Additive manufacturing method based on zoned process optimization and compensation

Abstract

The application belongs to the technical field of additive manufacturing, and particularly relates to an additive manufacturing method based on partition process optimization and compensation, which comprises the following steps: S1, classifying parts and dividing different parts into different printing areas; S2, separately configuring process parameters for the lower surface area, layer by layer model slicing for the compensation area, and judging whether any model slice needs compensation; S3, separately printing multiple different areas based on respective process parameters; S4, performing structural bias compensation and optical compensation on the printed model based on the actual size of the part; and S5, detecting the upper surface of the part as a machining reference surface. The method of the application can meet the use requirements of high-end manufacturing for precision parts without additional support, not only reducing the consumption of metal powder, but also avoiding damage to the surface of the part in the support removal process, and improving manufacturing efficiency.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, and specifically relates to an additive manufacturing method based on partitioned process optimization and compensation. Background Technology

[0002] With the development of high-end manufacturing fields such as aerospace and precision instruments, complex and delicate structures such as sharp-cornered thin-walled structures, micro-gap structures, transverse holes, and lattices are widely used in core components because they have functions such as lightweighting, precise positioning, and microfluidic flow guidance.

[0003] Traditional manufacturing processes such as machining, casting, and electrical discharge machining (EDM) are limited by the geometric characteristics of complex and intricate structures, making it difficult to achieve efficient and high-precision forming. Machining, in particular, is prone to tool interference and stress deformation when dealing with features such as micro-gaps, sharp corners, and thin walls, leading to feature damage. Casting, on the other hand, suffers from low forming accuracy and numerous internal defects, neither of which can meet the requirements of precision structures. Against this backdrop, selective laser melting (SLM) technology, with its unique advantages of "layered stacking and selective melting," can directly form metal powder into complex solid parts, breaking through the forming limitations of traditional processes and becoming the mainstream technology for manufacturing complex and intricate structures.

[0004] However, the complex geometric characteristics of intricate structures and the inherent characteristics of the SLM process are mutually restrictive, resulting in numerous bottlenecks in existing methods. The lack of targeted region segmentation strategies leads to issues such as warping and slag buildup in overhanging regions, overmelting deformation in thin-walled structures, and loss of lattice features. Furthermore, process parameter optimization lacks a systematic approach, relying on experience for parameter adjustments in the lower surface and compensation regions, exacerbating thermal stress concentration due to energy mismatch. Structural offset compensation does not follow structural characteristics, resulting in insufficient accuracy in gap and hole compensation, and blind compensation of thin-walled and columnar structures, which damages dimensional accuracy. Some solutions rely on additional support structures, increasing material and post-processing costs and easily damaging part surface precision. Existing solutions either add supports, leading to increased energy consumption and inefficiency, or only optimize the scanning path without coordinating process and structure, failing to meet the requirements of unsupported operation, high precision, and low defects.

[0005] Therefore, it is essential to develop a differentiated region division method based on structural characteristics, combined with systematic parameter optimization and precise offset compensation, to address issues such as non-targeted region division, poor adaptability of process parameters, and inaccurate offset compensation in SLM forming of complex and fine structures. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an additive manufacturing method based on partitioned process optimization and compensation. This method achieves technological breakthroughs through partitioning, parameter optimization, and offset compensation. Differentiated regions are divided and identified using 45° and minimum feature size rules, identifying the main body region, lower surface region, and compensation region. Process parameters are optimized specifically, with separate scanning strategies and parameters configured for the lower surface region and compensation region of overhanging or angled gradient structures. This is combined with auxiliary methods such as energy density optimization, layer thickness reduction, powder particle size refinement, and preheating temperature adjustment to reduce thermal stress and forming defects. Structural offset compensation is implemented, with positive and negative compensation for gaps and vertical holes based on dimensional deviations. For horizontal holes, the diameter difference in the X and Z directions is measured and compensated to form an elliptical model that adapts to thermal stress deformation patterns. This method improves the forming accuracy and surface quality of complex and delicate structures without the need for additional support, avoiding problems such as over-melting, warping, and dimensional deviations, thereby enhancing the adaptability of the SLM process to complex and delicate structures and improving mass production reliability.

[0007] To achieve the above objectives, this invention discloses an additive manufacturing method based on partitioned process optimization and compensation, which includes the following steps:

[0008] S1. Classify the parts and divide different types of parts into different printing areas:

[0009] S11. The parts are divided into overhanging or angle-gradient structure parts, thin-walled structure parts, and lattice angle-variable structure parts.

