A solid state additive method

Abstract

The application relates to a solid-state additive method, comprising the following steps: arranging a circular consumable rod in a hollow stirring tool; setting a gap between the bottom surface of the hollow stirring tool and a base surface according to a coating height; driving the hollow stirring tool to rotate at a first rotating speed; driving the consumable rod to rotate at a second rotating speed, the angular velocity of the second rotating speed being different from that of the first rotating speed to form a differential speed, so that heat deformation is generated by the friction between the consumable rod and the inner wall of the hollow stirring tool, and a plastic deformation flow is obtained in the hollow stirring tool; pressing the consumable rod to make the plastic deformation flow frictionally contact the base surface; translating the hollow stirring tool and stirring the base surface to make the plastic deformation flow form a coating on the base surface. In the application, the angular velocity of the second rotating speed is different from that of the first rotating speed to form a differential speed, so that heat deformation is generated by the friction between the consumable rod and the inner wall of the hollow stirring tool to form a plastic deformation flow, the required pressing force of the consumable rod is reduced, and the solid-state additive efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of solid-state additive manufacturing technology, and in particular to a solid-state additive manufacturing method. Background Technology

[0002] Solid additive manufacturing uses a hollow mixing tool filled with filament rods to rotate and move horizontally. While rotating, the filament rods also move downward relative to the hollow mixing tool and come into contact with the upper surface of the substrate or the upper surface of the substrate that has already formed a coating. The bottom end of the filament rod moves relative to the substrate and undergoes violent friction deformation to generate heat. After forming a plastic deformation flow, it interacts with the shoulder of the hollow mixing tool to form a coating and is applied to the substrate.

[0003] On the one hand, in existing technologies, the required downward pressure on the filament rod is too high, making it difficult to achieve solid-state additive manufacturing of high-temperature alloys. This is because the heat source in solid-state additive manufacturing is the intense deformation of the filament rod under rotational pressure and the action of a hollow stirring tool. For materials with excellent high-temperature properties, such as high-temperature alloys, the inability to achieve such intense deformation limits the application of solid-state additive manufacturing technology. Previous methods all require the filament rod to be subjected to significant downward pressure to generate heat through intense friction. The heat source in the additive process is located at the end face of the filament rod and the end face of the hollow stirring tool, and the large downward pressure limits the length of the filament rod.

[0004] On the other hand, existing technologies struggle to control temperature during solid-state additive manufacturing. Temperature control is crucial for the lifespan of solid-state additive manufacturing tools. For example, heat accumulation during the solid-state additive manufacturing process can affect the lifespan of the mixing head and the performance of the additive product. Excessive temperature in a subsequent coating can negatively impact the microstructure of the previous coating and ultimately the overall performance of the component.

[0005] Secondly, in existing solid-state additive manufacturing technologies, the rotation speed of the filament rod and the rotation speed of the hollow stirring tool need to be consistent, resulting in a small range of parameters such as welding speed, and these parameters are not optimal for the stirring process.

[0006] In addition, the filament rods used in solid additive manufacturing were too short, requiring frequent replacements and resulting in low efficiency, making it difficult to produce large-sized coatings in one go.

[0007] In addition, coatings prepared by solid additive manufacturing technology may have an effect where the coating layer is not located at the center line of the stirring tool, but is offset to the forward side, which is not conducive to precise control of the shape of solid additive components. Summary of the Invention

[0008] This invention provides a solid additive manufacturing method that at least solves the problem in the prior art that the required downward pressure for the filament rod is too high, making it difficult to achieve solid additive manufacturing of high-temperature alloys.

