An aluminum alloy cored fluxed welding wire and a method of making the same

Abstract

The application provides an aluminum alloy cored foaming welding wire and a preparation method thereof, and belongs to the technical field of aluminum alloy welding wire production. The application utilizes the principle of thermal decomposition and gas release of the foaming agent in the aluminum alloy foaming welding wire to generate uniform bubbles in the aluminum alloy molten pool, and obtains a porous welding seam with uniform pores through rapid cooling of the molten pool, thereby realizing wide-gap welding repair foaming filling and functional strengthening effect. Compared with the existing aluminum alloy welding wire, the application can realize rapid filling and connection of the welding seam area after aluminum alloy material welding, and the welding seam filling area presents a typical porous morphology; the application can realize direct welding of lightweight porous aluminum alloy material, avoids solidification of the welding seam area, and is helpful to lightweight design; the application can realize welding foaming filling of a metal component cavity, can greatly improve the cavity filling efficiency due to the molten pool foaming, and endows the formed metal component with damping and vibration reduction functions; and the application can be used as an additive manufacturing welding wire, and can directly perform additive preparation forming of the porous aluminum alloy material.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy welding technology, and more specifically, to an aluminum alloy flux-cored foamed welding wire and its preparation method. Background Technology

[0002] With the high-quality development of aerospace, rail transportation, and new energy vehicles, aluminum alloys have become the preferred material in modern industry due to their excellent specific strength, corrosion resistance, and ease of processing. Welding, as the core process for forming aluminum alloy parts, directly affects the service performance and safety reliability of the products. Fusion welding is currently the main process for aluminum alloy welding due to its economy and efficiency. It is a welding process that uses heat sources such as electric arcs, lasers, and electron beams to melt metal materials such as welding rods or welding wires to fill the weld seam and achieve metallurgical bonding of aluminum alloys.

[0003] Welding wire is an indispensable material for aluminum alloy fusion welding. However, due to the constraints of welding technology and conditions, traditional welding wire has several problems that urgently need to be solved in the welding process: First, traditional welding wire requires multiple welding passes for wide welds, resulting in low welding efficiency, large structural deformation, and a high tendency for coarsening of the base metal grains. Second, the welds formed by traditional welding wire are solid welds with a density close to that of aluminum alloys, which is not conducive to the lightweight design of parts under specific working conditions, especially for connecting aluminum alloy plates or structures with special functional designs such as lattice structures or porous features. Third, when traditional welding wire is used in arc additive manufacturing, the lightweight design and functional control of the part structure can only be achieved through structural optimization and adjustment. It cannot directly utilize the inherent properties of the welding wire metal to achieve functional characteristics such as weld damping, vibration reduction, sound insulation, and electromagnetic shielding.

[0004] Therefore, there is an urgent need to develop a special aluminum alloy foamed welding wire that can achieve foaming and filling during the fusion welding process, effectively solving the welding problems of lightweight lattice structures or porous aluminum alloy structural components. The newly developed aluminum alloy foamed welding wire must meet the requirements of low price and large-scale industrial production. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides an aluminum alloy flux-cored foamed welding wire and its preparation method. This addresses the problems of traditional welding wires failing to achieve efficient foam filling of wide weld seams and exhibiting poor functionality in solid weld seams, such as damping and vibration reduction, sound insulation and noise reduction, and electromagnetic shielding.

[0006] The present invention is achieved through the following technical solution: an aluminum alloy flux-cored foamed welding wire, wherein the aluminum alloy flux-cored foamed welding wire uses an aluminum alloy strip as the outer skin and is uniformly filled with a foamed flux core. The foamed flux core is formulated by the following components in the following mass percentages: high temperature foam content 3-20%, stabilizer content 5-20%, magnesium powder content 2-10%, and the balance being aluminum alloy powder.

[0007] As a preferred option, the aluminum alloy sheet and strip are made of one of the following: industrial-grade pure aluminum, Al-Cu aluminum alloy, Al-Mg aluminum alloy, Al-Si aluminum alloy, Al-Mg-Si aluminum alloy, or Al-Zn-Mg-Cu aluminum alloy, and the total mass fraction of alloying elements in the aluminum alloy sheet and strip does not exceed 20%.

