A periodic antibacterial composite magnesium alloy material and its preparation method and application

Abstract

The present invention provides a periodically antibacterial composite magnesium alloy material, a preparation method thereof, and an application thereof, which belong to the technical field of alloy materials. The present invention alternately stacks magnesium-zinc alloy plates and magnesium-copper alloy plates, and through multiple rolling-folding-rolling methods, can obtain a composite magnesium alloy material in which multiple layers of magnesium-zinc alloy and magnesium-copper alloy layers are alternately arranged. The present invention, through the alternating distribution of magnesium-zinc alloy and magnesium-copper alloy layers, on the one hand, can utilize the good mechanical properties of magnesium-zinc alloy to modify magnesium-copper alloy, thereby solving the defect of poor mechanical properties of magnesium-copper alloy. On the other hand, the alternating magnesium-zinc alloy layers and magnesium-copper alloy layers can realize the alternating interval release of zinc ions and copper ions, which can not only regulate the degradation rate of the composite magnesium alloy, but also achieve a periodic antibacterial effect through the intermittent release of copper ions. The resulting composite magnesium alloy material has excellent antibacterial properties.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and in particular to a periodically antibacterial composite magnesium alloy material, a preparation method thereof, and applications thereof. Background Art

[0002] Medical magnesium alloys, as biodegradable medical materials, are considered third-generation biomedical materials. Magnesium is a mild element with excellent absorbability and biocompatibility. In orthopedic implants, it possesses a density and elastic modulus close to that of bone. Medical magnesium alloys also have a controllable corrosion rate, holding great promise for applications in cardiovascular implants and bone repair.

[0003] Copper is a crucial trace element in human tissue, regulating metabolism and the function of various enzymes. Furthermore, copper ions possess excellent antibacterial properties, and introducing copper metal into magnesium alloys can impart these properties with excellent antibacterial properties. However, the mechanical properties of magnesium-copper alloys are far inferior to those of common magnesium alloy medical materials, and their corrosion degradation rate is relatively slow, making them difficult to meet the requirements of actual bone repair applications, which limits their practical use. Summary of the Invention

[0004] In view of this, the present invention aims to provide a composite magnesium alloy material with periodic antibacterial properties, as well as its preparation method and application. The composite magnesium alloy material provided by the present invention has significantly higher mechanical and degradation properties than magnesium-copper alloys, and achieves antibacterial effects through the intermittent release of copper ions.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a periodically antibacterial composite magnesium alloy material, comprising the following steps:

[0007] The magnesium-zinc alloy plate and the magnesium-copper alloy plate are alternately stacked to obtain a plurality of stacked plates; the zinc content of the magnesium-zinc alloy plate is 0.5-2wt%; the copper content of the magnesium-copper alloy plate is 0.1-0.4wt%;

[0008] performing a first high-temperature rolling on the plurality of stacked plates to obtain a first composite plate;

[0009] The first composite plate is folded in half, and the folded plate is subjected to a second high-temperature rolling to obtain a second composite plate. ... The steps of folding in half and high-temperature rolling are repeated multiple times to obtain a periodically antibacterial composite magnesium alloy material.

[0010] Preferably, the number of layers of the stacked multiple plates is 2 to 8.

[0011] Preferably, the thickness of a single magnesium-zinc alloy sheet is 0.1 to 2 mm;

[0012] The thickness of a single magnesium-copper alloy plate is 0.1 to 2 mm.

[0013] Preferably, the temperature of each high-temperature rolling is 100-300°C.

[0014] Preferably, the deformation amount of each high-temperature rolling pass is 10 to 90%.

[0015] Preferably, the folding and high-temperature rolling are repeated 2 to 6 times.

[0016] The present invention provides a periodically antibacterial composite magnesium alloy material prepared by the above preparation method, comprising alternately stacked magnesium-zinc alloy layers and magnesium-copper alloy layers;

[0017] The number of the magnesium-zinc alloy layer and the magnesium-copper alloy layer is 10 to 100 in total.

[0018] Preferably, the thickness of the periodically antibacterial composite magnesium alloy material is 0.2 to 2 mm.

[0019] The present invention provides the use of the periodically antibacterial composite magnesium alloy material in the preparation of bone repair materials.

