Multi-laser-area additive-detection-subtractive composite manufacturing method

Abstract

The invention discloses a multi-laser-area additive-detection-subtractive composite manufacturing method which comprises the following steps: establishing a three-dimensional model of a part to be formed, and adding a necessary support structure model for the three-dimensional model; laser printing process parameters are set, a model formed by combining the three-dimensional model and the supporting structure body model is sliced layer by layer, and a slicing program is obtained; the slicing program is imported into multi-laser powder bed fusion forming software, and a printing program is generated; a printing program is imported into the multi-laser-area material increasing-detecting-material decreasing composite device; the multi-laser-area additive-detection-subtractive composite device prints an entity of a part to be formed on a forming substrate of the multi-laser-area additive-detection-subtractive composite device according to the slicing program; and after printing is finished, the forming substrate is taken out of the multi-laser-area additive-detection-subtractive composite device, the entity of the to-be-formed part is cut off from the forming substrate, and the entity of the to-be-formed part is obtained. The forming efficiency is improved, and the machining quality and precision are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D laser printing, and in particular to a multi-laser area additive-detection-subtractive composite manufacturing method. Background Art

[0002] Multi-laser powder bed fusion technology is an additive manufacturing method that uses multiple high-energy-density fine laser beams to simultaneously act on the surface of the powder bed to melt and solidify metal powder layer by layer. Compared with a single laser beam, this technology accelerates the material deposition and solidification process through the collaborative work of multiple laser beams, thereby improving manufacturing efficiency and component quality. In addition, due to its unique manufacturing characteristics, multi-laser powder bed fusion technology provides designers with maximum freedom in manufacturing complex structural components, and has been applied to aerospace, biomedicine, automotive and other industries.

[0003] Although multi-laser powder bed fusion technology has the above advantages, more work needs to be done to effectively reduce the defects of components manufactured by laser beam powder bed fusion technology and improve manufacturing efficiency. As a heat source, the laser beam is closely related to the formation of defects and printing efficiency. The energy distribution pattern within the beam is crucial to the melting / solidification of the material and the formation of dense components. Therefore, the appropriate beam energy distribution pattern plays a decisive role in reducing defects and improving printing efficiency.

[0004] Currently, most commercial powder bed fusion equipment uses Gaussian beam output lasers. However, the nature of the Gaussian beam determines that the temperature gradient generated during the material processing is large, which may cause micro defects such as balling, humps, and unmelted layers in the printed layer. Summary of the invention

[0005] In order to solve the technical problems existing in the background technology, the present invention proposes a multi-laser area additive-detection-subtractive composite manufacturing method.

[0006] The present invention proposes a multi-laser region additive-detection-subtractive composite manufacturing method, comprising:

[0007] S1. Establish a three-dimensional model of the part to be molded and add necessary supporting structure models to the three-dimensional model;

[0008] S2, setting laser printing process parameters, and slicing the model formed by combining the three-dimensional model and the supporting structure model layer by layer to obtain a slicing program;

[0009] S3, importing the slicing program into the multi-laser powder bed fusion molding software to generate a printing program;

[0010] S4, importing the printing program into the multi-laser area additive-detection-subtractive composite device;

[0011] S5, the multi-laser area additive-detection-subtractive composite device prints out the entity of the part to be formed on its forming substrate according to the slicing program;

[0012] S6. After printing is completed, the molding substrate is taken out from the multi-laser area additive-detection-subtractive composite device, and the entity of the part to be molded is cut off from the molding substrate to obtain the entity of the part to be molded.

