Ultrafine grain titanium-tantalum-palladium alloy as well as preparation method and application thereof

Abstract

The invention provides an ultra-fine grain titanium-tantalum-palladium alloy and a preparation method and application thereof, and relates to the technical field of medical materials.The preparation method comprises the steps that firstly, alloy raw materials are obtained according to the alloy elements of, by weight, 10%-50% of tantalum, 0.5%-3.0% of palladium and 47%-89.5% of titanium; then alloy raw materials are subjected to vacuum consumable smelting for three times to prepare an alloy cast ingot, and the alloy cast ingot is subjected to cogging, upsetting and drawing and rolling processes to prepare an alloy bar; the alloy bar is subjected to multi-pass extrusion deformation through equal-channel extrusion, so that grains in the alloy bar are refined to be in the ultra-fine grain and / or nanocrystalline level, and the alloy bar with the ultra-fine grains is obtained; and finally, the surface of the alloy bar with the ultra-fine grains is subjected to acid pickling treatment, and the ultra-fine grain titanium-tantalum-palladium alloy is obtained. The surface of the ultra-fine grain titanium-tantalum-palladium alloy has a strong antibacterial effect, meanwhile, the ultra-fine grain titanium-tantalum-palladium alloy has high tensile strength and low elastic modulus, and the stress shielding effect of the ultra-fine grain titanium-tantalum-palladium alloy serving as an implant can be reduced.

Description

Technical Field

[0001] The present application relates to the field of medical material technology, and in particular to an ultrafine-grained titanium-tantalum-palladium alloy and a preparation method and application thereof. Background Art

[0002] As a biologically inert titanium alloy material, titanium and titanium alloys have good in vitro biocompatibility and corrosion resistance, and have good application prospects in the field of implant-level medical devices, such as dentistry, orthopedics, sports medicine, etc. However, the elastic modulus of titanium and titanium alloys is much higher than that of bones, resulting in a mismatch between the elastic modulus of the prepared implant and the bone, and a "stress shielding" phenomenon is very likely to occur, which causes the bone tissue around the implant to degenerate and absorb, and then cause the implant to loosen or break, such as the occurrence of adjacent vertebral disease after spinal surgery; in the use of micro-implanted medical devices, the mismatch between the strength and biomechanics of titanium alloys causes the mechanical properties to fail to meet the use standards, and cannot be adapted for a long time under the influence of various cyclic loads, and gradually cracks or even breaks appear. For example, the central screw of the implant attachment will break in clinical practice, which also limits its biomedical application. At the same time, after titanium and titanium alloys are implanted in the human body, it is easy to cause bacteria and other microorganisms to adhere to their surface, leading to infection and other problems. Summary of the invention

[0003] The present application provides an ultrafine-grained titanium-tantalum-palladium alloy and a preparation method and application thereof, so as to solve the problems existing in biomedical applications of existing titanium and titanium alloy materials, such as the mismatch between the elastic modulus and bones, insufficient mechanical properties, and susceptibility to infection.

[0004] In a first aspect, the present application provides a method for preparing an ultrafine-grained titanium-tantalum-palladium alloy, the method comprising the following steps: Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements including: tantalum, palladium and titanium, the weight percentages being: tantalum 10-50%, palladium 0.5-3.0%, titanium 47%-89.5%; Step 2: The alloy raw material is smelted in vacuum consumable process three times to obtain an alloy ingot, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter of the alloy rod ranges from 15 mm to 30 mm; Step 3: performing multiple extrusion deformation on the alloy rod by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, thereby obtaining an alloy rod with ultrafine grains, wherein the size of the ultrafine grains ranges from 0.2 μm to 0.5 μm; Step 4: The surface of the alloy rod having ultrafine grains is pickled to obtain an ultrafine grain titanium-tantalum-palladium alloy.

[0005] Optionally, in step 1, the weight percentages are: 20% to 40% tantalum, 1.5% to 2.0% palladium, and 57% to 79.5% titanium.

[0006] Optionally, in step 3, the temperature range of equal channel extrusion is 200°C~400°C, the extrusion rate range is 0.5 mm / s~3 mm / s, the number of extrusion channels is four, and the rotation angle is 90°.

[0007] Optionally, in step 3, the temperature range of equal channel extrusion is 300°C~350°C, the extrusion rate range is 1.5 mm / s~2 mm / s, the number of extrusion channels is four, and the rotation angle is 90°.

[0008] Optionally, in step 4, the volume ratio of the pickling solution used for the pickling treatment is: 5% to 20% hydrofluoric acid, 5% to 30% hydrochloric acid and 0.2% to 1% perchloric acid, and the pickling time ranges from 20 min to 60 min.