[0020] The present invention provides a method for preparing a composite magnesium alloy material with periodic antibacterial properties, comprising the following steps: alternately stacking magnesium-zinc alloy sheets and magnesium-copper alloy sheets to obtain a plurality of stacked sheets; the zinc content of the magnesium-zinc alloy sheets is 0.5-2 wt%; the copper content of the magnesium-copper alloy sheets is 0.1-0.4 wt%; subjecting the stacked sheets to a first high-temperature rolling process to obtain a first composite sheet; folding the first composite sheet in half, and subjecting the folded sheet to a second high-temperature rolling process to obtain a second composite sheet; and repeating the folding and high-temperature rolling processes multiple times to obtain a composite magnesium alloy material with periodic antibacterial properties. The present invention alternately stacks magnesium-zinc alloy sheets and magnesium-copper alloy sheets, and repeatedly rolls, folds, and rolls the sheets to obtain a composite magnesium alloy material having multiple layers of alternating magnesium-zinc alloy and magnesium-copper alloy layers. By alternating the magnesium-zinc alloy and magnesium-copper alloy layers, the present invention can utilize the excellent mechanical properties of the magnesium-zinc alloy to modify the magnesium-copper alloy, thereby addressing the poor mechanical properties of the magnesium-copper alloy. On the other hand, the alternating magnesium-zinc alloy layers and magnesium-copper alloy layers can realize the alternating release of zinc ions and copper ions, which can not only regulate the degradation rate of the composite magnesium alloy, but also achieve a periodic antibacterial effect through the intermittent release of copper ions. The resulting composite magnesium alloy material has excellent antibacterial properties.

[0021] The present invention provides a method for preparing the above-mentioned periodically antibacterial composite magnesium alloy material. The method is simple to operate, low in cost, and easy to realize industrialized batch production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of the composite magnesium alloy material with periodic antibacterial properties;

[0023] Figure 2 This is a cross-sectional metallographic image of the periodically antibacterial composite magnesium alloy plate of Example 1;

[0024] Figure 3 This is a cross-sectional metallographic image of the periodically antibacterial composite magnesium alloy plate of Example 2;

[0025] Figure 4 The pH value change of the composite magnesium alloy plate of Example 2 after being immersed in cast Mg-0.2Cu for 2 weeks;

[0026] Figure 5 The pH value change of the composite magnesium alloy plate of Example 1 after being immersed in rolled Mg-0.2Cu for 2 weeks. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a periodically antibacterial composite magnesium alloy material, comprising the following steps:

[0028] The magnesium-zinc alloy plate and the magnesium-copper alloy plate are alternately stacked to obtain a plurality of stacked plates; the zinc content of the magnesium-zinc alloy plate is 0.5-2wt%; the copper content of the magnesium-copper alloy plate is 0.1-0.4wt%;

[0029] performing a first high-temperature rolling on the plurality of stacked plates to obtain a first composite plate;

[0030] The first composite plate is folded in half, and the folded plate is subjected to a second high-temperature rolling to obtain a second composite plate. ... The steps of folding in half and high-temperature rolling are repeated multiple times to obtain a periodically antibacterial composite magnesium alloy material.

[0031] The present invention alternately stacks magnesium-zinc alloy sheets and magnesium-copper alloy sheets to produce multiple stacked sheets. In the present invention, the magnesium-zinc alloy sheets have a zinc content of 0.5 to 2 wt%, preferably 0.8 to 1.8 wt%, and more preferably 1 to 1.5 wt%, with the balance being magnesium. In the present invention, the thickness of a single magnesium-zinc alloy sheet is preferably 0.1 to 2 mm, more preferably 0.5 to 1 mm.

[0032] In the present invention, the copper content of the magnesium-copper alloy plate is 0.1-0.4 wt %, preferably 0.2-0.3 wt %. In the present invention, the thickness of a single magnesium-copper alloy plate is preferably 0.1-2 mm, more preferably 0.5-1 mm.

[0033] The present invention preferably pre-treats the magnesium-zinc alloy sheet and the magnesium-copper alloy sheet. The pre-treatment preferably includes grinding, polishing, cleaning, and drying, performed sequentially. In the present invention, the grinding method preferably involves sanding the surface with sandpaper from coarse to fine until the surface is free of oxide scale. The polishing method preferably involves chemically polishing the magnesium-zinc alloy sheet at 55±5°C using a phosphoric acid + ethylene glycol solution, with the volume ratio of phosphoric acid to ethylene glycol preferably being 2:3. In the present invention, the detergent used for cleaning is preferably ethanol, purified water, ethanol, and an ethanol solution. The cleaning is preferably ultrasonic cleaning, and the cleaning is performed multiple times. The present invention prevents polishing liquid residue through these multiple cleanings. In the present invention, the drying method preferably involves oven drying.

[0034] In the present invention, the number of layers of the stacked multiple plates is 2 to 8 layers, preferably 3 to 5 layers.

