Method for preparing high-melting ultrafine nanoparticles by laser-induced heating

Abstract

The application belongs to the technical field of nanometer materials, and particularly relates to a laser induction heating combined preparation method for high-melting-point superfine nanoparticles. The high-melting-point superfine nanoparticles are titanium, tantalum, niobium metal materials or metal oxides with a particle size of 10 nm to 20 nm. The laser induction heating combined preparation method is to ablate a metal material block subjected to pre-treatment by induction heating by using a laser under an argon or air atmosphere, and to initiate a high-temperature gas-solid phase reaction. The high-melting-point metal superfine nanoparticles are collected by blowing in argon, the metal oxide superfine nanoparticles are collected by blowing in air, and then the collected nanoparticles are washed, frozen and dried to obtain the nanoparticles. The application solves the problems of existing fine-particle powder, such as difficult preparation, low powder yield and high content of other impurities. The application has the advantages of simple preparation operation, good biocompatibility, green and environment-friendly and non-toxic materials, and is suitable for the fields of biomedicine and the like.

Description

Technical Field

[0001] This invention belongs to the field of metal nanomaterials technology, and specifically relates to a method for preparing high-melting-point ultrafine nanoparticles using laser induction heating. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Research in the field of ultrafine nanoparticles shows that when solid materials are nanoscaled, their melting points decrease significantly, especially when the particles are on the order of 10 nm. Due to their small size and high specific surface free energy, nanoparticles have a much higher chemical potential than bulk solids under the same conditions. This results in significantly lower melting points and sintering temperatures compared to bulk solids of the same material, and the smaller the particle size, the lower the melting point and sintering temperature. For example, the conventional melting point of gold is 1064 °C; when the particle size is reduced to 10 nm, it decreases by 27 °C, and the melting point at 2 nm is only around 327 °C. Adding 0.1%–0.5% ultrafine nickel particles to tungsten particles can lower the sintering temperature from 3000 °C to 1200–1300 °C.

[0004] Porous metal implant alloys used in bone repair include cobalt-chromium alloys, stainless steel, aluminum, and titanium alloys. These alloys possess advantages such as light weight, high strength, and good biocompatibility. Porous structures can improve surface bioactivity, wear resistance, and anticoagulation properties. High-melting-point metals such as tantalum and niobium exhibit low elastic modulus, corrosion resistance, excellent bone integration properties, biocompatibility, tissue inward growth characteristics, and high surface friction. Clinical studies have validated the application of porous tantalum implants in various clinical settings; the porous tantalum structure promotes cell adhesion, proliferation, differentiation, and even early biological fixation. Ultrafine-grained metal nanoparticles used in laser 3D printing require uniform composition, narrow particle size distribution, low oxygen content, high sphericity, and good flowability. However, the melting points of high-melting-point metals such as tantalum exceed 3000℃, making them unsuitable for most commercially available 3D printing equipment. Domestic research on refractory ultrafine nanoparticles for laser 3D printing is limited. The main difficulties in preparing ultrafine nanoparticles include uneven particle size, low yield, and high oxygen and other impurity content.

[0005] Conventional methods for preparing metal powders mainly include physical and chemical methods. Physical methods include high-energy ball milling, vapor deposition synthesis, and atomization; chemical methods include gas-phase chemical reduction, organometallic compound thermal decomposition, hydrothermal methods, and electrolysis. However, these methods require sophisticated production equipment, result in uneven particle distribution and irregular morphology, and are particularly difficult to controllably prepare ultrafine nanoparticles of high-melting-point metals. Laser methods use a laser as a heat source to induce a gas-solid phase reaction. Through the absorption of laser energy and collisional heat transfer, the metal solid instantly reaches its vaporization temperature and completes the reaction process of light absorption, vaporization, nucleation, and growth. The laser beam has the highest power density at the focal point, but the spot size is generally small, relying on the precise focusing and positioning of the laser beam by the processing equipment. Therefore, selecting a reasonable focal position and defocusing amount on the workpiece surface is crucial to ensuring a stable high-temperature reaction field near the laser spot, guaranteeing high yield and uniformity of nanoparticles. Heating the entire raw material workpiece can significantly improve the uniformity of the surface temperature field.

[0006] Induction heating is essentially similar to the Joule heating effect. The current used to heat the material is generated through electromagnetic induction, making it a non-contact heating process. Induction heating is fast, allowing the workpiece to reach the required temperature in a very short time, resulting in minimal surface oxidation and decarburization. The heating equipment is easy to integrate and install, convenient to use, simple to operate, and can be turned on or off at any time without the need for preheating.

