Improved tool head, additive manufacturing apparatus and additive manufacturing method

Abstract

The application provides an improved tool head, an additive manufacturing device and an additive manufacturing method. The improved tool head comprises a clamping handle and an additive reinforcement structure. One end of the clamping handle is connected with the additive reinforcement structure, and the other end is connected with the main shaft of the additive manufacturing machine tool. The additive reinforcement structure comprises an overflow prevention structure and a flow shaping structure, and the overflow prevention structure and the flow shaping structure form an additive area therebetween. The flow shaping structure is a double-cone structure with a smaller middle diameter than the diameters of the two ends, which is used to guide and promote the flow of materials during additive manufacturing, so that the materials are uniformly filled into the additive area, and the accumulation or vacancy of the materials is avoided. The overflow prevention structure is connected with the two ends of the double-cone structure, which is used to limit the overflow of the materials during additive manufacturing, so that the materials are involved in the filling and combination of the additive area by restricting the flow direction of the materials. The improved tool head can improve the bonding strength and additive efficiency of the additive layer, reduce the defects such as weak bonding and flash of the additive layer, and make the additive process stable and efficient.

Description

Technical Field

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

[0002] With scientific advancements and improved economic levels, traditional manufacturing methods relying on single-metal components can no longer meet the comprehensive needs of production. Integrating the superior properties of various single-metal materials to form heterogeneous composite structures is the future trend. Steel-copper composite structures combine the high strength and corrosion resistance of steel with the electrical and thermal conductivity of copper, making them widely used in electrolytic metallurgy, aerospace, and energy power industries. Common steel-copper welding processes include explosive welding, arc welding, diffusion welding, and friction stir welding. However, these methods all have their limitations, leading to problems such as difficulty in fusion, poor form, easy formation of weld porosity, and susceptibility to welding hot cracks and penetration cracks.

[0003] Additive Friction Rolling Deposition (AFRD) is a novel semi-solid additive manufacturing technology. Its mechanism is very similar to friction stir welding and friction stir additive manufacturing, but AFRD integrates the mechanisms of both. It converts the axial force of the forging force in friction stir welding into a radial force, utilizing the frictional heat of rolling to rapidly soften the material and complete the additive bonding. Furthermore, the larger diameter tool head ensures complete contact with the material, significantly improving material utilization and additive efficiency. AFRD can improve upon the problems encountered in steel-copper welding. Firstly, the additive temperature is only 60%–90% of the material's melting point, avoiding defects caused by melting and solidification in molten additive manufacturing. Secondly, compared to other solid-state processes, the modified tool head successfully solves the problem of continuous feeding of non-consumable tool heads and results in a more uniform bonding layer and mechanical properties.

[0004] Currently, AFRD (Alternating Current Research and Development) primarily uses shoulderless or single-shoulder tool heads. This leads to issues such as a higher center and lower sides in the additive layer, as well as material overflow, resulting in weak bonding and defects like flash. Furthermore, current research in solid-state additive manufacturing technology largely focuses on lightweight alloys, limiting the application of additive manufacturing equipment to high-melting-point dissimilar metal materials. The equipment not only struggles to meet the processing requirements of high-melting-point materials, but the tool heads also experience significant wear during processing. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an improved tool head, additive manufacturing equipment, and additive manufacturing method. During additive manufacturing, the improved tool head's overflow-prevention structure limits material spillage, and by constraining the material's flow direction, it ensures the material participates in the filling and bonding of the additive region. The improved tool head's flow-promoting and shaping structure guides and promotes material flow, ensuring uniform filling of the additive region and preventing material accumulation or gaps. The improved tool head is made of tungsten-rhenium alloy, which effectively improves the bonding strength and additive efficiency of the additive layer, reduces additive load and tool head wear, achieving green manufacturing. Furthermore, it reduces weak bonding and flash defects in the additive layer, making the additive process stable and efficient.

