A device for measuring droplet temperature in wire arc additive manufacturing based on magnetic field deflection of arc afterflame

Abstract

The application discloses a kind of based on magnetic field deflection arc tail flame's droplet temperature measurement device in wire arc additive manufacturing, it is related to electric arc additive manufacturing technical field.Wire feeding mechanism feeds welding wire, forms droplet under the action of arc;Electromagnet applies additional magnetic field, to produce arc tail flame deflection angle makes arc and metal droplet falling into calorimeter separate;Metal droplet drops into calorimeter, calorimeter monitors the temperature change of copper cylinder, calculates the temperature of droplet reaching calorimeter surface, utilizes infrared thermal imager to detect the temperature loss of droplet, and this part of temperature loss is compensated to the droplet temperature measured by solid copper calorimeter, obtains the relatively accurate temperature value of droplet itself.The application separates arc tail flame and droplet trajectory, to avoid arc tail flame heating solid calorimeter and interfering with the measurement of droplet temperature, to improve the precision of droplet temperature measurement, which has important theoretical significance and value to the temperature measurement and forming mechanism research of additive manufacturing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric arc additive manufacturing, and more particularly to a droplet temperature measuring device for wire arc additive manufacturing based on magnetic field deflection of arc afterflame. BACKGROUND

[0002] Additive manufacturing technology is also known as "3D printing" or "rapid prototyping", which is a method of manufacturing solid parts based on discrete and accumulation principles by layering materials according to the three-dimensional model of the parts. Aluminum alloy additive manufacturing has been widely used in the fields of aerospace and mechanical manufacturing. Due to the high melting and deposition efficiency, simple equipment and low cost of electric arc additive manufacturing technology, it has attracted attention from domestic and foreign researchers. In the additive manufacturing process, the state and transition process of the droplet directly determine the forming quality of the additive manufacturing process. Therefore, the measurement of the droplet temperature and the in-situ control of the droplet forming have important significance.

[0003] The non-melting electrode arc, especially the plasma, has the characteristics of good stability and high stiffness, which can ensure the stability of the droplet landing position and has great potential to improve the size accuracy of the deposited layer. However, the arc afterflame also interferes with the measurement of the droplet temperature. Secondly, the droplet will lose temperature during the falling process, which cannot reflect the true temperature of the droplet reaching the workpiece surface. Therefore, based on the measurement of the droplet temperature by solid copper calorimeter, a method of separating the arc afterflame and the droplet trajectory by external magnetic field is proposed to avoid the interference of the arc afterflame with the measurement of the droplet temperature. In addition, due to the advantages of fast response and high temperature field resolution of the infrared thermal imager, the infrared thermal imager is used to detect the temperature loss of the droplet falling a certain height, and this part of the temperature loss is compensated to the droplet temperature measured by the solid calorimeter. The comprehensive temperature value of the droplet is obtained, which has important theoretical significance and value for the temperature measurement and forming mechanism research of additive manufacturing. SUMMARY

[0004] In order to solve the above technical problems, the application provides a droplet temperature measuring device for wire arc additive manufacturing based on magnetic field deflection of arc afterflame. The device generates an arc afterflame deflection angle by applying an external magnetic field, separates the arc afterflame and the droplet trajectory, measures the droplet temperature by solid copper calorimeter, and uses infrared thermal imager to monitor and record the temperature of the droplet falling process in real time, analyzes the temperature loss of the droplet falling a certain height, and compensates the droplet temperature measured by the solid calorimeter.

[0005] To solve the above technical problems, the technical solution adopted by the application is:

[0006] A kind of measuring device of droplet temperature in wire arc additive manufacturing based on magnetic field deflection arc tail flame, including droplet acquisition device, external magnetic field device, droplet temperature measurement system;

[0007] The droplet acquisition device includes arc welding power supply, welding torch, wire feeder, anode water-cooled copper block, shielding gas cylinder;The wire feeder is connected with the welding torch by wire feeder connecting plate, so that the welding torch and the wire feeder move synchronously, the welding torch is also connected with the cylinder, and the wire feeder is also connected with the arc welding power supply;The anode water-cooled copper block is located below the welding torch;

