An aluminum alloy flux-cored wire suitable for arc wire additive manufacturing, its preparation method and application

Abstract

The present invention discloses an aluminum alloy flux-cored wire suitable for arc fuse additive manufacturing, and a preparation method and application thereof, belonging to the technical field of metal materials. An aluminum alloy flux-cored wire suitable for arc fuse additive manufacturing adopts O-state 1060 aluminum strip as a coating, and is filled with high-purity Mg wire and powder; the powder accounts for 3-4% of the total mass of the wire; the powder includes the following components in mass percentage: 50-80% zirconium hydride, 10-20% zirconium carbide, 5-30% hexafluorozirconate and 5-20% potassium fluoroaluminate. The present invention realizes fine grain strengthening and precipitation strengthening caused by high Zr content and precipitation strengthening caused by high Mg content, and significantly improves the mechanical properties of deposited materials. The prepared welding wire has the characteristics of uniform composition, smooth surface and few impurities. The sample after additive has high strength and excellent comprehensive performance, and can be widely used in aerospace, automobile manufacturing and other fields.

Description

Technical Field

[0001] The present invention relates to an aluminum alloy cored wire suitable for arc wire - feeding additive manufacturing, its preparation method and application, and particularly to a low - cost cored wire for arc wire - feeding additive manufacturing with high Mg and Zr contents, its manufacturing method, arc additive manufacturing process and application, belonging to the technical field of metal materials. Background Art

[0002] 5 - series aluminum alloys are a type of aluminum alloy with magnesium as the main alloying element, having excellent plasticity, good corrosion resistance and low yield strength. Compared with other aluminum alloy systems, a major advantage of 5 - series aluminum alloys is that stable mechanical properties can be obtained without heat treatment, which greatly simplifies the production process and reduces the manufacturing cost, especially showing unique advantages in the manufacture of complex structural parts. Therefore, 5 - series aluminum alloys are widely used in fields such as ships, transportation, and pressure vessels, where high requirements are placed on the ductility and corrosion resistance of materials, and the simplification of the manufacturing process and the improvement of production efficiency are more highly regarded.

[0003] Wire - arc additive manufacturing (WAAM) technology is an advanced manufacturing process that heats metal wire by an arc and deposits layers to construct parts, with high material utilization rate and manufacturing efficiency. For 5 - series aluminum alloys, the application of wire - arc additive manufacturing technology has significant advantages. Especially its characteristic of not requiring age hardening heat treatment enables the additive manufacturing process to avoid subsequent complex heat treatment steps, thus simplifying the process flow, shortening the production cycle and improving the dimensional accuracy of parts. Compared with aluminum alloy systems that require heat treatment, 5 - series aluminum alloys avoid problems such as part deformation, stress concentration and even cracking caused by high - temperature heat treatment and quenching during the additive manufacturing process, improving the manufacturing efficiency and geometric accuracy of parts.

[0004] In addition, 5 - series aluminum alloys do not form low - melting - point eutectic compounds at grain boundaries during solidification. This characteristic effectively inhibits the formation of pores, reduces defects in materials, and enables additive - manufactured parts to have higher density and better mechanical properties. However, although 5 - series aluminum alloys have good ductility and corrosion resistance, their low yield strength (110 - 140 MPa) limits their application in fields with relatively high material property requirements (≥300 MPa). Especially in fields such as aerospace and high - end automotive manufacturing, where strict requirements are placed on the comprehensive mechanical properties and high strength of materials, the strength of 5 - series aluminum alloys is relatively low and cannot fully meet the needs of these industries for high - performance materials. Therefore, the applicability of 5 - series aluminum alloys in such applications is limited to a certain extent.

[0005] In arc - wire - feed additive manufacturing, although the characteristic of the 5 - series aluminum alloy that it does not require complex heat treatment simplifies the process, the characteristic of its low strength remains a bottleneck when it is applied to parts with high - strength requirements. In addition, during the additive manufacturing process, due to rapid heating and cooling, residual stress and dimensional deformation problems may be triggered, and the high - temperature operating conditions will also lead to the formation of an oxide layer on the material surface, further reducing its corrosion resistance. To address these problems, it is still necessary to optimize the alloy composition and additive manufacturing process of the 5 - series aluminum alloy, aiming to improve the comprehensive properties of the material, especially the strength performance, so as to expand its application scope in the fields with high - performance requirements.

[0006] To address the problem of the low strength of the 5 - series aluminum alloy, we have developed a high - strength 5 - series aluminum alloy cored wire suitable for the arc - wire - feed additive manufacturing process. By precisely adjusting the alloy composition and optimizing the wire - making process, this alloy can obtain significantly improved mechanical properties during the additive manufacturing process without relying on complex heat treatment procedures, only through homogenization treatment or natural aging treatment, and especially achieves a good balance between strength and ductility. This innovative alloy design effectively solves the deficiency of the traditional 5 - series aluminum alloy with low strength, which restricts its application in high - performance fields, enabling this material to not only maintain the original excellent plasticity and corrosion resistance of the 5 - series aluminum alloy but also possess higher tensile strength and yield strength. Summary of the Invention

[0007] Aiming at the current problems faced by the 5 - series aluminum alloy in arc - wire - feed additive manufacturing, such as low strength, poor forming accuracy, and easy cracking, the present invention provides an aluminum alloy cored wire suitable for arc - wire - feed additive manufacturing.

