A multi-element alloy material for making a lactiferous needle and a preparation method thereof

Abstract

The present application relates to a new material technology, and aims to provide a multi-element alloy material and a preparation method for making a lactation needle. The chemical composition of the multi-element alloy material comprises eight metal elements of Ti, Al, Mo, Cu, Ag, Zr, Zn and Ta, and inevitable impurities; and the multi-element alloy material is prepared through step-by-step arc melting, ball milling and ingot casting. The multi-element alloy material has excellent mechanical properties, can meet the puncture requirements of high strength and high hardness of the lactation needle, has significant active antibacterial ability, effectively reduces the risk of bacterial residue after puncture, has excellent resistance to body fluid corrosion, effectively avoids the risk of local tissue poisoning caused by the precipitation of toxic ions, has good biocompatibility, meets the biological safety requirements of medical implant / intervention instruments, and solves the defects of the existing lactation needle material in antibacterial, mechanical properties and biological safety, and is a high-quality material suitable for the preparation of the lactation needle.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, specifically to a multi-element alloy material for making lactation-promoting needles and its preparation method. Background Technology

[0002] Postpartum milk stasis is a common condition during lactation, referring to the inability to effectively express milk, leading to blockage of the milk ducts, causing breast engorgement and local lumps, which is often a precursor to acute mastitis. Its main symptoms are localized breast engorgement and pain with a palpable, well-defined lump, but the skin surface is usually normal, and there are no systemic symptoms such as fever. The causes are varied and may include incorrect latching posture of the infant, insufficient suckling, irregular breastfeeding by the mother, excessive milk production, stress, and wearing overly tight underwear that compresses the breasts. The key to treatment is effective milk removal and ensuring adequate rest. Otherwise, prolonged stasis can easily worsen breast redness and swelling, leading to fever, and further developing into mastitis or abscess. The resulting persistent pain, anxiety, and recurring breast problems can severely affect the mother's rest, mood, and confidence, exacerbating postpartum fatigue and even inducing depression.

[0003] Lactation-promoting needles are a core traditional Chinese medicine instrument for resolving postpartum milk stasis and breast blockage. The material properties of these needles directly affect their safety and efficacy. Currently, clinically used lactation-promoting needles are mainly made of stainless steel or polymer materials, but these have significant drawbacks: stainless steel and polymer materials lack active antibacterial capabilities, making it easy for bacteria to remain after puncture of breast tissue, potentially inducing mastitis; stainless steel easily releases toxic metal ions such as Ni and Cr in body temperature and fluid environments, causing local poisoning symptoms; and polymer materials lack sufficient hardness, posing a risk of unsuccessful puncture on the first attempt, causing patient discomfort.

[0004] Therefore, there is an urgent need to develop a new material suitable for manufacturing lactation needles to solve the problems existing in the practical application of lactation needles made of stainless steel and polymer materials. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a multi-element alloy material for making lactation needles and a preparation method thereof.

[0006] To solve the technical problem, the solution of the present invention is:

[0007] A multi-element alloy material for use in lactation-promoting needles is provided. The chemical composition of this multi-element alloy material includes eight metallic elements: Ti (titanium), Al (aluminum), Mo (molybdenum), Cu (copper), Ag (silver), Zr (zirconium), Zn (zinc), and Ta (tantalum), as well as unavoidable impurities. The molar ratio of the eight metallic elements is Ti:Al:Mo:Cu:Ag:Zr:Zn:Ta:= 1:0.5:0.3:0.1~0.3:0.9~1.3:0.8:0.3~0.5:0.01~0.03.

[0008] This invention further provides a method for preparing the aforementioned multi-element alloy material, comprising the following steps:

[0009] (1) Step-by-step electric arc melting: First, molybdenum, zirconium, titanium and tantalum metals are used as raw materials for electric arc melting to obtain primary material; then silver and copper metals are added for a second electric arc melting to obtain secondary primary material; then aluminum and zinc metals are added for a third electric arc melting to obtain crude material; the arc current of the three electric arc meltings decreases, but the melting and holding time increases.

[0010] (2) Cast the crude material into ingots and repeat the electric arc melting process multiple times to obtain intermediate material;

[0011] (3) After cutting the intermediate material into blocks, ball mill it to obtain alloy powder;

[0012] (4) The alloy powder is subjected to electric arc melting and cast into an ingot to obtain a multi-element alloy material for making a duct needle.

[0013] As a preferred embodiment of the present invention, a copper crucible is used as the container for arc melting, and its inner wall is coated with a 50-80 μm thick BN (boron nitride) coating.

[0014] As a preferred embodiment of the present invention, the metal raw materials and the primary and secondary primary materials are subjected to the following treatment: after being cut into blocks, they are soaked in acid to remove the oxide scale; after cleaning, they are dried and stored under vacuum conditions for use in electric arc melting.

[0015] As a preferred embodiment of the present invention, the electric arc melting is carried out under vacuum conditions, and intermittent electromagnetic stirring is used during the melting process; in the three electric arc melting processes, the arc ignition current is controlled to be 80-100A, 50-70A and 20-40A respectively, and the holding time is 3-5min, 4-6min and 7-9min respectively.

[0016] As a preferred embodiment of the present invention, the ball milling is carried out under an inert atmosphere, the ball-to-material ratio is 3:1, and an appropriate amount of milling agent is added; after ball milling for 24 to 48 hours, the powder is washed with anhydrous ethanol and vacuum dried to obtain alloy powder; the milling agent is composed of N,N-dimethylformamide accounting for 30% of the mass of the intermediate material and sodium borohydride accounting for 1 to 3% of the mass of the intermediate material.

[0017] As a preferred embodiment of the present invention, the arc melting of the alloy powder is carried out in a nitrogen-hydrogen mixed atmosphere; wherein, the nitrogen gas component is 25%, the hydrogen gas component is 75%, and the arc ignition current is set to 20-40A.

