A zinc-based alloy composite material and a preparation method and application thereof

Abstract

This invention relates to the field of metal matrix composite material preparation technology, specifically to a zinc-based alloy composite material and its preparation method, particularly applicable to the field of biodegradable biomedical implant materials. The zinc-based alloy composite material comprises a zinc alloy matrix and nano-reinforcing particles. The zinc alloy matrix is ​​composed of Zn, Cu, and Li; wherein the mass percentage of Cu in the zinc alloy matrix is ​​1-2 wt%, and the mass percentage of Li in the zinc alloy matrix is ​​0.1-0.9 wt%; the volume percentage of the nano-reinforcing particles in the zinc alloy matrix is ​​<2.5 vol%; the particle size of the nano-reinforcing particles is <100 nm, and the nano-reinforcing particles are uniformly dispersed in the zinc alloy matrix. The invention also relates to the preparation and application of the above-mentioned zinc-based alloy composite material. This invention solves the problems of unstable microstructure and difficulty in balancing strength and ductility in existing zinc-copper-lithium alloys, thus improving the mechanical properties of the zinc-copper-lithium alloy system.

Description

Technical Field

[0001] This invention relates to the field of metal matrix composite material preparation technology, specifically to a zinc-based alloy composite material, its preparation method and application, and is particularly applicable to the field of biodegradable biomedical implant materials. Background Technology

[0002] Zinc and zinc-based alloys, as a class of biodegradable metallic materials, have shown broad application prospects in biomedical fields such as orthopedic implants and cardiovascular stents due to their suitable degradation rate, good biocompatibility, and mechanical properties similar to human bone tissue. The degradation products of pure zinc materials can be metabolized and absorbed by the human body, avoiding the need for a second surgery to remove traditional permanent implant materials, and therefore have attracted widespread attention from the medical and materials science communities.

[0003] However, existing pure zinc materials generally suffer from insufficient mechanical properties in practical applications. Pure zinc has low tensile strength and poor creep resistance at human body temperature (approximately 37°C), making it prone to plastic deformation under long-term physiological loads. This makes it difficult to meet the long-term mechanical stability requirements of load-bearing implants (such as orthopedic internal fixation devices). To improve the mechanical properties of pure zinc materials, researchers have explored various strengthening methods, among which introducing nanoscale reinforcing phases into the zinc matrix is ​​an effective technical approach.

[0004] Chinese patent CN109500396A discloses an intracrystalline-intercrystalline composite reinforced bio-zinc alloy and its preparation method. This method uses graphene to encapsulate nano-silicon carbide particles, and prepares the zinc-based composite material through batch cryogenic ball milling and selective laser melting. This method achieves the distribution of nano-ceramic particles in the zinc matrix, improving the mechanical properties of the material. However, this technical solution requires graphene as the encapsulation material, the process is complex, and it relies on expensive equipment such as powder metallurgy and laser melting, resulting in high manufacturing costs and making large-scale industrial production difficult. Furthermore, this solution does not clearly define the particle size range of the nanoparticles in the final product, and the precision of particle size control needs to be improved.

[0005] On the other hand, the method of directly adding nano-ceramic particles to zinc melt also faces many technical challenges. Due to the poor wettability between high-melting-point ceramic materials (such as titanium carbide and tungsten carbide) and zinc melt, nanoparticles are prone to floating, agglomeration, or interfacial separation in the zinc melt, making it difficult to form a stable and uniform dispersed distribution structure in the zinc matrix. While traditional physical dispersion methods such as mechanical stirring or ultrasonic treatment can improve particle distribution to some extent, they still cannot fundamentally solve the problem of nanoparticle agglomeration, and their ability to precisely control the nanoparticle size is limited. Especially when it is necessary to control the nanoparticle size to below 100 nanometers, existing technologies often struggle to achieve a stable preparation process.

[0006] Furthermore, introducing copper into zinc-lithium alloys can further improve their mechanical and functional properties. However, the microstructure of zinc-copper-lithium multi-element alloys is more complex and highly sensitive to processing and service conditions, making them prone to microstructural instability and performance fluctuations. Currently, there is a lack of an effective technical solution that can simultaneously achieve high strength, good ductility, and long-term structural stability in zinc-copper-lithium alloy systems. Summary of the Invention

[0007] The present invention aims to provide a zinc-based alloy composite material, its preparation method and application, to solve the problems of unstable microstructure and difficulty in balancing strength and ductility in existing zinc-copper-lithium alloys, thereby improving the mechanical properties of zinc-copper-lithium alloys.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A zinc-based alloy composite material includes a zinc alloy matrix and nano-reinforcing particles. The zinc alloy matrix is ​​composed of Zn, Cu, and Li. The mass percentage of Cu in the zinc alloy matrix is ​​1-2 wt%, and the mass percentage of Li in the zinc alloy matrix is ​​0.1-1.0 wt%. The volume percentage of the nano-reinforcing particles in the zinc alloy matrix is ​​<2.5 vol%. The particle size of the nano-reinforcing particles is <100 nm, and the nano-reinforcing particles are uniformly dispersed in the zinc alloy matrix.

