Multi-field auxiliary metal fuse additive melt directional transfer device and method

Abstract

The invention provides a multi-field auxiliary metal fuse additive melt directional transfer device and method. The device comprises a laser energy source system, a metal wire feeding system, a constant magnetic field system, an electric field system, a coaxial protective gas system, an ultrasonic generator, a multi-axis motion platform and a forming substrate. The forming base plate is fixedly installed above the multi-axis motion platform, and multi-degree-of-freedom motion of the forming base plate in space is achieved through the multi-axis motion platform. The laser energy source system is fixed above the forming substrate, so that laser emitted by the laser energy source system is irradiated to the upper surface of the forming substrate; the metal wire feeding system is fixed to the side face of the laser energy source system and conveys metal wires to the size range of laser spots. The constant magnetic field system, the electric field system and the ultrasonic generator are respectively fixed on the metal wire feeding system; the multi-axis motion platform comprises four degrees of freedom of X-axis motion, Y-axis motion, Z-axis motion and platform rotation. A specific field is applied to the end of the metal wire by distributing the installation position of the auxiliary field.

Description

Technical Field

[0001] The present invention relates to the field of laser additive manufacturing in a space microgravity environment, and in particular to a multi-field assisted metal fuse additive melt directional transfer device and method. Background Art

[0002] Space exploration and space resource development are the main areas of competition among countries. Therefore, it is urgent to develop technologies and equipment for metal additive manufacturing in a space microgravity environment, so as to provide in-situ manufacturing methods and means for parts for space projects such as space stations and space bases, and reduce the dependence of space exploration needs on ground supplies, which has important prospects and application value. -2 g~10 -5 g. The movement of matter is not constrained by gravity, and the flow behavior of the fluid is very different from that of the ground environment.

[0003] Laser metal fuse additive manufacturing under microgravity is one of the most effective ways of in-situ manufacturing in a space environment. During the manufacturing process, part of the laser energy is used to melt the metal wire, which absorbs the laser energy to form a liquid melt at the end; in addition, the laser energy acts on the forming substrate to form a liquid metal molten pool. Whether the melt at the end of the wire can enter the substrate molten pool is the key core issue that determines the metal fuse additive manufacturing technology in a space microgravity environment. However, the liquid melt formed at the end of the metal wire has no gravity constraints in the space environment, and the surface tension of the melt and the viscosity of the fluid become the main factors affecting the flow behavior of the melt. The metal melt is prone to balling and creeping back along the wire, and thus cannot enter the molten pool smoothly and in a directional manner; more seriously, the metal melt at the end of the wire creeps back along the wire, which will cause the wire feeding mechanism of the additive manufacturing equipment to be blocked, resulting in more serious consequences. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a multi-field assisted metal fuse additive melt directional transfer device and method, which applies auxiliary fields, such as electric fields, magnetic fields and ultrasonic vibrations, and allocates the installation positions of the auxiliary fields to achieve the application of a specific field at the end of the metal wire.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A multi-field assisted metal fuse additive melt directional transfer device comprises a laser energy source system, a metal wire feeding system, a constant magnetic field system, an electric field system, a coaxial protective gas system, an ultrasonic generator, a multi-axis motion platform and a forming substrate; the forming substrate is fixedly installed above the multi-axis motion platform, and the multi-axis motion platform is used to realize the multi-degree-of-freedom movement of the forming substrate in space; the laser energy source system is fixed above the forming substrate, so that the laser emitted by the laser energy source system irradiates the upper surface of the forming substrate; the metal wire feeding system is fixed on the side of the laser energy source system, and the metal wire is transported to the size range of the laser spot; the constant magnetic field system, the electric field system and the ultrasonic generator are respectively fixed on the metal wire feeding system; the multi-axis motion platform comprises four degrees of freedom of X, Y, Z axis movement and platform rotation.

[0007] Furthermore, the laser energy source system includes multiple laser beams, which are generated by multiple laser light sources or one laser beam through a spectroscope system; the spatial relationship between the laser irradiation position and the metal wire and the forming substrate is adjusted by a position adjustment mechanism.

