Preparation method of porous titanium-tin alloy material
Porous titanium tin alloy materials are prepared by ball milling vacuum sintering method of TiH2 powder, Sn powder and urea, which solves the problems of complex preparation, high cost and low performance of existing porous titanium alloy materials, and achieves improved mechanical properties and improved biocompatibility under high porosity.
Patent Information
- Application Number
- CN202510771052.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-10
- Publication Date
- 2025-08-15
AI Technical Summary
The existing porous titanium alloy materials have complex preparation processes and high cost. The high oxygen content of the product leads to a reduction in mechanical properties, which easily triggers inflammatory reactions, and it is difficult to maintain good mechanical strength under high porosity.
TiH2 powder, Sn powder and urea are used as raw materials, and then mixed by ball milling and vacuum sintering under the protection of inert gas to prepare porous titanium-tin alloy material. Urea is used as a pore-forming agent to decompose and extract hydrogen at low temperature, remove impurities simultaneously, and sintering at high temperature to form a porous structure.
It reduces the preparation cost, significantly improves the mechanical properties and corrosion resistance of the material, and synergistically improves porosity and mechanical properties. The elastic modulus of the material matches the human bones and is suitable for biomedical materials.
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Figure CN120480194A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of porous titanium alloy material preparation, and in particular to a method for preparing a porous titanium-tin alloy material. Background Art
[0002] The aging population is significantly increasing the clinical demand and development potential for orthopedic implants. Titanium and its alloys, due to their low elastic modulus, excellent corrosion resistance, and good biocompatibility, have become important choices in the field of biological bone replacement materials. However, it is important to note that their elastic modulus is still generally higher than that of human bone, which can easily induce a "stress shielding" effect, adversely affecting long-term implants.
[0003] To address this challenge, porous titanium alloys prepared by introducing pore-forming agents have demonstrated unique advantages: the porous structure not only significantly reduces the material's elastic modulus by reducing the effective load-bearing area, effectively alleviating the "stress shielding" effect; its internal open pore system is more conducive to bone cell infiltration and blood vessel growth, thereby accelerating the integration of implants and bones and significantly improving bone integration efficiency. These characteristics have made porous titanium alloys an increasingly popular choice for biomedical materials.
[0004] At present, the preparation of porous titanium is mostly done by first mixing titanium powder (such as HDH titanium powder) and pore-forming agents (such as ammonium bicarbonate or PMMA microspheres) in a certain proportion, and then forming a green body by cold isostatic pressing; then sintering in a vacuum or inert atmosphere to form a porous structure with interconnected pores, and finally removing the pore-forming agent by post-processing methods such as pickling. Due to the high price of titanium powder, the cost of this process is relatively high. In addition, the titanium powder used in this industry is generally industrial titanium powder, which has a high oxygen content. During the processing, the titanium powder is exposed to air, which also increases the possibility of titanium powder being oxidized, which leads to a high oxygen content in the porous titanium obtained. Since oxygen is a strong α-phase stabilizer, it is easy to form interstitial solid solutions in titanium, which will hinder dislocation movement, causing material embrittlement and deterioration of mechanical properties. In addition, oxides (such as TiO2) wrap around the surface of titanium particles, which will hinder diffusion bonding, requiring higher sintering temperatures during sintering, and high energy consumption. Excessive oxygen content in medical porous titanium may also trigger inflammatory reactions and endanger human health. In addition, the preparation of porous titanium using this process requires subsequent acid washing to remove the pore-forming agent, and the operation is relatively complicated. In addition, porous titanium has a problem of low mechanical strength due to its porous structure, and the existing porous titanium preparation method is difficult to maintain good mechanical strength while ensuring high porosity; these technical bottlenecks restrict the clinical promotion and application of this material. Summary of the Invention
[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing a porous titanium-tin alloy material, so as to solve the problems of the existing method for preparing porous titanium alloy, such as complex process, high cost, high oxygen content of the product, resulting in reduced mechanical properties of the material and easy to cause inflammatory reaction, as well as the difficulty in ensuring high porosity while taking into account mechanical strength.
[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:
[0007] A method for preparing a porous titanium-tin alloy material comprises the following steps:
[0008] (1) The raw materials TiH2 powder, Sn powder and urea are ball-milled and mixed uniformly under the protection of inert gas, and then pressed into a green body;
[0009] (2) The obtained green body is vacuum sintered to obtain a porous titanium-tin alloy material.
[0010] Furthermore, in the reaction raw materials, the added amount of Sn powder is 0-25wt%, the added amount of urea is 15-45wt%, and the rest is TiH2 powder.
