A method for preparing a microscale two-dimensional grid on a surface of a titanium alloy

Abstract

The application provides a method for preparing a micron two-dimensional grid on a titanium alloy surface, comprising the following steps: S1, pretreating the surface of a titanium alloy sample of a certain size; S2, preparing a continuous square grid on a soda glass mask plate; S3, coating the sample surface of step S1 with an AZ positive photoresist film, and then pre-baking; S4, placing the soda glass mask plate of step S2 above the photoresist film of step S3 for ultraviolet light exposure, and then post-baking; S5, developing the sample of step S3 for 40-50 seconds, and copying the square grid on the mask plate to the photoresist; S6, baking the developed sample; S7, gold plating the sample obtained in step S6; and S8, placing the gold-plated sample in an acetone solution to obtain a sample with a micron two-dimensional grid on the surface. The micron two-dimensional grid prepared on the titanium alloy surface can be used as a reference datum to determine whether interface slip occurs in the creep process, and provides a new perspective for micro-deformation mechanism analysis.

Description

Technical Field

[0001] This invention relates to the field of research on the microscopic deformation mechanism of materials, and more specifically, to a method for preparing micron-scale two-dimensional meshes on the surface of titanium alloys. Background Technology

[0002] Currently, titanium alloys are used in pressure chambers and high-pressure vessels. These applications expose titanium alloys to long-term, high-load operating environments. Titanium alloy pressure-resistant structures, under long-term service conditions, will experience creep in localized high-stress areas. The cumulative plastic strain generated by creep can severely reduce the structural safety and reliability. Therefore, researchers have conducted extensive studies on the low-temperature creep behavior and deformation mechanisms of titanium alloys. Most studies employ transmission electron microscopy (TEM), scanning electron microscopy (SEM), and EBSD to analyze deformation mechanisms such as dislocation slip, twinning, and grain boundary morphology. However, interface slip is also an important microscopic deformation mechanism, and current TEM, SEM, and EBSD techniques cannot determine whether interface slip exists. Summary of the Invention

[0003] In view of this, the present invention aims to propose a method for preparing micron-scale two-dimensional meshes on the surface of titanium alloys. This addresses the problem in existing technologies where transmission electron microscopy (TEM), scanning electron microscopy (SEM), and EBSD can observe deformations such as dislocations and twins, but cannot determine whether interfacial slip exists.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] A method for preparing micron-scale two-dimensional meshes on the surface of titanium alloys includes the following steps:

[0006] S1. Select a titanium alloy sample of a certain size and pretreat the surface of the titanium alloy sample.

[0007] S2. Prepare a continuous square grid with a linewidth of 1-3 μm and a line length of 10-15 μm on a soda glass mask of a certain size.

[0008] S3. Coat the surface of the sample treated in step S1 with an AZ positive photoresist film, and then pre-bake it.

[0009] S4. Place the soda glass mask from step S2 above the photoresist film obtained in step S3 and expose it to ultraviolet light for 10-60 seconds, then bake it.

[0010] S5. Use the AZ photoresist developing solution to develop the post-baked sample for 40-50 seconds, and copy the square grid on the mask onto the photoresist.

[0011] S6. Place the developed sample on a hot plate for baking to evaporate the solvent and improve the adhesion between the photoresist and the sample surface.

[0012] S7. Place the sample obtained in step S6 into a magnetron sputtering device for gold plating, with a gold plating thickness of 0.5-3μm;

[0013] S8. Place the gold-plated sample in an acetone solution to remove the photoresist, and obtain a sample with a micron-level two-dimensional mesh on the surface.

[0014] The micron-scale two-dimensional mesh prepared on the surface of titanium alloy in this invention can be used as a reference benchmark to determine whether interface slip occurs during creep, providing a new perspective for the analysis of micro-deformation mechanisms.

[0015] Furthermore, in step S1, the thickness of the titanium alloy sample is 0.5 mm to 1 mm.