[0008] At the same time, the present invention provides a preparation method for an aluminum alloy cored wire suitable for arc - wire - feed additive manufacturing. Through this method, an aluminum alloy wire with stable composition and smooth and clean wire surface can be prepared. During the single - pass and multi - layer additive process, the arc is stable without obvious spatter, the deposition layer is smooth without wavy undulations, the height of the single - layer deposition layer is stable (0.79 - 0.81 mm), the height difference between the sample deposited along the additive path without secondary correction and the 3D model does not exceed 2%, the surface of the deposition layer is bright without obvious oxidation inclusions, the grain size is significantly refined (<10 μm), and compared with the additive sample of the commercial 5083 wire, the grain size is reduced by more than 90%. The as - deposited mechanical properties are excellent, and after simple homogenization treatment, the mechanical properties of the alloy are further improved (tensile strength > 400 MPa), reaching the level of high - strength aluminum alloys, and it can be successfully applied to demanding fields such as aerospace, and finally, an aluminum alloy sample with high strength is prepared.

[0009] At the same time, the present invention provides an application of the aluminum alloy cored wire suitable for arc - wire - feed additive manufacturing in demanding and high - performance fields such as aerospace and high - end automotive manufacturing.

[0010] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0011] To achieve the above invention object, the present invention adopts the following processing method to prepare the aluminum alloy wire for arc additive manufacturing:

[0012] An Al-Mg-Zr cored powder flux-cored wire for arc additive manufacturing of high-strength aluminum alloy workpieces, and a corresponding low-cost manufacturing method. The wire prepared by this method has the characteristics of uniform composition, small powder coating ratio, smooth wire surface, not easy to leak powder, and less gas inclusions. The sample printed by using the wire with the arc additive manufacturing process has the characteristics of high surface quality, small grain size, uniform distribution of solute atoms, small and dispersed precipitation phases, and significant control of solidification hot cracking. The sample after arc deposition has high mechanical properties.

[0013] To achieve the above invention object, the present invention adopts the following processing method:

[0014] A low-cost aluminum alloy flux-cored wire for arc additive manufacturing of high-strength aluminum alloy parts

[0015] The present invention uses O-state 1060 pure aluminum as the coating, and uses high-purity Mg wire and ZrH 2 and hexafluorozirconate powder, etc. as additives of alloy elements. Thanks to the use of Mg wire, the powder coating amount is significantly reduced compared with the traditional flux-cored wire processing process. At the same time, the powder is used to fill the gap between the Mg wire and the coating, further reducing the risk of gas inclusions, effectively improving the moisture-proof performance and antioxidant performance of the flux-cored wire. There are no macroscopic pores in the additive sample (the H element content in the sample after additive manufacturing is lower than 12 mL / 100 g, and the O element content is lower than 17 mL / 100 g, lower than the additive sample of imported wire). The coating is made of O-state aluminum with a width of 7-10 mm and a thickness of 0.5-1.0 mm. After cleaning the surface oxide layer and oil stain with a scraper, high-purity Mg wire with a diameter of 0.7-1.5 mm and mixed powder are added according to the designed composition. The mass of the powder accounts for 3-4% of the total mass of the flux-cored wire. The powder composition includes the following components by mass percentage: 50-80% zirconium hydride (ZrH 2 ), 10-20% zirconium carbide, 5-30% hexafluorozirconate and 5-20% potassium fluoroaluminate (KAlF 4 ).

[0016] Furthermore, the particle size of zirconium carbide is less than 50 nm, and zirconium hydride, hexafluorozirconate and potassium fluoroaluminate are vacuum ball-milled to a particle size of 30-50 μm.

[0017] The proportion of each component is optimized and matched according to the coating size and the designed wire composition to ensure the stability and excellent performance of the final wire.

[0018] Further, use a scraper to mechanically scrape the surface of the aluminum strip to clean the oxide layer and oil stains, and avoid the influence of surface impurities on the properties of the wire.

[0019] Further, wipe and clean the surface of the aluminum strip with anhydrous ethanol or acetone to ensure that the surface of the coating is clean and free of residual substances. Place the cleaned aluminum strip in a drying oven and dry it at 80 - 100 °C for at least 1 hour.

[0020] Further, use professional flux-cored wire forming equipment, including an aluminum strip forming machine, a filler conveyor, and a wire rolling equipment. Bend the processed aluminum strip into a "U" - shaped groove through a roller forming machine for coating the core material.

[0021] Further, clamp the high - purity Mg wire and the aluminum strip at the top to ensure synchronous wire feeding of the Mg wire and the aluminum strip, and then pass them through a wire rolling mill. According to the formula ratio, use a filler conveyor between the roller forming machine and the wire rolling mill to fill the premixed powder. The powder is evenly filled into the "U" - shaped groove through a metering feeding device, and the powder filling ratio is controlled at 3 - 4% of the total mass of the flux - cored wire.

