A feed mechanism, a friction deposition additive manufacturing device and an additive manufacturing method

Abstract

The application provides a feeding mechanism of a friction deposition additive manufacturing device, the friction deposition additive manufacturing device and an additive manufacturing method. The feeding mechanism of the device comprises: a feeding channel arranged in a feeding rod, and a discharging port of the feeding channel located at a lower part of a side wall of the feeding rod; a stepped hole arranged on a tool head, and the discharging port of the feeding channel located in a large cavity of the stepped hole; the tool head and the feeding rod can rotate relative to each other; a spiral protruding part is arranged on an inner wall of the large cavity, and a blade is arranged on the spiral protruding part close to the feeding rod; and the method steps comprise: rotating the tool head at a rotating speed of 100 rpm to 2000 rpm, extruding the material to the surface of a substrate through the spiral protruding part, and realizing the deposition of the wire material to the surface of the substrate through the rotating and rolling of the tool head. The application can not only realize the continuous solid-phase deposition additive manufacturing of the same or different wire-shaped and powder-shaped materials smoothly, quickly and flexibly, but also effectively solve the problem of the blockage or even the blockage of the discharging channel.

Description

Technical Field

[0001] This invention relates to the field of solid-phase additive manufacturing technology, and in particular to a feeding mechanism, a triboelectric deposition additive manufacturing apparatus, and an additive manufacturing method. Background Technology

[0002] Solid-phase triboelectric additive manufacturing (STM) is a novel and preliminarily applied advanced additive manufacturing technology. This technology uses the friction between a tool and a substrate to deposit solid-phase raw materials onto the substrate surface, avoiding defects such as porosity and cracks commonly found in melt-based additive manufacturing. Furthermore, because no melting occurs during material deposition, it avoids the performance degradation of additive parts caused by coarse grain size and dissolution of reinforcing phases. In triboelectric additive manufacturing, raw materials are mainly supplied in four forms: plate, powder, rod, and filament. Rod and plate materials are difficult to deposit continuously, posing numerous challenges in improving forming efficiency. Powdered and filament materials have advantages in achieving continuous material deposition and controlling additive efficiency, but further optimization is needed in implementing these additive manufacturing schemes.

[0003] In existing technologies, the China Academy of Aeronautical Manufacturing Technology provides a flow friction additive manufacturing device and method (CN109202272B), including a shoulder, a base material, and a substrate. The shoulder has a cavity inside, and a central through hole communicating with the cavity is opened at the lower end of the shoulder. The base material is placed in the cavity inside the shoulder, and there is a forging force between the base material and the bottom surface of the cavity inside the shoulder, and a forging force between the shoulder and the substrate. However, this method can only guide the base material to the surface of the substrate to be additively processed after thermoplasticization, which is difficult to operate. Dalian University of Technology has developed a stirring friction additive manufacturing machine (CN108161448A), including a powder feeding system, a grinding system, a welding system, a powder outlet, and a baffle plate. The powder feeding system includes a threaded bearing and a feed cylinder. The threaded bearing is located inside the feed cylinder. Through the rotation of the bearing, downward pressure is generated to force the metal powder in the feed cylinder into the welding system. However, this additive manufacturing machine is only suitable for powdered raw materials. Harbin Institute of Technology has developed a synchronous, uninterrupted feeding method and apparatus for solid-state friction stir additive manufacturing (CN114799480A). Filament-like additive raw materials are synchronously and uninterruptedly fed into the space between the internal storage chamber of the feeding device and the shredding blades on the friction stir device through multiple feeding channels. The shredding blades on the friction stir device then pulverize the raw materials into granular additive materials, which accumulate downwards along the screw. As the friction stir device rotates continuously, the granular additive materials undergo thermoplasticization. The thermoplasticized additive materials are then mixed and stirred by multiple boss structures below the friction stir device. Finally, the homogeneous additive materials are additively formed through the gap between the feeding device and the substrate. However, this method and apparatus are only applicable to filament-like raw materials.

