Powder collecting device and method for laser near-net forming additive manufacturing process

Abstract

The invention provides a powder collecting device and method in the laser near-net forming additive manufacturing process, and relates to the technical field of additive manufacturing. According to the powder collecting device, a base plate and a nozzle are arranged in a powder suction head, an anti-overflow shell is arranged at an opening of the powder suction head, and therefore a sealing chamber can be defined by the anti-overflow shell and the powder suction head; a nozzle is communicated with an air pressure tank through an air injection guide pipe, so that the nozzle can spray air to a part located on a base plate, powder on the surface of the part is blown up, the powder floats in a sealing chamber, and the powder can be conveniently collected; a powder suction head is communicated with a negative pressure guide pipe and is communicated with a negative pressure tank and a recycling bottle, and the negative pressure tank can generate negative pressure in the sealing chamber; therefore, the siphonic effect is formed, gas carrying powder in the sealing chamber moves towards the recycling bottle, the powder collecting efficiency can be improved, and the powder collecting effect is good.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing, and more particularly to a powder collection device and method for laser near-net-shape additive manufacturing processes. Background Technology

[0002] Laser near-net-shape forming technology manufactures three-dimensional metal parts by cladding metal powder particles layer by layer with a laser. Compared with traditional processing methods, it can process parts with complex shapes and is widely used in fields such as biomedicine and aerospace.

[0003] In the laser near-net-shape forming technology, the three-dimensional CAD model is first layered by a computer according to a certain thickness, and the scanning scheme of each layer is planned. The two-dimensional planar data of each layer is converted into the motion trajectory of the laser head and the powder feeding rate of the nozzle. The high-energy laser beam melts the metal powder to form a molten pool. At the same time, the molten metal is rapidly cooled, so that it is printed from point to line and from line to surface in sequence, thereby completing the printing of a layer cross section. Then, the layers are stacked to manufacture the solid part according to the design requirements.

[0004] Due to the layer-by-layer laser cladding and rapid melting and solidification of metal powder particles in laser near-net-shape forming, the entire process continuously consumes metal powder. The metal powders used are mostly specialized powders, with low versatility and high cost. However, current laser near-net-shape forming equipment has low powder utilization, with a large amount of powder not being fully melted. Recycling and reusing the unmelted powder during processing would significantly reduce processing costs. Therefore, there is an urgent need to develop a metal powder recycling device for laser near-net-shape additive manufacturing processes.

[0005] Chinese patent CN111318699A discloses an additive manufacturing device with a powder collection function. This device uses an air inlet pipe at the bottom to blow air upwards, suspending excess powder generated during processing. The suspended powder floats upwards with the gas and is collected by a vortex separator at the top. However, while the device blows air upwards to suspend excess powder, it cannot lift powder from the surface of the part, resulting in some powder remaining uncollected and low powder collection efficiency. Summary of the Invention

[0006] In view of this, the present invention proposes a powder collection device and method for laser near-net-shape additive manufacturing process, which solves the problem of poor powder collection effect in laser near-net-shape technology.

[0007] The technical solution of this invention is implemented as follows:

[0008] This invention provides a powder collection device for a laser near-net-shape additive manufacturing process, which includes a substrate, a powder suction head, a nozzle, an anti-overflow shell, a jet duct, a pressure tank, a negative pressure duct, a recovery bottle, and a negative pressure tank.

[0009] The substrate and the nozzle are both disposed inside the powder suction head, and the nozzle and the substrate are disposed opposite to each other. The anti-overflow shell covers the opening of the powder suction head so that the anti-overflow shell and the powder suction head form a sealed chamber.

[0010] One end of the jet duct is connected to the pressure tank, and the other end of the jet duct is inserted into the sealed chamber and connected to the nozzle;

[0011] One end of the negative pressure conduit is connected to the powder suction head, and the other end of the negative pressure conduit is provided with two branch pipes, which are respectively connected to the recycling bottle and the negative pressure tank.

[0012] Based on the above technical solutions, preferably, the powder collection device further includes a powder filtration structure, which is disposed on the conduit between the powder suction head and the recovery bottle, and is used to filter powder.

[0013] Based on the above technical solutions, preferably, the powder filtration structure includes a filter chamber and a filter screen. The filter chamber is provided with an air inlet and an air outlet. The air inlet is connected to the powder suction head, and the air outlet is connected to the recovery bottle. The filter screen is disposed in the filter chamber and covers the air inlet.

