Preparation method of high-strength low-modulus multi-component titanium alloy and multi-component titanium alloy

Abstract

The invention relates to the technical field of alloy material preparation, and relates to a preparation method of a high-strength low-modulus multi-component titanium alloy and the multi-component titanium alloy, the high-strength low-modulus multi-component titanium alloy comprises the following components in percentage by metal atoms: 76-80% of Ti element, 4.5-5.5% of Zr element, 9.5-10.5% of Nb element, 3.5-4.5% of Sn element and 1-5% of Mo element, wherein the optimal metal atom ratio is as follows: 78% of Ti, 5% of Zr, 10% of Nb, 5% of Sn and 3% of Mo; the preparation method comprises the following steps: S1, smelting an alloy ingot; s2, solid solution strengthening; s3, rolling an alloy plate; s4, alloy post-treatment; according to the high-strength and low-modulus multi-component titanium alloy, specific alloy element doping is conducted, and the atomic proportion in the alloy is regulated and controlled, so that the alloy has the large yield strength / elastic modulus ratio and good biocompatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy material preparation, and particularly relates to a preparation method of a multi-component titanium alloy with high strength and low modulus and a multi-component titanium alloy. Background Art

[0002] Titanium and its alloys are widely used in the field of biomaterials due to their excellent low modulus, low elastic modulus and excellent biocompatibility. After the application of titanium alloys in medical device products such as artificial joints and dental implants, it has greatly improved and enhanced people's quality of life, made a revolutionary contribution to the development of medicine, and changed the status quo that major orthopedic diseases can only rely on drug treatment.

[0003] Pure titanium and Ti-6Al-4V alloy have become the most widely used metallic materials in biomedicine due to their excellent biocompatibility and good comprehensive mechanical properties. However, in clinical application tests, the mechanical strength of pure titanium is relatively low, and problems such as deformation and even fracture inevitably occur during use, making it difficult to be directly used; as a widely used bio-implant material, Ti-6Al-4V alloy has high concentrations of V 5+ ions and Al 3+ . Among them, V 5+ ions belong to biohazard factors that can cause allergic reactions in the human body, and Al 3+ ions are non-healthy elements that cause Alzheimer's disease. Therefore, there is an urgent need to study a new type of biomaterial that can meet the current titanium alloy usage environment, has high strength, low elastic modulus and low biological hazards. Summary of the Invention

[0004] Aiming at the problems of strength and material safety of pure titanium and TC4 commonly used in the current medical device manufacturing field, the present invention provides a preparation method of a multi-component titanium alloy with high strength and low modulus and a multi-component titanium alloy. By adding appropriate Zr element, Nb element, Sn element and Mo element to Ti, the solid solution strengthening effect is improved, the titanium alloy has a lower Young's modulus and better plasticity. In addition, by adjusting the types of elements in the alloy, the multi-component titanium alloy of the present invention has better usage safety.

[0005] The present invention provides a preparation method of a multi-component titanium alloy with high strength and low modulus, which comprises the following steps:

[0006] S1. Pretreat the Ti source, Zr source, Nb source, Sn source and Mo source and then melt them according to the metal atom ratio of (76-80):(4.5-5.5):(9.5-10.5):(3.5-4.5):(1-5) to obtain an alloy ingot;

[0007] S2. Solution-treat the alloy ingot obtained in step S1;

[0008] S21. Place the alloy ingot into a vacuum tube resistance furnace, fill it with inert gas, and then heat it up at a heating rate of 10 - 20 °C / min;

[0009] S22. Raise the furnace temperature of the vacuum tube resistance furnace to 900 - 950 °C and hold for 1.5 - 4 h;

[0010] S23. After holding, cool it to room temperature with water;

[0011] S3. Roll the alloy ingot after solution treatment in step S2 for 9 - 10 times to obtain alloy sheets;

[0012] S31. After heating the box-type resistance furnace to 750 - 850 °C, place the alloy ingot after solution treatment in step S2 into the box-type resistance furnace and hold for 20 - 40 min;

[0013] S32. Transfer the alloy ingot after holding in step S31 to a two-roll flat rolling mill for rolling, and control the rolling reduction to 7 - 8%, to complete the first rolling;

[0014] S33. Place the alloy ingot after the first rolling in step S32 into the box-type resistance furnace and hold for 3 - 5 min, and the holding temperature is 800 - 850 °C;

[0015] S34. Transfer the alloy ingot after holding in step S33 to a two-roll flat rolling mill for rolling, and control the rolling reduction to 7 - 8% of the total thickness, to complete the second rolling;

[0016] S35. Repeat steps S33 and S34 to successively complete the third rolling, fourth rolling, fifth rolling, sixth rolling, seventh rolling, eighth rolling, ninth rolling or the third to tenth rolling to obtain alloy sheets;

[0017] S4. Post-treat the alloy sheets in step S3 to obtain multi-component titanium alloys.

[0018] Preferably, step S1 includes the following specific steps:

[0019] S11. Ultrasonically clean the Ti source, Zr source, Nb source, Sn source and Mo source with absolute ethanol for 3 - 5 min, and then dry for 1 - 2 min;

[0020] S12, adding the dried Ti source, Zr source, Nb source, Sn source and Mo source into a vacuum non-consumable melting furnace and heating the mixture from the starting temperature to the ending temperature in a magnetic stirring environment, wherein the melting time of step S12 is 5-10 min, the starting temperature is room temperature, and the ending temperature is 2500-3000° C.;

[0021] S13, after the smelting time in step S12 ends, the furnace is cooled to room temperature, completing the first smelting;

[0022] S14, repeat step S12 and step S13, smelting 6-8 times.

