Controlled electric arc additive and controllable deformation composite forming method and device

Abstract

The invention relates to a controlled electric arc additive and controllable deformation composite forming method and device. The device comprises a robot controlled electric arc additive manufacturing system and a temperature controllable deformation system. The robot additive manufacturing system comprises a workbench, a longitudinal through type sliding rail is arranged on the workbench, and a base plate is connected with the rail through a sliding block; the temperature controllable deformation system comprises an induction heating device, an infrared temperature measuring device and a fixed gantry hydraulic loading deformation device; a workpiece is deposited on a base plate through an electric arc additive manufacturing system, then the base plate is conveyed to the position under a hydraulic loading deformation device through a sliding rail, the workpiece is heated to the preset temperature through an induction heating device, and then rolling wheels are pressed downwards for deformation treatment; according to the composite electric arc additive manufacturing technology and the deformation strengthening technology, after additive manufacturing is completed, by controlling different temperatures and deformation sizes, grains are refined in time, the air hole defect is compacted, the microstructure and forming quality of the workpiece are improved, and the comprehensive performance of the metal workpiece is improved.

Description

Technical Field

[0001] The present invention belongs to the field of metal additive manufacturing, relates to a metal manufacturing device, and specifically relates to a controlled arc additive and controllable deformation composite forming method and device. Background Art

[0002] Arc additive manufacturing technology uses arc as heat source to melt wire on a pre-planned additive path, and plans the motion path through the coding of mechanical equipment to form three-dimensional metal parts layer by layer. This technology has the characteristics of high deposition efficiency, good openness, high flexibility, low cost, and short production cycle. It is widely used in the manufacture of various medium and large complex parts, especially in the rapid prototyping of large structural parts such as aerospace, pressure vessels, and special vehicles.

[0003] However, the high heat input and large volume of the molten pool during arc additive manufacturing make it difficult to control the stability and precision of weld formation. In addition, due to the rapid non-equilibrium solidification process characteristics of arc additive manufacturing, it is easy to form epitaxially grown coarse columnar crystals and pores in the workpiece, which seriously affects the performance of arc additive manufacturing workpieces and restricts the development of this technology. Due to the high nitrogen content of high-nitrogen steel, problems such as loss of solid solution nitrogen, micro nitrogen pores, cracks, and nitride precipitation are prone to occur during the additive process, which seriously affects the performance of the formed parts. The CN202410111037.5 patent proposes a new composite deformation surface strengthening process of double-sided laser shock strengthening + double-sided shot peening strengthening to regulate and improve the alloy strengthening layer structure of additive manufacturing. The strengthening method used in this patent can only improve the mechanical properties of the workpiece surface, while the original performance of the workpiece is maintained. Patent CN202310138762.7 proposes to use a compression-torsion composite cold deformation process to improve the workpiece structure and mechanical properties through deformation strengthening. However, the cold deformation process proposed in this patent can only process workpieces of specific shapes and is difficult to process workpieces with complex structures. In addition, cold deformation is more difficult for materials with high yield strength and high resistance to plastic deformation. Summary of the invention

[0004] The purpose of the present invention is to provide a controlled arc additive and controllable deformation composite forming method and device, which applies plastic deformation to the added part of the workpiece in layers and lanes by composite rolling deformation process based on the arc additive forming process, so as to solve the problems of coarse structure and poor stability of weld bead forming quality caused by high heat input, large volume of molten pool and fast solidification rate of molten pool in the current arc additive manufacturing process of metal workpieces. The problems of solid solution nitrogen loss, micro nitrogen pores, cracks and nitride precipitation that are prone to occur in the additive process of high nitrogen steel are intended to be solved by this composite forming method and device.

