CN115958296A - Welding forming method for AlSi10Mg aluminum alloy structural member by selective laser melting forming - Google Patents

Abstract

The invention discloses a welding and forming method for laser selective melting and forming of AlSi10Mg aluminum alloy structural parts, which belongs to the field of additive manufacturing and welding technology; it solves the problem of serious problems inside the welding joint when welding the existing laser selective melting and forming of AlSi10Mg aluminum alloy structural parts The technical problem of stomatal defects. The welding forming method provided by the present invention includes: step 1, performing annealing heat treatment on the AlSi10Mg aluminum alloy structural part to be welded by selective melting of laser to be welded; step 2, assembling the joint to be welded in the form of butt joint; step 3, treating Perform tack welding on the welding head; step 4, after tack welding, formally weld the to-be-welded head. The invention can realize the high-quality welding forming of AlSi10Mg aluminum alloy structural parts formed by laser selective melting.

Description

A Welding Forming Method of AlSi10Mg Aluminum Alloy Structural Parts Formed by Laser Selective Melting

technical field

The invention relates to the technical field of additive manufacturing and welding, in particular to a welding forming method for laser selective melting and forming AlSi10Mg aluminum alloy structural parts.

Background technique

Aluminum alloys have been widely used in the aerospace field due to their low density, high specific strength, and excellent corrosion resistance. Different from the traditional casting or forging and then "material reduction" processing method, the laser selective melting additive manufacturing technology has the technical characteristics of "material" and "structure" forming at the same time. In addition, in terms of structural forming, it has the technical advantage of being able to realize special and complex structural forming that cannot be realized by traditional processing methods, such as lightweight lattice sandwich structure, spatial surface porous structure, complex cavity flow channel structure, etc.

Since laser selective melting additive manufacturing technology has the technical advantages of high efficiency, low cost and batch manufacturing of special complex components, it has received more and more attention and research applications in the aerospace field.

Although laser selective melting additive manufacturing technology has the technical characteristics of integrated forming of complex structures, it still faces the requirement of welding connection of structural parts in some applications. Therefore, under the background that laser selective melting and forming AlSi10Mg aluminum alloy structural parts are more and more widely used in the aerospace field, how to realize the subsequent high-quality connection of laser selective melting and forming AlSi10Mg aluminum alloy structural parts has become an urgent problem to be solved.

For the welding of AlSi10Mg aluminum alloy structural parts formed by laser selective melting abroad, there are serious porosity defects in the welded joints. Therefore, the welding problem of AlSi10Mg aluminum alloy structural parts formed by laser selective melting has not been effectively solved in the early stage.

Contents of the invention

In view of the above analysis, the present invention aims to provide a welding forming method for laser selective melting and forming of AlSi10Mg aluminum alloy structural parts, which is used to solve the problem of serious air holes inside the welded joint when the existing laser selective melting and forming of AlSi10Mg aluminum alloy structural parts is welded Defective technical issues.

The purpose of the present invention is mainly achieved through the following technical solutions:

The invention provides a welding forming method for forming an AlSi10Mg aluminum alloy structural part by laser selective melting, comprising the following steps:

Step 1. Perform annealing heat treatment on the AlSi10Mg aluminum alloy structural parts to be welded by laser selective melting before welding; the annealing temperature is 270°C-300°C, and the annealing time is 1.5h-2.5h;

Step 2. Assemble the joint to be welded in the form of butt joint;

The thickness δ of the joint to be welded is 2mm~4mm; when the joint to be welded is docked with a lock bottom, the width of the lock bottom is 3mm-5mm; the assembly gap is ≤0.1mm, and the assembly step difference is ≤0.15δ;

Step 3, perform positioning welding on the joint to be welded;

When performing positioning welding on the joint to be welded, the welding method adopts laser swing welding; during laser swing welding, the laser light source travels in the shape of "∞" swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded. In the direction of the weld seam as the center of symmetry, the welding is carried out in a "∞"-shaped trajectory in a spiral manner;

The welding process parameters during tack welding are: the swing range of the laser light source is 2mm-3mm, the swing frequency is 300Hz-350Hz; the incident angle of the laser beam is 80°-85°, the laser power is 3000W-5500W, and the welding speed is 1500-1800mm /min, the spot diameter is 0.2~0.3mm, and the defocus amount is +5mm;

