Heat-resistant high-strength aluminum alloy wire and electric arc additive manufacturing process thereof

Abstract

The present application relates to a kind of heat-resistant high-strength aluminum alloy wire and its electric arc additive manufacturing process, belong to metal material technical field, to solve one of the problems such as low strength, poor heat resistance of existing electric arc additive manufacturing aluminum alloy component.The aluminum alloy wire of the present application is based on Sc+Zr composite reinforced Al-Mg alloy, add certain proportion of Fe (1.0~5.0%) and Ni (0.45~0.55%) element, not only effectively reduce the Sc element content in wire, save production cost, improve the quality of aluminum alloy wire, but also greatly improve the electric arc additive manufacturing aluminum alloy component room temperature and high temperature mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of metal materials technology, and in particular to a heat-resistant high-strength aluminum alloy wire and its arc additive manufacturing process. Background Technology

[0002] With the rapid development of aerospace, launch vehicles, weaponry, and new energy vehicles, higher demands are being placed on materials for lightweighting, high strength, and heat resistance. Currently, aluminum alloys are the most widely used non-ferrous metal and the most ideal lightweight material. However, aluminum alloys still suffer from insufficient strength and heat resistance, severely restricting their widespread use in high-end structural materials. Therefore, to meet the high strength and heat resistance requirements of aluminum alloy components, it is necessary to develop a new generation of heat-resistant, high-strength aluminum alloy materials.

[0003] On the other hand, traditional manufacturing techniques for aluminum alloy components (forging, rolling, etc.) involve complex processing steps, long manufacturing cycles, and high production costs, especially for structurally complex components, where processing is extremely difficult. Arc additive manufacturing, a type of additive manufacturing technology, uses an electric arc as a heat source and metal wire as the deposition material to progressively build up metal components layer by layer. It offers advantages such as high deposition efficiency, low production costs, and the ability to form complex metal components. Therefore, arc additive manufacturing technology has been widely researched and applied in the manufacturing of large and complex components.

[0004] Currently, it is difficult to achieve both room temperature strength and heat resistance in aluminum alloy components prepared using electric arc additive manufacturing technology. Many studies have used wires with high Sc content, but the formed parts have significant porosity defects and minimal strengthening effect. At the same time, the production of high Sc aluminum alloy wires is extremely difficult. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a heat-resistant high-strength aluminum alloy wire and its arc additive manufacturing process to solve one of the problems of low strength and poor heat resistance of existing arc additive manufacturing aluminum alloy components.

[0006] In a first aspect, the present invention provides a heat-resistant high-strength aluminum alloy wire, the chemical composition of which, by mass percentage, comprises: Mg 7.0-8.0%, Sc 0.2-0.6%, Zr 0.1-0.3%, Mn 0.8-0.9%, Si 0.08-0.12%, Fe 1.0-5.0%, Ni 0.45-0.55%, Be 0.0001-0.0005%, with the balance being Al.

[0007] Furthermore, when 0.4% ≤ Sc ≤ 0.6%, then 1.0% ≤ Fe ≤ 3.5%; when 0.2% ≤ Sc < 0.4%, then 2.5% ≤ Fe ≤ 5.0%.

[0008] Furthermore, the Sc content is 0.3–0.5%, the Zr content is 0.15–0.25%, and the Fe content is 1.0–3.0%.

[0009] Secondly, the present invention provides a method for preparing the above-mentioned heat-resistant high-strength aluminum alloy wire, comprising the following steps: vacuum smelting → homogenization treatment → turning treatment → extrusion → wire rod → drawing → annealing treatment → scraping / sizing → ultrasonic cleaning → winding → packaging.

[0010] Furthermore, the vacuum degree in vacuum smelting is 0–5 Pa, the homogenization temperature is 420–460℃, the homogenization time is 24–36 h, the extrusion temperature is 450–480℃, the annealing temperature is 420–480℃, and the annealing time is 4–6 h.

[0011] Thirdly, the present invention provides an arc additive manufacturing process utilizing the above-mentioned heat-resistant high-strength aluminum alloy wire, comprising the following steps:

[0012] (1) Using high-temperature and high-strength aluminum alloy wire, variable polarity cold metal transfer (CMT Advanced) arc additive manufacturing is used to obtain shaped parts;

[0013] (2) The formed part is subjected to aging treatment to obtain an aluminum alloy component.