[0022] Further, completely coat the aluminum strip through the forming equipment, and tightly join the coated seam part by rolling to avoid gas infiltration.

[0023] Further, send the coated aluminum strip into a rolling mill and initially roll it into a round wire with a diameter of about 2 - 3 mm. During the rolling process, use low - speed (aluminum strip feeding speed 15 - 25 m / min) and high - pressure (700 - 1200 N / mm) rolling to avoid powder scattering or core material deviation.

[0024] Further, place the rolled wire in a vacuum annealing furnace and keep it at a temperature of 300 - 350 °C for 30 - 60 minutes to eliminate the rolling stress and improve the toughness of the wire.

[0025] Further, pass the annealed wire through a continuous drawing equipment to gradually reduce the wire diameter to 1.2 - 1.6 mm. The reduction amount after each drawing is controlled at 10% - 20% to avoid coating cracking or powder leakage.

[0026] Further, smooth the surface of the wire through a precision polishing equipment to ensure that the surface of the wire has no oxides, scratches or defects. Wind the wire into coils according to the specified length, ensure appropriate tightness, avoid the influence of deformation during transportation and storage on the wire, and at the same time, vacuum coat.

[0027] Through the above - mentioned processing flow, the flux - cored wire prepared by the present invention has the characteristics of uniform composition, smooth surface, and few impurities, is suitable for high - precision and high - performance arc additive manufacturing processes, and can significantly improve the mechanical properties and surface quality of the deposited samples.

[0028] The functions of the components in the flux-cored wire used in the present invention are as follows:

[0029] Mg wire: It is used to provide the main alloying element Mg in the composition design, playing a role in solid solution strengthening. By using Mg wire for cladding, compared with the process of cladding Mg powder in traditional flux-cored wires, the volume of the powder can be significantly reduced, making the powder coating more compact, and avoiding situations such as oxidation and powder leakage.

[0030] Zirconium hydride: Utilize the grain refinement strengthening and precipitation strengthening effects of Zr element during the arc deposition process.

[0031] Zirconium carbide: Use high-melting-point nanoscale zirconium carbide particles (less than 50 nm, preferably 40 nm) as the heterogeneous nucleation agent during the arc deposition molten pool process. As the heterogeneous nucleation source of Al 3 Zr, it promotes the crystallization and rapid coarsening of Al 3 Zr in the high-temperature molten pool. Subsequently, during the cooling process from 1027K to 912K, it promotes the nucleation of α-Al on the surface of Al 3 Zr and effectively refines the grains.

[0032] Zirconium hexafluoride: Utilize the decomposition of zirconium hexafluoride (one or more of sodium zirconium hexafluoride, potassium zirconium hexafluoride, and lithium zirconium hexafluoride). While increasing the Zr content, the generated fluoride promotes slag separation, reduces the surface tension of the melt, and promotes the polymerization and floating up and release of H 2

[0033] Potassium fluoroaluminate: It acts synergistically with zirconium hydride, zirconium carbide, and zirconium hexafluoride to reduce the surface tension of the melt, improve the interlayer wettability of the deposited layer, reduce hydrogen and other impurity gases in the molten pool, and reduce the porosity content.

[0034] The preparation method of the high-strength aluminum alloy arc melt wire additive in the present invention is as follows:

[0035] S01, Arc additive manufacturing:

[0036] Use an aluminum substrate as the deposition substrate. After cleaning and drying, it is fixed on the turntable workbench. Use an ABB six-axis robot and a Fronius servo power source, and set the following welding parameters: Current: 65A, voltage automatically matched, welding torch moving speed: 24 mm / s, shielding gas is pure Ar, flow rate 25 L / min;

[0037] S02, Post-treatment of the additive:

[0038] Perform homogenization treatment on the additive at 420 °C for 12 hours, and slowly cool it to room temperature to obtain the high-strength aluminum alloy arc melt wire additive.

[0039] ​The transverse tensile strength of the high-strength aluminum alloy by arc fused wire additive manufacturing is 428 - 457 MPa, the transverse yield strength is 294 - 325 MPa, the transverse fracture elongation is 19.4 - 22.5%, the longitudinal tensile strength is 424 - 462 MPa, the longitudinal yield strength is 285 - 313 MPa, and the longitudinal fracture elongation is 16.7 - 21.6%.

[0040] Applications of the high-strength aluminum alloy by arc fused wire additive manufacturing in the aerospace, high-end automotive manufacturing in harsh and high-performance fields.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] The present invention develops an aluminum alloy cored wire suitable for arc fused wire additive manufacturing, its preparation method and applications. Compared with the traditional aluminum alloy system, it has the following advantages:

[0043] The aluminum alloy wire prepared by the present invention has the characteristics of uniform distribution of alloy elements and smooth and clean wire surface.

[0044] The samples prepared by using the wire prepared by the present invention have good formability, no obvious macroscopic defects on the surface, uniform and fine microstructure, and the mechanical properties reach the level of ultra-high-strength aluminum alloy.

