Part machining method based on embedded dipping type 3D printing

Abstract

The invention provides a 3D printing part processing method for constructing a printing entity based on a powder material and a liquid binder, which comprises the following steps: in a 3D printing process, embedding a printing spray head into a certain depth below the plane of a printing powder bed and extruding out the liquid binder, and forming a water channel with certain depth and width on the surface of the powder bed by the moving printing spray head; and the dynamic water channel is immediately filled with the synchronous large-flow liquid binder, and then the liquid binder permeates, diffuses and solidifies in a controlled and constrainable state to form a printing entity. According to the method, the advantages of extrusion type printing and a powder bed structure are combined, the requirement of single extrusion printing for the formability of an extruded material is met, controllable printing of the large-flow, high-viscosity and large-layer-thickness printing shape and precision is achieved, the method is suitable for various kinds of binder materials, the variety and size range of powder bed materials is large, and the method is suitable for large-flow, high-viscosity and large-layer-thickness printing. And the rapid part forming machining requirements of wide material application range, large forming size and high part strength are met.

Description

Technical Field

[0001] The invention belongs to the field of additive manufacturing and relates to a parts processing method based on embedded immersion 3D printing. Background Art

[0002] 3D printing technology, also known as additive manufacturing technology, refers to the manufacturing process of constructing a three-dimensional object by adding a series of thin cross-sectional graphics layer by layer.

[0003] Traditional 3D printing methods based on powder materials and liquid binders to build printed entities are mainly material jetting technology and liquid binder jetting technology. In order to meet the needs of high precision, these two molding methods limit the diameter of the nozzle. If the nozzle diameter is too large, it will cause problems such as difficult to control the liquid falling trajectory or powder material splashing due to gravity. The limitation of the nozzle diameter further limits the size of the molded parts. This leads to the fact that when large-sized molded parts need to be quickly molded, the use of small-diameter nozzles cannot achieve the purpose of rapid molding, and the use of large-diameter nozzles cannot avoid the problems of difficult to control the liquid falling trajectory and powder material splashing, so the accuracy of the bonding layer cannot be guaranteed.

[0004] The current 3D printing method based on powder materials and liquid binders to construct printed entities still has shortcomings such as low bonding layer accuracy when printing large-size parts, slow molding speed when printing large-size parts, and a small variety of available powder material consumables, making it difficult to achieve a balance between efficiency, format, and accuracy. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide an embedded immersion 3D printing method, which can realize large-scale rapid prototyping of powder material bonding, and more types of powder materials can be selected. In the present invention, the print nozzle will penetrate to a specific depth below the printing plane during operation, and extrude the liquid binder in the process. As the print nozzle moves, it opens up channels with a specified depth and width in the powder material, and instantly fills these dynamically formed channels with a large flow of liquid binder. Subsequently, the liquid binder penetrates, diffuses and finally solidifies under controlled conditions to form the physical structure of the printed object. This method is not limited to using a single powder material as the printing material, and other materials such as toughening agents and reinforcing agents can be added to improve the performance of the molded parts. In addition, reinforcing materials can also be added to the liquid binder to improve the performance and printing accuracy of the molded parts.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A 3D printing parts processing method based on extrusion of powder materials and liquid binder to construct a printing entity. In this method, during the 3D printing process, the printing nozzle is buried to a certain depth below the printing plane and the liquid binder is extruded. The moving printing nozzle forms a channel of a certain depth and width on the surface of the powder material, and a large flow of liquid binder is synchronously used to instantly fill the dynamic channel. After that, the liquid binder penetrates, diffuses, and solidifies in a controlled and constrained state to form a printing entity. This method combines the advantages of extrusion printing and powder material printing, meets the requirements of single extrusion printing for the formability of the extruded material, and realizes controllable printing of the shape and precision of large flow, high viscosity, and large layer thickness printing. This method is applicable to a wide variety of binder materials, and the types and size range of powder bed materials are wide, meeting the needs of rapid prototyping of parts with wide material applicability, large molding size, and high part strength. Specifically, it includes the following steps:

