NiTi alloy multi-scale functional surface structure preparation equipment and method

Abstract

The application discloses a kind of NiTi alloy multi-scale functional surface structure preparation equipment and method, belong to material surface processing technical field, including preparation container, preparation container has working cavity in, preparation container working cavity upper portion is provided with electrochemical system cathode portion, preparation container working cavity bottom is provided with electrochemical system anode portion;The electrochemical system cathode portion includes electrolyte nozzle or platinum electrode as cathode electrode, and the electrochemical system anode portion includes NiTi alloy sample as anode electrode, and electrochemical jet processing is carried out by electrolyte nozzle and NiTi alloy sample cooperation, and electrochemical dealloying treatment is carried out by platinum electrode and NiTi alloy sample cooperation.

Description

Technical Field

[0001] The present invention belongs to the technical field of material surface processing, and in particular relates to a device and method for preparing a multi-scale functional surface structure of a NiTi alloy. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, with the development of science and technology and the urgent demand for functional surface structures and devices, many scientists have been actively conducting research on the design and preparation of new materials and new functional surface structures. The structural design and preparation methods of materials are often the basis for developing new materials and opening up new fields. By integrating the design ideas and optimized preparation of multi-scale structures on the surface of conventional materials, the surface of materials can be functionalized and the service performance of materials in different application contexts can be improved. At present, the research on multi-scale structures on surfaces has penetrated into the micro-nanoscale field, and the materials studied have been gradually applied to clean energy, tribology, heat conduction, biomedicine and advanced manufacturing. However, the preparation of multi-scale structures on the surface of materials currently relies mostly on high-precision multi-axis CNC machine tools or laser processing. Although high processing accuracy and quality consistency can be achieved, the processing route is relatively complex, the equipment is expensive, and the preparation cost is high.

[0004] Nickel-titanium alloy is a functional material with exceptional physical and mechanical properties, including shape memory, superelasticity, biocompatibility, and corrosion resistance. It is widely used in aerospace, micro-electromechanical systems, and other fields. Due to its similar density and elastic modulus to bone, its non-magnetic properties, and its excellent radiopacity, it has also become a commonly used material for human implants. Multi-scale surface structure fabrication of NiTi alloys can achieve new, specific functions without altering the overall properties of the substrate, such as promoting bone growth, enhancing cell adhesion to implant surfaces, and providing anti-fouling properties.

[0005] The inventors have found that nickel and its compounds are potentially toxic to the human body, affecting amino acid metabolism, denaturing proteins, having cytotoxicity and genotoxicity, affecting the immune, blood and other systems, and even causing teratogenicity and carcinogenesis. Excessive nickel ions often cause allergic reactions in local tissues. As research gradually deepens, the problem of nickel ion dissolution has attracted much attention, which has limited the further application of nickel-titanium alloys in the biomedical field. Therefore, achieving the removal of nickel ions on the surface of nickel-titanium alloys has important applications and economic value to the development of nickel-titanium alloy materials. Currently, a method of preparing a coating on the surface of nickel-titanium alloy materials is often used to reduce the release of toxic nickel ions in nickel-titanium alloys, but the physical properties between the coating and the nickel-titanium alloy are very different, the bonding strength is poor, and it is easy to cause premature failure. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a device and method for preparing NiTi alloy multi-scale functional surface structures. The device effectively combines the macro-scale structure forming of NiTi alloy electrochemical jet processing with the nickel-free micro-nano porous structure of electrochemical dealloying, thereby realizing a one-step and efficient preparation of NiTi alloy multi-scale surface structures.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0008] In the first aspect, the present invention provides a NiTi alloy multi-scale functional surface structure preparation device, including a preparation container, a working chamber in the preparation container, an electrochemical system cathode part is arranged at the upper part of the working chamber of the preparation container, and an electrochemical system anode part is arranged at the bottom of the working chamber of the preparation container; the electrochemical system cathode part includes an electrolyte nozzle or a platinum electrode as a cathode electrode, and the electrochemical system anode part includes a NiTi alloy sample as an anode electrode, the electrolyte nozzle and the NiTi alloy sample are combined to perform electrochemical jet processing, and the platinum electrode and the NiTi alloy sample are combined to perform electrochemical dealloying treatment.

[0009] As a further technical solution, the cathode part of the electrochemical system also includes a cathode electrode clamp, the bottom of the cathode electrode clamp is connected to the electrolyte nozzle or platinum electrode, the electrolyte nozzle or platinum electrode is vertically arranged, and the electrolyte nozzle or platinum electrode is directly above the NiTi alloy sample.