[0008] The external magnetic field device includes electromagnet and arc tail flame baffle with small hole;The electromagnet is arranged below the anode water-cooled copper block, and the arc tail flame baffle with small hole is arranged below the electromagnet;

[0009] The droplet temperature measurement system includes solid copper calorimeter, infrared thermal imager, data acquisition card and PC end, wherein the solid copper calorimeter is composed of copper cylinder, several thermocouples and peripheral quartz cotton heat insulation layer, protective shell, quartz cotton cover;The solid copper calorimeter is electrically connected with the data acquisition card, the data acquisition card is electrically connected with the PC end, and the infrared thermal imager focuses on the droplet between the solid copper calorimeter and the anode water-cooled copper block;The copper cylinder and the peripheral quartz cotton heat insulation layer are arranged in the protective shell, the quartz cotton cover is arranged on the protective shell, and the several thermocouples are arranged on the copper cylinder.

[0010] Preferably, in the plasma additive process, the measurement steps of the measurement device are as follows:

[0011] Step one: adjust the three-dimensional motion mechanism to keep the center of the anode water-cooled copper block and the welding torch on the same axis, and place the anode water-cooled copper block and the solid copper calorimeter 8 to 10 millimeters below the nozzle, and place the arc tail flame baffle with small hole between the anode water-cooled copper block and the solid copper calorimeter directly below the welding torch;

[0012] Step two: after igniting the arc, move the three-dimensional work slide to place the end of the welding wire below the nozzle, and move the copper plate to the position about 5 millimeters away from the tungsten electrode shaft on the copper plate side wall, so that the arc is suspended, and the droplet can normally drop downward;

[0013] Step three: start the heating device and then start the additive melting wire device, i.e., first start the liquid cooling water tank and the shielding gas, adjust the argon by opening the cylinder knob, start the welding torch, preheat the substrate, then start the wire feeder, get the molten metal droplet, and use the arc tail flame baffle with small hole to block the falling droplet;Observe the droplet acquisition device from the side direction, and the droplet will drop from the front side of one side of the anode water-cooled copper block;

[0014] Step four: according to the requirement, an electromagnet is placed below the anode water-cooled copper block to apply an external magnetic field parallel to the arc tail flame baffle with small holes, to produce deflection of the arc tail flame, so that the trajectory of the molten droplet in parabolic motion is separated from the arc tail flame, to avoid the arc tail flame heating the solid copper calorimeter and interfering with the measurement of the temperature of the molten droplet;

[0015] Step five: after the arc tail flame deviates by a certain distance and the molten droplet transition is stable, the position of the arc tail flame baffle with small holes is adjusted, so that the molten droplet passes through the small hole on the arc tail flame baffle with small holes and continues to fall, and a part of the baffle blocks the arc tail flame, so that the metal molten droplet drips into the solid copper calorimeter through the small hole on the arc tail flame baffle with small holes, the dropped molten droplet is collected, and the temperature change caused by the copper cylinder is monitored by using the thermocouple in the solid calorimeter, and the temperature curve of the molten droplet is recorded in real time;

[0016] Step six: after collecting the molten droplet for a period of time, stop feeding the wire and extinguish the arc, and after sufficient heat absorption, cover the solid copper calorimeter with an insulating quartz wool heat insulation pad to ensure that its temperature is constant and not easily lost;

[0017] Step seven: after the temperature curve is stable and the solid copper calorimeter completely absorbs the heat of the molten droplet, the infrared thermal camera is focused on the molten droplet between the anode water-cooled copper block and the solid copper calorimeter, the temperature loss of the molten droplet during falling a certain height is observed and recorded by using the infrared thermal camera, the temperature loss ΔT of the molten droplet during falling is analyzed and obtained, and the temperature loss ΔT is weighted and compensated to the temperature T of the molten droplet measured by the solid calorimeter, to obtain a more accurate temperature value of the molten droplet itself;

[0018] Step eight: repeat the above steps three or more times to make an error bar and enhance the reliability of the data.

[0019] Preferably, four to eight thermocouples are arranged in the solid copper calorimeter from top to bottom at different heights of the copper cylinder, and the temperature result data collected by the anode water-cooled copper block is averaged to avoid the adverse effects of the hysteresis of heat conduction on the temperature measurement results, to improve the temperature measurement accuracy.

