Nickel-aluminum bronze alloy with high mechanical property as well as preparation method and application of nickel-aluminum bronze alloy

Abstract

The invention discloses a nickel-aluminum bronze alloy with high mechanical property as well as a preparation method and application of the nickel-aluminum bronze alloy. The nickel-aluminum bronze alloy comprises the following elements in percentage by mass: 8.5-10.0 wt% of Al, 4.0-5.0 wt% of Fe, 4.0-5.0 wt% of Ni, 0.8-2.5 wt% of Mn, 0.2-0.6 wt% of Cr, 0.2-0.8 wt% of Ti, less than or equal to 1.0 wt% of impurity elements in total and the balance of copper. The nickel-aluminum bronze alloy has the beneficial effects that the Cu-Cr intermediate alloy and pure Ti are added into the nickel-aluminum bronze alloy, the Cu-Cr intermediate alloy and the pure Ti are separated out in the solidification process to serve as heterogeneous nucleation cores, the grain refining effect is achieved, the cores also have the precipitation strengthening effect at the same time, the comprehensive performance of the alloy is improved, the strength and hardness of the alloy are improved on the premise that the ductility is guaranteed, and the service life of the alloy is prolonged. Therefore, the alloy has relatively high comprehensive mechanical properties.

Description

TECHNICAL FIELD

[0001] The application relates to a material preparation method in the field of marine equipment, in particular to a high-corrosion-resistance and high-wear-resistance copper-nickel alloy material and a preparation method and application thereof. BACKGROUND

[0002] Nickel aluminum bronze (NAB) is a complex aluminum bronze alloy formed by adding alloying elements such as Fe, Ni and Mn on the basis of a binary aluminum bronze alloy. The research and development of nickel aluminum bronze can be traced back to the development and research of binary aluminum bronze in the early 20th century. Nickel aluminum bronze has high tensile strength, corrosion fatigue strength and excellent cavitation and erosion corrosion resistance, and is a typical wear-resistant and corrosion-resistant high-performance copper alloy, which is widely used in propellers, pumps, valves, gears and other components in complex service environments. As one of the most widely used copper alloys in the field of marine engineering, the microstructure and performance of nickel aluminum bronze are directly related to the service performance and service life of large marine equipment systems. The development of nickel aluminum bronze with more excellent mechanical properties can improve the fatigue limit of equipment components, enhance their cavitation and erosion corrosion resistance, delay plastic deformation failure and corrosion fatigue behavior, and provide support for the research and development and preparation of the next generation of advanced marine equipment. In addition, nickel aluminum bronze is also widely used in the manufacture of key components such as turbines, bearings, shaft sleeves, bearing shells and gears. With the development of science and technology, the performance of aluminum bronze alloy is required to be higher in various application fields. The development of nickel aluminum bronze with better performance can also expand its potential application scenarios. Micro-alloying of alloy materials is to add trace elements on the basis of the original chemical composition of the alloy to change the microstructure and improve the performance of the alloy. This process is very mature in steel materials. Micro-alloying can achieve very good alloy performance at low cost.

[0003] Chinese invention patent authorization publication No. CN102899522B discloses a zirconium micro-alloyed nickel aluminum bronze. First, the nickel aluminum bronze is melted, and then Al-Zr intermediate alloy is added. After complete melting, a slag remover is added, and then high-purity nitrogen gas is introduced for 3 minutes. Finally, it is poured into a ladle, and after standing for 1-5 minutes, the slag is removed and cast into an ingot. The invention improves the hardness and uniform corrosion rate by adding zirconium.

[0004] The Chinese invention patent publication No. CN117144184A discloses a new type of high-flow velocity erosion resistant nickel-aluminum bronze alloy for ship pump valves. The composition of the nickel-aluminum bronze alloy includes, by mass percentage: Al: 7.7-8.3%, Ni: 5.7-6.3%, Fe: 3.7-4.3%, Mn: 1.7-2.3%, and copper. The nickel-aluminum bronze alloy of the invention has excellent comprehensive performance, especially high resistance to high-flow velocity seawater erosion corrosion.