[0009] In one specific embodiment of the present invention, the nano-reinforcing particles are selected from any one of titanium carbide, tungsten carbide, and titanium boride.

[0010] In one specific embodiment of the present invention, the nano-ceramic fine particles are titanium carbide.

[0011] In one specific embodiment of the present invention, the particle size of the nano-ceramic fine particles is 60-90 nm.

[0012] In one specific embodiment of the present invention, the mass percentage of Cu in the zinc-based alloy is 1-2 wt%, and the mass percentage of Li in the zinc-based alloy is 0.8-0.9 wt%.

[0013] In one specific embodiment of the present invention, the zinc-based alloy composite material has a yield strength >400MPa, a tensile strength >500MPa, and an elongation >45%.

[0014] The above-mentioned method for preparing zinc-based alloy composite materials includes the steps of vacuum melting a zinc-based base material containing nano-reinforcing particles, and alloying it with a copper-lithium source to obtain a zinc-based alloy ingot or ingot, and further includes: The zinc-based alloy ingot or block is subjected to thermoplastic deformation treatment to obtain a zinc-based alloy composite material.

[0015] In one specific embodiment of the present invention, the copper-lithium source includes any one or any combination of elemental copper, elemental lithium, copper-lithium alloy, copper-lithium-zinc alloy, copper-zinc alloy, and lithium-zinc alloy.

[0016] In one specific embodiment of the present invention, the temperature of the vacuum melting is 400-600℃, and the vacuum degree is... - Pa; the alloying temperature is 550-600℃, and the holding time is 5-10 min.

[0017] In one specific embodiment of the present invention, the parameters of the thermoplastic deformation are controlled as follows: temperature 200-300℃, deformation amount 1:10-1:100.

[0018] In one specific embodiment of the present invention, the particle size of the nano-reinforcing particles in the zinc-based matrix is ​​50-99 nm.

[0019] The application of the zinc-based alloy composite material described above or the zinc-based alloy composite material prepared by the above preparation method in the preparation of biodegradable metal medical devices.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. In the zinc-based alloy composite material of the present invention, a multi-scale synergistic strengthening mechanism is formed in the zinc-copper-lithium alloy by introducing a uniformly dispersed nano-reinforcing phase with a particle size of 50-90nm, which significantly improves the yield strength and tensile strength of the alloy, while maintaining good ductility after plastic processing. 2. The nano-reinforcing particles in the zinc-based alloy composite material of the present invention can effectively inhibit grain boundary migration and alloy phase coarsening, and improve the microstructure stability and mechanical property repeatability of the alloy after plastic processing and under long-term service conditions. 3. The preparation method of this invention uses a zinc-based base material containing 50-90nm nano-reinforcing particles. Based on vacuum melting, alloying, and thermoplastic deformation, a zinc-based alloy composite material containing 50-99nm nano-reinforcing particles is prepared. This not only avoids the agglomeration of nano-reinforcing particles, but also effectively promotes the uniform dispersion of 50-99nm nano-reinforcing particles in the zinc-based alloy matrix, which is beneficial to obtaining zinc-based alloy composite materials with better mechanical properties. 4. The alloy described in this invention has broad application prospects in the field of high-performance biodegradable metal materials. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the thermoplastic deformation principle provided in Embodiment 1 of the present invention; Figure 2 These are photographs of the Zn-2Cu-0.8Li-TiC alloy ingot before and after thermoplastic deformation according to Example 1 of the present invention; wherein, a is a photograph of the Zn-2Cu-0.8Li-TiC alloy ingot, and b is a photograph of the Zn-2Cu-0.8Li-TiC alloy after thermoplastic deformation treatment; Figure 3 The diagram shows the mechanical properties of the Zn-2Cu-0.8Li-TiC alloy and the Zn-0.8Li alloy in Example 1 of this invention. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Example