[0009] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0010] A solid-state additive manufacturing method is provided, which uses a filament rod to form a coating on a base surface, said base surface including the upper surface of a substrate or an upper surface already coated. The solid-state additive manufacturing method includes the following steps:

[0011] The consumable rod is placed in a hollow stirring tool, and the consumable rod is circular;

[0012] The gap between the bottom surface of the hollow mixing tool and the base surface is set according to the coating height;

[0013] The hollow stirring tool is driven to rotate by a first rotational speed;

[0014] The consumable rod is driven to rotate by a second rotation speed. The second rotation speed has a different angular velocity than the first rotation speed, thus forming a differential speed. This causes the consumable rod to rub against the inner wall of the hollow stirring tool, generating thermal deformation. A plastic deformation flow is obtained in the hollow stirring tool, and the temperature of the plastic deformation flow is lower than the melting point temperature of the consumable rod.

[0015] Pressing down the consumable rod causes the plastic deformation flow to come into frictional contact with the base surface;

[0016] The hollow mixing tool is moved and the base surface is stirred so that the plastic deformation flow forms a coating on the base surface.

[0017] Optionally, the lower part of the inner wall of the hollow stirring tool is an outwardly expanding flared mouth, so as to decompose the reaction force generated by the expansion of the consumable rod on the inner wall of the hollow stirring tool into a lateral force and a vertical force.

[0018] Optionally, the outward expansion angle is 0.1-7 degrees.

[0019] Optionally, after placing the consumable rod in the hollow mixing tool, the method further includes:

[0020] Obtain the real-time temperature of the hollow stirring tool and / or the consumable rod in the hollow stirring tool;

[0021] If the real-time temperature is lower than the preset temperature, then heat the hollow stirring tool and / or the consumable rod in the hollow stirring tool to induce plastic deformation flow in the consumable rod.

[0022] Optionally, the heating step employs at least one of the following methods to heat the hollow stirring tool and / or the consumable rod in the hollow stirring tool: inductive heater, flame jet heating, laser heating, ultrasonic vibration heating, plasma jet heating, or electric arc heating.

[0023] Optionally, the method further includes:

[0024] Obtain the real-time temperature of the hollow stirring tool and / or the consumable rod in the hollow stirring tool;

[0025] Determine if the real-time temperature is higher than the preset temperature. If so, cool the bottom surface of the hollow stirring tool to adjust the temperature of the plastic deformation flow.

[0026] Optionally, the bottom surface of the hollow mixing tool can be cooled by air cooling.

[0027] Optionally, the first rotational speed and the second rotational speed are in the same direction, and the first rotational speed is lower than the second rotational speed.

[0028] Optionally, the first rotational speed and the second rotational speed are in opposite directions, so that the plastic deformation flow on the advancing side of the consumable rod is pushed in the opposite direction to the advancing side of the hollow stirring tool by the hollow stirring tool.

[0029] Optionally, the step of pressing down the consumable rod to cause the plastic deformation flow to come into frictional contact with the base surface includes:

[0030] After radially supporting the middle of the consumable rod, the consumable rod is pressed down to make the plastic deformation flow come into frictional contact with the base surface.

[0031] Optionally, the step of pressing down the consumable rod to cause the plastic deformation flow to come into frictional contact with the base surface includes:

[0032] After radially supporting the upper end of the consumable rod, the top of the consumable rod is pressed down to make the plastic deformation flow come into frictional contact with the base surface.

[0033] Optionally, the inner wall of the flared mouth is corrugated, and / or the bottom surface of the hollow stirring tool is non-planar.

[0034] Optionally, the hollow stirring tool is characterized in that at least one stirring needle is detachably connected to its bottom.

[0035] Optionally, the consumable rod is made of a metal alloy, a metal-ceramic composite material, or an organic material.

[0036] Optionally, the method further includes:

[0037] The substrate is cooled to reduce the temperature of the coating.

[0038] The beneficial effects of this invention are:

[0039] On the one hand, due to the different rotational speeds of the hollow mixing tool and the consumable rod, the second rotational speed differs from the first rotational speed in angular velocity, creating a speed difference. This causes thermal deformation through friction between the consumable rod and the inner wall of the hollow mixing tool. This allows the consumable rod to form a plastic deformation flow even before reaching the base surface. At this point, the consumable rod does not require significant downward pressure to form a plastic deformation flow. This method eliminates the need for the heat generated by the intense frictional deformation between the consumable rod and the base surface, as is present in existing technologies, thus significantly reducing the downward pressure required for additive coating. Furthermore, the speed difference accelerates the rotational speed of the consumable rod, thereby increasing the heat generated by friction and improving the mechanical properties and corrosion resistance of high-temperature alloys, cobalt-based alloys, and other high-temperature material coatings.

