Electric arc additive manufacturing apparatus and manufacturing method

Abstract

This invention discloses an arc additive manufacturing apparatus and method, relating to the field of additive manufacturing technology. The apparatus includes: a powder feeding nozzle comprising a first powder feeding section, a second powder feeding section, and a third powder feeding section arranged sequentially along the length of the nozzle. The first powder feeding section has a wire feeding channel and at least two first powder feeding channels, all of which are spaced apart on the outer periphery of the wire feeding channel. The second powder feeding section has at least one second powder feeding channel, and the third powder feeding section has at least one third powder feeding channel. A conductive tip assembly passes through the wire feeding channels of the powder feeding nozzle and has a wire feeding hole for the welding wire to pass through. This invention increases the stability of the additive manufacturing process, facilitates adjustment of the matrix composition and the type of reinforcing phase, and is beneficial for improving the uniformity of the distribution of reinforcing phases of different densities.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to an electric arc additive manufacturing apparatus and manufacturing method. Background Technology

[0002] In fields such as petrochemicals, agricultural machinery, rail transportation, mining machinery, new energy equipment, shipbuilding, marine engineering, and aerospace, key components of various mechanical equipment operate under complex and harsh conditions for extended periods. They commonly face problems such as wear, corrosion, high-temperature oxidation, and synergistic damage from wear and corrosion, severely impacting equipment stability, reliability, and service life, increasing maintenance costs, and even causing safety accidents. This has become one of the core bottlenecks restricting the development of industrial equipment towards high efficiency, long-term effectiveness, and energy conservation. Surface modification of components, specifically the preparation of high-performance composite materials with wear resistance, corrosion resistance, and high-temperature oxidation resistance, plays a crucial role in improving equipment reliability and service life. Commonly used surface modification methods (additive manufacturing methods) for preparing composite materials on component surfaces mainly include oxy-acetylene flame spraying, oxy-acetylene flame welding, supersonic flame spraying, laser additive manufacturing, gas metal arc welding, non-consumable electrode arc welding, and plasma cladding.

[0003] Composite materials generally consist of two parts: a matrix and a reinforcing phase. The matrix is ​​the main component of the composite material and is crucial in consolidating reinforcing particles and bearing and transferring loads. Its density, strength, hardness, plasticity, corrosion resistance, heat resistance, electrical conductivity, and thermal conductivity all have a significant impact on the overall performance of the components. Commonly used single-principal-element alloys include nickel-based, iron-based, and cobalt-based alloys. However, using a single principal element has certain limitations. Some multi-principal-element alloys (i.e., medium- and high-entropy alloys) possess high hardness, wear resistance, high-temperature curing resistance, impact resistance, and corrosion resistance, exhibiting excellent comprehensive performance. As the matrix of surface composite materials, they can significantly improve the performance of surface composite materials. Therefore, multi-principal-element alloys have broad application prospects as the matrix of composite materials. However, preparing a complex and homogeneous multi-principal-element alloy matrix is ​​extremely difficult, placing high demands on additive manufacturing methods. The reinforcing phase is an important component of composite materials. The type, volume fraction, particle size, hardness, density, morphology, and distribution of the reinforcing phase have a significant impact on the wear resistance, corrosion resistance, high-temperature oxidation resistance, impact resistance, and crack resistance of the composite material. Common reinforcing particles mainly include carbides, nitrides, oxides, silicides, and borides. Adding multiple reinforcing phases to form multiphase composite reinforcement will help improve the overall performance of particle-reinforced composite materials. However, it is extremely difficult to prepare high volume fraction reinforcing phases and ensure that various reinforcing phase powders are uniformly distributed in the cladding composite material, which poses a challenge to additive manufacturing methods. Summary of the Invention

[0004] The purpose of this invention is to provide an electric arc additive manufacturing apparatus and manufacturing method to solve the problems existing in the prior art, increase the stability of the additive manufacturing process, facilitate the adjustment of matrix composition and the type of reinforcing phase, and help improve the distribution uniformity of reinforcing phases of different densities.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides an electric arc additive manufacturing apparatus, comprising: The powder feeding nozzle includes a first powder feeding section, a second powder feeding section and a third powder feeding section arranged sequentially along the length direction of the powder feeding nozzle. The first powder feeding section is provided with a wire feeding channel and at least two first powder feeding channels. All the first powder feeding channels are spaced apart on the outer periphery of the wire feeding channel. The second powder feeding section is provided with at least one second powder feeding channel, and the third powder feeding section is provided with at least one third powder feeding channel. A conductive tip assembly passes through the wire feeding channel of the powder feeding nozzle, and the conductive tip assembly is provided with a wire feeding hole for the welding wire to pass through.

[0006] In one embodiment, the center lines of all the first powder feeding channels intersect at a point on the center line of the wire feeding hole, and the angle between the center line of each of the first powder feeding channels and the center line of the wire feeding hole is 6° to 18°. The outlet end of each of the first powder feeding channels is inclined towards the side closer to the wire feeding hole relative to the inlet end of the first powder feeding channel.

[0007] In one embodiment, the angle between the centerline of each of the second powder feeding channels and the centerline of the wire feeding hole is -15° to 15°.

[0008] In one embodiment, the angle between the centerline of each of the third powder feeding channels and the centerline of the wire feeding hole is -10° to 10°.

[0009] In one embodiment, the device further includes a protective gas nozzle, a nozzle body, and an insulating ferrule. The protective gas nozzle is cylindrical with openings at both ends. One end of the nozzle body is connected to the conductive nozzle assembly. The powder feeding nozzle, the conductive nozzle assembly, and the end of the nozzle body near the conductive nozzle assembly are all disposed within the inner cavity of the protective gas nozzle. The insulating ferrule is fitted outside the nozzle body and inside the protective gas nozzle. The inner wall of the insulating ferrule is sealed to the nozzle body, and the outer wall of the insulating ferrule is sealed to the inner wall of the end of the protective gas nozzle away from the conductive nozzle assembly.

[0010] In one embodiment, the system further includes powder feeding conduits corresponding one-to-one with the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel. The outlet of each powder feeding conduit passes through the insulating sleeve and is placed inside the cavity of the protective gas nozzle. The inlet of each first powder feeding channel, the inlet of each second powder feeding channel, and the inlet of each third powder feeding channel are all connected to the outlet of the corresponding powder feeding conduit. The powder feeding nozzle is provided with a cooling channel, and the coolant in the cooling channel can at least cool the first powder feeding section.

[0011] The present invention also provides an arc additive manufacturing method based on the aforementioned arc additive manufacturing apparatus, comprising the following steps: Welding wire is fed into the wire feeding hole, so that the welding wire extends out of the wire feeding hole. The conductive tip assembly is energized, so that the welding wire is energized, and an electric arc is generated between the end of the energized welding wire and the base material, and the welding wire melts under the heat of the electric arc. The powder is fed into at least one of the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel, so that the powder mixes with the molten welding wire and forms a molten pool together to perform arc additive manufacturing on the substrate.

[0012] In one embodiment, the method further includes: feeding reinforcing phase powder into at least one of the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel, so that the reinforcing phase powder mixes with the molten welding wire and together forms a molten pool; The method for adding the reinforcing phase powder includes: determining the position of the powder feeding channel where the reinforcing phase powder needs to be added based on the density and decomposition temperature of the reinforcing phase powder.

