In-situ nanoparticle reinforced aluminum-based welding wire, and preparation method and welding method therefor

Abstract

An in-situ nanoparticle reinforced aluminum-based welding wire, and a preparation method and a welding method therefor. The aluminum-based welding wire comprises a flux core, a coating and a protective layer, which are successively arranged from inside to outside. Under a high-temperature welding condition, ceramic powder components B2O3, ZrO2 and TiO2 in the flux core react in site with metal powder in a weldment, so as to generate ternary nano-ceramic particles ZrB2, TiB2 and Al2O3, polynary nanoparticles reinforcing phases affecting each other, and having a synergistic effect and better refining and reinforcing effects than single nanoparticles. In addition, since ZrB2, TiB2 and Al2O3 are good high-temperature absorption materials and may generate active sites on surfaces in welding processes, Sc, Er and Zr are more prone to be attached to the surfaces of ceramic particles, thereby improving the wettability between nano-ceramic particles and aluminum and obtaining nanoparticles distributed more uniformly. Furthermore, rare earth aluminide has remarkable refining and reinforcing effects on welding seams, thereby improving the welding property of welding wires.

Description

In-situ nanoparticle reinforced aluminum-based welding wire and preparation method and welding method thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 13, 2023, with application number 2023108612043 and invention name “A kind of in-situ nanoparticle reinforced aluminum-based welding wire and its preparation method and welding method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the technical field of welding wires, and in particular to an in-situ nanoparticle reinforced aluminum-based welding wire and a preparation method and a welding method thereof. Background Art

[0003] Aluminum alloys, with their low density, high strength, and excellent fatigue resistance, are widely used in the automotive, aerospace, and other fields. In the new century, key structural components in these fields are required to meet requirements such as lightweighting, toughening, large-scale construction, and high reliability, making improved weldability crucial. The difficulty in welding 6XXX and 7XXX aluminum alloys is partly due to their high sensitivity to hot cracking. Furthermore, the dissolution and coarsening of alloy precipitates during the welding thermal cycle significantly degrades the mechanical properties of the welded aluminum alloy plates.

[0004] Therefore, how to improve the welding performance of aluminum-based welding wire and thus improve the mechanical properties of welded plates has become a difficult problem that needs to be solved urgently in this field.

[0005] Summary of the Invention

[0006] The present invention aims to provide an in-situ nanoparticle reinforced aluminum-based welding wire and its preparation method and welding method. The in-situ nanoparticle reinforced aluminum-based welding wire provided by the present invention has excellent welding performance, so that the welded plate has excellent mechanical properties.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides an in-situ nanoparticle reinforced aluminum-based welding wire, comprising a flux core, an outer skin and a protective layer arranged in sequence from the inside out;

[0009] The core comprises the following components, in percentage by mass: B2O3 1.7% to 8.1%, ZrO2 1.0% to 5.4%, TiO2 1.1% to 5.7%, powder 0.1% to 1.0%, Mg 0.8% to 1.2%, Si 0.4% to 1.2%, Cu 0.1% to 0.4%, Cr 0.04% to 0.35%, Zn 0.15% to 0.25% and the balance of aluminum powder;

[0010] Alternatively, the core comprises the following components: B2O3 1.7% to 8.1%, ZrO2 1.0% to 5.4%, TiO2 1.1% to 5.7%, powder 0.1% to 1.0%, Zn 4.0% to 8.0%, Mg 1.0% to 3.5%, Cu 0% to 2.5% and the balance aluminum powder;

[0011] The powder is at least one of Sc, Er and Zr.

[0012] Preferably, the core comprises the following components, in percentage by mass: B2O3 2.0% to 8.0%, ZrO2 1.1% to 5.0%, TiO2 1.1% to 5.0%, powder 0.3% to 1.0%, Mg 1.0% to 1.2%, Si 0.6% to 1.0%, Cu 0.1% to 0.2%, Cr 0.1% to 0.30%, Zn 0.20% to 0.25% and the balance of aluminum powder.

[0013] Preferably, the core comprises the following components, in percentage by mass: B2O3 2.0% to 8.1%, ZrO2 1.1% to 5.4%, TiO2 1.5% to 5.0%, powder 0.45% to 0.6%, Zn 6.0% to 7.6%, Mg 1.6% to 2.4%, Cu 1.4% to 2.0% and the balance of aluminum powder.

[0014] Preferably, the powder is a mixed powder of Sc and Zr or a mixed powder of Er and Zr.

[0015] Preferably, the mass ratio of Sc to Zr in the mixed powder of Sc and Zr is 1:2; the mass ratio of Er to Zr in the mixed powder of Er and Zr is 2:1.

[0016] Preferably, the filling rate of the drug core is 5% to 34%.

[0017] Preferably, the outer skin is made of 1070 semi-hard pure aluminum strip.

[0018] Preferably, the thickness of the outer skin is 0.1 to 0.2 mm.

[0019] Preferably, the components of the protective layer are SiC and Al2O3.

[0020] Preferably, the mass ratio of SiC to Al2O3 is 3:1 to 3:2.

[0021] Preferably, the thickness of the protective layer is 0.1-0.2 mm.

[0022] The present invention also provides a method for preparing the in-situ nanoparticle reinforced aluminum-based welding wire described in the above technical solution, comprising the following steps:

[0023] (1) Rolling the outer skin into a U-shaped groove and then inserting the core into the groove, and then closing the U-shaped groove to obtain a semi-finished product;

[0024] (2) Covering the outer layer of the semi-finished product obtained in step (1) with a protective layer, and then drawing it to obtain an in-situ nanoparticle reinforced aluminum-based welding wire.

[0025] The present invention also provides a welding method for the in-situ nanoparticle reinforced aluminum-based welding wire described in the above technical solution or the in-situ nanoparticle reinforced aluminum-based welding wire prepared by the preparation method described in the above technical solution, which adopts microwave, dual magnetic field and ultrasonic field synchronous assisted laser welding.