[0040] On the other hand, differential speed can adjust the rotation speed of the hollow mixing tool and the rotation speed of the consumable rod to the optimal speed range, thereby generating plastic deformation flow within the hollow mixing tool. This can accelerate the translation speed of the hollow mixing tool and optimize the mixing effect between coatings, thus improving the efficiency of solid additive manufacturing and the mechanical properties of the coating.

[0041] Furthermore, the heating step provides additional heat input to promote the softening of high-temperature alloy materials, thereby achieving the purpose of additive manufacturing. Due to the additional heat input, solid-state additive manufacturing of low-melting-point alloys (aluminum alloys, magnesium alloys, copper alloys) and their composites is significantly beneficial. It also enables the successful preparation of other high-melting-point alloys (such as stainless steel, titanium alloys, nickel-based alloys, high-entropy alloys, cobalt-based alloys) and their composites with ceramics or cemented carbides as reinforcing phases in solid-state additive manufacturing with relatively low downforce.

[0042] Existing solid-state additive manufacturing temperature control methods adjust welding parameters, such as rotation speed, feed rate, and gap distance, to regulate the temperature of the plastic deformation flow, resulting in insufficient cooling response. This invention, based on traditional methods, allows heating and cooling to be applied directly to the hollow stirring tool, resulting in a shorter cooling response time and more sensitive temperature control.

[0043] In addition, by controlling the temperature of the substrate, excess heat accumulated during solid-state additive manufacturing can be dissipated, preventing the substrate or underlying components from softening due to overheating and failing to provide sufficient rigid support for the solid-state additive manufacturing process, thus causing additive manufacturing failure. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 from these drawings without creative effort.

[0045] Figure 1 This is a schematic flowchart of the solid-state additive manufacturing method of the present invention;

[0046] Figure 2 This is a schematic diagram illustrating the operation of the solid-state additive manufacturing method provided in an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the operation of the solid-state additive manufacturing method according to the first embodiment of the present invention;

[0048] Figure 4 This is a schematic diagram illustrating the operation of the solid-state additive manufacturing method according to the second embodiment of the present invention.

[0049] Figure 5 for Figure 4 A schematic diagram of the operation of the solid-state additive manufacturing method of the third embodiment provided in the intermediate embodiment;

[0050] Figure 6 This is a schematic diagram of the control device structure provided in an embodiment of the present invention.

[0051] Explanation of reference numerals: 10, Consumable rod; 20, Substrate; 30, Coating; 40, Hollow stirring tool; 41, Cooling channel; 50, Inductor coil; 60, Top support; 70, Middle support; 80, Stirring needle; 90, Temperature detector; 100, Main control device. Detailed Implementation

[0052] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0053] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. Therefore, they should not be construed as limitations on this invention.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0057] The invention will now be further described with reference to the accompanying drawings.

[0058] This invention provides a solid-state additive manufacturing method that uses a consumable rod 10 to form a coating 30 on a base surface, wherein the base surface includes the upper surface of a substrate 20 or the upper surface on which the coating 30 has already been formed. The solid-state additive manufacturing method includes the following steps:

[0059] Step S10: Place the consumable rod 10 in the hollow stirring tool 40, wherein the consumable rod 10 is circular;

[0060] Step S20: Set the gap between the bottom surface of the hollow mixing tool 40 and the base surface according to the height of the coating 30;

[0061] Step S30: Drive the hollow stirring tool 40 to rotate by the first rotation speed;

[0062] Step S40: Drive the consumable rod 10 to rotate by a second rotation speed. The second rotation speed is different from the angular velocity of the first rotation speed, thus forming a differential speed. This causes the consumable rod 10 to rub against the inner wall of the hollow stirring tool 40 and generate thermal deformation. A plastic deformation flow is obtained in the hollow stirring tool 40. The temperature of the plastic deformation flow is lower than the melting point temperature of the consumable rod 10.