[0005] However, the tensile strength, yield strength, and Brinell hardness of the nickel-aluminum bronze alloys of the above two patents are not satisfactory. SUMMARY

[0006] The technical problem to be solved by the present invention is the unsatisfactory strength and hardness of existing nickel-aluminum bronze alloys. Therefore, a high-mechanical-property nickel-aluminum bronze alloy, its preparation method and application are provided.

[0007] The technical solution of the present invention is: a high-mechanical-property nickel-aluminum bronze alloy, including the following mass percentages of elements: Al 8.5wt%-10.0wt%, Fe 4.0wt%-5.0wt%, Ni 4.0wt%-5.0wt%, Mn 0.8wt%-2.5wt%, Cr 0.2wt%-0.6wt%, Ti 0.2wt%-0.8wt%, total impurity elements ≤1.0wt%, and the balance being copper.

[0008] The preparation method of the high-mechanical-property nickel-aluminum bronze alloy includes the following steps: (1) melting the nickel-aluminum bronze alloy; (2) adding Cu-Cr intermediate alloy in a determined proportion; (3) after the Cu-Cr intermediate alloy is completely melted, adding pure Ti in a determined proportion; (4) adding a refining agent for refining treatment, adjusting the temperature, and pouring out of the furnace.

[0009] In the above scheme, the chemical composition of the nickel-aluminum bronze alloy of step (1) is Al 9.1wt%-9.3wt%, Fe 4.7wt%-4.8wt%, Ni 4.8wt%-4.9wt%, and Mn 1.4wt%-1.5wt%.

[0010] In the above scheme, the melting temperature of step (1) is 1250°C-1280°C.

[0011] In the above scheme, the Cu-Cr intermediate alloy of step (2) is CuCr10 or CuCr25.

[0012] In the above scheme, the refining agent used in step (4) includes the following components in a mass ratio: 40wt% of aluminum, iron, nickel, or manganese powder, 40wt% of calcium carbonate, 10wt% of flake graphene, and 10wt% of rare earth powder.

[0013] The temperature of the step (4) in the above scheme is adjusted to 1300-1400 DEG C.

[0014] The high mechanical property nickel-aluminum bronze alloy is applied to marine equipment such as marine propeller, pump, valve, gear and the like.

[0015] The beneficial effect of the present application is that Cu-Cr intermediate alloy and pure Ti are added in the nickel-aluminum bronze alloy, and the cores are precipitated as heterogeneous nucleation in the solidification process, which not only plays the role of refining grains, but also plays the role of precipitation strengthening, improves the comprehensive performance of the alloy, improves the strength and hardness of the alloy under the premise of ensuring the elongation, so that the alloy has high comprehensive mechanical property, and improves the operation reliability of the product; the mechanical property of the alloy is: tensile strength 752.8-780.3 MPa, yield strength 377.2-401.3 MPa, elongation 18.5%-23.6%, Brinell hardness 185.8-257.3. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the cast structure metallographic photo of NAB (9442); Figure 2 is the cast structure metallographic photo of NABC (9442Cr); Figure 3 is the cast structure metallographic photo of NABT (9442Ti); Figure 4 is the metallographic photo of NAB (9442) after heat treatment; Figure 5 is the metallographic photo of NABC (9442Cr) after heat treatment; Figure 6 is the metallographic photo of NABT (9442Ti) after heat treatment; Figure 7 is the 500 times and 1000 times size scanning electron microscope photos of NAB (9442) after composite treatment; Figure 8 is the 500 times and 1000 times size scanning electron microscope photos of NABC (9442Cr) after composite treatment; Figure 9 is the 500 times and 1000 times size scanning electron microscope photos of NABT (9442Ti) after composite treatment; Figure 10 is the metallographic photo of copper-nickel alloy prepared by the present application. DETAILED DESCRIPTION

[0017] With reference to the drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments made by any person of ordinary skill in the art without creative effort fall within the protection scope of the present application.

