Process method and system for self-adaptive adjustment of binder jet printing parameters

Abstract

The invention relates to a binder jet printing parameter self-adaptive adjustment process method, which comprises the following steps of: carrying out two-dimensional segmentation on a three-dimensional model according to layout placement so as to conveniently transmit the three-dimensional model to printing equipment for printing; after the slice file is imported into printing equipment, an equipment control end divides different areas of the printed slice file, and the divided areas comprise a lower surface area, a kernel area and an upper surface area; in the printing process, the roughness of the powder spreading surface is analyzed through online scanning, and corresponding printing parameters are called according to the roughness range, so that accurate control over the size and the surface quality is achieved; and printing by using the corresponding printing parameters according to the divided different printing area ranges and the powder surface recognition result. The invention further relates to a binder jet printing parameter self-adaptive adjusting system. According to the scheme, the problem of poor consistency caused by printing quality difference of different printing areas in an existing scheme can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of printing methods, and particularly to a process method and system for adaptively adjusting binder jet printing parameters. Background Art

[0002] BJAM technology, namely binder jet additive manufacturing technology, as a cutting-edge 3D printing method, precisely sprays a special binder onto a pre-laid metal powder layer through a precision nozzle, stacks and cures layer by layer, and finally forms a high-strength metal green body, which is then degreased and sintered to be transformed into high-performance metal parts. Due to its high efficiency, low-cost manufacturing of complex structures and excellent mechanical properties of products, this technology is widely favored in the fields of aerospace, automotive, and medical.

[0003] However, BJAM technology faces two major challenges in practical applications. First, the quality differences in different printing areas are significant. For example, the lower surface is affected by the powder laying quality and binder penetration, resulting in different roughness and bonding effects; the upper surface is restricted by the subsequent printing layers and curing process, and the surface quality is crucial for the final product. Second, the physical properties change during the recycling of the powder, and the traditional fixed printing parameters lead to differences between batches, affecting the product consistency. Currently, the industry mainly alleviates the ink bleeding problem through the strategy of reducing ink at the first layer sampling points, but this method is likely to increase the surface roughness of the bottom layer, restricting the application of BJAM technology in scenarios with high-precision or high surface quality requirements. Therefore, how to adaptively adjust the printing parameters according to different printing areas and powder states to achieve high-quality and high-efficiency printing of BJAM technology has become a key problem to be solved urgently. The purpose of the present invention is to solve the above problems and improve the printing quality and consistency of BJAM technology by intelligently identifying and adjusting printing parameters. Summary of the Invention

[0004] Based on this, it is necessary to provide a process method and system for adaptively adjusting binder jet printing parameters to solve the problem of poor consistency caused by different printing quality in different printing areas in the existing solutions.

[0005] To solve the above problems, the present invention adopts the following technical solutions:

[0006] In the first aspect, an embodiment of the present invention discloses a process method for adaptively adjusting binder jet printing parameters, including:

[0007] Performing two-dimensional slicing on the three-dimensional model according to the layout for transmission to the printing device for printing;

[0008] After importing the sliced file into the printing device, the device control end divides different areas of the printed sliced file, and the divided areas include the lower surface area, the core area, and the upper surface area;

[0009] During the printing process, the roughness of the powder spreading surface is analyzed by online scanning, and the corresponding printing parameters are retrieved according to the roughness range to achieve precise control of dimensions and surface quality;

[0010] Printing is performed using the corresponding printing parameters according to the different divided printing area ranges and the powder surface recognition results.

[0011] In one embodiment, the printing using the corresponding printing parameters according to the different divided printing area ranges and the powder surface recognition results includes:

[0012] First, the first printing parameters corresponding to each divided area are roughly adjusted according to the different divided printing area ranges;

[0013] On the basis of the first printing parameters, the second printing parameters corresponding to each powder surface are finely adjusted according to the roughness of each layer of powder surface in each printing area for printing.

[0014] In one embodiment, the printing of finely adjusting the second printing parameters corresponding to each powder surface according to the roughness of each layer of powder surface in each printing area on the basis of the first printing parameters includes:

[0015] During the powder spreading process, the roughness of the powder surface is scanned and judged in real time, and the printing parameter range is divided according to the scanned roughness value. If there are different roughnesses on a single layer of powder surface, the printing parameters corresponding to the high roughness are first used for printing, and then the printing parameters corresponding to the low roughness are used for printing again.

