A bias type high current rheological friction head and a method for strengthening additive tissue performance thereof

Abstract

The application discloses a bias type high flow deformation friction head and a method for strengthening and adding material organization performance, and the device comprises a high flow deformation friction extrusion shaft core and a material flow limiting-flow guiding static shaft shoulder module; the high flow deformation friction extrusion shaft core is connected with a friction extrusion equipment friction head mounting seat through a clamping handle; the device comprises a bias type friction extrusion head, an intermediate connecting structure and the clamping handle; the material flow limiting-flow guiding static shaft shoulder module is concentrically arranged outside the high flow deformation friction extrusion shaft core and connected with a friction extrusion equipment machine head through a connecting flange; the device comprises the connecting flange, a flow guiding surface, a flow guiding groove, a flow limiting surface and a static shaft shoulder surface. The bias type high flow deformation friction head and the high flow deformation (high plastic deformation) effect between the added material are utilized, the friction extrusion force of the high flow deformation friction head on the material to be friction extruded is strengthened, and the combination strength of the material and the organization performance of the whole added component are improved.

Description

Technical Field

[0001] This invention relates to the fields of additive manufacturing, friction extrusion, and friction stir welding equipment, and in particular to an offset high-rheological friction head and a method for enhancing the properties of additive materials. Background Technology

[0002] Additive manufacturing is a technology that uses digital model files as a basis and employs adhesive materials such as filaments, powdered metals, or plastics to construct objects layer by layer through printing. Due to its significant advantages in processing complex spatial structures, particularly in hollow structures, lightweight design, and topology optimization, additive manufacturing is now widely used in the automotive, shipbuilding, and aerospace industries. However, additive manufacturing suffers from relatively poor mechanical properties and is prone to defects such as porosity and cracks during the process.

[0003] Currently, methods for improving the microstructure and properties of additive manufacturing include heat treatment, laser / ultrasonic shock annealing, roller extrusion, and friction stir processing (FSP). However, heat treatment cannot eliminate metallurgical defects such as porosity and cracks, and may even enlarge pores during the process, resulting in limited improvement in microstructure and properties. Laser / ultrasonic shock annealing is mainly used for surface layer strengthening, with a small strengthening area and low degree of improvement in microstructure and properties. It is mainly used for surface strengthening of microstructures and precision devices, and cannot be used for strengthening the microstructure and properties of large structures. Roller extrusion is similar to rolling, causing plastic deformation of the material, but it has little effect on strengthening the internal microstructure of the additive part, with limited plastic deformation and a significant decrease in the plasticity of the material after strengthening.

[0004] Friction stir strengthening (FSP) utilizes a rotating friction stir head inserted into the material. Under the influence of the stir head, the material undergoes plastic deformation, resulting in a certain degree of strengthening of the material near the stirring pin. However, this method is prone to significant material overflow during the strengthening process. Because the stirring pin moves forward during rotation, the pressure on the pin is greatest in the first half of the rotation and decreases in the second half, resulting in less pressure on the treated material in the latter half and limited strengthening effect. Using existing friction stir heads for FSP is inefficient, with a limited strengthening area, making it difficult to perform large-area strengthening. Therefore, there is an urgent need to research a specialized friction head for strengthening additive manufacturing properties to enhance the bonding between treated materials and improve the overall strengthening effect. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the problem that the extrusion pressure between the stirring head and the friction-treated material weakens in the latter half of the stirring head in traditional stirring friction strengthening methods, resulting in limited material strengthening effect. The invention proposes an offset strong rheological friction head and a method for strengthening additive manufacturing properties.

[0006] The technical solution adopted by the present invention to solve its technical problem is: an offset high rheological friction head, including a high rheological friction extrusion shaft and a material flow limiting-guiding stationary shoulder module. The high rheological friction extrusion shaft is connected to an external friction extrusion main shaft motor through a clamping handle. The external friction extrusion main shaft motor drives the high rheological friction extrusion shaft to realize the rotation and movement friction extrusion function. The material flow limiting-guiding stationary shoulder module is concentrically installed on the outside of the high rheological friction extrusion shaft and is fixedly connected to the housing of the external friction extrusion main shaft motor through a connecting flange. During the friction extrusion strengthening process, it moves synchronously with the high rheological friction extrusion shaft but does not rotate. The high-rheological-friction extrusion shaft includes an offset friction extrusion head, an intermediate connecting structure, and a clamping handle. The offset friction extrusion head comprises a near-stationary shoulder structure and upper and lower high-friction extrusion bosses. The near-stationary shoulder structure includes several sets of friction extrusion surfaces, friction extrusion transition surfaces, and temporary storage surfaces for the material to be strengthened. These friction extrusion surfaces, friction extrusion transition surfaces, and temporary storage surfaces for the material to be strengthened are combined with the upper flow surface of the material flow-limiting and guiding stationary shoulder module to form a friction extrusion zone, a friction extrusion transition zone, and a temporary storage zone for the material to be strengthened, respectively. The high-friction extrusion bosses include... Several sets of high-friction extrusion surfaces, high-friction extrusion transition surfaces, and high-friction extrusion storage surfaces are provided. The outermost contour lines of the projections of the high-friction extrusion transition surfaces and the high-friction extrusion storage surfaces on the plane perpendicular to the axial direction coincide with the outermost contour lines of the projections of the friction extrusion transition surfaces on the side of the near-static shoulder structure and the temporary storage surfaces of the material to be strengthened on the plane perpendicular to the axial direction. The high-friction extrusion surfaces are offset outward beyond the static shoulder surface on the material flow limiting-guiding static shoulder module, forming a step with the material flow limiting-guiding static shoulder module. This can prevent material overflow and help enhance the friction extrusion strengthening effect on the material below the static shoulder surface. The friction extrusion surface on the near-static shoulder structure has a radius of... The arc surface of the friction extrusion surface has an angle of θ1. The outermost contour of the friction extrusion transition surface projected onto a plane perpendicular to the axial direction satisfies the following: the distance from the connection point between the friction extrusion transition surface and the friction extrusion surface contour to the center is equal to... The distance from the connection point of the temporary storage surface outline of the material to be reinforced to the center is equal to... , satisfy < The angle between the lines connecting the two ends of the friction-extrusion transition surface contour to the center is... Let θ be the angle between the line connecting any point on the contour line to the center and the line connecting the starting point to the center. Then the distance from that point to the center is equal to... When the angle increases by a small angle dθ, the distance from the corresponding point to the center becomes equal to... When 0≤θ+dθ≤ At that time, always satisfied ≤ < ≤ The outermost contour of the projection of the temporary storage surface of the material to be strengthened onto a plane perpendicular to the axial direction satisfies the following: the distance from the connection point between the temporary storage surface of the material to be strengthened and the contour of the friction-extrusion transition surface to the center is equal to... The angle between the lines connecting the two ends of the outline to the center is Let γ be the angle between the line connecting any point on the contour line to the center and the line connecting the starting point to the center. Then the distance from that point to the center is equal to R. γ When 0≤γ≤ At that time, always satisfied ≤ ; The outermost contour of the projection of the high-friction extrusion transition surface on the high-friction extrusion boss onto a plane perpendicular to the axial direction satisfies the following: the distance from the connection point between the high-friction extrusion transition surface and the high-friction extrusion surface contour to the center is equal to... , with the radius of the friction extrusion surface arc Equal, that is = R0, the distance from the center to the connection point between the high-friction extrusion transition surface and the high-friction extrusion material storage surface contour line is equal to R0. The distance from the center point to the connection point between the temporary storage surface of the material to be strengthened and the contour line of the friction extrusion transition surface. Equal, that is = R1, and satisfy < The angle between the lines connecting the two ends of the high-friction extrusion transition surface contour line to the center is... The angle between the line connecting the two ends of the friction-extrusion transition surface contour to the center. Equal, that is = Let the angle between the line connecting any point on the contour to the center and the line connecting the starting point to the center be . When, the distance from that point to the center is When the angle increases by a small angle dθ′, the distance from the corresponding point to the center is equal to... When 0≤ ≤ At that time, always satisfied ≤ < ≤ The outermost contour of the projection of the high-friction extrusion storage surface onto a plane perpendicular to the axial direction satisfies the following dimension: the angle between the lines connecting the two ends of the contour to the center is... The angle between the outline of the temporary storage surface of the material to be reinforced and the line connecting the two ends to the center is . Equal, that is = Let the angle between the line connecting any point on the contour to the center and the line connecting the starting point to the center be . When, the distance from that point to the center is equal to When 0≤ ≤ At that time, always satisfied ≤ The maximum distance from the center to the outermost contour line of the projection of the side surface corresponding to the high friction extrusion surface perpendicular to the axial plane is equal to... The minimum value is equal to And satisfy > The angle between the two ends of the outermost contour line of the projection of the side surface corresponding to the high friction extrusion surface perpendicular to the axial plane and the center line is . Angle with the arc surface of the friction extrusion surface Equal, that is = ; The material flow limiting-guiding stationary shoulder module includes a connecting flange, a flow guiding surface, a flow guiding groove, a flow limiting surface, and a stationary shoulder surface.

