A method of arc additive manufacturing of a nickel-aluminum bronze alloy shaped part

Abstract

The application discloses a kind of nickel-aluminum bronze alloy forming piece electric arc additive manufacturing method, belong to metal electric arc additive manufacturing technical field.The nickel-aluminum bronze alloy electric arc additive manufacturing forming is carried out by CMT power supply, by reasonably controlling electric arc pulse correction coefficient, reducing interlayer cooling time, and the forming piece with good mechanical property, stronger corrosion resistance, and almost no anisotropy is prepared, which can be directly used for industrialized production and manufacturing.The method provides a new part manufacturing method for nickel-aluminum bronze alloy in ship propeller manufacturing, ocean engineering and other fields.

Description

Technical Field

[0001] This invention relates to the technical field of metal arc additive manufacturing, and more particularly to a method for arc additive manufacturing of nickel-aluminum bronze alloy forming parts. Background Technology

[0002] Nickel-aluminum bronze alloy is an alloy developed from aluminum bronze. Adding nickel, iron, and manganese to aluminum bronze not only refines the grain size but also inhibits the formation of harmful γ-phase, resulting in high overall mechanical strength and good corrosion resistance. It has found wide application in components such as marine propellers, large pump blades, fasteners, and seawater pipe fittings. Currently, most nickel-aluminum bronze components are produced using sand casting. Due to limitations in the production process, castings inevitably contain numerous defects such as porosity, inclusions, and grain coarsening, severely reducing their mechanical and corrosion resistance. Furthermore, traditional machining methods generally suffer from drawbacks such as long processing time, high cost, low material utilization, and environmental unfriendliness. Additive manufacturing technology, a rapidly developing material manufacturing technology in recent years, offers a series of advantages, including the ability to form complex shapes, short production time, good surface quality, and fewer internal defects. It has already been practically applied to common metallic materials such as steel, aluminum alloys, and titanium alloys.

[0003] Additive manufacturing technology, aided by computer-aided design, uses a layer-by-layer material accumulation method to create solid parts. Unlike traditional methods involving material removal, cutting, and assembly, it is a manufacturing method that builds up material layer by layer from the bottom, overcoming the bottlenecks of manufacturing complex parts that traditional methods cannot achieve. In recent years, additive manufacturing technology for metal materials has been widely applied and developed, especially selective laser powder bed melting (SLM). However, unlike other metals, copper alloys have extremely high laser reflectivity and thermal conductivity: during additive manufacturing, the vast majority of the 1080nm laser energy (approximately 90%) will be reflected by the copper substrate. Therefore, SLM, widely used in other metal materials, often performs poorly in the preparation of copper alloy parts. Furthermore, SLM has low production efficiency and high cost, and the production of copper alloy parts requires a vacuum chamber, making it unsuitable for large-scale production in the shipbuilding industry. Summary of the Invention

[0004] The technical problem to be solved by this invention is: how to prepare nickel-aluminum bronze parts with good mechanical properties, corrosion resistance and low anisotropy.

[0005] To solve the above-mentioned technical problems, the inventors, through practice and summarization, derived the technical solution of this invention, which adopts the following technical solution:

[0006] A method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts, comprising:

[0007] The first step is to create a 3D model based on the required part shape to obtain the motion control program for the arc additive manufacturing system.

[0008] The second step is to perform surface treatment on the substrate, which is made of copper plate, and use tooling to fix the substrate.

[0009] The third step is to start the electric arc additive manufacturing system, run the motion system control program, coaxially feed the nickel-aluminum bronze welding wire, and deposit it layer by layer to obtain the required nickel-aluminum bronze shaped parts.

[0010] The process parameters for the arc additive manufacturing system are as follows: arc pulse correction coefficient is set to +3 to +5, welding torch tilt angle is 10 to 15°, welding wire extension is 10 to 15 mm, welding current is 110 to 160 A, arc voltage is 10.5 to 14.5 V, welding speed is 3.0 to 6.0 mm / s, gas flow rate is 15 to 20 L / min, welding torch height is 2.0 mm after each layer, welding torch oscillation width is 10 to 16 mm, interpass cooling time is 5 to 10 s, and the shielding gas is high-purity argon.

