A medical low elastic modulus Nb-Zr-Ti alloy rod and preparation method thereof

Abstract

The present invention provides a medical low elastic modulus Nb‑Zr‑Ti alloy rod and a preparation method thereof, and relates to the technical field of titanium alloy metal processing. The present invention reduces the elastic modulus of the alloy by adding Nb and Zr elements with good biocompatibility to the titanium-based alloy. At the same time, the present invention ensures that the elastic modulus of the rod is closer to human bone tissue by limiting the optimal composition ratio of the material. Compared with Ti‑6Al‑4V alloy and pure titanium TA2G rod, the elastic modulus of the alloy rod is reduced by about 10%, and the mechanical properties are better than those of pure titanium TA2G rod, which meets the strength requirements of special parts and has better biocompatibility in clinical medicine.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy metal processing, and in particular to a medical low elastic modulus Nb-Zr-Ti alloy rod and a preparation method thereof. Background Art

[0002] After a long period of clinical medical verification, it was found that the elastic modulus of the most widely used Ti-6Al-4V alloy is much greater than the elastic modulus of human bone tissue. If the joint prosthesis is subjected to biological stress for a long time, it will cause "stress fatigue phenomenon" and eventually lead to the fracture of the joint prosthesis. The elastic modulus of pure titanium TA2G is slightly lower than that of Ti-6Al-4V alloy, but it is still much higher than the elastic modulus of human bone tissue. Moreover, in medical implants, the mechanical properties of pure titanium TA2G rods cannot meet the strength requirements of certain special parts. Therefore, how to prepare a low elastic modulus alloy rod to overcome the "stress fatigue phenomenon" caused by the high elastic modulus of Ti-6Al-4V alloy and pure titanium TA2G and the problem of insufficient mechanical properties is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a medical low elastic modulus Nb-Zr-Ti alloy rod and a preparation method thereof. Compared with Ti-6Al-4V alloy and pure titanium TA2G rod, the elastic modulus of the alloy rod is reduced by about 10%, and the mechanical properties are better than those of pure titanium TA2G rod, which meets the strength requirements of special parts and has better biocompatibility in clinical medicine. The present invention reduces the elastic modulus of the alloy by adding Nb and Zr elements with good biocompatibility to the titanium-based alloy. At the same time, the present invention ensures that the elastic modulus of the rod is closer to human bone tissue by limiting the optimal composition ratio of the material. The preparation process of the medical low elastic modulus Nb-Zr-Ti alloy rod described in the present invention comprises the following steps:

[0004] (1) Add a certain proportion of alloy elements to titanium sponge to adjust the composition ratio;

[0005] (2) pressing the raw material in step (1) into an electrode rod using a hydraulic press;

[0006] (3) melting the pressed electrode rod twice in a vacuum furnace consumable melting furnace to obtain an ingot;

[0007] (4) Forging the smelted ingot;

[0008] (5) rolling the forged bar billet;

[0009] (6) annealing the rolled bar billet in an atmospheric furnace and then air cooling it to room temperature;

[0010] (7) The rod blank is straightened, cut, and polished to obtain a Φ12 mm Nb-Zr-Ti alloy rod.

[0011] Furthermore, the alloy elements in step (1) are Nb and Zr.

[0012] Furthermore, in the step (1), the amount of Nb added is 1 wt% to 4 wt%, and the amount of Zr added is 0.1 wt% to 0.5 wt%.

[0013] Furthermore, in step (3), the smelting current is 1300A, the smelting voltage is 30V, and the vacuum degree is 1.9×10 - 3 Pa, the AC arc stabilization current is 4A.

[0014] Furthermore, in the step (4), the smelting temperature is 900° C. and the holding time is 70 min.

[0015] Furthermore, in the step (4), the forging includes two times of upsetting and drawing, and the total forging deformation is 40-60%.

[0016] Furthermore, in the step (4), the rolling temperature is 700° C., the holding time is 60 min, and the rolling deformation is 80-90%.

[0017] Furthermore, the annealing temperature in step (6) is 600-750° C., and the annealing time is 50-70 min.

