An aluminum alloy arc additive manufacturing process

Abstract

The present invention discloses an arc additive manufacturing process for aluminum alloy, which relates to the technical field of arc additive manufacturing and comprises the following steps: Step S1, gradient melting of aluminum alloy; Step S2, preparation of aluminum alloy wire; Step S3, model design and slicing; Step S4, material and equipment preparation; Step S5, substrate pretreatment; Step S6, additive manufacturing; Step S7, heat treatment. This arc additive manufacturing process for aluminum alloy has high effectiveness and reliability, and the manufactured components have good mechanical properties and low porosity.

Description

Technical Field

[0001] The present invention relates to the technical field of arc additive manufacturing, and particularly to an arc additive manufacturing process for aluminum alloys. Background Art

[0002] Aluminum alloys have been widely used in many fields such as aerospace, automotive manufacturing, and shipbuilding industries due to their outstanding advantages such as low density, high strength, good corrosion resistance, and good processing performance. However, traditional aluminum alloy manufacturing processes, such as casting, forging, and machining, have many drawbacks. The casting process is prone to defects such as porosity and shrinkage in aluminum alloys, resulting in reduced material properties; the forging process has high requirements for equipment, high die costs, and it is difficult to manufacture components with complex shapes; during the machining process, a large amount of material is cut and removed, which not only causes material waste but also increases production costs. It is in this situation that the arc additive manufacturing technology for aluminum alloys has emerged, and its appearance has attracted wide attention in the industry.

[0003] Arc additive manufacturing is an advanced digital manufacturing technology that uses the principle of layer-by-layer cladding, and uses the arc generated by welding machines such as gas metal arc welding, gas tungsten arc welding, and plasma welding power sources as the heat source. Through the addition of wire materials, under the control of a software program, a metal part is gradually formed from line to surface to solid according to a three-dimensional digital model. Compared with laser and electron beam additive technologies, arc additive manufacturing has the advantages of high forming efficiency, low equipment cost, and high material utilization rate, and is particularly suitable for the manufacturing of large-sized aluminum alloy components. However, during the additive manufacturing process of aluminum alloys, it is difficult to precisely control the molten pool temperature, which is prone to cause molten pool fluctuations, and then defects such as porosity, cracks, and lack of fusion are generated; on the other hand, the multiple thermal cycles in the arc additive manufacturing process will make the microstructure of aluminum alloys coarse, resulting in anisotropy of material properties, which severely limits the application of aluminum alloy arc additive manufacturing components in high-end fields.

[0004] In order to solve the above technical problems, a Chinese invention patent with the authorization announcement number of CN116140755B discloses a method for forming a high-strength Al-Mg series alloy by arc additive manufacturing. Using a gas metal arc (MIG) additive manufacturing system, a high-magnesium wire (Mg 5.5 - 6.8wt%, Zr ≤ 0.1wt%) is used as the wire material, and a single-pass oscillating method is used for reciprocating layer-by-layer deposition and forming. By adjusting the welding process parameters, a high-strength Al-Mg series aluminum alloy forming part with excellent forming is obtained, with a maximum tensile strength of 365.0 MPa and an elongation after fracture of 25.5%, having an excellent combination of strength and plasticity. However, the mechanical properties of the forming parts made by this arc additive manufacturing process still need to be further improved, and the porosity needs to be further reduced.

[0005] It can be seen that it is particularly important to develop an arc additive manufacturing process for aluminum alloys with good mechanical properties and low porosity. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide an aluminum alloy arc additive manufacturing process with good mechanical properties and low porosity, which has high effectiveness and reliability.

[0007] To achieve the above object, the technical solution adopted by the present invention is: an aluminum alloy arc additive manufacturing process, comprising the following steps:

[0008] Step S1, gradient melting of aluminum alloy: ingredients are prepared according to the chemical composition formula of aluminum alloy wire; pure aluminum ingot is placed at the bottom of the crucible, and other raw materials are evenly spread, and pre-melted by electromagnetic suspension. After the alloy is melted, the temperature is adjusted to 695-705℃ and kept for 1-2 hours to promote uniform alloying; then, refining, deslagging, modification, refinement, static standing, and casting are carried out in sequence to obtain ingots; during casting, the pulling speed is dynamically adjusted according to the solidification process;

[0009] Step S2, preparing aluminum alloy wire: subjecting the ingot prepared in step S1 to homogenization heat treatment, followed by hot extrusion, intermediate annealing, and drawing to obtain Φ1.2 mm coiled wire;

[0010] Step S3, model design and slicing: Use SolidWorks software to build a rectangular parallelepiped model with dimensions of 200 mm × 100 mm × 50 mm, slice it using Cura slicing software, set the layer thickness to 0.5 mm, and generate the corresponding G code;

[0011] Step S4, material and equipment preparation: Use the Φ1.2 mm coiled wire produced in step S2 as the raw material, and prepare metal arc welding equipment and argon gas with a purity of ≥99.99%;

[0012] Step S5, substrate pretreatment: Select an aluminum alloy substrate with a thickness of 10 mm, and polish the substrate surface with sandpaper to remove the surface oxide film and impurities; then, clean the substrate surface with acetone, and then place it in a drying oven and dry it at 120°C for 30 minutes to ensure that the substrate surface is clean and dry;

[0013] Step S6, additive manufacturing: Additive manufacturing process: fix the pre-treated substrate on the workbench and start the GMAW equipment; according to the preset G code path, stack the aluminum alloy wire layer by layer, and pause for 5-10 seconds after each layer is stacked;

[0014] Step S7, heat treatment: After the additive manufacturing is completed, the component is subjected to stress relief annealing and aging strengthening treatment.