[0011] Furthermore, in the reaction raw materials, the added amount of Sn powder is 2-25 wt%, the added amount of urea is 20-30 wt%, and the rest is TiH2 powder.
[0012] Furthermore, the vacuum sintering is as follows: first heating the temperature to 400-500°C at a heating rate of 2-3°C / min and keeping the temperature for 20-30 minutes; then heating the temperature to 1000-1300°C at a heating rate of 8-9°C / min for sintering, and the sintering time is 0.5-3.5 hours.
[0013] Furthermore, during the ball milling process, the ball-to-material ratio is 5:1, the ball milling speed is 250-300 r / min, and the ball milling time is 30-120 min.
[0014] Furthermore, after ball milling, the particle size of the TiH2 powder and the Sn powder is less than 600 mesh, and the particle size of the urea is 60-80 μm.
[0015] Furthermore, during the pressing process, the pressing pressure is 150-350 MPa and the holding time is 5-8 minutes.
[0016] Furthermore, during the sintering process, the vacuum degree was 10 -2 ~10 -3 The whole sintering process is vacuumed to minimize the influence of oxygen on the experiment, while ensuring that the decomposition products of urea and the hydrogen removed by TiH2 are completely removed and leave the furnace in time to avoid material performance degradation or sintering failure.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] 1. The present invention uses TiH2 powder and tin powder as raw materials and urea as a pore-forming agent. After the three are evenly mixed by ball milling, the mixture is placed in a vacuum sintering furnace, and the urea is first removed at low temperature before sintering at high temperature in one step to produce a porous titanium-tin alloy material. This method uses TiH2 as the titanium matrix, which reduces the cost by 10% to 20% compared to directly using titanium powder as the titanium matrix. TiH2 itself has low oxygen properties, which can reduce the oxygen content of the product. The hydrogen decomposed during the sintering process can also achieve dual self-purification. On the one hand, it can effectively remove nitrogen and carbon impurities remaining from urea volatilization, and on the other hand, it can reduce titanium oxide on the powder surface, significantly reducing the oxygen content of the material, thereby avoiding the reduction of mechanical properties and inflammatory reactions caused by excessive oxygen content. In addition, the decomposed hydrogen can also form pores within the material, promoting diffusion and bonding between particles, improving sintering quality and further inhibiting the diffusion and dissolution of oxygen. The pore-forming agent (urea) used in the present invention can decompose at low temperature to form NH3 and CO2, and leave the furnace as it is vacuumed, without affecting the porous titanium material. There is no need for subsequent treatment of the pore-forming agent, and the process is relatively simple.
[0019] 2. The present invention also introduces tin, which significantly improves the mechanical properties of the material through a solid solution strengthening mechanism. The introduction of Sn can also optimize the corrosion potential of the alloy and enhance its corrosion resistance in physiological environments. By adjusting the addition ratio and mixing degree of TiH2 powder, Sn powder and urea, the present invention can accurately control the porosity (46.5%-52.95%) and pore size distribution while maintaining good mechanical properties (yield strength 76-191MPa), achieving a synergistic improvement in porosity and mechanical properties, and obtaining a porous titanium-tin alloy with matching elastic modulus and mechanical properties, which will greatly promote the wider application of porous titanium and its alloy materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a process flow chart of a method for preparing a porous titanium-tin alloy material according to the present invention;
[0021] Figure 2 This is a metallographic diagram of Example 2 of the present invention;
[0022] Figure 3 This is the compressive stress-strain curve of Example 2 of the present invention. DETAILED DESCRIPTION
[0023] The specific implementation methods of the present invention are further described in detail below with reference to specific examples.
[0024] The numerical ranges herein are understood to specifically disclose every intervening value between the upper and lower limits of the range. Each smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in that stated range is also encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
[0025] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art. Although the present invention has only described preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail. As used herein, "comprising", "including", "having", "containing", etc. are all open-ended terms, meaning including but not limited to.
[0026] Unless otherwise specified, the experimental methods used in the present invention are all conventional methods.
[0027] Unless otherwise specified, the materials, reagents, etc. used in the present invention can be purchased or synthesized by known methods.
[0028] The quantitative tests in the present invention were repeated three times and the results were averaged.
[0029] Example 1
[0030] This embodiment provides a method for preparing a porous titanium-tin alloy material. The process flow chart is as follows: Figure 1 As shown, the following steps are included:
[0031] (1) Weigh 4.6 g of TiH2 powder, 0.24 g of Sn powder, and 1.61 g of urea, place them in a ball mill, and mill them under an argon atmosphere with a ball-to-material ratio of 5:1, a milling time of 30 min, and a rotation speed of 250 r / min. After ball milling, the particle size of the TiH2 powder and Sn powder is less than 600 mesh, and the particle size of the urea is 60-80 μm. By adjusting the ball milling parameters, the pore size distribution of the porous titanium-tin alloy material can be adjusted. By adjusting the particle size of the pore-forming agent (urea), the pore size of the porous titanium-tin alloy material can be adjusted. In specific implementation, the ball milling parameters can be adjusted according to actual needs.