[0008] Step (1), creating a three-dimensional model of the target object to be printed, importing the created three-dimensional model of the target object into the 3D printing slicing software to set parameters, after the parameters are set, the slicing software automatically slices the three-dimensional model of the target object and obtains the printing data of the target object that can be used by the printer;

[0009] Step (2), loading the printing data of the target object in step (1) into the control system of the printer, and starting printing layer by layer, specifically:

[0010] First, the elevator 1 at the bottom of the printer moves according to the ascending action of the elevator 1 obtained in step (1). When the elevator 1 contacts the bottom surface 2 of the powder bed box, the electromagnet locks the two so that the two can achieve the effect of lifting together. The elevator 1 continues to rise and raises the bottom surface 2 of the powder bed box 4 to a position aligned with the printing plane 3, and then descends the distance of the printing layer thickness. At this time, the powder material 6 is loaded in the powder spreading device 5 waiting for powder spreading, the powder bed box 4 is empty, and the bottom surface 2 of the powder bed box is lower than the printing plane 3 by the distance of the printing layer thickness. Then, the powder spreading device 5 of the printer spreads powder on the printing plane 3 and scrapes the powder material 6 flat according to the powder spreading action of the powder spreading device 5 obtained in step (1) and the powder spreading thickness when printing the layer. The powder spreading action of the powder spreading device 5 is a two-way reciprocating powder spreading action, that is, when printing each layer, the powder spreading device 5 only moves once in one direction to complete the powder spreading action, and then the powder spreading device stops on one side of the printer, and when starting to spread the next layer of powder, it moves from this side to the other side, and so on. During the powder spreading process, the heating plate on the powder spreading device 5 will start to heat the lower area to adjust the process parameters such as the penetration rate, fluidity, reactivity and viscosity of the liquid binder 8.

[0011] Then, the print head 7 of the embedded printer starts to move to the starting position of the layer of graphics according to the moving trajectory of the print head 7 obtained in step (1), and then according to the embedding depth set in step (1), the print head 7 is embedded below the printing plane 3 and moved to squeeze out the liquid binder 8 from the print head 7. The moving print head 7 forms a channel 10 of a certain depth and width on the surface of the powder material 6, and the dynamic channel 10 is instantly filled with a large flow of liquid binder 8 at the same time. After that, the liquid binder penetrates and diffuses in a controlled and constrained state.

[0012] Step (3), looping step (2), obtaining an in-situ impregnation layer, in which the liquid binder 8 has been extruded, but the natural impregnation behavior is not completed. As the print head 7 moves, the penetration degree of the place where the liquid binder 8 is extruded first is greater than that of the place where the liquid binder 8 is extruded later.

[0013] Step (4), looping step (2), obtaining an interlayer bonding layer, in which the liquid binder 8 has been extruded and the natural impregnation behavior has exceeded the thickness of one printing layer and has begun to combine with the previous layer. As the printing nozzle 7 moves, the place where the liquid binder 8 is extruded first combines with the in-situ impregnation layer first, and the place where the liquid binder 8 is extruded later has not yet begun to combine with the in-situ impregnation layer.

[0014] Step (5), looping step (2), obtaining a completely impregnated layer, in which the liquid adhesive 8 has been extruded, the natural impregnation behavior has been completed and the layer has been completely bonded to the interlayer bonding layer, but the layer has not reached the time for the cross-linking reaction.

[0015] Step (6), looping step (2), as printing progresses, the liquid binder gradually solidifies to obtain a semi-solidified layer, in which the liquid binder 8 has been extruded, the natural impregnation behavior has been completed and the interlayer bonding layer has been completely combined, but the base material and the curing agent have only undergone limited cross-linking reaction. As the print head 8 moves, the degree of cross-linking reaction in the place where the liquid binder 8 is extruded first is greater than that in the place where the liquid binder 8 is extruded later.