[0008] Furthermore, the metal wire feeding system includes a metal wire, a metal wire angle adjustment bracket, an insulating sleeve, a wire coaxial air blowing pipe and a wire feeder; the insulating sleeve and the wire coaxial air blowing pipe are coaxially arranged and installed on the metal wire angle adjustment bracket with the metal wire, the metal wire angle adjustment bracket is used to adjust the angle between the direction of the metal wire being fed into the molten pool and the horizontal direction, and ensure that the wire coaxial air blowing pipe is always coaxial with the metal wire; the wire feeder is fixed on the metal wire angle adjustment bracket and is located at the metal wire inlet end of the wire coaxial air blowing pipe, and the position of the wire feeder is synchronously adjusted while adjusting the angle between the direction of the metal wire being fed into the molten pool and the horizontal direction.

[0009] Furthermore, the constant magnetic field system includes a permanent magnet, a magnet holder and a magnetic field measuring instrument; the magnet holder is used to fix the permanent magnet and the wire coaxial blowing pipe; there are two permanent magnets, which are symmetrically arranged on both sides of the end of the metal wire to generate a constant magnetic field, and the direction of the magnetic field generated by the permanent magnet is perpendicular to the axial direction of the metal wire; the magnetic field measuring instrument is located between the permanent magnet and the metal wire, and is used to measure the magnetic field strength at the end of the metal wire where the melt is formed.

[0010] Furthermore, the electric field system includes a DC power supply and a current clamp; there are two current clamps, which are fixed on the metal wire and the forming substrate respectively, and a stable current is formed between the metal wire and the forming substrate by using the DC power supply.

[0011] Furthermore, the coaxial protective gas system includes a laser coaxial air blowing pipe, a transparent lens, protective gas, a first flow meter and a second flow meter; two paths of protective gas are designed, the first path is: the laser coaxial air blowing pipe is arranged directly below the first continuous laser source among multiple laser light sources, ensuring that the laser of the first continuous laser source can be vertically and coaxially irradiated onto the forming substrate through the transparent lens directly below; the second path is: the protective gas is ejected through the second flow meter and the wire coaxial air blowing pipe, and the protective gas of the second path is coaxially ejected with the metal wire; the protective gas is an inert gas, and the flow rate of the protective gas entering the laser coaxial air blowing pipe is accurately adjusted by the first flow meter, and the flow rate of the protective gas entering the wire coaxial air blowing pipe is accurately adjusted by the second flow meter.

[0012] Furthermore, there are n types of metal wires, where n is a positive integer greater than or equal to 1; the metal wires are evenly arranged within a 360-degree geometric range according to the number of types; the metal wires are installed on an angle adjustment mechanism, and the angle adjustment mechanism can be used to adjust the angle between the metal wires and the horizontal plane; the types of the metal wires are materials of the same type or different types, including stainless steel wires, aluminum alloy wires, titanium alloy wires, flux-cored welding wires, high / medium entropy alloys, amorphous alloy wires, and composite material wires.

[0013] Furthermore, an ultrasonic generator is installed at a certain distance away from the end of the metal wire, and the ultrasonic vibration stirs the end melt, thereby promoting the directional transfer of the end melt from the metal wire to the forming substrate.

[0014] The present invention also provides a multi-field assisted metal fuse additive melt directional transfer method, which is implemented using the multi-field assisted metal fuse additive melt directional transfer device described above, and includes the following steps:

[0015] Step S1, adjusting the relative positions of the first continuous laser source and the first pulsed laser source of the laser energy source system and the metal wire and the initial processing position of the forming substrate;

[0016] Step S2, slicing data according to the three-dimensional model to be constructed, and ensuring that the wire feeding direction of the metal wire is always parallel to the forming direction and kept at the front end of the forming direction through the rotational freedom of the multi-axis motion platform;

[0017] Step S3, sequentially starting the shielding gas, the first continuous laser source and the first pulsed laser source, the DC power supply and the wire feeder, after the first metal wire contacts the forming substrate, a current loop is generated between the first metal wire and the forming substrate, the current is used as a control signal, and additive processing is started according to the slice trajectory data of the three-dimensional model;

[0018] Step S4, after processing according to the slice trajectory data in the current forming layer, the wire feeder, the DC power supply, the laser source and the protective gas are turned off in sequence, and the forming substrate is moved to the initial position of the next trajectory by the multi-axis motion platform;

[0019] Step S5, repeating steps S1, S2, S3 and S4 until the entire three-dimensional component is processed.

[0020] Furthermore, the flow rate of the shielding gas is 0L / min~50L / min; the laser source is used to output pulsed laser or continuous laser, its maximum output power is 4000W, the pulse frequency is 10Hz~1000HZ, the laser pulse width is 2~50ms, and the scanning speed is 50mm / min~2000mm / min; the maximum output current of the DC power supply is 400A; the wire feeder is used to achieve metal wire feeding with a wire diameter of 0.1mm~10mm.