[0013] In one embodiment, the method further includes adding metal powder through the first powder feeding channel, so that the metal powder mixes with the molten welding wire and together forms a molten pool.

[0014] In one embodiment, the method for adding the reinforcing phase powder further includes: If the density of the reinforcing phase powder is greater than the density of the molten pool, the reinforcing phase powder is added through the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel; if the density of the reinforcing phase powder is equal to or less than the density of the molten pool, the reinforcing phase powder is added at least through the first powder feeding channel. If the decomposition temperature of the reinforcing phase powder is lower than the first set temperature, the reinforcing phase powder is added through the third powder feeding channel; if the decomposition temperature of the reinforcing phase powder is between the second set temperature and the first set temperature, the reinforcing phase powder is added through the second powder feeding channel and the third powder feeding channel; if the decomposition temperature of the reinforcing phase powder is higher than the second set temperature, the reinforcing phase powder is added through the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel; the second set temperature is greater than the first set temperature.

[0015] The present invention achieves the following technical effects compared to the prior art: This invention provides an electric arc additive manufacturing apparatus and manufacturing method. The powder feeding nozzle includes a first powder feeding section, a second powder feeding section, and a third powder feeding section arranged sequentially along the length of the powder feeding nozzle. The first powder feeding section is provided with a wire feeding channel and at least two first powder feeding channels, all of which are spaced apart on the outer periphery of the wire feeding channel. The second powder feeding section is provided with at least one second powder feeding channel, and the third powder feeding section is provided with at least one third powder feeding channel. A conductive tip assembly passes through the wire feeding channel of the powder feeding nozzle, and the conductive tip assembly is provided with a wire feeding hole for the welding wire to pass through.

[0016] This invention features a multi-channel powder feeding system. Firstly, by using multiple channels, the flow rate of each feeding gas can be reduced, increasing the powder feeding volume. This improves the volume fraction of the reinforcing phase in the wear-resistant layer and enhances the stability of the additive manufacturing process. If a single-channel powder feeding system were used, increasing the feeding gas flow rate would necessitate increasing the powder feeding volume, interfering with the arc and droplet transfer, leading to instability in the additive manufacturing process. Secondly, it facilitates the adjustment of the matrix composition and the type of reinforcing phase. Furthermore, the first, second, and third powder feeding sections are all equipped with powder feeding channels, enabling independent powder feeding to the head, middle, and tail of the molten pool. This allows for the delivery of various powders to their corresponding positions within the molten pool as needed. Additionally, powder can be added to the head, middle, and tail of the molten pool, which helps improve the uniformity of the distribution of reinforcing phases with different densities. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the electric arc additive manufacturing apparatus in one or more embodiments; Figure 2This is a front view of an electric arc additive manufacturing apparatus in one or more embodiments; Figure 3 yes Figure 2 Sectional view of AA; Figure 4 This is a right view of an electric arc additive manufacturing apparatus in one or more embodiments; Figure 5 yes Figure 4 Sectional view of BB; Figure 6 yes Figure 4 Sectional view of CC; Figure 7 yes Figure 2 Top view; Figure 8 yes Figure 2 A bottom view; Figure 9 This is a schematic diagram of a cooling channel in one or more embodiments; Figure 10 This is a schematic diagram showing the extension direction of the powder feeding channel in one or more embodiments; Figure 11 It is a partition diagram of the powder feeding nozzle and the molten pool in one or more embodiments; Figure 12 This is a schematic diagram of the structure of the 4-channel powder delivery system; Figure 13 This is a schematic diagram of the structure of the 6-channel powder delivery system; Figure 14 This is a structural diagram of a 7-channel powder delivery system; Figure 15 This is a structural diagram of a 9-channel powder delivery system; Figure 16 This is a structural diagram of the 11-channel powder delivery system; Figure 17 This is a structural diagram of a 12-channel powder delivery system; Figure 18 This is a structural diagram of a 14-channel powder delivery system; Figure 19 This is a schematic diagram of the structure of a wire powder co-processed single melting electrode arc additive manufacturing system in one or more embodiments; Figure 20 This is a cross-sectional microstructure diagram of the composite material prepared in Example 2 using the method described in Example 1; Figure 21 This is a cross-sectional microstructure diagram of the composite material prepared using the method in Example 2 in Example 2; Figure 22 This is a cross-sectional microstructure diagram of the composite material prepared in Example 2 using the method described in Example 3; Figure 23This is a cross-sectional microstructure diagram of the composite material prepared in Example 2 using the method described in Example 4; Figure 24 This is a cross-sectional microstructure diagram of the composite material prepared in Example 2 using the method described in Example 5; Figure 25 This is a cross-sectional microstructure diagram of the composite material prepared in Example 2 using the method described in Example 6; Figure 26 This is a cross-sectional microstructure diagram of the composite material prepared in Example 2 using the method described in Example 7; Figure 27 This is a cross-sectional microstructure diagram of the composite material prepared in Example 2 using the method in Comparative Example 1; In the diagram: 100. Arc additive manufacturing device; 1. Protective gas nozzle; 2. Gun head body; 3. Conductive nozzle assembly; 4. Conductive nozzle base; 5. Conductive nozzle body; 6. Powder feeding conduit; 7. Powder feeding nozzle; 8. First powder feeding section; 9. Second powder feeding section; 10. Third powder feeding section; 11. First powder feeding channel; 12. Second powder feeding channel; 13. Third powder feeding channel; 14. Gas distributor; 15. Insulating ring; 16. Coolant conduit; 17. Cooling channel; 18. Welding machine; 19. Wire feeding mechanism; 20. Powder feeder; 21. Protective gas cylinder; 22. Powder feeding gas cylinder; 23. Traveling mechanism; 24. Controller; 25. Water cooling device; 26. Molten pool head; 27. Molten pool middle; 28. Molten pool tail; 29. ​​First powder feeding section; Powder channel centerline; 30, wire feeding hole centerline; 31-1, powder feeding channel one; 31-2, powder feeding channel two; 32-1, powder feeding channel three; 33-1, powder feeding channel four; 34-1, powder feeding channel five; 34-2, powder feeding channel six; 34-3, powder feeding channel seven; 35-1, powder feeding channel eight; 36-1, powder feeding channel nine; 36-2, powder feeding channel ten; 37-1, powder feeding channel eleven; 37-2, powder feeding channel twelve; 37-3, powder feeding channel thirteen; 38-1, powder feeding channel fourteen; 38-2, powder feeding channel fifteen; 39-1, powder feeding channel sixteen; 39-2, powder feeding channel seventeen; 40-1, powder feeding channel eighteen; 40-2, powder feeding channel nineteen; 40-3, powder feeding channel twentieth; 40- 4. Fan delivery channel 21; 41-1, Fan delivery channel 22; 41-2, Fan delivery channel 23; 42-1, Fan delivery channel 24; 42-2, Fan delivery channel 25; 42-3, Fan delivery channel 26; 43-1, Fan delivery channel 27; 43-2, Fan delivery channel 28; 43-3, Fan delivery channel 29; 43-4, Fan delivery channel 30; 44-1, Fan delivery channel 31; 44-2, Fan delivery channel 32; 44-3, Fan delivery channel 33; 45-1, Fan delivery channel 34; 45-2, Fan delivery channel 35; 45-3, Fan delivery channel 36; 45-4, Fan delivery channel 37; 46-1, Fan delivery channel 38; 46-2, Fan delivery channel 39; 46-3, Fan delivery... Channel 40; 46-4, Fan Delivery Channel 41; 47-1, Fan Delivery Channel 42; 47-2, Fan Delivery Channel 43; 47-3, Fan Delivery Channel 44; 47-4, Fan Delivery Channel 45; 48-1, Fan Delivery Channel 46; 48-2, Fan Delivery Channel 47; 48-3, Fan Delivery Channel 48; 48-4, Fan Delivery Channel 49; 49-1, Fan Delivery Channel 50; 49-2, Fan Delivery Channel 51; 49-3, Fan Delivery Channel 52; 49-4, Fan Delivery Channel 53; 49-5, Fan Delivery Channel 54; 49-6, Fan Delivery Channel 55; 50-1, Fan Delivery Channel 56; 50-2, Fan Delivery Channel 57; 50-3, Fan Delivery Channel 58; 50-4, Fan Delivery Channel 59;51-1, Follower delivery channel 60; 51-2, Follower delivery channel 61; 51-3, Follower delivery channel 62; 51-4, Follower delivery channel 63. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that in the description of this invention, the terms "upper," "lower," "left," "right," "inner," "outer," "front," "rear," "center," "longitudinal," "transverse," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "clockwise," and "counterclockwise," etc., indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] The purpose of this invention is to provide an electric arc additive manufacturing apparatus and manufacturing method to solve the problems existing in the prior art, increase the stability of the additive manufacturing process, facilitate the adjustment of matrix composition and the type of reinforcing phase, and help improve the distribution uniformity of reinforcing phases of different densities.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1 like Figures 1-18 As shown, this embodiment provides an arc additive manufacturing apparatus 100, comprising: The powder feeding nozzle 7 includes a first powder feeding section 8, a second powder feeding section 9, and a third powder feeding section 10 arranged sequentially along the length direction of the powder feeding nozzle 7. The first powder feeding section 8 is provided with a wire feeding channel and at least two first powder feeding channels 11. All the first powder feeding channels 11 are spaced apart on the outer periphery of the wire feeding channel. The second powder feeding section 9 is provided with at least one second powder feeding channel 12, and the third powder feeding section 10 is provided with at least one third powder feeding channel 13. The conductive nozzle assembly 3 passes through the wire feeding channel of the powder feeding nozzle 7, and the conductive nozzle assembly 3 is provided with a wire feeding hole for the welding wire to pass through.

