Biomedical six-element β-titanium alloy having low elastic modulus and high plasticity

Abstract

The present invention belongs to the fields of medical titanium alloys and biomedical materials, and the objective thereof is to provide a biomedical six-element β-titanium alloy having a low elastic modulus and high plasticity. The alloy elements comprise the β stabilizing elements Mo, Nb, Ta, Fe, and the neutral element Zr. The mass percentage ranges of the alloy components are: Ti-Mo (2-13%)-Nb (15-25%)-Zr (10-20%)-Ta (3-10%)-Fe (0.5-2%). Performance indicators of the alloy are respectively: an elastic modulus of 50.6-76.8 GPa; a tensile strength of 692.5-819.3 MPa; and an elongation of 26.4-35.2%. The six-element β-titanium alloy of the present invention does not contain alloy elements harmful to the human body such as Al, V, and Ni, and has a low elastic modulus while having high strength and plasticity. The six-element β-titanium alloy is a biomedical β-titanium alloy material having excellent comprehensive properties.

Description

A biomedical hexa-β titanium alloy with low elastic modulus and high plasticity Technical Field

[0001] This invention belongs to the field of medical titanium alloys and biomedical materials, specifically relating to a biomedical hexa-β titanium alloy with low elastic modulus and high plasticity. Background Technology

[0002] Titanium alloys possess advantages such as high specific strength, low elastic modulus, excellent corrosion resistance, good high and low temperature processing performance, and good biocompatibility. They are gradually replacing traditional biomedical metal materials such as stainless steel and cobalt-based alloys, becoming the preferred choice for medical implants such as artificial joints, cardiovascular repair products, bone trauma products, spinal orthopedic internal fixation systems, and dental implants, and have a broad market prospect in the biomedical field. Among them, Ti-6Al-4V alloy is widely used as a surgical implant material due to its excellent comprehensive properties, and is one of the most widely used and representative titanium alloys in the medical field to date. However, the Al and V elements in this alloy may pose potential hazards to the human body, and the alloy's elastic modulus (approximately 110 GPa) is much higher than that of human bone and other hard tissues (approximately 10-30 GPa). After implantation, this may lead to a "stress shielding" phenomenon, i.e., mechanical incompatibility between the implant and surrounding tissues, resulting in serious consequences such as bone tissue damage and implant failure. Therefore, the current research and development focus of biomedical titanium alloys is gradually shifting to β-titanium alloys. β-titanium alloys generally do not contain alloying elements harmful to the human body and have a low elastic modulus, exhibiting good biocompatibility and better matching the biological and mechanical properties of human tissues. However, most β-titanium alloys have lower strength and ductility compared to traditional α+β titanium alloys such as Ti-6Al-4V, and their elastic modulus is still higher than that of human bone, making it difficult to meet the mechanical performance requirements of implants in stress-bearing areas of the human body. Currently, only some β-titanium alloys, such as Ti-15Mo, Ti-13Nb-13Zr, Ti-12Mo-6Zr-2Fe, Ti-15Zr-4Nb-2Ta-0.2Pd, and Ti-15Mo-5Z-3Al, have been included in international standards and have been used clinically.

[0003] European patent EP0437079B1 reports a Ti-Nb-Zr ternary β-titanium alloy system with high strength and low elastic modulus. Among them, Ti-13Nb-13Zr exhibits the best comprehensive mechanical properties, with an elastic modulus of 60-65 GPa, a tensile strength of 700 MPa, and an elongation of 25%. US patent US6238491 reports a Ti-Nb-Zr-Mo quaternary β-titanium alloy system. This titanium alloy contains approximately 29-70% Nb, approximately 10-46% Zr, and approximately 3-15% Mo. The most preferred alloy is Ti-35Nb-25Zr-5Mo, which has an elastic modulus below 90 GPa after annealing, a tensile strength above 930 MPa, and an elongation of 16%. Patent CN1217022C reports a Ti-Mo-Nb-Zr-Sn pentagonal β-titanium alloy system with low elastic modulus, high strength, good plasticity, and relatively low cost. This titanium alloy specifically contains approximately 1.5-4.5% Zr, 0.5-5.5% Sn, 1.5-4.4% Mo, and 23.5-26.5% Nb. The Ti-3Mo-25Nb-3Zr-2Sn alloy has an elastic modulus of only 58 GPa, a tensile strength of 760 MPa, and an elongation of 21.5%. Patent CN101081312A reports a Ti-Nb-Zr-Mo-Fe pentagonal β-titanium alloy system with high strength, low elastic modulus, and good machinability. This titanium alloy contains approximately 25-30% Nb, 1%-5% Zr, 0.2-1% Fe, and 10-15% Mo. The Ti-25Nb-5Zr-0.2Fe-15Mo alloy has an elastic modulus of only 45 GPa, a tensile strength of 700 MPa, and an elongation of 18%.