[0016] Step (7), looping step (2) to obtain a completely cured layer, in which the cross-linking reaction between the matrix material and the curing agent has been completed, and the curing is achieved.

[0017] Step (8), loop step (2) until printing is completed. After printing is completed, the powder bed box 4 is left to stand for a period of time to wait for the liquid binder 8 to solidify and obtain a printed part with a certain mechanical strength.

[0018] Step (9), performing post-heating treatment on the printed part obtained in step (8) to obtain a printed part with enhanced mechanical strength, and then performing fine processing on the printed part to obtain the final target object entity.

[0019] Furthermore, one of the key parameters in the parameter setting in step (1) is the embedding depth. During the printing process of the target object, the print head 7 is embedded below the printing plane 3. This parameter refers to the distance from the lowest point of the print head 7 to the printing plane 3 with the printing plane 3 as the reference plane.

[0020] Furthermore, the printing data of the target object obtained in step (1) includes: the moving track of the print head 7, the powder spreading action of the powder spreading device 5, the powder spreading thickness during each layer printing, and the lifting action of the elevator 1. In the lifting action of the elevator 1, the height of each descent of the elevator 1 is the printing layer thickness of the layer.

[0021] Furthermore, the powder bed box 4 described in step (2) is a rectangular parallelepiped without a cover on the top, and the four sides of the powder bed box 4 are mechanically locked with the printer, so that the powder bed box 4 can be installed and removed at the beginning and end of printing. The bottom surface 2 of the powder bed box is a rectangular aluminum plate that can move up and down, and is locked with the elevator 1 through an electromagnet during the printing process to achieve a joint lifting effect. The entire printing process of the target object is also carried out on the bottom surface 2 of the powder bed box.

[0022] Furthermore, the printing plane 3 in step (2) is a flat aluminum plate, the middle of which is hollowed out into a rectangle, and the shape of the rectangle is the same as the shape of the bottom surface 2 of the powder bed box, so when the bottom surface 2 of the powder bed box rises to align with the printing plane 3, the positions of the bottom surface 2 of the powder bed box and the hollowed-out printing plane 3 are exactly complementary to form a complete plane. When the bottom surface 2 of the powder bed box drops by the thickness of the printing layer, the powder bed box 4 and the printing plane 3 will form a concave shape, and at this time, the powder material 6 spread by the powder spreading device 5 will fall on the bottom surface 2 of the powder bed box, and the remaining powder material 6 that falls on the printing plane 3 will be scraped into the recycling device.

[0023] Furthermore, the powder spreading device 5 mentioned in the step 2 consists of three parts: a powder spreading frame, a powder box and a heating plate. The powder spreading frame is fixed on the printer and moves with the printer. The powder box is fixed on the powder spreading frame. When using the printer, powder boxes of different shapes can be replaced according to different process requirements. The heating plate 21 is also fixed on the powder spreading frame. When the entire powder spreading device 5 is spreading powder, the heating plate 21 will start and heat the spread powder material 6.

[0024] Furthermore, the powder material 6 used in the embedded printer in step (2) is suitable for a variety of materials. The types of powder material 6 include metal powder materials, polymer powder materials, ceramic powder materials, polymer coated powder materials, mixed powder materials and various solid powder particles. Short fibers can also be added to the powder material 6 as reinforcing materials.

[0025] Furthermore, during the printing and forming process of the target layer in step (2), when the print head 7 is buried below the printing plane 3 and moves, the powder material 6 is pushed to both sides to accumulate into a powder material pile 9, forming a water channel 10 with a width equal to the diameter of the print head 7. The water channel 10 is the immersion track of the liquid binder 8. The print head 7 has a wide range of diameter choices, and the width of the formed water channel 10 can meet the needs of various application scenarios.