[0015] Preferably, the chemical composition of the aluminum alloy wire in step S1 is as follows by mass percentage: silicon 6.5 - 7.5%, magnesium 0.45 - 0.65%, titanium 0.12 - 0.18%, antimony 0.02 - 0.06%, zinc 0.05 - 0.1%, copper 0.05 - 0.1%, manganese 0.05 - 0.1%, iron ≤ 0.1%, and the balance is Al and other inevitable impurities.

[0016] Preferably, the titanium is added in two forms, and the mass added in the form of Al - Ti master alloy does not exceed 80% of the total added amount of titanium, and the remaining titanium is added in the form of Al - Ti - C - B refiner in the refining treatment stage.

[0017] Preferably, before the refining and slag skimming in step S1, there is also a step of sampling and analysis, and the composition of the alloy melt is adjusted according to the analysis results.

[0018] Preferably, the temperature control for the refining and slag skimming in step S1 is 710 - 720 °C, the refining time is 10 - 15 min, and after the refining is completed, the slag adhered to the inner wall of the crucible and the slag on the melt surface are completely removed.

[0019] Preferably, the modification treatment in step S1 is specifically as follows: the melt temperature is adjusted to 710 - 725 °C, and a composite modifier is injected using the rotary spray technology, with a rotation speed of 200 - 400 rpm. Argon is used to mix with the composite modifier and inject it into the melt, and the dispersion is strengthened through the Coriolis effect. The modification treatment time is 10 - 20 min.

[0020] Preferably, the composite modifier is a Mg - Sr composite modifier, and the addition amount is 0.02 - 0.05% of the total mass of the melt.

[0021] Preferably, the refining treatment in step S1 is specifically as follows: the temperature is raised to 730 - 745 °C, and an Al - Ti - B - C refiner is ejected along the depth direction of the melt using a porous diverter with a porosity of 60 - 80%, and stirred for 5 - 8 min.

[0022] Preferably, the Al - Ti - B - C refiner is AlTi5BC.

[0023] Preferably, the standing time in step S1 is 15 - 20 min, and the slag on the melt surface is removed after standing.

[0024] Preferably, the casting temperature in step S1 is 730 - 740 °C, the initial casting speed is 0.8 - 0.9 m / h, the speed is increased to 1.1 - 1.3 m / h after the melt pool is stable, and the speed is 0.6 - 0.7 m / h at the end of casting.

[0025] Preferably, in step S2, the temperature of the homogenization heat treatment is 455 - 485°C, the heat preservation time is 22 - 33 h, and it is air-cooled after being taken out of the furnace.

[0026] Preferably, in step S2, the extrusion ratio of the hot extrusion is (40 - 70):1, the extrusion speed is 2 - 4 mm / s, and the extrusion temperature is 420 - 460°C.

[0027] Preferably, in step S2, the temperature of the intermediate annealing treatment is 310 - 360°C, and the heat preservation time is 1 - 2 h.

[0028] Preferably, in step S6, the welding current of the GMAW device is 180 - 220 A, the welding voltage is 20 - 24 V, the wire feeding speed is 6 - 8 m / min, and the argon gas flow rate is 15 - 20 L / min.

[0029] Preferably, in step S7, the stress annealing treatment is specifically as follows: the component is placed in a heat treatment furnace and heated to 350 - 400°C at a heating rate of 5°C / min, heat-preserved for 2 - 3 h, and then cooled to room temperature with the furnace.

[0030] Preferably, in step S7, the age hardening treatment is specifically as follows: the component is placed in a heat treatment furnace at a temperature of 460°C - 540°C, heat-preserved for 3 - 4 h, quenched in water after the heat preservation ends, and then the quenched component is placed in a heat treatment furnace at a temperature of 130°C - 170°C and heat-preserved for 9 h - 18 h.

[0031] Due to the application of the above technical solutions, the present invention has the following beneficial effects:

[0032] (1) The aluminum alloy arc additive manufacturing process disclosed by the present invention is simple and easy to implement, has high manufacturing efficiency and finished product qualification rate, low dependence on equipment, is easy for large-scale industrial production, and has high popularization and application value.

[0033] (2)The aluminum alloy arc additive manufacturing process disclosed by the present invention has the chemical composition of the aluminum alloy wire as follows by mass percentage: silicon 6.5 - 7.5%, magnesium 0.45 - 0.65%, titanium 0.12 - 0.18%, antimony 0.02 - 0.06%, zinc 0.05 - 0.1%, copper 0.05 - 0.1%, manganese 0.05 - 0.1%, iron ≤ 0.1%, and the balance is Al and other inevitable impurities. Based on the composition formula of ZL114A aluminum alloy, by optimizing the types and dosage ratios of alloy components, especially the ratio of silicon to magnesium, the brittleness problem of traditional ZL114A aluminum alloy is overcome, and the ductility, crack resistance, fracture toughness and other properties of the additive manufacturing structural parts are improved; specifically, the dosages of the main alloying elements Si, Mg, and Ti are optimized, the beneficial effects of the impurity elements Zn, Cu, and Mn on the alloy are fully utilized, and the Sb high-efficiency modifier is introduced to regulate the structure, which can ensure that the manufactured components have excellent tensile properties, high yield strength and outstanding elongation. Be in the traditional ZL114A aluminum alloy is not added, avoiding the generation of toxic dust under the action of the arc to harm the health of operators, and also avoiding defects such as the appearance of hot cracks during the additive process, which may lead to a decline in performance. In the ZL114A alloy without Be, the high magnesium content will promote the formation of coarse Fe-containing impurity phases and increase the total volume fraction, reducing the alloy performance. By precisely controlling the magnesium content within the range of 0.45% - 0.65%, the present invention avoids the negative impact of magnesium on the embrittlement effect of the alloy, while ensuring the forming quality of the alloy during the arc additive manufacturing process; the addition of Sb, in combination with other components, can fully improve the morphology of eutectic silicon and reduce the porosity of the additive manufacturing structural parts; by adding appropriate amounts of Mn, Cu, and Zn elements, the present invention improves the strength, plasticity and elongation of the additive manufacturing structural parts. In the national standard of ZL114A alloy, Mn, Cu, and Zn are controlled as impurity elements. By reasonably controlling the dosages of these impurity elements and utilizing the beneficial effects of the "impurity" elements on the properties of the additive manufacturing structural parts, higher comprehensive mechanical properties are obtained.

