Self-adaptive layer thickness 3D printing method and application thereof
By performing multi-directional slicing and layer thickness matching of the digital model of 3D printed workpieces, the step effect problem of 3D printed workpieces on beveled or curved surfaces is solved, and an efficient 3D printing process and excellent workpiece surface morphology is achieved.
Patent Information
- Application Number
- CN202411758066.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-03-07
AI Technical Summary
3D printed workpieces are prone to step effects on inclined surfaces or curved surfaces with large inclination angles, which affects the dimensional precision. The prior art requires a very small layered thickness when weakening the step effect to extend the workpiece forming time.
By dividing the digital model of the workpiece to be printed in at least two directions of the X, Y and Z axes, dividing it into different regions, and matching the layer thickness of each region with the allowable layer thickness of the 3D printing device, each slice is divided into 1 or more printing areas, and slicing areas with similar layer thicknesses are combined for composite printing.
This method greatly improves 3D printing efficiency, reduces the occurrence of step effects, shortens printing time, and improves the surface morphology quality of the workpiece.
Smart Images
Figure CN119566330A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of 3D printing, and in particular to a 3D printing method with adaptive layer thickness and application thereof. Background Art
[0002] 3D printing technology is a layered manufacturing technology that slices the digital model of the workpiece to be printed and then stacks the materials layer by layer to form it. Due to the layered printing method, 3D printed workpieces often have certain steps. Such steps are often on inclined surfaces or curved surfaces with large inclination angles, which have a greater impact on some 3D printed workpieces with high dimensional precision requirements. If you want to reduce the step effect, you must use a very small layer thickness to print uniform and equal layer thickness slices, but this will prolong the workpiece molding time, and not all layers need to be printed with the minimum layer thickness.
[0003] In view of this, the present invention is proposed. Summary of the invention
[0004] The purpose of the present invention is to provide a 3D printing method with adaptive layer thickness and its application.
[0005] The present invention is achieved in that:
[0006] In a first aspect, the present invention provides a 3D printing method with adaptive layer thickness, comprising: cutting a digital model of a workpiece to be printed along at least two directions of an X-axis direction, a Y-axis direction or a Z-axis direction to obtain a plurality of slices, wherein the layer thickness in the Z-axis direction corresponding to a single slice is consistent, and then each slice is divided into printing areas of a plurality of thicknesses according to the allowed layer thickness of a 3D printing device; when the layer thicknesses corresponding to the printing areas of adjacent slices within the same Z-axis range are the same, the printing areas corresponding to the adjacent slices are merged into a composite printing area; when the layer thicknesses of the printing areas of adjacent slices are different, they are used as separate printing areas; and powder printing is performed according to the composite printing area and the separate printing area respectively to obtain a 3D printed workpiece.
[0007] The allowable layer thickness of the 3D printing device includes the minimum allowable layer thickness and other allowable layer thicknesses, the other allowable layer thicknesses are greater than the minimum allowable layer thickness, and the other allowable layer thicknesses are multiples of the minimum allowable layer thickness.
[0008] In an alternative embodiment, other allowed layer thicknesses are integer multiples of the minimum allowed layer thickness.
[0009] In an optional embodiment, the other allowed layer thickness is 2 to 10 times the minimum allowed layer thickness.
[0010] In an optional embodiment, when the layer thickness of each slice is greater than twice the minimum allowable layer thickness, the slice is first divided into printing areas using other allowable layer thicknesses, and the minimum allowable layer thickness is used to divide the printing areas for areas that are not divisible by other allowable layer thicknesses.
[0011] In an optional embodiment, other allowable layer thicknesses include an intermediate allowable layer thickness and a maximum allowable layer thickness. When the layer thickness of each slice is greater than twice the minimum allowable layer thickness, the maximum allowable layer thickness is first used to divide the slice into printing areas, and the area that is not divisible by the maximum allowable layer thickness is divided into printing areas using the minimum allowable layer thickness and / or the intermediate allowable layer thickness.
[0012] In an optional embodiment, the workpiece to be printed is cut along the X-axis direction and the Y-axis direction respectively.
[0013] In an optional embodiment, the workpiece to be printed is cut along the X-axis direction, the Y-axis direction and the Z-axis direction respectively.
[0014] In an optional embodiment, the 3D printing device includes any one of a selective laser cladding device, a selective laser sintering device, an electron beam cladding device, a binder jetting device, an arc fuse device, and a melt extrusion device.
[0015] In a second aspect, the present invention provides an application of a method as described in any one of the aforementioned embodiments in improving the printing efficiency of a 3D printed workpiece.
