Zn / Mg composite material with controllable degradation rate and preparation method thereof

Abstract

The invention discloses a Zn / Mg composite material with a controllable degradation rate and a preparation method thereof.The Zn / Mg composite material comprises a magnesium alloy net and a zinc alloy, the zinc alloy is compounded with the magnesium alloy net in an infiltration mode, the magnesium alloy net is a multi-layer space net made of a magnesium alloy material, the prism diameter of a magnesium alloy grid in the magnesium alloy net is 0.5-3.0 mm, and the prism diameter of the magnesium alloy grid in the magnesium alloy net is 0.5-3.0 mm. Each layer of meshes in the multi-layer space net is polygonal, the size of the meshes is 0.5-3.0 mm, and the interlayer spacing between every two adjacent layers of meshes is 0.5-2.5 mm. By utilizing the characteristic that the melting temperature difference between the zinc alloy and the magnesium alloy is large, the magnesium alloy material is firstly prepared into the magnesium alloy net, then the liquid zinc alloy permeates at a specific temperature by utilizing the liquidity and permeability of the liquid zinc alloy and is subjected to heat preservation, and finally the zinc alloy and the magnesium alloy are fused into the composite material; the composite material combines the rapid degradation characteristic of the magnesium alloy and the slow-release degradation performance of the zinc alloy, and the degradation rate is regulated and controlled by utilizing the galvanic corrosion difference of the magnesium alloy and the zinc alloy, so that the prepared Zn / Mg composite material becomes an ideal biomedical material.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and in particular to a Zn / Mg composite material with controllable degradation rate and a preparation method thereof. Background Art

[0002] In the field of biomedical materials, with the increasing aging of the population and the frequent occurrence of various types of accidental trauma, the demand for high-performance bone repair materials is becoming increasingly urgent. Traditional bone repair materials, such as stainless steel and titanium alloys, can provide mechanical support to a certain extent, but they also have many limitations. After stainless steel implants are implanted in the human body, due to their poor biocompatibility with human tissue, long-term retention can easily cause inflammation and tissue adhesions, causing significant pain to the patient. The subsequent need for secondary surgery for removal also increases the patient's physical burden and medical costs. Although titanium alloys have relatively good biocompatibility, their high density often causes patients to feel heavy and uncomfortable after implantation. Furthermore, the elastic modulus of titanium alloys differs significantly from that of human bone, which can easily cause stress shielding. This can lead to uneven stress distribution around the implant site, resulting in adverse conditions such as osteoporosis, which compromises bone repair effectiveness. Furthermore, in some cases, titanium alloy implants require secondary removal due to various factors, which undoubtedly imposes additional physical trauma and financial pressure on patients, further highlighting the drawbacks of traditional bone repair materials.

[0003] At the same time, magnesium alloys have gradually entered the field of vision of scientific researchers with their density advantage close to that of human bones. In theory, they can effectively reduce the foreign body sensation after implantation in patients and have a certain mechanical strength, making them an ideal bone repair material. However, magnesium alloys have extremely poor corrosion resistance in the complex physiological environment of the human body. The excessively fast corrosion rate may cause them to lose their mechanical support function before the bone is fully healed. In addition, a large amount of corrosion products accumulate in the body, which can easily cause local inflammation. This greatly limits the clinical application of magnesium alloys. In comparison, zinc alloys can greatly reduce the chance of postoperative infection due to their good biocompatibility (low risk of immune rejection) and antibacterial properties, but they also face the problem of mismatch between degradation cycle and bone healing time. Taking bone implant materials as an example, the complete degradation cycle of a single zinc alloy material often far exceeds the time required for natural healing of bone tissue, resulting in it occupying space for a long time during the degradation process, which may cause bone atrophy and adverse reactions of the host, hindering the normal repair and regeneration of bone tissue, thereby restricting its widespread application in the biomedical field.