[0013] Preferably, the laser printing process parameters include: flat-top beam focusing diameter, Gaussian beam focusing diameter, laser processing power, scanning rate, path spacing, powder layer thickness, number of boundary contours, inner and outer contour distances, spot compensation, boundary distance, scanning strategy and partition strategy;

[0014] Among them, the focusing diameter of the flat-top beam is 200-300μm, and the focusing diameter of the Gaussian beam is 60-120μm; the laser power of the flat-top beam is 2000-3000W, and the laser power of the Gaussian beam is 50-1000W; the scanning speed of the flat-top beam is 600-2000mm / s; the scanning speed of the Gaussian beam is 200-1800mm / s; the path spacing of the flat-top beam is 0.15-0.25mm, and the path spacing of the Gaussian beam is 0.05-0.10mm; the thickness of the powder layer is 0.02-0.12mm; the number of boundary contours is 0-2; the inner and outer contour distances are 0.06-0.12mm, and the spot compensation is 0.04-0.06mm; the boundary distance is -0.1-0.1mm; the scanning strategies are unidirectional scanning strategy, round-trip scanning strategy, spiral scanning strategy and contour scanning strategy; the partition strategies are non-partitioning, strip partitioning, island partitioning and honeycomb partitioning.

[0015] Preferably, the multi-laser area additive-detection-subtractive composite device includes: a molding mechanism, a laser emitting mechanism, a defect detection mechanism and a laser printing control mechanism; the additive laser emitting mechanism is used to generate a Gaussian beam or a flat-top beam; the subtractive mechanism emitting mechanism is used to generate a femtosecond laser; the laser printing control mechanism is used to focus the generated Gaussian beam or flat-top beam onto the molding substrate of the molding mechanism for printing or to focus the generated femtosecond laser onto the molding substrate of the molding mechanism for defect removal, and the defect detection mechanism is used to detect whether the current layer that has been printed on the molding substrate of the molding mechanism has defects; the control mechanism is used to control the molding mechanism, the laser emitting mechanism, the defect detection mechanism and the laser printing control mechanism to coordinate actions according to the slicing program to complete the printing of the part to be molded and the removal of defects.

[0016] Preferably, in S5, the multi-laser area additive-detection-subtractive composite device prints out the to-be-molded part according to the slicing program, specifically including:

[0017] S51, the control mechanism controls the molding mechanism to lay a powder layer of a predetermined thickness on its molding substrate;

[0018] S52, when the powder layer is laid, the control mechanism controls the additive laser emitting mechanism to generate a Gaussian beam, and then controls the laser printing control mechanism to focus the Gaussian beam onto the powder layer on the molding substrate of the molding mechanism to print the contour of the to-be-molded part;

[0019] S53, when the printing of the contour of the to-be-molded part is completed, the control mechanism controls the additive laser emitting mechanism to generate a flat-top beam, and then controls the laser printing control mechanism to focus the flat-top beam onto the molding substrate of the molding mechanism to fill the inner area of ​​the contour of the to-be-molded part;

[0020] S54, when the filling of the inner area of ​​the contour of the to-be-molded part is completed, the control mechanism controls the additive laser emitting mechanism to generate a Gaussian beam, and then controls the laser printing control mechanism to focus the Gaussian beam onto the molding substrate of the molding mechanism to fill the dead angle area of ​​the contour of the to-be-molded part, thereby completing the printing of the current layer;

[0021] S55, after the printing of the current layer is completed, the control mechanism controls the defect detection mechanism to obtain an image of the current layer that has been printed; and determines whether the current layer that has been printed has defects according to the obtained image and a preset defect detection database; wherein the preset defect detection database includes defects of different types and sizes and corresponding femtosecond laser subtractive process parameters;

[0022] S56, if yes, the control mechanism generates a defect elimination plan according to the defect and the corresponding femtosecond laser subtractive process parameters, controls the emission mechanism of the subtractive mechanism to generate femtosecond laser according to the defect elimination plan, and controls the laser printing control mechanism to focus the femtosecond laser onto the molding substrate of the molding mechanism to perform subtractive removal on the defect of the current layer;

[0023] S57. After the defects of the current layer are removed, the above S51-S56 are circulated until the processing of the molded part is completed.

