Inverted additive manufacturing method and device based on metal sheets

Abstract

The invention relates to an inverted additive manufacturing method and device based on a metal sheet, and the method comprises the steps: (1) drawing a three-dimensional model diagram according to a metal part needing to be processed, and slicing the three-dimensional model diagram to obtain a plurality of two-dimensional slice diagrams; (2) in a vacuum environment, sintering a metal sheet on the lower surface of the substrate or the upper sintering layer by an energy source according to the two-dimensional slice pattern; (3) cutting off the metal sheet from the substrate along the contour of the two-dimensional slice pattern; (4) driving the substrate to move upwards by a distance which is the same as the thickness of the metal sheet by a driving part; and the steps (2)-(4) are repeated until printing of the part is completed. According to the method, the load of the motor can be reduced, the movement stability of the base plate can be improved, parts with larger sizes can be printed through the same motor and the same torque, in addition, the requirement for the uniformity of a wind field is low, due to the fact that the metal sheets are adopted, possible splashing of metal powder is reduced in the material adding process, and the production efficiency is improved. And the product printing quality is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and in particular relates to a flip-chip additive manufacturing method and device based on metal sheets. Background Art

[0002] Additive Manufacturing (AM) technology is a technology that uses the method of gradually accumulating materials to manufacture physical parts. Compared with traditional material removal-cutting processing technology, it is a "bottom-up" manufacturing method.

[0003] SLM, Selective laser melting, is a major technical approach in additive manufacturing of metal materials. This technology uses laser as the energy source and scans the metal powder bed layer by layer according to the path planned in the 3D CAD slice model. The scanned metal powder is melted and solidified to achieve the effect of metallurgical bonding, and finally the metal parts designed by the model are obtained.

[0004] The existing Selective laser melting, SLM (selective laser melting), is a major technical approach in the additive manufacturing of metal materials. This technology uses laser as the energy source, and scans the metal powder bed layer by layer according to the path planned in the three-dimensional CAD slice model. The scanned metal powder is melted and solidified to achieve the effect of metallurgical bonding, and finally the metal parts designed by the model are obtained. The layer-by-layer scanning usually refers to the metal powder being laid on the substrate by the powder laying mechanism, and then the metal powder laid on the substrate is sintered by laser scanning. After one layer of printing is completed, the substrate drops to a preset height, and then the next layer is printed, and this cycle is repeated until the entire component is printed.

[0005] When the above-mentioned existing SLM metal 3D printing method is used for large or super-large parts, more metal powder needs to be laid on the substrate, and the weight will be greater, even exceeding dozens of tons. The weight leads to a large load, and the motor torque is insufficient at this time. In order to make the motor meet the load requirements, a larger power motor needs to be selected, resulting in larger equipment size, larger floor space, increased cost, and the stability of the equipment cannot be guaranteed.

[0006] The existing SLM metal printing method uses metal powder laser sintering. Since metal powder splashes during the laser sintering process, the uniformity of the wind field is required to be high during the printing process. The larger the product processing size, the higher the requirements for the wind field design. At the same time, it is more difficult for the wind field to effectively remove the residue generated during the laser sintering process. Moreover, if the wind field is uneven, the product roughness will be relatively high and the mechanical properties of the product will be reduced. Summary of the invention

[0007] In order to solve the problems existing in the background technology, the present invention provides a flip-chip additive manufacturing method and device based on metal foil, which can reduce the load of the motor and improve the stability of the substrate movement. The same motor and the same torque can print larger parts. At the same time, it can also reduce the requirements for the wind field, reduce the difficulty of wind field design, and improve the printing quality.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] In one aspect, the present invention provides a method for additive manufacturing based on metal sheets, comprising the steps of:

[0010] (1) drawing a three-dimensional model diagram according to the metal parts to be processed, and slicing the three-dimensional model diagram to obtain a plurality of two-dimensional slice diagrams;

[0011] (2) In a vacuum environment, an energy source located below the substrate sinters the metal sheet on the lower surface of the substrate or the upper sintered layer according to the two-dimensional slice pattern;

[0012] (3) cutting the metal sheet from the substrate along the contour of the two-dimensional slice pattern;

[0013] (4) The substrate is driven by a driving component to move upward by a distance equal to the thickness of the metal sheet, and the driving component is fixed on the top of the substrate;

[0014] Repeat steps (2) to (4) until the parts are printed.

[0015] Furthermore, the metal sheet is a rolled sheet, and the step (3) further includes, after cutting, the metal sheet is driven by a conveying device to move a certain distance in a horizontal direction to remove excess metal sheet from the substrate.

