CN115781023A - Dissimilar material double-molten pool additive manufacturing method based on thermal regulation - Google Patents

Abstract

The invention discloses a dissimilar material double-molten pool additive manufacturing method based on thermal regulation. The method comprises the following steps: placing a metal wire on a low-melting-point metal base material, wherein the front end of the metal wire is attached to the base material, and the rear end of the metal wire is at a certain inclination angle; partial melting of the metal wire is realized through heat input control, and partial solid wire is reserved at the lower end of the wire molten pool while the wire molten pool is formed; forming a matrix molten pool through heat conduction of the metal wire and the low-melting-point metal base material; the solid wire is used for separating mass transfer and convection between a wire molten pool and a base material molten pool so as to inhibit generation of intermetallic compounds in a transition region and realize performance optimization of the transition region; and excellent combination of dissimilar materials is ensured by controlling the contact force of the metal wire. The method does not need to improve the existing additive manufacturing equipment to a greater extent, is convenient and effective, and is easy to operate.

Description

Thermal regulation-based heterogeneous material double-molten pool additive manufacturing method

Technical Field

The invention belongs to the field of additive manufacturing, and particularly relates to a dissimilar material double-molten pool additive manufacturing method based on thermal regulation.

Background

The additive manufacturing technology based on the discrete-accumulation forming principle manufactures high-performance metal parts directly by 'manufacturing raw materials in layers and overlapping layer by layer' through CAD model data. The common point of the existing research on more extensive dissimilar materials, gradient structure materials and composite materials is that multiple materials with unique performance advantages are compounded, the performance short plate of a single material can be overcome, the method can meet the requirements of different working conditions on the performance of the materials, noble metals can be saved, the structure cost is reduced, and the performance advantages of the dissimilar materials are fully exerted. In the field of additive manufacturing, except for traditional single-metal additive manufacturing, controllable distribution of different materials in the same formed part can be realized by using the flexibility of powder feeding or wire feeding of a wide additive technology, and a new solution is provided for forming and manufacturing of a composite component integrated with different materials.

Take the example of studying and applying a relatively wide range of Al/Ti dissimilar materials. The titanium and the titanium alloy have the excellent characteristics of low density, high specific strength, high melting point, corrosion resistance, no magnetism, super memory, high toughness and the like, can meet the requirements of the fields of aerospace, biomedical treatment, petrochemical industry and the like on the structural complexity, functional diversity and high service performance of metal materials, are one of ideal materials for parts such as airplane fuselage fire walls, engine nacelles, skins, frames, keels and the like, and have the application level which becomes an important mark for measuring the advanced degree of the national manufacturing industry. On the other hand, aluminum alloy has a series of advantages of small density, high specific strength, good corrosion resistance, good reproducibility, low price and the like, and is widely applied to the fields of aviation, aerospace, chemical industry, transportation, petroleum industry and the like. At present, the demand of titanium alloys in China is increasing at a rate of 20% -30% per year, and its industrial application is gradually expanding from the military field to the civil field. On the other hand, aluminum alloy is a main structural material in aircraft manufacturing, accounts for about 55% of the framework mass, and is mainly used for manufacturing bearing parts such as wings, shells and empennages.

Because the preparation cost of the titanium alloy is high (about 17 times of steel and 4.5 times of aluminum alloy), and the problem of poor mechanical processing performance caused by low elastic modulus and poor thermal conductivity of the titanium alloy is solved, the traditional processing and application of the titanium alloy can not meet the environmental adaptation and economic requirements of modern industry, and the application field of the titanium alloy is still greatly limited at present. In order to solve the problems of high processing difficulty and high manufacturing cost of the titanium alloy, and simultaneously give full play to the excellent characteristics of large specific strength, high temperature resistance, corrosion resistance, high toughness and the like of the titanium alloy material, people put forward higher requirements on a new process for preparing titanium alloy parts so as to improve the utilization rate of the titanium alloy material and reduce the structural weight of the titanium alloy parts. Aluminum alloys are superior to titanium alloys in part properties, such as good workability, low density. The Al/Ti dissimilar material has the characteristics of light density, high strength and good stability, and is widely applied to the fields of aerospace, automobiles and the like. In the aspect of aerospace, the German BIAS Bremen light beam application institute welds 3003 aluminum alloy blades to a titanium alloy pipe through laser to realize the manufacturing of the aircraft cabin cooling fins; an Airbus (Airbus) takes a titanium plate and aluminum rib composite structure as an airplane seat guide rail, so that the weight of the airplane body and the manufacturing cost are reduced. In the automotive industry, germany Deutsche Titan corporation has developed an Al/Ti alloy exhaust system that is 40% lighter in weight than conventional steel exhaust systems.