[0005] Based on the above problems, the present invention proposes a controlled arc additive and temperature-controlled deformation composite forming process, which performs temperature-controlled deformation treatment on the additive part of the workpiece layer by layer, timely breaks up the internal grains of the workpiece, compacts the pore defects, improves the microstructure and forming quality, and solves the problem that complex structure workpieces are difficult to deform and strengthen as a whole, which is of great significance to improving the comprehensive performance of additive workpieces. The technical solutions to realize the present invention are:

[0006] Including robot-controlled arc additive manufacturing system and temperature-controlled deformation system;

[0007] The robot controlled arc additive manufacturing system is used for the additive of workpieces, including a six-axis arc welding robot and a control cabinet, a controlled arc additive gun body, an additive power supply, and a workbench. The workbench is provided with a longitudinal through-type sliding track, and the substrate is connected to the track through a slider to achieve smooth movement of the substrate during the additive process;

[0008] The temperature-controllable deformation system includes an induction heating device, an infrared temperature measuring device and a fixed gantry hydraulic loading deformation device. The induction heating device is used to heat the workpiece to a suitable temperature to ensure that the additive workpiece remains in a hot metal state before deformation; the infrared temperature measuring device is used to obtain the temperature of the additive workpiece in real time; the fixed gantry hydraulic loading deformation device is used to roll and deform the hot metal workpiece.

[0009] As a further configuration of the above scheme, the robot-controlled arc additive manufacturing system includes a workbench, on which a longitudinal through-type sliding track is provided, and a substrate is connected to the track through a slider to achieve smooth movement of the substrate during the additive process, and the substrate is used for metal deposition;

[0010] It also includes a controlled arc additive robot arm and a controlled arc additive gun body, wherein the controlled arc additive robot arm and the controlled arc additive gun body are fixed and used for performing metal deposition processing of a workpiece on a substrate;

[0011] It also includes an additive power supply, a wire feeder, a protective gas device, and a control system for controlling the additive motion trajectory of a controlled arc additive robot arm.

[0012] As a further configuration of the above scheme, the induction heating device includes a high-frequency induction heating device and an induction heating power supply; the high-frequency induction heating device is used for local heat treatment of the additive workpiece, the heating speed of the device is adjusted in the range of 0°C / s to 400°C / s, the power adjustment range is 0 to 100kW, and the output power can make the additive workpiece within a depth of 8mm from the surface reach 800 degrees Celsius in 3 to 5 seconds; the maximum heating temperature of the high-frequency induction heating device can reach 1000°C; the induction heating power supply is used to provide power to the heating device;

[0013] As a further configuration of the above scheme, the infrared temperature measuring device is an infrared thermal imager, the infrared thermal imager probe is facing the substrate, and the temperature measuring range is 0°C to 1500°C;

[0014] As a further configuration of the above scheme, the fixed gantry hydraulic loading deformation device includes a workbench, a movable crossbeam, an ejector cylinder, an upper crossbeam, a master cylinder, a hydraulic transmission system, an electronic control system, and a roller; the fixed gantry hydraulic loading deformation device utilizes the pressure of the hydraulic oil to transport the hydraulic oil to the master cylinder via a hydraulic pump. When the hydraulic oil enters the master cylinder, the piston squeezes the hydraulic oil in the master cylinder into the ejector cylinder to generate pressure, and the hydraulic oil in the ejector cylinder is also squeezed out by the piston to form a hydraulic compensation system, so that the hydraulic oil always maintains a certain pressure, thereby generating liquid pressure, and then pushing the piston of the master cylinder up and down to realize the operation of the hydraulic press. ; The hydraulic loading device can apply a maximum pressure of 200 tons, which can achieve large deformation of metal workpieces; the movement stroke of the main cylinder is controlled by the travel switch, the pressure of the main cylinder and the ejection cylinder is adjusted by the pressure regulating valve, and the movable crossbeam moves up and down to apply pressure to the roller; the roller pressure is adjusted, the roller pressure is amplified by the amplifier, and the output is applied to the servo valve to drive the hydraulic system to work, so that the roller pressure reaches the preset value; the position sensor in the main cylinder can capture the position of the roller in real time, thereby generating a feedback value. If the feedback value is the same as the preset value, it indicates that the roller has completed the preset pressure and the hydraulic system stops working;

[0015] A method for composite forming using the above-mentioned controlled arc material addition and controllable deformation comprises the following steps:

[0016] Step (1): planning the additive path;

[0017] Step (2): pre-treating the surface of the substrate, connecting the substrate to the sliding track on the workbench through a slider, fixing the infrared thermal imager and adjusting its angle so that its probe faces the substrate, so as to measure the temperature of the additive process in real time;

[0018] Step (3): starting arcing from the left end of the substrate, i.e., the side away from the fixed gantry hydraulic loading deformation device, to perform single-layer addition;

[0019] Step (4): After the material addition is completed, the substrate moves to the right side. When the substrate moves to the bottom of the hydraulic loading deformation device, the induction heating device heats the material addition workpiece to a suitable temperature.

