Semi-solid ultrasonic rolling synchronous auxiliary electric arc additive manufacturing deposition forming device and method

Abstract

The invention discloses a semi-solid ultrasonic rolling synchronous auxiliary electric arc additive manufacturing device and method, and the device comprises an ultrasonic rolling device, and further comprises an electric arc welding gun device, an automatic wire feeding device, a manipulator, a control system device, a protective gas cylinder and a clamp device. When semi-solid ultrasonic rolling synchronous auxiliary electric arc additive manufacturing is carried out, the electric arc welding gun is fixed to one mechanical arm, the synchronous ultrasonic rolling device is fixed to the other mechanical arm, and the two mechanical arms are controlled by the control system device to move synchronously. The invention provides a structure regulation and control method of applying ultrasound and rolling composite to a semi-solid area of an electric arc additive manufacturing near-molten pool, and utilizes stirring and cavitation effects of the ultrasound and a deformation-induced recovery recrystallization effect to promote escape of bubbles, effective welding of pores and full crushing and refining of dendritic crystals, so that the mechanical property of the electric arc additive manufacturing near-molten pool is improved. And finally, regulation and control of the compact equiaxed fine grain structure in electric arc additive manufacturing are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of arc additive manufacturing, and relates to a semi-solid ultrasonic rolling synchronous auxiliary arc additive manufacturing deposition forming device and method. Background Art

[0002] The rapid iteration of high-end equipment such as the new generation of aerospace aircraft and deep-sea submersibles drives the continuous development of high-performance metal structural parts towards the direction of large size, integrity, and light weight. The traditional manufacturing mode of combining casting and forging with machining has many technical limitations such as the difficulty in preparing complex integral components and the high dependence on heavy forging equipment. Additive manufacturing technology strongly supports the design innovation of high-end equipment with its powerful personalized rapid manufacturing ability, and provides a subversive new solution for the manufacturing of high-performance metal components of high-end equipment such as airplanes, rockets, and ships.

[0003] Among many metal additive manufacturing technologies, arc additive manufacturing technology has been widely used in the manufacturing of large-size metal components due to its advantages such as high utilization rate, fast deposition efficiency, and low cost. However, due to the constraints of the forming principle of "in-situ melting - layer-by-layer deposition" and the characteristics of high arc heat input, the arc additive manufacturing deposition process is often accompanied by a forced heat dissipation mode mainly based on unidirectional conduction and a low cooling rate, which easily forms defects such as thick columnar crystals growing epitaxially along the deposition height direction and unfused holes, thereby reducing the overall stability and reliability of the component. Therefore, how to achieve the densification of the deposited microstructure and the refinement and equiaxialization of grains has become an urgent problem to be solved in arc additive manufacturing.

[0004] Ultrasonic roll pressing assisted additive manufacturing has been proven to be an effective control process. Using this technology, Chinese Patent CN 202121404001.4 discloses an ultrasonic roll pressing control additive manufacturing deposition structure system. After each layer is deposited by the additive manufacturing system, interlayer ultrasonic roll pressing treatment is performed on each layer with a preset static pressure. The surface and internal structures of the component have been refined and homogenized, and the mechanical properties have been improved. However, in the solidification state, due to the large deformation resistance of the material, the grain refinement effect gradually decreases with the deposition direction. At the same time, for the interlayer ultrasonic roll pressing process, due to the structural limitations of the roll pressing equipment, the process flexibility is reduced, which brings difficulties to the manufacturing of complex components. In addition, Chinese Patent CN202410405589.7 discloses a preparation method for ultrasonic-assisted additive manufacturing of titanium alloy materials. Ultrasonic vibration is applied to the material substrate while arc additive manufacturing is carried out. The cavitation effect and convection are utilized to promote the fragmentation of columnar crystals and the formation of equiaxed crystals. However, the arc additive manufacturing molten pool has a small volume, fast solidification, and dynamic changes. At the same time, at present, it is difficult for the ultrasonic field to directly place the horn in the melt like traditional casting for action, and it can only be indirectly applied through the solidification region, which is prone to energy attenuation. This brings great challenges to the uniform and stable application and timely and sufficient control of the ultrasonic field. Another example is Chinese Patent CN 212683024 U, which discloses a continuous wire feeding induction heating composite rolling semi-solid additive manufacturing system. The wire is heated and maintained in a semi-solid state, and after deposition, the driving roller is used for multi-pass rolling treatment. However, the effect of the rolling treatment depends on subsequent multi-pass rolling, and the solidification behavior of the semi-solid region cannot be regulated in real time, which is prone to uneven deformation of the deposited layer, and then leads to uneven final microstructure. Therefore, it is of great research necessity to adopt a smaller and simpler mechanism to achieve uniform plastic deformation under a small roll pressure. Summary of the Invention