Step 4. After tack welding, formally weld the joint to be welded;

When the joint to be welded is formally welded, the welding method adopts laser swing welding; during laser swing welding, the laser light source travels in the shape of "∞" swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded, and in the vertical direction of the joint to be welded In the direction of the weld seam as the center of symmetry, the welding is carried out in a "∞"-shaped trajectory in a spiral manner;

For formal welding, the swing amplitude is 2mm-3mm, the swing frequency is 300Hz-350Hz, the incident angle of the laser beam is 80°-85°, the laser power is 3000W-5500W, the welding speed is 1500-1800mm/min, and the spot diameter is 0.2 ~0.3mm and +5mm defocus.

Further, in step 1, after the annealing heat treatment, the laser selective melting formed AlSi10Mg aluminum alloy structural part to be welded is cleaned before welding.

Further, in step 1, the cleaning process before welding includes: pickling to remove the oxide film on the surface, and then grinding the area to be welded until the metal color of the body is exposed.

Further, in step 1, the pre-weld cleaning process also includes: after grinding, use absolute ethanol to clean the joint to be welded of the AlSi10Mg aluminum alloy structure formed by laser selective melting.

Further, in step 3, during tack welding, high-purity argon gas with a purity greater than or equal to 99.99% is used for gas protection.

Further, in step 4, during formal welding, high-purity argon gas with a purity greater than or equal to 99.99% is used for gas shielding.

Further, in step 3, the welding length of the tack welding is 250mm-300mm.

Further, in step 4, after formal welding, the internal quality of the weld is detected by X-rays.

Further, in step 2, the docking method is bottom-lock docking or direct docking.

Further, in step 3 and step 4, a fiber laser is used for laser swing welding.

Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

(1) The present invention can realize welding forming of AlSi10Mg aluminum alloy structural parts formed by laser selective melting, and can obtain good internal quality and surface quality of forming.

(2) The present invention can realize high-quality welding and forming of AlSi10Mg aluminum alloy structural parts formed by laser selective melting and forming. scope.

In the present invention, the above technical solutions can also be combined with each other to realize more preferred combination solutions. Additional features and advantages of the invention will be set forth in the description which follows, and some of the advantages will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the present invention can be realized and obtained by the embodiments of the description and the contents particularly pointed out in the accompanying drawings.

Description of drawings

The accompanying drawings are only for the purpose of illustrating specific embodiments, and are not considered to limit the present invention. Throughout the accompanying drawings, the same reference symbols represent the same components;

Fig. 1 is the laser welding swing trajectory of the laser selective melting forming AlSi10Mg aluminum alloy provided by the present invention;

Fig. 2 is the bottom-locked butt joint form of the laser selective melting forming AlSi10Mg aluminum alloy provided by the present invention;

Fig. 3 is the direct butt joint form of laser selective melting forming AlSi10Mg aluminum alloy provided by the present invention;

Fig. 4 is a schematic flow chart of a welding forming method for forming an AlSi10Mg aluminum alloy structural part by laser selective melting.

Detailed ways

The preferred embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and together with the embodiments of the present invention are used to explain the principles of the present invention and are not intended to limit the scope of the present invention.

The present invention provides a welding forming method for laser selective melting forming AlSi10Mg aluminum alloy structural parts, as shown in Figure 4, the welding forming method comprises the following steps:

Step 1. Perform annealing heat treatment on the AlSi10Mg aluminum alloy structural parts to be welded by laser selective melting before welding; wherein, the annealing temperature is 270°C-300°C, and the annealing time is 1.5h-2.5h to remove thermal stress;

In the above step 1, after the annealing heat treatment, the laser selective melting and forming AlSi10Mg aluminum alloy structural parts to be welded are cleaned before welding. The cleaning process before welding includes: pickling to remove the surface oxide film, and then grinding the area to be welded until the body is exposed Metal color, ensure that there are no sharp corners and burrs, and then use absolute ethanol to clean the welded joints of AlSi10Mg aluminum alloy structural parts that are melted and formed by laser selection.

Step 2. Assemble the joints to be welded in the form of docking, as shown in Figure 2 and Figure 3, the docking method is direct docking or bottom-locked docking;

In the above-mentioned step 2, the thickness δ of the joint to be welded is 2mm ~ 4mm; the present invention controls the thickness of the joint to be welded within the scope of 2mm-4mm in order to avoid producing a large number of pores and ensure the welding quality at the welded joint; If the thickness of the welding head is greater than 4mm, the porosity defects will exceed the standard, resulting in the inability to achieve effective welding.

