A bionic automatic mixing device for gradient heterogeneous metal additive manufacturing

Abstract

The invention discloses a bionic automatic mixing device for gradient heterogeneous metal additive manufacturing, which relates to the technical field of heterogeneous metal additive manufacturing, including a double powder bin, an electric drive unloading component and a bionic mixing component; the middle part of the double powder bin is divided into a main bin and an auxiliary bin by a partition, the main bin and the auxiliary bin share a unloading port, and the oblique side walls of the main bin and the auxiliary bin are provided with a plurality of partition beams with asymmetric structures; when the motor of the electric drive unloading group is started, the eccentric shaft performs eccentric movement in the oblong hole on the baffle plate, driving the baffle plate to move in the horizontal direction, so that the valve port performs linear movement relative to the unloading port, thereby controlling the connection or blocking between the main bin and the auxiliary bin and the mixing chamber respectively, and finally obtaining heterogeneous metal powders with continuous gradient mixing; a plurality of micro-thorns imitating the bristle structure of camel spiders are distributed on the blade surface of the bionic impeller, which can effectively reduce the direct wear between the metal powder and the blade surface, so that the blade has wear resistance and erosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of heterogeneous metal additive manufacturing, and in particular to a bionic automatic material mixing device for gradient heterogeneous metal additive manufacturing. Background Art

[0002] With the development of aerospace technology, extreme service environments have posed severe challenges to the mechanical properties and multifunctional integration of core components such as aerospace, which are difficult to meet with traditional single material systems. In recent years, heterogeneous metal structural parts have attracted widespread attention due to their excellent mechanical and physicochemical properties. Using laser powder bed melting technology, multifunctional heterogeneous metal structural parts with high dimensional accuracy and complex geometric shapes can be manufactured through computer-aided design, achieving lightweight design of heterogeneous metal structural parts, and further optimizing the strength and corrosion resistance of heterogeneous metal structural parts. One of the core components of laser powder bed melting equipment is the feeding device, and its feeding effect directly affects the quality and performance of heterogeneous metal structural parts.

[0003] The main disadvantages of the existing laser powder bed melting equipment feeding device are:

[0004] Since traditional laser powder bed melting equipment only allows the use of a single material at a time and limited interlayer material transition, it is difficult to achieve effective connection of heterogeneous metals. It is necessary to improve the feeding device. By establishing a composition gradient between metals and optimizing the gradualness of the structure, the problem of interface mismatch during printing of heterogeneous metal powders can be effectively solved.

[0005] The particle size of metal powder used in laser powder bed melting technology is mostly between ten to several dozen microns, and it is a continuous medium with rheological properties. During printing, metal powder is very easy to agglomerate, electrostatically adsorb, accumulate, and fall arch during the feeding process, resulting in blockage of the feeding port or uneven mixing, affecting the printing quality;

[0006] 3. The mixing impeller will be impacted and worn by the metal powder during the mixing and feeding process, resulting in the loss of the mixing impeller and the need for frequent replacement, thereby reducing the durability and working efficiency of the equipment;

[0007] The leaves of Araucaria are composed of a sawtooth structure array with a double cantilever structure of transverse and longitudinal curvature. Its surface can induce the interface interaction between the asymmetric 3D wall and the fluid, regulate the spreading mode of continuous media with different surface tensions, and thus realize the autonomous orientation of the fluid on the same surface. Imitating the sawtooth structure of Araucaria leaves can provide important ideas for the design of bionic automatic mixing devices, so as to reduce the accumulation, blockage or grain arch phenomenon of metal powder and achieve the purpose of effective gradient transition of heterogeneous metals.

[0008] Camel spiders live in deserts and can move freely and quickly in the desert. Their bodies and feet are covered with dense bristles, and each bristle is covered with many smaller cilia to protect them from the wear and erosion of sand particles. Imitating the bristle structure of camel spiders can provide a blueprint for the design of mixing impellers, so as to improve the wear resistance and erosion resistance of mixing impellers, reduce equipment loss, and improve work efficiency.

[0009] Looking at the current status of the above-mentioned laser powder bed melting equipment, there is an urgent need for a bionic automatic mixing device for gradient heterogeneous metal additive manufacturing. Summary of the invention

[0010] The purpose of the present invention is to provide a bionic automatic mixing device for gradient heterogeneous metal additive manufacturing, which can prevent metal powder accumulation, blockage or grain arch phenomenon, and the bionic impeller has wear resistance and erosion resistance.