[0016] This setup not only maintains the mechanical strength and stability of the titanium alloy sample, preventing deformation and damage during processing, but also facilitates processes such as photoresist coating, exposure, development, gold plating, and photoresist removal. The thickness, in conjunction with the entire preparation process, makes the prepared grid lines more uniform and stable, improving measurement accuracy.

[0017] Furthermore, in step S1, the pretreatment includes sequentially performing grinding and polishing processes, wherein the grinding process results in scratches that are not visible to the naked eye, and the polishing process results in scratches that are not visible under a microscope.

[0018] The grinding and polishing process can improve the flatness and smoothness of the sample surface, ensuring the uniformity of subsequent photoresist coating, exposure effect, and adhesion of the gold plating layer. The resulting micron-level two-dimensional network has a clear and accurate mesh pattern, enabling more accurate analysis of the interfacial slip and micro-deformation mechanisms during creep.

[0019] Furthermore, the grinding process involves sequentially grinding with sandpaper containing silica particles of grades 240#, 400#, 800#, 1200#, and 2000# until scratches are no longer visible to the naked eye.

[0020] This setup gradually reduces the grit size of the sandpaper, which helps to progressively decrease the roughness of the titanium alloy surface and improve its smoothness. This is crucial for subsequent steps such as photolithography and gold plating, as an uneven surface can affect the quality and effectiveness of these processes.

[0021] Furthermore, the polishing process involves first polishing on a polishing machine until no scratches are visible under a microscope, and finally etching in an etchant for 10-30 seconds.

[0022] This setup first removes minor imperfections and scratches from the titanium alloy surface on a polishing machine, making the surface smoother and flatter. Then, it is treated with a short-time etchant to further refine the surface and remove any tiny burrs or uneven areas that may have been generated during polishing, thereby further improving the surface smoothness and flatness. Polishing and etching facilitate subsequent steps such as photolithography and gold plating. The resulting micron-level two-dimensional network has a clear and accurate mesh pattern, enabling more accurate analysis of the interfacial slip and micro-deformation mechanisms during creep.

[0023] Furthermore, during polishing, the polishing machine rotates at a speed of 200-400 r / min, and the polishing agent is a SiO2 suspension and H2O2 solution with a volume ratio of 1:1.

[0024] This design improves the flatness and smoothness of the titanium alloy surface, avoids damage to the titanium alloy surface, and provides favorable conditions for the preparation of micron-scale two-dimensional networks.

[0025] Furthermore, the etchant is a mixture of hydrofluoric acid, nitric acid, and water, wherein the volume ratio of hydrofluoric acid, nitric acid, and water is 1:(2-3):(16-17).

[0026] Furthermore, in step S2, the thickness of the soda glass mask is 2.1-2.5 mm.

[0027] This setup allows the pattern on the photomask to be transferred clearly and accurately onto the photoresist. A certain thickness further ensures the photomask's transmittance and flatness, thereby improving the quality and precision of the pattern transfer.

[0028] Furthermore, in step S3, the thickness of the AZ positive photoresist film is 0.5-3 μm.

[0029] This setup offers several advantages, including high-precision graphic transfer, increased processing speed and efficiency, enhanced compatibility and stability, and reduced costs and waste.

[0030] Furthermore, in step S3, the pre-baking temperature is 80-120℃ and the time is 10-15 min.

[0031] In this setup, pre-baking not only removes solvents from the photoresist and improves adhesion and sensitivity, but also reduces film stress and improves process stability and repeatability. As a result, the micron-scale two-dimensional network has a clear and accurate mesh pattern, enabling more accurate analysis of the interfacial slip and micro-deformation mechanisms during creep.

[0032] Furthermore, in step S4, the post-baking temperature is 80-120℃ and the time is 10-30 min.

[0033] This setup not only enables photochemical reactions and improves pattern quality, but also promotes the adhesion of photoresist to the substrate, removes residual solvents and moisture, and improves process stability and repeatability. The resulting micron-scale two-dimensional network has a clear and accurate mesh pattern, allowing for more accurate analysis of the interfacial slip and micro-deformation mechanisms during creep.