[0010] S12. Divide the suspended or angle-gradient structure parts into a first region and a second region. The first region is the main region, and the second region is the lower surface region and the main region. Divide the thin-walled structure parts into a compensation region and a main region. Divide the lattice angle-variable structure parts into a main region, a lower surface region and a compensation region.

[0011] S2. Configure process parameters separately for the lower surface area; slice the model layer by layer for the compensation area, determine whether any model slice needs compensation, generate a single scan line in the current layer model slice if compensation is needed, otherwise print according to the main area;

[0012] S3. Print multiple different areas separately based on their respective process parameters, and calculate whether the tolerance between the actual printed size and the target size meets the tolerance requirements. If not, proceed to step S4; if yes, proceed to step S5.

[0013] S4. After performing structural offset compensation on the printed model based on the actual size of the part, return to step S3 to continue printing until the tolerance requirements are met, and proceed to step S5.

[0014] S5. Inspect the upper surface of the part, which serves as the machining reference surface, to determine whether the height of the outer contour edge of the upper surface is consistent with the height of the upper surface. If they are inconsistent, determine the number of empty printing layers for the outer contour of the upper surface and return to step S3 to modify the printing parameters and continue printing until the height of the outer contour edge of the upper surface is consistent with the height of the upper surface. Specifically, the number of empty printing layers for the outer contour of the upper surface is determined as follows: assuming the part height is h, the total number of printing layers is Q, and the heights of the outer contour edge of the upper surface after printing are H1, H2, H3...Hp, with machining tolerances limited to... When +Td≥|Hp-h|, the number of empty printing layers for the outer contour is 0; if +Td<|Hp-h|, then empty printing of the outer contour is performed in layers Q1, Q2, Q3...Qp. The final number of empty printing layers for the outer contour, Qp, is the smallest positive integer that satisfies +Td≥|HQ-h|-T*(Q-Qp), where Q and p are both positive integers, and T is the layer thickness.

[0015] Preferably, the specific method for determining whether any model slice needs compensation in step S2 is as follows:

[0016] Take any point on the first side edge of the current layer model slice With center at any radius Draw a circle. When the circle is tangent to the nearest point on the second side of the model slice, the point of tangency is... Points along the line connecting the center of the circle and the nearest point of tangency are... ;

[0017] when At that time, a single scan line is generated in the current layer model slice, and the process parameters are configured separately for each scan line generated by compensation. Then print according to the main area; where n and m are both positive integers. This is the light compensation value.

[0018] Preferably, step S12 specifically includes:

[0019] S121. Transform the interlayer vectors of model slices in overhanging or angled gradient structural parts. The region with an angle greater than 45° to the XY plane is designated as the first region, and the model slice interlayer vectors are defined as follows: The region with an angle of less than 45° to the XY plane is designated as the second region;

[0020] S122. For thin-walled structural parts, when the thickness is less than or equal to twice the spot compensation, it is divided into a compensation area; when the thickness is greater than twice the spot compensation, it is divided into a main body area.

[0021] S123. For parts with varying lattice angles, when the thickness is less than or equal to twice the spot compensation, the area is designated as a compensation region; when the thickness is greater than twice the spot compensation, the interlayer vector of the model slice is determined. Whether the angle with the XY plane is greater than 45°, and the interlayer vector of the model slice. The region with an angle greater than 45° to the XY plane is designated as the first region, and the model slice interlayer vectors are defined as follows: The region with an angle of less than 45° to the XY plane is designated as the second region.

[0022] Preferably, in steps S121 and S123, the second region is further divided into a lower surface region and a main body region.

[0023] Preferably, in step S2, when compensation is required, a single scan line is generated at the center of the current layer model slice and the process parameters are configured separately.

[0024] Preferably, in step S2, the lower surface region is configured with separate process parameters, specifically to improve the lower surface filling energy density, use the lower surface printing parameters to outline the overhang boundary, reduce the scanning spacing, reduce the layer thickness, reduce the powder particle size, and adjust the preheating temperature.

[0025] Preferably, the energy density of the lower surface filling in step S2 is calculated using the following formula:

[0026] ;

[0027] Where E is the energy density of the lower surface filling, P is the power, V is the scanning speed, D is the scanning spacing, and T is the layer thickness.