[0020] Step (5): The infrared temperature measuring device obtains the temperature of the additive workpiece. When the temperature of the workpiece reaches a preset temperature, the roller is pressed down to complete the rolling deformation of the workpiece;

[0021] Step (6): the substrate returns to the initial position, and when the workpiece cools to a preset temperature, the next layer of material is added;

[0022] Step (7): Repeat steps (3)-(6) until the integrated additively molded part is completed.

[0023] Compared with the prior art, the advantages of the present invention are as follows: a controlled arc additive and controllable deformation composite forming method and device proposed by the present invention has reasonable structural design and simple operation, and different pressures can be set according to different deformation amounts to make the workpiece deform to different degrees, and the hydraulic loading device can apply a maximum pressure of 200 tons, which can be used to achieve large deformation of metal workpieces; the fixed gantry hydraulic loading deformation device and the robot controlled arc additive manufacturing platform are combined into an additive and deformation composite forming system, and an induction heating device is provided at the same time, so that the additive workpiece maintains a hot metal state before deformation, and an infrared thermal imager measures the additive workpiece in real time to ensure that the workpiece reaches a preset temperature before being pressed down by a roller, and realizes online hot rolling, so as to solve the problems that the high heat input and large molten pool volume in the current arc additive manufacturing process of metal workpieces easily lead to coarse organization, poor weld forming stability, low workpiece forming accuracy, and large deformation of the workpiece or even cracking due to the residual stress inside the additive workpiece, timely crushing of grains, compaction of pore defects, improvement of the internal microstructure and forming quality of the workpiece, and the purpose of improving the comprehensive performance of the metal additive workpiece are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the method flow of the present invention.

[0025] Figure 2 Schematic diagram of the robot-controlled arc additive manufacturing system of the present invention.

[0026] Figure 3 It is a schematic diagram of the induction heating device of the present invention.

[0027] Figure 4 It is a schematic diagram of the three-dimensional structure of the integrated forming device.

[0028] Figure 5 It is a three-dimensional schematic diagram of the fixed gantry hydraulic loading deformation device.

[0029] Figure 6 Three views of the fixed gantry hydraulic loading deformation device.

[0030] Figure 7 (a) is the OM image of a conventional additive part; (b) is the metallographic image of a sample with a deformation of 20%; (c) is the metallographic image of a sample with a deformation of 30%; (d) is the metallographic image of a sample with a deformation of 40%.

[0031] Description of the attached drawings

[0032] 1-control cabinet, 2-additive power supply, 3-wire feeder, 4-shielding gas device, 5-workbench, 51-sliding track, 6-substrate, 7-metal deposition layer, 8-additive gun body, 9-additive robot arm, 10-induction heating power supply, 11-high frequency induction heating equipment, 12-infrared thermal imager, 13-movable crossbeam, 14-ejection cylinder, 15-upper crossbeam, 16-main cylinder, 17-hydraulic transmission system, 18-electronic control system, 19-hydraulic cylinder, 20-roller. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0034] like Figures 2 to 5 As shown, a controlled arc additive and controllable deformation composite forming device includes a robot controlled arc additive manufacturing system 1-9, an induction heating device 10-11, an infrared temperature measuring device 12 and a fixed gantry hydraulic loading deformation device 13-20;

[0035] The robot-controlled arc additive manufacturing system includes: a control cabinet 1, an additive power supply 2, a wire feeder 3, a protective gas device 4, and a workbench 5. The workbench is provided with a sliding track 51 for the smooth movement of the substrate 6 during the additive process. Above the substrate 6 is a metal deposition layer 7. The arc additive equipment is turned on, the additive gun body 8 is energized, and the additive robot arm 9 drives the additive gun body 8 to perform additive. After the single-layer additive is completed, the control cabinet 1 issues a command to control the additive robot arm to move upward to a safe position above the metal deposition layer 7.

