阅读说明：本技术 一种生物医用NiTiFe-Ta复合板材及其制备方法 (Biomedical NiTiFe-Ta composite board and preparation method thereof ) 是由 郭顺 张慧慧 黄豪 丁旺 凌瀚宇 于 2021-04-14 设计创作，主要内容包括：本发明涉及生物医用复合材料技术领域,具体地说是一种兼具无细胞毒性、类线弹性变形及大的可恢复应变量的NiTiFe-Ta生物医用复合材料及其制备方法,通过该方法制备的NiTiFe-Ta复合材料能够同时具备无细胞毒性(即优异的生物相容性)和大的类线弹性变形能力(即应力能够随着应变的增加呈现近似线性的增长并伴有大的可恢复应变),能够解决现有NiTi基形状记忆合金无法兼具优良生物相容性和大类线弹性变形能力的性能瓶颈,拓宽新型复合材料在生物医用领域的应用范畴,满足某些生物医用领域对高性能复合材料的迫切需求。(The invention relates to the technical field of biomedical composite materials, in particular to a NiTiFe-Ta biomedical composite material with no cytotoxicity, linear elastic deformation and large recoverable strain capacity and a preparation method thereof.)

1. a preparation method of a biomedical NiTiFe-Ta composite board is characterized by comprising the following steps: A) the pretreatment step comprises the steps of mechanically polishing the cut high-purity Ta plate and NiTiFe plate respectively, and then cleaning the surfaces of the Ta plate and the NiTiFe plate by using an ultrasonic cleaner;

B) orderly stacking two high-purity Ta plates and one NiTiFe plate which are subjected to surface polishing and cleaning treatment in a rolling sheath according to the sequence of the high-purity Ta plates/the NiTiFe plates/the high-purity Ta plates, selecting commercial pure titanium as a sheath material, packaging the sheath, vacuumizing the sheath through a reserved air exhaust hole, and then sealing the air exhaust hole;

C) carrying out heat treatment on a sheath containing a high-purity Ta plate and a NiTiFe plate, heating the sheath at 500-600 ℃, carrying out heat preservation for 15-25 minutes, carrying out first rolling with the reduction rate of 45-65% on the sheath containing the high-purity Ta plate and the NiTiFe plate after heat treatment to realize compounding, carrying out second rolling with the reduction rate of 55-75% and third rolling with the reduction rate of 20-30%, and carrying out cold rolling deformation with the deformation amount of 70-80% after the sheath containing the high-purity Ta plate and the NiTiFe plate is completely cooled to obtain a NiTiFe-Ta composite plate;

D) Removing the sheath wrapped outside the NiTiFe-Ta composite plate after the first to third rolling and cold rolling deformation, and then carrying out acid cleaning and alcohol ultrasonic cleaning on the composite plate to obtain the biomedical NiTiFe-Ta large-class linear elastic composite material.

2. The method of claim 1, wherein:

the high-purity Ta plate and the NiTiFe plate are respectively cut from the high-purity Ta and NiTiFe blanks by adopting a wire cutting and/or machining method.

3. The method of claim 1, wherein:

the sheath comprises a middle frame, an upper cover plate and a lower cover plate, an air exhaust hole is prefabricated on the side surface of the middle frame,

the surfaces of the upper cover plate and the lower cover plate which are contacted with the plate are polished,

the packaging operation comprises the steps of placing the stacked high-purity Ta plate/NiTiFe plate/high-purity Ta plate into the sheath middle frame in a regular manner, fixing and welding the upper cover plate and the lower cover plate with the middle frame,

the step of vacuumizing the sheath comprises vacuumizing to 2 x 10^-1Vacuum range of 1 Pa.

4. The method of claim 1, wherein:

the thickness of the high-purity Ta plate is 0.2-0.3mm, and the thickness of the NiTiFe plate is 4.5-5.5 mm.

5. The biomedical NiTiFe-Ta composite board prepared by the preparation method according to one of claims 1 to 4.

The technical field is as follows:

the invention relates to the technical field of biomedical composite materials, in particular to a NiTiFe-Ta biomedical composite material with no cytotoxicity, linear elastic deformation and large recoverable strain and a preparation method thereof.

Background art:

along with the progress of society and the improvement of living standard of people, the demand of people on biomedical materials is increasing day by day, and simultaneously, more rigorous requirements are provided for the performance of the biomedical materials. For some medical fields (such as surgical drivers and self-expanding stents), there is a need for a novel biomedical material that can simultaneously have no cytotoxicity (i.e., excellent biocompatibility) and large linear elastic deformation capability (i.e., stress can show nearly linear growth with increasing strain and accompanied by large recoverable strain). Therefore, designing and developing new biomedical materials with the above comprehensive properties has become an academic research frontier and an application research hotspot in high and new technical fields of all countries in the world.

