Porous material polishing system, polishing method, and metal powder cryogenic deoxidation method

Abstract

The present application relates to the technical field of porous materials, and particularly relates to a porous material polishing system, a polishing method and a low-temperature oxygen removal method of metal powder, the porous material polishing system comprising a reactor, a cooling device, an ultrasonic device, a magnetic stirring device, a power supply device and an automatic control module. The system combines anodic oxidation and ultrasonic technology, uses the anodic oxidation principle to form an oxide film on the surface of the internal structure of the porous material, due to the unevenness of the oxide film, the surface of the porous material forms a layer of imperfect and crack-characteristic surface brittle shell after repeated breakdown for a long time, then the ultrasonic device is used to break the shell through specific frequency ultrasonic and make it brittle to fall off under low-frequency vibration, complete the stripping of the residual powder on the surface of the internal channel of the porous material, realize the polishing effect of high uniformity and smoothness in mesoscale, and enhance the biocompatibility without sacrificing the mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of porous materials, in particular to a porous material polishing system, a polishing method and a low-temperature oxygen removal method of metal powder. BACKGROUND

[0002] The emergence of additive manufacturing makes it possible to customize 3D printed implant design and preparation, especially the porous structure (or lattice structure) in the implant, which can only be prepared by additive manufacturing methods.

[0003] Through additive manufacturing methods such as SLM (Selective Laser Melting), EBM (Electron Beam Melting), etc., which are based on powder raw materials and are stacked layer by layer by selective melting, the surface of the metal 3D printed implant prepared contains a large amount of un-melted powder and loose powder, which is strongly or weakly combined with the surface of the implant, which is caused by the adsorption and adhesion of the molten pool periphery during the 3D printing process, which is affected by the molten pool heat affected zone. The current residual powder cleaning is carried out by dust collector, high-pressure air gun, ultrasonic cleaning, etc., and the polishing means such as mechanical polishing, mechanical polishing, magnetic fluid polishing, magnetic needle polishing, plasma polishing and laser polishing are used for processing.

[0004] However, the existing polishing technology can only meet the polishing of the outer surface of the implant, and the price is relatively high, for example, mechanical polishing requires a senior mechanic to spend a lot of time; for example, the plasma polishing equipment is extremely expensive, etc., and the pore size of the porous structure is between 200-500 μm, and there are various porous structure configurations with complex internal topological morphology. The existing polishing equipment and means cannot effectively polish the internal surface of the porous structure, and it is more difficult to strip the residual powder that is not completely melted on the surface. The latest research shows that these residual powders that are not stripped may fall off during the use of the implant, and once they fall off, they may be recognized as foreign matter by the immune system, causing macrophages to phagocytize, causing inflammation and even bone absorption around them, which will bring great risk to the application of the implant, and even more may cause medical accidents.

[0005] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0006] In view of the shortcomings of the prior art, the purpose of the present application is to provide a porous material polishing system, a polishing method and a low-temperature oxygen removal method of metal powder, which aims to solve the problem that the existing polishing equipment and means cannot effectively polish the internal surface of the porous structure, and it is more difficult to strip the residual powder that is not completely melted on the surface.

[0007] The technical scheme of the present application is as follows:

[0008] A porous material polishing system, comprising:

[0009] a reactor, wherein the reactor comprises an anodic oxidation cavity, a cathode column and an anode clamp column are arranged in the anodic oxidation cavity;

[0010] a cooling device for cooling the reactor;

[0011] an ultrasonic device arranged at the bottom of the reactor;

[0012] a magnetic stirring device arranged between the reactor and the ultrasonic device;

[0013] a power supply device electrically connected with the cathode column, the anode clamp column, the cooling device, the ultrasonic device and the magnetic stirring device respectively;

[0014] an automatic control module electrically connected with the power supply device.

[0015] The porous material polishing system, wherein the cooling device comprises a circulating box, a plurality of circulating fans arranged at the side of the circulating box, a heat exchanger and a condenser pipe arranged around the reactor; the condenser pipe, the heat exchanger and the circulating box are connected by pipes.

[0016] The porous material polishing system, wherein the cooling device further comprises a circulating pump for realizing the circulation of the liquid in the condenser pipe and the liquid in the heat exchanger with the liquid in the circulating box respectively.

[0017] The porous material polishing system, wherein the outer periphery of the circulating box is provided with a circulating air duct; the circulating air duct is provided with a plurality of circulating air openings, and a plurality of the circulating fans are arranged at part of the circulating air openings.