[0021] Beneficial effects:

[0022] 1. The present invention proposes to use a constant magnetic field and an electrostatic field to form a directional Lorentz force on the melt at the end of the metal wire, thereby promoting the directional transfer of the melt formed at the end of the metal wire to the molten pool.

[0023] 2. In the present invention, the constant magnetic field generates electromagnetic stirring on the metal molten pool, making the solidification structure of the material uniform and refined, thereby improving the performance of the formed part.

[0024] 3. The present invention proposes a solution of using multiple laser beams, and the molten pool generated by the multiple laser beams and the metal matrix reduces the temperature gradient of the molten pool, thereby reducing the surface tension and promoting the wetting and spreading of the molten metal.

[0025] 4. The present invention adopts ultrasonic vibration at the end of the metal wire, and utilizes ultrasonic vibration to increase the disturbance of the melt formed at the end of the metal wire, promotes the melt to separate from the end of the metal wire, and prevents the melt from crawling back along the wire.

[0026] 5. The present invention adopts a multi-layer inert gas protection jet, and utilizes the gas pressure formed by the jet acting on the melt at the metal end and the gas-liquid interface of the molten pool to promote the directional transport of the molten metal to the molten pool, avoiding the molten metal from creeping back along the wire under the condition of no gravity constraint, thereby stabilizing the molten pool and preventing the wire feeding mechanism from being blocked due to the creeping back of droplets. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the multi-field assisted metal fuse additive melt directional transfer device of the present invention;

[0028] Figure 2 It is a schematic diagram of the two laser distribution structures of a single metal wire;

[0029] Figure 3 It is a schematic diagram of the multi-continuous laser distribution structure of a single metal wire;

[0030] Figure 4 It is a top view schematic diagram of multiple laser distribution and positions of various metal wires;

[0031] Figure 5 It is the force analysis principle diagram of the present invention.

[0032] Among them, the reference numerals are: end melt 1, laser energy source system 111, metal wire feeding system 211, constant magnetic field system 311, electric field system 411, coaxial protective gas system 511, ultrasonic generator 6111, multi-axis motion platform 7111, forming substrate 7112, first continuous laser source 1111, second continuous laser source 1121, third continuous laser source 1131, fourth continuous laser source 1141, position adjustment mechanism 1113, metal wire angle adjustment bracket 2112, insulating sleeve 2113, wire coaxial blowing pipe 2114, wire feeding machine 21 15. permanent magnet 3111, magnet holder 3112, magnetic field measuring instrument 3113, magnetic field 3114, DC power supply 4111, current clamp 4112, laser coaxial air blowing tube 5111, light-transmitting lens 5112, protective gas 5113, first flow meter 5114, second flow meter 5115, first pulse laser source 1112, second pulse laser source 1122, third pulse laser source 1132, fourth pulse laser source 1142, first metal wire 2111, second metal wire 2121, third metal wire 2131, fourth metal wire 2141. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0034] like Figure 1As shown, the multi-field assisted metal fuse additive melt directional transfer device of the present invention includes a laser energy source system 111, a metal wire feeding system 211, a constant magnetic field system 311, an electric field system 411, a coaxial protective gas system 511, an ultrasonic generator 6111, a multi-axis motion platform 7111 and a forming substrate 7112. Among them, the forming substrate 7112 is fixedly installed above the multi-axis motion platform 7111, and the multi-axis motion platform 7111 can realize the movement of the forming substrate 7112 in multiple degrees of freedom in space; the laser energy source system 111 is fixed above the forming substrate 7112, so that the laser emitted by the laser energy source system 111 can irradiate the upper surface of the forming substrate 7112; the metal wire feeding system 211 is fixed on the side of the laser energy source system 111, and the metal wire can be transported to the size range of the laser spot; the constant magnetic field system 311, the electric field system 411 and the ultrasonic generator 6111 are respectively fixed on the metal wire feeding system 211, and the auxiliary field applied in the present invention includes electric field, magnetic field and ultrasonic vibration, and a specific field is applied to the end of the metal wire through the installation position of the auxiliary field.

[0035] The laser energy source system 111 includes a single or multiple laser beams, and the multiple laser beams can be generated by multiple laser sources or a laser beam through a spectroscope system. The multiple laser beams include various energy combination forms composed of continuous laser and pulsed laser.

