Aluminum alloy laser ceramic / high-entropy alloy composite powder filling welding method

Abstract

This invention discloses a laser-filled ceramic / high-entropy alloy composite powder welding method for aluminum alloys, belonging to the field of welding technology, including the following steps: (1) Composite powder preparation: ceramic powder and high-entropy alloy powder are mixed in a certain proportion and spheroidized by plasma to obtain ceramic / high-entropy alloy composite powder; (2) Pretreatment of welding samples: the surface of the aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film, and wiped clean with volatile organic solvents, and then placed in a drying equipment for drying; (3) The aluminum alloy plates in step (2) are placed together and fixed by pressure plates to form the structure to be welded; (4) The structure to be welded in step (3) is welded using laser-filled powder welding process. This invention relies on the stirring effect of laser on the molten pool to uniformly distribute the ceramic / high-entropy alloy composite powder in the weld, which has the advantages of both ceramic particle reinforcement and high-entropy alloy particle reinforcement, and can effectively improve the strength of the weld joint.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular provides a method for laser-welded aluminum alloys using ceramic / high-entropy alloy composite powder. Background Technology

[0002] Aluminum alloys, due to their low density, excellent mechanical properties, and corrosion resistance, have become the preferred lightweight material in the automotive industry, especially in the new energy vehicle sector, for reducing vehicle weight and improving fuel efficiency. In the manufacturing process of vehicle bodies and components, connection issues are inevitably considered; therefore, achieving efficient and high-quality connections with aluminum alloys is of great significance to vehicle body manufacturing. Laser welding, as an emerging welding technology, has attracted increasing attention in the field of aluminum alloy welding due to its advantages such as small welding deformation, small heat-affected zone, and wide processing range. However, aluminum alloys, as highly reflective materials, have low laser absorption rates. Furthermore, under laser irradiation, the original fine structure and nano-precipitates in the base material cannot be preserved, resulting in significant softening in the weld zone and a significant reduction in the strength of the weld joint compared to the base material.

[0003] Laser powder filler welding involves replenishing the molten pool with metallic or non-metallic powder during welding. Compared to laser autofusion welding, it offers improved utilization, lower assembly precision requirements, and easier adjustments during welding. Furthermore, it allows for a wider variety of filler materials with easily controllable composition, meeting diverse application needs. The addition of effective components results in more stable welding effects, improved weld formation, reduced defects, and enhanced joint mechanical properties.

[0004] Currently, most laser filler powders for aluminum alloys are elemental powders or mixtures thereof, such as Si powder, Cu powder, Zr powder, Mn powder, and some ceramic particles. For example, Chinese patent (CN108723596A) utilizes the stirring effect of the laser on the molten pool to uniformly distribute TiB2 particles in the weld seam. The stability of the ceramic particles during laser welding significantly improves the weld joint strength. High-entropy alloys possess excellent mechanical properties; compared to ceramic materials, they exhibit better wettability and higher interfacial bonding strength with the aluminum matrix. Currently, some researchers have attempted to apply high-entropy alloys to the welding field. For instance, Chinese patent (CN101554685A) discloses a high-entropy alloy brazing filler metal for welding copper and aluminum and its preparation method. However, there are currently no reports on using ceramic / high-entropy alloy composite powder as filler powder in aluminum alloy laser filler welding. Based on the above analysis, this patent application proposes using ceramic / high-entropy alloy composite powder as filler material in aluminum alloy laser filler welding, relying on the synergistic effect of the ceramic powder and high-entropy alloy powder to improve the weld joint strength. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a method for laser-welded aluminum alloy ceramic / high-entropy alloy composite powder.

[0006] The technical solution of this invention is:

[0007] A method for laser-welded aluminum alloy ceramic / high-entropy alloy composite powder, comprising the following steps:

[0008] (1) Preparation of composite powder: ceramic powder and high-entropy alloy powder are spheroidized by plasma in a certain proportion to obtain ceramic / high-entropy alloy composite powder;

[0009] (2) Pretreatment of welding test specimens: The surface of the aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film, and wiped clean with volatile organic solvents, and then placed in the drying equipment for drying.

[0010] (3) Place the aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded;

[0011] (4) The structure to be welded in step (3) is welded using laser powder filling welding process.