[0025] This embodiment features a multi-channel powder feeding system. Firstly, by using multiple channels, the flow rate of each feeding gas can be reduced, increasing the powder feeding volume and thus improving the volume fraction of the reinforcing phase in the wear-resistant layer, thereby enhancing the stability of the additive manufacturing process. If a single-channel powder feeding system were used, increasing the powder feeding gas flow rate would inevitably interfere with the arc and droplet transition, leading to instability in the additive manufacturing process. Secondly, it facilitates the adjustment of the matrix composition and the type of reinforcing phase. Furthermore, the first powder feeding section 8, the second powder feeding section 9, and the third powder feeding section 10 are all equipped with powder feeding channels, enabling independent powder feeding to the head 26, middle 27, and tail 28 of the molten pool. This facilitates the delivery of various powders to their corresponding positions within the molten pool, and powder can be added to the head 26, middle 27, and tail 28, which helps improve the uniformity of the distribution of reinforcing phases with different densities. The molten pool is elliptical in shape and is divided into a head 26, a middle part 27 and a tail 28 along the moving direction of the arc additive manufacturing device 100.

[0026] In some embodiments, the center lines 29 of all the first powder feeding channels intersect at a point on the center line 30 of the wire feeding hole. The angle between the center line of each first powder feeding channel 11 and the center line of the wire feeding hole is 6° to 18°. The outlet end of each first powder feeding channel 11 is inclined towards the side closer to the wire feeding hole relative to the inlet end of the first powder feeding channel 11. The first powder feeding channels 11 use a small angle and converge to feed powder nearly coaxially with the welding wire. Preferably, the center lines of all the first powder feeding channels 11 intersect at the center or approximately the center of the head of the molten pool, so that the powder feeding gas flow and the movement path of the powder in the first powder feeding channels 11 are almost consistent with the direction of the shielding gas flow, reducing interference with the shielding gas, preventing the shielding gas from forming turbulence, ensuring arc stability, and guaranteeing the stability of additive manufacturing.

[0027] In some embodiments, the angle between the centerline of each second powder feeding channel 12 and the centerline of the wire feeding hole is -15° to 15°. The second powder feeding channel 12 adopts a small angle for powder feeding, so that the powder feeding airflow and the movement path of the powder in the second powder feeding channel 12 are almost consistent with the direction of the protective gas flow, reducing interference with the protective gas, preventing the protective gas from forming turbulence, ensuring arc stability, and guaranteeing the stability of additive manufacturing.

[0028] In some embodiments, the angle between the centerline of each third powder feeding channel 13 and the centerline of the wire feeding hole is -10° to 10°. The third powder feeding channel 13 adopts a small-angle powder feeding, so that the powder feeding airflow and the movement path of the powder in the third powder feeding channel 13 are almost consistent with the direction of the protective gas flow. In addition, the tail powder feeding channel is far from the arc center, which can reduce the interference to the protective gas, prevent the protective gas from forming turbulence, ensure the stability of the arc, and guarantee the stability of additive manufacturing.

[0029] In some embodiments, the system further includes a protective gas nozzle 1, a nozzle body 2, and an insulating sleeve 15. The protective gas nozzle 1 is a cylindrical shape with openings at both ends. One end of the nozzle body 2 is connected to the conductive nozzle assembly 3. The powder feeding nozzle 7, the conductive nozzle assembly 3, and the end of the nozzle body 2 closest to the conductive nozzle assembly 3 are all disposed within the inner cavity of the protective gas nozzle 1. The insulating sleeve 15 is fitted outside the nozzle body 2 and inside the protective gas nozzle 1. The inner wall of the insulating sleeve 15 is sealed to the nozzle body 2, and the outer wall of the insulating sleeve 15 is sealed to the inner wall of the end of the protective gas nozzle 1 furthest from the conductive nozzle assembly 3. The conductive nozzle assembly 3 and the protective gas nozzle 1 are isolated by the insulating sleeve 15 to prevent the protective gas nozzle 1 from becoming energized.