[0014] Furthermore, the process parameters for arc additive manufacturing are as follows: current 80-110A, voltage 9.4-10.1V, wire feed speed 5.7-8.0m / min, and scanning speed 8-12mm / s;

[0015] The protective gas is 99.99% Ar, the gas flow rate is 20-25 L / min, the substrate preheating temperature is 100-200℃, and the inter-channel temperature is ≤100℃.

[0016] Furthermore, in step (2), the temperature of the aging heat treatment is 310-360℃, and the aging time is 4-8h.

[0017] Furthermore, in step (2), the room temperature tensile strength of the molded part is ≥415MPa;

[0018] The aluminum alloy components have a tensile strength ≥495MPa, an elongation after fracture ≥11.5%, and a tensile strength at 250℃ ≥245MPa.

[0019] Furthermore, in step (2), the microstructure of the molded part includes AlFe phase, Al3Ni phase and Al3(Sc,Zr) phase.

[0020] Furthermore, the AlFe phase size is 50–300 nm, the Al3Ni phase size is 50–100 nm, and the Al3(Sc,Zr) phase size is 10–50 nm;

[0021] By volume percentage, the AlFe phase is 2.00-3.20%, the Al3Ni phase is 1.10-1.30%, and the Al3(Sc,Zr) phase is 1.60-2.20%.

[0022] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0023] (1) The aluminum alloy wire of the present invention is based on the Sc+Zr composite reinforced Al-Mg alloy, with the addition of a certain proportion of Fe (1.0-5.0%) and Ni (0.45-0.55%) elements, which not only effectively reduces the Sc element content in the wire, saves production costs, and improves the quality of aluminum alloy wire, but also greatly improves the room temperature and high temperature mechanical properties of aluminum alloy components manufactured by electric arc additive manufacturing.

[0024] (2) The electric arc additive manufacturing process of the present invention adopts variable polarity cold metal transfer (CMT Advanced) electric arc additive manufacturing. By selecting specific process parameters, high-quality aluminum alloy components are obtained. The porosity of the formed parts is <0.31%, the room temperature tensile strength of the formed parts is ≥415MPa, the tensile strength of the aluminum alloy components is ≥495MPa, the elongation after fracture is ≥11.5%, and the tensile strength at 250℃ is ≥245MPa.

[0025] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] Figure 1 A photograph of the aluminum alloy wire prepared in Example 1 of this invention;

[0028] Figure 2 This is a cross-sectional morphology diagram of the aluminum alloy wire prepared in Example 1 of the present invention;

[0029] Figure 3 This is a physical image of the aluminum alloy component prepared according to Example 1 of the present invention;

[0030] Figure 4 This is a microstructure image of the molded part prepared in Example 1 of the present invention;

[0031] Figure 5 This is a microstructure image of the molded part prepared in Example 2 of the present invention;

[0032] Figure 6 The image shows the microstructure of the molded part prepared for Comparative Example 3. Detailed Implementation

[0033] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0034] A specific embodiment of the present invention discloses a heat-resistant high-strength aluminum alloy wire, the chemical composition of which, by mass percentage, comprises: Mg 7.0-8.0%, Sc 0.2-0.6%, Zr 0.1-0.3%, Mn 0.8-0.9%, Si 0.08-0.12%, Fe 1.0-5.0%, Ni 0.45-0.55%, Be 0.0001-0.0005%, with the balance being Al.

[0035] Compared with the prior art, the present invention makes a specific design for the composition of aluminum alloy wire. Specifically, Mg is an important strengthening element in Al-Mg alloy, and forms a β phase with the Al matrix to produce a solid solution strengthening effect. At the same time, considering the strong work hardening ability of Mg, the present invention appropriately increases the Mg content (7.0-8.0%) to maximize the solid solution strengthening effect of Mg.

[0036] In this invention, a certain proportion of Mn is added to the aluminum alloy wire composition. Its function is to dissolve into the matrix, resulting in solid solution strengthening. Furthermore, in alloys with high Mg content, the addition of Mn can reduce the tendency for welding cracks and improve strength. Simultaneously, the low diffusion rate of Mn in the aluminum matrix ensures the stability of the solid solution.

