Friction stir additive manufacturing device and method for aviation workpiece

Abstract

The invention discloses a friction stir additive manufacturing device and method for aviation workpieces, the manufacturing device comprises a shaft shoulder, a stirring needle and an ultrasonic vibration device, the lower portion of the shaft shoulder is in an inverted circular truncated cone shape, and a plurality of independent feeding channels are formed in the shaft shoulder; discharging ports of the feeding channel are formed in the inclined side wall of the inverted-circular-truncated-cone-shaped lower portion of the shaft shoulder at intervals, a rotating main shaft is arranged in the middle of the shaft shoulder, the stirring needle is connected with the rotating main shaft and extends out of the bottom circle of the inverted-circular-truncated-cone-shaped lower portion of the shaft shoulder, and the ultrasonic vibration device is arranged below the base material and used for emitting ultrasonic waves. The manufacturing method is realized by using the manufacturing device. According to the friction stir additive manufacturing device and method for the aviation workpiece, additive powder blockage can be avoided, additive powder can be preheated, the bonding strength can be improved, external force needed by additive manufacturing can be reduced, the material fluidity can be enhanced, material mixing and recrystallization can be promoted, and the product quality of the aviation workpiece can be improved.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and specifically provides a friction stir additive manufacturing device and a manufacturing method for aviation workpieces. Background Art

[0002] Additive manufacturing technology is a technology that constructs objects by stacking materials layer by layer. Compared with traditional subtractive manufacturing technology, additive manufacturing technology has the advantages of high material utilization, high design freedom, and the ability to manufacture complex structures. It has broad application prospects in the fields of aerospace, automobiles, etc. Traditional additive manufacturing technology usually uses laser beams, electric arcs, etc. as heat sources for additive manufacturing, which is suitable for the manufacture of high-temperature alloys.

[0003] Friction stir welding (FSW) is a solid-phase connection technology that uses the friction between a high-speed rotating stirring head and the workpiece to generate heat, so that the material reaches a thermoplastic state, and the material is connected under the action of the stirring head. In recent years, researchers have begun to explore the application of FSW technology in the field of additive manufacturing, namely Friction Stir Additive Manufacturing (FSAM) technology. FSAM technology uses the principle of FSW to manufacture three-dimensional solid parts by layer-by-layer stacking. Compared with traditional fusion welding additive manufacturing technology, FSAM materials are always in a solid state during the processing process, avoiding common defects such as pores, cracks and component segregation in the fusion welding process, and can obtain a dense deposition layer with excellent mechanical properties. In addition, FSAM has the characteristics of low heat input, small heat-affected zone, and low residual stress. It is particularly suitable for additive manufacturing of lightweight and high-strength aviation workpieces such as aluminum alloys, magnesium alloys, and copper alloys. This technology can achieve efficient, high-precision, and low-cost manufacturing of complex structural parts, while meeting the manufacturing needs of green and environmentally friendly manufacturing, and provides a new solution for low-cost and high-performance manufacturing of complex metal structural parts.

[0004] The commonly used additive materials for stir friction additive manufacturing are plates, rods and wires. While these additive forms can achieve additive manufacturing, they have disadvantages such as large structural size and insufficient feeding continuity. The use of powder additives solves these problems well. In addition, controlling the ratio of powder to substrate can also directionally manufacture structural parts that adapt to different use environments. However, due to the large differences in properties such as thermal conductivity and thermal expansion coefficient between dissimilar materials used to prepare aviation workpieces, it is easy to cause weak connections at the interface between dissimilar materials, affecting product quality.

[0005] Therefore, developing a stir friction additive manufacturing device and manufacturing method suitable for aviation workpieces to improve the production quality of stir friction additive manufacturing has become an urgent problem to be solved. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a friction stir additive manufacturing device and a manufacturing method for aviation workpieces, so as to solve the problems existing in manufacturing aviation workpieces using existing friction stir additive manufacturing devices.

