High-entropy alloy cast ingot and preparation method and application thereof

Abstract

The invention relates to the field of medical biological material manufacturing, in particular to the field of IPCC22C1, and more particularly relates to a high-entropy alloy cast ingot and a preparation method and application thereof. The preparation raw materials comprise the following metals: Ti, Cu, Zr, Nb, Ta and Ga. The molar ratio of the Ti to the Cu to the Zr to the Nb to the Ta is 1 to (0.5 to 1.5) to (0.5 to 1.5) to (0.5 to 1.5) to (0.5 to 1.5); the mass fraction of Ga in the high-entropy alloy cast ingot is not higher than 5%. The medical implant which is relatively convenient to process, high in biocompatibility, strong in antibacterial property and capable of promoting osseointegration is provided, the implant is a high-entropy metal alloy, meanwhile, copper and gallium are alloyed, the excellent mechanical property of pure titanium is kept, copper ions and gallium ions can be released, and antibacterial property and osseointegration in the early stage of implantation are achieved.

Description

Technical Field

[0001] The present invention relates to the field of medical biomaterial manufacturing, in particular to the field of IPCC22C1, and more specifically to a high entropy alloy ingot and a preparation method and application thereof. Background Art

[0002] At present, titanium and its alloys are the preferred materials for repairing and replacing human hard tissues such as artificial joints and dental implants due to their excellent mechanical properties and high corrosion resistance in human body fluid environments. Common titanium-based implant materials include Ti-6Al-4V, which has a tensile strength of 895MPa-930MPa and an elongation of about 10%. It is the most widely used implant material, but there are the following problems: (1) The alloy contains V and Al elements that are harmful to the human body, especially V, which is cytotoxic and poses a safety hazard in long-term use. (2) The elastic modulus of the alloy (110GPa) is much higher than the modulus of human bone (10-30GPa). The serious mismatch of the elastic modulus causes a "stress shielding effect" at the interface between the implant and the bone. Long-term use will lead to aseptic loosening of the implant and shorten its service life. (3) The corrosion resistance of the alloy in human body fluid environment is significantly lower than that of titanium alloys containing elements such as Nb and Zr (Dai Shijuan et al., Electrochemical Corrosion Behavior of New Medical Ti-35Nb-4Sn-6Mo-9Zr and Ti-35Nb-1.3Mo-3.7Zr Alloys in Ringer's Solution, Rare Metal Materials and Engineering, 2014, 43:91-95). Its corrosion resistance needs to be further improved to extend the service life of the implant. (4) Implants such as artificial joints have complex shapes and usually require large plastic deformation processing, but the plastic deformation capacity of Ti-6Al-4V is still insufficient, which affects the processing efficiency and quality of the product.

[0003] The research on high entropy alloys has opened up a new field in the field of materials science. It goes beyond the design concept of traditional alloys. It no longer uses one element as the main element, but multiple elements work together, and no one element is the main element. It is generally defined as a type of alloy that is composed of five or more elemental components, each of which has a content between 5% and 35%, and is alloyed in an equiatomic ratio or close to an equiatomic ratio. Its mixing entropy is higher than the melting entropy of the alloy, and generally forms a high entropy solid solution. High entropy alloys have excellent mechanical properties that traditional alloys cannot match, such as high hardness, wear resistance, compression and tensile properties, heat resistance, oxidation resistance and corrosion resistance. It is also a hot topic in current research, and it is urgent to develop high entropy alloys with excellent comprehensive performance. Summary of the invention

[0004] A first aspect of the present invention provides a high entropy alloy ingot, wherein the raw materials for preparing the ingot include the following metals: Ti (titanium), Cu (copper), Zr (zirconium), Nb (niobium), Ta (tantalum) and Ga (gallium).

[0005] The molar ratio of Ti, Cu, Zr, Nb and Ta is 1:(0.5-1.5):(0.5-1.5):(0.5-1.5):(0.5-1.5).

[0006] Preferably, the molar ratio of Ti, Cu, Zr, Nb and Ta is 1:(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2).

[0007] The mass fraction of Ga in the high entropy alloy ingot is not higher than 5%.

[0008] Preferably, the mass fraction of Ga in the high entropy alloy ingot is 0.5-3%.