[0026] Preferably, the output frequency of the microwave is 2.45 GHz, and the output power of the microwave is 0-3 kW.

[0027] Preferably, the dual magnetic field is an alternating magnetic field and a constant magnetic field; the excitation current of the alternating magnetic field is 250-300A and the frequency is 10-12Hz; the magnetic field strength of the constant magnetic field is 0.1-0.3T.

[0028] Preferably, the ultrasonic power of the ultrasonic field is 5-10 kW, and the ultrasonic frequency is 20-30 kHz.

[0029] The invention provides an in-situ nanoparticle reinforced aluminum-based welding wire, comprising a flux core, an outer skin and a protective layer which are sequentially arranged from the inside out; the flux core comprises the following components in percentage by mass: 1.7% to 8.1% of B2O3, 1.0% to 5.4% of ZrO2, 1.1% to 5.7% of TiO2, 0.1% to 1.0% of powder, 0.8% to 1.2% of Mg, 0.4% to 1.2% of Si, 0.1% to 0.4% of Cu, 0.04% to 0.35% of Cr, 0.15% to 0.25% of Zn and the balance of aluminum powder; or the flux core comprises the following components: 1.7% to 8.1% of B2O3, 1.0% to 5.4% of ZrO2, 1.1% to 5.7% of TiO2, 0.1% to 1.0% of powder, 4.0% to 8.0% of Zn, 0. 1.0% to 3.5%, Cu 0% to 2.5% and the balance of aluminum powder; the powder is at least one of Sc, Er and Zr. Under the high temperature conditions of welding, the ceramic powders B2O3, ZrO2 and TiO2 in the flux core of the aluminum-based welding wire provided by the present invention will react in situ with the metal powder in the weldment to generate ternary nano-ceramic particles of ZrB2, TiB2 and Al2O3, wherein TiB2 and ZrB2 are hexagonal metalloid compounds with good thermodynamic stability, high melting point, high elastic modulus and high temperature strength, the size of Al2O3 particles is very stable, the hardness is high, and they have good chemical compatibility with the matrix, and no interfacial chemical reaction will occur, and the multi-element nano-particles reinforce the weld metal. The phases interact with each other, creating a synergistic effect that produces a more refined and strengthening effect than single nanoparticles. Furthermore, ZrB2, TiB2, and Al2O3 are excellent high-temperature absorbers, creating active sites on the surface during welding. This allows Sc, Er, and Zr, which have good wettability with aluminum, to adhere more easily to the ceramic particle surface, improving the wettability of the nanoceramic particles with aluminum, resulting in a more evenly distributed nanoparticle. Furthermore, the aluminized rare earth phase can significantly refine and strengthen the weld, thereby improving the welding performance of the welding wire and, in turn, imparting excellent mechanical properties to the welded plate. Experimental results show that welded joints obtained using the in-situ nanoparticle-reinforced aluminum-based welding wire provided by the present invention have a tensile strength of 323 to 452 MPa, an elongation of 11.5 to 15.3%, and a joint coefficient of 76 to 88%. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram of the structure of a device for synchronously assisting laser welding using microwaves, dual magnetic fields, and ultrasonic fields according to the present invention;

[0031] In the figure, 1 is a microwave generator, 2 is an alternating electromagnetic field power supply, 3 is a constant electromagnetic field power supply, 4 is an ultrasonic transmitter, 5 is a laser welding head, 6 is a microwave transmitter, 7 is an alternating electromagnetic field coil, 8 is a magnetic field isolation plate, 9 is a constant electromagnetic field coil, 10 is an in-situ nanoparticle-reinforced aluminum-based welding wire, 11 is a welding plate, and 12 is an ultrasonic horn.

[0032] FIG2 is an OM image of the weld prepared in Application Example 4;

[0033] FIG3 is a SEM image of the weld prepared in Application Example 4. DETAILED DESCRIPTION

[0034] The present invention provides an in-situ nanoparticle reinforced aluminum-based welding wire, comprising a flux core, an outer skin and a protective layer arranged in sequence from the inside out;

[0035] The core comprises the following components, in percentage by mass: B2O3 1.7% to 8.1%, ZrO2 1.0% to 5.4%, TiO2 1.1% to 5.7%, powder 0.1% to 1.0%, Mg 0.8% to 1.2%, Si 0.4% to 1.2%, Cu 0.1% to 0.4%, Cr 0.04% to 0.35%, Zn 0.15% to 0.25% and the balance of aluminum powder;

[0036] Alternatively, the core comprises the following components: B2O3 1.7% to 8.1%, ZrO2 1.0% to 5.4%, TiO2 1.1% to 5.7%, powder 0.1% to 1.0%, Zn 4.0% to 8.0%, Mg 1.0% to 3.5%, Cu 0% to 2.5% and the balance aluminum powder;

[0037] The powder is at least one of Sc, Er and Zr.

[0038] The in-situ nanoparticle reinforced aluminum-based welding wire provided by the present invention includes a flux core.

[0039] In one technical solution of the present invention, the flux core comprises the following components, measured by mass: 1.7% to 8.1% B2O3, 1.0% to 5.4% ZrO2, 1.1% to 5.7% TiO2, 0.1% to 1.0% powder, 0.8% to 1.2% Mg, 0.4% to 1.2% Si, 0.1% to 0.4% Cu, 0.04% to 0.35% Cr, 0.15% to 0.25% Zn, and the balance, aluminum powder. The flux cored welding wire provided by the present invention is suitable for welding 6XXX aluminum alloy base materials in the automotive industry.