[0023] This embodiment provides a method for preparing Zn-2Cu-0.8Li-TiC, including the following steps: 1. Raw material preparation Zinc-based matrix containing TiC nanoparticles; wherein the volume percentage of TiC nanoparticles in the zinc-based matrix is ​​1.5 vol%, and the average particle size is within 50-99 nm (it is prepared by the molten salt displacement reaction of aluminum-based composite material and zinc dichloride). Copper source: High-purity metallic copper; Lithium source: elemental lithium metal; 2. Proportioning calculation and weighing Based on the target alloy composition Zn-2Cu-0.8Li-TiC, and using zinc-based base material as a basis, calculate the required copper and lithium content, and weigh the zinc-based base material, copper source, and lithium source respectively. 3. Loading and vacuuming The nano-zinc substrate and copper source are loaded into a crucible, which is then placed in a vacuum furnace and evacuated. After the first evacuation, the furnace is purged with argon gas, and then evacuated again until... Pa; 4. Smelting and Copper Alloying The zinc-based matrix is ​​heated to 500°C under vacuum or a controlled atmosphere to melt it. To promote the dissolution and diffusion of the copper source in the molten zinc-based matrix and to maintain the dispersed state of the TiC nanoparticles, mechanical stirring is performed during the melting process of the zinc-based matrix. 5. Introduction and alloying of lithium After the melt from step 4 has stabilized, a lithium source is introduced into the crucible and alloyed for 22.5 minutes to allow lithium to diffuse fully and form the target composition, thereby reducing lithium volatilization and oxidation loss.

[0024] 6. Homogenization treatment: The melt was held at a low temperature for 10 minutes to promote uniform distribution of Cu and Li and improve microstructure stability. 7. Casting and Shaping: The Zn-2Cu-0.8Li-TiC alloy ingot was obtained by casting and cooling under controlled conditions. 8. Thermoplastic deformation: Based on the appendix Figure 1 The Zn-2Cu-0.8Li-TiC alloy ingot was subjected to thermoplastic deformation treatment to obtain the Zn-2Cu-0.8Li-TiC alloy; wherein the thermoplastic deformation parameters were a temperature of 250℃ and a deformation ratio of 1:105.

[0025] 9. Heat treatment The Zn-2Cu-0.8Li-TiC alloy strips obtained by room temperature thermoplastic deformation were heat-treated at 250℃ for 2 hours to relieve stress, thus obtaining the Zn-2Cu-0.8Li-TiC alloy composite material. Example

[0026] In this embodiment, Zn-2Cu-0.8Li-WC was prepared using the same method as in Example 1. Example

[0027] In this embodiment, Zn-1.8Cu-0.8Li-TiB2 was prepared using the same method as in Example 1.

[0028] Performance characterization: 1. The Zn-2Cu-0.8Li-TiC alloy ingot and photographs of the Zn-2Cu-0.8Li-TiC alloy from Example 1 are attached. Figure 2 As shown.

[0029] 2. Based on ASRM E8 / E8,M tests, the yield strength (TYS), tensile strength (UTS), and elongation of the Zn-2Cu-0.8Li alloy of Example 1, as well as the Zn-0.8Li alloy and Zn-2Cu-0.8Li alloy prepared by conventional methods, were measured. The results are shown in Table 1.

[0030] Table 1

[0031] 3. Schematic diagram of the mechanical properties of TiC nanoparticle-reinforced alloys The schematic diagrams illustrating the mechanical properties of the Zn-2Cu-0.8Li-TiC alloy composite material and the traditional Zn-0.8Li alloy in Example 1 are attached. Figure 3 As shown.

[0032] In traditional Zn-Cu-Li alloy systems, their mechanical properties mainly rely on alloying strengthening and second-phase strengthening mechanisms. However, such alloy systems often face the problem of balancing strength improvement with ductility reduction, and are prone to microstructural instability, localized deformation concentration, and performance fluctuations during plastic processing or long-term service.

[0033] The Zn-2Cu-0.8Li-TiC alloy of Example 1 of this invention significantly improves the comprehensive mechanical properties of the material by introducing uniformly dispersed 50-99nm TiC nanoparticles into a zinc matrix and establishing a multi-scale synergistic strengthening and stabilization mechanism in the alloy system. Its mechanism mainly manifests in the following aspects: (1) The dispersion enhancement and dislocation regulation effect of nanoparticles Uniformly distributed TiC nanoparticles form a large number of stable interface structures in the zinc matrix, effectively hindering dislocation movement. Under external load, dislocations are pinned, bypassed, or accumulated around the TiC nanoparticles, thereby improving the yield strength and tensile strength of the zinc-copper-lithium alloy composite material. Compared with traditional micron-sized second phases, TiC nanoparticles have a smaller size and greater number, resulting in a more uniform and sustained strengthening effect.

