Eutectic high-entropy alloy with high strength, high corrosion resistance and antibacterial ability
By regulating the Cu content and controlling the microstructure, a CrFeCoNiNb0.5Cux eutectic high-entropy alloy was prepared, which solved the problem of insufficient antibacterial and corrosion resistance of high-entropy alloys in marine environments, and achieved a eutectic high-entropy alloy with high strength and high corrosion resistance, which is suitable for marine engineering.
Patent Information
- Application Number
- CN202510590870.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2025-09-19
AI Technical Summary
Existing high-entropy alloys are difficult to combine high strength, high corrosion resistance and antibacterial ability in marine environments, and cannot effectively resist bacterial erosion, which limits their application in marine engineering.
By precisely regulating the Cu content and controlling the alloy microstructure, a CrFeCoNiNb0.5Cux (x=0.1-0.3) eutectic high-entropy alloy was prepared to form a Cu-rich FCC phase and a Nb-rich Laves phase, thereby improving the antibacterial and mechanical properties.
It achieves high strength, high corrosion resistance and excellent antibacterial ability, is suitable for marine environment, significantly improves the comprehensive performance of the alloy, is easy to operate, and is suitable for industrial production.
Smart Images
Figure CN120666233A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of metal materials, and in particular relates to a eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability. Background Art
[0002] In recent years, high-entropy alloys (HEAs) have become a research hotspot in materials science, thanks to their innovative multi-principal component design and superior overall material properties. Eutectic high-entropy alloys (EHEAs), in particular, exhibit excellent casting properties due to their unique solidification characteristics, enabling the molding of complex structures. Furthermore, their mechanical properties, including high strength and hardness, along with excellent corrosion resistance, have garnered widespread attention in a wide range of fields, including aerospace and energy. In particular, these advantages make eutectic HEAs an ideal alternative to traditional marine engineering materials, offering enormous potential for application in marine environments. However, the marine environment is special, in which there are a large number of bacteria. These bacteria attach and grow on the surface of the alloy, which can cause serious bio-corrosion. Bio-corrosion has become an important factor leading to alloy corrosion loss and engineering accidents, greatly limiting the service life and reliability of the alloy in the marine environment. Although some high-entropy alloys currently have excellent mechanical properties and conventional corrosion resistance, there are relatively few studies on eutectic high-entropy alloys with good antibacterial properties to address the problem of bio-corrosion in the marine environment. Existing alloys are difficult to effectively resist bacterial erosion while ensuring high strength and high corrosion resistance, and cannot meet the stringent requirements for material properties in fields such as marine engineering.
[0003] Therefore, developing a eutectic high-entropy alloy with high strength, high corrosion resistance and antibacterial ability has important practical significance and broad market prospects for expanding the application of eutectic high-entropy alloys in complex environments such as the ocean and solving the problem of material corrosion in actual engineering. Summary of the Invention
[0004] The purpose of the present invention is to develop a eutectic high-entropy alloy with high strength, high corrosion resistance and antibacterial ability, specifically to overcome the difficulty of existing high-entropy alloys in achieving high strength, high corrosion resistance and antibacterial properties, and to fully meet the urgent demand for high-performance alloy materials in harsh environments such as the ocean.
[0005] To achieve the above object, the present invention is implemented according to the following technical solutions: A eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability, the chemical formula of the eutectic high entropy alloy is CrFeCoNiNb 0.5 Cu x , where x=0.1-0.3. Preferably, the eutectic high entropy alloy is prepared by the following steps: S1, mixing: according to the molar ratio of each element in the chemical formula of the eutectic high entropy alloy, respectively weigh the metal raw materials of Cr, Fe, Co, Ni, Nb, and Cu, and mix them to obtain a well-proportioned raw material; S2, smelting: Place the proportioned raw materials in a water-cooled copper crucible and smelt them in a non-consumable vacuum arc furnace (VAR) under a high-purity argon protection environment; S3, remelting: After the raw materials with the right proportions are completely melted and the composition is uniform, multiple remelting operations are performed to obtain an alloy melt; S4, cooling and solidification: injecting the alloy melt into the preheated mold for cooling and solidification to obtain an alloy ingot.
[0006] Furthermore, the alloy ingots are processed into samples of corresponding specifications according to different performance test requirements.
[0007] Preferably, in step S1, the purity of the metal raw materials of Cr, Fe, Co, Ni, Nb and Cu is greater than 99.9%.
[0008] Preferably, in step S2, the purity of the argon in the high-purity argon protection environment is greater than 99.99%.
[0009] Preferably, in step S3, the remelting is performed at least 5 times.