[0026] Furthermore, in step (2), the liquid binder 8 is formed by mixing the base material of the liquid binder 8 and the curing agent, and the mixture of the two will produce a cross-linking reaction, thereby achieving curing at room temperature. Natural impregnation refers to in-situ impregnation, that is, the position where the print head 7 sprays the liquid binder 8 is taken as the origin, and the liquid binder 8 gradually diffuses to the surroundings and fills the gaps in the powder material 6. The matrix includes thermosetting polymer materials such as epoxy resin and polyurethane; the curing agent includes universal epoxy resin curing agent, etc.; the mass ratio of the base material and the curing material is mixed according to the actual printing process parameters.

[0027] Furthermore, the finishing in step (9) refers to finishing the printed part obtained in step (8) using a CNC machine tool based on the three-dimensional model of the target object drawn in step (1), removing excess surface material, and obtaining an accurate target object model entity.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention proposes an extrusion embedded impregnation 3D printing method. By adopting the embedded printing technology, the precise distribution of the liquid binder is ensured, and the problem of insufficient accuracy of the bonding layer due to the lack of an impregnation track in the traditional impregnation process is solved; this method is not limited to a single type of powder material, it supports the use of multiple materials, and can also add reinforcing materials, thereby expanding the range of printable materials; the strategy of using powder material bonding printing and natural impregnation molding to complete rough processing meets the needs of large-format molding; a post-processing method is introduced to heat the bonding molding area as a whole to remove residual stress and improve the stability of the performance of the molded part.

[0030] (2) The printing process provided by the present invention can simplify the printing and molding of powder materials. Combined with thermal curing and fine processing, larger-sized molded parts with higher precision can be obtained, achieving the effect of taking into account efficiency, format and precision.

[0031] In summary, the present invention can realize multi-material, large-size, high-strength, and rapid prototyping 3D printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1The figure is a cross-sectional diagram of the extrusion embedded impregnation 3D printing process. 1 is the elevator, 2 is the bottom of the powder bed box, 3 is the printing plane, 4 is the powder bed box, 5 is the powder spreading device, 6 is the powder material used for printing, 7 is the printing nozzle, 8 is the liquid binder used for printing, 9 is the pile of powder material pushed away by the printing nozzle, 10 is the channel surrounded by the powder material pile, 11 is the interlayer bonding state where the liquid binder of this layer has been extruded, but the natural impregnation behavior has not been completed; 12 is the interlayer bonding state where the liquid binder of this layer has been extruded and the natural impregnation behavior has been completed, but the interlayer bonding with the previous layer has just begun; 13 is the 14 is the interlayer bonding state in which the liquid binder of this layer has been extruded, the natural impregnation behavior has been completed, and the interlayer bonding with the previous layer has been completed, but the layer has not been solidified; 15 is the printing of the first layer, 16 is the printing of the second layer, 17 is the printing of the third layer, 18 is the printing of the fourth layer, 19 is the printing of the fifth layer, 20 is the printing of the sixth layer, 21 is the started heating plate, and 22 is the unstarted heating plate.

[0033] Figure 2 This is a slice cross-section diagram of the L-shaped model.

[0034] Figure 3 It is an L-shaped 3D model.

[0035] Figure 4 This is a plan view of a layer after printing is completed. DETAILED DESCRIPTION

[0036] The present invention provides a 3D printing method using wood powder material and thermosetting epoxy resin material as printing materials. During the printing process, the print head 7 is buried below the printing plane 3, and a bonding layer with the same shape as the model is obtained through extrusion, impregnation, and curing. The stacked printing realizes additive manufacturing, and then the obtained model is finely processed by a lathe. The present invention solves the problem that the bonding layer has low accuracy due to the lack of an impregnation track in the previous impregnation process. The specific implementation plan is as follows:

[0037] (1) Figure 3 Draw the L-shaped 3D model to be printed as shown, import the created L-shaped 3D model into the 3D printing slicer software to set the parameters, set the embedding depth to half of the thickness of each printing layer, and set the other parameters to the default parameters. After setting the parameters, the slicer software automatically slices the L-shaped 3D model into 25 layers with a layer thickness of 1 cm, and obtains the L-shaped G code file that can be used by the printer;

