Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy, and preparation method and application thereof

Abstract

The application provides a Fe-Cr-Ni-Cu-Zn-Al multi-main element alloy and a preparation method and application thereof, the Fe-Cr-Ni-Cu-Zn-Al multi-main element alloy comprises the following components in percentage by mass: Ni: 12-16%, Cr: 20-25%, Cu: 16-20%, Zn: 1-6%, Al: 0.1-2%, and the balance is Fe and inevitable impurities. The application solves the problems of corrosion and marine biological fouling from the material itself, and through the innovation of new material design and manufacturing process, the metal structural part has excellent corrosion resistance and biological adhesion resistance, does not need to rely on external auxiliary means, is suitable for complex and special-shaped structural parts, can significantly reduce the maintenance cost, prolong the service life of equipment, and reduces the negative influence on the marine environment.

Description

[Technical Field]

[0001] This invention belongs to the fields of new metallic materials and additive manufacturing, specifically relating to a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy, its preparation method, and its application. [Background Technology]

[0002] Key metal structural components in marine engineering equipment are exposed to harsh marine environments for extended periods, facing severe corrosion and biofouling problems. Corrosion reduces material strength and shortens equipment lifespan, while biofouling increases fluid resistance, affects equipment performance, and can even clog piping systems. These issues not only increase maintenance costs but also threaten the safety and reliability of the equipment. Therefore, developing technologies to address corrosion and biofouling is crucial for improving the durability and operational efficiency of marine engineering equipment.

[0003] Currently, the main solutions to corrosion and biofouling problems in marine engineering equipment rely on external auxiliary methods, such as anti-corrosion coatings, electrochemical protection, and mechanical removal. However, these methods have certain limitations in practical applications. For example, most anti-corrosion coatings have relatively limited functions, are susceptible to mechanical damage or fatigue failure, and are complex to apply and costly to maintain. Furthermore, most antifouling coatings contain harmful substances, negatively impacting the marine ecosystem. Mechanical removal methods (such as scraping and high-pressure water cleaning) are not only complex and costly but can also damage structural surfaces, making them particularly unsuitable for complex or irregularly shaped components. Therefore, for complex or irregularly shaped components in marine engineering equipment, there is an urgent need to develop materials and methods that combine good corrosion resistance with the ability to inhibit marine biofouling, fundamentally alleviating the corrosion and biofouling problems of metal components.

[0004] Therefore, it is necessary to study a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy, its preparation method, and its application to address the shortcomings of existing technologies and solve or mitigate one or more of the aforementioned problems. [Summary of the Invention]

[0005] In view of this, the present invention provides a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy, its preparation method and application. The present invention solves the problems of corrosion and marine biofouling from the material itself. Through the innovation of new material design and manufacturing process, the metal structural components have excellent corrosion resistance and anti-biofouling performance, without relying on external auxiliary means. It is not only suitable for complex and irregular structural components, but also significantly reduces maintenance costs, extends the service life of equipment, and reduces the negative impact on the marine environment.

[0006] This invention provides a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy, the composition of which by mass percentage is: Ni: 12-16%, Cr: 20-25%, Cu: 16-20%, Zn: 1%-6%, Al: 0.1-2%, with the balance being Fe and unavoidable impurities.

[0007] In addition to the aspects and any possible implementations described above, an implementation is further provided in which the Fe-Cr-Ni-Cu-Zn-Al multi-principal alloy composition by mass percentage is: Ni: 12-15%, Cr: 20-25%, Cu: 16-20%, Zn: 2%-5%, Al: 0.5-1.2%, with the balance being Fe and unavoidable impurities.

[0008] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the multi-principal alloy is directly formed from alloy powder of corresponding mass percentages using laser additive manufacturing technology.

[0009] As described above and in any possible implementation, a further implementation is provided in which the multi-principal element alloy exhibits a self-corrosion current density of 80-200 nA / cm² in a neutral salt solution. 2 Within 12 hours, the antibacterial rate against typical marine fouling symbiotic bacteria reached 99.5%; within 48 hours, the attachment rate of marine algal fouling organisms was less than 5%.

[0010] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the multi-principal element alloy has a yield strength of 350-500 MPa, an elongation of 30-40%, and an impact toughness exceeding 200 J / cm. 2 .

[0011] In accordance with the aspects described above and any possible implementations, a method for preparing a Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy is further provided, for preparing the Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy, the preparation method comprising the following steps:

[0012] S1: Prepare multi-principal alloy powder according to the preset composition ratio, wherein the preset composition ratio is: mass percentage Ni: 12-16%, Cr: 20-25%, Cu: 16-20%, Zn: 1%-6%, Al: 0.1-2%, with the balance being Fe and unavoidable impurities;

[0013] S2: The multi-principal-element alloy powder in S1 is placed in a vacuum drying oven for drying to obtain the first alloy powder;

[0014] S3: The first alloy powder is formed by laser additive manufacturing using a laser powder bed melting method.

