Wear-resistant and corrosion-resistant multi-principal-element alloy as well as preparation method and application thereof

Abstract

The invention provides a wear-resistant and corrosion-resistant multi-principal-element alloy as well as a preparation method and application of the wear-resistant and corrosion-resistant multi-principal-element alloy. The multi-principal element alloy is composed of five elements of Ni, Co, Al, Cr and Fe. Or, the alloy is composed of four elements of Ni, Co, Al and Cr. The multi-principal-element alloy provided by the technical scheme of the invention has a near eutectic cellular tissue structure, the FCC phase movable slip systems of the cellular outer layer are many, the plasticity is good, the BCC / B2 coherent reticular tissue movable slip systems of the cellular inner part are few, and the dislocation motion is hindered by a high-density coherent interface, so that a cellular soft-hard combined structure with soft edge and hard inner part is formed; the volume fraction of the BCC / B2 coherent reticular structure phase can be increased by increasing the content of the chromium element and reducing the content of the iron element, so that the hardness of the alloy is improved; and meanwhile, the potential difference of each phase can be reduced through component regulation and control, and the stability of a passivation film is improved, so that the common galvanic corrosion rate in a traditional multi-phase alloy is reduced, and the corrosion resistance of the alloy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and in particular to a wear-resistant and corrosion-resistant multi-principal-element alloy and a preparation method and application thereof. Background Art

[0002] The friction pair components of marine equipment are subject to the interaction of corrosion caused by chemical / electrochemical factors and friction and wear caused by mechanical factors, which accelerates the damage and failure of components. For example, the key friction pair components of seawater plunger pumps and key components of ship power systems all have serious corrosion and wear early failure problems, which has become a bottleneck restricting the efficient, stable and long-life service of the new generation of marine equipment.

[0003] Propeller materials for marine vessels require high strength, toughness, good processability (such as casting properties), and corrosion resistance. Materials primarily include copper alloys, cast iron, cast steel, and titanium alloys. Copper alloys are the primary material for cast marine propellers. However, the limited strength and surface hardness of copper alloys restrict their use under high-load and high-wear conditions.

[0004] In recent years, emerging multi-principal alloy materials have demonstrated excellent mechanical properties, corrosion resistance, wear resistance, and oxidation resistance, showing potential application value in the field of marine engineering materials. Among them, multi-principal alloys with a multiphase structure contain hard and soft phases, achieving a balanced match between strength and toughness, with good toughness and high hardness, and exhibiting excellent wear resistance. However, due to the difference in the composition of the two phases, there is a potential difference in the corrosive environment, forming galvanic corrosion, which leads to localized surface corrosion. In particular, when the size of the low-potential alloy phase is large, the corrosion gradually penetrates the surface of the material and causes continuous damage to the material.

[0005] Based on the above technical problems, in order to meet the service requirements of key friction pair components and high-performance propellers of the new generation of marine engineering equipment, it is urgently necessary to provide an alloy material with high hardness, wear resistance and corrosion resistance to solve the problem of local corrosion of alloy materials caused by galvanic corrosion formed by potential difference in the existing technology. Summary of the Invention

[0006] In view of this, in order to solve the above problems, the present invention provides a wear-resistant and corrosion-resistant multi-principal-component alloy material and a preparation method and application thereof.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a wear-resistant and corrosion-resistant multi-principal alloy composed of five elements: Ni, Co, Al, Cr, and Fe; or composed of four elements: Ni, Co, Al, and Cr.

[0008] Preferably, the general formula of the multi-principal alloy material is Ni 34.5 Co16.5 Al 16.5 Cr x Fe y , wherein 27.5≤x≤32.5, 0≤y≤5.0, x+y=32.5, and x and y represent the atomic percentage of the element.

[0009] Preferably, the multi-principal element alloy is an in-situ composite material with a near-eutectic cellular structure, comprising three cubic phases: face-centered cubic phase (FCC phase), body-centered cubic phase (BCC phase) and ordered body-centered cubic phase (B2 phase); wherein the outer layer of the cellular structure is the FCC phase, and the interior of the cellular structure is a BCC / B2 coherent lattice structure formed by the BCC phase and the B2 phase, thereby obtaining a cellular structure with a soft edge and a hard interior and a combination of soft and hard.

[0010] Preferably, in the cellular structure, when the chromium content increases and the iron content decreases, the volume fraction of the FCC phase decreases and the volume fraction of the BCC / B2 coherent network phase increases.