[0008] As a preferred option, the foamed flux core accounts for 10 to 22% of the mass of the aluminum alloy flux-cored foamed welding wire.

[0009] As a preferred embodiment, the content of high-temperature foaming body accounts for 5 to 18% of the mass of the foaming core, and the high-temperature foaming body is composed of one or any combination of Class I and Class II foaming agents, and the particle size of the foaming agent is 250 to 600 mesh.

[0010] Further, the first type of foaming agent is one or any combination of metal hydrides that release H2 through thermal decomposition of TiH2, MgH2, and CaH2, and the preferred particle size of the first type of foaming agent is 300-400 mesh; the first type of foaming agent undergoes pre-oxidation treatment before being formulated into a foaming core, the pre-oxidation treatment temperature is 450-560℃, and the pre-oxidation treatment time is 1-8 h; the second type of foaming agent is one or any combination of carbonates that release CO2 through thermal decomposition of CaCO3, MgCO3, and CaMg(CO3)2, and the particle size of the second type of foaming agent is 400-500 mesh; the second type of foaming agent undergoes pretreatment before being formulated into a foaming core, the pretreatment temperature is 150-400℃, and the pretreatment time is 3-10 h.

[0011] As a preferred embodiment, the stabilizer content accounts for 10-20% of the mass of the foamed core. The stabilizer is one or any combination of Al2O3, ZrO2, SiC, TiC, B4C, and TiB2, which are powdered additives with high melting points. The stabilizer particle size is 200-800 mesh.

[0012] As a preferred option, the magnesium powder content accounts for 2 to 10% of the mass of the foamed core, the magnesium element mass ratio in the magnesium powder is >98%, and the magnesium powder particle size is 100 to 400 mesh.

[0013] As a preferred embodiment, the aluminum alloy powder is one or any combination of industrial-grade pure aluminum powder, Al-Cu series aluminum alloy powder, Al-Mg series aluminum alloy powder, Al-Si series aluminum alloy powder, Al-Mg-Si series aluminum alloy powder, and Al-Zn-Mg-Cu series aluminum alloy powder, and the particle size of the aluminum alloy powder is 200 to 600 mesh.

[0014] A method for preparing an aluminum alloy drug core specifically includes the following steps:

[0015] Step (1-1): Place the foamed core in a drying oven for drying. The drying temperature is 50-150℃ and the drying time is 1-6 hours.

[0016] Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 4:1 to 8:1, the ball milling speed is 200 to 800 r / min, and the ball milling time is 2 to 10 h.

[0017] A method for preparing aluminum alloy flux-cored foamed welding wire specifically includes the following steps:

[0018] Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device;

[0019] Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape;

[0020] Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin;

[0021] Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed;

[0022] Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm.

[0023] Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

[0024] By employing the above technical solutions, this invention has the following beneficial effects compared to existing technologies:

[0025] Compared with existing aluminum alloy welding wires, the present invention can achieve rapid filling and connection of the weld area after welding aluminum alloy materials, and the weld filling area exhibits a typical porous morphology.

[0026] Compared with existing aluminum alloy welding wires, this invention can realize the direct welding of lightweight porous aluminum alloy materials, avoid the solidification of the weld area, and contribute to lightweight design.

[0027] This invention can realize the welding foam filling of metal component cavities. Due to the foaming of the molten pool, the cavity filling efficiency can be greatly improved, and the metal component after forming can be endowed with functional characteristics such as damping and vibration reduction.

[0028] This invention can be used as an additive manufacturing welding wire, and can be used to directly prepare porous aluminum alloy materials through additive manufacturing.

[0029] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0031] Figure 1 A schematic diagram of the cross-section of aluminum alloy flux-cored foamed welding wire;

[0032] Figure 2 This is a flowchart of the preparation process of the present invention;

[0033] Figure 3 A schematic diagram of filling the weld seam with the aluminum alloy flux-cored foamed welding wire of the present invention. Detailed Implementation

[0034] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0035] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0036] The following is combined with Figures 1 to 3 The aluminum alloy flux-cored foamed welding wire and its preparation method according to embodiments of the present invention will be described in detail.