[0014] Based on the above technical solutions, preferably, the filter screen is provided with multiple filter holes, and the pore size of each filter hole is greater than or equal to 53μm and less than or equal to 150μm.

[0015] Based on the above technical solutions, preferably, the powder collection device further includes a switching valve, which is disposed on the conduit between the powder filtration structure and the recycling bottle.

[0016] Based on the above technical solutions, preferably, the gas filled in the pressure tank is an inert gas.

[0017] Based on the above technical solution, preferably, the nozzle is provided with four air nozzles, which are respectively disposed at the four corners of the powder suction head, and all four air nozzles are directed toward the substrate.

[0018] Based on the above technical solutions, preferably, the powder collection device further includes a powder collection chamber, which is a sealed cavity, and the substrate, the powder suction head, the nozzle and the anti-overflow shell are all disposed in the powder collection chamber.

[0019] Based on the above technical solutions, preferably, the anti-overflow shell is made of flexible material and can be detachably installed on the powder suction head.

[0020] Furthermore, the present invention also provides a powder collection method for a laser near-net-shape additive manufacturing process, using the powder collection device described above, which includes the following steps:

[0021] Open the pressure tank and blow air into the components on the substrate through the nozzle;

[0022] Open the negative pressure tank to create negative pressure in the sealed chamber formed by the overflow prevention shell and the powder suction head;

[0023] The gas carrying the powder enters the powder filter structure, the filter screen filters out the impurity powder, and the powder enters the recovery bottle;

[0024] Repeat the above steps until all the powder on the surface of the part is removed.

[0025] The powder collection device for laser near-net-shape additive manufacturing process of the present invention has the following advantages over the prior art:

[0026] (1) By setting the substrate and nozzle inside the powder suction head and setting the anti-overflow shell at the opening of the powder suction head, the anti-overflow shell and the powder suction head can form a sealed chamber. The nozzle is connected to the pressure tank through the jet duct, so that the nozzle can spray gas onto the parts located on the substrate, thereby blowing up the powder on the surface of the parts and the powder on the substrate, so that the powder is separated from the substrate and the surface of the parts, which can facilitate the collection of powder. The powder suction head can be connected to the negative pressure tank and the recovery bottle through the negative pressure duct. The negative pressure tank can generate negative pressure in the sealed chamber, thereby forming a siphon effect, so that the gas carrying the powder in the sealed chamber moves towards the recovery bottle, which can improve the efficiency of powder collection and the powder collection effect is good.

[0027] (2) By placing the substrate and nozzle in a sealed chamber surrounded by the anti-overflow shell and the powder suction head, the substrate and nozzle are in a smaller sealed chamber, and powder can be collected directly inside the sealed chamber. This avoids powder overflow and excessive inert gas being directly sucked into the powder suction head from the powder collection chamber, thus avoiding resource waste. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the powder collection device for a laser near-net-shape additive manufacturing process according to the present invention;

[0030] Figure 2 This is a perspective view of a powder collection device for a laser near-net-shape additive manufacturing process according to the present invention;

[0031] Figure 3 This is a schematic diagram of the nozzle structure of the present invention;

[0032] Figure 4 This is a flowchart illustrating the steps of a powder collection method in a laser near-net-shape additive manufacturing process according to the present invention.

[0033] Figure label:

[0034] 1. Substrate; 2. Powder suction head; 3. Nozzle; 31. Air jet nozzle; 4. Overflow prevention shell; 5. Air jet duct; 6. Pressure tank; 7. Negative pressure duct; 71. Branch pipe; 8. Recovery bottle; 9. Negative pressure tank; 10. Sealed chamber; 11. Powder filtration structure; 111. Filter chamber; 112. Filter screen; 12. Switch valve. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 and Figure 2 As shown, in one aspect, a powder collection device for a laser near-net-shape additive manufacturing process according to the present invention includes a substrate 1, a powder suction head 2, a nozzle 3, an anti-overflow shell 4, a jet duct 5, a pressure tank 6, a negative pressure duct 7, a recovery bottle 8, and a negative pressure tank 9.

[0037] The substrate 1 and the nozzle 3 are both disposed inside the powder suction head 2, and the nozzle 3 and the substrate 1 are disposed opposite to each other. The anti-overflow shell 4 covers the opening of the powder suction head 2 so that the anti-overflow shell 4 and the powder suction head 2 form a sealed chamber 10.