[0012] In the above method, in step (1), the ceramic powder includes TiB2, TiC, TiN, SiC, ZrO2, etc.; the high-entropy alloy powder includes FeCoCrNi system, FeCoCrNiMn system, FeCoCrNiMo system, AlCoCrFeNi system, AlTiCrNiCu system, WTaMoNbV system, TiNbZrTa system, etc.

[0013] In the above method, in step (1), the mass fraction of ceramic in the ceramic / high-entropy alloy composite powder is between 1% and 50%, the mass fraction of high-entropy alloy is between 50% and 99%, and the sum of the two is equal to 1. The ceramic powder is in the form of flakes or other irregular shapes with a particle size of 0.05 to 1 μm, the high-entropy alloy powder is spherical with a particle size of 1 to 100 μm, and the ceramic / high-entropy alloy composite powder is spherical with a particle size of 1 to 100 μm.

[0014] In the above method, in step (2), the aluminum alloy includes cast aluminum alloys, such as Al-Si system, Al-Cu system, Al-Mg system, and Al-Zn system; it also includes wrought aluminum alloys.

[0015] In the above method, in step (2), the thickness of the aluminum alloy to be welded is 1-6 mm.

[0016] In the above method, in step (2), when the thickness of the aluminum alloy to be welded is 1-3mm, no beveling is required; when the thickness is 4-6mm, a beveling is required, and the beveling shape includes "I" shape, "V" shape, "Y" shape, etc.

[0017] In the above method, the volatile organic solvent in step (2) includes ethanol, acetone, etc.

[0018] In the above method, in step (2), the drying temperature is 60-80℃ and the drying time is 20-40min.

[0019] In the above method, in step (4), the filling method of ceramic / high entropy alloy composite powder includes pre-powder method and synchronous powder feeding method, wherein synchronous powder feeding method includes coaxial powder feeding and off-axis powder feeding.

[0020] In the above method, in step (4), high-purity argon gas with a mass concentration of not less than 99.99% is used for coaxial protection during welding, and the flow rate of the protective gas is 10-20L / min.

[0021] The present invention has the following advantages over the prior art:

[0022] 1. This invention incorporates ceramic / high-entropy alloy composite powder into aluminum alloy welds using a laser powder filling welding process, thereby significantly improving weld strength through the dispersion strengthening effect of the composite powder.

[0023] 2. This invention incorporates ceramic / high-entropy alloy composite powder into aluminum alloy welds using a laser powder filling welding process. The high-entropy alloy's delayed diffusion effect reduces the formation of intermetallic compounds in the weld.

[0024] 3. By adjusting the types and proportions of different ceramic powders and high-entropy alloy powders, this invention can be applied to different aluminum alloy materials to obtain different strengthening effects. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of laser powder filling welding of aluminum alloy according to the present invention.

[0026] Figure 2 This is a macroscopic morphology diagram of the weld seam in Embodiment 1 of the present invention.

[0027] Figure 3 This is a macroscopic morphology diagram of the weld seam, which is a comparative example of the present invention. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to specific embodiments, but it is not limited thereto.

[0029] Example 1

[0030] This embodiment provides a method for laser-welded ceramic / high-entropy alloy composite powder with a thickness of 1mm for 6063 aluminum alloy, specifically including:

[0031] (1) Preparation of composite powder: TiC ceramic powder with an average particle size of 0.5 μm and AlCoCrFeNi high-entropy alloy powder with an average particle size of 15~53 μm are plasma spheroidized at a mass ratio of 10:90 to obtain ceramic / high-entropy alloy composite powder.

[0032] (2) Pretreatment of welding test specimens: The surface of the 1mm thick 6063 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film. No beveling is required. The specimens are then wiped clean with anhydrous ethanol and placed in an 80℃ drying equipment for 30 minutes to dry.

[0033] (3) Place the 6063 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0034] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 1100W, welding speed is 30mm / s, defocusing amount is 0, powder feeding amount is 3.5g / min, and shielding gas flow rate is 10L / min.

[0035] The macroscopic morphology of the weld in this embodiment is as follows: Figure 2 As shown, the weld surface is well formed, without undercut or spatter and other forming defects. The tensile strength of the welded specimen is 215.8 MPa, and the weld strength coefficient is 82.7%.

[0036] Example 2

[0037] This embodiment provides a method for laser-welded ceramic / high-entropy alloy composite powder with a thickness of 2mm to fill the gap in 2mm thick 2024 aluminum alloy, specifically including:

[0038] (1) Preparation of composite powder: TiB2 ceramic powder with an average particle size of 0.1 μm and AlCoCrFeNi high-entropy alloy powder with an average particle size of 15~53 μm were obtained by plasma spheroidization at a mass ratio of 30:70 to obtain ceramic / high-entropy alloy composite powder.