[0034] Furthermore, in step S6, the temperature of the hot plate is 100-200℃, and the baking time is 10-30 minutes.

[0035] This setup not only enhances the adhesion between the photoresist and the substrate, removes residual solvents and moisture, and improves etching resistance, but also reduces stress and improves process stability and repeatability. The resulting micron-scale two-dimensional network has a clear and accurate mesh pattern, enabling more accurate analysis of the interfacial slip and micro-deformation mechanisms during creep.

[0036] Furthermore, it also includes the following steps:

[0037] S9. Place the titanium alloy sample prepared in step S8 under a metallographic microscope for observation, measure the line width and line length of the grid, and take pictures of the grid line shape and its position in the grains.

[0038] S10. Place the sample from step S9 on a creep testing machine for creep testing;

[0039] S11. Place the sample after the creep test under a metallographic microscope and compare it with the metallographic photograph before the creep test to determine whether interface slip occurred during the creep process.

[0040] S111. If the grid lines passing through the grain boundary are twisted or broken, it indicates that interface slip has occurred during creep; otherwise, interface slip has not occurred.

[0041] This setup allows for more accurate analysis of the interfacial slip and microscopic deformation mechanisms during the creep process.

[0042] Compared with existing technologies, the method for preparing micron-scale two-dimensional meshes on the surface of titanium alloys described in this invention has the following advantages:

[0043] (1) The surface grid lines of titanium alloy obtained by the method of the present invention can be used as a reference. If the grid lines passing through the grain boundary are twisted or broken, it indicates that interface slip has occurred during the creep process, providing a new perspective for the analysis of micro deformation mechanism.

[0044] (2) This invention uses a developing method to copy the square grid on the photomask onto the photoresist, and then obtains the grid lines on the titanium alloy surface through a gold plating-removal process. It has a clear and accurate grid pattern, which can more accurately analyze the interface slip and micro deformation mechanism in the creep process.

[0045] (3) The preparation method in this invention is simple, feasible, and has great application prospects. Attached Figure Description

[0046] Figure 1 This is a flowchart illustrating the fabrication process of the micron-scale two-dimensional mesh of the present invention.

[0047] Figure 2 This is a metallographic image of the titanium alloy sample of the present invention after polishing and etching.

[0048] Figure 3 This is a metallographic image of the titanium alloy surface with gold wire mesh prepared in Example 2 of the present invention. Detailed Implementation

[0049] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0050] A method for preparing micron-scale two-dimensional meshes on the surface of titanium alloys includes the following steps:

[0051] S1. Select a titanium alloy sample of a certain size and pretreat the surface of the titanium alloy sample.

[0052] Specifically, the thickness of the titanium alloy sample is 0.5mm-1mm.

[0053] Specifically, the pretreatment includes grinding and polishing in sequence, wherein the grinding process ensures that no scratches are visible to the naked eye on the surface of the titanium alloy sample, and the polishing process ensures that no scratches are visible under a microscope on the surface of the titanium alloy sample.

[0054] Specifically, the grinding process involves sequentially grinding with sandpaper containing silica particles of grades 240#, 400#, 800#, 1200#, and 2000# until no scratches are visible to the naked eye.

[0055] Specifically, the polishing process involves first polishing on a polishing machine until no scratches are visible under a microscope, and finally etching in an etchant.

[0056] More specifically, during polishing, the polishing machine rotates at a speed of 200-400 r / min, and the polishing agent is a SiO2 suspension and H2O2 solution with a volume ratio of 1:1.

[0057] Specifically, the etchant is a mixture of hydrofluoric acid, nitric acid, and water, wherein the volume ratio of hydrofluoric acid, nitric acid, and water is 1:(2-3):(16-17). Preferably, the volume ratio of hydrofluoric acid, nitric acid, and water is 5:12:83.

[0058] S2. Prepare a continuous square grid with a linewidth of 1-3 μm and a line length of 10-15 μm on a soda glass mask of a certain size.

[0059] The micron-scale two-dimensional mesh prepared in this setup is not only stable, but also more accurate in determining whether interface slippage has occurred during creep.