[0006] Specifically, the improved tool head includes a clamping shank and an additively reinforced structure; one end of the additively reinforced structure is connected to one end of the clamping shank, and the other end of the clamping shank is connected to a machine tool spindle for additive manufacturing.

[0007] The additive reinforcement structure includes an overflow barrier structure and a flow-promoting shaping structure, which together form the additive region. The flow-promoting shaping structure is a double-cone structure with a middle diameter larger than its two ends. It is used to guide and promote the flow of material during additive manufacturing, so that the material is evenly filled into the additive region and avoids material accumulation or gaps. The overflow barrier structure is connected to the two ends of the double-cone structure to limit the overflow of material during additive manufacturing. By constraining the flow direction of the material, it enables the material to participate in the filling and bonding of the additive region. The overflow barrier structure and the flow-promoting shaping structure work together to improve the density, bonding strength and additive efficiency of the additive layer.

[0008] Preferably, the improved tool head is made of tungsten-rhenium alloy.

[0009] Preferably, the overflow barrier structure is a double-shoulder structure, which includes an inner shoulder and an outer shoulder;

[0010] The inner shoulder is connected to one end of the clamping shank, the other end of the inner shoulder is connected to one end of the double-cone structure, and the other end of the double-cone structure is connected to the outer shoulder; during additive manufacturing, the material is confined to the additive region between the inner shoulder, the outer shoulder, and the double-cone structure.

[0011] Preferably, the double-cone structure consists of two mirror-symmetrical double cones, and a central annular groove is provided at the joint of the two double cones. The central annular groove is used to make frictional contact with the material during additive manufacturing to promote material softening, material flow and shaping.

[0012] Both conical heads have annular grooves and arc grooves on their curved sides. The annular grooves are used to ensure that the material is evenly filled into the additive manufacturing area, avoiding material accumulation or gaps. The arc grooves on both sides of the annular grooves are inclined toward the central annular convex groove, which guides and promotes the flow of material along the opening direction of the arc grooves.

[0013] According to specific embodiments provided by the present invention, the improved tool head discloses the following technical effects:

[0014] 1) The improved tool head employs a double-cone structure for promoting flow and shaping, as well as an overflow-blocking structure. This unique structure better guides and promotes material flow during rolling friction. Under the action of the improved tool head, material can fill the area requiring additive manufacturing more evenly, avoiding material accumulation or gaps, thereby improving the uniformity and density of the additive layer and enhancing bonding strength. The flow-promoting structure also increases the contact area and friction between the improved tool head and the material. During rolling friction, the increased friction generates more heat, which helps soften the material, reduces its deformation resistance, and makes it easier for the material to undergo plastic deformation and flow under the action of the improved tool head, thus improving additive manufacturing efficiency. The overflow-blocking structure effectively limits material overflow during the additive manufacturing process. By constraining the flow direction of the material, it ensures that more material participates in the filling and bonding of the additive region, rather than flowing outwards, thereby guaranteeing the dimensional accuracy and shape stability of the additive layer and reducing defects such as weak bonding and flash.

[0015] 2) The improved tool head uses a tungsten-rhenium alloy. This alloy, in its heat-treated state, has a Rockwell hardness of 75-80 HRA (HRA refers to Rockwell A standard), and its wear resistance is improved by about 30% compared to traditional tool head materials, allowing it to maintain good performance when processing high-melting-point metals. During processing, the improved tool head made of tungsten-rhenium alloy effectively resists wear and extends its service life. At the same time, tungsten-rhenium alloy also has good high-temperature stability, enabling it to withstand high temperatures during additive manufacturing without deformation or damage, ensuring the structural stability and machining accuracy of the improved tool head, which is beneficial for achieving high-quality additive manufacturing.

[0016] Additive manufacturing equipment includes: a grooved worktable, a heating plate, and a heat insulation pad;

[0017] The heating plate is embedded in the groove of the workbench, and the contact part between the heating plate and the groove is padded with a heat insulation pad.