[0004] Therefore, there is an urgent need to develop a new type of biomedical material with excellent mechanical properties, good biocompatibility and controllable degradation rate. Summary of the Invention

[0005] The purpose of the present invention is to provide a Zn / Mg composite material with controllable degradation rate and a preparation method thereof, so as to solve the problem that the above alloy materials cannot take into account mechanical properties, biocompatibility and controllable degradation performance.

[0006] To achieve the above objectives, the first aspect of the present invention provides a Zn / Mg composite material with controllable degradation rate. The Zn / Mg composite material comprises a magnesium alloy mesh and a zinc alloy, wherein the zinc alloy is composited with the magnesium alloy mesh by infiltration.

[0007] Preferably, the magnesium alloy mesh is a multi-layer space mesh made of magnesium alloy material.

[0008] Preferably, the diameter of the magnesium alloy wire in the magnesium alloy mesh is 0.5-3.0 mm, the mesh shape of each layer in the multi-layer space mesh is polygonal, the mesh size is 0.5-3.0 mm, and the interlayer spacing between two adjacent mesh layers is 0.5-2.5 mm.

[0009] The mesh shape in the present invention includes but is not limited to triangle, quadrilateral and hexagon, preferably quadrilateral. The mesh size refers to the diameter of the circumscribed circle of the polygon.

[0010] Preferably, the layers of the multi-layer space net are staggered, wherein the meshes of the upper layer net and the meshes of the lower layer net are staggered on the horizontal projection plane, and the staggering ratio is 30-70%.

[0011] The magnesium alloy mesh of the present invention has a specific structure. By adjusting the number of layers of the multi-layer mesh, the interlayer spacing between each layer, the mesh size and the staggered structure between layers, a magnesium alloy mesh structure with different mesh gaps is constructed. The magnesium alloy mesh is used to control the subsequent zinc alloy infiltration amount, thereby adjusting the ratio of magnesium alloy to zinc alloy in the composite material.

[0012] Preferably, in terms of mass percentage, the composition of the magnesium alloy material includes Zn 3-8%, Ca 0-2.0%, Sr 0-0.5%, and the balance is Mg; the composition of the zinc alloy includes Mg 1-8%, Fe 0-2.0%, Ca 0-2.0%, Li 0-1.0%, and the balance is Zn.

[0013] A second aspect of the present invention provides a method for preparing a Zn / Mg composite material with controllable degradation rate, comprising the following steps:

[0014] S1: forming a magnesium alloy mesh from a magnesium alloy material;

[0015] S2: subjecting the magnesium alloy mesh to stress annealing and surface pretreatment in sequence;

[0016] S3: weighing raw materials according to the composition of the zinc alloy and mixing them, and smelting them at 460-650° C. under argon protection to obtain a zinc alloy liquid;

[0017] S4: subjecting the magnesium alloy mesh after surface pretreatment to infiltration treatment with zinc alloy liquid to form a magnesium-zinc interpenetrating network to obtain an alloy composite material;

[0018] S5: Post-processing the alloy composite material to obtain a Zn / Mg composite material.

[0019] The magnesium alloy mesh of the present invention includes various methods for preparing the mesh, such as plain weave, 3D printing, investment casting, and laser cutting. The first method involves preparing a multilayered magnesium alloy mesh using a plain weave process using magnesium alloy wire. During the preparation process, specific process parameters are first determined based on the parameters of the resulting magnesium alloy mesh, and the mesh is then prepared according to these process parameters. The second method involves preparing the multilayered magnesium alloy mesh using 3D printing. During the preparation process, a three-dimensional model of the mesh is first constructed based on the parameters of the resulting magnesium alloy mesh. The constructed three-dimensional model is then used to produce a magnesium alloy mesh with a specific structure using 3D printing. The third method involves investment casting, which primarily involves preparing a wax mold according to the desired shape and size of the mesh, assembling the wax molds into a module, and coating the mold with a refractory coating to form a shell. The wax mold is then melted to produce a hollow shell, into which molten magnesium alloy is poured. After cooling and solidification, the shell is removed to produce a preformed magnesium alloy mesh. Finally, cleaning, heat treatment, and surface treatment are performed to obtain the desired magnesium alloy mesh. The fourth process is laser cutting. Based on the target magnesium alloy mesh's pattern and dimensions, laser cutting equipment is used to precisely cut the magnesium alloy block material according to pre-set cutting paths and process parameters. After cutting, the cut edges are ground, polished, and treated for corrosion to enhance the overall quality and performance of the magnesium alloy mesh.