[0004] As mentioned earlier, existing additive manufacturing equipment is only suitable for introducing a single raw material onto the surface of the area to be additively manufactured. To date, there is no continuous solid-phase deposition additive manufacturing technology that can produce both filamentous and powdered materials.

[0005] More importantly, existing commonly used additive manufacturing equipment will produce flash at the edge of the central through hole of the tool head. This flash can easily cause blockage or even complete blockage of the discharge channel. Summary of the Invention

[0006] The purpose of this invention is to provide a feeding mechanism for a triboelectric deposition additive manufacturing apparatus, a triboelectric deposition additive manufacturing apparatus, and an additive manufacturing method, which at least solves the problem of "easily causing blockage or even complete blockage of the discharge channel" in the existing additive manufacturing process.

[0007] To achieve the above objectives, the present invention adopts the following technical solution.

[0008] A feeding mechanism for a triboelectric deposition additive manufacturing apparatus includes: a feeding rod with a feeding channel inside, the outlet of which is located on the lower part of the side wall of the feeding rod; a tool head with a stepped hole, the feeding rod being fitted into the stepped hole with clearance, the outlet of the feeding channel being located in the large cavity of the stepped channel, and the tool head and the feeding rod being able to rotate relative to each other; a helical protrusion is provided on the inner wall of the large cavity, a cutting edge is provided on the helical protrusion near the feeding rod, and the bottom of the helical protrusion is flush with the working surface of the tool head. In this invention, the stepped hole consists of two parts: a large cavity and a small cavity, which are relative to each other.

[0009] To allow for smoother and more flexible feeding, the feed inlet of the feeding channel is located at the top of the feeding rod, and the feeding channel has a "J" shaped structure.

[0010] To facilitate feeding, the top of the spiral protrusion is higher than the outlet of the feeding channel.

[0011] To ensure smoother and more efficient feeding, the spiral protrusion rotates 0.1-0.6 times within the large chamber, and the vertical height of the spiral protrusion is equal to the height of the large chamber.

[0012] As a preferred embodiment, the inner end of the spiral protrusion has one or two angular lines, which are used as the cutting edge.

[0013] As a preferred embodiment, the distance between the lowest point of the discharge port of the feeding channel and the bottom end face of the feeding rod is 1.5-20mm, and the top of the spiral protrusion is 2-10mm higher than the apex of the discharge port of the feeding channel.

[0014] A triboelectric deposition additive manufacturing apparatus employing the aforementioned feeding mechanism includes a spindle, a transmission mechanism connected to the upper part of the spindle, and a clamping structure provided at the lower part of the spindle. The feeding mechanism is mounted on the clamping structure, and the feeding rod of the feeding mechanism vertically passes through the transmission mechanism, the spindle, the clamping structure, and extends into the stepped hole of the tool head.

[0015] As a preferred embodiment, the spindle and the feed rod are fixed together to the same displacement motion device to achieve synchronous movement of the tool head and the feed rod; a feeding mechanism is installed above the feed rod.

[0016] One additive manufacturing method using the aforementioned triboelectric deposition additive manufacturing apparatus includes the following steps:

[0017] Step 11: The feeding mechanism is used to feed the filament into the feeding channel. After entering the feeding channel, the filament finally extends into the large cavity of the tool head.

[0018] Step 12: Control the tool head to rotate at a speed of 100rpm to 2000rpm. The rotation direction of the tool head meets the requirement that "the top of the spiral protrusion passes through the vertical line of the same discharge port of the feeding channel before the bottom of the spiral protrusion". The filament is squeezed onto the substrate surface through the spiral protrusion and deposited onto the substrate surface by the rotation and rolling action of the tool head.

[0019] Step 13: Control the tool head to move along the preset path until the single-layer deposition of material is completed;

[0020] Step 14: Control the tool head to move upward by the set amount, and repeat step 13;

[0021] Step 15: Repeat step 14 multiple times until the desired structure is formed.