[0018] Copper and steel strips are stacked on the heating plate. The lower surface of the steel strip is in direct contact with the heating surface of the heating plate, while the upper surface of the copper strip is in contact with the improved tool head, which enables additive manufacturing.

[0019] Additive manufacturing methods, implemented using additive manufacturing equipment, include the following steps:

[0020] Step 1: Polish the steel and copper strips to remove the oxide film on the surface;

[0021] Step 2: Clean the polished steel and copper strips with anhydrous ethanol to remove surface contaminants;

[0022] Step 3: Dry the steel and copper bars after cleaning;

[0023] Step 4: Clamp the steel bar onto the heating plate, and then stack the copper bar on top of the steel bar;

[0024] Step 5: Turn on the heating plate, adjust the power of the heating plate to reach the preset temperature and preheat the bottom of the steel bar, so that the steel bar and copper bar soften.

[0025] Step 6: Perform composite additive manufacturing according to the set process parameters:

[0026] Step 61: Place the improved tool head on the upper surface of the copper strip, and make the inner side of the inner shoulder and the inner side of the outer shoulder of the improved tool head fit against the two sides of the copper strip respectively.

[0027] Step 62: Press down: Rotate the improved tool head so that it rolls along the upper surface of the copper strip and presses down to the preset depth inside the steel strip;

[0028] Step 63: Feeding: While maintaining the improved tool head at the preset depth, move the improved tool head along the copper strip at the preset speed. During the feeding process, the softened copper and steel strips are prevented from overflowing through the inner and outer shoulders. At the same time, the softened copper and steel strips are guided and promoted to flow along the opening direction of the arc groove through the arc groove. The softened copper and steel strips are evenly filled into the additive manufacturing area through the annular groove. The softened copper and steel strips are rubbed and contacted through the middle annular groove to promote softening and flow. The softened copper and steel strips evenly filled in the additive manufacturing area are pressed together through the middle annular groove to form a steel-copper strip until the feeding ends, completing the steel-copper strip additive manufacturing process.

[0029] Preferably, the preset temperature in step 5 is 300–600°C.

[0030] Preferably, during the pressing phase of step 62, the rolling speed of the improved tool head is 750–1000 r / min.

[0031] Preferably, during the feeding phase of step 63, the improved tool head moves along the copper strip at a speed of 60–240 mm / min.

[0032] Preferably, the preset temperature is 500°C, the rolling speed of the improved tool head is 850 r / min, and the improved tool head moves along the copper strip at a speed of 60 mm / min.

[0033] According to specific embodiments provided by the present invention, the additive manufacturing equipment and additive manufacturing method disclose the following technical effects:

[0034] 1) By using an improved tool head and a heating plate for synergistic heating, the overall performance of rolling friction additive manufacturing of steel-copper strips can be significantly improved. During the additive manufacturing process, the improved tool head and the preheating of the heating plate work synergistically to effectively improve the bonding strength and efficiency of the additive layers, successfully overcoming the technical bottlenecks posed by high-melting-point metal materials. On the one hand, the special structural design of the improved tool head promotes material flow and increases frictional heat generation, providing excellent material shaping conditions for additive manufacturing; on the other hand, the preheating using the heating plate further increases heat input, ensuring sufficient melting and uniform distribution of the material, reducing the generation of internal defects and residual stress. The synergistic effect of both makes the additive process more stable and efficient, ultimately achieving the goal of green manufacturing.

[0035] 2) Before additive manufacturing, the material is heated to a preset temperature using a heating plate. This ensures the material is at a relatively high temperature when entering the rolling friction additive manufacturing stage, reducing energy consumption during subsequent processing and helping the material reach plastic deformation more quickly, thus improving additive manufacturing efficiency. Appropriate auxiliary heating temperature can further improve the material's plastic flow properties. During rolling friction, the material is more prone to plastic deformation and flow under the coupling effect of heat and force, allowing it to better fill all corners of the additive region, reducing porosity and defects, and improving the density and bonding strength of the additive layer. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a single-axis shoulder tool head in the prior art;

[0038] Figure 2 This is a schematic diagram of the structure of a shoulderless tool head in the prior art;

[0039] Figure 3 This is a schematic diagram of the structure of the improved tool head in Embodiment 1 of the present invention;

[0040] Figure 4 This is a schematic diagram of the additive reinforcement structure in Embodiment 1 of the present invention;

[0041] Figure 5 This is a schematic diagram of the additive manufacturing equipment in Embodiment 2 of the present invention;

[0042] Figure 6 This is a surface morphology image of the macrostructure of the cross-section of the additive region obtained by the additive manufacturing method in Embodiment 3 of the present invention.

