Graphene oxide reinforced zinc-based alloy composite material and preparation method thereof

Abstract

This invention discloses a graphene oxide-reinforced zinc-based alloy composite material and its preparation method, comprising: adding graphene oxide prepared by a modified Hummers method to water and sonicating to obtain GO colloid; adding zinc alloy powder to water, followed by simultaneous mechanical stirring and ice-water bath sonication to obtain a Zn suspension; adding the GO colloid dropwise into the Zn suspension under stirring, then vacuum filtering and drying to obtain a GO / Zn powder mixture; and obtaining the graphene oxide-reinforced zinc-based alloy composite material by selective laser melting (SLM). The graphene oxide-reinforced zinc-based alloy composite material prepared by this invention exhibits excellent mechanical properties, maintaining material strength through load transfer and grain refinement strengthening effects, thereby achieving a zinc-based alloy composite material with synergistic improvement in strength and plasticity. This provides a feasible strategy for the design and development of high-performance zinc-based alloy implants.

Description

Technical Field

[0001] This invention belongs to the field of biomaterial preparation technology, and more specifically, this invention relates to a graphene oxide-reinforced zinc-based alloy composite material and its preparation method. Background Technology

[0002] Zinc and zinc alloys, as structural and functional materials, have broad application prospects in aerospace, automotive manufacturing, and biomedicine. In recent years, in particular, biodegradable zinc-based biomaterials have attracted much attention due to their suitable degradation rate and good biocompatibility. However, pure zinc has poor mechanical properties; the tensile strength of cast pure zinc is only 20–40 MPa, and its elongation is also low, far from meeting the requirements for load-bearing structural components. Alloying and composite strengthening are the main approaches to improving the mechanical properties of zinc-based materials.

[0003] Graphene and its derivatives (such as graphene oxide) are considered ideal reinforcing phases for metal matrix composites due to their excellent mechanical properties and large specific surface area. In existing technologies, graphene-reinforced metal matrix composites mainly improve material strength through mechanisms such as load transfer effect, grain refinement, dislocation strengthening, and dispersion strengthening. For example, existing technologies use reduced graphene oxide to prepare zinc-based medical materials, but this method mainly relies on physical embedding and weak chemical bonding, lacking uniform dispersion and interfacial reaction strengthening mechanisms. This results in zinc-based medical materials with low ultimate tensile strength and poor load-bearing capacity, affecting their safety and lifespan as implantable medical structural materials. Furthermore, traditional composite materials often sacrifice plasticity in pursuit of high strength; while strength increases, elongation decreases significantly. This is mainly because the interfacial bonding between the reinforcing phase and the matrix is ​​too strong, restricting dislocation movement and leading to early fracture. Recent studies have shown that graphene oxide, due to its abundant oxygen-containing functional groups (hydroxyl, epoxy, carboxyl, etc.) on its surface, allows its interlayer interactions to be modulated by the degree of oxidation. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0005] To achieve these objectives and other advantages of the present invention, a method for preparing graphene oxide-reinforced zinc-based alloy composite materials is provided, comprising the following steps: Step 1: Add graphene oxide prepared using the modified Hummers method to water and sonicate to obtain GO colloid; Step 2: Add zinc alloy powder to water, and then simultaneously perform mechanical stirring and ice-water bath ultrasonic treatment to obtain a Zn suspension; Step 3: While stirring, drop the GO colloid into the Zn suspension, then vacuum filter and dry to obtain a GO / Zn powder mixture; Step 4: Obtain graphene oxide-reinforced zinc-based alloy composite material by selective laser melting technology of GO / Zn powder mixture.

[0006] Preferably, in step one, the modified Hummers method is as follows: graphite powder is added to a sulfuric acid-phosphoric acid mixture and dispersed evenly in an ice bath at 0°C. Potassium permanganate is added slowly in batches, and the temperature of the reaction system is controlled below 10°C throughout the process. Subsequently, the temperature is raised to 40-50°C and stirred for 4-8 hours. After the reaction is completed and cooled to room temperature, the mixture is slowly poured into 80-150 mL of ice water, and 30% hydrogen peroxide is added dropwise until the solution turns bright yellow to terminate the reaction. After centrifugation, the product is washed successively with dilute hydrochloric acid and deionized water until neutral, and then dialyzed for 3 days to remove residual metal ions, acid radicals and other impurity ions from the system. Finally, it is dried to obtain graphene oxide. The volume ratio of concentrated sulfuric acid to concentrated phosphoric acid in the sulfuric acid-phosphoric acid mixture is 8-10:1, and the mass-volume ratio of graphite powder, sulfuric acid-phosphoric acid mixture and potassium permanganate is 0.3-1g:50-100mL:0.5-1.5g. The average sheet size of graphene oxide is 1-10. μm, with an average sheet thickness of 1~5 nm.