[0007] The paper "Preparation Technology and Application of (Nano) Powder by Laser-Induction Composite Heating Method" discloses the technical principle of preparing (nano) powder by laser-induction composite heating method, but does not cover the preparation of high melting point metal ultrafine nanoparticles. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a method for preparing high-melting-point metal ultrafine nanoparticles using laser technology. This method overcomes the difficulties in preparing fine-particle-size powders, low powder yield, and high content of other impurities found in existing methods. The preparation process of this invention is simple, biocompatible, and the resulting material is green, environmentally friendly, and non-toxic, making it suitable for applications in biomedicine and other fields.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a method for preparing high-melting-point ultrafine nanoparticles using laser-induced heating, comprising:

[0011] High-melting-point metal sheets are cleaned and dried to serve as the metal substrate;

[0012] The metal substrate is placed in an induction heating cavity, and the metal is vaporized and etched by the thermal effect generated by the interaction between the laser and the substrate. The metal vapor is then purged with gas, filtered, and the ultrafine nanoparticles are collected to obtain the final product.

[0013] The high-melting-point metal plate is made of titanium, tantalum, or niobium.

[0014] This invention utilizes a combination of laser and induction heating to induce a high-temperature gas-solid phase reaction in metals. This method ensures optimal particle size, reduces impurity content, and increases yield. It is particularly suitable for synthesizing high-melting-point metal ultrafine nanoparticle powders that are difficult to obtain using conventional methods.

[0015] In some embodiments, the thickness of the high melting point metal sheet is 1.0 mm to 5.0 mm.

[0016] In some embodiments, the cleaning process uses cyclohexane, anhydrous ethanol, and ultrapure water as cleaning agents, and performs ultrasonic cleaning for 15-30 minutes in sequence. Finally, the cleaning process is completed by rinsing with ultrapure water and drying with nitrogen.

[0017] Unlike traditional methods that use laser-induction combined heating to prepare nanoparticles, this invention uses induction heating to provide an electromagnetic field, ensuring that the sputtered particles do not cool down rapidly. The primary action is laser etching of a metal substrate followed by a high-temperature gas-phase in-situ reaction to produce ultrafine nanoparticles. Therefore, in some embodiments, the laser wavelength is 355nm-1064nm, and the pulse width is 0.4ns-20ns. The laser power density is 0.5J / cm². 2 -15.0J / cm 2 The processing time is 5-30 minutes, and the processing area is 1 cm². 2 -20cm 2 To prepare high-melting-point ultrafine nanoparticles.

[0018] In some implementations, the frequency range of induction heating is 40kHz-100kHz, and the heating time is 5min-30min.

[0019] In some embodiments, the gas purging uses high-purity argon or air, with a purging rate ranging from 50 mL / min to 350 mL / min. When high-purity argon is used for purging, the ultrafine metal nanoparticles are collected after filtration through a filter membrane; when air is used, ultrafine metal oxide nanoparticles are collected.

[0020] In some embodiments, the method further includes: dispersing the collected ultrafine nanoparticles in anhydrous ethanol, washing them thoroughly, freeze-drying them, and then sealing and storing them.

[0021] In some implementations, the freeze-drying time is 6-12 hours.

[0022] More specifically, including:

[0023] (1) First, use high melting point metal plates as raw materials, clean the smooth metal plates with cleaning agent to remove organic matter and oil stains on the surface, then blow dry with nitrogen and seal for storage.

[0024] (2) Place the cleaned metal substrate in the induction heating chamber of the reaction device, adjust the laser focal length, set the laser processing parameters, including power density and processing time, set the induction heating parameters, and use the thermal effect generated by the interaction between the laser and the substrate to perform vaporization etching on the metal. The metal vapor is purged by gas, and the cooled ultrafine nanoparticles are collected by filter membrane.

[0025] (3) Disperse the ultrafine nanoparticles collected in step (2) in anhydrous ethanol, wash thoroughly, freeze dry, and then seal and store.

[0026] In a second aspect, the present invention provides high-melting-point ultrafine nanoparticles prepared by the above method, wherein the size range of the high-melting-point ultrafine nanoparticles is 10 nm-20 nm.

[0027] The present invention also provides ultrafine nanoparticles having uses in at least one of the following (1-2):

[0028] (1) As a main component of 3D printing powder raw materials;

[0029] (2) As an auxiliary component of 3D printing powder raw materials.

[0030] A third aspect of the present invention provides the application of the above-mentioned high-melting-point ultrafine nanoparticles in the biomedical field.