[0020] More preferably, when 3D printing technology is adopted, a selective laser melting (SLM) process is used, with a laser power of 100 to 300 W and a scanning speed of 500 to 1200 mm / s.

[0021] Preferably, in step S2, the stress annealing treatment process is: keeping the temperature at 250-350° C. for 1-3 hours, and cooling with the furnace to eliminate internal stress;

[0022] The specific process of surface pretreatment is as follows:

[0023] First, the magnesium alloy mesh is pickled with a dilute sulfuric acid solution with a concentration of 5 to 15 vol.%, and the pickling time is 3 to 8 minutes. After pickling, it is immediately rinsed with pure water for 2 to 5 minutes. Then, the rinsed magnesium alloy mesh is secondary cleaned with an ultrasonic cleaning process to quickly remove the dilute sulfuric acid solution remaining on the magnesium alloy mesh to prevent excessive corrosion. The cleaning medium is a mixed solution of ethanol and acetone, wherein the volume ratio of ethanol to acetone is 3 to 5:1, and the cleaning time is 15 to 30 minutes. After cleaning with the ethanol and acetone mixed solution, it is rinsed with pure water for 1 to 3 minutes.

[0024] The present invention adopts the steps of pickling combined with ultrasonic cleaning to remove the oxide layer and impurities on the surface of the magnesium alloy mesh, so as to ensure good subsequent zinc alloy liquid infiltration effect and form a close metallurgical bond between the zinc alloy and the magnesium alloy.

[0025] Preferably, in step S4, the specific process of the infiltration treatment is as follows:

[0026] S41: placing the magnesium alloy mesh in a mold, preheating the mold to 200-300° C., and injecting zinc alloy liquid into the mold;

[0027] S42: performing infiltration treatment under an inert gas protective atmosphere, with an inert gas flow rate of 10 to 20 L / min, an infiltration pressure of 5 to 20 MPa, and a holding time of 10 to 30 minutes, to ensure that the zinc alloy liquid fully fills the pores of the magnesium alloy mesh;

[0028] S43: After the infiltration is completed, cooling is performed at a cooling rate of 0.1 to 3°C / min.

[0029] Preferably, in step S5, the post-processing includes hot isostatic pressing, machining, homogenization, hot extrusion and aging treatment in sequence.

[0030] Preferably, in step S5, the specific process of post-processing is as follows:

[0031] S51: performing hot isostatic pressing on the alloy composite material, wherein the hot isostatic pressing temperature is 200-400° C., the pressure is 50-150 MPa, and the time is 1-2 hours;

[0032] S52: Adjusting the size and surface roughness of the alloy composite material after hot isostatic pressing by machining;

[0033] S53: Under argon protection, heating the machined alloy composite material to 350-420° C. and keeping the temperature for 4-6 hours to perform homogenization treatment;

[0034] S54: hot extruding the homogenized alloy composite material at a hot extrusion ratio of 8 to 20:1;

[0035] S55: subjecting the hot extruded alloy composite material to an aging treatment at 180-200° C. for 3-8 hours, and then to an aging treatment at 200-210° C. for 2-6 hours.

[0036] The infiltration step of the present invention allows the liquid zinc alloy to penetrate the magnesium alloy mesh more quickly and evenly, ensuring the depth and uniformity of the infiltration and forming a close composite of the two alloys. The present invention enables infiltration between the magnesium alloy mesh and the zinc alloy liquid. This is primarily due to the difference in melting points between the magnesium alloy and the zinc alloy, allowing the zinc alloy liquid to be directly filled into the magnesium alloy mesh. The method for preparing this composite material is also applicable to other alloy materials with significantly different melting points, demonstrating the universality of the method for preparing the composite material.

