites.

4. The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the removal method in step S2 includes grinding, polishing, washing, and drying.

5. The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the metal material of the metal surface in step S2 is a pure metal material, a metal alloy material, or a metal sintered material in which the oxidative properties of the partial or overall components are lower than the oxidative properties of the microbial conversion product.

6. The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the components of the metal material include, but are not limited to, iron, cobalt, copper, and tin.

7. The pattern on the mask surface in step S3 is a combination of figures having regular microstructure shapes and arrangements; The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the figures include circles and rectangles, and the patterns include rectangles, sines, and hexagons, but are not limited thereto.

8. The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the pattern transfer apparatus used includes a laser printer and an inkjet printer.

9. The masking material used in step S3 does not react with the oxidizing substance and adheres closely to the metal substrate; The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the mask material comprises carbon powder, resin powder, and toner.

10. The method for producing a microtextured metal surface by biojet and thermal transfer according to claim 1, characterized in that the weakly oxidizing substance generated in the solution after the reaction in step S4 is converted back into a strongly oxidizing substance by a biochemical reaction within microorganisms.

Images