It should be noted that in the above step 2, when the butt joint method of the joint to be welded is the bottom-lock butt joint, the bottom-lock width is 3mm-5mm; the reason why the bottom-lock width is controlled within the range of 3mm-5mm is that the width and thickness of the bottom-lock are too narrow , can not play the role of positioning and supporting the molten pool, but too wide is not convenient for assembly and wastes materials.

In the above step 2, the assembly gap is ≤0.1mm, and the assembly step difference is ≤0.15δ. When the assembly step difference is greater than 0.15δ, effective welding cannot be achieved.

Step 3, performing tack welding on the joint to be welded, the welding length of the tack welding is 250mm-300mm;

In the above step 3, when the positioning welding of the joint to be welded is performed, the welding method adopts laser swing welding; The seam maintains the welding speed as Vx, and in the direction perpendicular to the joint to be welded, with the weld seam as the center of symmetry, the welding proceeds in a spiral manner with a "∞"-shaped trajectory.

In the above step 3, the welding process parameters during tack welding are as follows: the swing range of the laser light source is 2mm-3mm, and the "∞" shape trajectory with the swing frequency of 300Hz-350Hz is used for spiral forward welding, and the incident angle of the laser beam is 80° -85°, the laser power is 3000W-5500W, the welding speed is 1500-1800mm/min, the spot diameter is 0.2-0.3mm, and the defocus is +5mm.

During positioning welding, strictly control the swing amplitude and swing frequency within the above range, so as to suppress the generation of air holes inside the welded joint and avoid the occurrence of excessive air holes in the welded joint. Strictly control the incident angle of the laser beam, laser power, welding speed, spot diameter and defocus within the above range, so as to ensure good internal quality and surface quality of the forming, and avoid poor fusion caused by too small or too large heat input Or serious phenomenon of reverse penetration, affecting the forming quality of welded joints.

It should be noted that during tack welding, high-purity argon gas with a purity greater than or equal to 99.99% is used for gas protection.

Step 4. After tack welding, formally weld the joint to be welded;

In the above step 4, the welding method and welding process parameters of the formal welding are the same as those of the positioning welding; specifically: when the formal welding of the joint to be welded is performed, the welding method adopts laser swing welding; as shown in Figure 1, during laser swing welding, The walking track of the laser light source is "∞" shaped swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded. welding.

When formally welding, the "∞"-shaped track with a swing amplitude of 2mm-3mm and a swing frequency of 300Hz is used for welding, so as to suppress the generation of internal pores in the welded joint and avoid the occurrence of excessive pores in the welded joint. At the same time, the incident angle of the laser beam is 80°-85°, the laser power is 3000W-5500W, the welding speed is 1500-1800mm/min, the welding process parameters are 0.2-0.3mm in spot diameter and +5mm in defocus, so as to ensure Good forming internal quality and surface quality can be obtained, and poor fusion or serious reverse penetration caused by too small or too large heat input can be avoided, which affects the forming quality of welded joints.

It should be noted that during formal welding, high-purity argon with a purity greater than or equal to 99.99% is used for gas protection.

In step 4 above, a fiber laser is used for laser welding.

In the above step 4, there is no need to perform post-weld heat treatment after welding; the welded joint is well formed after welding, and there are no defects such as undercuts, cracks, and lack of fusion. Use X-rays to detect the internal quality of the weld, meeting the requirements for grade 1 joints specified in the QJ 20660 standard.

Compared with the prior art, the present invention adopts laser swing welding in both positioning welding and formal welding, thereby avoiding excessive pores in the welding joint and realizing high-quality welding of AlSi10Mg aluminum alloy structural parts formed by laser selective melting.

Example 1

This embodiment provides a welding and forming method for forming AlSi10Mg aluminum alloy structural parts by laser selective melting, which specifically includes the following processes:

Step 1. Perform annealing heat treatment on the AlSi10Mg aluminum alloy structural parts to be welded by laser selective melting before welding; wherein, the annealing temperature is 270°C and the annealing time is 1.5h to remove thermal stress;

In the above step 1, after the annealing heat treatment, the laser selective melting and forming AlSi10Mg aluminum alloy structural parts to be welded are cleaned before welding. The cleaning process before welding includes: pickling to remove the surface oxide film, and then grinding the area to be welded until the body is exposed Metal color, ensure that there are no sharp corners and burrs, and then use absolute ethanol to clean the welded joints of AlSi10Mg aluminum alloy structural parts that are melted and formed by laser selection.