[0007] Furthermore, the near-static shoulder structure side and the high-friction extrusion boss side can be configured as spiral grooves, threads or other structures to promote material flow during the friction extrusion process.

[0008] Furthermore, the height of the near-stationary shoulder structure is... The height of the high-friction extrusion boss is , , The thickness of the friction extrusion reinforcement layer in the additive component is determined by the required thickness to meet the following conditions. + It is greater than the thickness of the friction extrusion reinforcement layer of the additive component.

[0009] Furthermore, the shoulder portion of the near-stationary shoulder structure can be provided with a boss of any shape, which is beneficial for enhancing material flow during friction and extrusion. The height of the boss is less than the height of the near-stationary shoulder structure. .

[0010] Furthermore, the aforementioned , , satisfy ≥ When friction extrusion strengthening is optimal, the number of friction extrusion surfaces, friction extrusion transition surfaces, and temporary storage surfaces of the material to be strengthened on the near-static shoulder structure is n, where n is an integer greater than or equal to 1. Specifically, when n=1, , , Satisfying π≤ ≤ When π, n≥2, , , satisfy =2π / n, the friction extrusion strengthening effect is the best.

[0011] Furthermore, the aforementioned , , satisfy ≥ When friction extrusion strengthens the material, the number of sets of strong friction extrusion surfaces, transition surfaces, and storage surfaces on the strong friction extrusion boss is n, where n is an integer greater than or equal to 1. Specifically, when n=1, , , satisfy ≤ When π, n≥2, , , satisfy =2π / n, the friction extrusion strengthening effect is the best.

[0012] Furthermore, the upper flow surface contour radius of the material flow-limiting-guiding static shaft shoulder module is... , with the radius of the friction extrusion surface arc Equal, that is = The width of the material flow limiting-guiding static shoulder module is W1, which satisfies 1.2. ≤W1≤1.5 The angle between the guide surface and the horizontal plane on the material flow limiting-guide static shoulder module is α, where α is 0~1°. The width of the guide surface is W2, which satisfies 0.3W1≤W2≤0.5W1. The guide surface facilitates the backward flow of the material and prevents the material from being squeezed to the outside of the shoulder during the friction and extrusion process.

[0013] Furthermore, the guide surface is provided with a guide groove, which is "trumpet-shaped". The angle between the guide groove and the horizontal plane is β, where β is 0~2.5° and satisfies β>α. The distance from the opening of the guide groove to the center is W3, which satisfies W3 being greater than the radius of the contour of the guide surface. The guide channel can prevent material from overflowing outwards and help the material to converge towards the center of the friction and extrusion area, thereby enhancing the friction and extrusion effect.

[0014] The method for enhancing the properties of additive manufacturing structures using this biased high-rheological friction head includes the following steps: Step 1: Select a suitable additive manufacturing process based on the component material, structure, and size; and write an additive manufacturing program based on the pre-researched optimal additive manufacturing process parameters, additive manufacturing path, and attitude. Step 2: Select an offset high-rheological friction head with an appropriate diameter based on the material, structure, and size of the component to be processed; Step 3: Adjust the center axis of the offset high rheological friction head to be perpendicular to the surface of the additive component. After setting the rotation speed and downward pressure of the high rheological friction extrusion shaft, move it downward so that the offset friction extrusion head of the high rheological friction extrusion shaft is inserted into the material to be strengthened. Step 4: After the static shoulder surface of the material flow limiting-guiding static shoulder module is in close contact with the surface of the material to be strengthened, friction extrusion strengthening treatment is carried out according to the predetermined process parameters and strengthening treatment path; Step 5: When using an offset high-rheological friction head to strengthen the internal structure of the additive body, if the component does not reach the predetermined additive size, continue adding material on the surface after friction extrusion strengthening treatment, and repeat steps 3 to 4 until completion.