[0030] In some embodiments, a powder feeding conduit 6 is also included, corresponding one-to-one with the first powder feeding channel 11, the second powder feeding channel 12, and the third powder feeding channel 13. The outlet of each powder feeding conduit 6 passes through the insulating sleeve 15 and is placed inside the cavity of the protective gas nozzle 1. The inlet of each first powder feeding channel 11, the inlet of each second powder feeding channel 12, and the inlet of each third powder feeding channel 13 are all connected to the outlet of the corresponding powder feeding conduit 6. A cooling channel 17 is provided on the powder feeding nozzle 7, and the coolant in the cooling channel 17 can at least cool the first powder feeding part 8. The cooling channel 17 is used to cool the powder feeding nozzle 7, prevent the powder feeding nozzle 7 from overheating under the action of electric arc heat, thereby improving the service life of the powder feeding nozzle 7.

[0031] In some embodiments, the coolant in the cooling channel 17 can also cool the second powder feeding section 9 and the third powder feeding section 10.

[0032] In some embodiments, the conductive nozzle assembly 3 includes a conductive nozzle base 4 and a conductive nozzle body 5. The two ends of the conductive nozzle base 4 are respectively connected to the conductive nozzle body 5 and the nozzle head body 2. Both the conductive nozzle body 5 and the conductive nozzle base 4 are provided with wire feeding holes. The conductive nozzle base 4 is isolated from the protective gas nozzle 1 by an insulating collar 15.

[0033] In some embodiments, a gas splitter 14 is also included, which is sleeved around the conductive nozzle base 4. The gas splitter 14 has multiple outlets, all of which are connected to the inner cavity of the protective gas nozzle 1. The inlet of the gas splitter 14 is used to introduce protective gas. The gas splitter 14 can convert the high-pressure, turbulent protective gas flow into laminar flow, uniformly split the protective gas, prevent turbulence and porosity in the cladding layer, and ensure the stability of the additive manufacturing process.

[0034] In some implementations, the total number of powder delivery channels is 4 to 14.

[0035] In some embodiments, the internal shape of the cross-section of the protective gas outlet portion of the protective gas nozzle 1 is consistent with the external shape of the bottom cross-section of the powder feeding nozzle 7. This homogenizes the airflow pressure and velocity entering the protective gas nozzle 1 along the inner cavity cross-section, reduces the turbulence of the protective gas, and forms a near-wall laminar flow within the protective gas nozzle 1. This ensures that the ejected protective gas forms a laminar flow, thereby ensuring arc stability and achieving excellent gas protection effect.

[0036] Example 2 This embodiment provides an arc additive manufacturing method based on the arc additive manufacturing apparatus 100 of Embodiment 1, comprising the following steps: Feed the welding wire into the wire feeding hole so that the welding wire extends out of the wire feeding hole and is energized to the conductive tip assembly 3. This energizes the welding wire, generates an electric arc between the end of the energized welding wire and the base material, and melts the welding wire under the heat of the electric arc. The powder is fed into at least one of the first powder feeding channel 11, the second powder feeding channel 12 and the third powder feeding channel 13, so that the powder is mixed with the molten welding wire and together forms a molten pool for arc additive manufacturing of the substrate.

[0037] In some embodiments, the reinforcing phase powder is fed into at least one of the first powder feeding channel 11, the second powder feeding channel 12, and the third powder feeding channel 13, so that the reinforcing phase powder mixes with the molten welding wire and together forms a molten pool. The method of adding the reinforcing phase powder includes: determining the location of the powder feeding channel where the reinforcing phase powder needs to be added based on the density and decomposition temperature of the reinforcing phase powder. The powder feeding locations are located in the first powder feeding section 8, the second powder feeding section 9, and the third powder feeding section 10. Based on the temperature and viscosity distribution of the molten pool head 26, the middle part of the molten pool 27, and the tail part of the molten pool 28, as well as the flow law of the molten pool, the optimal combination of powder feeding channels is used to ensure the uniformity of the reinforcing phase particle distribution and reduce the large-scale decomposition of the reinforcing phase.

[0038] In some embodiments, the method further includes adding metal powder through the first powder feeding channel 11, so that the metal powder mixes with the molten welding wire and together forms a molten pool. Since the metal powder is part of the composite matrix, it is required to be uniformly distributed in the matrix. Therefore, by feeding the powder through the first powder feeding channel 11 of the first powder feeding section 8, it can be ensured that the metal powder enters the center of the molten pool. Under the action of various forces (including electromagnetic convection caused by electromagnetic force generated by the current flowing into the molten pool, molten pool convection caused by plasma flow force, surface tension convection caused by surface tension difference on the surface of the molten pool, impact convection caused by the impact force of molten droplets and powder, and buoyancy convection caused by density difference of molten liquid metal inside the molten pool, etc.), the liquid metal in the center of the molten pool flows violently, and the various convections generated are conducive to the uniform diffusion of various metal matrix components in the molten pool.

[0039] In some embodiments, the method for adding the reinforcing phase powder further includes: If the density of the reinforcing phase powder is greater than the density of the molten pool, the reinforcing phase powder is added through the first powder feeding channel 11, the second powder feeding channel 12, and the third powder feeding channel 13; if the density of the reinforcing phase powder is equal to or less than the density of the molten pool, the reinforcing phase powder is added at least through the first powder feeding channel 11, and the second powder feeding channel 12 and the third powder feeding channel 13 may or may not participate in the addition.

[0040] If the decomposition temperature of the reinforcing phase powder is lower than the first set temperature, the reinforcing phase powder is added through the third powder feeding channel 13; if the decomposition temperature of the reinforcing phase powder is between the second set temperature and the first set temperature, the reinforcing phase powder is added through the second powder feeding channel 12 and the third powder feeding channel 13; if the decomposition temperature of the reinforcing phase powder is higher than the second set temperature, the reinforcing phase powder is added through the first powder feeding channel 11, the second powder feeding channel 12, and the third powder feeding channel 13; the second set temperature is higher than the first set temperature. It should be noted that, since the temperature of the electric arc is higher than the temperature of the molten pool, the reinforcing phase powder is generally not easily decomposed in the molten pool after entering it. The density of the reinforcing phase powder is the main basis for determining the position of the powder feeding channel. That is, if there is a conflict when determining the position of the powder feeding channel based on the density and decomposition temperature of the reinforcing phase powder, the density of the reinforcing phase powder shall be used as the judgment basis.

[0041] In some embodiments, when the density of the reinforcing phase powder is equal to or less than the density of the molten pool, the first powder feeding channel 11 must participate in the addition of the reinforcing phase powder. Based on this, the participation of the second powder feeding channel 12 and the third powder feeding channel 13 in the addition can be determined by combining the decomposition temperature of the reinforcing phase powder.

[0042] In some implementations, the first set temperature is 1000°C and the second set temperature is 1500°C.

[0043] In some embodiments, the welding wire types include solid welding wire and flux-cored welding wire; solid welding wire can adjust the composition of the composite matrix, while flux-cored welding wire can adjust not only the matrix composition, but also the type, volume fraction, and morphology of the reinforcing phase.

[0044] In some embodiments, the flux-cored wire comprises a metal strip and flux core powder, wherein the flux core powder comprises metal powder and reinforcing phase powder. This allows for convenient adjustment of the matrix composition and content of the composite material, as well as the morphology, type, and volume fraction of the reinforcing phase.

[0045] In some embodiments, the method further includes: determining the type, diameter, composition, and content of the welding wire, as well as the type, particle size, morphology, and content of the powder, based on the structural and performance requirements of the composite material to be prepared.