Step 2. Assemble the joint to be welded in the form of butt joint, as shown in Figure 2 and Figure 3, the butt joint method is direct butt joint or bottom lock butt joint; wherein, the thickness δ of the joint to be welded is 2mm, and the joint joint method adopts When the lock bottom is docked, the width of the lock bottom is 3mm, the assembly gap is 0.1mm, and the assembly step difference is 0.15δ.

Step 3, perform tack welding on the joint to be welded, and the welding length of the tack weld is 250mm;

During positioning welding, the welding method adopts laser swing welding; as shown in Figure 1, during laser swing welding, the laser light source travels in the shape of "∞" swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded. In the direction of the head, with the welding seam as the center of symmetry, the welding is carried out in a "∞"-shaped trajectory.

During positioning welding, the "∞"-shaped trajectory with a swing amplitude of 2 mm and a swing frequency of 300 Hz is used for welding, so as to suppress the generation of internal pores in the welded joint and avoid the occurrence of excessive pores in the welded joint. At the same time, with the laser beam incident angle of 80°, laser power of 3000W, welding speed of 1500mm/min, spot diameter of 0.2mm and defocus of +5mm welding process parameters, so as to ensure good internal quality and surface forming Quality, to avoid poor fusion or serious reverse penetration caused by too small or too large heat input, which will affect the forming quality of welded joints.

It should be noted that during tack welding, high-purity argon gas with a purity greater than or equal to 99.99% is used for gas protection.

Step 4. After the positioning welding, perform formal welding of the joint to be welded. The welding method and welding process parameters of the formal welding are the same as those of the positioning welding; specifically: when the formal welding of the joint to be welded is performed, the welding method adopts laser swing welding; as shown in Figure 1 As shown, during laser swing welding, the laser light source travels in a "∞"-shaped swing, and maintains a welding speed of Vx along the weld seam of the joint to be welded. ∞" glyph trajectory spiral forward for welding.

The welding process parameters during formal welding are: the swing amplitude of the laser light source is 2 mm, and the "∞" shape trajectory with a swing frequency of 300 Hz is used for spiral forward welding, the incident angle of the laser beam is 80°, the laser power is 3000 W, and the welding speed is 1500 , the spot diameter is 0.2mm, and the defocus amount is +5mm.

When formally welding, the "∞"-shaped track with a swing amplitude of 2mm-3mm and a swing frequency of 300Hz is used for welding, so as to suppress the generation of internal pores in the welded joint and avoid the occurrence of excessive pores in the welded joint. At the same time, the incident angle of the laser beam is 80°, the laser power is 3000W, the welding speed is 1500mm/min, the welding process parameters are the spot diameter of 0.2 and the defocus of +5mm, so as to ensure that good internal and surface quality of the forming can be obtained. , to avoid poor fusion or serious reverse penetration caused by too small or too large heat input, which will affect the forming quality of welded joints.

It should be noted that during formal welding, high-purity argon with a purity greater than or equal to 99.99% is used for gas protection.

The welded joints are in good shape without undercuts, cracks, lack of fusion and other defects. The internal quality of the X-ray inspection welds meets the requirements for grade 1 joints specified in the QJ20660 standard.

Example 2

The present invention provides a welding forming method for laser selective melting forming AlSi10Mg aluminum alloy structural parts, as shown in Figure 4, the welding forming method comprises the following steps:

Step 1. Perform annealing heat treatment on the AlSi10Mg aluminum alloy structural parts to be welded by laser selective melting before welding; wherein, the annealing temperature is 280°C and the annealing time is 2.0h to remove thermal stress;

In the above step 1, after the annealing heat treatment, the laser selective melting and forming AlSi10Mg aluminum alloy structural parts to be welded are cleaned before welding. The cleaning process before welding includes: pickling to remove the surface oxide film, and then grinding the area to be welded until the body is exposed Metal color, ensure that there are no sharp corners and burrs, and then use absolute ethanol to clean the welded joints of AlSi10Mg aluminum alloy structural parts that are melted and formed by laser selection.