[0007] On the one hand, the present invention provides a stir friction additive manufacturing device for aviation workpieces, which is used to complete the stir friction additive manufacturing of aviation workpieces on a substrate. The stir friction additive manufacturing device for aviation workpieces includes: a shoulder, a stirring needle and an ultrasonic vibration device, wherein the lower part of the shoulder is in an inverted cone shape, and a plurality of independent feed channels are arranged in the shoulder, and the discharge ports of the feed channels are arranged at intervals on the inclined side walls of the inverted cone-shaped lower part of the shoulder, a rotating main shaft is arranged in the middle part of the shoulder, the stirring needle is connected to the rotating main shaft and extends out of the bottom circle of the inverted cone-shaped lower part of the shoulder, and the ultrasonic vibration device is arranged below the substrate for emitting ultrasonic waves.

[0008] Preferably, the discharge port of the feed channel is arranged to be inclined downward.

[0009] Further preferably, the discharge ports of the feed channel are arranged at equal intervals along the inclined side walls of the lower portion of the shoulder frustum cone.

[0010] More preferably, the stirring needle is in the shape of an inverted frustum.

[0011] Further preferably, the bottom of the stirring needle is provided with a plurality of spiral gradient bosses which are symmetrical about the center center of the bottom surface of the stirring needle, and the width of the spiral gradient bosses gradually narrows from the outside to the inside.

[0012] Further preferably, the ultrasonic vibration device is a variable frequency ultrasonic vibration device.

[0013] Further preferably, the friction stir additive manufacturing apparatus for aviation workpieces further includes an ultrasonic pad disposed between the ultrasonic vibration device and the substrate.

[0014] The present invention also provides a friction stir additive manufacturing method for aviation workpieces, using the above-mentioned friction stir additive manufacturing device for aviation workpieces, and the manufacturing method comprises the following steps:

[0015] S1: moving the shaft shoulder and the stirring needle in the friction stir additive manufacturing device for aviation workpieces to above the starting position of additive manufacturing, setting the ultrasonic vibration device in the friction stir additive manufacturing device for aviation workpieces below the substrate, and feeding the additive material into different feeding channels of the shaft shoulder accordingly;

[0016] S2: Start the ultrasonic vibration device and the stirring needle, and press the stirring needle into the substrate;

[0017] S3: using the discharge port of the shoulder to deposit the required additive powder on the forward path of the stirring needle, and using the stirring friction effect of the advancing stirring needle to cause the additive powder deposited on the forward path to undergo plastic deformation, and finally, combining the extrusion of the shoulder and the stirring friction effect of the stirring needle to melt the plastic material in the additive direction and form a deposition layer;

[0018] S4: After a deposition layer is completed, the discharge port is controlled to stop discharging, and the shaft shoulder and stirring needle are moved to the position of the previous deposition layer, and the retreating side of the previous stage is changed to the advancing side of this stage, and the discharge port on the advancing side of this stage is controlled to accumulate the required additive powder on the advancing path of the stirring needle, and the stirring friction effect of the advancing stirring needle is used to cause the accumulated additive powder to undergo plastic deformation, and finally, the extrusion of the combined shaft shoulder and the stirring friction effect of the stirring needle are used to melt the plastic material in the additive direction and form a deposition layer;

[0019] S5: Repeat S3 and S4 until the friction stir additive manufacturing goal is achieved.

[0020] Preferably, the friction stir additive manufacturing method for aviation workpieces further comprises the step of adjusting the ultrasonic frequency of the ultrasonic vibration device, wherein the ultrasonic frequency of the ultrasonic vibration device increases as the distance between the ultrasonic vibration device and the stirring needle increases.

[0021] Further preferably, the friction stir additive manufacturing method for aviation workpieces also includes the step of rotating the shoulder so that the discharge port containing the required additive powder faces the advancing direction of the stirring needle.

[0022] The friction stir additive manufacturing device and manufacturing method for aviation workpieces provided by the present invention can avoid clogging of additive materials, preheat additive powder, improve bonding strength, reduce the external force required for additive manufacturing, enhance material fluidity, promote material mixing and recrystallization, and improve the product quality of aviation workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0024] Figure 1 A schematic diagram of the structure of the friction stir additive manufacturing device for aviation workpieces provided by the present invention;

[0025] Figure 2 It is a cross-sectional view of the shaft shoulder and the stirring needle;

[0026] Figure 3 This is the layout diagram of the spiral gradient boss of the stirring needle. DETAILED DESCRIPTION

[0027] The present invention will be further explained below in conjunction with specific implementation schemes, but the present invention is not limited thereto.

