CN117817076A - Sharp angle and longitudinal coupling magnetic field generating device, additive manufacturing system and working method thereof - Google Patents

Abstract

The invention belongs to the field of additive manufacturing, and discloses a sharp angle and longitudinal coupling magnetic field generating device which comprises a bearing bracket and a sleeve; the sleeve is sleeved outside the tail end of the welding gun, and an excitation coil is wound on the lower part of the sleeve to form a longitudinal magnetic field; the bearing bracket is connected with the sleeve; four core columns are fixedly connected to the inner wall of the bearing bracket; each core column is wound with an excitation coil to form a sharp-angle magnetic field; and an excitation device cooling channel which is communicated with the inside of the bearing bracket and the core column is prefabricated, and the excitation device cooling channel is connected with a cooling circulation system. The additive manufacturing system comprises the sharp angle and the longitudinal coupling magnetic field generating device, and solves the problem that the heat input is increased in the additive manufacturing process due to the additional magnetic field while utilizing the sharp angle and the longitudinal coupling magnetic field to compress an electric arc, stir a molten pool and refine grains.

Description

Sharp angle and longitudinal coupling magnetic field generating device, additive manufacturing system and working method thereof

Technical Field

The invention belongs to the technical field of fuse wire/powder feeding type additive manufacturing (3D printing) of metal structural members, and particularly relates to a sharp-angle magnetic field generating device, an additive manufacturing system and a working method thereof.

Background

The additive manufacturing (additive manufacturing, AM) technology is a technology for manufacturing solid parts by CAD design data models and adopting a material layer-by-layer accumulation method, and the additive manufacturing process can rapidly and accurately manufacture parts with complex shapes by utilizing three-dimensional data without traditional cutters and clamps, so that the processing procedure is simplified, and the manufacturing period of parts is shortened. With the rapid development of additive manufacturing technology, metal additive manufacturing can realize direct manufacturing of highly complex metal components which are difficult to realize by traditional manufacturing methods. The metal additive manufacturing mainly uses electric arc, laser, electron beam and the like as heat sources, and the metal structural member is manufactured by accumulating the molten metal layer by melting the metal at high temperature into a liquid state.

At present, when the aluminum alloy is manufactured by the additive material by the traditional CMT welding technology, defects such as coarse crystal structure, hot cracks, air holes and the like easily occur, so that the forming precision of a formed part is lower, and the mechanical property is poorer.

The magnetic control arc welding technology is based on the basic principle of electromagnetic induction, utilizes an external magnetic field to control each step of the welding process, and because of the action of electromagnetic force, the liquid metal in a molten pool can generate forced convection phenomenon, agitate the molten pool and refine grains; the motion trail of charged particles in the electric arc is changed under the action of a magnetic field, so that the energy distribution condition of the electric arc is influenced, the interface temperature gradient is reduced, and the interface microstructure is improved. By varying the shape of the arc, the associated droplet transfer and liquid metal conversion process is controlled, thereby further optimizing the associated weld formation. The technology is introduced into the arc fuse additive manufacturing process, and the arc fuse forming process is optimized, so that the purpose of reinforcing the mechanical property of the metal printing part is achieved.

However, the magnetic field is introduced to assist, the heat input is increased along with the compression of the electric arc, the heat accumulation is increased along with the continuous rising of the deposition layer number, the molten pool is easy to flow down, the welding process becomes unstable, splashing is easy to generate, and the forming appearance and quality are greatly influenced.

Disclosure of Invention

The invention aims to provide a sharp angle and longitudinal coupling magnetic field generating device, an additive manufacturing system and a working method thereof, which solve the problem that the heat input is increased in the additive manufacturing process by using an external magnetic field while utilizing the sharp angle and the longitudinal coupling magnetic field to compress an electric arc, stir a molten pool and refine grains.

The invention is realized by the following technical scheme:

a sharp angle and longitudinal coupling magnetic field generating device comprises a bearing bracket and a sleeve; the bearing bracket is connected with the sleeve, and the welding gun is positioned at the center of the bearing bracket;

the sleeve is sleeved outside the tail end of the welding gun, and an excitation coil is wound on the lower part of the sleeve;

four core columns are fixedly connected to the inner wall of the bearing bracket, and gaps exist between the free ends of the four core columns and the welding gun;

each core column is wound with an excitation coil, and the spiral winding directions of the adjacent excitation coils on the core columns are respectively clockwise and anticlockwise, so that a sharp-angle magnetic field is formed;

and an excitation device cooling channel which is communicated with the inside of the bearing bracket and the core column is prefabricated, and a water inlet and a water outlet are arranged at two ends of the excitation device cooling channel and are connected with a cooling circulation system.