[0009] Optionally, in step 4, the volume ratio of the pickling solution used for the pickling treatment is: 10%~16% hydrofluoric acid, 21%~25% hydrochloric acid and 0.8%~1% perchloric acid, and the pickling time ranges from 40 min to 60 min.

[0010] In a second aspect, the present application proposes an ultrafine-grained titanium tantalum palladium alloy, which is prepared according to the preparation method of the ultrafine-grained titanium tantalum palladium alloy described in any one of the first aspects above.

[0011] Optionally, the surface of the ultrafine-grained titanium-tantalum-palladium alloy has an oxide layer rich in tantalum and palladium elements, and the oxide layer is used to inhibit bacterial growth and reproduction; After equal channel extrusion treatment, the ultrafine-grained titanium-tantalum-palladium alloy forms palladium-rich areas at the grain boundaries and palladium-poor areas in other areas, and the antibacterial effect is achieved by the potential difference between the palladium-rich area and the palladium-poor area.

[0012] Optionally, the ultrafine-grained titanium tantalum palladium alloy has a tensile strength range of 850 MPa to 1060 MPa, an elongation range of 20% to 28%, an elastic modulus range of 70 GPa to 98 GPa, and an antibacterial rate range of 95% to 99%.

[0013] On the third aspect, the present application proposes an application of an ultrafine-grained titanium-tantalum-palladium alloy, and the ultrafine-grained titanium-tantalum-palladium alloy is used to prepare oral implants, abutments, orthopedic, and sports medicine implantable medical devices.

[0014] The present application proposes an ultrafine-grained titanium-tantalum-palladium alloy and its preparation method and application. First, the alloy raw material is obtained according to the weight percentage of the alloy elements, and the alloy elements include: tantalum, palladium and titanium, and the weight percentage is: tantalum 10~50%, palladium 0.5~3.0%, titanium 47%~89.5%; then the alloy raw material is subjected to three vacuum consumable smelting to obtain an alloy ingot, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, and the diameter range of the alloy rod is 15 mm~30 mm; the alloy rod is subjected to multiple extrusion deformation by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels to obtain an alloy rod with ultrafine grains, and the size range of the ultrafine grains is 0.2 μm~0.5 μm; finally, the surface of the alloy rod with ultrafine grains is pickled to obtain an ultrafine-grained titanium-tantalum-palladium alloy. The advantages include the following: (1) The ultrafine-grained titanium-tantalum-palladium alloy prepared in this application has a strong antibacterial effect on the surface, with an antibacterial rate of up to 99%; (2) The ultrafine-grained titanium-tantalum-palladium alloy prepared in this application does not contain antibacterial but toxic alloying elements such as Cu and Ag, and has higher biological safety; (3) Compared with pure titanium and titanium alloy, the ultrafine-grained titanium-tantalum-palladium alloy prepared in this application has a tensile strength increased from less than 800 MPa to 850 MPa~1060 MPa, which improves implant safety; and the elastic modulus is reduced from 110 GPa to 70 GPa~95 GPa, which is beneficial to reduce its stress shielding effect as an implant. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 This is a scanning electron microscope image of the grains of an ultrafine-grained titanium-tantalum-palladium alloy prepared in Example 6 provided in the examples of the present application; Figure 2 It is a schematic diagram of the colonies of titanium tantalum palladium alloys prepared in a comparative example, Example 5 and Example 6 provided in the examples of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] In order to solve the problems of insufficient elastic modulus and mechanical properties of titanium and titanium alloys, and being easily infected by bacteria, the embodiment of the present application proposes an ultrafine-grained titanium-tantalum-palladium alloy with high strength, low modulus and antibacterial properties, so as to expand its application in biomedicine. Tantalum and palladium elements are added to titanium, and then treated by equal channel angular extrusion and pickling to obtain a palladium-rich phase in a local area on the metal surface, forming a local microelectrode system, obtaining antibacterial properties, and finally obtaining an ultrafine-grained titanium-tantalum-palladium alloy with high strength, low modulus and antibacterial properties.

[0019] In a first aspect, an embodiment of the present application provides a method for preparing an ultrafine-grained titanium-tantalum-palladium alloy, the method comprising the following steps: Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements include: tantalum, palladium and titanium, the weight percentage is: tantalum 10% to 50%, palladium 0.5% to 3.0%, titanium 47% to 89.5%.