Although the laser additive manufacturing integrated complex structure forming preparation method of the titanium alloy and the aluminum alloy which are typical dissimilar materials can fully exert the unique advantages of the two alloy materials theoretically, the titanium alloy and the aluminum alloy have obvious difference in chemical and physical properties, and in the forming process, the mechanical property deterioration caused by the intermetallic compound generated by microcrack and element mixing and dissolving reaction due to the difference in properties such as thermal expansion coefficient, dissimilar atom mutual solubility and low melting point element evaporation among the dissimilar materials often exists in a dissimilar material connection transition area. In order to solve the problems, jiangsu university discloses a dissimilar material connecting method combining laser additive manufacturing and laser welding, which is characterized in that a transition metal plate with gradient change of additive elements is manufactured through an additive manufacturing process, and then the transition metal plate is connected with a base metal through a laser welding process. Although this process can solve the problem of connection of dissimilar materials, it is not suitable for high-frequency alternating additive manufacturing of dissimilar materials, and the manufacturing efficiency is low. University of the major connecting theory of technology discloses an electric arc additive manufacturing method (CN 109332860) of a 5083 aluminum alloy/TC 4 titanium alloy structure, which is characterized in that the connection of aluminum alloy and titanium alloy is firstly realized on the surface of the titanium alloy by the electric arc additive manufacturing method, and then the aluminum alloy structure is prepared by the additive manufacturing process. The method can ensure the connection of the aluminum alloy and the titanium alloy, but still cannot effectively solve the problem of intermetallic compounds in the transition zone of dissimilar materials. Therefore, how to realize effective regulation and control of the microstructure and the mechanical property of the transition region of the dissimilar material while ensuring good combination of the aluminum alloy and the titanium alloy in the laser additive manufacturing of the dissimilar material still remains a technical problem to be solved by the technical staff in the field.

Disclosure of Invention

The invention aims to overcome the problems in the prior art, and provides a dissimilar material dual-molten pool additive manufacturing method based on thermal regulation, which is different from the traditional additive manufacturing idea.

The purpose of the invention is realized by the following technical scheme: a heterogeneous material double-molten pool additive manufacturing method based on thermal regulation mainly comprises the following steps:

a heterogeneous material double-molten pool additive manufacturing method based on thermal regulation realizes heterogeneous material double-molten pool additive manufacturing of liquid wire material-solid wire material-liquid substrate two interface combination through thermal regulation, and specifically comprises the following steps: placing a metal wire on a low-melting-point metal substrate, wherein the front end of the metal wire is attached to the substrate, and the rear end of the metal wire is at a certain inclination angle; partial melting of the metal wire is realized through heat input control, and partial solid wire is reserved at the lower end of the wire molten pool while the wire molten pool is formed; forming a matrix molten pool through heat conduction of the metal wire and the low-melting-point metal base material; the convection between a wire molten pool and a base material molten pool is separated by utilizing solid wires so as to inhibit the generation of intermetallic compounds in a transition region and realize the optimization of the performance of the transition region; and then the excellent combination of dissimilar materials is ensured through the contact force control on the metal wire.

Further, the heterogeneous material double-molten pool additive manufacturing method based on thermal regulation comprises the following steps:

s1) cleaning and fixing a low-melting-point metal substrate:

s2) feeding the metal wire to enable the front end of the metal wire to be attached to the base material and the rear end of the metal wire to form a certain inclination angle; carrying out heat input scanning on the metal wire from the front end to the rear end, and combining the metal wire with the low-melting-point metal base material through partial material melting or softening and extrusion;

s3) detecting the performance of the bonding metal through an online detection system;

s4) continuously adjusting process parameters to obtain excellent combined process parameters;

s5) performing a dissimilar material additive manufacturing process.

Further, the heat in the thermal input is heat radiated to the surface of the metal wire or heat absorbed by the metal wire. Preferably, the heat input means may be a laser or an arc or an electron beam.