At present, the material of the surgical driver, the self-expanding stent and other related medical fields is mainly NiTi-based shape memory alloy. NiTi-based shape memory alloys generally exhibit good wire-like elastic deformation behavior after thermo-mechanical processing (e.g., plastic deformation plus annealing) with respect to only wire-like elastic deformability. For example, high Ni content NiTi-based alloys can undergo linear elastic deformation (i.e., stress can exhibit a strictly linear increase with increasing strain), with relatively low recoverable strain (typically less than 1%); the NiTi-based alloy with low Ni content can show linear elastic deformation (namely, stress can show approximately linear growth along with the increase of strain) by regulating and controlling martensite phase transformation by virtue of microstructure factors (comprising dislocation, grain boundary, twin crystal and the like), and is accompanied with larger recoverable strain (about 3.5 percent). However, the poor biocompatibility (i.e. the cytotoxicity of the surface Ni element) of the NiTi-based shape memory alloy is very easy to cause various adverse reactions (such as allergy, even cancer, etc.) of human bodies, and the wide application of the NiTi-based shape memory alloy in the biomedical field is limited.

Disclosure of Invention

In summary, the existing NiTi-based shape memory alloys have not been able to fully satisfy the comprehensive requirements of some biomedical devices (such as surgical drivers and self-expanding stents) on biocompatibility (no cytotoxicity) and general linear elasticity (i.e., linear-like elastic deformation accompanied by large recoverable strain). In order to solve the problems, the invention provides a novel biomedical NiTiFe-Ta composite material and a preparation method thereof, which fully utilize the good biocompatibility (no cytotoxicity) of the outer-layer high-purity Ta and the large linear elastic deformation characteristic of the inner-layer NiTiFe alloy, can obtain the novel composite material with excellent biocompatibility (no cytotoxicity), linear elastic deformation and large recoverable strain capacity, and meet the urgent requirements of certain biomedical fields on the novel high-performance composite material.

Aiming at the problem that the existing NiTi-based shape memory alloy can not completely meet the comprehensive performance requirements of certain biomedical devices (such as surgical drivers, self-expanding stents and the like) on the biocompatibility (no cytotoxicity) and the large linear elasticity (namely the linear elasticity and the large recoverable strain) of materials, the invention provides a novel biomedical NiTiFe-Ta composite material and a preparation method thereof, which fully utilize the good biocompatibility (no cytotoxicity) of the outer-layer high-purity Ta and the large linear elastic deformation characteristic of the inner-layer NiTiFe alloy, can realize the preparation of the novel composite material with good biocompatibility (no cytotoxicity), linear elastic deformation and large recoverable strain capacity, and have important application prospects in the field of biomedicine.

The technical scheme of the invention is as follows:

(1) raw material categories, including:

outer layer material: high-purity Ta (the mass percentage of Ta is more than 99.9%);

inner layer material: the commercial NiTiFe shape memory alloy (wherein, the atomic percentage of Ti is 49.5-50.0%, the atomic percentage of Fe is 0.1-0.5%, and the rest is Ni).

The raw materials with the purity are not required to be imported, can be purchased in batches at home, and can also be prepared by self. The outer Ta material and the inner NiTiFe material finally form a sandwich structure shown in figure 1.

(2) Raw material selection principle, wherein:

outer layer Ta material: ta belongs to a non-cytotoxic element, has excellent biocompatibility, can effectively isolate the direct contact between the inner NiTiFe shape memory alloy layer and human cells, and ensures that the composite material has good biocompatibility.

Inner layer NiTiFe material: after the NiTiFe shape memory alloy is subjected to subsequent cladding rolling and cold rolling treatment, the composite material can be endowed with large linear elastic deformation-like capacity (namely, stress can show approximately linear growth along with the increase of strain and is accompanied with large recoverable strain) by virtue of the regulation and control of microstructure factors (comprising dislocation, grain boundary, twin crystal and the like) on martensite phase transformation and an internal twin crystal structure of the martensite phase transformation.

(3) The specific preparation process comprises the following steps:

firstly, cutting two high-purity Ta plates and a NiTiFe plate from high-purity Ta and NiTiFe blanks by adopting a linear cutting and/or machining method;

secondly, mechanically polishing the cut high-purity Ta plate and NiTiFe plate on 200-mesh, 500-mesh, 1000-mesh and 1500-mesh abrasive paper in sequence, and then cleaning the surfaces of the Ta plate and the NiTiFe plate by using an ultrasonic cleaner;

thirdly, polishing and cleaning the surfaces of two high-purity Ta plates and one NiTiFe plate according to the high-purity Ta plate/NiTiFe plate/high-purity TaThe plates are orderly stacked in a sheath middle frame (detailed stacking sequence is shown in figure 1), the sheath is made of commercial pure titanium and comprises a middle frame, an upper cover plate and a lower cover plate, and an air exhaust hole is prefabricated on the side surface of the middle frame; polishing the surfaces of the upper cover plate and the lower cover plate, which are in contact with the plate, and then fixing and welding the upper cover plate and the lower cover plate with the middle frame; then the inner part of the bag is vacuumized by the reserved air exhaust hole (the vacuum degree range is 2 multiplied by 10)^-1About 1Pa), and finally sealing the air exhaust hole by using a screw and a raw adhesive tape;

fourthly, performing heat treatment on the sheath containing the high-purity Ta plate and the NiTiFe plate, wherein the heating temperature is 500-600 ℃, and the heat preservation time is 15-25 minutes; then, performing first rolling with the reduction rate of 45-65% on the heat-treated sheath containing the high-purity Ta plate and the NiTiFe plate to realize compounding, and performing second rolling with the reduction rate of 55-75% and third rolling with the reduction rate of 20-30%; after the sheath containing the high-purity Ta plate and the NiTiFe plate is completely cooled, performing cold rolling deformation with the deformation amount of 70-80% to obtain the NiTiFe-Ta composite plate;