[0023] Preferably, the post-treatment process in step S4 includes water cooling the alloy plate after rolling in step S3 to room temperature, followed by peeling and surface treatment.

[0024] Preferably, the Ti source in step S1 is Ti single substance, the Zr source is Zr single substance, the Nb source is Nb single substance, the Sn source is Sn single substance, and the Mo source is Mo single substance. The smelting current of the vacuum non-consumable smelting furnace in step S1 is 350-400A, and the vacuum degree during the smelting process is 1×10 -3 -8×10 -3 Pa, the inert gas in step S21 is argon, the furnace temperature in step S22 is below 1050°C, and the total deformation of the alloy plate obtained after the rolling process in step S3 is 70-80% of the alloy ingot.

[0025] The second aspect of the present invention provides a high-strength and low-modulus multi-component titanium alloy, wherein the multi-component titanium alloy includes 76-80% Ti elements, 4.5-5.5% Zr elements, 9.5-10.5% Nb elements, 3.5-4.5% Sn elements, and 1-5% Mo elements, and the proportion of each element is the percentage of metal atoms.

[0026] Furthermore, the atomic percentage of Ti:Zr:Nb:Sn:Mo in the multi-component titanium alloy is 78:5:10:4:3.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1. The multi-component titanium alloy with high strength and low modulus of the present invention improves the yield strength of the titanium alloy and has a low Young's modulus by introducing Zr element, Nb element, Sn element and Mo element into the alloy. Since Ti element and Zr element can be infinitely solid-solved to form an infinite solid solution, the lattice strength is enhanced, and the solid solution strengthening effect is significantly improved, increasing the yield strength of the material. The Sn element can inhibit the formation of brittle phases, thereby reducing the formation of metastable ω phase in the alloy, and thus obtaining a lower elastic modulus. The Mo element has an important influence on the strength improvement of the alloy.

[0029] 2. The Zr element, Nb element, Sn element and Mo element in the multi-component titanium alloy with high strength and low modulus of the present invention have good β-stabilizing ability. The present invention regulates the alloy composition by adopting a non-equiatomic ratio method, and then obtains a metastable phase alloy by adjusting β-stability, and finally controls the phase stability and microstructure of the alloy to achieve a combination of mechanical properties of low elastic modulus and high strength, and obtains a titanium alloy with a large yield strength / elastic modulus ratio.

[0030] 3. The yield strength of the multi-component titanium alloy with high strength and low modulus of the present invention is 325 - 816 MPa, the Young's modulus is 42 - 82 GPa, and the plasticity is 12.5 - 30.5%. Compared with conventional commercial pure titanium and TC4, it is more suitable for the field of biomedical medical devices. The Nb element added to the titanium alloy of the present invention is beneficial to the proliferation and differentiation of cells and has stronger biocompatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 SEM diagram of the high-strength and low-modulus titanium alloy prepared in Example 1 of the present invention;

[0032] Figure 2 SEM diagram of the high-strength and low-modulus titanium alloy prepared in Example 2 of the present invention;

[0033] Figure 3 SEM diagram of the high-strength and low-modulus titanium alloy prepared in Example 3 of the present invention;

[0034] Figure 4 SEM diagram of the high-strength and low-modulus titanium alloy prepared in Example 4 of the present invention;

[0035] Figure 5 SEM diagram of the high-strength and low-modulus titanium alloy prepared in Example 5 of the present invention;

[0036] Figure 6 X-ray diffraction pattern of the multi-component titanium alloy prepared in Examples 1 - 5 of the present invention;

[0037] Figure 7 is Figure 6 Local enlarged view of the diffraction angle of 36° - 37.5° in

[0038] Figure 8 Inverted pole figures of multi-component titanium alloys prepared in Example 1, Example 2, Example 3, and Example 5 of the present invention;

[0039] Figure 9 Grain orientation distribution maps of multi-component titanium alloys prepared in Example 1, Example 2, Example 3, and Example 5 of the present invention;

[0040] Figure 10 Statistical chart of alloy grain sizes of multi-component titanium alloys prepared in Example 1, Example 2, Example 3, and Example 5 of the present invention;

[0041] Figure 11 Alloy transmission photograph of Example 1 of the present invention and enlarged view of some selected diffraction spots;

[0042] Figure 12 Enlarged view of some selected diffraction spots of the alloy transmission photograph of Example 1 of the present invention;

[0043] Figure 13 Alloy transmission photograph of Example 2 of the present invention and enlarged view of some selected diffraction spots;

[0044] Figure 14 Alloy transmission photograph of Example 3 of the present invention and enlarged view of some selected diffraction spots;

[0045] Figure 15 Engineering stress-strain curves of multi-component titanium alloys prepared in Example 1, Example 2, Example 3, Example 4, and Example 5 of the present invention;

[0046] Figure 16 True stress-strain curves and work hardening curves of multi-component titanium alloys prepared in Example 1, Example 2, Example 3, Example 4, and Example 5 of the present invention;

[0047] Figure 17 Comparison chart of grain sizes and yield strengths of multi-component titanium alloys prepared in Example 1, Example 2, Example 3, and Example 5 of the present invention;

[0048] Figure 18 Comparison of the combination of Young's modulus and yield stress of the multi-component titanium alloy of the present invention with other alloy materials;

[0049] Figure 19 Comparison chart of the ratio of yield strength to elastic modulus between the high-strength and low-modulus multi-component titanium alloy of the present invention and some bioalloys;

[0050] Figure 20 Process flow chart for preparing the high-strength and low-modulus multi-component titanium alloy of the present invention. Detailed implementation manners

[0051] To elaborate on the technical content, achieved objectives and effects of the present invention, the following will be a detailed description in conjunction with the accompanying drawings of the specification.