[0028] like Figures 1 to 3 As shown, the present invention provides a stir friction additive manufacturing device for aviation workpieces, which is used to complete the stir friction additive manufacturing of aviation workpieces on a substrate 10. The stir friction additive manufacturing device for aviation workpieces comprises: a shoulder 1, a stirring needle 2 and an ultrasonic vibration device 3, wherein the lower part of the shoulder 1 is in an inverted cone shape, and a plurality of independent feed channels 11 are arranged in the shoulder 1, and the discharge ports 111 of the feed channels 11 are arranged at intervals on the inclined side walls of the inverted cone-shaped lower part of the shoulder 1, a rotating spindle 12 is arranged in the middle part of the shoulder 1, and the stirring needle 2 is connected to the rotating spindle 12 and extends out of the bottom circle of the inverted cone-shaped lower part of the shoulder 1, and the ultrasonic vibration device 3 is arranged below the substrate 10 for emitting ultrasonic waves. Preferably, the ultrasonic vibration device is arranged in the middle position of the stirring needle's forward path.

[0029] The friction stir additive manufacturing device for aviation workpieces sets the discharge port on the inclined side wall of the shoulder. Compared with the traditional structure in which the discharge port is located inside the shoulder, it avoids the blockage problem caused by material accumulation. In addition, during the friction stir additive manufacturing process, the friction between the stirring needle and the substrate generates heat to plasticize the material. In this process, the heat radiates from the position of the stirring needle to the surrounding substrate, which can increase the temperature of the surrounding substrate, and then preheat the additive powder accumulated in the forward direction of the stirring needle from the discharge port, which is conducive to the mixing of the additive powder and the substrate and improves the bonding strength. In addition, by setting up an ultrasonic vibration device, the energy generated by ultrasonic vibration can be used to increase the temperature of the substrate and the additive during the additive manufacturing process, thereby promoting plastic deformation of the material and reducing the external force required for additive manufacturing. In addition, ultrasonic vibration can effectively enhance the fluidity of the material, make it easier for the stirring needle to stir and mix the material, promote dynamic recrystallization, refine the grains, and improve the product quality of aviation workpieces.

[0030] As an improvement of the technical solution, Figure 1 , Figure 2 As shown, the discharge port 111 of the feed channel 11 is arranged to be inclined downward, and the feed port 112 is arranged above the shoulder, and the discharge port is used to accumulate the additive powder in the direction of the stirring needle. Preferably, the feed channel 11 is a cylindrical channel, and the direction of the discharge port 111 is perpendicular to the inclined side wall of the inverted frustum-shaped lower part of the shoulder 1, wherein the angle θ between the discharge direction of the discharge port 111 and the horizontal plane is between 30 and 60 degrees.

[0031] As an improvement of the technical solution, Figure 1 , Figure 2 As shown, the discharge ports 111 of the feed channel 11 are arranged at equal intervals along the oblique side wall of the frustum-shaped lower part of the shoulder 1. When the additive powder needs to be adjusted, it is only necessary to rotate the shoulder so that the corresponding discharge port is located in the forward direction of the stirring needle. Figure 1 , Figure 2An embodiment in which there are two feed channels is given.

[0032] As an improvement of the technical solution, Figure 1 , Figure 2 As shown, the stirring needle 2 is in the shape of an inverted frustum, and the diameter of the bottom of the stirring needle is smaller than the diameter of the top.

[0033] As an improvement of the technical solution, Figure 2 , Figure 3 As shown, the bottom of the stirring needle 2 is provided with a plurality of spiral gradual bosses 21 symmetrical about the center of the bottom circle of the stirring needle 2, and the width of the spiral gradual bosses 21 gradually narrows from the outside to the inside, as shown in FIG. Figure 3 As shown, the outer width w2 of the boss is greater than the inner width w1 of the boss. The spiral gradient boss can achieve the aggregation and mixing of the end surface materials in the friction stir additive manufacturing process. Figure 3 An example of a six-helix gradient boss is given.

[0034] As an improvement of the technical solution, the ultrasonic vibration device 3 is a variable-frequency ultrasonic vibration device. The consistency of the ultrasonic auxiliary effect can be ensured by adjusting the ultrasonic frequency of the ultrasonic vibration device. Specifically: the ultrasonic frequency of the ultrasonic vibration device increases as the distance between it and the stirring needle 2 increases.