[0018] The present invention also provides a lactation-clearing needle, which is a slender straight rod or a slightly arc-shaped integral structure made of the aforementioned multi-element alloy material; the manufacturing method includes: forging the ingot of the multi-element alloy material to form a round bar blank; then performing multiple cold drawing to obtain a needle-shaped blank; and finally obtaining the lactation-clearing needle of the multi-element alloy material through shaping processing.

[0019] As a preferred embodiment of the present invention, during cold drawing, the diameter reduction per pass is controlled to be 5 to 8 mm, and the cumulative number of cold drawing passes is 10 to 16, so as to obtain a needle-shaped blank of the target size.

[0020] As a preferred embodiment of the present invention, the shaping process is at least one of the following processing techniques: precision grinding, upsetting, laser micromachining, and CNC bending.

[0021] Description of the invention principle:

[0022] This invention is based on the principle of synergistic enhancement of multi-element alloys and a step-by-step precise preparation process. By rationally proportioning eight metallic elements, Ti, Al, Mo, Cu, Ag, Zr, Zn, and Ta, and combining them with staged electric arc melting, ball milling, and forging densification processes, the material properties can be precisely controlled, thereby achieving synergistic optimization of the material's mechanical properties, antibacterial properties, and biocompatibility.

[0023] At the chemical composition design level: This invention uses Ag, Cu, and Zn as the core antibacterial elements to form a synergistic antibacterial effect. In addition to enhancing the alloy's antibacterial properties, Zn can further strengthen the surface passivation capability. Ti, Zr, and Ta possess excellent biocompatibility and corrosion resistance, forming a stable passivation film in body fluid environments to prevent excessive dissolution of metal ions. The entropy stabilization effect brought about by the co-doping of multiple metal elements further inhibits the dissolution of metal ions. Mo and Al enhance the alloy's hardness and mechanical stability, matching the puncture requirements of lactation needles.

[0024] In terms of alloy material processing technology: This invention employs a step-by-step melting process based on the differences in metal melting points (high-melting-point Mo, Zr, Ti, and Ta are melted first, followed by medium-melting-point Ag and Cu, and low-melting-point Al and Zn are melted last), avoiding the loss of low-melting-point elements through volatilization. Intermittent electromagnetic stirring ensures compositional uniformity. Ball milling refines the grains, and subsequent forging processes further refine the microstructure and improve density. Ultimately, this allows the alloy to simultaneously meet the requirements for use in emulsion needles, exhibiting antibacterial properties, corrosion resistance, low toxicity, and high hardness.

[0025] In the first step of arc melting, high-melting-point pure metals such as Mo, Zr, Ti, and Ta are completely melted to form a homogeneous primary alloy (Alloy 1). The melting point of this alloy matrix is ​​much lower than the individual melting points of each pure high-melting-point metal (alloying significantly reduces the melting point of metals). When Ag, Cu (medium melting point) and Al, Zn (low melting point) elements are added in subsequent stages, it is only necessary to heat the existing alloy matrix to a molten state to achieve element fusion, without needing to reach the high melting points of pure Mo, Ti, etc. Therefore, a relatively low arc current is sufficient to maintain the melting of the alloy matrix.

[0026] In this invention, during the arc melting process, the arc-starting current is gradually reduced with each melting step, while the holding time increases progressively: For the first melting step (high-melting-point metal), the arc-starting current is 80–100 A, and the holding time is 3–5 min; for the second step (adding medium-melting-point metal), the arc-starting current is 50–70 A, and the holding time is 4–6 min; for the third step (adding low-melting-point metal), the arc-starting current is 20–40 A, and the holding time is 7–9 min. The longer holding time ensures sufficient heat input at low currents, maintaining the alloy's molten state and achieving uniform diffusion of the newly added elements. The lower currents in subsequent steps are not used to remelt the high-melting-point metal, but rather to maintain the molten pool temperature, control volatilization, and achieve uniform mixing. Since the melting of the high-melting-point metal is completed in the first step, there is no need to apply high currents again in subsequent steps.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. In the multi-element alloy material of the present invention, three antibacterial elements, Ag, Cu and Zn, are combined, and the antibacterial rate against common pathogenic bacteria of the breast (such as Staphylococcus aureus and Escherichia coli) is ≥99%, which solves the problem that existing lactation-promoting injection materials do not have active antibacterial properties and are prone to inducing mastitis.

[0029] 2. Through the entropy stabilization effect brought about by multi-metal co-doping, surface passivation under body temperature and body fluid environment, and the Ti, Zr, and Ta bio-friendly element-dominated matrix, the risk of heavy metal ion dissolution is reduced, local poisoning is avoided, and cytotoxicity is significantly reduced.

[0030] 3. Hardness ≥ HV450, tensile strength ≥ 800MPa, which can effectively improve puncture efficiency and overcome the patient pain caused by insufficient hardness of polymer materials;

[0031] 4. Excellent biocompatibility: The passivation film on the alloy surface does not cause rejection reaction with breast tissue, and the cytotoxicity level is Grade 1.

[0032] 5. An innovative ball milling process combining N,N-dimethylformamide and sodium borohydride is introduced to solve the problem of localized oxidation in the processing of multi-element alloys. Detailed Implementation

[0033] Part 1 Overview of the Implementation Scheme of the Invention

[0034] 1. Chemical composition of multi-element alloy materials

[0035] This invention provides a multi-element alloy material for use in lactation-promoting needles. The chemical composition of this multi-element alloy material includes eight metallic elements: Ti (titanium), Al (aluminum), Mo (molybdenum), Cu (copper), Ag (silver), Zr (zirconium), Zn (zinc), and Ta (tantalum), as well as unavoidable impurities. The molar ratio of the eight metallic elements is Ti:Al:Mo:Cu:Ag:Zr:Zn:Ta:= 1:0.5:0.3:0.1~0.3:0.9~1.3:0.8:0.3~0.5:0.01~0.03.