[0060] Specifically, in step S2, the thickness of the soda glass mask is 2.1-2.5 mm.

[0061] S3. Coat the surface of the sample treated in step S1 with an AZ positive photoresist film, and then pre-bake it.

[0062] Specifically, in step S3, the thickness of the AZ positive photoresist film is 0.5-3 μm.

[0063] Specifically, in step S3, the pre-baking temperature is 80-120℃ and the time is 10-15min.

[0064] S4. Place the soda glass mask from step S2 above the photoresist film obtained in step S3 and expose it to ultraviolet light for 10-60 seconds, then bake it.

[0065] Specifically, in step S4, the post-baking temperature is 80-120℃ and the time is 10-30 min.

[0066] S5. Use the AZ photoresist developing solution to develop the post-baked sample for 40-50 seconds, and copy the square grid on the mask onto the photoresist.

[0067] S6. Place the developed sample on a hot plate for baking to evaporate the solvent and improve the adhesion between the photoresist and the sample surface.

[0068] Specifically, in step S6, the temperature of the hot plate is 100-200℃, and the baking time is 10-30 minutes.

[0069] S7. Place the sample obtained in step S6 into a magnetron sputtering device for gold plating, with a gold plating thickness of 0.5-3μm;

[0070] S8. Place the gold-plated sample in an acetone solution to remove the photoresist, and obtain a sample with a micron-level two-dimensional mesh on the surface.

[0071] This invention uses a developing process to copy a square grid from a photomask onto a photoresist, and then obtains a grid line on the titanium alloy surface through a gold plating-removal process. This results in a clear and accurate grid pattern, enabling more accurate analysis of the interfacial slip and micro-deformation mechanisms during creep.

[0072] S9. Place the titanium alloy sample prepared in step S8 under a metallographic microscope for observation, measure the line width and line length of the grid, and take pictures of the grid line shape and its position in the grains.

[0073] S10. Place the sample from step S9 on a creep testing machine for creep testing;

[0074] S11. Observe the sample after the creep test under a metallographic microscope and compare it with the metallographic photograph before the creep test to determine whether interface slip occurred during the creep process.

[0075] S111. If the grid lines passing through the grain boundary are twisted or broken, it indicates that interface slip has occurred during creep; otherwise, interface slip has not occurred.

[0076] The surface grid lines of titanium alloys obtained by the method of this invention can be used as a reference benchmark. If the grid lines passing through the grain boundaries are twisted or broken, it indicates that interface slip has occurred during creep, providing a new perspective for the analysis of micro-deformation mechanisms. This method is simple, highly operable, and has great application prospects.

[0077] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0078] Example 1

[0079] A titanium alloy sample with a thickness of 1 mm, a length of 60 mm, and a width of 10 mm was prepared. The prepared sample was sequentially ground with 240#, 400#, 800#, 1200#, and 2000# sandpaper containing silica particles until no scratches were visible to the naked eye. It was then further polished on a polishing machine until no scratches were visible under a microscope. The polishing machine speed was 200 r / min, and the polishing agent was a 1:1 volume ratio of SiO2 suspension and H2O2 solution. Finally, the sample was etched for 20 s in an etchant consisting of 5 ml hydrofluoric acid, 12 ml nitric acid, and 83 ml water. A continuous square grid with a line width of 1 μm and a line length of 10 μm was prepared on a 2.3 mm thick soda ash glass mask. A 0.5 μm thick layer of AZ 1518 positive photoresist was uniformly coated onto the metallographically etched titanium alloy surface. The photoresist film on the titanium alloy sample surface was then pre-baked at 80 °C for 15 min to remove solvent and increase the adhesion between the photoresist and the titanium alloy. A photomask with a square grid was placed over a photoresist film and exposed to ultraviolet light for 10 seconds. The exposed photoresist was then baked at 80°C for 30 minutes. Next, AZ 351B developer (prepared by diluting deionized water and AZ 351B at a volume ratio of 4:1) was used for 40 seconds to replicate the square grid from the photomask onto the photoresist. The developed sample was then baked on a hot plate at 150°C for 15 minutes to evaporate the solvent and improve the adhesion between the photoresist and the sample surface. The sample was then plated with gold using a magnetron sputtering apparatus to a thickness of 0.5 μm. Finally, the sample was placed in an acetone solution to remove the photoresist, resulting in a sample with a micron-scale two-dimensional grid on its surface.