[0016] In one embodiment, the high roughness value is ≥ Ra 6.3um, and the low roughness value is ≤ Ra6.3um.

[0017] In one embodiment, the printing parameters include the fine adjustment of the dot pitch, the nozzle printing speed, and the printing layer thickness.

[0018] In one embodiment, it also includes fine-tuning the printing parameters for the physical property identification of different powder states and different cyclic batches of powder.

[0019] In one embodiment, the loose bulk density of different powder states is actually measured to determine the powder filling rate data. The number of pre-spread powder layers and the powder feeding amount per layer before printing are fixed, and the weight after pre-spreading the powder for different state powders is weighed. The equipment control system automatically calculates its powder bulk density, so as to determine the loose bulk density and powder filling rate data size of this batch of powder for printing parameter fine-tuning.

[0020] In one of the embodiments, during the printing process, the printing parameters of the lower surface area are set to meet a smaller Z - direction penetration range (1 - 2 layers) to avoid Z - direction dimensional deviation caused by ink bleeding and adhesion; the printing parameters of the core area are set to meet a larger Z - direction penetration range (3 - 5 layers) and a smaller XY - level diffusion range to meet the higher bonding strength requirements; the printing parameters of the upper surface area are set to meet a larger XY - level diffusion range to achieve supersaturation of the effective addition amount.

[0021] In a second aspect, an embodiment of the present invention discloses an adaptive adjustment system for binder jet printing parameters, including the process method for adaptive adjustment of binder jet printing parameters described above.

[0022] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0023] The process method for adaptive adjustment of binder jet printing parameters disclosed in the embodiments of the present invention realizes intelligent adaptive adjustment of printing parameters through precise file slicing, detailed file analysis and area division, real - time powder surface recognition, and flexible partition printing. This method not only improves the dimensional accuracy and surface quality of printed products but also significantly enhances the consistency of produced products. In addition, through the physical property identification of different powder states and powders in different cycle batches, the present invention can also perform parameter fine - tuning, thereby further improving the printing efficiency and product quality. In short, the present invention provides an efficient and intelligent process method for binder jet printing technology, with broad application prospects. Description of the Drawings

[0024] None Detailed Embodiments

[0025] The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0026] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there may also be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a middle element at the same time. The terms "vertical", "horizontal", "left", "right", "top", "bottom", "bottom end", "top end" and similar expressions used herein are only for illustrative purposes and do not represent the only embodiments.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of this invention herein are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0028] An embodiment of the present invention discloses a process method for adaptively adjusting binder jet printing parameters. The disclosed process method for adaptively adjusting binder jet printing parameters includes:

[0029] Two-dimensionally slice the three-dimensional model according to the layout for transmission to a printing device for printing; this step simplifies the complex three-dimensional model into a series of two-dimensional layers, facilitating subsequent transmission to the printing device for layer-by-layer printing.

[0030] After importing the sliced file into the printing device, the device control terminal divides different regions of the printed sliced file. The divided regions include a lower surface region, a core region, and an upper surface region; these regions include a lower surface region (which can be the bottommost 1 - 3 layers), a core region (which can be the middle region except for the bottommost and topmost layers), and an upper surface region (which can be the topmost 1 - 2 layers). This step is to identify and distinguish different parts of the printed object for subsequent application of different printing parameters.

[0031] During the printing process, analyze the roughness of the powder spreading surface through on-line scanning and retrieve corresponding printing parameters according to the roughness range to achieve precise control of dimensions and surface quality; in this step, based on the roughness value obtained from the scanning, the system can intelligently retrieve the matching printing parameters. This step ensures precise control of dimensions and surface quality during the printing process.

[0032] Perform printing using the corresponding printing parameters according to the divided different printing region ranges and the powder surface recognition result. This step realizes the adoption of the most suitable printing conditions for different regions, thereby improving the overall printing quality and product consistency.

[0033] As can be seen from the above, the process method for self-adaptive adjustment of binder jet printing parameters disclosed in the embodiments of the present invention realizes intelligent self-adaptive adjustment of printing parameters through precise file slicing, meticulous file analysis and area division, real-time powder surface recognition, and flexible partition printing. This method not only improves the dimensional accuracy and surface quality of printed products, but also significantly enhances the consistency of the produced products. In addition, through the physical property recognition of different powder states and powders in different circulation batches, the present invention can also perform fine parameter adjustment, thereby further improving the printing efficiency and product quality. In short, the present invention provides an efficient and intelligent process method for binder jet printing technology, which has broad application prospects.