[0037] The Zn / Mg composite material prepared by the present invention is prepared into a standard sample and subjected to a tensile test according to ASTM E8 / E8M-21 "Standard Test Methods for Tensile Testing of Metallic Materials". The mechanical properties thereof are a yield strength between 150 and 220 MPa, a tensile strength between 220 and 320 MPa, and an elongation between 12 and 22%. The Zn / Mg composite material prepared by the present invention has good mechanical properties.

[0038] The Zn / Mg composite material prepared by the present invention not only exhibits excellent mechanical properties but also exhibits biocompatibility and controllable degradation. Biocompatibility is demonstrated by good cell adhesion, proliferation, and differentiation when co-cultured with osteoblasts and vascular endothelial cells in vitro. Furthermore, after in vivo implantation into animal bone and muscle tissue, the material exhibits minimal inflammatory responses in the surrounding tissues and allows for normal tissue repair, without rejection or toxicity. Controllable degradation is demonstrated by the ability to precisely control the degradation rate in simulated human body fluids by adjusting the ratio of the zinc alloy to the magnesium alloy and the elemental content of each alloy, allowing for a configurable degradation cycle ranging from months to years.

[0039] Specifically, the present invention adjusts the ratio of magnesium alloy to zinc alloy by changing the diameter of the magnesium alloy wire, the pore size of the magnesium alloy mesh, and the interlayer spacing; and controls the ratio of the second phase in the magnesium alloy to the zinc alloy by selecting magnesium alloy raw materials with different compositions, or changing the content of elements such as Mg and Fe in the zinc alloy. Generally, the zinc alloy composition is mainly regulated to thereby control the degradation rate of the composite material.

[0040] The homogenization treatment performed by the present invention can eliminate the internal stress concentration caused by uneven composition and temperature during the infiltration process, strengthen the diffusion bonding of the zinc alloy and the magnesium alloy, and optimize the overall mechanical properties.

[0041] Therefore, the present invention adopts the above-mentioned Zn / Mg composite material with controllable degradation rate and its preparation method, which has the following beneficial effects:

[0042] (1) The present invention utilizes the large difference in melting temperature between zinc alloy and magnesium alloy. After first preparing the magnesium alloy into a porous preform magnesium alloy mesh, the fluidity and permeability of the liquid zinc alloy are utilized to allow the liquid zinc alloy to infiltrate and maintain the temperature at a specific temperature, and finally the two are fused into a composite material. This composite material combines the density advantages and mechanical properties of the magnesium alloy with the biocompatibility and controllable degradation properties of the zinc alloy, and can become an ideal biomedical material.

[0043] (2) The foam network formed after the corrosion of the magnesium alloy mesh in the present invention makes its elastic modulus closer to that of human bone, has a small stress shielding effect, and has a large contact area with the corrosive liquid, which can effectively accelerate the corrosion of the zinc alloy. Combined with the fine process control of the magnesium alloy mesh and zinc alloy infiltration in the early stage, the overall degradation rate of the composite material can be flexibly set according to actual needs, overcoming the shortcomings of a single material and better meeting the growing clinical needs.

[0044] (3) The process steps of the present invention are simple, do not require high-end equipment, are low-cost, and can well combine the characteristics of magnesium alloy being light and high-strength and zinc alloy being good in corrosion resistance. The prepared composite material takes into account mechanical properties, biocompatibility, and controllable degradation properties.

[0045] The technical solution of the present invention is further described in detail below through examples. DETAILED DESCRIPTION

[0046] The present invention will be further described below. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the present invention is not limited to this embodiment.

[0047] Example 1

[0048] A method for preparing a Zn / Mg composite material with controllable degradation rate comprises the following steps:

[0049] S1: Using 3D printing technology to prepare a magnesium alloy multilayer space network to obtain a magnesium alloy network;

[0050] The specific structure of magnesium alloy mesh is as follows:

[0051] The diameter of the magnesium alloy grid prism in the magnesium alloy mesh is 1.0 mm. The mesh shape of each layer in the multi-layer space mesh is quadrilateral, the mesh size is 2.2 mm, and the interlayer spacing between two adjacent layers of mesh is 1.2 mm. The layers are staggered, and the mesh of the upper layer mesh and the mesh of the lower layer mesh are staggered on the horizontal projection plane, with a stagger ratio of 45%.