[0036] Preferably, when the multiple laser beams are composed of continuous laser and pulsed laser, the laser energy source system 111 may include a first continuous laser 1111 and a first pulsed laser source 1112. The spatial relationship between the laser irradiation position and the first metal wire 2111 and the forming substrate 7112 may be adjusted by a position adjustment mechanism 1113. The first continuous laser source 1111 irradiates the forming substrate 7112 through the laser coaxial blowing pipe 5111 to form a stable molten pool on the forming substrate 7112. The laser of the first pulsed laser source 1112 irradiates the end of the first metal wire 2111. The first pulsed laser source 1112 has the following functions: (1) melting the end of the first metal wire 2111 to form an end melt 1; and (2) forming a recoil pressure on the surface of the end melt 1 to promote the transfer of the end melt 1 to the molten pool on the forming substrate 7112.

[0037] The metal wire feeding system 211 includes a first metal wire 2111, a metal wire angle adjustment bracket 2112, an insulating sleeve 2113, a wire coaxial air blowing pipe 2114 and a wire feeder 2115. The insulating sleeve 2113 and the wire coaxial air blowing pipe 2114 are coaxially arranged and installed on the metal wire angle adjustment bracket 2112 with the first metal wire 2111. The metal wire angle adjustment bracket 2112 is used to adjust the angle between the direction of the wire feeding into the molten pool and the horizontal direction, and ensure that the wire coaxial air blowing pipe 2114 is always coaxial with the first metal wire 2111. The wire feeder 2115 is fixed on the metal wire angle adjustment bracket 2112 and is located at the metal wire inlet end of the wire coaxial air blowing pipe 2114. The position of the wire feeder 2115 can be adjusted synchronously while adjusting the angle between the direction of the first metal wire 2111 feeding into the molten pool and the horizontal direction.

[0038] The constant magnetic field system 311 includes a permanent magnet 3111, a magnet holder 3112 and a magnetic field measuring instrument 3113. The magnet holder 3112 is used to fix the permanent magnet 3111 to the wire coaxial blowing pipe 2114. There are two permanent magnets 3111, which are symmetrically arranged on both sides of the end of the first metal wire 2111, and are used to generate a constant magnetic field. The direction of the magnetic field 3114 generated by the permanent magnet 3111 is perpendicular to the axial direction of the first metal wire 2111. The magnetic field measuring instrument 3113 is located between the permanent magnet 3111 and the first metal wire 2111, and is used to measure the magnetic field strength at the end of the first metal wire 2111 where the melt is formed.

[0039] The electric field system 411 includes a DC power supply 4111 and a current clamp 4112. There are two current clamps 4112, which are fixed on the first metal wire 2111 and the forming substrate 7112 respectively. The present invention uses the DC power supply 4111 to form a stable current between the first metal wire 2111 and the forming substrate 7112.

[0040] The coaxial protective gas system 511 includes a laser coaxial air blowing pipe 5111, a light-transmitting lens 5112, a protective gas 5113, a first flowmeter 5114 and a second flowmeter 5115. Two paths of protective gas are designed in the present invention. The first path is: the laser coaxial air blowing pipe 5111 is arranged directly below the first continuous laser source 1111, ensuring that the laser of the first continuous laser source 1111 can be vertically and coaxially irradiated onto the forming substrate 7112 through the light-transmitting lens 5112 directly below. The protective gas 5113 is an inert gas, and the flow rate of the protective gas 5113 entering the laser coaxial air blowing pipe 5111 can be accurately adjusted by the first flowmeter 5114. The second path is: the protective gas 5113 is ejected through the second flowmeter 5115 and the wire coaxial air blowing pipe 2114, and the protective gas 5113 of the second path can be ejected coaxially with the first metal wire 2111. The first flow meter 5114 is installed on the air flow path between the laser coaxial air blowing pipe 5111 and the shielding gas 5113 ; the second flow meter 5115 is installed on the air flow path between the wire coaxial air blowing pipe 2114 and the shielding gas 5113 .

[0041] In the present invention, an ultrasonic generator 6111 is installed at a certain distance away from the end of the first metal wire 2111, and ultrasonic vibration stirs the end melt 1 to promote the directional transfer of the end melt 1 from the metal wire to the forming substrate 7112.