[0028] Preferably, step S121 specifically includes:

[0029] Assume the contour points of the nth layer slice are The contour points corresponding to the (n-1)th layer are The inter-layer vector of the model slice is: The inter-layer vector of the model slice is calculated using the following formula. Angle θ with the XY plane:

[0030] ;

[0031] in, Slice the interlayer vectors of the model. These are the contour points of the nth and (n-1)th layer slices, respectively, and θ is the inter-layer vector of the model slices. The angle between the plane and the XY plane.

[0032] Preferably, the specific compensation method in step S4 is as follows: determine whether to perform positive or negative compensation on the model based on the size, and adjust the compensation amount according to the actual printing size.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] (1) The additive manufacturing method based on partitioned process optimization and compensation of the present invention adopts a differentiated region division strategy for different structural characteristics. The lower surface region and the main body region are precisely defined by the 45° rule. The scan line compensation of thin-walled and ultra-thin features is combined with the minimum feature size rule. With partitioned process parameter optimization and precise offset compensation, the problems of warping and slag in the overhanging area, thin-walled overmelting deformation, transverse hole size offset and lattice feature loss in the SLM process can be effectively solved. It can greatly improve the forming accuracy of complex and fine structures and meet the requirements of high-end manufacturing for precision parts.

[0035] (2) The additive manufacturing method based on partition process optimization and compensation of the present invention relies on the scientific partitioning of the overhang or angled gradient structure by the 45° rule and the design of special process parameters for the lower surface area. It can complete the molding of parts with overhang features without the need to add additional support structures. This not only reduces the consumption of metal powder, but also avoids damage to the surface of the parts during the support removal process, eliminates the need for post-processing steps such as support grinding, shortens the production cycle, and improves manufacturing efficiency and economy.

[0036] (3) The additive manufacturing method based on partitioned process optimization and compensation of the present invention can adapt to various fine structures with different geometric characteristics such as inclined plates, horizontal holes, thin walls, and lattices through the collaborative design of dual-rule fusion partitioning, differentiated parameter control and targeted bias compensation. At the same time, it is compatible with the deformation compensation requirements of gaps and hole structures of different sizes and specifications, enhances process adaptability, covers the manufacturing needs of multiple types of complex fine structures, and broadens the application scenarios of metal additive manufacturing.

[0037] (4) The additive manufacturing method based on partitioned process optimization and compensation of the present invention effectively reduces the temperature gradient of the molten pool and the concentration of thermal stress by reducing the layer thickness, refining the powder particle size, adjusting the preheating temperature, and other parameter optimization methods, combined with precise control of partitioned energy density. This reduces the risk of deformation and cracking of the parts after forming, while ensuring the quality of interlayer bonding, enabling the formed parts to have stable mechanical properties, optimizing the thermal stress distribution, and improving the mechanical stability of the parts. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the additive manufacturing method based on partitioned process optimization and compensation of the present invention.

[0039] Figure 2 This is a schematic diagram of the inclined plate structure in Embodiment 1 of the additive manufacturing method based on partitioning process optimization and compensation of the present invention;

[0040] Figure 3 This is a schematic diagram of the transverse hole structure in Embodiment 2 of the additive manufacturing method based on partitioning process optimization and compensation of the present invention;

[0041] Figure 4This is a schematic diagram of a thin-walled structure in Embodiment 3 of the additive manufacturing method based on partitioned process optimization and compensation of the present invention;

[0042] Figure 5 This is a schematic diagram of the thin-walled structure before compensation in Example 3 of the additive manufacturing method based on partitioned process optimization and compensation of the present invention;

[0043] Figure 6 This is a schematic diagram of the thin-walled structure after compensation in Example 3 of the additive manufacturing method based on partitioning process optimization and compensation of the present invention. Detailed Implementation

[0044] To provide a detailed description of the technical content, objectives, and effects of this invention, the following description will be provided in conjunction with the accompanying drawings.

[0045] This invention provides an additive manufacturing method based on partitioned process optimization and compensation, such as... Figure 1 As shown, it includes the following steps:

[0046] S1. Classify the parts and divide different types of parts into different printing areas:

[0047] S11. The parts are divided into parts with overhanging or gradually changing angles, thin-walled parts, and parts with varying lattice angles.