[0018] The present invention also provides a medical low elastic modulus Nb-Zr-Ti alloy rod prepared according to the method.

[0019] Compared with the prior art, the beneficial technical effects of the present invention are:

[0020] The present invention adds Nb and Zr elements with good biocompatibility to the titanium-based alloy, so that the elastic modulus of the Nb-Zr-Ti alloy rod is 10% lower than that of the Ti-6Al-4V alloy and pure titanium TA2G rods, which is closer to human bone tissue and has better biocompatibility in clinical medicine. The mechanical properties are better than those of the pure titanium TA2G rods, and the strength requirements of some special parts are met. DETAILED DESCRIPTION

[0021] The present invention provides a preparation process of a medical low elastic modulus Nb-Zr-Ti alloy rod, comprising the following steps:

[0022] (1) Add a certain proportion of alloy elements to titanium sponge to adjust the composition ratio;

[0023] (2) pressing the raw material in step (1) into an electrode rod using a hydraulic press;

[0024] (3) melting the pressed electrode rod twice in a vacuum furnace consumable melting furnace to obtain an ingot;

[0025] (4) Forging the smelted ingot;

[0026] (5) rolling the forged bar billet;

[0027] (6) annealing the rolled bar billet in an atmospheric furnace and then air cooling it to room temperature;

[0028] (7) The rod blank is straightened, cut, and polished to obtain a Φ12 mm Nb-Zr-Ti alloy rod.

[0029] In one embodiment, the alloying elements in step (1) are Nb and Zr.

[0030] In one embodiment, in step (1), the amount of Nb added is 1 wt% to 4 wt%, and the amount of Zr added is 0.1 wt% to 0.5 wt%.

[0031] In one embodiment, in step (3), the melting current is 1300A, the melting voltage is 30V, and the vacuum degree is 1.9×10 -3 Pa, the AC arc stabilization current is 4A.

[0032] In one embodiment, in step (4), the smelting temperature is 900° C. and the holding time is 70 min.

[0033] In one embodiment, the forging in step (4) includes two upsetting and drawing operations, and the total forging deformation is 40-60%.

[0034] In one embodiment, in step (4), the rolling temperature is 700° C., the holding time is 60 min, and the rolling deformation is 80-90%.

[0035] In one embodiment, the annealing temperature in step (6) is 600-750° C., and the annealing time is 50-70 min.

[0036] The present invention also provides a medical low elastic modulus Nb-Zr-Ti alloy rod prepared according to the method.

[0037] The technical solution provided by the present invention is further described below in conjunction with embodiments.

[0038] Example 1

[0039] (1) Adding Nb and Zr to titanium sponge, wherein Nb is 2.50% and Zr is 0.28%;

[0040] (2) pressing the raw material in step (1) into an electrode rod using a hydraulic press;

[0041] (3) The pressed electrode rod is placed in a vacuum of 1.9×10 -3 Pa, a melting current of 1300A, a melting voltage of 30V, and an AC arc stabilization current of 4A, and smelting twice in a vacuum furnace consumable melting furnace to obtain an ingot;

[0042] (4) forging the smelted ingot, wherein the forging deformation rate is 40% to 60%;

[0043] (5) rolling the forged bar billet, wherein the rolling deformation rate is 80% to 90%;

[0044] (6) annealing the rolled bar billet in an atmospheric furnace at 620° C. for 70 min;

[0045] (7) The rod blank is straightened, cut, and polished to obtain a Φ12 mm Nb-Zr-Ti alloy rod.

[0046] The chemical composition of the ingot was tested and the results are as follows:

[0047] element Nb / % Zr / ％ Fe / % C / ％ N / ％ O / ％ H / ％ Detection value 2.50 0.21 0.014 0.022 0.006 0.090 0.0033

[0048] The mechanical properties of the Nb-Zr-Ti alloy rod prepared in Example 1 were measured according to the method described in GB / T 228.1-2010, and the results are as follows:

[0049] Tensile strength / Mpa Yield strength / Mpa Elongation / % Shrinkage / % Elastic modulus / Gpa 555 457 31.5 68 97

[0050] Comparative Example 1 is the same as Example 1, except that the alloy elements in the titanium sponge are set according to the composition ratio of TA2G in GB / T 3620.1-2016 “Titanium and Titanium Alloy Grades and Chemical Compositions”.