And fifthly, removing the sheath wrapped outside the NiTiFe-Ta composite plate after the first to third rolling and cold rolling deformation, and then carrying out acid washing and alcohol ultrasonic cleaning on the composite plate to obtain the biomedical NiTiFe-Ta large-class linear elastic composite material.

The advantages of the invention include:

1. the NiTiFe-Ta composite material prepared by the invention fully exerts the good biocompatibility (no cytotoxicity) of the high-purity Ta at the outer layer and the large linear elastic deformation characteristic of the NiTiFe alloy at the inner layer, and realizes the good matching of the excellent biocompatibility (no cytotoxicity), the linear elastic deformation and the large recoverable strain capacity. Compared with the traditional NiTi-based shape memory alloy, the prepared NiTiFe-Ta large-class linear elastic composite material has more excellent biocompatibility, can meet the comprehensive requirements of certain biomedical devices (such as surgical drivers, self-expanding stents and the like) on the biocompatibility (no cytotoxicity) and the large-class linear elasticity (namely the linear elastic deformation with large recoverable strain) of the material, and is applied to the field of biomedicine.

2. Compared with the prior surface modification method (such as a coating method and an oxidation method) adopted for the NiTi-based alloy, the preparation method of the NiTiFe-Ta composite material has the following obvious advantages: (1) the coating prepared on the surface of the NiTi-based alloy by surface modification methods such as a coating method, an oxidation method and the like easily has the problems of cracks, micropores and unevenness on the surface of the coating and low bonding strength (easy peeling) between the coating and a matrix, the composite plate prepared by the sheathing and rolling method has the defects of uniform and flat surface, no cracks, micropores and the like, and the bonding strength between the layers in the composite plate is very high; (2) because the NiTiFe-Ta composite board prepared by the method has higher bonding strength among layers and has no defects of cracks, micropores and the like on the surface layer, the thickness of the Ta on the surface layer in the NiTiFe-Ta composite board prepared by the method can be freely regulated and controlled by regulating the initial thickness of the Ta raw material before the pack rolling (namely the thickness of the Ta on the outer layer in the NiTiFe-Ta can be larger or smaller), and the problem that the surface of a coating is easy to crack commonly existing in the process of preparing a large-thickness coating by using surface modification methods such as a coating method, an oxidation method and the like can be solved.

Drawings

FIG. 1 is a schematic view of the sandwich structure of a biomedical NiTiFe-Ta large-class linear elastic composite material.

FIG. 2 shows Ni for biomedical use prepared according to example 1 of the present invention_50.4Ti_49.5Fe_0.1-scanning electron micrographs of cross sections of a large class of linear elastic composites of Ta.

FIG. 3 shows Ni biomedical material prepared according to example 1 of the present invention_50.4Ti_49.5Fe_0.1-stress-strain curve of Ta major class of linear elastic composites during stretch-unload.

FIG. 4 shows Ni for biomedical use prepared according to example 1 of the present invention_50.4Ti_49.5Fe_0.1-Ta Large class Linear elastic composite and Ni_50.4Ti_49.5Fe_0.1The cytotoxicity test results of the alloys are compared.

FIG. 5 shows Ni for biomedical use prepared according to example 2 of the present invention_50.0Ti_49.7Fe_0.3Cross-section scanning electrode of-Ta large-class linear elastic composite materialA mirror photograph.

FIG. 6 shows Ni for biomedical use prepared according to example 2 of the present invention_50.0Ti_49.7Fe_0.3-stress-strain curve of Ta major class of linear elastic composites during stretch-unload.

FIG. 7 shows Ni for biomedical use prepared according to example 2 of the present invention_50.0Ti_49.7Fe_0.3-Ta Large class Linear elastic composite and Ni_50.0Ti_49.7Fe_0.3The cytotoxicity test results of the alloys are compared.

FIG. 8 shows Ni for biomedical use prepared according to example 3 of the present invention_49.5Ti_50.0Fe_0.5-scanning electron micrographs of cross sections of a large class of linear elastic composites of Ta.

FIG. 9 shows Ni for biomedical use prepared according to example 3 of the present invention_49.5Ti_50.0Fe_0.5-stress-strain curve of Ta major class of linear elastic composites during stretch-unload.

FIG. 10 shows Ni for biomedical use prepared according to example 3 of the present invention_49.5Ti_50.0Fe_0.5-Ta Large class Linear elastic composite and Ni_49.5Ti_50.0Fe_0.5The cytotoxicity test results of the alloys are compared.