[0035] After obtaining the plurality of stacked sheets, the present invention performs a first high-temperature rolling on the stacked sheets to obtain a first composite sheet. In the present invention, the temperature of the first high-temperature rolling is preferably 100-300°C, more preferably 150-250°C, and even more preferably 200°C. In the present invention, the deformation per pass of the first high-temperature rolling is preferably 10-90%, more preferably 30-60%.

[0036] After obtaining the first composite sheet, the present invention folds the first composite sheet in half and subjects the folded sheet to a second high-temperature rolling process to obtain a second composite sheet. The folding and high-temperature rolling steps are repeated multiple times to obtain a composite magnesium alloy material with periodic antibacterial properties. In the present invention, the folding is preferably performed along the centerline. This folding process exponentially increases the number of layers in the composite sheet.

[0037] In the present invention, the temperature of the second high temperature rolling is preferably 100-300° C., more preferably 150-250° C., and even more preferably 200° C. In the present invention, the deformation of the second high temperature rolling pass is preferably 10-90%, more preferably 30-60%.

[0038] In the present invention, the folding and high-temperature rolling are repeated preferably 2 to 6 times, more preferably 3 to 5 times. In the present invention, the temperature of each high-temperature rolling is preferably 100 to 300°C, more preferably 150 to 250°C, and even more preferably 200°C; the deformation per pass is preferably 10 to 90%, more preferably 30 to 60%.

[0039] The present invention provides a periodically antibacterial composite magnesium alloy material prepared by the above preparation method, comprising alternately stacked magnesium-zinc alloy layers and magnesium-copper alloy layers;

[0040] The total number of the magnesium-zinc alloy layer and the magnesium-copper alloy layer is 10 to 100 layers, preferably 20 to 80 layers, and more preferably 30 to 50 layers.

[0041] In the present invention, the thickness of the periodically antibacterial composite magnesium alloy material is preferably 0.2 to 2 mm, more preferably 0.5 to 1.5 mm, and even more preferably 0.8 to 1.2 mm.

[0042] In the present invention, the thickness of each of the single magnesium-zinc alloy layer and the magnesium-copper alloy layer is preferably 4 to 40 μm, more preferably 10 to 30 μm.

[0043] In the present invention, the structural diagram of the periodically antibacterial composite magnesium alloy material is as follows: Figure 1 shown.

[0044] The present invention provides the use of the above-mentioned periodically antibacterial composite magnesium alloy material in the preparation of bone repair materials. In the present invention, the periodically antibacterial composite magnesium alloy material is preferably a bone plate material.

[0045] The periodic antibacterial composite magnesium alloy material provided by the present invention, its preparation method and application are described in detail below in conjunction with the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0046] Example 1

[0047] Two magnesium-zinc alloy sheets with a zinc content of 1 wt% and two magnesium-copper alloy sheets with a copper content of 0.2 wt%, each 2 mm thick, were prepared. The magnesium-zinc alloy sheets and the magnesium-copper alloy sheets were ground, polished, cleaned, and dried to remove the oxide layer on the surface of the sheets.

[0048] The above magnesium-zinc alloy sheets and magnesium-copper alloy sheets were alternately stacked. The alternating multilayer sheets were subjected to a first high-temperature rolling (4 layers) at a temperature of 300°C and a deformation of 60% per pass. The sheets were then folded in half. The folded sheets were then subjected to a second high-temperature rolling (8 layers) at a temperature of 300°C and a deformation of 60% per pass. The sheets were folded in half again and subjected to a third high-temperature rolling (16 layers) at a temperature of 300°C and a deformation of 40% per pass. The resulting composite magnesium alloy sheet with periodic antibacterial properties comprises 16 alternating layers of high-purity magnesium and magnesium-zinc alloy. The total number of layers is 16, with a final thickness of 1.2 mm and an average single-layer thickness of 0.075 mm. Mechanical testing showed that the material had a tensile strength of 153 MPa.

[0049] Figure 2 This is a cross-sectional metallographic image of the periodically antibacterial composite magnesium alloy plate of Example 1 (scale is 100 μm). It can be seen that the entire material cross-section is clearly layered and the different layers are well fused.

[0050] Example 2

[0051] Four magnesium-zinc alloy sheets with a zinc content of 1 wt% and four magnesium-copper alloy sheets with a copper content of 0.2 wt%, each 2 mm thick, were prepared. The magnesium-zinc alloy sheets and magnesium-copper alloy sheets were ground, polished, cleaned, and dried to remove the oxide layer on the surface of the sheets.