[0036] As a further configuration of the above scheme, the induction heating device includes an induction heating power supply 10 and a high-frequency induction heating device 11; the handheld high-frequency induction heating device 11 is used for local heat treatment of the metal deposition layer 7 during the additive process, the adjustment range of the heating speed of the high-frequency induction heating device 11 is 0°C / s to 400°C / s, the maximum output power is 100kW, and the output power can make the metal deposition layer 7 within a depth of 8mm from the surface reach 800 degrees Celsius in 3 to 5 seconds; for heating in the additive process, for the connection of metal materials, the maximum heating temperature of the high-frequency induction heating device 11 can reach 1000°C; the induction heating power supply 10 is used to provide power to the high-frequency induction heating device 11; the high-frequency induction heating device 11 can evenly heat various metal parts;

[0037] As a further configuration of the above scheme, the infrared temperature measuring device is an infrared thermal imager 12, the probe of the infrared thermal imager 12 is facing the substrate, and its temperature measurement range is 0°C to 1500°C; the infrared thermal imager 12 is fixed on one side of the workbench 5, and the probe is facing the substrate 6, which is used to measure the temperature of the additive process in real time.

[0038] As a further setting of the above scheme, Figure 5-6The fixed gantry hydraulic loading deformation device includes a workbench 5, a movable crossbeam 13, an ejection cylinder 14, an upper crossbeam 15, a master cylinder 16, a hydraulic transmission system 17, an electronic control system 18, and a roller 20; the fixed gantry hydraulic loading deformation device utilizes the pressure of the hydraulic oil to deliver the hydraulic oil to the master cylinder 16 through the hydraulic pump. When the hydraulic oil enters the master cylinder 16, the piston squeezes the hydraulic oil in the master cylinder 16 into the ejection cylinder 14 to generate pressure. The hydraulic oil in the ejection cylinder 14 is also squeezed out by the piston to form a hydraulic compensation system, so that the hydraulic oil always maintains a certain pressure, thereby generating a hydraulic pressure, and then pushing the piston of the master cylinder 16 to move up and down, realizing the hydraulic press The hydraulic loading device can apply a maximum pressure of 200 tons, which can achieve large deformation of metal workpieces. The movement stroke of the main cylinder 16 is controlled by the travel switch. The pressure of the main cylinder 16 and the ejection cylinder 14 is adjusted by the pressure regulating valve. The movable crossbeam moves up and down to apply pressure to the roller 20. The roller pressing amount is adjusted, and the roller pressing amount is amplified by the amplifier, and the output is applied to the servo valve to drive the hydraulic system to work, so that the roller pressing amount reaches the preset value. The position sensor in the main cylinder 16 can capture the position of the roller in real time, thereby generating a feedback value. If the feedback value is the same as the preset value, it indicates that the roller has completed the preset pressing amount and the hydraulic system stops working.

[0039] A method for composite forming using the above-mentioned additive and controllable deformation comprises the following steps:

[0040] Step (1): partition, layer and slice the geometric model of the additive workpiece, import it into the robot offline programming software, and generate the corresponding additive path and program;

[0041] Step (2): After pre-treating the surface of the substrate 6, the substrate 6 is connected to the sliding track 51 on the workbench 5 through a slider, and the infrared thermal imager 12 is fixed and adjusted in angle so that its probe is facing the substrate 6, so as to measure the temperature of the additive process in real time;

[0042] Step (3): starting arcing from the left end of the substrate 6, i.e., the side away from the fixed gantry hydraulic loading deformation device, to perform single-layer material addition;

[0043] Step (4): after the additive process is completed, the substrate moves to the right, and when the substrate moves to the bottom of the hydraulic loading deformation device, the high-frequency induction heating device 11 heats the additive workpiece;

[0044] Step (5): The infrared thermal imager 12 obtains the temperature of the additive workpiece. When the temperature of the workpiece reaches a preset temperature, the roller 20 is pressed down to complete the rolling deformation of the workpiece;

[0045] Step (6): the substrate 6 returns to the initial position, and when the workpiece cools to a preset temperature, the next layer of material is added;

[0046] Step (7): Repeat steps (3)-(6) until the integrated additively molded part is completed.