[0037] A type of aluminum alloy flux-cored foamed welding wire is disclosed. The wire uses an aluminum alloy strip as its outer sheath, uniformly filling it with a foamed flux core. The foamed flux core is formulated from the following components by mass percentage: 6% high-temperature foaming agent, 12% stabilizer, 4% magnesium powder, and the remainder being aluminum alloy powder. The aluminum alloy strip is made of industrial-grade pure aluminum, with a total alloy element mass fraction of 0.5%. The foamed flux core accounts for 14% of the total mass fraction. The high-temperature foaming agent is a type of foaming agent with a particle size of 300 mesh. The type of foaming agent is TiH2, preferably with a particle size of 300 mesh. Before being formulated into the foamed flux core, the type of foaming agent undergoes pre-oxidation treatment at 450℃ for 3 hours. The stabilizer is a combination of Al2O3 and ZrO2, with a stabilizer particle size of 600 mesh. The magnesium powder contains >98% magnesium by mass and has a particle size of 300 mesh. The aluminum alloy powder is an Al-Cu series aluminum alloy powder with a particle size of 400 mesh.

[0038] A method for preparing an aluminum alloy drug core specifically includes the following steps:

[0039] Step (1-1): Place the foamed core in a drying oven for drying at a temperature of 100°C for 3 hours.

[0040] Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 5:1, the ball milling speed is 400 r / min, and the ball milling time is 5 h.

[0041] A method for preparing aluminum alloy flux-cored foamed welding wire specifically includes the following steps:

[0042] Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device;

[0043] Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape;

[0044] Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin;

[0045] Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed;

[0046] Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm.

[0047] Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

[0048] A type of aluminum alloy flux-cored foamed welding wire is disclosed. The wire uses an aluminum alloy strip as its outer sheath, uniformly filled with a foamed flux core. The foamed flux core is formulated with the following components by mass percentage: 7% high-temperature foaming agent, 10% stabilizer, 10% magnesium powder, and the remainder being aluminum alloy powder. The aluminum alloy strip is made of Al-Cu series aluminum alloy, with a total alloy element mass fraction of 10%. The foamed flux core mass fraction is 10%. The high-temperature foaming agent is a type I foaming agent with a particle size of 300 mesh. The type I foaming agent is MgH2, preferably with a particle size of 300 mesh. Before being formulated into the foamed flux core, the type I foaming agent undergoes pre-oxidation treatment at a temperature of 510℃ for 2.5 h. The stabilizer is a combination of SiC and TiC, with a stabilizer particle size of 300 mesh. The magnesium powder contains >98% magnesium by mass and has a particle size of 300 mesh. The aluminum alloy powder is an Al-Cu series aluminum alloy powder with a particle size of 400 mesh.

[0049] A method for preparing an aluminum alloy drug core specifically includes the following steps:

[0050] Step (1-1): Place the foamed core in a drying oven for drying at 100°C for 1 hour.

[0051] Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 4:1, the ball milling speed is 800 r / min, and the ball milling time is 3 h.

[0052] A method for preparing aluminum alloy flux-cored foamed welding wire specifically includes the following steps:

[0053] Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device;

[0054] Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape;

[0055] Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin;

[0056] Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed;

[0057] Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm.

[0058] Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

[0059] A type of aluminum alloy flux-cored foamed welding wire is disclosed. The wire uses an aluminum alloy strip as its outer sheath, with a uniformly filled foamed flux core. The foamed flux core is formulated with the following components by mass percentage: 18% high-temperature foam, 14% stabilizer, 6% magnesium powder, and the remainder being aluminum alloy powder. The aluminum alloy strip is made of Al-Mg alloy, with a total alloy element mass fraction of 14%. The foamed flux core accounts for 18% of the total mass fraction. The high-temperature foam is a combination of a primary foaming agent and a secondary foaming agent, with the foaming agent particle size being 400 mesh. The foaming agent is composed of MgH2 and CaH2, with a preferred particle size of 400 mesh. Before being formulated into the foam core, the foaming agent undergoes pre-oxidation treatment at 520℃ for 5 hours. The foaming agent is CaMg(CO3)2, also with a particle size of 400 mesh. Before being formulated into the foam core, the foaming agent undergoes pre-treatment at 150℃ for 10 hours. The stabilizer is TiB2 with a particle size of 500 mesh. The magnesium powder contains >98% magnesium by mass and has a particle size of 350 mesh. The aluminum alloy powder is a combination of Al-Si and Al-Mg-Si aluminum alloy powders, with a particle size of 200 mesh.