[0015] Furthermore, in the friction extrusion strengthening process described in step 4, the material to be strengthened by friction extrusion in front of the offset high-rheological friction head flows backward under the rotational friction extrusion action of the near-static shoulder structure and the high-friction extrusion boss on the high-rheological friction extrusion shaft. In the area near the near-static shoulder structure, the material first enters the temporary storage area. The gap between the temporary storage surface of the material to be strengthened and the flow-limiting surface in the temporary storage area is large, which helps to prevent material overflow. As the high-rheological friction extrusion shaft rotates, the material flows to the friction extrusion transition area. In the friction extrusion transition area, the gap between the friction extrusion transition surface and the flow-limiting surface decreases from large to small, and the friction extrusion force on the material gradually increases, and the degree of plastic deformation of the material becomes more intense. The material continues to flow into the friction extrusion area. The friction extrusion surface and the flow-limiting surface are designed to have equal radii of their outlines in the vertical axial plane. However, in actual applications, due to differences in machining accuracy, assembly clearance, and surface morphology, the two interfaces may differ. There are minute gaps between the materials, within which the material undergoes more intense plastic rheology, resulting in greater extrusion bonding force between the material and the subsequently reinforced material, and a better frictional extrusion strengthening effect. Near the high-frictional extrusion boss, the high-frictional extrusion surface, high-frictional extrusion transition surface, and high-frictional extrusion storage surface are not complete equal-diameter arc surfaces, but have unevenness, which can drive more material to undergo plastic deformation, resulting in more intense plastic deformation. During the backward flow of the material, under the action of the high-frictional extrusion surface and the high-frictional extrusion transition surface, the extrusion force between the material and the subsequently reinforced material is greater. Furthermore, because the high-frictional extrusion surface extends outward beyond the static shoulder surface of the material flow-limiting-guiding static shoulder module, forming a step with the module, the material cannot overflow under the high frictional extrusion force and can only form a strong bond with the subsequent material, further enhancing the material strengthening effect.