[0052] The first aspect of the present invention provides a method for preparing a multi-component titanium alloy with high strength and low modulus, and the specific steps are as follows:

[0053] S1. After pre-treating the Ti source, Zr source, Nb source, Sn source and Mo source, melt them according to the metal atom ratio of (76 - 80):(4.5 - 5.5):(9.5 - 10.5):(3.5 - 4.5):(1 - 5) to obtain an alloy ingot.

[0054] S11. Ultrasonically clean the Ti source, Zr source, Nb source, Sn source and Mo source with absolute ethanol for 3 - 5 min, and then dry for 1 - 2 min.

[0055] S12. Add the dried Ti source, Zr source, Nb source, Sn source and Mo source into a vacuum non-consumable melting furnace and raise the temperature from the starting temperature to the ending temperature in a magnetically stirred environment. Among them, the melting time in step S12 is 5 - 10 min, the starting temperature is room temperature, and the ending temperature is 2500 - 3000 °C.

[0056] S13. After the melting time in step S12 ends, cool the furnace to room temperature to complete the first melting.

[0057] S14. Repeat steps S12 and S13 for 6 - 8 times.

[0058] S2. Perform solution treatment on the alloy ingot obtained in step S1.

[0059] S21. Place the alloy ingot into a vacuum tube resistance furnace, fill it with an inert gas, and then raise the temperature at a heating rate of 10 - 20 °C / min.

[0060] S22. Raise the temperature inside the vacuum tube resistance furnace to 900 - 950 °C and hold for 1.5 - 4 h.

[0061] S23. After the holding process is completed, cool it to room temperature with water.

[0062] S3. Perform 9 - 10 times of rolling on the alloy ingot after solution treatment in step S2 to obtain alloy sheets.

[0063] S31. After heating the box-type resistance furnace to 750 - 850 °C, place the alloy ingot after solution treatment in step S2 into the box-type resistance furnace and hold for 20 - 40 min.

[0064] S32. Transfer the alloy ingot after heat preservation in step S31 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount within 7-8% of the initial thickness of the alloy ingot to complete the first rolling.

[0065] S33. Put the alloy ingot after the first rolling in step S32 into a box-type resistance furnace for heat preservation for 3-5 min, and the heat preservation temperature is 800-850 °C.

[0066] S34. Transfer the alloy ingot after heat preservation in step S33 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount within 7-8% to complete the second rolling.

[0067] S35. Repeat step S33 and step S34 to successively complete the third rolling, the fourth rolling, the fifth rolling, the sixth rolling, the seventh rolling, the eighth rolling, the ninth rolling, or the third to the tenth rolling.

[0068] S4. Water-cool the alloy sheet after rolling in step S3 to room temperature, and then successively carry out peeling and surface treatment to obtain a multi-component titanium alloy.

[0069] As Figure 20 shown, the second aspect of the present invention provides a multi-component titanium alloy with high strength and low modulus, which includes 76-80% Ti element, 4.5-5.5% Zr element, 9.5-10.5% Nb element, 3.5-4.5% Sn element, and 1-5% Mo element in terms of the atomic percentage of metals. Among them, the technical term high strength in this application means that the yield strength of the alloy is above 800 MPa; low modulus means that the Young's modulus of the alloy is below 80 GPa. When the alloy has a low modulus and a relatively high yield strength at the same time, that is, the larger the ratio of the yield strength to the modulus, the better the current medical materials.

[0070] Furthermore, the multi-component titanium alloy of the present invention realizes the coexistence of a relatively high yield strength and a relatively low elastic modulus through the interaction of multiple metals. Its main mechanism of action is that by adding multiple metals, the degree of disorder of the alloy system is increased, thereby improving the mechanical strength of the alloy. On this basis, the traditional equiatomic ratio method is improved, and the alloy composition is regulated by using a non-equiatomic ratio method. Then, by adjusting the β stability, a metastable phase alloy is obtained, and finally, the phase stability and microstructure of the alloy are controlled. While increasing the yield strength of the alloy, the addition of metals that can reduce the elastic modulus is increased to achieve the consideration of high yield strength and low elastic modulus.

[0071] Specifically, in the multi-component titanium alloy of the present invention, the addition of Sn element and Mo element effectively reduces the elastic modulus of the alloy. The Sn element itself can inhibit the formation of brittle phases, reduce the phenomenon that the continuous ductile matrix is divided, thereby increasing the elastic modulus of the alloy. The Mo element has a strong β-stabilizing ability and has a positive effect on martensitic transformation, thus being able to effectively increase the yield strength of the alloy. Since Ti and Zr have similar crystal structures, they can achieve unlimited solid solution and there is no rejection reaction between them. However, Zr can improve the applicability of titanium alloy in the medical field and has high biocompatibility. In addition, the Nb element itself is beneficial to cell proliferation and differentiation, and doping with the Nb element can effectively improve the biocompatibility of the titanium alloy.