[0020] Preferably, an electromagnet is used to apply an external magnetic field parallel to the aluminum alloy baffle, and the size of the external magnetic field is 270 to 290 millitesla, to produce an arc tail flame deflection angle, so that the arc is separated from the metal molten droplet falling into the solid copper calorimeter, to achieve the purpose of deviating the arc tail flame and the molten droplet trajectory, to avoid the arc tail flame heating the solid calorimeter and interfering with the measurement of the temperature of the molten droplet, to improve the accuracy of the measurement of the temperature of the molten droplet.

[0021] Preferably, the arc tail flame baffle with small holes is provided with a round hole, so that the molten droplets can pass through the round hole of the arc tail flame baffle with small holes evenly, and drop into the solid copper calorimeter; and a part of the arc tail flame baffle with small holes can shield the arc tail flame, so as to eliminate the interference of the arc tail flame on the temperature of the molten droplets.

[0022] Preferably, the welding wire used is an aluminum or copper non-ferrous metal wire.

[0023] The technical scheme has the beneficial effects that:

[0024] (1) Compared with the prior art, the discharge magnet of the present application applies an external magnetic field, uses the electromagnetic magnet to apply an external magnetic field, thereby generating an arc tail flame deflection angle, separating the arc from the metal molten droplets falling into the solid copper calorimeter, achieving the purpose of deviating the arc tail flame and the molten droplet trajectory, avoiding the interference of the arc tail flame heating the solid calorimeter with the measurement of the molten droplet temperature, and improving the accuracy of the molten droplet temperature measurement.

[0025] (2) The present application uses a solid copper calorimeter, which can better overcome the errors caused by temperature loss in the measurement of the molten droplet temperature, and the average value of the temperature data collected by the copper block can avoid the adverse effects of the hysteresis of heat conduction on the temperature measurement results, thereby improving the temperature measurement accuracy.

[0026] (3) The present application uses an infrared thermal imager to measure the temperature of the molten droplets, which can observe and record the temperature of the molten droplets in real time during the falling process, analyze the temperature loss during the falling process, and analyze and compensate the temperature of the molten droplets measured by the solid calorimeter, so as to obtain the more accurate temperature of the molten droplets. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a front view structural schematic diagram of the measuring device, which uses a side shaft wire feeder;

[0028] Figure 2 is a left view structural schematic diagram of the molten droplet acquisition device;

[0029] Figure 3 is a structural schematic diagram of the solid copper calorimeter;

[0030] Figure 4 is a temperature curve diagram measured by the thermocouple in the solid calorimeter;

[0031] In the diagram: 1. Arc welding power source; 2. Welding torch; 3. Wire feeder; 4. Anode water-cooled copper block; 5. Electromagnet; 6. PC terminal; 7. Protective gas cylinder; 8. Infrared thermal imager; 9. Solid copper calorimeter; 91. Copper cylinder; 911. First thermocouple; 912. Second thermocouple; 913. Third thermocouple; 914. Fourth thermocouple; 915. Fifth thermocouple; 916. Sixth thermocouple; 92. Outer quartz wool insulation layer; 93. Protective shell; 94. Quartz wool cover; 10. Arc tail flame baffle with small holes; 11. Data acquisition card. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0033] The basic idea of ​​this invention is to improve the accuracy of droplet temperature measurement by separating the arc tail flame and the molten droplet trajectory using an external magnetic field, thus avoiding interference from the arc tail flame heating the solid-state calorimeter. A solid-state copper calorimeter 9 is used to measure the droplet temperature. Four to eight thermocouples are arranged sequentially from top to bottom at different heights on a copper cylinder 91 within the solid-state copper calorimeter 9. The average value of the collected temperature results is taken to avoid the adverse effects of heat conduction lag on the temperature measurement results. An infrared thermal imager 8 is used to detect the temperature loss of the droplet after falling a certain height, and this temperature loss is compensated for in the droplet temperature measured by the solid-state calorimeter, resulting in a more accurate temperature value of the droplet itself.