[0040] The flux core of the present invention comprises 1.7% to 8.1% B2O3 by mass, preferably 2.0% to 8.0%, more preferably 3.0% to 7.0%, and even more preferably 4.0% to 5.0%. During welding, the B2O3 reacts in situ with the metal powder in the weldment to form nano-ceramic particles, significantly refining and strengthening the weld.

[0041] The flux core of the present invention also comprises 1.0% to 5.4% ZrO2, preferably 1.1% to 5.0% ZrO2, by mass percentage. During welding, the ZrO2 reacts in situ with the metal powder in the weldment to form nano-ceramic particles, which significantly refine and strengthen the weld.

[0042] The flux core of the present invention also comprises 1.1% to 5.7% TiO2 by mass, preferably 1.1% to 5.0%. During welding, the TiO2 reacts in situ with the metal powder in the weldment to form nano-ceramic particles, which significantly refine and strengthen the weld.

[0043] In terms of mass percentage, the flux core of the present invention also includes 0.1% to 1.0% powder, preferably 0.3% to 1.0%. In the present invention, the powder is at least one of Sc, Er, and Zr, preferably a mixed powder of Sc and Zr or a mixed powder of Er and Zr. The mass ratio of Sc to Zr in the mixed powder of Sc and Zr is preferably 1:2; the mass ratio of Er to Zr in the mixed powder of Er and Zr is preferably 2:1. In the present invention, the powder has good wettability with aluminum and can adhere to the surfaces of in-situ synthesized ZrB2, TiB2, and Al2O3 during the welding process, improving the wettability of the nano-ceramic particles with aluminum, thereby obtaining a more evenly distributed nano-particles. At the same time, the aluminized rare earth phase can also significantly refine and strengthen the weld, thereby improving the welding performance of the welding wire.

[0044] In terms of mass percentage, the flux core of the present invention further comprises 0.8% to 1.2% Mg, preferably 1.0% to 1.2%. In the present invention, Mg is a component of the 6XXX aluminum alloy base material, which is more suitable for welding the 6XXX aluminum alloy base material.

[0045] In terms of mass percentage, the flux core of the present invention further comprises 0.4% to 1.2% Si, preferably 0.6% to 1.0%. In the present invention, Si is a component of the 6XXX aluminum alloy base material and is more suitable for welding the 6XXX aluminum alloy base material.

[0046] In terms of mass percentage, the flux core of the present invention further comprises 0.1% to 0.4% Cu, preferably 0.1% to 0.2%. In the present invention, Cu is a component of the 6XXX aluminum alloy base material, and is more suitable for welding the 6XXX aluminum alloy base material.

[0047] In terms of mass percentage, the flux core of the present invention further comprises 0.04% to 0.35% Cr, preferably 0.1% to 0.30%. In the present invention, Cr is a component of the 6XXX aluminum alloy base material, and is more suitable for welding the 6XXX aluminum alloy base material.

[0048] In terms of mass percentage, the flux core of the present invention further comprises 0.15% to 0.25% Zn, preferably 0.20% to 0.25%. In the present invention, Zn is a component of the 6XXX aluminum alloy base material and is more suitable for welding the 6XXX aluminum alloy base material.

[0049] In terms of mass percentage, the components of the core of the present invention also include the balance of aluminum powder. In the present invention, the aluminum powder is the matrix material.

[0050] In another embodiment of the present invention, the flux core comprises the following components: 1.7% to 8.1% B2O3, 1.0% to 5.4% ZrO2, 1.1% to 5.7% TiO2, 0.1% to 1.0% powder, 4.0% to 8.0% Zn, 1.0% to 3.5% Mg, 0% to 2.5% Cu, and the balance aluminum powder. The flux cored welding wire provided by the present invention is suitable for welding 7XXX aluminum alloy base materials in the aerospace and rail transportation fields.

[0051] The flux core of the present invention comprises 1.7% to 8.1% B2O3 by mass, preferably 2.0% to 8.1%, more preferably 3.0% to 7.0%, and even more preferably 4.0% to 5.0%. During welding, the B2O3 reacts in situ with the metal powder in the weldment to form nano-ceramic particles, significantly refining and strengthening the weld.

[0052] The flux core of the present invention also comprises 1.0% to 5.4% ZrO2, preferably 1.1% to 5.4% by mass. During welding, the ZrO2 reacts in situ with the metal powder in the weldment to form nano-ceramic particles, which significantly refine and strengthen the weld.

[0053] The flux core of the present invention also comprises 1.1% to 5.7% TiO2 by mass, preferably 1.5% to 5.0%. During welding, the TiO2 reacts in situ with the metal powder in the weldment to form nano-ceramic particles, which significantly refine and strengthen the weld.

[0054] In terms of mass percentage, the flux core of the present invention also includes 0.1% to 1.0% powder, preferably 0.45% to 0.6%. In the present invention, the powder is at least one of Sc, Er, and Zr, preferably a mixed powder of Sc and Zr or a mixed powder of Er and Zr. The mass ratio of Sc to Zr in the mixed powder of Sc and Zr is preferably 1:2; the mass ratio of Er to Zr in the mixed powder of Er and Zr is preferably 2:1. In the present invention, the powder has good wettability with aluminum and can adhere to the surfaces of in-situ synthesized ZrB2, TiB2, and Al2O3 during the welding process, improving the wettability of the nano-ceramic particles with aluminum, thereby obtaining a more evenly distributed nanoparticles. At the same time, the rare earth aluminide phase can also significantly refine and strengthen the weld, thereby improving the welding performance of the welding wire.

[0055] In terms of mass percentage, the flux core of the present invention further comprises 4.0% to 8.0% Zn, preferably 6.0% to 7.6%. In the present invention, Zn is a component of the 7XXX aluminum alloy base material and is more suitable for welding the 7XXX aluminum alloy base material.