Step 2. Assemble the joint to be welded in the form of butt joint, as shown in Figure 2 and Figure 3, the butt joint method is direct butt joint or bottom lock butt joint; when the butt joint of the welded joint adopts lock bottom butt joint, the width of the lock bottom is 4mm . The thickness δ of the joint to be welded is 3 mm, the assembly gap is 0.09 mm, and the assembly step difference is 0.14 δ.

Step 3, perform tack welding on the joint to be welded, and the welding length of the tack weld is 280mm;

In the above step 3, when the positioning welding of the joint to be welded is performed, the welding method adopts laser swing welding; The seam maintains the welding speed as Vx, and in the direction perpendicular to the joint to be welded, with the weld seam as the center of symmetry, the welding proceeds in a spiral manner with a "∞"-shaped trajectory.

In the above step 3, the welding process parameters during tack welding are: the swing amplitude of the laser light source is 2.2 mm, and the "∞" shape trajectory with the swing frequency of 320 Hz is used for spiral forward welding, the incident angle of the laser beam is 83°, and the laser power It is 4500W, the welding speed is 1600mm/min, the spot diameter is 0.25mm, and the defocus is +5mm.

During positioning welding, the "∞"-shaped trajectory with a swing amplitude of 2.2mm and a swing frequency of 320Hz is used for welding, so as to suppress the generation of internal pores in the welded joint and avoid the occurrence of excessive pores in the welded joint. At the same time, the incident angle of the laser beam is 83°, the laser power is 4500W, the welding speed is 1600mm/min, the welding process parameters are 0.25mm in spot diameter and +5mm in defocus, so as to ensure good internal quality and surface forming. Quality, to avoid poor fusion or serious reverse penetration caused by too small or too large heat input, which will affect the forming quality of welded joints.

It should be noted that during tack welding, high-purity argon gas with a purity greater than or equal to 99.99% is used for gas protection.

Step 4. After tack welding, formally weld the joint to be welded;

In the above step 4, the welding method and welding process parameters of the formal welding are the same as those of the positioning welding; specifically: when the formal welding of the joint to be welded is performed, the welding method adopts laser swing welding; as shown in Figure 1, during laser swing welding, The walking track of the laser light source is "∞" shaped swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded. welding.

In the above step 4, the welding process parameters for formal welding are: the swing amplitude of the laser light source is 2.2 mm, and the "∞" shape trajectory with a swing frequency of 320 Hz is used for spiral forward welding, the incident angle of the laser beam is 83°, and the laser power It is 4500W, the welding speed is 1600mm/min, the spot diameter is 0.25mm, and the defocus is +5mm.

During formal welding, the "∞"-shaped trajectory with a swing amplitude of 2.2mm and a swing frequency of 320Hz is used for welding, so as to suppress the generation of internal pores in the welded joint and avoid the occurrence of excessive pores in the welded joint. At the same time, the incident angle of the laser beam is 83°, the laser power is 4500W, the welding speed is 1600mm/min, the welding process parameters are 0.25mm in spot diameter and +5mm in defocus, so as to ensure good internal quality and surface forming. Quality, to avoid poor fusion or serious reverse penetration caused by too small or too large heat input, which will affect the forming quality of welded joints.

It should be noted that during formal welding, high-purity argon with a purity greater than or equal to 99.99% is used for gas protection.

The welded joints are in good shape without undercuts, cracks, lack of fusion and other defects. The internal quality of the X-ray inspection welds meets the requirements for grade 1 joints specified in the QJ20660 standard.

Example 3

The present invention provides a welding forming method for laser selective melting forming AlSi10Mg aluminum alloy structural parts, as shown in Figure 4, the forming method comprises the following steps:

Step 1. Perform annealing heat treatment on the AlSi10Mg aluminum alloy structural parts to be welded by laser selective melting before welding; wherein, the annealing temperature is 300°C and the annealing time is 2.5h to remove thermal stress;

In the above step 1, after the annealing heat treatment, the laser selective melting and forming AlSi10Mg aluminum alloy structural parts to be welded are cleaned before welding. The cleaning process before welding includes: pickling to remove the surface oxide film, and then grinding the area to be welded until the body is exposed Metal color, ensure that there are no sharp corners and burrs, and then use absolute ethanol to clean the welded joints of AlSi10Mg aluminum alloy structural parts that are melted and formed by laser selection.