[0011] By using a CMT power supply to perform arc additive manufacturing of nickel-aluminum bronze alloys, and by reasonably controlling the arc pulse correction coefficient and reducing the interlayer cooling time, shaped parts with good mechanical properties, strong corrosion resistance, and almost no anisotropy can be prepared and directly used for industrial production.

[0012] Preferably, the welding torch of the arc additive manufacturing system is a reciprocating deposition type, that is, the welding torch starts from the arc starting point and stops at the arc ending point, and the upper layer starts the arc from the arc ending point of the lower layer and stops at the arc starting point of the next layer.

[0013] Preferably, before the welding begins, the welding robot is placed in a three-dimensional ignition mechanism, the arc is turned off, and the welding robot walks in an empty torch without arc to conduct a simulation test.

[0014] Preferably, the process involves initiating an arc on one layer of the substrate to begin the first additive manufacturing process. After the first layer is completed, the welding torch is moved to a safe point to extinguish the arc before proceeding with the second layer of additive manufacturing. This process is repeated layer by layer, with the welding torch height set to 2.0 mm for each layer and an interlayer cooling time of 10 seconds.

[0015] Preferably, the nickel-aluminum bronze welding wire comprises 8-12 wt% Al, 3.5-6.5 wt% Ni, 2.5-5.5 wt% Fe, 1.2-2.6 wt% Mn, and the remainder Cu.

[0016] The molded parts were tested and found to have a tensile strength of 550–580 MPa, an elongation at break of 32–44%, an annual corrosion rate of 0.0449 mm / a, and longitudinal mechanical properties that are 95.6% of transverse mechanical properties.

[0017] Preferably, the nickel-aluminum bronze welding wire comprises 8-12 wt% Al, 3.5-6.5 wt% Ni, 2.5-5.5 wt% Fe, 0.5-1.6 wt% Mn, 0.1-0.18 wt% Ti, 0.1-0.15 wt% La, 0.2-0.4 wt% Cr, 0.05-0.15 wt% Gd, 0.05-0.15 wt% As, 1-2 wt% Mo, 0.05-0.15 wt% Sc, 0.05-0.1 wt% Zr, and the remainder Cu. The proportions of each component are controlled as follows: 0.013 ≤ (Sc+Zr) / Al ≤ 0.018; 0.015 ≤ (Mo+Sc+Zr+La) / Cu ≤ 0.031.

[0018] This invention is based on arc additive manufacturing technology. Due to the layer-by-layer stacking process, the properties at the layer-to-layer overlaps are often weaker, resulting in significant anisotropy in arc-added parts. Copper alloys exhibit high porosity sensitivity and a tendency to form low-melting-point eutectics at layer-to-layer overlaps during additive manufacturing, leading to pronounced anisotropy. Compared to the transverse direction, the longitudinal tensile mechanical properties of reported copper alloy arc-added parts often show a significant decrease, reaching only 70-80% of the transverse properties, severely limiting the application of arc additive manufacturing technology in copper alloys.

[0019] This invention improves the welding wire composition by rationally introducing Ti, La, Cr, Gd, Sc, Mo, and Zr elements, and controlling their ranges to 0.013≤(Sc+Zr) / Al≤0.018, 0.15≤(Mo+Sc+Zr+La) / Cu≤0.023, thereby effectively overcoming the problems of high porosity sensitivity and the easy formation of low-melting-point eutectic at layer-to-layer overlap. The addition of Ti can refine the grain size of the formed part, suppress porosity, and effectively improve the stability of the arc during additive manufacturing. The addition of Gd can effectively reduce high-temperature rheological stress, refine the grain size, and improve mechanical properties. Simultaneously, the addition of La can significantly reduce the influence of impurity elements. The addition of As can reduce low-melting-point eutectic at grain boundaries, and the introduction of Mo helps to improve mechanical properties and enhance the anisotropy of the formed part. Furthermore, Mo can effectively improve corrosion resistance. In addition, elements such as Sc, Zr, and Cr are added. Sc and Zr synergistically promote grain refinement and the formation of a multi-component solid solution phase, improving corrosion resistance. The addition of Cr helps to form a dense Cr2O3 protective film on the surface of the molded part, improving corrosion resistance. La is also introduced to hinder the combination of Cu ions and electron holes, inhibiting the diffusion rate of copper ions in the oxide layer, thereby improving the corrosion resistance of the molded part.