[0037] The aluminum alloy wire of this invention incorporates a certain proportion of Sc (0.2-0.6%) and Zr (0.1-0.3%) elements, which can produce composite microalloying, forming micron-sized Al3(Sc,Zr) phase and nano-sized Al3Sc phase. The micron-sized Al3(Sc,Zr) phase has a very small mismatch with the Al matrix, which can significantly refine the grains; the nano-sized Al3Sc phase is completely coherent with the Al matrix, which can hinder dislocation movement and has good high-temperature thermal stability, thereby improving the mechanical properties of the material.

[0038] In this invention, a certain proportion of Si (0.08–0.12%) is added to the aluminum alloy wire composition. Trace amounts of Si can accelerate the precipitation of the Al3Sc phase. However, Si and Sc in the aluminum alloy not only form the compound Sc2AlSi2 phase, but also affect the decomposition of Sc-containing alloy solid solutions. Therefore, the Si content needs to be strictly controlled.

[0039] The aluminum alloy wire of this invention incorporates a certain proportion of Fe (1.0–5.0%) to form the AlFe phase (Al13Fe4, Al6Fe, etc.) with Al, exhibiting excellent heat resistance. This not only improves the mechanical properties of the material but also reduces the amount of Sc used, thereby lowering production costs. Furthermore, the addition of a certain proportion of Ni (0.45–0.55%) to the aluminum alloy wire of this invention forms the heat-resistant Al3Ni phase with Al, significantly enhancing the high-temperature performance of the material.

[0040] The aluminum alloy wire composition of this invention also includes 0.0001-0.0005% Be to solve the cracking problem caused by high Mg content.

[0041] Under the above conditions, the H content in aluminum alloy wire can be controlled to be ≤0.10mL / 100gAl, preventing excessive H content from affecting the performance of aluminum alloy components.

[0042] In one specific implementation, when 0.4% ≤ Sc ≤ 0.6%, then 1.0% ≤ Fe ≤ 3.5%; when 0.2% ≤ Sc < 0.4%, then 2.5% ≤ Fe ≤ 5.0%.

[0043] In a preferred embodiment, the Sc content is 0.3-0.5%, the Zr content is 0.15-0.25%, and the Fe content is 1.0-3.0%.

[0044] Another specific embodiment of the present invention discloses a method for preparing the above-mentioned heat-resistant high-strength aluminum alloy wire, comprising the following steps: vacuum smelting → homogenization treatment → turning treatment → extrusion → wire rod → drawing → annealing treatment → scraping / sizing → ultrasonic cleaning → winding → packaging.

[0045] All of the above aluminum alloy wires are prepared using existing technologies.

[0046] In one specific embodiment, the vacuum degree in vacuum smelting is 0-5 Pa, the homogenization temperature is 420-460°C, the homogenization time is 24-36 h, the extrusion temperature is 450-480°C, the annealing temperature is 420-480°C, and the annealing time is 4-6 h.

[0047] In one specific embodiment, the diameter of the aluminum alloy wire is 1.2 mm.

[0048] The aluminum alloy wire of this invention is based on Sc+Zr composite reinforced Al-Mg alloy, with the addition of a certain proportion of Fe (1.0-5.0%) and Ni (0.45-0.55%) elements. This not only effectively reduces the Sc element content in the wire, saves production costs, and improves the quality of the aluminum alloy wire, but also greatly improves the room temperature and high temperature mechanical properties of aluminum alloy components manufactured by arc additive manufacturing.

[0049] Another specific embodiment of the present invention discloses an arc additive manufacturing process for the above-mentioned heat-resistant high-strength aluminum alloy wire, comprising the following steps:

[0050] (1) Using high-temperature and high-strength aluminum alloy wire, variable polarity cold metal transfer (CMT Advanced) arc additive manufacturing is used to obtain shaped parts;

[0051] (2) The formed part is subjected to aging treatment to obtain an aluminum alloy component.

[0052] In one specific implementation, step (1) is further performed by polishing and cleaning the substrate to remove the surface oxide film.

[0053] In one specific implementation, in step (1), the electric arc additive manufacturing process parameters are as follows: current is 80-110A, voltage is 9.4-10.1V, wire feeding speed is 5.7-8.0m / min, and scanning speed is 8-12mm / s;

[0054] The protective gas is 99.99% Ar, the gas flow rate is 20-25 L / min, the substrate preheating temperature is 100-200℃, and the inter-channel temperature is ≤100℃.

[0055] In one specific implementation, in step (1), additive manufacturing employs a reciprocating layer-by-layer deposition forming strategy.