[0016] The present invention has the following beneficial effects:
[0017] The present invention provides a 3D printing method with adaptive layer thickness and its application. By slicing the digital model of the workpiece to be printed along at least two directions of the X, Y and Z axes, the workpiece to be printed can be divided into different areas, and then the layer thickness of each area is matched with the allowed layer thickness of the 3D printing device, and each slice is divided into one or more printing areas. When the printing areas of adjacent slices within the same Z-axis range are the same, the printing areas corresponding to the multiple slices can be divided into composite printing areas, and the rest are used as separate printing areas for powder spreading printing. This method can greatly improve the efficiency of 3D printing, while avoiding the step effect, which is conducive to the further promotion of 3D printing technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.
[0019] Figure 1 A schematic diagram of the printing process of a workpiece provided in Example 1 of the present invention;
[0020] Figure 2 A schematic diagram of the printing process of a workpiece provided in Example 2 of the present invention;
[0021] Figure 3 Schematic diagram of the printing process of the workpiece provided in Examples 3 and 4 of the present invention. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.
[0023] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.
[0024] In a first aspect, the present invention provides a 3D printing method with adaptive layer thickness, comprising:
[0025] S01. Slice the digital model of the workpiece to be printed along at least two directions of the X-axis direction, the Y-axis direction or the Z-axis direction to obtain multiple slices. The layer thickness in the Z-axis direction corresponding to a single slice is consistent. Therefore, it can be understood that the top surface of each slice in the Z-axis direction is a plane.
[0026] Due to the different structures of the workpiece to be printed, the layer thickness of different slices in the Z-axis direction may not be the same. The powder laying method and printing path can be determined according to the layer thickness of each slice, as follows.
[0027] S02. Divide each slice into printing areas of multiple thicknesses according to the allowed layer thickness of the 3D printing device.
[0028] Among them, the allowable layer thickness of the 3D printing device includes the minimum allowable layer thickness and other allowable layer thicknesses.
[0029] Since 3D printing is generally a technology that processes powders through laser to form powders, the laser parameters corresponding to different 3D printing devices are also certain. Correspondingly, the 3D printing device also has a certain allowable layer thickness. Only under the corresponding layer thickness and its corresponding laser parameters can the reliability and accuracy of the obtained 3D printed part structure be guaranteed.
[0030] The minimum allowable layer thickness is the minimum allowable layer thickness of the 3D printing device. For the same powder material, the minimum allowable layer thickness corresponds to a fixed 3D printing process parameter to ensure that the powder layer thickness printed under this parameter can obtain a structurally reliable 3D workpiece.
[0031] The other allowable layer thickness is the layer thickness that can be adjusted by the 3D printing equipment beyond the minimum allowable layer thickness. When the layer thickness increases, the corresponding laser processing strategy and other parameters will also increase to ensure the workpiece molding. Therefore, the other allowable layer thickness is greater than the minimum allowable layer thickness, and the other allowable layer thickness is a multiple of the minimum allowable layer thickness.
[0032] In the existing 3D printing process, in order to ensure the accuracy of the workpiece structure, the minimum allowable layer thickness is often used for layer-by-layer printing. Due to the large number of printed layers, it will not only cause a step effect and affect the workpiece structure, but also prolong the workpiece molding time, reduce the 3D printing efficiency, and affect the widespread application of 3D printing.
[0033] The present invention can divide the workpiece to be printed into different areas by dividing in at least two directions of the X, Y and Z axes, and then match the layer thickness of each area with the allowed layer thickness of the 3D printing device to divide each slice into one or more printing areas.
[0034] S03. When the layer thicknesses corresponding to the printing areas of adjacent slices within the same Z-axis range are the same, the printing areas corresponding to the adjacent slices are merged into a composite printing area; when the layer thicknesses of the printing areas of adjacent slices are different, they are used as separate printing areas; powder printing is performed according to the composite printing area and the separate printing area respectively to obtain a 3D printed workpiece.
[0035] Since the layer thickness of the composite printing area is consistent, powder printing can be performed together in the X direction and / or Y direction. Only laser parameters corresponding to the layer thickness need to be used to quickly shape the workpiece, thereby improving the printing efficiency of the workpiece and reducing the occurrence of step effects, which is conducive to the promotion of 3D printing technology.
[0036] In an optional embodiment, in order to facilitate the powder spreading and the adjustment of the laser power, other allowable layer thicknesses are integer multiples of the minimum allowable layer thickness. However, the control accuracy varies according to different devices, so in other embodiments, other allowable layer thicknesses may also be non-integer multiples of the minimum allowable layer thickness, such as 1.5 times, 1.6 times, 2.2 times or 2.8 times.