[0045] In summary, the present invention provides an aluminum alloy cored wire suitable for arc fused wire additive manufacturing, its preparation method and applications. It is suitable for arc fused wire additive manufacturing workpieces, has the characteristics of uniform and stable composition and smooth surface, the additive manufacturing workpieces have good formability, high surface quality, uniform microstructure and the ability to inhibit hot cracks, and finally the high-strength aluminum alloy additive manufacturing workpieces prepared can be widely applied in the field of high-strength aluminum alloy arc fused wire additive manufacturing.

[0046] The present invention provides an aluminum alloy cored wire suitable for arc fused wire additive manufacturing, its preparation method and applications. The welding wire is filled with high-purity Mg wire to achieve high Mg content and low powder volume. The filled powder is composed of zirconium hydride, zirconium carbide, zirconium hexafluoride and potassium fluoroaluminate, which is used to fill the gap between the Mg wire and the coating. Significantly reduce the gas content in the powder and improve the wire quality. During the arc additive manufacturing process, this design realizes the fine grain strengthening and precipitation strengthening caused by high Zr content and the precipitation strengthening caused by high Mg content, significantly improving the mechanical properties of the as-deposited material. The prepared welding wire has the characteristics of uniform composition, smooth surface and few impurities. The samples after additive manufacturing have high strength and excellent comprehensive properties, and can be widely applied in the fields of aerospace, automotive manufacturing, etc., solving the problems of low strength and process defects of traditional aluminum alloy welding wires. Description of the Drawings

[0047] Figure 1The ZrC and Al in the sample obtained by printing the wire material using the arc additive manufacturing process in Embodiment 1 of the present invention 3 Microstructure diagram of the core-shell structure of Zr; where the inner core of the core-shell structure is ZrC and the outer shell is Al 3 Zr;

[0048] Figure 2 It is the surface diagram of the arc additive deposition sample in Embodiment 1 of the present invention;

[0049] Figure 3 It is the microstructure diagram of the arc additive deposition sample in Embodiment 1 of the present invention. Detailed implementation manners

[0050] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0051] Unless otherwise noted, the equipment, devices, materials, etc. used in the following embodiments are all obtained through conventional commercial channels or can be prepared by existing mature processes.

[0052] Embodiment 1

[0053] An aluminum alloy cored wire suitable for arc wire additive manufacturing prepared in this embodiment selects an O-state 1060 aluminum strip with a width of 7 mm and a thickness of 0.8 mm as the coating (the mass percentage of each element is: Si 0.25 wt%, Fe: 0.29 wt%, Mn: 0.03 wt%, and the balance is Al), and a high-purity Mg wire with a diameter of 1.1 mm (purity greater than 99%) is selected. The powder filling ratio is 3.5 wt%, and the mass percentage composition of the powder is: zirconium hydride (ZrH 2 ) 60 wt%, zirconium carbide (ZrC) 15 wt%, lithium hexafluorozirconate 15 wt%, potassium fluoroaluminate (KAlF 4 ) 10 wt%.

[0054] A preparation method of an aluminum alloy cored wire suitable for arc wire additive manufacturing includes the following steps:

[0055] S0: Treatment and cleaning of the aluminum strip (coating)

[0056] Select an O-state 1060 aluminum strip with a width of 7 mm and a thickness of 0.8 mm as the coating. Mechanically clean the oxide layer and oil stain on the surface of the aluminum strip with a scraper. Wipe the surface of the aluminum strip with anhydrous ethanol to ensure no residual substances. Dry the cleaned aluminum strip in an 80°C drying oven for 1 hour for standby.

[0057] S1: Preparation of powder and core material

[0058] Mix zirconium hydride, zirconium carbide, lithium hexafluorozirconate and potassium fluoroaluminate according to the ratio. The particle size of zirconium carbide is less than 50 nm, preferably 40 nm, and use a ball milling equipment to mix them evenly. The particle size of other powders is controlled at 30 - 50 μm, preferably 30 μm.

[0059] Select a high-purity Mg wire with a diameter of 1.1 mm, clean it and fix it to the wire feeding turntable.

[0060] S2: Forming of the flux-cored wire

[0061] Use a roller equipment to bend the aluminum strip into a "U"-shaped groove for coating the core material.

[0062] After the high-purity Mg wire is fixed to the top of the "U"-shaped aluminum strip, they are fed into the equipment synchronously. The powder is evenly filled into the "U"-shaped groove through a filler, and the powder filling ratio is 3.5% of the wire mass. The aluminum strip is coated to form a circular wire, and the roller equipment is used to seal and roll the wire to ensure that the joint is tight and seamless.

[0063] S3: Post-treatment of the wire

[0064] Preliminarily roll the wire to a diameter of 2 mm. During the rolling process, use low speed (aluminum strip feeding speed 20 m / min) and high pressure (1000 N / mm) rolling.

[0065] Subsequently, send it into a vacuum annealing furnace and keep it at 300 °C for 30 minutes to eliminate the processing stress. Use a continuous drawing equipment to gradually draw the wire to 1.3 mm, and control the reduction of each cross-section at 15%.

[0066] Perform surface polishing treatment to ensure that the surface of the wire is smooth and flawless. Finally, wind it up and store it in vacuum packaging.