[0034] like Figure 1 As shown, the droplet acquisition device includes: an arc welding power source 1, a welding torch 2, a wire feeding device 3, an anode water-cooled copper block 4, and a shielding gas cylinder 7; the wire feeding device 3 is connected to the welding torch 2 through a wire feeding device connecting plate, so that the welding torch 2 and the wire feeding device 3 move synchronously. The welding torch 2 is also connected to the gas cylinder 7, and the wire feeding device 3 is also connected to the arc welding power source 1. The anode water-cooled copper block 4 is located below the welding torch 2.

[0035] The external magnetic field device includes: an electromagnet 5 and an arc tail flame baffle 10 with small holes; the electromagnet 5 is located below the anode water-cooled copper block 4, and the arc tail flame baffle 10 with small holes is located below the electromagnet 5.

[0036] The droplet temperature measurement system includes: a solid copper calorimeter 9, an infrared thermal imager 8, a data acquisition card 11, and a PC terminal 6, such as... Figure 3As shown, the solid copper calorimeter 9 consists of a copper cylinder 91, several thermocouples, an outer quartz wool insulation layer 92, a protective shell 93, and a quartz wool cover 94. The solid copper calorimeter 9 is electrically connected to a data acquisition card 11, which is electrically connected to a PC terminal 6. An infrared thermal imager 8 focuses on the molten droplet between the solid copper calorimeter 9 and the anode water-cooled copper block 4. The copper cylinder 91 and the outer quartz wool insulation layer 92 are located inside the protective shell 93, and the quartz wool cover 94 covers the protective shell 93. Several thermocouples are located on the copper cylinder 91.

[0037] In the plasma additive manufacturing process, the wire feeding device 3 is connected to the welding torch 2 via a wire feeding device connecting plate, so that the welding torch 2 and the wire feeding device 3 move synchronously. The welding torch 2 is also connected to the gas cylinder 7 to adjust the argon gas output flow rate. In this device, the nozzle is 8 mm away from the anode water-cooled copper block 4, the end of the welding wire is 3 mm below the nozzle, and the axis of the anode water-cooled copper block 4 is offset from the axis of the welding torch 2 by 5 mm. By adjusting the three-dimensional motion mechanism, the anode water-cooled copper block and the axis of the welding torch are made to have a suitable relative position. By adding an external electromagnet 5, a directional magnetic field is generated below the anode water-cooled copper block 4 to change the direction of the arc tail flame, so that the molten droplet falls in a similar projectile-like trajectory and separates from the arc tail flame trajectory. After the arc tail flame deviates by a certain distance and the molten droplet transition stabilizes, the position of the arc tail flame baffle 10 with small holes is adjusted so that the molten droplet continues to fall through the small holes on the arc tail flame baffle 10 and part of the baffle blocks the arc tail flame. The molten droplet acquisition device (such as the side view) is observed from the side. Figure 2 As shown, the molten droplet will fall from one side of the water-cooled copper block. A solid copper calorimeter 9 is used to collect the molten droplet passing through the small hole. A thermocouple measures the temperature change caused by the molten droplet on the copper cylinder 91. Combined with the temperature change of the copper cylinder 91, the temperature of the molten droplet upon reaching the surface of the solid copper calorimeter 9 can be calculated. An infrared thermal camera 8 focuses on the molten droplet between the anode water-cooled copper block 4 and the solid copper calorimeter 9 to monitor the temperature loss due to the droplet's fall height and compensate for the temperature of the molten droplet measured by the solid copper calorimeter 9.

[0038] like Figure 3 The solid copper calorimeter 9 shown consists of a copper cylinder 91 wrapped with quartz wool insulation material, a first thermocouple 911 to a sixth thermocouple 916, an outer quartz wool insulation layer 92, a protective shell 93, and a quartz wool cover 94. The copper cylinder 91 absorbs the heat from the molten droplet; the quartz wool surrounding the copper cylinder 91 and the top quartz wool cover 94 provide insulation to minimize droplet temperature loss. Six thermocouples are arranged sequentially from top to bottom at different heights on the copper cylinder 91, and the average value of the temperature data collected from the anode water-cooled copper block 4 is taken. The copper cylinder 9 has a diameter of 50 mm and a height of 50 mm. The solid copper calorimeter 9 is located 150 mm below the nozzle, and the nozzle is 110 mm away from the perforated arc tail baffle 10. Real-time temperature measurement is performed using the solid copper calorimeter 9, and the temperature curve measured by the thermocouples in the solid copper calorimeter 9 is shown below.Figure 4 As shown.