[0011] Preferably, the micro-Vickers hardness of the wear-resistant and corrosion-resistant multi-principal component alloy is between 330 and 560 HV. High hardness is beneficial to improving the wear resistance of the alloy, which is better than the common aluminum bronze used for propellers. Thanks to the near-eutectic cellular structure of the alloy, the FCC phase in the outer layer of the cell has many movable slip systems and good plasticity, while the BCC / B2 coherent network structure inside the cell has few movable slip systems and high-density coherent interfaces that hinder dislocation movement, thus forming a soft-hard combination structure with soft cell edges and hard interiors. Based on this, by increasing the chromium content and reducing the iron content, the volume fraction of the BCC / B2 coherent organizational phase can be increased, thereby increasing the hardness of the alloy. Therefore, the present invention can obtain a multi-principal component alloy with high hardness and wear resistance by adjusting the content of chromium and iron elements in the alloy.

[0012] Furthermore, although the multi-principal component alloy has three phases: face-centered cubic phase (FCC), body-centered cubic phase (BCC) and ordered body-centered cubic phase (B2), the potential difference between the phases can be reduced by controlling the composition, thereby reducing the galvanic corrosion rate commonly seen in traditional multi-phase alloys and improving the electrochemical corrosion performance of the multi-principal component alloy. As a result, the self-corrosion potential of the multi-principal component alloy provided by the technical solution of the present invention in a 3.5wt.% NaCl (simulated seawater) solution is significantly higher than that of common propeller aluminum bronze, and the corrosion current is also significantly lower than that of common propeller aluminum bronze, showing excellent corrosion resistance.

[0013] As another purpose, the present invention also provides a method for preparing the above-mentioned wear-resistant and corrosion-resistant multi-principal component alloy, comprising mixing the raw materials of each component and then melting them in a high vacuum non-consumable arc melting furnace to obtain the wear-resistant and corrosion-resistant multi-principal component alloy.

[0014] Furthermore, the order of placing the raw materials of each component is Al at the bottom, Cr and Fe in the middle, and Co and Ni at the top.

[0015] Furthermore, the working condition of the high vacuum non-consumable arc melting furnace is to evacuate to 5×10 -3 Pa, and then backfill with inert gas to 4×10 2 Pa~6×10 2 Pa.

[0016] Furthermore, the inert gas is argon, but is not limited thereto.

[0017] Furthermore, the step of arc melting the metal element raw material using the high vacuum non-consumable arc melting furnace includes:

[0018] (1) Turn on the main power supply, start the water cooler, open the air valve to balance the air pressure in the furnace with the atmospheric pressure, and then open the furnace cover;

[0019] (2) Place the metal raw materials in a water-cooled crucible in the furnace according to the ratio, with Al at the bottom, Cr and Fe in the middle, and Co and Ni at the top;

[0020] (3) Close the furnace cover and air valve, start the mechanical pump, open the pre-vacuum valve, and evacuate to below 10Pa. Then open the molecular pump and the molecular pump stop valve and evacuate to 5×10 -3 Pa, and then backfill with argon to 4×10 2 Pa~6×10 2 Pa;

[0021] (4) Turn on the heating power switch, adjust the arc current to 60-90A, keep the arc gun tip 5-10mm away from the top of the raw material, slowly increase the current after the arc is successfully struck, and turn on the magnetic stirring power supply and gradually increase the current after the raw material is completely melted. The raw material begins to flow under the action of the magnetic field, forming stirring, which lasts for 10-20s, and then reduce and turn off the magnetic stirring current and arc current in turn;

[0022] (5) After cooling to room temperature, backfill the furnace chamber with air to atmospheric pressure, open the furnace door, and take out the ingot.

[0023] Preferably, the atomic percentage of each component of the metal element raw material is Ni:Co:Al:Cr:Fe=34.5:16.5:16.5:(27.5~32.5):(0~5).

[0024] Preferably, the above step (4) is repeated for 3-5 times to ensure that the components are evenly mixed.

[0025] The beneficial technical effects obtained by the present invention are:

[0026] 1. The multi-principal element alloy provided by the technical solution of the present invention has a near-eutectic cellular structure. The FCC phase in the outer layer of the cell has many mobile slip systems and good plasticity, while the BCC / B2 coherent network structure inside the cell has few mobile slip systems and high-density coherent interfaces that hinder dislocation movement, thereby forming a soft-hard structure with soft cell edges and hard interiors. Furthermore, by increasing the chromium content and reducing the iron content, the volume fraction of the BCC / B2 coherent network structure phase can be increased, thereby increasing the hardness of the alloy. At the same time, the potential difference between the phases can be reduced by composition regulation, thereby reducing the galvanic corrosion rate commonly seen in traditional multiphase alloys and improving the corrosion resistance of the alloy.

