Powder laying type TIG electric arc powder melting additive manufacturing method and device

Abstract

The invention discloses a powder laying type TIG electric arc powder melting additive manufacturing method and device. The method creatively combines an arc heat source and a powder raw material for an additive manufacturing process. The device mainly comprises a powder feeding device, a welding gun, a non-contact thermodetector and a strong cold restraining device. And the welding gun is clamped on the walking mechanism through a fixed clamping block. The powder feeding device is connected with the welding gun through a fixing clamping block, and powder feeding starting and stopping and accurate control over the powder feeding amount can be achieved through on-off of an electric drive device in the powder feeding device and adjustment of input electric signals. The non-contact thermodetector is connected with the welding gun through the fixing clamping block, the connecting strip and the mounting support, and real-time monitoring of the temperature of deposited metal is achieved. The strong cold restraining device is fixed and tightly attached to the base plate and used for forming restraining and rapid cooling of the powder layer and the deposited metal. The problem that part of material wires are difficult to prepare is solved, and the adaptability of an electric arc heat source in the field of additive manufacturing is greatly improved; and meanwhile, the density of a powder additive manufacturing part is greatly improved, and the service performance is improved. According to the device, the stable and efficient arc molten powder additive manufacturing process can be achieved, meanwhile, the cooling process of deposited metal is accelerated, heat accumulation is improved, and the structure performance is improved.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and more specifically to a powder-spreading TIG arc powder additive manufacturing method and device. Background Art

[0002] Metal additive manufacturing, also known as 3D printing, is an advanced technology that uses materials to stack layer by layer to manufacture physical parts. Arc additive manufacturing uses arc as a heat source and metal wire as raw material to stack layer by layer. Arc additive manufacturing has the advantages of low cost, high efficiency, and dense deposited parts. It is widely popular in engineering manufacturing fields such as aerospace, automobiles, nuclear power and ships.

[0003] With the continuous improvement of industrial demand, the application of high-strength, high-hardness and complex composition materials has gradually increased, and wire preparation is difficult. In addition, the density of parts obtained by laser powder additive manufacturing is poor, and fatigue performance has become an important factor hindering its promotion and application. In addition, the heat input of the arc additive manufacturing process is very high, and serious heat accumulation will occur during the layer-by-layer stacking process, resulting in coarsening of the microstructure of the parts and deterioration of the mechanical properties. Summary of the invention

[0004] In view of this, the main purpose of the present invention is to solve the problems of difficult control of raw material composition and serious heat accumulation in arc additive manufacturing, and to provide a device and method that can realize stable and efficient arc powder additive manufacturing process.

[0005] The first aspect of the present invention provides a powder spreading TIG arc powder additive manufacturing device, comprising a powder feeding device, a welding gun, a non-contact temperature measuring instrument and a strong cooling restraint device. The welding gun is fixed on a walking mechanism.

[0006] Preferably, the powder feeding device comprises a powder feeding nozzle, a powder feeding pipe and a powder feeding block, and the powder feeding block is connected to the welding gun through a fixed clamp block.

[0007] Preferably, the powder feeding device is characterized in that the powder feeding pipe is connected to the end of the powder flow channel in the powder feeding block through a thread.

[0008] Preferably, the powder feeding device is characterized in that the raw material powder enters the powder feeding block through the powder inlet on the powder feeding block, and under the driving action of the electric drive device inside the powder feeding block and gravity, flows out of the powder feeding block, flows through the powder feeding pipe, flows out of the powder feeding nozzle, and is then spread on the surface of the substrate.

[0009] Preferably, the powder feeding device is characterized in that the start and stop of the powder feeding is controlled by a switch of the electric drive device.

[0010] Preferably, the powder feeding device is characterized in that the thickness of the powder layer is adjusted by changing the electrical signal input parameters of the electric drive device, the angle between the powder feeding block and the powder feeding tube and the direction of gravity, and the travel speed of the powder feeding nozzle.

[0011] Preferably, the powder feeding device is characterized in that the smoothness of the powder flowing in the powder feeding tube and the impact force of the powder falling on the substrate surface are adjusted by the angle between the powder feeding block and the powder feeding tube and the gravity direction.