[0022] A second additive manufacturing method using the aforementioned triboelectric deposition additive manufacturing apparatus includes the following steps:

[0023] Step 21: The powder is fed into the feeding channel by the feeding mechanism. After entering the feeding channel, the powder finally falls into the large chamber of the tool head.

[0024] Step 22: Control the tool head to rotate at a speed of 100rpm to 2000rpm. The rotation direction of the tool head meets the requirement that "the top of the spiral protrusion passes through the vertical line of the same discharge port of the feeding channel before the bottom of the spiral protrusion". The powder is squeezed onto the substrate surface through the spiral protrusion and deposited onto the substrate surface through the friction forging action of the tool head.

[0025] Step 23: Control the tool head to move along the preset path until the single-layer deposition of material is completed;

[0026] Step 24: Control the tool head to move upward by the set amount, and repeat step 13;

[0027] Step 25: Repeat step 24 multiple times until the desired structure is formed.

[0028] Beneficial Effects: This invention provides a novel triboelectric deposition additive manufacturing technology that can smoothly, quickly, and flexibly achieve continuous solid-state deposition additive manufacturing of the same or different filamentary materials, as well as the same or different powdered materials. It also optimizes the manufacturing process and significantly improves manufacturing efficiency. In this invention, the discharge port of the feeding channel primarily transports materials without participating in the dynamic deposition process. The spiral protrusions, during rotation, cause the filaments to break and fall onto the substrate surface. During this process, the feeding rod does not participate in the plasticization of the filaments. The spiral protrusions, during rotation, can also effectively break up the flash generated during material plasticization deposition (flash at the edge of the central through-hole / large chamber), effectively solving the problem of the discharge channel being blocked or even completely blocked.

[0029] In this invention, the material is plasticized and deposited on the substrate through the thermomechanical interaction between the tool head and the material. The temperature during the material deposition stage is lower than the melting point, so the material does not melt. Moreover, the material undergoes a strong thermomechanical interaction, which can avoid the coarsening of the structure and dissolution of the reinforcing phase caused by overheating of the material, reduce stress concentration, and obtain high-quality manufactured parts. Attached Figure Description

[0030] Figure 1 This is an isometric view of the feeding mechanism of the triboelectric deposition additive manufacturing apparatus in the embodiment;

[0031] Figure 2 for Figure 1 Cross-sectional view;

[0032] Figure 3 This is an isometric view of the tool head of the triboelectric deposition additive manufacturing apparatus in the embodiment;

[0033] Figure 4 for Figure 3 Cross-sectional view;

[0034] Figure 5 This is a schematic diagram of the triboelectric deposition additive manufacturing apparatus in Example 1;

[0035] Figure 6 This is a schematic diagram of the triboelectric deposition additive manufacturing apparatus in Example 2. Implementation

[0036] The technical solution 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. Example

[0037] like Figures 1 to 5 As shown, a triboelectric deposition additive manufacturing apparatus includes a spindle 3, a transmission mechanism 4 connected to the upper part of the spindle 3, and a clamping structure 2 disposed at the lower part of the spindle 3. A feeding mechanism is mounted on the clamping structure 2. The transmission mechanism 4 is connected to a motor via a belt, and the motor drives the belt to rotate, thereby rotating the spindle 3. The feeding rod 5 of the feeding mechanism vertically passes through the transmission mechanism 4, the spindle 3, and the clamping structure 2 and extends into the stepped hole of the tool head 1. The spindle 3 and the feeding rod 5 are fixed together on the same displacement motion device to achieve synchronous movement between the tool head 1 and the feeding rod 5. A feeding mechanism is mounted above the feeding rod 5.