[0056] In one specific implementation, in step (2), the temperature of the aging heat treatment is 310-360°C and the aging time is 4-8 hours.

[0057] In one specific implementation, in step (1), the room temperature tensile strength of the molded part is ≥415MPa.

[0058] In one specific implementation, in step (2), the aluminum alloy component has a tensile strength ≥495MPa, an elongation after fracture ≥11.5%, and a tensile strength at 250℃ ≥245MPa.

[0059] In one specific implementation, in step (2), the microstructure of the molded part includes AlFe phase, Al3Ni phase and Al3(Sc,Zr) phase.

[0060] In a preferred embodiment, the AlFe phase comprises 2.00-3.20% by volume, the Al3Ni phase comprises 1.10-1.30% and the Al3(Sc,Zr) phase comprises 1.60-2.20%.

[0061] In a preferred embodiment, the porosity of the molded part is <0.31%.

[0062] The electric arc additive manufacturing process of this invention adopts variable polarity cold metal transfer (CMT Advanced) electric arc additive manufacturing. By selecting specific process parameters, high-quality aluminum alloy components are obtained. The porosity of the formed parts is <0.31%, the room temperature tensile strength of the formed parts is ≥415MPa, the tensile strength of the aluminum alloy components is ≥495MPa, the elongation after fracture is ≥11.5%, and the tensile strength at 250℃ is ≥245MPa.

[0063] The technical solution of the present invention will be further explained below with reference to specific embodiments.

[0064] Example 1

[0065] The chemical composition of a heat-resistant, high-strength aluminum alloy wire according to this embodiment is shown in Table 1, and a physical image of the aluminum alloy wire is shown below. Figure 1 As shown, the cross-sectional morphology is as follows Figure 2 As shown, the diameter of the aluminum alloy wire is 1.2 mm.

[0066] The method for preparing aluminum alloy wire in this embodiment includes the following steps: vacuum smelting → homogenization treatment → turning treatment → extrusion → wire rod → drawing → annealing treatment → scraping / sizing → ultrasonic cleaning → winding → packaging.

[0067] The vacuum degree in vacuum smelting is 1 Pa, the homogenization temperature is 440℃, the homogenization time is 30h, the extrusion temperature is 465℃, the annealing temperature is 450℃, and the annealing time is 5h.

[0068] This embodiment conducts a single-pass multi-layer thin-walled component manufacturing experiment using aluminum alloy wire. Specifically, this embodiment utilizes the above-mentioned aluminum alloy wire arc additive manufacturing process, which includes the following steps:

[0069] (1) First, the substrate is polished and cleaned to remove the surface oxide film. The substrate is preheated to 120°C and the interpass temperature is 90°C. Using variable polarity cold metal transfer (CMTA advanced) arc additive manufacturing technology, a reciprocating layer-by-layer deposition forming strategy is adopted. The current is 80A, the voltage is 9.4V, the wire feed speed is 5.7m / min, and the scanning speed is 8mm / s. The protective gas is 99.99%Ar and the gas flow rate is 20L / min to obtain the formed part.

[0070] (2) The formed part is subjected to aging treatment at a temperature of 335°C and an aging time of 6 hours to obtain an aluminum alloy component.

[0071] A physical image of the single-pass multilayer thin-walled aluminum alloy component prepared in this embodiment is shown below. Figure 3 As shown in the figure, the component is well-formed with no obvious surface defects. The microstructure of the formed part is as follows: Figure 4 As shown in the figure, the microstructure of the formed parts is equiaxed, with an average grain size of approximately 9.3 μm. The microstructure contains a large number of precipitates such as Al3(Sc,Zr), AlFe, and Al3Ni. Al3(Sc,Zr) is spherically dispersed in the α-Al matrix, with a size of 10–50 nm (e.g., Al3(Sc,Zr)). Figure 5 As shown in the figure, Al3Ni is spherical with a size of 50-100 nm, and AlFe is rod-shaped or quadrilateral with a size of 80-300 nm. These precipitated phases can significantly improve the mechanical properties of aluminum alloys. The volume ratios of Al3(Sc,Zr) phase, Al3Ni phase, and AlFe phase are shown in Table 2. The porosity and mechanical properties of the formed parts of this embodiment are shown in Table 2.