[0043] Symbol explanation:

[0044] 1-Clamping handle; 11-Tool holder groove; 2-Additive reinforcement structure; 21-Intermediate annular protrusion; 22-Annular groove; 23-Arc groove; 24-Inner shoulder; 25-Outer shoulder; 3-Worktable; 4-Heating plate; 5-Heat insulation pad; 6-Steel strip; 7-Copper strip. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] like Figure 1 As shown, this is the single-shoulder tool head currently used by AFRD. One end of the single shoulder is connected to one end of the clamping shank 1, and the end of the part that comes into friction with the material is connected to the other end of the shoulder. (See diagram below.) Figure 2 As shown, this is the shoulderless tool head currently used by AFRD. The part that comes into frictional contact with the material is directly connected to one end of the clamping shank 1.

[0048] Adopting such Figure 1 and Figure 2 The tool head shown, when used in additive manufacturing, exhibits issues such as a higher center and lower sides in the additive layer, as well as material overflow, leading to weak bonding and defects like flash. Furthermore, as described in the background section, current research on solid-state additive manufacturing technology largely focuses on lightweight alloys, limiting the application of additive manufacturing equipment to high-melting-point dissimilar metal materials. The equipment not only struggles to meet the processing requirements of high-melting-point materials, but the tool head also experiences significant wear during processing.

[0049] To address the above problems, the present invention provides an improved tool head in Embodiment 1.

[0050] Example 1:

[0051] like Figure 3 As shown, the improved tool head includes a clamping shank 1 and an additive reinforcing structure 2; one end of the additive reinforcing structure 2 is connected to one end of the clamping shank 1, and the other end of the clamping shank 1 is connected to a machine tool spindle used for additive manufacturing.

[0052] Additive reinforcement structure 2 includes an overflow barrier structure and a flow-promoting shaping structure, which together enclose the additive manufacturing region. The flow-promoting shaping structure is a biconical structure with a middle diameter smaller than its two end diameters. It guides and promotes material flow during additive manufacturing, ensuring uniform material filling within the additive region and preventing material accumulation or gaps. The overflow barrier structure connects to the two ends of the biconical structure, limiting material spillage during additive manufacturing and constraining the material flow direction to ensure its participation in the filling and bonding of the additive region. The combined use of the overflow barrier structure and the flow-promoting shaping structure improves the density, bonding strength, and additive efficiency of the additive layer.

[0053] The improved tool head also includes a tool holder groove 11, which is located on the outer surface of the clamping handle 1 and serves to fix it in place.

[0054] Specifically, such as Figure 4 As shown, the overflow barrier structure is a double-shoulder structure, which includes an inner shoulder 24 and an outer shoulder 25. The inner shoulder 24 is connected to one end of the clamping handle 1, and the other end of the inner shoulder 24 is connected to one end of the double-cone structure. The other end of the double-cone structure is connected to the outer shoulder 25. During additive manufacturing, the material is confined in the additive manufacturing area between the inner shoulder 24, the outer shoulder 25, and the double-cone structure.

[0055] The double-cone structure consists of two mirror-symmetrical cone heads. A central annular groove 21 is provided at the junction of the two cone heads. The central annular groove 21 is used to make frictional contact with the material during additive manufacturing to promote material softening, material flow and shaping. Both cone heads have annular grooves 22 and arc grooves 23 on both sides of the annular grooves 22. The annular grooves 22 are used to make the material fill the additive area evenly and avoid material accumulation or material gaps. The arc grooves 23 on both sides of the annular grooves 22 are inclined towards the central annular groove 21 to guide and promote the material to flow along the opening direction of the arc grooves 23.