[0015] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the process parameters of the laser powder bed melting method in S3 are: laser power 60-100W, scanning speed 800-1000mm / s, scanning spacing 0.04-0.06mm, layer thickness 0.02mm, interlayer rotation angle of 67° or 123°, and protective gas of argon.

[0016] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the first alloy powder in S3 is prepared by an inert gas atomization method and has a particle size of 30-53 μm.

[0017] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the drying process in S2 specifically involves drying at 85-95°C for 2-3 hours.

[0018] In addition to the aspects described above and any possible implementation, an application of Fe-Cr-Ni-Cu-Zn-Al multi-principal alloy is further provided, in which complex, lightweight and high-performance metallic irregular structural parts in marine engineering equipment are prepared by using the Fe-Cr-Ni-Cu-Zn-Al multi-principal alloy, so as to improve their corrosion resistance and marine biofouling inhibition performance.

[0019] Compared with the prior art, the present invention can achieve the following technical effects:

[0020] (1) This invention provides a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy prepared by laser powder bed melting. The alloy has a yield strength of 350-500MPa, an elongation of 30-40%, and an impact toughness of more than 200J / cm2, which is significantly higher than that of 316L stainless steel.

[0021] (2) The present invention provides a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy prepared by laser powder bed melting. The alloy has a self-corrosion current density of 80-200 μA / cm2 in neutral salt solution, and the antibacterial rate against typical marine fouling symbiotic bacteria reaches 99.5% within 12h; and it has a significant inhibitory effect on the attachment of marine algal fouling organisms within 48h, with an attachment rate of less than 5%.

[0022] (3) The Fe-Cr-Ni-Cu-Zn-Al multi-principal alloy and its preparation method provided by the present invention can directly form complex, lightweight and high-performance metal irregular structural parts in one step without any post-processing.

[0023] (4) The laser powder bed molten Fe-Cr-Ni-Cu-Zn-Al multi-principal alloy provided by the present invention has good mechanical properties, corrosion resistance and the function of inhibiting the attachment of marine organisms. It can be used as a structural component material and preparation method in the manufacturing of key components of marine engineering equipment.

[0024] Of course, any product implementing this invention does not necessarily need to achieve all of the technical effects described above at the same time. [Attached Image Description]

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a flowchart illustrating the preparation process of a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy according to an embodiment of the present invention.

Detailed Implementation Methods

[0027] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0030] This invention provides a Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy, the composition of which by mass percentage is: Ni: 12-16%, Cr: 20-25%, Cu: 16-20%, Zn: 1%-6%, Al: 0.1-2%, with the balance being Fe and unavoidable impurities.

[0031] The Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy composition by mass percentage is as follows: Ni: 12-15%, Cr: 20-25%, Cu: 16-20%, Zn: 2%-5%, Al: 0.5-1.2%, with the balance being Fe and unavoidable impurities.

[0032] The multi-principal alloy is directly formed from alloy powder of corresponding mass percentages using laser additive manufacturing technology.

[0033] In this invention, the excellent comprehensive performance of the Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy is mainly attributed to the rational design of its components and its coordination with the preparation method. Cu is crucial for ensuring the alloy's resistance to marine biofouling; however, under traditional preparation methods, the solubility of Cu in Fe-based alloys is limited. Excessive solubility leads to a large amount of Cu-rich precipitates, reducing the machinability of the as-cast alloy; insufficient solubility makes it difficult to significantly kill bacteria and improve biofouling. Therefore, the Cu content and its synergistic effect with other elements in the alloy design, along with the preparation process, are of paramount importance.

[0034] This invention cleverly designs the matching of Ni and Zn element content and preparation process, specifically in the following ways: First, it utilizes the characteristics of laser powder bed melting technology to significantly increase the solubility of Cu, ensuring bactericidal and antifouling properties; second, it leverages the similar atomic radii, electronegativity, and crystal structures of Ni and Cu to effectively promote the formation of CuNi solid solution; third, given the similar electronegativity of Zn and Cu, by effectively controlling the Zn element content, it forms an FCC solid solution with Cu during rapid solidification, further expanding the solubility of Cu and promoting the overall single-phase structure of the alloy, ensuring the overall corrosion resistance and formability of the alloy. Simultaneously, Zn is also a typical antibacterial element, which can synergistically enhance antibacterial and antifouling effects with Cu; fourth, using Zn as a sacrificial anode can effectively protect the alloy's corrosion resistance. However, excessive Zn may increase alloy brittleness and affect its formability, and the introduction of excessive Zn can lead to grain boundary segregation or the formation of coarse β phases, reducing the alloy's plasticity and corrosion resistance. Because Zn has a low potential and a large atomic radius, the introduction of a small amount of Al can increase the alloy potential, reduce the dissolution rate of Zn, and enhance the overall corrosion resistance of the alloy. However, the content of Al needs to be carefully designed to avoid forming intermediate phases with other elements, which would increase the tendency of galvanic corrosion in the alloy. Finally, with the help of laser powder bed melting technology, the layer-by-layer deposition and rapid cooling control of the large number of subgrain boundaries formed inside the alloy can provide an effective channel for the diffusion of corrosion-resistant and antibacterial elements to reach the alloy surface, thereby achieving efficient and long-lasting corrosion resistance and antifouling function.