[0018] In recent years, with the progress of analytical testing and process control technology, the alloy smelting and casting process control level is continuously improved, and on this basis, it is expected to obtain higher performance copper alloy materials by optimizing alloy composition, forming technology and post-processing technology. In the solid state phase transition process, the process of metal material changing from one crystal structure to another crystal structure with temperature change (heating or cooling) is called polymorphic transformation or allotropy transformation; if the crystal structure of the alloy matrix solid solution does not change due to temperature change, only the generation of new phase or the disappearance of original phase in the alloy is transformed, which is called non-polymorphic transformation. Unlike steel materials, copper alloys do not undergo allotropy transformation during heating and cooling, and their strengthening methods include solid solution strengthening, fine-grain strengthening, second phase strengthening, deformation strengthening and their mixed use. The present application attempts to take appropriate process measures to precipitate second phase particles, increase nucleation core, refine alloy organization, and play precipitation strengthening effect, and improve the comprehensive performance. Specifically, in the alloy composition design, micro-alloying is adopted, and at the same time, certain heat treatment process is supplemented to realize the goal of improving alloy performance.

[0019] In the cast copper alloy, low solid solubility alloying elements are added to precipitate as heterogeneous nucleation core during solidification, which not only plays a role in refining grains, but also plays a precipitation strengthening effect, thereby improving the comprehensive performance of the alloy.

[0020] Heat treatment is an important means to improve the performance of alloy materials, and the comprehensive performance of aluminum bronze can be greatly improved by optimizing the heat treatment process and parameters. Although cast copper alloy cannot change the organizational structure through polymorphic transformation, the existing state of alloy elements can be controlled through heat treatment. The distribution form and volume fraction of precipitated phase can be controlled by adopting the heat treatment process of solid solution + aging, so as to effectively improve the comprehensive mechanical properties of the alloy.

[0021] The development of nickel-aluminum bronze alloy in China started in the late 1970s, and was used on fast boats and bulk carriers and other civilian equipment in the 1980s. The composition of the bronze propeller casting specified by China Classification Society is Cu77.0~82.0, Al7.0~11.0, Fe2.0~6.0, Ni3.0~6.0, Mn0.5~4.0, Zn0.1, Sn0.1, Pb0.03, which is within the scope of GB / T1176-2013 "Casting Copper and Copper Alloy", and is more extensive. Therefore, within this range, the alloy composition can be optimized to obtain an alloy with better performance.

[0022] Alloy composition design Aluminum equivalent The change of aluminum content affects the comprehensive performance of aluminum bronze. When 9.4wt%≤Al<15.6wt% is added in the binary alloy, the β→α+γ2 eutectoid transformation occurs in the aluminum bronze alloy when it is slowly cooled to 565℃, a large amount of γ2 phase is precipitated, and a clear lamellar structure is formed. When 10 wt%≤Al<11.8 wt% in the alloy, the β phase undergoes a non-diffusion phase transition, producing needle-like β'martensite metastable phase with a cubic close-packed structure, and a compound Cu3Al-based body-centered cubic solid solution is a hard phase. When Al≥11.8wt% in the alloy, the solid solution in the alloy gradually transitions to the ordered solid solution β', and with the continuous increase of Al content, it further transitions to needle-like β'martensite or β'+γ2 two-phase mixture. For nickel-aluminum bronze, the content of nickel and iron is close, and the content of manganese element is low, so the effect of Al element on the performance of the alloy can be investigated by aluminum equivalent, and the effect can be evaluated.

[0023] The calculation method of aluminum equivalent of nickel-aluminum bronze is: Al equivalent=Al+Ni-Fe+1 / 6Mn The range of aluminum equivalent is 9.4wt%~9.8wt%, and the mechanical properties of the alloy are better. The higher the aluminum equivalent, the higher the tensile strength and yield strength of the alloy, and the lower the elongation. However, the sample with the highest mechanical properties does not have the highest Al content, but the highest Al equivalent. Therefore, Al equivalent has certain guiding significance compared with Al content.