[0027] 2. By adopting the technical solution of the present invention, by regulating the constituent elements and percentages of high-entropy alloys, the alloy element mixing effect and lattice distortion effect are effectively increased, the solid solution strengthening and second phase strengthening effects of the alloy are enhanced, thereby improving the hardness, corrosion resistance and high strength and toughness of the multi-principal component alloy. In addition, by optimizing the smelting environment, the influence of impurity elements on the alloy is avoided, the alloy purity is improved, and the corrosion resistance and high strength and toughness of the alloy are enhanced.

[0028] 3. The technical solution of the present invention is prepared by arc melting in a vacuum atmosphere, which can be cooled with the crucible or suction-casted. It has the characteristics of a simple preparation method, especially without the need for heat treatment and subsequent complex processing technology, to prepare a multi-principal component alloy with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The X-ray diffraction pattern of the wear-resistant and corrosion-resistant cast multi-principal-element alloy provided in Example 1 at room temperature;

[0030] Figure 2a and Figure 2b They are low-magnification and high-magnification images of the microstructure of the wear-resistant and corrosion-resistant multi-principal-element alloy provided in Example 1;

[0031] Figure 3 The wear-resistant and corrosion-resistant multi-element alloy provided in Example 1 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 Column comparison of micro-Vickers hardness of different Fe3Ni2 alloys at room temperature;

[0032] Figure 4a The wear-resistant and corrosion-resistant multi-element alloy provided in Example 1 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 Curve comparison of wear scar cross section of Fe3Ni2 wear resistance;

[0033] Figure 4bThe wear-resistant and corrosion-resistant multi-element alloy provided in Example 1 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 Column comparison chart of specific wear rate of Fe3Ni2 wear resistance:

[0034] Figure 5 The wear-resistant and corrosion-resistant multi-element alloy provided in Example 1 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 Comparison of potentiodynamic polarization curves of Fe3Ni2 in 3.5wt.% NaCl solution for electrochemical corrosion test;

[0035] Figure 6 The X-ray diffraction pattern of the wear-resistant and corrosion-resistant cast multi-principal element alloy provided in Example 2 at room temperature;

[0036] Figure 7a and Figure 7b Low-magnification and high-magnification images of the microstructure of the wear-resistant and corrosion-resistant multi-principal-element alloy provided in Example 2;

[0037] Figure 8 The wear-resistant and corrosion-resistant multi-element alloy provided in Example 2 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn2 provided in Comparative Examples 1-2 14 Column comparison chart of micro Vickers hardness of Fe3Ni2 at room temperature;

[0038] Figure 9a The wear-resistant and corrosion-resistant multi-element alloy provided in Example 2 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn2 provided in Comparative Examples 1-2 14 Curve comparison of wear scar cross section of Fe3Ni2 wear resistance;

[0039] Figure 9b The wear-resistant and corrosion-resistant multi-element alloy provided in Example 2 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn2 provided in Comparative Examples 1-2 14 Column comparison chart of specific wear rate of Fe3Ni2 wear resistance:

[0040] Figure 10 The wear-resistant and corrosion-resistant multi-element alloy provided in Example 2 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn2 provided in Comparative Examples 1-2 14 Comparison of the potentiodynamic polarization curves of Fe3Ni2 in electrochemical corrosion tests in 3.5wt.% NaCl solution. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously,

[0042] The described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0043] The present invention provides a wear-resistant and corrosion-resistant multi-principal alloy composed of five elements: Ni, Co, Al, Cr, and Fe; or composed of four elements: Ni, Co, Al, and Cr; wherein the general formula of the multi-principal alloy is Ni 34.5 Co 16.5 Al 16.5 Cr x Fe y , wherein 27.5≤x≤32.5, 0≤y≤5.0, x+y=32.5, and x and y represent the atomic percentage of the element; the alloy is obtained by melting the metal element raw material into a master alloy button ingot in a high vacuum non-consumable arc melting furnace under inert gas protection, thereby obtaining the alloy material.