[0056] In terms of mass percentage, the flux core of the present invention further comprises Mg 1.0% to 3.5%, preferably 1.6% to 2.4%. In the present invention, Mg is a component of the 7XXX aluminum alloy base material, and is more suitable for welding the 7XXX aluminum alloy base material.

[0057] In terms of mass percentage, the flux core of the present invention further comprises 0% to 2.5% Cu, preferably 1.4% to 2.0%. In the present invention, the Cu is a component of the 7XXX aluminum alloy base material, which is more suitable for welding the 7XXX aluminum alloy base material.

[0058] In terms of mass percentage, the components of the core of the present invention also include the balance of aluminum powder. In the present invention, the aluminum powder is the matrix material.

[0059] In the present invention, the particle sizes of B2O3, ZrO2 and TiO2 are independently preferably <5 μm; the particle sizes of Mg, Si, Cu, Cr, Zn and powders are independently preferably <30 μm; and the particle size of aluminum powder is preferably <10 μm.

[0060] In the present invention, the purity of each component in the drug core is preferably independently greater than 99.9%.

[0061] The present invention has no particular limitation on the sources of the components in the drug core, and commercially available products well known to those skilled in the art may be used.

[0062] In the present invention, the filling rate of the drug core is preferably 5% to 34%, more preferably 10% to 20%.

[0063] The in-situ nanoparticle-reinforced aluminum-based welding wire provided herein also includes a sheath; the sheath is preferably made from 1070 semi-hard pure aluminum strip and preferably has a thickness of 0.1 to 0.2 mm. The source of the sheath is not particularly limited; commercially available products known to those skilled in the art may be used.

[0064] The in-situ nanoparticle-reinforced aluminum-based welding wire provided herein also includes a protective layer; the components of the protective layer are preferably SiC and Al2O3; the mass ratio of SiC to Al2O3 is preferably 3:1 to 3:2; and the thickness of the protective layer is preferably 0.1 to 0.2 mm. The SiC and Al2O3 used in the protective layer of the present invention have excellent wear resistance and oxidation resistance, as well as good microwave absorption properties.

[0065] In the present invention, the diameter of the in-situ nanoparticle reinforced aluminum-based welding wire is preferably 1 to 3 mm.

[0066] In the aluminum-based welding wire provided by the present invention, the ceramic powders B2O3, ZrO2 and TiO2 in the flux core react with the metal powder in the weldment in situ under high temperature conditions to generate ternary nano-ceramic particles of ZrB2, TiB2 and Al2O3. Among them, TiB2 and ZrB2 are hexagonal metalloid compounds with good thermodynamic stability, high melting point, high elastic modulus and high temperature strength. The size of Al2O3 particles is very stable, the hardness is high, and they have good chemical compatibility with the matrix and will not undergo interfacial chemical reaction. In addition, the multi-element nano-particles reinforce the phase. They influence each other and have a synergistic effect, which has a better refinement and strengthening effect than single nanoparticles; at the same time, ZrB2, TiB2 and Al2O3 are good high-temperature absorption materials, which can generate active sites on the surface during the welding process, making Sc, Er and Zr with good wettability with aluminum more easily attached to the surface of ceramic particles, improving the wettability of nano-ceramic particles with aluminum, thereby obtaining more evenly distributed nanoparticles; and the aluminized rare earth phase can also play a significant role in refining and strengthening the weld, thereby improving the welding performance of the welding wire, and thus making the welded plate have excellent mechanical properties.

[0067] The present invention also provides a method for preparing the in-situ nanoparticle reinforced aluminum-based welding wire described in the above technical solution, comprising the following steps:

[0068] (1) Rolling the outer skin into a U-shaped groove and then inserting the core into the groove, and then closing the U-shaped groove to obtain a semi-finished product;

[0069] (2) Covering the outer layer of the semi-finished product obtained in step (1) with a protective layer, and then drawing it to obtain an in-situ nanoparticle reinforced aluminum-based welding wire.

[0070] The invention rolls the outer skin into a U-shaped groove, then installs the medicine core, and then closes the U-shaped groove to obtain a semi-finished product.

[0071] In the present invention, the outer skin preferably further comprises removing the oxide film on the outer skin surface by sandpaper before use. The present invention has no particular limitation on the operation of removing the oxide film on the outer skin surface by sandpaper, and the operation well known to those skilled in the art can be used.

[0072] The present invention has no special limitation on the operations of rolling the outer skin into a U-shaped groove, loading the core therein, and then closing the U-shaped groove, and operations well known to those skilled in the art can be used.

[0073] After obtaining the semi-finished product, the present invention covers the outer layer of the semi-finished product with a protective layer, and then draws it to obtain an in-situ nano-particle reinforced aluminum-based welding wire.

[0074] The present invention has no particular limitation on the method for preparing the protective layer, and any operation familiar to those skilled in the art may be used.

[0075] The present invention has no special limitation on the operation of covering the outer layer of the semi-finished product with the protective layer, and operations well known to those skilled in the art may be used.

[0076] In the present invention, the drawing temperature is preferably 350-400° C.; the drawing speed is preferably 3-5 m / min.

[0077] The preparation method provided by the invention has simple process.

[0078] The present invention also provides a method for welding the in-situ nanoparticle-reinforced aluminum-based welding wire described in the above technical solution or the in-situ nanoparticle-reinforced aluminum-based welding wire prepared by the preparation method described in the above technical solution, using microwave, dual magnetic field, and ultrasonic field synchronously assisted laser welding. The welding method of the present invention utilizes the characteristics of microwave low-temperature rapid burning, selective heating, and non-contact heating to generate active sites on the surface of nano-ceramic particles, promoting the adsorption of rare earth elements on the particle surface and improving the wettability of the ceramic particles with aluminum. At the same time, the coupling effect of the magnetic field electromagnetic force and high-energy ultrasonic waves is used to promote heat transfer and flow of the molten aluminum in the molten pool, effectively improving the distribution of nanoparticles and suppressing the occurrence of weld cracks.