The specific implementation mode is as follows:

the technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

Example 1:

the preparation operation of this example includes the following steps:

(1) selecting raw materials, comprising:

outer layer material: selecting high-purity Ta (the content of Ta is 99.96 wt.%);

inner layer material: selecting Ni_50.4Ti_49.5Fe_0.1And (3) alloying.

(2) Biomedical Ni_50.4Ti_49.5Fe_0.1Preparation of a wide range of linear-elastic composites of-Ta, comprising：

First, a wire cutting and/or machining process is used to remove high purity Ta and Ni_50.4Ti_49.5Fe_0.1Cutting two high-purity Ta plates with the length of 70mm, the width of 70mm and the thickness of 0.2mm and a NiTiFe plate with the length of 70mm, the width of 70mm and the thickness of 4.5mm on the blank respectively;

secondly, mechanically polishing the cut high-purity Ta plate and NiTiFe plate on 200-mesh, 500-mesh, 1000-mesh and 1500-mesh abrasive paper in sequence, and then cleaning the surfaces of the Ta plate and the NiTiFe plate by using an ultrasonic cleaner;

Thirdly, two high-purity Ta plates and one Ni plate which are subjected to surface polishing and cleaning treatment_50.4Ti_49.5Fe_0.1Plate according to high purity Ta plate/Ni_50.4Ti_49.5Fe_0.1The order of the plates/the high-purity Ta plates (detailed stacking order is shown in figure 1) is orderly stacked in a sheath middle frame, the sheath is made of commercial pure titanium and comprises a middle frame, an upper cover plate and a lower cover plate, and an air suction hole is prefabricated on the side surface of the middle frame; polishing the surfaces of the upper cover plate and the lower cover plate, which are in contact with the plate, and then fixing and welding the upper cover plate and the lower cover plate with the middle frame; then the inner part of the bag is vacuumized by the reserved air exhaust hole (the vacuum degree is 2 multiplied by 10)^-1Pa), and finally sealing the air exhaust hole by using a screw and a raw adhesive tape;

fourthly, the Ta plate and Ni with high purity are internally contained_50.4Ti_49.5Fe_0.1The sheathing of the plate is subjected to heat treatment, the heating temperature is 500 ℃, and the temperature is kept for 15 minutes; then carrying out heat treatment on the Ta plate containing high purity and Ni_50.4Ti_49.5Fe_0.1Firstly, performing first rolling with the reduction rate of 45% on a sheath of the plate to realize compounding, and then performing second rolling with the reduction rate of 55% and third rolling with the reduction rate of 20%; to include high purity Ta plate and Ni_50.4Ti_49.5Fe_0.1After the sheath of the plate is completely cooled, the cold rolling deformation with the deformation of 70 percent is carried out on the plate to obtain Ni_50.4Ti_49.5Fe_0.1-a Ta composite panel;

removing Ni coated on the first to third rolling and cold rolling deformation _50.4Ti_49.5Fe_0.1-Ta compositeSheathing the outside of the board, and then carrying out acid washing and alcohol ultrasonic cleaning on the composite board to obtain the biomedical Ni_50.4Ti_49.5Fe_0.1-Ta major class of linear elastic composites.

(3) Alloy detection

Biomedical Ni was observed with FEI Nova Nano 450 scanning Electron microscope_50.4Ti_49.5Fe_0.1The cross-sectional morphology of the-Ta general linear elastic composite material, FIG. 2 is the biomedical Ni of this example_50.4Ti_49.5Fe_0.1Scanning electron micrographs of cross sections of the Ta bulk linear elastic composite, from which it can be seen that the composite exhibits a typical sandwich structure.

Biomedical Ni-based alloy material by wire cutting_50.4Ti_49.5Fe_0.1Cutting a tensile sample with the gauge length of 25mm in the original cold rolling direction of the Ta large-class linear elastic composite material, and polishing the tensile sample on sand paper to remove oxide skin and linear cutting marks; the room temperature stretch-unload test was performed on an Instron-8801 type tensile tester with the upper and lower grips holding both ends of the tensile test specimen and an electronic extensometer clamped to the tensile test specimen to measure the strain value of the specimen during the stretch-unload process, with a strain rate of 1X 10 during the test^-3s^-1. FIG. 3 shows Ni for biomedical use in the present example_50.4Ti_49.5Fe_0.1-stress-strain curve of Ta major class of linear elastic composites during stretch-unload. It can be seen that Ni _50.4Ti_49.5Fe_0.1Ta exhibits an approximately linear increase in stress with increasing strain during stretching, indicating that the composite exhibits a linear-like elastic deformation; it can also be seen that Ni_50.4Ti_49.5Fe_0.1After stretch-unloading, Ta can recover its strain completely and has a large recoverable strain (about 3.05%). The above results show that Ni_50.4Ti_49.5Fe_0.1The Ta composite material can combine the linear elastic deformation and large recoverable strain.