[0032] (2) The ball-milled raw material was pressed using a mold with a diameter of 16 mm to obtain a pressed green body; before pressing, the mold surface was coated with zinc stearate to facilitate subsequent demolding. The pressing pressure was 150 MPa and the holding time was 5 min.
[0033] (3) Place the pressed green body into a corundum crucible, and then place the corundum crucible containing the green body into a vacuum sintering furnace (vacuum degree is 10 -2 ~10 -3 Pa), firstly raised the temperature to 400°C at 2°C / min and kept at 400°C for 30min to decompose and remove urea, then raised the temperature to 1200°C at 8°C / min and sintered for 2h to obtain a porous titanium-tin alloy material.
[0034] (4) After sintering, the material was subjected to metallographic observation and porosity test, and its porosity was 51.22%.
[0035] (5) The sintered product was cut into a cylindrical shape with a diameter of 10 mm and a height of 12 mm according to the porous titanium compression test method, and a compression test was performed, and its initial yield strength was obtained to be 126 MPa.
[0036] Examples 2-5, Comparative Example 1
[0037] Examples 2-5 all provide a method for preparing a porous titanium-tin alloy material, and Comparative Example 1 provides a method for preparing a porous titanium material. Examples 2-5 and Comparative Example 1 are mainly the same as Example 1, except that the addition amounts of reactants (TiH2, Sn) are different. The comparison table of reactant addition amounts and performance is shown in Table 1.
[0038] Table 1 Comparison of reactant addition amount and performance
[0039] Example <![CDATA[TiH2 / g]]> Sn / g Urea / g Porosity Yield strength / MPa Example 1 4.6 0.24 1.61 51.22％ 126 Example 2 4.45 0.5 1.61 50.49％ 155 Example 3 4.31 0.76 1.61 49.26％ 163 Example 4 4.16 1.04 1.61 48.36％ 182 Example 5 4.0 1.33 1.61 46.5％ 191 Comparative Example 1 4.71 0 1.61 52.95％ 76
[0040] Example 6
[0041] This example provides a method for preparing a porous titanium-tin alloy material. This method is similar to Example 1, except that the pressing pressure is 100 MPa and the dwell time is 5 minutes. After sintering, the material is subjected to porosity and compression testing, revealing a porosity of 53.56% and an initial yield strength of 107 MPa.
[0042] Example 7
[0043] This example provides a method for preparing a porous titanium-tin alloy material. The method is similar to that of Example 1, except that the pressing pressure is 200 MPa and the holding time is 5 minutes. After sintering, the material is subjected to porosity and compression tests, revealing a porosity of 52.89% and an initial yield strength of 115 MPa.
[0044] Example 8
[0045] This example provides a method for preparing a porous titanium-tin alloy material. This method is similar to Example 1, except that the temperature is first raised to 400°C at a rate of 2°C / min and held at 400°C for 30 minutes to decompose and remove urea. The temperature is then raised to 1000°C at a rate of 8°C / min and sintered for 2 hours to obtain the porous titanium-tin alloy material. After sintering, the material was subjected to porosity and compression tests, revealing a porosity of 53.43% and an initial yield strength of 83 MPa.
[0046] Example 9
[0047] This example provides a method for preparing a porous titanium-tin alloy material. This method is similar to Example 1, except that the temperature is first raised to 400°C at a rate of 2°C / min and held at 400°C for 30 minutes to decompose and remove urea. The temperature is then raised to 1100°C at a rate of 8°C / min and sintered for 2 hours to obtain the porous titanium-tin alloy material. After sintering, porosity and compression tests were performed on the material, revealing a porosity of 52.59% and an initial yield strength of 104 MPa.
[0048] Example 10
[0049] This example provides a method for preparing a porous titanium-tin alloy material. This method is similar to Example 1, except that the temperature is first raised to 400°C at a rate of 2°C / min and held at 400°C for 30 minutes to decompose and remove urea. The temperature is then raised to 1200°C at a rate of 8°C / min and sintered for 1 hour to obtain the porous titanium-tin alloy material. After sintering, porosity and compression tests were performed on the material, revealing a porosity of 52.61% and an initial yield strength of 110 MPa.