[0079] In the present invention, the output frequency of the microwave is preferably 2.45 GHz; the output power of the microwave is preferably 0 to 3 kW, more preferably 0.4 to 0.5 kW.

[0080] In the present invention, the dual magnetic field preferably comprises an alternating magnetic field and a constant magnetic field; the excitation current of the alternating magnetic field is preferably 250 to 300 A, more preferably 280 to 300 A; the frequency of the alternating magnetic field is preferably 10 to 12 Hz; and the magnetic field intensity of the constant magnetic field is preferably 0.1 to 0.3 T, more preferably 0.2 to 0.3 T. By controlling the process parameters of the dual magnetic field, the present invention can further improve the distribution of nanoparticles, thereby further suppressing the generation of weld cracks.

[0081] In the present invention, a magnetic field isolation plate is preferably provided between the alternating magnetic field and the constant magnetic field; the constant magnetic field is preferably applied to the trailing edge of the molten pool; and the direction of the constant magnetic field is preferably opposite to the flow direction of the molten pool.

[0082] In the present invention, the ultrasonic power of the ultrasonic field is preferably 5 to 10 kW, more preferably 8 to 10 kW; the ultrasonic frequency of the ultrasonic field is preferably 20 to 30 kHz, more preferably 25 to 28 kHz; the ultrasonic field is preferably applied to the back of the weld; the ultrasonic vibrator used in the ultrasonic field is preferably on the straight line of the weld.

[0083] In the present invention, the laser beam of the microwave, dual magnetic field and ultrasonic field synchronously assisted laser welding is preferably on the weld straight line; the spacing between the laser beam and the ultrasonic vibrator is preferably 10 to 20 mm, more preferably 15 mm; the power of the laser welding is preferably 0.2 to 1.5 kW, more preferably 0.4 to 1.2 kW.

[0084] In the present invention, the laser beam is preferably annular and centrally centered. During welding, the positions of the laser beam, microwaves, dual magnetic fields, and ultrasonic transducers are preferably fixed, while the base material is moved. The welding speed is preferably 200 to 500 mm / min, more preferably 450 to 480 mm / min. By controlling the laser beam shape, the present invention can prevent excessively high temperatures and vaporization of the central material.

[0085] In the present invention, the microwave, dual magnetic field and ultrasonic field synchronous assisted laser welding is preferably performed in a protective gas; the protective gas is preferably argon; and the purity of the argon is preferably 99.99%.

[0086] In the present invention, the mass ratio of B2O3 to ZrO2 in the weld obtained by the microwave, dual magnetic field and ultrasonic field synchronous assisted laser welding is preferably 1:1, and the mass ratio of B2O3 to TiO2 is preferably 1:1; the mass of ZrB2 nanoparticles in the weld is preferably 1% to 5% of that of the in-situ nanoparticle reinforced aluminum-based welding wire; the mass of TiB2 nanoparticles in the weld is preferably 1% to 5% of that of the in-situ nanoparticle reinforced aluminum-based welding wire; the mass of Al2O3 nanoparticles in the weld is preferably 3.9% to 19.6% of that of the in-situ nanoparticle reinforced aluminum-based welding wire.

[0087] The structural schematic diagram of the microwave, dual magnetic field and ultrasonic field synchronous assisted laser welding of the present invention is shown in Figure 1. In the figure, 1 is a microwave generator, 2 is an alternating electromagnetic field power supply, 3 is a constant electromagnetic field power supply, 4 is an ultrasonic transmitter, 5 is a laser welding head, 6 is a microwave transmitter, 7 is an alternating electromagnetic field coil, 8 is a magnetic field isolation plate, 9 is a constant electromagnetic field coil, 10 is an in-situ nanoparticle reinforced aluminum-based welding wire, 11 is a welding plate, and 12 is an ultrasonic amplitude transformer.

[0088] From Figure 1, it can be clearly seen that the positional relationship of each component during laser welding assisted by microwave, dual magnetic field and ultrasonic field synchronously.

[0089] In order to improve the weldability of aluminum alloys, the present invention organically combines welding wire technology and in-situ synthesis technology. Laser heat is directly induced to cause in-situ reaction between reactive powder in the welding wire and the weldment to synthesize nano-ceramic particles. Microwaves, dual magnetic fields and ultrasonic fields are used to synchronously assist laser welding, promote heat transfer and flow of molten aluminum in the molten pool, form a relatively uniform temperature field, regulate the nucleation, growth and distribution of nano-particles, promote bubble escape, inhibit the generation of welding defects, improve the quality of laser welding weld formation, and obtain joints with excellent mechanical properties.

[0090] The present invention adopts microwave, dual magnetic field and ultrasonic field to synchronously assist laser welding. The alternating magnetic field is electromagnetic stirring. The coupling effect of the magnetic field electromagnetic force and high-energy ultrasonic wave promotes the heat transfer and flow of aluminum liquid in the molten pool, forms a relatively uniform temperature field, improves the distribution of nanoparticles, is conducive to the floating and escape of bubbles, and inhibits the generation of welding cracks. At the same time, a constant magnetic field is applied, and the direction of the Lorentz magnetic force generated by it is always opposite to the direction of the flow of the molten pool, which inhibits the flow of the molten pool and reduces the solidification rate of the molten pool, thereby playing a role in assisting the coupling effect of the alternating magnetic field and ultrasonic field on the molten pool.