Further, a heat insulating baffle is connected to the free end of the stem and the bottom of the sleeve.

Further, a plurality of heat dissipation holes are prefabricated on the sleeve.

Further, the sleeve is fixedly connected with the bearing bracket through a plurality of reinforcing ribs.

Further, the sleeve is connected with the welding gun through a screw, and a baffle disc is arranged at the joint of the screw.

Further, the cooling channels penetrating through the core column are U-shaped channels.

Further, the core column and the bearing support are cast, and the cooling pipeline is determined by a hollow pipeline casting mould when the core column and the bearing support are cast;

the materials of the core column and the sleeve are pure iron, silicon steel or permalloy.

Further, two symmetrical cold constraint devices are detachably connected to the bearing bracket and used for cooling the deposited workpiece;

the cooling device comprises a cold constraint device I-shaped connecting plate, a position regulator and a cooling block, wherein the upper section of the I-shaped connecting plate is connected with a bearing bracket, the lower section of the I-shaped connecting plate is connected with the position regulator, the position regulator is connected with the cooling block, a cooling block cooling pipeline is arranged in the cooling block, and two ends of the cooling block cooling pipeline are provided with a water inlet and a water outlet which are respectively connected with a cooling circulation system;

and the position regulator is used for regulating the distance between the two cooling blocks and two sides of the deposition state workpiece.

The invention also discloses an additive manufacturing system, which comprises a workbench, a substrate, a laser source, a magnetic field control system, a camera, an upper computer and a sharp angle and longitudinal coupling magnetic field generating device;

the magnetic field control system comprises a direct current excitation power supply, an alternating current excitation power supply and a sliding rheostat, wherein four excitation coils on a core column are connected through wires and then connected with the alternating current excitation power supply in series through the wires and the sliding rheostat; the exciting coil on the sleeve is connected with a direct-current exciting power supply in series through a lead and a sliding rheostat;

the substrate is placed on the workbench, and the camera is arranged on one side of the substrate and is used for aligning the deposition piece;

the camera is connected with the upper computer; the sharp angle and longitudinal coupling magnetic field generating device is arranged on the welding gun head;

the emission direction of the laser source is toward the deposition member.

The invention also discloses a working method of the additive manufacturing system, which comprises the following steps:

when the welding gun head prints, a cooling circulation system, a direct-current excitation power supply, an alternating-current excitation power supply and a laser source are started, and the arc morphology, the molten drop transition and the molten pool flow are observed at the upper computer end in real time through a camera;

the cooling circulation system continuously supplies a cooling medium to a cooling channel of the excitation device to cool the excitation coil, so that the influence of temperature on the magnetic field intensity and stability is reduced;

adjusting an alternating current excitation power supply to form a sharp angle magnetic field;

the direct-current excitation power supply is regulated, a longitudinal magnetic field is introduced, the longitudinal magnetic field is coupled with a sharp-angle magnetic field, the spatial distribution and strength of the magnetic field are changed, the Lorentz force and the action frequency of arc plasma and metal molten drops are further changed, the arc morphology, the molten drop transition state and the molten pool state are affected, grains are refined, and the forming quality is improved.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention discloses a sharp angle and longitudinal coupling magnetic field generating device, which comprises a bearing bracket and a sleeve, wherein four core columns are arranged in the bearing bracket, exciting coils are wound on each core column, the spiral winding directions of the adjacent exciting coils on the core columns are respectively clockwise and anticlockwise, so that the internal current directions of the adjacent exciting coils are opposite after current is introduced, and the polarities of the adjacent four magnetic poles are N-S-N-S, so that a sharp angle magnetic field is formed; the sharp-angle magnetic field can change the shape of an electric arc in the welding process, so that the cross section shape of the electric arc is compressed from a round shape to an oval shape, electromagnetic stirring is generated to accelerate the flow of a molten pool, and grains are thinned; meanwhile, the sharp-angle magnetic field generated by the exciting coil can control the periodical rotation motion of a welding arc, welding wire melting, formation and separation of molten drops at the tail end of the welding wire, the motion state of a liquid flow beam and the like, so that a periodical and stable rotary jet flow transition state of the molten drops is formed, the scale patterns on the surface of the deposition state are more uniform, fine and attractive, and the forming quality and efficiency are improved. In addition, alternating sharp-angle magnetic fields with different frequencies reduce bottom arc pressure and side wall arc pressure along with the increase of magnetic flux density, and the magnetic arcs enable the arc pressure distribution to be more uniform and inhibit arc expansion;