[0024] Iron-nickel ratio The K phase in nickel-aluminum bronze can be in the form of fine particles, blocks or layers, which has a great influence on the mechanical properties of the alloy, and the precipitation form of K phase is affected by the content and mutual ratio of aluminum, nickel and iron in the alloy. When the content of nickel is greater than that of iron, the K phase is precipitated in the form of layers; when the content of iron is greater than that of nickel, the K phase is in the form of blocks; only when the content of nickel and iron is roughly the same, the K phase is in the form of fine particles, which is beneficial to obtain good mechanical properties. The performance is better when the Fe / Ni ratio is 0.97~0.98.

[0025] Micro-alloying elements Cu-Ti alloy belongs to age hardening alloy, and the β-Cu4Ti formed by the supersaturated solid solution during cooling forms precipitation strengthening, which gives the alloy excellent strength, hardness and elasticity.

[0026] The micro-alloying element addition amount of 0.25wt.% Cr and 0.3wt% Ti was designed respectively, and the test alloy composition was designed as shown in Table 1.

[0027]

[0028] Prepare the wedge-shaped test block mold according to GB / T 1176-2013, manufacture the sand mold, and pour the test sample.

[0029] (1) Raw material preparation. First, according to the mass ratio of each component in the target material, weigh the return material, pure copper, pure nickel, pure iron, pure manganese, pure chromium, and sponge titanium, and dry for use (materials with intermediate alloy use intermediate alloy).

[0030] (2) Melting. Preheat the crucible, then add the iron, manganese, nickel, copper, and return material weighed according to the proportion, and if there is an intermediate alloy, add it before the return material. After the furnace charge is melted, add the covering agent and stir the slag. Control the copper liquid temperature at about 1300℃, add pure chromium or intermediate alloy, or add sponge titanium.

[0031] (3) Casting. After the alloy is melted and cleaned, prepare to pour out, and control the temperature at about 1250℃.

[0032] Sprinkle the slag collector before pouring out, and stir the slag after standing for a while; then sprinkle the covering agent on the surface of the copper liquid, and control the pouring temperature at about 1150℃.

[0033] (4) Sample preparation. First, take samples on the wedge-shaped test block for chemical composition analysis, then remove surface inclusions and other defects on the milling machine, mark the steel stamp number to distinguish different alloy test blocks, and finally prepare the test block into the required size of the test sample, and perform various organizational and performance tests.

[0034] (5) Heat treatment. ZCuA19Fe4Ni4Mn2 nickel aluminum bronze adopts two kinds of heat treatment processes: ① 980℃ for 2 hours, furnace cooling to 580℃, then pouring out and air cooling.

[0035] ② 980℃ for 2 hours water quenching, then respectively 350℃ for 2 hours water quenching and 600℃ for 10 minutes water quenching.

[0036] The chemical composition of the test alloy measured by a spectrometer is shown in Table 2.

[0037]

[0038] The microstructure of the samples was observed by metallographic microscope to study the effect of micro-alloying on the microstructure of the alloy. The specific preparation process of the metallographic sample is as follows: first, the sample is cut into a 10mmx10mmx10mm block by an electric spark line cutting machine. Different grits of water sandpaper and different particle sizes of polishing agent are used on the sample grinder for mechanical polishing until the sample becomes a smooth mirror surface. Finally, the polished sample is uniformly etched in FeCl3 aqueous solution by surface immersion method. The etching time of the sample in the etching solution is about 10-15s until the polished surface of the sample piece becomes dark.

[0039] As shown in Figure 1 , the ZCuAl9Fe4Ni4Mn2 alloy (9442) is a needle-like α solid solution. As shown in Figure 2 , after adding micro-alloying element Cr, the α solid solution is transformed into blocky structure, and petal-shaped phase is precipitated between the blocky structures. The petal-shaped phase is a phase rich in Fe, Al and Cr, indicating that the addition of Cr promotes the formation of petal-shaped phase. As shown in Figure 3 , micro-alloying with Ti, strip-shaped Ti-rich phase is precipitated in the structure, and eutectic phase is formed between the α solid solution.