Further, the "force" in the thermal input is the traction force applied to the metal wire, the extrusion force of the solid wire and the substrate molten pool, and comprises a contact force F1 inclining downwards along the metal wire, a plasma recoil pressure F2, and a supporting force F3 vertically upwards provided by the substrate. The inclined contact force F1 can be decomposed into a horizontal force Fx which is opposite along the direction parallel to the scanning direction and a vertical force Fz which is downward perpendicular to the scanning direction, and the horizontal force Fx mainly acts to ensure the supply of the metal wire along the horizontal direction; the supporting force F3, the recoil pressure F2 and the vertical force Fz mainly provide the extrusion effect along the vertical direction for the solid wire and the substrate molten pool, so that the infiltration of the solid wire and the substrate molten pool is ensured, and the excellent combination of dissimilar metals is ensured.

Furthermore, the detection of the performance of the bonding metal by the online detection system means that the bonding performance of the dissimilar materials is detected by the molten pool data in the manufacturing process acquired by the online detection equipment in real time. Preferably, the spectrum intensity acquired by the spectrometer is not higher than the spectrum intensity generated by elements or gasification, the existence of unmelted solid wires at the front end of the molten pool can be obviously observed in the molten pool image acquired by the high-speed camera, and the molten pool has no obvious agglomeration phenomenon.

Further, the maximum value of the contact force F1 is in the range of 0.001-10N, the contact force is parallel to the direction of the metal wire, and the contact force F1 can be a constant static force or a force with periodic variation, such as a periodic vibration force.

Further, the melting point of the low-melting-point metal base material is lower than that of the metal wire, the melting point range of the low-melting-point metal base material is 30-1100 ℃, and the melting point range of the metal wire is 1100-3000 ℃. Preferably, the low-melting-point metal comprises aluminum, aluminum alloy, bismuth, cadmium, tin, lead, dysprosium, indium or eutectic low-melting-point alloy consisting of the aluminum, the aluminum alloy, the bismuth, the cadmium, the tin, the lead, the dysprosium, the indium or eutectic low-melting-point alloy consisting of the aluminum, the aluminum alloy, the bismuth, the titanium alloy, the high-entropy alloy, the iron-based alloy, the cobalt-based alloy and the nickel-based alloy.

Further, the double molten pools comprise a wire molten pool and a substrate molten pool, the wire molten pool is formed by partial melting of the wire, and the substrate molten pool is formed by melting through heat conduction between the wire and the low-melting-point substrate.

Further, the solid-state wire is an unmelted solid wire in a thermal softening state, can be plastically deformed under the action of heat and can be extruded into the substrate molten pool.

Further, the two interfaces of the liquid wire-solid wire-liquid substrate are two interfaces between the double molten pools.

Further, the angle range of the metal wire is 0-90 degrees.

Further, the heat input in the step S3 is to ensure that the wire is partially melted and is lower than the heat input required for complete melting of the metal wire, and the heat input regulation is realized by regulating the laser power or the scanning speed or the wire feeding speed or the scanning speed or the defocusing amount.

Further, the process parameters in step S4 include heating power, scanning speed and wire feeding speed. Preferably, the power parameters include laser power, scanning speed, wire feed speed, scanning speed, and defocus adjustment.

Further, the dissimilar material additive manufacturing device in step S5 includes a laser additive manufacturing device or an arc additive manufacturing or electron beam additive manufacturing device. Preferably a laser additive manufacturing apparatus.

The invention has the beneficial effects that:

according to the method for manufacturing the dissimilar material double-molten pool additive based on thermal regulation, the partial melting of the metal wire is realized through thermal input control, the double-molten pool and the liquid wire-solid wire-liquid substrate interface combination design is realized, the convection between the substrate molten pool and the wire molten pool can be prevented through the unmelted solid wire layer, the combination between dissimilar atoms is inhibited, and the formation of intermetallic compounds can be effectively controlled. In addition, through contact force control, the extrusion of the liquid base material and the solid wire material is realized, and good combination of dissimilar materials is ensured. The method does not need to improve the existing additive manufacturing equipment to a greater extent, is convenient and effective, and is easy to operate.