[0042] Preferably, the types of the first metal wire 2111 can be set to n. According to the number of types of metal wires, they are evenly arranged within a 360-degree geometric range. The metal wire angle adjustment bracket 2112 is used to adjust the angle between the first metal wire 2111 and the horizontal plane. The types of the metal wires can be the same type of material and different types of materials, including but not limited to stainless steel wires, aluminum alloy wires, titanium alloy wires, flux-cored welding wires, high / medium entropy alloys, amorphous alloy wires and composite wires. The multi-axis motion platform 7111 includes four degrees of freedom of X, Y, Z axis motion and platform rotation. The multi-axis motion platform 7111 is used to support the forming substrate 7112 to achieve multi-axis motion control of the forming substrate 7112.

[0043] The working principle of the present invention includes:

[0044] 1. Principle of ultrasonic vibration assistance: In the present invention, an ultrasonic generator is installed at a certain distance away from the end of the first metal wire 2111, and ultrasonic vibration stirs the end melt 1, promoting the directional transfer of the end melt 1 from the metal wire to the forming substrate 7112. In addition, ultrasonic vibration can break solidified crystals, induce recrystallization, refine grains, and improve the organization and mechanical properties of the formed component.

[0045] 2. Stable magnetic field auxiliary principle: According to the Lorentz force on moving charges in a magnetic field, the present invention applies a constant magnetic field in the horizontal plane of the first metal wire 2111, and at the same time applies a constant current between the first metal wire 2111 and the forming substrate 7112. According to the left-hand rule of the Lorentz force, the directions of the current and the constant magnetic field are matched, so that the electrons in the melt generate a Lorentz force (Z+ direction) pointing to the forming substrate 7112, thereby promoting the transfer of the metal melt to the substrate molten pool through the Lorentz force.

[0046] 3. Analysis of the force on the end melt: The force on the end melt 1 of the first metal wire 2111 is as follows: Figure 5 As shown. The forces acting on the end melt 1 mainly include surface tension Fs, air pressure Fw of metal wire coaxial blowing, recoil force Fr generated by metal evaporation, air pressure Fg of laser coaxial blowing, viscous force Fd between the metal end melt 1 and the substrate molten pool, Lorentz force Fb and thrust Ft of the metal wire on the end melt. The surface tension Fs of these forces generates a component force Fs_Z in the Z-direction. The air pressure Fw of metal wire coaxial blowing generated by the structure of the present invention on the end melt 1, the recoil force Fr generated by metal evaporation, air pressure Fg of laser coaxial blowing and Lorentz force Fb are all conducive to the directional transfer of the melt to the substrate molten pool. When the gas pressure Fw of the coaxial blowing of the metal wire, the recoil force Fr generated by metal evaporation, the gas pressure Fg of the coaxial blowing of the laser, the viscous force Fd between the metal end melt 1 and the substrate molten pool, the Lorentz force Fb and the thrust Ft of the metal wire on the end melt in the Z direction are greater than the component of the surface tension Fs in the Z direction, that is: Fw_Z + Fr_Z + Fg_Z + Fd_Z + Fb_Z + Ft_Z >Fs_Z, the end melt 1 can be smoothly transported into the molten pool.

[0047] In the present invention, the gas pressure generated by the coaxial airflow, the recoil force generated by metal evaporation and the Lorentz force generated by the electromagnetic field are all conducive to the separation of the metal end melt from the metal wire material and the directionally transported to the molten pool of the forming substrate.

[0048] The present invention also provides a multi-field assisted metal fuse additive melt directional transfer method, which is implemented by using the multi-field assisted metal fuse additive melt directional transfer device, and the method comprises the following steps:

[0049] Step S1, manufacturing preparation: adjusting the relative positions of the first continuous laser source 1111 and the first pulse laser source 1112 and the first metal wire 2111 and the initial processing position of the forming substrate 7112;

[0050] Step S2, data preparation: data slicing is performed according to the three-dimensional model to be constructed, and the wire feeding direction of the first metal wire 2111 is ensured to be always parallel to the forming direction and kept at the front end of the forming direction through the rotational freedom of the multi-axis motion platform 7111;

[0051] Step S3, start processing: start the shielding gas 5113, the first continuous laser source 1111 and the first pulsed laser source 1112, the DC power supply 4111 and the wire feeder 2115 in sequence, after the first metal wire 2111 contacts the forming substrate 7112, a current loop is generated between the first metal wire 2111 and the forming substrate 7112, the current is used as a control signal, and additive processing is started according to the slice trajectory data of the three-dimensional model;

[0052] Step S4, processing end: after processing according to the slice trajectory data in the current forming layer, the wire feeder 2115, the DC power supply 4111, the laser source and the shielding gas 5113 are turned off in sequence, and the forming substrate 7112 is moved to the initial position of the next trajectory by the multi-axis motion platform 7111;

[0053] Step S5, repeating steps S1, S2, S3 and S4 until the entire three-dimensional component is processed.