[0035] As an improvement of the technical solution, Figure 1 As shown, the friction stir additive manufacturing device for aviation workpieces also includes an ultrasonic pad 4 arranged between the ultrasonic vibration device 3 and the substrate 10.

[0036] The present invention also provides a friction stir additive manufacturing method for aviation workpieces, using the above-mentioned friction stir additive manufacturing device for aviation workpieces, and the manufacturing method comprises the following steps:

[0037] S1: Move the shoulder 1 and the stirring needle 2 in the friction stir additive manufacturing device for aviation workpieces to above the starting position of additive manufacturing, set the ultrasonic vibration device 3 in the friction stir additive manufacturing device for aviation workpieces below the substrate 10, and feed the additive material (powder) into different feeding channels of the shoulder 1 accordingly, wherein the type of additive powder is not limited to metal materials;

[0038] S2: Start the ultrasonic vibration device 3 and the stirring needle 2, and press the stirring needle 2 into the substrate 10;

[0039] S3: using the discharge port 111 of the shoulder 1 to deposit the required additive powder 9 on the forward path of the stirring needle 2, and using the stirring friction effect of the advancing stirring needle 2 to cause the additive powder 9 deposited on the forward path to undergo plastic deformation, and finally, combining the extrusion of the shoulder 1 and the stirring friction effect of the stirring needle 2 to melt the plastic material in the additive direction and form a deposition layer 8;

[0040] S4: After a deposition layer is completed, the discharge port 111 is controlled to stop discharging, and the shoulder 1 and the stirring needle 2 are moved to the position of the previous deposition layer, and the retreating side of the previous stage is changed to the advancing side of this stage, and the discharge port 111 on the advancing side of this stage is controlled to accumulate the required additive powder 9 on the advancing path of the stirring needle 2, and the stirring and friction effect of the advancing stirring needle 2 is used to cause the accumulated additive powder 9 to undergo plastic deformation, and finally, the extrusion of the shoulder 1 and the stirring and friction effect of the stirring needle 2 are combined to melt the plastic material in the additive direction and form a deposition layer 8;

[0041] S5: Repeat S3 and S4 until the friction stir additive manufacturing goal is achieved.

[0042] The friction stir additive manufacturing method for aviation workpieces utilizes the above-mentioned friction stir additive manufacturing device for aviation workpieces, which can avoid clogging of additive materials, preheat additive powder, improve bonding strength, reduce the external force required for additive manufacturing, enhance material fluidity, promote material mixing and recrystallization, and improve the product quality of aviation workpieces.

[0043] As an improvement of the technical solution, the friction stir additive manufacturing method for aviation workpieces also includes a step of adjusting the ultrasonic frequency of the ultrasonic vibration device, wherein the ultrasonic frequency of the ultrasonic vibration device increases with the increase of the distance between the ultrasonic vibration device and the stirring needle 2 to ensure the consistency of ultrasonic assistance.

[0044] As an improvement of the technical solution, the friction stir additive manufacturing method for aviation workpieces also includes the step of rotating the shoulder 1 so that the discharge port 111 filled with the required additive powder 9 faces the forward direction of the stirring needle 2.

[0045] Example 1

[0046] The steps of manufacturing an aviation battery box by using the friction stir additive manufacturing device for aviation workpieces provided by the present invention are as follows:

[0047] S1: Move the shoulder 1 and the stirring needle 2 in the friction stir additive manufacturing device for aviation workpieces to above the starting position of additive manufacturing, set the ultrasonic vibration device 3 in the friction stir additive manufacturing device for aviation workpieces below the substrate 10, and feed the manually selected magnesium alloy and aluminum alloy powders as additive materials into the two feed channels of the shoulder 1 respectively, wherein the two feed channels are symmetrically arranged about the main axis;

[0048] S2: Start the ultrasonic vibration device 3 and the stirring needle 2. The stirring needle 2 rotates at a speed of 1000 r / min and penetrates into the additively manufactured 2024 aluminum alloy substrate 10 in the rotating state. During the penetration process, the stirring needle rubs against the substrate 10 for preheating;