[0056] In the process of triboelectric deposition additive manufacturing, the tool head needs to withstand a large forging force. The melting point of 316L stainless steel is 1530℃, and the melting point of pure copper is 1083℃. Triboelectric deposition additive manufacturing is a solid-state additive manufacturing method, and the additive temperature is only 60% to 90% of the material's melting point.

[0057] In this embodiment, the improved tool head is made of tungsten-rhenium alloy. Tungsten-rhenium alloy possesses excellent properties such as high hardness and strength, good wear resistance, high-temperature stability, good electrical and thermal conductivity, ease of machining and additive manufacturing, excellent oxidation resistance, and high recrystallization temperature. It is capable of withstanding loads without fracture during additive manufacturing of high-melting-point dissimilar materials and can be used for steel-copper rolling additive manufacturing. The annular groove 22 and arc groove 23 are symmetrically distributed. Combining the annular groove 22 and arc groove 23 with the central annular protrusion 21 promotes material flow and increases frictional heat generation. The design of the inner shoulder 24 and outer shoulder 25 restricts material overflow, allowing material backflow and increasing bonding strength.

[0058] The following shows the preferred parameters of the improved tool head in this embodiment.

[0059] Table 1. Optimal Parameters for Improved Tool Head

[0060]

[0061]

[0062] In this embodiment, the flow-promoting shaping structure adopts a double-cone structure. The annular groove 22 serves as a material guide channel, guiding the material flow to the area to be shaped, preventing deviation or accumulation of material during filling, and controlling the distribution range and thickness of the material. The arc groove 23 disperses stress, provides additional support, enhances structural strength, guides and controls material removal, allowing the improved tool head to cut in better and reducing friction and wear. The central annular protrusion 21 disperses and guides the material collected in the middle section. The flow of the mixed plastic deformation material at both ends is restricted from overflow by the inner shoulder 24 and outer shoulder 25, and allows this material to flow back, avoiding defects such as burrs and flash, and helping to fill the tiny gaps in the bonding layer, making it denser and more uniform.

[0063] In the rolling friction additive manufacturing process, the improved tool head can rotate rapidly and press into the upper surface of the copper strip. The rapid contact friction between the flow-forming structure and the steel-copper strip generates heat, creating a softened plastic zone around it. The copper strip 7 is conveyed to the significantly heated contact interface, where it is softened and plastically deformed, and then rolled into the plastic zone, mixing and bonding with the plastic material on the steel substrate. As the improved tool head moves forward, the mixed steel-copper plastically deformed material is rolled and flowed to the rear side of the improved tool head, forming a steel-copper bonding layer.

[0064] Example 2

[0065] like Figure 5As shown, an additive manufacturing apparatus is provided, including a worktable 3 with a groove, a heating plate 4, and a heat insulation pad 5. The heating plate 4 is embedded in the groove of the worktable 3, and the heat insulation pad 5 is placed on the contact portion between the heating plate 4 and the groove. Copper strips 7 and steel strips 6 are stacked on the heating plate 4, with the lower surface of the steel strips 6 in direct contact with the heating surface of the heating plate 4; the upper surface of the copper strips 7 is in contact with the improved tool head in Embodiment 1, and additive manufacturing is achieved through the improved tool head.

[0066] Example 3:

[0067] This embodiment provides an additive manufacturing method based on the additive manufacturing equipment described in Embodiment 2. The method includes the following steps:

[0068] Step 1: Grind the steel strip 6 and copper strip 7 to remove the oxide film on the surface;

[0069] Step 2: Clean the polished steel strip 6 and copper strip 7 with anhydrous ethanol to remove surface dirt;

[0070] Step 3: After cleaning, dry the steel strip 6 and copper strip 7;

[0071] Step 4: Clamp the steel strip 6 onto the heating plate 4, and then stack the copper strip 7 on top of the steel strip 6;

[0072] Step 5: Power on the heating plate 4, adjust the power of the heating plate 4 to reach the preset temperature and preheat the bottom of the steel strip 6, so that the steel strip 6 and the copper strip 7 soften.