[0054] Preferably, the flow rate of the shielding gas 5113 is 0L / min~50L / min; the laser source is used to output pulsed laser or continuous laser, its maximum output power is 4000W, the pulse frequency is 10Hz~1000HZ, the laser pulse width is 2~50ms, and the scanning speed is 50mm / min~2000mm / min; the maximum output current of the DC power supply 4111 is 400A; the wire feeder 2115 is used to realize metal wire feeding with a wire diameter of 0.1mm~10mm.

[0055] Embodiment 1:

[0056] As Figure 2The two laser beams shown are used as an example for explanation. In this embodiment, the number of metal wires n=1. The laser energy source system 111 includes a first continuous laser source 1111 and a first pulsed laser source 1112. The laser of the first continuous laser source 1111 acts on the forming substrate 7112, and the end of the metal wire is not within the action range of the light spot of the first continuous laser source 1111; the light spot of the first pulsed laser source 1112 directly irradiates the end of the metal wire. The first pulsed laser source 1112 acts on the metal wire directly, and on the other hand, the instantaneous high energy of the pulsed laser interacts with the metal wire to generate recoil steam pressure, which is conducive to the end melt being separated from the metal wire and being transported to the substrate molten pool in a directional manner. The protective gas flows in the wire coaxial air blowing tube 2114 and the laser coaxial air blowing tube 5111 are respectively set, and the flow rate of the protective gas is 10L / min~50L / min; the parameters of the first pulse laser source 1112 are set, and the maximum output power of the pulse laser is 200W~4000W, the pulse frequency is 10Hz~1000HZ, and the laser pulse width is 2~50ms; the parameters of the first continuous laser source 1111 are set, and the continuous laser power is 200W~1000W.

[0057] Embodiment 2:

[0058] As Figure 3 The multiple continuous laser beams shown in the figure are used as an example for explanation. In this embodiment, the material number of the metal wire material n=1, and the number of the multiple continuous laser beams is 4. The laser energy source system 111 includes multiple continuous laser beams, which are respectively a first continuous laser source 1111, a second continuous laser source 1121, a third continuous laser source 1131, and a fourth continuous laser source 1141. The multiple laser beams are evenly arranged within a 360° circumferential range, and form a circular laser energy distribution form in space. The multiple laser beams act on the forming substrate 7112, and the end of the metal wire is inserted into the geometric center position of the multiple laser beams through the position adjustment mechanism 1113 and contacts the forming substrate 7112. Since the laser acts on the end of the metal wire and the forming substrate 7112 at the same time, the metal wire can be melted while the molten pool is formed on the forming substrate. The annular distribution of the multiple laser beams makes the temperature field of the molten pool formed on the forming substrate more uniform, and the laser light pressure is further used to promote the transfer of the metal wire melt to the molten pool of the forming substrate 7112. At the same time, protective gas flows are set in the wire coaxial air blowing pipe 2114 and the laser coaxial air blowing pipe 5111 respectively, and the flow rate of the protective gas is 10L / min~50L / min; the protective gas is used to prevent the molten pool from being oxidized and to generate gas pressure to promote melt transfer, and the laser power is 200W~1000W.

[0059] Embodiment 3:

[0060] As Figure 4As shown, in this embodiment, the number of metal wire materials n=4, and the number of laser beams is set to 5, including a first pulse laser source 1112, a second pulse laser source 1122, a third pulse laser source 1132 and a fourth pulse laser source 1142. The four pulse lasers are respectively irradiated on the ends of the first metal wire 2111, the second metal wire 2121, the third metal wire 2131 and the fourth metal wire 2141. The laser of the first continuous laser source 1111 is irradiated on the center of the four pulse lasers. The first continuous laser source 1111 is used to form a stable molten pool on the forming substrate 7112. The present invention can realize the directional transfer of the melt at the end of the metal wire by only using the gas pressure generated by the coaxial airflow and the recoil force generated by the metal evaporation. The protective gas flow in the wire coaxial air blowing pipe 2114 and the laser coaxial air blowing pipe 5111 is set respectively, and the flow rate of the protective gas is 10L / min to 50L / min; the parameters of the first pulse laser source 1112, the second pulse laser source 1122, the third pulse laser source 1132 and the fourth pulse laser source 1142 are set respectively, and the maximum output power of the pulse laser is 200W to 4000W, the pulse frequency is 10Hz to 1000HZ, and the laser pulse width is 2 to 50ms; the parameters of the first continuous laser source 1111 are set, and the continuous laser power is 200W to 1000W. In this embodiment, the order of adding the four metal wires can be controlled by the control system, thereby realizing the metal fuse additive manufacturing of the gradient structure.