[0063] Step S50: Press down the consumable rod 10 to make the plastic deformation flow come into frictional contact with the base surface;

[0064] Step S60: Move the hollow stirring tool 40 and stir the base surface so that the plastic deformation flow forms a coating 30 on the base surface.

[0065] In some embodiments of this application, the substrate 20 can be a relatively ordinary alloy plate, while the consumable rod 10 can be a relatively high-performance alloy material. For example, the substrate 20 can be aluminum alloy, stainless steel, 625 nickel-based alloy, or carbon steel. The consumable rod 10 can be 7A04 high-strength aluminum alloy, 904 super austenitic stainless steel, 304 austenitic stainless steel, or 718 nickel-based alloy.

[0066] In this embodiment, due to the different rotational speeds of the hollow stirring tool 40 and the consumable rod 10, the second rotational speed has a different angular velocity than the first rotational speed, thus creating a speed difference. This causes the consumable rod 10 to undergo thermal deformation due to friction with the inner wall of the hollow stirring tool 40. This allows the consumable rod 10 to form a plastic deformation flow before reaching the base surface. This means the consumable rod 10 does not need to be subjected to a large downward pressure to form a plastic deformation flow. This method eliminates the need for the heat generated by the intense frictional deformation between the consumable rod 10 and the base surface, as is done in the prior art, thus significantly reducing the downward pressure required for the additive coating 30. Furthermore, the presence of the speed difference allows for a faster rotational speed of the consumable rod 10, thereby accelerating the generation of more heat through friction. This can lead to excellent mechanical properties for high-temperature materials such as high-temperature alloys and cobalt-based alloys.

[0067] On the other hand, differential speed can adjust the rotation speed of the hollow mixing tool 40 and the rotation speed of the consumable rod 10 to the optimal speed range, thereby generating plastic deformation flow within the hollow mixing tool 40. This can accelerate the translation speed of the hollow mixing tool 40 and optimize the mixing effect between coatings, thus improving the efficiency of solid additive manufacturing and the performance of the coatings.

[0068] Optionally, the lower part of the inner wall of the hollow stirring tool 40 is an outwardly expanding flared mouth, so as to decompose the reaction force generated by the expansion of the consumable rod 10 on the inner wall of the hollow stirring tool 40 into a lateral force and a vertical force.

[0069] In this embodiment, the relative motion between the consumable rod 10 and the hollow stirring tool 40 generates heat, causing the consumable rod 10 to expand. This could potentially lead to the consumable rod 10 becoming stuck inside the hollow stirring tool 40. By designing the lower part of the inner wall of the hollow stirring tool 40 as an outwardly expanding flared opening, the expansion and jamming of the consumable rod 10 within the hollow stirring tool 40 can be reduced or prevented. The plastic deformation flow, under the downward pressure of the consumable rod 10, is then transported to the outlet end of the hollow stirring tool 40, and then coated onto the substrate 20 or the surface of the previous coating 30 by the shoulder of the hollow stirring tool 40, thus achieving the purpose of additive manufacturing. Simultaneously, the consumable rod 10 can interact with the inner wall of the flared opening, resulting in intense plastic deformation and heat generation. This helps the consumable rod 10 soften rapidly, forming a plastic deformation flow, further reducing the downward pressure required for the consumable rod 10 and improving the efficiency of solid-state additive manufacturing.

[0070] Furthermore, the angle of the flared mouth expanding outward is 0.1-7 degrees, the inner wall of the flared mouth can be corrugated, and the bottom surface of the hollow stirring tool 40 can be set as non-planar, such as concave inward or convex outward, or patterned, to increase the roughness of the coating surface and facilitate better bonding between the coatings.

