Double-material-source in-situ cooling stirring friction additive manufacturing device

Abstract

The invention discloses a double-material-source in-situ cooling stirring friction additive manufacturing device, and relates to the technical field of additive manufacturing, the double-material-source in-situ cooling stirring friction additive manufacturing device comprises a shaft shoulder and a mixing area arranged in the middle of the shaft shoulder; the powder feeding mechanism and the wire feeding mechanism are assembled on the upper portion and the side wall of the shaft shoulder correspondingly, and a powder amount adjusting mechanism is further arranged at the inlet position of the powder feeding mechanism; the stirring mechanism and the spiral conveying rod are coaxially distributed at the upper part and the lower part in the shaft shoulder; and the in-situ cooling mechanism is assembled on the periphery of the shaft shoulder. Through the design of integrating double material source supply, built-in stirring and mixing and in-situ cooling into the same equipment, in-situ compounding and homogenization of raw materials are achieved, meanwhile, the conveying rate of the raw materials is flexibly adjusted, and dynamic regulation and control of material components of a deposition layer are further achieved; and performance deterioration caused by heat accumulation can be effectively inhibited.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically to a dual-source in-situ cooling stirring friction additive manufacturing apparatus. Background Technology

[0002] Additive manufacturing is currently mainly divided into two categories: melting additive manufacturing and solid-state additive manufacturing. Melting additive manufacturing is mainly used in the preparation of high-melting-point metals such as steel, titanium alloys, and nickel alloys. However, its applicability to low-melting-point metals such as aluminum alloys and magnesium alloys faces challenges such as high heat input, melting defects, and dissolution of strengthening phases, making it difficult to apply widely. Friction stir additive manufacturing, which is based on friction stir welding, continues the advantages of solid-state processing and has become an ideal choice for additive manufacturing of low-melting-point metals.

[0003] Currently, the most widely used method is friction stir deposition additive manufacturing, which uses bar stock as the feed material. This method enables solid-phase additive manufacturing of various materials without defects and preserves the properties of the raw materials to a great extent. For example, document CN114799480A discloses a synchronous uninterrupted wire feeding method and device for solid-phase friction stir deposition additive manufacturing. Based on the traditional AFSD process, the raw material is changed to wire, avoiding the interruption of the additive manufacturing process caused by material change and realizing continuous feeding and additive manufacturing. Another example is a powder bed feeding composite friction stir deposition additive manufacturing device and method (CN2023114488876), which proposes a powder bed composite additive manufacturing process based on powder core wire friction stir deposition additive manufacturing. This process can realize the rapid preparation of reinforced phase strengthened alloys. However, this invention is difficult to precisely control in terms of the content of different material components and the uniformity of wire-powder mixing.

[0004] Furthermore, in the cooling process of additive manufacturing, both the apparatus and the deposited layer are immersed in water. However, this method not only easily causes the filament to be affected by water immersion, thus affecting the density of the deposited layer, but also results in poor additive manufacturing performance. To address this, a dual-source in-situ cooling stirring friction additive manufacturing apparatus is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-source in-situ cooled stirring friction additive manufacturing device. This device integrates dual-source supply, built-in stirring and mixing, and in-situ cooling into a single unit. This not only achieves in-situ compounding and homogenization of raw materials, but also allows for flexible adjustment of the raw material delivery rate, further enabling dynamic control of the composition of the deposited layer material. In addition, the synchronous cooling process of the spiral conveyor and the deposited layer can effectively suppress performance degradation caused by heat accumulation, significantly improving the manufacturing quality of the deposited components. Furthermore, the cooling tube is annularly assembled on the outer wall of the shaft shoulder, ensuring that the filament does not directly contact the coolant before deposition, thus keeping the filament dry and ensuring the density of the deposited layer.

[0006] To achieve the above objectives, the present invention provides the following technical solution.

[0007] A dual-source in-situ cooled stirring friction additive manufacturing apparatus includes: a shoulder; a mixing zone located in the middle of the shoulder; a powder feeding mechanism and a wire feeding mechanism respectively mounted on the upper part and side wall of the shoulder, wherein the powder feeding mechanism and the wire feeding mechanism are used to transport powder and wire into the mixing zone, and the powder feeding mechanism is also provided with a powder quantity adjustment mechanism at the inlet position for flexible control of the powder feeding rate; a stirring mechanism and a spiral conveying rod coaxially distributed on the upper and lower parts of the shoulder for thorough mixing of powder and wire; and an in-situ cooling mechanism mounted on the outer periphery of the shoulder, wherein the in-situ cooling mechanism includes cooling pipes and jet components disposed on the upper and lower parts of the shoulder, wherein the jet components are arranged in a ring array and aligned with the shoulder.