[0020] The molded parts were tested and found to have a tensile strength of 570-600 MPa, an elongation at break of 35-38%, an annual corrosion rate of 0.0413 mm / a, and longitudinal mechanical properties that are 97.6% of transverse mechanical properties.

[0021] Preferably, the process further includes a fourth step: solution aging treatment of the nickel-aluminum bronze forming part. Specifically, the part is placed in a vacuum furnace, heated to 870–950°C, held for 1–2 hours, cooled in a quenching medium to below 60°C, and then air-cooled to room temperature. Then, it is placed in a vacuum furnace, heated to 400–480°C, held for 1.5–2.5 hours, cooled to below 100°C, and then air-cooled to room temperature to obtain a solution-strengthened forming part. The components introduced by the welding wire are effectively utilized.

[0022] Preferably, the surface of the welding wire is further provided with a composite coating, which includes 7-8 parts of binder and 2-3 parts of metal powder. The binder consists of 80-90 parts of alcohol and 10-20 parts of flakes. The metal powder comprises 0.1-0.5 parts of Y₂O₃, 0.5-1.2 parts of Al₂O₃, and 0.2-0.8 parts of TiO₂. TiO₂ causes shrinkage of the anodic spots and arc on the workpiece surface, and changes the surface tension gradient of the molten pool, which plays a role in refining the molten droplets, improving arc stability, reducing spatter, and improving deposition efficiency. Al₂O₃ has a repairing effect on the surface of the welding wire substrate and plays a bonding role between the phases in the deposition process, improving the material density. Y₂O₃ has good fluidity and high-temperature lubricity, which helps to ensure the uniformity of the coating liquid dispersion, while reducing rheological stress to automatically fill pores, refining grains, and improving density.

[0023] Preferably, the surface of the welding wire is acid-etched and etched with a mixed solution of citric acid and dilute sulfuric acid, wherein the dilute sulfuric acid accounts for 2% to 3% and the citric acid accounts for 3% to 4%. After cleaning and drying, the coating solution is electrostatically sprayed onto the surface of the welding wire, and then dried to obtain the finished welding wire. The acid-etching roughening treatment facilitates the application of the composite coating.

[0024] The tensile strength is 600-620 MPa, the elongation at break is 38-40%, the annual corrosion rate is 0.0401 mm / a, and the longitudinal mechanical properties can reach 99.7% of the transverse mechanical properties.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] By using a CMT power supply to perform arc additive manufacturing of nickel-aluminum bronze alloys, and by reasonably controlling the arc pulse correction coefficient and reducing the interlayer cooling time, shaped parts with good mechanical properties, strong corrosion resistance, and almost no anisotropy can be prepared and directly used for industrial production.

[0027] The method described in this invention provides a novel method for manufacturing nickel-aluminum bronze alloy parts for applications such as marine propeller manufacturing and marine engineering. Attached Figure Description

[0028] Figure 1 This is a forming diagram of a straight-walled part manufactured using CMT additive manufacturing of nickel-aluminum bronze alloy according to the present invention.

[0029] Figure 2 Metallographic photograph of the interlayer overlap of the nickel-aluminum bronze alloy prepared for an embodiment of the present invention.

[0030] Figure 3 The stress-strain diagram is shown for the tensile mechanical property testing of a nickel-aluminum bronze alloy CMT additive specimen as an example.

[0031] Figure 4 The image shown is a scanning electron microscope (SEM) image of the longitudinal fracture surface in an example. Detailed Implementation

[0032] Example 1: A method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts. The welding machine used in this example is a Phonix VR7000, and the welding wire is a 1.2mm diameter nickel-aluminum bronze welding wire. The welding torch performs reciprocating deposition, meaning the torch starts at the arc ignition point and stops at the arc termination point. The next layer starts its arc at the termination point of the previous layer and stops at the starting point of the next layer. The specific steps are as follows:

[0033] The first step is to create a 3D model based on the required part shape to obtain the motion control program for the arc additive manufacturing system.