[0039] (2) Pretreatment of welding test specimens: The surface of the 2mm thick 2024 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film. No beveling is required. The specimens are wiped clean with anhydrous ethanol and then placed in an 80℃ drying equipment for 30 minutes to dry.

[0040] (3) Place the 2024 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0041] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 1700W, welding speed is 30mm / s, defocusing amount is +1, powder feeding amount is 6g / min, and shielding gas flow rate is 12L / min.

[0042] In this embodiment, the weld surface has good formation, with no forming defects such as undercut and spatter. The tensile strength of the welded specimen is 335.4 MPa, and the weld strength coefficient is 72.9%.

[0043] Example 3

[0044] This embodiment provides a method for laser-welded ceramic / high-entropy alloy composite powder with a thickness of 4mm ZL101 aluminum alloy, specifically including:

[0045] (1) Preparation of composite powder: TiB2 ceramic powder with an average particle size of 0.8 μm and FeCoCrNi high-entropy alloy powder with an average particle size of 15~53 μm were obtained by plasma spheroidization at a mass ratio of 20:80 to obtain ceramic / high-entropy alloy composite powder.

[0046] (2) Pretreatment of welding test specimens: The surface of the 4mm thick ZL101 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film, a "V" shaped bevel is opened, and the plate is wiped clean with acetone. Then it is placed in an 80℃ drying equipment for 30 minutes to dry.

[0047] (3) Place the ZL101 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0048] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is off-axis powder feeding. The specific welding parameters are as follows: laser power is 2800W, welding speed is 20mm / s, defocusing amount is -1, powder feeding amount is 12g / min, and shielding gas flow rate is 15L / min.

[0049] In this embodiment, the weld surface has good formation, with no forming defects such as undercut and spatter. The tensile strength of the welded sample is 230.4 MPa, and the weld strength coefficient is 78.1%.

[0050] Example 4

[0051] This embodiment provides a laser ceramic / high entropy alloy composite powder filler welding method for 6mm thick 7075 aluminum alloy, specifically including:

[0052] (1) Preparation of composite powder: ZrO2 ceramic powder with an average particle size of 0.6 μm and TiNbZrTa high-entropy alloy powder with an average particle size of 1~25 μm were plasma spheroidized at a mass ratio of 50:50 to obtain ceramic / high-entropy alloy composite powder.

[0053] (2) Pretreatment of welding test specimens: The oxide film on the surface of the 6mm thick 7075 aluminum alloy plate to be welded and the area around the weld 25mm are ground off, a "Y" shaped bevel is opened, and the specimens are wiped clean with anhydrous ethanol and then placed in an 80℃ drying equipment for 30 minutes to dry.

[0054] (3) Place the 7075 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0055] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 4300W, welding speed is 25mm / s, defocusing amount is -2, powder feeding amount is 15g / min, and shielding gas flow rate is 15L / min.

[0056] In this embodiment, the weld surface has good formation, with no forming defects such as undercut and spatter. The tensile strength of the welded specimen is 385.8 MPa, and the weld strength coefficient is 70.7%.

[0057] Example 5

[0058] This embodiment provides a method for laser-welded ceramic / high-entropy alloy composite powder with a thickness of 4mm for 5083 aluminum alloy, specifically including:

[0059] (1) Preparation of composite powder: TiB2 ceramic powder with an average particle size of 0.5 μm and AlTiCrNiCu high-entropy alloy powder with an average particle size of 15~53 μm were obtained by plasma spheroidization at a mass ratio of 40:60 to obtain ceramic / high-entropy alloy composite powder.

[0060] (2) Pretreatment of welding test specimens: The surface of the 4mm thick 5083 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film, an "I" bevel is opened, and the specimens are wiped clean with anhydrous ethanol and then placed in an 80℃ drying equipment for 30 minutes to dry.

[0061] (3) Place the 5083 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0062] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 3200W, welding speed is 25mm / s, defocusing amount is -1, powder feeding amount is 11g / min, and shielding gas flow rate is 15L / min.

[0063] In this embodiment, the weld surface has good formation, with no forming defects such as undercut and spatter. The tensile strength of the welded specimen is 297.6 MPa, and the weld strength coefficient is 86.3%.