[0046] In some embodiments, the metal powder includes pure metal powder and alloy powder.

[0047] In some embodiments, the shielding gas used for additive manufacturing is at least one of Ar, He, CO2, O2, and N2, with a gas flow rate of 10-50 L / min. This ensures the additive manufacturing process is carried out under gas protection, preventing oxidation and nitriding of the molten pool and cladding metal, avoiding defects such as inclusions, and guaranteeing cladding quality. Simultaneously, the welding shielding gas serves as the medium for generating the electric arc, maintaining stable arc combustion and stabilizing the additive manufacturing process. The powder feeding gas used for additive manufacturing is at least one of Ar, He, CO2, O2, and N2, with a gas flow rate of 10-50 L / min. This ensures stable powder feeding and stable additive manufacturing processes.

[0048] In some embodiments, the reinforcing phase powder includes carbides, nitrides, borides, oxides, carbonitrides, diamond, graphite, boron, etc., which allows for convenient selection of a suitable reinforcing phase for the composite material according to its performance requirements.

[0049] In some implementations, a fused electrode arc is used as the heat source. A moderate heat source temperature improves cladding efficiency and composite material density, while preventing excessive decomposition of the reinforcing phase, thus enabling the preparation of composite materials with added particle reinforcement. Since reinforcing phases such as WC are prone to decomposition at high temperatures, the heat source temperature in additive manufacturing methods must be appropriate. On the one hand, high melting efficiency must be ensured; on the other hand, the temperature cannot be too high to avoid excessive decomposition of reinforcing phases such as WC. Comparing the temperatures of the main heat sources currently available, flame-type heat sources have lower temperatures than electric arc-type heat sources, which in turn have lower temperatures than plasma arc or laser heat sources. Flame-type heat sources have low energy density, dispersed heat sources, and low thermal efficiency, with temperatures around 3000℃, resulting in less WC decomposition, but the temperature is relatively low. Laser and plasma arc heat sources have temperatures exceeding 10000℃, which is too high, leading to significant decomposition of reinforcing phases such as WC during the transition process. MIG, MAG, and CO2 gas-protected arcs have temperatures around 5000℃, while TIG arcs have slightly higher temperatures, around 6000℃-8000℃. Therefore, using gas-protected arcs as a heat source is more suitable, as it ensures high melting efficiency, avoids excessive decomposition of reinforcing phases such as carbides due to excessive temperature, and can form a molten pool with a certain degree of fluidity, ensuring the density of the composite material.

[0050] In this invention, the various convection currents generated during the wire-powder co-processing fused electrode arc additive manufacturing process facilitate the diffusion of various matrix components and the movement of various reinforcing phases in the molten pool, thereby promoting the uniform distribution of matrix components and various reinforcing phases. The molten pool is not only subjected to the thermal effect of the arc, but also to the arc force and other forces, resulting in regular convective flow in the molten pool. Specifically, this includes electromagnetic convection caused by the electromagnetic force generated by the current flowing into the molten pool, molten pool convection caused by the plasma flow force, surface tension convection caused by the surface tension difference on the surface of the molten pool, impact convection caused by the impact force of molten droplets and powder, and buoyancy convection caused by the density difference of the molten liquid metal inside the molten pool. The flow of the molten pool enhances the rapid diffusion of different elements within the pool, which is beneficial to the uniformity of different matrix elements. On the other hand, convection has a significant impact on the stress and distribution of the reinforcing phase. Electromagnetic convection and impingement convection have the greatest impact on the flow inside the molten pool. Electromagnetic convection and impingement convection promote the flow of liquid metal from the surface center into the molten pool. In the lower part of the molten pool, the liquid metal flows to the upper sides, thereby promoting the movement of the reinforcing phase and increasing its uniformity.

[0051] Based on the shape characteristics of the molten pool and the physicochemical properties of different regions within the molten pool, this invention designs a multi-position channel powder feeding nozzle 7. This nozzle 7 structure not only achieves a uniform distribution of the high-density reinforcing phase but also promotes a further uniform distribution of the medium-density and low-density reinforcing phases. The density of the high-density reinforcing phase is significantly greater than the density of the molten pool. Using conventional convergent powder feeding, the high-density reinforcing phase, under the influence of gravity, will mainly distribute in the lower and middle parts of the molten pool, resulting in uneven distribution. The molten pool of a metal arc welding (MAW) weld is generally elliptical, divided into a head 26, a middle section 27, and a tail section 28, as shown below. Figure 11 As shown, the head 26 of the molten pool is located below the center of the electric arc, with the highest temperature, the greatest melting depth, and violent movement. The middle 27 of the molten pool is adjacent to the center of the electric arc, with the widest molten pool, stable liquid metal flow, higher temperature, and a melting depth that gradually narrows from front to back. The tail 28 of the molten pool is far from the center of the electric arc, with a narrower molten pool width, shallowest melting depth, and lowest temperature. Based on the shape characteristics of each region of the molten pool, the temperature distribution characteristics, viscosity changes, and physicochemical properties such as the flow law of the molten pool, the corresponding multi-position channel powder feeding nozzle 7 is designed to consist of a first powder feeding section 8, a second powder feeding section 9, and a third powder feeding section 10 at the head, as shown below. Figure 11 As shown, this design can achieve a uniform distribution of reinforcing phases with different densities.

[0052] The forces acting on reinforcing phase particles within the molten pool mainly include their own weight, buoyancy, and viscous forces. The viscous force acting on the reinforcing phase is relatively complex. According to Stokes' law, the viscous force acting on the reinforcing phase is proportional to the hydrodynamic viscosity, relative velocity, and diameter of the reinforcing phase particles. Its direction depends on the relative magnitude of the reinforcing phase's velocity and the molten pool's flow velocity. When the reinforcing phase first enters the molten pool at a certain velocity, its velocity is greater than the molten pool's flow velocity, and the viscous force acts as a resistance to the reinforcing phase's movement. Under the influence of viscous forces, the velocity of the reinforcing phase gradually decreases until it is less than the molten pool's flow velocity, at which point the viscous force becomes the driving force for the reinforcing phase's movement. In the lower part of the molten pool, the flow direction is upwards and to the sides. At this point, the direction of the viscous force acting on the reinforcing phase is the same as the molten pool's flow direction, also upwards and to the sides, acting as the driving force for the reinforcing phase's movement. The velocity of the reinforcing phase particles gradually increases in the direction of the viscous force, while the relative velocity between the molten pool fluid and the reinforcing phase decreases, leading to a gradual decrease in the viscous force.