[0034] Further, the step of printing using the corresponding printing parameters according to the divided different printing area ranges and the powder surface recognition results may specifically include:

[0035] Coarsely adjust the first printing parameters corresponding to each divided area according to the divided different printing area ranges first;

[0036] On the basis of the first printing parameters, finely adjust the second printing parameters corresponding to each powder surface according to the roughness of each powder surface in each printing area for printing.

[0037] Specifically, in the partition printing stage, first, according to the results of file analysis, the printing area is divided into a lower surface area, a core area, and an upper surface area, and the corresponding basic printing parameters, that is, the first printing parameters, are selected and called for these areas respectively. Subsequently, during the printing process, through the powder surface recognition function, the roughness of the powder surface in each different area of each layer is scanned and analyzed in real time. Based on these roughness data, the set first printing parameters are further finely adjusted to form the second printing parameters corresponding to each powder surface, so as to ensure that the final printing effect not only meets the basic requirements of each area, but also can adapt to the subtle differences in the roughness of different powder surfaces in the same area.

[0038] In the above case, by first coarsely adjusting the first printing parameters according to the printing area range and then finely adjusting the second printing parameters according to the powder surface roughness, a dual adjustment mechanism for printing parameters is realized. This mechanism not only ensures that different printing areas (such as the lower surface, the core, and the upper surface) can obtain printing parameters matching their characteristics to improve the overall quality and consistency of the product; moreover, within the same printing area, personalized parameter adjustment can also be performed for powder surfaces with different roughnesses, further optimizing the printing effect.

[0039] Furthermore, the step of finely adjusting the second printing parameters corresponding to each powder surface according to the roughness of each layer of powder surface in each printing area on the basis of the first printing parameters may specifically include: scanning and determining the powder surface roughness in real time during the powder laying process, and dividing the printing parameter range according to the scanned roughness value; if a single layer of powder surface has different roughnesses, the printing parameters corresponding to the high roughness are printed first, and then the printing parameters corresponding to the low roughness are printed again.

[0040] Specifically, during the printing process, especially in the powder surface identification stage, the present invention analyzes the roughness of the powder surface through online scanning. According to the roughness value obtained by scanning, the system will intelligently divide different printing parameter ranges. This step is followed by the partition printing stage, that is, after the basic printing areas such as the lower surface, the inner core and the upper surface have been determined according to the file analysis, a more detailed partition determination is further performed within the same layer according to the difference in the roughness of the powder surface. If there are different roughness areas on a single layer of powder surface, the system will give priority to inkjet printing with printing parameters for high roughness areas (generally ≥Ra 6.3um). These parameters generally include larger droplets and higher ink addition amounts to ensure that high-roughness powders can be fully wrapped. Subsequently, the system will use printing parameters for low roughness areas (generally ≤Ra 6.3um) for secondary inkjet printing. These parameters focus more on using smaller droplets and moderate ink addition amounts to match the requirements of low roughness peaks.

[0041] This process allows for fine tuning of printing parameters, especially when considering the critical factor of powder surface roughness. This fine tuning not only improves the accuracy and flexibility of printing, but also significantly improves the quality and consistency of the final product. Prioritizing high-roughness areas ensures that these areas penetrate and sink as early as possible, while subsequently treating low-roughness areas helps reduce frictional resistance of the powder spreader to the high points of the powder surface, thereby avoiding possible degradation of product quality due to friction. The high roughness value can be ≥Ra 6.3um, and the low roughness value can be ≤Ra 6.3um.