[0010] Preferably, the yield strength of the eutectic high entropy alloy is greater than 996 MPa, and the plastic strain is greater than 9.8%.
[0011] Preferably, the eutectic high entropy alloy is tested in a 3.5 wt% NaCl aqueous solution using a saturated calomel electrode as a reference electrode, and its pitting potential is not less than 0.36 V.
[0012] Preferably, the 18-hour antibacterial rate of the eutectic high entropy alloy against Pseudomonas aeruginosa is greater than 15% when tested by the plate count method.
[0013] Working principle of the invention: Since copper (Cu) plays an important role in enhancing the antibacterial properties of alloys, the inventors found that by precisely regulating the Cu content and finely controlling the microstructure of the alloy, the performance of the eutectic high entropy alloy with a specific composition can be significantly optimized. 0.5 Cu xWhen the Cu content in the alloy varies within the range of x = 0.1-0.3, the distribution and characteristics of the FCC phase and Laves phase within the alloy will change accordingly. The enrichment of Cu in the FCC phase can effectively improve the antibacterial properties of the alloy. At the same time, by rationally controlling the morphology and distribution of the Laves phase, the mechanical properties and corrosion resistance of the alloy can be enhanced. In terms of microstructure, the alloy exhibits a typical eutectic structure, including a Cu-rich FCC phase and a Nb-rich Laves phase. This unique microstructure provides an important structural basis for the alloy's high strength, high corrosion resistance, and antibacterial ability.
[0014] Beneficial effects of the present invention: (1) Excellent comprehensive performance: The eutectic high entropy alloy of the present invention combines high strength, high corrosion resistance and excellent antibacterial ability. Its corrosion resistance is comparable to that of stainless steel, and its antibacterial activity is significant. It can easily survive in harsh environments such as the ocean.
[0015] (2) Clever composition design: By precisely controlling the Cu content, its antibacterial potential is fully exploited, and the corrosion resistance of the eutectic high-entropy alloy is simultaneously improved with minimal interference to the mechanical properties.
[0016] (3) Simple preparation process: The eutectic high entropy alloy of the present invention adopts conventional processes such as vacuum arc melting, which is convenient to operate and easy to control, paving the way for industrial large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 The comparison results of the eutectic high entropy alloys in Example 1 and Example 2 of the present invention are shown, wherein: Figure 1 (a) is a comparison of X-ray diffraction (XRD) patterns of the eutectic high entropy alloys in Example 1 and Example 2; Figure 1 (b) and Figure 1 (c) Backscattered images of the eutectic high entropy alloy in Example 1 at different magnifications; Figure 1 (d) and Figure 1 (e) is the backscattered image of the eutectic high entropy alloy in Example 2 at different magnifications; Figure 1 (f) is the phase diagram of the eutectic high entropy alloy in Example 1; Figure 1 (g) is the phase diagram of the eutectic high entropy alloy in Example 2; Figure 1 (h) Inverse pole figure (IPF) image of the eutectic high entropy alloy in Example 1; Figure 1 (i) Inverse pole figure (IPF) image of the eutectic high-entropy alloy in Example 2; Figure 1 (j) is the FCC phase of the eutectic high entropy alloy in Example 2; Figure 1 (k) is an IPF image of the Laves phase of the eutectic high entropy alloy in Example 2; Figure 2 The Tafel plot comparison results of the eutectic high entropy alloy in Example 1 and Example 2 of the present invention, wherein Ecorr is the self-corrosion potential and Epit is the pitting potential; Figure 3 The strength comparison results of the eutectic high entropy alloys in Example 1 and Example 2 of the present invention are shown, wherein: Figure 3 (a) is a comparison diagram of typical stress-strain curves of eutectic high entropy alloys in Example 1 and Example 2; Figure 3 (b) is a comparison of the yield strength of the eutectic high entropy alloys in Example 1 and Example 2; Figure 3 (c) is a comparison diagram of the plasticity of the eutectic high entropy alloys in Example 1 and Example 2; Figure 4 The antibacterial rate test results of the eutectic high entropy alloy in Example 1 and Example 2 of the present invention are shown, wherein: Figure 4 (a) is a graph showing the bacterial growth observed by the plate count method after the surface of the eutectic high entropy alloy sample in Example 1 was exposed to the bacterial solution for 18 hours; Figure 4 (b) is a graph showing the bacterial growth observed by the plate count method after the surface of the eutectic high entropy alloy sample in Example 2 was exposed to the bacterial solution for 18 hours; Figure 4 (c) The bacterial growth observation graph of the blank sample surface after 18 hours of interaction with the bacterial solution was measured by the spread plate counting method; Figure 4 (d) is a comparison chart of the antibacterial rates of the eutectic high entropy alloys in Example 1 and Example 2. DETAILED DESCRIPTION
[0018] The present invention will be further described below with reference to specific embodiments. The illustrative embodiments and descriptions of the present invention are intended to explain the present invention but are not intended to limit the present invention.