[0018] The porous material polishing system, wherein the reactor further comprises a reactor sealing cover; the reactor sealing cover is provided with a first through hole and a second through hole, and the cathode column and the anode clamp column are arranged through the first through hole and the second through hole respectively.

[0019] The porous material polishing system, wherein the magnetic stirring device comprises a constant temperature magnetic stirrer arranged between the reactor and the ultrasonic device and a magnetic stirring sub arranged in the reactor.

[0020] The porous material polishing system, wherein the power supply device comprises a direct current stabilized power supply and an alternating current power supply; the positive electrode of the direct current stabilized power supply is connected with the anode clamp column, and the negative electrode of the direct current stabilized power supply is connected with the cathode column; the alternating current power supply is used for supplying power to the cooling device, the ultrasonic device and the magnetic stirring device.

[0021] A polishing method based on a porous material polishing system, comprising the steps of:

[0022] Fixing the porous material by using an anode clamping column, starting a magnetic stirring device and setting an anodization parameter;

[0023] After the porous material completes anodization, starting an ultrasonic device to perform ultrasonic treatment;

[0024] After completing the ultrasonic treatment, a smooth porous material is obtained.

[0025] The polishing method, wherein the anodization parameter comprises: a power supply voltage of 100V-300V, a power supply current of 0.3A-2A, and a power of 30W-600W.

[0026] The polishing method, wherein the ultrasonic treatment has a sound wave frequency of 25kHz-40kHz, and the ultrasonic treatment has a sound wave application duration of 30min-60min.

[0027] A preparation method of a nano-structured film based on a porous material polishing system, comprising the steps of:

[0028] Fixing a surface-smoothed substrate by using an anode clamping column, starting a magnetic stirring device and setting an anodization parameter;

[0029] After the surface-smoothed substrate completes anodization, starting an ultrasonic device to perform ultrasonic treatment;

[0030] After completing the ultrasonic treatment, a nano-structured film is obtained.

[0031] A low-temperature oxygen removal method of metal powder based on a porous material polishing system, comprising the steps of:

[0032] Placing metal powder in a reactor, starting a magnetic stirring device and setting an anodization parameter;

[0033] After the metal powder completes anodization, starting an ultrasonic device to perform ultrasonic treatment;

[0034] After completing the ultrasonic treatment, performing separation treatment to obtain micron-sized metal powder.

[0035] Beneficial effects: The application provides a porous material polishing system, a polishing method and a metal powder low-temperature deoxidization method, and the porous material polishing system comprises: a reactor, wherein the reactor comprises an anodic oxidation cavity; a cathode column and an anode clamping column are arranged in the anodic oxidation cavity; a cooling device is arranged for cooling the reactor; an ultrasonic device is arranged at the bottom of the reactor; a magnetic stirring device is arranged between the reactor and the ultrasonic device; a power supply device is electrically connected with the cathode column, the anode clamping column, the cooling device, the ultrasonic device and the magnetic stirring device respectively; and an automatic control module is electrically connected with the power supply device and is used for controlling the power supply power and the power supply time of the power supply device. The system combines anodic oxidation and ultrasonic technology, utilizes the anodic oxidation principle to form an oxide film on the surface of the internal structure of the porous material, and due to the non-uniformity of the oxide film, the oxide film is randomly broken down and nanoscale holes are generated under the action of an electric field; due to the higher electric field strength at the nanoholes, the nanoholes continue to break down, and after a long time of repeated breakdown, a surface brittle shell with imperfect and cracking characteristics is formed on the surface of the porous material; then the ultrasonic device is used to break the shell through specific frequency ultrasonic waves and make the shell brittle and fall off under low-frequency vibration, the adhesion of the powder particles on the surface of the internal channel of the porous material is stripped, the polishing effect of the mesoscale highly uniform and smooth surface is realized, and the mechanical properties are not sacrificed while the biocompatibility is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of the porous material polishing system of the application;

[0037] Figure 2 It is a sectional structure schematic diagram of the porous material polishing system of the application;

[0038] Figure 3 It is a principle demonstration diagram of realizing the polishing of the porous material by using the porous material polishing system;

[0039] Figure 4 It is a flowchart schematic diagram of preparing a nanostructure film on a smooth plane based on the porous material polishing system;

[0040] Figure 5 It is a flowchart schematic diagram of preparing a nanostructure film on a smooth curved surface based on the porous material polishing system;

[0041] Figure 6 It is a flowchart schematic diagram of preparing nano-scale metal oxide particles based on the porous material polishing system;