[0011] A bionic automatic mixing device for gradient heterogeneous metal additive manufacturing, comprising a double powder bin, an electric drive unloading component and a bionic mixing component;

[0012] The upper end of the double powder silo is covered with a silo cover, and the middle of the double powder silo is divided into a main silo and an auxiliary silo by a partition. The main silo and the auxiliary silo share a discharge port. A mixing chamber is provided at the lower end of the double powder silo, and the discharge port is connected to the mixing chamber. The oblique side walls of the main silo and the auxiliary silo are provided with a plurality of asymmetric separation beams, which divide the main silo and the auxiliary silo into a plurality of asymmetric discharge spaces, and a plurality of through slideways are provided on the mixing chamber.

[0013] The electric drive unloading assembly includes a motor, a motor stator housing is fixedly connected to the outer wall of the double powder silo, a baffle is slidably connected in the slideway, an oblong hole is provided at one end of the baffle, an eccentric shaft is eccentrically connected to the outer wall of the motor rotor, the eccentric shaft is slidably connected in the oblong hole, and a valve port with the same diameter as the unloading port is provided on the side of the baffle away from the oblong hole. When the motor is started, the eccentric shaft moves eccentrically in the oblong hole on the baffle, driving the baffle to move in the horizontal direction, so that the valve port moves linearly relative to the unloading port, thereby controlling the connection or blocking between the main silo and the auxiliary silo and the mixing chamber respectively, and finally obtaining heterogeneous metal powders with continuous gradient mixing;

[0014] The bionic mixing component includes an axis skeleton, a plurality of discharge ports are provided through the axis skeleton, an upper end of a connecting bridge is connected to the axis skeleton between two adjacent discharge ports, a lower end of the connecting bridge is rotatably connected to a bionic impeller, the bionic impeller is arranged inside the axis skeleton, after the metal powder enters the axis skeleton under the action of gravity, it can drive the bionic impeller to rotate, and a plurality of micro-thorns imitating the bristle structure of a camel spider are arrayed on the blade surface of the bionic impeller;

[0015] Sub-millimeter-level capillary serration structures imitating the leaves of Araucaria ovata are evenly distributed on the inner wall of the double powder bin, and the tooth tips of the capillary serration structures are all facing the feeding direction of the metal powder.

[0016] Preferably, the shaft skeleton is a cylindrical structure, and the closing caps are covered at both ends of the shaft skeleton.

[0017] Preferably, the root of the capillary sawtooth structure is fixedly connected to the inner wall of the double powder silo, the tip of the capillary sawtooth structure is tilted, the length of the capillary sawtooth structure is 550μm~790μm, and it is formed by the cross-sectional profile curve AB with thickness being drafted to point D along the central curve CD of the longitudinal section, and its thickness dimension is 320μm~380μm; the equation of the central curve CD of the longitudinal section is: f(x)=ax 3 +bx 2 +cx, where a ranges from -0.15 to -0.3, b ranges from -0.2 to -0.35, c ranges from -0.05 to -0.25, and x ranges from 0 mm to 1.2 mm; the cross-sectional profile AB is obtained by the intersection of the upper profile curve and the lower profile curve, and the equation of the upper profile curve is: f(x)= (-r 2 +0.8r+0.48)cos(dx), where r is the vertical distance from the cross section to the inner wall of the double powder silo, and its value range is 0mm~1.2mm, d is 1.05~1.3, and x is -1.5 mm~1.5 mm; the lower contour curve equation is: f(x)= (-r 2 +0.8r+0.48)(-qx 2 +0.8), where r is the vertical distance from the cross section to the inner wall of the double powder silo, and its value range is 0mm~1.2mm, q is in the range of 0.12-0.2, and x is in the range of 1.5 mm~1.5 mm.

[0018] Preferably, the distance between two adjacent microthorns is 125 μm to 300 μm, the length of the microthorn is 20 μm to 50 μm, the diameter of the microthorn is 5 μm to 7 μm, the tip of the microthorn is a conical structure, and the angle range of the cone top angle is 6° to 10°.

[0019] Preferably, a plurality of secondary microthorn structures are distributed on the surface of the microthorns, the length of the secondary microthorn structure is 2μm~4μm, and the diameter of the secondary microthorn structure is 550nm~800nm; 9 layers of secondary microthorn structures are axially distributed on the microthorns, 6 secondary microthorn structures are evenly distributed on each layer, the spacing between two adjacent layers of secondary microthorn structures is 1μm~1.6μm, and the two adjacent layers of secondary microthorn structures are arranged on the same vertical line, and the angle between the axis ab of any secondary microthorn structure and the axis cd of the microthorn is 30°~40°.