[0005] Aiming at the problems proposed in the above background technology, the present invention provides a semi-solid ultrasonic roll pressing synchronous assisted arc additive manufacturing deposition forming device and method, which apply ultrasonic vibration and synchronous roll pressing in the semi-solid stage during the arc additive manufacturing process to realize the real-time regulation of the solidification behavior of the deposited layer.

[0006] For this purpose, the technical solution adopted by the present invention is as follows:

[0007] A semi-solid ultrasonic roll pressing synchronous assisted arc additive manufacturing deposition forming device includes an arc welding torch device, an automatic wire feeding device, an ultrasonic roll pressing device, a first manipulator, a second manipulator, a control system device, an arc additive deposition processing platform, and a forming substrate;

[0008] The ultrasonic roll pressing device is connected to the first manipulator; the arc welding torch device is connected to the second manipulator, and the automatic wire feeding device is used to supply welding wire to the arc welding torch device; both the first manipulator and the second manipulator are connected to the control system device, and the two manipulators are controlled by the control system device to move synchronously, so that the arc welding torch device and the ultrasonic roll pressing device can act together on the forming substrate of the arc additive manufacturing platform, and the roller of the ultrasonic roll pressing device can act in the semi-solid region generated by the arc of the arc welding torch device.

[0009] Further, the ultrasonic roll pressing device includes a ultrasonic power supply, a ultrasonic transducer, a horn, a tool head and a roller connected in sequence. The ultrasonic power supply emits a vibration signal, which is converted into a vibration signal by the ultrasonic transducer and then amplified by the horn, and transmitted to the tool head to drive the roller to perform ultrasonic rolling.

[0010] Further, the arc welding torch is connected with a shielding gas cylinder.

[0011] Further, the ultrasonic roll pressing device is connected to the first manipulator through a fixture. The fixture includes a fixture flat plate and two U-shaped grooves. One end of the fixture device is bolted to the first manipulator through the fixture flat plate, and the other end is connected to the ultrasonic roll pressing device in a bolted connection manner through the two U-shaped grooves.

[0012] The present invention also discloses a semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing deposition forming method, which includes the following steps:

[0013] Step 1: Load the wire into the arc welding torch, control the second manipulator to move the arc welding torch to the deposition starting point through the control system device, and at the same time fix the ultrasonic roll pressing device on the first manipulator and move it behind the arc welding torch;

[0014] Step 2: Adjust the ultrasonic roll pressing device and the arc welding torch to be on the same horizontal line and ensure that the roller can act in the arc semi-solid region. Turn on the ultrasonic power supply, and then turn on the arc heat source to start additive manufacturing. At the same time, the ultrasonic roll pressing device moves synchronously along the trajectory of the arc welding torch;

[0015] Step 3: When the deposition of the current layer is completed, first turn off the arc heat source, wait for the roller to roll the remaining semi-solid region, then turn off the ultrasonic power supply, and control the double manipulators to move the welding torch and the ultrasonic roll pressing device to the deposition starting point of the next layer;

[0016] Step 4: Wait for the arc welding torch to issue a movement command, turn on the ultrasonic power supply, and then turn on the arc heat source, and repeat this process until the component is deposited and formed, and then turn off all equipment.

[0017] As a preferred embodiment of the semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing deposition forming method of the present invention: the roll pressing methods of the ultrasonic roll pressing equipment include vertical roll pressing, inclined roll pressing, rotary roll pressing and other methods.

[0018] As a preferred embodiment of the semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing deposition forming method of the present invention: the process parameters are as follows: the minimum distance between the ultrasonic roll pressing equipment and the arc additive welding torch is 5 mm, the minimum roll pressure output by the ultrasonic roll pressing is 10 N, the minimum ultrasonic vibration frequency is 20 kHz, and the minimum ultrasonic power is 100 W.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) The present invention uses a follow-up ultrasonic device to directly contact the semi-solid region of the molten pool, strengthens the convection of the molten pool through vibration stirring, and promotes the fragmentation of dendrites and the escape of gas by the stirring and cavitation effects of ultrasound to obtain high-quality semi-solid slurry.