[0009] The present application has found that the molar ratio of Ti, Cu, Zr, Nb and Ta is 1: (0.5-1.5): (0.5-1.5): (0.5-1.5): (0.5-1.5), which can not only maintain the excellent mechanical properties of pure titanium, but also release copper and gallium ions to achieve long-lasting antibacterial and bone integration. Further research has found that the mass fraction of Ga in the high entropy alloy ingot is not more than 5%, which can inhibit bacterial adhesion, hinder biofilm formation, and prevent biofilm-related infections while maintaining mechanical properties; on the other hand, it can significantly inhibit the activity of osteoclast activation and has the potential to promote bone integration.

[0010] A second aspect of the present invention provides a method for preparing a high entropy alloy ingot, comprising the following steps: placing a metal in a crucible, evacuating the crucible, filling it with an inert gas, and melting it using an electric arc to obtain a high entropy alloy ingot.

[0011] Preferably, the smelting specifically comprises the following steps:

[0012] Step 1: Adjust the direction and distance between the electrode in the furnace and the electrode on the crucible so that they are aligned;

[0013] Step 2: Adjust the melting current, move the electrode in the furnace and the electrode on the crucible to make them contact and start an arc, separate the two electrodes after the arc is started, and use the arc to melt the metal;

[0014] Step 3: Repeat steps 1 and 2 to melt the metal repeatedly to ensure uniform melting.

[0015] The vacuum degree is 0.0001-0.0004Pa.

[0016] The smelting current is 570-610A.

[0017] Preferably, the smelting current is 580-597A.

[0018] The smelting is performed 10-15 times.

[0019] Preferably, the smelting is performed 11-14 times.

[0020] A third aspect of the present invention provides an application of a high entropy alloy ingot as a hard tissue repair and replacement material in the field of medical implants.

[0021] Beneficial effects:

[0022] 1. The high entropy alloy ingot prepared in this application can be used as a hard tissue repair and replacement material in the field of medical implants and has good biosafety.

[0023] 2. The mass fraction of Ga in the high entropy alloy ingot is not higher than 5%, which can inhibit bacterial adhesion, hinder biofilm formation, and prevent biofilm-related infections while maintaining mechanical properties; on the other hand, it can significantly inhibit the activity of osteoclast activation and has the potential to promote bone integration.

[0024] 3. The preparation method of the present application is simple and easy to control.

[0025] 4. The molar ratio of Ti, Cu, Zr, Nb and Ta is 1: (0.5-1.5): (0.5-1.5): (0.5-1.5):

[0026] (0.5-1.5), which can not only maintain the excellent mechanical properties of pure titanium, but also release copper and gallium ions.

[0027] Achieve early antibacterial and bone integration after implantation.

[0028] 5. The alloy material prepared in this application has a good angiogenic effect and provides nutritional support for tissues. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an electron microscope image of the high entropy alloy ingot prepared in Example 1.

[0030] Figure 2 The Ti element distribution in the high entropy alloy ingot prepared in Example 1.

[0031] Figure 3 The Ta element distribution in the high entropy alloy ingot prepared in Example 1.

[0032] Figure 4 The Nb element distribution in the high entropy alloy ingot prepared in Example 1.

[0033] Figure 5 The Zr element distribution in the high entropy alloy ingot prepared in Example 1.

[0034] Figure 6 The Cu element distribution in the high entropy alloy ingot prepared in Example 1.

[0035] Figure 7 The Ga element distribution in the high entropy alloy ingot prepared in Example 1.

[0036] Figure 8 It is a diagram showing the effect of bacterial growth on the surface of a high entropy alloy ingot under a laser confocal microscope, wherein the upper row of bacteria are Pa (Pseudomonas aeruginosa), and the lower row of bacteria are MRSA (Methicillin-resistant Staphylococcus aureus); from left to right, they correspond to the high entropy alloy ingots prepared by comparative example 2, comparative example 1, example 1, example 2, and example 3, respectively.

[0037] Fig. 9 These are the ALP (alkaline phosphatase) staining results after co-incubation of osteoclasts with different alloy extracts, which from left to right correspond to the high entropy alloy ingots prepared by comparative example 2, comparative example 1, example 1, example 2, and example 3, respectively.