[0044] The multi-element alloy provided by the present invention is compared with the aluminum bronze materials in the prior art (ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn i4 Fe3Ni2), its hardness is 2 to 3 times that of aluminum bronze. Under the same test conditions, its wear rate is one order of magnitude lower; its self-corrosion current density is 1 to 2 orders of magnitude lower than that of aluminum bronze, showing excellent corrosion resistance.

[0045] The multi-principal component alloy provided by the above technical solution has a near-eutectic cellular structure and is an in-situ composite material. Its cellular structure contains three phases: face-centered cubic phase (FCC phase), body-centered cubic phase (BCC phase) and ordered body-centered cubic phase (B2 phase); wherein the outer layer of the cellular structure is the FCC phase, and the interior of the cellular structure is a BCC / B2 coherent lattice structure formed by the BCC phase and the B2 phase, thereby obtaining a cellular structure with a soft edge and a hard interior and a combination of soft and hard.

[0046] Preferably, in the cellular structure, when the chromium content increases and the iron content decreases, the volume fraction of the FCC phase decreases and the volume fraction of the BCC / B2 coherent network phase increases.

[0047] Preferably, the wear-resistant and corrosion-resistant multi-principal component alloy has a micro-Vickers hardness of 420 to 560 HV in the cast state. High hardness is beneficial to improving the wear resistance of the alloy, which is better than the common aluminum bronze used for propellers. Thanks to the near-eutectic cellular structure of the alloy, the FCC phase in the outer layer of the cell has many movable slip systems and good plasticity, while the BCC / B2 coherent network structure inside the cell has few movable slip systems, high-density coherent interfaces that hinder dislocation movement, and high strength, thus forming a soft-hard combination structure with soft cell edges and hard interiors. Based on this, by increasing the chromium content and reducing the iron content, the volume fraction of the BCC / B2 coherent network structure phase can be increased, thereby increasing the hardness of the alloy. Therefore, the present invention can obtain a multi-principal component alloy with high hardness and wear resistance by adjusting the content of chromium and iron elements in the alloy.

[0048] Furthermore, although the multi-principal component alloy has three phases: ferro-centered cubic phase (FCC), body-centered cubic phase (BCC) and ordered body-centered cubic phase (B2), the potential difference between the phases can be reduced through composition regulation, thereby reducing the galvanic corrosion rate common in traditional multi-phase alloys and improving the electrochemical corrosion performance of the multi-principal component alloy. As a result, the self-corrosion potential of the multi-principal component alloy provided by the technical solution of the present invention in 3.5wt.% NaCl (simulated seawater) solution is significantly higher than that of common propeller aluminum bronze, and the corrosion current is also significantly lower than that of common propeller aluminum bronze, showing excellent corrosion resistance.

[0049] In some specific embodiments, a method for preparing the above-mentioned multi-principal component alloy is further provided by arc melting the metal element raw material in a high vacuum non-consumable arc melting furnace, the specific steps comprising:

[0050] (1) Turn on the main power supply, start the water cooler, open the air valve to balance the air pressure in the furnace with the atmospheric pressure, and then open the furnace cover;

[0051] (2) Place the metal raw materials in a water-cooled crucible in the furnace according to the ratio, with Al at the bottom, Cr and Fe in the middle, and Co and Ni at the top;

[0052] (3) Close the furnace cover and air valve, start the mechanical pump, open the pre-vacuum valve, and evacuate to below 10Pa. Then open the molecular pump and the molecular pump stop valve and evacuate to 5×10 -3 Pa, and then backfill with argon to 4×10 2 Pa~6×10 2 Pa;

[0053] (4) Turn on the heating power switch, adjust the arc current to 60-90A, keep the arc gun tip 5-10mm away from the top of the raw material, slowly increase the current after the arc is successfully struck, and turn on the magnetic stirring power supply and gradually increase the current after the raw material is completely melted. The raw material begins to flow under the action of the magnetic field, forming stirring, which lasts for 10-20s, and then reduce and turn off the magnetic stirring current and arc current in turn;

[0054] (5) After cooling to room temperature, backfill the furnace chamber with air to atmospheric pressure, open the furnace door, and take out the ingot.

[0055] Preferably, the atomic percentage of each component of the metal element raw material is Ni:Co:Al:Cr:Fe=34.5:16.5:16.5:(26~32.5):(0~6.5).

[0056] Preferably, the above step (4) is repeated for 3-5 times to ensure uniform composition.