To evaluate biomedical Ni_50.4Ti_49.5Fe_0.1-Ta Large class Linear elastic compositeMaterial and single Ni_50.4Ti_49.5Fe_0.1Biocompatibility of the alloy, both of which were subjected to cytotoxicity test using murine fibroblast (L-929) cells. First from biomedical Ni_50.4Ti_49.5Fe_0.1-Ta Large class of Linear elastic composite and Single Ni_50.4Ti_49.5Fe_0.1Cutting plate samples of 10mm × 10mm on the alloy, grinding, polishing, ultrasonically cleaning in acetone, absolute ethyl alcohol and distilled water, and sterilizing with ultraviolet lamp; then press for 6cm²Leaching ratio/mL the sample was immersed in a Duchen modified Medium (DMEM) and placed in an incubator for 3 days to prepare a leaching solution of the sample; subsequently, L-929 cells cultured in DMEM at 3X 10³One/100 μ Ι _ was inoculated in a 96-well plate and cultured in an incubator for 1 day to allow cells to adhere; replacing the culture medium with the leaching liquor of the sample after the cells adhere to the wall, and then respectively culturing the L-929 cells in the leaching liquor of the sample for 1, 7 and 14 days; and the absorbance value of each well (reference wavelength: 630nm) was measured at a wavelength of 570nm using a microplate reader (model 680, Bio-Rad). FIG. 4 shows Ni for biomedical use in the present example _50.4Ti_49.5Fe_0.1-Ta Large class Linear elastic composite and Ni_50.4Ti_49.5Fe_0.1Cytotoxicity test results of the alloys. It can be seen that L-929 cells were in Ni throughout the culture period (including 1, 7 and 14 days)_50.4Ti_49.5Fe_0.1The survival rate of the-Ta sample in the leaching solution is higher than that of the-Ta sample in Ni_50.4Ti_49.5Fe_0.1Viability in the leach solution of the sample. This indicates the presence of Ni_50.4Ti_49.5Fe_0.1Alloy phase comparison, Ni_50.4Ti_49.5Fe_0.1The Ta composite material has more excellent biocompatibility.

Through the above tests and characterization, it can be found that the biomedical Ni of the embodiment_50.4Ti_49.5Fe_0.1The Ta large class linear elastic composite material realizes good matching of excellent biocompatibility (no cytotoxicity), linear elastic deformation and large recoverable strain (about 3.05 percent), and is expected to be applied to the field of biomedicine. The raw material prepared in this exampleNi for biomedical use_50.4Ti_49.5Fe_0.1The performance pair of-Ta bulk linear elastic composite with existing high Ni content NiTi alloys and low Ni content NiTi alloys is shown in table 1:

TABLE 1

As can be seen from Table 1, the biomedical Ni prepared in this example_50.4Ti_49.5Fe_0.1the-Ta large-class linear elastic composite material not only has good biocompatibility (no cytotoxicity), but also has mechanical properties (larger recoverable strain) superior to those of the existing NiTi alloy with high Ni content and mechanical properties (slightly lower recoverable strain) equivalent to those of the existing NiTi alloy with low Ni content.

Example 2:

the preparation operation of this example includes the following steps:

(1) selecting raw materials, comprising:

outer layer material: selecting high-purity Ta (the content of Ta is 99.97 wt.%);

inner layer material: selecting Ni_50.0Ti_49.7Fe_0.3And (3) alloying.

(2) Biomedical Ni_50.0Ti_49.7Fe_0.3-preparation of a Ta generic linear elastic composite comprising:

first, a wire cutting and/or machining process is used to remove high purity Ta and Ni_50.0Ti_49.7Fe_0.3Cutting two high-purity Ta plates with the length of 75mm, the width of 75mm and the thickness of 0.25mm and a NiTiFe plate with the length of 75mm, the width of 75mm and the thickness of 5mm on the blank respectively;

secondly, mechanically polishing the cut high-purity Ta plate and NiTiFe plate on 200-mesh, 500-mesh, 1000-mesh and 1500-mesh abrasive paper in sequence, and then cleaning the surfaces of the Ta plate and the NiTiFe plate by using an ultrasonic cleaner;

thirdly, two high-purity Ta plates and one Ni plate which are subjected to surface polishing and cleaning treatment_50.0Ti_49.7Fe_0.3The number of the plates is such that,according to high purity Ta plate/Ni_50.0Ti_49.7Fe_0.3The order of the plates/the high-purity Ta plates (detailed stacking order is shown in figure 1) is orderly stacked in a sheath middle frame, the sheath is made of commercial pure titanium and comprises a middle frame, an upper cover plate and a lower cover plate, and an air suction hole is prefabricated on the side surface of the middle frame; polishing the surfaces of the upper cover plate and the lower cover plate, which are in contact with the plate, and then fixing and welding the upper cover plate and the lower cover plate with the middle frame; then the inner part of the bag is vacuumized by the reserved air exhaust hole (the vacuum degree is 6 multiplied by 10) ^-1Pa), and finally sealing the air exhaust hole by using a screw and a raw adhesive tape;