in addition, the existing single sharp-angle magnetic field can play a role in obviously compressing the electric arc only by the large change of the magnetic field intensity, and has no obvious influence on an arc column region of the electric arc; the lower part of the sleeve is wound with an excitation coil, after a direct-current longitudinal magnetic field is introduced, the strength of the longitudinal magnetic field is changed under the coupling action, the compression effect of the electric arc is greatly improved, the shape of an arc column region of the electric arc is obviously changed, the electric arc is controlled more accurately, the energy loss of the electric arc is reduced, the heat is concentrated, and the splashing is reduced.

The cooling channels are arranged in the core column and the bearing support, so that the problem that an existing magnetic control arc magnetic field generating device generates heat and scalds during working is solved, the resistance of an exciting coil is reduced at high temperature caused by electric arc, and a stable magnetic field is provided.

Further, the heat insulation baffle plates are arranged at the end parts of the four core columns and the bottom of the sleeve, so that the excitation coil is prevented from being damaged due to heat generated during the working of the magnetic control arc magnetic field generating device.

Furthermore, the sleeve on the welding gun is provided with a heat dissipation hole, and when in welding, the temperature of the welding pool is extremely high, and the temperature of the tail part of the welding gun is low, so that self-circulation airflow can be generated, and the purpose of heat dissipation is achieved.

Further, the magnetic field generating device is detachably provided with a cold constraint device, and the cooling block is used for cooling the deposited workpiece, so that heat input is reduced.

Furthermore, the core column and the bearing bracket are cast into a whole in a casting mode, so that the cost is low, the economic benefit is good, the size can be automatically changed according to actual needs, and the freedom is high.

Furthermore, the invention is provided with a plurality of reinforcing ribs for connecting the sleeve and the bearing bracket, thereby improving the rigidity and strength of the device.

Drawings

FIG. 1 is a functional block diagram of an additive manufacturing system including a cusp and longitudinally coupled magnetic field generating device according to the present invention;

FIG. 2 is a schematic structural diagram of a device for generating a magnetic field by coupling sharp corners and longitudinally according to embodiment 1 of the present invention;

FIG. 3 is a schematic structural diagram of a device for generating a magnetic field by coupling sharp corners and longitudinally according to embodiment 2 of the present invention;

FIG. 4 is a cross-sectional view of the cusp-to-longitudinal coupling magnetic field generator of FIG. 2;

FIG. 5 is an isometric view of an integrated stem and carrier structure according to the present invention;

FIG. 6 is a cross-sectional view of a cooling channel structure disposed within a stem and a carrier;

FIG. 7 is a schematic diagram of a magnetic field generating device and a cold confinement device;

fig. 8 is a top view of a magnetic field formed in accordance with the present invention.

1, a welding gun; 2. a sleeve; 3. reinforcing ribs; 4. a load bearing bracket; 5. a thermally insulating barrier; 6. a bolt; 7. a position adjuster; 8-1, cooling a cooling block cooling pipeline; 8-2, an excitation device cooling channel; 9. a cooling block; 10. a stem; 11. an exciting coil; 12. an I-shaped connecting plate; 13. a heat radiation hole; 14. a set screw; 15. a baffle disc.

Detailed Description

The objects, technical solutions and advantages of the present invention will be more apparent from the following detailed description with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention, i.e., the embodiments described are merely some, but not all, of the embodiments of the invention.

The components illustrated in the figures and described and shown in the embodiments of the invention may be arranged and designed in a wide variety of different configurations, and thus the detailed description of the embodiments of the invention provided in the figures below is not intended to limit the scope of the invention as claimed, but is merely representative of selected ones of the embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present invention, based on the figures and embodiments of the present invention.

It should be noted that: the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, element, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, element, method, article, or apparatus.

The features and properties of the present invention are described in further detail below with reference to examples.

As shown in fig. 1, the invention discloses an additive manufacturing system, which comprises a workbench, a substrate, a laser source, a magnetic field control system, a camera, an upper computer and a sharp angle and longitudinal coupling magnetic field generating device;

the magnetic field control system comprises a direct current excitation power supply, an alternating current excitation power supply and a sliding rheostat, wherein four excitation coils 11 on a core column 10 are connected through wires and then are connected with the alternating current excitation power supply in series through the wires and the sliding rheostat; the exciting coil 11 on the sleeve 2 is connected with a direct-current exciting power supply in series through a lead and a sliding rheostat;

the substrate is placed on the workbench, and the camera is arranged on one side of the substrate and is used for aligning the deposition piece;

the camera is connected with the upper computer; the magnetic field generating device is arranged on the welding gun head;

the emission direction of the laser source is toward the deposition member.