Step 2. Assemble the joints to be welded in the form of docking, as shown in Figure 2 and Figure 3, the docking method is direct docking or bottom-locked docking;

In the above step 2, the thickness δ of the joint to be welded is 4mm; the purpose of controlling the thickness of the joint to be welded within the range of 4mm in the present invention is to avoid a large number of pores and ensure the welding quality at the welded joint.

It should be noted that, in the above step 2, when the butt joint method of the welded joint adopts the bottom-lock butt joint, the width of the bottom-lock is 5 mm. The welding depth of the joint to be welded is 5mm, the assembly gap is 0.07mm, and the assembly step difference is 0.10δ.

Step 3, perform tack welding on the joint to be welded, and the welding length of the tack weld is 300mm;

In the above step 3, when the positioning welding of the joint to be welded is performed, the welding method adopts laser swing welding; The seam maintains the welding speed as Vx, and in the direction perpendicular to the joint to be welded, with the weld seam as the center of symmetry, the welding proceeds in a spiral manner with a "∞"-shaped trajectory.

In the above step 3, the welding process parameters during tack welding are: the swing amplitude of the laser light source is 2 mm, and the "∞" shape trajectory with the swing frequency of 350 Hz is used for spiral forward welding, the incident angle of the laser beam is 85°, and the laser power is 5500W, the welding speed is 1800mm/min, the spot diameter is 0.3mm, and the defocus is +5mm.

During positioning welding, the "∞"-shaped trajectory with a swing amplitude of 2 mm and a swing frequency of 350 Hz is used for welding, so as to suppress the generation of internal pores in the welded joint and avoid the occurrence of excessive pores in the welded joint. At the same time, the incident angle of the laser beam is 80°-85°, the laser power is 5500W, the welding speed is 1800mm/min, the welding process parameters are 0.3mm in spot diameter and +5mm in defocus, so as to ensure that a good forming interior can be obtained Quality and surface quality, to avoid poor fusion or severe reverse penetration caused by too small or too large heat input, which will affect the forming quality of welded joints.

It should be noted that during tack welding, high-purity argon gas with a purity greater than or equal to 99.99% is used for gas protection.

Step 4. After tack welding, formally weld the joint to be welded;

In the above step 4, the welding method and welding process parameters of the formal welding are the same as those of the positioning welding; specifically: when the formal welding of the joint to be welded is performed, the welding method adopts laser swing welding; as shown in Figure 1, during laser swing welding, The walking track of the laser light source is "∞" shaped swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded. welding.

In the above step 4, the welding process parameters during formal welding are: the swing amplitude of the laser light source is 2 mm, and the "∞" shape trajectory with the swing frequency of 350 Hz is used for spiral forward welding, the incident angle of the laser beam is 85°, and the laser power is 5500W, the welding speed is 1800mm/min, the spot diameter is 0.3mm, and the defocus is +5mm.

When formally welding, the "∞"-shaped track with a swing amplitude of 2mm and a swing frequency of 350Hz is used for welding, so as to suppress the generation of internal pores in the welded joint and avoid the occurrence of excessive pores in the welded joint. At the same time, the incident angle of the laser beam is 80°-85°, the laser power is 5500W, the welding speed is 1800mm/min, the welding process parameters are 0.3mm in spot diameter and +5mm in defocus, so as to ensure that a good forming interior can be obtained Quality and surface quality, to avoid poor fusion or severe reverse penetration caused by too small or too large heat input, which will affect the forming quality of welded joints.

It should be noted that during formal welding, high-purity argon with a purity greater than or equal to 99.99% is used for gas protection.

The laser selective melting forming AlSi10Mg aluminum alloy weldment obtained in embodiment 1, embodiment 2 and embodiment 3 is directly made tensile sample 1, and then according to the method of embodiment 1, embodiment 2 and embodiment 3, prepares respectively again Three parts of AlSi10Mg aluminum alloy structural parts were formed by selective laser melting, and then annealed and heat treated, and then tensile specimen 2 was made. The tensile strength test results are shown in Table 1:

Table 1 Tensile strength data of AlSi10Mg aluminum alloy structural parts formed by selective laser melting

The results show that by adopting the welding method provided by the invention, the mechanical properties of the welded joint can reach more than 85% of that of the base metal, and the annealing heat treatment is not required for welding.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention.