fourthly, the Ta plate and Ni with high purity are internally contained_50.0Ti_49.7Fe_0.3The plate sheath is subjected to heat treatment, the heating temperature is 550 ℃, and the temperature is kept for 20 minutes; then carrying out heat treatment on the Ta plate containing high purity and Ni_50.0Ti_49.7Fe_0.3Firstly, performing first rolling with the reduction rate of 55% on a sheath of the plate to realize compounding, and then performing second rolling with the reduction rate of 65% and third rolling with the reduction rate of 25%; to include high purity Ta plate and Ni_50.0Ti_49.7Fe_0.3After the sheath of the plate is completely cooled, the cold rolling deformation with the deformation of 75 percent is carried out on the plate to obtain Ni_50.0Ti_49.7Fe_0.3-a Ta composite panel;

removing Ni coated on the first to third rolling and cold rolling deformation_50.0Ti_49.7Fe_0.3Sheathing the outside of the-Ta composite board, and then carrying out acid washing and alcohol ultrasonic cleaning on the composite board to obtain the biomedical Ni_50.0Ti_49.7Fe_0.3-Ta major class of linear elastic composites.

(3) Alloy detection

Biomedical Ni was observed with FEI Nova Nano 450 scanning Electron microscope_50.0Ti_49.7Fe_0.3The cross-sectional morphology of the-Ta general linear elastic composite material, FIG. 5 shows the biomedical Ni of this example_50.0Ti_49.7Fe_0.3Scanning electron micrographs of cross sections of the Ta bulk linear elastic composite, from which it can be seen that the composite exhibits a typical sandwich structure.

Biomedical Ni-based alloy material by wire cutting _50.0Ti_49.7Fe_0.3Cutting a tensile sample with the gauge length of 25mm in the original cold rolling direction of the Ta large-class linear elastic composite material, and polishing the tensile sample on sand paper to remove oxide skin and linear cutting marks; the room temperature stretch-unload test was performed on an Instron-8801 type tensile tester with the upper and lower grips holding both ends of the tensile test specimen and an electronic extensometer clamped to the tensile test specimen to measure the strain value of the specimen during the stretch-unload process, with a strain rate of 1X 10 during the test^-3s^-1. FIG. 6 shows Ni for biomedical use in the present example_50.0Ti_49.7Fe_0.3-stress-strain curve of Ta major class of linear elastic composites during stretch-unload. It can be seen that Ni_50.0Ti_49.7Fe_0.3Ta exhibits an approximately linear increase in stress with increasing strain during stretching, indicating that the composite exhibits a linear-like elastic deformation; it can also be seen that Ni_50.0Ti_49.7Fe_0.3After stretch-unloading, Ta is fully strain recoverable, with a large recoverable strain (about 3.35%). The above results show that Ni_50.0Ti_49.7Fe_0.3The Ta composite material can combine the linear elastic deformation and large recoverable strain.

To evaluate biomedical Ni_50.0Ti_49.7Fe_0.3-Ta Large class of Linear elastic composite and Single Ni_50.0Ti_49.7Fe_0.3Biocompatibility of the alloy, both of which were subjected to cytotoxicity test using murine fibroblast (L-929) cells. First from biomedical Ni _50.0Ti_49.7Fe_0.3-Ta Large class of Linear elastic composite and Single Ni_50.0Ti_49.7Fe_0.3Cutting plate samples of 10mm × 10mm on the alloy, grinding, polishing, ultrasonically cleaning in acetone, absolute ethyl alcohol and distilled water, and sterilizing with ultraviolet lamp; then press for 6cm²Leaching ratio/mL the sample was immersed in a Duchen modified Medium (DMEM) and placed in an incubator for 3 days to prepare a leaching solution of the sample; subsequently, L-929 cells cultured in DMEM at 3X 10³One/100 μ Ι _ was inoculated in a 96-well plate and cultured in an incubator for 1 day to allow cells to adhere; replacing the culture medium with the leaching liquor of the sample after the cells adhere to the wall, and then respectively culturing the L-929 cells in the leaching liquor of the sample for 1, 7 and 14 days; and the absorbance value of each well (reference wavelength: 630nm) was measured at a wavelength of 570nm using a microplate reader (model 680, Bio-Rad). FIG. 7 shows Ni for biomedical use in the present example_50.0Ti_49.7Fe_0.3-Ta Large class Linear elastic composite and Ni_50.0Ti_49.7Fe_0.3Cytotoxicity test results of the alloys. It can be seen that L-929 cells were in Ni throughout the culture period (including 1, 7 and 14 days)_50.0Ti_49.7Fe_0.3The survival rate of the-Ta sample in the leaching solution is higher than that of the-Ta sample in Ni_50.0Ti_49.7Fe_0.3Viability in the leach solution of the sample. This indicates the presence of Ni_50.0Ti_49.7Fe_0.3Alloy phase comparison, Ni _50.0Ti_49.7Fe_0.3The Ta composite material has more excellent biocompatibility.