[0042] Figure 7 It is a principle schematic diagram of preparing nano-scale metal oxide particles based on the porous material polishing system;

[0043] Figure 8Electrical field distribution schematic diagram for common reactor

[0044] Figure 9 Electrical field distribution schematic diagram for powder deoxidization treatment reactor

[0045] Figure 10 Structure schematic diagram for porous arched platinum plate and porous arched graphite plate

[0046] Figure 11 SEM diagram of porous titanium sheet before polishing treatment in Example 1

[0047] Figure 12 SEM diagram of porous titanium sheet after polishing treatment in Example 1

[0048] Figure 13 SEM diagram of nanoscale coating prepared on the surface of the flat sample in Example 2

[0049] Figure 14 SEM diagram of nanostructured film formed after the nanoscale coating falls off in Example 2

[0050] Figure 15 SEM diagram of sample substrate after the nanostructured film is removed in Example 2

[0051] Figure 16 Surface topography diagram of printed porous TC4 sample before anodic oxidation treatment in Example 3

[0052] Figure 17 Surface topography diagram of printed porous TC4 sample after anodic oxidation treatment in Example 3

[0053] Figure 18 Surface topography diagram of printed porous TC4 sample after polishing treatment in Example 3

[0054] Figure 19 Surface topography detail diagram of printed porous TC4 sample after polishing treatment in Example 3

[0055] Figure 20 SEM diagram of nanoscale metal oxide particles prepared in Example 4

[0056] Figure 21 SEM diagram of micrometer scale metal powder with low oxygen content or thin oxide layer formed after separating the nanoscale oxide tortoise-like brittle shell and nanoscale metal oxide particles in Example 4

[0057] Explanation of reference numerals: reactor 10, cathode column 11, anode clamp column 12, reactor sealing cover 13, cooling device 20, circulating box 21, circulating fan 22, condenser tube 23, circulating pump 24, ultrasonic device 30, magnetic stirring device 40. DETAILED DESCRIPTION

[0058] The present application provides a porous material polishing system, a polishing method and a metal powder low-temperature deoxidization method. In order to make the purpose, technical scheme and effect of the present application more clear and definite, the present application is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0059] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood as having meanings consistent with those in the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as such.

[0060] The residual powder in the internal structure of the porous material may fall off during the use of the implant, causing phagocytosis by macrophages, inflammation and even bone resorption around them, which will bring great risk to the application of the implant, and may even cause medical accidents. The wide application of 3D printing customized medical implants, especially titanium-based implants, must have reliable polishing technology for the internal structure of the porous structure as a health and safety guarantee.

[0061] Based on this, as shown in the present application, a porous material polishing system is provided, comprising: Figures 1-2 A reactor 10, the reactor 10 comprising an anodic oxidation cavity; a cathode column 11 and an anode clamp column 12 are arranged in the anodic oxidation cavity;

[0062] A cooling device 20 for cooling the reactor 10;

[0063] An ultrasonic device 30 arranged at the bottom of the reactor 10;

[0064] A magnetic stirring device 40 arranged between the reactor 10 and the ultrasonic device 30;

[0065] A power supply device electrically connected with the cathode column, the anode clamp column, the cooling device, the ultrasonic device and the magnetic stirring device respectively;

[0066] An automatic control module electrically connected with the power supply device.

[0067]

[0068] ​In the embodiment, the porous material polishing system combines anodic oxidation and ultrasonic technology, utilizes the anodic oxidation principle to make the porous material undergo an anodic oxidation reaction in the reactor, simultaneously utilizes a magnetic stirring device for stirring, and a cooling device for cooling the reactor, so that an oxide film is formed on the internal structure surface of the porous material, due to the non-uniformity of the oxide film, the oxide film is randomly broken down under the action of an electric field and nanoscale holes are generated, due to the higher electric field strength at the nanoholes, the nanoholes continue to break down, after a long time of repeated breakdown, a "crack" shaped surface shell is formed on the surface of the porous material, then the ultrasonic device is utilized to shake and break the porous material after anodic oxidation at a low frequency, the adhesion of powder particles on the surface of the internal channel of the porous material is stripped, and a polishing effect of a mesoscale highly uniform and smooth surface is realized.