[0067] S4: Arc additive manufacturing

[0068] Use a 10-mm-thick aluminum substrate as the deposition substrate. After cleaning and drying, fix it on the workbench of the positioner. Use an ABB six-axis robot and a Fronius servo power supply, and set the following welding parameters: current: 65 A, voltage automatically matched, welding torch moving speed: 24 mm / s, shielding gas is pure Ar, and the flow rate is 25 L / min.

[0069] The additive printing path adopts a single-pass mode, and multi-layer stacking additive manufacturing is carried out according to the designed path to prepare a columnar ring part as shown Figure 2 (height 95 mm, perimeter 684 mm, hemisphere diameter 100 mm).

[0070] S5: Post-treatment after additive manufacturing

[0071] The additive plates were homogenized at 420 °C for 12 hours and slowly cooled to room temperature. Samples of the additively manufactured specimens were taken and analyzed for composition using ICP-MS. The elemental mass percentages of the actual additively manufactured specimens were as follows: Mg: 8.83%, Mn: 0.04%, Zr: 1.13%, Fe: 0.31%, Si: 0.17%, and the balance being Al and inevitable impurity elements.

[0072] Application of an aluminum alloy cored wire suitable for arc wire additive manufacturing in high-strength aluminum alloy arc wire additive manufacturing.

[0073] Application of high-strength aluminum alloy arc wire additive manufacturing in aerospace, high-end automotive manufacturing in harsh and high-performance fields.

[0074] As Figure 1 shown, the microstructure diagram of the core-shell structure of ZrC and Al 3 Zr in the sample printed by the wire using the arc additive process obtained in this example; wherein, the inner core of the core-shell structure is ZrC and the outer shell is Al 3 Zr.

[0075] As Figure 3 shown, the microstructure diagram of the arc additive deposition state sample of this example. In this example, fine grain strengthening caused by high Zr content and precipitation strengthening, and precipitation strengthening caused by high Mg content were achieved. The surface of the deposition layer was bright and had no obvious oxidation inclusions, and the grain size was significantly refined (<10 μm).

[0076] Comparative Example 1

[0077] S0: A commercial 5183 finished wire was used, with a wire diameter of 1.2 mm. The elemental mass percentages of the actual composition of the wire were as follows: Si: 0.4%, Fe: 0.12%, Mn: 0.40%, Mg: 5.8%, Al: the balance;

[0078] S1: An aluminum alloy plate was used as the substrate, with a plate thickness of 10 mm. The specific elemental mass percentages were as follows: Si: 0.36%, Fe: 0.70%, Al: the balance; The surface was polished using a grinding machine to remove the surface oxide layer, cleaned with alcohol and dried, sandblasted using 80-mesh sand in a sandblasting machine, taken out, cleaned with alcohol again and dried, and placed on the working table of the arc wire additive manufacturing robot positioner;

[0079] S2: Use an ABB six-axis robot and a Fronius servo power supply. Set the current parameter to 70 A, automatically match the voltage with one-variable regulation, automatically match the wire feeding speed, set the welding torch forward speed to 24 mm / s, select high-purity Ar as the shielding gas, set the shielding gas flow rate to 25 L / min, and set the program to the Fronius Al-5Mg professional program. Perform additive manufacturing in a multi-pass stacking manner. Finally, the prepared sample has a height of 94.3 mm, a circumference of 687 mm, and a hemisphere diameter of 100.6 mm (the dimensional accuracy deviation is less than 1.1%).

[0080] S3: Cut off the additively manufactured sheet and perform homogenization treatment. The heat treatment process is to hold at 450 °C for 12 hours and then take it out for subsequent experiments.

[0081] The following experiments were conducted to test the various properties of Example 1 and Comparative Example 1 in the present invention:

[0082] 1. Mechanical property test

[0083] Use an electronic universal testing machine to test the tensile properties of the additively manufactured samples of Example 1 and Comparative Example 1 after heat treatment in the transverse and longitudinal directions. The measured mechanical properties are shown in Table 1.

[0084] Table 1 Mechanical properties of Example 1 and Comparative Example 1

[0085]

[0086] The present invention developed an aluminum alloy wire and its application method suitable for arc wire feeding additive manufacturing of high-strength aluminum alloys. Compared with the traditional aluminum alloy system, it has the following advantages:

[0087] The aluminum alloy wire prepared by this invention has the characteristics of uniform distribution of alloying elements and a smooth and clean wire surface.

[0088] The samples prepared using the wire prepared by this invention have good formability, no obvious macroscopic defects on the surface, uniform and fine microstructure, and mechanical properties reaching the level of ultra-high-strength aluminum alloys.

[0089] In summary, the present invention provides a wire and its application method that can be used for preparing high-strength aluminum alloy workpieces by arc wire feeding additive manufacturing. It is suitable for arc wire feeding additive manufacturing workpieces, has the characteristics of uniform and stable composition and smooth surface, the additively manufactured workpieces have good formability, high surface quality, uniform microstructure, and the ability to suppress hot cracks. Finally, the prepared high-strength aluminum alloy additively manufactured workpieces can be widely applied in the field of arc wire feeding additive manufacturing of high-strength aluminum alloys.

