CN218503350U

CN218503350U - 3D printing system

Info

Publication number: CN218503350U
Application number: CN202222771686.7U
Authority: CN
Inventors: 沈李耀威
Original assignee: Yunyao Shenwei Jiangsu Technology Co ltd
Current assignee: Yunyao Shenwei Jiangsu Technology Co ltd
Priority date: 2022-10-21
Filing date: 2022-10-21
Publication date: 2023-02-21
Anticipated expiration: 2032-10-21

Abstract

The application provides a 3D printing system, has: a first laser (11), the first laser (11) being arranged to selectively emit a laser beam according to a processing path of a shaped object (12) to melt powder on a powder bed (20) to form a cross-sectional layer (121) of the shaped object (12); a second laser (13), the second laser (13) being arranged to scan along a contour (122) of the cross-sectional layer (121) to remove powder particles adhering to the contour (122). So as to realize the surface finish of the formed object (12) at the current section layer profile and improve the surface quality of the formed object (12).

Description

3D printing system

Technical Field

The utility model relates to a vibration material disk field especially relates to a 3D printing system.

Background

The 3D printing technique melts the powder on the powder bed according to the planed cross section of the component by a heat source, such as laser, during the forming process of the component, so as to form a cross section layer of the component, and forms the complete 3D printed component by stacking layer by layer.

The surface of a component in the conventional 3D printing mode has a remarkable layer step effect due to layer-by-layer accumulation, and in addition, at the section profile, a part of incompletely-melted powder particles are adhered to a laser melting pass and are finally adhered to the surface of the component, so that the surface of the component is very rough, the direct requirement of the 3D printing component is difficult to meet, or the rough surface often needs a large amount of post-treatment such as manual polishing and grinding, and the forming delivery efficiency of the 3D printing component is reduced.

SUMMERY OF THE UTILITY MODEL

In order to reduce the roughness on 3D printing component surface, improve the surface quality that 3D printed the component, the utility model discloses an one of them aspect provides a 3D printing system, has: a first laser configured to selectively emit a laser beam according to a processing path of a shaped object to melt powder on a powder bed to form a cross-sectional layer of the shaped object; and a second laser arranged to scan along the profile of the cross-sectional layer to remove powder particles adhering to the profile.

Optionally, the working depth of the laser beam emitted by the second laser acting on the powder bed is greater than or equal to the depth of the molten pool formed on the powder bed by the laser beam emitted by the first laser acting on the powder bed.

Optionally, the second laser is a pulsed laser.

Optionally, the laser emitted by the second laser is a femtosecond laser.

Optionally, the femtosecond laser has a duration of 5 femtoseconds to 1000 picoseconds.

Optionally, the 3D printing system of the present invention has a galvanometer system that adjusts the path of movement of the laser beam based on the deflection motion; the first laser and the second laser share a galvanometer system.

Optionally, the 3D printing system of the present invention has a flat field focusing lens for adjusting the size of the laser beam spot based on focusing so that it is incident on the processing platform; wherein the first laser and the second laser share a flat field focusing mirror.

Optionally, the profile of the cross-sectional layer has an outer profile and/or an inner profile.

Optionally, the second laser is arranged to scan along the profile of the cross-sectional layer to vaporise powder particles adhered to the profile.

Wherein the utility model discloses a first laser instrument is according to the machining path selectivity transmission laser beam of shaping object in order to melt the cross-section layer that the powder formed the shaping object on the powder bed, scans the powder granule in order to drive glutinous on the profile through the profile of second laser instrument along the cross-section layer to realize the surface finish of the current cross-section layer profile department of shaping object, improved the shaping object and also the surface quality that 3D printed the component.

Wherein the utility model discloses a working depth that the laser beam that will second laser instrument transmission is used on the powder bed sets up the depth h that the laser beam that more than or equal to first laser instrument transmission was used in the molten bath that forms on the powder bed, can guarantee that the profile surface that the laser beam clearance of second laser instrument transmission was accomplished does not receive the influence of lower one deck molten bath to can keep the laser beam clearance profile's of second laser instrument transmission effect.