[0038] (2) Load the L-shaped G-code file in step (1) into the control system of a printer with a print head 7 having a diameter of 2 cm, and start printing layer by layer, specifically:

[0039] First, the printer's elevator 1 moves upward according to the G code file obtained in step (1). When the elevator 1 contacts the bottom surface 2 of the powder bed box, the electromagnet locks the two so that the two can achieve the effect of lifting together. The elevator 1 continues to rise and raises the bottom surface 2 of the powder bed box to a position aligned with the printing plane 3, and then drops 1 cm. At this time, the powder bed box 4 is empty, and the bottom surface 2 of the powder bed box is 1 cm lower than the printing plane. Then the printer's powder spreading device 5 spreads powder on the printing plane 3 and scrapes the wood powder 6 flat according to the G code file obtained in step (1). The powder spreading action of the powder spreading device 5 is to spread powder from left to right, and the height of the wood powder 6 spread on the bottom surface 2 of the powder bed box is 1 cm. At the same time, the heating plate 21 on the left side of the powder spreading device is started, and the heating plate 22 on the right side is turned off.

[0040] Then, the print head 7 of the embedded printer starts to install the G code file obtained in step (1) and first moves to the starting position of the first layer of the L shape. Then, according to the half layer thickness set in step (1), i.e., 5 mm, the print head 7 is embedded 5 mm below the printing plane 3 and moves, and the thermosetting epoxy resin 8 is extruded from the print head 7. The moving print head 7 forms a channel 10 of a certain depth and width on the surface of the wood powder 6. The thermosetting epoxy resin 8 with a large flow rate simultaneously fills the dynamic channel 10 immediately. After that, the thermosetting epoxy resin penetrates and diffuses in a controlled and constrained state, and gradually solidifies at room temperature. The printing of this layer is completed; and the thermosetting epoxy resin 8 is extruded from the print head 7. When the print head 7 is embedded below the printing plane 3 and moves, the wood powder 6 is pushed to both sides to accumulate into a wood powder pile 9, forming a channel 10 with a width equal to the diameter of the print head 7. The thermosetting epoxy resin 8 extruded from the print head 7 flows into the L-shaped channel 10 formed when the print head 7 moves in the wood powder 6, and naturally penetrates from the L-shaped channel 10, enters the gap between the wood powder 6 and wraps the wood powder 6, and gradually solidifies at room temperature, and the printing of this layer is completed;

[0041] (3) Repeat step 2 to complete the printing of a layer of L-shaped model, and then print layer by layer. When printing to the seventh layer, the powder bed box 4 now includes Figure 1The first layer 15 is a fully cured layer, in which the thermosetting epoxy resin 8 has been extruded, the natural impregnation has been completed, and the bonding with the previous layer has been completed, and the layer has been cured; the second layer 16 is a semi-cured layer, in which the thermosetting epoxy resin 8 has been extruded, the natural impregnation has been completed, and the bonding with the previous layer has been completed, and the layer has been cured, but the curing 14 has not been completed; the third layer 17 is a fully impregnated layer, in which the thermosetting epoxy resin 8 has been extruded, the natural impregnation has been completed, and the bonding with the previous layer has been completed, and the layer has been cured, but the curing 14 has not been completed; The fourth layer 18 is an interlayer bonding layer, in which the thermosetting epoxy resin 8 has been extruded and the natural impregnation has been completed, but the interlayer bonding with the previous layer has just begun 12; the fifth layer 19 is an in-situ impregnation layer, in which the thermosetting epoxy resin 8 has been extruded, but the natural impregnation has not been completed 11; the sixth layer 20 is a printing layer, in which the thermosetting epoxy resin 8 is being extruded; printing continues until the last layer is printed and the printing work is finished;

[0042] (4) After printing is completed, the powder bed box 4 is left to stand for a period of time to wait for the liquid binder 8 to solidify and obtain a printed part with a certain mechanical strength. The powder bed box 4 is unloaded from the printer. According to the process characteristics of wood powder and thermosetting epoxy resin, the powder bed box 4 and the wood powder in the powder bed box 4 are heated at 135 degrees Celsius for 120 minutes to obtain an L-shaped printed part with enhanced mechanical strength.