[0020] Preferably, the outer contour of the secondary microthorn structure is formed by rotating the curve ef around the axis ab, and the equation of the curve ef is f(x)=e x , the value range of e is 2.2~2.9, and the value range of x is 0μm ~2μm.

[0021] Preferably, the inner wall surface of the bionic automatic mixing device is sprayed with a polyimide coating with a thickness of 80 μm to 90 μm.

[0022] Beneficial effects of the present invention:

[0023] By controlling the feeding ratio of the two metal powders through the electric-driven feeding component, controllable gradient transition additive manufacturing of gradient heterogeneous metal materials can be achieved;

[0024] When feeding heterogeneous metal powders, the bionic impeller can rotate spontaneously under the impact of the metal powder fluid, so that different metal powders are fully mixed to obtain heterogeneous metal powders with continuous and uniform composition and quality;

[0025] The inner wall of the double powder silo has a sawtooth structure, which can induce the interface interaction between the asymmetric 3D wall and the fluid, thereby realizing the function of directional flow guidance and promoting the discharge of metal powder. Since the sawtooth structure has the characteristics of variable curvature, when the metal powder contacts it, the metal powder at different positions of the sawtooth structure is subjected to different friction forces, so it is difficult for the boundary layer of the metal powder to form a balanced steady state. The metal powder in the boundary layer is in a state of continuous flow along the wall direction, thereby preventing the metal powder from agglomerating, piling up and falling grain arching.

[0026] The inclined side walls of the main material bin and the auxiliary material bin are both provided with partition beams, which divide the main material bin and the auxiliary material bin into several unloading spaces with asymmetrical structures, which can effectively reduce the occurrence of falling grain arch phenomenon. The inner wall of the double powder bin is coated with a polyimide layer, which can realize the charge transfer function and prevent the metal powder from generating static electricity during the unloading process, thereby causing the metal powder to adsorb, agglomerate or ignite.

[0027] The surface of the bionic impeller's blades is distributed with several micro-thorns that imitate the structure of camel spider bristles. When metal powder falls and impacts the blades and produces friction with the blades, this micro-thorn and the secondary micro-thorn structure can absorb the kinetic potential energy of the metal powder like a spring, and effectively change the direction of movement of the metal powder, reduce the impact force, and play a buffering role. It can effectively reduce the direct wear between the metal powder and the blade surface, thereby making the blade wear-resistant and erosion-resistant. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the internal structure of the present invention;

[0029] Figure 2It is a schematic diagram of the three-dimensional structure of the present invention;

[0030] Figure 3 for Figure 2 A partial enlarged schematic diagram in the middle;

[0031] Figure 4 It is a schematic diagram of the structure at the feeding port;

[0032] Figure 5 It is a schematic diagram of the three-dimensional structure of the bionic mixed material component;

[0033] Figure 6 It is a schematic diagram of the connection between the connecting bridge and the bionic impeller;

[0034] Figure 7 It is a schematic diagram of the cross section of the capillary sawtooth structure;

[0035] Figure 8 It is a schematic diagram of the horizontal and vertical sections of the capillary sawtooth structure;

[0036] Fig. 9 It is a schematic diagram of the structure in which the secondary micro-thorn structure is connected to the micro-thorn;

[0037] Fig.10 It is a schematic diagram of the local structure in which the capillary serration structure is connected to the inner wall of the double powder silo;

[0038] Fig.11 A schematic diagram of the three-dimensional structure of the micro-thorns connected to the bionic impeller blades;

[0039] In the figure: 10, silo cover; 11, partition; 12, main silo; 13, auxiliary silo; 14, discharge port; 15, mixing chamber; 16, partition beam; 17, slideway;

[0040] 20. Motor; 21. Baffle; 22. Long round hole; 23. Eccentric shaft;

[0041] 30. Shaft skeleton; 31. Discharge port; 32. Connecting bridge; 33. Bionic impeller; 34. Closing cap;

[0042] 40. Capillary serration structure. DETAILED DESCRIPTION

[0043] Referring to the accompanying drawings, a bionic automatic mixing device for gradient heterogeneous metal additive manufacturing includes a double powder bin, an electric drive unloading component and a bionic mixing component;