Claims (10)

1. A welding forming method of laser selective melting forming AlSi10Mg aluminum alloy structural parts, is characterized in that, comprises the following steps: Step 1. Perform annealing heat treatment on the AlSi10Mg aluminum alloy structural parts to be welded by laser selective melting before welding; the annealing temperature is 270°C-300°C, and the annealing time is 1.5h-2.5h; Step 2. Assemble the joint to be welded in the form of butt joint; The thickness δ of the joint to be welded is 2mm~4mm; when the joint to be welded is docked with a bottom lock, the width of the bottom lock is 3mm-5mm; the assembly gap is ≤0.1mm, and the assembly step difference is ≤0.15δ; Step 3, perform positioning welding on the joint to be welded; When performing positioning welding on the joint to be welded, the welding method adopts laser swing welding; during laser swing welding, the laser light source travels in a "∞" shape swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded. In the direction of the weld seam as the center of symmetry, the welding is carried out in a "∞"-shaped trajectory in a spiral manner; The welding process parameters during tack welding are: the swing range of the laser light source is 2mm-3mm, the swing frequency is 300Hz-350Hz; the incident angle of the laser beam is 80°-85°, the laser power is 3000W-5500W, and the welding speed is 1500-1800mm /min, the spot diameter is 0.2~0.3mm, and the defocus amount is +5mm; Step 4. After tack welding, formally weld the joint to be welded; When the joint to be welded is formally welded, the welding method adopts laser swing welding; during laser swing welding, the laser light source travels in the shape of "∞" swing, and the welding speed is kept at Vx along the weld seam of the joint to be welded, and in the vertical direction of the joint to be welded In the direction of the weld seam as the center of symmetry, the welding is carried out in a "∞"-shaped trajectory in a spiral manner; For formal welding, the swing amplitude is 2mm-3mm, the swing frequency is 300Hz-350Hz, the incident angle of the laser beam is 80°-85°, the laser power is 3000W-5500W, the welding speed is 1500-1800mm/min, and the spot diameter is 0.2 ~0.3mm and +5mm defocus. 2. The welding forming method of laser selective melting forming AlSi10Mg aluminum alloy structural parts according to claim 1, characterized in that, in the step 1, after annealing heat treatment, the laser selective melting forming AlSi10Mg aluminum alloy structure to be welded Parts are cleaned before welding. 3. The welding forming method of laser selective melting forming AlSi10Mg aluminum alloy structural parts according to claim 2, characterized in that, in the step 1, the cleaning process before welding comprises: pickling to remove the surface oxide film, and then Grind the area to be welded until the metal color of the body is exposed. 4. The welding forming method of laser selective melting and forming AlSi10Mg aluminum alloy structural parts according to claim 3, characterized in that, in the step 1, the cleaning process before welding further comprises: after pickling, anhydrous Ethanol scrubs clean the welded joints of AlSi10Mg aluminum alloy structural parts formed by laser selective melting. 5. The welding forming method of laser selective melting forming AlSi10Mg aluminum alloy structural parts according to claim 1, characterized in that, in the step 3, during tack welding, high-purity argon with a purity greater than or equal to 99.99% is used Gas for gas protection. 6. The welding forming method of laser selective melting forming AlSi10Mg aluminum alloy structural parts according to claim 1, characterized in that, in the step 4, when formally welding, high-purity argon with a purity greater than or equal to 99.99% is used Gas for gas protection. 7 . The welding forming method of laser selective melting forming AlSi10Mg aluminum alloy structural parts according to claim 1 , characterized in that, in the step 3, the welding length of the tack welding is 250mm-300mm. 8. The method for welding and forming AlSi10Mg aluminum alloy structural parts by selective laser melting according to claim 1, characterized in that, in the step 4, after formal welding, the internal quality of the weld is detected by X-rays. 9. The method for welding and forming AlSi10Mg aluminum alloy structural parts by laser selective melting according to claim 1, characterized in that, in the step 2, the butt joint method is bottom-lock butt joint or direct butt joint. 10. The method for welding and forming AlSi10Mg aluminum alloy structural parts by laser selective melting according to any one of claims 1 to 9, characterized in that, in the steps 3 and 4, fiber lasers are used for welding.

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