[0024] Preferably, the femtosecond laser process parameters include laser power, femtosecond laser beam focus diameter, frequency, scanning speed, overlap spacing and scanning path; wherein, the femtosecond laser power is 5-20w, the femtosecond laser focus diameter is 15-30μm, the frequency is 80-120KHz, the scanning speed is 50-200mm / s, the overlap spacing is 0.015-0.025mm, and the scanning path is zigzag, grid and rotary;

[0025] Among them, for defects with thickness > 7μm and maximum horizontal cross-sectional area > 2500μm2, the scanning path adopted is a grid scanning path; for defects with thickness > 7μm and maximum horizontal cross-sectional area < 2500μm2, the scanning path adopted is a rotary scanning path, and the rest adopt a zigzag scanning path.

[0026] Preferably, the laser printing control mechanism includes a beam deflection component and a printing component; wherein the printing component includes at least two Gaussian beam field lenses, at least one flat-top beam field lens and at least one femtosecond laser field lens; the beam deflection component includes a first beam deflection device corresponding one-to-one to the Gaussian beam field lens, a second beam deflection device corresponding one-to-one to the flat-top beam field lens and a third beam deflection device corresponding one-to-one to the femtosecond laser field lens.

[0027] Preferably, the number of Gaussian beam field lenses is 4, the number of flat-top beam field lenses is 2, and the number of femtosecond laser field lenses is 2.

[0028] Preferably, the laser printing process parameters include: a flat-top beam focusing diameter of 240 μm, a flat-top beam laser power of 2200 W, a flat-top beam path spacing of 0.26 mm, a flat-top beam scanning speed of 1200 mm / s, and a powder thickness of 60 μm; a Gaussian beam focusing diameter of 80 μm, a Gaussian beam laser power of 300 W, a Gaussian beam path spacing of 0.1 mm, a Gaussian beam scanning speed of 1000 mm / s, and a powder thickness of 50 μm; the scanning strategy is a reciprocating scanning strategy; the internal filling of the contour adopts a 67° rotation, strip partitioning, and a reciprocating scanning strategy; the contour adopts a single-channel scanning strategy.

[0029] In the present invention, the proposed multi-laser area additive-detection-subtractive composite manufacturing method combines traditional multi-laser additive manufacturing, defect detection and laser subtraction, and uses the combined multi-laser area additive-detection-subtractive composite device for printing. It can use multiple Gaussian beams and flat-top beams to collaboratively perform additive manufacturing of metal components, and through online identification, judgment, positioning and removal of metallurgical defects, ultimately obtain a defect-free or less-defective entity of the to-be-molded part.

[0030] The present invention overcomes the limitations of a single manufacturing method, improves forming efficiency, ensures processing quality and precision, and greatly expands the process window for forming metal components. It has significant advantages for manufacturing components with large volume, complex structure, high processing precision and short processing cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the process of a multi-laser region additive-inspection-subtractive composite manufacturing method in one embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of a model of a part to be formed in an embodiment of the present invention.

[0033] Figure 3 It is a schematic diagram of the processing range of a Gaussian beam and a flat-top beam in one embodiment of the present invention.

[0034] Figure 4 It is a schematic diagram of the scanning area of ​​a Gaussian beam and a flat-top beam in a certain printing layer according to an embodiment of the present invention.

[0035] Figure 5 A schematic diagram of the partitioning and scanning of a Gaussian beam and a flat-top beam on a certain printing layer in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] Reference Figure 1 The present invention proposes a multi-laser region additive-detection-subtractive composite manufacturing method, comprising:

[0038] S1. Establish a three-dimensional model of the part to be molded and add necessary supporting structure models to the three-dimensional model;

[0039] S2, setting laser printing process parameters, and slicing the model formed by combining the three-dimensional model and the supporting structure model layer by layer to obtain a slicing program;

[0040] S3, importing the slicing program into the multi-laser powder bed fusion molding software to generate a printing program;

[0041] S4, importing the printing program into the multi-laser area additive-detection-subtractive composite device;

[0042] S5, the multi-laser area additive-detection-subtractive composite device prints out the entity of the part to be formed on its forming substrate according to the slicing program;

[0043] S6. After printing is completed, the molding substrate is taken out from the multi-laser area additive-detection-subtractive composite device, and the entity of the part to be molded is cut off from the molding substrate to obtain the entity of the part to be molded.