[0034] (3)The aluminum alloy arc additive manufacturing process disclosed by the present invention adds an Al-Ti-C-B refining agent, which can effectively reduce the alloy's dependence on TiAl3 refining, reduce excess Ti, reduce the tendency of the alloy to be "poisoned", and avoid the coarsening of α-Al grains and abnormal structures. The present invention proposes a raw material trial production method of gradient melting + dynamic drawing for the problems of uncontrollable oxidation and burning loss, uneven distribution of modifiers, and insufficient melt cleanliness of the cast aluminum alloy manufactured by the traditional melting process, resulting in a low burning loss rate of active elements, high melt uniformity, and obvious grain refinement, thereby effectively reducing the porosity and crack sensitivity of the additive structure and improving its mechanical properties.

[0035] (4) The aluminum alloy arc additive manufacturing process disclosed in the present invention effectively reduces the generation of defects such as pores and cracks by optimizing the alloy composition and combining reasonable process parameter control, refines the microstructure of the aluminum alloy, and improves the density and quality of the components. Through the reasonable selection of process parameters, the microstructure of the aluminum alloy components is made more uniform, the anisotropy of the material properties is significantly improved, and the overall performance of the components is enhanced. Arc additive manufacturing technology itself has the characteristics of high forming efficiency and high material utilization. Combined with the process parameters of the present invention, it further improves production efficiency and reduces production costs.

[0036] (5) The aluminum alloy arc additive manufacturing process disclosed in the present invention performs stress relief annealing and aging strengthening treatment on the component after the additive manufacturing is completed, which can effectively eliminate the residual stress inside the component, stabilize the component size, and improve its mechanical properties. DETAILED DESCRIPTION

[0037] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0038] Example 1:

[0039] An aluminum alloy arc additive manufacturing process comprises the following steps:

[0040] Step S1, gradient melting of aluminum alloy: ingredients are prepared according to the chemical composition formula of aluminum alloy wire; pure aluminum ingot is placed at the bottom of the crucible, and other raw materials are evenly spread, and pre-melted by electromagnetic suspension. After the alloy is melted, the temperature is adjusted to 695°C and kept for 1 hour to promote uniform alloying; then, refining, deslagging, modification, refinement, static standing, and casting are carried out in sequence to obtain an ingot; during casting, the pulling speed is dynamically adjusted according to the solidification process;

[0041] Step S2, preparing aluminum alloy wire: subjecting the ingot prepared in step S1 to homogenization heat treatment, followed by hot extrusion, intermediate annealing, and drawing to obtain Φ1.2 mm coiled wire;

[0042] Step S3, model design and slicing: Use SolidWorks software to build a rectangular parallelepiped model with dimensions of 200 mm × 100 mm × 50 mm, slice it using Cura slicing software, set the layer thickness to 0.5 mm, and generate the corresponding G code;

[0043] Step S4, material and equipment preparation: Use the Φ1.2 mm coiled wire produced in step S2 as the raw material, and prepare metal arc welding equipment and argon gas with a purity of ≥99.99%;

[0044] Step S5, Substrate Pretreatment: Select an aluminum alloy substrate with a thickness of 10 mm, use sandpaper to polish the surface of the substrate to remove the surface oxide film and impurities; then, clean the surface of the substrate with acetone, and then put it into a drying oven and dry it at 120 °C for 30 min to ensure that the surface of the substrate is clean and dry;

[0045] Step S6, Additive Manufacturing: The process of additive manufacturing: Fix the pretreated substrate on the workbench and start the GMAW equipment; Stack the aluminum alloy wire layer by layer according to the preset G-code path, and pause for 5 s after each layer is stacked;

[0046] Step S7, Heat Treatment: After additive manufacturing is completed, perform stress relief annealing treatment and aging strengthening treatment on the component.

[0047] The chemical composition of the aluminum alloy wire described in Step S1 is as follows by mass percentage: silicon 6.5%, magnesium 0.45%, titanium 0.12%, antimony 0.02%, zinc 0.05%, copper 0.05%, manganese 0.05%, iron ≤ 0.1%, and the balance is Al and other inevitable impurities; The titanium is added in two forms, and the mass added in the form of Al-Ti master alloy does not exceed 80% of the total added amount of titanium, and the rest of the titanium is added in the form of Al-Ti-C-B refining agent in the refining treatment stage.

[0048] Before the refining and slag skimming in Step S1, there is also a step of sampling and analysis, and the composition of the alloy melt is adjusted according to the analysis results; The temperature control for refining and slag skimming in Step S1 is 710 °C, the refining time is 10 min, and after refining, the slag adhered to the inner wall of the crucible and the slag on the surface of the melt are completely removed; The modification treatment in Step S1 is specifically: adjust the temperature of the melt to 710 °C, inject the composite modifier by rotary spray technology, the rotation speed is 200 rpm, use argon to mix the composite modifier and inject it into the melt, and strengthen the dispersion through the Coriolis effect, and the modification treatment time is 10 min; The composite modifier is Mg-Sr composite modifier, and the addition amount is 0.02% of the total mass of the melt; The refinement treatment in Step S1 is specifically: raise the temperature to 730 °C, and use a porous diverter with a porosity of 60% to spray the Al-Ti-B-C refining agent along the depth direction of the melt and stir for 5 min; The Al-Ti-B-C refining agent is AlTi5BC; The standing time in Step S1 is 15 min, and the slag on the surface of the melt is removed after standing; The casting temperature in Step S1 is 730 °C, the initial casting speed is 0.8 m / h, and the speed is increased to 1.1 m / h after the molten pool is stable, and the speed is 0.6 m / h at the end of casting.