[0034] The second step is to clean the substrate. Use a wire brush and sandpaper to polish the surface of the pure copper substrate, pickle to remove the oxide film on the surface of the substrate, wipe it with acetone, and fix it on the fixture of the workbench.

[0035] The third step is to place the robot in a three-dimensional ignition mechanism before welding begins, turn off the arc ignition, and allow the welding robot to walk in an empty torch without arc ignition for simulation testing.

[0036] Start the electric arc additive manufacturing system, run the motion system control program, coaxially feed the nickel-aluminum bronze welding wire, and deposit the required nickel-aluminum bronze shaped parts layer by layer.

[0037] Position the welding torch above the substrate, select CMT mode for the welding power supply, with a pulse correction factor of +5, and use a robot arm to add material layer by layer by swinging left and right. The swing width is 14mm, the welding torch tilt angle is 15°, and the welding wire extension is 1.2mm.

[0038] Adjust and set the process parameters in the controller. The first pass is the root pass, with the welding current set to 130A, the arc voltage to 12.8V, and the material addition speed to 4.0mm / s. For subsequent passes, the welding current is set to 120A, the arc voltage to 12.1V, and the material addition speed to 4.0mm / s.

[0039] An arc is formed on one layer of the substrate to begin the first additive manufacturing process, with a length of 160mm.

[0040] After the first layer is completed, the welding torch is moved to a safe point to extinguish the arc, and then the additive manufacturing of the second layer is carried out. The layers are stacked back and forth, with the welding torch height set at 2.0 mm for each layer and the interlayer cooling time at 10 seconds.

[0041] The additive parts manufactured according to this invention were subjected to performance testing and processed into standard tensile test specimens in accordance with GB / T 39254-2020 "General Rules for Evaluation of Mechanical Properties of Additively Manufactured Metal Parts". The chemical composition of the welding wire in this embodiment is: Al 9.1wt%, Ni 5.3wt%, Mn 2.4wt%, Fe 3.3wt%, with the remainder being Cu.

[0042] Table 1. Test results of corrosion rate of the molded body in the embodiment.

[0043] Experimental temperature Annual corrosion rate / mm·a⁻¹ Corrosion level Example 1 25℃ 0.0449 4 (Corrosion Resistance)

[0044] The molded parts were tested and found to have a tensile strength of 565 MPa, an elongation at break of 32%, an annual corrosion rate of 0.0449 mm / a, and longitudinal mechanical properties that are 95.6% of transverse mechanical properties.

[0045] Example 2: The nickel-aluminum bronze welding wire comprises 8 wt% Al, 3.5 wt% Ni, 2.5 wt% Fe, 0.5 wt% Mn, 0.15 wt% Ti, 0.12 wt% La, 0.3 wt% Cr, 0.08 wt% Gd, 0.06 wt% As, 1.5 wt% Mo, 0.07 wt% Sc, 0.06 wt% Zr, and the remainder is Cu. The proportions of each component are controlled as follows:

[0046] 0.013≤(Sc+Zr) / Al≤0.018; 0.15≤(Mo+Sc+Zr+La) / Cu≤0.023.