[0044] The present invention combines traditional multi-laser additive manufacturing, defect detection and laser subtractive manufacturing, and uses the combined multi-laser area additive-detection-subtractive composite device for printing. It can use multiple Gaussian beams and flat-top beams to collaboratively perform additive manufacturing of metal components, and through online identification, determination, positioning and removal of metallurgical defects, ultimately obtain a defect-free or less-defective entity of the to-be-molded part.

[0045] The present invention overcomes the limitations of a single manufacturing method, improves forming efficiency, ensures processing quality and precision, and greatly expands the process window for forming metal components. It has significant advantages for manufacturing components with large volume, complex structure, high processing precision and short processing cycle.

[0046] Among them, the multi-laser area additive-detection-subtractive composite device includes: a molding mechanism, a laser emitting mechanism, a defect detection mechanism and a laser printing control mechanism; the additive laser emitting mechanism is used to generate a Gaussian beam or a flat-top beam; the subtractive mechanism emitting mechanism is used to generate a femtosecond laser; the laser printing control mechanism is used to focus the generated Gaussian beam or flat-top beam onto the molding substrate of the molding mechanism for printing or to focus the generated femtosecond laser onto the molding substrate of the molding mechanism for defect removal, and the defect detection mechanism is used to detect whether the current layer that has been printed on the molding substrate of the molding mechanism has defects; the control mechanism is used to control the molding mechanism, the laser emitting mechanism, the defect detection mechanism and the laser printing control mechanism to coordinate actions according to the slicing program to complete the printing of the part to be molded and the removal of defects.

[0047] The present embodiment is configured in such a way that it is possible to combine traditional multi-laser additive manufacturing, defect detection and laser subtractive manufacturing, and to use the combined multi-laser regional additive-detection-subtractive composite device for printing. It is possible to use multiple Gaussian beams and flat-top beams to collaboratively perform additive manufacturing of metal components, and to perform online identification, determination, positioning and removal of metallurgical defects, thereby ultimately obtaining a solid body of a part to be formed with no or few defects.

[0048] Among them, the laser printing process parameters include: flat-top beam focusing diameter, Gaussian beam focusing diameter, laser processing power, scanning rate, path spacing, powder layer thickness, number of boundary contours, inner and outer contour distances, spot compensation, boundary distance, scanning strategy and partition strategy;

[0049] Among them, the focusing diameter of the flat-top beam is 200-300μm, and the focusing diameter of the Gaussian beam is 60-120μm; the laser power of the flat-top beam is 2000-3000W, and the laser power of the Gaussian beam is 50-1000W; the scanning speed of the flat-top beam is 600-2000mm / s; the scanning speed of the Gaussian beam is 200-1800mm / s; the path spacing of the flat-top beam is 0.15-0.25mm, and the path spacing of the Gaussian beam is 0.05-0.10mm; the thickness of the powder layer is 0.02-0.12mm; the number of boundary contours is 0-2; the inner and outer contour distances are 0.06-0.12mm, and the spot compensation is 0.04-0.06mm; the boundary distance is -0.1-0.1mm; the scanning strategies are unidirectional scanning strategy, round-trip scanning strategy, spiral scanning strategy and contour scanning strategy; the partition strategies are non-partitioning, strip partitioning, island partitioning and honeycomb partitioning.