[0049] The homogenization heat treatment in step S2 is performed at a temperature of 455°C, a holding time of 22 hours, and air cooling after removal from the furnace; the hot extrusion in step S2 has an extrusion ratio of 50:1, an extrusion speed of 2 mm / s, and an extrusion temperature of 420°C; the intermediate annealing in step S2 is performed at a temperature of 310°C, and a holding time of 1 hour; the welding current of the GMAW equipment in step S6 is 180A, the welding voltage is 20V, the wire feed speed is 6 m / min, and the argon flow rate is 15 L / min; the stress annealing in step S7 is specifically as follows: placing the component in a heat treatment furnace, heating it to 350°C at a heating rate of 5°C / min, holding it for 2 hours, and then cooling it to room temperature with the furnace; the aging strengthening treatment in step S7 is specifically as follows: placing the component in a heat treatment furnace at a temperature of 460°C, holding it for 3 hours, and then placing it in water for quenching after the holding period, and then placing the quenched component in a heat treatment furnace at a temperature of 130°C and holding it for 9 hours.

[0050] Example 2:

[0051] An aluminum alloy arc additive manufacturing process comprises the following steps:

[0052] Step S1, gradient melting of aluminum alloy: ingredients are prepared according to the chemical composition formula of aluminum alloy wire; pure aluminum ingot is placed at the bottom of the crucible, and other raw materials are evenly spread, and pre-melted by electromagnetic suspension. After the alloy is melted, the temperature is adjusted to 698°C and kept warm for 1.2 hours to promote uniform alloying; then, refining, deslagging, modification, refinement, static standing, and casting are carried out in sequence to obtain an ingot; during casting, the billet pulling speed is dynamically adjusted according to the solidification process;

[0053] Step S2, preparing aluminum alloy wire: subjecting the ingot prepared in step S1 to homogenization heat treatment, followed by hot extrusion, intermediate annealing, and drawing to obtain Φ1.2 mm coiled wire;

[0054] Step S3, model design and slicing: Use SolidWorks software to build a rectangular parallelepiped model with dimensions of 200 mm × 100 mm × 50 mm, slice it using Cura slicing software, set the layer thickness to 0.5 mm, and generate the corresponding G code;

[0055] Step S4, material and equipment preparation: Use the Φ1.2 mm coiled wire produced in step S2 as the raw material, and prepare metal arc welding equipment and argon gas with a purity of ≥99.99%;

[0056] Step S5, substrate pretreatment: Select an aluminum alloy substrate with a thickness of 10 mm, and polish the substrate surface with sandpaper to remove the surface oxide film and impurities; then, clean the substrate surface with acetone, and then place it in a drying oven and dry it at 120°C for 30 minutes to ensure that the substrate surface is clean and dry;

[0057] Step S6, Additive manufacturing: Additive manufacturing process: Fix the pre-treated substrate on the workbench and start the GMAW equipment; layer by layer stack the aluminum alloy wire according to the preset G-code path, and pause for 6 s after each layer is stacked.

[0058] Step S7, Heat treatment: After additive manufacturing is completed, perform stress relief annealing treatment and age hardening treatment on the component.

[0059] The chemical composition of the aluminum alloy wire described in Step S1 is as follows by mass percentage: silicon 6.7%, magnesium 0.5%, titanium 0.14%, antimony 0.03%, zinc 0.06%, copper 0.07%, manganese 0.06%, iron ≤ 0.1%, and the balance is Al and other inevitable impurities.

[0060] The titanium is added in two forms, and the mass added in the form of Al-Ti master alloy does not exceed 80% of the total added amount of titanium, and the remaining titanium is added in the form of Al-Ti-C-B refiner in the refinement treatment stage; before the refining and slag skimming in Step S1, there is also a step of sampling and analysis, and the composition of the alloy melt is adjusted according to the analysis result; the temperature control for the refining and slag skimming in Step S1 is 713 °C, the refining time is 12 min, and after the refining is completed, the slag adhered to the inner wall of the crucible and the slag on the surface of the melt are completely removed.

[0061] The modification treatment described in Step S1 is specifically: adjust the temperature of the melt to 715 °C, inject the composite modifier by the rotary injection technology, the rotation speed is 250 rpm, use argon to mix the composite modifier and inject it into the melt, and strengthen the dispersion through the Coriolis effect, and the modification treatment time is 12 min; the composite modifier is Mg-Sr composite modifier, and the addition amount is 0.03% of the total mass of the melt; the refinement treatment described in Step S1 is specifically: raise the temperature to 735 °C, and spray the Al-Ti-B-C refiner along the depth direction of the melt by a porous diverter with a porosity of 65%, and stir for 6 min; the Al-Ti-B-C refiner is AlTi5BC.

[0062] The standing time described in Step S1 is 16 min, and the slag on the surface of the melt is removed after standing; the casting temperature described in Step S1 is 733 °C, the initial casting speed is 0.83 m / h, and the speed is increased to 1.15 m / h after the melt pool is stable, and the speed is 0.63 m / h at the end of casting; the temperature of the homogenization heat treatment described in Step S2 is 465 °C, the holding time is 25 h, and it is air-cooled after being taken out of the furnace; the extrusion ratio of the hot extrusion described in Step S2 is 50:1, the extrusion speed is 2.5 mm / s, and the extrusion temperature is 435 °C; the temperature of the intermediate annealing treatment described in Step S2 is 330 °C, and the holding time is 1.3 h.