[0069] Moreover, after a long time of repeated breakdown, a layer of imperfect and crack-characterized surface brittle shell is formed on the surface of the porous material, which is very fine, generally at the level of tens of microns in particle size, and will drive the free powder, weakly combined surface ball powder or microdefects attached during the formation to be simultaneously brittlely stripped, and the strong combined boundaries nearby are cracked and stripped, so that a layer of strong combined and large-area continuous micro-smooth surface is obtained, and the specific shell structure and crack lines formed will leave a micro-nano continuous structure with fine lines after stripping, effectively reducing the surface defects of the porous material, improving the surface quality, completing the removal of residual powder on the internal channel surface of the porous material, realizing the polishing effect of a mesoscale highly uniform and smooth surface, and enhancing the biocompatibility while not sacrificing the mechanical properties.

[0070] The present application utilizes the porous material polishing system to realize the polishing of the surface of the porous material, and the principle is as follows Figure 3As shown, taking the local porous structure of the surface with two protruding weakly bonded spherical powders as an example, after the anodization process treatment of the porous material polishing system, a high brittle crack-like oxide shell is formed on the surface, and then it is crushed by special frequency ultrasonic treatment. The brittle fracture is accompanied by the detachment of the attached bonding part, and the surface with strong bonding performance is exposed. The broken object is far smaller than the pore size of the porous structure, and then it is vibrated out of the porous structure pores with liquid. Through scanning electron microscopy (SEM) observation, it is found that the oxide shell formed is composed of nanoscale rod-shaped / hexagonal-shaped / random-shaped structure micro-units arranged closely, and the broken object is a sub-nanometer fragment combined by several units. At the same time, it is found that the strong bonding surface after detachment still retains the root structure of the nanoscale structure during growth, that is, it has a continuous nanowire or nanosurface texture with a size of 300-900 nanometers. The nanoscale texture has the advantages of increasing biocompatibility, promoting cell proliferation, increasing surface adhesion and attachment during physical vapor deposition and chemical vapor deposition, etc.

[0071] In some embodiments, the cooling device 20 comprises a circulating box 21, a plurality of circulating fans 22 arranged on the side of the circulating box 21, a heat exchanger, and a condensing pipe 23 arranged around the reactor 10; the condensing pipe 23 is connected to the circulating box 21 through a pipeline. By using the condensing pipe around the tank wall of the reactor and the circulating box connected to the condensing pipe through the pipeline, the reactor can be cooled by water cooling, and the cathode column and the anode column do not contact the condensing pipe. At the same time, the heat exchanger is combined to realize the heat exchange of the reactor and the heat dissipation of the circulating box by the circulating fan, thereby improving the condensing effect.

[0072] Specifically, the condensing pipe is a copper pipe arranged around the inner wall of the reactor in a "spring structure", which improves the condensing effect of the reactor.

[0073] In some embodiments, the cooling device 20 further comprises a circulating pump 24 for realizing the circulation of the liquid in the condensing pipe 23 and the liquid in the heat exchanger with the liquid in the circulating box 21, respectively. By using the circulating pump, the circulation flow rate of the liquid in the circulating box with the liquid in the condensing pipe and the liquid in the heat exchanger can be enhanced, so that the condensing effect is better, and the purpose of cooling the reactor is achieved.

[0074] In some embodiments, the liquid in the condensing pipe can be, but is not limited to, water, coolant, and other liquids that can achieve the condensing effect.

[0075] In some embodiments, the outer periphery of the circulating box 21 is provided with a circulating air duct; the circulating air duct is provided with a plurality of circulating air ports, and a plurality of circulating air fans 22 are arranged at part of the circulating air ports.

[0076] Specifically, the outer edge of the circulating box is wrapped with a shell, a gap is left between the shell and the circulating box to form a circulating air duct, and the circulating air duct is formed by opening the shell to obtain a circulating air port, wherein part of the circulating air ports are provided with the circulating air fan, and the circulating air fan is used to replace the hot air in the circulating air duct with the cold air from the outside atmosphere to improve the condensation effect of the reactor.

[0077] In a preferred embodiment, the circulating box adopts a multi-layer channel structure, which increases the cold and heat exchange area to make the cooling device work more efficiently; and the circulating air fan is arranged at the mutually symmetrical circulating air ports to avoid air flow disorder.

[0078] In some embodiments, the reactor 10 further comprises a reactor sealing cover 13; the reactor sealing cover 13 is provided with a first through hole and a second through hole, and the cathode column 11 and the anode clamping column 12 are arranged through the first through hole and the second through hole respectively. The first through hole and the second through hole can be used to fix the cathode column and the anode clamping column, and the connection between the cathode column 11 and the anode clamping column 12 and the first through hole and the second through hole is provided with a rubber sealing ring to improve the sealing performance of the reactor.