[0072] The following further describes a multi-component titanium alloy with high strength and low modulus of the present invention in conjunction with embodiments:

[0073] Example 1

[0074] S11. Charge Ti single element, Zr single element, Nb single element, Sn single element and Mo single element according to the metal atom ratio of 80:5:10:4:1, ultrasonically clean with absolute ethanol for 3 min, and then dry for 1 min.

[0075] S12. Put the dried Ti single element, Zr single element, Nb single element, Sn single element and Mo single element into a vacuum non-consumable melting furnace with a vacuum degree of 5×10 -3 Pa, and raise the temperature from room temperature to 2800 °C under the environment of magnetic stirring. The melting time is 8 min.

[0076] S13. After the melting time in step S12 ends, cool the furnace to room temperature to complete the first melting.

[0077] S14. Repeat steps S12 and S13 for 6 times to obtain an alloy ingot.

[0078] S21. Put the alloy ingot into a vacuum tube resistance furnace, fill it with argon, and then raise the temperature at a heating rate of 15 °C / min.

[0079] S22. Raise the furnace temperature in the vacuum tube resistance furnace to 900 °C and keep it warm for 4 h.

[0080] S23. After the heat preservation process is completed, cool it to room temperature with water.

[0081] S31. After heating the box-type resistance furnace to 850 °C, put the alloy ingot after solution treatment in step S2 into the box-type resistance furnace and keep it warm for 30 min.

[0082] S32. Transfer the alloy ingot after heat preservation in step S31 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount within 7-8% to complete the first rolling.

[0083] S33. Put the alloy ingot after the first rolling in step S32 into a box-type resistance furnace and keep it warm for 5 min at a temperature of 850 °C.

[0084] S34. Transfer the alloy ingot after heat preservation in step S33 to a two-high flat rolling mill for rolling, and control the rolling deformation amount within 7-8%, thus completing the second rolling.

[0085] S35. Repeat step S33 and step S34 to complete the third rolling, the fourth rolling, the fifth rolling, the sixth rolling, the seventh rolling, the eighth rolling, the ninth rolling and the tenth rolling in sequence.

[0086] S4. Water-cool the alloy plate after rolling in step S3 to room temperature, and then carry out peeling and surface treatment in sequence to obtain a multi-component titanium alloy, denoted as TZNS1Mo.

[0087] Example 2

[0088] S11. Charge Ti, Zr, Nb, Sn and Mo in a metal atomic ratio of 79:5:10:4:2, ultrasonically clean with absolute ethanol for 3 min, and then dry for 1 min.

[0089] S12. Put the dried Ti, Zr, Nb, Sn and Mo into a vacuum non-consumable melting furnace with a vacuum degree of 5×10 -3 Pa and raise the temperature from room temperature to 2800 °C under the environment of magnetic stirring, and the melting time is 8 min.

[0090] S13. After the melting time in step S12 ends, cool the furnace to room temperature to complete the first melting.

[0091] S14. Repeat step S12 and step S13 for 6 times to obtain an alloy ingot.

[0092] S21. Put the alloy ingot into a vacuum tube resistance furnace, fill it with argon, and then raise the temperature at a heating rate of 15 °C / min.

[0093] S22. Raise the temperature inside the vacuum tube resistance furnace to 900 °C and keep it warm for 4 h.

[0094] S23. After the heat preservation process is completed, cool it to room temperature with water.

[0095] S31. After heating the box-type resistance furnace to 850 °C, put the alloy ingot after solution treatment in step S2 into the box-type resistance furnace and keep it warm for 30 min.

[0096] S32. Transfer the alloy ingot after heat preservation in step S31 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount within 7 - 8%, thus completing the first rolling.

[0097] S33. Put the alloy ingot after the first rolling in step S32 into a box-type resistance furnace for heat preservation for 5 min, and the heat preservation temperature is 850 °C.

[0098] S34. Transfer the alloy ingot after heat preservation in step S33 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount within 7 - 8%, thus completing the second rolling.

[0099] S35. Repeat step S33 and step S34 to complete the third rolling, fourth rolling, fifth rolling, sixth rolling, seventh rolling, eighth rolling, ninth rolling and tenth rolling in sequence.

[0100] S4. Water-cool the alloy plate after rolling in step S3 to room temperature, and then carry out peeling and surface treatment in sequence to obtain a multi-component titanium alloy, denoted as TZNS2Mo.

[0101] Example 3

[0102] S11. Charge Ti element, Zr element, Nb element, Sn element and Mo element according to the metal atom ratio of 78:5:10:4:3, ultrasonically clean with absolute ethanol for 3 min, and then dry for 1 min.

[0103] S12. Put the dried Ti element, Zr element, Nb element, Sn element and Mo element into a vacuum non-consumable melting furnace with a vacuum degree of 5×10 -3 Pa and raise the temperature from room temperature to 2800 °C under the environment of magnetic stirring, and the melting time is 8 min.

[0104] S13. After the melting time in step S12 ends, cool the furnace to room temperature to complete the first melting.