[0040] As shown in Figures 4-6 , the microstructure of the three alloys after solution treatment at 980℃ for 2 hours, furnace cooling to 580℃ and then air cooling. As shown in Figure 4 , after solution treatment, the microstructure of the alloy has a certain degree of coarsening, but the morphology has no obvious change. As shown in Figure 5 , a large number of fine α phases in Cr micro-alloyed 9442Cr alloy disappear, and the petal-shaped phase becomes smaller. As shown in Figure 6 , there are still a small amount of precipitated phases in 9442Ti alloy micro-alloyed with Ti, and the number of eutectic phases has decreased to a certain extent.

[0041] As shown in Figures 7-9 , the microstructure of the three alloys after solution treatment at 980℃ for 2 hours, water quenching, and then respectively at 350℃ for 2 hours and water quenching and at 600℃ for 10 minutes and water quenching. As shown in Figure 7 , after composite heat treatment, the microstructure of the original alloy is composed of long needle-like α phase and blocky needle-like phase. As shown in Figure 8 , under the scale of 500 times, the precipitated phase in Cr micro-alloyed 9442Cr alloy disappears, and the microstructure is composed of blocky α phase and blocky needle-like phase. Under the scale of 1000 times, there are also independent α phases in the blocky needle-like phase. As shown in Figure 9As shown, in the scale of 500 times, the precipitated phase disappears in the Ti micro-alloyed 9442Ti alloy, and the structure is composed of block alpha phase and clumped acicular phase. In the scale of 1000 times, the clumped acicular phase is composed of needle strip-shaped structure arranged in parallel and oriented differently.

[0042] The mechanical properties of the above three alloys were tested (1) Brinell hardness According to GB / T 231.1-2018 Metal Materials Brinell Hardness Test Part 1: Test Method, the hardness of the alloy was tested by using a Brinell hardness tester, three samples were taken for each alloy, five points were tested for each sample, and then the average value was taken as the final experimental data. The hardness values of the three alloys in different states are shown in Table 3.

[0043]

[0044] (2) Mechanical properties According to GB / T 228.1-2021 Metal Materials Tensile Test Part 1: Room Temperature Test Method, room temperature tensile test was carried out by using a universal testing machine, three samples were taken for each sample for tensile test, all samples were tested at room temperature and the average value was taken, the tensile rate was 0.5mm / min. The mechanical properties of the three alloys in different states are shown in Table 4.

[0045]

[0046] As can be seen from Table 4, the performance of the three alloys in the same heat treatment state is compared: in the as-cast state, the strength (tensile, yield) of NABC and NABT is much higher than that of NAB, which proves that the addition of Cr or Ti can greatly improve the strength through grain refinement or the formation of strengthening phase during casting. The plasticity (elongation) of the three alloys is not much different, which shows that the addition of strengthening elements does not significantly damage the plasticity of the material. Solid solution + aging state (optimal state): NABC has the highest tensile strength (781.4MPa), which shows that the strengthening effect of Cr element is very significant. Although NAB has the lowest absolute strength, its performance has the largest improvement. After optimized heat treatment, the strength, plasticity and elongation of the three alloys are greatly improved. Although the hardness of NABC and NABT is greatly improved, the tensile strength, yield strength and elongation are not greatly improved or even decreased.

[0047] On this basis, the present application attempts to add Cu-Cr intermediate alloy and pure Ti as micro-alloy at the same time, without heat treatment, because heat treatment will bring additional cost, prolong production time, and the comprehensive mechanical properties will decrease, and the following examples 1-4 are obtained.

[0048] Example 1

[0049] (1) Smelting nickel-aluminum bronze ZCuAl9Fe4Ni4Mn2 alloy; (2) After the alloy melts, the temperature is raised to 1250℃, and Cu-Cr10 master alloy is added in a certain proportion; (3) After the Cu-Cr10 master alloy has completely melted, add pure Ti in a certain proportion; (4) Add refining agent for refining treatment. The refining agent includes the following components in the following mass ratio: 40wt% aluminum powder, 40wt% calcium carbonate, 10wt% flake graphene, and 10wt% rare earth powder. Adjust the temperature to 1300℃ and pour it out of the furnace.