[0047] This invention is based on arc additive manufacturing technology. Due to the layer-by-layer stacking process, the performance at the layer-to-layer overlaps is often weak, resulting in significant anisotropy in arc-added parts. Copper alloys exhibit high porosity sensitivity and a tendency for low-melting-point eutectics to form at layer-to-layer overlaps during additive manufacturing, leading to pronounced anisotropy. Compared to the transverse direction, the longitudinal tensile mechanical properties of reported copper alloy arc-added parts often show a significant decrease, reaching only 70-80% of the transverse properties, severely limiting the application of arc additive manufacturing technology in copper alloys. This invention addresses this issue by improving the welding wire composition, rationally introducing Ti, La, Cr, Gd, Sc, Mo, and Zr elements, and controlling their ranges to 0.013≤(Sc+Zr) / Al≤0.018, 0.15≤(Mo+Sc+Zr+La) / Cu≤0.023, thereby effectively overcoming the problems of high porosity sensitivity and the tendency for low-melting-point eutectics to form at layer-to-layer overlaps. The addition of Ti can refine the grain size of the formed part, suppress the formation of porosity, and effectively improve the stability of the arc during additive manufacturing. The addition of Gd can effectively reduce high-temperature rheological stress, refine the grain size, and improve mechanical properties. Meanwhile, the addition of La can significantly reduce the influence of impurity elements. The addition of As can reduce the low-melting eutectic at grain boundaries, and the introduction of Mo helps to improve mechanical properties and anisotropy of the formed part, while Mo effectively improves corrosion resistance. In addition, elements such as Sc, Zr, and Cr are added. Sc and Zr synergistically promote grain refinement and the formation of a multi-component solid solution phase to improve corrosion resistance, while the addition of Cr helps to form a dense Cr2O3 protective film on the surface of the formed part, improving corrosion resistance. The introduction of La also helps to hinder the binding of Cu ions with electron-hole pairs, inhibiting the diffusion rate of copper ions in the oxide layer, thereby improving the corrosion resistance of the formed part.

[0048] Table 2. Results of corrosion rate test on the molded body in Example 2

[0049] Experimental temperature Annual corrosion rate / mm·a⁻¹ Corrosion level Example 1 25℃ 0.0413 3 (Corrosion Resistance)

[0050] The molded parts were tested and found to have a tensile strength of 575 MPa, an elongation at break of 36%, an annual corrosion rate of 0.0413 mm / a, and longitudinal mechanical properties that are 97.6% of transverse mechanical properties.

[0051] Example 3: The nickel-aluminum bronze welding wire comprises 8–12 wt% Al, 3.5–6.5 wt% Ni, 2.5–5.5 wt% Fe, 0.5–1.6 wt% Mn, 0.5–1.5 wt% Zn, 0.2–0.5 wt% Mg, 0.2–0.5 wt% Si, 0.2–0.5 wt% Nb, with the remainder being Cu. The proportions of each component are controlled as follows:

[0052] 0.08≤Zn / (Mg+Al)≤0.15, 0.13≤(Nb+Zn) / Cu≤0.27, 0.015≤(Zn+Mg+Si) / (Cu+Al)≤0.031.

[0053] This invention improves the welding wire composition by rationally introducing Zn, Mg, Nb, and Si elements, and controlling their ranges to 0.08≤Zn / (Mg+Al)≤0.15, 0.13≤(Nb+Zn) / Cu≤0.27, and 0.015≤(Zn+Mg+Si) / (Cu+Al)≤0.031. This effectively overcomes the problems of high porosity sensitivity and easy formation of low-melting-point eutectic at the layer-to-layer overlap. It utilizes the strong interaction between Mg and Si in the alloy and Cu to form atomic pairs, resulting in composite clusters (Mg / Si / Cu) in the alloy. These composite clusters can act as nucleation sites for β”, increasing the solid solution aging effect during the later stages of alloy heat treatment, enhancing the amount of β” precipitates, improving the aging effect, and improving the high strength and corrosion resistance of the formed parts. Furthermore, rationally introduced elements can form solid solution phases and intermetallic compound phases, offering advantages such as high hardness, high strength, and high corrosion resistance. Simultaneously, they can effectively inhibit grain growth, making the material structure more compact, thereby increasing wear resistance and impact toughness. The alloy structure also exists in the form of CuAl2 phase, CuMgAl2 phase, and Al2Cu2Mg8Si7 phase. These precipitates are dispersed in the matrix during aging treatment, pinning dislocations and hindering grain boundaries, thus causing alloy strengthening. The CuAl2 second phase can act as heterogeneous nuclei, providing nucleation sites, increasing the alloy nucleation rate, and refining the alloy grains. Cu atoms can also segregate at the Q / α(Al) interface, leading to Mg2Si precipitates becoming dominant at the grain boundaries of the Al-Mg-Si alloy. Under certain conditions, these precipitates hydrolyze to form Mg(OH)2 and SiO2H2O, which provides some protection to the alloy. However, the Al compounds have a large potential difference with the matrix, thus forming a galvanic cell and accelerating the dissolution of solute-poor regions in the alloy, exacerbating intergranular corrosion. The segregation of Cu atoms at the Q / α(Al) interface also intensifies intergranular corrosion. Therefore, adding an appropriate amount of Zn to copper alloys precipitates T-Mg32(AlZn)49 at the grain boundaries, replacing β-Al3Mg2, thereby reducing the gap and potential difference between the matrix and the grain boundary phases, causing them to deviate from the interface and improving the alloy's resistance to intergranular corrosion. Simultaneously, the appropriate introduction of Zn reduces high-temperature rheological stress, decreases grain size, improves the alloy's ductility and formability, and enhances its age-hardening effect.