[0048] S12. Divide the suspended or angle-gradient structure parts into a first region and a second region. The first region is the main region, and the second region is the lower surface region and the main region. Divide the thin-walled structure parts into a compensation region and a main region. Divide the lattice angle-variable structure parts into a main region, a lower surface region, and a compensation region.

[0049] Step S12 is as follows:

[0050] S121. Transform the interlayer vectors of model slices in overhanging or angled gradient structural parts. The region with an angle greater than 45° to the XY plane is designated as the first region, and the model slice interlayer vectors are defined as follows: The region with an angle of less than 45° to the XY plane is designated as the second region.

[0051] Step S121 is as follows:

[0052] Assume the contour points of the nth layer slice are The contour points corresponding to the (n-1)th layer are The inter-layer vector of the model slice is: The inter-layer vector of the model slice is calculated using the following formula. Angle θ with the XY plane:

[0053] ;

[0054] in, Slice the interlayer vectors of the model. These are the contour points of the nth and (n-1)th layer slices, respectively, and θ is the inter-layer vector of the model slices. The angle between the plane and the XY plane.

[0055] S122. For thin-walled structural parts, when the thickness is less than or equal to twice the spot compensation, it is divided into a compensation area; when the thickness is greater than twice the spot compensation, it is divided into a main area.

[0056] S123. For parts with varying lattice angles, when the thickness is less than or equal to twice the spot compensation, the area is designated as a compensation region; when the thickness is greater than twice the spot compensation, the interlayer vector of the model slice is determined. Whether the angle with the XY plane is greater than 45°, and the interlayer vector of the model slice. The region with an angle greater than 45° to the XY plane is designated as the first region, and the model slice interlayer vectors are defined as follows: The region with an angle of less than 45° to the XY plane is designated as the second region.

[0057] In steps S121 and S123, the second region is further divided into a lower surface region and a main body region.

[0058] S2. Configure process parameters separately for the lower surface area; slice the model layer by layer for the compensation area, determine whether any model slice needs compensation, generate a single scan line in the current layer model slice if compensation is needed, otherwise print according to the main area.

[0059] The specific method for determining whether any model slice needs compensation in step S2 is as follows:

[0060] Take any point on the first side edge of the current layer model slice With center at any radius Draw a circle. When the circle is tangent to the nearest point on the second side of the model slice, the point of tangency is... Points along the line connecting the center of the circle and the nearest point of tangency are... .

[0061] when At that time, a single scan line is generated in the current layer model slice, and the process parameters are configured separately for each scan line generated by compensation. Then print according to the main area; where n and m are both positive integers. This is the light compensation value.

[0062] When compensation is required in step S2, a single scan line is generated at the center of the current layer model slice and the process parameters are configured separately.

[0063] In step S2, the process parameters for the lower surface region are configured separately, specifically to improve the lower surface filling energy density, use the lower surface printing parameters to outline the overhang boundary, reduce the scanning spacing, reduce the layer thickness, reduce the powder particle size, and adjust the preheating temperature.

[0064] Specifically, this includes the following aspects:

[0065] Improving the energy density of the lower surface filler involves an interaction between scanning spacing, filling power, and scanning speed. Laser scanning is instantaneous, and the energy is absorbed by the powder instantaneously, reaching its maximum absorption rate. Therefore, it is necessary to reduce the scanning spacing, reduce the filling power, and increase the scanning speed to achieve appropriate heat input, sufficient overlap of the molten pool in the XY direction, and sufficient absorption of the instantaneous output power by the powder to prevent excessive melting and sagging caused by heat accumulation.

[0066] The energy density of the lower surface filling is calculated using the following formula:

[0067] ;

[0068] Where E is the energy density of the lower surface filling, P is the power, V is the scanning speed, D is the scanning spacing, and T is the layer thickness.

[0069] Use the lower surface printing parameters to outline the overhang boundary and distinguish it from the main body area. For the lower surface area divided by the 45° rule, the smaller the included angle, the greater the "offset" of the current printed layer relative to the next layer. The newly melted metal may not have enough solid area to adhere and solidify stably. The bottom heat dissipation path is long, and heat transfer only through the solidified layer can easily form a high temperature zone. Thermal stress concentration can easily lead to warping. Therefore, it is necessary to reduce the scanning strip width to reduce the possibility of thermal stress warping.

[0070] Reducing layer thickness decreases the amount of material that needs to be melted per layer, reduces heat input requirements, significantly shrinks the heat-affected zone, and improves interlayer bonding and surface accuracy.