[0051] The chemical composition of the ingot was tested and the results are as follows:

[0052] element Fe / % C / ％ N / ％ O / ％ H / ％ Detection value 0.226 0.018 0.008 0.190 0.002

[0053] The mechanical properties of the Nb-Zr-Ti alloy rod prepared in Example 1 were measured according to the method described in GB / T 228.1-2010, and the results are as follows:

[0054] Tensile strength / Mpa Yield strength / Mpa Elongation / % Shrinkage / % Elastic modulus / Gpa 570 368 30.0 46 103

[0055] By comparison, it can be seen that the Φ12 mm rods are prepared by the same process as in Example 1, and the elastic modulus of the rods is tested, and it is found that the elastic modulus of Example 1 is about 10% lower than that of Comparative Example 1. At the same time, the mechanical properties of the rod prepared in Example 1 are better than those of Comparative Example 1, providing reliable strength requirements for clinical medicine.

[0056] Comparative Example 2

[0057] The same as Example 1, except that the alloy elements in the titanium sponge are set according to the composition ratio of TC4 in GB / T 3620.1-2016 "Titanium and Titanium Alloy Grades and Chemical Compositions".

[0058] The chemical composition of the ingot was tested and the results are as follows:

[0059] element Al / ％ V / ％ Fe / % C / ％ N / ％ O / ％ H / ％ Detection value 6.070 3.91 0.18 0.012 0.013 0.095 0.0006

[0060] The mechanical properties of the Nb-Zr-Ti alloy rod prepared in Example 2 were measured according to the method described in GB / T 228.1-2010, and the results are as follows:

[0061] Tensile strength / Mpa Yield strength / Mpa Elongation / % Shrinkage / % Elastic modulus / Gpa 1023 976 16.5 46 109

[0062] By comparison, it can be seen that the Φ12 mm rods are prepared by the same process as that of Example 1 and the elastic modulus of the rods is tested and it is found that the elastic modulus of the example is reduced by about 10% compared with that of the comparative example 1.

[0063] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A preparation process of a medical low elastic modulus Nb-Zr-Ti alloy rod, characterized in that: The following steps are involved: (1) Nb and Zr are added to titanium sponge, wherein Nb is 2.50% and Zr is 0.28% by mass; (2) Pressing the raw material in step (1) into an electrode rod using a hydraulic press; (3) melting the pressed electrode rod twice in a vacuum consumable melting furnace to obtain an ingot; (4) Forging the smelted ingot; (5) rolling the forged bar billet; (6) The rolled billet is annealed in an atmospheric furnace and then air-cooled to room temperature; (7) The rod blank is straightened, cut, and polished to obtain a Φ12 mm Nb-Zr-Ti alloy rod.

2. The preparation process according to claim 1, characterized in that: In step (3), the melting current is 1300 A, the melting voltage is 30 V, and the vacuum degree is 1.9×10 -3 Pa, the AC arc stabilization current is 4 A.

3. The preparation process according to claim 1, characterized in that: In the step (3), the smelting temperature is 900° C. and the holding time is 70 min.

4. The preparation process according to claim 1, characterized in that: In the step (4), the forging includes two upsetting and drawing operations, and the total forging deformation is 40-60%.

5. The preparation process according to claim 1, characterized in that: In the step (5), the rolling temperature is 700° C., the holding time is 60 min, and the rolling deformation is 80-90%.

6. The preparation process according to claim 1, characterized in that: The annealing temperature in step (6) is 600-750° C., and the annealing time is 50-70 min.

7. A medical low elastic modulus Nb-Zr-Ti alloy rod, characterized in that: Prepared by the process according to any one of claims 1 to 6.