[0063] The welding current of the GMAW equipment in step S6 is 190A, the welding voltage is 21V, the wire feed speed is 6.5m / min, and the argon gas flow rate is 17L / min. The stress annealing treatment in step S7 is specifically as follows: placing the component in a heat treatment furnace, heating it to 370°C at a heating rate of 5°C / min, holding it for 2.3 hours, and then cooling it to room temperature with the furnace; the aging strengthening treatment in step S7 is specifically as follows: placing the component in a heat treatment furnace at a temperature of 480°C, holding it for 3.3 hours, and then placing it in water for quenching treatment after the holding period. The quenched component is then placed in a heat treatment furnace at a temperature of 145°C and held for 11 hours.

[0064] Example 3:

[0065] An aluminum alloy arc additive manufacturing process comprises the following steps:

[0066] Step S1, gradient melting of aluminum alloy: ingredients are prepared according to the chemical composition formula of aluminum alloy wire; pure aluminum ingot is placed at the bottom of the crucible, and other raw materials are evenly spread, and pre-melted by electromagnetic suspension. After the alloy is melted, the temperature is adjusted to 700°C and kept warm for 1.5 hours to promote uniform alloying; then, refining, deslagging, modification, refinement, static standing, and casting are carried out in sequence to obtain an ingot; during casting, the pulling speed is dynamically adjusted according to the solidification process;

[0067] Step S2, preparing aluminum alloy wire: subjecting the ingot prepared in step S1 to homogenization heat treatment, followed by hot extrusion, intermediate annealing, and drawing to obtain Φ1.2 mm coiled wire;

[0068] Step S3, model design and slicing: Use SolidWorks software to build a rectangular parallelepiped model with dimensions of 200 mm × 100 mm × 50 mm, slice it using Cura slicing software, set the layer thickness to 0.5 mm, and generate the corresponding G code;

[0069] Step S4, material and equipment preparation: Use the Φ1.2 mm coiled wire produced in step S2 as the raw material, and prepare metal arc welding equipment and argon gas with a purity of ≥99.99%;

[0070] Step S5, substrate pretreatment: Select an aluminum alloy substrate with a thickness of 10 mm, and polish the substrate surface with sandpaper to remove the surface oxide film and impurities; then, clean the substrate surface with acetone, and then place it in a drying oven and dry it at 120°C for 30 minutes to ensure that the substrate surface is clean and dry;

[0071] Step S6, Additive manufacturing: Additive manufacturing process: Fix the pre-treated substrate on the workbench and start the GMAW equipment; layer by layer stack the aluminum alloy wire according to the preset G-code path, and pause for 7.5 s after each layer is stacked.

[0072] Step S7, Heat treatment: After additive manufacturing is completed, perform stress relief annealing treatment and age hardening treatment on the component.

[0073] Preferably, the chemical composition of the aluminum alloy wire described in step S1 is as follows by mass percentage: silicon 7%, magnesium 0.55%, titanium 0.15%, antimony 0.04%, zinc 0.07%, copper 0.07%, manganese 0.08%, iron ≤ 0.1%, and the balance is Al and other inevitable impurities; the titanium is added in two forms, wherein the mass added in the form of Al-Ti master alloy does not exceed 80% of the total added amount of titanium, and the remaining titanium is added in the form of Al-Ti-C-B refiner in the refinement treatment stage.

[0074] Before the refining and slag skimming in step S1, there is also a step of sampling and analysis, and the composition of the alloy melt is adjusted according to the analysis results; the temperature control for the refining and slag skimming in step S1 is 715 °C, the refining time is 13 min, and after the refining is completed, the slag adhered to the inner wall of the crucible and the slag on the surface of the melt are completely removed; the modification treatment in step S1 is specifically: adjust the temperature of the melt to 718 °C, inject the composite modifier by the rotary injection technology, the rotation speed is 300 rpm, use argon to mix the composite modifier and inject it into the melt, and strengthen the dispersion through the Coriolis effect, and the modification treatment time is 15 min; the composite modifier is Mg-Sr composite modifier, and the addition amount is 0.035% of the total mass of the melt; the refinement treatment in step S1 is specifically: raise the temperature to 738 °C, and spray the Al-Ti-B-C refiner along the depth direction of the melt using a porous diverter with a porosity of 70%, and stir for 6.5 min; the Al-Ti-B-C refiner is AlTi5BC; the standing time in step S1 is 17 min, and the slag on the surface of the melt is removed after standing; the casting temperature in step S1 is 735 °C, the initial casting speed is 0.85 m / h, and the speed is increased to 1.2 m / h after the melt pool is stable, and the speed is 0.65 m / h at the end of casting.

[0075] The homogenization heat treatment temperature in step S2 is 470°C, the holding time is 28 hours, and the furnace is air-cooled; the extrusion ratio of the hot extrusion in step S2 is 50:1, the extrusion speed is 3 mm / s, and the extrusion temperature is 440°C; the intermediate annealing temperature in step S2 is 340°C, and the holding time is 1.5 hours; the welding current of the GMAW equipment in step S6 is 200A, the welding voltage is 22V, the wire feed speed is 7m / min, and the argon flow rate is 18L / m in; the stress annealing treatment in step S7 is specifically as follows: placing the component in a heat treatment furnace, heating it to 380°C at a heating rate of 5°C / min, holding it for 2.5 hours, and then cooling it to room temperature with the furnace; the aging strengthening treatment in step S7 is specifically as follows: placing the component in a heat treatment furnace at a temperature of 500°C, holding it for 3.5 hours, and after the holding period, placing it in water for quenching treatment, and continuing to place the quenched component in a heat treatment furnace at a temperature of 150°C and holding it for 12 hours.