[0091] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0092] Example 1

[0093] In the in-situ nanoparticle reinforced aluminum-based welding wire, from the inside out, there are the core, the outer skin and the protective layer;

[0094] The core consists of the following components in percentage by mass: B2O3 1.7%, ZrO2 1.1%, TiO2 1.1%, Sc powder 0.1%, Zr powder 0.2%, Mg powder 1.2%, Si powder 1.0%, Cu powder 0.1%, Cr powder 0.1%, Zn powder 0.2% and the balance of aluminum powder;

[0095] Among them, the particle sizes of B2O3, ZrO2 and TiO2 are all less than 5μm, the particle sizes of Mg powder, Si powder, Cu powder, Cr powder, Zn powder, Sc powder and Zr powder are all less than 30μm, and the particle size of aluminum powder is less than 10μm; the purity of each component in the core is greater than 99.9%;

[0096] The filling rate of the core is 6.8%;

[0097] The outer skin is 1070 pure aluminum strip with a thickness of 0.1mm;

[0098] The diameter of the core layer (consisting of the core and the outer layer) is 1 mm;

[0099] The protective layer is composed of SiC and Al2O3; the mass ratio of SiC to Al2O3 is 3:1; the thickness of the protective layer is 0.15mm;

[0100] The preparation method of the in-situ nanoparticle reinforced aluminum-based welding wire is as follows:

[0101] (1) Using sandpaper to remove the oxide film on the surface of the outer skin, then rolling the outer skin into a U-shaped groove and inserting the core, and then closing the U-shaped groove to obtain a semi-finished product;

[0102] (2) Covering the outer layer of the semi-finished product obtained in step (1) with a protective layer, and then drawing to obtain an in-situ nanoparticle reinforced aluminum-based welding wire; wherein the drawing temperature is 350° C.; and the drawing speed is 3 m / min.

[0103] Application Example 1

[0104] The in-situ nanoparticle-reinforced aluminum-based welding wire prepared in Example 1 and the 6082 aluminum alloy weldment were welded using microwave, dual magnetic field, and ultrasonic field synchronous assisted laser welding. The welding process parameters are as follows:

[0105] The laser beam is in the shape of a ring + central beam; during the welding process, the positions of the laser beam, microwave, dual magnetic field and ultrasonic vibrator are fixed, the 6082 aluminum alloy weldment is moved, and argon gas with a purity of 99.99% is applied to the front and back of the weldment at the same time; the laser welding power is 0.8kW, and the welding speed is 480mm / min; the microwave output frequency is 2.45GHz, and the output power is 0.4kW; the alternating magnetic field excitation current is 250A, the frequency is 10Hz, the constant magnetic field strength is 0.3T, and a magnetic field isolation plate is set between the alternating magnetic field and the constant magnetic field; the ultrasonic field is applied to the back of the weld, the laser beam and ultrasonic vibrator are both on the weld straight line, the spacing is set to 15mm, the ultrasonic power is 8kW, and the ultrasonic frequency is 20kHz.

[0106] The mass contents of ZrB2, TiB2 and Al2O3 particles in the formed weld are 1%, 1% and 3.9% respectively.

[0107] Example 2

[0108] In the in-situ nanoparticle reinforced aluminum-based welding wire, from the inside out, there are the core, the outer skin and the protective layer;

[0109] The core consists of the following components in percentage by mass: B2O3 4.9%, ZrO2 3.3%, TiO2 3.4%, Sc powder 0.15%, Zr powder 0.3%, Mg powder 1.2%, Si powder 0.6%, Cu powder 0.2%, Cr powder 0.1%, Zn powder 0.25% and the balance of aluminum powder;

[0110] Among them, the particle sizes of B2O3, ZrO2 and TiO2 are all less than 5μm, the particle sizes of Mg powder, Si powder, Cu powder, Cr powder, Zn powder, Sc powder and Zr powder are all less than 30μm, and the particle size of aluminum powder is less than 10μm; the purity of each component in the core is greater than 99.9%;

[0111] The filling rate of the core is 14.4%;

[0112] The outer skin is 1070 pure aluminum strip with a thickness of 0.1mm;

[0113] The diameter of the core layer (consisting of the core and the outer layer) is 1 mm;

[0114] The protective layer is composed of SiC and Al2O3; the mass ratio of SiC to Al2O3 is 3:1; the thickness of the protective layer is 0.15mm;

[0115] The preparation method of the in-situ nanoparticle reinforced aluminum-based welding wire is as follows:

[0116] (1) Using sandpaper to remove the oxide film on the surface of the outer skin, then rolling the outer skin into a U-shaped groove and inserting the core, and then closing the U-shaped groove to obtain a semi-finished product;

[0117] (2) Covering the outer layer of the semi-finished product obtained in step (1) with a protective layer, and then drawing to obtain an in-situ nanoparticle reinforced aluminum-based welding wire; wherein the drawing temperature is 380° C.; and the drawing speed is 4 m / min.

[0118] Application Example 2

[0119] The in-situ nanoparticle-reinforced aluminum-based welding wire prepared in Example 2 and the 6061 aluminum alloy weldment were welded using microwave, dual magnetic field, and ultrasonic field synchronously assisted laser welding. The welding process parameters are as follows:

[0120] The laser beam is in the shape of a ring + central beam; during the welding process, the positions of the laser beam, microwave, dual magnetic field and ultrasonic vibrator are fixed, the 6061 aluminum alloy weldment is moved, and argon gas with a purity of 99.99% is applied to the front and back of the weldment at the same time; the laser welding power is 0.8kW, and the welding speed is 480mm / min; the microwave output frequency is 2.45GHz, and the output power is 0.4kW; the alternating magnetic field excitation current is 280A, the frequency is 12Hz, the constant magnetic field strength is 0.3T, and a magnetic field isolation plate is set between the alternating magnetic field and the constant magnetic field; the ultrasonic field is applied to the back of the weld, the laser beam and ultrasonic vibrator are both on the weld straight line, the spacing is set to 15mm, the ultrasonic power is 10kW, and the ultrasonic frequency is 25kHz.