[0038] One end of the jet duct 5 is connected to the pressure tank 6, and the other end of the jet duct 5 is inserted into the sealing chamber 10 and connected to the nozzle 3;

[0039] One end of the negative pressure conduit 7 is connected to the powder suction head 2, and the other end of the negative pressure conduit 7 is provided with two branch pipes 71, which are respectively connected to the recycling bottle 8 and the negative pressure tank 9.

[0040] Specifically, the substrate 1 can be disposed inside the powder suction head 2, and the component can be located on the substrate 1. The nozzle 3 can also be disposed inside the powder suction head 2. The nozzle 3 can be disposed opposite to the substrate 1, so that the nozzle 3 can spray gas toward the component. The anti-overflow shell 4 can cover the opening of the powder suction head 2, so that the anti-overflow shell 4 and the powder suction head 2 can form a sealed chamber 10, and the substrate 1, the nozzle 3 and the component on the substrate 1 are all located inside the sealed chamber 10.

[0041] The jet duct 5 is a long cylindrical tube. One end of the jet duct 5 can be connected to the pressure tank 6, and the other end of the jet duct 5 can be inserted into the sealed chamber 10. The other end of the jet duct 5 can also be connected to the nozzle 3. Thus, the pressure tank 6 can provide positive pressure gas to the nozzle 3 through the jet duct 5, so that the nozzle 3 can spray gas onto the parts located on the substrate 1, thereby blowing up the powder on the surface of the parts and making the powder float in the sealed chamber 10, which can facilitate the collection of powder.

[0042] The negative pressure conduit 7 is also an elongated tube. One end of the negative pressure conduit 7 can be connected to the powder suction head 2, and the other end of the negative pressure conduit 7 can be provided with two branch pipes 71. The two branch pipes 71 can be connected to the recycling bottle 8 and the negative pressure tank 9 respectively. Thus, the negative pressure tank 9 can generate negative pressure in the sealed chamber 10 and form a siphon effect, so that the gas carrying powder in the sealed chamber 10 moves towards the recycling bottle 8, which can improve the efficiency of powder collection and the powder collection effect is good.

[0043] like Figure 1 and Figure 2 As shown, in some embodiments, the powder collection device further includes a powder filter structure 11, which is disposed on a conduit connecting the powder suction head 2 and the recycling bottle 8, and is used to filter powder.

[0044] Specifically, the powder collection device may also include a powder filter structure 11. The powder filter structure 11 may be installed on the conduit between the powder suction head 2 and the recovery bottle 8. The gas moving from the powder suction head 2 toward the recovery bottle 8 needs to pass through the powder filter structure 11 first. The powder filter structure 11 can filter the powder and collect the powder from the gas. Then the collected powder can be uniformly put into the recovery bottle 8, which can further facilitate the collection of powder.

[0045] like Figure 1 As shown, in some embodiments, the powder filtration structure 11 includes a filter chamber 111 and a filter screen 112. The filter chamber 111 is provided with an air inlet and an air outlet. The air inlet is connected to the powder suction head 2, and the air outlet is connected to the recycling bottle 8. The filter screen 112 is disposed in the filter chamber 111 and covers the air inlet.

[0046] Specifically, the powder filtration structure 11 may include a filter chamber 111 and a filter screen 112. The filter chamber 111 is a sealed cavity structure, and the filter chamber 111 may be provided with an air inlet and an air outlet. In this embodiment, the filter chamber 111 is provided with an air inlet and an air outlet on opposite sides. The air inlet can be connected to the powder suction head 2, and the air outlet can be connected to the recovery bottle 8. The gas carrying the powder can enter the filter chamber 111 from the air inlet.

[0047] The filter screen 112 can be installed inside the filter chamber 111 and can cover the air inlet, so that the gas entering the filter chamber 111 will first come into contact with the filter screen 112. The filter screen 112 can filter out the powder carried by the gas, and the filtered powder will be uniformly put into the recycling bottle 8 for convenient collection.

[0048] In some embodiments, the filter screen 112 is provided with a plurality of filter holes, and the pore size of each filter hole is greater than or equal to 53 μm and less than or equal to 150 μm.

[0049] Specifically, the impurity powder is spherical large-particle powder or large-particle oxide sputtering formed during the laser near-net-shape forming process. The diameter of the powder is between 200μm and 800μm. The filter screen 112 is provided with multiple filter holes, and the pore size range of the filter holes is greater than or equal to 53μm and less than or equal to 150μm, so that the filter screen 112 can filter out most of the impurity powder.