[0008] Preferably, the powder feeding mechanism includes a column fixed to one side of the shoulder, a first crossbar and a second crossbar fixed to the side wall near the top of the column, a fixed tube and a transmission ring respectively fixed to the first crossbar and the second crossbar, wherein a movable tube rotatably installed inside the transmission ring is rotatably connected to the bottom of the fixed tube; and a powder feeding channel annularly opened inside the movable tube, wherein the bottom ends of several powder feeding channels extend toward and communicate with the mixing zone, and their top ends converge upward and present a funnel shape with the tip pointing downward; and also includes a first powder inlet pipe connected to the top of the fixed tube and assembled with the powder quantity adjustment mechanism.

[0009] Preferably, the stirring mechanism includes a central shaft movably mounted in the middle of the fixed tube, a sleeve fixed to the middle of the powder feeding channel and externally disposed on the central shaft, wherein the bottom end of the central shaft is assembled with the top end of the spiral conveying rod; and a first crushing tooth and a second crushing tooth respectively fixed to the bottom end of the central shaft and the sleeve and rotating in opposite directions; and further includes a meshing transmission assembly disposed on the top end of the central shaft and the sleeve for synchronous driving of the central shaft and the sleeve.

[0010] Preferably, the meshing transmission assembly includes a first transmission gear fixed near the outer wall of the top end of the movable tube; and an extension frame fixed on the column, wherein a second transmission gear fixed to the top end of the second crossbar is rotatably mounted in the middle of the extension frame via a first rotating shaft, and a third transmission gear and a fourth transmission gear are rotatably mounted at both ends of the extension frame via a second rotating shaft, wherein the third transmission gear meshes with the second transmission gear, and the fourth transmission gear meshes with both the third transmission gear and the first transmission gear; it also includes an extension plate fixed to the side wall of the transmission ring, wherein a motor is mounted at the bottom of the extension plate, and its output shaft passes through a through hole opened in the extension plate and is fixed to the fourth transmission gear.

[0011] Preferably, the powder quantity adjustment mechanism includes a connecting frame fixed to the column, on which a first fixing ring and a second fixing ring are fixedly connected to each other. The first fixing ring contains a transmission disc, and a circular hole in the center of the transmission disc connects to the end of the first powder inlet pipe. It also includes a connecting rod annularly fixed to the inner side of the second fixing ring, and a circular ring fixed to several connecting rods, with a second powder inlet pipe communicating with the circular ring. Furthermore, it includes a petal-shaped adjusting valve internally disposed within the first and second fixing rings and positioned between the circular hole and the circular ring, for adjusting the powder delivery from the second powder inlet pipe to the first powder inlet pipe. The powder quantity, the petal regulating valve includes several grooves formed on the outer periphery of the transmission disc, each groove having one end extending outward and the other end extending into its adjacent groove and communicating with its middle; and a slider disposed in each groove, the slider having a petal block fixed on it, the petal block having a transmission column disposed in its middle; it also includes a transmission groove formed on each connecting rod, the transmission groove being sleeved and installed with its corresponding transmission column and being able to slide relative to it; the outer periphery of the first fixing ring is also provided with an arc-shaped through groove; and a handle extending into the arc-shaped through groove and fixed to the outer edge of the transmission disc for conveniently moving the transmission disc.

[0012] Preferably, the wire feeding mechanism includes a wire inlet tube that is laterally installed through the side wall of the shoulder, wherein one end of the wire inlet tube extends into the mixing zone and the other end is equipped with a wire feeder.

[0013] Preferably, a power linkage mechanism is also assembled between the wire feeder and the powder quantity adjustment mechanism. The power linkage mechanism includes a sliding resistor fixed on the connecting frame and partially surrounding the transmission disk; a handle is fitted around the outer periphery of the sliding resistor through an assembly groove on its outer side and a sliding plate is provided in the assembly groove; and a microcontroller is mounted on the connecting frame, wherein the microcontroller is connected to the wire feeder through a first wire and is connected to the end of the sliding resistor away from it through a second wire.

[0014] Preferably, the cooling pipe component includes an assembly box fixed on the shoulder; and a cooling pipe body disposed inside the assembly box and spirally distributed, wherein the inlet end of the cooling pipe body is connected to a liquid inlet pipe provided on the side wall of the shoulder, and its outlet end is connected to an annular groove opened at the bottom of the assembly box; further, each jet component includes a nozzle mounted at the bottom of the assembly box, wherein one end of the nozzle extends into and communicates with the annular groove, and the other end faces the shoulder.

[0015] Preferably, cooling boxes are provided on both sides of the assembly box, and the cooling boxes enclose the cooling pipes to achieve refrigeration during the cooling process of the cooling pipes.

[0016] Preferably, the shoulder sidewall is provided with an exhaust hole.