Wherein the utility model discloses a make first laser instrument and second laser instrument sharing one set of galvanometer system, the course of working that can guarantee different laser instruments realizes accurate repeated positioning.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only the embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a mechanical unit of a 3D printing system according to an embodiment of the present invention;

fig. 2 is a schematic diagram illustrating a structure of an optical path unit of a 3D printing system according to an embodiment of the present invention;

fig. 3 (a) is a schematic diagram showing a laser beam laser1 forming a cross-sectional layer of a forming object on a processing platform according to an embodiment of the present invention, and (b) is a schematic diagram showing a laser beam laser2 scanning a profile of the cross-sectional layer according to an embodiment of the present invention;

fig. 4 is an expanded schematic view of cross-sectional layers of a formed object according to an embodiment of the present invention;

fig. 5 (a) is a schematic diagram showing a laser beam laser1 constructed to form a cross-sectional layer of a forming object on a processing platform according to another embodiment of the present invention, and (b) is a schematic diagram showing a laser beam laser2 scanning a profile of the cross-sectional layer according to another embodiment of the present invention;

fig. 6 is a schematic view showing the working depth of laser beam laser2 acting on the powder bed according to one embodiment of the present invention;

FIG. 7 is a schematic view of the molten bath topography during forming provided by one embodiment of the present invention;

fig. 8 is a schematic structural diagram of a laser according to an embodiment of the present invention;

fig. 9 (a) is a schematic structural diagram of a blood vessel stent provided in one embodiment of the present invention, and (b) is a schematic structural diagram of a cross-sectional layer of a blood vessel stent scanned by laser beam laser2 provided in one embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary intended for explaining the present invention, and should not be construed as limiting the present invention.

According to the utility model discloses wherein 3D printing system that provides, it can be a 3D printing device, and the 3D printing device that describes here preferably uses the laser beam/electron beam as the 3D printing classification of energy source, for example Selective Laser Sintering (SLS), selective Laser Melting (SLM) and so on classification.

Powder bed based 3D printing techniques all require pre-laying of powder in a fabrication room, laser scanning to melt the material and allow the loose powder to solidify together, scanning one layer after the other, laying the powder one layer after the other, the telescopic platform sinking down and finally obtaining the entity wrapped by the powder.

The utility model discloses 3D printing system comprises several parts such as mechanical unit, light path unit and computer control system at least. In a specific spatial arrangement form, the optical path unit can be arranged above the mechanical unit, and can also be arranged on the basis of the core invention point taught by the application according to the actual structural design. In the control logic, the control of the mechanical unit and the optical path unit is realized by a computer control system.

Referring to fig. 1, in some embodiments, the mechanical unit of the 3D printing system of the present invention is composed of at least a building chamber 29,

powder feeding cylinders

24,25, a building piston 27,

powder feeding pistons

26,28, and a powder spreading device 23.

Specifically, the build chamber 29 is also called a forming cylinder in which the build of the formed object 12 (the formed object 12 described herein is a 3D printed part/component/workpiece) is performed, the distance each time the forming cylinder is lowered is the layer thickness; after the build of the object 12 is completed, the forming cylinder is raised to facilitate removal of the built workpiece and to prepare it for the next build. The lifting of the forming cylinder is driven by the building piston 27. The

powder feeding cylinders

24,25 are provided at one side of the building chamber 29 for supplying the powder material to the building chamber 29 and/or collecting the powder remnants. The

powder supply cylinders

24 and 25 are interchangeable, as temporary powder supply cylinders or surplus collecting cylinders, in the direction of movement of the powder laying device 23 for supplying the powder to be laid or for storing surplus powder on the processing platform 22 intermediate the

powder supply cylinders

24 and 25 after each powder laying process. The

powder feeding cylinders

24,25 are driven to move up and down by

powder feeding pistons

26, 28. The powder spreading device 23, which may be in particular one of a powder spreading brush, a powder spreading roller and a scraper, is arranged above the building chamber 29 and the

powder supply cylinders

24,25 for evenly spreading the powder material on the processing platform 22 and/or for conveying the powder residue to the

powder supply cylinders

24,25. The powder described herein refers to the material to be processed, and is used in a powder state. For example, the powder may consist essentially of a material made of metal or polymer. During the build process, the powder is laid layer by layer on the processing platform 22, thereby forming the powder bed 20 in the build chamber 29.