[0054] Table 3. Results of corrosion rate test on the molded body in Example 3

[0055] Experimental temperature Annual corrosion rate / mm·a⁻¹ Corrosion level Example 1 25℃ 0.0411 2 (Corrosion Resistance)

[0056] The molded parts were tested and found to have a tensile strength of 582 MPa, an elongation at break of 36%, an annual corrosion rate of 0.0413 mm / a, and longitudinal mechanical properties that are 98.3% of transverse mechanical properties.

[0057] Example 4 also includes step four, which involves solution aging treatment of the nickel-aluminum bronze forming part. Specifically, the part is placed in a vacuum furnace, heated to 870–950°C, held for 1–2 hours, cooled in a quenching medium to below 60°C, and then air-cooled to room temperature. Then, it is placed in a vacuum furnace, heated to 400–480°C, held for 1.5–2.5 hours, cooled to below 100°C, and then air-cooled to room temperature to obtain a solution-strengthened forming part. The components introduced by the welding wire are effectively utilized.

[0058] Table 4. Results of corrosion rate test on the molded body in Example 4

[0059] Experimental temperature Annual corrosion rate / mm·a⁻¹ Corrosion level Example 1 25℃ 0.0408 2 (Corrosion Resistance)

[0060] The molded parts were tested and found to have a tensile strength of 591 MPa, an elongation at break of 38%, an annual corrosion rate of 0.0408 mm / a, and longitudinal mechanical properties that are 98.3% of transverse mechanical properties.

[0061] Example 5: Based on the above examples, the surface of the welding wire is further provided with a composite coating. The composite coating includes 8 parts of binder and 2 parts of metal powder. The binder consists of 85 parts of alcohol and 15 parts of flakes. The metal powder comprises 0.3 parts of Y₂O₃, 1.1 parts of Al₂O₃, and 0.6 parts of TiO₂. TiO₂ causes shrinkage of the anodic spots and arc on the workpiece surface, and changes the surface tension gradient of the molten pool, which refines the molten droplets, improves arc stability, reduces spatter, and improves deposition efficiency. Al₂O₃ has a repairing effect on the surface of the welding wire substrate and plays a bonding role between the phases in the cladding process, improving the material density. Y₂O₃ has good fluidity and high-temperature lubricity, which helps to ensure the uniformity of the coating liquid dispersion, while reducing rheological stress to automatically fill pores, refine grains, and improve density.

[0062] The surface of the welding wire is acid-etched and etched with a mixed solution of citric acid and dilute sulfuric acid, with the dilute sulfuric acid accounting for 2%–3% and the citric acid accounting for 3%–4%. After cleaning and drying, the coating solution is electrostatically sprayed onto the surface of the welding wire, and then dried to obtain the finished welding wire. The acid-etching roughening treatment facilitates the application of the composite coating.

[0063] Table 5. Results of corrosion rate test on the molded body in Example 2

[0064] Experimental temperature Annual corrosion rate / mm·a⁻¹ Corrosion level Example 1 25℃ 0.0401 2 (Corrosion Resistance)

[0065] The molded parts were tested and found to have a tensile strength of 603 MPa, an elongation at break of 40%, an annual corrosion rate of 0.0401 mm / a, and longitudinal mechanical properties that are 99.7% of transverse mechanical properties.