[0012] Preferably, the non-contact temperature measuring instrument is fixed to the welding gun through a fixing clamp, a connecting bar and a mounting bracket to monitor the temperature of the deposited metal in real time. The temperature measurement position is adjusted through the connecting bar and the mounting bracket.

[0013] Preferably, the interlayer temperature of the metal in the additive manufacturing process is controlled according to the temperature of the deposited metal measured by a non-contact thermometer to avoid heat accumulation causing coarsening of the structure and degradation of mechanical properties.

[0014] The electrode material, electrode diameter, shape of the electrode end or taper angle of the welding gun are adjusted according to actual needs.

[0015] Preferably, the angle between the electrode and the traveling direction of the welding gun is adjusted according to demand to change the distribution characteristics of the arc force and temperature and the effect of the arc on the powder and the deposited metal.

[0016] Preferably, the strong cooling restraint device is tightly fitted to the side of the substrate by clamping, and a cooling channel is provided inside the strong cooling restraint device, and is connected to a cooling pump through a pipeline. The cooling liquid circulating inside the device continuously takes away the heat of the deposited metal, allowing it to cool quickly, improve the organizational properties, and increase the deposition efficiency.

[0017] Preferably, the upper surface of the strong cooling restraint device is higher than the surface of the substrate when clamped, so as to restrain the forming of the powder layer and the deposition layer.

[0018] Preferably, when the relative position of the forced cooling restraint device and the additive manufacturing component needs to be changed, the relative position of the two is adjusted by loosening the clamp, and then re-clamping after the adjustment.

[0019] The second aspect of the present invention provides two methods for additive manufacturing using the above-mentioned powder-spreading TIG arc powder melting additive manufacturing device. The first method includes the following steps.

[0020] Step 1: Turn on the travel mechanism, non-contact thermometer, and welding power supply.

[0021] Step 2: Clamp the strong cooling restraint device to the substrate at a suitable position and turn on the cooling pump.

[0022] Step 3: Turn on the power of the powder feeding block electric drive device and adjust the parameters.

[0023] Step 4: Move the end of the powder delivery nozzle to a position 0-20mm above the starting end of the substrate, turn on the electric drive device, stay for a certain time according to the height of the deposition layer at the starting end, move the powder delivery nozzle to the end end of the substrate, and stay for a certain time according to the height of the deposition layer at the end end after moving to the end end, turn off the electric drive device, and move the powder delivery nozzle to other specified positions.

[0024] Step 5: Move the electrode end to the position 0-20mm above the arc starting end of the substrate, turn on the welding gun, and introduce protective gas into the welding gun nozzle. After the gas covers the arc starting end, an arc is generated. The welding gun stays for a certain period of time as required, then drives the arc to move to the arc extinguishing end. The arc continuously heats the powder layer, causing it to melt and solidify to form a deposition layer. After the arc moves to the arc extinguishing end, it stays for a period of time as required, turn off the welding gun, extinguish the arc, delay gas supply for a period of time, and move the welding gun to other specified positions.

[0025] Step 6: Repeat steps 4 and 5 to deposit and stack materials layer by layer.

[0026] Step 7: After the deposition process is completed and the substrate is cooled, remove the strong cooling restraint device, clean it and keep it for next use.

[0027] The second aspect of the present invention provides two methods for additive manufacturing using the above-mentioned powder-spreading TIG arc powder melting additive manufacturing device, and the second method includes the following steps.

[0028] Step 1: Turn on the travel mechanism, non-contact thermometer, and welding power supply.

[0029] Step 2: Clamp the strong cooling restraint device to the substrate at a suitable position and turn on the cooling pump.

[0030] Step 3: Turn on the power of the powder feeding block electric drive device and adjust the parameters.

[0031] Step 4: Move the end of the powder feeding nozzle to a position 0-20mm above the starting end of the substrate, turn on the electric drive device, stay for a certain time according to the height of the deposition layer at the starting end, move the powder feeding nozzle to the end end of the substrate, and when the end of the electrode moves to a position 0-20mm above the arc starting end of the substrate, an arc is generated between the electrode and the substrate, and the welding gun drives the arc to move toward the arc extinguishing end. The arc continuously heats the powder layer to melt and solidify it to form a deposition layer. When the end of the powder feeding nozzle moves above the end end of the substrate, turn off the electric drive device. When the arc moves to the arc extinguishing end, stay for a period of time as needed, extinguish the arc, delay gas supply for a period of time, and move the welding gun to other specified positions.