[0050] In order to obtain a defect-free or defect-free entity of the molded part, in S5, the multi-laser area additive-detection-subtractive composite device prints the molded part according to the slicing program, specifically including:

[0051] S51, the control mechanism controls the molding mechanism to lay a powder layer of a predetermined thickness on its molding substrate;

[0052] S52, when the powder layer is laid, the control mechanism controls the additive laser emitting mechanism to generate a Gaussian beam, and then controls the laser printing control mechanism to focus the Gaussian beam onto the powder layer on the molding substrate of the molding mechanism to print the contour of the to-be-molded part;

[0053] S53, when the printing of the contour of the to-be-molded part is completed, the control mechanism controls the additive laser emitting mechanism to generate a flat-top beam, and then controls the laser printing control mechanism to focus the flat-top beam onto the molding substrate of the molding mechanism to fill the inner area of ​​the contour of the to-be-molded part;

[0054] S54, when the filling of the inner area of ​​the contour of the to-be-molded part is completed, the control mechanism controls the additive laser emitting mechanism to generate a Gaussian beam, and then controls the laser printing control mechanism to focus the Gaussian beam onto the molding substrate of the molding mechanism to fill the dead angle area of ​​the contour of the to-be-molded part, thereby completing the printing of the current layer;

[0055] S55, after the printing of the current layer is completed, the control mechanism controls the defect detection mechanism to obtain an image of the current layer that has been printed; and determines whether the current layer that has been printed has defects according to the obtained image and a preset defect detection database; wherein the preset defect detection database includes defects of different types and sizes and corresponding femtosecond laser subtractive process parameters;

[0056] S56, if yes, the control mechanism generates a defect elimination plan according to the defect and the corresponding femtosecond laser subtractive process parameters, controls the emission mechanism of the subtractive mechanism to generate femtosecond laser according to the defect elimination plan, and controls the laser printing control mechanism to focus the femtosecond laser onto the molding substrate of the molding mechanism to perform subtractive removal on the defect of the current layer;

[0057] S57. After the defects of the current layer are removed, the above S51-S56 are circulated until the processing of the molded part is completed.

[0058] The present embodiment is configured in such a way that multiple Gaussian beams and flat-top beams can be used to collaboratively perform additive manufacturing of metal components. Metallurgical defects are identified, determined, located, and adaptively removed online, thereby ultimately obtaining a solid body of the part to be formed with no or few defects, thereby effectively improving the printing quality.

[0059] Of course, the powder raw materials in the powder layer in this embodiment are screened and dried before spreading to ensure that spherical powder with a suitable particle size is obtained, so that its maximum particle size does not exceed twice the corresponding layer thickness, and the diameter range of the metal powder particles is controlled within 15 to 65 μm and conforms to the normal distribution.

[0060] It should be noted that the thickness of the molding substrate in this embodiment is not less than 20 mm, and its material composition is similar to or the same as that of the part to be molded.

[0061] The defect detection mechanism in this embodiment is a camera, a video camera, an infrared camera or a four-dimensional imaging monitor. Among them, the four-dimensional imaging monitor involves key technologies such as in-situ suppression calibration of stereoscopic imaging distortion, high-precision splicing and fusion of multi-viewpoint clouds, and online recognition of stress deformation defects, and online acquisition of imaging field of view ≥450×450mm, resolution ≥4500×4500 pixels, and accuracy error ≤45μm.

[0062] Since the defects are mainly humps of different sizes, spheroidization, and incompletely melted particle clusters of various shapes (needle-shaped, square, round, etc.), in order to be able to adaptively remove defects, the femtosecond laser process parameters in this embodiment are set according to the material type of the component, the defect thickness and the maximum defect cross-sectional area in the horizontal direction. Specifically, the femtosecond laser process parameters include laser power, focusing diameter of the femtosecond laser beam, frequency, scanning speed, overlap spacing and scanning path; wherein, the femtosecond laser power is 5-20w, the focusing diameter of the femtosecond laser is 15-30μm, the frequency is 80-120KHz, the scanning speed is 50-200mm / s, the overlap spacing is 0.015-0.025mm, and the scanning paths are zigzag, grid and rotary; wherein, for defects with a thickness of more than 7μm and a horizontal maximum cross-sectional area of ​​more than 2500μm2, the scanning path adopted is a grid scanning path; for defects with a thickness of more than 7μm and a horizontal maximum cross-sectional area of ​​less than 2500μm2, the scanning path adopted is a rotary scanning path, and the rest adopt a zigzag scanning path.

