High-strength low-modulus Ti-Nb-Zr biomedical titanium alloy and preparation method thereof

Abstract

The application discloses a kind of high-strength low elastic modulus Ti-Nb-Zr biomedical titanium alloy and preparation method thereof, alloy ingot is prepared using vacuum melting, and solid solution quenching, titanium alloy plate is prepared using cold working large deformation.The biomedical titanium alloy preparation method of the application, control cold working deformation rate reaches more than 90%.The alloy obtained using the method of the application has low modulus, high strength, superelasticity, shape memory, damping characteristics, corrosion resistance and high biocompatibility.The modulus of the titanium alloy obtained by the application is similar to the modulus of human bone, and can be used as a bone graft or medical device.The Ti-Nb-Zr alloy prepared using the method of the application has excellent performance, the tensile strength is not less than 1000MPa, the elastic modulus is not higher than 60GPa, and the superelastic strain is not less than 2.2%.

Description

Technical Field

[0001] This invention relates to the field of alloy materials technology, and in particular to a novel high-strength, low-elastic-modulus Ti-Nb-Zr biomedical titanium alloy material and its preparation method. Background Technology

[0002] With rapid economic development and an aging population, the market demand for biomedical materials is growing strongly. Biomedical materials specifically refer to a class of functional structural materials used in biomedical engineering, particularly in the production and manufacturing of surgical implants and orthopedic devices.

[0003] Titanium alloys possess excellent biomechanical properties and good corrosion resistance, and are currently widely used in biomedical implant materials. While the elongation of implant materials has largely met requirements, the high elastic modulus remains a key issue limiting their implantation outcomes. Currently, the most widely used biomedical alloys in clinical medicine are 316 stainless steel (elastic modulus ~200 GPa) and α+β type titanium alloy Ti-6Al-4V (elastic modulus 110 GPa). Both have moduli far exceeding the modulus of human bone (cortical bone modulus ~30 GPa). Implanting these materials into the human body will cause a serious "stress shielding" problem. The difference in modulus causes the implant to bear greater stress, significantly reducing the stress borne by the bone. This leads to the bone near the implant not receiving the necessary exercise and gradually atrophying, ultimately resulting in implant failure.

[0004] Furthermore, 316 stainless steel and Ti-6Al-4V contain a large number of toxic metallic elements. When these materials are implanted in the human body, due to prolonged wear and tear and corrosion from bodily fluids, metal ions migrate out of the implant and into the body, causing serious toxic side effects. For example, Cr ions in 316 stainless steel can damage the skin and respiratory tract, causing inflammation, ulcers, and even acute renal failure; excessive Cu ions can also lead to hemolysis. Similarly, Al ions in Ti-6Al-4V can cause osteoporosis and mental disorders, while V ions have been proven to cause malignant tissue reactions.

[0005] Ti-Ni-based titanium alloys exhibit excellent superelasticity around body temperature (~37°C), making them an important biomedical implant material. However, the migration of Ni ions can cause allergic reactions in humans, raising concerns about their long-term safety. Beta-type titanium alloys, such as Ti-13Nb-13Zr and "Gum" titanium alloys, offer advantages in biocompatibility and mechanical properties. Therefore, beta-type titanium alloys have become a research hotspot for novel medical titanium alloys.

[0006] To further reduce the elastic modulus of β-type titanium alloys and better enable their application in the biomedical field, researchers have begun to study the influence of elemental doping on the properties of β-type titanium alloys. For example, patent CN113215442A discloses a biomedical titanium alloy and its preparation method. The alloy's chemical composition, by mass percentage, includes 5-20% Zr, 5.5-6% Al, 6.5-7.5% Nb, and the remainder Ti. While doping Al and Zr into the TiNb alloy helps reduce the elastic modulus, the resulting Ti-Al-Nb-Zr alloy still has a relatively high elastic modulus, exceeding 60 GPa. On the other hand, the alloy's tensile strength is low, below 900 MPa. The low tensile strength and high modulus will limit the widespread application of β-type titanium alloys in the biomedical field, necessitating further improvements.