[0121] The mass contents of ZrB2, TiB2 and Al2O3 particles in the formed weld are 3%, 3% and 11.8% respectively.

[0122] Example 3

[0123] In the in-situ nanoparticle reinforced aluminum-based welding wire, from the inside out, there are the core, the outer skin and the protective layer;

[0124] The core consists of the following components in percentage by mass: B2O3 8.1%, ZrO2 5.4%, TiO2 5.7%, Er powder 0.3%, Zr powder 0.15%, Mg powder 2.4%, Cu powder 2.0%, Zn powder 6.0% and the balance aluminum powder;

[0125] Among them, the particle sizes of B2O3, ZrO2 and TiO2 are all less than 5μm, the particle sizes of Mg powder, Cu powder, Zn powder, Er powder and Zr powder are all less than 30μm, and the particle size of aluminum powder is less than 10μm; the purity of each component in the core is greater than 99.9%;

[0126] The filling rate of the core is 30.05%;

[0127] The outer skin is 1070 pure aluminum strip with a thickness of 0.1mm;

[0128] The diameter of the core layer (consisting of the core and the outer layer) is 1 mm;

[0129] The protective layer is composed of SiC and Al2O3; the mass ratio of SiC to Al2O3 is 3:2; the thickness of the protective layer is 0.15mm;

[0130] The preparation method of the in-situ nanoparticle reinforced aluminum-based welding wire is as follows:

[0131] (1) Using sandpaper to remove the oxide film on the surface of the outer skin, then rolling the outer skin into a U-shaped groove and inserting the core, and then closing the U-shaped groove to obtain a semi-finished product;

[0132] (2) Covering the outer layer of the semi-finished product obtained in step (1) with a protective layer, and then drawing to obtain an in-situ nanoparticle reinforced aluminum-based welding wire; wherein the drawing temperature is 400° C.; and the drawing speed is 5 m / min.

[0133] Application Example 3

[0134] The in-situ nanoparticle-reinforced aluminum-based welding wire prepared in Example 3 and the 7050 aluminum alloy weldment were welded using microwave, dual magnetic field, and ultrasonic field synchronous assisted laser welding. The welding process parameters are as follows:

[0135] The laser beam is in the shape of a ring + central beam; during the welding process, the positions of the laser beam, microwave, dual magnetic field and ultrasonic vibrator are fixed, the 7050 aluminum alloy weldment is moved, and argon gas with a purity of 99.99% is applied to the front and back of the weldment at the same time; the laser welding power is 0.8kW, and the welding speed is 480mm / min; the microwave output frequency is 2.45GHz, and the output power is 0.4kW; the alternating magnetic field excitation current is 300A, the frequency is 12Hz, the constant magnetic field strength is 0.3T, and a magnetic field isolation plate is set between the alternating magnetic field and the constant magnetic field; the ultrasonic field is applied to the back of the weld, the laser beam and ultrasonic vibrator are both on the weld straight line, the spacing is set to 15mm, the ultrasonic power is 10kW, and the ultrasonic frequency is 28kHz.

[0136] The mass contents of ZrB2, TiB2 and Al2O3 particles in the formed weld are 5%, 5% and 19.6% respectively.

[0137] Example 4

[0138] In the in-situ nanoparticle reinforced aluminum-based welding wire, from the inside out, there are the core, the outer skin and the protective layer;

[0139] The core consists of the following components in percentage by mass: B2O3 1.7%, ZrO2 1.1%, TiO2 1.1%, Er powder 0.4%, Zr powder 0.2%, Mg powder 1.6%, Cu powder 1.4%, Zn powder 7.6% and the balance aluminum powder;

[0140] Among them, the particle sizes of B2O3, ZrO2 and TiO2 are all less than 5μm, the particle sizes of Mg powder, Cu powder, Zn powder, Er powder and Zr powder are all less than 30μm, and the particle size of aluminum powder is less than 10μm; the purity of each component in the core is greater than 99.9%;

[0141] The filling rate of the core is 15%;

[0142] The outer skin is 1070 pure aluminum strip with a thickness of 0.1mm;

[0143] The diameter of the core layer (consisting of the core and the outer layer) is 1 mm;

[0144] The protective layer is composed of SiC and Al2O3; the mass ratio of SiC to Al2O3 is 3:2; the thickness of the protective layer is 0.15mm;

[0145] The preparation method of the in-situ nanoparticle reinforced aluminum-based welding wire is as follows:

[0146] (1) Using sandpaper to remove the oxide film on the surface of the outer skin, then rolling the outer skin into a U-shaped groove and inserting the core, and then closing the U-shaped groove to obtain a semi-finished product;

[0147] (2) Covering the outer layer of the semi-finished product obtained in step (1) with a protective layer, and then drawing to obtain an in-situ nanoparticle reinforced aluminum-based welding wire; wherein the drawing temperature is 400° C.; and the drawing speed is 5 m / min.

[0148] Application Example 4

[0149] The in-situ nanoparticle-reinforced aluminum-based welding wire prepared in Example 4 and the 7085 aluminum alloy weldment were welded using microwave, dual magnetic field, and ultrasonic field synchronous assisted laser welding. The welding process parameters are as follows:

[0150] The laser beam is in the shape of a ring + central beam; during the welding process, the positions of the laser beam, microwave, dual magnetic field and ultrasonic vibrator are fixed, the 7085 aluminum alloy weldment is moved, and argon gas with a purity of 99.99% is applied to the front and back of the weldment at the same time; the laser welding power is 0.8kW, and the welding speed is 480mm / min; the microwave output frequency is 2.45GHz, and the output power is 0.4kW; the alternating magnetic field excitation current is 300A, the frequency is 12Hz, the constant magnetic field strength is 0.3T, and a magnetic field isolation plate is set between the alternating magnetic field and the constant magnetic field; the ultrasonic field is applied to the back of the weld, the laser beam and ultrasonic vibrator are both on the weld straight line, the spacing is set to 15mm, the ultrasonic power is 10kW, and the ultrasonic frequency is 30kHz.