[0063] In this embodiment, the laser printing control mechanism includes a beam deflection component and a printing component; wherein the printing component includes at least two Gaussian beam field lenses, at least one flat-top beam field lens and at least one femtosecond laser field lens; the beam deflection component includes a first beam deflection device corresponding one-to-one to the Gaussian beam field lens, a second beam deflection device corresponding one-to-one to the flat-top beam field lens and a third beam deflection device corresponding one-to-one to the femtosecond laser field lens.

[0064] In a specific implementation, the first beam deflection assembly is used to deflect the Gaussian beam onto the Gaussian beam field lens, and the Gaussian beam field lens is used to focus the Gaussian beam onto the molding substrate of the molding mechanism to print the contour of the part to be molded or to focus the Gaussian beam onto the molding substrate of the molding mechanism to fill the dead angle area of ​​the contour of the part to be molded;

[0065] Alternatively, the second beam deflection assembly is used to transfer the flat-top beam to a flat-top beam field lens, and the flat-top beam field lens is used to focus the flat-top beam onto a molding substrate of a molding mechanism to fill the inner area of ​​the contour of the part to be molded;

[0066] Alternatively, the third beam deflection assembly is used to transfer the femtosecond laser sheet to the femtosecond laser field mirror, and the femtosecond laser field mirror is used to focus the femtosecond laser onto the molding substrate of the molding mechanism to perform subtractive removal of defects in the current layer.

[0067] The overlapping method in this embodiment adopts periodic overlapping, the overlapping area width is set to 5-15mm, the overlapping line moves layer by layer from left to right in the overlapping area, the overlapping area is repeatedly divided from left to right, the overlapping line movement amount is 20% of the overlapping area width, and the overlapping distance is 0.01-0.02mm.

[0068] In one specific embodiment, the first beam deflection device, the second beam deflection device and the third beam deflection device are all galvanometers, and the deflection angle of a single galvanometer is adjustable within a range of ±10° in any direction.

[0069] Of course, the additive laser emitting mechanism includes a Gaussian beam laser emitting assembly corresponding one-to-one to the Gaussian beam field lens and a flat-top beam laser emitting assembly corresponding one-to-one to the flat-top beam field lens; the femtosecond laser emitting mechanism includes a femtosecond laser emitting assembly corresponding one-to-one to the femtosecond laser field lens, and the Gaussian beam laser emitting assembly, the flat-top beam laser emitting assembly and the femtosecond laser emitting assembly are electrically connected to the control mechanism respectively.

[0070] In one specific embodiment, when the molded part is as follows Figure 2 As shown in the tubular metal component, the number of Gaussian beam field lenses in this embodiment is 4, the number of flat-top beam field lenses is 2, the two flat-top beam field lenses are symmetrically arranged, and the four Gaussian beam field lenses are arranged around the two flat-top beam field lenses. The processing range is as follows Figure 3 As shown, top-hat light 1 and top-hat light 2 represent top-hat beam field lenses, and Gaussian light 1, Gaussian light 2, Gaussian light 3 and Gaussian light 4 represent Gaussian beam field lenses.