[0032] Step 5: Repeat step 4 to deposit and stack materials layer by layer.

[0033] Step 6: After the deposition process is completed and the substrate has cooled, remove the forced cooling restraint device, clean it and keep it for next use. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0035] Figure 1 It is a schematic structural diagram of the powder-spreading TIG arc powder additive manufacturing device of the present invention.

[0036] In the figure, 1 is a welding gun, 2 is an electrode, 3 is a non-contact temperature measuring instrument, 4 is a powder feeding nozzle, 5 is a powder feeding tube, 6 is a powder feeding block, 7 is a powder inlet, 8 is a strong cooling restraint device, 9 is a water hole, 10 is a base plate, 11 is a fixed clamp block, 12 is a connecting strip, and 13 is a mounting bracket.

[0037] Figure 2 It is a schematic diagram of the structure of the powder feeding block.

[0038] In the figure, 1 is the main body of the powder feeding block, 2 is the powder inlet, 3 is the electric drive device, and 4 is the powder flow channel.

[0039] Figure 3 Schematic diagram of the powder-laying TIG arc powder additive manufacturing process.

[0040] In the figure, 1 is the electrode, 2 is the arc, 3 is the powder layer, 4 is the deposition layer, 5 is the substrate, and 6 is the strong cooling restraint device.

[0041] These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention. DETAILED DESCRIPTION

[0042] The present invention is described below based on examples, but the present invention is not limited to these examples. In the detailed description of the present invention below, some specific details are described in detail. It is possible for those skilled in the art to fully understand the present invention without the description of these details. In order to avoid confusing the essence of the present invention, known methods, processes, flows, and elements are not described in detail.

[0043] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes only and are not necessarily drawn to scale.

[0044] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising" and similar words should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0045] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for description and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0046] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. The described exemplary embodiments are intended to help understand the present invention and are not intended to limit the scope of the present invention in any way.

[0047] The present invention provides a powder-laying TIG arc powder additive manufacturing method which creatively combines arc heat source and powder raw materials for additive manufacturing process. The basic principle is as follows: Figure 3 As shown. During the additive manufacturing process, the strong cooling restraint device 6 is tightly clamped on the side of the substrate 5, and the upper end surface of the strong cooling restraint device 6 is higher than the surface of the substrate 5. The powder is evenly spread on the surface of the substrate 5 in advance to form a powder layer 3. The end of the electrode 1 generates an arc 2 to heat the powder layer 3 so that it undergoes a melting and solidification process to form a deposition layer 4. The powder spreading, arc heating, powder melting and molten pool solidification processes are repeated continuously to complete the material layer-by-layer superposition, i.e., the additive manufacturing process.

[0048] The present invention provides a powder-spreading TIG arc powder additive manufacturing device for realizing stable and efficient operation of the arc powder additive manufacturing process. The structure and use method of the powder-spreading TIG arc powder additive manufacturing device of the present invention are introduced below in conjunction with specific examples.

[0049] like Figure 1As shown, the powder-spreading TIG arc powder-melting additive manufacturing device provided by the present invention includes a powder feeding device, a welding gun, a non-contact thermometer and a forced cooling restraint device. The welding gun 1 is clamped on the walking mechanism through a fixed clamp block 11. The powder feeding device includes a powder feeding block 6, a powder feeding pipe 5 and a powder feeding nozzle 4. The powder feeding block is connected to the welding gun 1 through a fixed clamp block 11. The powder enters the powder feeding block 6 from the powder inlet 7, flows through the powder feeding pipe 5 and the powder feeding nozzle 4, and falls on the surface of the substrate 10 to complete the powder feeding process. Preferably, the angle between the powder block 6, the powder feeding pipe 5, the powder feeding nozzle 4 and the direction of gravity, and the distance between the end of the powder feeding nozzle and the end of the electrode are adjusted by the posture of the fixed clamp block 11 and the welding gun 1 to ensure that the powder flows smoothly and accurately falls on the appropriate position on the surface of the substrate. The non-contact thermometer 3 is connected to the welding gun through a fixed clamp block 11, a connecting bar 12 and a mounting bracket 13 to monitor the temperature of the deposited metal in real time. Preferably, the temperature measurement position is adjusted by the fixed clamp block 11, the connecting strip 12 and the mounting bracket 13. Preferably, the angle between the welding gun 1 and the direction of travel of the welding gun is adjusted by the walking mechanism, so as to change the distribution characteristics of the arc force and temperature and the effect of the arc on the powder and the deposited metal. The material, diameter, end shape or taper angle of the electrode 2 are adjusted according to actual needs. The strong cooling constraint device 8 is tightly fitted with the side of the substrate 10 by clamping, and a cooling channel is provided inside the strong cooling constraint device 8, and is connected to the cooling pump through a pipeline. The cooling liquid circulating inside the device continuously takes away the heat of the deposited metal, so that it cools rapidly. Preferably, when the relative position of the strong cooling constraint device 8 and the substrate 10 needs to be changed, the relative position of the two is adjusted by loosening the clamp, and the clamp is re-clamped after adjustment. Preferably, when the strong cooling constraint device 8 is clamped, the upper surface is higher than the surface of the substrate 10, so as to constrain the forming of the powder layer and the deposited layer.