[0016] The biased high-rheological friction head and the method for enhancing the properties of additive manufacturing processes of the present invention have the following advantages: 1. The near-static shoulder structure friction extrusion surface, friction extrusion transition surface and temporary material storage surface of the material to be strengthened on the offset high rheological friction head of the present invention can solve the problem that the extrusion force between the stirring head and the friction-treated material in the rear half circle of the stirring head weakens in the traditional friction stirring (FSP) method. It strengthens the friction extrusion force between the friction-treated material and the friction head, enhances the friction extrusion treatment effect, and improves the mechanical properties of the material. 2. The near-static shoulder structure friction extrusion surface, friction extrusion transition surface, and temporary material storage surface of the material to be strengthened on the offset high rheological friction head of the present invention can cause the material to undergo strong plastic deformation during the processing, effectively refine the additive structure, and improve the mechanical properties of the additive component. 3. In this invention, the gap between the near-static shaft shoulder junction friction extrusion transition surface and the flow-limiting surface on the offset high-rheological friction head gradually decreases, which can gradually increase the friction extrusion force on the material and make the degree of plastic deformation of the material more intense. 4. In this invention, the near-static axis shoulder friction extrusion surface and the flow-limiting surface of the offset strong rheological friction head are designed with equal radii. However, in actual application, due to the presence of small gaps in processing and assembly, the material undergoes more intense plastic strong rheology in the small gaps, resulting in a greater extrusion bonding force between the material and the reinforced material behind it, and a better friction extrusion strengthening effect. 5. The strong friction extrusion boss on the offset strong rheological friction head of the present invention has a strong friction extrusion surface that extends outward beyond the static shoulder surface on the material flow limiting-guiding static shoulder module. This can form a step with the material flow limiting-guiding static shoulder module, which can prevent material overflow and increase the friction extrusion processing range. 6. The offset high rheological friction head material flow limiting-guiding static shaft shoulder module of the present invention is provided with a guiding surface and a guiding groove, which can promote the material to converge towards the central friction extrusion area and prevent the material from being squeezed to the outside of the shaft shoulder under the action of the shaft shoulder during the friction extrusion process; 7. The offset high rheological friction head near static shaft shoulder structure and the high friction extrusion boss side are provided with multiple sets of friction extrusion surfaces, friction extrusion transition surfaces and temporary material storage surfaces for the material to be strengthened, which can greatly improve the friction extrusion effect, enhance the refinement effect on the additive structure, and improve the mechanical properties of the additive components. 8. The device of the present invention can perform large-area additive body or surface strengthening layer processing by friction extrusion in a single process. The strengthening process is highly efficient and the surface forming after processing is excellent, and the surface does not require subsequent machining. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of an offset high-rheological friction head according to the present invention; Figure 2 This is a front view of the high rheological friction extrusion shaft of the present invention; Figure 3 This is a cross-sectional view of the material flow-limiting and flow-guiding static shoulder module of the present invention; Figure 4 This is a bottom view of the material flow-limiting and flow-guiding static shoulder module of the present invention; Figure 5 This is a schematic diagram of the cross-sectional profile of the near-static shoulder structure on the high rheological friction extrusion shaft of the present invention; Figure 6 This is a schematic diagram of the cross-sectional profile of the high-friction extrusion boss on the high-rheological-friction extrusion shaft of the present invention; In the diagram: 1 is the high-rheological friction extrusion shaft, 2 is the material flow limiting-guiding stationary shoulder module, 1.1 is the offset friction extrusion head, 1.2 is the intermediate connection structure, 1.3 is the clamping handle, 1.1.1 is the near-stationary shoulder structure, 1.1.2 is the high-friction extrusion boss, 1.1.1.1 is the friction extrusion surface, 1.1.1.2 is the friction extrusion transition surface, 1.1.1.3 is the temporary storage surface for the material to be strengthened, 1.1.2.1 is the high-friction extrusion surface, 1.1.2.2 is the high-friction extrusion transition surface, 1.1.2.3 is the high-friction extrusion storage surface, 2.1 is the connecting flange, 2.2 is the guide surface, 2.3 is the guide groove, 2.4 is the flow limiting surface, and 2.5 is the stationary shoulder surface. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0020] As shown in the figure, the offset high-rheological friction head includes a high-rheological friction extrusion shaft 1 and a material flow limiting-guiding stationary shoulder module 2. The high-rheological friction extrusion shaft 1 is connected to an external friction extrusion spindle motor through a clamping handle. The external friction extrusion spindle motor drives the high-rheological friction extrusion shaft 1 to achieve the rotational movement friction extrusion function. The material flow limiting-guiding stationary shoulder module 2 is concentrically installed on the outside of the high-rheological friction extrusion shaft 1 and is fixedly connected to the housing of the external friction extrusion spindle motor through a connecting flange 2.1. During the friction extrusion strengthening process, it moves synchronously with the high-rheological friction extrusion shaft 1 but does not rotate. The intense rheological friction extrusion spindle 1 comprises an offset friction extrusion head 1.1, an intermediate connection structure 1.2 and a clamping shank 1.3. The offset friction extrusion head 1.1 includes an upper part and a lower part which are a near-static shoulder structure 1.1.1 and an intense friction extrusion boss 1.1.2 respectively. The side surface of the near-static shoulder structure 1.1.1 comprises several sets of friction extrusion surfaces 1.1.1.1, friction extrusion transition surfaces 1.1.1.2 and temporary material storage surfaces for to-be-strengthened material 1.1.1.3. The friction extrusion surfaces 1.1.1.1, the friction extrusion transition surfaces 1.1.1.2 and the temporary material storage surfaces for to-be-strengthened material 1.1.1.3 respectively combine with the upper flow limiting surface 2.4 of the material flow limiting-guiding static shoulder module 2 to form a friction extrusion zone, a friction extrusion transition zone and a temporary material storage zone for to-be-strengthened material. The side surface of the intense friction extrusion boss 1.1.2 comprises several sets of intense friction extrusion surfaces 1.1.2.1, intense friction extrusion transition surfaces 1.1.2.2 and intense friction extrusion material storage surfaces 1.1.2.3. The outermost profile lines of the projections of the intense friction extrusion transition surfaces 1.1.2.2 and the intense friction extrusion material storage surfaces 1.1.2.3 on the plane perpendicular to the axial direction coincide with the outermost profile lines of the projections of the friction extrusion transition surfaces 1.1.1.2 and the temporary material storage surfaces for to-be-strengthened material 1.1.1.3 on the side surface of the near-static shoulder structure 1.1.1 on the plane perpendicular to the axial direction, respectively. The intense friction extrusion surfaces 1.1.2.1 are outwardly offset beyond the static shoulder surface 2.5 on the material flow limiting-guiding static shoulder module 2, forming a step with the material flow limiting-guiding static shoulder module 2, which can prevent material overflow and help enhance the friction extrusion strengthening effect on the material below the static shoulder surface 2.5; The friction extrusion surface 1.1.1.1 on the near-static shoulder structure 1.1.1 is an arc surface with a radius of R0, the arc surface angle of the friction extrusion surface 1.1.1.1 is θ1, and the outermost profile line dimension of the projection of the friction extrusion transition surface 1.1.1.2 on the plane perpendicular to the axial direction satisfies: the distance from the connection point between the profile line of the friction extrusion transition surface 1.1.1.2 and the profile line of the friction extrusion surface 1.1.1.1 to the center is equal to R0, the distance from the connection point between the profile line of the friction extrusion transition surface 1.1.1.2 and the profile line of the temporary material storage surface for to-be-strengthened material 1.1.1.3 to the center is equal to R1, and R1 satisfies R1<R0. The included angle between the connecting lines from the two ends of the profile line of the friction extrusion transition surface 1.1.1.2 to the center is θ2, and when the included angle between the connecting line from any point on the profile line to the center and the connecting line from the starting point to the center is θ, the distance from this point to the center is equal to R θ , when the angle increases by a tiny angle dθ, the distance from the corresponding point to the center is equal to R θ+dθ , when 0≤θ+dθ≤θ2, it is always satisfied that R1≤R θ+dθ <R θ≤R0, the outermost contour of the projection of the temporary storage surface 1.1.1.3 of the material to be strengthened onto the plane perpendicular to the axial direction satisfies the following: the distance from the connection point of the temporary storage surface 1.1.1.3 of the material to be strengthened and the contour of the friction extrusion transition surface 1.1.1.2 to the center is equal to R1, and the angle between the two ends of the contour line and the line connecting the center is θ3. Let γ be the angle between the line connecting any point on the contour line to the center and the line connecting the starting point to the center; then the distance from that point to the center is equal to R. γ When 0 ≤ γ ≤ θ3, R always satisfies γ ≤R1; The outermost contour of the projection of the high-friction extrusion boss 1.1.2 and the high-friction extrusion transition surface 1.1.2.2 onto the plane perpendicular to the axial direction satisfies the following dimension: the distance from the connection point between the high-friction extrusion transition surface 1.1.2.2 and the high-friction extrusion surface 1.1.2.1 contour to the center is equal to... It is equal to the radius R0 of the arc surface of the friction extrusion surface 1.1.1.1, that is... =R0, the distance from the center to the connection point of the contour lines of the high-friction extrusion transition surface 1.1.2.2 and the high-friction extrusion material storage surface 1.1.2.3 is equal to R0. The distance R1 from the center of the connection point between the temporary storage surface 1.1.1.3 of the material to be strengthened and the contour line of the friction extrusion transition surface 1.1.1.2 is equal to that of the temporary storage surface 1.1.1.3 of the material to be strengthened. =R1, and satisfy < The angle between the lines connecting the two ends of the contour line of the high-friction extrusion transition surface 1.1.2.2 to the center is... The angle θ2 between the two ends of the contour line of the friction-extrusion transition surface 1.1.1.2 and the center line is equal to that of the other end. =θ2, let the angle between the line connecting any point on the contour line to the center and the line connecting the starting point to the center be θ2. When, the distance from that point to the center is When the angle increases by a small angle dθ′, the distance from the corresponding point to the center is equal to... When 0≤ + ≤ At that time, always satisfied ≤ < ≤ The outermost contour line of the high-friction extrusion storage surface 1.1.2.3 projected onto a plane perpendicular to the axial direction satisfies the following dimension: the angle between the lines connecting the two ends of the contour line to the center is... The angle θ3 between the two ends of the outline of the temporary storage surface of the material to be strengthened (1.1.1.3) and the center line is equal to that of the other end. =θ3, let the angle between the line connecting any point on the contour line to the center and the line connecting the starting point to the center be θ3. When, the distance from that point to the center is equal to When 0≤ ≤ At that time, always satisfied ≤ The maximum distance from the center to the outermost contour line of the projection of the side surface corresponding to the high-friction extrusion surface 1.1.2.1 perpendicular to the axial plane is equal to... The minimum value is equal to And satisfy > The angle between the two ends of the outermost contour line of the projection of the side surface corresponding to the high-friction extrusion surface 1.1.2.1 perpendicular to the axial plane and the center line is . The angle θ1 of the arc surface of the friction and extrusion surface 1.1.1.1 is equal to that of the arc surface, i.e. =θ1; The material flow limiting-guide stationary shoulder module 2 includes a connecting flange 2.1, a flow guiding surface 2.2, a flow guiding groove 2.3, a flow limiting surface 2.4, and a stationary shoulder surface 2.5.