[0007] Preferably, in step one, the graphene oxide is modified by means of: S1. Add graphene oxide and lithium hydroxide to deionized water, sonicate for 10-30 min, then add to a reaction vessel, purge the reaction vessel with nitrogen gas, and react at 100-120℃ for 2-4 h under nitrogen protection of 1-6 MPa. After the reaction is completed, centrifuge, wash the solid with deionized water until neutral, and vacuum dry at 60-70℃ for 6-12 h to obtain hydroxylated graphene oxide. S2. Add hydroxylated graphene oxide to deionized water, sonicate for 20-40 min until uniformly dispersed, add 0.1 mol / L silver nitrate solution and urea and stir until uniform, then transfer to a reaction vessel and hydrothermally treat at 90-110℃ for 2-6 h, cool to room temperature, filter, wash 2-4 times with deionized water and anhydrous ethanol, and vacuum dry at 60-80℃ for 8-10 h to obtain modified graphene oxide.

[0008] Preferably, in S1, the mass-to-volume ratio of graphene oxide, lithium hydroxide, and deionized water is 1~5g:0.5~3g:100~200mL.

[0009] Preferably, in S2, the mass-to-volume ratio of hydroxylated graphene oxide, deionized water, silver nitrate solution, and urea is 1~3g:80~120mL:20~50mL:1~3g.

[0010] Preferably, in step one, the water is deionized water; the mass-to-volume ratio of graphene oxide to water is 50 mg: 50~200 mL; and the ultrasonic time is 20~40 min.

[0011] Preferably, in step two, the zinc alloy powder is one of pure Zn alloy powder, Zn-Mg alloy powder, Zn-Cu alloy powder, Zn-Ag alloy powder, or Zn-Li alloy powder, with a particle size of 15~75 μm and a total mass percentage of alloying elements in the zinc alloy powder of 0.1~5.0%.

[0012] Preferably, in step two, the water is deionized water, and the mass-to-volume ratio of zinc alloy powder to water is 10-30g:300mL; the ultrasonic treatment time is 1-3h.

[0013] Preferably, in step three, the volume ratio of GO colloid to Zn suspension is 50~150:300; the vacuum drying temperature is 330~340K, and the drying time is 2~6h.

[0014] Preferably, in step four, the selective laser melting technology is carried out under an argon atmosphere with an argon purity of 99.99%, and the process parameters are: laser spot diameter 50~70 μm, powder layer thickness 50~70 μm, scanning spacing 70~90 μm, laser power 110~120W, and laser scanning rate 500~700 mm / s.

[0015] Preferably, in step four, the tensile strength of the graphene oxide-reinforced zinc-based alloy composite material is 200-253 MPa, and the elongation is 10-15%; the mass percentage of graphene oxide in the graphene oxide-reinforced zinc-based alloy composite material is 0.05-0.5%.

[0016] The present invention also provides a graphene oxide reinforced zinc-based alloy composite material prepared by the preparation method described above.

[0017] The present invention also provides the application of the graphene oxide reinforced zinc-based alloy composite material prepared by the preparation method described above in medical device implant materials.

[0018] The present invention has at least the following beneficial effects: (1) The preparation method of the graphene oxide-reinforced zinc-based alloy composite material of the present invention is formed by selective laser melting technology; wherein, graphene oxide is used as the reinforcing phase, and the graphene oxide is uniformly coated on the surface of zinc powder through electrostatic self-assembly, and then in the laser powder bed melting (LPBF) forming process, the abundant oxygen-containing functional groups on the surface of graphene oxide undergo in-situ chemical bonding with the zinc matrix to form a strong interfacial bond. The reinforcing phase graphene oxide is uniformly coated on the surface of zinc-based alloy powder particles through electrostatic self-assembly process, and the graphene oxide-reinforced zinc-based alloy composite material is successfully obtained.