Example 1

Referring to fig. 2, the invention discloses a sharp angle and longitudinal coupling magnetic field generating device, which comprises a bearing bracket 4 and a sleeve 2; the sleeve 2 is sleeved outside the tail end of the welding gun 1, and an excitation coil 11 is wound on the lower part of the sleeve 2; the bearing bracket 4 is connected with the sleeve 2, and the welding gun 1 is positioned at the center of the bearing bracket 4; four core columns 10 are fixedly connected to the inner wall of the bearing bracket 4, and gaps exist between the free ends of the four core columns 10 and the welding gun 1; an exciting coil 11 is wound around each of the core legs 10; the spiral winding directions of the adjacent exciting coils 11 on the core column 10 are respectively clockwise and anticlockwise, so that the internal current directions of the adjacent exciting coils 11 are opposite after current is introduced, and the polarities of the adjacent four magnetic poles are N-S-N-S; the inside of the bearing bracket 4 and the core column 10 is prefabricated with an excitation device cooling channel 8-2 which is communicated with the inside of the bearing bracket and the core column into a whole, and two ends of the excitation device cooling channel 8-2 are provided with a water inlet and a water outlet which are connected with a cooling circulation system.

As shown in fig. 4-6, the exciting coil 11 is wound on four core columns 10 and the sleeve 2 respectively, the core columns 10 and the bearing bracket 4 are cast into a whole and welded with the sleeve 2 through the reinforcing ribs 3, and the water cooling channel 8-2 of the exciting device is determined by a hollow pipeline casting mould during casting and is connected with the cooling circulation system; the sleeve 2 is fixed on the welding gun 1, four exciting coils 11 on the core column are connected together through wires, and then are connected in series with an alternating current exciting power supply through wires and a sliding rheostat; the exciting coil on the sleeve is connected with a direct-current exciting power supply in series through a lead and a sliding rheostat.

More preferably, as shown in fig. 4, the end of the stem 10, which is close to the welding gun 1, is fixedly provided with a heat insulation baffle plate 5, so that the damage to the stem 10 and the exciting coil 11 caused by heat generated during the operation of the magnetic control arc magnetic field generating device is avoided.

Specifically, as shown in fig. 4, the sleeve 2 is fixed on the welding gun 1 through a set screw 14, and a baffle 15 is further arranged in the screw hole to prevent the set screw 14 from damaging the outer surface of the welding gun 1 during tightening.

The ac power source is frequency-converted to thereby produce cusped magnetic fields of different frequencies. The sharp-angle magnetic field can change the shape of an electric arc in the welding process, so that the cross section shape of the electric arc is compressed from a round shape to an oval shape, and electromagnetic stirring is generated to accelerate the flow of a molten pool, so that grains are refined; meanwhile, the sharp-angle magnetic field generated by the exciting coil 11 can control the periodical rotation motion of a welding arc, welding wire melting, formation and separation of molten drops at the tail end of the welding wire, the motion state of a liquid flow beam and the like, so that a periodical and stable rotary jet transition state of the molten drops is formed, scale patterns on the surface of a deposition state are more uniform, fine and attractive, and the forming quality and efficiency are improved. In addition, alternating sharp-angle magnetic fields with different frequencies reduce bottom arc pressure and side wall arc pressure along with the increase of magnetic flux density, and the magnetic arcs enable the arc pressure distribution to be more uniform and inhibit arc expansion. The longitudinal magnetic field is generated by a direct current excitation power supply to form a stable coupling magnetic field, under the coupling effect, the strength of the longitudinal magnetic field is changed, the compression effect of the electric arc is greatly improved, the shape of an arc column region of the electric arc is obviously changed, the electric arc is controlled more accurately, the energy loss of the electric arc is reduced, the heat is concentrated, and the splashing is reduced.

Example 2

On the basis of embodiment 1, as shown in fig. 3 and 7, cold restraint devices are also symmetrically and detachably connected to the carrying bracket 4.