[0105] S14. Repeat step S12 and step S13 for 6 times to obtain an alloy ingot.

[0106] S21. Put the alloy ingot into a vacuum tube resistance furnace, fill it with argon, and then raise the temperature at a heating rate of 15 °C / min.

[0107] S22. Raise the furnace temperature in the vacuum tube resistance furnace to 900 °C and then keep it at this temperature for 4 h.

[0108] S23. After the heat preservation process is completed, cool it to room temperature with water.

[0109] S31. After heating the box-type resistance furnace to 850 °C, put the alloy ingot after solution treatment in step S2 into the box-type resistance furnace for heat preservation for 30 min.

[0110] S32. Transfer the alloy ingot after heat preservation in step S31 to a two-high flat rolling mill for rolling, and control the rolling deformation amount within 7-8%, thus completing the first rolling.

[0111] S33. Put the alloy ingot after the first rolling in step S32 into a box-type resistance furnace for heat preservation for 5 min, and the heat preservation temperature is 850 °C.

[0112] S34. Transfer the alloy ingot after heat preservation in step S33 to a two-high flat rolling mill for rolling, and control the rolling deformation amount within 7-8%, thus completing the second rolling.

[0113] S35. Repeat step S33 and step S34 to successively complete the third rolling, the fourth rolling, the fifth rolling, the sixth rolling, the seventh rolling, the eighth rolling, the ninth rolling and the tenth rolling.

[0114] S4. Water-cool the alloy sheet after rolling in step S3 to room temperature, and then successively carry out peeling and surface treatment, and denote it as TZNS3Mo.

[0115] Example 4

[0116] S11. Charge Ti element, Zr element, Nb element, Sn element and Mo element according to the metal atom ratio of 77:5:10:4:4, ultrasonically clean with absolute ethanol for 3 min, and then dry for 1 min.

[0117] S12. Put the dried Ti element, Zr element, Nb element, Sn element and Mo element into a vacuum non-consumable melting furnace with a vacuum degree of 5×10 -3 Pa and raise the temperature from room temperature to 2800 °C under the environment of magnetic stirring, and the melting time is 8 min.

[0118] S13. After the melting time in step S12 ends, cool the furnace to room temperature to complete the first melting.

[0119] S14. Repeat step S12 and step S13 for 6 times to obtain an alloy ingot.

[0120] S21. Put the alloy ingot into a vacuum tube resistance furnace, fill it with argon, and then raise the temperature at a heating rate of 15 °C / min.

[0121] S22. Raise the temperature inside the vacuum tube resistance furnace to 900 °C and then keep it warm for 4 h.

[0122] S23. After the heat preservation process is completed, cool it to room temperature with water.

[0123] S31. After heating the box-type resistance furnace to 850 °C, put the alloy ingot after solution treatment in step S2 into the box-type resistance furnace and keep it warm for 30 min.

[0124] S32. Transfer the alloy ingot after heat preservation in step S31 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount at 7-8%, thus completing the first rolling.

[0125] S33. Put the alloy ingot after the first rolling in step S32 into the box-type resistance furnace and keep it warm for 5 min, and the heat preservation temperature is 850 °C.

[0126] S34. Transfer the alloy ingot after heat preservation in step S33 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount at 7-8%, thus completing the second rolling.

[0127] S35. Repeat step S33 and step S34 to successively complete the third rolling, the fourth rolling, the fifth rolling, the sixth rolling, the seventh rolling, the eighth rolling, the ninth rolling and the tenth rolling.

[0128] S4. Water-cool the alloy sheet after rolling in step S3 to room temperature, and then successively carry out peeling and surface treatment to obtain a multi-component titanium alloy, denoted as TZNS4Mo.

[0129] Example 5

[0130] S11. Charge Ti, Zr, Nb, Sn and Mo in accordance with the metal atom ratio of 76:5:10:4:5, ultrasonically clean with absolute ethanol for 3 min, and then dry for 1 min.

[0131] S12. Put the dried Ti, Zr, Nb, Sn and Mo into a vacuum non-consumable melting furnace with a vacuum degree of 5×10 -3 Pa, and raise the temperature from room temperature to 2800 °C under the environment of magnetic stirring, and the melting time is 8 min.

[0132] S13. After the melting time in step S12 ends, cool the furnace to room temperature to complete the first melting.

[0133] S14. Repeat step S12 and step S13 for 6 times to obtain an alloy ingot.

[0134] S21. Put the alloy ingot into a vacuum tube resistance furnace, fill it with argon, and then raise the temperature at a heating rate of 15 °C / min.

[0135] S22. Raise the temperature inside the vacuum tube resistance furnace to 900 °C and keep it warm for 4 h.

[0136] S23. After the heat preservation process is completed, cool it to room temperature with water.

[0137] S31. After heating the box-type resistance furnace to 850 °C, put the alloy ingot after solution treatment in step S2 into the box-type resistance furnace and keep it warm for 30 min.

[0138] S32. Transfer the alloy ingot after heat preservation in step S31 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount within 7 - 8%, thus completing the first rolling.

[0139] S33. Put the alloy ingot after the first rolling in step S32 into the box-type resistance furnace and keep it warm for 5 min, and the heat preservation temperature is 850 °C.

[0140] S34. Transfer the alloy ingot after heat preservation in step S33 to a two-roll flat rolling mill for rolling, and control the rolling deformation amount within 7 - 8%, thus completing the second rolling.