During the construction of the formed object 12, a current planing cross section layer of the formed object 12 is constructed on the powder bed 20 layer by layer, after the construction is completed, the processing platform 22 descends by a first layer thickness Δ d, the powder spreading device 23 drives the powder to be formed to move, a next powder layer is laid on the processing platform 22, the laser beam forms the next powder layer of the formed object 12 on the next powder layer according to a preset path, a tiny molten pool appears at the position where the laser spot scans in the forming process, so that the metal powder is melted to form the current layer, and the process is repeated in a circulating manner until the construction of the formed object 12 is completed.

Referring to fig. 1 to 3, in some embodiments, the optical path unit of the 3D printing system of the present invention has a first laser 11 and a second laser 13. The first laser 11 is arranged to selectively emit a laser beam according to a processing path of the shaped object 12 to melt powder on the powder bed 20 to form a cross-sectional layer 121 of the shaped object 12, i.e. the first laser 11 is used to perform the above described building process of the shaped object 12. While the second laser 13 is arranged to scan along the profile 122 of the cross-sectional layer 121 to remove powder particles adhering to the profile 122 to achieve a surface finish at the profile 122 of the current cross-sectional layer 121 of the shaped object 12. In other alternative embodiments, the second laser may cut the first laser-shaped residual, and since the second laser is a femtosecond very small spot laser, the surface finish at the cross-sectional profile 122 may be achieved by cutting the residual.

In fig. 3 (a), laser beam laser1 selectively emitted by first laser 11 acts on processing platform 22 of powder bed 20 to melt powder to form cross-sectional layer 121 of formed object 12, and the edge of cross-sectional layer 121 forms contour 122. In fig. 3 (b), laser beam laser2 selectively emitted by second laser 13 performs a clockwise or counterclockwise closed-loop scan along profile 122 of cross-sectional layer 121 to remove powder particles adhered on profile 122. When the laser beam laser2 scans the contour 122 of the cross-sectional layer 121, the laser beam laser1 is selectively emitted by the first laser 11 according to a predetermined path to construct a new cross-sectional layer above the cross-sectional layer 121.

In one embodiment, each time laser beam laser1 completes the construction of one cross-sectional layer 121, the profile 122 of the current cross-sectional layer 121 is scanned by laser beam laser2 once, i.e., in a manner of scanning layer by layer, i.e., scanning profile by profile, until the complete construction of the formed object 12 is completed. In another embodiment, the laser beam laser1 does not perform a cumulative scan of the profile 122 of the cumulative cross-sectional layer 121 until the laser beam laser1 completes the building of several layers of the cross-sectional layer 121, that is, the cumulative scan is performed in a profile-by-profile scanning manner until the forming object 12 is completely built. The number of layers described herein may be 2, 3 or even more layers (depending on whether the multi-layer cross-section is consistent in the vertical projection in the shaped object 12 relative to the processing platform 22, the working depth of the second laser, etc.). Referring to fig. 4, 121-1,121-2,121-3, and 121-4 are the first to fourth interface layers of the formed object 12, respectively, in the order from bottom to top. According to the layer-by-layer scanning mode, after the laser beam laser1 completes the construction of the section layer 121-1, the profile of the section layer 121-1 is scanned by the laser beam laser2, and so on until the profile scanning of the section layer 121-4 is completed. In the cumulative scanning mode, for example, after the laser beam laser1 completes the construction of the cross-sectional layers 121-1,121-2,121-3,121-4, the profile of the cross-sectional layers 121-1,121-2,121-3,121-4 is cumulatively scanned by the laser beam laser 2. The cumulative scan described here means that the working depth of the laser beam laser2 on the processing platform 22 is at least equal to or greater than the depth of the cross-sectional layers 121-1,121-2,121-3, 121-4.

Wherein, the utility model discloses preferably take the former, the mode of successive layer scanning.