[0036] 2. Preparation of multi-element alloy materials

[0037] This invention produces the multi-element alloy material through a step-by-step process of electric arc melting, ball milling, ingot forging, cold drawing and shrinking, and molding. Specifically, the process is as follows:

[0038] (1) Primary materials are prepared by electric arc melting using molybdenum, zirconium, titanium and tantalum metals as raw materials;

[0039] Molybdenum, zirconium, titanium, and tantalum metal raw materials are cut into 5-10 mm blocks, and then soaked in 3-5 wt% nitric acid solution for 10-20 min (to remove oxide scale), followed by ultrasonic cleaning with deionized water for 15-45 min, and then cleaning the surface of each metal block 3-5 times with anhydrous ethanol. After cleaning, each metal raw material block is placed in a vacuum oven, vacuumed to 3 Pa, dried at 60°C for 12-24 hours, cooled to room temperature, and then stored in the vacuum oven for later use.

[0040] Using a copper crucible with an inner wall coated with a 50-80 μm thick BN (boron nitride) layer, add molybdenum, zirconium, titanium, and tantalum metal raw material blocks according to the preset proportions in the alloy. Evacuate the vacuum system to 5 × 10⁻⁶. -3 After Pa, the furnace is purged three times with high-purity argon gas with a purity of ≥99.999% to control the oxygen content in the furnace to ≤10ppm;

[0041] Arc melting is performed with an arc ignition current of 80–100 A, maintained for 3–5 minutes. Electromagnetic stirring is used during the melting process. The electromagnetic stirring is set to intermittent stirring mode (on for 30 seconds, off for 15 seconds), with a current intensity of 20–40 A and a frequency of 1–3 Hz. After heating is stopped and the mixture is cooled to room temperature, alloy one (primary material) is obtained.

[0042] (2) Add silver and copper metals for a second electric arc smelting to obtain secondary primary material;

[0043] Alloy 1 and silver and copper metals are cut into blocks of 5-10 mm. They are then soaked in 3-5 wt% nitric acid solution for 10-20 min (to remove oxide scale), ultrasonically cleaned with deionized water for 15-45 min, and then cleaned with anhydrous ethanol 3-5 times. After that, the cleaned alloy and metal raw material blocks are placed in a vacuum oven, vacuumed to 3 Pa, dried at 60°C for 12-24 hours, cooled to room temperature, and stored in the vacuum oven for later use.

[0044] Alloy raw material blocks, along with silver and copper raw material blocks, are added to a copper crucible in a predetermined ratio according to the alloy composition. The vacuum system is then evacuated to 5 × 10⁻⁶. -3 After Pa, the furnace is purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current is set to 50-70A, and the melting current is maintained for 4-6 minutes. Electromagnetic stirring is used during the melting process. The electromagnetic stirring is set to intermittent stirring mode (on for 40 seconds, off for 10 seconds), with a current intensity of 10-30A and a frequency of 0.5-1.5Hz. After heating is stopped and the furnace is cooled to room temperature, alloy two (secondary primary material) is obtained.

[0045] (3) Add aluminum and zinc metals for a third electric arc melting process to obtain crude material.

[0046] Alloy II, along with aluminum and zinc raw materials, are cut into 5-10 mm blocks. They are then soaked sequentially in a 2-4 wt% nitric acid solution for 10-20 minutes (to remove oxide scale), followed by ultrasonic cleaning with deionized water for 15-45 minutes, and then cleaning the surface of each metal block 3-5 times with anhydrous ethanol. After cleaning, the metal blocks are placed in a vacuum oven, evacuated to 3 Pa, and dried at 60°C for 12-24 hours. Once cooled to room temperature, they are stored in the vacuum oven for later use.

[0047] Alloy II raw material blocks, along with aluminum and zinc raw material blocks, are added to a copper crucible in a predetermined ratio according to the alloy composition. The vacuum system is then evacuated to 5 × 10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current was set to 20–40A, and the melting current was maintained for 7–9 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 5–7A and a frequency of 0.5–1.5Hz. After heating was stopped and the furnace was cooled to room temperature, alloy three (rough material) was obtained.

[0048] (4) The crude material is melted by electric arc multiple times to obtain the intermediate material.

[0049] The alloy ingot was flipped 180 degrees after casting. o Refill the copper crucible and evacuate the vacuum system to 5 × 10⁻⁶. -3After Pa, the furnace is purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current is set to 20–40A, and the melting current is maintained for 7–9 minutes. Electromagnetic stirring is used during the melting process. The electromagnetic stirring is set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 5–7A and a frequency of 0.5–1.5Hz. Heating is stopped, and the furnace is cooled to room temperature.

[0050] Repeat this step 3 to 5 times to obtain Alloy 4 (intermediate material);

[0051] (5) Ball milling intermediate material to obtain alloy powder

[0052] Alloy IV was cut into 2-4 mm pieces and placed in a gas-fillable, sealed ball mill jar. The ball-to-material ratio was 3:1. A milling agent consisting of 30% N,N-dimethylformamide (by mass of Alloy IV) and 1-3% sodium borohydride (by mass of Alloy IV) was added to the jar. Nitrogen gas (99.99% purity) was introduced into the jar to a pressure of 0.2-0.4 MPa. After closing the gas filling valve, the jar was milled in a planetary ball mill for 24-48 hours. The jar was then removed, the lid opened, and the milled Alloy IV was washed out with anhydrous ethanol. The jar was then rinsed three times with anhydrous ethanol and then... (The sentence is incomplete and ends abruptly). o C. After evacuating to 3 Pa, vacuum dry for 24 hours to obtain alloy powder;

[0053] (6) Arc melting of alloy powder

[0054] The alloy powder was added to a copper crucible, and the vacuum system was evacuated to 5 × 10⁻⁶. -3 After Pa, the gas is purged three times with high-purity argon gas (≥99.999%), and then purged three times with a nitrogen-hydrogen mixed gas (nitrogen 25% and hydrogen 75%). The arc-starting current is set to 20–40 A, and the melting current is maintained for 10–12 min. Electromagnetic stirring is used during the melting process. The electromagnetic stirring is set to intermittent stirring mode (on for 20 s, off for 20 s), with a current intensity of 15–25 A and a frequency of 1–3 Hz.