[0016] Furthermore, the energy source is a laser, the power of the laser is less than 2000W, and the scanning speed is ≤10m / s.

[0017] Furthermore, the thickness of the metal sheet is less than 1 mm.

[0018] On the other hand, the present invention also provides a flip-chip additive manufacturing device based on a metal sheet, comprising:

[0019] frame;

[0020] A driving component, wherein the driving component is fixed on the top of the frame;

[0021] A substrate, the output end of the driving component is connected to the substrate, the substrate is located below the driving component, and the driving component drives the substrate to move upward during printing;

[0022] An energy source, the energy source is located below the substrate and is used to sinter and fix the metal sheet on the lower surface of the substrate;

[0023] The cutting mechanism is used to cut off the excess metal sheet from the substrate along the two-dimensional slice contour.

[0024] Furthermore, it also includes a conveying device, which is used to convey the metal sheet to the base for sintering and remove the cut metal sheet from the substrate.

[0025] Furthermore, the conveying device includes a first roller and a second roller, the first roller is used for unwinding, and the second roller is used for winding, one end of the metal sheet is wound on the first roller, and the other end passes through the lower surface of the substrate and is wound on the second roller.

[0026] Furthermore, the driving mechanism is a motor.

[0027] Furthermore, the energy source is a laser or an electron beam.

[0028] Furthermore, the energy source is a first laser, the cutting mechanism is a second laser, the first laser is used for sintering, the second laser is used for cutting, the power of the first laser is less than 2000W, the scanning speed is ≤10m / s, the power of the second laser is less than 3000W, and the scanning speed is ≤10 / s.

[0029] The present invention adopts the above technical solution, which has the following advantages:

[0030] (1) The additive manufacturing method based on metal foil provided by the present invention adopts an inverted driving component. After sintering a layer, the driving component drives the substrate to move upward a distance equal to the thickness of the metal foil, which can reduce the load of the motor and improve the stability of the substrate movement. Under the same motor and the same torque conditions, larger parts can be printed.

[0031] (2) Compared with the existing SLM metal printing, which generates metal powder splashes during the laser sintering process, and has a high requirement for the uniformity of the wind field during the printing process, an uneven wind field will result in a relatively high roughness of the product. The metal sheet provided by the present invention is sintered with a low requirement for the uniformity of the wind field, and the wind field flow rate can be made large enough without worrying about the problem of powder blowing. Because there is enough air volume to take away the metal splashes generated by sintering, the impact of metal powder splashes on the sintering surface is reduced during the additive process, the roughness of the printed product is reduced, and the quality of the printed product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the following detailed description of the preferred embodiment.The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting the invention.

[0033] Throughout the drawings, the same reference numerals are used to denote the same components. In the drawings:

[0034] Figure 1 is a schematic structural diagram of an embodiment of a flip-chip additive manufacturing device based on a metal sheet;

[0035] Figure 2 It is a schematic structural diagram of another embodiment of a flip-chip additive manufacturing device based on metal foil.

[0036] Figure 3 It is a schematic diagram of sintering a metal sheet onto a substrate according to a two-dimensional slice pattern;

[0037] Figure 4 The part is prepared by the metal sheet-based additive manufacturing method provided by the present invention.

[0038] The symbols in the accompanying drawings are as follows:

[0039] 1-motor, 2-piston, 3-laser, 4-substrate, 5-first roller, 6-second roller, 7-connecting plate, 8-lead screw, 9-fixing plate, 10-light rod, 11-metal sheet, 12-cutting mechanism, 13-parts. DETAILED DESCRIPTION

[0040] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0041] The present invention provides an additive manufacturing method based on metal foil, the method comprising: (1) drawing a three-dimensional model diagram according to the metal parts to be processed, slicing the three-dimensional model diagram to obtain a plurality of two-dimensional slice patterns; (2) in a vacuum environment, an energy source sintering the metal foil on the lower surface of the substrate or the upper sintering layer according to the two-dimensional slice pattern; (3) cutting the metal foil from the substrate along the contour of the two-dimensional slice pattern; (4) driving the substrate to move upward by a distance equal to the thickness of the metal foil by a driving component; repeating steps (2) to (4) until the printing of the parts is completed. The method provided by the present invention is used for additive manufacturing, and the driving component is inverted. After sintering a layer, the driving component drives the substrate to move upward by a distance equal to the thickness of the metal foil, which can reduce the load of the motor, improve the stability of the substrate movement, and the same motor and the same torque can print parts of larger sizes. Compared with the existing SLM metal printing, which will produce metal powder splashing during the laser sintering process, and has high requirements for the uniformity of the wind field during the printing process, if the wind field is uneven, it will cause the product roughness to be relatively high. The metal sheet provided by the present invention is sintered, and the requirements for the uniformity of the wind field are low. The possible splashing of metal powder in the additive process is reduced, the roughness of the printed product is reduced, and the quality of product printing is improved.