[0042] Optionally, the printing parameters may include dot pitch, nozzle printing speed, and fine-tuning of the printing layer thickness. Specifically, in the file parsing stage, the device control terminal will identify and retrieve corresponding basic printing parameters according to different regions of the printing slice file (lower surface region, core region, upper surface region). Then, in the powder surface recognition stage, by online scanning and analyzing the roughness of the powder-laying surface, the device will further adjust the printing parameters according to the roughness range. Finally, in the partition printing stage, according to the results of the powder surface recognition, regions with different roughness ranges are determined for partition, and different printing parameters are selected for inkjet printing. Among them, for different printing regions (such as the lower surface, core, and upper surface), the fine-tuning of the printing parameters specifically involves the adjustment of dot pitch, nozzle printing speed, and printing layer thickness to meet the printing requirements of different regions. For example, for 316L stainless steel material, the dot pitch of the printing points in the lower surface region is controlled at 37 - 43um, the nozzle printing speed is 100 - 150mm / s, and the printing layer thickness adjustment range is 50 - 80um; while the dot pitch of the printing points in the core and upper surface regions is controlled at 32 - 37um, the nozzle printing speed is 150 - 250mm / s, and the printing layer thickness adjustment range is 60 - 100um.

[0043] The above method can achieve the best matching of different printing regions (such as the lower surface, core, and upper surface) by precisely adjusting printing parameters such as dot pitch, nozzle printing speed, and printing layer thickness, thereby improving the consistency and quality of the produced products. In addition, this method can also fine-tune the parameters according to different powder states and the physical properties of powders in different circulation batches to ensure the stability and reliability of the printing process. By intelligently scanning and identifying the roughness of the powder surface in different regions of the same layer and dividing different printing regions accordingly, the printing efficiency and accuracy are further improved.

[0044] The process method for adaptive adjustment of binder jet printing parameters disclosed in the embodiments of the present invention may further include fine-tuning the printing parameters based on the identification of the physical properties of powders in different states and different circulation batches.

[0045] Furthermore, the loose bulk density of powders in different states is actually measured to determine the powder filling rate data. The number of pre-laid powder layers and the powder feeding amount per single layer before printing are fixed. After pre-laying the powder for different state powders, weighing is carried out, and the device control system automatically calculates its powder bulk density, so as to determine the loose bulk density and powder filling rate data size of this batch of powders for printing parameter fine-tuning.

[0046] The above steps specifically include: First, actually measure the loose density of powders in different states. The purpose of this step is to obtain the density data of the powders in the loose state, providing a basis for calculating the powder filling rate subsequently. Next, fix the number of pre-laid powder layers and the powder feeding amount per single layer prepared before printing. For powders in different states, weigh them after pre-laying the powder. The purpose of this step is to obtain the weight data after actual powder laying, so as to calculate the bulk density of the powder subsequently. The equipment control system automatically calculates the bulk density of the powder using the above measurement and weighing data, and determines the printing loose density and the data size of the powder filling rate of this batch of powders accordingly. These data will be directly used for fine-tuning the printing parameters to ensure that the printing quality matches the powder state.

[0047] The above method significantly improves the flexibility and adaptability of binder jet printing by increasing the physical property identification of powders in different states and different cycle batches, and fine-tuning the printing parameters accordingly. This method can ensure that the printing parameters always match the powder characteristics under different powder states, thereby improving the consistency and stability of the printing quality. At the same time, through automatic calculation and parameter fine-tuning, manual intervention is reduced, and the production efficiency is improved. In addition, this self-adaptive adjustment process method also helps to reduce printing defects caused by changes in powder state, further improving the overall quality of the product.

[0048] Furthermore, during the printing process, the printing parameters in the lower surface area are set to meet a smaller Z-direction penetration range (1 - 2 layers) to avoid Z-direction dimensional tolerance caused by ink bleeding and adhesion; the printing parameters in the core area are set to meet a larger Z-direction penetration range (3 - 5 layers) and a smaller XY horizontal diffusion range to meet the higher bonding strength requirements; the printing parameters in the upper surface area are set to meet a larger XY horizontal diffusion range to achieve supersaturation of the effective addition amount.

[0049] That is, during the printing process, according to the results of file analysis, the printing area is divided into the lower surface area, the core area, and the upper surface area. For the lower surface area, since the powder laying surface usually has a relatively high roughness, when setting the printing parameters, it is necessary to meet a smaller Z-direction penetration range (1 - 2 layers) to avoid Z-direction dimensional tolerance caused by problems such as ink bleeding and adhesion, and ensure the dimensional accuracy of the printed part. For the core area, in order to eliminate internal defects and improve the bonding strength of adjacent layers in the XY plane, the printing parameters are set to meet a larger Z-direction penetration range (3 - 5 layers) and a smaller XY horizontal diffusion range, which can ensure the strength and stability of the internal structure of the printed part. For the upper surface area, in order to achieve a higher surface quality, the printing parameters are set to meet a larger XY horizontal diffusion range to achieve supersaturation of the effective addition amount, thereby obtaining a smooth and flat printing surface. X, Y, and Z respectively represent the three directions of length, width, and height corresponding to the printing equipment.