[0055] After stopping heating and cooling to room temperature, an ingot of alloy five is obtained, which is the multi-element alloy material used to make lactation needles as described in this invention.

[0056] 3. Preparation of lactation-promoting needles

[0057] The specific manufacturing process of the lactation-promoting needle of this invention adopts existing technology, and the example manufacturing method is as follows:

[0058] The ingot of the multi-element alloy material is forged to form a round bar billet; then, it undergoes multiple cold drawing processes to obtain a needle-shaped billet; finally, through shaping treatment, the multi-element alloy material lubrication needle is obtained. Specific manufacturing processes and parameters can be referenced from existing metal medical device processing technologies.

[0059] For example, alloy 5 ingots are heated to 750–850°C and held for 1 hour. At this holding temperature, they are forged using an air hammer into round bar blanks with a diameter of 20–40 mm. During cold drawing, the diameter reduction per pass is controlled at 5–8 mm, with a cumulative cold drawing pass of 10–16 passes, ultimately producing a needle-shaped blank of the target size. The shaping process can be at least one of the following: precision grinding, upsetting, laser micromachining, or CNC bending, ultimately producing a thread-clearing needle that meets the design requirements.

[0060] As an example of the final product, this lactation-promoting needle is a one-piece structure, with an overall shape that is slender, straight, or slightly curved. It includes: a thin-walled, hollow, cylindrical needle body; a blunt, rounded tip with a closed end and an end hole communicating with the inner cavity; a thickened needle tail with knurled texture on the surface (for easy hand handling), or a thickened needle tail with a Luer connector structure (which can be directly connected to a syringe to achieve simultaneous drug infusion and lactation); the transitions between the needle tip, needle tail, and needle body are all smooth.

[0061] Part Two: Specific Embodiments and Comparative Examples

[0062] In the following specific embodiments and comparative examples, the performance of the materials used in the lactation-promoting needles was tested using the following test methods:

[0063] The compressive strength test method refers to the standard GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Test at room temperature" to obtain the tensile strength of the material.

[0064] The hardness test method refers to standard GB / T 4340.1-2024 "Metallic materials - Vickers hardness test - Part 1: Test method" to obtain the Vickers hardness of alloy materials.

[0065] The antibacterial performance test method refers to the standard GB / T 31402-2023 "Determination of antibacterial activity of plastics and other non-porous materials" to obtain the antibacterial activity value of the alloy material.

[0066] The corrosion resistance test method (simulated body fluid) was performed using an electrochemical workstation in simulated body fluid (SBF, pH=7.4) at 37℃, employing potentiodynamic polarization curve testing. The working electrode was the alloy sample, the reference electrode was a saturated calomel electrode, and the auxiliary electrode was a platinum sheet. The scan rate was 1 mV / s, and the potential range was -1.0 V to +1.5 V (relative to open circuit potential). The corrosion current density (Icorr) was recorded to evaluate the material's corrosion resistance.

[0067] Cytotoxicity testing was conducted in accordance with standard GB / T 16886.5-2017 "Biological Evaluation of Medical Devices - Part 5: In Vitro Cytotoxicity Tests" to obtain the cytotoxicity rating of the alloy material.

[0068] Example 1

[0069] A multi-element alloy material for lactation-promoting needles contains eight metallic elements: Ti (titanium), Al (aluminum), Mo (molybdenum), Cu (copper), Ag (silver), Zr (zirconium), Zn (zinc), and Ta (tantalum). The molar ratio of each metal is Ti:Al:Mo:Cu:Ag:Zr:Zn:Ta:= 1:0.5:0.3:0.1:0.9:0.8:0.3:0.01. The preparation method includes the following steps:

[0070] (1) Cut each metal raw material into 5mm blocks, then soak them in 3wt% nitric acid solution for 10min (to remove oxide scale), then ultrasonically clean them with deionized water for 15min, and then clean the surface of each metal block three times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3Pa, dry them at 60℃ for 12 hours, cool them to room temperature, and store them in the vacuum oven for later use.

[0071] (2) Using a copper crucible with an inner wall coated with a 50-80 μm thick BN (boron nitride) coating, add molybdenum, zirconium, titanium, and tantalum metal raw material blocks according to the preset ratio in the alloy, and evacuate the vacuum system to 5×10 -3 After Pa, the furnace is purged three times with high-purity argon gas with a purity of ≥99.999% to control the oxygen content in the furnace to ≤10ppm;

[0072] (3) Arc melting: the arc starting current is set to 80A, the melting current is maintained for 3 min, and electromagnetic stirring is used during the melting process; the electromagnetic stirring is set to intermittent stirring mode (on for 30s, off for 15s), the current intensity is 20A, and the frequency is set to 1Hz; after stopping heating and cooling to room temperature, alloy one is obtained.