[0007] Therefore, it is necessary to develop a method for preparing β-type titanium alloy materials so that the prepared alloy has both a lower elastic modulus and a higher tensile strength, thereby improving the biomechanical properties of β-type titanium alloy materials and further expanding their application fields. Summary of the Invention

[0008] This invention addresses the problems of insufficient strength and relatively high elastic modulus in current titanium alloy implant materials. It aims to provide a novel biomedical titanium alloy with high strength and low elastic modulus, as well as its preparation method, to obtain a β-type titanium alloy with both higher strength and lower modulus.

[0009] To achieve the above objectives, this invention provides a method for preparing a high-strength, low-elastic-modulus Ti-Nb-Zr biomedical titanium alloy, comprising the following steps:

[0010] (1) Put three metal particles of titanium (Ti), niobium (Nb) and zirconium (Zr) into a vacuum melting furnace to produce Ti-Nb-Zr alloy ingots;

[0011] (2) The Ti-Nb-Zr alloy ingot obtained in step (1) is packaged in a quartz tube and filled with argon gas. After being heated to 800-1200℃ in a heat treatment furnace, the sample is placed in the quartz tube and homogenized for 6-48 hours. After cooling, a solid solution Ti-Nb-Zr alloy is obtained.

[0012] (3) The solid solution Ti-Nb-Zr alloy obtained in step (2) is subjected to cold working to obtain Ti-Nb-Zr alloy material, and the deformation during cold working is greater than 90%.

[0013] To improve the tensile strength of Ti-Nb-Zr alloys while maintaining a low elastic modulus, this invention employs a method that involves cold-working the prepared solid-solution Ti-Nb-Zr alloy to achieve a deformation rate greater than 90%. By increasing the cold-working deformation, the strength of the material is improved while its elastic modulus is reduced.

[0014] In one embodiment of the present invention, the Ti-Nb-Zr alloy material, by atomic percentage, has an Nb content of 10-30%, a Zr content of 1-25%, and the balance being Ti.

[0015] In one embodiment of the present invention, the Ti-Nb-Zr alloy material, by atomic percentage, has an Nb content of 13-28%, a Zr content of 1-15%, and the balance being Ti.

[0016] In one embodiment of the present invention, the Ti-Nb-Zr alloy material, by atomic percentage, has an Nb content of 15-26%, a Zr content of 2-10%, and the balance being Ti.

[0017] In one embodiment of the present invention, the Ti-Nb-Zr alloy material, by atomic percentage, has an Nb content of 15-25%, a Zr content of 3-10%, and the balance being Ti.

[0018] In one embodiment of the present invention, the Ti-Nb-Zr alloy material, by atomic percentage, has an Nb content of 18-22%, a Zr content of 3-8%, and the balance being Ti.

[0019] In one embodiment of the present invention, the purity of Ti, Nb, and Zr is not less than 99.9%.

[0020] In one embodiment of the present invention, in step (1), the titanium, niobium and zirconium metal particles are melted in a vacuum melting furnace 6 to 10 times, preferably 8 times.

[0021] In one embodiment of the present invention, step (2) further includes the step of using an electrical discharge machining (EDM) machine to cut off the four corners of the ingot before encapsulating the Ti-Nb-Zr alloy ingot.

[0022] In one embodiment of the present invention, in step (2), the cooling method includes water quenching or ice-salt water quenching.

[0023] In one embodiment of the present invention, before cold working the solution-treated Ti-Nb-Zr alloy in step (3), the method further includes removing the oxide scale on the surface of the solution-treated Ti-Nb-Zr alloy using a grinding wheel. Removing the oxide scale from the alloy surface before cold working prevents cracks in the ingot during the cold working process, which could lead to cold working failure.

[0024] In one embodiment of the present invention, in step (3), the cold working includes at least one of cold rolling, cold drawing, cold forging or cold heading.

[0025] In one embodiment of the present invention, in step (3), the deformation during cold working is 92-98%.

[0026] In one embodiment of the present invention, in step (3), multiple cold working processes are required, with a single deformation amount of 0.1 to 4%.

[0027] In one embodiment of the present invention, in step (3), the number of cold working processes is 30 to 55.

[0028] The present invention also discloses a Ti-Nb-Zr alloy obtained according to the above preparation method.

[0029] The purpose of this invention is to provide an application of the above-mentioned Ti-Nb-Zr alloy in biomedical devices, aerospace equipment, and sports equipment.