[0050] The prepared copper alloy was tested, and the mass percentages of each element were as follows: Al 9.08 wt%; Fe 4.87 wt%; Ni 4.50 wt%; Mn 1.53 wt%; Cr 0.23 wt%; Ti 0.36 wt%, with the balance being copper and unavoidable impurities.

[0051] The mechanical properties of the alloy are as follows: tensile strength 762.5 MPa, yield strength 387.2 MPa, elongation 20.5%, and Brinell hardness 225.8. It can be seen that the overall mechanical properties are better than those of NAB, NABC, and NABT in the as-cast state and solution-treated state, and comparable to those of NAB, NABC, and NABT treated with solution and aging.

[0052] Example 2

[0053] (1) Smelting nickel-aluminum bronze ZCuAl9Fe4Ni4Mn2 alloy; (2) After the alloy melts, the temperature is raised to 1260℃, and Cu-Cr25 master alloy is added in a certain proportion; (3) After the Cu-Cr25 master alloy has completely melted, add pure Ti in a determined proportion; (4) Add refining agent for refining treatment. The refining agent includes the following components in the following mass ratio: 40wt% iron powder, 40wt% calcium carbonate, 10wt% flake graphene, and 10wt% rare earth powder. Adjust the temperature to 1350℃ and pour it out of the furnace.

[0054] The prepared copper alloy was tested, and the mass percentages of each element were as follows: Al 9.28 wt%; Fe 4.76 wt%; Ni 4.87 wt%; Mn 1.55 wt%; Cr 0.38 wt%; Ti 0.46 wt%, with the balance being copper and unavoidable impurities.

[0055] The mechanical properties of the alloy are: tensile strength 770.8 MPa, yield strength 381.6 MPa, elongation 20.5%, and Brinell hardness 225.6. It can be seen that the overall mechanical properties are better than those of NAB, NABC, and NABT in the as-cast state and solution-treated state, and comparable to those of NAB, NABC, and NABT treated with solution and aging.

[0056] Example 3

[0057] (1) Smelting nickel-aluminum bronze ZCuAl9Fe4Ni4Mn2 alloy; (2) After the alloy melts, the temperature is raised to 1270℃, and Cu-Cr10 master alloy is added in a certain proportion; (3) After the Cu-Cr10 master alloy has completely melted, add pure Ti in a certain proportion; (4) Add refining agent for refining treatment. The refining agent includes the following components in the following mass ratio: 40wt% nickel powder, 40wt% calcium carbonate, 10wt% flake graphene, and 10wt% rare earth powder. Adjust the temperature to 1380℃ and pour it out of the furnace.

[0058] The prepared copper alloy was tested, and the mass percentages of each element were as follows: Al 8.55wt%; Fe 4.06wt%; Ni 4.11wt%; Mn 0.85wt%; 0.22wt% Cr, 0.25wt% Ti, with the balance being copper and unavoidable impurities.

[0059] The mechanical properties of the alloy are as follows: tensile strength 752.8 MPa, yield strength 377.2 MPa, elongation 23.6%, and Brinell hardness 185.7. It can be seen that the overall mechanical properties are better than those of NAB, NABC, and NABT in the as-cast state and solution-treated state, comparable to those of NAB, NABC, and NABT treated by aging, and lower than those of NAB, NABC, and NABT treated by solution treatment and aging.

[0060] Example 4

[0061] (1) Smelting nickel-aluminum bronze ZCuAl9Fe4Ni4Mn2 alloy; (2) After the alloy melts, the temperature is raised to 1280℃, and Cu-Cr10 master alloy is added in a certain proportion; (3) After the Cu-Cr10 master alloy has completely melted, add pure Ti in a certain proportion; (4) Add refining agent for refining treatment. The refining agent includes the following components in the following mass ratio: 40wt% manganese powder, 40wt% calcium carbonate, 10wt% flake graphene, and 10wt% rare earth powder. Adjust the temperature to 1400℃ and pour it out of the furnace.