[0079] In some embodiments, the materials of the reactor 10 and the reactor sealing cover 13 are both polytetrafluoroethylene.

[0080] In some embodiments, a temperature sensor (not shown in the figure) is arranged in the reactor 10 to monitor the temperature in the reactor.

[0081] In some embodiments, the magnetic stirring device comprises a constant-temperature magnetic stirrer arranged between the reactor and the ultrasonic device and a magnetic stirring sub arranged in the reactor. The constant-temperature magnetic stirrer and the magnetic stirring sub can be used to stir the solution in the reactor, accelerate the anodization rate, and shorten the polishing time.

[0082] In some embodiments, the power supply device (not shown in the figure) comprises a direct-current stabilized power supply and an alternating-current power supply; the positive electrode of the direct-current stabilized power supply is connected with the anode clamping column, and the negative electrode of the direct-current stabilized power supply is connected with the cathode column; and the alternating-current power supply is used to supply power to the cooling device, the ultrasonic device, and the magnetic stirring device.

[0083] In addition, the application further provides a polishing method based on the porous material polishing system, which comprises the following steps:

[0084] Step S10: fixing the porous material by using an anode clamp column, starting a magnetic stirring device and setting an anodization parameter;

[0085] Step S20: after the porous material is anodized, starting an ultrasonic device to perform ultrasonic treatment;

[0086] Step S30: after the ultrasonic treatment is completed, a smooth porous material is obtained.

[0087] In the embodiment, the polishing method combines anodization and ultrasonic technology. After the porous material is fixed by using an anode clamp column, a magnetic stirring device is started and an anodization parameter is set, the porous material is subjected to an anodization reaction in a reactor by using an anodization principle, and the reactor is cooled by using a cooling device, so that an oxide film is formed on the internal structure surface of the metal or alloy porous material. Due to the non-uniformity of the oxide film, the oxide film is randomly broken down and nanoscale holes are generated under the action of an electric field. Due to the higher electric field strength at the nanoholes, the nanoholes continue to break down. After a long time of repeated breakdown, a “cracked” surface shell is formed on the surface of the porous material. Then, the ultrasonic device is used to perform ultrasonic crushing treatment on the anodized porous material, so that the “cracked” surface shell is detached, the adhesion of the powder particles on the internal channel surface of the porous material is peeled off, and a mesoscale highly uniform and smooth polishing effect is achieved. Moreover, the polishing method is simple to operate and environmentally friendly.

[0088] In some embodiments, the anodization parameter includes a power supply voltage of 100V-300V, a power supply current of 0.3A-2A, and a power of 30W-600W. Controlling the anodization parameter in this range can form a “cracked” surface shell on the internal structure surface of the porous material, and the surface shell includes a soft thin layer and a hard thin layer. The soft thin layer has a thickness of 1-10pm, and the hard thin layer has a thickness of 10-50pm. The “cracked” surface shell is more easily detached when performing ultrasonic crushing treatment.

[0089] In some embodiments, the ultrasonic treatment has a sound wave frequency of 25kHz-40kHz, and the sound wave application time of the ultrasonic treatment is 30min-60min. Under this ultrasonic treatment parameter, the “cracked” surface shell can be effectively crushed to obtain a smooth porous material.

[0090] In some embodiments, the magnetic stirring parameter of the magnetic stirring device is 0-2500r / min.

[0091] In some embodiments, in step S10, after the porous material is fixed by using an anode clamp column, a magnetic stirring device is started and an anodization parameter is set, the cooling device is turned on, and the temperature of the anodization reaction is controlled at about 40℃.

[0092] In addition, the application further provides a preparation method of a nano-structured film based on a porous material polishing system, comprising the steps of:

[0093] Step S100: fixing a substrate with a smooth surface by using an anode clamping column, starting a magnetic stirring device and setting an anodization parameter;

[0094] Step S200: after the anodization of the substrate with the smooth surface is completed, starting an ultrasonic device to perform ultrasonic treatment;

[0095] Step S300: obtaining a nano-structured film after the ultrasonic treatment is completed.

[0096] In the embodiment, a nano-scale easy-to-crack shell layer can be formed on the metal surface by combining anodization and ultrasonic technology, and the shell layer can be cracked by ultrasonic vibration; as shown in Figure 4 and Figure 5 by adjusting the process, a nano-scale coating with a specific shape (such as a hexagon or a circular tube) can be obtained by treating a smooth plane or a curved surface with a specific shape, and the nano-structured layer can be peeled off by means of adhesive film adhesion, specific frequency ultrasonic vibration, etc., so as to form a film with a nano structure, and therefore the porous material polishing system can also be used for the preparation of a nano film.