[0061] Embodiment 4:

[0062] The present invention can realize the directional transfer of the melt at the end of the metal wire by only using the Lorentz force generated by the electromagnetic field and the recoil force generated by metal evaporation. The parameters of the first pulse laser source 1112, the second pulse laser source 1122, the third pulse laser source 1132 and the fourth pulse laser source 1142 are respectively set, the maximum output power of the pulse laser is 200W~4000W, the pulse frequency is 10Hz~1000HZ, and the laser pulse width is 2~50ms; the parameters of the first continuous laser 1111 are set, the continuous laser power is 200W~1000W; the parameters of the DC power supply 4111 are set, and the DC power supply current adjustment range is 0.2A~10A; the steady-state magnetic field is provided by the permanent magnet, and the magnetic field strength of the permanent magnet 3111 is 0.5~1.8T.

[0063] Embodiment 5:

[0064] The present invention can realize the directional transfer of the melt at the end of the metal wire by only using the stirring of the melt by ultrasonic vibration and the recoil force generated by metal evaporation. The parameters of the first pulse laser source 1112, the second pulse laser source 1122, the third pulse laser source 1132 and the fourth pulse laser source 1142 are respectively set, the maximum output power of the pulse laser is 200W~4000W, the maximum pulse frequency is 10Hz~1000HZ, and the laser pulse width is 2~50ms; the parameters of the first continuous laser source 1111 are set, the continuous laser power is 200W~1000W; the parameters of the ultrasonic generator 6111 are set, the working frequency of the ultrasonic generator is 20kHz, and the amplitude is 5μm~100μm.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention, such as changing the heating form of the metal wire to arc heating. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A multi-field assisted metal fuse additive melt directional transfer device, characterized in that: It includes a laser energy source system, a metal wire feeding system, a constant magnetic field system, an electric field system, a coaxial protective gas system, an ultrasonic generator, a multi-axis motion platform and a forming substrate; the forming substrate is fixedly installed above the multi-axis motion platform, and the multi-axis motion platform is used to realize the multi-degree-of-freedom movement of the forming substrate in space; the laser energy source system is fixed above the forming substrate, so that the laser emitted by the laser energy source system irradiates the upper surface of the forming substrate; the metal wire feeding system is fixed on the side of the laser energy source system to transport the metal wire material within the size range of the laser spot; the constant magnetic field system, the electric field system and the ultrasonic generator are respectively fixed on the metal wire feeding system; the multi-axis motion platform includes four degrees of freedom of X, Y, Z axis movement and platform rotation.

2. The multi-field assisted metal fuse additive melt directional transfer device according to claim 1, characterized in that: The laser energy source system includes multiple laser beams, which are generated by multiple laser light sources or one laser beam through a spectroscope system; the spatial relationship between the laser irradiation position and the metal wire and the forming substrate is adjusted by a position adjustment mechanism.

3. The multi-field assisted metal fuse additive melt directional transfer device according to claim 1, characterized in that: The metal wire feeding system includes a metal wire, a metal wire angle adjustment bracket, an insulating sleeve, a wire coaxial air blowing pipe and a wire feeder; the insulating sleeve and the wire coaxial air blowing pipe are coaxially arranged and installed on the metal wire angle adjustment bracket together with the metal wire; the metal wire angle adjustment bracket is used to adjust the angle between the direction in which the metal wire is fed into the molten pool and the horizontal direction, and ensure that the wire coaxial air blowing pipe is always coaxial with the metal wire; the wire feeder is fixed on the metal wire angle adjustment bracket and is located at the metal wire inlet end of the wire coaxial air blowing pipe, and the position of the wire feeder is synchronously adjusted while adjusting the angle between the direction in which the metal wire is fed into the molten pool and the horizontal direction.