[0038] Fig.10 The alloy extract was co-incubated with L929 cells, and the absorbance at OD450 (ordinate: optical density measurement under light with a wavelength of 450 nm) was measured. The blank control was the extract without adding the alloy.

[0039] Fig.11 The results of the tube formation experiment (observing whether the cells grow into a circle and form a vascular framework) of co-incubation of endothelial cells with different alloy extracts, which correspond from left to right to the high entropy alloy ingots prepared by comparative example 2, comparative example 1, example 1, example 2, and example 3. DETAILED DESCRIPTION

[0040] Example 1

[0041] A high entropy alloy ingot is prepared from the following metals: Ti (titanium), Cu (copper), Zr (zirconium), Nb (niobium), Ta (tantalum) and Ga (gallium).

[0042] The molar ratio of Ti, Cu, Zr, Nb and Ta is 1:1:1:1:1.

[0043] The mass fraction of Ga in the high entropy alloy ingot is 0.625%.

[0044] A method for preparing a high entropy alloy ingot, specifically comprising:

[0045] Preparation stage: (1) Open the furnace body, clean the electrodes and crucible, and use alcohol for cleaning, which evaporates quickly. (2) Put the metal to be smelted into the crucible, close the furnace body, tighten all fasteners evenly, and check that all valves of each device are in the closed state. (3) Turn on the main power switch, the circulating water valve, and turn on the circulating water power switch and power switch on the equipment in turn. After the equipment runs stably, turn on the molecular pump power switch of the control cabinet.

[0046] Vacuuming stage: (1) First stage vacuuming. After the equipment is stable, open the furnace valve and the machine pump switch power supply, start the pressure display screen, and during the vacuuming process, tighten the fasteners on the furnace cover and the furnace seal to ensure the sealing. (2) Second stage vacuuming. After the pressure in the furnace reaches the primary setting, open the molecular pump valve and molecular pump switch in turn, close the furnace valve, and turn off the machine pump switch. (3) After the pressure in the furnace reaches the setting, close the molecular pump valve and molecular pump button switch in turn, and the equipment is vacuumed. (4) Fill the vacuumed furnace with 99.99% high-purity argon gas to reach one atmosphere.

[0047] Melting stage: (1) Align the moving electrode with the electrode on the crucible, and observe in real time through the observation window during the movement to ensure that the distance between the two reaches the required value. (2) Increase the current, prepare for melting, press the arc starting button, and use the hand wheel on the joystick to move the two electrodes in the furnace to contact and start the arc. After the arc is started, immediately turn the hand wheel to separate the two electrodes, and use the joystick to move the moving electrode away to prevent burning the electrode on the crucible. (3) Use the arc to melt the metals to be melted in turn. After melting is completed, turn off the arc. (4) Use the robot to flip the metal in the crucible and melt the metal repeatedly to ensure uniform melting.

[0048] Ending stage: (1) Open the furnace body, clean the furnace cavity, remove smoke, sand and splashed metal, clean the copper mold and put it back into the mold channel, and tighten the sealing cover. (2) After the furnace cavity is cleaned and blown dry, close the furnace body and evacuate at the same time. (3) After evacuation, turn off the molecular pump switch, circulating water switch, external circulating water valve, power switch, etc. in turn. (4) Check the switches of the equipment and the valves are in the correct opening and closing state. The experiment is completed.

[0049] The vacuum degree is 0.0001 Pa; the smelting current is 590 A; and the number of smelting is 12 times.

[0050] Example 2

[0051] The specific implementation is the same as in Example 1; the difference is that in Example 2, the mass fraction of Ga in the high entropy alloy ingot is 1.25%.

[0052] Example 3

[0053] The specific implementation is the same as in Example 1; the difference is that in Example 3, the mass fraction of Ga in the high entropy alloy ingot is 2.5%.

[0054] Comparative Example 1

[0055] The specific implementation is the same as that of Example 1; the difference is that in Comparative Example 1, no metal Ga (gallium) is added.

[0056] Comparative Example 2

[0057] A high entropy alloy ingot made of TC-4 titanium alloy purchased from Baoti Group.