[0010] As a further technical solution, the cathode electrode clamp is installed on a mobile platform, which is arranged on the upper part of the working chamber of the preparation container. The mobile platform can move in three dimensions. Driven by the mobile platform, the electrolyte nozzle moves in space to realize electrochemical jet processing of the NiTi alloy surface layer.

[0011] As a further technical solution, the cathode electrode clamp is also connected to an electrolyte supply device, and the electrolyte provided by the electrolyte supply device can enter the electrolyte nozzle through the cathode electrode clamp and be sprayed out or directly enter the working chamber.

[0012] As a further technical solution, the electrolyte supply device includes an electrolyte clear liquid tank for storing electrolyte, the electrolyte clear liquid tank is connected to the cathode electrode clamp through an electrolyte delivery pipeline, and the electrolyte delivery pipeline is provided with an electrolyte supply power device.

[0013] As a further technical solution, an electrolyte turbid liquid tank is set under the preparation container, and a discharge outlet is opened at the bottom of the working chamber of the preparation container, and the discharge outlet is connected to the electrolyte turbid liquid tank through a pipeline; a flow blocking plug can be set at the discharge outlet of the working chamber to block the discharge outlet.

[0014] As a further technical solution, the anode part of the electrochemical system also includes an anode electrode clamp, which clamps the NiTi alloy sample. The anode electrode clamp is fixed to the top of the sample mounting platform, and the sample mounting platform is arranged at the bottom of the working chamber of the preparation container; the cathode part of the electrochemical system is connected to the cathode of the processing power supply, the anode part of the electrochemical system is connected to the anode of the processing power supply, and the processing power supply is connected to the voltage and current control device.

[0015] In a second aspect, the present invention further provides a method for preparing a device for preparing a multi-scale functional surface structure of a NiTi alloy as described above, comprising the following steps:

[0016] An electrochemical system is composed of a NiTi alloy sample as the anode and an electrolyte nozzle as the cathode. The surface layer of the NiTi alloy is electrochemically jet processed to obtain a NiTi alloy surface containing macro-scale microgrooves. An electrochemical system is composed of a NiTi alloy sample as the anode and a platinum electrode as the cathode. The processed NiTi alloy surface is electrochemically dealloyed to remove the nickel element and further generate a nickel-free micro-nanopore structure on the above macro-scale microgroove surface.

[0017] As a further technical solution, the process of electrochemical jet machining is as follows: the electrolyte is supplied to the cathode electrode clamp by the electrolyte supply device, and the electrolyte is sprayed from the electrolyte nozzle; the NiTi alloy sample serves as the anode and the electrolyte nozzle serves as the cathode. The electrolyte nozzle realizes electrochemical jet machining of the NiTi alloy surface layer by moving the mobile platform, and obtains a NiTi alloy surface containing macro-scale microgrooves according to the preset pattern.

[0018] As a further technical solution, the electrochemical dealloying process is as follows: the electrolyte nozzle is removed from the cathode electrode clamp, and the electrolyte is supplied to the cathode electrode clamp by the electrolyte supply device, flowing into the working chamber, and then the platinum electrode is installed on the cathode electrode clamp, and it is ensured that the electrolyte does not cover the end of the platinum electrode; the platinum electrode is used as the cathode, and the NiTi alloy sample is used as the anode. Voltage is applied, and by removing the nickel element, a nickel-free micro-nanopore structure is further generated on the above macro-scale microgroove surface.

[0019] The beneficial effects of the present invention are as follows:

[0020] The NiTi alloy multi-scale functional surface structure preparation equipment of the present invention performs electrochemical jet processing by forming an electrochemical system through the combination of an electrolyte nozzle and a NiTi alloy sample, and performs electrochemical dealloying treatment by forming an electrochemical system through the combination of a platinum electrode and a NiTi alloy sample. In the process of macro-scale structure forming and preparation of micro-nano porous structure, electrochemical methods are adopted to achieve one-step efficient preparation of NiTi alloy multi-scale surface structure. The method is simple, the preparation efficiency is high, and it has good economic value.