[0071] The laser printing process parameters in this embodiment include: the focusing diameter of the flat-top beam is 240 μm, the laser power of the flat-top beam is 2200W, the path spacing of the flat-top beam is 0.26mm, the scanning speed of the flat-top beam is 1200mm / s, and the powder thickness is 60μm; the focusing diameter of the Gaussian beam is 80μm, the laser power of the Gaussian beam is 300W, the path spacing of the Gaussian beam is 0.1mm, the scanning speed of the Gaussian beam is 1000mm / s, and the powder thickness is 60μm; the scanning strategy is a round-trip scanning strategy; the internal filling of the contour adopts a 67° rotation, strip partitioning, and a round-trip scanning strategy; the contour adopts a single-channel scanning strategy. The scanning area of ​​one layer is as follows Figure 4 As shown, the partition and scan path are as follows Figure 5 shown.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multi-laser area additive-detection-subtractive composite manufacturing method, characterized in that: include: S1. Establish a three-dimensional model of the part to be molded and add necessary supporting structure models to the three-dimensional model; S2, setting laser printing process parameters, and slicing the model formed by combining the three-dimensional model and the supporting structure model layer by layer to obtain a slicing program; S3, importing the slicing program into the multi-laser powder bed fusion molding software to generate a printing program; S4, importing the printing program into the multi-laser area additive-detection-subtractive composite device; S5, the multi-laser area additive-detection-subtractive composite device prints out the entity of the to-be-molded part on its molding substrate according to the slicing program; S6. After printing is completed, the molding substrate is taken out from the multi-laser area additive-detection-subtractive composite device, and the entity of the part to be molded is cut off from the molding substrate to obtain the entity of the part to be molded.

2. The multi-laser region additive-detection-subtractive composite manufacturing method according to claim 1, characterized in that: Laser printing process parameters include: flat-top beam focusing diameter, Gaussian beam focusing diameter, laser processing power, scanning rate, path spacing, powder layer thickness, number of boundary contours, inner and outer contour distances, spot compensation, boundary distance, scanning strategy, and partition strategy; Among them, the focusing diameter of the flat-top beam is 200-300μm, and the focusing diameter of the Gaussian beam is 60-120μm; the laser power of the flat-top beam is 2000-3000W, and the laser power of the Gaussian beam is 50-1000W; the scanning speed of the flat-top beam is 600-2000mm / s; the scanning speed of the Gaussian beam is 200-1800mm / s; the path spacing of the flat-top beam is 0.15-0.25mm, and the path spacing of the Gaussian beam is 0.05-0.10mm; the thickness of the powder layer is 0.02-0.12mm; the number of boundary contours is 0-2; the inner and outer contour distances are 0.06-0.12mm, and the spot compensation is 0.04-0.06mm; the boundary distance is -0.1-0.1mm; the scanning strategies are unidirectional scanning strategy, round-trip scanning strategy, spiral scanning strategy and contour scanning strategy; the partition strategies are non-partitioning, strip partitioning, island partitioning and honeycomb partitioning.

3. The multi-laser region additive-detection-subtractive composite manufacturing method according to claim 1, characterized in that: The multi-laser area additive-detection-subtractive composite device includes: a molding mechanism, a laser emitting mechanism, a defect detection mechanism and a laser printing control mechanism; the additive laser emitting mechanism is used to generate a Gaussian beam or a flat-top beam; the subtractive mechanism emitting mechanism is used to generate a femtosecond laser; the laser printing control mechanism is used to focus the generated Gaussian beam or flat-top beam onto the molding substrate of the molding mechanism for printing or to focus the generated femtosecond laser onto the molding substrate of the molding mechanism for defect removal, and the defect detection mechanism is used to detect whether the current layer that has been printed on the molding substrate of the molding mechanism has defects; the control mechanism is used to control the molding mechanism, the laser emitting mechanism, the defect detection mechanism and the laser printing control mechanism to coordinate actions according to the slicing program to complete the printing of the part to be molded and the removal of defects.