[0097] In addition, the application further provides a low-temperature oxygen removal method of metal powder based on a porous material polishing system, comprising the steps of:

[0098] Step SS10: placing metal powder in a reactor, starting a magnetic stirring device and setting an anodization parameter;

[0099] Step SS20: after the anodization of the metal powder is completed, starting an ultrasonic device to perform ultrasonic treatment;

[0100] Step SS30: after the ultrasonic treatment is completed, performing separation treatment to obtain micron-scale metal powder.

[0101] In the embodiment, the polishing of the porous material is realized by combining anodization and ultrasonic technology, and by-products are formed, such as Figure 6As shown, the byproduct is a perfect spherical nanometer metal oxide with a particle size of 200-800 nm; the formation principle is: under the action of high-voltage electric field breakdown, fine particles with nanometer size are released, and under the action of magnetic stirring, the fine particles carry negative charges on the surface when they are transported to the vicinity of the cathode, and then rotate and stir to the vicinity of the anode, the metal cations in the reaction solution obtain electrons to form elements and are affected by the anode oxidation to form oxides rapidly, and so on, gradually forming nanometer metal oxide particles with a perfect spherical degree.

[0102] Specifically, the technology combining anode oxidation and ultrasonic waves can be used for removing the oxide film of metal powder / microsphere and deoxidizing; generally, the high oxygen content of metal powder is mainly caused by the oxide film formed on the outer layer, and obviously, the above principle can also be used to remove the oxide layer of metal powder, thereby greatly reducing the oxygen content; for example, Figure 7 As shown, the metal powder can be directly placed in the reaction liquid in the reactor and mixed together, and the metal powder follows the liquid flow migration movement in the magnetic stirring process, and is constantly converted under the action of anode electric field and cathode electric field, and gradually forms a sphere with a high brittle oxide shell, and then is broken and falls off by a specific ultrasonic frequency, and then is separated, and since the size of the broken fragments is much smaller than the particle size of the original powder sphere (diameter distribution of the powder), the metal powder with low oxygen content or thin oxide layer can be separated by screening or water flow or micro wind field; wherein, the electric field distribution schematic diagram of the ordinary reactor and the electric field distribution schematic diagram of the powder deoxidation treatment reactor are shown in Figure 8 and Figure 9 .

[0103] In some embodiments, in the step SS30, the separation treatment includes: separating by screening, water flow or micro wind field to obtain micron metal powder with low oxygen content or thin oxide layer.

[0104] In some embodiments, in order to expand the influence range of the cathode and anode electric field and improve the treatment efficiency, the cathode column and anode column are replaced by a porous arched platinum plate and a porous graphite plate, as shown in Figure 10 .

[0105] The following further examples are used to illustrate the present application in detail. It should also be understood that the following examples are only used to further illustrate the present application, and cannot be understood as limiting the scope of protection of the present application, and some non-essential improvements and adjustments made by those skilled in the art according to the above content of the present application are within the scope of protection of the present application.

[0106] Example 1

[0107] The porous titanium sheet is fixed by an anode clamp, and a magnetic stirring device and a cooling device are started, and an anodizing parameter is set, wherein the anodizing parameter is that the power supply voltage is 120 V, the power supply current is 0.7 A, and the power is 70 W.

[0108] After the anodization of the porous titanium sheet is completed, an ultrasonic device is started to perform ultrasonic crushing treatment, the ultrasonic treatment has a sound wave frequency of 30 kHz, and the ultrasonic treatment has a sound wave application time length of 50 min; after the ultrasonic treatment is completed, a smooth porous material is obtained.

[0109] The smooth porous material treated by polishing in this embodiment is characterized, the SEM image of the porous titanium sheet before polishing treatment is as shown in Figure 11 , and the SEM image after polishing treatment is as shown in Figure 12 , as can be seen from the figures, the porous titanium sheet treated by the polishing method based on the polishing system of the porous material has a smooth surface.