[0141] S35. Repeat step S33 and step S34 to successively complete the third rolling, the fourth rolling, the fifth rolling, the sixth rolling, the seventh rolling, the eighth rolling, the ninth rolling and the tenth rolling.

[0142] S4. Water-cool the alloy sheet after rolling in step S3 to room temperature, and then successively carry out peeling and surface treatment, and denote it as TZNS5Mo.

[0143] As Figures 1 - 5 shown, they are respectively the SEM diagrams of multi-component titanium alloys prepared in Example 1, Example 2, Example 3, Example 4 and Example 5 of the present invention. It can be seen from Figures 1 - 5 them that with the change of the proportion of each alloy in the composition of the multi-component titanium alloy of the present invention, the main constituent phases of the titanium alloy do not change, and it is still mainly β-phase titanium alloy. Due to the good plasticity and low Young's modulus of β-phase titanium alloy, it ensures that the multi-component titanium alloy has a relatively high yield strength and a relatively low elastic modulus while being doped with multi-components.

[0144] Comparative Example 1:

[0145] Roll the medical pure titanium according to the above steps, and carry out surface treatment after ten times of rolling to obtain the test sample 1 to be tested.

[0146] Comparative Example 2:

[0147] Forging and several times of rolling are carried out on TC4, and then surface treatment is carried out to obtain the test sample 2 to be tested.

[0148] Carry out performance tests on the products of Examples 1 - 5 and Comparative Examples 1 and 2 for tensile strength, elongation and elastic modulus. The specific test standards refer to GB / T228 - 1987 "Metallic Materials - Tensile Testing". The test results are shown in Table 1. In addition, Figures 15 - 16The stress-strain curves of the mechanical properties of the multi-component titanium alloy doped with Mo atoms in the present invention when the Mo atomic ratio changes from 1% to 5%. Figure 15 It is an engineering stress-strain curve graph. Figure 16 It is a true stress-strain curve and the corresponding work-hardening rate curve. Table 1 shows the mechanical properties of the multi-component titanium alloy of the present invention, including Young's modulus, yield strength, tensile strength, and maximum elongation. From Figure 15 Combined with Table 1, it can be seen that the yield strength of the multi-component titanium alloy prepared in Examples 1-5 of the present invention is 325-816 MPa, the tensile strength is 778-864 MPa, the total elongation is 12-30%, and the elastic modulus is 42-82 GPa. As the Mo atomic ratio increases, the Young's modulus of the multi-component titanium alloy shows a monotonically increasing trend. The multi-component titanium alloy prepared in Example 1 has the smallest Young's modulus of 42 GPa among Examples 1-5, and the multi-component titanium alloy prepared in Example 5 has the largest Young's modulus of 81 GPa among Examples 1-5. From Figure 16 It can be known that as the Mo content increases, the mechanical properties of the alloy show different types of change trends. The yield strength of the titanium alloy prepared in Example 1 is only 324 MPa at the lowest, but there is an obvious secondary yield phenomenon. After yielding at 324 MPa, it reaches a secondary yield at 860 MPa with a relatively high work-hardening rate. After yielding, the work-hardening rate gradually decreases with plastic deformation, and the elongation of the alloy is relatively low. This is the trip effect in metastable β titanium alloy, which is a stress-induced phase transformation that improves the yield strength of the alloy. Such alloys often have a relatively low elongation. The yield strength of the titanium alloy prepared in Example 2 increases significantly, and it shows obvious work-hardening after yielding, with a tensile strength reaching 846 MPa. At the same time, the alloy has a good maximum elongation. The titanium alloy prepared in Example 3 shows the same type of yield fracture form. After the alloy yields, the tensile strength gradually decreases until the tensile specimen breaks, and the work-hardening curve also shows the same trend. After reaching the yield strength, there is a weak work-hardening rate with plastic deformation. From the tensile curves of the alloys prepared in Examples 3-5, it can also be seen that the titanium alloy prepared in Example 3 has the best mechanical properties in the system, with an elastic modulus of 60 GPa, a yield strength of 816 MPa, a tensile strength of 841 MPa, and a maximum elongation of 30%. Based on the above analysis, the multi-component titanium alloy of the present invention has the best comprehensive performance when the atomic percentage ratio of Ti: Zr: Nb: Sn: Mo is 78:5:10:4:3, and can better meet the design requirements.

[0149] Table 1 Test results of the mechanical properties of the alloys prepared in Examples 1-5 and Comparative Examples 1-2.