[0064] Example 6

[0065] This embodiment provides a method for laser-welded ceramic / high-entropy alloy composite powder with a thickness of 3mm for 3003 aluminum alloy, specifically including:

[0066] (1) Preparation of composite powder: TiC ceramic powder with an average particle size of 0.5 μm and FeCoCrNiMn high-entropy alloy powder with an average particle size of 15~53 μm were obtained by plasma spheroidization at a mass ratio of 25:75.

[0067] (2) Pretreatment of welding test specimens: The surface of the 3mm thick 3003 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film. No beveling is required. The specimens are then wiped clean with anhydrous ethanol and placed in an 80℃ drying equipment for 30 minutes to dry.

[0068] (3) Place the 3003 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0069] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 2600W, welding speed is 20mm / s, defocusing amount is 0, powder feeding amount is 10.5g / min, and shielding gas flow rate is 15L / min.

[0070] In this embodiment, the weld surface has good formation, with no forming defects such as undercut and spatter. The tensile strength of the welded sample is 253 MPa, and the weld strength coefficient is 85%.

[0071] Example 7

[0072] This embodiment provides a laser ceramic / high entropy alloy composite powder filler welding method for 2.5mm thick 6005A aluminum alloy, specifically including:

[0073] (1) Preparation of composite powder: ZrO2 ceramic powder with an average particle size of 0.5 μm and TiNbZrTa high-entropy alloy powder with an average particle size of 1~25 μm were plasma spheroidized at a mass ratio of 5:95 to obtain ceramic / high-entropy alloy composite powder.

[0074] (2) Pretreatment of welding test specimens: The surface of the 2.5mm thick 6005A aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film. No beveling is required. The specimens are then wiped clean with anhydrous ethanol and placed in an 80℃ drying equipment for 30 minutes to dry.

[0075] (3) Place the 6005A aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0076] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 2400W, welding speed is 30mm / s, defocusing amount is 0, powder feeding amount is 9.8g / min, and shielding gas flow rate is 14L / min.

[0077] In this embodiment, the weld surface has good formation, with no forming defects such as undercut and spatter. The tensile strength of the welded specimen is 248.7 MPa, and the weld strength coefficient is 74.9%.

[0078] Example 8

[0079] This embodiment provides a laser ceramic / high-entropy alloy composite powder filler welding method for 2mm thick 6016 aluminum alloy, specifically including:

[0080] (1) Preparation of composite powder: TiN ceramic powder with an average particle size of 0.5 μm and AlCoCrFeNi2.1 high entropy alloy powder with an average particle size of 1~25 μm were obtained by plasma spheroidization at a mass ratio of 15:85 to obtain ceramic / high entropy alloy composite powder.

[0081] (2) Pretreatment of welding test specimens: The surface of the 2mm thick 6016 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film. No beveling is required. The specimens are then wiped clean with anhydrous ethanol and placed in an 80℃ drying equipment for 30 minutes to dry.

[0082] (3) Place the 6016 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0083] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 1900W, welding speed is 35mm / s, defocusing amount is -1, powder feeding amount is 7.8g / min, and shielding gas flow rate is 12L / min.

[0084] In this embodiment, the weld surface is well formed, without forming defects such as undercut and spatter. The tensile strength of the welded sample is 183.4 MPa, and the weld strength coefficient is 78.4%.

[0085] Example 9

[0086] This embodiment provides a method for laser-welded ceramic / high-entropy alloy composite powder with a thickness of 2mm for welding ZL101 aluminum alloy, specifically including:

[0087] (1) Preparation of composite powder: TiB2 ceramic powder with an average particle size of 0.5 μm and AlTiCrNiCu high-entropy alloy powder with an average particle size of 15~53 μm were obtained by plasma spheroidization at a mass ratio of 1:99 to obtain ceramic / high-entropy alloy composite powder.

[0088] (2) Pretreatment of welding test specimens: The surface of the 2mm thick ZL101 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film. No beveling is required. The specimens are then wiped clean with anhydrous ethanol and placed in an 80℃ drying equipment for 30 minutes to dry.

[0089] (3) Place the ZL101 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0090] (4) The structure to be welded in step (3) is welded using laser powder filling welding process, and the powder feeding method is coaxial powder feeding. The specific welding parameters are as follows: laser power is 1800W, welding speed is 30mm / s, defocusing amount is -1, powder feeding amount is 6.2g / min, and shielding gas flow rate is 12L / min.