[0042] Combination Figures 1 to 4 As shown, an embodiment of the present invention provides an additive manufacturing method based on metal sheets, comprising the steps of:

[0043] (1) Draw a three-dimensional model diagram according to the metal parts to be processed, slice the three-dimensional model diagram to obtain multiple two-dimensional slice diagrams; the thickness of the slice is the same as the thickness of the metal sheet. The thickness of the metal sheet 11 is preferably less than 1 mm.

[0044] (2) In a vacuum environment, the energy source 3 located below the substrate sintered the metal sheet 11 on the lower surface of the substrate 4 or the upper sintered layer according to the two-dimensional slice pattern, thereby completing the sintering of a metal layer;

[0045] (3) cutting off the excess metal sheet 11 from the substrate 4 along the contour of the two-dimensional slice pattern;

[0046] (4) The substrate 4 is driven by the driving component 1 to move upward by a distance equal to the thickness of the metal sheet 11, and the driving component is fixed on the top of the substrate;

[0047] (5) Repeat steps S2 to S4 until the printing of component 13 is completed.

[0048] In the step (3), after the energy source 3 sintered and fixed the metal sheet 11 on the substrate 4 or the lower surface of the previous sintered layer, the metal sheet 11 is cut or punched along the contour of the two-dimensional slice pattern to remove excess metal sheet.

[0049] After cutting, the metal sheet 11 is moved horizontally by the conveying device for a certain distance, so that a new complete metal sheet 11 covers the lower surface of the substrate 4 .

[0050] The energy source 3 is a laser or an electron beam. The laser is emitted by a first laser. The power of the first laser is less than 2000 W, and the scanning speed is ≤10 m / s.

[0051] By adopting the method provided by the present invention, the metal sheet 11 passes through the lower surface of the substrate 4 and is sintered on the lower surface of the substrate 4. After sintering a metal layer, the motor 1 drives the substrate 4 to move upward by a distance of the thickness of the metal sheet 11. The method can reduce the load of the motor, improve the stability of the movement of the substrate 4, and the same motor with the same torque can print larger parts. In addition, the existing SLM metal printing method has high requirements for the uniformity of the wind field during the printing process. Since metal powder splashes during the laser sintering process, an uneven wind field will cause the product to have a relatively high roughness. The method of sintering the metal sheet 11 provided by the present invention has low requirements for the uniformity of the wind field, because the metal sheet 11 is used, so the splash of metal powder that may occur during the additive process is reduced, and the quality of product printing is improved.

[0052] The present invention also provides a flip-chip additive manufacturing device based on metal sheets, comprising a frame, a driving component 1, a substrate 4, an energy source 3 and a cutting mechanism 12. The driving component 1 is fixed on the top of the frame; the output end of the driving component 1 is connected to the substrate 4, the substrate 4 is located below the driving component 1, and the driving component 1 drives the substrate 4 to move upward during printing; the energy source 3 is located below the substrate 4, and is used to sinter and fix the metal sheet 11 on the lower surface of the substrate 4; the cutting mechanism 12 is used to cut off the excess metal sheet 11 from the substrate 4 along the two-dimensional slice contour.

[0053] The driving component 1 is fixed on the top of the frame, and after each layer is sintered, the driving component 1 drives the substrate 4 to move upward by a distance equal to the thickness of the metal sheet 11 during printing. Compared with the prior art method in which the driving component is fixed at the bottom of the substrate and the substrate is lowered to a certain height after each layer is printed, the present invention adopts a reverse mounting method of the driving component, and after sintering a layer, the driving component drives the substrate to move upward by a distance equal to the thickness of the metal sheet, which can reduce the load of the motor, improve the stability of the substrate movement, and can print larger parts under the same motor and the same torque conditions.

[0054] The flip-chip device further includes a conveying device, which is used to convey the metal sheet 11 to the substrate 4 for sintering and remove the cut metal sheet 11 from the substrate 4 .

[0055] As a preferred embodiment, the conveying device includes a first roller 5 and a second roller 6, the first roller 5 is used for unwinding, and the second roller 6 is used for winding, one end of the metal sheet 11 is wound around the first roller 5, and the other end passes through the lower surface of the substrate 4 and is wound around the second roller 6.