[0057] The technical solution of the present invention is further described in detail below through specific embodiments.

[0058] Example 1

[0059] This embodiment provides a wear- and corrosion-resistant multi-element alloy comprising the following components in atomic percentages: Ni: 34.5 parts; Co: 16.5 parts; Al: 16.5 parts; Cr: 27.5 parts; and Fe: 5.0 parts. The Ni, Co, Al, Cr, and Fe are all industrial-grade, with a purity of 99.5 wt.% or greater.

[0060] The preparation method of the wear-resistant and corrosion-resistant multi-principal alloy provided in this embodiment is as follows: when melting the alloy, Al is placed at the bottom, Cr and Fe are placed in the middle, Co and Ni are placed at the top, and the furnace cover is closed; the mechanical pump is turned on and the vacuum is pumped to below 10 Pa; the molecular pump is turned on and the vacuum is pumped to 5×10 -3 Pa, close the exhaust valve, and backfill with argon to 4-6×10 2 Pa; turn on the heating power supply, adjust the arc current to 60-90A, keep the arc gun tip 5-10mm away from the top of the raw material, slowly increase the current after the arc is successfully struck, and after the raw material is completely melted, turn on the magnetic stirring power supply and gradually increase the current. The raw material begins to flow under the action of the magnetic field, forming stirring, which lasts for 10-20s, and then reduce and turn off the magnetic stirring current and arc current in turn; repeat the smelting 3-5 times to ensure uniform composition; after the ingot is cooled to room temperature, backfill the furnace chamber with air to atmospheric pressure, open the furnace door, and take out the ingot, which is a multi-principal element alloy.

[0061] Figure 1 The X-ray diffraction pattern of the multi-principal alloy of the embodiment is shown in FIG. Figure 1As shown in FIG, this embodiment is mainly composed of three phases: FCC phase, BCC phase and B2 phase. The (110), (200), (211) and (220) diffraction peak positions of the BCC phase and B2 coincide, indicating that the BCC phase and B2 phase are in a coherent relationship.

[0062] Figure 2a and Figure 2b They are respectively the microscopic morphology pictures of the multi-principal element alloys of the embodiments. Figure 2a This is the low-magnification morphology of the multi-principal element alloy, showing a cellular structure; Figure 2b This is the high-magnification morphology of the multi-principal element alloy, and it can be seen that it presents a cellular structure; the outer layer of the cellular structure is the FCC phase, and the interior of the cellular structure is a coherent network structure formed by the BCC phase and the B2 phase.

[0063] Example 2

[0064] This embodiment discloses a wear-resistant and corrosion-resistant multi-principal alloy comprising the following components in atomic percentages: Ni: 34.5 parts; Co: 16.5 parts; Al: 16.5 parts; Cr: 32.5 parts. The Ni, Co, Al, and Cr are all industrial-grade pure materials with a purity of 99.5 wt.% or higher.

[0065] The preparation method of the wear-resistant and corrosion-resistant multi-principal alloy of this embodiment is as follows: when melting the alloy, Al is placed at the bottom, Cr is placed in the middle, Co and Ni are placed at the top, and the furnace cover is closed; the mechanical pump is turned on and the vacuum is pumped to below 10 Pa; the molecular pump is turned on and the vacuum is pumped to 5×10 -3 Pa, close the exhaust valve, and backfill with argon to 4-6×10 2 Pa; turn on the heating power supply, adjust the arc current to 60-90A, keep the arc gun tip 5-10mm away from the top of the raw material, slowly increase the current after the arc is successfully struck, and after the raw material is completely melted, turn on the magnetic stirring power supply and gradually increase the current. The raw material begins to flow under the action of the magnetic field, forming stirring, which lasts for 10-20s, and then reduce and turn off the magnetic stirring current and arc current in turn; repeat the smelting 3-5 times to ensure uniform composition; after the ingot cools to room temperature, backfill the furnace chamber with air to atmospheric pressure, open the furnace door, and take out the ingot.

[0066] The structure of the multi-principal alloy obtained in this embodiment is similar to that of Example 1; further, see Figure 6 , is the X-ray diffraction pattern of the multi-principal component alloy prepared in this example. As can be seen from the figure, the multi-principal component alloy provided in this example is primarily composed of three phases: FCC, BCC, and B2. The diffraction peaks (110), (200), (211), and (220) of the BCC and B2 phases overlap, indicating a coherent relationship between the BCC and B2 phases. Figure 7a and Figure 7bThe following are photos of the microstructure of the multi-principal component alloy of the embodiment at different magnifications. Figure 7a This is the low-magnification morphology of the multi-principal element alloy, showing a cellular structure; Figure 7b This is a high-magnification image of a multi-principal alloy, showing a cellular structure. The outer layer of the cellular structure is the FCC phase, while the inner part of the cellular structure is a fine structure of a coherent network formed by the BCC phase and the B2 phase.