[0031] Beneficial effects of the present invention

[0032] (1) The material of the present invention can be used as the main component of 3D printing metal powder raw material alone, or as an auxiliary component of raw material, or can be used to realize a mixture of raw materials.

[0033] (2) The method for preparing ultrafine nanoparticle powder of the present invention is simple, fast, low cost and has good toughness, and is suitable for mass production.

[0034] (3) The high melting point ultrafine nanoparticle powder of the present invention is particularly suitable for 3D printing of porous medical implants.

[0035] (4) Unlike the traditional method of preparing nanoparticles by laser-induction composite heating, this invention uses induction heating to provide an electromagnetic field to ensure that the splashed particles do not cool down quickly. The laser is the main agent, and ultrafine nanoparticles are produced by laser etching of metal plates and high-temperature gas phase in-situ reaction. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0037] Figure 1 Laser induction heating combined processing device, wherein: (1) laser, (2) laser beam membrane, (3) optical window, (4) reaction chamber, (5) gas inlet, (6) gas outlet, (7) bulk raw material, (8) induction heating pipeline system, and (9) powder collection filter membrane.

[0038] Figure 2 X-ray diffraction pattern of titanium nanoparticles.

[0039] Figure 3 Transmission electron microscopy image of titanium nanoparticles.

[0040] Figure 4 X-ray diffraction pattern of niobium nanoparticles.

[0041] Figure 5 Transmission electron microscopy image of niobium nanoparticles.

[0042] Figure 6 X-ray diffraction pattern of tantalum nanoparticles.

[0043] Figure 7 Transmission electron microscopy image of tantalum nanoparticles.

[0044] Figure 8 X-ray diffraction pattern of niobium oxide nanoparticles.

[0045] Figure 9 Transmission electron microscopy image of niobium oxide nanoparticles.

[0046] Figure 10 Raman spectra of niobium oxide nanoparticles.

[0047] Figure 11 X-ray diffraction pattern of tantalum oxide nanoparticles.

[0048] Figure 12 Transmission electron microscopy image of tantalum oxide nanoparticles.

[0049] Figure 13 Raman spectra of tantalum oxide nanoparticles. Detailed Implementation

[0050] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0051] As introduced in the background section, there is limited research on high-melting-point ultrafine nanopowders for laser 3D printing of medical implants, which are difficult to prepare and suffer from problems such as low yield and high content of other impurities.

[0052] Based on this, the purpose of this invention is to provide a laser preparation method for high-melting-point ultrafine nanoparticles. This invention involves laser ablation of an induction-heated metal plate, inducing the metal solid to instantly reach its vaporization temperature, resulting in a gas-solid phase reaction that completes the processes of light absorption, vaporization, nucleation, and growth. This successfully synthesizes some high-melting-point metal ultrafine nanoparticle powders that are difficult to obtain using conventional methods.

[0053] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0054] Example 1

[0055] Taking the preparation of titanium ultrafine nanoparticles using laser induction heating as an example.

[0056] (1) Instruments and related operating conditions

[0057] 1) 1064nm nanosecond pulsed fiber laser (Wuhan Raycus);

[0058] 2) Flow meter (MKS, USA)

[0059] 3) High-purity argon cylinder

[0060] (2) Laser preparation of tantalum ultrafine nanoparticles

[0061] 1) The 3mm titanium plate was ultrasonically treated with cyclohexane, anhydrous ethanol and ultrapure water for 15 minutes in sequence. Finally, it was rinsed with ultrapure water and dried with nitrogen.

[0062] 2) The cleaned titanium plate is placed Figure 1 Inside the cavity of the laser reaction device shown, the induction heating operating frequency is set at 100kHz. After the workpiece is red-hot, a nanosecond pulsed laser with a wavelength of 1064nm is used to ablate the surface of the titanium plate, with a laser power density of 10J / cm². 2 Processing area 5cm 2The processing time was 20 min, and the argon purging rate was 100 mL / min. The collected titanium ultrafine nanoparticles were washed, freeze-dried, and then characterized; their X-ray diffraction patterns were as follows. Figure 2 As shown, the characteristic diffraction peaks observed at 35.08°, 38.39°, 40.16°, 52.98°, and 62.94° of the laser-prepared titanium nanoparticles correspond to the (100), (002), (101), (102), and (110) crystal planes of Ti(PDF#89-3073), respectively. The results indicate that the laser-prepared nanoparticles are pure titanium phase nanoparticles. Simultaneously, transmission scanning electron microscopy images (…) Figure 3 The results show that the particle size is 10nm-20nm, with good uniformity.