[0034] (2) Homogenization effect on the plastic deformation process During plastic deformation, TiC nanoparticles can effectively suppress local strain concentration and promote the uniform distribution of plastic deformation within the material. This "deformation homogenization" effect significantly delays the necking and crack initiation process, enabling the zinc-copper-lithium alloy composite material to maintain high strength while still having a high elongation, thereby achieving a synergistic improvement in strength and ductility.

[0035] (3) Enhancing effect on the stability of Zn-Cu-Li alloy microstructure In the Zn-Cu-Li multi-element alloy system, the alloy phase and grain boundary structure are relatively complex and are prone to microstructure evolution during processing or service. The introduction of TiC nanoparticles can effectively inhibit grain boundary migration and alloy phase coarsening, improve the microstructure stability of the alloy after plastic processing and under long-term service conditions, and thus improve the repeatability and reliability of the material's mechanical properties.

[0036] (4) Synergistic effect of multi-scale reinforcement mechanisms By combining the solid solution and second-phase strengthening effects provided by alloying elements (Cu, Li) with the dispersion strengthening and interface strengthening effects provided by nanoparticles, a multi-scale strengthening system with synergistic effects of micron and nanoscale is formed in the Zn-2Cu-0.8Li alloy of Example 1 of this invention. This synergistic mechanism breaks through the inherent limitations between strength and ductility in the traditional zinc alloy system, and makes the material show significant improvement in key indicators such as yield strength, tensile strength and elongation.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A zinc-based alloy composite material, comprising a zinc alloy matrix and nano-reinforcing particles, characterized in that: The zinc alloy matrix is ​​composed of Zn, Cu and Li; wherein the mass percentage of Cu in the zinc alloy matrix is ​​1-2 wt%, and the mass percentage of Li in the zinc alloy matrix is ​​0.1-1.0 wt%; the volume percentage of the nano-reinforcing particles in the zinc alloy matrix is ​​<2.5 vol%; the particle size of the nano-reinforcing particles is <100 nm, and the nano-reinforcing particles are uniformly dispersed in the zinc alloy matrix.

2. The zinc-based alloy composite material according to claim 1, characterized in that: The nano-reinforcing particles are selected from any one of titanium carbide, tungsten carbide, and titanium boride; preferably, the nano-ceramic fine particles are titanium carbide.

3. The zinc-based alloy composite material according to claim 1, characterized in that: The particle size of the nano-ceramic fine particles is 60-90 nm.

4. The zinc-based alloy composite material according to claim 1, characterized in that: The zinc-based alloy contains 1-2 wt% Cu by mass and 0.8-0.9 wt% Li by mass.

5. The zinc-based alloy composite material according to claim 1, characterized in that: The zinc-based alloy composite material has a yield strength >400MPa, a tensile strength >550MPa, and an elongation >40%.

6. A method for preparing the zinc-based alloy composite material according to any one of claims 1-5, comprising the steps of vacuum melting a zinc-based base material containing nano-reinforcing particles, and alloying with a copper-lithium source to obtain a zinc-based alloy ingot or ingot, characterized in that, Also includes: The zinc-based alloy ingot or block is subjected to thermoplastic deformation treatment to obtain a zinc-based alloy composite material.

7. The preparation method according to claim 6, characterized in that: The copper-lithium source includes any one or any combination of elemental copper, elemental lithium, copper-lithium alloy, copper-lithium-zinc alloy, copper-zinc alloy, and lithium-zinc alloy.

8. The preparation method according to claim 6, characterized in that: The vacuum melting temperature is 500-650℃, and the vacuum degree is... - Pa; the alloying temperature is 500-600℃, and the time is 15-30min.

9. The preparation method according to claim 6, characterized in that: The parameters for thermoplastic deformation are controlled as follows: temperature 200-300℃, deformation ratio 1:10-1:

100.

10. The preparation method according to claim 6, characterized in that: The particle size of the nano-reinforcing particles in the zinc-based matrix is ​​50-99 nm.

11. The use of the zinc-based alloy composite material according to any one of claims 1-5 or the zinc-based alloy composite material prepared by the preparation method according to any one of claims 6-9 in the preparation of biodegradable metal medical devices.

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