[0019] (2) In view of the problem that it is difficult to improve the strength and ductility of zinc alloys in a coordinated manner, the present invention achieves uniform dispersion and strong interfacial bonding of graphene oxide on the surface of zinc powder through electrostatic self-assembly, preserves the complete structure of graphene oxide through the rapid melting and solidification characteristics of selective laser melting technology, and utilizes its interlayer slip mechanism in the plastic deformation process to achieve stress relaxation and energy dissipation.

[0020] (3) The graphene oxide reinforced zinc-based alloy composite material prepared by the present invention has excellent mechanical properties. The material strength is maintained through load transfer and fine grain strengthening effect, thereby obtaining a zinc-based alloy composite material with synergistic improvement in strength and plasticity.

[0021] (4) The present invention also provides a method for modifying graphene oxide. First, the hydroxyl groups on the surface of graphene oxide are increased by hydrothermal method, which increases the oxygen-containing functional groups on the surface of graphene oxide. Then, the hydroxylated graphene oxide is subjected to hydrothermal reaction with silver nitrate and urea. Under hydrothermal conditions, urea slowly decomposes to release ammonia, and the pH of the system is adjusted to promote the in-situ hydrolysis of silver ions to generate silver oxide and load it on the surface of graphene. The hydroxylation and silver oxide loading work together to improve the dispersibility and stability of graphene oxide and provide strong interfacial binding sites for subsequent zinc-based composites, while also improving the strength of the material.

[0022] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0023] Figure 1 The image shows the morphology of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 1 of this invention. Figure 2 This is a cross-sectional morphology diagram of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 1 of the present invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0025] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0026] The graphene oxide in the embodiments and comparative examples of this invention was prepared using a modified Hummers method. The specific method is as follows: 0.5 g of graphite powder was weighed and added to 66.75 mL of a sulfuric acid-phosphoric acid mixture (60 mL of concentrated sulfuric acid and 6.75 mL of concentrated phosphoric acid). The mixture was dispersed evenly in an ice bath at 0°C. 1 g of potassium permanganate was slowly added in batches, and the temperature of the reaction system was controlled to be below 10°C throughout the process. Subsequently, the temperature was raised to 45°C and stirred for 6 h. After the reaction was completed and cooled to room temperature, the mixture was slowly poured into 100 mL of ice water, and 30% hydrogen peroxide was added dropwise until the solution turned bright yellow to terminate the reaction. After centrifugation, the product was washed successively with dilute hydrochloric acid and deionized water until neutral. Then, it was dialyzed for 3 days to remove residual metal ions, acid radicals and other impurity ions from the system. Finally, it was dried to obtain graphene oxide. The average sheet size of the graphene oxide was 4 μm and the average sheet thickness was 2 nm.

[0027] Example 1 A method for preparing a graphene oxide-reinforced zinc-based alloy composite material includes the following steps: Step 1: Add 50 mg of graphene oxide to 100 mL of deionized water and sonicate for 30 min to obtain GO colloid with a concentration of 0.5 mg / mL; Step 2: Add 15g of pure Zn alloy powder (zinc content 99.99wt%, particle size 15~75 μm) to 300mL of deionized water, and then simultaneously perform mechanical stirring and ice-water bath ultrasonic treatment for 2h to obtain Zn suspension; Step 3: While stirring, add 100 mL of GO colloid to 300 mL of Zn suspension, then vacuum filter and dry in a vacuum drying oven at 333 K for 4 h to obtain a GO / Zn powder mixture. Step 4: Under an argon atmosphere (purity 99.99%), selective laser melting technology was used to shape GO / Zn mixed powder under process parameters of 60 μm laser spot diameter, 60 μm powder layer thickness, 80 μm scanning spacing, 115 W laser power, and 600 mm / s scanning rate, thus preparing a graphene oxide-reinforced zinc-based alloy composite material with a graphene oxide mass percentage of 0.33%.

[0028] Figure 1 This image shows the morphology of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 1 of this invention. Microstructural analysis using scanning electron microscopy revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibits good bonding.

[0029] Figure 2 The image shows the cross-sectional morphology of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 1 of this invention. Microstructure analysis using scanning electron microscopy revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material has a density of 99%.

[0030] Tensile tests showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 1 was 243 MPa, and the elongation was 13%.

[0031] Example 2 The preparation method of this embodiment is basically the same as that of Example 1, except that in step three, 100 mL of GO colloid is replaced with 50 mL of GO colloid. Other parameters and preparation methods are the same as those of Example 1. The mass percentage of graphene oxide in the prepared graphene oxide reinforced zinc-based alloy composite material is 0.17%.