[0039] During the droplet descent process, an external magnetic field is applied by electromagnet 5 to change the deflection angle of the arc tail flame, thereby causing the arc tail flame and the trajectory of the molten metal droplet to deviate. This is to prevent the arc tail flame from heating the solid copper calorimeter 9 and interfering with the measurement of the droplet temperature, thus improving the accuracy of the droplet temperature measurement.

[0040] Solid copper, with its excellent thermal conductivity, low thermal inertia, and rapid temperature response, is well-suited for temperature measurement. A solid copper calorimeter 9 is used to measure the temperature of the molten droplet. The molten droplet temperature measurement system consists of the solid copper calorimeter 9 and an infrared thermal camera 8. The solid copper calorimeter 9 comprises a copper cylinder 91 wrapped in insulating quartz wool and six thermocouples. It averages the temperature data collected from the anode water-cooled copper block 4 to avoid the adverse effects of heat conduction lag on the measurement results, thereby improving accuracy. The infrared thermal camera 8 is used to analyze the measurement error of the solid copper calorimeter 9. It detects the temperature loss from the molten droplet falling a certain height and compensates for this temperature loss to the molten droplet temperature measured by the solid calorimeter, thus obtaining a more accurate temperature value for the droplet itself.

[0041] Example 1:

[0042] Taking the measurement of the deposition droplet temperature using an improved plasma arc additive manufacturing device as an example, Figure 1 As shown in the figure, connect the required equipment. The power supply used in the additive manufacturing process is a plasma arc welding power supply. By adjusting the three-dimensional motion mechanism, the anode water-cooled copper block 4 and the center of the welding torch 2 are kept on the same axis, and the welding wire and the welding torch can maintain a synchronous relationship of relative movement.

[0043] Specifically, the following steps are included:

[0044] Step 1: Adjust the three-dimensional motion mechanism to keep the anode water-cooled copper block 4 and the center of the welding torch 2 on the same axis, and place the anode water-cooled copper block 4 and the solid copper calorimeter 9 8 to 10 mm below the nozzle. Place the arc tail flame baffle 10 with small holes directly below the welding torch 2 between the anode water-cooled copper block 4 and the solid copper calorimeter.

[0045] Step 2: After igniting the electric arc, move the three-dimensional working slide to place the end of the welding wire below the nozzle. Move the copper plate to a position about 5 mm away from the tungsten electrode axis on the side wall of the copper plate, so that the electric arc is suspended in the air and the molten droplets can drip down normally.

[0046] Step three: After starting the heating device, start the additive wire melting device, put the aluminum alloy wire into the wire feeder, turn on the power of the wire feeder and set the wire feeding speed to 3 m / min, the distance between the wire head and the anode water-cooled copper block 4 is 5 mm, the angle is 20°, adjust the argon gas flow to 20 L / min, turn off the argon gas after 5 minutes, then turn on the welding machine and select alternating current to start the arc; start the wire feeder and power supply, run according to the pre-edited program, start additive manufacturing, get molten metal droplets, and use the arc afterflame baffle 10 with small holes to block the falling droplets. From the side direction of the droplet acquisition device, the droplets will fall from the front side of the anode water-cooled copper block 4.

[0047] Step four: according to the requirements, place an electromagnet 5 under the anode water-cooled copper block 4 to apply an external magnetic field with a size of 280 millitesla, which is parallel to the aluminum alloy baffle, so as to produce an arc afterflame deflection angle, separate the droplet trajectory from the arc afterflame, and avoid the arc afterflame heating the solid calorimeter to interfere with the measurement of the droplet temperature.