[0035] In addition, the Cr element in the alloy ensures the overall corrosion resistance of the alloy system; the single-phase structure and a large number of fine grains of the alloy provide a guarantee for the excellent mechanical properties of the alloy.

[0036] The improved mechanical properties, corrosion resistance, and antifouling properties of the multi-principal alloy in this invention are mainly achieved through the combined effect of the design of its own composition and the reasonable matching of the preparation method. It is not determined by any single element, but all of them are indispensable. Of course, it cannot be obtained by just a limited number of experiments.

[0037] The self-corrosion current density of the multi-principal element alloy in neutral salt solution is 80-200 nA / cm². 2 Within 12 hours, the antibacterial rate against typical marine fouling symbiotic bacteria reached 99.5%; within 48 hours, the attachment rate of marine algal fouling organisms was less than 5%.

[0038] The multi-principal element alloy has a yield strength of 350-500 MPa, an elongation of 30-40%, and an impact toughness exceeding 200 J / cm. 2 .

[0039] like Figure 1 As shown, the present invention also provides a method for preparing Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloys, which are used to prepare the Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloys. The preparation method includes the following steps:

[0040] S1: Prepare multi-principal alloy powder according to the preset composition ratio, wherein the preset composition ratio is: mass percentage Ni: 12-16%, Cr: 20-25%, Cu: 16-20%, Zn: 1%-6%, Al: 0.1-2%, with the balance being Fe and unavoidable impurities;

[0041] S2: The multi-principal-element alloy powder in S1 is placed in a vacuum drying oven for drying to obtain the first alloy powder;

[0042] S3: The first alloy powder is formed by laser additive manufacturing using a laser powder bed melting method.

[0043] The process parameters of the laser powder bed melting method in S3 are as follows: laser power 60-100W, scanning speed 800-1000mm / s, scanning interval 0.04-0.06mm, layer thickness 0.02mm, interlayer rotation angle 67° or 123°, and protective gas argon.

[0044] The first alloy powder in S3 is prepared by an inert gas atomization method, and has a particle size of 30-53 μm.

[0045] The drying process in S2 specifically involves drying at 85-95℃ for 2-3 hours.

[0046] This invention also provides an application of Fe-Cr-Ni-Cu-Zn-Al multi-principal alloy, which is used to prepare complex, lightweight and high-performance metallic irregular structural parts for marine engineering equipment, thereby improving their corrosion resistance and inhibition of marine biofouling.

[0047] Example 1:

[0048] The specific implementation process of this invention is as follows:

[0049] (1) Based on the composition information shown in Table 1, alloy powder was prepared by inert gas atomization. The powder impurities were less than 0.05 wt.%. The powder was sieved, and the particle size range was selected to be 30-53 μm. 316 stainless steel substrate was selected as the substrate, and the surface was pretreated to remove dirt before printing.

[0050] (2) Alloy preparation was carried out using a laser powder bed melting equipment (EOS M100), with argon as the protective gas, and alloy forming was performed according to the process parameters shown in Table 2.

[0051] (2) Quasi-static tensile mechanical property testing: A CMT4305 microcomputer electronic universal testing machine was used for room temperature quasi-static tensile testing. The test specimens were tested according to the method for room temperature tensile testing of metallic materials. The specimen thickness was 1.0 mm, the width was 3.14 mm, the parallel section length was 10 mm, the gauge length was greater than 5 mm, and the strain rate was 1×10⁻⁶. -3 s -1 .

[0052] (3) Pendulum impact test: WanCe PIT752H testing machine, length 55mm, cross section 10mm×10mm, V-shaped or U-shaped opening, impact speed 5.2m / s, maximum impact energy 450J.

[0053] (4) Antibacterial performance test: According to the relevant standards of GB / T 2591-2003 "Test Methods and Antibacterial Effects of Antibacterial Plastics", the antibacterial rate of the laser additive manufacturing multi-principal alloy shown in the example against typical bacteria (Pseudomonas aeruginosa) in the marine environment was quantitatively tested. The concentration of bacteria in the co-culture was set at (1-2) × 10⁻⁶. 8 The concentration of CFU / mL was measured, and the incubation time was 12 hours. The results of the antibacterial performance test are shown in Table 3. The antibacterial rate was calculated using the following formula: Antibacterial rate (%) = [(Number of viable bacteria on the surface of the control alloy sample - Number of viable bacteria on the surface of the multi-principal element alloy) / Number of viable bacteria on the surface of the control alloy sample] × 100%. The control alloy was a conventional cast 316L stainless steel block material.