[0020] First, alloy raw materials are obtained according to the weight percentage of alloy elements tantalum, palladium and titanium. The raw materials containing alloy elements tantalum, palladium and titanium include: sponge palladium, sponge titanium and titanium-tantalum master alloy. After obtaining the above raw materials, the required weight of each raw material is calculated according to the important percentage.

[0021] It should be noted that the obtained alloy raw materials contain inevitable impurity elements, which are carried by the alloy raw materials themselves.

[0022] Illustratively, the weight percentage of tantalum can be: 10%, 20%, 30%, 40%, 50%, etc.; the weight percentage of palladium can be: 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, etc.; the weight percentage of titanium can be: 47%, 58%, 68%, 78%, 84%, 89%, 89.5%, etc.

[0023] In an optional embodiment, in the above step 1, the weight percentages of tantalum, palladium and titanium are 20-40%, 1.5-2.0%, and 57%-79.5%, respectively.

[0024] Illustratively, the weight percentage of tantalum can be: 20%, 30%, 40%, 50%, etc.; the weight percentage of palladium can be: 1.5%, 2.0%, 2.5%, 3.0%, etc.; the weight percentage of titanium can be: 57%, 58%, 68.5%, 78%, 84%, 89%, 89.5%, etc.

[0025] Step 2: The alloy raw material is smelted in vacuum consumable process three times to obtain an alloy ingot, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter of the alloy rod ranges from 15 mm to 30 mm.

[0026] In step 2, the conditions for vacuum consumable melting of the alloy raw material are: vacuum degree is lower than 1Pa and temperature is higher than 1700°C.

[0027] After obtaining the alloy ingot, the alloy ingot is subjected to the processes of blanking, upsetting and rolling to obtain the alloy rod, wherein the temperature of the blanking process is 1150° C., the temperature of the upsetting process is 900° C., and the temperature of the rolling process is 850° C. The specific operation process of the above-mentioned process is the same as the conventional process mode, and will not be repeated here.

[0028] It should be noted that the diameter of the alloy rod can be directly measured by a ruler, vernier caliper or micrometer. The diameter of the alloy rod has little effect on the alloy properties, but it affects the difficulty of preparing the alloy. When the rod diameter is less than 15 mm, it will lead to insufficient rigidity and easy bending during equal channel extrusion processing; when the rod diameter is greater than 30 mm, the extrusion force required for equal channel extrusion processing is very large, and the equipment capacity is difficult to meet the requirements.

[0029] Step 3: The alloy rod is subjected to multiple extrusion deformations by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, thereby obtaining an alloy rod with ultrafine grains, wherein the size of the ultrafine grains ranges from 0.2 μm to 0.5 μm.

[0030] The present application embodiment utilizes the antibacterial and bactericidal properties of palladium to solve the problem that bacteria and other microorganisms adhere to the alloy surface, causing infection, etc. At the same time, the addition of palladium reduces the proportion of tantalum, which reduces the elastic modulus of the alloy. The antibacterial principle of palladium is to act on the microbial cell membrane and nucleic acid chain through redox reaction, causing them to lose vitality, thereby achieving the purpose of antibacterial. However, the titanium-tantalum alloy prepared by adding only palladium itself has no antibacterial effect, because the palladium content is low and is evenly dissolved in the alloy, and the alloy surface cannot have antibacterial properties.

[0031] Based on this, equal channel extrusion is used to perform multiple extrusion deformation on the above alloy rods to reduce the grain size inside the alloy, so that the grains inside the material are refined to ultrafine or even nanocrystalline levels, and the grain boundaries are increased, thereby increasing the tensile strength and yield strength of the alloy, while maintaining a good elongation. Moreover, equal channel angular extrusion treatment of titanium-tantalum-palladium alloy forms palladium-rich areas at the grain boundaries and palladium-poor areas in other areas. Because the potential of palladium is higher than that of titanium, the potential of the palladium-rich area is higher than that of the palladium-poor area, forming a potential difference. The size of ultrafine grains is about 0.2 μm~0.5 μm (see Figure 1 ), the size of bacteria is between 0.3 μm-700 μm, and the size of bacteria spans multiple potential differences, so that multiple sections of microcurrent can be formed inside the bacteria, thereby stimulating the bacteria and achieving an antibacterial effect.