Drawings

FIG. 1 is a heterogeneous material double-molten pool additive manufacturing method based on thermal regulation and control, which comprises the following steps: in the figure, 1-continuous laser, 2-metal wire, 3-metal substrate, 4-wire molten pool, 5-keyhole, 6-solid wire, 7-substrate molten pool;

FIG. 2 shows the experimental results for low heat input: in the figure, (a) a molten pool image captured by a high-speed camera, (b) a sample cross section metallographic image, and (c) a real-time spectrum test result;

FIG. 3 shows the experimental results for the case of too high a heat input: the images comprise (a) a molten pool image captured by a high-speed camera, (b) a sample cross section metallographic image, and (c) a real-time spectrum test result;

fig. 4 is the experimental result without contact force regulation: the images comprise (a) a molten pool image captured by a high-speed camera, (b) a sample cross section metallographic image, and (c) a real-time spectrum test result;

FIG. 5 shows the online detection result of the dissimilar material dual-bath additive manufacturing method based on thermal regulation of the present invention: in the figure, (a) a molten pool image captured by a high-speed camera, (b) a molten pool image enlarged image, and (c) a real-time spectrum test result;

fig. 6 shows the microstructure and performance test results of the dissimilar material dual-molten pool additive manufacturing method based on thermal regulation and control of the present invention: in the figure, (a) a gold phase diagram of a sample cross section, (b) a transition region SEM image, (c) a transition region nano indentation test result, (d) a transition region Al/Ti element surface distribution diagram, (e) a transition region Al element surface distribution diagram, and (f) a transition region Ti element surface distribution diagram.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

Example 1

A dissimilar material double-molten pool additive manufacturing method based on thermal regulation comprises the following steps:

referring to fig. 1, the following is included: the method realizes the dissimilar material double-molten pool additive manufacturing of two interface combinations of a liquid wire material molten pool 4-a solid wire material 6-a liquid substrate molten pool 7 through thermal regulation and control, and specifically comprises the following steps: partial melting of the wire is realized through heat input control, a part of solid wire 6 is reserved while a wire molten pool 4 is formed, and a matrix molten pool 7 is formed through heat conduction of the metal wire and the low-melting-point metal substrate; the convection and mass transfer behaviors of the wire molten pool 4 and the base material molten pool 7 are separated by using the solid wires 6, the formation of metal interphase in a dissimilar material transition zone is inhibited, and the mechanical property of the dissimilar material transition zone is improved; force control is realized by adjusting an inclined contact force F1 applied to the metal wire 2 and an upward supporting force balance F1 component Fz provided by the base material, so that excellent combination of dissimilar metals is ensured; the contact force F can be decomposed into a horizontal force Fx which is opposite along a direction parallel to the scanning direction and a vertical force Fz which is downward perpendicular to the scanning direction, the horizontal force Fx mainly serves to guarantee the supply of the metal wire 2 along the horizontal direction, and the vertical force Fz and the supporting force F3 mainly provide a squeezing effect along the vertical direction for the solid wire 6 and the substrate molten pool 7 to guarantee the infiltration of the solid wire 6 and the substrate molten pool 7.

In this embodiment, the manufacturing is performed based on a laser additive manufacturing platform, and the more specific steps are as follows:

s1) cleaning and fixing a base material: in the embodiment, oil stain and dust on the surface of the metal substrate 3 are wiped off by using alcohol and acetone, in the embodiment, the metal substrate 3 is a 6061 aluminum alloy plate with the thickness of 4mm, the wiped 6061 aluminum alloy plate is dried by using a blower, and then the 6061 aluminum alloy substrate is fixed on an additive test bed through a clamp;

s2) setting metal wires: fixing a wire feeding head at the front end of a laser head along a scanning direction, wherein in the embodiment, a titanium alloy wire with the diameter of 1mm is selected as a metal wire material 2, the angle of the wire feeding head is adjusted to 60 degrees, and the contact force F1 of the metal wire material 2 and a metal base material 3 is set to be 0.1N;

s3) establishing an online detection system: in this embodiment, a heterogeneous material additive manufacturing online detection system including a spectrometer and a high-speed camera is built in a laser additive manufacturing platform, the sampling frequency of the spectrometer is 100ms, and the wavelength range is set to 400nm-100nm.

S4) setting process parameters and heat input: in the embodiment, the heat input is regulated and controlled by laser power, the laser power is set to be 400W-900W, the scanning speed is 9mm/s, the wire feeding speed is 60mm/s, and the defocusing amount is 1mm.

And S5) starting laser and executing the laser additive manufacturing process of the dissimilar materials.