[0076] Example 4:

[0077] An aluminum alloy arc additive manufacturing process comprises the following steps:

[0078] Step S1, gradient melting of aluminum alloy: ingredients are prepared according to the chemical composition formula of aluminum alloy wire; pure aluminum ingot is placed at the bottom of the crucible, and other raw materials are evenly spread, and pre-melted by electromagnetic suspension. After the alloy is melted, the temperature is adjusted to 703°C and kept warm for 1.8 hours to promote uniform alloying; then, refining, deslagging, modification, refinement, static standing, and casting are carried out in sequence to obtain an ingot; during casting, the pulling speed is dynamically adjusted according to the solidification process;

[0079] Step S2, preparing aluminum alloy wire: subjecting the ingot prepared in step S1 to homogenization heat treatment, followed by hot extrusion, intermediate annealing, and drawing to obtain Φ1.2 mm coiled wire;

[0080] Step S3, model design and slicing: Use SolidWorks software to build a rectangular parallelepiped model with dimensions of 200 mm × 100 mm × 50 mm, slice it using Cura slicing software, set the layer thickness to 0.5 mm, and generate the corresponding G code;

[0081] Step S4, material and equipment preparation: Use the Φ1.2 mm coiled wire produced in step S2 as the raw material, and prepare metal arc welding equipment and argon gas with a purity of ≥99.99%;

[0082] Step S5. Substrate pretreatment: Select an aluminum alloy substrate with a thickness of 10 mm, and use sandpaper to polish the surface of the substrate to remove the oxide film and impurities on the surface; then, clean the surface of the substrate with acetone, and then put it into a drying oven and dry it at 120 °C for 30 min to ensure that the surface of the substrate is clean and dry;

[0083] Step S6. Additive manufacturing: The process of additive manufacturing: Fix the pretreated substrate on the workbench and start the GMAW equipment; stack the aluminum alloy wire layer by layer according to the preset G-code path, and pause for 9 s after each layer is stacked;

[0084] Step S7. Heat treatment: After additive manufacturing is completed, perform stress relief annealing treatment and age hardening treatment on the component.

[0085] The chemical composition of the aluminum alloy wire described in Step S1 is as follows by mass percentage: silicon 7.3%, magnesium 0.6%, titanium 0.17%, antimony 0.05%, zinc 0.09%, copper 0.09%, manganese 0.09%, iron ≤ 0.1%, and the balance is Al and other inevitable impurities; the titanium is added in two forms, of which the mass added in the form of Al-Ti master alloy does not exceed 80% of the total added amount of titanium, and the remaining titanium is added in the form of Al-Ti-C-B refiner in the refinement treatment stage; before the refining and slag skimming in Step S1, there is also a step of sampling and analysis, and the composition of the alloy melt is adjusted according to the analysis results; the temperature control of the refining and slag skimming in Step S1 is 718 °C, the refining time is 14 min, and after the refining is completed, the slag adhered to the inner wall of the crucible and the slag on the surface of the melt are completely removed; the modification treatment in Step S1 is specifically: adjust the temperature of the melt to 723 °C, inject the composite modifier by the rotary spraying technology, the rotation speed is 350 rpm, use argon to mix the composite modifier and inject it into the melt, and strengthen the dispersion through the Coriolis effect, and the modification treatment time is 18 min; the composite modifier is Mg-Sr composite modifier, and the addition amount is 0.04% of the total mass of the melt; the refinement treatment in Step S1 is specifically: raise the temperature to 743 °C, and use a porous diverter with a porosity of 75% to spray the Al-Ti-B-C refiner along the depth direction of the melt and stir for 7.5 min; the Al-Ti-B-C refiner is AlTi5BC; the standing time in Step S1 is 19 min, and the slag on the surface of the melt is removed after standing; the casting temperature in Step S1 is 738 °C, the initial casting speed is 0.88 m / h, and the speed is increased to 1.25 m / h after the molten pool is stable, and the speed is 0.68 m / h at the end of casting.

[0086] The homogenization heat treatment temperature in step S2 is 480°C, the holding time is 32 hours, and the furnace is air-cooled; the extrusion ratio of the hot extrusion in step S2 is 50:1, the extrusion speed is 3.5 mm / s, and the extrusion temperature is 450°C; the intermediate annealing temperature in step S2 is 350°C, and the holding time is 1.8 hours; the welding current of the GMAW equipment in step S6 is 210A, the welding voltage is 23V, the wire feed speed is 7.5m / min, and the argon flow rate is 19L / min; the stress annealing treatment in step S7 is specifically as follows: placing the component in a heat treatment furnace, heating it to 390°C at a heating rate of 5°C / min, holding it for 2.8 hours, and then cooling it to room temperature with the furnace; the aging strengthening treatment in step S7 is specifically as follows: placing the component in a heat treatment furnace at a temperature of 530°C, holding it for 3.8 hours, placing it in water for quenching after the end of the holding period, and continuing to place the quenched component in a heat treatment furnace at a temperature of 165°C and holding it for 16 hours.

[0087] Example 5:

[0088] An aluminum alloy arc additive manufacturing process comprises the following steps:

[0089] Step S1, gradient melting of aluminum alloy: ingredients are prepared according to the chemical composition formula of aluminum alloy wire; pure aluminum ingot is placed at the bottom of the crucible, and other raw materials are evenly spread, and pre-melted by electromagnetic suspension. After the alloy is melted, the temperature is adjusted to 705°C and kept for 2 hours to promote uniform alloying; then, refining, deslagging, modification, refinement, static standing, and casting are carried out in sequence to obtain an ingot; during casting, the pulling speed is dynamically adjusted according to the solidification process;

[0090] Step S2, preparing aluminum alloy wire: subjecting the ingot prepared in step S1 to homogenization heat treatment, followed by hot extrusion, intermediate annealing, and drawing to obtain Φ1.2 mm coiled wire;