Through the above tests and characterization, it can be found that the biomedical Ni of the embodiment_50.0Ti_49.7Fe_0.3The Ta large class linear elastic composite material realizes good matching of excellent biocompatibility (no cytotoxicity), linear elastic deformation and large recoverable strain (about 3.35 percent), and is expected to be applied to the field of biomedicine. Biomedical Ni prepared in this example_50.0Ti_49.7Fe_0.3The performance pair of-Ta bulk linear elastic composite with existing high Ni content NiTi alloys and low Ni content NiTi alloys is shown in table 2:

TABLE 2

As can be seen from Table 2, the biomedical Ni prepared in this example_50.0Ti_49.7Fe_0.3the-Ta large-class linear elastic composite material not only has good biocompatibility (no cytotoxicity), but also has better NiTi alloy with high Ni content than the prior NiTi alloyThe mechanical properties of gold (greater recoverable strain) and mechanical properties comparable to those of existing NiTi alloys with low Ni content (slightly lower recoverable strain).

Example 3:

the preparation operation of this example includes the following steps:

(1) selecting raw materials, wherein:

outer layer material: selecting high-purity Ta (the content of Ta is 99.98 wt.%);

inner layer material: selecting Ni_49.5Ti_50.0Fe_0.5And (3) alloying.

(2) Biomedical Ni_49.5Ti_50.0Fe_0.5-preparation of a Ta generic linear elastic composite comprising:

First, a wire cutting and/or machining process is used to remove high purity Ta and Ni_49.5Ti_50.0Fe_0.5Cutting two high-purity Ta plates with the length of 80mm, the width of 80mm and the thickness of 0.3mm and a NiTiFe plate with the length of 80mm, the width of 80mm and the thickness of 5.5mm on the blank respectively;

secondly, mechanically polishing the cut high-purity Ta plate and NiTiFe plate on 200-mesh, 500-mesh, 1000-mesh and 1500-mesh abrasive paper in sequence, and then cleaning the surfaces of the Ta plate and the NiTiFe plate by using an ultrasonic cleaner;

thirdly, two high-purity Ta plates and one Ni plate which are subjected to surface polishing and cleaning treatment_49.5Ti_50.0Fe_0.5Plate according to high purity Ta plate/Ni_49.5Ti_50.0Fe_0.5The order of the plates/the high-purity Ta plates (detailed stacking order is shown in figure 1) is orderly stacked in a sheath middle frame, the sheath is made of commercial pure titanium and comprises a middle frame, an upper cover plate and a lower cover plate, and an air suction hole is prefabricated on the side surface of the middle frame; polishing the surfaces of the upper cover plate and the lower cover plate, which are in contact with the plate, and then fixing and welding the upper cover plate and the lower cover plate with the middle frame; then, vacuumizing the inner sleeve of the bag by a reserved air exhaust hole (the vacuum degree is 1Pa), and finally sealing the air exhaust hole by a screw and a raw adhesive tape;

fourthly, the Ta plate and Ni with high purity are internally contained_49.5Ti_50.0Fe_0.5The sheathing of the plate is heat-treated at a temperature of Keeping the temperature at 600 ℃ for 25 minutes; then carrying out heat treatment on the Ta plate containing high purity and Ni_49.5Ti_50.0Fe_0.5Firstly, performing first rolling with the reduction rate of 65% on a sheath of the plate to realize compounding, and then performing second rolling with the reduction rate of 75% and third rolling with the reduction rate of 30%; to include high purity Ta plate and Ni_49.5Ti_50.0Fe_0.5After the sheath of the plate is completely cooled, cold rolling deformation with the deformation of 80 percent is carried out on the plate to obtain Ni_49.5Ti_50.0Fe_0.5-a Ta composite panel;

removing Ni coated on the first to third rolling and cold rolling deformation_49.5Ti_50.0Fe_0.5Sheathing the outside of the-Ta composite board, and then carrying out acid washing and alcohol ultrasonic cleaning on the composite board to obtain the biomedical Ni_49.5Ti_50.0Fe_0.5-Ta major class of linear elastic composites.

(3) Alloy detection

Biomedical Ni was observed with FEI Nova Nano 450 scanning Electron microscope_49.5Ti_50.0Fe_0.5Cross-sectional morphology of the-Ta major class of linear elastic composites, FIG. 8 for this example is Ni biomedical_49.5Ti_50.0Fe_0.5Scanning electron micrographs of cross sections of the Ta bulk linear elastic composite, from which it can be seen that the composite exhibits a typical sandwich structure.

Biomedical Ni-based alloy material by wire cutting_49.5Ti_50.0Fe_0.5Cutting a tensile sample with the gauge length of 25mm in the original cold rolling direction of the Ta large-class linear elastic composite material, and polishing the tensile sample on sand paper to remove oxide skin and linear cutting marks; the room temperature stretch-unload test was performed on an Instron-8801 type tensile tester with the upper and lower grips holding both ends of the tensile test specimen and an electronic extensometer clamped to the tensile test specimen to measure the strain value of the specimen during the stretch-unload process, with a strain rate of 1X 10 during the test ^-3s^-1. FIG. 9 shows Ni for biomedical use of this example_49.5Ti_50.0Fe_0.5-Ta Large class of Linear elastic composites during stretch-unloadStress-strain curve of (a). It can be seen that Ni_49.5Ti_50.0Fe_0.5Ta exhibits an approximately linear increase in stress with increasing strain during stretching, indicating that the composite exhibits a linear-like elastic deformation; it can also be seen that Ni_49.5Ti_50.0Fe_0.5Ta is nearly fully recovered in strain (only about 0.04% residual strain) after stretch-unloading and has a large recoverable strain (about 3.40%). The above results show that Ni_49.5Ti_50.0Fe_0.5The Ta composite material can combine the linear elastic deformation and large recoverable strain.