[0073] (4) Cut the alloy obtained in step (3) into 5mm blocks, then soak them in 3wt% nitric acid solution for 10min (to remove oxide scale), then ultrasonically clean them with deionized water for 15min, and then clean the surface of each metal block three times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3Pa, dry them at 60℃ for 12 hours, cool them to room temperature, and store them in the vacuum oven for later use as alloy raw material blocks;

[0074] (5) Add the alloy raw material block obtained in step (4), along with the silver raw material block and the copper raw material block, into a copper crucible in a predetermined ratio according to the alloy composition. Evacuate the vacuum system to 5×10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current was set to 50A, and the melting current was maintained for 4 min. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 40s, off for 10s), with a current intensity of 10A and a frequency of 0.5Hz. After heating was stopped and the furnace was cooled to room temperature, alloy II was obtained.

[0075] (6) Cut the alloy II obtained in step (5) and the aluminum and zinc raw material blocks into 5mm blocks, then soak them in 2wt% nitric acid solution for 10min (to remove oxide scale), then ultrasonically clean them with deionized water for 15min, and then clean the surface of each metal block three times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3Pa, dry them at 60℃ for 12 hours, cool them to room temperature, and store them in the vacuum oven for later use as alloy II raw material blocks;

[0076] (7) Add the alloy raw material block obtained in step (6), along with the aluminum raw material block and the zinc raw material block, into a copper crucible in a predetermined ratio according to the alloy composition. Evacuate the vacuum system to 5×10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current was set to 20A, and the melting current was maintained for 7 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 5A and a frequency of 0.5Hz. After heating was stopped and the furnace was cooled to room temperature, alloy III was obtained.

[0077] (8) Flip the alloy ingot obtained in step (7) 180 degrees. o Refill the copper crucible and evacuate the vacuum system to 5 × 10⁻⁶. -3After Pa, the furnace is purged three times with high-purity argon gas with a purity of ≥99.999% to control the oxygen content in the furnace to ≤10ppm; the arc ignition current is set to 20A, and the melting current is maintained for 7min. Electromagnetic stirring is used during the melting process; the electromagnetic stirring is set to intermittent stirring mode (on for 20s, off for 20s), the current intensity is 5A, and the frequency is set to 0.5Hz; heating is stopped, and the furnace is cooled to room temperature.

[0078] (9) Repeat step (8) three times to obtain alloy four;

[0079] (10) Cut the alloy 4 obtained in step (9) into 2mm blocks and put them into an inflatable sealed ball mill jar. The ball-to-material ratio for ball milling is 3:1. Add 30% N,N-dimethylformamide and 1% sodium borohydride (by mass of alloy 4) to the ball mill jar. Then, introduce 99.99% pure nitrogen gas into the ball mill jar to 0.2MPa. After closing the gas filling valve, ball mill the alloy 4 in a planetary ball mill for 24 hours. Remove the ball mill jar, open the lid, and wash out the ball-milled alloy 4 inside the ball mill jar with anhydrous ethanol. Clean the jar three times with anhydrous ethanol and then clean it at 80°C. o C. After evacuating to 3 Pa, vacuum dry for 24 hours to obtain alloy powder;

[0080] (11) Add the alloy powder obtained in step (10) into a copper crucible, and evacuate the vacuum system to 5×10 -3 After Pa, the mixture was purged three times with high-purity argon gas (≥99.999%), followed by three purgings with a nitrogen-hydrogen mixed gas (25% nitrogen and 75% hydrogen). The arc-starting current was set to 20A, and the melting current was maintained for 10 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 15A and a frequency of 1Hz. After heating was stopped and the mixture was cooled to room temperature, an ingot of alloy five was obtained.

[0081] Samples were taken for testing. The tensile strength was 860 MPa, the hardness was HV490, the antibacterial activity value R was 4.2, and the corrosion current was 4.5 × 10⁻⁶. -9 A / cm 2 The cytotoxicity level is 0.

[0082] (12) Heat the alloy five ingot obtained in step (11) to 750°C, hold for 1 hour, and forge it into a round bar with a diameter of 20 mm using an air hammer at the holding temperature;

[0083] (13) The round bar billet is cold-drawn in 10 passes, with a diameter reduction of 5 mm per pass. It is then air-cooled to room temperature to obtain a needle-shaped billet. Finally, through shaping treatment, the multi-element alloy material is used to make the duct needle.

[0084] Example 2

[0085] A multi-element alloy material for lactation-promoting needles contains eight metallic elements: Ti (titanium), Al (aluminum), Mo (molybdenum), Cu (copper), Ag (silver), Zr (zirconium), Zn (zinc), and Ta (tantalum). The molar ratio of each metal is Ti:Al:Mo:Cu:Ag:Zr:Zn:Ta:= 1:0.5:0.3:0.3:1.3:0.8:0.5:0.03. The preparation method includes the following steps:

[0086] (1) Cut each metal raw material into 10mm blocks, then soak them in 5wt% nitric acid solution for 20min (to remove oxide scale), then ultrasonically clean them with deionized water for 45min, and then clean the surface of each metal block 5 times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3Pa, dry them at 60℃ for 24 hours, cool them to room temperature, and store them in the vacuum oven for later use.

[0087] (2) Using a copper crucible with an inner wall coated with a 50-80 μm thick BN (boron nitride) coating, add molybdenum, zirconium, titanium, and tantalum metal raw material blocks according to the preset ratio in the alloy, and evacuate the vacuum system to 5×10 -3 After Pa, the furnace is purged three times with high-purity argon gas with a purity of ≥99.999% to control the oxygen content in the furnace to ≤10ppm;

[0088] (3) Arc melting: the arc starting current is set to 100A, the melting current is maintained for 4 min, and electromagnetic stirring is used during the melting process; the electromagnetic stirring is set to intermittent stirring mode (on for 30s, off for 15s), the current intensity is 40A, and the frequency is set to 3Hz; after stopping heating and cooling to room temperature, alloy one is obtained.