[0017] Compared with the prior art, the beneficial effects of the present invention include: This invention, through the coaxially distributed stirring mechanism and spiral conveying rod, not only ensures the full and uniform mixing of reinforcing particles and matrix, avoiding defects such as powder agglomeration and segregation, reducing stress concentration sources inside the material, and improving the density and uniformity of mechanical properties of the deposited layer, but also enhances the stability and reliability of the process. In another embodiment of the present invention, the powder quantity adjustment mechanism set at the inlet position of the powder feeding mechanism can flexibly change the powder feeding rate during the manufacturing process, realize the continuous gradient change of material composition and properties in the construction direction, and complete the rapid preparation of gradient materials; the in-situ cooler composed of cooling pipes and jet components, the upper cooling component can be used to control the shoulder temperature to prevent overheating (causing material blockage and uneven mixing problems), while the lower jet component directly targets the newly formed deposition layer and performs rapid cooling. This design prevents the deposition layer from deformation, collapse or coarsening of the structure caused by heat accumulation during continuous manufacturing by actively managing the heat accumulation effect. At the same time, the cooling pipe is annularly assembled on the outer wall of the shoulder, so that the filament does not directly contact the coolant before deposition, thus keeping the filament dry and ensuring the density of the deposition layer; The solution employed in this invention can also prevent grain coarsening and strengthening phase loss caused by thermal cycling, achieving dynamically adjustable local thermal field control and avoiding problems such as dead zones in the cooling path and limitations on equipment or workpiece size caused by water-immersion additive manufacturing. Attached Figure Description

[0018] Figure 1 This is a first-view three-dimensional structural diagram of the dual-source in-situ cooled stirring friction additive manufacturing apparatus in the embodiment. Figure 2 This is a second-view perspective three-dimensional structural diagram of the dual-source in-situ cooling stirring friction additive manufacturing apparatus in the embodiment. Figure 3 This is a third-view perspective three-dimensional structural diagram of the dual-source in-situ cooling stirring friction additive manufacturing device in the embodiment; Figure 4 This is a side view of the dual-source in-situ cooling stirring friction additive manufacturing apparatus in the embodiment. Figure 5 This is a top view of the dual-source in-situ cooling stirring friction additive manufacturing apparatus in the embodiment. Figure 6 for Figure 4 A schematic diagram of the cross-sectional structure of AA; Figure 7 for Figure 5 Schematic diagram of the cross-sectional structure of BB; Figure 8 for Figure 7 A front view structural diagram; Figure 9 for Figure 1 Enlarged structural schematic diagram of the intermediate meshing transmission assembly; Figure 10 for Figure 9 A schematic diagram showing the disassembled structure of the medium-powder quantity adjustment mechanism; Figure 11 The image shows the grain pattern of the sample obtained in the examples; Figure 12 The above are the statistical results of the grain size of the samples prepared in the examples; Figure 13 The grain pattern of the sample prepared by conventional friction stir additive manufacturing.

[0019] In the diagram: 111, shoulder; 112, mixing zone; 113, column; 114, first crossbar; 115, fixed tube; 116, second crossbar; 117, transmission ring; 118, movable tube; 119, powder feeding channel; 120; 121, wire inlet tube; 124, screw conveyor; 125, assembly box; 127, cooling box; 128, cooling tube body; 129, liquid inlet tube; 130, annular groove; 131, nozzle; 211. Central shaft; 212. Sleeve; 213. Second crushing tooth; 214. First crushing tooth; 215. First transmission gear; 216. Extension plate; 217. Motor; 218. Fourth transmission gear; 219. Extension frame; 220. Second transmission gear; 221. Third transmission gear; 311. Second powder inlet pipe; 312. Petal regulating valve; 3121. Transmission disc; 3122. Circular hole; 3123. Slide groove; 3124. Slider; 3125. Transmission column; 3126. Petal block; 3127. Ring; 3128. Second fixing ring; 31281. First fixing ring; 3129. Connecting rod; 31291. Transmission groove; 313. Microcontroller; 314. Connecting frame; 315. Sliding resistor; 316. Handle; 317. Assembly groove; 318. First wire. Detailed Implementation

[0020] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. The various embodiments of this invention are described in detail below with reference to the accompanying drawings. Example 1

[0021] Please see Figures 1 to 10A dual-source in-situ cooling friction stir additive manufacturing apparatus includes: a shoulder 111; a mixing zone 112 located in the middle of the shoulder 111; a powder feeding mechanism and a wire feeding mechanism respectively mounted on the upper part and side wall of the shoulder 111, wherein the powder feeding mechanism and the wire feeding mechanism are used to transport powder and wire to the interior of the mixing zone 112, and the powder feeding mechanism is also provided with a powder quantity adjustment mechanism at the inlet position for flexible control of the powder feeding rate; a stirring mechanism and a spiral conveying rod 124 coaxially distributed on the upper and lower parts inside the shoulder 111 for thorough mixing of powder and wire; and an in-situ cooling mechanism mounted on the outer periphery of the shoulder 111, the in-situ cooling mechanism including cooling pipes and jet components arranged on the upper and lower parts of the shoulder 111, wherein the jet components are arranged in a ring array and aligned with the shoulder 111.