[0090] Example 2

[0091] The difference between this example and Example 1 is only that:

[0092] An aluminum alloy cored wire suitable for arc wire - feed additive manufacturing prepared in this embodiment selects an O - state 1060 aluminum strip with a width of 10 mm and a thickness of 1.0 mm as the coating, and a high - purity Mg wire with a diameter of 1.5 mm (purity greater than 99%). The powder filling ratio is 4 wt%, and the mass percentage composition of the powder is: zirconium hydride (ZrH 2 ) 50 wt%, zirconium carbide (ZrC) 10 wt%, potassium hexafluorozirconate 30 wt%, potassium fluoroaluminate (KAlF 4 ) 10 wt%.

[0093] A preparation method of an aluminum alloy cored wire suitable for arc wire - feed additive manufacturing includes the following steps:

[0094] S0: Treatment and cleaning of the aluminum strip (coating)

[0095] Select an O - state 1060 aluminum strip with a width of 10 mm and a thickness of 1.0 mm as the coating. Mechanically clean the oxide layer and oil stain on the surface of the aluminum strip with a scraper. Wipe the surface of the aluminum strip with acetone to ensure no residual substances. Dry the cleaned aluminum strip in a 100 °C drying oven for 1.5 hours for standby.

[0096] S1: Preparation of powder and core material

[0097] Mix zirconium hydride, zirconium carbide, potassium hexafluorozirconate, and potassium fluoroaluminate according to the ratio. The particle size of zirconium carbide is less than 50 nm, preferably 30 nm, and use a ball - milling device to mix evenly. The particle size of other powders is controlled at 30 - 50 μm, preferably 50 μm.

[0098] Select a high - purity Mg wire with a diameter of 1.5 mm, clean it and fix it on the wire - feeding turntable.

[0099] S2: Forming of the cored wire

[0100] Use a roller device to bend the aluminum strip into a "U" - shaped groove for coating the core material.

[0101] After the high - purity Mg wire is fixed to the top of the "U" - shaped aluminum strip, they are fed into the device synchronously. The powder is evenly filled into the "U" - shaped groove through a filler, and the powder filling ratio is 4% of the wire mass. The aluminum strip is coated to form a circular wire, and a roller device is used to roll - seal the wire to ensure a tight and seamless joint.

[0102] S3: Post - treatment of the wire

[0103] Preliminarily roll the wire to a diameter of 3 mm. During the rolling process, use low - speed (aluminum strip feeding speed of 25 m / min) and high - pressure (1200 N / mm) rolling,

[0104] Subsequently, it is sent into a vacuum annealing furnace and kept at 350°C for 60 minutes to eliminate processing stress. The wire is gradually drawn to 1.6 mm using continuous drawing equipment, with the cross-sectional diameter reduction controlled at 20% each time.

[0105] Surface polishing treatment is carried out to ensure that the surface of the wire is smooth and free of defects. Finally, it is coiled and stored in vacuum packaging.

[0106] The elemental mass percentages of the actual additive sample obtained by the additive method of Example 1 in this example are as follows: Mg: 10.85%, Mn: 0.05%, Zr: 1.42%, Fe: 0.17%, Si: 0.21%, and the rest are Al and inevitable impurity elements.

[0107] The transverse tensile strength of the high-strength aluminum alloy arc fuse additive obtained in this example is 451 MPa, the transverse yield strength is 325 MPa, the transverse fracture elongation is 19.4%, the longitudinal tensile strength is 462 MPa, the longitudinal yield strength is 313 MPa, and the longitudinal fracture elongation is 16.7%.

[0108] Example 3

[0109] The difference between this example and Example 1 is only that:

[0110] An aluminum alloy cored wire suitable for arc fuse additive manufacturing prepared in this example selects an O-state 1060 aluminum strip with a width of 8 mm and a thickness of 0.5 mm as the coating, and a high-purity Mg wire with a diameter of 0.7 mm (purity greater than 99%). The powder filling ratio is 3 wt%, and the mass percentage composition of the powder is: zirconium hydride (ZrH 2 ) 80 wt%, zirconium carbide (ZrC) 10 wt%, sodium hexafluorozirconate 5 wt%, potassium hexafluoroaluminate (KAlF 4 ) 5 wt%.

[0111] A preparation method of an aluminum alloy cored wire suitable for arc fuse additive manufacturing includes the following steps:

[0112] S0: Treatment and cleaning of the aluminum strip (coating)

[0113] Select an O-state 1060 aluminum strip with a width of 8 mm and a thickness of 0.5 mm as the coating. Mechanically clean the oxide layer and oil stain on the surface of the aluminum strip with a scraper. Wipe the surface of the aluminum strip with anhydrous ethanol to ensure no residual substances. Dry the cleaned aluminum strip in a drying oven at 90°C for 1.2 hours for standby.

[0114] S1: Preparation of powder and core material

[0115] Mix zirconium hydride, zirconium carbide, sodium hexafluorozirconate and potassium fluoroaluminate according to the ratio. The particle size of zirconium carbide is less than 50 nm, preferably 50 nm, and use a ball milling device to mix evenly. The particle size of other powders is controlled at 30 - 50 μm, preferably 40 μm.