[0032] During the equal channel angular extrusion process of titanium tantalum palladium alloy, the formation of palladium-rich and palladium-poor areas is closely related to the presence of tantalum. The role of tantalum in the alloy includes: Tantalum plays a role in lattice stabilization in the alloy, affects the phase separation behavior of the alloy, promotes the separation of different components in the alloy, and thus forms a potential difference; it enhances the electrochemical activity of palladium in the alloy, making the potential of the palladium-rich area higher than that of the palladium-poor area, thus forming a potential difference in the alloy; it affects the phase change process in the alloy, including phase stability and phase change temperature, resulting in microstructural changes in the alloy during equal channel angular pressing, affecting the plastic deformation behavior of the alloy, changing the strain distribution and microstructural evolution of the alloy during equal channel angular pressing, and further affecting the formation of palladium-rich and palladium-poor areas; as a dispersant, it promotes the uniform distribution or local enrichment of palladium in the alloy. This dispersion effect cannot be achieved in the absence of tantalum, resulting in the inability to form obvious palladium-rich and palladium-poor areas.

[0033] It can be seen that the presence of tantalum in titanium-tantalum-palladium alloy is crucial to the formation of palladium-rich and palladium-poor areas. It promotes the formation of potential differences in the alloy by affecting the alloy's lattice structure, electrochemical properties, phase change behavior, and plastic deformation. In the absence of tantalum, these effects cannot be achieved, so palladium-rich and palladium-poor areas cannot be formed.

[0034] In an optional embodiment, in step 3, the temperature range of equal channel extrusion is 200°C~400°C, the extrusion rate range is 0.5 mm / s~3 mm / s, the number of extrusion channels is four, and the rotation angle is 90°.

[0035] Illustratively, the temperature of the equal channel pressing can be 200°C, 300°C, 400°C, etc., and the extrusion rate can be 0.5 mm / s, 1 mm / s, 1.5 mm / s, 2 mm / s, 2.5 mm / s, 3 mm / s, etc.

[0036] In a preferred embodiment, in the above step 3, the temperature range of equal channel extrusion is 300°C~350°C, the extrusion rate range is 1.5 mm / s~2 mm / s, the number of extrusion channels is four, and the rotation angle is 90°.

[0037] For example, the temperature of the equal channel pressing may be 300° C., 350° C., etc., and the extrusion rate may be 1.5 mm / s, 2 mm / s, etc.

[0038] Step 4: The surface of the alloy rod having ultrafine grains is pickled to obtain an ultrafine grain titanium-tantalum-palladium alloy.

[0039] After obtaining the alloy rod with ultrafine grains, in order to make the surface of the alloy rod have antibacterial properties, the surface of the alloy rod is pickled to form an oxide layer rich in tantalum and palladium elements on the surface of the alloy rod. The oxide layer can effectively inhibit the growth and reproduction of bacteria, making the surface of the alloy rod have antibacterial properties. Since the solid solubility of palladium in the tantalum matrix is ​​not high, it can be further enriched by pickling treatment, thereby improving the antibacterial effect.

[0040] In an optional embodiment, in step 4, the pickling solution used for pickling treatment includes hydrofluoric acid, hydrochloric acid and perchloric acid, wherein the fluoride ions in the hydrofluoric acid have a strong corrosive effect on titanium; the addition of hydrochloric acid ensures that the hydrogen ions in the pickling solution work together with the fluoride ions to enhance the corrosion effect; the hydrofluoric acid reacts with the oxidized titanium dioxide to generate TiF6 2- Complex, perchloric acid is a strong oxidizing acid, and the addition of perchloric acid enhances the oxidation effect on titanium, making titanium dioxide more susceptible to corrosion by fluoride ions.

[0041] The volume ratio of the pickling solution used in the pickling treatment is: 5%~20% hydrofluoric acid, 5%~30% hydrochloric acid and 0.2%~1% perchloric acid, and the pickling time ranges from 20 min to 60 min.

[0042] Illustratively, the volume ratio of hydrofluoric acid contained in the pickling solution may be: 5%, 7%, 10%, 13%, 15%, 16%, 17%, 20% and the like; the volume ratio of hydrochloric acid contained in the pickling solution may be: 5%, 10%, 13%, 15%, 16%, 20%, 25%, 30% and the like; the volume ratio of perchloric acid contained in the pickling solution may be: 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% and the like.

[0043] The pickling treatment time can be 20 min, 30 min, 40 min, 50 min, 60 min, etc.

[0044] In a preferred embodiment, in the above step 4, the volume ratio of the pickling solution used for the pickling treatment is: 10%~16% hydrofluoric acid, 21%~25% hydrochloric acid and 0.8%~1% perchloric acid, and the pickling time ranges from 40 min to 60 min.

[0045] Exemplarily, the volume ratio of hydrofluoric acid contained in the pickling solution can be: 10%, 13%, 15%, 16% and the like; the volume ratio of hydrochloric acid contained in the pickling solution can be: 21%, 23%, 25% and the like; the volume ratio of perchloric acid contained in the pickling solution can be: 0.8%, 0.9%, 1% and the like.