[0038] In this embodiment, the feeding mechanism includes: a feeding rod 5, which has four feeding channels 51 symmetrically arranged along its axis. The inlet of the feeding channel 51 is located at the top of the feeding rod 5, and the outlet of the feeding channel 51 is located at the lower part of the side wall of the feeding rod 5. The feeding channel 51 has a "J" shaped structure. A tool head 1 is provided with a stepped hole, which is composed of a large chamber 12 and a small chamber 11. The feeding rod 5 is fitted into the stepped hole with clearance. The outlet of the feeding channel 51 is located in the large chamber 12 of the stepped channel. The tool head 1 and the feeding rod 5 can rotate relative to each other. A spiral protrusion 13 is provided on the inner wall of the large chamber 12. A blade is provided on the spiral protrusion 13 near the feeding rod 5. The bottom of the spiral protrusion 13 is flush with the working surface of the tool head 1.

[0039] Wherein: the top of the spiral protrusion 13 is 2mm higher than the apex of the discharge port of the feeding channel 51; the spiral protrusion 13 rotates 0.2 times in the large chamber 12, and the vertical height of the spiral protrusion 13 is equal to the height of the large chamber 12; the two angular lines on the inner end of the spiral protrusion 13 are used as the cutting edge; the distance between the lowest point of the discharge port of the feeding channel 51 and the bottom end face of the feeding rod 5 is 3mm. Wherein: the outer diameter of the feeding rod 5 is 10mm, the diameter of its internal feeding channel 51 is 2mm, the outer diameter of the tool head 1 is 30mm, the diameter of its internal small chamber 11 is 12mm, and the diameter of its internal large chamber 12 is 20mm.

[0040] An additive manufacturing method using the additive manufacturing apparatus of this embodiment includes the following steps:

[0041] Step 11: Homogeneous or heterogeneous filamentous materials are fed into the feeding channel 51 through the wire spool 6 and wire feeding wheel 7 of the automatic feeder (feeding mechanism), and further extend out of the discharge port of the feeding channel 51, and finally extend into the large chamber 12 of the tool head 1.

[0042] Step 12: Control the tool head 1 to rotate at a speed of 800 rpm. The rotation direction of the tool head 1 meets the requirement that "the top of the spiral protrusion 13 passes through the vertical line of the same discharge port of the feeding channel 51 before the bottom of the spiral protrusion 13". The filament is squeezed onto the surface of the substrate 9 by the spiral protrusion 13 and deposited onto the surface of the substrate 9 by the rotation and rolling action of the tool head 1.

[0043] Step 13: Control the tool head 1 to move along the preset path until the single-layer deposition of material is completed;

[0044] Step 14: Control tool head 1 to move upward by the set amount (height), and repeat step 13;

[0045] Step 15: Repeat step 14 multiple times until a structure of the required size is formed, such as... Figure 5 The three-dimensional component 8 is shown. Example

[0046] like Figures 1 to 4 , Figure 6 As shown, a triboelectric deposition additive manufacturing apparatus includes a spindle 3, a transmission mechanism 4 connected to the upper part of the spindle 3, and a clamping structure 2 disposed at the lower part of the spindle 3. A feeding mechanism is mounted on the clamping structure 2. The transmission mechanism 4 is connected to a motor via a belt, and the motor drives the belt to rotate, thereby rotating the spindle 3. The feeding rod 5 of the feeding mechanism vertically passes through the transmission mechanism 4, the spindle 3, and the clamping structure 2 and extends into the stepped hole of the tool head 1. The spindle 3 and the feeding rod 5 are fixed together on the same displacement motion device to achieve synchronous movement between the tool head 1 and the feeding rod 5. A feeding mechanism is mounted above the feeding rod 5.

[0047] In this embodiment, the feeding mechanism includes: a feeding rod 5, which has two feeding channels 51. The inlet of the feeding channel 51 is located at the top of the feeding rod 5, and the outlet of the feeding channel 51 is located at the lower part of the side wall of the feeding rod 5. The feeding channel 51 has a "J" shaped structure. A tool head 1 is provided with a stepped hole, which is composed of a large chamber 12 and a small chamber 11. The feeding rod 5 is fitted into the stepped hole with clearance. The outlet of the feeding channel 51 is located in the large chamber 12 of the stepped channel. The tool head 1 and the feeding rod 5 can rotate relative to each other. A spiral protrusion 13 is provided on the inner wall of the large chamber 12. A blade is provided on the spiral protrusion 13 near the feeding rod 5. The bottom of the spiral protrusion 13 is flush with the working surface of the tool head 1.