[0080] The prepared gridded specimens were observed under a metallographic microscope. The linewidth and length of the grid were measured, and the shape and position of the grid lines within the grains were photographed for comparison after creep testing. Tensile creep testing at a stress of 0.9Rp was performed according to GB / T 2039 on a tensile creep testing machine. 0.2 Tensile creep test for 200 hours; after creep test, the sample is observed under a metallographic microscope. If the grid lines passing through the grain boundary are twisted or broken, it indicates that interface slip occurred during creep.

[0081] Example 2

[0082] A titanium alloy sample with a thickness of 0.5 mm, a length of 60 mm, and a width of 10 mm was prepared. The prepared sample was sequentially ground with 240#, 400#, 800#, 1200#, and 2000# sandpaper containing silica particles until no scratches were visible to the naked eye. It was then further polished on a polishing machine until no scratches were visible under a microscope. The polishing machine speed was 300 r / min, and the polishing agent was a 1:1 SiO2 suspension and H2O2 solution. Finally, the sample was etched for 10 seconds in an etchant consisting of 5 ml hydrofluoric acid, 12 ml nitric acid, and 83 ml water. A continuous square grid with a line width of 1 μm and a line length of 15 μm was prepared on a 2.3 mm thick soda ash glass mask. A 2 μm thick layer of AZ 1518 positive photoresist was uniformly coated onto the metallographically etched titanium alloy surface. The photoresist film on the titanium alloy sample surface was then pre-baked at 90℃ for 10 min to remove solvent and increase the adhesion between the photoresist and the titanium alloy. A photomask with a square grid was placed over a photoresist film and exposed to ultraviolet light for 10 seconds. The exposed photoresist was then baked at 120°C for 30 minutes. Next, AZ 351B developer (prepared by diluting deionized water and AZ 351B at a volume ratio of 4:1) was used for 40 seconds to replicate the square grid from the photomask onto the photoresist. The developed sample was then baked on a hot plate at 100°C for 30 minutes to evaporate the solvent and improve the adhesion between the photoresist and the sample surface. The sample was then plated with gold using a magnetron sputtering apparatus to a thickness of 3 μm. Finally, the sample was placed in an acetone solution to remove the photoresist, resulting in a sample with a micron-scale two-dimensional grid on its surface.

[0083] The prepared gridded specimens were observed under a metallographic microscope. The linewidth and length of the grid were measured, and the shape and position of the grid lines within the grains were photographed for comparison after creep testing. Tensile creep testing at a stress of 0.9Rp was performed according to GB / T 2039 on a tensile creep testing machine. 0.2 Tensile creep test for 200 hours; after creep test, the sample is observed under a metallographic microscope. If the grid lines passing through the grain boundary are twisted or broken, it indicates that interface slip occurred during creep.