[0030] In one embodiment of the present invention, the use includes the use of Ti-Nb-Zr alloy in biomedical human implants, the biomedical human implants including artificial knee joints, hip joints, femoral stems, pelvic bones, bone marrow, screws, and tooth roots, etc.

[0031] Beneficial effects

[0032] 1. This invention uses a vacuum melting process to produce a Ti-Nb-Zr alloy, followed by heat treatment and cold working to obtain the alloy material. By controlling the deformation during cold working to be greater than 90%, the elastic modulus of the alloy is reduced, and the tensile strength of the alloy is increased.

[0033] 2. The alloy obtained by the method of this invention possesses low modulus, high strength, superelasticity, shape memory, damping properties, corrosion resistance, and high biocompatibility. The titanium alloy obtained by this invention has a modulus similar to that of human bone, making it suitable for use as a bone graft or medical device.

[0034] 3. The Ti-Nb-Zr alloy prepared by the method of the present invention has excellent properties, with a tensile strength of not less than 1000 MPa, an elastic modulus of not more than 60 GPa, and a hyperelastic strain of not less than 2.2%. Attached Figure Description

[0035] Figure 1 This is a diagram showing the dimensions of the tensile test sample.

[0036] Figure 2 The metallographic microstructure of the Ti-20Nb-3Zr alloy after solution treatment in Example 1;

[0037] Figure 3 The tensile hyperelastic curve of the finished product of cold-deformed titanium alloy Ti-20Nb-3Zr in Example 1;

[0038] Figure 4 The tensile stress-strain curve of the cold-deformed titanium alloy Ti-20Nb-3Zr sheet product in Example 1 is shown.

[0039] Figure 5 The metallographic microstructure of the Ti-20Nb-6Zr alloy after solution treatment in Example 2;

[0040] Figure 6 The tensile hyperelastic curve of the finished product of cold-deformed titanium alloy Ti-20Nb-6Zr in Example 2;

[0041] Figure 7 The tensile stress-strain curve of the cold-deformed titanium alloy Ti-20Nb-6Zr sheet product in Example 2 is shown.

[0042] Figure 8 The tensile hyperelastic curve of the cold-deformed titanium alloy Ti-20Nb-6Zr sheet product in Example 3;

[0043] Figure 9 The tensile stress-strain curve of the cold-deformed titanium alloy Ti-20Nb-6Zr sheet material in Example 3 is shown.

[0044] Figure 10 The tensile hyperelastic curve of the finished product of cold-deformed titanium alloy Ti-20Nb in Comparative Example 1;

[0045] Figure 11 The tensile stress-strain curves of the cold-deformed titanium alloy Ti-20Nb sheet material in Comparative Example 1 are shown. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1

[0048] Titanium (Ti), niobium (Nb), and zirconium (Zr) particles were weighed according to an atomic percentage of 77:20:3. These particles were repeatedly melted eight times in a vacuum non-consumable argon arc melting furnace to produce an alloy ingot. The four corners of the alloy ingot were removed using an EDM machine, and the ingot was encapsulated in a quartz tube filled with argon gas. After being heated to 1100°C in a heat treatment furnace, the sample was placed in the quartz tube and homogenized for 24 hours. Then, it was quenched with ice-salt water to obtain a solution-treated Ti-20Nb-3Zr alloy. The oxide scale on the quenched alloy surface was removed using a grinding wheel. At room temperature, the solution-treated Ti-20Nb-3Zr alloy was cold-rolled into a sheet using a two-roll mill with a cold deformation rate of 95% and a reduction of 2–3% per roll, resulting in the finished titanium alloy Ti-20Nb-3Zr sheet.

[0049] Ti-20Nb-3Zr plates were cut using an electrical discharge machining (EDM) machine to prepare samples for microstructure observation. The samples were then placed in a heat treatment furnace heated to 800°C, subjected to solution treatment for 1 hour, and then quenched in ice-salt water to obtain the solution-treated Ti-20Nb-3Zr alloy. Figure 2 The image shows the metallographic microstructure of the Ti-20Nb-3Zr alloy after solution treatment, with a grain size of approximately 15 μm.