[0071] Optionally, after placing the consumable rod 10 in the hollow stirring tool 40, the method further includes step S70:

[0072] Obtain the real-time temperature of the hollow stirring tool 40 and / or the consumable rod 10 in the hollow stirring tool 40;

[0073] If the real-time temperature is lower than the preset temperature, then heat the hollow stirring tool 40 or the consumable rod 10 in the hollow stirring tool 40, or both together, so that the consumable rod 10 produces plastic deformation flow.

[0074] Step S70 can be interspersed among various steps depending on the actual situation, such as after step S20 or before step S60.

[0075] The heating step provides additional heat input to promote the softening of high-temperature alloy materials, thereby achieving the purpose of additive manufacturing. Due to the additional heat input, solid-state additive manufacturing of low-melting-point alloys (aluminum alloys, magnesium alloys, copper alloys) and their composites is significantly beneficial. It also enables the successful preparation of other high-melting-point alloys (such as stainless steel, titanium alloys, nickel-based alloys, high-entropy alloys, cobalt-based alloys) and their composites with ceramics or cemented carbides as reinforcing phases in solid-state additive manufacturing with relatively low downforce.

[0076] Optionally, the heating step may employ at least one of the following methods to heat the hollow stirring tool 40 and / or the consumable rod 10 in the hollow stirring tool 40: inductive heater, flame jet heating, laser heating, ultrasonic vibration heating, plasma jet heating, or electric arc heating.

[0077] This step heats the hollow stirring tool 40, transferring the heat to the filament rod 10, which in turn heats the rod itself. Since the filament rod 10 is made of alloy, it is also heated by the inductor coil. Therefore, the heat required for material softening no longer relies entirely on the drastic deformation of the filament rod 10 as in previous methods. This reduces the downforce required for solid additive coating and increases the translational speed of the hollow stirring tool 40, thereby improving solid additive manufacturing efficiency. Furthermore, for high-temperature alloys and cobalt-based alloys with excellent mechanical properties near their melting points, traditional solid additive manufacturing techniques struggle to generate sufficient heat to soften the material and induce plastic deformation flow. Inductor coil heating provides additional heat input to promote the softening of high-temperature alloy materials, thus achieving the additive manufacturing objective.

[0078] The heating components used in the heating step may include an inductor coil 50 sleeved on the outside of the hollow stirring tool 40, and a controller connected to the inductor coil 50 and used to control the temperature of the inductor coil 50.

[0079] The inductor coil 50 can be spirally wrapped around the outside of the hollow stirring tool 40 and located at the lower end of the hollow stirring tool 40 near the substrate 20, so that the plastic deformation flow formed by the consumable rod 10 after being heated by the inductor coil 50 can be directly coated on the surface of the substrate 20 or the previous coating 30. The controller is connected to the inductor coil 50 through a wire and is used to control the temperature of the inductor coil.

[0080] As a further preferred embodiment of this invention, the method may further include step S80:

[0081] Take the real-time temperature of the hollow stirring tool and / or the consumable rod in the hollow stirring tool;

[0082] If the real-time temperature is higher than the preset temperature, then the bottom surface of the hollow stirring tool 40 is cooled to adjust the temperature of the plastic deformation flow.

[0083] Step S80 can be interspersed among various steps depending on the actual situation, such as after step S20 or before step S60.

[0084] Preferably, the bottom surface of the hollow stirring tool 40 can be cooled by air cooling.

[0085] Cooling the bottom surface of the hollow mixing tool 40 can reduce the temperature of the hollow mixing tool 40, extend its service life, and ensure the performance of additive products.

[0086] Specifically, a cooling channel 41 can be opened on the hollow mixing tool 40. The cooling channel 41 includes an inner flow channel inside the hollow mixing tool 40 and an inlet and an outlet connected to both ends of the inner flow channel on the side wall of the hollow mixing tool 40. The cooling medium is input into the inner flow channel through the inlet, cools the hollow mixing tool 40, and is discharged from the outlet.