[0021] (2) The present invention uses roll pressing to achieve timely and sufficient deformation of the semi-solid region with low resistance, real-time regulates the solidification behavior of the semi-solid region, promotes the effective welding of pore defects at high temperature, and has a significant grain refinement effect.

[0022] (3) The present invention utilizes the comprehensive regulation advantages of follow-up ultrasonic external field assistance and synchronous roll pressing deformation assistance to refine and equiaxialize the grains of the deposited layer through dynamic recrystallization.

[0023] (4) The present invention is green and pollution-free, has strong process flexibility. The ultrasonic roll pressing acts on the structure of the additive component as a physical effect, and different roll pressures can be applied to the deposited layer in the semi-solid stage, enabling the deposited layer to undergo sufficient plastic deformation under low resistance, providing a new regulation idea for difficult-to-machine materials. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing deposition forming device of the present invention.

[0025] Figure 2 It is a schematic diagram of the relative positions of the arc welding torch and the ultrasonic roll pressing equipment in the semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing of the present invention.

[0026] Figure 3 It is a flow chart of the semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing deposition forming steps of the present invention.

[0027] In the figure: 1. Substrate; 2. Processing platform; 3. Deposition component; 4. Ultrasonic power supply; 5. First manipulator; 6. Ultrasonic roll pressing device: 6-1. Ultrasonic transducer, 6-2. Horn, 6-3. Tool head, 6-4. Positioning round pin, 6-5. Roll wheel; 7. Clamping device: 7-1. Clamping flat plate, 7-2. Bolt, 7-3. U-shaped groove; 8. Control system device; 9. Automatic wire feeding device; 10. Second manipulator; 11. Arc welding torch device: 11-1. Bolt, 11-2. Welding torch, 11-3. Wire; 12. Protection gas cylinder; 13. Infrared thermal imager. Specific implementation mode

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in more detail below in conjunction with embodiments.

[0029] In the middle and late stages of solidification, that is, there is a special semi-solid state between the molten state and the solidified state. Within a reasonable solid-phase content range, the semi-solid metal has both thixotropy and rheology. For arc additive manufacturing, this characteristic of the molten pool solidification makes it possible to implement regulation in the semi-solid stage.

[0030] Please refer to Figure 1 - Figure 2 As shown, an apparatus for semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing according to an embodiment of the present invention includes a substrate 1, a processing platform 2, a deposition component 3, an ultrasonic power supply 4, a manipulator 5, an ultrasonic roll pressing device 6, a clamping device 7, a control system device 8, an automatic wire feeding device 9, a manipulator 10, an arc welding torch device 11, and a protection gas cylinder 12;

[0031] In this embodiment, the ultrasonic roll pressing device 6 includes an ultrasonic transducer 6-1, a horn 6-2, a tool head 6-3, a positioning round pin 6-4 and a roll wheel 6-5. The ultrasonic power supply 4 emits a vibration signal, which is converted into a vibration signal by the ultrasonic transducer 6-1 and then amplified by the horn 6-2 and transmitted to the tool head 6-3 to drive the roll wheel 6-5. The tool head 6-3 and the roll wheel 6-5 are connected by the positioning round pin 6-4; the ultrasonic roll pressing device 6 is connected to the first manipulator 5 through the clamping device 7. One end of the clamping device 7 is bolted to the first manipulator 5 through the clamping flat plate 7-1 with bolts 7-2, and the other end U-shaped groove 7-3 is an open groove structure. The bolt passes through the opening of the U-shaped groove and is fixed at the corresponding positions of the clamping device and the ultrasonic roll pressing device. The arc welding torch device 11 is fixed on the second manipulator 10 through bolts 11-1, and the two manipulators are controlled to move synchronously through the control system device 8; the protection gas cylinder 12 is connected to the arc welding torch device 11.