[0052] The specific process of 3D printing technology is: constructing a three-dimensional model based on the parameters of the above-mentioned magnesium alloy mesh, and then using magnesium alloy material as raw material to prepare the magnesium alloy mesh using conventional 3D printing technology.

[0053] Calculated by mass percentage, the magnesium alloy material comprises Zn 6%, Ca 1.0%, Sr 0.2%, and the balance Mg.

[0054] S2: performing stress annealing and surface pretreatment on the magnesium alloy mesh in sequence, wherein the surface pretreatment can remove the oxide layer and impurities on the surface of the magnesium alloy mesh;

[0055] The stress annealing process is: keep at 300℃ for 2h, and cool with the furnace to eliminate internal stress;

[0056] The specific process of surface pretreatment is as follows:

[0057] The magnesium alloy mesh was first pickled with a dilute sulfuric acid solution with a concentration of 8 vol.%, and the pickling time was 6 minutes. After pickling, it was immediately rinsed with pure water for 3 minutes. Then, the rinsed magnesium alloy mesh was secondary cleaned using an ultrasonic cleaning process to quickly remove the dilute sulfuric acid solution remaining on the magnesium alloy mesh to prevent excessive corrosion. The cleaning medium was a mixed solution of ethanol and acetone with a volume ratio of ethanol to acetone of 4:1. The cleaning time was 20 minutes. After cleaning with the mixed solution of ethanol and acetone, it was rinsed with pure water for 3 minutes.

[0058] S3: weighing raw materials according to the composition of the zinc alloy and mixing them, and smelting them at 550° C. under argon protection to obtain a zinc alloy liquid;

[0059] Calculated by mass percentage, the zinc alloy comprises Mg 5%, Fe 1.0%, Ca 1.0%, Li 0.5%, and the balance is Zn.

[0060] S4: subjecting the magnesium alloy mesh after surface pretreatment to infiltration treatment with zinc alloy liquid to form a magnesium-zinc interpenetrating network to obtain an alloy composite material;

[0061] The specific process of infiltration treatment is as follows:

[0062] S41: placing the magnesium alloy mesh in a mold, preheating the mold to 250° C., and injecting zinc alloy liquid into the mold;

[0063] S42: performing infiltration treatment under an inert gas protective atmosphere, with an inert gas flow rate of 15 L / min, an infiltration pressure of 10 MPa, and a holding time of 15 min to ensure that the zinc alloy liquid fully fills the pores of the magnesium alloy mesh;

[0064] S43: Cooling after infiltration, with a cooling rate of 8°C / min.

[0065] S5: post-treating the alloy composite material to obtain a Zn / Mg composite material;

[0066] The specific process of post-processing is as follows:

[0067] S51: performing hot isostatic pressing on the alloy composite material, wherein the hot isostatic pressing temperature is 300° C., the pressure is 100 MPa, and the time is 1.5 h;

[0068] S52: Adjusting the size and surface roughness of the alloy composite material after hot isostatic pressing by machining;

[0069] S53: Under argon protection, the machined alloy composite material is heated to 400° C. and kept at this temperature for 5 hours for homogenization treatment;

[0070] S54: performing a hot extrusion treatment on the alloy composite material after the homogenization treatment at a hot extrusion ratio of 10:1;

[0071] S55: subjecting the hot extruded alloy composite material to an aging treatment at 190° C. for 4 hours and then to an aging treatment at 210° C. for 3 hours to obtain a Zn / Mg composite material.