[0087] By heating and cooling, the temperature of the hollow stirring tool 40 and the consumable rod 10 can be controlled during the solid additive manufacturing process, making it suitable for solid additive manufacturing of high melting point alloys.

[0088] In solid-state additive manufacturing, hollow mixing tools 40 often need to operate at high temperatures for extended periods. When excess heat cannot be dissipated in time, heat accumulation occurs, causing the temperature of the hollow mixing tool 40 to rise, leading to a decrease in its high-temperature mechanical properties, accelerated wear, and a reduced lifespan. Furthermore, overheating of the hollow mixing tool 40 and the coating will have a heat treatment effect on the underlying coating. For example, recrystallization can cause the grains of the previous coating to grow, resulting in decreased mechanical properties and affecting the overall performance of the coating. Therefore, reducing the temperature of the mixing tool extends its lifespan and ensures the performance of the coating.

[0089] Both steps S70 and S80 involve real-time temperature monitoring, which can be achieved using methods such as... Figure 6 The control device shown includes a main control device 100 and a temperature detector 90 connected to the main control device 100. The controller includes a first control valve and a second control valve.

[0090] The main control device 100 can be an external computer, mobile phone, or tablet. The temperature detector 90 can be a thermocouple or an infrared imager, used to measure the temperature of the hollow stirring tool 40 and / or the consumable rod 10 in the hollow stirring tool 40 in real time and send the data to the main control device 100. A first control valve is located between the main control device 100 and the inductor coil 50 to control the temperature of the inductor coil 50. One end of the second control valve is connected to the main control device 100, and the other end is connected to the storage tank of the cooling medium and the output pipe of the cooling medium, respectively.

[0091] Temperature detector 90 can acquire the temperature of hollow mixing tool 40 and / or consumable rod 10 in real time and transmit the temperature information to main control device 100. Main control device 100 determines whether to heat or cool hollow mixing tool 40 and / or consumable rod 10 based on the temperature information. If the detected temperature value is greater than the preset temperature value, the main control device 100 controls the first control valve to close or decrease its opening, and / or controls the second control valve to open or increase its opening, in order to cool hollow mixing tool 40 and / or consumable rod 10. If the detected temperature value is less than the preset temperature value, the main control device 100 controls the first control valve to open or increase its opening, and / or controls the second control valve to close or decrease its opening, in order to heat hollow mixing tool 40 and / or consumable rod 10.

[0092] The temperature detector 90 can be a thermocouple temperature measuring device or an infrared imaging temperature measuring device.

[0093] As a further preferred embodiment, the first rotational speed and the second rotational speed are in the same direction, and the first rotational speed is lower than the second rotational speed.

[0094] In this embodiment, since the consumable rod 10 needs to generate heat through friction to soften and form a plastic deformation flow, while the hollow stirring tool 40 only needs to provide stirring force to the plastic deformation flow, the required rotational speed of the consumable rod 10 is relatively high, while the required rotational speed of the hollow stirring tool 40 is relatively low. This allows both the consumable rod 10 and the hollow stirring tool 40 to work within their respective optimal rotational speed ranges, which not only improves the efficiency of solid additive manufacturing but also enhances the bonding force between the coatings, thereby improving the mechanical properties of the coatings.

[0095] Optionally, the first rotational speed and the second rotational speed are in opposite directions, so that the plastic deformation flow on the advancing side of the consumable rod 10 is pushed in the opposite direction to the advancing side of the hollow stirring tool 40.

[0096] It should be noted that when the consumable rod 10 rotates, viewed from a direction away from the consumable rod 10, the side facing the direction of rotation is the forward side, and the side opposite to the forward side is the reverse side. For example, when the consumable rod 10 rotates clockwise, viewed from a direction away from the consumable rod 10 ( Figure 2 In the V2 direction), the forward side is located on the left side of the consumable rod 10 ( Figure 2 (Top left of the middle).