[0089] (4) Cut the alloy obtained in step (3) into blocks of 5-10 mm, and then soak them in 5 wt% nitric acid solution for 20 min (to remove oxide scale), then ultrasonically clean them with deionized water for 45 min, and then clean the surface of each metal block 5 times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3 Pa, dry them at 60°C for 24 hours, cool them to room temperature, and store them in the vacuum oven for later use as alloy raw material blocks;

[0090] (5) Add the alloy raw material block obtained in step (4), along with the silver raw material block and the copper raw material block, into a copper crucible in a predetermined ratio according to the alloy composition. Evacuate the vacuum system to 5×10⁻⁶. -3After Pa, the furnace was purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current was set to 70A, and the melting current was maintained for 5 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 40 seconds, off for 10 seconds), with a current intensity of 30A and a frequency of 1.5Hz. After heating was stopped and the furnace was cooled to room temperature, alloy II was obtained.

[0091] (6) Cut the alloy II obtained in step (5) and the aluminum and zinc raw material blocks into 10mm blocks, then soak them in 4wt% nitric acid solution for 20min (to remove oxide scale), then ultrasonically clean them with deionized water for 45min, and then clean the surface of each metal block 5 times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3Pa, dry them at 60℃ for 24 hours, cool them to room temperature, and store them in the vacuum oven for later use as alloy II raw material blocks;

[0092] (7) Add the alloy raw material block obtained in step (6), along with the aluminum raw material block and the zinc raw material block, into a copper crucible in a predetermined ratio according to the alloy composition. Evacuate the vacuum system to 5×10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current was set to 40A, and the melting current was maintained for 9 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 7A and a frequency of 1.5Hz. After heating was stopped and the furnace was cooled to room temperature, alloy III was obtained.

[0093] (8) Flip the alloy ingot obtained in step (7) 180 degrees. o Refill the copper crucible and evacuate the vacuum system to 5 × 10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas with a purity of ≥99.999% to control the oxygen content in the furnace to ≤10ppm; the arc ignition current was set to 40A, and the melting current was maintained for 9min. Electromagnetic stirring was used during the melting process; the electromagnetic stirring was set to intermittent stirring mode (on for 20s, off for 20s), the current intensity was 7A, and the frequency was set to 1.5Hz; heating was stopped, and the furnace was cooled to room temperature.

[0094] (9) Repeat step (8) 5 times to obtain alloy four;

[0095] (10) Cut the alloy 4 obtained in step (9) into 4mm blocks and put them into an inflatable sealed ball mill jar. The ball-to-material ratio for ball milling is 3:1. Add 30% N,N-dimethylformamide and 3% sodium borohydride (by mass of alloy 4) to the ball mill jar. Then, introduce 99.99% pure nitrogen gas into the ball mill jar to a pressure of 0.4 MPa. After closing the gas filling valve, ball mill the alloy 4 in a planetary ball mill for 48 hours. Remove the ball mill jar, open the lid, and wash out the ball-milled alloy 4 with anhydrous ethanol. Clean the jar three times with anhydrous ethanol and then clean it at 80°C. o C. After evacuating to 3 Pa, vacuum dry for 24 hours to obtain alloy powder;

[0096] (11) Add the alloy powder obtained in step (10) into a copper crucible, and evacuate the vacuum system to 5×10 -3 After Pa, the mixture was purged three times with high-purity argon gas (≥99.999%), followed by three purgings with a nitrogen-hydrogen mixed gas (25% nitrogen and 75% hydrogen). The arc-starting current was set to 40A, and the melting current was maintained for 12 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 25A and a frequency of 3Hz. After heating was stopped and the mixture was cooled to room temperature, an ingot of alloy five was obtained.

[0097] Samples were taken for testing. The tensile strength was 980 MPa, the hardness was HV570, the antibacterial activity value R was 6.1, and the corrosion current was 1.2 × 10⁻⁶. -9 A / cm 2 The cytotoxicity level is 0.

[0098] (12) Heat the alloy five ingot obtained in step (11) to 850°C, hold for 1 hour, and forge it into a round bar with a diameter of 40 mm using an air hammer at the holding temperature;

[0099] (13) The round bar billet is cold-drawn in 16 passes, with a diameter reduction of 8 mm per pass. It is then air-cooled to room temperature to obtain a needle-shaped billet. Finally, through shaping treatment, the multi-element alloy material is used to make the duct needle.

[0100] Example 3

[0101] A multi-element alloy material for lactation-promoting needles contains eight metallic elements: Ti (titanium), Al (aluminum), Mo (molybdenum), Cu (copper), Ag (silver), Zr (zirconium), Zn (zinc), and Ta (tantalum). The molar ratio of each metal is Ti:Al:Mo:Cu:Ag:Zr:Zn:Ta:= 1:0.5:0.3:0.2:1.1:0.8:0.4:0.02. The preparation method includes the following steps:

[0102] (1) Cut each metal raw material into 7mm blocks, then soak them in 4wt% nitric acid solution for 15min (to remove oxide scale), then ultrasonically clean them with deionized water for 30min, and then clean the surface of each metal block 4 times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate to 3Pa, dry at 60℃ for 18 hours, cool to room temperature, and store in the vacuum oven for later use.

[0103] (2) Using a copper crucible with an inner wall coated with a 50-80 μm thick BN (boron nitride) coating, add molybdenum, zirconium, titanium, and tantalum metal raw material blocks according to the preset ratio in the alloy, and evacuate the vacuum system to 5×10 -3 After Pa, the furnace is purged three times with high-purity argon gas with a purity of ≥99.999% to control the oxygen content in the furnace to ≤10ppm;

[0104] (3) Arc melting: the arc starting current is set to 90A, the melting current is maintained for 5 min, and electromagnetic stirring is used during the melting process; the electromagnetic stirring is set to intermittent stirring mode (on for 30s, off for 15s), the current intensity is 30A, and the frequency is set to 2Hz; after stopping heating and cooling to room temperature, alloy one is obtained.