[0072] Example 2

[0073] A method for preparing a Zn / Mg composite material with controllable degradation rate comprises the following steps:

[0074] S1: preparing a magnesium alloy multilayer space mesh by using a plain weave process to obtain a magnesium alloy mesh;

[0075] The specific structure of magnesium alloy mesh is as follows:

[0076] The diameter of the magnesium alloy grid prism in the magnesium alloy mesh is 0.8 mm. The mesh shape of each layer in the multi-layer space mesh is quadrilateral, the mesh size is 2.5 mm, and the interlayer spacing between two adjacent layers of mesh is 1.5 mm. The layers are staggered, and the mesh of the upper layer mesh and the mesh of the lower layer mesh are staggered on the horizontal projection plane, with a stagger ratio of 30%.

[0077] The specific process of the plain weaving process is as follows: magnesium alloy wire with a diameter of 0.8mm is used as raw material, and the magnesium alloy wire is installed on the warp and weft axes of the weaving machine. The warp and weft are interwoven according to the plain weaving rule to form a quadrilateral mesh with a mesh size of 2.5mm to complete the weaving of the first layer of mesh; then the second layer of mesh is woven to ensure that the mesh of the second layer of mesh is staggered with the mesh of the first layer of mesh on the horizontal projection plane, with an interlacing ratio of 30%, and this is repeated until the required number of layers of multi-layer spatial mesh is reached; during the weaving process, the interlayer spacing between adjacent two layers of mesh is controlled to be 1.5mm by introducing appropriate spacer materials or adjusting the weaving parameters of the weaving machine; at the same time, the weaving quality is monitored in real time to ensure that the mesh shape is regular, the size is uniform, and the wire is not broken or loose. If there is any abnormality, the weaving parameters are adjusted in time or the machine is shut down for processing.

[0078] Calculated by mass percentage, the composition of the magnesium alloy material includes Zn 3%, Ca 0.5%, Sr 0.1%, and the balance is Mg; the composition of the zinc alloy includes Mg 1%, Fe 0.5%, Ca 0.3%, Li 1.0%, and the balance is Zn.

[0079] S2: performing stress annealing and surface pretreatment on the magnesium alloy mesh in sequence, wherein the surface pretreatment can remove the oxide layer and impurities on the surface of the magnesium alloy mesh;

[0080] The stress annealing process is: keep at 300℃ for 2h, and cool with the furnace to eliminate internal stress;

[0081] The specific process of surface pretreatment is as follows:

[0082] First, the magnesium alloy mesh was pickled with a dilute sulfuric acid solution with a concentration of 10 vol.%, and the pickling time was 5 minutes. After pickling, it was immediately rinsed with pure water for 5 minutes. Then, the rinsed magnesium alloy mesh was secondary cleaned using an ultrasonic cleaning process to quickly remove the dilute sulfuric acid solution remaining on the magnesium alloy mesh to prevent excessive corrosion. The cleaning medium was a mixed solution of ethanol and acetone, with a volume ratio of ethanol to acetone of 5:1. The cleaning time was 40 minutes. After cleaning with the mixed solution of ethanol and acetone, it was rinsed with pure water for 1 minute.

[0083] S3: Raw materials are weighed and mixed according to the composition of the zinc alloy, and smelted at 550° C. under argon protection to obtain a zinc alloy liquid; the composition of the zinc alloy includes, by mass percentage, Mg 1%, Fe 0.5%, Ca 0.3%, Li 1.0%, and the balance Zn.

[0084] S4: subjecting the magnesium alloy mesh after surface pretreatment to infiltration treatment with zinc alloy liquid to form a magnesium-zinc interpenetrating network to obtain an alloy composite material;

[0085] The specific process of infiltration treatment is as follows:

[0086] S41: placing the magnesium alloy mesh in a mold, preheating the mold to 250° C., and injecting zinc alloy liquid into the mold;

[0087] S42: performing infiltration treatment under an inert gas protective atmosphere, with an inert gas flow rate of 15 L / min, an infiltration pressure of 10 MPa, and a holding time of 15 min to ensure that the zinc alloy liquid fully fills the pores of the magnesium alloy mesh;

[0088] S43: During the infiltration process, the cooling rate is controlled at 8°C / min.