[0021] The NiTi alloy multi-scale functional surface structure preparation equipment of the present invention adopts an electrochemical dealloying method to prepare a micro-nano porous surface, thereby removing toxic nickel elements from the NiTi alloy surface, making it possible to apply NiTi alloys with multi-scale surface structures in biomedical related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 Schematic diagram of the NiTi alloy multi-scale functional surface structure preparation device during electrochemical jet processing of the present invention;

[0024] Figure 2 Schematic diagram of the NiTi alloy multi-scale functional surface structure preparation device of the present invention during electrochemical dealloying treatment;

[0025] Figure 3 This is a metallographic image of the multi-scale functional surface structure of the NiTi alloy of the present invention;

[0026] In the figure: the distances or sizes between parts are exaggerated to show the positions of the parts, and the diagram is for illustration only;

[0027] Among them, 1 mobile platform, 2 cathode part of electrochemical system, 201 cathode electrode clamp, 202 electrolyte nozzle, 203 platinum electrode, 3 anode part of electrochemical system, 301 NiTi alloy sample, 302 anode electrode clamp, 303 sample installation platform, 4 electrolyte supply device, 401 electrolyte delivery pipeline, 402 electrolyte supply power device, 403 electrolyte clear liquid tank, 404 electrolyte turbid liquid tank, 405 electrolyte, 406 flow plug, 5 processing power supply, 6 voltage and current control device, 7 working chamber, 8 preparation container. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0029] Example 1:

[0030] In a typical embodiment of the present invention, Figure 1-Figure 2As shown, a NiTi alloy multi-scale functional surface structure preparation device is proposed, which comprises a moving platform 1, an electrochemical system cathode part 2, an electrochemical system anode part 3, an electrolyte supply device 4, a processing power supply 5, a voltage and current control device 6, and a working cavity 7.

[0031] The preparation device has a preparation container 8 with the working cavity 7 inside, in which the NiTi alloy multi-scale functional surface structure is prepared.

[0032] The moving platform 1 is arranged at the upper part of the preparation container 8 and can move in three dimensions. The three-dimensional movement is realized by using the existing technology, which will not be described here.

[0033] The electrochemical system cathode part 2 comprises a cathode electrode clamp 201, the bottom of which is connected with an electrolyte nozzle 202 or a platinum electrode 203. The electrolyte nozzle 202 or the platinum electrode 203 is arranged vertically and is opposite to the upper part of the electrochemical system anode part 3. The electrolyte nozzle 202 is connected with the cathode electrode clamp 201 as a cathode electrode by screwing, and the electrolyte provided by the electrolyte supply device 4 can be sprayed out of the electrolyte nozzle 202 through the cathode electrode clamp 201; the platinum electrode 203 can also be connected with the cathode electrode clamp 201 as a cathode electrode by screwing.

[0034] The cathode electrode clamp 201 is installed on the moving platform 1 and can be driven by the moving platform 1 to move the electrolyte nozzle 202 up and down and left and right, realizing the electrochemical jet processing of the surface layer of the NiTi alloy.

[0035] The electrochemical system anode part 3 comprises an anode electrode clamp 302 and a sample mounting platform 303. The sample mounting platform 303 is arranged at the bottom of the working cavity 7 of the preparation container 8, and the anode electrode clamp 302 is fixedly arranged at the top of the sample mounting platform 303. The anode electrode clamp 302 clamps the NiTi alloy sample 301, so that the NiTi alloy sample is clamped and fixed on the sample mounting platform as an anode electrode.

[0036] The anode electrode is arranged opposite to the bottom of the cathode electrode. The electrochemical system cathode part 2 is connected with the cathode of the processing power supply 5, the electrochemical system anode part 3 is connected with the anode of the processing power supply 5, the processing power supply 5 is connected with the voltage and current control device 6, and the voltage and current control device 6 can control the applied voltage and current of the electrochemical system and adjust them as needed.

[0037] Among them, the electrolyte supply device 4 includes an electrolyte delivery pipe 401, an electrolyte supply power device 402, an electrolyte clear liquid tank 403, an electrolyte turbid liquid tank 404, electrolyte 405, and a flow blocker 406. The electrolyte clear liquid tank 403 is used to store electrolyte. The electrolyte clear liquid tank 403 is connected to the cathode electrode clamp 201 through the electrolyte delivery pipe 401, and the cathode electrode clamp 201 is connected to the electrolyte nozzle 202. The electrolyte delivery pipe 401 is provided with the electrolyte supply power device 402. The electrolyte 405 in the electrolyte clear liquid tank 403 flows into the cathode electrode clamp 201 through the electrolyte delivery pipe 401 under the power provided by the electrolyte supply power device 402 and is ejected from the electrolyte nozzle 202 or directly flows into the working chamber 7.

[0038] The electrolyte turbid liquid tank 404 is arranged below the preparation container 8. A discharge outlet is opened at the bottom of the working chamber 7 of the preparation container 8. The discharge outlet can be connected to the electrolyte turbid liquid tank 404 through a pipeline to discharge the electrolyte turbid liquid; a flow blocking plug 406 can be set at the discharge outlet of the working chamber 7 to block the discharge outlet for electrochemical dealloying treatment.