[0043] (5) The L-shaped printed part is placed in the machine tool for installation. The L-shaped three-dimensional model drawn in step (1) is finely processed to finally obtain the L-shaped model.

[0044] The above-described embodiments merely express the implementation methods of the present invention, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A parts processing method based on embedded immersion 3D printing, characterized in that: The parts processing method is to bury the printing nozzle below the printing plane and extrude liquid binder during the 3D printing process. The moving printing nozzle forms a dynamic water channel of a certain depth and width on the surface of the powder material, and at the same time, the dynamic water channel is instantly filled with liquid binder to form a printed entity.

2. A parts processing method based on embedded immersion 3D printing according to claim 1, characterized in that: The parts processing method comprises the following steps: Step (1), creating a three-dimensional model of the target object to be printed, and obtaining printing data of the target object; the printing data includes: the movement trajectory of the printing nozzle (7), the powder spreading action of the powder spreading device (5), the powder spreading thickness during each layer printing, and the lifting action of the elevator (1); wherein in the lifting action of the elevator (1), the height of each descent of the elevator (1) is the printing layer thickness of the layer; Step (2), starting to print layer by layer based on the printing data of the target object obtained in step (1), specifically: First, the elevator (1) at the bottom of the printer moves according to the ascending action of the elevator (1) obtained in step (1). When the elevator (1) contacts the bottom surface (2) of the powder bed box, the two are locked by an electromagnet so that the two can achieve the effect of lifting together; the elevator (1) continues to rise to raise the bottom surface (2) of the powder bed box (4) to a position aligned with the printing plane (3), and then descends by the thickness of the printing layer; at this time, the powder material (6) is loaded in the powder spreading device (5) waiting for powder spreading, the powder bed box (4) is empty, and the bottom surface (2) of the powder bed box is lower than the printing plane (3) by the thickness of the printing layer; Secondly, the powder spreading device (5) of the printer spreads powder on the printing plane (3) and scrapes the powder material (6) flat according to the powder spreading action in step (1) and the powder spreading thickness when printing the layer, and the powder spreading action of the powder spreading device (5) is bidirectional reciprocating powder spreading; Finally, the print head (7) of the embedded printer begins to move to the starting position of the layer of graphics according to the moving trajectory of the print head (7) obtained in step (1), and then moves the print head (7) below the printing plane (3) according to the embedding depth set in step (1), and squeezes out the liquid binder (8) from the print head (7), and the moving print head (7) forms a dynamic channel (10) on the surface of the powder material (6), and the liquid binder (8) instantly fills the dynamic channel (10), and then the liquid binder penetrates and diffuses in a controlled and constrained state to form a printed entity; Step (3), looping step (2), obtaining an in-situ impregnation layer, in which the liquid binder (8) has been extruded, but the natural impregnation behavior has not been completed, and as the print head (7) moves, the penetration degree of the area where the liquid binder (8) is extruded first is greater than that of the area where the liquid binder (8) is extruded later; Step (4), looping step (2), obtaining an interlayer bonding layer, in which the liquid binder (8) has been extruded and the natural impregnation behavior has exceeded the thickness of one printing layer and has begun to bond with the previous layer, and as the printing nozzle (7) moves, the area where the liquid binder (8) is extruded first is first bonded with the in-situ impregnation layer, and the area where the liquid binder (8) is extruded later has not yet begun to bond with the in-situ impregnation layer; Step (5), looping step (2), obtaining a completely impregnated layer, in which the liquid binder (8) has been extruded, the natural impregnation behavior has been completed and the layer has been completely combined with the interlayer bonding layer, but the layer has not reached the time for the crosslinking reaction; Step (6), looping step (2), as printing progresses, the liquid binder gradually solidifies to obtain a semi-solidified layer, in which the liquid binder (8) has been extruded, the natural impregnation behavior has been completed and the semi-solidified layer has been completely combined with the interlayer bonding layer, and as the print head 8 moves, the cross-linking reaction degree of the area where the liquid binder (8) is extruded first is greater than that of the area where the liquid binder (8) is extruded later; Step (7), looping step (2) to obtain a completely cured layer, in which the cross-linking reaction between the matrix material and the curing agent has been completed, and the curing is achieved; Step (8), looping step (2) until printing is completed; after printing is completed, the powder bed box (4) is left to stand until the liquid binder (8) is completely solidified, so as to obtain a printed part with a certain mechanical strength; Step (9), performing post-heating treatment on the printed part obtained in step (8) to obtain a printed part with enhanced mechanical strength, and then performing fine processing on the printed part to obtain the final target object entity.