[0048] Step five: after the arc afterflame deviates a certain distance and the droplet transition is stable, adjust the position of the arc afterflame baffle 10 with small holes, so that the droplets continue to fall through the small holes on the arc afterflame baffle 10 with small holes and a part of the baffle blocks the arc afterflame, so that the metal droplets drop into the solid copper calorimeter 9 through the small holes on the arc afterflame baffle 10 with small holes, collect the falling droplets and use the thermocouple in the solid copper calorimeter 9 to monitor the temperature change caused by the copper cylinder 91, and record the droplet temperature curve in real time.

[0049] Step six: after collecting the droplets for a period of time, stop the wire feeding and extinguish the arc, and then cover the solid copper calorimeter 9 with an insulating quartz wool heat insulation pad to ensure that its temperature is constant and not easy to dissipate.

[0050] Step seven: after the temperature curve is stable and the solid copper calorimeter completely absorbs the heat of the droplets, cooperate with the temperature curve fitting method, focus the infrared thermal camera 8 on the droplets between the anode water-cooled copper block 4 and the solid copper calorimeter 9, use the infrared thermal camera 8 to observe and record the temperature loss of the droplets during the falling process, analyze the temperature loss during the falling process of the droplets, and add the temperature loss to the measured droplet temperature of the solid copper calorimeter 9, to obtain the more accurate temperature value of the droplets itself.

[0051] Step eight: repeat the above steps several times, three times or more, to make error bars and enhance the reliability of the data.

[0052] The above merely describes preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes within the technical scope disclosed by the present application and according to the technical solutions and inventive concept of the present application, which should be covered within the protection scope of the present application.

Claims

1. A device for measuring the droplet temperature in wire arc additive manufacturing based on magnetic field deflection of the arc tail flame, characterized in that, Includes a droplet acquisition device, an external magnetic field device, and a droplet temperature measurement system; The droplet acquisition device includes: an arc welding power source (1), a welding torch (2), a wire feeding device (3), an anode water-cooled copper block (4), and a shielding gas cylinder (7); the wire feeding device (3) is connected to the welding torch (2) through a wire feeding device connecting plate, so that the welding torch (2) and the wire feeding device (3) move synchronously. The welding torch (2) is also connected to the shielding gas cylinder (7), and the wire feeding device (3) is also connected to the arc welding power source (1). The anode water-cooled copper block (4) is located below the welding torch (2). The external magnetic field device includes: an electromagnet (5) and an arc tail flame baffle (10) with small holes; the electromagnet (5) is located below the anode water-cooled copper block (4), and the arc tail flame baffle (10) with small holes is located below the electromagnet (5). The droplet temperature measurement system includes: a solid copper calorimeter (9), an infrared thermal camera (8), a data acquisition card (11), and a PC terminal (6). The solid copper calorimeter (9) consists of a copper cylinder (91), several thermocouples, an outer quartz wool insulation layer (92), a protective shell (93), and a quartz wool cover (94). The solid copper calorimeter (9) is electrically connected to the data acquisition card (11), and the data acquisition card (11) is electrically connected to the PC terminal (6). The infrared thermal camera (8) focuses on the droplet between the solid copper calorimeter (9) and the anode water-cooled copper block (4). The copper cylinder (91) and the outer quartz wool insulation layer (92) are located inside the protective shell (93), and the quartz wool cover (94) is placed on the protective shell (93). Several thermocouples are located on the copper cylinder (91).