4. The multi-laser region additive-detection-subtractive composite manufacturing method according to claim 3, characterized in that: In S5, the multi-laser area additive-detection-subtractive composite device prints out the parts to be formed according to the slicing program, specifically including: S51, the control mechanism controls the molding mechanism to lay a powder layer of a predetermined thickness on its molding substrate; S52, when the powder layer is laid, the control mechanism controls the additive laser emitting mechanism to generate a Gaussian beam, and then controls the laser printing control mechanism to focus the Gaussian beam onto the powder layer on the molding substrate of the molding mechanism to print the contour of the to-be-molded part; S53, when the printing of the contour of the to-be-molded part is completed, the control mechanism controls the additive laser emitting mechanism to generate a flat-top beam, and then controls the laser printing control mechanism to focus the flat-top beam onto the molding substrate of the molding mechanism to fill the inner area of ​​the contour of the to-be-molded part; S54, when the filling of the inner area of ​​the contour of the to-be-molded part is completed, the control mechanism controls the additive laser emitting mechanism to generate a Gaussian beam, and then controls the laser printing control mechanism to focus the Gaussian beam onto the molding substrate of the molding mechanism to fill the dead angle area of ​​the contour of the to-be-molded part, thereby completing the printing of the current layer; S55, after the printing of the current layer is completed, the control mechanism controls the defect detection mechanism to obtain an image of the current layer that has been printed; and determines whether the current layer that has been printed has defects according to the obtained image and a preset defect detection database; wherein the preset defect detection database includes defects of different types and sizes and corresponding femtosecond laser subtractive process parameters; S56, if yes, the control mechanism generates a defect elimination plan according to the defect and the corresponding femtosecond laser subtractive process parameters, controls the emission mechanism of the subtractive mechanism to generate femtosecond laser according to the defect elimination plan, and controls the laser printing control mechanism to focus the femtosecond laser onto the molding substrate of the molding mechanism to perform subtractive removal on the defect of the current layer; S57. After the defects of the current layer are removed, the above S51-S56 are circulated until the processing of the molded part is completed.

5. The multi-laser region additive-detection-subtractive composite manufacturing method according to claim 4, characterized in that: The femtosecond laser process parameters include laser power, femtosecond laser beam focus diameter, frequency, scanning speed, overlap spacing and scanning path; wherein, the femtosecond laser power is 5-20w, the femtosecond laser focus diameter is 15-30μm, the frequency is 80-120KHz, the scanning speed is 50-200mm / s, the overlap spacing is 0.015-0.025mm, and the scanning path is zigzag, grid and rotary; Among them, for defects with thickness > 7μm and maximum horizontal cross-sectional area > 2500μm2, the scanning path adopted is a grid scanning path; for defects with thickness > 7μm and maximum horizontal cross-sectional area < 2500μm2, the scanning path adopted is a rotary scanning path, and the rest adopt a zigzag scanning path.

6. The multi-laser region additive-detection-subtractive composite manufacturing method according to claim 3, characterized in that: The laser printing control mechanism includes a beam deflection component and a printing component; wherein the printing component includes at least two Gaussian beam field lenses, at least one flat-top beam field lens and at least one femtosecond laser field lens; the beam deflection component includes a first beam deflection device corresponding one-to-one to the Gaussian beam field lens, a second beam deflection device corresponding one-to-one to the flat-top beam field lens and a third beam deflection device corresponding one-to-one to the femtosecond laser field lens.

7. The multi-laser region additive-detection-subtractive composite manufacturing method according to claim 6, characterized in that: The number of Gaussian beam field lenses is 4, the number of flat-top beam field lenses is 2 and the number of femtosecond laser field lenses is 2.

8. The multi-laser region additive-detection-subtractive composite manufacturing method according to claim 7, characterized in that: The laser printing process parameters include: the focusing diameter of the flat-top beam is 240μm, the flat-top beam laser power is 2200W, the flat-top beam path spacing is 0.26mm, the flat-top beam scanning speed is 1200mm / s, and the powder thickness is 60μm; the focusing diameter of the Gaussian beam is 80μm, the Gaussian beam laser power is 300W, the Gaussian beam path spacing is 0.1mm, the Gaussian beam scanning speed is 1000mm / s, and the powder thickness is 60μm; the scanning strategy is a reciprocating scanning strategy; the internal filling of the contour adopts 67° rotation, strip partitioning, and reciprocating scanning strategy; the contour adopts a single-channel scanning strategy.

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