[0053] At this point, if the density of the reinforcing phase is less than the density of the molten metal in the molten pool, the buoyancy force on the reinforcing phase is greater than its gravity. Viscous force, as the main driving force for the upward movement of the reinforcing phase particles, will cause the reinforcing phase to move with the flow of the molten metal, resulting in a more uniform distribution within the molten pool. Conversely, if the density of the reinforcing phase is greater than the density of the molten metal, the buoyancy force on the reinforcing phase is less than its gravity. Gravity, as a resistance force to the upward movement of the reinforcing phase, becomes increasingly significant, and the movement speed of the reinforcing phase gradually decreases. This results in the reinforcing phase being mainly distributed in the lower and middle parts of the molten pool. (Stokes' law refers to the hydrodynamic viscosity.) Strongly dependent on temperature, the hydrodynamic viscosity of the liquid metal increases as the temperature decreases. At the tail end of the molten pool 28, the liquid metal is further away from the arc center, the temperature decreases, and the hydrodynamic viscosity increases. Furthermore, the electromagnetic convection and droplet impact convection weaken, resulting in reduced convection of the liquid metal in the molten pool and a significant decrease in the molten pool flow velocity. When the reinforcing phase flies towards the middle molten pool 27 and the tail end 28 at a certain speed, its velocity is much greater than the flow velocity of the liquid metal when it first enters the molten pool. Due to the relatively high velocity between the reinforcing phase and the molten pool metal, and the relatively high hydrodynamic viscosity of the metal in the middle molten pool 27 and the tail end 28, the reinforcing phase experiences significant upward viscous resistance according to Stokes' theorem, further reducing its velocity. Simultaneously, as the liquid metal in the lower part of the middle molten pool 27 and the tail end 28 gradually solidifies, the molten pool becomes shallower, causing the reinforcing phase to mainly distribute in the upper middle part of the tail end 28 after entering the molten pool. For the denser reinforcing phase, the first powder feeding channel 11 feeds the reinforcing phase onto the upper surface of the head of the molten pool along its length. Under the influence of gravity, buoyancy, and viscosity, the reinforcing phase powder is mainly distributed in the lower middle part of the molten pool. The second and third powder feeding channels 12 and 13 feed the reinforcing phase onto the upper surface of the middle and tail of the molten pool, respectively. Under the influence of gravity, buoyancy, and viscosity, the reinforcing phase powder is mainly distributed in the upper middle part of the molten pool. During continuous processing, the molten pool head 26 (where more reinforcing powder is added to the lower middle part) at one moment becomes the molten pool middle 27 and tail 28 (where more reinforcing powder is added to the upper middle part) at the next moment, thus achieving a uniform distribution of the high-density reinforcing phase throughout the molten pool.

[0054] This invention employs a multi-channel powder feeding and wire feeding system to facilitate the delivery of filler materials. This allows for convenient adjustment of the matrix composition and content, as well as the morphology, type, and volume fraction of the reinforcing phase, enabling the preparation of composite materials with high volume fractions of multiple reinforcing phases and multi-principal-element matrices. On one hand, solid welding wire or flux-cored welding wire can be used as the consumable electrode filler wire. Flux-cored welding wire, in particular, can be filled with either reinforcing phases or metal powder in its core, allowing for easy adjustment of the matrix composition and the morphology, type, and volume fraction of the reinforcing phases. On the other hand, the multi-channel powder feeding system allows for the delivery of both metal powder and reinforcing phase powder through multiple channels, further facilitating the adjustment of the matrix composition and the morphology, type, and volume fraction of the reinforcing phases. Therefore, through the synergistic addition of materials by wire and powder, complex composite materials with high volume fractions, multiple reinforcing phases, and multi-principal-element matrices can be easily prepared.

[0055] Based on the interaction mechanism of droplets, molten pool, powder, gas and electric arc in the additive manufacturing process, this invention optimizes the number, position and angle of powder feeding channels, which can reduce the flow rate of each powder feeding gas, hardly interfere with the protective gas, prevent the protective gas from forming turbulence, ensure the stability of the electric arc, the stability of the droplet transition, and the stability of the additive manufacturing process. As a result, the quality of the prepared composite material is stable and the matrix composition can be easily adjusted.

[0056] In some embodiments, the system further includes: establishing a wire-powder co-processing single-electrode arc additive manufacturing system, comprising a welding machine 18, a wire feeding mechanism 19, a powder feeder 20, a protective gas cylinder 21, a powder feeding gas cylinder 22, a traveling mechanism 23, an arc additive manufacturing device 100, a controller 24, and a water cooling device 25. The welding machine 18 is electrically connected to the conductive nozzle body 5. The wire feeding mechanism 19 is used to feed welding wire into the wire feeding hole. Powder is transported to the powder feeding channel using gas from the powder feeding gas cylinder 22. The protective gas cylinder 21 is used to input protective gas into the protective gas nozzle 1. The traveling mechanism 23 is used to drive the arc additive manufacturing device 100 to move along a set direction. The water cooling device 25 is used to introduce coolant into the cooling channel 17. The controller 24 can be connected to the welding machine 18, the wire feeding mechanism 19, the powder feeder 20, the traveling mechanism 23, and the water cooling device 25.

[0057] In some embodiments, the process further includes: setting wire-powder co-processing single-electrode arc additive manufacturing process parameters, activating the controller 24, and controlling the operation of the welding machine 18, powder feeder 20, and traveling mechanism 23, etc., to perform wire-powder co-processing arc additive manufacturing on the surface of a metal matrix. By setting the process parameters, the microstructure and composition of the composite material can be further precisely controlled, making the additive manufacturing process stable. For example, by adjusting the wire feeding speed, powder feeding speed, and cladding speed, the type and quantity of reinforcing phases, matrix composition and content of the welding wire and powder transitioning to the molten pool can be adjusted, thereby achieving precise adjustment of the type and volume fraction of reinforcing phases, matrix composition and content of the composite material, and thus realizing the preparation of high-performance composite materials.

[0058] In some embodiments, the welding wire diameter is 0.6–2.4 mm, the wire feed speed is 3–20 m / min, the powder particle size is 10–500 μm, the powder feed rate is 8–240 g / min, the average welding current is 20–450 A, the average arc voltage is 8–40 V, and the cladding speed is 0.2–2.0 m / min. By adjusting the additive manufacturing process parameters, the composition and structure of the composite material can be controlled to meet the requirements for preparing high-performance composite materials.

[0059] This invention features high efficiency, low cost, stable additive manufacturing process, reduced decomposition of reinforcing phases such as carbides, uniform distribution of high-density reinforcing phases in cladding composites, preparation of composites with high volume fraction of reinforcing phases, preparation of composites with multi-principal matrix, and good comprehensive properties such as wear resistance, corrosion resistance, and crack resistance of the prepared composites.

[0060] To better illustrate the filament-powder co-processing single-melting-electrode arc additive manufacturing apparatus 100 for composite material preparation provided by the present invention, further examples 1-7 are given below.

[0061] The arc additive manufacturing apparatus 100 provided in Examples 1-7 of the present invention is a wire-powder co-processing single-melting-electrode arc additive manufacturing apparatus 100 for the preparation of composite materials. It includes a protective gas nozzle 1, a conductive nozzle, a conductive nozzle base 4, a powder feeding conduit 6, a powder feeding nozzle 7, a gas distributor 14, an insulating sleeve 15, a coolant conduit 16, and a gun head body 2. The powder feeding nozzle 7 is composed of a first powder feeding section 8, a second powder feeding section 9, and a third powder feeding section 10 at the head. Its internal structure includes a powder feeding channel and a cooling channel 17. The conductive nozzle base 4 is connected to the conductive nozzle and the gun head body 2. The gas distributor 14 is sleeved around the conductive nozzle base 4. The conductive nozzle base 4 and the protective gas nozzle 1 are isolated by the insulating sleeve 15. The powder feeding conduit 6 passes through the insulating sleeve 15 and then connects to the powder feeding channel.