[0067] Comparative Example 1

[0068] This comparative example provides an aluminum bronze alloy, ZCuAl9Fe4Ni4Mn2, a cast copper alloy primarily used for critical castings requiring high strength and excellent corrosion resistance. It is a primary material for ship propellers and can also be used in wear-resistant parts such as bearings, gears, flanges, and valve bodies. Comparative Example 1 was purchased from a copper alloy manufacturer as forged plates. To minimize the effects of heat treatment and machining on the alloy's properties, it was remelted in a non-consumable arc melting furnace to its as-cast state.

[0069] The preparation method of ZCuAl9Fe4Ni4Mn2 copper alloy in this comparative example 1 is as follows: 120g of the industrial alloy is cut from the industrial alloy by wire-cutting electric discharge, the surface oxide scale is polished and cleaned, and then the alloy is placed in a water-cooled copper crucible in an electric arc furnace, and the furnace cover is closed; the mechanical pump is turned on and the vacuum is evacuated to below 10Pa, and the molecular pump is turned on and the vacuum is evacuated to 5×10 -3 Pa, close the exhaust valve, and backfill with argon to 4-6×10 2 Pa; turn on the heating power supply, adjust the arc current to 60-90A, keep the arc gun tip 5-10mm away from the top of the raw material, slowly increase the current after the arc is successfully struck, and after the raw material is completely melted, turn on the magnetic stirring power supply and gradually increase the current. The raw material begins to flow under the action of the magnetic field, forming stirring, which lasts for 10-20s, and then reduce and turn off the magnetic stirring current and arc current in turn; repeat the smelting 3-5 times to ensure uniform composition; after the ingot cools to room temperature, backfill the furnace chamber with air to atmospheric pressure, open the furnace door, and take out the ingot.

[0070] Comparative Example 2

[0071] This comparative example provides an aluminum bronze alloy, ZCuAl8Mn 14 Fe3Ni2 cast copper alloy is primarily used for critical castings requiring high strength and excellent corrosion resistance. It is one of the primary materials for manufacturing ship propellers and can also be used in wear-resistant parts such as bearings, gears, flanges, and valve bodies. Comparative Example 2 was purchased from a copper alloy manufacturer as hot-extruded bar. To minimize the effects of heat treatment and processing on the alloy's properties, it was remelted in a non-consumable arc melting furnace to its as-cast state.

[0072] The ZCuAl8Mn 14The preparation method of Fe3Ni2 copper alloy is as follows: 120g of the industrial alloy is cut from the industrial alloy by wire-cutting electric discharge, the surface oxide scale is polished and cleaned, and then the alloy is placed in a water-cooled copper crucible in an electric arc furnace with the furnace cover closed; the mechanical pump is turned on and the vacuum is pumped to below 10Pa; the molecular pump is turned on and the vacuum is pumped to 5×10 -3 Pa, close the exhaust valve, and backfill with argon to 4-6×10 2 Pa; turn on the heating power supply, adjust the arc current to 60-90A, keep the arc gun tip 5-10mm away from the top of the raw material, slowly increase the current after the arc is successfully struck, and after the raw material is completely melted, turn on the magnetic stirring power supply and gradually increase the current. The raw material begins to flow under the action of the magnetic field, forming stirring, which lasts for 10-20s, and then reduce and turn off the magnetic stirring current and arc current in turn; repeat the smelting 3-5 times to ensure uniform composition; after the ingot cools to room temperature, backfill the furnace chamber with air to atmospheric pressure, open the furnace door, and take out the ingot.

[0073] Performance characterization:

[0074] The hardness, wear rate and corrosion resistance of the embodiment and the comparative example were tested and compared.

[0075] Figure 3 For example, the multi-principal alloy and aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 Comparison of micro-Vickers hardness of Fe3Ni2. The hardness of the multi-principal alloys in the embodiment is ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 1.8 times that of Fe3Ni2.