[0097] When the rotation direction of the hollow stirring tool 40 is opposite to that of the consumable rod 10, the offset effect of the coating 30 towards the forward side will cancel each other out. That is, although the plastic deformation flow generated by the consumable rod 10 will move towards the forward side of the consumable rod 10 under the influence of the consumable rod 10, it will be immediately pushed to the forward side of the hollow stirring tool 10 by the reverse-rotating hollow stirring tool 10. In this way, the center position of the coating 30 is basically located at the center line of the hollow stirring tool 40 and the consumable rod 10.

[0098] In some embodiments of this application, the step of pressing down the consumable rod 10 to cause the plastic deformation flow to come into frictional contact with the base surface includes:

[0099] After radially supporting the middle part of the consumable rod 10, the consumable rod 10 is pressed down to make the plastic deformation flow come into frictional contact with the base surface.

[0100] The middle part of the radial support consumable rod 10 can be adopted as follows: Figure 4 The central support member 70 shown has one end sleeved on the consumable rod 10 and can slide along the axial direction of the consumable rod 10, thereby adjusting the support position according to the change in the length of the consumable rod 10, so that the central support member 70 can always be kept in the middle position of the unconsumed consumable rod 10.

[0101] In this embodiment, by supporting the middle part of the consumable rod 10, it is possible to prevent excessive deflection in the middle part of the consumable rod 10 during the solid additive manufacturing process, and avoid large bending deformation in the middle part of the consumable rod 10.

[0102] Optionally, the step of pressing down the consumable rod 10 to cause the plastic deformation flow to come into frictional contact with the base surface includes:

[0103] After radially supporting the upper end of the consumable rod 10, the top end of the consumable rod 10 is pressed down to make the plastic deformation flow come into frictional contact with the base surface.

[0104] The upper end of the radial support consumable rod 10 can be adopted as follows: Figure 4 The top support 60 shown includes a positioning sleeve fixedly connected to the top of the consumable rod 10 and a support seat sleeved on the outside of the positioning sleeve. The support seat can rotate relative to the positioning sleeve and can drive the positioning sleeve to move vertically, pressing down the consumable rod 10 to make the plastic deformation flow rub against the base surface.

[0105] In this embodiment, by supporting the upper end of the filament rod 10, vibration during movement can be prevented, thus improving its stability. Furthermore, the cooperation between the middle support member 70 and the top support member 60 enables the solid-state additive manufacturing device to load longer filament rods 10, achieving the manufacture of larger parts in a single operation.

[0106] Optionally, at least one stirring needle 80 is detachably connected to the bottom of the hollow stirring tool 40.

[0107] At least one stirring pin 80 is provided; if two are used, they are located at different radial positions on the hollow stirring tool 40 body. The stirring pin 80 stirs the coating 30 located at the bottom, thus improving the bonding between the coatings. The stirring pin 80 can be cylindrical or have a pointed bottom to reduce resistance during the stirring process. The stirring pin 80 can be detachably connected to the bottom of the hollow stirring tool 40 by means of plug-in or threaded connection, which facilitates the removal and replacement of the stirring pin 80. It also allows adjustment of the length of the stirring pin 80 extending to the outside of the hollow stirring tool 40 to accommodate solid-state additive manufacturing of different materials.

[0108] Optionally, the consumable rod 10 is made of a metal alloy, a metal-ceramic composite material, or an organic material.

[0109] Optionally, the method further includes cooling the substrate 20 to cool the temperature of the coating 30.

[0110] The cooling substrate 20 can be achieved by water cooling or air cooling. Specifically, a clamping base can be provided at the bottom of the substrate 20, and a cooling channel can be provided inside the clamping base, with the cooling channel located below the substrate 20. The side wall of the clamping base has an inlet and an outlet that are respectively connected to both ends of the cooling channel. The cooling medium enters the cooling channel through the inlet and is discharged through the outlet, thereby dissipating heat from the substrate 20 and the lower coating 30, preventing the substrate 20 and / or the lower coating 30 from overheating and softening, which could cause the entire coating to collapse.