[0063] Example 2

[0064] Taking the preparation of niobium ultrafine nanoparticles using laser induction heating as an example.

[0065] (1) Instruments and related operating conditions

[0066] 1) 355nm nanosecond pulsed fiber laser (Coherent Laser, USA);

[0067] 2) Flow meter (MKS, USA)

[0068] 3) High-purity argon cylinder

[0069] (2) Laser preparation of niobium ultrafine nanoparticles

[0070] 1) The 2mm niobium plate was ultrasonicated with cyclohexane, anhydrous ethanol and ultrapure water for 15 minutes in sequence. Finally, it was rinsed with ultrapure water and dried with nitrogen.

[0071] 2) The cleaned niobium plate is placed in the reaction apparatus, and the induction heating frequency is set to 60kHz. After the workpiece is red-hot, a 355nm nanosecond pulsed laser is used for surface ablation, with a laser power density of 5J / cm². 2 Processing area 15cm 2 The processing time was 20 min, and the argon purging rate was 300 mL / min. The collected tantalum ultrafine nanoparticles were washed, freeze-dried, and then characterized; their X-ray diffraction patterns were as follows. Figure 4As shown, the characteristic diffraction peaks observed at 36.77°, 42.71°, 62.00°, and 74.30° of the laser-prepared niobium nanoparticles correspond to the (111), (200), (220), and (311) crystal planes of Nb(PDF#88-2330), respectively. Simultaneously, the diffraction peaks observed at 38.46°, 55.53°, 69.58°, and 82.42° correspond to the (110), (200), and (211) crystal planes of Nb(PDF#88-2330), respectively. The results indicate that the laser-prepared niobium nanoparticles are pure niobium phase nanoparticles. (Transmission scanning electron microscope images) Figure 5 The results show that the particle size is 10nm-20nm, with good uniformity.

[0072] Example 3

[0073] Taking the preparation of tantalum ultrafine nanoparticles using laser induction heating as an example.

[0074] (1) Instruments and related operating conditions

[0075] 1) 532nm nanosecond pulsed fiber laser (Coherent Laser, USA);

[0076] 2) Flow meter (MKS, USA)

[0077] 3) High-purity argon cylinder

[0078] (2) Laser preparation of tantalum ultrafine nanoparticles

[0079] 1) The 2mm tantalum plate was ultrasonically treated with cyclohexane, anhydrous ethanol and ultrapure water for 15 minutes in sequence. Finally, it was rinsed with ultrapure water and dried with nitrogen.

[0080] 2) The cleaned niobium plate is placed in the reaction apparatus, and the induction heating frequency is set to 60kHz. After the workpiece is red-hot, the surface of the tantalum plate is ablated using a 532nm nanosecond pulsed laser with a laser power density of 15J / cm². 2 Processing area 10cm 2 The processing time was 15 min, and the argon purging rate was 200 mL / min. The collected tantalum ultrafine nanoparticles were washed, freeze-dried, and then characterized. Their X-ray diffraction (XRD) was analyzed. Figure 6 The characteristic diffraction peaks observed at 38.47° and 55.54° of tantalum nanoparticles correspond to the (110) and (200) crystal planes of Ta (PDF#89-4763), respectively, while the characteristic diffraction peaks observed at 33.55°, 36.62°, and 40.45° correspond to the (002), (100), and (101) crystal planes of Ta (PDF#89-1545). (Transmission scanning electron microscope images) Figure 7 The results show that the particle size is 10nm-20nm, with good uniformity.

[0081] Example 4

[0082] Taking the preparation of tantalum oxide ultrafine nanoparticles using laser in an air atmosphere as an example.

[0083] (1) Instruments and related operating conditions

[0084] 1) 1064nm nanosecond pulsed laser (Wuhan Raycus);

[0085] 2) Flow meter (MKS, USA);

[0086] 3) Air pump.

[0087] (2) Laser preparation of tantalum oxide ultrafine nanoparticles

[0088] 1) A 2mm tantalum plate was ultrasonically treated with cyclohexane, anhydrous ethanol and ultrapure water for 15 minutes in sequence. Finally, it was rinsed with ultrapure water and dried with nitrogen gas before being placed in a reactor.