[0060] A method for preparing an aluminum alloy drug core specifically includes the following steps:

[0061] Step (1-1): Place the foamed core in a drying oven for drying at a temperature of 80°C for 1 hour.

[0062] Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 7:1, the ball milling speed is 500 r / min, and the ball milling time is 7 h.

[0063] A method for preparing aluminum alloy flux-cored foamed welding wire specifically includes the following steps:

[0064] Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device;

[0065] Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape;

[0066] Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin;

[0067] Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed;

[0068] Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm.

[0069] Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

[0070] A type of aluminum alloy flux-cored foamed welding wire is disclosed. The wire uses an aluminum alloy strip as its outer sheath, with a uniformly filled foamed flux core. The foamed flux core is formulated with the following components by mass percentage: 10% high-temperature foam, 20% stabilizer, 8% magnesium powder, and the remainder being aluminum alloy powder. The aluminum alloy strip is made of Al-Si alloy, with a total alloy element mass fraction of 10%. The foamed flux core accounts for 18% of the total mass fraction. The high-temperature foam is a combination of a primary foaming agent and a secondary foaming agent, with the foaming agent particle size being 400 mesh. The foaming agent is of type I, CaH2, with a preferred particle size of 400 mesh. Before being formulated into the foam core, the type I foaming agent undergoes pre-oxidation treatment at 450℃ for 1 hour. The type II foaming agent is a combination of CaCO3 and MgCO3, with a particle size of 400 mesh. Before being formulated into the foam core, the type II foaming agent undergoes pretreatment at 300℃ for 8 hours. The stabilizer is a combination of TiC and B4C, with a stabilizer particle size of 200 mesh. The magnesium powder has a magnesium element mass ratio >98% and a particle size of 400 mesh. The aluminum alloy powder is a combination of Al-Si and Al-Mg-Si aluminum alloy powders, with a particle size of 200 mesh.

[0071] A method for preparing an aluminum alloy drug core specifically includes the following steps:

[0072] Step (1-1): Place the foamed core in a drying oven for drying at a temperature of 50°C for 5 hours.

[0073] Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 8:1, the ball milling speed is 200 r / min, and the ball milling time is 7 h.

[0074] A method for preparing aluminum alloy flux-cored foamed welding wire specifically includes the following steps:

[0075] Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device;

[0076] Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape;

[0077] Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin;

[0078] Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed;

[0079] Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm.

[0080] Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

[0081] A type of aluminum alloy flux-cored foamed welding wire is disclosed. The wire uses an aluminum alloy strip as its outer sheath, with a uniformly filled foamed flux core. The foamed flux core is formulated with the following components by mass percentage: 5% high-temperature foam, 15% stabilizer, 6% magnesium powder, and the remainder being aluminum alloy powder. The aluminum alloy strip is made of Al-Zn-Mg-Cu alloy, with a total alloy element mass fraction of 8%. The foamed flux core accounts for 22% of the total mass fraction. The high-temperature foam is a combination of a primary foaming agent and a secondary foaming agent, with the foaming agent particle size being 400 mesh. The foaming agent is CaH2, with a preferred particle size of 400 mesh. Before being formulated into the foaming core, the foaming agent undergoes pre-oxidation treatment at 450℃ for 6 hours. The foaming agent is CaMg(CO3)2, with a particle size of 400 mesh. Before being formulated into the foaming core, the foaming agent undergoes pre-treatment at 400℃ for 3 hours. The stabilizer is ZrO2, with a particle size of 400 mesh. The magnesium powder contains >98% magnesium by mass and has a particle size of 400 mesh. The aluminum alloy powder is a combination of Al-Mg-Si and Al-Zn-Mg-Cu aluminum alloy powders, with a particle size of 600 mesh.