[0071] Reducing powder particle size: Finer powder can spread into a denser, flatter layer, reducing surface undulations caused by large powder particles. A flat starting plane is the basis for forming a precise molten pool.

[0072] Adjust the preheating temperature to 80~120℃ to reduce the temperature difference between the molten pool and the substrate, improve the fluidity and wettability of the molten pool, and reduce thermal stress.

[0073] S3. Print multiple different areas separately based on their respective process parameters, and calculate whether the tolerance between the actual printed size and the target size meets the tolerance requirements. If not, proceed to step S4; if yes, proceed to step S5.

[0074] S4. After performing structural offset compensation on the printed model based on the actual dimensions of the part, return to step S3 to continue printing until the tolerance requirements are met, and proceed to step S5. The specific compensation method in step S4 is: determine whether to perform positive or negative compensation on the model based on the dimensions, and adjust the compensation amount according to the actual printed dimensions. In some other embodiments, the printed dimensions of the part can also be adjusted by performing optical compensation.

[0075] In a specific embodiment, the compensation method is as follows: For the transverse hole structure, it is necessary to measure the diameter of the transverse hole in the X and Z directions. Based on the difference between the measured diameter and the model diameter, offset compensation is performed in the X and Z directions respectively, so that the compensated model transverse hole has an elliptical structure, which can accommodate the local concave or convex deformation of the transverse hole caused by the inability to symmetrically offset thermal stress. The compensation amount is adjusted according to the diameter of the transverse hole.

[0076] S5. Inspect the upper surface of the part, which serves as the machining reference surface, to determine whether the height of the outer contour edge of the upper surface is consistent with the height of the upper surface. If they are inconsistent, determine the number of empty printing layers for the outer contour of the upper surface and return to step S3 to modify the printing parameters and continue printing until the height of the outer contour edge of the upper surface is consistent with the height of the upper surface. Specifically, the number of empty printing layers for the outer contour of the upper surface is determined as follows: assuming the part height is h, the total number of printing layers is Q, and the heights of the outer contour edge of the upper surface after printing are H1, H2, H3...Hp, with machining tolerances limited to... When +Td≥|Hp-h|, the number of empty printing layers for the outer contour is 0; if +Td<|Hp-h|, then empty printing of the outer contour is performed in layers Q1, Q2, Q3...Qp. The final number of empty printing layers for the outer contour, Qp, is the smallest positive integer that satisfies +Td≥|HQ-h|-T*(Q-Qp), where Q and p are both positive integers, and T is the layer thickness.

[0077] The specific application of the process optimization and bias compensation method of the present invention will be described in detail below with reference to specific embodiments.

[0078] Example 1:

[0079] S1. Classify the parts and divide different types of parts into different printing areas. The structure in this embodiment 1 is as follows: Figure 2 The diagram shows a sloping plate structure 1, which is divided into a suspended or angled gradient structure, and then further divided into a first region containing only the main body area and a second region containing both the lower surface area and the main body area.

[0080] S2. For the lower surface area, process parameters are configured separately. In this embodiment, within the low angle region of 20°~45°, the scanning power, scanning spacing, scanning speed, and layer thickness are optimized respectively. The specific optimized parameter data are shown in Tables 1 and 2. The scanning spacing is set to 0.03~0.09mm, the layer thickness to 0.03~0.06mm, the strip width to 5mm, the XY layer offset to 2mm, and the rotation amount of the angle between each layer to 67° for fine processing.

[0081] Table 1

[0082]

[0083] Table 2

[0084]

[0085] 45° is the critical angle for printing. The lower the angle, the more difficult it is to form the print. By using the above optimized parameters, not only can the problem of difficult forming be solved, but also the printing will not warp and will be completed smoothly, with less and more uniform residue at the bottom.

[0086] S3. Print multiple different areas separately based on their respective process parameters. In this embodiment, the tolerance between the actual printed size and the target size meets the tolerance requirements. Proceed to step S5.

[0087] S5. The upper surface of the part, which serves as the machining reference surface, is inspected. In this embodiment, the upper surface of the part is normal.

[0088] Example 2:

[0089] S1. Classify the parts and divide different types of parts into different printing areas. The structure in this embodiment 2 is as follows: Figure 3 The diagram shows a transverse hole structure 2, which is divided into a hanging or angled gradient structure, and then further divided into a first region containing only the main body region and a second region containing the lower surface region and the main body region.