[0110] Embodiment 2

[0111] This embodiment provides a nanostructured film prepared based on a polishing system of a porous material, and the preparation steps are as follows:

[0112] 1. TC4 material with a size of 10 mm x 10 mm x 2 mm is selected, polished to 200 mesh, and then sequentially cleaned with acetone, alcohol and deionized water for 10 min;

[0113] 2. The cleaned TC4 material is used as an anode and placed in an ammonium fluoride-based electrolyte (0.5wt% ammonium fluoride, 94v% ethylene glycol and 6v% deionized water), and anodized under the conditions of constant voltage 90 V and magnetic stirring speed 800 rpm, the whole process is cooled and the electrolyte temperature is maintained below 40℃, and the anodizing time is 60 min;

[0114] 3. After the oxidation is completed, an ultrasonic device is started to perform ultrasonic treatment, then deionized water is used for simple cleaning and drying treatment in an electric heating air drying oven, at this time a nano-scale coating with a long thickness is prepared on the surface of the flat sample, and the SEM image is as shown in Figure 13 ;

[0115] A scanning electron microscope (SEM, Merlin, Germany) is used to observe the surface morphology of the TC4 sample after oxidation under an acceleration voltage of 5 kV, as shown in Figure 13 , many honeycomb-shaped TiO2 nanotubes are attached to the surface of the TC4 after oxidation, and some nanotubes can also be seen falling off. Through the ultrasonic vibration falling method, the nanostructure layer can be made to fall off, thereby forming a film with a honeycomb-shaped nanostructure, and the film is as shown in Figure 14The system can also be used to prepare nanometer thin films. In addition, after the thin film is removed, the sample substrate also presents a flat honeycomb nanometer structure morphology, as shown in Figure 15

[0116] Example 3

[0117] The embodiment provides a polishing method based on a porous material polishing system, and specific steps are as follows:

[0118] 1. A 3D printed 10mmx10mmx4mm porous TC4 material is selected, the porous structure is gyriod, the unit cell is 2.5, and the porosity is 70%; the 3D printed porous TC4 material is sequentially cleaned with alcohol and deionized water for 20 minutes through ultrasonic cleaning of the polished sample, so as to remove some loose powder and satellite powder as much as possible;

[0119] 2. The cleaned 3D printed porous TC4 material is used as an anode and is placed in an ammonium fluoride electrolyte (0.5wt% ammonium fluoride, 94v% ammonium fluoride and 6v% deionized water), and anodic oxidation is performed under the conditions of constant voltage 90V and magnetic stirring speed 800rpm, the whole process is cooled and the electrolyte temperature is maintained below 40℃, and the anodic oxidation time is 60 minutes;

[0120] 3. After the oxidation polishing is completed, the polished sample is placed in a low-frequency ultrasonic machine of 25KHz, and is simply cleaned with deionized water for 20 minutes through ultrasonic cleaning, and then is dried in an electric heating air drying box, at this time, the nanotubes grown on the pore wall are completed to fall off, and some nanostructures are formed.

[0121] A scanning electron microscope (SEM, Merlin, Germany) is used to observe the surface morphology of the 3D printed porous TC4 sample before and after anodic oxidation treatment under an acceleration voltage of 5kV. As shown in Figure 16 As shown in Figure 17 , the porous TC4 material after oxidation polishing, the low magnification can obviously see that part of the residual powder has been removed, and the pore wall surface is attached with many honeycomb nanometer TiO2 nanotubes and some fallen nanotubes. Through subsequent low-frequency ultrasonic, a large amount of residual powder in the pore wall and the pore is fallen, and some nanometer structures are formed on the wall surface, and the structure morphology is as shown in Figure 18 and Figure 19 ​As shown, the original rough surface with a large amount of residual powder is transformed into an active surface with lower roughness and micro / nano structures. This surface structure can effectively promote osteoblast proliferation, osteogenic mineralization, and accelerate bone tissue healing and growth. Furthermore, the porous material polishing system exhibits three micro / nano structures: spherical particles, after being shaken to remove the surrounding nanotubes, form a morphology similar to a "vertebra"; the unmelted powder protrusions exhibit a "golf ball surface pit" morphology; and the smooth front or side surfaces form a "honeycomb or honeycomb serrated" morphology.

[0122] Example 4

[0123] This embodiment also provides a low-temperature deoxidation method for metal powder based on a porous material polishing system, including the following steps:

[0124] 1. Place the metal powder in the reactor, start the magnetic stirrer and set the anodizing parameters;

[0125] 2. After the metal powder has undergone anodizing, an ultrasonic device is activated to perform ultrasonic treatment and obtain nanoscale metal oxide particles;

[0126] 3. After ultrasonic treatment, the particles are separated by sieving, or by water flow or a micro-wind field to obtain micron-sized metal powder with low oxygen content or a thin oxide layer.