[0046] The pickling time can be 40 min, 50 min, 60 min, etc.

[0047] In a second aspect, an embodiment of the present application provides an ultrafine-grained titanium-tantalum-palladium alloy, wherein the ultrafine-grained titanium-tantalum-palladium alloy is prepared according to the preparation method of the ultrafine-grained titanium-tantalum-palladium alloy described in the first aspect above.

[0048] Specifically, the surface of the ultrafine-grained titanium tantalum palladium alloy is provided with an oxide layer rich in tantalum and palladium elements, which is used to inhibit the growth and reproduction of bacteria. The palladium in the oxide layer acts on the cell membranes and nucleic acid chains of microorganisms through redox reactions, causing them to lose vitality, thereby achieving the purpose of antibacterial.

[0049] After equal channel extrusion treatment, ultrafine-grained titanium-tantalum-palladium alloy forms palladium-rich areas at the grain boundaries and palladium-poor areas in other areas, forming a potential difference between the palladium-rich and palladium-poor areas. The size of bacteria spans across multiple potential differences, forming multiple microcurrents inside the bacteria, which stimulate the bacteria through the microcurrents formed by the potential differences, achieving an antibacterial effect.

[0050] At present, the tensile strength of pure titanium and titanium alloys is less than 800 MPa. The tensile strength of the ultrafine-grained titanium tantalum palladium alloy prepared based on the above implementation method is increased to 850 MPa~1060 MPa, the elastic modulus of pure titanium and titanium alloys is as high as 110 GPa, and the elastic modulus of the ultrafine-grained titanium tantalum palladium alloy is reduced to 70 GPa~98 GPa, and the elongation range is 20%~28%, and the antibacterial rate range is 95%~99%.

[0051] Based on the above implementation, the ultrafine-grained titanium-tantalum-palladium alloy has good elastic modulus, higher strength, good corrosion resistance and good antibacterial properties, and can be used to prepare oral implants, abutments, orthopedic and sports medicine implant medical devices. At the same time, the ultrafine-grained titanium-tantalum-palladium alloy does not contain antibacterial but toxic alloy elements such as Cu and Ag, and has higher biological safety.

[0052] In order to facilitate the understanding of the ultrafine-grained titanium-tantalum-palladium alloy and its preparation method and application proposed in this application, the application will be described in detail in conjunction with specific embodiments below. The following embodiments will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be pointed out that for those skilled in the art, without departing from the concept of the application, the application can also make several variations and improvements, which all belong to the scope of protection of the application.

[0053] The materials and reagents used in the following examples, unless otherwise specified, can be obtained from commercial sources. The percentages used in the following examples, unless otherwise specified, are all by mass percentage.

[0054] Example 1: Preparation of Ti-10Ta-1Pd alloy Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements include: tantalum, palladium and titanium, and the weight percentage is: tantalum 10%, palladium 1%, titanium 89%; Step 2: After three vacuum consumable melting of the alloy raw material, an alloy ingot is obtained, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter range of the alloy rod is 30 mm; Step 3: The alloy rod is subjected to multiple extrusion deformation by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, and an alloy rod with ultrafine grains is obtained. The temperature of the equal channel extrusion is 200°C, the extrusion rate is 3 mm / s, the extrusion channel is four-pass, the rotation angle is 90°, and the size range of the ultrafine grains is 0.2 μm~0.5 μm; Step 4: The surface of the alloy rod with ultrafine grains is pickled to obtain an ultrafine grain titanium tantalum palladium alloy. The volume ratio of the pickling solution used in the pickling treatment is: 5% hydrofluoric acid, 15% hydrochloric acid and 0.5% perchloric acid, and the pickling time is 20 minutes.

[0055] Example 2: Preparation of Ti-15Ta-1Pd alloy Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements include: tantalum, palladium and titanium, and the weight percentage is: tantalum 15%, palladium 1%, titanium 84%; Step 2: After three vacuum consumable melting of the alloy raw material, an alloy ingot is obtained, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter range of the alloy rod is 25 mm; Step 3: The alloy rod is subjected to multiple extrusion deformation by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, and an alloy rod with ultrafine grains is obtained. The temperature of the equal channel extrusion is 300°C, the extrusion rate is 1 mm / s, the extrusion channel is four-pass, the rotation angle is 90°, and the size range of the ultrafine grains is 0.2 μm~0.5 μm; Step 4: The surface of the alloy rod with ultrafine grains is pickled to obtain an ultrafine grain titanium tantalum palladium alloy. The volume ratio of the pickling solution used in the pickling treatment is: 15% hydrofluoric acid, 5% hydrochloric acid and 1% perchloric acid, and the pickling time is 60 minutes.