[0076] Figure 4a and Figure 4b The embodiment of the multi-principal alloy and aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 The wear scar cross section and specific wear rate comparison of Fe3Ni2. The specific wear rate of the multi-principal alloy is one order of magnitude lower than that of aluminum bronze, which is 7.7% of ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 8.3% of Fe3Ni2.

[0077] Figure 5 The multi-element alloy prepared in Example 1 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn prepared in Comparative Examples 1-2 14Potentiodynamic polarization curves of Fe3Ni2 electrochemical corrosion tests in 3.5wt.% NaCl solution. As can be seen from the figure, the three potentiodynamic polarization curves all contain active dissolution, passivation zone, and over-passivation zone, and the short-term active to passive transition indicates that the three alloys undergo spontaneous passivation at the corrosion potential. The self-corrosion potential and self-corrosion current density fitted by the Tafel extrapolation method, the higher the self-corrosion potential and the higher the self-corrosion current density, the better the corrosion resistance of the material; the self-corrosion potential of the multi-principal element alloy provided in the embodiment is -160.19mV, and the self-corrosion current density is 4.04nA / cm 2 The self-corrosion potential of ZCuAl9Fe4Ni4Mn2 is -267.66mV, and the self-corrosion current density is 510.43nA / cm 2 ;ZCuAl8Mn 14 The self-corrosion potential of Fe3Ni2 is -360.02mV, and the self-corrosion current density is 186.68nA / cm 2 It can be seen that the multi-principal element alloy of the embodiment not only has a higher self-corrosion potential than aluminum bronze, but also has a self-corrosion current density reduced by 1 to 2 orders of magnitude, showing excellent corrosion resistance.

[0078] Figure 8 The multi-element alloys provided in Example 2 and Comparative Examples 1-2 are respectively provided with aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14 The hardness of the multi-principal alloy is 3.2 times that of aluminum bronze ZCuAl9Fe4Ni4Mn2, ZCuAl8Mn 14 2.5 times that of Fe3Ni2.

[0079] Figure 9a and Figure 9b The multi-element alloy provided in Example 2 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn2 provided in Comparative Examples 1-2 are respectively 14 The wear scar cross section and specific wear rate comparison of Fe3Ni2. The specific wear rate of the multi-principal alloy provided in Example 2 is about one order of magnitude lower than that of aluminum bronze, which is 15.0% of ZCuAl9Fe4Ni4Mn2 and 15.0% of ZCuAl8Mn2. 14 16.3% of Fe3Ni2.

[0080] Figure 10 The multi-principal alloy provided in Example 2 and the aluminum bronze ZCuAl9Fe4Ni4Mn2 and ZCuAl8Mn 14Potentiodynamic polarization curves of Fe3Ni2 electrochemical corrosion tests in 3.5wt.% NaCl solution. As can be seen from the figure, the three potentiodynamic polarization curves all contain active dissolution, passivation zone, and over-passivation zone, and the short-term active to passive transition indicates that the three alloys undergo spontaneous passivation at the corrosion potential. The self-corrosion potential and self-corrosion current density fitted by the Tafel extrapolation method show that the higher the self-corrosion potential and the higher the self-corrosion current density, the better the corrosion resistance of the material. The self-corrosion potential of the multi-principal alloy in the embodiment is -157.22mV, and the self-corrosion current density is 3.60nA / cm 2 The self-corrosion potential of ZCuAl9Fe4Ni4Mn2 is -267.66mV, and the self-corrosion current density is 510.43nA / cm 2 ;ZCuAl8Mn 14 The self-corrosion potential of Fe3Ni2 is -360.02mV, and the self-corrosion current density is 186.68nA / cm 2 It can be seen that the multi-principal element alloy of the embodiment not only has a higher self-corrosion potential than aluminum bronze, but also has a self-corrosion current density reduced by 1 to 2 orders of magnitude, showing excellent corrosion resistance.

[0081] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter changes to these embodiments, which fall within the spirit and principles of the present invention and achieve the same functionality through conventional substitutions, without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. A wear-resistant and corrosion-resistant multi-principal alloy composed of five elements: Ni, Co, Al, Cr, and Fe; or composed of four elements: Ni, Co, Al, and Cr.

2. The multi-principal-component alloy according to claim 1, characterized in that: The general formula of the multi-principal alloy is Ni 34.5 Co 16.5 Al 16.5 Cr x Fe y , wherein 27.5≤x≤32.5, 0≤y≤5, x+y=32.5, and x and y represent the atomic percentage of the element.