[0127] The result is as follows Figure 20 As shown, under low magnification, a layer of oxide can be seen around the original powder; under high magnification, the nanoscale metal oxide particles obtained in this embodiment can be seen, with a particle size between 400 and 800 nm. Combined with... Figure 9 The diagram illustrates that during the anodizing process, when the powder is at the anode, a nano-oxide shell forms on its surface under the influence of an electric field. When the powder is at the cathode, it will not participate in the chemical reaction that forms the oxide film, but may instead corrode under specific electrolyte conditions, leading to its detachment. Finally, under magnetic stirring, the back-and-forth collisions of the powder and the nano-oxide shell form nanoscale metal oxide particles. The growth mechanism of the powder nano-oxide shell may involve field-assisted plastic flow or field-assisted dissolution, depending on the type of electrolyte and water content. During anodizing, the applied potential and electrolyte composition are key factors determining the size of the nanoparticles.

[0128] like Figure 21 As shown, the micron-sized metal powder with low oxygen content or a thin oxide layer obtained in this embodiment has a nano-pitted structure formed on its surface after ultrasonic vibration removes the brittle, tortoise-shell-like shell of nano-oxide and nano-metal oxide particles. The formation of this nano-pitted structure is attributed to two points: firstly, the removal of the nano-oxide shell leads to the formation of a honeycomb-like pitted structure in the powder, the principle of which is similar to...Figure 3 The same; furthermore, the nano-sized metal oxide particles under the action of the magnetic fluid collide with the powder, and the concave structure is also formed. The low content of the powder is that the powder is further crushed and separated by a specific ultrasonic frequency. Since the size of the crushed fragments is much smaller than the particle size of the original powder ball (diameter distribution of the powder), the separation can be performed by screening, or by water flow or micro-wind field, to obtain a metal powder with low oxygen content or a thin oxide layer.

[0129] In summary, the present application provides a porous material polishing system, a polishing method and a metal powder low-temperature deoxidation method. The porous material polishing system comprises a reactor, the reactor comprising an anodic oxidation cavity; a cathode column and an anode clamping column are arranged in the anodic oxidation cavity; a cooling device is used to cool the reactor; an ultrasonic device is arranged at the bottom of the reactor; a magnetic stirring device is arranged between the reactor and the ultrasonic device; a power supply device is electrically connected with the cathode column, the anode clamping column, the cooling device, the ultrasonic device and the magnetic stirring device. The system combines anodic oxidation and ultrasonic technology. The anodic oxidation principle is used to form an oxide film on the surface of the internal structure of the porous material. Due to the unevenness of the oxide film, random breakdown occurs under the action of the electric field and nanoscale holes are generated. Due to the higher electric field strength at the nanohole, the nanohole continues to break down. After a long time of repeated breakdown, a “cracked” surface shell is formed on the surface of the porous material. Then, the ultrasonic device is used to perform ultrasonic crushing, the adhesion of the powder particles on the surface of the internal channel of the porous material is stripped, and a mesoscale highly uniform and smooth polishing effect is achieved.

[0130] It should be understood that the application of the present application is not limited to the above examples. Those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A polishing method based on a porous material polishing system, characterized by, The specific steps are as follows: A 3D-printed porous TC4 material with a size of 10 mm*10 mm*4 mm is selected, the porous structure is a helical dodecahedron, the unit cell is 2.5, and the porosity is 70%; the 3D-printed porous TC4 material is ultrasonically cleaned with alcohol and deionized water for 20 min in sequence; The cleaned 3D-printed porous TC4 material is used as an anode and is placed in an ammonium fluoride electrolyte, and anodic oxidation is carried out under the conditions of a constant voltage of 90 V and a magnetic stirring speed of 800 rpm, the whole oxidation process is cooled, the electrolyte temperature is maintained below 40℃, and the anodic oxidation time is 60 min; After the polishing is completed, the polished sample is placed in a low-frequency ultrasonic machine at 25 KHz, and is simply ultrasonically cleaned with deionized water for 20 min, and then is dried in an electric heating air drying oven, to complete the polishing of the porous material; The polishing system of the porous material comprises: a reactor, the reactor comprising an anodic oxidation cavity; a cathode column and an anode clamping column are arranged in the anodic oxidation cavity; a cooling device for cooling the reactor; an ultrasonic device arranged at the bottom of the reactor; a magnetic stirring device arranged between the reactor and the ultrasonic device; a power supply device electrically connected with the cathode column, the anode clamping column, the cooling device, the ultrasonic device and the magnetic stirring device respectively; an automatic control module electrically connected with the power supply device.

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