Referring to fig. 5, in some embodiments, profile 122 of cross-sectional layer 121 has an outer profile 123 and/or an inner profile 124.

In fig. 5 (a), laser beam laser1 selectively emitted by first laser 11 acts on processing platform 22 of powder bed 20 to melt powder to form cross-sectional layer 121 of formed object 12, and outer edge of cross-sectional layer 121 forms outer contour 123 and inner edge forms inner contour 124. In fig. 5 (b), the laser beam laser2 selectively emitted by the second laser 13 performs a clockwise or counterclockwise closed-loop scan along the outer contour 123 of the cross-sectional layer 121 to remove the powder particles adhered to the outer contour 123, and performs a clockwise or counterclockwise closed-loop scan along the inner contour 124 of the cross-sectional layer 121 to remove the powder particles adhered to the inner contour 124. After laser beam laser2 scans both outer contour 123 and inner contour 124 of cross-sectional layer 121, laser beam laser1 is selectively emitted by first laser 11 according to a predetermined path to build a new cross-sectional layer above cross-sectional layer 121.

It was described above that a small puddle may occur at the location where the laser spot is scanned during the forming process. In practice, the depth of the molten pool will usually be greater than the thickness of the layer of laid powder, i.e. the molten pool will remelt the previous layer of melted cross-sectional layer 121 of the formed object 12, so that the current layer can form a very reliable metallurgical bond with the previous layer. FIG. 7 shows a schematic view of the topography of the melt pool 21 during the forming process. During forming, the depth h of the melt pool 21 tends to be greater than the spread thickness Δ d to achieve bonding with the previous layer.

For this reason, as shown with reference to fig. 6 to 7, in some embodiments, the working depth of laser beam laser2 emitted by second laser 13 acting on powder bed 20 is set to be equal to or greater than depth h of molten pool 21 formed by laser beam laser1 emitted by first laser 11 acting on powder bed 20. By setting the working depth of second laser 13 to be equal to or greater than h, it can be ensured that the contour surface finished by laser2 cleaning is not affected by the molten pool melting the next layer of powder, so that the effect of laser2 cleaning the contour can be retained.

First laser 11 and second laser as used in the present applicationClasses of optical devices 13 include, but are not limited to, ultraviolet lasers, fiber lasers, and CO ₂ A laser, etc. For example, fig. 8 shows a specific structure diagram of a laser, which can be used as both the first laser 11 and the second laser 13.

In some embodiments, first laser 11 and/or second laser 13 are pulsed lasers. The laser light emitted by the first laser 11 and/or the second laser 13 is femtosecond laser light. The duration of the femtosecond laser is 5 femtoseconds to 1000 picoseconds.

In some embodiments, the second laser 13 is configured to scan along the profile 122 of the cross-sectional layer 121 to gasify and clean powder particles adhered to the profile 122, thereby maintaining a low roughness of the surface of the profile 122, and remelting the surface of the profile 122 improves the surface quality of the formed object 12.

Referring to fig. 2, in some embodiments, the optical path unit of the 3D printing system of the present invention further has a galvanometer system 14 for adjusting the moving path of the laser beam based on the deflection motion; the first laser 11 and the second laser 13 share a galvanometer system 14. The first laser 11 and the second laser 13 can ensure that the processing processes of different lasers can realize accurate repeated positioning by sharing a set of vibrating mirror system 14.

In some embodiments, the optical path unit of the 3D printing system of the present invention further has a flat field focusing mirror 15 for adjusting the size of the laser beam spot based on focusing so that the laser beam spot is incident on the processing platform 22; wherein the first laser 11 and the second laser 13 share a flat field focusing mirror 15.