[0054] (5) Biofouling inhibition performance test: Adhesion experiment was conducted using a typical marine algae, Navicula naviculae, which was cultured in a constant temperature shaking incubator at 22℃. A concentration of (5-6)×10⁻¹ mL of biofouling agent was used. 6 mL -1 The samples were submerged in a seawater suspension of *Navicula* and incubated in a 22°C constant-temperature shaking incubator for 48 hours. After removal, the samples were rinsed with sterile artificial seawater to remove any unattached *Navicula* algae. The samples were then fixed with 2.5% glutaraldehyde prepared from the artificial seawater at 4°C for 4 hours. The samples were photographed using a fluorescence microscope, and the *Navicula* coverage area was quantitatively analyzed using Image software to calculate the attachment rate. The test results are shown in Table 3.

[0055] (5) Corrosion resistance test: Using an electrochemical workstation, the potentiodynamic polarization curves of the alloy in a 3.5 wt.% NaCl salt solution were tested to obtain the corrosion current density and self-corrosion potential, thereby quantitatively evaluating the corrosion resistance of the multi-principal element alloy. The test results are shown in Table 3.

[0056] Table 1. Chemical composition of powders used for preparing multi-principal element alloys in the examples and comparative examples.

[0057]

[0058] Table 2. Setting of process parameters for the preparation of multi-principal element alloys in the examples and comparative examples.

[0059]

[0060] Table 3. Experimental results of relevant performance tests for the embodiments and comparative examples.

[0061]

[0062]

[0063] The foregoing has provided a detailed description of a Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy, its preparation method, and its applications, as provided in the embodiments of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the methods and core ideas of this application; furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

[0064] Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising / including but not limited to". "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of illustrating the general principles of this application and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0065] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0066] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0067] The foregoing description illustrates and describes several preferred embodiments of this application. However, as previously stated, it should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the application concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. A Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy, characterized in that: Its composition by mass percentage is: Ni: 12-16%, Cr: 20-25%, Cu: 16-20%, Zn: 1%-6%, Al: 0.1-2%, with the balance being Fe and unavoidable impurities. The Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy is obtained by the following preparation method, which includes the following steps: S1: Prepare multi-principal alloy powder according to the preset composition ratio, wherein the preset composition ratio is: mass percentage Ni: 12-16%, Cr: 20-25%, Cu: 16-20%, Zn: 1%-6%, Al: 0.1-2%, with the balance being Fe and unavoidable impurities; S2: The multi-principal-element alloy powder in S1 is placed in a vacuum drying oven for drying to obtain the first alloy powder; S3: The first alloy powder is formed by laser additive manufacturing using a laser powder bed melting method; The process parameters of the laser powder bed melting method in S3 are as follows: laser power 60-100W, scanning speed 800-1000mm / s, scanning interval 0.04-0.06mm, layer thickness 0.02mm, interlayer rotation angle 67° or 123°, and protective gas argon.

2. The Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy according to claim 1, characterized in that, The Fe-Cr-Ni-Cu-Zn-Al multi-principal-element alloy composition by mass percentage is as follows: Ni: 12-15%, Cr: 20-25%, Cu: 16-20%, Zn: 2%-5%, Al: 0.5-1.2%, with the balance being Fe and unavoidable impurities.

3. The Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy according to claim 1, characterized in that, The multi-principal element alloy has a self-corrosion current density of 80-200 nA / cm 2 The antibacterial rate of the alloy to typical marine symbiotic bacteria reaches 99.5% within 12 hours, and the attachment rate of marine algal fouling organisms is less than 5% within 48 hours.

4. The Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy according to claim 1, characterized in that, The multi-principal element alloy has a yield strength of 350-500 MPa, an elongation of 30-40%, and an impact toughness exceeding 200 J / cm. 2 .

5. The Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy according to claim 1, characterized in that, The first alloy powder in S3 is prepared by an inert gas atomization method, and has a particle size of 30-53 μm.

6. The Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy according to claim 1, characterized in that, The drying process in S2 specifically involves drying at 85-95℃ for 2-3 hours.

7. An application of a Fe-Cr-Ni-Cu-Zn-Al multi-principal element alloy, characterized in that, Complex, lightweight, and high-performance metallic irregular structural components for marine engineering equipment can be prepared using Fe-Cr-Ni-Cu-Zn-Al multi-principal alloys as described in any one of claims 1-6, thereby improving their corrosion resistance and ability to inhibit marine biofouling.

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