[0056] Example 3: Preparation of Ti-50Ta-0.5Pd alloy Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements include: tantalum, palladium and titanium, and the weight percentage is: tantalum 50%, palladium 0.5%, titanium 49.5%; Step 2: After three vacuum consumable melting of the alloy raw material, an alloy ingot is obtained, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter range of the alloy rod is 15 mm; Step 3: The alloy rod is subjected to multiple extrusion deformation by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, thereby obtaining an alloy rod with ultrafine grains. The temperature of the equal channel extrusion is 400°C, the extrusion rate is 0.5 mm / s, the extrusion channel is four-pass, the rotation angle is 90°, and the size range of the ultrafine grains is 0.2 μm~0.5 μm; Step 4: The surface of the alloy rod with ultrafine grains is pickled to obtain an ultrafine grain titanium tantalum palladium alloy. The volume ratio of the pickling solution used in the pickling treatment is: 20% hydrofluoric acid, 30% hydrochloric acid and 0.2% perchloric acid, and the pickling time is 40 minutes.

[0057] Example 4: Preparation of Ti-40Ta-2Pd alloy Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements include: tantalum, palladium and titanium, and the weight percentage is: tantalum 40%, palladium 2%, titanium 58%; Step 2: After three vacuum consumable melting of the alloy raw material, an alloy ingot is obtained, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter range of the alloy rod is 15 mm; Step 3: The alloy rod is subjected to multiple extrusion deformation by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, thereby obtaining an alloy rod with ultrafine grains. The temperature of the equal channel extrusion is 350°C, the extrusion rate is 1.5 mm / s, the number of extrusion channels is four, the rotation angle is 90°, and the size range of the ultrafine grains is 0.2 μm~0.5 μm; Step 4: The surface of the alloy rod with ultrafine grains is pickled to obtain an ultrafine grain titanium tantalum palladium alloy. The volume ratio of the pickling solution used in the pickling treatment is: 16% hydrofluoric acid, 25% hydrochloric acid and 0.8% perchloric acid, and the pickling time is 40 minutes.

[0058] Example 5: Preparation of Ti-20Ta-2Pd alloy Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements include: tantalum, palladium and titanium, and the weight percentage is: tantalum 20%, palladium 2.0%, titanium 78%; Step 2: After three vacuum consumable melting of the alloy raw material, an alloy ingot is obtained, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter range of the alloy rod is 30 mm; Step 3: The alloy rod is subjected to multiple extrusion deformation by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, thereby obtaining an alloy rod with ultrafine grains. The temperature of the equal channel extrusion is 300°C, the extrusion rate is 2 mm / s, the extrusion channel is four-pass, the rotation angle is 90°, and the size range of the ultrafine grains is 0.2 μm~0.5 μm; Step 4: The surface of the alloy rod with ultrafine grains is pickled to obtain an ultrafine grain titanium tantalum palladium alloy. The volume ratio of the pickling solution used in the pickling treatment is: 13% hydrofluoric acid, 23% hydrochloric acid and 1.0% perchloric acid, and the pickling time is 60 minutes.

[0059] Example 6: Preparation of Ti-30Ta-1.5Pd alloy Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements include: tantalum, palladium and titanium, and the weight percentage is: tantalum 30%, palladium 1.5%, titanium 68.5%; Step 2: After three vacuum consumable melting of the alloy raw material, an alloy ingot is obtained, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter range of the alloy rod is 25 mm; Step 3: The alloy rod is subjected to multiple extrusion deformation by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, thereby obtaining an alloy rod with ultrafine grains. The temperature of the equal channel extrusion is 300°C, the extrusion rate is 1.5 mm / s, the number of extrusion channels is four, the rotation angle is 90°, and the size range of the ultrafine grains is 0.2 μm~0.5 μm; Step 4: The surface of the alloy rod with ultrafine grains is pickled to obtain an ultrafine grain titanium tantalum palladium alloy. The volume ratio of the pickling solution used in the pickling treatment is: 10% hydrofluoric acid, 21% hydrochloric acid and 0.8% perchloric acid, and the pickling time is 60 minutes.

[0060] Comparative Example: Preparation of Ti-30Ta-1.5Pd alloy The titanium tantalum palladium alloy was obtained by following steps 1 and 2 of Example 6 without performing equal channel pressing and pickling treatment.