[0021] The near-stationary shoulder structure 1.1.1 and the high-friction extrusion boss 1.1.2 can be configured as a spiral groove, thread, or other structure to promote material flow during the friction extrusion process. The near-stationary shoulder structure 1.1.1 has a height of h1, and the high-friction extrusion boss 1.1.2 has a height of h2. h1 and h2 are determined by the thickness of the additive component's friction extrusion reinforcement layer, satisfying that h1 + h2 is greater than the thickness of the additive component's friction extrusion reinforcement layer.

[0022] The near-stationary shoulder structure 1.1.1 can be equipped with a boss structure of any shape, which is beneficial to enhance the flow of material during friction extrusion. The height of the boss is less than the height h1 of the near-stationary shoulder structure 1.1.1.

[0023] θ1, θ2, and θ3 satisfy ≥ When friction extrusion strengthening is optimal, the number of friction extrusion surfaces 1.1.1.1, friction extrusion transition surfaces 1.1.1.2, and temporary storage surfaces of the material to be strengthened 1.1.1.3 on the near-static shoulder structure 1.1.1 is n, where n is an integer greater than or equal to 1. When n=1, θ1, θ2, and θ3 satisfy π≤θ1+θ2+θ3≤ When π and n≥2, θ1, θ2, and θ3 satisfy θ1+θ2+θ3=2π / n, and the friction extrusion strengthening effect is optimal.

[0024] , , satisfy ≥ When the friction extrusion strengthening effect is optimal, the number of sets of strong friction extrusion surfaces 1.1.2.1, strong friction extrusion transition surfaces 1.1.2.2, and strong friction extrusion storage surfaces 1.1.2.3 on the strong friction extrusion boss 1.1.2 is n, where n is an integer greater than or equal to 1. Specifically, when n=1, , , satisfy ≤ When π, n≥2, , , satisfy =2π / n, the friction extrusion strengthening effect is the best.

[0025] Material flow limiting - flow guiding stationary shoulder module 2 upper flow surface 2.4 contour radius is It is equal to the radius R0 of the arc surface of the friction extrusion surface 1.1.1.1, that is... =R0, the width of the material flow limiting-guiding static shaft shoulder module 2 is W1, which satisfies 1.2 ≤W1≤1.5 The angle between the guide surface 2.2 on the material flow limiting-guide stationary shoulder module 2 and the horizontal plane is α, where α is 0~1°. The width of the guide surface 2.2 is W2, which satisfies 0.3W1≤W2≤0.5W1. The guide surface 2.2 facilitates the backward flow of material and prevents the material from being squeezed to the outside of the shoulder during the friction and extrusion process.

[0026] A guide groove 2.3 is provided on the guide surface 2.2. The guide groove 2.3 is "trumpet-shaped". The angle between the guide groove 2.3 and the horizontal plane is β, where β is between 0 and 2.5° and satisfies β > α. The distance from the opening of the guide groove to the center is W3, which satisfies W3 being greater than the radius of the outline of the guide surface. The guide channel 2.3 can prevent the material from overflowing outwards and help the material to converge towards the center to the friction and extrusion area, thereby enhancing the friction and extrusion effect.

[0027] The method for enhancing the properties of additive manufacturing structures using this biased high-rheological friction head includes the following steps: Step 1: Select a suitable additive manufacturing process based on the component material, structure, and size; and write an additive manufacturing program based on the pre-researched optimal additive manufacturing process parameters, additive manufacturing path, and attitude. Step 2: Select an offset high-rheological friction head with an appropriate diameter based on the material, structure, and size of the component to be processed; Step 3: Adjust the center axis of the offset high rheological friction head to be perpendicular to the surface of the additive component. After setting the rotation speed and downward pressure of the high rheological friction extrusion shaft, move it downward so that the offset friction extrusion head of the high rheological friction extrusion shaft is inserted into the material to be strengthened. Step 4: After the static shoulder surface of the material flow limiting-guiding static shoulder module is in close contact with the surface of the material to be strengthened, friction extrusion strengthening treatment is carried out according to the predetermined process parameters and strengthening treatment path; Step 5: When using an offset high-rheological friction head to strengthen the internal structure of the additive body, if the component does not reach the predetermined additive size, continue adding material on the surface after friction extrusion strengthening treatment, and repeat steps 3 to 4 until completion.

[0028] In step 4, the material to be frictionally extruded and strengthened in front of the offset high-rheological friction head flows backward under the rotational frictional extrusion action of the near-static shoulder structure and the high-rheological extrusion boss on the high-rheological friction extrusion shaft. In the area near the near-static shoulder structure, the material first enters the temporary storage area. The gap between the temporary storage surface and the flow-limiting surface of the material to be strengthened in the temporary storage area is large, which helps to prevent material overflow. As the high-rheological friction extrusion shaft rotates, the material flows to the friction extrusion transition zone. In the friction extrusion transition zone, the gap between the friction extrusion transition surface and the flow-limiting surface decreases, and the frictional extrusion force on the material gradually increases, and the degree of plastic deformation of the material becomes more intense. The material continues to flow into the friction extrusion zone. The friction extrusion surface and the flow-limiting surface are designed to have equal radii of their outlines in the vertical axial plane. However, in actual applications, due to differences in machining accuracy, assembly clearance, and surface morphology, there are slight gaps between the two interfaces. The material undergoes more intense plastic rheology within minute gaps, resulting in greater compressive bonding force between the material and the subsequently reinforced material, leading to better frictional extrusion strengthening. Near the high-frictional extrusion boss, the high-frictional extrusion surface, transition surface, and storage surface are not perfectly uniform arc surfaces, exhibiting unevenness and height differences. This allows for more intense plastic deformation of the material. As the material flows backward, the action of the high-frictional extrusion surface and transition surface further intensifies the compressive force between the material and the subsequently reinforced material. Furthermore, because the high-frictional extrusion surface extends outward beyond the static shoulder surface of the material flow-limiting and guiding static shoulder module, forming a step, the material cannot overflow under the high frictional extrusion force and can only form a strong bond with the subsequent material, further enhancing the material strengthening effect.