The cold constraint device specifically comprises an I-shaped connecting plate 12, wherein the upper section of the I-shaped connecting plate 12 is connected with a bearing bracket 4 through a bolt 6, the lower section of the I-shaped connecting plate is connected with a position regulator 7 through the bolt 6, the position regulator 7 is connected with cooling blocks 9, the cooling blocks 9 are connected with a cooling circulation system through cooling block cooling pipelines 8-1, and the distance between the two cooling blocks 9 and two sides of a deposition state workpiece is regulated through the position regulator 7.

Specifically, the position regulator 7 includes a round bar and a spring wound around the round bar.

As shown in fig. 1, a CMT welding robot is connected to the welding torch 1, a welding power supply is connected to the CMT welding robot, and a negative electrode of the welding power supply is connected to the substrate.

The exciting coil 11 is made of copper enameled wires with the diameter of 1mm, the number of turns is 450, when the exciting coil 11 is wound, the turns are guaranteed to be closely connected one by one, the turns are uniformly wound in the radial direction and the axial direction, the spiral winding directions of the adjacent exciting coils 11 on the four core columns 10 are respectively clockwise and anticlockwise, the directions of currents inside the adjacent exciting coils 11 after the currents are introduced are guaranteed to be opposite, and the polarities of four magnetic poles close to the welding gun 1 are N-S-N-S, as shown in fig. 8.

The bearing bracket 4 is a round bearing bracket 4, which is not limited to a round shape, but can be square or other shapes, and the core column 10 can be an iron core, permalloy or silicon steel;

the material of the heat insulating baffle 5 can be selected from nonmagnetic stainless steel, aluminum alloy, glass fiber reinforced plastic and the like according to different sample properties.

The sleeve 2 is made of iron core, permalloy or silicon steel.

The number and the size of the heat dissipation holes 13 can be changed according to the heat input of different welding gun 1 modes.

The material of the reinforcing ribs 3 can be aluminum alloy, steel, etc.

The exciting device cooling channel 8-2 is determined by a hollow pipeline casting mould when the core column 10 and the bearing bracket 4 are cast.

The cooling block 9 is a thin-wall metal block, the material can be aluminum alloy or magnesium alloy, and the cooling block 9 is hollow and filled with cooling liquid.

As shown in fig. 1, the invention discloses a working method of an additive manufacturing system, which comprises the following steps:

s1, respectively connecting a welding gun 1 and a workbench with the anode and the cathode of a welding power supply, and placing and fixing a substrate on the workbench. And setting additive process parameters including wire feeding speed, welding mode, protective air flow and the like. The dry elongation of the welding wire is between 12 and 20 mm.

S2, installing a sharp angle and longitudinal coupling magnetic field generating device on the head of the welding gun 1, adjusting the position of the sharp angle and longitudinal coupling magnetic field generating device so that the bottom of the sharp angle and the end point of the welding wire are positioned on the same horizontal plane, connecting an exciting coil 11 on a core column 10 with an alternating current exciting power supply through a wire, and connecting the exciting coil 11 on a sleeve 2 with the direct current exciting power supply to form a closed loop. And then the cooling channel is connected with the cooling circulation system through a hose.

S3, when the welding gun head prints, a cooling circulation system, an excitation power supply and a laser source are started, and the arc morphology, the molten drop transition and the molten pool flow are observed at the upper computer end in real time through a high-speed camera; the cooling system continuously radiates heat and cools the excitation device, so that the influence of temperature on the magnetic field intensity and the stability is reduced; the cooling block 9 simultaneously cools the deposited layer workpiece.

S4, adjusting a knob on the alternating current excitation power supply, and changing excitation current and excitation frequency to form a sharp-angle magnetic field; the knob on the direct current excitation power supply is adjusted, the longitudinal magnetic field is introduced to be coupled with the sharp-angle magnetic field, the spatial distribution and intensity of the magnetic field are changed, the Lorentz force and the action frequency of arc plasma and metal molten drops are further changed, the arc morphology, the molten drop transition state and the molten pool state are affected, and the effects of refining grains and improving forming quality are achieved.

Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.

Claims (10)

1. The sharp angle and longitudinal coupling magnetic field generating device is characterized by comprising a bearing bracket (4) and a sleeve (2); the bearing bracket (4) is connected with the sleeve (2), and the welding gun (1) is positioned at the center of the bearing bracket (4);

the sleeve (2) is sleeved outside the tail end of the welding gun (1), and an excitation coil (11) is wound on the lower part of the sleeve (2);

four core columns (10) are fixedly connected to the inner wall of the bearing bracket (4), and gaps exist between the free ends of the four core columns (10) and the welding gun (1);

each core column (10) is wound with an excitation coil (11), and the spiral winding directions of the adjacent excitation coils (11) on the core columns (10) are respectively clockwise and anticlockwise to form a sharp-angle magnetic field;

an excitation device cooling channel (8-2) which is communicated with the inside of the bearing bracket (4) and the core column (10) is prefabricated, two ends of the excitation device cooling channel (8-2) are provided with a water inlet and a water outlet, and the water inlet and the water outlet are connected with a cooling circulation system.