[0049] S3: magnesium alloy powder is deposited on the forward path of the stirring needle 2 by using the discharge port 111 on the shoulder 1, and the high-temperature aluminum alloy substrate preheats the additive powder; at the same time, the stirring needle rotates at a speed of 1000r / min and advances at a speed of 120mm / min. During this process, the frequency of the ultrasonic vibration device increases with the increase in the distance between the stirring needle and the ultrasonic vibration device, and the additive powder undergoes plastic deformation under the stirring friction of the stirring needle. Under the extrusion of the shoulder, the stirring friction of the stirring needle and the auxiliary action of ultrasound, the plasticized material melts in the additive direction and forms a deposition layer 8;

[0050] S4: After a deposition layer is completed, the discharge port 111 on the forward side is controlled to stop discharging (magnesium alloy powder), and the shoulder 1 and the stirring needle 2 are moved to the position of the previous deposition layer, and the retreating side of the previous stage is changed to the forward side of this stage, and the discharge port 111 on the forward side of this stage is controlled to accumulate aluminum alloy powder on the forward path of the stirring needle 2, and the stirring needle starts to advance in the next stage to form a new deposition layer 8;

[0051] S5: Repeat S3 and S4 until the friction stir additive manufacturing goal is achieved.

[0052] The aviation battery box manufactured by additive manufacturing using this method can not only improve the metallurgical bonding quality of dissimilar alloys and enhance the strength of the material, but also has a good shock absorption effect after adding magnesium alloy powder, thereby greatly increasing the service life of the aviation battery.

[0053] Example 2

[0054] The steps of manufacturing an aircraft landing gear by using the friction stir additive manufacturing device for aviation workpieces provided by the present invention are as follows:

[0055] S1: Move the shoulder 1 and the stirring needle 2 in the friction stir additive manufacturing device for aviation workpieces to above the starting position of additive manufacturing, set the ultrasonic vibration device 3 in the friction stir additive manufacturing device for aviation workpieces below the substrate 10, and feed the manually selected carbon fiber powder and aluminum alloy powder as additive materials into the two feeding channels of the shoulder 1 respectively, wherein the two feeding channels are symmetrically arranged about the main axis;

[0056] S2: Start the ultrasonic vibration device 3 and the stirring needle 2. The stirring needle 2 rotates at a speed of 800 r / min and penetrates into the additively manufactured aluminum alloy substrate 10 in a rotating state. During the penetration process, the stirring needle rubs against the substrate 10 for preheating.

[0057] S3: The discharge port 111 on the shoulder 1 is used to deposit carbon fiber powder on the forward path of the stirring needle 2. The high-temperature 7075 aluminum alloy substrate will preheat the additive powder. At the same time, the stirring needle rotates at a speed of 800 r / min and advances at a speed of 120 mm / min. During this process, the frequency of the ultrasonic vibration device increases as the distance between the stirring needle and the ultrasonic vibration device increases. The additive powder undergoes plastic deformation under the stirring friction of the stirring needle. Under the extrusion of the shoulder, the stirring friction of the stirring needle and the auxiliary action of ultrasound, the plasticized material melts in the additive direction and forms a deposition layer 8.

[0058] S4: After a deposition layer is completed, the discharge port 111 on the forward side is controlled to stop discharging (carbon fiber powder), and the shoulder 1 and the stirring needle 2 are moved to the position of the previous deposition layer, and the retreating side of the previous stage is changed to the forward side of this stage, and the discharge port 111 on the forward side of this stage is controlled to accumulate aluminum alloy powder on the forward path of the stirring needle 2, and the stirring needle starts to advance in the next stage to form a new deposition layer 8;

[0059] S5: Repeat S3 and S4 until the friction stir additive manufacturing goal is achieved.

[0060] The aircraft landing gear manufactured using this method can not only improve the metallurgical bonding quality of dissimilar alloys and enhance the strength of the material, but also after adding carbon fiber powder, the aircraft landing gear can effectively resist low-temperature impact when operating in a low-temperature environment, thereby greatly improving the fatigue life of the aircraft landing gear.