[0029] Example: A 400mm long, 400mm wide, and 100mm high 5083 aluminum alloy block was added to a 500mm*500mm*50mm aluminum alloy substrate using MIG arc additive manufacturing technology, and the additive structure was strengthened using this invention. The specific implementation steps are as follows: Step 1: Select a suitable additive manufacturing process based on the component's material, structure, and dimensions. Write the additive manufacturing program based on the pre-researched optimal additive manufacturing process parameters, additive path, and orientation, as follows: The additive manufacturing wire used was ER5083 aluminum alloy welding wire with a diameter of 1.2mm. The welding machine used was a Fonnius TPS500i. The additive manufacturing process used was the MIG arc additive manufacturing process in the AlMg5 process package. The wire feed speed was 6m / min, the additive current was 150A, the additive voltage was 16V, the additive speed was 3mm / s, the layer thickness was 3mm, the pass width was 12mm, and the pass spacing was 6mm. Surface additive manufacturing was performed on the surface of the aluminum alloy block along the length of the block in a reciprocating bow-shaped path. The additive gun was always set to be perpendicular to the additive surface. 34 layers were added, and each layer had 67 passes.

[0030] Step 2: Select an offset high-rheological friction head with an appropriate diameter based on the material, structure, and size of the component to be processed; The height of the near-static shoulder structure of the offset high-rheological friction head and the high-friction extrusion boss is determined by the thickness of the friction extrusion strengthening layer of the additive component. In this embodiment, h1 is 1 mm and h2 is 9 mm. Six sets of high-friction extrusion surfaces, high-friction extrusion transition surfaces, and high-friction extrusion storage surfaces are set on the side of the high-friction extrusion boss. The radius R0 of the friction extrusion surface arc is 100 mm, the angle θ1 of the friction extrusion surface arc is 20°, the angle θ2 between the two ends of the friction extrusion transition surface contour line and the center is 5°, the distance R1 from the connection point of the friction extrusion transition surface and the contour line of the temporary storage surface of the material to be strengthened to the center is 90 mm, and the angle θ3 between the two ends of the contour line of the temporary storage surface of the material to be strengthened to the center is 5°. Take 100mm, the distance from the connection point of the high-friction extrusion transition surface and the high-friction extrusion material storage surface contour line to the center is equal to Take 90mm, the angle between the two ends of the high-friction extrusion transition surface contour line and the center line. Take 5°, the angle between the two ends of the outline of the high-friction extrusion material storage surface and the line connecting the center. Take 5° as the maximum distance from the center to the outermost contour line of the high-friction extrusion surface. Take 120mm, the angle between the two ends of the outermost contour line of the high-friction extrusion surface and the center line is . Take 20°.

[0031] The width W1 of the material flow limiting-guide stationary shaft shoulder module is 150mm, the angle α between the guide surface and the horizontal plane is 0.5°, the width W2 of the backflow surface is 50mm, the angle β between the guide channel and the horizontal plane is 2°, and the distance W3 from the opening of the guide channel to the center is 120mm. The upper flow surface contour radius of the material flow limiting-guide stationary shaft shoulder module is... Take 100mm.

[0032] Step 3: With the center axis of the offset high rheological friction head perpendicular to the surface of the additive component, set the rotation speed of the high rheological friction extrusion shaft to 500 r / min and the pressing depth to 10 mm, and then move it downward so that the offset friction extrusion head of the high rheological friction extrusion shaft is inserted into the material to be strengthened.

[0033] Step 4: After the surface of the stationary shoulder on the material flow limiting-guiding stationary shoulder module is in close contact with the surface of the material to be strengthened, friction extrusion strengthening treatment is carried out according to the predetermined process parameters and strengthening treatment path. The friction extrusion advance speed is 200mm / min.

[0034] During the friction extrusion strengthening process, the material to be strengthened in front of the offset high-rheological friction head flows backward under the rotational friction extrusion action of the near-static shoulder structure and the high-friction extrusion boss on the high-rheological friction extrusion shaft. In the area near the near-static shoulder structure, the material first enters the temporary storage area. The gap between the temporary storage surface and the flow-limiting surface of the material to be strengthened in the temporary storage area is large, which helps to prevent material overflow. As the high-rheological friction extrusion shaft rotates, the material flows to the friction extrusion transition zone. In the friction extrusion transition zone, the gap between the friction extrusion transition surface and the flow-limiting surface decreases, and the friction extrusion force on the material gradually increases, resulting in more severe plastic deformation. The material continues to flow into the friction extrusion zone. The friction extrusion surface and the flow-limiting surface are designed to have equal radii of their outlines in the vertical axial plane. However, in actual applications, due to differences in machining accuracy, assembly clearance, and surface morphology, there are slight differences between the two interfaces. Within the small gaps, the material undergoes more intense plastic rheology, resulting in greater extrusion bonding force between the material and the subsequently reinforced material, leading to better frictional extrusion strengthening. Near the high-friction extrusion boss, the high-friction extrusion surface, transition surface, and storage surface are not perfectly uniform arc surfaces, exhibiting unevenness and height differences, which drives more material to undergo plastic deformation, resulting in more intense plastic deformation. During the backward flow, the high-friction extrusion surface and transition surface further enhance the extrusion force between the material and the subsequently reinforced material. Furthermore, because the high-friction extrusion surface extends outward beyond the static shoulder surface of the material flow-limiting and guiding static shoulder module, forming a step with the module, the material cannot overflow under the high frictional extrusion force and can only form a strong bond with the subsequent material, further improving the material strengthening effect.

[0035] Step 5: When using an offset high-rheological friction head to strengthen the internal structure of the additive body, if the component does not reach the predetermined additive size, continue adding material on the surface after friction extrusion strengthening treatment, and repeat steps 3 to 4 until completion.