[0047] In order to further verify the effect, the embodiment specifically includes the following steps:

[0048] Step (1): Using CMT arc additive manufacturing technology, select HNS6T high nitrogen steel wire with a diameter of 1.2 mm, and select a 316L stainless steel substrate with a size of 400 mm*400 mm*10 mm. The geometric model of the additive block workpiece is partitioned, layered and sliced, and imported into the robot offline programming software to generate the corresponding additive path and program.

[0049] Step (2): Grind the surface of the substrate, remove the oxide film, and then clean the surface of the substrate with acetone reagent. Connect the substrate to the sliding track on the workbench through a slider so that the substrate can move smoothly during the additive process. Fix the infrared thermal imager at a distance of 1.5 m from the substrate, with the probe facing the substrate position, to measure the temperature of the additive process in real time.

[0050] Step (3): Adjust the roller pressure to 1 mm, according to the formula F = σ y *A shows that to make high nitrogen steel undergo plastic deformation, the pressure should be set to 29KN.

[0051] Step (4): Turn on the CMT arc additive equipment, power on the additive gun, call the program, and set the following process parameters: the protective gas is a ternary mixture of 93.5% Ar + 5% N2 + 1.5% O2, the gas flow rate is set to 20L / min, the wire feeding speed is 9m / min, the arc travel speed is 7mm / s, and the control system uses the additive robot arm to drive the additive gun according to the set additive path, starting the arc from the left end of the substrate (i.e., away from the side of the fixed gantry hydraulic loading deformation device) to perform single-layer additive.

[0052] Step (5): After the material addition is completed, the substrate moves to the right. When the substrate moves to the bottom of the hydraulic loading deformation device, the high-frequency induction heating device heats the material addition workpiece to 1000°C.

[0053] Step (6): The temperature of the additive workpiece is obtained by an infrared thermal imager. When the temperature of the workpiece reaches 1000° C., the roller is pressed down to complete the rolling deformation of the additive workpiece.

[0054] Step (7): the substrate returns to the initial position, and when the workpiece cools to a preset temperature, the next layer of material is added;

[0055] Step (8): Repeat steps (3)-(7) until a high nitrogen steel integrated arc additively formed block is obtained.

[0056] Experimental results: The surfaces of high nitrogen steel blocks with deformations of 20%, 30% and 40% prepared by a controlled arc additive and controlled deformation composite forming method and device are smooth and flat, with good forming quality, and defects such as pores are effectively bridged. Compared with the conventional controlled arc additive forming process, the grains of the workpieces prepared by the controlled arc additive and controlled deformation composite forming method and device are refined as a whole, such as Figure 7 , the performance has been improved. For workpieces with different deformation amounts under the same conditions, as the deformation amount increases, the degree of grain refinement deepens and the performance improvement becomes more obvious.

Claims

1. A controlled arc additive and controllable deformation composite forming device, characterized in that: Including robot-controlled arc additive manufacturing system and temperature-controlled deformation system; The robot controlled arc additive manufacturing system is used for the additive of workpieces, including a six-axis arc welding robot and a control cabinet, a controlled arc additive gun body, an additive power supply, and a workbench. The workbench is provided with a longitudinal through-type sliding track, and the substrate is connected to the track through a slider to achieve smooth movement of the substrate during the additive process; The temperature-controlled deformation system includes an induction heating device, an infrared temperature measuring device and a fixed gantry hydraulic loading deformation device. The induction heating device is used to heat the workpiece to a suitable temperature to ensure that the additive workpiece remains in a hot metal state before deformation; the infrared temperature measuring device is used to obtain the temperature of the additive workpiece in real time; The fixed gantry hydraulic loading deformation device is used to roll and deform a hot metal workpiece, and the degree of deformation of the workpiece is changed by controlling the loading pressure.