[0044] The upper end cover of the double powder silo is covered with a silo cover 10, and the interior of the double powder silo is arranged in a V-shaped structure. The middle part of the double powder silo is divided into a main silo 12 and an auxiliary silo 13 by a partition 11. The main silo 12 and the auxiliary silo 13 share a discharge port 14. A mixing chamber 15 is arranged at the lower end of the double powder silo, and the discharge port 14 is communicated with the mixing chamber 15. The oblique side walls of the main silo 12 and the auxiliary silo 13 are provided with a plurality of asymmetric separation beams 16. The asymmetric separation beams 16 divide the main silo 12 and the auxiliary silo 13 into a plurality of asymmetric discharge spaces to reduce the occurrence of grain falling arch phenomenon. A plurality of through slideways 17 are arranged on the mixing chamber 15;

[0045] The electric drive unloading assembly includes a motor 20, the stator housing of the motor 20 is fixedly connected to the outer wall of the double powder silo, the baffle 21 is slidably connected in the slideway 17, one end of the baffle 21 is provided with an oblong hole 22, the outer wall of the rotor of the motor 20 is eccentrically connected with an eccentric shaft 23, the eccentric shaft 23 is slidably connected in the oblong hole 22, and the baffle 21 is provided with a valve port with the same diameter as the unloading port 14 on the side away from the oblong hole 22. When the motor 20 is started, the eccentric shaft 23 makes an eccentric movement in the oblong hole 22 on the baffle 21 to drive the baffle 21 to move in the horizontal direction, so that the valve port makes a linear movement relative to the unloading port 14, thereby controlling the connection or blocking between the main material silo 12 and the auxiliary material silo 13 and the mixing chamber 15 respectively, and finally obtaining heterogeneous metal powders with continuous gradient mixing;

[0046] The bionic mixing component includes an axis skeleton 30, which is a cylindrical structure. The closing caps 34 cover both ends of the axis skeleton 30. A plurality of discharge ports 31 are provided on the axis skeleton 30. The upper end of the connecting bridge 32 is connected to the axis skeleton 30 between two adjacent discharge ports 31. The lower end of the connecting bridge 32 is rotatably connected to a bionic impeller 33. The bionic impeller 33 is arranged inside the axis skeleton 30. After the metal powder enters the axis skeleton 30 under the action of gravity, it can drive the bionic impeller 33 to rotate. The fan surface of the bionic impeller 33 is arrayed with a plurality of micro-thorns imitating the bristle structure of a camel spider.

[0047] Sub-millimeter-level capillary serration structures 40 imitating Araucaria leaves are evenly distributed on the inner wall of the double powder bin, and the tooth tips of the capillary serration structures 40 are all facing the feeding direction of the metal powder.

[0048] Furthermore, the capillary serration structure 40 has its tooth root fixedly connected to the inner wall of the double powder silo, and its tooth tip is tilted. The capillary serration structure 40 has a length of 550 μm to 790 μm, and is formed by drawing a cross-sectional profile AB with thickness along the center curve CD of the longitudinal section to point D, and its thickness is 320 μm to 380 μm. The longitudinal section profile curve perpendicular to the inner wall of the double powder silo imitates the serration structure of the Araucaria leaf, and the equation of the center curve CD of the longitudinal section obtained by image processing and data fitting technology is: f(x)=ax 3 +bx2 +cx, where a ranges from -0.15 to -0.3, b ranges from -0.2 to -0.35, c ranges from -0.05 to -0.25, and x ranges from 0 mm to 1.2 mm; the cross-sectional profile curve parallel to the inner wall of the double powder silo also imitates the sawtooth structure of the Araucaria leaf. The upper profile curve equation of the cross-sectional profile AB obtained by image processing and data fitting technology is: f(x)= (-r 2 +0.8r+0.48)cos(dx), where r is the vertical distance from the upper contour curve to the inner wall of the double powder silo, and its value range is 0mm~1.2mm, d is in the range of 1.05~1.3, and x is in the range of -1.5 mm~1.5 mm; the equation of the lower contour curve of the cross-sectional profile AB is: f(x)= (-r 2 +0.8r+0.48)(-qx 2 +0.8), where r is the vertical distance from the lower contour curve to the inner wall of the double powder silo, and its value range is 0 mm~1.2 mm, q is in the range of 0.12-0.2, and x is in the range of 1.5 mm~1.5 mm; the upper contour curve intersects the lower contour curve to obtain a cross-sectional profile AB, and the cross-sectional profile AB is drafted along the center curve CD to the vertex point D to form a capillary serration structure 40 imitating the leaves of Araucaria.