[0090] S2. Configure process parameters separately for the lower surface area. In this embodiment, for transverse flow channel areas of different sizes, the scanning power for the lower surface area is set to 100W~400W, scanning spacing to 0.03~0.09mm, scanning speed to 1000~2000mm / s, layer thickness to 0.03~0.06mm, and optical compensation to -0.1~-0.18mm. The model structure compensation values ​​are shown in Table 3, and fine processing is performed.

[0091] Table 3

[0092]

[0093] S3. Print multiple different areas separately based on their respective process parameters. In this embodiment, the tolerance between the actual printed size and the target size meets the tolerance requirements. Proceed to step S5.

[0094] S5. The upper surface of the part, which serves as the machining reference surface, is inspected. In this embodiment, the upper surface of the part is normal.

[0095] The printed model, after applying the above structural and optical compensation, has dimensions that are closer to the target dimensions, thus meeting tolerance requirements.

[0096] Example 3:

[0097] S1. Classify the parts and divide different types of parts into different printing areas. For example... Figure 4 As shown, the structure in this embodiment is a thin-walled structure 3. The thin-walled structure part is divided into a compensation region and a main body region.

[0098] S2. Slice the model layer by layer for the compensation area, and determine whether any model slice needs compensation. If compensation is needed, generate a single scan line in the current layer model slice; otherwise, print according to the main area. Figure 5 This is a schematic diagram of one of the model slices, 4. In this embodiment, the model slice is determined to require compensation, so a single scan line is generated in the current layer model slice for compensation. The compensated model slice 4 is as follows: Figure 6 As shown.

[0099] S3. Print multiple different areas separately based on their respective process parameters. In this embodiment, after comparing the size of the scanned image with the size of the original model, the material expands and contracts with heat during the printing process. After cooling, the residual stress causes shrinkage, so warping or depressions appear in specific areas, that is, there will be deviations in size. Proceed to step S4.

[0100] S4. After performing structural offset compensation and optical compensation on the printed model based on the actual size of the part, return to step S3 to continue printing until the tolerance requirements are met, and proceed to step S5.

[0101] S5. The upper surface of the part, which serves as the machining reference surface, is inspected, and in this embodiment, the requirements are met.

[0102] In some other embodiments, the contour is distinct and higher than the upper surface, requiring traditional CNC machining for subsequent processing. Clamping fixtures are needed, and the clamping reference surface must be flat and free of high points. If the reference surface has high points, the part will undergo micro-deformation due to uneven force during clamping, causing deviations between the tool path and the designed trajectory during CNC machining. It is necessary to determine the number of empty printing layers for the upper surface outer contour and return to step S3 to modify the printing parameters before continuing printing until the edge height of the upper surface outer contour matches the height of the upper surface. For example, if the determined number of empty printing layers for the upper surface outer contour is four, the contour parameters will automatically switch to the upper surface contour parameters when printing the top four layers, i.e., empty printing will be performed. Specifically, the upper surface contour power is set to 0 for the top four layers, and the scanning speed is given a certain setting value. In practical applications, after process optimization of the upper surface and contour, the contour deviation in areas with dimensional deviations becomes less noticeable.