[0091] Step S3, model design and slicing: Use SolidWorks software to build a rectangular parallelepiped model with dimensions of 200 mm × 100 mm × 50 mm, slice it using Cura slicing software, set the layer thickness to 0.5 mm, and generate the corresponding G code;

[0092] Step S4, material and equipment preparation: Use the Φ1.2 mm coiled wire produced in step S2 as the raw material, and prepare metal arc welding equipment and argon gas with a purity of ≥99.99%;

[0093] Step S5, Substrate Pretreatment: Select an aluminum alloy substrate with a thickness of 10 mm, use sandpaper to polish the surface of the substrate to remove the oxide film and impurities on the surface; then, clean the surface of the substrate with acetone, and then put it into a drying oven and dry it at 120 °C for 30 min to ensure that the surface of the substrate is clean and dry;

[0094] Step S6, Additive Manufacturing: The additive manufacturing process: Fix the pretreated substrate on the workbench and start the GMAW equipment; Stack the aluminum alloy wire layer by layer according to the preset G-code path, and pause for 10 s after each layer is stacked;

[0095] Step S7, Heat Treatment: After additive manufacturing is completed, perform stress relief annealing treatment and age hardening treatment on the component.

[0096] The chemical composition of the aluminum alloy wire described in Step S1 is as follows by mass percentage: silicon 7.5%, magnesium 0.65%, titanium 0.18%, antimony 0.06%, zinc 0.1%, copper 0.1%, manganese 0.1%, iron ≤ 0.1%, and the balance is Al and other inevitable impurities; The titanium is added in two forms, and the mass added in the form of Al-Ti master alloy does not exceed 80% of the total added amount of titanium, and the rest of the titanium is added in the form of Al-Ti-C-B refiner in the refinement treatment stage; Before the refining and slag skimming in Step S1, there is also a step of sampling and analysis, and the composition of the alloy melt is adjusted according to the analysis results; The temperature control of the refining and slag skimming in Step S1 is 720 °C, the refining time is 15 min, and after the refining is completed, the slag adhered to the inner wall of the crucible and the slag on the surface of the melt are completely removed; The modification treatment in Step S1 is specifically: adjust the temperature of the melt to 725 °C, inject the composite modifier by the rotary injection technology, the rotation speed is 400 rpm, use argon to mix the composite modifier and inject it into the melt, and strengthen the dispersion through the Coriolis effect, and the modification treatment time is 20 min; The composite modifier is Mg-Sr composite modifier, and the addition amount is 0.05% of the total mass of the melt; The refinement treatment in Step S1 is specifically: raise the temperature to 745 °C, and use a porous diverter with a porosity of 80% to spray the Al-Ti-B-C refiner along the depth direction of the melt and stir for 8 min; The Al-Ti-B-C refiner is AlTi5BC; The standing time in Step S1 is 20 min, and the slag on the surface of the melt is removed after standing; The casting temperature in Step S1 is 740 °C, the initial casting speed is 0.9 m / h, and the speed is increased to 1.3 m / h after the molten pool is stable, and the speed is 0.7 m / h at the end of casting.

[0097] In step S2, the temperature of the homogenization heat treatment is 485 °C, the holding time is 33 h, and it is air-cooled after being taken out of the furnace; in step S2, the extrusion ratio of the hot extrusion is 50:1, the extrusion speed is 4 mm / s, and the extrusion temperature is 460 °C; in step S2, the temperature of the intermediate annealing treatment is 360 °C, and the holding time is 2 h; in step S6, the welding current of the GMAW equipment is 220 A, the welding voltage is 24 V, the wire feeding speed is 8 m / min, and the argon gas flow rate is 20 L / min; in step S7, the stress annealing treatment is specifically as follows: the component is placed in a heat treatment furnace and heated to 400 °C at a heating rate of 5 °C / min, held for 3 h, and then cooled to room temperature with the furnace; in step S7, the age hardening treatment is specifically as follows: the component is placed in a heat treatment furnace at a temperature of 540 °C, held for 4 h, and after the holding is completed, it is quenched in water, and the quenched component is continued to be placed in a heat treatment furnace at a temperature of 170 °C and held for 18 h.

[0098] Comparative Example 1:

[0099] An aluminum alloy arc additive manufacturing process is basically the same as that of Example 1, except that antimony is not added and there is no refinement treatment step.

[0100] Comparative Example 2:

[0101] An aluminum alloy arc additive manufacturing process is basically the same as that of Example 1, except that there is no modification treatment step, and the drawing speed is not dynamically adjusted according to the solidification process during casting and is fixed at 0.8 m / h.

[0102] In order to further illustrate the beneficial technical effects of the aluminum alloy arc additive manufacturing processes involved in the embodiments of the present invention, the components made of the aluminum alloy arc additive manufacturing processes involved in Examples 1-5 and Comparative Examples 1-2 are subjected to relevant performance tests. The test results are shown in Table 1, and the test methods are as follows: Standard tensile specimens are processed in accordance with GB / T 39254-2020 "General Rules for Mechanical Property Evaluation of Additive Manufactured Metal Parts", and tensile tests are carried out on a universal material testing machine with reference to GB / T 228.1-2021 "Metallic Materials - Tensile Testing - Part 1: Method of Test at Room Temperature" to determine the mechanical properties of the components. The Image ProPlus 6.0 software is used to assist in the microscopic analysis of the porosity of the components, and the average porosity and average pore diameter are statistically analyzed.

[0103]

[0104] As can be seen from Table 1, the components made by the aluminum alloy arc additive manufacturing process involved in the embodiments of the present invention have better mechanical properties, lower porosity and pore size than those of the products in the comparative examples; the combined use of antimony, the refinement treatment step, the modification treatment step, and dynamically adjusting the drawing speed according to the solidification process during casting is beneficial to improving the above properties. Through the optimization of the above manufacturing process and the composition formula, the performance of the traditional ZL114A aluminum alloy is significantly improved, and its application range is broadened.