[0050] like Figure 1 and Figure 2 As shown, in some embodiments, the powder collection device further includes a switching valve 12, which is disposed on a conduit between the powder filtration structure 11 and the recycling bottle 8.

[0051] Specifically, the powder collection device may also include a switch valve 12, which may be installed on the conduit between the powder filter structure 11 and the recycling bottle 8, so that the opening or closing of the recycling bottle 8 can be controlled by the switch valve 12. More specifically, when the recycling bottle 8 is full of powder, the switch valve 12 can be closed to facilitate the replacement of a new recycling bottle 8. When it is necessary to collect powder, the valve can be opened to further facilitate the collection of powder.

[0052] In some embodiments, the gas filled in the pressure tank 6 is an inert gas.

[0053] Specifically, the gas filled in the pressure tank 6 is an inert gas, which allows the nozzle 3 to spray the inert gas onto the parts. Thus, the powder collection process is carried out in an inert gas-protected environment, preventing the parts from oxidizing due to contact with air, and also preventing the powder from oxidizing due to contact with air.

[0054] like Figure 3 As shown, in some embodiments, the nozzle 3 is provided with four air jets 31, which are respectively disposed at the four corners of the powder suction head 2, and all four air jets 31 are disposed facing the substrate 1.

[0055] Specifically, the nozzle 3 can be provided with four air jets 31, the powder suction head 2 has a square structure, the four air jets 31 can be respectively set at the four corners of the powder suction head 2, and the four air jets 31 can all be set facing the substrate 1, so that the four air jets 31 can be located around the part respectively, and the four air jets 31 can spray air onto the part from four directions, which can blow up all the powder on the surface of the part and clean the powder on the surface of the part more thoroughly.

[0056] In some embodiments, the powder collecting device further includes a powder collecting chamber, which is a sealed cavity, and the substrate 1, the powder suction head 2, the nozzle 3 and the anti-overflow shell 4 are all disposed in the powder collecting chamber.

[0057] Specifically, the powder collection device may also include a powder collection chamber, which may be a sealed cavity. The substrate 1, the powder suction head 2, the nozzle 3 and the overflow prevention shell 4 are all disposed in the powder collection chamber. The powder collection chamber can prevent powder from leaking out of the powder suction head 2, and the powder collection chamber can also prevent inert gas leakage.

[0058] like Figure 1 and Figure 2 As shown, in some embodiments, the overflow shell 4 is made of a flexible material and is detachably mounted on the powder suction head 2.

[0059] Specifically, the overflow shell 4 can be made of a flexible material, so that by changing the shape of the overflow shell 4, it is convenient to match the opening of the powder suction head 2. More clearly, it is convenient to install the overflow shell 4 at the opening of the powder suction head 2. In this embodiment, the overflow shell 4 can be detachably installed at the opening of the powder suction head 2, so that the parts can be easily removed from the powder suction head 2.

[0060] like Figure 4As shown, on the other hand, a powder collection method for a laser near-net-shape additive manufacturing process according to the present invention, applied to the powder collection device described above, includes the following steps:

[0061] Open the pressure tank 6 and blow air into the parts on the substrate 1 through the nozzle 3;

[0062] Open the negative pressure tank 9 to create negative pressure in the sealed chamber 10 formed by the overflow prevention shell 4 and the powder suction head 2;

[0063] The gas carrying the powder enters the powder filter structure 11, the filter screen 112 filters out the impurity powder, and the powder enters the recovery bottle 8.

[0064] Repeat the above steps until all the powder on the surface of the part is removed.

[0065] Step S1: Open the air pressure tank 6 and blow air from the nozzle 3 toward the components on the substrate 1;

[0066] Specifically, in step S1, the pressure tank 6 can be opened so that the pressure tank 6 can blow positive pressure gas to the nozzle 3 through the jet duct 5. The nozzle 3 can then blow air toward the parts on the substrate 1, thereby blowing up the powder on the surface of the parts. This causes the powder to float in the sealed chamber 10 formed by the anti-overflow shell 4 and the powder suction head 2, which facilitates subsequent powder collection.