[0050] Ti-20Nb-3Zr plates were cut using an electrical discharge machining (EDM) machine to produce finished products, such as... Figure 1 The tensile test specimen is shown. Strain was measured using an extensometer at room temperature and at a strain rate of 2 × 10⁻⁶. -4 s -1 Tensile tests were conducted on the prepared tensile test specimens under the specified conditions, and the mechanical properties were as follows: Figure 3 , 4 As shown. From Figure 3 As can be seen, after stretching training, the obtained Ti-20Nb-3Zr titanium alloy exhibits a hyperelastic strain of 2.24% and an elastic modulus of 49 GPa; from Figure 4 It can be seen that the tensile strength of Ti-20Nb-3Zr titanium alloy is 1055MPa and the elastic modulus is 55GPa.

[0051] Example 2

[0052] Titanium (Ti), niobium (Nb), and zirconium (Zr) particles were weighed according to an atomic percentage ratio of 74:20:6. These particles were repeatedly melted eight times in a vacuum non-consumable argon arc melting furnace to produce an alloy ingot. The four corners of the alloy ingot were removed using an EDM machine, and the ingot was encapsulated in a quartz tube filled with argon gas. After being heated to 1100°C in a heat treatment furnace, the sample was placed in the quartz tube and homogenized for 24 hours. Then, it was quenched in ice-salt water to obtain a solution-treated Ti-20Nb-6Zr alloy. The oxide scale on the surface of the quenched alloy was removed using a grinding wheel. At room temperature, the solution-treated Ti-20Nb-6Zr alloy was cold-rolled into a sheet using a two-roll mill with a cold deformation rate of 95% and a reduction of 2–3% per roll, thus obtaining the finished titanium alloy Ti-20Nb-6Zr sheet.

[0053] Ti-20Nb-6Zr titanium alloy plates were obtained, and samples for observation of microstructure were prepared using an electric discharge cutting machine. The samples were placed in a heat treatment furnace heated to 800℃ and subjected to solution treatment for 1 hour. The samples were then quenched in ice-salt water after solution treatment to obtain the solution-treated Ti-20Nb-6Zr alloy. Figure 5 The image shows the metallographic microstructure of Ti-20Nb-6Zr after solution treatment, with a grain size of approximately 28 μm.

[0054] Ti-20Nb-6Zr plates were cut using an electrical discharge machining (EDM) machine to produce finished products, such as... Figure 1 The tensile test specimen is shown. Strain was measured using an extensometer at room temperature and at a strain rate of 2 × 10⁻⁶. -4 s -1 Tensile tests were conducted on the prepared tensile test specimens under the specified conditions, and the mechanical properties were as follows: Figure 6 , 7 As shown. From Figure 6 As can be seen, after stretching training, the obtained Ti-20Nb-6Zr titanium alloy exhibits a hyperelastic strain of 2.37% and an elastic modulus of 52 GPa; from Figure 7 As can be seen, the tensile strength of Ti-20Nb-6Zr titanium alloy is 1021MPa and the elastic modulus is 59GPa.

[0055] Example 3

[0056] Titanium (Ti), niobium (Nb), and zirconium (Zr) particles were weighed according to an atomic percentage of 74:20:6. These particles were repeatedly melted eight times in a vacuum non-consumable argon arc melting furnace to produce an alloy ingot. The four corners of the alloy ingot were removed using an EDM machine, and the ingot was encapsulated in a quartz tube filled with argon gas. After being heated to 1100°C in a heat treatment furnace, the sample was placed in the quartz tube and homogenized for 24 hours. Then, it was quenched in ice-salt water to obtain a solution-treated Ti-20Nb-6Zr alloy. The oxide scale on the surface of the quenched alloy was removed using a grinding wheel. At room temperature, the solution-treated Ti-20Nb-6Zr alloy was cold-rolled into a sheet using a two-roll mill with a cold deformation rate of 97% and a pressing amount of 2% per roll, thus obtaining the finished titanium alloy Ti-20Nb-6Zr sheet.