[0091] In this embodiment, the weld surface is well formed, without forming defects such as undercut and spatter. The tensile strength of the welded sample is 237.8 MPa, and the weld strength coefficient is 80.6%.

[0092] Comparative example:

[0093] This comparative example provides a laser self-fusion welding method for 1mm thick 6063 aluminum alloy, specifically including:

[0094] (1) Pretreatment of welding test specimens: The surface of the 1mm thick 6063 aluminum alloy plate to be welded and the area around the weld 25mm are ground to remove the oxide film. No beveling is required. The specimens are then wiped clean with anhydrous ethanol and placed in an 80℃ drying equipment for 30 minutes to dry.

[0095] (2) Place the 6063 aluminum alloy plates from step (2) together and fix them with pressure plates to form a structure to be welded.

[0096] (3) The structure to be welded in step (2) is welded using laser autofusion welding process. The specific welding parameters are as follows: laser power is 950W, welding speed is 30mm / s, defocusing amount is 0, and shielding gas flow rate is 10L / min.

[0097] The macroscopic morphology of the comparative weld is as follows: Figure 3 As shown, the weld face is slightly collapsed, the tensile strength of the welded specimen is 188.7 MPa, and the weld strength coefficient is 72.3%.

[0098] The above description is only one specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention are covered within the protection scope of the present invention.

Claims

1. A method for laser-welding aluminum alloy ceramic / high-entropy alloy composite powder, characterized in that, The process includes the following steps: (1) Preparation of composite powder: ceramic powder and high-entropy alloy powder are spheroidized by plasma at a certain mass ratio to obtain ceramic / high-entropy alloy composite powder; the mass fraction of ceramic in the ceramic / high-entropy alloy composite powder is between 1% and 50%, the mass fraction of high-entropy alloy is between 50% and 99%, and the sum of the two is equal to 1; the ceramic powder is in the form of flakes or other irregular shapes with a particle size of 0.05-1μm, the high-entropy alloy powder is spherical with a particle size of 1-100μm, and the ceramic / high-entropy alloy composite powder is spherical with a particle size of 1-100μm; (2) Pretreatment of welding samples: the surface of the aluminum alloy plate to be welded and the area around the weld seam within 25mm are ground to remove the oxide film, and wiped clean with volatile organic solvents, and then placed in a drying equipment for drying; (3) The aluminum alloy plates from step (2) are placed together and fixed by a pressure plate to form the structure to be welded; (4) The structure to be welded in step (3) is welded using laser powder filling welding process. The powder filling method is synchronous powder feeding, including coaxial powder feeding or off-axis powder feeding. High-purity argon gas with a mass concentration of not less than 99.99% is used for coaxial protection during welding, and the protective gas flow rate is 10-15L / min.

2. The method for laser-welded aluminum alloy ceramic / high-entropy alloy composite powder according to claim 1, characterized in that, In step (1), the ceramic powder includes TiB2, TiC, TiN, SiC or ZrO2; the high-entropy alloy powder includes FeCoCrNi system, FeCoCrNiMn system, FeCoCrNiMo system, AlCoCrFeNi system, AlTiCrNiCu system, WTaMoNbV system or TiNbZrTa system.

3. The aluminum alloy laser ceramic / high-entropy alloy composite powder filler welding method according to claim 1, characterized in that, In step (2), the aluminum alloy includes cast aluminum alloy and wrought aluminum alloy, and the cast aluminum alloy includes Al-Si system, Al-Cu system, Al-Mg system or Al-Zn system.

4. The method for laser-welded aluminum alloy ceramic / high-entropy alloy composite powder according to claim 1, characterized in that, In step (2), the thickness of the aluminum alloy to be welded is 1-6 mm.

5. The aluminum alloy laser ceramic / high-entropy alloy composite powder filler welding method according to claim 4, characterized in that, In step (2), when the thickness of the aluminum alloy to be welded is 1-3mm, no beveling is required; when the thickness is 4-6mm, a beveling is required, and the beveling shape includes "I", "V" or "Y".

6. The method for laser-welded aluminum alloy ceramic / high-entropy alloy composite powder according to claim 1, characterized in that, In step (2), the volatile organic solvent includes ethanol or acetone.

7. The method for laser-welded aluminum alloy ceramic / high-entropy alloy composite powder according to claim 1, characterized in that, In step (2), the drying temperature is 60-80℃ and the drying time is 20-40min.

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