[0036] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An offset high rheological friction head, characterized in that: it includes a high rheological friction extrusion shaft (1) and a material flow limiting-guiding stationary shoulder module (2). The high rheological friction extrusion shaft (1) is connected to an external friction extrusion spindle motor through a clamping handle. The external friction extrusion spindle motor drives the high rheological friction extrusion shaft (1) to realize the rotational movement friction extrusion function. The material flow limiting-guiding stationary shoulder module (2) is concentrically installed on the outside of the high rheological friction extrusion shaft (1) and fixedly connected to the housing of the external friction extrusion spindle motor through a connecting flange (2.1). During the friction extrusion strengthening process, it moves synchronously with the high rheological friction extrusion shaft (1) but does not rotate. The high-rheological friction extrusion shaft (1) includes an offset friction extrusion head (1.1), an intermediate connecting structure (1.2), and a clamping handle (1.3). The offset friction extrusion head (1.1) includes an upper and lower part of a near-static shoulder structure (1.1.1) and a high-friction extrusion boss (1.1.2). The near-static shoulder structure (1.1.1) includes several sets of friction extrusion surfaces (1.1.1.1), friction extrusion transition surfaces (1.1.1.2), and temporary storage surfaces for the material to be strengthened (1.1.1.3) on its side. The friction extrusion surfaces (1.1.1.1), friction extrusion transition surfaces (1.1.1.2), and temporary storage surfaces for the material to be strengthened (1.1.1.3) are combined with the upper flow surface (2.4) of the material flow limiting-guiding static shoulder module (2) to form a friction extrusion zone, a friction extrusion transition zone, and a temporary storage zone for the material to be strengthened. The high-friction extrusion boss (1.1.1.2) is also included. .1.2) The side includes several sets of strong friction extrusion surfaces (1.1.2.1), strong friction extrusion transition surfaces (1.1.2.2), and strong friction extrusion storage surfaces (1.1.2.3). The outermost contour of the projection of the strong friction extrusion transition surfaces (1.1.2.2) and the strong friction extrusion storage surfaces (1.1.2.3) on the plane perpendicular to the axial direction coincides with the outermost contour of the projection of the friction extrusion transition surfaces (1.1.1.2) and the temporary storage surfaces (1.1.1.3) of the near-static shoulder structure (1.1.1) on the side perpendicular to the axial direction. The strong friction extrusion surface (1.1.2.1) extends outward beyond the static shoulder surface (2.5) of the material flow limiting-guiding static shoulder module (2) and forms a step with the material flow limiting-guiding static shoulder module (2), which can prevent material overflow and help enhance the friction extrusion strengthening effect on the material below the static shoulder surface (2.5). The friction extrusion surface (1.1.1.1) on the near-static shoulder structure (1.1.1) is an arc surface with radius R0, and the arc angle of the friction extrusion surface (1.1.1.1) is θ1. The outermost contour of the friction extrusion transition surface (1.1.1.2) projected onto the plane perpendicular to the axial direction satisfies the following: the distance from the connection point between the contours of the friction extrusion transition surface (1.1.1.2) and the friction extrusion surface (1.1.1.1) to the center is equal to... The distance from the connection point of the temporary storage surface of the material to be reinforced (1.1.1.3) to the center is equal to... , satisfy < The angle between the two ends of the contour line of the friction-extrusion transition surface (1.1.1.2) and the line connecting the center to the two ends is . Let θ be the angle between the line connecting any point on the contour line to the center and the line connecting the starting point to the center. Then the distance from that point to the center is equal to... When the angle increases by a small angle dθ, the distance from the corresponding point to the center becomes equal to... When 0≤θ+dθ≤ At that time, always satisfied ≤ < ≤ The outermost contour of the projection of the temporary storage surface (1.1.1.3) of the material to be strengthened onto the plane perpendicular to the axial direction has the following dimensions: the distance from the connection point between the contour of the temporary storage surface (1.1.1.3) and the friction extrusion transition surface (1.1.1.2) to the center is equal to... The angle between the lines connecting the two ends of the outline to the center is Let γ be the angle between the line connecting any point on the contour line to the center and the line connecting the starting point to the center. Then the distance from that point to the center is equal to R. γ When 0≤γ≤ At that time, always satisfied ≤ ; The outermost contour of the projection of the high-friction extrusion transition surface (1.1.2.2) on the plane perpendicular to the axial direction on the high-friction extrusion boss (1.1.2) satisfies the following: the distance from the connection point between the contours of the high-friction extrusion transition surface (1.1.2.2) and the high-friction extrusion surface (1.1.2.1) to the center is equal to... The radius of the arc surface of the friction extrusion surface (1.1.1.1) Equal, that is = The distance from the connection point of the outline of the high-friction extrusion transition surface (1.1.2.2) and the high-friction extrusion material storage surface (1.1.2.3) to the center is equal to... The temporary storage surface of the material to be strengthened (1.1.1.3) and the friction extrusion transition surface (1.1.1.2) Distance from the connection point of the outline to the center Equal, that is = ,and satisfy < The angle between the lines connecting the two ends of the contour line of the high-friction extrusion transition surface (1.1.2.2) to the center is... The angle between the line connecting the two ends of the contour line of the friction-extrusion transition surface (1.1.1.2) and the center line. Equal, that is = Let the angle between the line connecting any point on the contour to the center and the line connecting the starting point to the center be . When, the distance from that point to the center is When the angle increases by a small angle dθ′, the distance from the corresponding point to the center is equal to... When 0≤ ≤ At that time, always satisfied ≤ < ≤ The outermost contour of the high-friction extrusion storage surface (1.1.2.3) projected onto a plane perpendicular to the axial direction satisfies the following dimension: the angle between the lines connecting the two ends of the contour to the center is... The angle between the outline of the temporary storage surface of the material to be reinforced (1.1.1.3) and the line connecting the two ends to the center is . Equal, that is = Let the angle between the line connecting any point on the contour to the center and the line connecting the starting point to the center be . When, the distance from that point to the center is equal to When 0≤ ≤ At that time, always satisfied ≤ The maximum distance from the center to the outermost contour line of the projection of the side surface corresponding to the high-friction extrusion surface (1.1.2.1) perpendicular to the axial plane is equal to... The minimum value is equal to And satisfy > The angle between the two ends of the outermost contour line of the projection of the side surface corresponding to the high-friction extrusion surface (1.1.2.1) perpendicular to the axial plane and the center line is . The angle between the arc surface and the friction extrusion surface (1.1.1.1) Equal, that is = ; The material flow limiting-guide stationary shoulder module (2) includes a connecting flange (2.1), a flow guiding surface (2.2), a flow guiding groove (2.3), a flow limiting surface (2.4), and a stationary shoulder surface (2.5).