[0105] The above embodiments are only for illustrating the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. An arc additive manufacturing process for aluminum alloy, characterized in that, The steps include: Step S1: Prepare the ingredients according to the chemical composition formula of the aluminum alloy wire; place a pure aluminum ingot as the bottom of the crucible, and evenly spread the other raw materials. Pre-melt the alloy by electromagnetic levitation. After the alloy is melted, adjust the temperature to 695-705°C and hold for 1-2 hours to promote uniform alloying. Then, perform refining, deslagging, modification, refinement, static treatment, and casting in sequence to obtain an ingot. During casting, the casting speed is dynamically adjusted according to the solidification process. The chemical composition of the aluminum alloy wire is as follows by mass percentage: silicon 6.5-7. 5%, magnesium 0.45-0.65%, titanium 0.12-0.18%, antimony 0.02-0.06%, zinc 0.05-0.1%, copper 0.05-0.1%, manganese 0.05-0.1%, iron ≤0.1%, and the balance is Al and other inevitable impurities; the titanium is added in two forms, of which the mass added in the form of Al-Ti master alloy does not exceed 80% of the total titanium addition, and the remaining titanium is added in the form of Al-Ti-CB refiner during the refinement treatment stage; Step S2: subjecting the ingot obtained in step S1 to homogenization heat treatment, followed by hot extrusion, intermediate annealing, and drawing to obtain Φ1.2 mm coiled wire; Step S3: Use SolidWorks software to build a rectangular parallelepiped model with a size of 200 mm × 100 mm × 50 mm, slice it using Cura slicing software, set the layer thickness to 0.5 mm, and generate the corresponding G code; Step S4: Select the Φ1.2 mm coiled wire produced in step S2 as raw material, and prepare metal arc welding equipment and argon gas with a purity of ≥99.99%; Step S5: Select an aluminum alloy substrate with a thickness of 10 mm and polish the surface of the substrate with sandpaper to remove the oxide film and impurities on the surface; then, clean the surface of the substrate with acetone and place it in a drying oven at 120° C. for 30 minutes to ensure that the substrate surface is clean and dry; Step S6, additive manufacturing process: fix the pre-treated substrate on the workbench and start the GMAW equipment; stack the aluminum alloy wire layer by layer according to the preset G code path, and pause for 5-10 seconds after each layer is stacked; Step S7: After the additive manufacturing is completed, the component is subjected to stress relief annealing and aging strengthening treatment.

2. The aluminum alloy arc additive manufacturing process according to claim 1, wherein, Before the refining and slagging in step S1, a sampling and analysis step is also included, and the composition of the alloy melt is adjusted according to the analysis results; the temperature of the refining and slagging in step S1 is controlled at 710-720°C, and the refining time is 10-15 minutes. After the refining is completed, the slag adhered to the inner wall of the crucible and the slag on the surface of the melt are removed.

3. The aluminum alloy arc additive manufacturing process according to claim 1, wherein, The modification treatment in step S1 specifically includes: adjusting the melt temperature to 710-725°C, injecting a composite modifier using a rotary injection technique at a rotation speed of 200-400 rpm, injecting argon mixed with the composite modifier into the melt, and enhancing dispersion through the Coriolis effect. The modification treatment time is 10-20 minutes. The composite modifier is a Mg-Sr composite modifier, and the addition amount is 0.02-0.05% of the total mass of the melt.

4. The aluminum alloy arc additive manufacturing process according to claim 1, characterized in that, The refinement treatment described in step S1 is specifically as follows: Raise the temperature to 730 - 745 °C, and use a porous diverter with a porosity of 60 - 80% to eject the Al-Ti-B-C grain refiner along the depth direction of the melt, and stir for 5 - 8 min; the Al-Ti-B-C grain refiner is AlTi5BC.

5. The aluminum alloy arc additive manufacturing process according to claim 1, characterized in that, The standing time described in step S1 is 15 - 20 min. After standing, skim the slag on the surface of the melt; the casting temperature described in step S1 is 730 - 740 °C, the initial casting speed is 0.8 - 0.9 m / h, and the speed is increased to 1.1 - 1.3 m / h after the melt pool is stable. The speed at the end of casting is 0.6 - 0.7 m / h.

6. The aluminum alloy arc additive manufacturing process according to claim 1, characterized in that, The temperature of the homogenization heat treatment described in step S2 is 455 - 485 °C, the holding time is 22 - 33 h, and it is air-cooled after being taken out of the furnace; the extrusion ratio of the hot extrusion described in step S2 is (40 - 70):1, the extrusion speed is 2 - 4 mm / s, and the extrusion temperature is 420 - 460 °C; the temperature of the intermediate annealing treatment described in step S2 is 310 - 360 °C, and the holding time is 1 - 2 h.

7. The aluminum alloy arc additive manufacturing process according to claim 1, characterized in that, The welding current of the GMAW equipment described in step S6 is 180 - 220 A, the welding voltage is 20 - 24 V, the wire feeding speed is 6 - 8 m / min, and the argon gas flow rate is 15 - 20 L / min.

8. The aluminum alloy arc additive manufacturing process according to claim 1, characterized in that, The stress annealing treatment described in step S7 is specifically as follows: Place the component in a heat treatment furnace, heat it to 350 - 400 °C at a heating rate of 5 °C / min, hold for 2 - 3 h, and then cool it to room temperature with the furnace.

9. The aluminum alloy arc additive manufacturing process according to claim 1, characterized in that, The age hardening treatment described in step S7 is specifically as follows: Place the component in a heat treatment furnace at a temperature of 460 °C to 540 °C, hold for 3 - 4 h. After the holding is completed, quench it in water. Then continue to place the quenched component in a heat treatment furnace at a temperature of 130 °C to 170 °C and hold for 9 h to 18 h.

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