[0105] (4) Cut the alloy obtained in step (3) into 7mm blocks, then soak them in 4wt% nitric acid solution for 15min (to remove oxide scale), then ultrasonically clean them with deionized water for 30min, and then clean the surface of each metal block 4 times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3Pa, dry them at 60℃ for 18 hours, cool them to room temperature, and store them in the vacuum oven for later use as alloy raw material blocks;

[0106] (5) Add the alloy raw material block obtained in step (4), along with the silver raw material block and the copper raw material block, into a copper crucible in a predetermined ratio according to the alloy composition. Evacuate the vacuum system to 5×10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas with a purity ≥99.999% to control the oxygen content in the furnace to ≤10ppm; the arc ignition current was set to 60A, and the melting current was maintained for 6 min. Electromagnetic stirring was used during the melting process; the electromagnetic stirring was set to intermittent stirring mode (on for 40s, off for 10s), the current intensity was 20A, and the frequency was set to 1Hz; after heating was stopped and cooled to room temperature, alloy II was obtained.

[0107] (6) Cut the alloy II obtained in step (5) and the aluminum and zinc raw material blocks into 7mm blocks, then soak them in 3wt% nitric acid solution for 15min (to remove oxide scale), then ultrasonically clean them with deionized water for 30min, and then clean the surface of each metal block 4 times with anhydrous ethanol; then put the cleaned metal raw material blocks into a vacuum oven, evacuate them to 3Pa, dry them at 60℃ for 18 hours, cool them to room temperature, and store them in the vacuum oven for later use as alloy II raw material blocks;

[0108] (7) Add the alloy raw material block obtained in step (6), along with the aluminum raw material block and the zinc raw material block, into a copper crucible in a predetermined ratio according to the alloy composition. Evacuate the vacuum system to 5×10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas (≥99.999%) to control the oxygen content in the furnace to ≤10ppm. The arc-starting current was set to 30A, and the melting current was maintained for 8 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 6A and a frequency of 1Hz. After heating was stopped and the furnace was cooled to room temperature, alloy III was obtained.

[0109] (8) Flip the alloy ingot obtained in step (7) 180 degrees. o Refill the copper crucible and evacuate the vacuum system to 5 × 10⁻⁶. -3 After Pa, the furnace was purged three times with high-purity argon gas with a purity of ≥99.999% to control the oxygen content in the furnace to ≤10ppm; the arc ignition current was set to 30A, and the melting current was maintained for 8min. Electromagnetic stirring was used during the melting process; the electromagnetic stirring was set to intermittent stirring mode (on for 20s, off for 20s), the current intensity was 6A, and the frequency was set to 1Hz; heating was stopped, and the furnace was cooled to room temperature.

[0110] (9) Repeat step (8) four times to obtain alloy four;

[0111] (10) Cut the alloy 4 obtained in step (9) into 3mm blocks and put them into an inflatable sealed ball mill jar. The ball-to-material ratio for ball milling is 3:1. Add 30% N,N-dimethylformamide and 2% sodium borohydride (by mass of alloy 4) to the ball mill jar. Purge the ball mill jar with 99.99% pure nitrogen gas to 0.3MPa. After closing the gas filling valve, ball mill the alloy 4 in a planetary ball mill for 36 hours. Remove the ball mill jar, open the lid, and wash out the ball milled alloy 4 with anhydrous ethanol. Clean the jar three times with anhydrous ethanol and then clean it at 80°C. o C. After evacuating to 3 Pa, vacuum dry for 24 hours to obtain alloy powder;

[0112] (11) Add the alloy powder obtained in step (10) into a copper crucible, and evacuate the vacuum system to 5×10 -3After Pa, the mixture was purged three times with high-purity argon gas (≥99.999%), followed by three purgings with a nitrogen-hydrogen mixed gas (25% nitrogen and 75% hydrogen). The arc-starting current was set to 30A, and the melting current was maintained for 11 minutes. Electromagnetic stirring was used during the melting process. The electromagnetic stirring was set to intermittent stirring mode (on for 20 seconds, off for 20 seconds), with a current intensity of 20A and a frequency of 2Hz. After heating was stopped and the mixture was cooled to room temperature, an ingot of alloy five was obtained.

[0113] Samples were taken for testing. The tensile strength was 920 MPa, the hardness was HV510, the antibacterial activity value R was 5.3, and the corrosion current was 3.4 × 10⁻⁶. -9 A / cm 2 The cytotoxicity level is 0.

[0114] (12) Heat the alloy five ingot obtained in step (11) to 800°C, hold for 1 hour, and forge it into a round bar with a diameter of 30 mm using an air hammer at the holding temperature;

[0115] (13) The round bar billet is cold-drawn in 13 passes, with a diameter reduction of 7 mm per pass. It is then air-cooled to room temperature to obtain a needle-shaped billet. Finally, through shaping treatment, the multi-element alloy material is used to make the duct needle.

[0116] Comparative Example 1

[0117] Samples of commercially available 304 stainless steel lactation needles were taken for testing:

[0118] The tensile strength is 520 MPa, the hardness is HV200, the antibacterial activity value R is 0, and the corrosion current is 2.6 × 10⁻⁶. -7 A / cm 2 The cytotoxicity level is 1.

[0119] Comparative Example 2

[0120] Samples of commercially available lactation-promoting needles made of 316 medical stainless steel were taken for testing:

[0121] The tensile strength is 480 MPa, the hardness is HV180, the antibacterial activity value R is 0, and the corrosion current is 3.7 × 10⁻⁶. -8 A / cm 2 The cytotoxicity level is 1.

[0122] Comparative Example 3

[0123] Samples were taken and tested from lactation-promoting needles made of polylactic acid (Resomer® L Evonik):

[0124] The tensile strength is 70 MPa; the hardness is 110 (Rockwell hardness); the antibacterial activity value R is 0; there is no corrosion due to charge transfer; it undergoes hydrolytic degradation in body fluids, and its strength decreases significantly to 25 MPa after immersion in body fluids for one week; the cytotoxicity is grade 0.