[0062] In Examples 1-7, the number of powder feeding channels in the first powder feeding section 8, the second powder feeding section 9, and the third powder feeding section 10 are shown in Table 1. The number of first powder feeding channels 11, second powder feeding channels 12, and third powder feeding channels 13 in Examples 1-7, the angle between the center line of each first powder feeding channel 11 and the center line of the wire feeding hole, the angle between the center line of each second powder feeding channel 12 and the center line of the wire feeding hole, and the angle between the center line of each third powder feeding channel 13 and the center line of the wire feeding hole are shown in Table 1.

[0063] Table 1. Number, location, and angle of powder delivery channels

[0064] Examples 1-7 illustrate the following steps for composite material preparation using a filament-powder co-processing single-melting-electrode arc additive manufacturing: (1) Based on the structural and performance requirements of the composite material to be prepared, Example 1-7 designed a composite material for single melting electrode arc additive manufacturing, including welding wire and powder. The type, diameter, composition and content of the welding wire are shown in Table 2. The type, particle size and morphology of the powder in each powder feeding channel are shown in Tables 3-9. (2) The location of the powder feeding channel for the reinforcing phase powder was determined based on the density and decomposition temperature of the reinforcing phase powder, as shown in Tables 3-9. (3) In Example 5-7, metal powder was added. The metal powder was located in the powder feeding channel of the first powder feeding section 8 at the head of the powder feeding nozzle 7, as shown in Tables 7-9. (4) Establish a wire-powder co-processing single-melting-electrode arc additive manufacturing system, such as Figure 19 As shown, the device includes an electric welding machine 18, a wire feeding mechanism 19, a powder feeder 20, a protective gas cylinder 21, a powder feeding gas cylinder 22, a walking mechanism 23, an electric arc additive manufacturing device 100, a controller 24, and a water cooling device 25. The wire feeding mechanism 19 feeds welding wire to the electric arc additive manufacturing device 100, and the powder feeder 20 feeds powder to the electric arc additive manufacturing device 100. (5) Set the wire-powder co-processing single melting electrode arc additive manufacturing process parameters as shown in Table 10, start the controller 24, control the operation of the welding machine 18, the powder feeder 20 and the walking mechanism 23, and perform wire-powder co-processing arc additive manufacturing on the surface of the metal substrate.

[0065] Table 2 shows the type, diameter, composition, and content of welding wire in each example.

[0066] Table 3. Location of powder feeding channels and types, particle sizes, and morphologies of powders in Example 1.

[0067] In Example 1, the powder delivery channel is as follows: Figure 12 As shown, these are powder delivery channels 1 (31-1), 2 (31-2), 3 (32-1), and 4 (33-1), respectively.

[0068] Table 4. Location of powder feeding channels and types, particle sizes, and morphologies of powders in Example 2.

[0069] In Example 2, the powder delivery channel is as follows: Figure 13 As shown, these are the following channels: fan delivery channel 5 (34-1), fan delivery channel 6 (34-2), fan delivery channel 7 (34-3), fan delivery channel 8 (35-1), fan delivery channel 9 (36-1), and fan delivery channel 10 (36-2).

[0070] Table 5. Location of powder feeding channels and types, particle sizes, and morphologies of powders in Example 3.

[0071] In Example 3, the powder delivery channel is as follows: Figure 14As shown, these are the following channels: fan delivery channel 11 (37-1), fan delivery channel 12 (37-2), fan delivery channel 13 (37-3), fan delivery channel 14 (38-1), fan delivery channel 15 (38-2), fan delivery channel 16 (39-1), and fan delivery channel 17 (39-2).

[0072] Table 6 shows the location of the powder feeding channel and the type, particle size, and morphology of the powder in Example 4.

[0073] In Example 4, the powder delivery channel is as follows: Figure 15 As shown, these are the following channels: 40-1 (eighteenth channel), 40-2 (nineteenth channel), 40-3 (twentieth channel), 40-4 (twenty-first channel), 41-1 (twenty-second channel), 41-2 (twenty-third channel), 42-1 (twenty-fourth channel), 42-2 (twenty-fifth channel), and 42-3 (twenty-sixth channel).

[0074] Table 7. Location of powder feeding channels and types, particle sizes, and morphologies of powders in Example 5.

[0075] In Example 5, the powder delivery channel is as follows: Figure 16 As shown, these are the following fan delivery channels: 27-43-1, 28-43-2, 29-43-3, 30-43-4, 31-44-1, 32-44-2, 33-44-3, 34-45-1, 35-45-2, 36-45-3, and 37-45-4.

[0076] Table 8 shows the location of the powder feeding channel and the type, particle size, and morphology of the powder in Example 6.

[0077] In Example 6, the powder delivery channel is as follows: Figure 17 As shown, these are the following fan delivery channels: 46-1 (38), 46-2 (39), 46-3 (40), 46-4 (41), 47-1 (42), 47-2 (43), 47-3 (44), 47-4 (45), 48-1 (46), 48-2 (47), 48-3 (48), and 48-4 (49).

[0078] Table 9 shows the location of the powder feeding channel and the type, particle size, and morphology of the powder in Example 7.

[0079] In Example 7, the powder delivery channel is as follows: Figure 18As shown, these are the following fan delivery channels: 5049-1, 5149-2, 5249-3, 5349-4, 5449-5, 5549-6, 5650-1, 5750-2, 5850-3, 5950-4, 6051-1, 6151-2, 6251-3, and 6351-4.

[0080] Table 10. Process parameters for each example of arc additive manufacturing

[0081] Figures 20-27 For the cross-sectional microstructure of the composite materials prepared in each example and Comparative Example 1, Comparative Example 1 uses powder feeding channels 31-1 and 31-2 of the first powder feeding section 8 of Example 1 for powder feeding. The welding wire and powder used are the same as those in Example 1, and the process parameters used are the same as those in Example 1. Since WC is fed through the powder feeding channel of the first powder feeding section 8 only, and the density of WC is large, much greater than the density of the molten pool, under the action of various forces, WC is mainly distributed in the middle and lower parts, resulting in uneven distribution of WC reinforcing phase and low volume fraction. In contrast, the reinforcing phase of Examples 1 to 7 is evenly distributed and has a high volume fraction.

[0082] Friction and wear tests were conducted on the composite materials using a friction and wear testing device. Table 11 shows the wear resistance of the composite materials prepared by arc additive manufacturing in each example and the composite material prepared by plasma cladding in Comparative Example 2. Comparative Example 2 was prepared by plasma cladding, and the composition and content of the reinforcing phase powder used were the same as those in Example 2. The composition and content of the metal powder used were the same as those of the welding wire in Example 2. Moreover, by adjusting the process parameters, the mass ratio of reinforcing phase powder to metal powder in Comparative Example 2 was the same as that of reinforcing phase powder to metal matrix in Example 2. The experimental process was to conduct friction and wear tests for 12 hours a day for 7 consecutive days, and the abrasive grains were replaced every 12 hours. The abrasive grains were sand grains. The composite materials prepared in each example had very small mass loss and excellent wear resistance, while the composite material prepared by plasma cladding had a larger mass loss and cracks appeared. This was because the plasma arc heat source temperature was high, resulting in more decomposition of the reinforcing phase. On the one hand, this reduced the wear resistance, and on the other hand, the decomposed carbon increased the carbon equivalent of the matrix, leading to crack formation.