[0037] In an optional embodiment, other allowable layer thicknesses are 2 to 10 times the minimum allowable layer thickness, for example, any value among 2 times, 4 times, 6 times, 8 times or 10 times.
[0038] Generally speaking, the larger the allowed layer thickness of a 3D printing device is, the higher the required laser power is. Since the laser power of a 3D printing device has an upper limit, the allowed layer thickness of a 3D printing device also has an upper limit.
[0039] In an optional embodiment, when the layer thickness of each slice is greater than twice the minimum allowable layer thickness, the slice is first divided into printing areas using other allowable layer thicknesses, and the minimum allowable layer thickness is used to divide the printing areas for areas that are not divisible by other allowable layer thicknesses.
[0040] In an optional embodiment, other allowable layer thicknesses include an intermediate allowable layer thickness and a maximum allowable layer thickness. When the layer thickness of each slice is greater than twice the minimum allowable layer thickness, the maximum allowable layer thickness is first used to divide the slice into printing areas, and the area that is not divisible by the maximum allowable layer thickness is divided into printing areas using the minimum allowable layer thickness and / or the intermediate allowable layer thickness.
[0041] For example, assuming that the layer thickness of a slice is 9 units (the unit can be, for example, mm, cm or m, etc., which can be specifically confirmed according to the size of different workpieces), the minimum allowable layer thickness of the 3D printing equipment used is 1 unit, and the maximum allowable layer thickness is 3 units. Therefore, the slice can be divided into three printing areas along the Z axis, and the layer thickness of each printing area is 3 units. The laser parameters corresponding to the maximum allowable layer thickness can be used for powder printing.
[0042] Although in the above example, the slices with 9 unit layer thickness can also be divided into three printing areas with a layer thickness of 2 units and one printing area with a layer thickness of 3 units, or divided into four printing areas with a layer thickness of 2 units and one printing area with a layer thickness of 1 unit, etc., the efficiency of 3D printing can be improved by giving priority to the method of dividing with the maximum allowable layer thickness.
[0043] In an optional embodiment, for some workpieces with relatively simple structures, such as workpieces with a triangular cross-sectional shape, the workpiece to be printed may be processed by cutting along the X-axis direction and the Y-axis direction.
[0044] In an optional embodiment, for some workpieces with relatively complex structures, the workpiece to be printed is divided along the X-axis direction, the Y-axis direction and the Z-axis direction respectively.
[0045] In an optional embodiment, the 3D printing equipment includes any one of a selective laser cladding equipment, a selective laser sintering equipment, an electron beam cladding equipment, a binder jetting equipment, an arc fuse equipment, a melt extrusion equipment, and the like.
[0046] In a second aspect, the present invention provides an application of a method as described in any of the aforementioned embodiments to improve the printing efficiency of a 3D printed workpiece. In a complex model, by slicing the digital model of the workpiece to be printed along at least two directions of the X, Y, and Z axes, different printing strategies can be designed according to the characteristics of the slices. In the complex model, the molding efficiencies of different printing strategies can be compared to adaptively select the most efficient printing strategy.
[0047] Example 1
[0048] This embodiment provides a 3D printing method with adaptive layer thickness, comprising the following steps:
[0049] S01, using 400W selective laser cladding equipment to print Figure 1 The stainless steel workpiece shown. The selective laser cladding equipment has three laser sintering parameters of 20μm, 40μm and 60μm layer thickness. Among them, the minimum allowable layer thickness is 20μm, the other allowable layer thicknesses are 40μm and 60μm, and the maximum allowable layer thickness is 60μm.
[0050] like Figure 1 As shown, when the minimum allowable layer thickness is recorded as Z, the other allowable layer thickness is recorded as 2Z when it is 40 μm, and the other allowable layer thickness is recorded as 3Z when it is 60 μm.
[0051] Through the allowable layer thickness design of the above-mentioned 3D printing equipment, the printed workpiece does not lose details and does not produce unacceptable step effects.
[0052] S02, cut the stainless steel workpiece along the X-axis direction to obtain Figure 1 a, and then Figure 1 The structure shown in a is cut along the Y-axis to obtain multiple strip-shaped slices, such as Figure 1 As shown in b, the top surface of each strip slice is horizontal, and then the height of each strip slice in the Z-axis direction is counted, which is the layer thickness of each strip slice.