[0058] Performance Testing Methods and Data

[0059] 1. Scanning electron microscope image ( Figure 1 ) and the corresponding element distribution analysis ( Figure 2-7 ), Figure 1-7 The test results show that the Ti, Cu, Zr, Nb, Ta and Ga alloy system was successfully prepared.

[0060] 2. Antibacterial effect test: observe the biofilm formation of Pa (Pseudomonas aeruginosa) and MRSA (Methicillin-resistant Staphylococcus aureus) on the alloy. The results are as follows: Figure 8 As shown, the antibacterial effect of the high entropy alloy ingots of Examples 1-3 shows an increasing trend, the antibacterial effect of the high entropy alloy ingot of Comparative Example 1 is significantly weaker than that of Examples 1-3, and Comparative Example 2 has almost no antibacterial effect.

[0061] 3. Test of the effect of inhibiting osteoclast differentiation: Observe the results of osteoclast tartrate-resistant acid phosphatase (TRAP) staining in different alloy extracts. Fig. 9 As shown, with the increase of Ga addition, the effect of the alloy in inhibiting osteoclast differentiation gradually improves, indicating that the alloy prepared in the present application has a good effect of inhibiting osteoclast differentiation.

[0062] 4. Cytotoxicity test: The alloy extract was co-incubated with L929 cells (3 days), and the absorbance at OD450 (optical density measurement under light with a wavelength of 450nm) was observed to test its cytotoxicity, such as Fig.10 As shown, compared with the commonly used TC-4 titanium alloy (Comparative Example 2), the gallium-containing high entropy alloy has no cytotoxicity and can be considered to have good biosafety.

[0063] 5. Test of promoting angiogenesis: Co-incubate the alloy extract with endothelial cells and observe the results of the tube formation experiment (observe whether the cells grow into a circle and form a vascular framework). Fig.11 As shown, the introduction of Cu element makes the alloy have a better effect in promoting angiogenesis.

[0064] The alloy leaching solution: Calculate the alloy surface area, based on 1.25cm 2 The alloy was immersed in α-MEM complete medium (10% FBS, 1% double antibody) at a ratio of 5:1 / mL and immersed at 37°C for 24 h. The alloy had a diameter of 5 mm and a thickness of 1 mm.

Claims

1. A high entropy alloy ingot, characterized in that: The raw materials for preparation include the following metals: Ti, Cu, Zr, Nb, Ta and Ga.

2. The high entropy alloy ingot according to claim 1, characterized in that: The molar ratio of Ti, Cu, Zr, Nb and Ta is 1:(0.5-1.5):(0.5-1.5):(0.5-1.5):(0.5-1.5).

3. The high entropy alloy ingot according to claim 2, characterized in that: The mass fraction of Ga in the high entropy alloy ingot is not higher than 5%.

4. The high entropy alloy ingot according to claim 3, characterized in that: The mass fraction of Ga in the high entropy alloy ingot is 0.5-3%.

5. A method for preparing a high entropy alloy ingot according to any one of claims 1 to 4, characterized in that: The following steps are involved: The metal is placed in a crucible, evacuated and filled with inert gas, and then melted using an electric arc to obtain a high entropy alloy ingot.

6. The method for preparing a high entropy alloy ingot according to claim 5, characterized in that: The smelting specifically comprises the following steps: Step 1: Adjust the direction and distance between the electrode inside the furnace and the electrode on the crucible; Step 2: Adjust the melting current, and move the electrode in the furnace and the electrode on the crucible to make them contact and start an arc. After the arc is started, separate the two electrodes and use the arc to melt the metal. Step 3: Repeat steps 1 and 2 to melt the metal repeatedly.

7. The method for preparing a high entropy alloy ingot according to claim 6, characterized in that: The vacuum degree is 0.0001-0.0004Pa.

8. The method for preparing a high entropy alloy ingot according to claim 7, characterized in that: The smelting current is 570-610A.

9. The method for preparing a high entropy alloy ingot according to claim 6, characterized in that: The smelting is performed 10-15 times.

10. An application of the high entropy alloy ingot according to any one of claims 1 to 4, characterized in that: It is used as a hard tissue repair material in the field of medical implants.

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