[0082] A method for preparing an aluminum alloy drug core specifically includes the following steps:

[0083] Step (1-1): Place the foamed core in a drying oven for drying at a temperature of 150°C for 6 hours.

[0084] Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 6:1, the ball milling speed is 400 r / min, and the ball milling time is 6 h.

[0085] A method for preparing aluminum alloy flux-cored foamed welding wire specifically includes the following steps:

[0086] Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device;

[0087] Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape;

[0088] Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin;

[0089] Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed;

[0090] Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm.

[0091] Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

[0092] A type of aluminum alloy flux-cored foamed welding wire is disclosed. The wire uses an aluminum alloy strip as its outer sheath, with a uniformly filled foamed flux core. The foamed flux core is formulated with the following components by mass percentage: 12% high-temperature foam, 10% stabilizer, 2% magnesium powder, and the remainder being aluminum alloy powder. The aluminum alloy strip is made of Al-Mg-Si alloy, with a total alloy element mass fraction of 10%. The foamed flux core accounts for 14% of the total mass fraction. The high-temperature foam is a combination of a primary foaming agent and a secondary foaming agent, with the foaming agent particle size being 400 mesh. One type of foaming agent is a combination of TiH2 and CaH2, with a preferred particle size of 400 mesh. This foaming agent undergoes pre-oxidation treatment before being formulated into the foaming core at 500℃ for 8 hours. A second type of foaming agent is a combination of CaCO3 and MgCO3, also with a particle size of 400 mesh. This second type of foaming agent undergoes pre-treatment before being formulated into the foaming core at 300℃ for 4 hours. The stabilizer is TiB2 with a particle size of 800 mesh. The magnesium powder contains >98% magnesium by mass and has a particle size of 400 mesh. The aluminum alloy powder is Al-Si based aluminum alloy powder with a particle size of 300 mesh.

[0093] A method for preparing an aluminum alloy drug core specifically includes the following steps:

[0094] Step (1-1): Place the foamed core in a drying oven for drying at a temperature of 80°C for 6 hours.

[0095] Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 4:1, the ball milling speed is 800 r / min, and the ball milling time is 3 h.

[0096] A method for preparing aluminum alloy flux-cored foamed welding wire specifically includes the following steps:

[0097] Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device;

[0098] Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape;

[0099] Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin;

[0100] Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed;

[0101] Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm.

[0102] Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

[0103]

[0104]

[0105] Table 2 shows different welding wires prepared with different diameters, including 1.2 mm, 1.6 mm, 2.0 mm, 3.2 mm, and 4.0 mm. Compared with existing aluminum alloy welding wires, this invention enables rapid filling and connection of aluminum alloy weld areas, and the weld filling area exhibits a typical porous morphology. The average size of the pores in the weld area (0.8 ~ 2.4 mm) and the porosity (52% ~ 80%) are affected by the high-temperature foam in the aluminum alloy flux-cored foamed welding wire and the welding process parameters. The porous weld area allows the aluminum alloy flux-cored foamed welding wire to be directly applied to the welding and forming of porous aluminum alloy materials, avoiding the solid weld that occurs after forming with traditional aluminum alloy welding wires. Using the examples, “surfacing” on the aluminum alloy surface yields a lightweight foamed layer with a porous morphology that is well bonded to the aluminum alloy matrix, with a load-bearing strength of 4.2 ~ 21.5 MPa. The porous surface structure can endow metal components with damping and vibration reduction functional properties. The aluminum alloy flux-cored foamed welding wire of the embodiment can be used as an additive manufacturing welding wire to realize the additive manufacturing of porous aluminum alloy materials and improve production efficiency.