[0125] As can be seen from the data in the above embodiments and comparative examples:

[0126] The multi-element alloy material of this invention has excellent mechanical properties, with a tensile strength of 860-980 MPa and a hardness of HV490-570, which are far higher than those of 304 stainless steel (520 MPa / HV 200), 316 stainless steel (480 MPa / HV 180) and polylactic acid (70 MPa / Rockwell hardness 110). It can meet the high-strength and high-hardness puncture requirements of lubrication treatment and effectively overcome the problem of puncture failure caused by insufficient hardness of polymer materials.

[0127] The multi-element alloy material of this invention exhibits significant active antibacterial capabilities, with an antibacterial activity value (R) of 4.2–6.1 against common breast pathogens such as Staphylococcus aureus and Escherichia coli. In contrast, commercially available stainless steel and polylactic acid materials have an antibacterial activity value of 0 and do not possess active antibacterial function. Therefore, the material of this invention can effectively reduce the risk of bacterial residue after puncture.

[0128] The multi-element alloy material of this invention exhibits excellent resistance to body fluid corrosion: the corrosion current density in simulated body fluid is 1.2 × 10⁻⁶. -9 ~4.5×10 -9 A / cm², far lower than 304 stainless steel (2.6×10⁻⁶). -7 A / cm 2 ) and 316 stainless steel (3.7×10 -8 A / cm 2 This indicates that its passivation film is stable and the dissolution of metal ions is extremely low, which can effectively avoid the risk of local tissue poisoning caused by the precipitation of toxic ions.

[0129] The multi-element alloy material of this invention has good biocompatibility and a cytotoxicity level of 0 (better than the level 1 of stainless steel and comparable to polylactic acid), indicating that the material does not cause rejection reaction with breast tissue and meets the biosafety requirements for medical implants / interventional devices.

[0130] This multi-element alloy material combines high mechanical strength, excellent antibacterial properties, strong corrosion resistance, and high biocompatibility, solving the single or combined defects of existing lactation needle materials in terms of antibacterial properties, mechanical properties, and biological safety. It is a high-quality material suitable for the preparation of lactation needles.

[0131] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A multi-element alloy material for manufacturing lactation-promoting needles, characterized in that, The chemical composition of this multi-element alloy material includes eight metallic elements: Ti, Al, Mo, Cu, Ag, Zr, Zn, and Ta, as well as unavoidable impurities; the molar ratio of the eight metallic elements is Ti:Al:Mo:Cu:Ag:Zr:Zn:Ta = 1:0.5:0.3:0.1~0.3:0.9~1.3:0.8:0.3~0.5:0.01~0.

03.

2. The method for preparing the multi-element alloy material according to claim 1, characterized in that, Includes the following steps: (1) Step-by-step electric arc melting: First, molybdenum, zirconium, titanium and tantalum metals are used as raw materials for electric arc melting to obtain primary material; then silver and copper metals are added for a second electric arc melting to obtain secondary primary material; then aluminum and zinc metals are added for a third electric arc melting to obtain crude material; the arc current of the three electric arc meltings decreases, but the melting and holding time increases. (2) Cast the crude material into ingots and repeat the electric arc melting process multiple times to obtain intermediate material; (3) After cutting the intermediate material into blocks, ball mill it to obtain alloy powder; (4) The alloy powder is subjected to electric arc melting and cast into an ingot to obtain a multi-element alloy material for making a duct needle.

3. The method according to claim 2, characterized in that, A copper crucible was used as the container for electric arc melting, and its inner wall was coated with a boron nitride coating of 50–80 μm thickness.

4. The method according to claim 2, characterized in that, The metal raw materials and the primary and secondary primary materials are processed as follows: after being cut into blocks, they are soaked in acid to remove the oxide scale; after cleaning, they are dried and stored under vacuum conditions for use in electric arc melting.

5. The method according to claim 2, characterized in that, The electric arc melting is carried out under vacuum conditions, and intermittent electromagnetic stirring is used during the melting process; in the three electric arc melting processes, the arc starting current is controlled to be 80-100A, 50-70A and 20-40A respectively, and the holding time is 3-5min, 4-6min and 7-9min respectively.

6. The method according to claim 2, characterized in that, The ball milling is carried out under an inert atmosphere with a ball-to-material ratio of 3:1 and an appropriate amount of milling agent is added. After milling for 24 to 48 hours, the powder is washed with anhydrous ethanol and vacuum dried to obtain alloy powder. The milling agent is composed of N,N-dimethylformamide at 30% of the mass of the intermediate material and sodium borohydride at 1 to 3% of the mass of the intermediate material.

7. The method according to claim 2, characterized in that, The arc melting of the alloy powder was carried out in a nitrogen-hydrogen mixed atmosphere; wherein the nitrogen gas component was 25%, the hydrogen gas component was 75%, and the arc current was set to 20-40A.

8. A lactation-promoting needle, characterized in that, The lactation needle is slender and straight or slightly arc-shaped, and is an integral structure made of the multi-element alloy material described in claim 1. Its manufacturing method includes: forging the ingot of the multi-element alloy material to form a round bar blank; then performing multiple cold drawing to obtain a needle-shaped blank; and finally obtaining the lactation needle of the multi-element alloy material through shaping processing.

9. The lactation-promoting needle according to claim 8, characterized in that, During cold drawing, the diameter reduction per pass is controlled to be 5-8 mm, and the cumulative number of cold drawing passes is 10-16, to obtain a needle-shaped blank of the target size.

10. The lactation-promoting needle according to claim 8, characterized in that, The shaping process is at least one of the following processing techniques: precision grinding, upsetting, laser micromachining, or CNC bending.