[0032] Embodiment 1

[0033] Taking the TDN 5000MB pulsed MIG as the heat source for arc additive manufacturing, 2319 aluminum alloy as the additive metal material, the substrate being 2319 aluminum alloy, and using the unidirectional scanning method to additively manufacture 2319 aluminum alloy components as an example. The automatic wire feeding device 9 uses a TFN 6000F wire feeder, the controller is a YRC 1000, DX200 control cabinet, and the motion execution mechanism is a MH12 model robot.

[0034] The arc additive manufacturing process parameters adopted are as follows: the distance between the welding torch 11-2 and the substrate 1 is set to 15 mm, the current is 100 - 140 A, the scanning speed is 3 - 5 mm / s, the shielding gas flow rate is 20 L / min, the minimum distance between the ultrasonic roller pressing device 6 and the welding torch 11-2 is 5 mm, the output roller pressure of the ultrasonic roller pressing device 6 is 10 - 200 N, the ultrasonic vibration frequency is 20 - 40 kHz, the ultrasonic power is 100 - 1200 W, and the semi-solid ultrasonic roller pressing intervention temperature is 580 - 620 °C.

[0035] As Figure 3 shown, it specifically includes the following steps:

[0036] Step 1: The wire 11-3 selects a 2319 aluminum alloy welding wire with a diameter of 1.2 mm. Before the experiment, the surface oxide layer of the substrate 1 on the processing platform 2 is polished. First, load the wire 11-3 into the arc welding torch 11-2. Use the control system device 8 to program the second robot 10 so that it can accurately move the arc welding torch to the starting point of deposition. During this process, the ultrasonic roller pressing device 6 also needs to be fixed on the first robot 5, and the following trajectory of the ultrasonic roller pressing device 6 is calculated according to the target trajectory of the arc welding torch 11-2. A smooth motion trajectory is generated through the interpolation algorithm and decomposed into the joint motion instructions of the first robot 5 to ensure that the ultrasonic roller pressing device 6 can accurately follow synchronously during the deposition process. At the same time, use the encoder to obtain the position data of the arc welding torch 11-2 and the ultrasonic roller pressing device 6 in real time, calculate the position error between the two, and dynamically adjust the motion instructions of the two robots based on the feedback control algorithm to correct the trajectory in real time to effectively eliminate the position deviation.

[0037] Step 2: Determine the distance between the semi-solid ultrasonic roll pressing intervention temperature of 580 - 620°C and the center position of the arc molten pool through the infrared thermal imager 13. After the arc welding torch 11-2 and the ultrasonic roll pressing device 6 reach the deposition starting point, adjust the position of the ultrasonic roll pressing device 6 to the semi-solid ultrasonic roll pressing intervention temperature and make it on the same horizontal line as the arc welding torch 11-2. At the same time, ensure that the roller 6-5 can effectively act on the semi-solid region generated by the arc. At this time, start the ultrasonic power supply 4 to prepare for the operation of the ultrasonic roll pressing device. During the processing, the ultrasonic roll pressing device 6 needs to move synchronously along the trajectory of the arc welding torch 11-2. This synchronous movement enables the ultrasonic roll pressing device 6 to continuously apply pressure to the semi-solid welding region, thereby adjusting and optimizing the microstructure of the deposited layer.

[0038] Step 3: When the deposition of the current layer is completed, first turn off the arc heat source to stop the welding process. Subsequently, wait for the ultrasonic roll pressing device 6 to continue rolling the remaining semi-solid region to ensure the density and uniformity of the deposited layer. After the rolling is completed, turn off the ultrasonic power supply 4. At this time, control the first manipulator 5 and the second manipulator 10 to move the welding torch 11-2 and the ultrasonic roll pressing device 6 to the deposition starting point of the next layer.

[0039] Step 4: After waiting for the movement instruction issued by the arc welding torch 11-2, restart the ultrasonic power supply 4 and then start the arc heat source to start the deposition process of the new layer. During the entire deposition process, the arc welding torch 11-2 and the ultrasonic roll pressing device 6 will continuously repeat the above steps until the deposition of the deposited component 3 is completed. After the deposition of all layers is completed, turn off all equipment, including the arc heat source and the ultrasonic power supply, to ensure the safe shutdown of the entire system.

[0040] During the implementation process, various parameters need to be strictly monitored, including the temperature, current of arc additive manufacturing, the pressure of ultrasonic roll pressing, and the accuracy of synchronous movement. Through the above steps, the combined technology of arc additive manufacturing and ultrasonic roll pressing can be effectively utilized to improve the overall performance of the component.