[0032] Analysis of the microstructure of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 2 revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibits good bonding.

[0033] Tensile testing showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 2 was 217 MPa, and the elongation was 11%.

[0034] Example 3 The preparation method of this embodiment is basically the same as that of Example 1, except that in step three, 100 mL of GO colloid is replaced with 150 mL of GO colloid. Other parameters and preparation methods are the same as those of Example 1. The mass percentage of graphene oxide in the prepared graphene oxide reinforced zinc-based alloy composite material is 0.5%.

[0035] Analysis of the microstructure of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 3 revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibits good bonding.

[0036] Tensile testing showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 3 was 238 MPa, and the elongation was 13%.

[0037] Example 4 The preparation method of this embodiment is basically the same as that of Example 1, except that in step two, pure Zn alloy powder is replaced with Zn-Cu alloy powder (zinc content is 98%, copper content is 2%, and particle size is 15~75 μm). Other parameters and preparation methods are the same as those of Example 1. The mass percentage of graphene oxide in the prepared graphene oxide reinforced zinc-based alloy composite material is 0.33%.

[0038] Analysis of the microstructure of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 4 revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibits good bonding.

[0039] Tensile tests showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 4 was 246 MPa, and the elongation was 14%.

[0040] Example 5 The preparation method in this embodiment is basically the same as that in Example 1, except that in step one, graphene oxide is replaced with modified graphene oxide; the preparation method of modified graphene oxide is as follows: S1. Add 1g of graphene oxide and 0.6g of lithium hydroxide to 100mL of deionized water, sonicate for 20min, then add to a reaction vessel, purge the reaction vessel with nitrogen gas, and react at 100℃ for 3h under nitrogen protection at 1MPa. After the reaction is completed, centrifuge, wash the solid with deionized water until neutral, and dry under vacuum at 60℃ for 8h to obtain hydroxylated graphene oxide. S2. Add 1g of hydroxylated graphene oxide to 100mL of deionized water, sonicate for 30min until uniformly dispersed, add 30mL of 0.1mol / L silver nitrate solution and 1g of urea and stir until uniform, then transfer to a reaction vessel and hydrothermally treat at 100℃ for 3h, cool to room temperature, filter, wash twice each with deionized water and anhydrous ethanol, and vacuum dry at 60℃ for 10h to obtain modified graphene oxide.

[0041] Analysis of the microstructure of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 5 revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibits good bonding.

[0042] Tensile tests showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 5 was 253 MPa, and the elongation was 14%.

[0043] Example 6 The preparation method in this embodiment is basically the same as that in Example 1, except that in step one, graphene oxide is replaced with modified graphene oxide; the preparation method of modified graphene oxide is as follows: 1g of graphene oxide and 0.6g of lithium hydroxide were added to 100mL of deionized water and sonicated for 20min. Then the mixture was added to a reaction vessel, and nitrogen gas was introduced into the reaction vessel. The reaction was carried out at 100℃ for 3h under nitrogen protection at 1MPa. After the reaction was completed, the solid was centrifuged, washed with deionized water until neutral, and dried under vacuum at 60℃ for 8h to obtain modified graphene oxide.

[0044] Analysis of the microstructure of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 6 revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibits good bonding.

[0045] Tensile tests showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Example 6 was 249 MPa, and the elongation was 13%.

[0046] Comparative Example 1 The preparation method of this comparative example is basically the same as that of Example 1, except that in step three, 100 mL of GO colloid is replaced with 20 mL of GO colloid. Other parameters and preparation methods are the same as those of Example 1. The mass percentage of graphene oxide in the prepared graphene oxide reinforced zinc-based alloy composite material is 0.06%.

[0047] Analysis of the microstructure of the graphene oxide-reinforced zinc-based alloy composite material prepared in Comparative Example 1 revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibits good bonding.

[0048] Tensile tests showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Comparative Example 1 was 190 MPa, and the elongation was 8%.

[0049] Comparative Example 2 The preparation method of this comparative example is basically the same as that of Example 1, except that in step three, 100 mL of GO colloid is replaced with 200 mL of GO colloid. Other parameters and preparation methods are the same as those of Example 1. The mass percentage of graphene oxide in the prepared graphene oxide reinforced zinc-based alloy composite material is 0.66%.

[0050] Analysis of the microstructure of the graphene oxide-reinforced zinc-based alloy composite material prepared in Comparative Example 2 revealed that the obtained graphene oxide-reinforced zinc-based alloy composite material exhibited good bonding.