[0022] The specific steps for using this manufacturing device are as follows: Step 1: Grinding. Grind and clean the surface of the substrate to remove impurities and oxides. Install and fix it on the equipment platform. Write the additive manufacturing program according to the additive manufacturing plan and zero the spindle in the X / Y / Z directions. This step is a mature existing technology and will not be described in detail. Step 2: Preheating. The shoulder 111 is pressed down to a position close to the substrate and stays there. At this time, the spiral conveyor 124 is aligned with the substrate. Step 3: Feeding. Start the filament feeding mechanism and powder feeding mechanism to feed the additive raw material filaments and powder into the mixing zone 112 and mix and crush them through the stirring mechanism. Then, the crushed and mixed additive raw material is further mixed by the rotating screw conveyor 124 and extruded from the bottom of the shoulder 111. At this time, the mixture of filament particles and powder comes into contact with the substrate and heats up and plasticizes under the action of heat, depositing onto the substrate. Step 4: Deposition. After the raw material can successfully form a deposition layer, the preheating ends, and the shoulder 111 and the screw conveyor 124 rise to the designated height and move forward. Step 5: Layer-by-layer additive manufacturing. According to the programmed instructions, the raw material forms a deposition layer under the extrusion of the screw conveyor 124, and the component is printed layer by layer to perform the additive manufacturing task. Step 6: End. After the components are prepared, the spiral conveyor rod 124 is raised, the wire feeding mechanism and powder feeding mechanism are turned off, all structures stop operating, and additive manufacturing is completed.

[0023] The core innovation of this device lies in the integration of a dual-source supply system, a built-in mixing system, and an in-situ cooling system, in order to overcome the problems of limited component mixing uniformity and performance degradation caused by heat accumulation during multi-material additive manufacturing in traditional additive manufacturing devices. Specifically, the appearance diagram of this device is as follows: Figure 1 , 2As shown in Figures 3, 4, and 5, the shoulder 111, which serves as the main assembly body, is equipped with a powder feeding mechanism, a wire feeding mechanism, and a screw conveyor 124 on its upper, side, and lower parts, respectively. Simultaneously, a stirring mechanism and a screw conveyor 124 are coaxially distributed inside the shoulder 111. The running end of the stirring mechanism can extend into the mixing zone 112 for thorough mixing of the powder and wire. The screw conveyor 124 is connected to the stirring mechanism for further mixing of the powder and wire, achieving in-situ composite and homogenization of the material. This design not only ensures thorough and uniform mixing of the reinforcing particles and the matrix, avoiding defects such as powder agglomeration and segregation, thereby reducing stress concentration sources within the material and improving the density and uniformity of the mechanical properties of the deposited layer, but also enhances the stability and reliability of the process. At the same time, a powder quantity adjustment mechanism is installed at the inlet of the powder feeding mechanism to control the powder feeding speed, such as Figure 1 , 2 As shown in Figure 8, the powder quantity adjustment mechanism can achieve continuous gradient changes in material composition and properties in the construction direction by flexibly changing the powder feeding rate during the manufacturing process, so as to complete the rapid preparation of gradient materials. Here, the powder material includes different components such as metal powder, metal particles, non-metal powder, and non-metal particles. In addition, the in-situ cooling mechanism provided on the outer periphery of the shoulder 111 consists of cooling pipes and jet components. The upper cooling component can be used to control the temperature of the shoulder 111 and prevent overheating, while the lower jet component is directly aimed at the newly formed deposited layer and rapidly cooled. This process actively manages the heat accumulation effect to prevent problems such as deformation, collapse or coarsening of the deposited layer caused by heat accumulation during continuous manufacturing.

[0024] The powder feeding mechanism includes a column 113 fixed to one side of the shoulder 111. A first crossbar 114 and a second crossbar 116 are fixed to the side wall of the column 113 near the top. A fixed tube 115 and a transmission ring 117 are fixed to the first crossbar 114 and the second crossbar 116, respectively. A movable tube 118 rotatably installed inside the transmission ring 117 is rotatably connected to the bottom of the fixed tube 115. A powder feeding channel 119 is annularly opened inside the movable tube 118. The bottom ends of several powder feeding channels 119 extend toward and communicate with the mixing zone 112, and their top ends converge upward and present a funnel shape with the tip pointing downward. It also includes a first powder inlet pipe 120 connected to the top of the fixed tube 115 and assembled with the powder quantity adjustment mechanism.