[0049] Furthermore, the distance between two adjacent microthorns is 125μm~300μm, the length of the microthorn is 20μm~50μm, the diameter of the microthorn is 5μm~7μm, the tip of the microthorn is a conical structure, and the angle of the cone top ranges from 6° to 10°.

[0050] Furthermore, there are multiple secondary microthorn structures distributed on the surface of the microthorn, the length of the secondary microthorn structure is 2μm ~ 4μm, and the diameter of the secondary microthorn structure is 550nm ~ 800nm; there are 9 layers of secondary microthorn structures distributed axially on the microthorn, and 6 secondary microthorn structures are evenly distributed on each layer. The spacing between two adjacent layers of secondary microthorn structures is 1μm ~ 1.6μm, and the two adjacent layers of secondary microthorn structures are arranged on the same vertical line. The angle between the axis ab of any secondary microthorn structure and the axis cd of the microthorn is 30° ~ 40°.

[0051] Furthermore, the outer contour of the secondary microthorn structure is formed by rotating the curve ef around the axis ab, and the equation of the curve ef is f(x)=e x , the value range of e is 2.2~2.9, and the value range of x is 0μm ~2μm.

[0052] Furthermore, the inner wall surface of the bionic automatic mixing device is sprayed with a polyimide coating with a thickness of 80μm~90μm to improve its resistance to metal powder friction, prevent static electricity generated by friction between the metal powder and the bionic automatic mixing device, and reduce powder accumulation caused by the static electricity effect.

[0053] The working principle and process of the present invention are as follows:

[0054] During operation, the main material bin 12 and the auxiliary material bin 13 of the double powder bin are respectively filled with different metal powders, and the two metal powders can enter the mixing chamber 15 through the common discharge port 14; the electric drive discharge component is started according to the program design time, and the eccentric shaft 23 is driven by the motor 20 to eccentrically move in the oblong hole 22 to drive the baffle 21 to move horizontally. The other end of the baffle 21 is provided with a valve port. When the motor 20 is not started, the valve port is staggered with the discharge port 14 and is located on one side of the edge of the discharge port 14. When the motor 20 is started, the baffle 21 is displaced in the horizontal direction, so that the valve port moves linearly relative to the discharge port 14. The bionic impeller 33 is used to move the material in the mixing chamber 15, thereby gradually connecting the feed port 14 with the valve port, and the metal powder entering the mixing chamber 15 gradually changes from one metal powder to another metal powder. The two metal powders are fully mixed under the action of the bionic impeller 33, thereby ensuring that the quality of the heterogeneous metal powders is continuous and uniform during the printing process; by controlling the connection or blocking between the main material bin 12 and the auxiliary material bin 13 and the mixing chamber 15 respectively, a continuously gradient mixed heterogeneous metal component is finally obtained; in addition, the movement speed of the valve port relative to the feed port 14 can be controlled by program design, thereby adjusting the mixing gradient change of the heterogeneous metal components.

Claims

1. A bionic automatic mixing device for gradient heterogeneous metal additive manufacturing, characterized by: It includes double powder silos, electric drive unloading components and bionic mixing components; The upper end cover of the double powder material bin is covered with a bin cover (10), the middle of the double powder material bin is divided into a main material bin (12) and an auxiliary material bin (13) by a partition (11), the main material bin (12) and the auxiliary material bin (13) share a discharge port (14), a mixing chamber (15) is provided at the lower end of the double powder material bin, the discharge port (14) is communicated with the mixing chamber (15), the oblique side walls of the main material bin (12) and the auxiliary material bin (13) are provided with a plurality of asymmetric separation beams (16), the asymmetric separation beams (16) divide the main material bin (12) and the auxiliary material bin (13) into a plurality of asymmetric discharge spaces, and a plurality of slideways (17) are provided on the mixing chamber (15); The electric drive unloading assembly comprises a motor (20), the stator housing of the motor (20) is fixedly connected to the outer wall of the double powder bin, the baffle (21) is slidably connected in the slideway (17), one end of the baffle (21) is provided with an oblong hole (22), the outer wall of the rotor of the motor (20) is eccentrically connected to an eccentric shaft (23), the eccentric shaft (23) is slidably connected in the oblong hole (22), and a valve port having the same diameter as the unloading port (14) is provided on the side of the baffle (21) away from the oblong hole (22). When the motor (20) is started, the eccentric shaft (23) moves eccentrically in the oblong hole (22) on the baffle (21), driving the baffle (21) to move in the horizontal direction, so that the valve port moves linearly relative to the unloading port (14), thereby controlling the connection or blocking between the main bin (12) and the auxiliary bin (13) and the mixing chamber (15), respectively, and finally obtaining heterogeneous metal powders with continuous gradient mixing; The bionic mixing component comprises an axis skeleton (30), a plurality of discharge openings (31) are provided through the axis skeleton (30), an upper end of a connecting bridge (32) is connected to the axis skeleton (30) between two adjacent discharge openings (31), a lower end of the connecting bridge (32) is rotatably connected to a bionic impeller (33), the bionic impeller (33) is arranged inside the axis skeleton (30), and after metal powder enters the axis skeleton (30) under the action of gravity, the bionic impeller (33) can be driven to rotate, and a plurality of micro-thorns imitating the structure of camel spider bristles are arrayed on the surface of the blade of the bionic impeller (33); Sub-millimeter-level capillary serration structures (40) imitating Araucaria leaves are evenly distributed on the inner wall of the double powder bin, and the tooth tips of the capillary serration structures (40) are all oriented toward the feeding direction of the metal powder.