[0072] Example 2

[0073] The chemical composition of a heat-resistant high-strength aluminum alloy wire in this embodiment is shown in Table 1. The diameter of the aluminum alloy wire is 1.2 mm.

[0074] The method for preparing aluminum alloy wire in this embodiment includes the following steps: vacuum smelting → homogenization treatment → turning treatment → extrusion → wire rod → drawing → annealing treatment → scraping / sizing → ultrasonic cleaning → winding → packaging.

[0075] The vacuum degree in vacuum smelting is 3 Pa, the homogenization temperature is 420℃, the homogenization time is 36 h, the extrusion temperature is 480℃, the annealing temperature is 480℃, and the annealing time is 4 h.

[0076] This embodiment conducts a single-pass multi-layer thin-walled component manufacturing experiment using aluminum alloy wire. Specifically, this embodiment utilizes the above-mentioned aluminum alloy wire arc additive manufacturing process, which includes the following steps:

[0077] (1) First, the substrate is polished and cleaned to remove the surface oxide film. The substrate is preheated to 150°C and the interpass temperature is 100°C. Using variable polarity cold metal transfer (CMTA advanced) arc additive manufacturing technology, a reciprocating layer-by-layer deposition forming strategy is adopted. The current is 100A, the voltage is 9.9V, the wire feed speed is 7.3m / min, and the scanning speed is 10mm / s. The protective gas is 99.99%Ar and the gas flow rate is 22L / min to obtain the formed part.

[0078] (2) The formed part is subjected to aging treatment at a temperature of 360°C for 4 hours to obtain an aluminum alloy component.

[0079] The single-pass multilayer thin-walled aluminum alloy component prepared in this embodiment has similar properties and microstructure to that of Example 1. The aluminum alloy component exhibits good forming and no obvious surface defects. The microstructure of the formed parts is equiaxed, with an average grain size of approximately 8.4 μm. The microstructure contains a large number of precipitates such as Al3(Sc,Zr), AlFe, and Al3Ni. Al3(Sc,Zr) is spherically dispersed in the α-Al matrix, with a size of 10–50 nm; Al3Ni is spherical, with a size of 50–100 nm; and the AlFe phase is rod-shaped or quadrilateral, with a size of 80–300 nm. These precipitates significantly improve the mechanical properties of the aluminum alloy. The volume ratios of the Al3(Sc,Zr), Al3Ni, and AlFe phases are shown in Table 2. The porosity and mechanical properties of the formed parts in this embodiment are shown in Table 2.

[0080] Example 3

[0081] The chemical composition of a heat-resistant high-strength aluminum alloy wire in this embodiment is shown in Table 1. The diameter of the aluminum alloy wire is 1.2 mm.

[0082] The method for preparing aluminum alloy wire in this embodiment includes the following steps: vacuum smelting → homogenization treatment → turning treatment → extrusion → wire rod → drawing → annealing treatment → scraping / sizing → ultrasonic cleaning → winding → packaging.

[0083] The vacuum degree in vacuum smelting is 3 Pa, the homogenization temperature is 460℃, the homogenization time is 24h, the extrusion temperature is 450℃, the annealing temperature is 420℃, and the annealing time is 6h.

[0084] This embodiment conducts a single-pass multi-layer thin-walled component manufacturing experiment using aluminum alloy wire. Specifically, this embodiment utilizes the above-mentioned aluminum alloy wire arc additive manufacturing process, which includes the following steps:

[0085] (1) First, the substrate is polished and cleaned to remove the surface oxide film. The substrate is preheated to 180°C and the interpass temperature is 100°C. Using variable polarity cold metal transfer (CMTA advanced) arc additive manufacturing technology, a reciprocating layer-by-layer deposition forming strategy is adopted. The current is 90A, the voltage is 9.7V, the wire feed speed is 6.5m / min, and the scanning speed is 10mm / s. The protective gas is 99.99%Ar and the gas flow rate is 25L / min to obtain the formed part.

[0086] (2) The formed part is subjected to aging treatment at a temperature of 310°C and an aging time of 8 hours to obtain an aluminum alloy component.