[0106] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0107] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An aluminum alloy flux-cored foamed welding wire, characterized in that... The aluminum alloy-cored foamed welding wire uses aluminum alloy strip as its outer sheath, with a uniformly filled foamed core inside. The foamed core is formulated from the following components by mass percentage: 3-20% high-temperature foam, 5-20% stabilizer, 2-10% magnesium powder, and the remainder being aluminum alloy powder. The high-temperature foam consists of one or any combination of a first-class foaming agent and a second-class foaming agent. The first-class foaming agent is one or any combination of metal hydrides that release H2 through thermal decomposition of TiH2, MgH2, and CaH2. The particle size of the first-class foaming agent is 300-400 mesh. The first-class foaming agent undergoes pre-oxidation treatment before being formulated into the foamed core. The pre-oxidation treatment temperature is 450-560℃, and the pre-oxidation treatment time is 1-8 minutes. h; the second type of foaming agent is one or any combination of CaCO3, MgCO3, and CaMg(CO3)2 carbonates that release CO2 through thermal decomposition; the particle size of the second type of foaming agent is 400-500 mesh; the second type of foaming agent is pretreated before being formulated into a foaming core, the pretreatment temperature is 150-400℃, and the pretreatment time is 3-10 h; the stabilizer is one or any combination of Al2O3, ZrO2, SiC, TiC, B4C, and TiB2 powdered additives with high melting points.

2. The aluminum alloy flux-cored foamed welding wire according to claim 1, characterized in that, The aluminum alloy sheet / strip is made of one of the following: Al-Cu aluminum alloy, Al-Mg aluminum alloy, Al-Si aluminum alloy, Al-Mg-Si aluminum alloy, or Al-Zn-Mg-Cu aluminum alloy, and the total mass fraction of alloying elements in the aluminum alloy sheet / strip does not exceed 20%.

3. The aluminum alloy flux-cored foamed welding wire according to claim 1, characterized in that, The foamed core has a mass fraction of 10-22%.

4. The aluminum alloy flux-cored foamed welding wire according to claim 1, characterized in that, The content of the high-temperature foaming body accounts for 5 to 18% of the mass of the foaming core, and the particle size of the foaming agent is 250 to 600 mesh.

5. The aluminum alloy flux-cored foamed welding wire according to claim 1, characterized in that, The stabilizer content accounts for 10-20% of the mass of the foaming core, and the stabilizer particle size is 200-800 mesh.

6. The aluminum alloy flux-cored foamed welding wire according to claim 1, characterized in that, The magnesium powder content accounts for 2 to 10% of the mass of the foamed core, the magnesium element mass ratio in the magnesium powder is >98%, and the magnesium powder particle size is 100 to 400 mesh.

7. The aluminum alloy flux-cored foamed welding wire according to claim 1, characterized in that, The aluminum alloy powder is one or any combination of Al-Cu aluminum alloy powder, Al-Mg aluminum alloy powder, Al-Si aluminum alloy powder, Al-Mg-Si aluminum alloy powder, and Al-Zn-Mg-Cu aluminum alloy powder, and the particle size of the aluminum alloy powder is 200 to 600 mesh.

8. A method for preparing an aluminum alloy flux-cored foamed welding wire as described in any one of claims 1-7, characterized in that, Specifically, the following steps are included: Step (1-1): Place the foamed core in a drying oven for drying at a temperature of 50-150°C for 1-6 hours. Step (1-2): Place the foamed core in a ball mill mixing device for mixing. The ball-to-material ratio of the ball mill is 4:1 to 8:1, the ball milling speed is 200 to 800 r / min, and the ball milling time is 2 to 10 h. Step (2-1): Remove the oxide film from the inner surface of the aluminum alloy outer skin and feed it into a multi-pass continuous forming device; Step (2-2): In the rolling passes of the multi-pass continuous forming device, the aluminum alloy outer skin is formed into a U-shape; Step (2-3): Evenly add the prepared foamed core to the U-shaped outer skin; Steps (2-4): In the multi-pass continuous forming device, the U-shaped outer skin with added foam core is continuously closed; Steps (2-5): In a multi-pass continuous forming device, the foamed core outer skin after the joint is drawn through drawing dies of different diameters in multiple passes to obtain aluminum alloy foamed welding wire with a diameter of 0.5 ~ 5 mm. Steps (2-6): Coil the aluminum alloy flux-cored foamed welding wire and vacuum package it.

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