2. The bionic automatic mixing device for gradient heterogeneous metal additive manufacturing according to claim 1 is characterized by: The shaft frame (30) is a cylindrical structure, and the closing caps (34) are covered at both ends of the shaft frame (30).

3. The bionic automatic mixing device for gradient heterogeneous metal additive manufacturing according to claim 1 is characterized by: The tooth root of the capillary sawtooth structure (40) is fixedly connected to the inner wall of the double powder silo, the tooth tip of the capillary sawtooth structure (40) is tilted, the length of the capillary sawtooth structure (40) is 550 μm to 790 μm, and is formed by drawing a cross-sectional profile AB with thickness along the central curve CD of the longitudinal section to point D, and its thickness dimension is 320 μm to 380 μm; the equation of the central curve CD of the longitudinal section is: f(x)=ax 3 +bx 2 +cx, where a ranges from -0.15 to -0.3, b ranges from -0.2 to -0.35, c ranges from -0.05 to -0.25, and x ranges from 0 mm to 1.2 mm; the cross-sectional profile AB is obtained by the intersection of the upper profile curve and the lower profile curve, and the equation of the upper profile curve is: f(x)= (-r 2 +0.8r+0.48)cos(dx), where r is the vertical distance from the cross section to the inner wall of the double powder silo, and its value range is 0mm~1.2mm, d is 1.05~1.3, and x is -1.5 mm~1.5 mm; the lower contour curve equation is: f(x)= (-r 2 +0.8r+0.48)(-qx 2 +0.8), where r is the vertical distance from the cross section to the inner wall of the double powder silo, and its value range is 0mm~1.2mm, and the value range of q is 0.12-0.

2.

4. The bionic automatic mixing device for gradient heterogeneous metal additive manufacturing according to claim 1 is characterized by: The distance between two adjacent microthorns is 125μm~300μm, the length of a microthorn is 20μm~50μm, the diameter of a microthorn is 5μm~7μm, the tip of the microthorn is a conical structure, and the angle of the cone top ranges from 6° to 10°.

5. The bionic automatic mixing device for gradient heterogeneous metal additive manufacturing according to claim 4 is characterized by: There are multiple secondary microthorn structures distributed on the surface of the microthorns, the length of the secondary microthorn structure is 2μm ~4μm, and the diameter of the secondary microthorn structure is 550nm ~ 800nm; there are 9 layers of secondary microthorn structures distributed axially on the microthorns, and 6 secondary microthorn structures are evenly distributed on each layer. The spacing between two adjacent layers of secondary microthorn structures is 1μm ~ 1.6μm, and the two adjacent layers of secondary microthorn structures are arranged on the same vertical line. The angle between the axis ab of any secondary microthorn structure and the axis cd of the microthorn is 30° ~ 40°.

6. The bionic automatic mixing device for gradient heterogeneous metal additive manufacturing according to claim 5, characterized in that: The outer contour of the secondary microthorn structure is formed by rotating the curve ef around the axis ab. The equation of the curve ef is f(x)=e x , the value range of e is 2.2~2.9, and the value range of x is 0μm ~2μm.

7. The bionic automatic mixing device for gradient heterogeneous metal additive manufacturing according to claim 6 is characterized by: The inner wall surface of the bionic automatic mixing device is sprayed with a polyimide coating with a thickness of 80μm~90μm.

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