[0087] The single-pass multilayer thin-walled aluminum alloy component prepared in this embodiment has similar properties and microstructure to that of Example 1. The aluminum alloy component exhibits good forming and no obvious surface defects. The microstructure of the formed parts is equiaxed, with an average grain size of approximately 7.9 μm. The microstructure contains a large number of precipitates such as Al3(Sc,Zr), AlFe, and Al3Ni. Al3(Sc,Zr) is spherically dispersed in the α-Al matrix, with a size of 10–50 nm; Al3Ni is spherical, with a size of 50–100 nm; and the AlFe phase is rod-shaped or quadrilateral, with a size of 80–300 nm. These precipitates significantly improve the mechanical properties of the aluminum alloy. The volume fractions of the Al3(Sc,Zr), Al3Ni, and AlFe phases are shown in Table 2. The porosity and mechanical properties of the formed parts in this embodiment are shown in Table 2.

[0088] Example 4

[0089] The chemical composition of a heat-resistant high-strength aluminum alloy wire in this embodiment is shown in Table 1. The diameter of the aluminum alloy wire is 1.2 mm.

[0090] The method for preparing aluminum alloy wire in this embodiment includes the following steps: vacuum smelting → homogenization treatment → turning treatment → extrusion → wire rod → drawing → annealing treatment → scraping / sizing → ultrasonic cleaning → winding → packaging.

[0091] The vacuum degree in vacuum smelting is 5 Pa, the homogenization temperature is 440℃, the homogenization time is 30 h, the extrusion temperature is 465℃, the annealing temperature is 450℃, and the annealing time is 5 h.

[0092] This embodiment conducts a single-pass multi-layer thin-walled component manufacturing experiment using aluminum alloy wire. Specifically, this embodiment utilizes the above-mentioned aluminum alloy wire arc additive manufacturing process, which includes the following steps:

[0093] (1) First, the substrate is polished and cleaned to remove the surface oxide film. The substrate is preheated to 200°C and the interpass temperature is 100°C. Using variable polarity cold metal transfer (CMTA advanced) arc additive manufacturing technology, a reciprocating layer-by-layer deposition forming strategy is adopted. The current is 110A, the voltage is 10.1V, the wire feed speed is 8.0m / min, and the scanning speed is 12mm / s. The protective gas is 99.99%Ar and the gas flow rate is 20L / min to obtain the formed part.

[0094] (2) The formed part is subjected to aging treatment at a temperature of 335°C and an aging time of 6 hours to obtain an aluminum alloy component.

[0095] The single-pass multilayer thin-walled aluminum alloy component prepared in this embodiment has similar properties and microstructure to that of Example 1. The aluminum alloy component exhibits good forming characteristics, with no deformation or cracking. The microstructure of the formed parts is equiaxed, with an average grain size of approximately 7.1 μm. The formed microstructure contains a large number of precipitates such as Al3(Sc,Zr), AlFe, and Al3Ni. Al3(Sc,Zr) is spherically dispersed in the α-Al matrix, with a size of 10–50 nm; Al3Ni is spherical, with a size of 50–100 nm; and the AlFe phase is rod-shaped or quadrilateral, with a size of 80–300 nm. These precipitates significantly improve the mechanical properties of the aluminum alloy. The volume fractions of the Al3(Sc,Zr), Al3Ni, and AlFe phases are shown in Table 2. The porosity and mechanical properties of the formed parts in this embodiment are shown in Table 2.

[0096] Comparative Example 1

[0097] The chemical composition of the aluminum alloy wire in this comparative example is shown in Table 1. Other methods are the same as in Example 1 to prepare aluminum alloy components.

[0098] The porosity and mechanical properties of the molded parts of this comparative example are shown in Table 2.

[0099] Comparative Example 2

[0100] The chemical composition of the aluminum alloy wire in this comparative example is the same as that in Example 1. The difference is that the electric arc additive manufacturing process parameters are as follows: current is 120A, voltage is 10.6V, wire feeding speed is 8.8m / min, scanning speed is 8mm / s; protective gas is 99.99%Ar, and gas flow rate is 20L / min.

[0101] The porosity and mechanical properties of the molded parts of this comparative example are shown in Table 2.

[0102] Comparative Example 3

[0103] The chemical composition of the aluminum alloy wire in this comparative example is shown in Table 1. Other methods were the same as in Example 4 to prepare the aluminum alloy components. Due to the excessively high Sc content, coarse Al3(Sc,Zr) particles (size 5–10 μm) appeared in the formed microstructure. Figure 6 As shown in the figure, this reduces the strengthening effect of the Al3(Sc,Zr) phase and the ratio of AlFe and Al3Ni phases.