[0151] The mass contents of ZrB2, TiB2 and Al2O3 particles in the formed weld are 1%, 1% and 3.9% respectively.

[0152] FIG2 is an OM image of the weld prepared in Application Example 4, and FIG3 is an SEM image of the weld prepared in Application Example 4.

[0153] As can be seen from Figures 2 and 3, the nanoparticles in the weld are evenly distributed in the matrix, which can effectively refine the grains and strengthen the weld.

[0154] The laser welded joints prepared in Application Examples 1 to 4 were subjected to room temperature tensile tests according to the ASTM E8M-09 experimental standard, and compared with the welded joints obtained by direct laser butt welding of 6082, 6061, 7050, and 7085 aluminum alloys without external field assistance. The results are shown in Table 1.

[0155] Table 1 Mechanical properties of laser welded joints in welded state

[0156] As shown in Table 1, compared with direct laser butt welding of 6082, 6061, 7050, and 7085 without external field assistance, the tensile strength, elongation, and joint coefficient of the laser welded joints in this application example are significantly improved. This demonstrates that the essence of the present invention is based on the in-situ endogenous nanoparticles and rare earth precipitates uniformly distributed within the matrix, which can effectively refine the grains, significantly alleviate weld thermal cracking, and significantly improve the mechanical properties of the joints. Specifically, the generation and distribution of the nano-reinforced phase is regulated by the coupling of microwave, dual magnetic field, and ultrasonic fields, enabling it to effectively exert its refinement and strengthening effects.

[0157] The description of the above embodiments is only intended to help understand the method of the present invention and its core concept. It should be noted that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An in-situ nanoparticle-reinforced aluminum-based welding wire, comprising a flux core, an outer skin and a protective layer arranged in sequence from the inside to the outside; The core comprises the following components by mass percentage: B2O3 1.7% to 8.1%, ZrO2 1.0% to 5.4%, TiO2 1.1% to 5.7%, powder 0.1% to 1.0%, Mg 0.8% to 1.2%, Si 0.4% to 1.2%, Cu 0.1% to 0.4%, Cr 0.04% to 0.35%, Zn 0.15% to 0.25% and the balance of aluminum powder; Alternatively, the drug core comprises the following components: B2O3 1.7% to 8.1%, ZrO2 1.0% to 5.4%, TiO2 1.1% to 5.7%, powder 0.1% to 1.0%, Zn 4.0% to 8.0%, Mg 1.0% to 3.5%, Cu 0% to 2.5% and the balance of aluminum powder; The powder is at least one of Sc, Er and Zr.

2. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1, characterized in that: The core comprises the following components in percentage by mass: B2O3 2.0% to 8.0%, ZrO2 1.1% to 5.0%, TiO2 1.1% to 5.0%, powder 0.3% to 1.0%, Mg 1.0% to 1.2%, Si 0.6% to 1.0%, Cu 0.1% to 0.2%, Cr 0.1% to 0.30%, Zn 0.20% to 0.25% and the balance of aluminum powder.

3. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1, characterized in that: The core comprises the following components in percentage by mass: B2O3 2.0% to 8.1%, ZrO2 1.1% to 5.4%, TiO2 1.5% to 5.0%, powder 0.45% to 0.6%, Zn 6.0% to 7.6%, Mg 1.6% to 2.4%, Cu 1.4% to 2.0% and the balance of aluminum powder.

4. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1, characterized in that: The powder is a mixed powder of Sc and Zr or a mixed powder of Er and Zr.

5. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 4, characterized in that: The mass ratio of Sc to Zr in the mixed powder of Sc and Zr is 1:2; the mass ratio of Er to Zr in the mixed powder of Er and Zr is 2:

1.

6. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1, characterized in that: The filling rate of the drug core is 5% to 34%.

7. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1, characterized in that: The outer skin is prepared by using 1070 semi-hard pure aluminum strip.

8. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1 or 7, characterized in that: The thickness of the outer skin is 0.1-0.2 mm.

9. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1, characterized in that: The components of the protective layer are SiC and Al2O3.

10. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 9, characterized in that: The mass ratio of SiC to Al2O3 is 3:1 to 3:

2.

11. The in-situ nanoparticle reinforced aluminum-based welding wire according to claim 1 or 9, characterized in that: The thickness of the protective layer is 0.1-0.2 mm.

12. The method for preparing the in-situ nanoparticle reinforced aluminum-based welding wire according to any one of claims 1 to 11, comprising the following steps: (1) rolling the outer skin into a U-shaped groove, loading the core into the groove, and then closing the U-shaped groove to obtain a semi-finished product; (2) Covering the outer layer of the semi-finished product obtained in step (1) with a protective layer, and then drawing it to obtain an in-situ nanoparticle reinforced aluminum-based welding wire.

13. A method for welding the in-situ nanoparticle reinforced aluminum-based welding wire according to any one of claims 1 to 11 or the in-situ nanoparticle reinforced aluminum-based welding wire prepared by the preparation method according to claim 12, using microwave, dual magnetic field and ultrasonic field synchronous assisted laser welding.

14. The welding method according to claim 13, characterized in that: The output frequency of the microwave is 2.45 GHz, and the output power of the microwave is 0-3 kW.

15. The welding method according to claim 13, characterized in that: The dual magnetic field is an alternating magnetic field and a constant magnetic field; the excitation current of the alternating magnetic field is 250-300A, and the frequency is 10-12Hz; the magnetic field strength of the constant magnetic field is 0.1-0.3T.

16. The welding method according to claim 13, characterized in that: The ultrasonic power of the ultrasonic field is 5-10 kW, and the ultrasonic frequency is 20-30 kHz.

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