[0111] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A solid-state additive manufacturing method, comprising forming a coating on a base surface using a filament rod, said base surface including the upper surface of a substrate or an upper surface already coated, characterized in that, Includes the following steps: The consumable rod is placed in a hollow stirring tool, and the consumable rod is circular; The lower part of the inner wall of the hollow stirring tool is an outwardly expanding flared mouth with an outward expansion angle of 0.1-7 degrees, so as to decompose the reaction force generated by the expansion of the consumable bar on the inner wall of the hollow stirring tool into a horizontal force and a vertical force. The gap between the bottom surface of the hollow mixing tool and the base surface is set according to the coating height; The hollow stirring tool is driven to rotate by a first rotational speed; The consumable rod is driven to rotate by a second rotation speed. The first rotation speed and the second rotation speed are in the same direction, and the first rotation speed is lower than the second rotation speed. The second rotation speed and the first rotation speed have different angular velocities, thus forming a speed difference. This causes the consumable rod to rub against the inner wall of the hollow stirring tool and generate thermal deformation. A plastic deformation flow is obtained in the hollow stirring tool. The temperature of the plastic deformation flow is lower than the melting point temperature of the consumable rod. Pressing down the consumable rod causes the plastic deformation flow to come into frictional contact with the base surface; The hollow mixing tool is moved and the base surface is stirred so that the plastic deformation flow forms a coating on the base surface.

2. The solid-state additive manufacturing method according to claim 1, characterized in that, After placing the consumable rod in the hollow mixing tool, the method further includes: Obtain the real-time temperature of the hollow stirring tool and / or the consumable rod in the hollow stirring tool; If the real-time temperature is lower than the preset temperature, then heat the hollow stirring tool and / or the consumable rod in the hollow stirring tool to induce plastic deformation flow in the consumable rod.

3. The solid-state additive manufacturing method according to claim 2, characterized in that, The heating step employs at least one of the following methods to heat the hollow stirring tool and / or the consumable rod in the hollow stirring tool: inductive heater, flame jet heating, laser heating, ultrasonic vibration heating, plasma jet heating, or electric arc heating.

4. The solid-state additive manufacturing method according to any one of claims 1-3, characterized in that, The method further includes: Obtain the real-time temperature of the hollow stirring tool and / or the consumable rod in the hollow stirring tool; Determine if the real-time temperature is higher than the preset temperature. If so, cool the bottom surface of the hollow stirring tool to adjust the temperature of the plastic deformation flow. The bottom surface of the hollow mixing tool is cooled by air cooling.

5. The solid-state additive manufacturing method according to any one of claims 1-3, characterized in that: The first rotational speed is opposite to the second rotational speed, causing the plastic deformation flow on the advancing side of the consumable rod to be pushed in the opposite direction to the advancing side of the hollow stirring tool by the hollow stirring tool.

6. The solid-state additive manufacturing method according to any one of claims 1-3, characterized in that, The step of pressing down the consumable rod to cause the plastic deformation flow to come into frictional contact with the base surface includes: After radially supporting the middle of the consumable rod, the consumable rod is pressed down to make the plastic deformation flow come into frictional contact with the base surface.

7. The solid-state additive manufacturing method according to any one of claims 1-3, characterized in that, The step of pressing down the consumable rod to cause the plastic deformation flow to come into frictional contact with the base surface includes: After radially supporting the upper end of the consumable rod, the top of the consumable rod is pressed down to make the plastic deformation flow come into frictional contact with the base surface.

8. The solid-state additive manufacturing method according to claim 1, characterized in that: The inner wall of the flared mouth is corrugated, and / or the bottom surface of the hollow stirring tool is non-planar.

9. The solid-state additive manufacturing method according to any one of claims 1-3, characterized in that, At least one stirring needle is detachably connected to the bottom of the hollow stirring tool.

10. The solid-state additive manufacturing method according to any one of claims 1-3, characterized in that, The consumable rod is made of metal alloy, metal-ceramic composite material or organic material.

11. The solid-state additive manufacturing method according to any one of claims 1-3, characterized in that, The method further includes: The substrate is cooled to reduce the temperature of the coating.

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