[0103] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An additive manufacturing method based on partitioned process optimization and compensation, characterized in that: It includes: S1. Classify the parts and divide different types of parts into different printing areas: S11. The parts are divided into overhanging or angle-gradient structure parts, thin-walled structure parts, and lattice angle-variable structure parts. S12. Divide the overhanging or angled gradient structure part into a first region and a second region, and divide the interlayer vector of the model slice in the overhanging or angled gradient structure part. The region with an angle greater than 45° to the XY plane is designated as the first region, and the model slice interlayer vectors are calculated. The region with an angle less than 45° to the XY plane is designated as the second region; the first region is the main region, and the second region is the lower surface region and the main region. Thin-walled structural parts are divided into compensation regions and main regions, and structural parts with variable lattice angles are divided into main regions, lower surface regions and compensation regions. S2. Configure process parameters separately for the lower surface area; slice the model layer by layer for the compensation area, determine whether any model slice needs compensation, generate a single scan line in the current layer model slice if compensation is needed, otherwise print according to the main area; S3. Print multiple different areas separately based on their respective process parameters, and calculate whether the tolerance between the actual printed size and the target size meets the tolerance requirements. If not, proceed to step S4; if yes, proceed to step S5. S4. After performing structural offset compensation on the printed model based on the actual size of the part, return to step S3 to continue printing until the tolerance requirements are met, and proceed to step S5. S5. Inspect the upper surface of the part, which serves as the machining reference surface, to determine whether the height of the outer contour edge of the upper surface is consistent with the height of the upper surface. If they are inconsistent, determine the number of empty printing layers for the outer contour of the upper surface and return to step S3 to modify the printing parameters and continue printing until the height of the outer contour edge of the upper surface is consistent with the height of the upper surface. Specifically, the number of empty printing layers for the outer contour of the upper surface is determined as follows: assuming the part height is h, the total number of printing layers is Q, and the heights of the outer contour edge of the upper surface after printing are H1, H2, H3...Hp, with machining tolerances limited to... When +Td≥|Hp-h|, the number of empty printing layers for the outer contour is 0; if +Td<|Hp-h|, then empty printing of the outer contour is performed in layers Q1, Q2, Q3...Qp. The final number of empty printing layers for the outer contour, Qp, is the smallest positive integer that satisfies +Td≥|HQ-h|-T*(Q-Qp), where Q and p are both positive integers, and T is the layer thickness.

2. The additive manufacturing method based on partitioned process optimization and compensation according to claim 1, characterized in that: The specific method for determining whether any model slice needs compensation in step S2 is as follows: Take any point on the first side edge of the current layer model slice With center at any radius Draw a circle. When the circle is tangent to the nearest point on the second side of the model slice, the point of tangency is... Points along the line connecting the center of the circle and the nearest point of tangency are... , when At that time, a single scan line is generated in the current layer model slice, and the process parameters are configured separately for each scan line generated by compensation. Then print according to the main area; where n and m are both positive integers. This is the light compensation value.

3. The additive manufacturing method based on partitioned process optimization and compensation according to claim 1, characterized in that: Step S12 is as follows: S121. For thin-walled structural parts, when the thickness is less than or equal to twice the spot compensation, it is divided into a compensation area; when the thickness is greater than twice the spot compensation, it is divided into a main body area. S122. For parts with varying lattice angles, when the thickness is less than or equal to twice the spot compensation, the area is designated as a compensation region; when the thickness is greater than twice the spot compensation, the interlayer vector of the model slice is determined. Whether the angle with the XY plane is greater than 45°, and the interlayer vector of the model slice. The region with an angle greater than 45° to the XY plane is designated as the first region, and the model slice interlayer vectors are calculated. The region with an angle of less than 45° to the XY plane is designated as the second region.

4. The additive manufacturing method based on partitioned process optimization and compensation according to claim 3, characterized in that: In step S123, the second region is further divided into a lower surface region and a main body region.

5. The additive manufacturing method based on partitioned process optimization and compensation according to claim 1, characterized in that: When compensation is required in step S2, a single scan line is generated at the center of the current layer model slice and the process parameters are configured separately.

6. The additive manufacturing method based on partitioned process optimization and compensation according to claim 1, characterized in that: In step S2, the process parameters for the lower surface region are configured separately, specifically to improve the lower surface filling energy density, use the lower surface printing parameters to outline the overhang boundary, reduce the scanning spacing, reduce the layer thickness, reduce the powder particle size, and adjust the preheating temperature.

7. The additive manufacturing method based on partitioned process optimization and compensation according to claim 6, characterized in that: In step S2, the energy density of the lower surface filling is calculated using the following formula: ； Where E is the energy density of the lower surface filling, P is the power, V is the scanning speed, D is the scanning spacing, and T is the layer thickness.

8. The additive manufacturing method based on partitioned process optimization and compensation according to claim 3, characterized in that: Assume the contour points of the nth layer slice are The contour points corresponding to the (n-1)th layer are The inter-layer vector of the model slice is: The inter-layer vector of the model slice is calculated using the following formula. Angle θ with the XY plane: ； in, Slice the interlayer vectors of the model. These are the contour points of the nth and (n-1)th layer slices, respectively, and θ is the inter-layer vector of the model slices. The angle between the plane and the XY plane.

9. The additive manufacturing method based on partitioned process optimization and compensation according to claim 1, characterized in that: The specific compensation method in step S4 is as follows: determine whether to perform positive or negative compensation on the model based on the size, and adjust the compensation amount according to the actual printing size.

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