[0019] All raw materials of the present invention are not particularly limited in their sources and can be purchased from the market or prepared according to conventional methods well known to those skilled in the art.
[0020] The devices used in the present invention are not particularly limited and can be devices commonly used in the art.
[0021] Example 1: This embodiment proposes a eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability, whose chemical formula is CrFeCoNiNb 0.5 Cu 0.1 , the preparation process of the eutectic high entropy alloy is as follows: (1) According to the chemical formula CrFeCoNiNb 0.5 Cu 0.1 The molar ratio of each element in the mixture is precisely weighed. Metal raw materials of Cr, Fe, Co, Ni, Nb and Cu with a purity of 99.9% are mixed to obtain a well-proportioned raw material. (2) Place the proportioned raw materials in a water-cooled copper crucible and smelt them in a non-consumable vacuum arc furnace (VAR) under the protection of 99.99% pure argon gas, using an electric arc to completely melt the raw materials and mix them evenly; (3) Remelting is performed five times in a water-cooled copper crucible to ensure uniform composition and obtain an alloy melt; (4) The alloy melt is poured into a preheated mold and cooled and solidified to obtain an alloy ingot, which is recorded as Cu0.1.
[0022] The performance test of Cu0.1 yielded the following results: (1) Microstructure observation: With the help of XRD, SEM, EBSD and other techniques, the microstructure of the alloy was observed, including phase composition, morphology and distribution. It was found that it is a typical FCC+Laves type lamellar eutectic high entropy alloy, in which Cu is enriched in the FCC phase.
[0023] (2) Corrosion resistance test: In a 3.5 wt% NaCl aqueous solution, the corrosion resistance of the alloy was measured using electrochemical polarization curves and other methods. The self-corrosion potential, corrosion current density, and pitting potential were evaluated. It was found that the pitting potential could reach 1.05 V (reference electrode: saturated calomel electrode).
[0024] (3) Mechanical property test: The compression properties of the alloy were measured using a universal material testing machine, and the yield strength was determined to be 1198 (±60) MPa and the plastic strain was 11.5 (±1.7)%.
[0025] (4) Antibacterial performance test: The plate count method was used to measure the antibacterial rate of Pseudomonas aeruginosa, which was 15% after 18 hours.
[0026] Example 2: The only difference between this embodiment and embodiment 1 is that the chemical formula of the eutectic high entropy alloy is CrFeCoNiNb 0.5 Cu 0.3 , the alloy ingot obtained in step (4) is recorded as Cu0.3.
[0027] The performance test of Cu0.3 obtained the following results: (1) Microstructure observation: With the help of XRD, SEM, EBSD and other techniques, the microstructure of the alloy was observed, including phase composition, morphology and distribution. It was found that it is a typical FCC+Laves type lamellar eutectic high entropy alloy, in which Cu is enriched in the FCC phase.
[0028] (2) Corrosion resistance test: In a 3.5 wt% NaCl aqueous solution, the corrosion resistance of the alloy was measured using electrochemical polarization curves and other methods. The self-corrosion potential, corrosion current density, and pitting potential were evaluated. It was found that the pitting potential could reach 0.36 V (reference electrode: saturated calomel electrode).
[0029] (3) Mechanical property test: The compression properties of the alloy were measured using a universal material testing machine, and the yield strength was determined to be 1104 (±108) MPa and the plastic strain was 16.7 (±3.0)%.
[0030] (4) Antibacterial performance test: The plate count method was used to measure the antibacterial rate of Pseudomonas aeruginosa, which was 40% after 18 hours.