[0089] S5: post-treating the alloy composite material to obtain a Zn / Mg composite material;

[0090] The specific process of post-processing is as follows:

[0091] S51: performing hot isostatic pressing on the alloy composite material, wherein the hot isostatic pressing temperature is 300° C., the pressure is 100 MPa, and the time is 1.5 h;

[0092] S52: Adjusting the size and surface roughness of the alloy composite material after hot isostatic pressing by machining;

[0093] S53: Under argon protection, the machined alloy composite material is heated to 400° C. and kept at this temperature for 5 hours for homogenization treatment;

[0094] S54: performing a hot extrusion treatment on the alloy composite material after the homogenization treatment at a hot extrusion ratio of 10:1;

[0095] S55: subjecting the hot extruded alloy composite material to an aging treatment at 180° C. for 5 hours and then to an aging treatment at 200° C. for 3 hours to obtain a Zn / Mg composite material.

[0096] Test example

[0097] (1) The mechanical properties of the Zn / Mg composite materials prepared in Examples 1 and 2 were tested.

[0098] The test process is as follows: prepare standard samples and conduct tensile tests in accordance with ASTM E8 / E8M-21 “Standard Test Methods for Tensile Testing of Metallic Materials”. The test results are shown in Table 1.

[0099] Table 1 Mechanical properties test results

[0100]

[0101] (2) The biocompatibility of the Zn / Mg composite materials prepared in Examples 1 and 2 was tested.

[0102] The testing process is as follows: the Zn / Mg composite material is co-cultured with osteoblasts and vascular endothelial cells respectively to observe cell adhesion, proliferation and differentiation; at the same time, the composite material is implanted into the animal's bones and muscle tissue to observe the inflammatory response and tissue repair of the tissues around the implantation site.

[0103] The results showed that when co-cultured with osteoblasts and vascular endothelial cells in vitro, the cells adhered, proliferated and differentiated well. After being implanted into animal bones and muscle tissues in vivo, the inflammatory reaction of the tissues around the implantation site was mild and tissue repair could proceed normally without rejection or toxic reactions.

[0104] (3) The degradation performance of the Zn / Mg composite materials prepared in Examples 1 and 2 was tested.

[0105] The test process is as follows: According to the ASTM G31-12a standard, a Zn / Mg composite material sample with an exposed area of 3 cm was immersed in 60 ml of simulated body fluid at 37°C. The solution was changed regularly, and the corrosion products were removed by using a CrO3 solution. The weight difference of the sample before and after corrosion was measured and the corrosion rate was calculated based on the time to evaluate its degradability in simulated body fluid.

[0106] The results showed that in simulated human body fluids, the magnesium alloy mesh was preferentially corroded in both examples. The average initial corrosion rates of the composite materials of Example 1 and Example 2 were 0.85 mm / year and 0.70 mm / year, respectively. After the corrosion of the magnesium alloy mesh was essentially complete, the corrosion rate significantly decreased. In the later stages of the composite materials of Example 1 and Example 2, the zinc alloy skeleton was the primary corrosion component, with corrosion rates of 0.16 mm / year and 0.13 mm / year, respectively. This demonstrates that the present invention can achieve control over the corrosion rate by controlling the structure of the magnesium alloy and the composition of the magnesium alloy and zinc alloy materials.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A Zn / Mg composite material with controllable degradation rate, characterized in that: The Zn / Mg composite material comprises a magnesium alloy mesh and a zinc alloy, and the zinc alloy is composited with the magnesium alloy mesh by a melt infiltration method.

2. The Zn / Mg composite material with controllable degradation rate according to claim 1, characterized in that: Magnesium alloy mesh is a multi-layer space mesh made of magnesium alloy material.

3. The Zn / Mg composite material with controllable degradation rate according to claim 2, characterized in that: The diameter of the magnesium alloy grid prism in the magnesium alloy mesh is 0.5~3.0mm, the shape of each layer of mesh in the multi-layer space mesh is polygonal, the mesh size is 0.5~3.0mm, and the interlayer spacing between two adjacent layers of mesh is 0.5~2.5mm.