[0104] The porosity and mechanical properties of the molded parts of this comparative example are shown in Table 2.

[0105] Table 1

[0106]

[0107] Table 2

[0108]

[0109] *Note: The precipitated phase is Al3(Sc,Ti).

[0110] Compared with Examples 1-4, the precipitated phase in Comparative Example 1 is Al3(Sc,Ti), indicating that only by using the chemical composition of the aluminum alloy wire of the present invention, the precipitated phases are Al3(Sc,Zr) phase, Al3Ni phase and AlFe phase, and the resulting molded parts have better mechanical properties.

[0111] Compared with Example 1, only the part prepared by the arc additive manufacturing process parameters of the present invention has a larger volume fraction of Al3(Sc,Zr) phase, AlFe phase and Al3Ni phase, and thus better mechanical properties.

[0112] Compared with Example 4, when the Sc content in the aluminum alloy wire exceeded the range defined by the present invention, coarse Al3(Sc,Zr) appeared in the formed structure, and the volume fraction of AlFe phase and Al3Ni phase decreased, resulting in a deterioration in the mechanical properties of the formed part.

[0113] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An electric arc additive manufacturing process for heat-resistant high-strength aluminum alloy wire, characterized in that, Includes the following steps: (1) Using heat-resistant high-strength aluminum alloy wire, variable polarity cold metal transition arc additive manufacturing is carried out to obtain the formed part; The heat-resistant high-strength aluminum alloy wire has the following chemical composition by mass percentage: Mg 7.0~8.0%, Sc 0.2~0.6%, Zr 0.1~0.3%, Mn 0.8~0.9%, Si 0.08~0.12%, Fe 1.0~5.0%, Ni 0.45~0.55%, Be 0.0001~0.0005%, with the balance being Al; The process parameters for arc additive manufacturing are as follows: current 80~110A, voltage 9.4~10.1V, wire feed speed 5.7~8.0m / min, scanning speed 8~12mm / s; The protective gas is 99.99%Ar, the gas flow rate is 20~25L / min, the substrate preheating temperature is 100~200℃, and the inter-channel temperature is ≤100℃; The microstructure of the molded part includes AlFe phase, Al3Ni phase and Al3(Sc, Zr) phase; the size of AlFe phase is 50~300nm, the size of Al3Ni phase is 50~100nm, and the size of Al3(Sc, Zr) phase is 10~50nm. By volume percentage, the AlFe phase is 2.00-3.20%, the Al3Ni phase is 1.10-1.30%, and the Al3(Sc, Zr) phase is 1.60-2.20%. (2) The formed part is subjected to aging treatment at a temperature of 310~360℃ and an aging time of 4~8h to obtain an aluminum alloy component.

2. The arc additive manufacturing process for heat-resistant high-strength aluminum alloy wire according to claim 1, characterized in that, When 0.4%≤Sc≤0.6%, then 1.0≤Fe≤3.5%; when 0.2%≤Sc<0.4%, then 2.5%≤Fe≤5.0%.

3. The arc additive manufacturing process for heat-resistant high-strength aluminum alloy wire according to claim 1, characterized in that, The Sc content is 0.3~0.5%, the Zr content is 0.15~0.25%, and the Fe content is 1.0~3.0%.

4. The arc additive manufacturing process for a heat-resistant high-strength aluminum alloy wire according to any one of claims 1-3, characterized in that, The preparation method of the heat-resistant high-strength aluminum alloy wire includes the following steps: vacuum smelting → homogenization treatment → turning treatment → extrusion → wire rod → drawing → annealing treatment → scraping / sizing → ultrasonic cleaning → winding → packaging.

5. The arc additive manufacturing process for heat-resistant high-strength aluminum alloy wire according to claim 4, characterized in that, The vacuum degree in vacuum smelting is 0~5Pa, the homogenization temperature is 420~460℃, the homogenization time is 24~36h, the extrusion temperature is 450~480℃, the annealing temperature is 420~480℃, and the annealing time is 4~6h.

6. The arc additive manufacturing process for heat-resistant high-strength aluminum alloy wire according to claim 1, characterized in that, In step (2), the room temperature tensile strength of the formed part is ≥415MPa; The aluminum alloy components have a tensile strength ≥495MPa, an elongation after fracture ≥11.5%, and a tensile strength at 250℃ ≥245MPa.

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