[0057] The Ti-20Nb-6Zr plate obtained by electrical discharge machining is used to prepare the following... Figure 1 The tensile test specimen is shown. Strain was measured using an extensometer at room temperature and at a strain rate of 2 × 10⁻⁶. -4 s -1 Tensile tests were conducted on the prepared tensile test specimens under the specified conditions, and the mechanical properties were as follows: Figure 8 , 9 As shown. From Figure 8 As can be seen, after stretching training, the obtained Ti-20Nb-6Zr titanium alloy exhibits a hyperelastic strain of 2.58% and an elastic modulus of 43 GPa; from Figure 9 As can be seen, the tensile strength of Ti-20Nb-6Zr titanium alloy is 1060MPa and the elastic modulus is 47GPa.

[0058] Comparative Example 1

[0059] Titanium (Ti) and niobium (Nb) particles were weighed at an atomic ratio of 80:20 and repeatedly melted eight times in a vacuum non-consumable argon arc melting furnace to produce an alloy ingot. The four corners of the alloy ingot were removed using an electric discharge cutting machine, and the ingot was encapsulated in a quartz tube and filled with argon gas. After being heated to 1100°C in a heat treatment furnace, the sample was placed in the quartz tube and homogenized for 24 hours. Then, it was quenched with ice-salt water to obtain a solution-treated Ti-20Nb alloy. The oxide scale on the surface of the quenched alloy was removed using a grinding wheel. At room temperature, the solution-treated Ti-20Nb alloy was cold-rolled into a sheet using a two-roll mill with a cold deformation of 95% and a pressing amount of 2% per roll to obtain the finished titanium alloy Ti-20Nb sheet.

[0060] Ti-20Nb plates were cut using an electrical discharge machining (EDM) machine to produce finished products, such as... Figure 1 The tensile test specimen is shown. Strain was measured using an extensometer at room temperature and at a strain rate of 2 × 10⁻⁶. -4 s -1Tensile tests were conducted on the prepared tensile test specimens under the specified conditions, and the mechanical properties were as follows: Figure 10 , 11 As shown. From Figure 10 As can be seen, after stretching training, the obtained Ti-20Nb titanium alloy exhibits a hyperelastic strain of 2.07% and an elastic modulus of 60 GPa; from Figure 11 As can be seen, the tensile strength of Ti-20Nb titanium alloy is 956MPa and the elastic modulus is 67GPa.

Claims

1. A method for preparing a high-strength, low-modulus Ti-Nb-Zr biomedical titanium alloy, characterized in that, Includes the following steps: (1) Put three metal particles of titanium (Ti), niobium (Nb) and zirconium (Zr) into a vacuum melting furnace to produce Ti-Nb-Zr alloy ingots. In the Ti-Nb-Zr alloy ingots, the Nb content is 18-22% and the Zr content is 3-6% by atomic percentage, with the balance being Ti. (2) The Ti-Nb-Zr alloy ingot obtained in step (1) is packaged in a quartz tube and filled with argon gas. After being heated to 800-1200℃ in a heat treatment furnace, the sample is placed in the quartz tube and homogenized for 6-48 hours. After cooling, a solid solution Ti-Nb-Zr alloy is obtained. (3) The solid solution Ti-Nb-Zr alloy obtained in step (2) is subjected to cold working to obtain Ti-Nb-Zr alloy material. The deformation during cold working is 95-97%; the number of cold working treatments is 30-55 times, and the deformation during a single cold working treatment is 0.1-4%.

2. The preparation method according to claim 1, characterized in that, The purity of the Ti, Nb, and Zr is not less than 99.9%.

3. The preparation method according to claim 1, characterized in that, In step (2), before encapsulating the Ti-Nb-Zr alloy ingot, the process also includes cutting off the four corners of the ingot using an electrical discharge machine.

4. The preparation method according to claim 1, characterized in that, In step (2), the cooling method includes water quenching or ice-salt water quenching.

5. The preparation method according to claim 1, characterized in that, In step (3), before the solid solution Ti-Nb-Zr alloy is cold-worked, the step of removing the oxide scale on the surface of the solid solution Ti-Nb-Zr alloy using a grinding wheel is also included.

6. The preparation method according to claim 1, characterized in that, The cold working includes at least one of cold rolling, cold drawing, cold forging, and cold heading.

7. The Ti-Nb-Zr alloy material prepared by the preparation method according to any one of claims 1 to 6.

8. The use of the Ti-Nb-Zr alloy material according to claim 7 in biomedical devices, aerospace equipment, and sports equipment.

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