4. The Zn / Mg composite material with controllable degradation rate according to claim 3, characterized in that: The layers of the multi-layer space network are staggered in structure. The mesh holes of the upper layer network and the mesh holes of the lower layer network are staggered on the horizontal projection plane, and the staggering ratio is 30~70%.

5. The Zn / Mg composite material with controllable degradation rate according to claim 2, characterized in that: Calculated by mass percentage, the composition of the magnesium alloy material includes Zn 3~8%, Ca 0~2.0%, Sr 0~0.5%, and the balance is Mg; the composition of the zinc alloy includes Mg 1~8%, Fe 0~2.0%, Ca 0~2.0%, Li 0~1.0%, and the balance is Zn.

6. The method for preparing a Zn / Mg composite material with controllable degradation rate according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: forming a magnesium alloy mesh from a magnesium alloy material; S2: subjecting the magnesium alloy mesh to stress annealing and surface pretreatment in sequence; S3: weighing raw materials according to the composition of the zinc alloy and mixing them, and smelting them at 460-650° C. under argon protection to obtain a zinc alloy liquid; S4: subjecting the magnesium alloy mesh after surface pretreatment to infiltration treatment with zinc alloy liquid to form a magnesium-zinc interpenetrating network to obtain an alloy composite material; S5: Post-processing the alloy composite material to obtain a Zn / Mg composite material.

7. The method for preparing a Zn / Mg composite material with controllable degradation rate according to claim 6, characterized in that: In step S2, the stress annealing process is: keeping the temperature at 250-350°C for 1-3 hours, and cooling with the furnace to eliminate internal stress; The specific process of surface pretreatment is as follows: First, the magnesium alloy mesh is pickled with a dilute sulfuric acid solution with a concentration of 5~15vol.%, and the pickling time is 3~8 minutes. After pickling, it is immediately rinsed with pure water for 2~5 minutes. Then, the rinsed magnesium alloy mesh is cleaned for a second time using an ultrasonic cleaning process to quickly remove the dilute sulfuric acid solution remaining on the magnesium alloy mesh to prevent excessive corrosion. The cleaning medium is a mixed solution of ethanol and acetone, wherein the volume ratio of ethanol to acetone is 3~5:1, and the cleaning time is 15~30 minutes. After cleaning with the ethanol and acetone mixed solution, it is rinsed with pure water for 1~3 minutes.

8. The method for preparing a Zn / Mg composite material with controllable degradation rate according to claim 6, characterized in that: In step S4, the specific process of the infiltration treatment is as follows: S41: placing the magnesium alloy mesh in a mold, preheating the mold to 200-300° C., and injecting zinc alloy liquid into the mold; S42: performing infiltration treatment under an inert gas protective atmosphere, with an inert gas flow rate of 10-20 L / min, an infiltration pressure of 5-20 MPa, and a holding time of 10-30 min, to ensure that the zinc alloy liquid fully fills the pores of the magnesium alloy mesh; S43: After the infiltration is completed, cooling is carried out at a cooling rate of 5~10℃ / min.

9. The method for preparing a Zn / Mg composite material with controllable degradation rate according to claim 6, characterized in that: In step S5, the post-processing includes hot isostatic pressing, machining, homogenization, hot extrusion and aging treatment in sequence.

10. The method for preparing a Zn / Mg composite material with controllable degradation rate according to claim 9, characterized in that: In step S5, the specific process of post-processing is as follows: S51: performing hot isostatic pressing on the alloy composite material, wherein the hot isostatic pressing temperature is 200-400° C., the pressure is 50-150 MPa, and the time is 1-2 h; S52: Adjusting the size and surface roughness of the alloy composite material after hot isostatic pressing by machining; S53: Under argon protection, heating the machined alloy composite material to 350-420°C and keeping the temperature for 4-6 hours for homogenization treatment; S54: performing a hot extrusion treatment on the alloy composite material after the homogenization treatment under a hot extrusion ratio of 8 to 20:1; S55: The hot-extruded alloy composite material is first subjected to aging treatment at 180-200° C. for 3-8 hours, and then subjected to aging treatment at 200-210° C. for 2-6 hours.

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