[0061] Example 7: Performance Characterization The performance of the ultrafine-grained titanium-tantalum-palladium alloys prepared in Examples 1 to 6 was characterized, wherein the mechanical properties: tensile strength, elongation, and elastic modulus were tested by a tensile method. The characterization results are shown in Table 1.

[0062]

[0063] The antibacterial properties of ultrafine-grained titanium-tantalum-palladium alloys were tested by the plate count method. The test method is as follows: All embedded specimens (the specimens are ultrafine-grained titanium-tantalum-palladium alloys prepared in Examples 1 to 6) are placed at the bottom of a culture dish with the experimental surface facing upward, artificial saliva is added, and the specimens are placed on a clean bench at room temperature. After 1 hour, all specimens are taken out with sterile tweezers and placed in another clean culture dish, with the experimental surface facing upward, 5 ml of the prepared Streptococcus mutans bacterial suspension is added, and the dish is placed in an anaerobic glove box. After 6 hours, the samples are taken out, rinsed, and the specimens are placed in centrifuge tubes and culture fluid is added respectively. Each centrifuge tube is placed on a vortex mixer and shaken for 30 seconds. 10 ul of bacterial solution is taken with a micro-sampling gun and injected onto an agar plate culture medium. After fully spreading and anaerobic culture for 48 hours, the colony forming units are counted. The antibacterial results are shown in the antibacterial rate. The antibacterial rate is shown in Table 1, and the number of colonies on the plate is shown in Table 2. Figure 2 , Figure 2 Part (a) is a colony diagram of the titanium-tantalum-palladium alloy prepared in the comparative example. Figure 2 Part (b) is a colony diagram of the ultrafine-grained titanium-tantalum-palladium alloy prepared in Example 5. Figure 2 Part (c) is the colony image of the ultrafine-grained titanium-tantalum-palladium alloy prepared in Example 6.

[0064] From Table 1 and Figure 2It can be seen that the titanium-tantalum-palladium alloy prepared in the comparative example has no antibacterial effect, and there are more bacteria on the surface of its colony. However, through the medium channel extrusion treatment and pickling treatment in Examples 1 to 6 of the present application, an ultrafine-grained titanium-tantalum-palladium alloy with antibacterial performance (95%~99%) can be prepared, wherein the titanium-tantalum-palladium alloy treated with equal channel extrusion forms a palladium-rich area at the grain boundary, and other areas form a palladium-poor area. A potential difference is formed between the palladium-rich area and the palladium-poor area, and the size of the bacteria spans multiple potential differences. By forming multiple microcurrents inside the bacteria, the bacteria are stimulated to achieve an antibacterial effect. At the same time, the pickling treatment forms an oxide layer rich in tantalum and palladium elements on the surface of the alloy, which acts on the microbial cell membrane and nucleic acid chain through redox reactions, causing them to lose vitality and effectively inhibiting bacterial growth and reproduction.

[0065] The prepared ultrafine-grained titanium-tantalum-palladium alloy has good antibacterial properties, which can solve the problem of bacteria and other microorganisms adhering to the alloy surface and causing infection. It can be further used to prepare implantable medical devices such as oral implants, abutments, orthopedics, and sports medicine.

[0066] At the same time, the addition of palladium reduces the proportion of tantalum in the alloy, reducing the elastic modulus of the prepared ultrafine-grained titanium tantalum palladium alloy to 70 GPa, which is beneficial to reduce the stress shielding effect of the implant, enable it to match the elastic modulus between bones, and improve the effectiveness of the implant.

[0067] Furthermore, equal channel extrusion processing can also reduce the grain size inside the alloy, obtain ultrafine grains, increase grain boundaries, and increase the tensile strength of the alloy to 1060MPa compared with the tensile strength of the comparative tantalum-palladium alloy (650MPa), while maintaining a high elongation of 28%. It can be seen that the mechanical properties of the ultrafine-grained titanium-tantalum-palladium alloy have been greatly improved, which can meet the standards for implant use, and can be adapted for a long time under the influence of various cyclic loads without breaking, thereby improving the effectiveness of its use as an implant.

[0068] It can be seen that the ultrafine-grained titanium-tantalum-palladium alloy prepared in Example 6 has the best performance, namely: tensile strength 1060 MPa, elongation 28%, elastic modulus 70 GPa, and antibacterial rate 99%.