4. The multi-field assisted metal fuse additive melt directional transfer device according to claim 1, characterized in that: The constant magnetic field system includes a permanent magnet, a magnet bracket and a magnetic field measuring instrument; the magnet bracket is used to fix the permanent magnet and the wire coaxial blowing pipe; the number of permanent magnets is 2, and they are symmetrically arranged on both sides of the end of the metal wire to generate a constant magnetic field, and the direction of the magnetic field generated by the permanent magnet is perpendicular to the axial direction of the metal wire; the magnetic field measuring instrument is located between the permanent magnet and the metal wire, and is used to measure the magnetic field strength at the end of the metal wire where the melt is formed.

5. The multi-field assisted metal fuse additive melt directional transfer device according to claim 1, characterized in that: The electric field system includes a DC power supply and a current clamp; there are two current clamps, which are fixed on the metal wire and the forming substrate respectively, and a stable current is formed between the metal wire and the forming substrate by using the DC power supply.

6. The multi-field assisted metal fuse additive melt directional transfer device according to claim 1, characterized in that: The coaxial protective gas system comprises a laser coaxial air blowing pipe, a light-transmitting lens, protective gas, a first flow meter and a second flow meter; two paths of protective gas are designed, the first path is: the laser coaxial air blowing pipe is arranged directly below the first continuous laser source among multiple laser light sources, ensuring that the laser of the first continuous laser source can be vertically and coaxially irradiated onto the forming substrate directly below through the light-transmitting lens; the second path is: the protective gas is ejected through the second flow meter and the wire coaxial air blowing pipe, and the protective gas of the second path is coaxially ejected with the metal wire; the protective gas is an inert gas, and the flow rate of the protective gas entering the laser coaxial air blowing pipe is accurately adjusted by the first flow meter, and the flow rate of the protective gas entering the wire coaxial air blowing pipe is accurately adjusted by the second flow meter.

7. The multi-field assisted metal fuse additive melt directional transfer device according to claim 6, characterized in that: The metal wires are arranged in n types, where n is a positive integer greater than or equal to 1; the metal wires are evenly arranged within a 360-degree geometric range according to the number of types; the metal wires are installed on an angle adjustment mechanism, and the angle adjustment mechanism can be used to adjust the angle between the metal wires and a horizontal plane; the types of the metal wires are materials of the same type or different types, including stainless steel wires, aluminum alloy wires, titanium alloy wires, flux-cored welding wires, high / medium entropy alloys, amorphous alloy wires, and composite material wires.

8. The multi-field assisted metal fuse additive melt directional transfer device according to claim 6, characterized in that: An ultrasonic generator is installed at a certain distance away from the end of the metal wire. The ultrasonic vibration stirs the end melt, promoting the directional transfer of the end melt from the metal wire to the forming substrate.

9. A multi-field assisted metal fuse additive melt directional transfer method, characterized in that: The method is implemented by using the multi-field assisted metal fuse additive melt directional transfer device as claimed in any one of claims 1 to 8, comprising the following steps: Step S1, adjusting the relative positions of the first continuous laser source and the first pulsed laser source of the laser energy source system and the metal wire and the initial processing position of the forming substrate; Step S2, slicing data according to the three-dimensional model to be constructed, and ensuring that the wire feeding direction of the metal wire is always parallel to the forming direction and kept at the front end of the forming direction through the rotational freedom of the multi-axis motion platform; Step S3, sequentially starting the shielding gas, the first continuous laser source and the first pulsed laser source, the DC power supply and the wire feeder, after the first metal wire contacts the forming substrate, a current loop is generated between the first metal wire and the forming substrate, the current is used as a control signal, and additive processing is started according to the slice trajectory data of the three-dimensional model; Step S4, after processing according to the slice trajectory data in the current forming layer, the wire feeder, the DC power supply, the laser source and the protective gas are turned off in sequence, and the forming substrate is moved to the initial position of the next trajectory by the multi-axis motion platform; Step S5, repeating steps S1, S2, S3 and S4 until the entire three-dimensional component is processed.

10. The multi-field assisted metal fuse additive melt directional transfer method according to claim 9, characterized in that: The flow rate of the shielding gas is 0L / min~50L / min; the laser source is used to output pulsed laser or continuous laser, its maximum output power is 4000W, the pulse frequency is 10Hz~1000HZ, the laser pulse width is 2~50ms, and the scanning speed is 50mm / min~2000mm / min; the maximum output current of the DC power supply is 400A; the wire feeder is used to realize metal wire feeding with a wire diameter of 0.1mm~10mm.

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