[0089] 2) Set the induction heating operating frequency to 60kHz. After the workpiece is red-hot, use a 1064nm nanosecond pulsed laser to ablate the tantalum oxide micron powder. The laser power density is 15J / cm². 2 The processing time was 20 min, and the air purging rate was 300 mL / min. The collected tantalum oxide ultrafine nanoparticles were washed, freeze-dried, and then characterized. Their X-ray diffraction (XRD) results were analyzed. Figure 8 The characteristic diffraction peaks observed in tantalum oxide nanoparticles at 22.84°, 28.29°, 36.67°, 46.67°, and 55.46° correspond to the (001), (110), (200), (002), and (021) crystal planes of Ta2O5 (PDF#89-2843), respectively. (Transmission scanning electron microscope images are shown.) Figure 9 The data shows that the particle size is 10nm-20nm, and Raman spectroscopy indicates that at 250cm², the particle size is within the range of 10nm-20nm. -1 492cm -1 525cm -1 628cm -1 667cm -1 A characteristic peak of lattice vibrations of tantalum pentoxide was observed at the wavenumber. Figure 10 ).

[0090] Example 5

[0091] Taking the preparation of niobium oxide ultrafine nanoparticles using lasers in an air atmosphere as an example.

[0092] (1) Instruments and related operating conditions

[0093] 1) 1064nm nanosecond pulsed laser (Wuhan Raycus);

[0094] 2) Flow meter (MKS, USA);

[0095] 3) Air pump.

[0096] (2) Laser preparation of niobium oxide ultrafine nanoparticles

[0097] 1) A 2mm niobium plate was ultrasonically treated with cyclohexane, anhydrous ethanol and ultrapure water for 15 minutes in sequence. Finally, it was rinsed with ultrapure water and dried with nitrogen gas before being placed in a reactor.

[0098] 2) Set the induction heating operating frequency to 60kHz. After the workpiece is red-hot, use a 1064nm nanosecond pulsed laser to ablate the niobium oxide micron powder. The laser power density is 10J / cm². 2 The processing time was 20 min, and the air purging rate was 300 mL / min. The collected niobium oxide ultrafine nanoparticles were washed, freeze-dried, and then characterized. Their X-ray diffraction (XRD) results were analyzed. Figure 11 The diffraction peaks observed at 22.84°, 28.29°, 36.67°, 46.67°, and 55.46° of niobium oxide nanoparticles correspond to the (002) and (100) crystal planes of Nb2O5 (PDF#74-0312), respectively. (Transmission scanning electron microscope images) Figure 12 The data shows that the particle size is 20nm-30nm, and Raman spectroscopy indicates that at 235cm⁻¹… -1 585cm -1 1102cm -1 The characteristic peak of niobium pentoxide lattice vibration was observed at the wavenumber. Figure 13 ).

[0099] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing high-melting-point ultrafine nanoparticles using laser induction heating, characterized in that, include: High-melting-point metal sheets are cleaned and dried to serve as the metal substrate; The metal substrate is placed in an induction heating cavity, and the metal substrate is vaporized and etched by the thermal effect generated by the interaction between the laser and the metal substrate. The metal vapor is then purged with gas, filtered, and the ultrafine nanoparticles are collected to obtain the final product. The high-melting-point metal plate is made of titanium, tantalum, or niobium. The wavelength of the laser is 355nm-1064nm, and the pulse width is 0.4ns-20ns; The power density of the laser is 0.5 J / cm². 2 -15.0J / cm 2 The processing time is 5-30 minutes, and the processing area is 1 cm². 2 -20cm 2 ; The frequency range of induction heating is 40kHz-100kHz, and the heating time is 5min-30min; The gas purging uses high-purity argon or air, and the purging speed ranges from 50 mL / min to 350 mL / min. The high-melting-point ultrafine nanoparticles have a size range of 10nm-20nm.

2. The method for preparing high-melting-point ultrafine nanoparticles using laser induction heating as described in claim 1, characterized in that, The thickness of the high melting point metal sheet is 1.0mm-5.0mm.

3. The method for preparing high-melting-point ultrafine nanoparticles using laser induction heating as described in claim 1, characterized in that, The cleaning process uses cyclohexane, anhydrous ethanol, and ultrapure water as cleaning agents. The cleaning is performed by ultrasonic cleaning for 15-30 minutes in sequence, followed by rinsing with ultrapure water and drying with nitrogen.

4. The method for preparing high-melting-point ultrafine nanoparticles using laser induction heating as described in claim 1, characterized in that, The method further includes: dispersing the collected ultrafine nanoparticles in anhydrous ethanol, washing them thoroughly, freeze-drying them, and then sealing and storing them.

5. The method for preparing high-melting-point ultrafine nanoparticles using laser induction heating as described in claim 4, characterized in that, The freeze-drying time is 6-12 hours.

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