3. The multi-principal-component alloy according to claim 1, characterized in that: The multi-principal alloy is an in-situ composite material with a near-eutectic cellular structure, comprising three cubic phases: a face-centered cubic phase (FCC), a body-centered cubic phase (BCC), and an ordered body-centered cubic phase (B2); The outer layer of the cellular structure is an FCC phase, and the interior of the cellular structure is a BCC / B2 coherent network structure formed by a BCC phase and a B2 phase, thereby forming a soft-hard cellular structure with a soft edge and a hard interior; In the cellular structure, as the chromium content increases and the iron content decreases, the volume fraction of the FCC phase decreases and the volume fraction of the BCC / B2 coherent network phase increases.

4. The multi-principal-component alloy according to claim 1, characterized in that: The wear-resistant and corrosion-resistant multi-principal-element alloy has a micro-Vickers hardness of 420 to 560 HV in the cast state.

5. The method for preparing the wear-resistant and corrosion-resistant multi-principal-component alloy according to any one of claims 1 to 4, characterized in that: The method comprises placing metal single substance raw materials Ni, Co, Al, Cr, Fe, or Ni, Co, Al and Cr in a high vacuum non-consumable arc melting furnace for melting, and then electromagnetically stirring the raw materials to obtain a wear-resistant and corrosion-resistant multi-principal alloy.

6. The method for preparing a wear-resistant and corrosion-resistant multi-principal-component alloy according to claim 5, characterized in that: The order of placing the metal element raw materials in the high vacuum non-consumable arc melting furnace includes: Al at the bottom, Cr and Fe in the middle, Co and Ni at the top, or Al at the bottom, Cr in the middle, Co and Ni at the top; And / or, the metal element raw materials Al, Ni, Fe, Co, Cr are all selected with a mass purity of 99.5% or more; And / or, the working condition of the high vacuum non-consumable arc melting furnace is to evacuate to 5×10 -3 Pa, and then backfill with inert gas to 4×10 2 Pa~6×10 2 Pa; Preferably, the inert gas is argon.

7. The method for preparing a wear-resistant and corrosion-resistant multi-principal-component alloy according to claim 5, characterized in that: First, the high vacuum non-consumable arc melting furnace is used to arc melt the metal element raw material. After the metal element raw material is completely melted to form molten metal, electromagnetic stirring is performed to make the molten metal flow and stir evenly. The stirring duration is 10 to 20 seconds, and the magnetic stirring current and arc current are turned off in turn.

8. The method for preparing a wear-resistant and corrosion-resistant multi-principal-component alloy according to any one of claims 5 to 7, characterized in that: The steps of arc melting the metal element raw material using the high vacuum non-consumable arc melting furnace include: (1) Turn on the main power supply, start the water cooler, open the air valve to balance the air pressure in the furnace with the atmospheric pressure, and then open the furnace cover; (2) placing the metal element raw materials in a water-cooled crucible in a furnace, placing Al at the bottom, Cr and Fe in the middle, and Co and Ni at the top, or placing Al at the bottom, Cr in the middle, and Co and Ni at the top; (3) Close the furnace cover and air valve, start the mechanical pump, open the pre-vacuum valve, and evacuate to below 10Pa. Then open the molecular pump and the molecular pump stop valve and evacuate to 5×10 -3 Pa, and then backfill with argon to 4×10 2 Pa~6×10 2 Pa; (4) Turn on the heating power switch, adjust the arc current to 60-90A, keep the arc gun tip 5-10mm away from the top of the raw material, slowly increase the current after the arc is successfully struck, wait until the metal element raw material is completely melted, turn on the magnetic stirring power supply and gradually increase the current, the raw material begins to flow under the action of the magnetic field, forming stirring, which lasts for 10-20s, and then reduce and turn off the magnetic stirring current and arc current in turn; (5) After the furnace chamber cools to room temperature, air is backfilled into the furnace chamber to atmospheric pressure, the furnace door is opened, and the ingot is taken out to obtain the multi-principal alloy.

9. The method for preparing a wear-resistant and corrosion-resistant multi-principal-component alloy according to any one of claim 8, characterized in that: In step (4), the metal element raw material is repeatedly smelted 3 to 5 times to mix the metal components evenly.

10. Application of the wear-resistant and corrosion-resistant multi-principal-element alloy according to any one of claims 1 to 4 in the field of marine engineering facilities and equipment.

Images