[0116] Select high-purity Mg wire with a diameter of 0.6 mm, clean it and fix it to the wire feeding turntable.

[0117] S2: Forming of the cored wire

[0118] Use a roller device to bend the aluminum strip into a "U"-shaped groove for coating the core material.

[0119] After the high-purity Mg wire is fixed to the top of the "U"-shaped aluminum strip, they are fed into the device synchronously. The powder is evenly filled into the "U"-shaped groove through a filler, and the powder filling ratio is 3% of the wire mass. The aluminum strip is coated to form a circular wire, and a roller device is used to seal and roll the wire to ensure a tight and seamless joint.

[0120] S3: Post-treatment of the wire

[0121] Preliminarily roll the wire to a diameter of 2 mm. During the rolling process, use low speed (aluminum strip feeding speed of 15 m / min) and high pressure (700 N / mm) rolling.

[0122] Subsequently, send it into a vacuum annealing furnace and keep it at 300 °C for 40 minutes to eliminate processing stress. Use a continuous drawing device to gradually draw the wire to 1.2 mm, and control the cross-sectional diameter reduction at 10% each time.

[0123] Perform surface polishing treatment to ensure that the surface of the wire is smooth and free of defects. Finally, wind it up and store it in vacuum packaging.

[0124] The elemental mass percentages of the actual additive sample obtained by the additive method of Example 1 in this example are: Mg: 5.57%, Mn: 0.04%, Zr: 1.23%, Fe: 0.25%, Si: 0.18%, and the rest are Al and inevitable impurity elements.

[0125] The transverse tensile strength of the high-strength aluminum alloy arc fuse additive obtained in this example is 428 MPa, the transverse yield strength is 294 MPa, the transverse fracture elongation is 22.5%, the longitudinal tensile strength is 424 MPa, the longitudinal yield strength is 285 MPa, and the longitudinal fracture elongation is 21.6%.

[0126] Example 4

[0127] The difference between this example and Example 1 is only that:

[0128] The mass percentage of the powder composition is: zirconium hydride (ZrH 2) 50 wt%, zirconium carbide (ZrC) 20 wt%, sodium hexafluorozirconate 10 wt%, potassium fluoroaluminate (KAlF 4 ) 20 wt%.

[0129] The elemental mass percentages of the actual additive manufacturing samples obtained by the additive manufacturing method of Example 1 in this example are: Mg: 8.73%, Mn: 0.03%, Zr: 0.98%, Fe: 0.28%, Si: 0.16%, and the rest are Al and inevitable impurity elements.

[0130] The transverse tensile strength of the high-strength aluminum alloy arc wire additive manufacturing obtained in this example is 457 MPa, the transverse yield strength is 313 MPa, the transverse fracture elongation is 20.9%, the longitudinal tensile strength is 442 MPa, the longitudinal yield strength is 309 MPa, and the longitudinal fracture elongation is 19.3%.

[0131] Comparative Example 2

[0132] The difference between this comparative example and Example 1 is only that:

[0133] Lithium hexafluorozirconate is replaced with zirconium fluoride ZrF 4 , after replacement, no ZrC and Al 3 The core-shell structure of Zr was observed in the samples printed by the arc additive manufacturing process; the grain size became significantly larger (greater than 30 μm), and the mechanical properties of the as-deposited material also decreased significantly. The transverse tensile strength of the arc wire additive manufacturing obtained in Comparative Example 2 is 369 MPa, the transverse yield strength is 261 MPa, the transverse fracture elongation is 23.4%, the longitudinal tensile strength is 330 MPa, the longitudinal yield strength is 245 MPa, and the longitudinal fracture elongation is 22.1%.

[0134] The elemental mass percentages of the arc wire additive manufacturing obtained in this comparative example are: Mg: 8.66%, Mn: 0.05%, Zr: 1.15%, Fe: 0.29%, Si: 0.12%, and the rest are Al and inevitable impurity elements.

[0135] Comparative Example 3

[0136] The difference between this comparative example and Example 1 is only that:

[0137] The mass percentage of the powder composition is: zirconium hydride (ZrH 2 ) 50 wt%, zirconium carbide (ZrC) 5 wt%, lithium hexafluorozirconate 35 wt%, potassium fluoroaluminate (KAlF 4 ) 10 wt%.

[0138] No ZrC and Al were observed in the samples printed by the arc additive manufacturing process in this comparative example 3The core-shell structure of Zr; the grain size becomes significantly larger (greater than 30 μm), and the mechanical properties of the as-deposited material also decrease significantly. The transverse tensile strength of the arc wire additive manufactured in Comparative Example 2 is 352 MPa, the transverse yield strength is 245 MPa, the transverse fracture elongation is 17.8%, the longitudinal tensile strength is 315 MPa, the longitudinal yield strength is 223 MPa, and the longitudinal fracture elongation is 16.9%.

[0139] The elemental mass percentages of the arc wire additive manufactured in this comparative example are as follows: Mg: 8.48%, Mn: 0.05%, Zr: 0.83%, Fe: 0.34%, Si: 0.19%, and the rest are Al and inevitable impurity elements.