[0084] Example 3

[0085] A titanium alloy sample with a thickness of 0.8 mm, a length of 60 mm, and a width of 10 mm was prepared. The prepared sample was sequentially ground with 240#, 400#, 800#, 1200#, and 2000# sandpaper containing silica particles until no scratches were visible to the naked eye. It was then further polished on a polishing machine until no scratches were visible under a microscope. The polishing machine speed was 400 r / min, and the polishing agent was a 1:1 SiO2 suspension and H2O2 solution. Finally, the sample was etched for 30 s in an etchant consisting of 5 ml hydrofluoric acid, 12 ml nitric acid, and 83 ml water. A continuous square grid with a line width of 3 μm and a line length of 10 μm was prepared on a 2.3 mm thick soda ash glass mask. A 3 μm thick layer of AZ 1518 positive photoresist was uniformly coated onto the metallographically etched titanium alloy surface. The photoresist film on the titanium alloy sample surface was then pre-baked at 120℃ for 10 min to remove solvent and increase the adhesion between the photoresist and the titanium alloy. A pre-prepared photomask with a square grid was placed over a photoresist film and exposed to ultraviolet light for 30 seconds. The exposed photoresist was then post-baked at 120°C for 30 minutes. Next, AZ 351B developer (prepared by diluting deionized water and AZ 351B at a volume ratio of 4:1) was used for 40 seconds to replicate the square grid from the photomask onto the photoresist. The developed sample was then baked on a 200°C hot plate for 10 minutes to evaporate the solvent and improve the adhesion between the photoresist and the sample surface. The sample was then plated with gold using a magnetron sputtering apparatus to a thickness of 1 μm. Finally, the sample was placed in an acetone solution to remove the photoresist, yielding a sample with a micron-scale two-dimensional grid on its surface.

[0086] The prepared gridded specimens were observed under a metallographic microscope. The linewidth and length of the grid were measured, and the shape and position of the grid lines within the grains were photographed for comparison after creep testing. Tensile creep testing at a stress of 0.9Rp was performed according to GB / T 2039 on a tensile creep testing machine. 0.2 Tensile creep test for 200 hours; after creep test, the sample is observed under a metallographic microscope. If the grid lines passing through the grain boundary are twisted or broken, it indicates that interface slip occurred during creep.

[0087] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing micron-scale two-dimensional meshes on the surface of titanium alloys, characterized in that, Includes the following steps: S1. Select a titanium alloy sample of a certain size and pretreat the surface of the titanium alloy sample. The pretreatment includes grinding and polishing in sequence. The grinding process ensures that the titanium alloy sample is not visible to the naked eye, and the polishing process ensures that the titanium alloy sample is not visible to the microscope. The grinding process specifically involves using sandpaper containing silica particles of grades 240#, 400#, 800#, 1200#, and 2000# in sequence to grind until no scratches are visible to the naked eye; The polishing process specifically involves first polishing on a polishing machine until no scratches are visible under a microscope, and finally etching in an etchant for 10-30 seconds. The etchant is a mixture of hydrofluoric acid, nitric acid, and water, wherein the volume ratio of hydrofluoric acid, nitric acid, and water is 1:(2-3):(16-17). S2. Prepare a continuous square grid with a linewidth of 1-3 μm and a line length of 10-15 μm on a soda glass mask of a certain size. S3. Coat the surface of the sample treated in step S1 with an AZ positive photoresist film, and then pre-bake it; the pre-bake temperature is 80-120℃. S4. Place the soda glass mask from step S2 above the photoresist film obtained in step S3 and expose it to ultraviolet light for 10-60 seconds, then bake it; the baking temperature is 80-120℃. S5. Develop the sample from step S3 for 40-50 seconds using the AZ photoresist developing solution to copy the square grid on the photoresist. S6. The developed sample is placed on a hot plate for baking to evaporate the solvent and improve the adhesion between the photoresist and the sample surface; the temperature of the hot plate is 100-200℃. S7. Place the sample obtained in step S6 into a magnetron sputtering device for gold plating, with a gold plating thickness of 0.5-3μm; S8. Place the gold-plated sample in an acetone solution to remove the photoresist, and obtain a sample with a micron-level two-dimensional mesh on the surface.

2. The method according to claim 1, characterized in that, In step S1, the thickness of the titanium alloy sample is 0.5 mm to 1 mm.

3. The method according to claim 1, characterized in that, During polishing, the polishing machine rotates at 200-400 r / min, and the polishing agent is a SiO2 suspension and H2O2 solution with a volume ratio of 1:

1.

4. The method according to claim 1, characterized in that, In step S3, the pre-baking time is 10-15 minutes.

5. The method according to claim 1, characterized in that, In step S4, the post-baking time is 10-30 minutes.

6. The method according to claim 1, characterized in that, In step S6, the baking time is 10-30 minutes.

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