[0025] like Figure 6 , 7 As shown in Figure 8, the movable tube 118, which can rotate on its own, can be rotatably installed with the fixed tube 115 at its top end, and its bottom end extends into the shoulder 111. The powder feeding channel 119, which is opened in a ring in the middle, is used for direct connection between the first powder inlet tube 120 and the mixing zone 112 to realize the powder feeding operation. It is worth noting that the design of several powder feeding channels 119 converging upwards at the top to form a funnel shape with the tip pointing downwards can facilitate the intake of powder driven by the airflow above into the powder feeding channel 119, ensuring powder feeding efficiency. The number of powder feeding channels 119 can be selected from 1 to 6, with a single diameter of not less than 1.5 mm, so that the powder can pass through smoothly without clogging.

[0026] The stirring mechanism includes a central shaft 211 movably mounted in the middle of the fixed tube 115, and a sleeve 212 fixed to the middle of the powder feeding channel 119 and externally disposed on the central shaft 211, wherein the bottom end of the central shaft 211 is assembled with the top end of the screw conveyor 124; and a first crushing tooth 214 and a second crushing tooth 213 respectively fixed to the bottom ends of the central shaft 211 and the sleeve 212 and rotating in opposite directions; it also includes a meshing transmission assembly disposed at the top ends of the central shaft 211 and the sleeve 212 for synchronous driving of the central shaft 211 and the sleeve 212; further, the meshing transmission assembly includes a first transmission gear 215 fixed near the outer wall of the top end of the movable tube 118; and a gear fixed to the column 1 The extension frame 219 on the 13 has a second transmission gear 220 fixed to the top of the second crossbar 116 rotatably mounted on the middle of the extension frame 219 via a first rotating shaft. The two ends of the extension frame 219 are respectively rotatably mounted with a third transmission gear 221 and a fourth transmission gear 218 via a second rotating shaft. The third transmission gear 221 meshes with the second transmission gear 220, and the fourth transmission gear 218 meshes with both the third transmission gear 221 and the first transmission gear 215. The extension frame 216 is also fixed to the side wall of the transmission ring 117. The motor 217 is mounted at the bottom of the extension plate 216. Its output shaft passes through the through hole opened on the extension plate 216 and is fixed to the fourth transmission gear 218.

[0027] This embodiment combines Figure 3 , 4 As shown in Figures 5 and 9, the stirring mechanism is installed with the central shaft 211 and the inner and outer sleeves 212. One end of the central shaft 211 is rotatably mounted to the middle of the fixed tube 115, and the other end is fixed with the first crushing tooth 214. Figure 6 , 7 As shown in Figure 8, one end of the sleeve 212 is fixed to the middle of the movable tube 118, and the other end is fixed with the second crushing tooth 213. Therefore, when the central shaft 211 and the sleeve 212 are running synchronously, the first crushing tooth 214 and the second crushing tooth 213 can crush and mix the material. In order to improve the uniformity of mixing, the central shaft 211 and sleeve 212 provided in this application can rotate in opposite directions under the action of the meshing transmission assembly, so as to realize the rapid crushing and mixing process of wire and powder by relative shearing force; Specific examples Figure 9As shown, a first transmission gear 215 is fixed to the outer periphery of the column 113, while a second transmission gear 220 is fixed to the top of the central shaft 211. At the same time, a third transmission gear 221 meshes with the second transmission gear 220. A fourth transmission gear 218 is placed between the third transmission gear 221 and the first transmission gear 215 and meshes with both of them. Therefore, when the fourth transmission gear 218 rotates in a certain direction with the power provided by the motor 217, the third transmission gear 221 and the first transmission gear 215, which are directly meshed with the fourth transmission gear 218, rotate in the opposite direction to the fourth transmission gear 218. Since the second transmission gear 220 is directly meshed with the third transmission gear 221, the second transmission gear 220 rotates in the running direction of the fourth transmission gear 218. In this way, the first transmission gear 215 and the second transmission gear 220 are driven in opposite directions and synchronously.

[0028] The powder quantity adjustment mechanism includes a connecting frame 314 fixed on a column 113, on which a first fixing ring 31281 and a second fixing ring 3128 are fixedly connected to each other. The first fixing ring 31281 contains a transmission disc 3121, and a circular hole 3122 in the center of the transmission disc 3121 connects to the end of the first powder inlet pipe 120. It also includes a connecting rod 3129 annularly fixed inside the second fixing ring 3128, and a circular ring 3127 fixed to several connecting rods 3129, with the second powder inlet pipe 311 connected to the circular hole 3122. Furthermore, it includes a petal-shaped adjusting valve 312 internally disposed between the first fixing ring 31281, the second fixing ring 3128, and the circular hole 3122 and the circular ring 3127, for adjusting the powder delivery from the second powder inlet pipe 311 to the first powder inlet pipe. The powder quantity is 120. The petal regulating valve 312 includes several grooves 3123 formed on the outer periphery of the transmission disk 3121, with one end of each groove 3123 extending outward and the other end extending into its adjacent groove 3123 and communicating with its middle; and a slider 3124 provided in each groove 3123, with a petal block 3126 fixed on the slider 3124, and a transmission column 3125 provided in the middle of the petal block 3126; it also includes a transmission groove 31291 formed on each connecting rod 3129, and the transmission groove 31291 and its corresponding transmission column 3125 are sleeved and installed and can slide relative to each other; an arc-shaped through groove is also formed on the outer periphery of the first fixing ring 31281; and a handle 316 extending into the arc-shaped through groove and fixed to the outer edge of the transmission disk 3121 for conveniently moving the transmission disk 3121.