[0051] Tensile tests showed that the ultimate tensile strength of the graphene oxide-reinforced zinc-based alloy composite material prepared in Comparative Example 2 was 176 MPa, and the elongation was 17%.

[0052] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for producing a graphene oxide reinforced zinc-based alloy composite material, characterized by, Includes the following steps: Step 1: Add graphene oxide prepared using the modified Hummers method to water and sonicate to obtain GO colloid; Step 2: Add zinc alloy powder to water, and then simultaneously perform mechanical stirring and ice-water bath ultrasonic treatment to obtain a Zn suspension; Step 3: While stirring, drop the GO colloid into the Zn suspension, then vacuum filter and dry to obtain a GO / Zn powder mixture; Step 4: Obtain graphene oxide-reinforced zinc-based alloy composite material by selective laser melting technology of GO / Zn powder mixture.

2. The method of producing a graphene oxide reinforced zinc-based alloy composite according to claim 1, wherein In step one, the modified Hummers method is as follows: graphite powder is added to a sulfuric acid-phosphoric acid mixture and dispersed evenly in an ice bath at 0°C. Potassium permanganate is added slowly in batches, and the temperature of the reaction system is controlled below 10°C throughout the process. Then, the temperature is raised to 40-50°C and stirred for 4-8 hours. After the reaction is completed and cooled to room temperature, the mixture is slowly poured into 80-150 mL of ice water, and 30% hydrogen peroxide is added dropwise until the solution turns bright yellow to terminate the reaction. After centrifugation, the product is washed sequentially with dilute hydrochloric acid and deionized water until neutral, and then dialyzed through a dialysis bag and dried to obtain graphene oxide. The volume ratio of concentrated sulfuric acid to concentrated phosphoric acid in the sulfuric acid-phosphoric acid mixture is 8-10:1, and the mass-volume ratio of graphite powder, sulfuric acid-phosphoric acid mixture, and potassium permanganate is 0.3-1 g: 50-100 mL: 0.5-1.5 g. The average sheet size of graphene oxide is 1-10 μm, and the average sheet thickness is 1-5 nm.

3. The method of producing a graphene oxide reinforced zinc-based alloy composite according to claim 1, wherein In step one, the water is deionized water; the mass-to-volume ratio of graphene oxide to water is 50 mg: 50~200 mL; and the ultrasonic time is 20~40 min.

4. The method of producing a graphene oxide reinforced zinc-based alloy composite according to claim 1, wherein In step two, the zinc alloy powder is one of pure Zn alloy powder, Zn-Mg alloy powder, Zn-Cu alloy powder, Zn-Ag alloy powder, or Zn-Li alloy powder, with a particle size of 15~75 μm and a total mass percentage of alloying elements in the zinc alloy powder of 0.1~5.0%.

5. The method for preparing the graphene oxide-reinforced zinc-based alloy composite material as described in claim 1, characterized in that, In step two, the water is deionized water, and the mass-to-volume ratio of zinc alloy powder to water is 10-30g:300mL; the ultrasonic treatment time is 1-3h.

6. The method for preparing the graphene oxide-reinforced zinc-based alloy composite material as described in claim 1, characterized in that, In step three, the volume ratio of GO colloid to Zn suspension is 50~150:300; the vacuum drying temperature is 330~340K, and the drying time is 2~6h.

7. The method for preparing the graphene oxide-reinforced zinc-based alloy composite material as described in claim 1, characterized in that, In step four, the selective laser melting technology is carried out under an argon atmosphere with a purity of 99.99%. The process parameters are: laser spot diameter 50~70 μm, powder layer thickness 50~70 μm, scanning interval 70~90 μm, laser power 110~120W, and laser scanning rate 500~700 mm / s.

8. The method for preparing the graphene oxide-reinforced zinc-based alloy composite material as described in claim 1, characterized in that, In step four, the tensile strength of the graphene oxide-reinforced zinc-based alloy composite material is 200-253 MPa, and the elongation is 10-15%; the mass percentage of graphene oxide in the graphene oxide-reinforced zinc-based alloy composite material is 0.05-0.5%.

9. A graphene oxide-reinforced zinc-based alloy composite material prepared by the preparation method according to any one of claims 1-8.

10. The application of a graphene oxide-reinforced zinc-based alloy composite material prepared by the preparation method according to any one of claims 1-8 in medical device implant materials.

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