[0140] It should be understood that, in order to streamline the present disclosure and assist in understanding one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting the intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims, the inventive aspects lie in less than all of the features of the previously disclosed embodiments. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim stands on its own as a separate embodiment of the present invention.

[0141] Although the present invention has been described based on a limited number of embodiments, those skilled in the art within this technical field will understand, from the above description, that other embodiments can be envisioned within the scope of the present invention thus described. In addition, it should be noted that the language used in this specification is mainly selected for readability and teaching purposes, rather than for the purpose of interpreting or limiting the subject matter of the present invention. Therefore, many modifications and variations will be apparent to those of ordinary skill in this technical field without departing from the scope and spirit of the appended claims. For the scope of the present invention, the disclosure of the present invention is illustrative, not restrictive, and the scope of the present invention is defined by the appended claims.

[0142] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in this technical field, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An aluminum alloy cored wire suitable for arc fuse additive manufacturing, characterized in that: Aluminum strip is used as the coating, and high-purity Mg wire and powder are used for filling; The powder accounts for 3-4% of the total mass of aluminum alloy core wire; The powder is composed of the following components in percentage by mass: 50-80% zirconium hydride, 10-20% zirconium carbide, 5-30% hexafluorozirconate and 5-20% potassium fluoroaluminate; The particle size of zirconium carbide is less than 50nm; The aluminum strip is an O-state 1060 aluminum strip with a width of 7-10 mm and a thickness of 0.5-1.0 mm; The diameter of high purity Mg wire is 0.7-1.5mm.

2. The aluminum alloy cored wire suitable for arc fuse additive manufacturing according to claim 1, characterized in that: The hexafluorozirconate includes one or more of sodium hexafluorozirconate, potassium hexafluorozirconate, and lithium hexafluorozirconate.

3. The aluminum alloy cored wire suitable for arc fuse additive manufacturing according to claim 1, characterized in that: Zirconium hydride, hexafluorozirconate and potassium fluoroaluminate were vacuum ball-milled to a particle size of 30-50 μm.

4. A method for preparing an aluminum alloy cored wire suitable for arc fuse additive manufacturing according to any one of claims 1 to 3, characterized in that: The following steps are involved: S0, skin treatment and cleaning; S1, Preparation of drug powder and core material: Zirconium hydride, zirconium carbide, lithium hexafluorozirconate and potassium fluoroaluminate are mixed according to the proportions. Clean and fix the high-purity Mg wire to the wire feeding turntable; S2, cored wire forming: Use roller equipment to bend the coating into a U-shaped groove to obtain a U-shaped aluminum strip. The high-purity Mg wire and the top of the U-shaped aluminum strip are fixed and fed into the equipment simultaneously. The powder is evenly filled into the U-shaped groove through the filler, and the U-shaped aluminum strip is coated to form a round wire. The wire is sealed and rolled using a roller device. S3, wire post-processing The wire is initially rolled to a diameter of 2-3 mm, with low speed and high pressure rolling. Then it is sent to the vacuum annealing furnace and kept at 300-350℃ for 30-60 minutes; then the wire is gradually drawn to 1.2-1.6mm using a continuous drawing device, and the cross-sectional diameter reduction is controlled at 10%-20% each time; The surface is then polished, rolled and vacuum packed for storage.

5. The preparation method according to claim 4, characterized in that: In S0, the method for treating and cleaning the coating is as follows: use a scraper to mechanically clean the oxide layer and oil stains on the surface of the coating; use anhydrous ethanol or acetone to wipe the surface of the coating to ensure that there is no residual substance, and dry the cleaned coating in a drying oven at 80-100℃ for at least 1 hour for use.

6. The preparation method according to claim 4, characterized in that: In S3, the low speed in the low-speed and high-pressure rolling is an aluminum strip feed speed of 15-25 m / min, and the high pressure is 700-1200 N / mm.

7. Use of the aluminum alloy flux-cored wire suitable for arc fuse additive manufacturing according to any one of claims 1 to 3 in high-strength aluminum alloy arc fuse additive manufacturing.

8. The use according to claim 7, characterized in that: The preparation method of high-strength aluminum alloy arc fuse additive is: S01, Arc Additive Manufacturing: An aluminum substrate was used as the deposition substrate, which was fixed on the positioner workbench after cleaning and drying. A six-axis robot and servo power supply were used, and the following welding parameters were set: current: 65A, voltage automatic matching, welding gun moving speed: 24mm / s, shielding gas was pure Ar, flow rate 25L / min; S02, Additive Post-Processing: The additive material was homogenized at 420°C for 12 hours and then slowly cooled to room temperature to obtain a high-strength aluminum alloy arc fuse additive material.

9. The use according to claim 8, characterized in that: The transverse tensile strength of high-strength aluminum alloy arc fuse additive is 428-457MPa, the transverse yield strength is 294-325MPa, the transverse elongation at break is 19.4-22.5%, the longitudinal tensile strength is 424-462MPa, the longitudinal yield strength is 285-313MPa, and the longitudinal elongation at break is 16.7-21.6%.

10. The use according to claim 7, characterized in that: The application of high-strength aluminum alloy arc fuse additive in aerospace and automobile manufacturing fields.

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