[0029] In this embodiment, as Figure 9 , 10As shown, a first fixed ring 31281 and a second fixed ring 3128, which are fixed in a fixed state and connected to each other, are respectively set at the opposite ends of the first powder inlet pipe 120 and the second powder inlet pipe 311. The circular hole 3122 in the middle of the transmission disk 3121 is connected to the end of the first powder inlet pipe 120, while the circular ring 3127 of the second fixed ring 3128, which is fixed by several connecting rods 3129, is connected to the end of the second powder inlet pipe 311. When the petal regulating valve 312 set between the circular hole 3122 and the circular ring 3127 expands or contracts, the flow rate of the circular ring 3127 and the circular hole 3122 can be flexibly adjusted. Specific examples Figure 10 As shown, each groove 3123 has one end pointing outwards and the other end extending into its adjacent groove 3123 and communicating with its middle portion. Each groove 3123 has a slider 3124 with fixed segments 3126. The transmission column 3125 fixed at the center of the edge of each segment 3126 can extend into the divergent transmission groove 31291. Therefore, when the slider 3124 rotates, the segments 3126, under the limiting action of the transmission column 3125 and the transmission groove 31291, achieve a circular expansion or contraction process, thereby adjusting the degree of obstruction of the circular hole 3122 by the segments 3126, and adjusting the flow rate of the first powder inlet pipe 120 and the second powder inlet pipe 311. Specifically, as shown... Figure 10 As shown, when the handle 316 is rotated counterclockwise, causing several segments 3126 to retract inward, the powder feeding rate can be reduced; conversely, rotating it counterclockwise increases the powder feeding rate.

[0030] The wire feeding mechanism includes a wire inlet tube 122 that is transversely installed through the side wall of the shoulder 111. One end of the wire inlet tube 122 extends into the mixing zone 112, and the other end is equipped with a wire feeder. Furthermore, a power linkage mechanism is also installed between the wire feeder and the powder quantity adjustment mechanism. The power linkage mechanism includes a sliding resistor 315 that is fixed on the connecting frame 314 and partially surrounds the transmission disk 3121. A handle 316 is sleeved on the outer periphery of the sliding resistor 315 through an assembly groove 317 on its outer side, and a sliding piece is provided in the assembly groove 317. A microcontroller 313 is installed on the connecting frame 314, and the microcontroller 313 is connected to the wire feeder through a first wire 318, and is connected to the end of the sliding resistor 315 away from it through a second wire.

[0031] In this embodiment, in order to achieve consistency in the material conveying of the powder feeding mechanism and the wire feeding mechanism and ensure a suitable ratio, a power linkage mechanism is installed between the wire feeder and the powder quantity adjustment mechanism. Here, the power linkage mechanism can convert the degree of offset of the handle 316 of the powder quantity adjustment mechanism into the resistance magnitude. The resistance magnitude information is received by the microcontroller 313 and used as a parameter to control the wire feeding rate of the wire feeding mechanism. Specific examples Figure 1 ,9 As shown in Figure 10, the sliding resistor 315 and the wire feeding mechanism are both existing mature technologies. Because the end of the sliding resistor 315 furthest from the microcontroller 313 is connected to the microcontroller 313, the handle 316, as shown in Figure 10, is connected to the microcontroller 313. Figure 10 When the counterclockwise rotation causes several segments 3126 to retract and reduce the powder feeding rate, the resistance between the starting end of the sliding resistor 315 and the slider increases and the current decreases. Then, the microcontroller 313 controls the wire feeding mechanism in real time to reduce the wire feeding rate. Conversely, the powder feeding speed increases and the wire feeding rate increases.

[0032] The cooling pipe assembly includes an assembly box 125 fixed on a shoulder 111; and a cooling pipe body 128 disposed inside the assembly box 125 and spirally distributed, wherein the inlet end of the cooling pipe body 128 is connected to a liquid inlet pipe 129 provided on the side wall of the shoulder 111, and its outlet end is connected to an annular groove 130 opened at the bottom of the assembly box 125; further, each jet component includes a nozzle 131 mounted at the bottom of the assembly box 125, wherein one end of the nozzle 131 extends into and communicates with the annular groove 130, and the other end faces the shoulder 111.