2. The device for measuring the droplet temperature in wire arc additive manufacturing based on magnetic field deflection of the arc tail flame, as described in claim 1, is characterized in that... The measurement steps of this measuring device during plasma additive manufacturing are as follows: Step 1: Adjust the three-dimensional motion mechanism to keep the center of the anode water-cooled copper block (4) and the welding torch (2) on the same axis, and place the anode water-cooled copper block (4) and the solid copper calorimeter (9) 8 to 10 mm below the nozzle. Place an arc tail flame baffle (10) with small holes between the anode water-cooled copper block (4) and the solid copper calorimeter (9) directly below the welding torch (2). Step 2: After igniting the electric arc, move the three-dimensional working slide table and place the end of the welding wire below the nozzle. Move the anode water-cooled copper block (4) to a position 5 mm away from the tungsten electrode axis on the side wall of the anode water-cooled copper block (4), so that the electric arc is suspended and the molten droplets fall downward normally. Step 3: Start the heating device and then start the additive welding wire device. First, start the liquid cooling water tank and protective gas, turn on the gas cylinder knob to adjust the argon gas, start the welding torch (2) to preheat the substrate, and then turn on the wire feeding device (3) to obtain molten metal droplets. Use the arc tail flame baffle (10) with small holes to block the dripping droplets. Observe the droplet acquisition device from the side. The droplets will drip from the front of one side of the anode water-cooled copper block (4). Step 4: According to the requirements, place an electromagnet under the anode water-cooled copper block (4) to apply an external magnetic field parallel to the arc tail flame baffle (10) with small holes to generate the deflection of the arc tail flame, so that the trajectory of the molten droplet that is doing a projectile motion is separated from the arc tail flame, so as to avoid the arc tail flame heating the solid copper calorimeter (9) and interfering with the measurement of the molten droplet temperature. Step 5: After the arc tail flame deviates by a certain distance and the molten droplet transition stabilizes, adjust the position of the arc tail flame baffle (10) with small holes so that the molten droplet passes through the small holes on the arc tail flame baffle (10) and continues to fall, and part of the baffle blocks the arc tail flame, so that the molten metal droplet drips into the solid copper calorimeter (9) through the small holes on the arc tail flame baffle (10). Collect the dripping molten droplets and use the thermocouple in the solid calorimeter to monitor the temperature change caused by the copper cylinder (91) and record the molten droplet temperature curve in real time. Step 6: After collecting the molten droplets for a period of time, stop feeding the wire and extinguish the arc. After sufficient heat absorption, cover the solid copper calorimeter (9) with an insulating quartz wool cover (94) to ensure that its temperature is constant and not easily lost. Step 7: After the temperature curve stabilizes and the solid copper calorimeter (9) has completely absorbed the heat of the molten droplet, the infrared thermal camera (8) is focused on the molten droplet between the anode water-cooled copper block (4) and the solid copper calorimeter (9) using the temperature curve fitting method. The infrared thermal camera (8) is used to observe and record the temperature loss of the molten droplet during its fall to a certain height. The temperature loss ΔT during the molten droplet's fall is analyzed and the temperature loss ΔT is weighted and compensated into the molten droplet temperature T measured by the solid calorimeter to obtain a more accurate temperature value of the molten droplet itself. Step 8: Repeat the above steps three or more times to create error bars and enhance the reliability of the data.

3. The device for measuring the droplet temperature in wire arc additive manufacturing based on magnetic field deflection of the arc tail flame, as described in claim 1, is characterized in that... In the solid copper calorimeter (9), four to eight thermocouples are arranged from top to bottom at different heights of the copper cylinder (91). The average value of the temperature data collected by the anode water-cooled copper block (4) is taken to avoid the adverse effects of the lag in heat conduction on the temperature measurement results and to improve the accuracy of temperature measurement.

4. The device for measuring the droplet temperature in wire arc additive manufacturing based on magnetic field deflection of the arc tail flame, as described in claim 1, is characterized in that... An external magnetic field of 270 to 290 millitalas is applied by an electromagnet (5), with its direction parallel to the arc tail flame baffle (10), thereby generating an arc tail flame deflection angle, causing the arc to separate from the metal droplet falling into the solid copper calorimeter (9), achieving the purpose of deviating the arc tail flame and the droplet trajectory, so as to avoid the arc tail flame heating the solid copper calorimeter and interfering with the measurement of the droplet temperature, thereby improving the accuracy of the droplet temperature measurement.

5. The device for measuring the droplet temperature in wire arc additive manufacturing based on magnetic field deflection of the arc tail flame, as described in claim 1, is characterized in that... The perforated arc tail flame baffle (10) has a round hole, which allows the molten droplet to pass evenly through the round hole on the perforated arc tail flame baffle (10) and drip into the solid copper calorimeter (9); and a part of the perforated arc tail flame baffle (10) blocks the arc tail flame to eliminate the interference of the arc tail flame on the temperature of the molten droplet itself.

6. The device for measuring the droplet temperature in wire arc additive manufacturing based on magnetic field deflection of the arc tail flame, as described in claim 1, is characterized in that... The welding wire used is a non-ferrous metal wire made of aluminum or copper.

Images