[0039] Example 2:

[0040] In another typical embodiment of the present invention, a method for preparing a multi-scale functional surface structure of a NiTi alloy is proposed. The preparation method is performed using the preparation equipment described above. The specific process of the preparation method is as follows:

[0041] An electrochemical system is composed of a NiTi alloy sample as the anode and an electrolyte nozzle as the cathode. The surface layer of the NiTi alloy is electrochemically jet processed to obtain a NiTi alloy surface containing macro-scale microgrooves. An electrochemical system is composed of a NiTi alloy sample as the anode and a platinum electrode as the cathode. The processed NiTi alloy surface is electrochemically dealloyed to remove the nickel element and further generate a nickel-free micro-nanopore structure on the above macro-scale microgroove surface.

[0042] In electrochemical jet machining, electrolyte supply power device 402 provides power to electrolyte 405 in electrolyte clear tank 403, allowing it to flow through electrolyte delivery pipe 401 into cathode electrode holder 201 and be ejected from electrolyte nozzle 202. Electrolyte nozzle 202, driven by the movement of mobile platform 1, performs electrochemical jet machining on the surface layer of the NiTi alloy, resulting in a NiTi alloy surface with macroscopic microgrooves according to a pre-set pattern. During machining, used electrolyte flows through a pipe into electrolyte turbid tank 404.

[0043] Among them, the electrochemical dealloying treatment process is as follows: first, the pipe flowing into the electrolyte turbid liquid tank 404 is blocked with a flow plug 406 to prevent the electrolyte from flowing out; the electrolyte nozzle 202 is removed from the cathode electrode clamp 201, and the electrolyte 405 in the electrolyte clear liquid tank 403 is flowed into the working chamber 7 through the electrolyte delivery pipe 401 under the power provided by the electrolyte supply power device 402, and then the platinum electrode 203 is installed on the cathode electrode clamp 201, and it is ensured that the flowing electrolyte 405 will not exceed the end of the platinum electrode 203; finally, the processing power supply 5 is energized, the platinum electrode 203 serves as the cathode, and the NiTi alloy sample 301 is still the anode, and voltage is applied. After a period of time, the nickel element is removed, and a nickel-free micro-nano pore structure is further generated on the above macro-scale micro-groove surface.

[0044] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0045] The preparation process of the multi-scale functional surface structure of NiTi alloy specifically includes the following steps:

[0046] (1) Pretreatment of NiTi alloy sample 301: The NiTi alloy sample 301 was ground and polished step by step with metallographic paper, ultrasonically cleaned in acetone, anhydrous ethanol, and distilled water for 15 min respectively, and dried for later use;

[0047] (2) Electrochemical jet processing is performed on the sample prepared in step (1): a mixed solution of HNO3, H2O2, and CaCl2 with concentrations of 0.5-2 mol / L, 0.5-1 mol / L, and 0.1-0.4 mol / L is prepared as an electrolyte 405, and the electrolyte supply power device 402 provides power to the electrolyte 405 in the electrolyte clear liquid tank 403, so that the electrolyte flows into the cathode electrode clamp 201 through the electrolyte delivery pipe 401 and is ejected from the electrolyte nozzle 202. The injection pressure used is 2-10 MPa, and the processing voltage is 5-20 V. The electrolyte nozzle 202 realizes electrochemical jet processing of the NiTi alloy surface layer by the movement of the mobile platform 1. The processing trajectory is horizontal and vertical linear scanning to obtain a NiTi alloy surface containing macro-scale microgrooves. During the processing, the used electrolyte flows into the electrolyte turbid liquid tank 404 through the pipeline;

[0048] (3) The sample prepared in step (2) is dealloyed: first, the pipe flowing into the electrolyte turbid liquid tank 404 is blocked with a flow plug 406 to prevent the electrolyte 405 from flowing out; and the electrolyte nozzle 202 is removed from the cathode electrode clamp 201, and then the electrolyte 405 in the electrolyte clear liquid tank 403 is flowed into the working chamber 7 through the electrolyte delivery pipe 401 under the power provided by the electrolyte supply power device 402, and then the platinum electrode 203 is installed on the cathode electrode clamp 201 to ensure that the electrolyte flowing in will not exceed the end of the platinum electrode 203; finally, the processing power supply 5 is energized, the platinum electrode 203 is used as the cathode, and the NiTi alloy sample 301 is still the anode. The applied voltage is 1.5~1.9V, the dealloying time is 1~5h, and the dealloyed sample is washed with distilled water and dried, and a nickel-free micro-nano pore structure is further generated on the above macro-scale micro-groove surface, such as Figure 3 shown.