[0050] In the above method, the smaller Z-direction penetration range in the lower surface area avoids problems such as ink bleeding and adhesion, ensuring the Z-direction dimensional accuracy of the printed part; the larger Z-direction penetration range and smaller XY horizontal diffusion range in the core area improve the internal strength and bonding strength of the printed part; the larger XY horizontal diffusion range in the upper surface area enables supersaturation of the effective addition amount, resulting in a smooth and flat printed surface.

[0051] Based on the process method for adaptive adjustment of binder jet printing parameters disclosed in the embodiments of the present invention, the embodiments of the present invention disclose an adaptive adjustment system for binder jet printing parameters, including the process method for adaptive adjustment of binder jet printing parameters described in any of the above embodiments.

[0052] The above embodiments only represent several implementation manners of the present invention. The descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A process method for adaptively adjusting binder jet printing parameters, characterized in that: include: The three-dimensional model is divided into two dimensions according to the layout so as to be transferred to the printing device for printing; After the slice file is imported into the printing device, the device control end divides the different areas of the printing slice file, and the divided areas include the lower surface area, the core area and the upper surface area; During the printing process, the roughness of the powder-laying surface is analyzed through online scanning, and the corresponding printing parameters are called according to the roughness range to achieve precise control of size and surface quality; Printing is performed using corresponding printing parameters according to the different divided printing area ranges and the powder surface recognition results.

2. The process method for adaptively adjusting binder jet printing parameters according to claim 1, characterized in that: The printing using corresponding printing parameters according to the divided different printing area ranges and the powder surface recognition results includes: Firstly, roughly adjusting the first printing parameters corresponding to each divided area according to the different divided printing area ranges; On the basis of the first printing parameters, the second printing parameters corresponding to each powder surface are finely adjusted according to the roughness of each powder surface in each printing area to perform printing.

3. The process method for adaptively adjusting binder jet printing parameters according to claim 2, characterized in that: The method of finely adjusting the second printing parameters corresponding to each powder surface according to the roughness of each powder surface in each printing area on the basis of the first printing parameters includes: During the powder laying process, the roughness of the powder surface is scanned and determined in real time, and the printing parameter range is divided according to the scanned roughness value. If a single layer of powder surface has different roughness, the printing parameters corresponding to the high roughness are printed first, and then the printing parameters corresponding to the low roughness are printed again.

4. The process for adaptively adjusting binder jet printing parameters according to claim 3, characterized in that: The high roughness value is ≥Ra 6.3um, and the low roughness value is ≤Ra 6.3um.

5. The process for adaptively adjusting binder jet printing parameters according to claim 1, characterized in that: The printing parameters include fine adjustment of dot spacing, nozzle printing speed, and printing layer thickness.

6. The process for adaptively adjusting binder jet printing parameters according to claim 1, characterized in that: It also includes fine-tuning of printing parameters based on identification of physical properties of powders in different powder states and different cycle batches.

7. The process for adaptively adjusting binder jet printing parameters according to claim 6, characterized in that: Actual measurements are made on the loose density of powders in different states to determine the powder filling rate data, fix the number of pre-powder layers and the amount of powder per layer before printing, weigh the powders in different states after pre-powdering, and the equipment control system automatically calculates the powder stacking density, thereby determining the loose density and powder filling rate data for this batch of powder printing to fine-tune the printing parameters.

8. The process for adaptively adjusting binder jet printing parameters according to claim 1, characterized in that: During the printing process, the printing parameters of the lower surface area are set to meet a smaller Z-direction penetration range (1-2 layers) to avoid Z-direction dimensional deviations caused by ink seepage and adhesion; the printing parameters of the inner core area are set to meet a larger Z-direction penetration range (3-5 layers) and a smaller XY horizontal diffusion range to meet higher bonding strength requirements; the printing parameters of the upper surface area are set to meet a larger XY horizontal diffusion range to achieve effective addition amount oversaturation.

9. A binder jet printing parameter adaptive adjustment system, characterized in that: A process for adaptively adjusting binder jet printing parameters comprising any one of claims 1 to 8.