[0053] Since the structure obtained after the stainless steel workpiece is cut along the X-axis direction is a right triangle, in order to ensure the morphology of its hypotenuse, the number of times the workpiece is cut along the Y-axis direction should be as dense as possible.
[0054] S03, such as Figure 1 As shown in c, the layer thickness of each strip slice in step S02 is divided by the allowed layer thickness of the 3D printing equipment in step S01 to obtain multiple printing areas.
[0055] because Figure 1The layer thickness of the first strip slice from left to right in c is greater than the maximum allowable layer thickness, so the maximum allowable layer thickness is used preferentially for area division, which can be divided into two printing areas with maximum allowable layer thickness; the layer thickness of the second to fourth strip slices is greater than the maximum allowable layer thickness, so the maximum allowable layer thickness is used preferentially for area division, and the remaining areas that cannot be divided by the maximum allowable layer thickness are divided by other allowable layer thicknesses (2Z), and so on.
[0056] S04. Finally, adjacent slices with the same printing area within the same Z-axis range are merged. For example, the layer thickness of the printing area at the bottom of the first to fourth strip slices is the maximum allowable layer thickness, and they can be merged into a composite printing area; the layer thickness of the printing area at the top of the second to fourth strip slices is the other allowable layer thickness (2Z), and they can be merged into a composite printing area, and so on, until the following is obtained. Figure 1 The 3D printing path planning area shown in d can be based on Figure 1 The printing area shown in d is powdered, and the corresponding laser parameters are selected for 3D printing to obtain a stainless steel workpiece.
[0057] Example 2
[0058] This embodiment provides a 3D printing method with adaptive layer thickness, comprising the following steps:
[0059] S01, using 400W selective laser cladding equipment to print Figure 2 The stainless steel workpiece shown. The selective laser cladding equipment has three laser sintering parameters of 20μm, 40μm and 60μm layer thickness. Among them, the minimum allowable layer thickness is 20μm, the other allowable layer thicknesses are 40μm and 60μm, and the maximum allowable layer thickness is 60μm.
[0060] like Figure 2 As shown, when the minimum allowable layer thickness is recorded as Z, the other allowable layer thickness is recorded as 2Z when it is 40 μm, and the other allowable layer thickness is recorded as 3Z when it is 60 μm.
[0061] Through the allowable layer thickness design of the above-mentioned 3D printing equipment, the printed workpiece does not lose details and does not produce unacceptable step effects.
[0062] S02, cut the stainless steel workpiece along the X-axis direction to obtain Figure 2 The structure shown in a is then printed using the allowable layer thickness of the 3D printing equipment in step S01, and the Z-axis direction is Figure 2 The structure shown in a is marked to obtain Figure 2 The structure shown in b.
[0063] Depend on Figure 2 b shows that the slice shapes of the minimum allowable layer thickness of the three middle layers of the trapezoidal structure are exactly the same, such as Figure 2 As shown in c, it is divided into a composite printing area for 3D printing.
[0064] S03. For Figure 2 The remaining area shown in c is divided along the Y-axis direction to obtain multiple strip slices, the top surface of each strip slice is horizontal, and then the height of each strip slice in the Z-axis direction is counted, that is, the layer thickness of each strip slice.
[0065] According to the method of step S03 and step S04 of embodiment 1, the strip slices are divided into regions to obtain the following: Figure 2 d, the print area is as follows Figure 2 The printing area shown in d is powdered, and the corresponding laser parameters are selected for 3D printing to obtain a stainless steel workpiece.
[0066] Example 3
[0067] This embodiment provides a 3D printing method with adaptive layer thickness, comprising the following steps:
[0068] S01, using 400W selective laser cladding equipment to print Figure 3 The stainless steel workpiece shown. The selective laser cladding equipment has three laser sintering parameters of 20μm, 40μm and 60μm layer thickness. Among them, the minimum allowable layer thickness is 20μm, the other allowable layer thicknesses are 40μm and 60μm, and the maximum allowable layer thickness is 60μm.
[0069] like Figure 3 As shown, when the minimum allowable layer thickness is recorded as Z, the other allowable layer thickness is recorded as 2Z when it is 40 μm, and the other allowable layer thickness is recorded as 3Z when it is 60 μm.
[0070] Through the allowable layer thickness design of the above-mentioned 3D printing equipment, the printed workpiece does not lose details and does not produce unacceptable step effects.
[0071] S02, cutting the stainless steel workpiece along the X-axis direction to obtain a side-lying "convex" shaped structure, and then dividing it along the Z-axis direction using step S02 of Example 2. The slice shapes of the three middle layers of the structure with the minimum allowable layer thickness are exactly the same, and can also be used as a composite printing area for 3D printing.