[0083] Table 12 shows the corrosion resistance of the example electric arc additive manufacturing composite materials and the comparative example 3 powder-fed laser additive manufacturing composite material in chlorine-containing media. Comparative example 3 uses laser additive manufacturing composite material, and the composition and content of the reinforcing phase powder used are the same as those of example 3. The composition and content of the metal powder used are the same as those of the welding wire in example 3. Moreover, by adjusting the process parameters, the mass ratio of reinforcing phase powder to metal powder in comparative example 3 is the same as that of reinforcing phase powder to metal matrix in example 3. It can be seen that comparative example 3 has the highest corrosion rate and the worst corrosion resistance, while the corrosion rates of each example are relatively small and the corrosion resistance is excellent. This is because when the matrix composition is relatively large, due to the small laser molten pool, the fast cooling rate, and the poor fluidity of the molten pool, the elements do not have enough time to diffuse evenly, resulting in uneven matrix composition prepared by laser additive manufacturing, thereby reducing corrosion resistance.

[0084] Table 11 shows the wear resistance of composite materials manufactured by arc additive manufacturing in various examples and by plasma cladding in Comparative Example 2.

[0085] Table 12 Corrosion resistance of composite materials from various examples of arc additive manufacturing and Comparative Example 3 (powder-fed laser additive manufacturing)

[0086] In summary, each example has the advantages of high efficiency, low cost, and stable additive manufacturing process of wire-powder synergistic arc additive manufacturing. Moreover, the arc temperature is moderate, which can reduce the decomposition of reinforcing phases such as carbides. Through multi-positional powder feeding, the uniform distribution of high-density reinforcing phases in the cladding composite material is achieved. Through multi-path powder feeding, the preparation of composite materials with high volume fraction reinforcing phases is realized. Through multi-path metal powder feeding and welding wire feeding, the preparation of composite materials with multi-principal matrix is ​​conveniently realized. The prepared composite materials have good comprehensive properties such as wear resistance, corrosion resistance, and crack resistance.

[0087] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An electric arc additive manufacturing apparatus, characterized in that, include: The powder feeding nozzle includes a first powder feeding section, a second powder feeding section and a third powder feeding section arranged sequentially along the length direction of the powder feeding nozzle. The first powder feeding section is provided with a wire feeding channel and at least two first powder feeding channels. All the first powder feeding channels are spaced apart on the outer periphery of the wire feeding channel. The second powder feeding section is provided with at least one second powder feeding channel, and the third powder feeding section is provided with at least one third powder feeding channel. A conductive tip assembly passes through the wire feeding channel of the powder feeding nozzle, and the conductive tip assembly is provided with a wire feeding hole for the welding wire to pass through.

2. The electric arc additive manufacturing apparatus according to claim 1, characterized in that, The center lines of all the first powder feeding channels intersect at a point on the center line of the wire feeding hole. The angle between the center line of each first powder feeding channel and the center line of the wire feeding hole is 6° to 18°. The outlet end of each first powder feeding channel is inclined towards the side closer to the wire feeding hole relative to the inlet end of the first powder feeding channel.

3. The electric arc additive manufacturing apparatus according to claim 1, characterized in that, The angle between the centerline of each of the second powder feeding channels and the centerline of the wire feeding hole is -15° to 15°.

4. The electric arc additive manufacturing apparatus according to claim 1, characterized in that, The angle between the centerline of each of the third powder feeding channels and the centerline of the wire feeding hole is -10° to 10°.

5. The electric arc additive manufacturing apparatus according to claim 1, characterized in that, It also includes a protective gas nozzle, a nozzle body, and an insulating ferrule. The protective gas nozzle is a cylindrical shape with openings at both ends. One end of the nozzle body is connected to the conductive nozzle assembly. The powder feeding nozzle, the conductive nozzle assembly, and the end of the nozzle body near the conductive nozzle assembly are all disposed within the inner cavity of the protective gas nozzle. The insulating ferrule is fitted outside the nozzle body and inside the protective gas nozzle. The inner wall of the insulating ferrule is sealed to the nozzle body, and the outer wall of the insulating ferrule is sealed to the inner wall of the end of the protective gas nozzle away from the conductive nozzle assembly.

6. The electric arc additive manufacturing apparatus according to claim 5, characterized in that, It also includes powder feeding conduits that correspond one-to-one with the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel. The outlet of each powder feeding conduit passes through the insulating sleeve and is placed inside the cavity of the protective gas nozzle. The inlet of each first powder feeding channel, the inlet of each second powder feeding channel, and the inlet of each third powder feeding channel are all connected to the outlet of the corresponding powder feeding conduit. The powder feeding nozzle is provided with a cooling channel, and the coolant in the cooling channel can at least cool the first powder feeding section.

7. An arc additive manufacturing method based on the arc additive manufacturing apparatus according to any one of claims 1 to 6, characterized in that, Includes the following steps: Welding wire is fed into the wire feeding hole, so that the welding wire extends out of the wire feeding hole. The conductive tip assembly is energized, so that the welding wire is energized, and an electric arc is generated between the end of the energized welding wire and the base material, and the welding wire melts under the heat of the electric arc. The powder is fed into at least one of the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel, so that the powder mixes with the molten welding wire and forms a molten pool together to perform arc additive manufacturing on the substrate.

8. The electric arc additive manufacturing method according to claim 7, characterized in that, Also includes: The reinforcing phase powder is fed into at least one of the first powder feeding channel, the second powder feeding channel and the third powder feeding channel, so that the reinforcing phase powder is mixed with the molten welding wire and together forms a molten pool. The method for adding the reinforcing phase powder includes: determining the position of the powder feeding channel where the reinforcing phase powder needs to be added based on the density and decomposition temperature of the reinforcing phase powder.

9. The electric arc additive manufacturing method according to claim 8, characterized in that, Also includes: Metal powder is added through the first powder feeding channel, so that the metal powder mixes with the molten welding wire and together forms a molten pool.

10. The electric arc additive manufacturing method according to claim 8, characterized in that, The method for adding the reinforcing phase powder further includes: If the density of the reinforcing phase powder is greater than the density of the molten pool, the reinforcing phase powder is added through the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel; if the density of the reinforcing phase powder is equal to or less than the density of the molten pool, the reinforcing phase powder is added at least through the first powder feeding channel. If the decomposition temperature of the reinforcing phase powder is lower than the first set temperature, the reinforcing phase powder is added through the third powder feeding channel; if the decomposition temperature of the reinforcing phase powder is between the second set temperature and the first set temperature, the reinforcing phase powder is added through the second powder feeding channel and the third powder feeding channel; if the decomposition temperature of the reinforcing phase powder is higher than the second set temperature, the reinforcing phase powder is added through the first powder feeding channel, the second powder feeding channel, and the third powder feeding channel; the second set temperature is greater than the first set temperature.

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