2. A cusp and longitudinal coupling magnetic field generating device according to claim 1, wherein a thermally insulating barrier (5) is attached to the free end of the stem (10) and to the bottom of the sleeve (2).

3. A cusp and longitudinal coupling magnetic field generating device according to claim 1, wherein a plurality of heat dissipating holes (13) are preformed in the sleeve (2).

4. A cusp and longitudinal coupling magnetic field generator according to claim 1, wherein the sleeve (2) is fixedly connected to the support frame (4) by a plurality of reinforcing ribs (3).

5. A sharp angle and longitudinal coupling magnetic field generating device according to claim 1, characterized in that the sleeve (2) is connected with the welding gun (1) by a screw, and a baffle disc (15) is arranged at the screw connection.

6. A cusp and longitudinal coupling magnetic field generating device according to claim 1, wherein the cooling passage extending through the stem (10) is a U-shaped passage.

7. The sharp angle and longitudinal coupling magnetic field generating device according to claim 1, wherein the core column (10) and the bearing bracket (4) are cast, and the cooling pipeline is determined by a hollow pipeline casting mould when the core column (10) and the bearing bracket (4) are cast;

the materials of the core column (10) and the sleeve (2) are pure iron, silicon steel or permalloy.

8. The sharp angle and longitudinal coupling magnetic field generating device according to claim 1, wherein two symmetrical cold constraint devices are detachably connected to the bearing bracket (4) and used for cooling the deposited workpiece;

the cooling device comprises a cold constraint device I-shaped connecting plate (12), a position regulator (7) and cooling blocks (9), wherein the upper section of the I-shaped connecting plate (12) is connected with a bearing bracket (4), the lower section of the I-shaped connecting plate is connected with the position regulator (7), the position regulator (7) is connected with the cooling blocks (9), cooling block cooling pipelines (8-1) are arranged in the cooling blocks (9), and two ends of each cooling block cooling pipeline (8-1) are provided with a water inlet and a water outlet which are respectively connected with a cooling circulation system;

and the position regulator (7) is used for regulating the distance between the two cooling blocks (9) and the two sides of the deposited workpiece.

9. An additive manufacturing system, comprising a workbench, a substrate, a laser source, a magnetic field control system, a camera, an upper computer and the sharp angle and longitudinal coupling magnetic field generating device according to any one of claims 1-8;

the magnetic field control system comprises a direct current excitation power supply, an alternating current excitation power supply and a sliding rheostat, wherein four excitation coils (11) on a core column (10) are connected through wires and then are connected with the alternating current excitation power supply in series through the wires and the sliding rheostat; an exciting coil (11) on the sleeve (2) is connected with a direct-current exciting power supply in series through a lead and a sliding rheostat;

the substrate is placed on the workbench, and the camera is arranged on one side of the substrate and is used for aligning the deposition piece;

the camera is connected with the upper computer; the sharp angle and longitudinal coupling magnetic field generating device is arranged on the head of the welding gun (1);

the emission direction of the laser source is toward the deposition member.

10. A method of operating an additive manufacturing system of claim 9, comprising the process of:

when the welding gun (1) head prints, a cooling circulation system, a direct-current excitation power supply, an alternating-current excitation power supply and a laser source are started, and the arc morphology, molten drop transition and molten pool flow are observed at the upper computer end in real time through a camera;

the cooling circulation system continuously supplies a cooling medium to the cooling channel (8-2) of the excitation device, so as to radiate and cool the excitation coil (11) and reduce the influence of temperature on the intensity and stability of the magnetic field;

adjusting an alternating current excitation power supply to form a sharp angle magnetic field;

the direct-current excitation power supply is regulated, a longitudinal magnetic field is introduced, the longitudinal magnetic field is coupled with a sharp-angle magnetic field, the spatial distribution and strength of the magnetic field are changed, the Lorentz force and the action frequency of arc plasma and metal molten drops are further changed, the arc morphology, the molten drop transition state and the molten pool state are affected, grains are refined, and the forming quality is improved.