[0049] The size of the macro-scale microgrooves prepared by this method is between 100 μm and 500 μm, and the pore size of the nickel-free micro-nanoporous structure is between 50 nm and 300 nm.

[0050] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing a NiTi alloy multi-scale functional surface structure preparation device, characterized in that: The following steps are involved: The NiTi alloy surface layer was electrochemically jet-machined using a NiTi alloy sample as the anode and an electrolyte nozzle as the cathode to obtain a NiTi alloy surface containing macroscale microgrooves. The processed NiTi alloy surface was electrochemically dealloyed using a NiTi alloy sample as the anode and a platinum electrode as the cathode to remove nickel and further generate nickel-free micro-nanoporous structures on the macroscale microgrooved surface. Among them, the preparation method adopts NiTi alloy multi-scale functional surface structure preparation equipment, including a preparation container, a working chamber is provided in the preparation container, an electrochemical system cathode part is arranged at the upper part of the working chamber of the preparation container, and an electrochemical system anode part is arranged at the bottom of the working chamber of the preparation container; the cathode part of the electrochemical system includes an electrolyte nozzle or a platinum electrode as a cathode electrode, and the anode part of the electrochemical system includes a NiTi alloy sample as an anode electrode. The electrolyte nozzle and the NiTi alloy sample are combined to perform electrochemical jet processing, and the platinum electrode and the NiTi alloy sample are combined to perform electrochemical dealloying treatment.

2. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device according to claim 1, wherein: The cathode part of the electrochemical system also includes a cathode electrode clamp, the bottom of the cathode electrode clamp is connected to the electrolyte nozzle or the platinum electrode, the electrolyte nozzle or the platinum electrode is vertically arranged, and the electrolyte nozzle or the platinum electrode is directly above the NiTi alloy sample.

3. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device as claimed in claim 2, characterized in that: The cathode electrode clamp is installed on a mobile platform, which is arranged on the upper part of the working chamber of the preparation container. The mobile platform can move in three dimensions. Driven by the mobile platform, the electrolyte nozzle moves in space to realize electrochemical jet processing of the NiTi alloy surface layer.

4. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device as claimed in claim 2, characterized in that: The cathode electrode clamp is also connected to an electrolyte supply device, and the electrolyte provided by the electrolyte supply device can enter the electrolyte nozzle through the cathode electrode clamp and be sprayed out or directly enter the working chamber.

5. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device as claimed in claim 4, characterized in that: The electrolyte supply device includes an electrolyte clear liquid tank for storing electrolyte, the electrolyte clear liquid tank is connected to the cathode electrode clamp through an electrolyte delivery pipeline, and the electrolyte delivery pipeline is provided with an electrolyte supply power device.

6. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device according to claim 5, characterized in that: An electrolyte turbid liquid tank is provided below the preparation container, and a discharge port is provided at the bottom of the working chamber of the preparation container, which is connected to the electrolyte turbid liquid tank through a pipeline; a flow blocking plug can be provided at the discharge port of the working chamber to block the discharge port.

7. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device according to claim 1, characterized in that: The anode part of the electrochemical system also includes an anode electrode clamp, which clamps the NiTi alloy sample and is fixed to the top of the sample mounting platform. The sample mounting platform is arranged at the bottom of the working chamber of the preparation container; the cathode part of the electrochemical system is connected to the cathode of the processing power supply, the anode part of the electrochemical system is connected to the anode of the processing power supply, and the processing power supply is connected to the voltage and current control device.

8. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device according to claim 1, wherein: The process of electrochemical jet machining is as follows: the electrolyte is supplied to the cathode electrode clamp by the electrolyte supply device, and the electrolyte is sprayed from the electrolyte nozzle; the NiTi alloy sample serves as the anode and the electrolyte nozzle serves as the cathode. The electrolyte nozzle realizes electrochemical jet machining of the NiTi alloy surface layer by moving the mobile platform, and obtains the NiTi alloy surface containing macro-scale microgrooves according to the preset pattern.

9. The method for preparing a NiTi alloy multi-scale functional surface structure preparation device according to claim 1, wherein: The electrochemical dealloying process is as follows: the electrolyte nozzle is removed from the cathode electrode clamp, and the electrolyte is supplied to the cathode electrode clamp by the electrolyte supply device, flowing into the working chamber, and then the platinum electrode is installed on the cathode electrode clamp, and it is ensured that the electrolyte does not cover the end of the platinum electrode; the platinum electrode is used as the cathode and the NiTi alloy sample is used as the anode. Voltage is applied, and by removing the nickel element, a nickel-free micro-nanopore structure is further generated on the above macro-scale microgroove surface.

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