[0073] Step 6: Perform composite additive manufacturing according to the set process parameters:

[0074] Step 61: Place the improved tool head on the upper surface of the copper strip 7, and make the inner side of the inner shoulder and the inner side of the outer shoulder of the improved tool head fit against the two sides of the copper strip 7 respectively.

[0075] Step 62: Press down: Rotate the improved tool head so that it rolls along the upper surface of the copper strip 7 and presses down the improved tool head to a preset depth inside the steel strip 6;

[0076] Step 63: Feeding: While maintaining the improved tool head at the preset depth, move the improved tool head along the copper strip 7 at a preset speed. During the feeding process, the softened copper strip 7 and steel strip 6 are blocked by the inner shoulder 24 and the outer shoulder 25. At the same time, the softened copper strip 7 and steel strip 6 are guided and promoted to flow along the opening direction of the arc groove 23 by the arc groove 23. The softened copper strip 7 and steel strip 6 are evenly filled into the additive manufacturing area by the annular groove 22. The softened copper strip 7 and steel strip 6 are rubbed and contacted by the middle annular groove 21 to promote softening and flow. The softened copper strip 7 and steel strip 6 evenly filled in the additive manufacturing area are pressed by the middle annular groove 21 to form a steel-copper strip until the feeding ends, completing the steel-copper strip additive manufacturing process.

[0077] The thickness of the copper strip 7 is preferably 2mm, and the thickness of the steel strip 6 is preferably 4mm.

[0078] Furthermore, preferably, the preset temperature in step 5 is 300-600℃; in the pressing stage of step 62, the rolling speed of the improved tool head is 750-1000 r / min, and the preset depth is preferably 0.3 mm; in the feeding stage of step 63, the improved tool head moves along the copper strip 7 at a speed of 60-240 mm / min.

[0079] Within the range of the above process parameters, the optimal combination of process parameters obtained through additive manufacturing experiments is shown in the table below.

[0080] Table 2 Optimal Process Parameters for Additive Manufacturing Methods

[0081]

[0082] like Figure 6 As shown, the sample obtained by additive manufacturing experiments using optimal process parameters exhibits good surface finish and smooth texture. Metallographic examination of the sample cross-section revealed that the deposited layer is completely dense, without inclusions, cracks, or other defects, forming a good metallurgical bond.

[0083] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An improved tool head, comprising a clamping shank (1), characterized in that, It also includes an additive reinforcement structure (2); one end of the additive reinforcement structure (2) is connected to one end of the clamping handle (1), and the other end of the clamping handle (1) is connected to the machine tool spindle used for additive manufacturing; The additive reinforced structure (2) includes an overflow structure and a flow-promoting shaping structure, with the overflow structure and the flow-promoting shaping structure forming an additive region; The flow-promoting and shaping structure is a double-conical structure with a middle diameter smaller than the diameters at both ends. It is used to guide and promote the flow of material during additive manufacturing, so that the material is evenly filled into the additive region and avoids material accumulation or gaps. The overflow barrier structure is connected to both ends of the double-conical structure and is used to limit the overflow of material during additive manufacturing. By constraining the flow direction of the material, it enables the material to participate in the filling and bonding of the additive region. The overflow barrier structure and the flow-promoting and shaping structure work together to improve the density, bonding strength and additive efficiency of the additive layer. The double-cone structure consists of two mirror-symmetrical cone heads. A central annular groove (21) is provided at the junction of the two cone heads. The central annular groove (21) is used to make frictional contact with the material during additive manufacturing to promote material softening, material flow and shaping. Both conical heads have annular grooves (22) and arc grooves (23) on both sides of the curved surface. The annular grooves (22) are used to make the material fill the additive area evenly and avoid material accumulation or material gaps. The arc grooves (23) on both sides of the annular grooves (22) are inclined towards the central annular protrusion (21) to guide and promote the material to flow along the opening direction of the arc grooves (23). The improved tool head is made of tungsten-rhenium alloy; The overflow barrier structure is a double-shoulder structure, which includes an inner shoulder (24) and an outer shoulder (25). The inner shoulder (24) is connected to one end of the clamping handle (1), the other end of the inner shoulder (24) is connected to one end of the double cone structure, and the other end of the double cone structure is connected to the outer shoulder (25); during additive manufacturing, the material is confined in the additive region between the inner shoulder (24), the outer shoulder (25) and the double cone structure.