[0004] Most of the β-titanium alloys currently reported in patents are binary to pentagonal alloy systems. These alloys each have their own characteristics in terms of composition and mechanical properties, but they also have shortcomings. For example, while some β-titanium alloys have a low elastic modulus, their strength and plasticity are also low, making processing and forming difficult and failing to meet the performance requirements of titanium alloy implants. In addition, some alloys use a large amount of expensive refractory metals, such as Ta and Nb, which makes the alloy ingot smelting process difficult and the quality difficult to control effectively, leading to increased raw material and processing costs. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a biomedical hexa-β titanium alloy with high strength, high elongation, and low elastic modulus.

[0006] The present invention adopts the following technical solution:

[0007] A biomedical hexa-β titanium alloy with low elastic modulus and high plasticity, wherein the alloying elements include β-stabilizing elements Mo, Nb, Ta, and Fe, and neutral element Zr, and the mass percentage of the alloy composition range is: Ti-Mo (2%-13%)-Nb (15%-25%)-Zr (10%-20%)-Ta (3%-10%)-Fe (0.5%-2%).

[0008] Furthermore, the mass percentage of the alloy composition is: Ti-%10Mo-%20Nb-%10Zr-%5Ta-%1Fe.

[0009] Furthermore, the mass percentage of the alloy composition is: Ti-%5Mo-%20Nb-%10Zr-%5Ta-%1Fe.

[0010] Furthermore, the mass percentage of the alloy composition is: Ti-%5Mo-%20Nb-%10Zr-%5Ta-%1.5Fe.

[0011] The preparation process of the alloy of this invention is as follows: High-purity Ti, Mo, Nb, Ta, Fe, and Zr raw material metals, or high-purity intermediate alloys, are selected and batched according to the alloy composition, then mixed uniformly. The alloy is smelted using methods suitable for β-titanium alloys, such as a vacuum arc furnace or a vacuum induction furnace, and smelted repeatedly 3-5 times to obtain an alloy ingot. The smelted alloy ingot needs to be solution-treated at 800-1200 °C for 1-5 hours and then water-cooled to room temperature to obtain a uniform microstructure.

[0012] The beneficial effects of this invention are as follows:

[0013] 1. It does not contain alloying elements such as Ni, Al, and V that are harmful to the human body, and has excellent biocompatibility;

[0014] 2. The alloy has a low elastic modulus, but also high strength and plasticity, resulting in excellent comprehensive mechanical properties;

[0015] 3. By adding appropriate amounts of low-cost elements such as Mo and Fe to partially replace expensive β-alloying elements such as Nb and Ta, the cost of the alloy can be reduced. Attached Figure Description

[0016] Figure 1 is a metallographic diagram of the Ti-10Mo-20Nb-10Zr-5Ta-1Fe alloy in Example 1 provided by the present invention.

[0017] Figure 2 is an X-ray diffraction pattern of the Ti-10Mo-20Nb-10Zr-5Ta-1Fe alloy in Example 1 provided by the present invention.

[0018] Figure 3 is a metallographic diagram of the Ti-5Mo-20Nb-10Zr-5Ta-1Fe alloy in Example 2 of the present invention.

[0019] Figure 4 is an X-ray diffraction pattern of the Ti-5Mo-20Nb-10Zr-5Ta-1Fe alloy in Example 2 provided by the present invention.

[0020] Figure 5 shows the metallographic structure of the Ti-5Mo-20Nb-10Zr-5Ta-1.5Fe alloy in Example 3 of the present invention.

[0021] Figure 6 is an X-ray diffraction pattern of the Ti-5Mo-20Nb-10Zr-5Ta-1.5Fe alloy in Example 3 of the present invention. Detailed Implementation

[0022] A biomedical hexa-β titanium alloy with low elastic modulus and high plasticity, wherein the alloying elements include β-stabilizing elements Mo, Nb, Ta, and Fe, and neutral element Zr, and the mass percentage of the alloy composition range is: Ti-Mo (2%-13%)-Nb (15%-25%)-Zr (10%-20%)-Ta (3%-10%)-Fe (0.5%-2%). Example

[0023] This embodiment relates to a Ti-Mo-Nb-Zr-Ta-Fe hexa-element β-titanium alloy, specifically with the alloy composition Ti-10Mo-20Nb-10Zr-5Ta-1Fe (wt.%).

[0024] This embodiment also relates to a method for the preparation and analysis of a hexa-element β-titanium alloy, which mainly includes the following steps:

[0025] Step one: Select high-purity Ti, Mo, Nb, Ta, Fe, and Zr raw material metals, and mix them evenly according to the alloy composition. Melt the alloy three times repeatedly in a vacuum arc melting furnace to obtain an alloy ingot. The melting process must be carried out under argon protection. The resulting alloy ingot is approximately 9 cm high and 10 cm in diameter.

[0026] Step 2: Place the smelted alloy ingot in a box furnace for solution treatment at a temperature of 1000 ℃ for 2 hours. After solution treatment, cool it to room temperature with water.