[0048] Wherein: the top of the spiral protrusion 13 is 5mm higher than the apex of the discharge port of the feeding channel 51; the spiral protrusion 13 rotates 0.3 times within the large chamber 12, and the vertical height of the spiral protrusion 13 is equal to the height of the large chamber 12; the two angular lines on the inner end of the spiral protrusion 13 are used as the cutting edge; the distance between the lowest point of the discharge port of the feeding channel 51 and the bottom end face of the feeding rod 5 is 3mm. Wherein: the outer diameter of the feeding rod 5 is 8mm, the diameter of its internal feeding channel 51 is 3mm, the outer diameter of the tool head 1 is 25mm, the diameter of its internal small chamber 11 is 9mm, and the diameter of its internal large chamber 12 is 18mm.

[0049] An additive manufacturing method using the triboelectric deposition additive manufacturing apparatus of this embodiment includes the following steps:

[0050] Step 21: Homogeneous or heterogeneous powdered materials in silo 10 are fed into feeding channel 51 through feeding rod 5. After entering feeding channel 51, the powder finally falls into the large chamber 12 of tool head 1.

[0051] Step 22: Control the tool head 1 to rotate at a speed of 1000 rpm. The rotation direction of the tool head 1 meets the requirement that "the top of the spiral protrusion 13 passes through the vertical line of the same discharge port of the feeding channel 51 before the bottom of the spiral protrusion 13". The powder is squeezed onto the surface of the substrate 9 through the spiral protrusion 13, and the powder is deposited onto the surface of the substrate 9 through the friction forging action of the tool head 1.

[0052] Step 23: Control the tool head 1 to move along the preset path until the single-layer deposition of material is completed;

[0053] Step 24: Control tool head 1 to move upward by the set amount, and repeat step 13;

[0054] Step 25: Repeat step 24 multiple times until a structure of the required size is formed, such as... Figure 6 The three-dimensional component 8 is shown.

[0055] In other embodiments, the number of rotations of the spiral protrusion 13 within the large chamber 12 can be any integer value between 0.1 and 0.6 rotations, the distance between the lowest point of the discharge port of the feeding channel 51 and the bottom end face of the feeding rod 5 can be any value between 1.5 and 20 mm, and the top of the spiral protrusion 13 is any value between 2 and 10 mm higher than the apex of the discharge port of the feeding channel 51.

[0056] This invention provides a novel triboelectric deposition additive manufacturing technology that enables smooth, rapid, and flexible continuous solid-state deposition additive manufacturing of both similar and dissimilar filamentary materials, as well as similar, dissimilar, and powdered materials. It also optimizes the manufacturing process and significantly improves manufacturing efficiency. In this invention, the discharge port of the feeding channel primarily transports materials without participating in the dynamic deposition process. The spiral protrusions, during rotation, cause the filaments to break and fall onto the substrate surface. During this process, the feeding rod does not participate in the plasticization of the filaments. The spiral protrusions also effectively break up the flash generated during material plasticization deposition (flash at the edges of the central through-hole / large chamber), effectively solving the problem of blocked or even completely blocked discharge channels. In this invention, the material is plasticized and deposited on the substrate through the thermomechanical interaction between the tool head and the material. The temperature during the material deposition stage is below the melting point, preventing melting. The intense thermomechanical interaction avoids overheating that leads to coarsening of the microstructure and dissolution of the reinforcing phase, reducing stress concentration and resulting in high-quality manufactured parts.