[0033] like Figure 6 , 7 As shown in Figure 8, the inlet end of the cooling tube 128 is connected to the liquid inlet pipe 129 provided on the side wall of the shoulder 111, and its outlet end is connected to the annular groove 130 opened at the bottom of the assembly box 125. When the external pressure pump draws coolant from the liquid inlet pipe 129 into the cooling tube 128, the spirally distributed cooling tube 128 allows the coolant to fully interact with the shoulder 111 and accumulate at the position of the annular groove 130. At this time, the nozzle 131 connected to the annular groove 130 can spray out the coolant to complete the rapid cooling of the deposited layer. Since the spray angle of the nozzle 131 is designed to be opposite to the deposition position, several coolant jets form an annular array and surround the cooling position, realizing all-round cooling of the deposited layer, effectively suppressing heat accumulation, improving anisotropy and coarsening of the structure. At the same time, the cooling tube 128 is annularly assembled on the outer wall of the shoulder 111, so that the filament will not directly contact the coolant before deposition, thus keeping the filament dry and ensuring the density of the deposited layer.

[0034] The assembly box 125 has cooling boxes 127 on both sides, which enclose the cooling pipes 128 to achieve refrigeration during the cooling process of the cooling pipes 128. Figure 1 , 2 As shown in Figures 6 and 7, this ensures the cooling effect of the coolant in the cooling pipe 128.

[0035] Among them, the shoulder 111 has an exhaust hole 133 on its side wall, such as Figure 1 , 2As shown, the vent 133 here can discharge the airflow of the powder feeding mechanism, balance the internal pressure of the shoulder 111, and avoid the formation of pore defects in the deposited layer. The diameter of the vent 133 here does not exceed 3 mm to prevent unplasticized granules from flying out of the vent 133.

[0036] Using the dual-source in-situ cooled friction stir additive manufacturing apparatus in this embodiment, additive manufacturing was performed on the sample (additive process parameters: rotation speed 600 rpm, feed speed 150 mm / min, deposition layer thickness 1.5 mm; Al-Cu alloy wire and substrate were used, wire diameter 1.6 mm, substrate size 200 mm * 150 mm * 8 mm). The resulting sample grain size and its statistical data are as follows: Figure 11 and Figure 12 As shown, the results indicate that this method significantly suppresses grain coarsening, and the grain size of the deposited / additive layer is significantly reduced compared to conventional additive manufacturing (the grain size of the deposited / additive layer in samples obtained from conventional additive manufacturing is typically about 10~20 μm, and the proportion of grains larger than 10 μm exceeds half, such as...). Figure 13 As shown in the figure, the grain orientation is more randomized during the additive manufacturing process, the continuous dynamic recrystallization effect is enhanced, the texture strength is significantly reduced, and the occurrence of mechanical property anisotropy can be suppressed. In the additive manufacturing cooling process, the scheme in the example significantly optimizes the density of the deposited layer and the additive effect is better.

Claims

1. A dual-source in-situ cooling stirring friction additive manufacturing apparatus, characterized in that... ,include: Shoulder (111), with a mixing zone (112) located in the middle of the shoulder (111). The powder feeding mechanism and the filament feeding mechanism are respectively assembled with the upper part and the side wall of the shoulder (111). The powder feeding mechanism and the filament feeding mechanism are respectively used to transport powder and filament to the mixing zone (112). The powder feeding mechanism is also provided with a powder quantity adjustment mechanism at the inlet position for flexible control of the powder feeding rate. And a stirring mechanism and a screw conveyor (124) coaxially distributed inside the shoulder (111) for thorough mixing of powder and filament; It also includes an in-situ cooling mechanism assembled on the outer periphery of the shoulder (111), the in-situ cooling mechanism including cooling pipes and jet components disposed on and below the shoulder (111), wherein the jet components are arranged in a ring array and aligned with the shoulder (111).

2. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 1, characterized in that: The powder feeding mechanism includes a column (113) fixed to one side of the shoulder (111). A first crossbar (114) and a second crossbar (116) are fixed to the side wall of the column (113) near the top. A fixed tube (115) and a transmission ring (117) are fixed to the first crossbar (114) and the second crossbar (116) respectively. The movable tube (118) rotatably installed inside the transmission ring (117) is rotatably connected to the bottom of the fixed tube (115). And a powder feeding channel (119) is opened in a ring inside the active tube (118), and the bottom ends of several powder feeding channels (119) extend toward and communicate with the mixing zone (112), and their top ends converge upward and present a funnel shape with the tip pointing downward; It also includes a first powder inlet pipe (120) connected to the top of the fixed pipe (115) and assembled with the powder quantity adjustment mechanism.

3. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 2, characterized in that: The stirring mechanism includes a central shaft (211) movably installed in the middle of the fixed tube (115), and a sleeve (212) fixed in the middle of the powder feeding channel (119) and externally disposed on the central shaft (211), wherein the bottom end of the central shaft (211) is assembled with the top end of the spiral conveying rod (124); And a first crushing tooth (214) and a second crushing tooth (213) respectively fixed to the bottom end of the central shaft (211) and the sleeve (212) and rotating in opposite directions; It also includes a meshing transmission assembly disposed at the top of the central shaft (211) and the sleeve (212) for synchronous driving of the central shaft (211) and the sleeve (212).

4. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 3, characterized in that: The meshing transmission assembly includes a first transmission gear (215) fixed near the outer wall of the top end of the movable tube (118). And an extension frame (219) fixed on the column (113), and a second transmission gear (220) fixed to the top of the second crossbar (116) is rotatably mounted in the middle of the extension frame (219) via a first rotating shaft, and a third transmission gear (221) and a fourth transmission gear (218) are rotatably mounted at both ends via the second rotating shaft, and the third transmission gear (221) meshes with the second transmission gear (220), and the fourth transmission gear (218) meshes with the third transmission gear (221) and the first transmission gear (215); It also includes an extension plate (216) fixed to the side wall of the transmission ring (117), and a motor (217) mounted at the bottom of the extension plate (216), the output shaft of which passes through a through hole opened on the extension plate (216) and is fixed to the fourth transmission gear (218).

5. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 2, characterized in that: The powder quantity adjustment mechanism includes a connecting frame (314) fixed on the column (113). The connecting frame (314) is provided with a first fixing ring (31281) and a second fixing ring (3128) that are fixed to each other. The first fixing ring (31281) is provided with a transmission disc (3121). The circular hole (3122) in the middle of the transmission disc (3121) is connected to the end of the first powder inlet pipe (120). And a connecting rod (3129) fixed in a ring on the inner side of the second fixing ring (3128), and a ring (3127) fixed to several connecting rods (3129), wherein a second powder inlet pipe (311) is connected to the ring (3127). It also includes a petal regulating valve (312) disposed within the first fixing ring (31281), the second fixing ring (3128) and positioned between the circular hole (3122) and the circular ring (3127), for adjusting the amount of powder delivered from the second powder inlet pipe (311) to the first powder inlet pipe (120); The petal regulating valve (312) includes a plurality of grooves (3123) formed on the outer periphery of the transmission disc (3121), and each groove (3123) extends outward at one end and extends into its adjacent groove (3123) at the other end and communicates with its middle part. And a slider (3124) is provided in each of the slide grooves (3123), a petal block (3126) is fixed on the slider (3124), and a transmission column (3125) is provided in the middle of the petal block (3126). It also includes a transmission groove (31291) formed on each of the connecting rods (3129), and the transmission groove (31291) and its corresponding transmission column (3125) are sleeved and installed and can slide relative to each other; The outer periphery of the first fixing ring (31281) is also provided with an arc-shaped through groove; And a handle (316) that extends into the arc-shaped through groove and is fixed to the outer edge of the transmission disc (3121) for easy actuation of the transmission disc (3121).

6. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 5, characterized in that: The wire feeding mechanism includes a wire inlet tube (122) that is laterally installed through the side wall of the shoulder (111), wherein one end of the wire inlet tube (122) extends into the mixing zone (112) and the other end is equipped with a wire feeder.

7. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 6, characterized in that: A power linkage mechanism is also assembled between the wire feeder and the powder quantity adjustment mechanism. The power linkage mechanism includes a sliding resistor (315) fixed on the connecting frame (314) and partially enclosed above the transmission disk (3121). The handle (316) is fitted around the outer periphery of the sliding resistor (315) through the mounting groove (317) opened on its outer side, and a sliding piece is provided in the mounting groove (317). And a microcontroller (313) is mounted on the connecting frame (314), and the microcontroller (313) is connected to the wire feeder via a first wire (318), and is connected to the end of the sliding resistor (315) away from it via a second wire.

8. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 1, characterized in that: The cooling pipe includes an assembly box (125) fixed on the shoulder (111); And a cooling pipe body (128) is provided inside the assembly box (125) and spirally distributed, wherein the inlet end of the cooling pipe body (128) is connected to the liquid inlet pipe (129) provided on the side wall of the shoulder (111), and its outlet end is connected to the annular groove (130) opened at the bottom of the assembly box (125); Each of the jet components includes a nozzle (131) mounted on the lower part of the assembly box (125), wherein one end of the nozzle (131) extends into and communicates with the annular groove (130), and the other end faces the shoulder (111).

9. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 8, characterized in that: Cooling boxes (127) are provided on both sides of the assembly box (125). The cooling boxes (127) enclose the cooling pipe body (128) to realize the refrigeration operation of the cooling pipe body (128) during the cooling process.

10. The dual-source in-situ cooling stirring friction additive manufacturing apparatus according to claim 1, characterized in that: The shoulder (111) has an exhaust hole (133) on its side wall.

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