[0027] Step 3: The microstructure, phase composition and mechanical properties of the alloy are obtained by using a metallographic microscope, XRD diffractometer and uniaxial tensile test.

[0028] Results: The Ti-10Mo-20Nb-10Zr-5Ta-1Fe alloy β-titanium alloy prepared in this embodiment consists of a single β phase, with equiaxed and uniformly distributed β grains. After three uniaxial tensile tests, the alloy's average elastic modulus was 76.8 GPa, average tensile strength was 819.3 MPa, and average elongation was 29.7%. The as-cast alloy exhibits high strength and plasticity, demonstrating excellent comprehensive mechanical properties. Example

[0029] This embodiment relates to a Ti-Mo-Nb-Zr-Ta-Fe hexa-element β-titanium alloy, specifically with the alloy composition Ti-5Mo-20Nb-10Zr-5Ta-1Fe (wt.%).

[0030] This embodiment also relates to a method for the preparation and analysis of a hexa-element β-titanium alloy, which mainly includes the following steps:

[0031] Step one: Select high-purity Ti, Mo, Nb, Ta, Fe, and Zr raw material metals, and mix them evenly according to the alloy composition. Melt the alloy three times repeatedly in a vacuum arc melting furnace to obtain an alloy ingot. The melting process must be carried out under argon protection. The resulting alloy ingot is approximately 9 cm high and 10 cm in diameter.

[0032] Step 2: Place the smelted alloy ingot in a box furnace for solution treatment at a temperature of 1000 ℃ for 2 hours. After solution treatment, cool it to room temperature with water.

[0033] Step 3: The microstructure, phase composition and mechanical properties of the alloy are obtained by using a metallographic microscope, XRD diffractometer and uniaxial tensile test.

[0034] Results: The Ti-5Mo-20Nb-10Zr-5Ta-1Feβ titanium alloy prepared in this embodiment consists of a single β phase, with equiaxed and uniformly distributed β grains. After three uniaxial tensile tests, the alloy exhibited an average elastic modulus of 50.6 GPa, a tensile strength of 755.2 MPa, and an elongation of 26.4%. The alloy demonstrates a low elastic modulus while possessing high strength and plasticity, exhibiting excellent overall mechanical properties. Example

[0035] This embodiment relates to a Ti-Mo-Nb-Zr-Ta-Fe hexa-element β-titanium alloy, specifically with the alloy composition Ti-5Mo-20Nb-10Zr-5Ta-1.5Fe (wt.%).

[0036] This embodiment also relates to a method for the preparation and analysis of a hexa-element β-titanium alloy, which mainly includes the following steps:

[0037] Step one: Select high-purity Ti, Mo, Nb, Ta, Fe, and Zr raw material metals, and mix them evenly according to the alloy composition. Melt the alloy three times repeatedly in a vacuum arc melting furnace to obtain an alloy ingot. The melting process must be carried out under argon protection. The resulting alloy ingot is approximately 9 cm high and 10 cm in diameter.

[0038] Step 2: Place the smelted alloy ingot in a box furnace for solution treatment at a temperature of 1000 ℃ for 2 hours. After solution treatment, cool it to room temperature with water.

[0039] Step 3: The microstructure, phase composition and mechanical properties of the alloy are obtained by using a metallographic microscope, XRD diffractometer and uniaxial tensile test.

[0040] Results: The Ti-5Mo-20Nb-10Zr-5Ta-1.5Feβ titanium alloy prepared in this embodiment consists of a single β phase, with equiaxed and uniformly distributed β grains. After three uniaxial tensile tests, the alloy exhibited an average elastic modulus of 57.3 GPa, a tensile strength of 692.5 MPa, and an elongation of 35.2%. The alloy has a low elastic modulus but high plasticity, resulting in excellent overall mechanical properties.

Claims

1. A low elastic modulus, high ductility, biomedical, six-membered beta titanium alloy, characterized by: The alloy elements include β-stabilizing elements Mo, Nb, Ta, Fe and neutral element Zr; The alloy component ranges in mass percentage: Ti-Mo(2%-13%)-Nb(15%-25%)-Zr(10%-20%)-Ta(3%-10%)-Fe(0.5%-2%).

2. The bio-medical six-element beta titanium alloy with low elastic modulus and high ductility according to claim 1, characterized in that: The alloy component ranges in mass percentage: Ti-%10Mo-%20Nb-%10Zr-%5Ta-%1Fe.

3. The bio-medical six-element beta titanium alloy with low elastic modulus and high ductility according to claim 1, characterized in that: The alloy component ranges in mass percentage: Ti-%5Mo-%20Nb-%10Zr-%5Ta-%1Fe.

4. The bio-medical six-element beta titanium alloy with low elastic modulus and high ductility according to claim 1, characterized in that: The alloy component ranges in mass percentage: Ti-%5Mo-%20Nb-%10Zr-%5Ta-%1.5Fe.

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