[0072] The remaining area is divided along the Y-axis direction to obtain a plurality of strip slices, the top surface of each strip slice is horizontal, and then the height of each strip slice in the Z-axis direction is counted, that is, the layer thickness of each strip slice, and then the strip slices are divided into regions according to the method of step S03 and step S04 of embodiment 1 to obtain the following: Figure 3 The printing area shown in a is as follows Figure 3The printing area shown in a is powdered, and the corresponding laser parameters are selected for 3D printing to obtain a stainless steel workpiece.
[0073] Example 4
[0074] This embodiment provides a 3D printing method with adaptive layer thickness. The workpiece and 3D printing device are exactly the same as those in Embodiment 3, and the only difference is that the printing area is divided differently, as follows:
[0075] The stainless steel workpiece is cut along the X-axis direction to obtain a sideways "convex" shaped structure, and then cut along the Y-axis direction to obtain multiple strip slices, each strip slice has a horizontal top surface, and then the height of each strip slice in the Z-axis direction is counted, that is, the layer thickness of each strip slice.
[0076] Then, the strip slices are divided into regions according to the method of step S03 and step S04 of embodiment 1 to obtain the following: Figure 3 b shows the printing area, according to Figure 3 The printing area shown in b is powdered, and the corresponding laser parameters are selected for 3D printing to obtain a stainless steel workpiece.
[0077] An adaptive layer thickness 3D printing method provided by an embodiment of the present invention can prepare workpieces of various shapes more quickly. Compared with the method of printing in sequence with the minimum allowable layer thickness throughout the process, the printing time can be shortened by 1 / 3 to 1 / 2, greatly improving the printing efficiency of 3D printing, and at the same time, the surface morphology of the obtained workpiece is excellent.
[0078] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A 3D printing method with adaptive layer thickness, characterized in that: The method comprises cutting a digital model of a workpiece to be printed along at least two directions of an X-axis direction, a Y-axis direction or a Z-axis direction to obtain a plurality of slices, wherein the layer thickness in the Z-axis direction corresponding to each slice is consistent, and then dividing each slice into printing areas of a plurality of thicknesses according to the layer thickness allowed by the 3D printing device; When the layer thicknesses corresponding to the printing areas of adjacent slices within the same Z-axis range are the same, the printing areas corresponding to the adjacent slices are merged into a composite printing area; When the layer thicknesses of the printing areas of the adjacent slices are different, they are used as separate printing areas; powder printing is performed on the composite printing area and the separate printing area respectively to obtain a 3D printed workpiece; The allowable layer thickness of the 3D printing device includes a minimum allowable layer thickness and other allowable layer thicknesses, wherein the other allowable layer thicknesses are greater than the minimum allowable layer thickness, and the other allowable layer thicknesses are multiples of the minimum allowable layer thickness.
2. The method according to claim 1, characterized in that The other permissible layer thicknesses are integral multiples of the minimum permissible layer thickness.
3. The method according to claim 2, characterized in that The other allowable layer thickness is 2 to 10 times the minimum allowable layer thickness.
4. The method according to claim 1, characterized in that: When the layer thickness of each slice is greater than twice the minimum allowable layer thickness, the slice is first divided into printing areas using other allowable layer thicknesses, and the area that is not divisible by other allowable layer thicknesses is divided into printing areas using the minimum allowable layer thickness.
5. The method according to claim 1, characterized in that The other allowable layer thicknesses include an intermediate allowable layer thickness and a maximum allowable layer thickness. When the layer thickness of each slice is greater than twice the minimum allowable layer thickness, the maximum allowable layer thickness is first used to divide the printing area of the slice, and the area that is not divisible by the maximum allowable layer thickness is divided into the printing area using the minimum allowable layer thickness and / or the intermediate allowable layer thickness.
6. The method according to any one of claims 2 to 5, characterized in that: The process includes cutting the workpiece to be printed along the X-axis direction and the Y-axis direction respectively.
7. The method according to any one of claims 2 to 5, characterized in that: The process includes cutting the workpiece to be printed along the X-axis direction, the Y-axis direction and the Z-axis direction respectively.
8. The method according to claim 1, characterized in that The 3D printing equipment includes any one of a selective laser cladding equipment, a selective laser sintering equipment, an electron beam cladding equipment, a binder jetting equipment, an arc fuse equipment and a melt extrusion equipment.
9. Use of the method according to any one of claims 1 to 8 in improving the printing efficiency of 3D printed workpieces.