In order to prove the necessity of the dissimilar material additive manufacturing method based on thermal regulation, a dissimilar material additive manufacturing experiment under the conditions of too low or too high heat input and contact force is designed, and the experimental materials are consistent with the above.

Performing section cutting on Al/Ti dissimilar material additive samples prepared under different thermal parameters by wire cut electrical discharge machining, performing grinding and polishing treatment on the cut samples, observing the macroscopic geometric morphology of the sample sections by using an optical microscope, and analyzing the defects and the bonding performance in the samples; element surface distribution scanning is carried out on the dissimilar material transition region through SEM-EDS, the element mutual solubility condition in the transition region is represented, and the generation condition of the metal inter-phase in the transition region is judged; analyzing the online detection data of the additive manufacturing of the dissimilar materials, and establishing a correlation between the forming quality and the additive manufacturing data; and measuring the mechanical property of the sample by a nano-indenter.

As can be seen from fig. 2 (a), although the titanium alloy wire can be melted under the condition of low heat input, a molten pool cannot be formed on the surface of the aluminum alloy substrate due to insufficient heat input, and a phenomenon of solid-liquid connection is formed in the bonding area of the dissimilar materials, so that a "pseudo bonding phenomenon" is formed, as shown in a gold phase diagram in fig. 2 (b), and further, as can be seen from a spectrum signal in fig. 2 (c), a spectrum signal of the molten pool area is measured only within 1s after the laser is turned on (0 s), and then the spectrum signal disappears, the insufficient heat input causes an Al molten pool not to be formed, the wetting phenomenon of the Al/Ti dissimilar metals does not occur, the melted wire is separated from the surface of the Al substrate after 1s, and bonding of the Al/Ti dissimilar metals cannot be achieved; however, the excessive laser heat input may cause the thickness of the deposited layer to decrease (fig. 3 (a)), and the depth of the molten pool to be too large (fig. 3 (b)), and as can be seen from the spectrum signal in fig. 3 (c), the spectral intensity of the molten pool is too high, which indicates that there is a phenomenon of element gasification, therefore, the excessive heat input may cause excessive melting of Al, and the large amount of fusion of the molten dissimilar materials may generate an excessive intermetallic phase in the transition region, which is not favorable for additive forming and mechanical properties of the dissimilar material formed part. On the other hand, in the case of unilateral regulation of heat input, as shown in fig. 4, the good state of the molten pool can be seen from the spectrum signal within 0s-3s (fig. 4 (c)), but due to insufficient contact force input, the front end of the molten pool cannot completely adhere to the surface of the substrate (fig. 4 (a)), so that the transition region of the Al/Ti dissimilar material has obvious hole defects, which is not favorable for the mechanical properties of the transition region of the dissimilar material. As can be seen from the above two comparative examples, the thermal regulation strategy proposed by the present invention is necessary for additive manufacturing of dissimilar materials.

The results of the online monitoring of the preferred embodiment of the dissimilar material dual-bath additive manufacturing method based on thermal regulation according to the present invention are shown in fig. 5. As can be seen from the high-speed camera images in fig. 5 (a) and (b) and the spectrum signal in fig. 5 (c), the molten pool has a good shape, and the thermal coupling control can ensure the continuity of the molten pool and the complete bonding with the substrate. In addition, as can be seen from the gold phase diagram (fig. 6 (a)) and the SEM image (fig. 6 (b)) of the cross section of the deposition layer, the bonding of the Al/Ti dissimilar materials is good, no defects such as holes and micro cracks are observed in the transition region, the Al alloy on both sides of the molten pool overflows the molten pool, and the bonding interface in the transition region is tortuous, which indicates that the thermal regulation can realize the extrusion action along the vertical direction by partially melting the molten pool of the solid wire and the substrate, ensure the infiltration of the molten pool of the solid wire and the substrate, and ensure the excellent bonding of the dissimilar metals. The results of the element surface distribution analysis of the transition region (fig. 6 (d) - (f)) did not reveal significant miscibility of the hetero atoms over a large area, and there was a uniform element mixture distribution in the partial bonding region. In addition, as can be seen from the nanoimprint test result in fig. 6 (c), the mechanical property in the Al/Ti dissimilar material transition region is good, the hardness thereof is 421HV, the elastic modulus can reach 123GPa, and is close to that of titanium alloy, which indicates that the method for manufacturing the dissimilar material dual-molten pool additive based on thermal regulation and control of the invention can effectively inhibit convection and mass transfer behaviors between the dual molten pools, inhibit the bonding of dissimilar atoms and the generation of intermetallic compounds, effectively improve the mechanical property of the dissimilar material transition region, and prove the effectiveness and feasibility of the invention, while the method for realizing the bonding of two interfaces of the liquid wire, the solid wire and the liquid substrate by thermal regulation and control can realize the good bonding of dissimilar materials.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention, and such modifications and adaptations are intended to be within the scope of the invention.