[0050] Example 11
[0051] This example provides a method for preparing a porous titanium-tin alloy material. This method is similar to Example 1, except that the temperature is first raised to 400°C at a rate of 2°C / min and held at 400°C for 30 minutes to decompose and remove urea. The temperature is then raised to 1200°C at a rate of 8°C / min and sintered for 3 hours to obtain the porous titanium-tin alloy material. After sintering, the material was subjected to porosity and compression tests, revealing a porosity of 50.75% and an initial yield strength of 135 MPa.
[0052] Comparison of Examples 1-5 and Comparative Example 1 shows that the porous titanium-tin alloy materials prepared using the method of the present invention all have high porosity. Compared with the preparation method without adding tin, the addition of tin significantly improves the alloy strength, and the strength gradually increases with the increase of tin. Although the alloy porosity decreases slightly with the increase of tin, the porosity can be stably maintained at above 45% by reasonably controlling the addition amount of Sn. In actual use, the addition amount of Sn can be adjusted according to actual needs to achieve a synergistic improvement in porosity and strength.
[0053] In addition, since Sn powder is an element that is non-toxic, non-allergenic and has excellent biocompatibility to the human body, the addition of tin to porous titanium-tin alloy can not only improve the performance of the material, such as increasing strength, hardness and corrosion resistance, but more importantly, it is very suitable for bone implantation without causing harm to the human body.
[0054] From the comparison between Example 1 and Examples 8-11, it can be seen that with the increase of sintering temperature and sintering time, the porosity gradually decreases and the yield strength gradually increases. In actual use, the sintering temperature and sintering time can be flexibly adjusted according to the use requirements to meet actual needs.
[0055] Figure 2 is the metallographic diagram of Example 2, Figure 2 It can be seen that the prepared material consists of a titanium matrix (off-white) and evenly distributed irregular pores (black). The formation of large pores is mainly due to the volatilization of urea at low temperatures, while the formation of small pores is due to the diffusion and release of hydrogen in titanium hydride, forming small and dispersed pores; on the other hand, the "Kirkendall" effect caused by the difference in the diffusion rate of elements leads to the aggregation of vacancies, thus forming additional small pores. These processes form the unique porosity of porous titanium and further enrich the diversity of pores.
[0056] Figure 3 is the compressive stress-strain curve of Example 2 of the present invention, Figure 3 The compressive stress-strain curve of the porous titanium-tin alloy prepared by the present invention exhibits typical characteristics of porous materials, including three distinct phases: elastic deformation, plastic plateau, and densification. Test results indicate that the material has an initial yield strength of 155 MPa and an elastic modulus of 1.55 GPa, which closely matches that of human cancellous bone (elastic modulus range of 0.01-2 GPa), demonstrating good biomechanical compatibility.
[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the technical solutions. Those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present invention that do not depart from the purpose and scope of the technical solutions of the present invention should be included in the scope of the claims of the present invention.
Claims
1. A method for preparing a porous titanium-tin alloy material, characterized in that: The following steps are involved: (1) The raw materials TiH2 powder, Sn powder and urea are ball-milled and mixed uniformly under the protection of inert gas, and then pressed into a green body; (2) The obtained green body is vacuum sintered to obtain a porous titanium-tin alloy material.
2. The method for preparing the porous titanium-tin alloy material according to claim 1, characterized in that: Among the reaction raw materials, the added amount of Sn powder is 0-25wt%, the added amount of urea is 15-45wt%, and the rest is TiH2 powder.
3. The method for preparing the porous titanium-tin alloy material according to claim 1, characterized in that: Among the reaction raw materials, the added amount of Sn powder is 2-25wt%, the added amount of urea is 20-30wt%, and the rest is TiH2 powder.
4. The method for preparing a porous titanium-tin alloy material according to claim 1, wherein: The vacuum sintering is as follows: firstly heating the temperature to 400-500°C at a heating rate of 2-3°C / min and keeping the temperature for 20-30min; then heating the temperature to 1000-1300°C at a heating rate of 8-9°C / min and sintering for 0.5-3.5h.
5. The method for preparing the porous titanium-tin alloy material according to claim 1, characterized in that: During the ball milling process, the ball-to-material ratio is 5:1, the ball milling speed is 250-300 r / min, and the ball milling time is 30-120 min.
6. The method for preparing a porous titanium-tin alloy material according to claim 1, wherein: After ball milling, the particle size of TiH2 powder and Sn powder is less than 600 mesh, and the particle size of urea is 60-80 μm.
7. The method for preparing a porous titanium-tin alloy material according to claim 1, characterized in that: During the pressing process, the pressing pressure is 150-350 MPa and the holding time is 5-8 minutes.
8. The method for preparing a porous titanium-tin alloy material according to claim 1, wherein: During the sintering process, the vacuum degree is 10 -2 ~10 -3 Pa.