[0052] The above magnesium-zinc alloy sheet and magnesium-copper alloy sheet were alternately stacked, and the alternately stacked multi-layer sheet was subjected to a first high-temperature rolling (8 layers) at a temperature of 300°C and a deformation of 60%. The sheet was then folded in half and subjected to a second high-temperature rolling (16 layers) at a temperature of 300°C and a deformation of 60%. The sheet was folded in half again and subjected to a third high-temperature rolling (32 layers) at a temperature of 300°C and a deformation of 60%. The resulting composite magnesium alloy sheet has periodic antibacterial properties, including 32 alternating layers of high-purity magnesium and magnesium-zinc alloy. The total number of layers is 1.9 mm, with an average single-layer thickness of 0.06 mm. Mechanical testing showed that the material had a tensile strength of 160 MPa.

[0053] Figure 3 This is a cross-sectional metallographic image of the periodically antibacterial composite magnesium alloy plate of Example 2 (scale is 100 μm). It can be seen that the entire material cross-section is clearly layered and the different layers are well fused.

[0054] Comparative Example 1

[0055] A 2 mm thick cast magnesium-copper alloy plate with a copper content of 0.2 wt% (referred to as cast Mg-0.2Cu) was prepared for comparison with Example 2. The tensile strength of the alloy was 60 MPa, significantly lower than the mechanical properties of the materials in Examples 1 and 2.

[0056] Figure 4 The changes in pH values ​​after corrosion of the composite magnesium alloy plate of Example 2 and cast Mg-0.2Cu were immersed in 200 mL of PBS solution for 2 weeks. It can be seen that the corrosion rate of cast Mg-0.2Cu was faster than that of the antibacterial material in the first 7 days. In the later period, the corrosion rate slowed down as the material was dissolved. The composite magnesium alloy plate of Example 2 showed a significant decrease after 14 days, indicating that the corrosion rate of Example 2 lasted longer than that of cast Mg-0.2Cu.

[0057] Comparative Example 2

[0058] Two 2mm thick magnesium-copper alloy sheets with a copper content of 0.2wt% were laminated and subjected to high-temperature rolling at 300°C using a twin-roll mill, with a deformation of 60% per pass. A 1.8mm thick magnesium-copper alloy sheet (hereinafter referred to as rolled Mg-0.2Cu) was obtained for comparison with Example 1. The resulting alloy had a tensile strength of 116 MPa, significantly lower than the mechanical properties of the materials in Examples 1 and 2.

[0059] Figure 5 Figure 3 shows the changes in pH value after corrosion of the composite magnesium alloy plate of Example 1 and rolled Mg-0.2Cu after immersion in 200 mL of PBS solution for 2 weeks. It can be seen that the corrosion rate of rolled Mg-0.2Cu is faster than that of the antibacterial material in the first 4 days. In the later period, the corrosion rate slows down as the material dissolves. The composite magnesium alloy plate of Example 1 shows a significant decrease after 14 days, indicating that the corrosion rate of Example 1 can be maintained for a much longer time than that of rolled Mg-0.2Cu.

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a periodically antibacterial composite magnesium alloy material, comprising the following steps: The magnesium-zinc alloy plate and the magnesium-copper alloy plate are alternately stacked to obtain a plurality of stacked plates; the zinc content of the magnesium-zinc alloy plate is 0.5-2wt%; the copper content of the magnesium-copper alloy plate is 0.1-0.4wt%; performing a first high-temperature rolling on the plurality of stacked plates to obtain a first composite plate; The first composite plate is folded in half, and the folded plate is subjected to a second high-temperature rolling to obtain a second composite plate. ... The steps of folding in half and high-temperature rolling are repeated multiple times to obtain a periodically antibacterial composite magnesium alloy material.

2. The preparation method according to claim 1, characterized in that The number of layers of the stacked plates is 2 to 8.

3. The preparation method according to claim 1, characterized in that The thickness of a single magnesium-zinc alloy sheet is 0.1 to 2 mm; The thickness of a single magnesium-copper alloy plate is 0.1 to 2 mm.

4. The preparation method according to claim 1, characterized in that The temperature of each high temperature rolling is 100-300°C.

5. The preparation method according to claim 1 or 4, characterized in that The deformation amount of each high temperature rolling pass is 10 to 90%.

6. The preparation method according to claim 1, characterized in that The folding and high-temperature rolling are repeated 2 to 6 times.

7. The periodically antibacterial composite magnesium alloy material prepared by the preparation method according to any one of claims 1 to 6, comprising alternately stacked magnesium-zinc alloy layers and magnesium-copper alloy layers; The number of the magnesium-zinc alloy layer and the magnesium-copper alloy layer is 10 to 100 in total.

8. The periodically antibacterial composite magnesium alloy material according to claim 7, characterized in that: The thickness of the periodically antibacterial composite magnesium alloy material is 0.2 to 2 mm.

9. Use of the periodically antibacterial composite magnesium alloy material according to claim 7 or 8 in the preparation of bone repair materials.

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