2. An additive manufacturing apparatus, characterized in that, include: A worktable with grooves (3), a heating plate (4), and a heat insulation pad (5); The heating plate (4) is embedded in the groove of the workbench (3), and the contact part between the heating plate (4) and the groove is padded with a heat insulation pad (5). Copper strips (7) and steel strips (6) are stacked on the heating plate (4). The lower surface of the steel strip (6) is in direct contact with the heating surface of the heating plate (4). The upper surface of the copper strip (7) is in contact with the improved tool head as described in claim 1, and additive manufacturing is achieved through the improved tool head.

3. An additive manufacturing method, implemented using the additive manufacturing equipment described in claim 2, characterized in that, Includes the following steps: Step 1: Grind the steel strip (6) and copper strip (7) to remove the oxide film on the surface; Step 2: Clean the polished steel strip (6) and copper strip (7) with anhydrous ethanol to remove surface contaminants; Step 3: After cleaning, dry the steel strip (6) and copper strip (7); Step 4: Clamp the steel strip (6) onto the heating plate (4), and then stack the copper strip (7) on the steel strip (6); Step 5: Power on the heating plate (4), adjust the power of the heating plate (4) to reach the preset temperature and preheat the bottom of the steel strip (6) so that the steel strip (6) and copper strip (7) soften. Step 6: Perform composite additive manufacturing according to the set process parameters: Step 61: Place the improved tool head on the upper surface of the copper strip (7), and make the inner side of the inner shoulder and the inner side of the outer shoulder of the improved tool head fit against the two sides of the copper strip (7) respectively. Step 62: Press down: Rotate the improved tool head so that it rolls along the upper surface of the copper strip (7) and press down the improved tool head to a preset depth inside the steel strip (6); Step 63: Feed: While keeping the improved tool head at the preset depth, move the improved tool head along the copper strip (7) at the preset speed. During the feeding process, the softened copper strip (7) and steel strip (6) are blocked from overflowing by the inner shoulder (24) and outer shoulder (25). At the same time, the softened copper strip (7) and steel strip (6) are guided and promoted to flow along the opening direction of the arc groove (23) by the arc groove (23). The softened copper strip (7) and steel strip (6) are evenly filled into the additive area by the annular groove (22). The softened copper strip (7) and steel strip (6) are rubbed and contacted by the middle annular groove (21) to promote softening and flow. The softened copper strip (7) and steel strip (6) evenly filled in the additive area are pressed together by the middle annular groove (21) to form a steel-copper strip until the feeding ends, thus completing the steel-copper strip additive manufacturing process.

4. The additive manufacturing method according to claim 3, characterized in that, The preset temperature in step 5 is 300~600℃.

5. The additive manufacturing method according to claim 4, characterized in that, During the pressing phase of step 62, the rolling speed of the improved tool head is 750~1000 r / min.

6. The additive manufacturing method according to claim 5, characterized in that, During the feed phase of step 63, the improved tool head moves along the copper strip (7) at a speed of 60~240 mm / min.

7. The additive manufacturing method according to claim 6, characterized in that, The preset temperature is 500℃, the rolling speed of the improved tool head is 850r / min, and the improved tool head moves along the copper strip (7) at a speed of 60mm / min.

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