[0069] The ultrafine-grained titanium-tantalum-palladium alloy prepared in the embodiment of the present application has good antibacterial properties, can prevent bacteria from adhering to its surface, and also has good tensile strength and elongation, and is not prone to abnormal fracture. It has a low elastic modulus, which is conducive to reducing the stress shielding effect of the implant, so that it can match the elastic modulus between bones and improve the effectiveness of the implant. Therefore, the ultrafine-grained titanium-tantalum-palladium alloy prepared in the present application has good application prospects in the biomedical field, especially as implantable medical devices such as oral implants, abutments, orthopedics, and sports medicine.

[0070] The above is a detailed introduction to an ultrafine-grained titanium-tantalum-palladium alloy and its preparation method and application provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for preparing an ultrafine-grained titanium-tantalum-palladium alloy, characterized in that: The method comprises the following steps: Step 1: Obtain alloy raw materials according to the weight percentage of alloy elements, the alloy elements including: tantalum, palladium and titanium, the weight percentages being: tantalum 10-50%, palladium 0.5-3.0%, titanium 47%-89.5%; Step 2: The alloy raw material is smelted in vacuum consumable process three times to obtain an alloy ingot, and the alloy ingot is subjected to blanking, upsetting and rolling processes to obtain an alloy rod, wherein the diameter of the alloy rod ranges from 15 mm to 30 mm; Step 3: performing multiple extrusion deformation on the alloy rod by equal channel extrusion to refine the internal grains of the alloy rod to ultrafine grains and / or nanocrystalline levels, thereby obtaining an alloy rod with ultrafine grains, wherein the size of the ultrafine grains ranges from 0.2 μm to 0.5 μm; Step 4: The surface of the alloy rod having ultrafine grains is pickled to obtain an ultrafine grain titanium-tantalum-palladium alloy.

2. The method for preparing an ultrafine-grained titanium-tantalum-palladium alloy according to claim 1, characterized in that: In step 1, the weight percentages are: 20% to 40% tantalum, 1.5% to 2.0% palladium, and 57% to 79.5% titanium.

3. The method for preparing an ultrafine-grained titanium-tantalum-palladium alloy according to claim 1, characterized in that: In step 3, the temperature range of equal channel extrusion is 200°C~400°C, the extrusion rate range is 0.5 mm / s~3 mm / s, the number of extrusion channels is four, and the rotation angle is 90°.

4. The method for preparing an ultrafine-grained titanium-tantalum-palladium alloy according to claim 1, characterized in that: In step 3, the temperature range of equal channel extrusion is 300°C~350°C, the extrusion rate range is 1.5 mm / s~2 mm / s, the number of extrusion channels is four, and the rotation angle is 90°.

5. The method for preparing ultrafine-grained titanium-tantalum-palladium alloy according to claim 1, characterized in that: In step 4, the volume ratio of the pickling solution used in the pickling treatment is: 5% to 20% hydrofluoric acid, 5% to 30% hydrochloric acid and 0.2% to 1% perchloric acid, and the pickling time ranges from 20 min to 60 min.

6. The method for preparing ultrafine-grained titanium-tantalum-palladium alloy according to claim 1, characterized in that: In step 4, the volume ratio of the pickling solution used in the pickling treatment is: 10% to 16% hydrofluoric acid, 21% to 25% hydrochloric acid and 0.8% to 1% perchloric acid, and the pickling time ranges from 40 min to 60 min.

7. An ultrafine-grained titanium-tantalum-palladium alloy, characterized in that: The ultrafine-grained titanium-tantalum-palladium alloy is prepared according to the method for preparing an ultrafine-grained titanium-tantalum-palladium alloy according to any one of claims 1-6.

8. The ultrafine-grained titanium-tantalum-palladium alloy according to claim 7, characterized in that: The surface of the ultrafine-grained titanium-tantalum-palladium alloy is provided with an oxide layer rich in tantalum and palladium elements, and the oxide layer is used to inhibit the growth and reproduction of bacteria; After equal channel extrusion treatment, the ultrafine-grained titanium-tantalum-palladium alloy forms palladium-rich areas at the grain boundaries and palladium-poor areas in other areas, and the antibacterial effect is achieved by the potential difference between the palladium-rich area and the palladium-poor area.

9. The ultrafine-grained titanium-tantalum-palladium alloy according to claim 7, characterized in that: The ultrafine-grained titanium-tantalum-palladium alloy has a tensile strength range of 850 MPa to 1060 MPa, an elongation range of 20% to 28%, an elastic modulus range of 70 GPa to 98 GPa, and an antibacterial rate range of 95% to 99%.

10. An application of an ultrafine-grained titanium-tantalum-palladium alloy, characterized in that: The ultrafine-grained titanium-tantalum-palladium alloy is used to prepare oral implants, abutments, and implantable medical devices for orthopedics and sports medicine.

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