[0031] In order to further clarify the technical effects achieved by the present invention, Figure 1 The comparative results of the eutectic high entropy alloys in Example 1 and Example 2 are given in FIG. , wherein: Figure 1 (a) is a comparison of X-ray diffraction (XRD) patterns of the eutectic high entropy alloys in Example 1 and Example 2; Figure 1 (b) and Figure 1 (c) Backscattered images of the eutectic high entropy alloy in Example 1 at different magnifications; Figure 1 (d) and Figure 1 (e) is the backscattered image of the eutectic high entropy alloy in Example 2 at different magnifications; Figure 1 (f) is the phase diagram of the eutectic high entropy alloy in Example 1; Figure 1 (g) is the phase diagram of the eutectic high entropy alloy in Example 2; Figure 1 (h) Inverse pole figure (IPF) image of the eutectic high entropy alloy in Example 1; Figure 1 (i) Inverse pole figure (IPF) image of the eutectic high-entropy alloy in Example 2; Figure 1 (j) is the FCC phase of the eutectic high entropy alloy in Example 2; Figure 1(k) is an IPF image of the Laves phase of the eutectic high entropy alloy in Example 2; Figure 2 The Tafel plot comparison results of the eutectic high entropy alloys in Example 1 and Example 2 are given, where Ecorr is the self-corrosion potential and Epit is the pitting potential; Figure 3 The strength comparison results of the eutectic high entropy alloys in Example 1 and Example 2 are given in FIG, wherein: Figure 3 (a) is a comparison diagram of typical stress-strain curves of eutectic high entropy alloys in Example 1 and Example 2; Figure 3 (b) is a comparison of the yield strength of the eutectic high entropy alloys in Example 1 and Example 2; Figure 3 (c) is a comparison diagram of the plasticity of the eutectic high entropy alloys in Example 1 and Example 2; Figure 4 The comparative results of the antibacterial rate detection of the eutectic high entropy alloy in Example 1 and Example 2 are given in the table, wherein: Figure 4 (a) is a graph showing the bacterial growth observed by the plate count method after the surface of the eutectic high entropy alloy sample in Example 1 was exposed to the bacterial solution for 18 hours; Figure 4 (b) is a graph showing the bacterial growth observed by the plate count method after the surface of the eutectic high entropy alloy sample in Example 2 was exposed to the bacterial solution for 18 hours; Figure 4 (c) The bacterial growth observation graph of the blank sample surface after 18 hours of interaction with the bacterial solution was measured by the spread plate counting method; Figure 4 (d) is a comparison chart of the antibacterial rates of the eutectic high entropy alloys in Example 1 and Example 2.
[0032] Through the above comparison, it can be seen that the present invention has excellent comprehensive performance, can combine high strength, high corrosion resistance and excellent antibacterial ability in one, its corrosion resistance is comparable to that of stainless steel, its antibacterial activity is significant, and it can easily survive in harsh environments such as the ocean. And the composition design is ingenious: by precisely controlling the Cu content, its antibacterial potential is fully tapped, and the corrosion resistance of the eutectic high entropy alloy is simultaneously improved, with little interference with mechanical properties. In addition, the eutectic high entropy alloy of the present invention adopts conventional processes such as vacuum arc melting, which is convenient to operate and easy to control, paving the way for industrial large-scale production.
[0033] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Any technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.
Claims
1. A eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability, characterized in that: The chemical formula of the eutectic high entropy alloy is CrFeCoNiNb 0.5 Cu x , where x=0.1-0.
3.
2. The eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability according to claim 1, characterized in that: The eutectic high entropy alloy is prepared by the following steps: S1, mixing: according to the molar ratio of each element in the chemical formula of the eutectic high entropy alloy, respectively weigh the metal raw materials of Cr, Fe, Co, Ni, Nb, and Cu, and mix them to obtain a well-proportioned raw material; S2, smelting: placing the proportioned raw materials in a water-cooled copper crucible and smelting them in a non-consumable vacuum arc furnace under a high-purity argon protection environment; S3, remelting: After the raw materials with the right proportions are completely melted and the composition is uniform, multiple remelting operations are performed to obtain an alloy melt; S4, cooling and solidification: injecting the alloy melt into the preheated mold for cooling and solidification to obtain an alloy ingot.
3. The eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability according to claim 2, characterized in that: In step S1, the purity of the metal raw materials of Cr, Fe, Co, Ni, Nb, and Cu is greater than 99.9%.
4. The eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability according to claim 2, characterized in that: In step S2, the purity of the argon in the high-purity argon protection environment is greater than 99.99%.
5. The eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability according to claim 2, characterized in that: In step S3, the remelting is performed at least 5 times.
6. A eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability according to any one of claims 1 to 5, characterized in that: The yield strength of the eutectic high entropy alloy is greater than 996 MPa, and the plastic strain is greater than 9.8%.
7. A eutectic high entropy alloy with high strength, high corrosion resistance and antibacterial ability according to any one of claims 1 to 5, characterized in that: The eutectic high entropy alloy is tested in a 3.5 wt % NaCl aqueous solution using a saturated calomel electrode as a reference electrode, and its pitting potential is not less than 0.36 V.
8. The eutectic high entropy alloy having high strength, high corrosion resistance and antibacterial ability according to any one of claims 1 to 5, characterized in that: According to the plate count method test, the 18-hour antibacterial rate of the eutectic high entropy alloy against Pseudomonas aeruginosa is greater than 15%.