2. The controlled arc material addition and controllable deformation composite forming device according to claim 1, characterized in that: The upper surface of the substrate is a metal deposition layer; It also includes a controlled arc additive robot arm and a controlled arc additive gun body, wherein the controlled arc additive robot arm and the controlled arc additive gun body are fixed and used for performing metal deposition processing of a workpiece on a substrate; It also includes an additive power supply, a wire feeder, a protective gas device, and a control system for controlling the additive motion trajectory of a controlled arc additive robot arm.

3. The controlled arc material addition and controllable deformation composite forming device according to claim 2, characterized in that: The induction heating device includes a high-frequency induction heating device and an induction heating power supply; The high-frequency induction heating device is used for local heat treatment of the additive workpiece.

4. The controlled arc material addition and controllable deformation composite forming device according to claim 3, characterized in that: The device has a heating speed adjustment range of 0℃ / s to 400℃ / s, a power adjustment range of 0 to 100kW, and an output power capable of enabling the additive workpiece within a depth of 8mm from the surface to reach 800 degrees Celsius in 3 to 5 seconds.

5. The controlled arc material addition and controllable deformation composite forming device according to claim 3, characterized in that: The maximum heating temperature of the high-frequency induction heating device is 1000°C.

6. The controlled arc material addition and controllable deformation composite forming device according to claim 3, characterized in that: The induction heating power supply is used to provide power to the heating device.

7. The controlled arc material addition and controllable deformation composite forming device according to claim 3, characterized in that: The infrared temperature measuring device is an infrared thermal imager, the probe of the infrared thermal imager is facing the substrate, and the temperature measuring range is 0°C to 1500°C.

8. The controlled arc material addition and controllable deformation composite forming device according to claim 1, characterized in that: The fixed gantry hydraulic loading deformation device includes a workbench, a movable crossbeam, an ejector cylinder, an upper crossbeam, a master cylinder, a hydraulic transmission system, an electronic control system, and a roller; the fixed gantry hydraulic loading deformation device utilizes the pressure of the hydraulic oil to transport the hydraulic oil to the master cylinder through a hydraulic pump. When the hydraulic oil enters the master cylinder, the piston squeezes the hydraulic oil in the master cylinder into the ejector cylinder to generate pressure, and the hydraulic oil in the ejector cylinder is also squeezed out by the piston to form a hydraulic compensation system, so that the hydraulic oil always maintains a certain pressure, thereby generating a hydraulic pressure, and then pushing the piston of the master cylinder to move up and down to realize the operation of the hydraulic press; The hydraulic loading device can apply a maximum pressure of 200 tons, which can achieve large deformation of metal workpieces; The moving stroke of the master cylinder is controlled by the stroke switch, the pressure of the master cylinder and the ejector cylinder is adjusted by the pressure regulating valve, and the movable crossbeam moves up and down to apply pressure to the roller; The roller pressure is adjusted, the roller pressure is amplified by the amplifier, and the output is applied to the servo valve to drive the hydraulic system to work, so that the roller pressure reaches the preset value; The position sensor in the master cylinder can capture the position of the roller in real time, thereby generating a feedback value. If the feedback value is the same as the preset value, it indicates that the roller has completed the preset downward pressure and the hydraulic system stops working.

9. A method for material addition based on the arc material addition system according to any one of claims 1 to 8, characterized in that: The steps include: Step (1): planning the additive path; Step (2): pre-treating the surface of the substrate, connecting the substrate to the sliding track on the workbench through a slider, fixing the infrared thermal imager and adjusting its angle so that its probe faces the substrate, so as to measure the temperature of the additive process in real time; Step (3): starting arcing from the left end of the substrate, i.e., the side away from the fixed gantry hydraulic loading deformation device, to perform single-layer addition; Step (4): After the material addition is completed, the substrate moves to the right side. When the substrate moves to the bottom of the hydraulic loading deformation device, the induction heating device heats the material addition workpiece to a suitable temperature. Step (5): The infrared temperature measuring device obtains the temperature of the additive workpiece. When the temperature of the workpiece reaches a preset temperature, the roller is pressed down to complete the rolling deformation of the workpiece; Step (6): the substrate returns to the initial position, and when the workpiece cools to a preset temperature, the next layer of material is added; Step (7): Repeat steps (3)-(6) until the integrated additively molded part is completed.

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