[0050] like Figure 2 As shown, the powder feeding block includes a powder feeding block body 1, a powder inlet 2, an electric drive device 3 and a powder flow channel 4. The powder enters the powder feeding block body 1 under the action of gravity, and flows into the powder flow channel 4 through the joint drive of the electric drive device 2 and gravity. Preferably, the end of the powder flow channel 4 is sealed and connected to the powder feeding pipe through threads. Preferably, the start and stop of the powder feeding is controlled by the switch of the electric drive device, and the powder feeding amount per unit time is adjusted by the input electrical signal parameter of the electric drive device.

[0051] The present invention provides two methods for using an arc powder additive manufacturing device, which are specifically as follows.

[0052] Example 1: Adjust the welding gun, powder feeding device and non-contact thermometer as required. Grind the surface of the substrate clean, wipe the surface with ethanol or acetone and dry it, and clamp the substrate on the additive manufacturing platform. Clamp the strong cooling restraint device with the substrate in a suitable position and turn on the cooling pump. Turn on the walking mechanism, non-contact thermometer, welding power supply and electric drive device power supply, and adjust the parameters. After the above preparations are completed, move the end of the powder feeding nozzle to a position 0-20mm above the starting end of the substrate, turn on the electric drive device, and stay for a certain time according to the height of the deposition layer at the starting end. The powder feeding nozzle moves to the end end of the substrate, and after moving to the end end, stays for a certain time according to the height of the deposition layer at the end end, and turns off the electric drive device. Move the powder feeding nozzle to other specified positions. Move the end of the electrode to a position 0-20mm above the arc-starting end of the substrate, turn on the welding gun, and introduce protective gas into the nozzle of the welding gun. When the gas covers the arc-starting end, an arc is generated. The welding gun stays for a certain period of time as required, and then drives the arc to move to the arc-extinguishing end. The arc continuously heats the powder layer to melt and solidify it to form a deposition layer. After the arc moves to the arc-extinguishing end, it stays for a period of time as required, extinguishes the arc, delays the gas supply for a period of time, and moves the welding gun to other designated positions. Repeat the above powder feeding and melting process to deposit and superimpose layer by layer. After the deposition process is completed and the substrate is cooled, remove the forced cooling restraint device, clean it up and leave it for next use.

[0053] Example 2: Adjust the welding gun, powder feeding device and non-contact thermometer as required. Polish the surface of the substrate, wipe it with ethanol or acetone and dry it, and clamp the substrate on the additive manufacturing platform. Clamp the strong cooling restraint device with the substrate in a suitable position and turn on the cooling pump. Turn on the walking mechanism, non-contact thermometer, welding power supply and electric drive device power supply, and adjust the parameters. After the above preparations are completed, move the end of the powder feeding nozzle to a position 0-20mm above the starting end of the substrate, turn on the electric drive device, and stay for a certain time according to the height of the deposition layer at the starting end. The powder feeding nozzle moves to the end end of the substrate. When the electrode end moves to a position 0-20mm above the arc starting end of the substrate, an arc is generated between the electrode and the substrate, and the welding gun drives the arc to move to the arc extinguishing end. The arc continuously heats the powder layer, causing it to melt and solidify to form a deposition layer. When the powder feeding nozzle end moves to the end end of the substrate, turn off the electric drive device and stop feeding powder. When the arc moves to the arc extinguishing end, stay for a period of time as needed, extinguish the arc, delay gas supply for a period of time, and move the welding gun to other specified positions.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A powder-spreading TIG arc powder additive manufacturing method, characterized in that: The method uses TIG arc as a heat source and powder as a raw material for additive manufacturing.