[0150]

[0151] Figure 6 X-ray diffraction patterns of multi-component titanium alloys prepared in Examples 1-5 of the present invention Figure 7 is Figure 6 a partial enlarged view at a diffraction angle of 36°-37.5° in Figure 7 wherein the abscissa is the diffraction angle and the ordinate is the diffraction peak value. It can be seen from

[0152] Figures 8 - 9 the inverse pole figures and grain orientation spread figures of multi-component titanium alloys prepared in Examples 1, 2, 3 and 5 of the present invention respectively. As Figure 9 shown, the grain orientation spread figure is obtained by further analyzing the inverse pole figure of the multi-component titanium alloy. Among them, the yellow area in the figure is the recrystallization recovery area, the blue area is the recrystallization area, and the red area is the stress residue area. Through the change of the color area in the inverse pole figure, with the increase of the Mo content, the yellow area in the inverse pole figure gradually increases, indicating that the recovery degree of the alloy has improved. At the same time, the blue area gradually decreases, representing the reduction of the fully recrystallized area. Therefore, it shows that Mo, as a strong β-stabilizing element, with the increase of its content, the recrystallization temperature of the alloy also increases, and the difficulty of recrystallization increases, ultimately resulting in a decrease in the recrystallization degree of the alloy. In addition, the multi-component titanium alloys prepared in Examples 2 and 3 have a relatively large red area, and there are residual stresses in these grains during the hot rolling process. These stress-containing areas may be helpful for improving the mechanical properties of the alloy. The existence of residual stresses may combine mechanisms such as grain refinement and phase transformation strengthening to enhance the strength and toughness of the alloy. Therefore, the content of Mo element in the titanium alloy of the present invention affects the microstructure and performance optimization of the alloy, and has a relatively obvious impact on the final performance of the alloy.

[0153] Figure 10 The alloy grain size statistical chart of multi-component titanium alloys prepared in Examples 1, 2, 3 and 5 of the present invention. As Figure 10 shown, with the increase of the Mo atom ratio, the grain size of the multi-component titanium alloy shows an obvious refinement phenomenon. The average grain size of the multi-component titanium alloy prepared in Example 1 is 139 microns, the average grain size of the multi-component titanium alloy prepared in Example 2 is 111 microns, the average grain size of the multi-component titanium alloy prepared in Example 3 is 75 microns, and the average grain size of the multi-component titanium alloy prepared in Example 5 is 62 microns.

[0154] As Figures 11 - 14 shown, through Figure 11From the diffraction spots in [Figure], it can be found that the large area in the figure is the spot of the β phase with the crystal orientation index of

[100] , which indicates that the β phase is the matrix in the multi-component titanium alloy. There is still a small amount of α phase in the β matrix. In addition, Figure 12 is Figure 11 the enlarged view of the dashed area, Figure 11 the dashed area in [Figure] is the two-phase coexistence area, Figure 12 the diffraction spots in [Figure] prove that the lath-like structure in the figure is the α phase with the crystal orientation index of [00-1] contained in the alloy. Figure 13 is the strip area found in the β matrix of the alloy. It can be found from the figure that there are obvious regular strip phases on the β matrix in the titanium alloy prepared in Example 2. Figure 13 The electron diffraction spots in the lower right corner of [Figure] are calibrated to determine that this twin band is an α-phase twin with the crystal orientation index of [00-1]. Due to the small number of twins, it is not detected in the XRD diffraction pattern. Figure 14 It can be found in [Figure] that the transmission electron micrographs of the titanium alloys prepared in Alloy Example 3 to [Example] show that the alloy matrix contains a large number of dislocation pile-ups and slip bands. Through the diffraction spots, it can be found that the matrix is still the β phase, and there is no appearance of α phase or other precipitation phases, showing the classic hot-rolled β-phase morphology. Thus, it can be concluded that the introduction of elements such as Mo in the multi-component titanium alloy does not change the matrix phase structure of itself.

[0155] Figure 17 This is the comparison chart of the grain size and yield strength of the multi-component titanium alloys prepared in Example 1, Example 2, Example 3 and Example 5 of the present invention. The columnar area in the figure represents the grain size of the alloy, and the dotted line represents the yield strength. As Figure 17 shown, we can find that with the increase of the Mo content, the alloy grains decrease from 139 μm of TZNS1Mo to 62 μm of TZNS5Mo, and the grains show an obvious refinement phenomenon. It can be found from the dotted line graph that the alloy properties do not show a linear distribution with the refinement of the grains. This indicates that grain refinement does not play a dominant role in the alloy system. There are many non-β-phase diffraction peaks in the XRD pattern after the fracture of the multi-component titanium alloy of the present invention, and some initial β-phase diffraction peaks disappear. The first yield of the titanium alloy is due to the stress-induced β→α martensite transformation, and the second yield is mainly due to the start of plastic deformation. Stress-induced phase transformation is common in quenched metastable β titanium alloys and is a typical TRIP effect. Due to the existence of the TRIP effect, alloy TZNS1Mo has the highest tensile strength. Although the grains of the TZNS1Mo alloy prepared in Example 1 are the largest in the system, the TRIP effect will sacrifice the maximum elongation rate of the titanium alloy, which results in that the TZNS1Mo alloy only has an elongation rate of 12%. While the optimal formulation of the present invention, i.e., TZNS3Mo prepared in Example 3, has an elongation rate of 30%. With the increase of Mo element as a β-stabilizing element, the alloy stability increases, and the phase transformation in the alloy is reduced, thus increasing the elongation rate of the alloy.