Claims (10)

1. A dissimilar material double-molten pool additive manufacturing method based on thermal regulation is characterized in that the dissimilar material double-molten pool additive manufacturing of liquid wire material-solid wire material-liquid substrate two interface combination is realized through thermal regulation, and the method specifically comprises the following steps: placing a metal wire on a low-melting-point metal substrate, wherein the front end of the metal wire is attached to the substrate, and the rear end of the metal wire is at a certain inclination angle; partially melting the metal wire through heat input control, and reserving a part of solid wire at the lower end of the molten pool of the wire while forming the molten pool of the wire; forming a matrix molten pool through heat conduction of the metal wire and the low-melting-point metal base material; the solid wire is used for separating mass transfer and convection between a wire molten pool and a base material molten pool so as to inhibit generation of intermetallic compounds in a transition region and realize performance optimization of the transition region; and then the excellent combination of dissimilar materials is ensured through the contact force control on the metal wire.

2. The method of claim 1, comprising the steps of:

s1) cleaning and fixing a low-melting-point metal substrate:

s2) feeding the metal wire to enable the front end of the metal wire to be attached to the base material and the rear end of the metal wire to form a certain inclination angle; carrying out thermal input scanning on the metal wire from the front end to the rear end, and combining the metal wire with the low-melting-point metal base material through partial material melting or softening and extrusion;

s3) detecting the performance of the bonding metal through an online detection system;

s4) continuously adjusting the process parameters to obtain the process parameters with excellent combination;

s5) executing a dissimilar material additive manufacturing process.

3. The method according to claim 1 or 2, characterized in that: the heat in the thermal input is the heat radiated to the surface of the metal wire or the heat absorbed by the metal wire; the "heat" input means may be a laser or an arc or an electron beam.

4. The method according to claim 1 or 2, characterized in that: the 'force' in the thermal power input is traction force applied to the metal wire, and extrusion force of the solid wire and a substrate molten pool, and comprises a contact force F1 inclining downwards along the metal wire, a plasma recoil pressure F2 and a vertical upward supporting force F3 provided by the substrate; and the contact force F1 is a constant static force or a periodically varying force with a maximum value in the range of 0.001-10N.

5. The method according to claim 1 or 2, characterized in that: the double molten pools comprise a metal wire molten pool and a low-melting-point metal substrate molten pool, the wire molten pool is formed by partial melting of wires, and the substrate molten pool is formed by heat conduction melting between the wires and the low-melting-point substrate; the melting point of the low-melting-point metal base material is lower than that of the metal wire material, the melting point range of the low-melting-point metal base material is 30-1100 ℃, and the melting point range of the metal wire material is 1100-3000 ℃; the low-melting-point metal comprises aluminum or aluminum alloy or bismuth or cadmium or tin or lead or dysprosium or indium or eutectic low-melting-point alloy consisting of the aluminum or the aluminum alloy or the bismuth or the cadmium or the tin or the lead or the dysprosium or the indium, and the metal wire comprises iron or titanium or steel or titanium alloy or high-entropy alloy or iron-based alloy or cobalt-based alloy or nickel-based alloy.

6. The method according to claim 1 or 2, characterized in that: the solid wire is an unmelted solid wire in a heat softening state, can be subjected to plastic deformation under the action of heat and can be extruded into the substrate molten pool.

7. The method according to claim 1 or 2, characterized in that: the two interfaces of the liquid wire, the solid wire and the liquid substrate are two interfaces between the double molten pools.

8. The method according to claim 1 or 2, characterized in that: the angle range of the metal wire is 0-90 degrees.

9. The method of claim 2, wherein: the process parameters in the step S4 comprise heating power, scanning speed and wire feeding speed.

10. The method of claim 2, wherein: and S5, the dissimilar material additive manufacturing equipment comprises laser additive manufacturing equipment, arc additive manufacturing equipment or electron beam additive manufacturing equipment.

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