[0041] The present invention proposes a method for regulating the microstructure by applying ultrasonic and roll pressing compound in the semi-solid region near the molten pool of arc additive manufacturing. Utilizing the stirring, cavitation effect of ultrasonic waves, and the restoration and recrystallization effect induced by deformation, it promotes the escape of bubbles, the effective welding of pores, and the sufficient fragmentation and refinement of dendrites, ultimately realizing the regulation of the dense equiaxed fine-grained structure of arc additive manufacturing.

[0042] The above describes the specific implementation manners of the present invention in conjunction with the accompanying drawings, but these descriptions should not be construed as limiting the scope of the present invention. The protection scope of the present invention is defined by the appended claims, and any modification based on the claims of the present invention falls within the protection scope of the present invention.

Claims

1. A device for semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing, characterized in that, It includes an arc welding torch device, an automatic wire feeding device, an ultrasonic roll pressing device, a first manipulator, a second manipulator, a control system device, an arc additive manufacturing platform and a forming substrate; The ultrasonic roll pressing device is connected to the first manipulator; the arc welding torch device is connected to the second manipulator, and the automatic wire feeding device is used to supply welding wire for the arc welding torch device; both the first manipulator and the second manipulator are connected to the control system device, and the two manipulators are controlled by the control system device to move synchronously, so that the arc welding torch device and the ultrasonic roll pressing device can act together on the forming substrate of the arc additive manufacturing platform, and the roller of the ultrasonic roll pressing device can act in the semi-solid region generated by the arc of the arc welding torch device.

2. The device for semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing according to claim 1, wherein: The ultrasonic roll pressing device includes a ultrasonic power supply, a ultrasonic transducer, a horn, a tool head and a roller connected in sequence. The ultrasonic power supply emits a vibration signal, which is converted into a vibration signal by the ultrasonic transducer and then amplified by the horn, and is transmitted to the tool head to drive the roller to perform ultrasonic rolling.

3. The device for semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing according to claim 1, characterized in that: The arc welding torch is connected with a protective gas cylinder.

4. The device for semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing according to claim 1, characterized in that: The ultrasonic roll pressing device is connected to the first manipulator through a fixture. The fixture includes a fixture flat plate and two U-shaped grooves. One end of the fixture device is bolt-connected to the first manipulator through the fixture flat plate, and the other end is bolt-connected to the ultrasonic roll pressing device through the two U-shaped grooves.

5. The device for semi-solid ultrasonic roll pressing synchronous auxiliary arc additive manufacturing according to claim 1, wherein: The rolling methods of the ultrasonic roll pressing equipment include vertical rolling, inclined rolling and rotary rolling.

6. A method for semi-solid ultrasonic roll pressing synchronous assisted arc additive manufacturing, characterized in that, It includes the following steps: Step 1: Load the wire into the arc welding torch, control the second manipulator to move the arc welding torch to the deposition starting point through the control system device. At the same time, fix the ultrasonic roll pressing device on the first manipulator and move it behind the arc welding torch; Step 2: Adjust the ultrasonic roll pressing device and the arc welding torch to be on the same horizontal line and ensure that the rolling wheel can act in the arc semi-solid region. Turn on the ultrasonic power supply, and then turn on the arc heat source to start additive manufacturing. At the same time, the ultrasonic roll pressing device moves synchronously along the trajectory of the arc welding torch; Step 3: When the deposition of the current layer ends, first turn off the arc heat source, wait for the rolling wheel to roll the remaining semi-solid region, then turn off the ultrasonic power supply, and control the double manipulators to move the welding torch and the ultrasonic roll pressing device to the deposition starting point of the next layer; Step 4: Wait for the arc welding torch to send a movement instruction, turn on the ultrasonic power supply, and then turn on the arc heat source, and repeat this process until the component is deposited and formed, and then turn off all equipment.

7. The method according to claim 6, wherein: The process parameters are that the minimum distance between the ultrasonic roll pressing equipment and the arc additive welding torch is 5 mm, the minimum roll pressure output by the ultrasonic roll pressing is 10 N, the minimum ultrasonic vibration frequency is 20 kHz, and the minimum ultrasonic power is 100 W.

Images