2. The biased high-rheological friction head according to claim 1, characterized in that: The near-static shoulder structure ( 1.1.1) Side and high friction extrusion boss (1.1.2) The side can be set as a spiral groove, thread or other structure to promote material flow during the friction extrusion process.

3. The biased high-rheological friction head according to claim 2, characterized in that: The near-static shoulder structure ( 1.1.1) Height is The height of the high-friction extrusion boss (1.1.2) is... , , The thickness of the friction extrusion reinforcement layer in the additive component is determined by the required thickness to meet the following conditions. + It is greater than the thickness of the friction extrusion reinforcement layer of the additive component.

4. The biased high-rheological friction head according to claim 1, characterized in that: The near-static shoulder structure ( 1.1.1) The shoulder area can be equipped with a boss structure of any shape, which is beneficial to enhance the flow of material during friction and extrusion. The height of the boss is smaller than that of the near-static shoulder structure. 1.1.1) Height .

5. The biased high-rheological friction head according to claim 1, characterized in that: The aforementioned , , satisfy ≥ At that time, friction and extrusion reinforcement effect is the best, near static shoulder structure ( Friction extrusion surface on 1.1.1) 1.1.1.1) Friction-extrusion transition surface ( 1.1.1.2) and the temporary storage surface of the material to be reinforced ( The number of groups in 1.1.1.3) is n, where n is an integer greater than or equal to 1, and when n=1, , , Satisfying π≤ ≤ When π, n≥2, , , satisfy =2π / n, the friction extrusion strengthening effect is the best.

6. The biased high-rheological friction head according to claim 1, characterized in that: The aforementioned , , satisfy ≥ When friction extrusion strengthens the surface, the friction extrusion surface (1.1.2.1) and the friction extrusion transition surface (1.1.2.1) on the high friction extrusion boss (1.1.2) are the best. 1.1.2.2) and high friction extrusion storage surface ( The number of groups in 1.1.2.3) is n, where n is an integer greater than or equal to 1, and when n=1, , , satisfy ≤ When π, n≥2, , , satisfy =2π / n, the friction extrusion strengthening effect is the best.

7. The biased high-rheological friction head according to claim 1, characterized in that: The upper flow surface (2.4) of the material flow-limiting-guide stationary shoulder module (2) has a contour radius of [missing information]. The radius of the arc surface of the friction extrusion surface (1.1.1.1) Equal, that is = The width of the material flow limiting-guiding static shoulder module (2) is W1, which satisfies 1.

2. ≤W1≤1.5 The material flow limiting-guide static shoulder module (2) has an angle of α between the guide surface (2.2) and the horizontal plane, where α is 0~1°. The width of the guide surface (2.2) is W2, which satisfies 0.3W1≤W2≤0.5W1. The guide surface (2.2) is conducive to the backward flow of the material and prevents the material from being squeezed to the outside of the shoulder during the friction and extrusion process.

8. The biased high-rheological friction head according to claim 7, characterized in that: The guide surface (2.2) is provided with a guide groove (2.3), which is "trumpet-shaped". The guide groove (2.3) makes an angle β with the horizontal plane, where β is 0~2.5° and satisfies β>α. The distance from the opening of the guide groove to the center is W3, which satisfies W3 being greater than the radius of the outline of the guide surface. The guide channel (2.3) can prevent the material from overflowing outwards and facilitate the material to converge towards the center to the friction and extrusion area, thereby enhancing the friction and extrusion effect.

9. A method for enhancing the properties of additive manufacturing structures using the biased high-rheological friction head as described in claim 1, characterized in that: Includes the following steps: Step 1: Select a suitable additive manufacturing process based on the component material, structure, and size; and write an additive manufacturing program based on the pre-researched optimal additive manufacturing process parameters, additive manufacturing path, and attitude. Step 2: Select an offset high-rheological friction head with an appropriate diameter based on the material, structure, and size of the component to be processed; Step 3: Adjust the center axis of the offset high rheological friction head to be perpendicular to the surface of the additive component. After setting the rotation speed and downward pressure of the high rheological friction extrusion shaft, move it downward so that the offset friction extrusion head of the high rheological friction extrusion shaft is inserted into the material to be strengthened. Step 4: After the static shoulder surface of the material flow limiting-guiding static shoulder module is in close contact with the surface of the material to be strengthened, friction extrusion strengthening treatment is carried out according to the predetermined process parameters and strengthening treatment path; Step 5: When using an offset high-rheological friction head to strengthen the internal structure of the additive body, if the component does not reach the predetermined additive size, continue adding material on the surface after friction extrusion strengthening treatment, and repeat steps 3 to 4 until completion.

10. The method for enhancing additive manufacturing properties using an offset high-rheological friction head according to claim 9, characterized in that: in In the friction extrusion strengthening process described in step 4, the material to be strengthened by friction extrusion in front of the offset high-rheological friction head flows backward under the rotational friction extrusion action of the near-static shoulder structure and the high-friction extrusion boss on the high-rheological friction extrusion shaft. In the area near the near-static shoulder structure, the material first enters the temporary storage area. The gap between the temporary storage surface and the flow-limiting surface of the material to be strengthened in the temporary storage area is large, which helps to prevent material overflow. As the high-rheological friction extrusion shaft rotates, the material flows to the friction extrusion transition area. In the friction extrusion transition area, the gap between the friction extrusion transition surface and the flow-limiting surface decreases, and the friction extrusion force on the material gradually increases, and the degree of plastic deformation of the material becomes more intense. The material continues to flow into the friction extrusion area. The friction extrusion surface and the flow-limiting surface are designed to have equal radii of their outlines in the vertical axial plane. However, in actual applications, due to differences in machining accuracy, assembly clearance, and surface morphology, the two interfaces may have different radii. The presence of minute gaps allows for more intense plastic rheology within the material, resulting in greater compressive bonding force between the material and the subsequently reinforced material, leading to better frictional extrusion reinforcement. Near the high-frictional extrusion boss, the non-uniform, uneven surfaces of the high-frictional extrusion surface, transition surface, and storage surface facilitate more plastic deformation, resulting in more severe deformation. As the material flows backward, the combined pressure between the high-frictional extrusion surface and transition surface increases the compressive force between the material and the subsequently reinforced material. Furthermore, because the high-frictional extrusion surface extends outward beyond the static shoulder surface of the material flow-limiting and guiding static shoulder module, forming a step, the material cannot overflow under high frictional extrusion force and instead forms a strong bond with the subsequent material, further enhancing the material reinforcement effect.

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