In some embodiments, the optical path unit of the 3D printing system of the present invention further has a first collimating mirror 16 and a first reflecting mirror 17 cooperating with the first laser 11, and a second collimating mirror 18 and a second reflecting mirror 19 cooperating with the second laser 13. Based on the fact that the path of the laser beam emitted by the first laser 11 is set to be derived into a parallel laser beam through the first collimating mirror 16, the projection direction of the laser beam is changed through the first reflecting mirror 17 after the laser beam is emitted from the first collimating mirror 16, the moving path of the laser beam is adjusted through the vibrating mirror system 14 after the laser beam is emitted from the first reflecting mirror 17, and finally the size of the laser beam spot is adjusted through the flat field focusing mirror 15 so that the laser beam spot is incident on the processing platform 22 to construct the formed object 12. Based on the fact that the path of the laser beam emitted by the second laser 13 is set to be changed into a parallel laser beam by the second collimating mirror 18, the beam projection direction is changed by the second reflecting mirror 19 after being emitted from the second collimating mirror 18, the laser beam moving path is adjusted by the galvanometer system 14 after being emitted from the second reflecting mirror 19, and finally the size of the laser beam spot is adjusted by the flat field focusing mirror 15 so that the laser beam spot is incident on the processing platform 22 to scan along the profile 122 of the cross-section layer 121 to remove the powder particles adhered on the profile 122.

It should be noted that the schematic illustrations of the forming object 12 in fig. 3, 5, and 6 do not represent an actual form thereof, but are merely simplified for convenience of describing the present invention.

Wherein fig. 9 (a) shows a shaped object in a practical form, in particular a vascular stent; fig. 9 (b) shows a schematic representation of the scanning of the profile of one of the cross-sectional layers by laser beam laser2 emitted by a second laser employed in the present invention. Through the utility model discloses a two laser beam machining modes can effectively improve vascular support's surface quality.

In the present application, unless expressly stated or limited otherwise, a first feature "on" or "under" a second feature may be directly contacting the second feature or the first and second features may be indirectly contacting the second feature through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature "under," "beneath," and "under" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

In the above mentioned figures:

first laser 11 powder bed 20

Molten bath-21 of formed object-12

Second laser-13 processing platform-22

Heat dissipation runner-13 powder laying device-23

Galvanometer system-14 powder supply cylinder-24, 25

Flat field focusing lens-15 powder supply pistons-26, 28

First collimating mirror-16 build piston-27

First reflector-17 building chamber-29

Second collimator-18 inner contour-124

Second mirror-19 first layer section layer-121-1

Cross-sectional layer-121 second layer cross-sectional layer-121-2

Profile-122 third layer cross-sectional layer-121-3

Outer contour-123 fourth cross-sectional layer-121-4.

Claims

1. A3D printing system, comprising:

a first laser (11), the first laser (11) being arranged to selectively emit a laser beam according to a processing path of a shaped object (12) to melt powder on a powder bed (20) to form a cross-sectional layer (121) of the shaped object (12);

a second laser (13), the second laser (13) being arranged to scan along a contour (122) of the cross-sectional layer (121) to remove powder particles adhering to the contour (122).

2. A 3D printing system according to claim 1, wherein:

the working depth of the laser beam emitted by the second laser (13) acting on the powder bed (20) is more than or equal to the depth of a molten pool (21) formed on the powder bed (20) by the laser beam emitted by the first laser (11).

3. A 3D printing system according to claim 1, wherein:

the second laser (13) is a pulsed laser.

4. A 3D printing system according to claim 1 or 3, characterized in that:

the laser emitted by the second laser (13) is femtosecond laser.

5. A3D printing system according to claim 4, characterized in that:

the duration of the femtosecond laser is 5 femtoseconds to 1000 picoseconds.

6. A 3D printing system according to claim 1, having:

a galvanometer system (14) for adjusting the moving path of the laser beam based on the deflection motion; wherein the first laser (11) and the second laser (13) share a galvanometer system (14).

7. A3D printing system according to claim 1 or 6, having:

a flat field focusing mirror (15) for adjusting the spot size of the laser beam based on focusing so as to make the laser beam incident on the processing platform (22); wherein the first laser (11) and the second laser (13) share a flat field focusing mirror (15).

8. A 3D printing system according to claim 1, wherein:

the contour (122) of the cross-sectional layer (121) has an outer contour (123) and/or an inner contour (124).

9. A 3D printing system according to claim 1, wherein:

the second laser (13) is arranged to scan along a contour (122) of the cross-sectional layer (121) to vaporize powder particles adhering to the contour (122).