Claims

1. A triboelectric deposition additive manufacturing apparatus, characterized in that, The tool head (1) includes a spindle (3), a transmission mechanism (4) connected to the upper part of the spindle (3), a clamping structure (2) provided at the lower part of the spindle (3), a feeding mechanism installed on the clamping structure (2), and a feeding rod (5) of the feeding mechanism vertically passing through the transmission mechanism (4), the spindle (3), the clamping structure (2) and extending into the stepped hole of the tool head (1); the spindle (3) and the feeding rod (5) are fixed together to the same displacement motion device to realize the synchronous movement of the tool head (1) and the feeding rod (5); a feeding mechanism is installed above the feeding rod (5); The feeding mechanism includes: a feeding rod (5), a feeding channel (51) is provided inside the feeding rod (5), and the outlet of the feeding channel (51) is located at the lower part of the side wall of the feeding rod (5); a tool head (1), a stepped hole is provided on the tool head (1), the feeding rod (5) is fitted into the stepped hole with clearance, the outlet of the feeding channel (51) is located in the large chamber (12) of the stepped channel, and the tool head (1) and the feeding rod (5) can rotate relative to each other; a spiral protrusion (13) is provided on the inner wall of the large chamber (12), and a blade is provided on the spiral protrusion (13) near the feeding rod (5), the bottom of the spiral protrusion (13) is flush with the working surface of the tool head (1); the feeding channel (5 1) The feed inlet is located at the top of the feed rod (5), and the feed channel (51) has a "J" shaped structure; the top of the spiral protrusion (13) is higher than the outlet of the feed channel (51); the spiral protrusion (13) rotates 0.1-0.6 times in the large chamber (12), and the vertical height of the spiral protrusion (13) is equal to the height of the large chamber (12); the inner end of the spiral protrusion (13) has one or two angular lines, and the angular line is used as the blade; the distance between the low point of the outlet of the feed channel (51) and the bottom end face of the feed rod (5) is 1.5-20mm, and the top of the spiral protrusion (13) is 2-10mm higher than the top of the outlet of the feed channel (51).

2. An additive manufacturing method using the triboelectric deposition additive manufacturing apparatus of claim 1, characterized in that the steps include... include: Step 11: The filament is fed into the feeding channel (51) by the feeding mechanism. After entering the feeding channel (51), the filament finally extends into the large chamber (12) of the tool head (1). Step 12, control the tool head (1) to rotate at a speed of 100rpm to 2000rpm. The rotation direction of the tool head (1) meets the requirement that "the top of the spiral protrusion (13) passes through the vertical line corresponding to the discharge port of the feeding channel (51) before the bottom of the spiral protrusion (13). The filament is squeezed onto the surface of the substrate (9) through the spiral protrusion (13) and deposited onto the surface of the substrate (9) by the rotation and rolling action of the tool head (1). Step 13: Control the tool head (1) to move along the preset path until the single-layer deposition of material is completed; Step 14: Control the tool head (1) to move upward by the set amount, and repeat step 13; Step 15: Repeat step 14 multiple times until the desired structure is formed.

3. An additive manufacturing method using the triboelectric deposition additive manufacturing apparatus of claim 1, characterized in that the steps include... include: Step 21: The powder is fed into the feeding channel (51) by the feeding mechanism. After entering the feeding channel (51), the powder finally falls into the large chamber (12) of the tool head (1). Step 22, control the tool head (1) to rotate at a speed of 100rpm to 2000rpm. The rotation direction of the tool head (1) meets the requirement that "the top of the spiral protrusion (13) passes through the vertical line of the same outlet of the feeding channel (51) before the bottom of the spiral protrusion (13). The powder is squeezed onto the surface of the substrate (9) through the spiral protrusion (13) and deposited onto the surface of the substrate (9) through the friction forging action of the tool head (1). Step 23: Control the tool head (1) to move along the preset path until the single-layer deposition of material is completed; Step 24: Control the tool head (1) to move upward by the set amount, and repeat step 13; Step 25: Repeat step 24 multiple times until the desired structure is formed.

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