[0056] The driving component 1 includes a motor. In order to improve the running accuracy of the substrate 4, the driving component 1 also includes a lead screw 8, a transmission nut, a connecting plate 7 and a polished rod 10. The output end of the motor 1 is connected to the lead screw 10, and the transmission nut sleeved on the lead screw 10 is fixedly connected to the connecting plate 7. The connecting plate 7 moves up and down under the driving action of the lead screw 8 and the transmission nut. The two ends of the connecting plate 7 are also fixedly connected to the polished rod 10. The bottoms of the lead screw 8 and the polished rod 10 pass through the fixed plate 9 and are fixed to the fixed plate 9. The lead screw 8 and the polished rod 10 are rotatably matched with the fixed plate 9, and the bottom of the polished rod 10 is fixedly connected to the piston 2. The structure can improve the stability and accuracy of the transmission and improve the quality of printing.

[0057] like Figure 2 As shown, when a layer of laser sintering is completed, in order to cut the sintered layer from the metal sheet 11, the flip-chip additive manufacturing device based on the metal sheet further includes the cutting mechanism 12, which is used to cut the metal sheet 11 from the substrate along the contour of the two-dimensional slice pattern according to the planned path. The cutting mechanism 12 can use an existing tool for cutting. As another embodiment, the cutting mechanism 12 can also be laser cutting.

[0058] The laser includes a first laser and a second laser, the first laser is used for sintering, the second laser is used for cutting, the power of the first laser is less than 2000W, the scanning speed is ≤10m / s, the power of the second laser is less than 3000W, the scanning speed is ≤10 / s.

[0059] The method can reduce the load of the motor 1, improve the stability of the movement of the substrate 4, and the same motor 1 can print larger parts under the same torque conditions. The method of sintering the metal sheet 11 provided by the present invention has lower requirements on the uniformity of the wind field, because the metal sheet 11 is used, so the splash of metal powder that may occur during the additive process is reduced, and the quality of product printing is improved.

[0060] 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flip-chip additive manufacturing method based on metal sheets, characterized in that: Includes steps: (1) Drawing a three-dimensional model diagram according to the metal parts to be processed, and slicing the three-dimensional model diagram to obtain a plurality of two-dimensional slice diagrams; (2) In a vacuum environment, an energy source located below the substrate sinters the metal sheet onto the lower surface of the substrate or the upper sintered layer according to the two-dimensional slice pattern; (3) cutting the metal sheet from the substrate along the contour of the two-dimensional slice pattern; (4) The driving component drives the substrate to move upward a distance equal to the thickness of the metal sheet; Repeat steps (2) to (4) until the parts are printed.

2. The flip-chip additive manufacturing method based on metal foil according to claim 1, characterized in that: The metal sheet is a rolled sheet, and the step (3) further includes, after cutting, the metal sheet is driven by a conveying device to move a certain distance in a horizontal direction to remove excess metal sheet from the substrate.

3. The flip-chip additive manufacturing method based on metal foil according to claim 1, characterized in that: The energy source is a laser, the power of the laser is less than 2000W, and the scanning speed is ≤10m / s.

4. The flip-chip additive manufacturing method based on metal foil according to claim 1, characterized in that: The thickness of the metal sheet is less than 1 mm.

5. A flip-chip additive manufacturing device based on metal sheets, characterized in that: include: frame; A driving component, wherein the driving component is fixed on the top of the frame; A substrate, the output end of the driving component is connected to the substrate, the substrate is located below the driving component, and the driving component drives the substrate to move upward during printing; An energy source, the energy source is located below the substrate and is used to sinter and fix the metal sheet on the lower surface of the substrate; The cutting mechanism is used to cut off the excess metal sheet from the substrate along the two-dimensional slice contour.

6. The metal sheet-based flip-chip additive manufacturing device according to claim 5, characterized in that: It also includes a conveying device, which is used to convey the metal sheet to the substrate for sintering and remove the cut metal sheet from the substrate.

7. The metal sheet-based flip-chip additive manufacturing device according to claim 5, characterized in that: The conveying device includes a first roller and a second roller, the first roller is used for unwinding, and the second roller is used for winding, one end of the metal sheet is wound on the first roller, and the other end passes through the lower surface of the substrate and is wound on the second roller.

8. The metal sheet-based flip-chip additive manufacturing device according to claim 5, characterized in that: The driving mechanism is a motor.

9. The metal sheet-based flip-chip additive manufacturing device according to claim 5, characterized in that: The energy source is a laser or an electron beam.

10. The metal sheet-based flip-chip additive manufacturing device according to claim 5, characterized in that: The energy source is a first laser, the cutting mechanism is a second laser, the first laser is used for sintering, the second laser is used for cutting, the power of the first laser is less than 2000W, the scanning speed is ≤10m / s, the power of the second laser is less than 3000W, the scanning speed is ≤10 / s.

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