2. A powder-spreading TIG arc powder additive manufacturing device, characterized in that: The invention comprises a powder feeding device, a welding gun, a non-contact temperature measuring instrument and a strong cooling restraint device. The welding gun is fixed on the walking mechanism.

3. A powder-spreading TIG arc powder additive manufacturing device according to claim 2, characterized in that: The powder feeding device includes a powder feeding nozzle, a powder feeding tube and a powder feeding block. The powder feeding block is connected to the welding gun through a fixed clamp. The raw material powder enters the powder feeding block through the powder inlet, is fed into the powder feeding tube by the electric drive device in the powder feeding block, flows out of the powder feeding nozzle and is spread on the surface of the substrate.

4. The powder-spreading TIG arc powder additive manufacturing device according to claim 2, characterized in that: The start and stop of powder feeding is controlled by the electric drive device in the powder feeding block, and the powder feeding amount is adjusted by the input electrical signal parameters of the electric drive device, the angle between the powder feeding block and the powder feeding tube and the direction of gravity, and the travel speed of the powder feeding nozzle.

5. The powder-spreading TIG arc powder additive manufacturing device according to claim 2, characterized in that: The non-contact thermometer is fixed to the welding gun through a fixed clamp, a connecting strip and a mounting bracket to monitor the temperature of the deposited metal in real time. The temperature measurement position is adjusted by the connecting strip and the mounting bracket.

6. The powder-spreading TIG arc powder additive manufacturing device according to claim 2, characterized in that: The electrode material, electrode diameter, shape of the electrode end or the cone angle are adjusted according to actual needs. The angle between the electrode and the direction of travel of the welding gun is adjusted according to needs to change the distribution characteristics of the arc force and temperature and the effect of the arc on the powder and deposited metal.

7. The powder-spreading TIG arc powder additive manufacturing device according to claim 2, characterized in that: The strong cooling restraint device is tightly fitted to the side of the substrate through clamping. A cooling channel is provided inside the strong cooling restraint device and is connected to a cooling pump through a pipeline. The cooling liquid circulating inside the device continuously removes the heat of the deposited metal, allowing it to cool quickly, improve the organizational properties, and increase the deposition efficiency.

8. The powder-spreading TIG arc powder additive manufacturing device according to claim 2, characterized in that: The strong cooling restraint device is clamped above the surface of the substrate to restrain the powder layer and the deposition layer from forming. The clamping between the strong cooling restraint device and the substrate can be loosened, adjusted and disassembled as needed.

9. A method for additive manufacturing using the powder-spreading TIG arc powder additive manufacturing device according to any one of claims 1 to 10, characterized in that: The steps include: Step 1: Clamp the strong cooling restraint device with the substrate at a suitable position; Step 2: Turn on the cooling pump to allow the cooling liquid to circulate in the forced cooling restraint device; Step 3: Move the end of the powder delivery nozzle to a position 0-20mm above the starting end of the substrate through the walking mechanism, turn on the electric drive device in the powder delivery block, and stay for a certain time according to the height of the deposition layer at the starting end. The powder delivery nozzle moves to the end end of the substrate, and stays for a certain time according to the height of the deposition layer at the end end after moving to the end end. Turn off the electric drive device and move the powder delivery nozzle to other specified positions; Step 4: Move the end of the electrode to a position 0-20mm above the arc starting end of the substrate, turn on the welding gun and generate an arc. The welding gun stays for a certain period of time as required and then drives the arc to move to the arc extinguishing end. The arc continuously heats the powder layer to melt and solidify it to form a deposition layer. After the arc moves to the arc extinguishing end, it stays for a period of time as required, extinguishes the arc, and moves the welding gun to other specified positions.

10. The powder-spreading TIG arc powder additive manufacturing method according to claim 11, characterized in that: When the powder feeding nozzle and the arc travel speed are consistent, step three and step four, namely the powder feeding and arc scanning processes, can be performed simultaneously.

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