To evaluate biomedical Ni_49.5Ti_50.0Fe_0.5-Ta Large class of Linear elastic composite and Single Ni_49.5Ti_50.0Fe_0.5Biocompatibility of the alloy, both of which were subjected to cytotoxicity test using murine fibroblast (L-929) cells. First from biomedical Ni_49.5Ti_50.0Fe_0.5-Ta Large class of Linear elastic composite and Single Ni_49.5Ti_50.0Fe_0.5Cutting plate samples of 10mm × 10mm on the alloy, grinding, polishing, ultrasonically cleaning in acetone, absolute ethyl alcohol and distilled water, and sterilizing with ultraviolet lamp; then press for 6cm²Leaching ratio/mL the sample was immersed in a Duchen modified Medium (DMEM) and placed in an incubator for 3 days to prepare a leaching solution of the sample; subsequently, L-929 cells cultured in DMEM at 3X 10 ³One/100 μ Ι _ was inoculated in a 96-well plate and cultured in an incubator for 1 day to allow cells to adhere; replacing the culture medium with the leaching liquor of the sample after the cells adhere to the wall, and then respectively culturing the L-929 cells in the leaching liquor of the sample for 1, 7 and 14 days; and the absorbance value of each well (reference wavelength: 630nm) was measured at a wavelength of 570nm using a microplate reader (model 680, Bio-Rad). FIG. 10 shows Ni for biomedical use of this example_49.5Ti_50.0Fe_0.5-Ta Large class Linear elastic composite and Ni_49.5Ti_50.0Fe_0.5Cytotoxicity test results of the alloys. It can be seen that L-929 cells were in Ni throughout the culture period (including 1, 7 and 14 days)_49.5Ti_50.0Fe_0.5The survival rate of the-Ta sample in the leaching solution is higher than that of the-Ta sample in Ni_49.5Ti_50.0Fe_0.5Viability in the leach solution of the sample. This indicates the presence of Ni_49.5Ti_50.0Fe_0.5Alloy phase comparison, Ni_49.5Ti_50.0Fe_0.5The Ta composite material has more excellent biocompatibility.

Through the above tests and characterization, it can be found that the biomedical Ni of the embodiment_49.5Ti_50.0Fe_0.5The Ta large class linear elastic composite material realizes good matching of excellent biocompatibility (no cytotoxicity), linear elastic deformation and large recoverable strain (about 3.40 percent), and is expected to be applied to the field of biomedicine. Biomedical Ni prepared in this example_49.5Ti_50.0Fe_0.5The performance pair of-Ta bulk linear elastic composite with existing high Ni content NiTi alloys and low Ni content NiTi alloys is shown in table 3:

TABLE 3

As can be seen from Table 3, the biomedical Ni prepared in this example_49.5Ti_50.0Fe_0.5the-Ta large-class linear elastic composite material not only has good biocompatibility (no cytotoxicity), but also has mechanical properties (larger recoverable strain) superior to those of the existing NiTi alloy with high Ni content and mechanical properties (slightly lower recoverable strain) equivalent to those of the existing NiTi alloy with low Ni content.

Reference documents:

[1]M.R.Aboutalebi,M.Karimzadeh,M.T.Salehi,S.M.Abbasi,M. Morakabati,Influences of aging and thermomechanical treatments on the martensitic transformation and superelasticity of highly Ni-rich Ti-51.5at.％ Ni shape memory alloy,Thermochimica Acta 616(2015)14-19.

[2]M.Karimzadeh,M.R.Aboutalebi,M.T.Salehi,S.M.Abbasi,M. Morakabati,Adjustment of aging temperature for reaching superelasticity in highly Ni-rich Ti-51.5Ni NiTi shape memory alloy,Materials and Manufacturing Processes 31(2016)1014-1021.

[3]J.Y.Chen,H.Yin,Q.P.Sun,Effects of grain size on fatigue crack growth behaviors of nanocrystalline superelastic NiTi shape memory alloys,Acta Materialia 195(2020)141-150.

[4]Y.F.Zheng,B.M.Huang,J.X.Zhang,L.C.Zhao,The microstructure and linear superelasticity of cold-drawn TiNi alloy,Materials Science and Engineering A 279(2000)25-35.

[5]J.Y.Chen,L.L.Xing,G.Fang,L.P.Lei,W.Liu,Improved elastocaloric cooling performance in gradient-structured NiTi alloy processed by localized laser surface annealing,Acta Materialia 208(2021)116741。