[0067] Step S2: Open the negative pressure tank 9 to create negative pressure in the sealed chamber 10 formed by the anti-overflow shell 4 and the powder suction head 2;

[0068] Specifically, in step S2, the negative pressure tank 9 can be opened. The negative pressure tank 9 is connected to the powder suction head 2 through the negative pressure conduit 7, so that the negative pressure tank 9 can generate negative pressure in the sealed chamber 10, so that the gas carrying the powder in the sealed chamber 10 moves towards the recovery bottle 8.

[0069] Step S3: The gas carrying the powder enters the powder filter structure 11, the filter screen 112 filters out the impurity powder, and the powder enters the recovery bottle 8;

[0070] Specifically, in step S3, the gas carrying the powder first enters the powder filter structure 11, which is equipped with a filter screen 112. The filter screen 112 filters out the impurity powder from the gas and collects the powder in one place. The collected powder will enter the recycling bottle 8, thereby improving the efficiency of powder collection and achieving good powder collection effect.

[0071] Step S4: Repeat the above steps until the powder on the surface of the part is completely removed.

[0072] Specifically, steps S1, S2 and S3 can be repeated so that the powder on the surface of the part is continuously blown up, and the powder can be continuously collected by generating negative pressure in the sealed chamber 10 until the powder on the surface of the part is completely removed.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A powder collection device for a laser near-net-shape additive manufacturing process, characterized in that: It includes a substrate (1), a powder suction head (2), a nozzle (3), an overflow prevention shell (4), a jet duct (5), a pressure tank (6), a negative pressure duct (7), a recycling bottle (8), and a negative pressure tank (9); The substrate (1) and the nozzle (3) are both disposed inside the powder suction head (2), and the nozzle (3) and the substrate (1) are disposed opposite to each other. The anti-overflow shell (4) covers the opening of the powder suction head (2) so that the anti-overflow shell (4) and the powder suction head (2) form a sealed chamber (10). One end of the jet duct (5) is connected to the pressure tank (6), and the other end of the jet duct (5) is inserted into the sealing chamber (10) and connected to the nozzle (3); One end of the negative pressure conduit (7) is connected to the powder suction head (2), and the other end of the negative pressure conduit (7) is provided with two branch pipes (71), which are respectively connected to the recycling bottle (8) and the negative pressure tank (9).

2. The powder collecting device as described in claim 1, characterized in that: It also includes a powder filter structure (11), which is disposed on a conduit between the powder suction head (2) and the recycling bottle (8), and the powder filter structure (11) is used to filter powder.

3. The powder collecting device as described in claim 2, characterized in that: The powder filtration structure (11) includes a filter chamber (111) and a filter screen (112). The filter chamber (111) is provided with an air inlet and an air outlet. The air inlet is connected to the powder suction head (2), and the air outlet is connected to the recycling bottle (8). The filter screen (112) is disposed in the filter chamber (111) and covers the air inlet.

4. The powder collecting device as described in claim 3, characterized in that: The filter screen (112) is provided with a plurality of filter holes, and the pore size of each filter hole is greater than or equal to 54 μm and less than or equal to 150 μm.

5. The powder collecting device as described in claim 2, characterized in that: It also includes a switching valve (12) disposed on a conduit between the powder filter structure (11) and the recycling bottle (8).

6. The powder collecting device as described in claim 1, characterized in that: The gas filled in the pressure tank (6) is an inert gas.

7. The powder collecting device as described in claim 1, characterized in that: The nozzle (3) is provided with four air nozzles (31), which are respectively located at the four corners of the powder suction head (2), and all four air nozzles (31) are facing the substrate (1).

8. The powder collecting device as described in claim 1, characterized in that: It also includes a powder collection chamber, which is a sealed cavity, and the substrate (1), the powder suction head (2), the nozzle (3) and the anti-overflow shell (4) are all disposed in the powder collection chamber.

9. The powder collecting device as described in claim 1, characterized in that: The overflow shell (4) is made of flexible material and can be detachably installed on the powder suction head (2).

10. A powder collection method for a laser near-net-shape additive manufacturing process, using the powder collection device as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Open the pressure tank (6) and blow air into the parts on the substrate (1) through the nozzle (3); Open the negative pressure tank (9) to create negative pressure in the sealed chamber (10) formed by the overflow shell (4) and the powder suction head (2); The gas carrying the powder enters the powder filter structure (11), the filter screen (112) filters out the impurity powder, and the powder enters the recovery bottle (8); Repeat the above steps until all the powder on the surface of the part is removed.

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