[0061] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A friction stir additive manufacturing device for aviation workpieces, used for completing the friction stir additive manufacturing of aviation workpieces on a substrate (10), characterized in that: include: A shoulder (1), a stirring needle (2) and an ultrasonic vibration device (3), wherein the lower part of the shoulder (1) is in the shape of an inverted cone, a plurality of independent feed channels (11) are arranged in the shoulder (1), and the discharge ports (111) of the feed channels (11) are arranged at intervals on the inclined side walls of the inverted cone-shaped lower part of the shoulder (1), a rotating main shaft (12) is arranged in the middle part of the shoulder (1), the stirring needle (2) is connected to the rotating main shaft (12) and extends out of the bottom circle of the inverted cone-shaped lower part of the shoulder (1), and the ultrasonic vibration device (3) is arranged below the substrate (10) for emitting ultrasonic waves.

2. The friction stir additive manufacturing device for aviation workpieces according to claim 1, characterized in that: The discharge port (111) of the feed channel (11) is arranged to be inclined downward.

3. The friction stir additive manufacturing device for aviation workpieces according to claim 1, characterized in that: The discharge ports (111) of the feed channel (11) are arranged at equal intervals along the oblique side wall of the frustoconical lower portion of the shaft shoulder (1).

4. The friction stir additive manufacturing device for aviation workpieces according to claim 1, characterized in that: The stirring needle (2) is in the shape of an inverted truncated cone.

5. The friction stir additive manufacturing device for aviation workpieces according to claim 1, characterized in that: The bottom of the stirring needle (2) is provided with a plurality of spiral gradual bosses (21) which are symmetrical about the center of the bottom circle of the stirring needle (2), and the width of the spiral gradual bosses (21) gradually narrows from the outside to the inside.

6. The friction stir additive manufacturing device for aviation workpieces according to claim 1, characterized in that: The ultrasonic vibration device (3) is a variable frequency ultrasonic vibration device.

7. The friction stir additive manufacturing device for aviation workpieces according to claim 1, characterized in that: It also includes an ultrasonic pad (4) arranged between the ultrasonic vibration device (3) and the substrate (10).

8. A friction stir additive manufacturing method for aviation workpieces, characterized in that: Using the friction stir additive manufacturing device for aviation workpieces according to any one of claims 1 to 7, the manufacturing method comprises the following steps: S1: moving the shaft shoulder (1) and the stirring needle (2) in the friction stir additive manufacturing device for aviation workpieces to above the starting position of additive manufacturing, setting the ultrasonic vibration device (3) in the friction stir additive manufacturing device for aviation workpieces below the substrate (10), and feeding the additive materials into different feeding channels (11) of the shaft shoulder (1) accordingly; S2: starting the ultrasonic vibration device (3) and the stirring needle (2), and pressing the stirring needle (2) into the substrate (10); S3: using the discharge port (111) of the shoulder (1) to deposit the required additive powder (9) on the forward path of the stirring needle (2), and using the stirring friction effect of the advancing stirring needle (2) to cause the additive powder (9) deposited on the forward path to undergo plastic deformation, and finally, combining the extrusion of the shoulder (1) and the stirring friction effect of the stirring needle (2) to melt the plastic material in the additive direction and form a deposition layer (8); S4: After a deposition layer is completed, the discharge port (111) is controlled to stop discharging, and the shoulder (1) and the stirring needle (2) are moved to the position of the previous deposition layer, and the retreating side of the previous stage is changed to the advancing side of this stage. The discharge port (111) on the advancing side of this stage is controlled to deposit the required additive powder (9) on the advancing path of the stirring needle (2), and the stirring and friction effect of the advancing stirring needle (2) is used to cause the deposited additive powder (9) to undergo plastic deformation. Finally, the extrusion of the shoulder (1) and the stirring and friction effect of the stirring needle (2) are combined to melt the plastic material in the additive direction and form a deposition layer (8); S5: Repeat S3 and S4 until the friction stir additive manufacturing goal is achieved.

9. The friction stir additive manufacturing method for aviation workpieces according to claim 8, characterized in that: The method further comprises the step of adjusting the ultrasonic frequency of the ultrasonic vibration device, wherein the ultrasonic frequency of the ultrasonic vibration device increases as the distance between the ultrasonic vibration device and the stirring needle (2) increases.

10. The friction stir additive manufacturing method for aviation workpieces according to claim 8, characterized in that: The method also includes the step of rotating the shaft shoulder (1) so that the discharge port (111) filled with the required additive powder (9) faces the advancing direction of the stirring needle (2).

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