Claims

1. A method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts, characterized in that, include: The first step is to create a 3D model based on the required part shape to obtain the motion control program for the arc additive manufacturing system. The second step is to perform surface treatment on the substrate, which is made of copper plate, and use tooling to fix the substrate. The third step is to start the electric arc additive manufacturing system, run the motion system control program, coaxially feed the nickel-aluminum bronze welding wire, and deposit it layer by layer to obtain the required nickel-aluminum bronze shaped parts. The process parameters for the arc additive manufacturing system are as follows: arc pulse correction coefficient is set to +3~+5, welding torch tilt angle is 10~15°, welding wire extension is 10~15mm, welding current is 110~160A, arc voltage is 10.5~14.5V, welding speed is 3.0~6.0mm / s, gas flow rate is 15~20L / min, welding torch height is 2.0mm after each layer, welding torch oscillation width is 10~16mm, interpass cooling time is 5~10s, and shielding gas is high-purity argon. The composition of the nickel-aluminum bronze welding wire includes 8~12 wt% Al, 3.5~6.5 wt% Ni, 2.5~5.5 wt% Fe, 0.5~1.6 wt% Mn, 0.1~0.18 wt% Ti, 0.1~0.15 wt% La, 0.2~0.4 wt% Cr, 0.05~0.15 wt% Gd, 0.05~0.15 wt% As, 1~2 wt% Mo, 0.05~0.15 wt% Sc, 0.05~0.1 wt% Zr, and the remainder is Cu. The proportions of each component are controlled as follows: 0.013≤(Sc+Zr) / Al≤0.018; 0.015≤(Mo+Sc+Zr+La) / Cu≤0.

031.

2. The method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts according to claim 1, characterized in that, The welding torch of the electric arc additive manufacturing system is a reciprocating deposition method, that is, the welding torch starts from the arc starting point and stops at the arc ending point, and the upper layer starts the arc from the arc ending point of the lower layer and stops at the arc starting point of the next layer.

3. The method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts according to claim 1, characterized in that, The first layer of the substrate is started with an arc, and the first additive manufacturing process begins. After the first layer is completed, the welding torch is moved to a safe point to extinguish the arc, and the second layer of additive manufacturing is then carried out. The process is repeated layer by layer, with the welding torch height set to 2.0 mm for each layer and the interlayer cooling time set to 10 seconds.

4. The method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts according to claim 1, characterized in that, The process also includes step four, which involves solution aging treatment of the nickel-aluminum bronze molded parts. Specifically, the parts are placed in a vacuum furnace and heated to 870-950°C, held for 1-2 hours, cooled in a quenching medium to below 60°C, and then air-cooled to room temperature. The parts are then placed in a vacuum furnace, heated to 400-480°C, held for 1.5-2.5 hours, cooled to below 100°C, and then air-cooled to room temperature to obtain the solution-strengthened molded parts.

5. The method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts according to claim 1, characterized in that, The surface of the welding wire is also provided with a composite coating, which includes 7-8 parts of binder and 2-3 parts of metal powder. The binder consists of 80-90 parts of alcohol and 10-20 parts of flakes. The metal powder consists of 0.1-0.5 parts of Y2O3, 0.5-1.2 parts of Al2O3 and 0.2-0.8 parts of TiO2.

6. The method for arc additive manufacturing of nickel-aluminum bronze alloy formed parts according to claim 1, characterized in that, The surface of the welding wire is pickled and etched with a mixed solution of citric acid and dilute sulfuric acid, with the dilute sulfuric acid accounting for 2% to 3% and the citric acid accounting for 3% to 4%. After cleaning and drying, the coating solution is electrostatically sprayed onto the surface of the welding wire and then dried to obtain the finished welding wire.

7. The molded part obtained by the arc additive manufacturing method as described in claim 1, characterized in that, The nickel-aluminum bronze molded parts have a tensile strength of 570~600MPa, an elongation at break of 35~40%, an annual corrosion rate of 0.0413mm / a, and longitudinal mechanical properties that can reach 99.6% of transverse mechanical properties.

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