[0156] Figure 18 This is a comparison chart of the combination of Young's modulus and yield stress of the multi-component titanium alloy of the present invention with other alloy materials, where the vertical axis is the yield strength and the horizontal axis is the elastic modulus. As shown in the figure, the multi-component titanium alloy of the present invention has great advantages over other medical alloys represented by Ti15Mo, Ti45Nb, and Ti6Al4V in terms of yield tensile stress and elastic modulus. The elastic modulus is usually determined by a tensile test, and the usage method of the extensometer during tensile testing is related to the final result of the elastic modulus. In superelastic materials, the average elastic modulus of the entire elastic stage is often used to express it. Some materials also do not consider the ductility of the material, sacrificing ductility in exchange for mechanical strength, resulting in limited elongation of high-strength materials. Finally, the cold-rolled specimens limit the size and use of the samples through a large deformation process that reduces the volume by 90%. Figure 19 This is a comparison chart of the ratio of yield strength to elastic modulus between the multi-component titanium alloy of the present invention and some biological alloys. Among them, the dotted line in the figure is the ratio of the yield strength and elastic modulus of the currently reported alloys. As shown in the figure, the ratio of the yield strength to the elastic modulus of the multi-component titanium alloy prepared in Example 3, which is the optimal formulation of the present invention, is in a dominant position and is much greater than that of other medical alloys. Compared with most other alloys, the multi-component titanium alloys prepared in other embodiments of the present invention have the characteristics of high strength and low elastic modulus. These properties are achieved through simple alloying, and only through hot rolling, which effectively reduces the convenience of the processing technology. In addition, the multi-component titanium alloy of the present invention has better biocompatibility and higher application value compared with other medical alloys.

[0157] The above-described embodiments are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a high-strength and low-modulus multi-component titanium alloy, characterized in that: It includes the following steps: S1. Pre-treating Ti source, Zr source, Nb source, Sn source and Mo source and smelting them according to the metal atomic ratio of (76-80): (4.5-5.5): (9.5-10.5): (3.5-4.5): (1-5) to obtain an alloy ingot; S2, subjecting the alloy ingot obtained in step S1 to solid solution treatment; S21, placing the alloy ingot into a vacuum tube resistance furnace, filling it with inert gas, and then heating it at a heating rate of 10-20° C. / min; S22, raising the temperature inside the vacuum tube resistance furnace to 900-950° C. and keeping the temperature for 1.5-4 hours; S23, water cooling to room temperature after the insulation is completed; S3, rolling the alloy ingot after the solution treatment in step S2 for 9-10 times to obtain an alloy plate; S31, after heating the box-type resistance furnace to 750-850°C, placing the alloy ingot after the solution treatment in step S2 into the box-type resistance furnace and keeping it warm for 20-40 minutes; S32, transferring the alloy ingot after the heat preservation in step S31 to a two-roller flat rolling mill for rolling, wherein the rolling deformation is controlled at 7-8%, and the first rolling is completed; S33, placing the alloy ingot after the first rolling in step S32 into the box-type resistance furnace for insulation for 3-5 minutes, wherein the insulation temperature is 800-850° C.; S34, transferring the alloy ingot after the heat preservation in step S33 to a two-roller flat rolling mill for rolling, wherein the rolling deformation is controlled at 7-8% of the total thickness, and the second rolling is completed; S35, repeating step S33 and step S34 to sequentially complete the third rolling, the fourth rolling, the fifth rolling, the sixth rolling, the seventh rolling, the eighth rolling, the ninth rolling or the third to the tenth rolling to obtain an alloy plate; S4, post-processing the alloy plate in step S3 to obtain a multi-component titanium alloy.

2. The method for preparing a high-strength and low-modulus multi-component titanium alloy according to claim 1, characterized in that: The step S1 comprises the following specific steps: S11, ultrasonically cleaning the Ti source, the Zr source, the Nb source, the Sn source and the Mo source with anhydrous ethanol for 3-5 minutes, and then drying for 1-2 minutes; S12, adding the dried Ti source, Zr source, Nb source, Sn source and Mo source into a vacuum non-consumable melting furnace and heating the mixture from the starting temperature to the ending temperature in a magnetic stirring environment, wherein the melting time of step S12 is 5-10 min, the starting temperature is room temperature, and the ending temperature is 2500-3000° C.; S13, after the smelting time in step S12 ends, the furnace is cooled to room temperature, completing the first smelting; S14, repeat step S12 and step S13, smelting 6-8 times.

3. The method for preparing a high-strength and low-modulus multi-component titanium alloy according to claim 1, characterized in that: The post-treatment process in step S4 includes water cooling the alloy plate after rolling in step S3 to room temperature, and then performing peeling and surface treatment in sequence.

4. The method for preparing a high-strength and low-modulus multi-component titanium alloy according to any one of claims 1 to 3, characterized in that: The Ti source in step S1 is Ti single substance, the Zr source is Zr single substance, the Nb source is Nb single substance, the Sn source is Sn single substance, and the Mo source is Mo single substance. The smelting current of the vacuum non-consumable smelting furnace in step S1 is 350-400A, and the vacuum degree during the smelting process is 1×10 -3 Up to 8×10 -3 Pa, the inert gas in step S21 is argon, the temperature in the furnace in step S22 is below 1050° C., and the total deformation of the alloy plate obtained after the rolling process in step S3 is 70-80% of the initial thickness of the alloy ingot.

5. A high-strength, low-modulus multi-component titanium alloy, characterized in that: It includes 76-80% Ti element, 4.5-5.5% Zr element, 9.5-10.5% Nb element, 3.5-4.5% Sn element, and 1-5% Mo element, and the proportion of each element is the percentage of metal atoms.

6. The high-strength, low-modulus multi-component titanium alloy according to claim 5, characterized in that: The atomic percentage of Ti:Zr:Nb:Sn:Mo is 78:5:10:4:3.

Images