[0062] The prepared copper alloy was tested, and the mass percentages of each element were as follows: Al 9.85 wt%; Fe 4.86 wt%; Ni 4.91 wt%; Mn 2.45 wt%; Cr 0.22 wt%; Ti 0.25 wt%, with the balance being copper and unavoidable impurities.

[0063] The mechanical properties of the alloy are: tensile strength 752.8 MPa, yield strength 401.3 MPa, elongation 18.5%, and Brinell hardness 257.3. It can be seen that the overall mechanical properties are better than those of NAB, NABC, and NABT in the as-cast state.

[0064] As can be seen from Examples 1-4, the obtained alloys do not require heat treatment to possess excellent comprehensive mechanical properties. Figure 10 As shown, the grains are significantly refined. The grain size is smaller and the morphology is more irregular. This indicates that the added Cr and Ti elements play a role in heterogeneous nucleation and inhibiting grain growth, thus refining the solidification structure. Numerous fine, bright white second-phase particles are dispersed throughout the grain boundaries and grains. These particles are likely high-melting-point, high-hardness intermetallic compounds formed by the added Cr and Ti elements. These particles pin the grain boundaries, effectively preventing their migration during hot working or heat treatment, thereby inhibiting grain growth and maintaining a fine-grained structure. These dispersed fine particles effectively hinder dislocation movement, which is the primary mechanism for improving the alloy's strength and hardness. Through grain refinement and dispersion strengthening mechanisms, the alloy's strength, hardness, and wear resistance are significantly improved.

[0065] Cu-Cr master alloy is a pre-alloyed material formed by adding a specific proportion of chromium (Cr) to a copper (Cu) matrix. It is mainly used for the precise addition of chromium during the copper alloy smelting process.

Claims

1. A high-mechanical-performance nickel-aluminum bronze alloy, characterized by: The composition includes the following elements by mass percentage: Al 8.5wt%~10.0wt%, Fe 4.0wt%~5.0wt%, Ni 4.0wt%~5.0wt%, Mn 0.8wt%~2.5wt%, Cr 0.2wt%~0.6wt%, Ti 0.2wt%~0.8wt%, total impurity elements ≤1.0wt%, and the balance is copper.

2. The method for preparing the high-mechanical-performance nickel-aluminum bronze alloy as described in claim 1, characterized in that: Includes the following steps: (1) Smelt nickel-aluminum bronze alloy; (2) Add Cu-Cr master alloy in a certain proportion; (3) After the Cu-Cr master alloy is completely melted, add pure Ti in a certain proportion; (4) Add refining agent for refining treatment, adjust the temperature, and pour out of the furnace.

3. The method for preparing the high-mechanical-performance nickel-aluminum bronze alloy as described in claim 2, characterized in that: The chemical composition of the nickel-aluminum bronze alloy in step (1) is Al 9.1wt%~9.3wt%, Fe 4.7wt%~4.8wt%, Ni 4.8wt%~4.9wt%, and Mn 1.4wt%~1.5wt%.

4. The method for preparing the high-mechanical-performance nickel-aluminum bronze alloy as described in claim 2, characterized in that: The melting temperature in step (1) is 1250℃~1280℃.

5. The method for preparing the high-mechanical-performance nickel-aluminum bronze alloy as described in claim 2, characterized in that: The Cu-Cr master alloy in step (2) is CuCr10 or CuCr25.

6. The method for preparing the high-mechanical-performance nickel-aluminum bronze alloy as described in claim 2, characterized in that: The refining agent used in step (4) includes the following components in the following mass ratio: 40 wt% aluminum, iron, nickel or manganese powder, 40 wt% calcium carbonate, 10 wt% flake graphene, and 10 wt% rare earth powder.

7. The method for preparing the high-mechanical-performance nickel-aluminum bronze alloy as described in claim 2, characterized in that: The temperature in step (4) is adjusted to 1300℃~1400℃.

8. The application of the high-mechanical-performance nickel-aluminum bronze alloy as described in claim 1, characterized in that: Used in marine equipment.

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