3. A parts processing method based on embedded immersion 3D printing according to claim 2, characterized in that: The step (1) is specifically as follows: A three-dimensional model of a target object to be printed is created, and the created three-dimensional model of the target object is imported into 3D printing slicing software for parameter setting. After the parameters are set, the slicing software automatically slices the three-dimensional model of the target object and obtains printing data of the target object that can be used by the printer; the key parameter in the parameter setting is the embedding depth; the embedding parameter refers to the distance from the lowest point of the printing nozzle (7) to the printing plane (3) with the printing plane (3) as the reference plane.

4. A part processing method based on embedded immersion 3D printing according to claim 2, characterized in that: The bidirectional reciprocating powder spreading in step (2) is specifically as follows: when printing each layer, the powder spreading device (5) only moves once in one direction to complete the powder spreading action, and then the powder spreading device (5) stops at one side of the printer, and when starting to spread the next layer of powder, it moves from this side to the other side, and repeats this process; during the powder spreading process, the heating plate on the powder spreading device (5) heats the area below.

5. A part processing method based on embedded immersion 3D printing according to claim 2, characterized in that: In the step (2): The powder bed box (4) is a rectangular block without a cover on the top, and the four sides of the powder bed box (4) are mechanically locked with the printer; the bottom surface (2) of the powder bed box is an aluminum plate that can move up and down, and during the printing process, it is locked with the elevator (1) through an electromagnet to achieve a joint lifting effect; the entire printing process of the target object is completed on the bottom surface (2) of the powder bed box.

6. A part processing method based on embedded immersion 3D printing according to claim 2, characterized in that: In the step (2): The printing plane (3) is a hollow aluminum plate, and its shape is the same as that of the bottom surface (2) of the powder bed box. When the bottom surface (2) of the powder bed box rises to align with the printing plane (3), the bottom surface (2) of the powder bed box and the hollow position of the printing plane (3) form a complete plane; when the bottom surface (2) of the powder bed box drops a distance equal to the thickness of the printing layer, the powder material (6) spread by the powder spreading device (5) falls onto the bottom surface (2) of the powder bed box, and the powder material (6) that falls onto the printing plane (3) is scraped into the recycling device.

7. A part processing method based on embedded immersion 3D printing according to claim 2, characterized in that: The powder spreading device (5) in the step (2) is composed of three parts: a powder spreading frame, a powder box and a heating plate.

8. A part processing method based on embedded immersion 3D printing according to claim 2, characterized in that: The powder material (6) includes metal powder material, polymer powder material, ceramic powder material, polymer coated powder material, mixed powder material and various solid powder particles; short fibers can also be added to the powder material (6) as a reinforcing material.

9. A part processing method based on embedded immersion 3D printing according to claim 2, characterized in that: The liquid adhesive (8) is formed by mixing a base material and a curing agent.

10. A part processing method based on embedded immersion 3D printing according to claim 9, characterized in that: The matrix includes epoxy resin, polyurethane or other thermosetting polymer materials; the curing agent includes universal epoxy resin curing agent.

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