Laser scanning method based on molten pool monitoring, additive manufacturing equipment and computer storage medium

Abstract

The invention discloses a laser scanning method based on molten pool monitoring, additive manufacturing equipment and a computer storage medium. The scanning method comprises the steps that a model of a to-be-printed piece is sliced to obtain the contour section of each layer; scanning the contour section of each layer according to a preset direction by adopting a plurality of preset filling vectors; analyzing the heat of the formed contour section of each layer, and determining a scanning path of the contour section of the next layer according to the following mode: projecting the overheating area of the current layer to the contour section of the next layer to obtain a to-be-processed area when the contour section of a certain layer has an overheating area of which the heat exceeds a threshold value, and scanning the to-be-processed area of the to-be-processed area of the to-be-processed area of the to-be-processed area of the to-be-processed area; all filling vectors passing through the to-be-processed area are extracted and broken, and breaking points are located in the to-be-processed area and the boundary of the to-be-processed area. The heat of the overheat area is homogenized by changing the scanning path and scanning energy of the filling vector, so that heat concentration of the overheat area is avoided, and the success rate and the surface quality of the to-be-printed piece are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a laser scanning method based on molten pool monitoring, additive manufacturing equipment and computer storage medium. Background Art

[0002] Additive manufacturing technology is an advanced manufacturing technology with distinctive features such as digital manufacturing, high flexibility and adaptability, direct CAD model drive, fast, and rich and diverse material types. Since it is not limited by the complexity of the part shape and does not require any tooling, it has a very wide range of applications. Selective Laser Sintering (SLS) is one of the additive manufacturing technologies that has developed rapidly in recent years. It uses powder materials as raw materials and uses lasers to scan the cross-section of three-dimensional entities layer by layer to complete prototype manufacturing. Its basic working process is: the powder feeding device delivers a certain amount of powder to the working platform surface, the powder spreading device spreads a layer of powder material on the bottom plate of the working cavity or the upper surface of the formed part, and the laser galvanometer system controls the laser to scan the solid part powder layer according to the cross-sectional profile of the layer with an approximately constant spot size and beam energy, so that the powder melts and bonds with the formed part below; when a layer of cross section is sintered, the working platform drops a layer of thickness, and the powder spreading device spreads a layer of uniform and dense powder on it, and scans and sinters a new layer of cross section, and after several layers of scanning and superposition, the entire prototype manufacturing is completed.

[0003] The laser scanning method of the prior art mainly generates a filling vector inside the contour, starting from the contour and ending at the contour, including parallel line scanning, contour equidistant line scanning, and a mixed scanning of the two. In these laser scanning methods of the prior art, due to the characteristics of the laser scanning method and the workpiece to be printed, heat concentration is prone to occur in local areas, forming a local overheating phenomenon, which leads to warping and deformation, affecting the printing quality of the workpiece. In severe cases, the molding process of the workpiece cannot proceed normally, resulting in the scrapping of the workpiece and increased product costs. Summary of the invention

[0004] In view of this, the present invention provides a laser scanning method based on melt pool monitoring, an additive manufacturing device and a computer storage medium. The laser scanning method based on melt pool monitoring can even out the heat in the overheating area by changing the scanning path and scanning energy of the filling vector, thereby avoiding further concentration of heat in the overheating area and preventing warping during the printing process.

[0005] In order to achieve the above object, the present invention provides a laser scanning method based on molten pool monitoring, comprising the following steps:

[0006] Slice the model of the part to be printed to obtain the contour section of each layer;

[0007] Scanning the contour section of each layer in a preset direction using a plurality of preset filling vectors, wherein the energy of the preset filling vectors is a first preset energy value;

[0008] Based on the molten pool monitoring, the heat of each layer of the formed profile section is analyzed. When the profile section of a layer has an overheated area with a heat value exceeding the threshold, the profile section of the next layer re-determines the scanning path and scanning energy in the following way:

[0009] The overheated area of ​​the current layer is projected onto the contour section of the next layer to obtain the area to be processed, and all the filling vectors passing through the area to be processed are extracted and interrupted, and the interruption points are within the area to be processed and at its boundary;

[0010] The energy of the filling vector in the area to be processed is controlled to be a second preset energy value, where the second preset energy value is smaller than the first preset energy value.

[0011] As a further preferred solution of the present invention, the contour section of each layer is scanned using a plurality of mutually parallel preset filling vectors.

[0012] As a further preferred embodiment of the present invention, the contour section includes a plurality of closed polygons, and at least one polygon of the next layer redefines the scanning path and scanning energy in the following manner:

[0013] The overheated area of ​​the current layer is projected onto at least one polygon of the next layer to obtain the area to be processed, which includes at least one closed virtual area. When the virtual area coincides with the corresponding polygon, the break point in the virtual area is the starting point of all filling vectors in the virtual area; when the virtual area is a local area of ​​the corresponding polygon, the break point in the virtual area is the end point of all filling vectors in the virtual area.

[0014] As a further preferred solution of the present invention, when the virtual area is a local area of ​​a corresponding polygon, the polygon of the next layer redefines the scanning path and scanning energy in the following manner:

[0015] Extracting all filling vectors passing through the virtual area and interrupting them, wherein the interruption points of each filling vector include at least one intersection point with the virtual area and a midpoint of the filling vector located in the virtual area;

[0016] Control at least one interrupted fill vector outside the virtual area of ​​the polygon to scan according to a preset direction and a first preset energy value; control the direction of at least one interrupted fill vector within the virtual area to remain unchanged or rotate 180 degrees, so that the end points of all interrupted fill vectors within the virtual area are the midpoints of the fill vectors within the virtual area, and control the energy of all interrupted fill vectors within the virtual area to be a second preset energy value.

[0017] As a further preferred solution of the present invention, when the virtual area overlaps with the corresponding polygon, the polygon of the next layer redefines the scanning path and scanning energy in the following manner:

[0018] Obtain two quarter points close to the contour boundary of each filling vector in the polygon, and record them as the first quarter point and the second quarter point respectively;

[0019] Connect the first equally divided points of all the filling vectors on one side in sequence to form a first line, connect the second equally divided points of all the filling vectors on the other side in sequence to form a second line, and then extend the first line and the second line to both ends to intersect to obtain a closed random area;

[0020] All filling vectors are interrupted, and the interruption point of each filling vector is randomly located on the filling vector in the random area;

[0021] The directions of the interrupted filling vectors are controlled to remain unchanged or rotated 180 degrees, so that the starting points of all the interrupted filling vectors are interruption points, and the energies of all the interrupted filling vectors are controlled to be a second preset energy value.

[0022] As a further preferred embodiment of the present invention, the second preset energy value is a constant value Y, and it satisfies the following formula:

[0023] Y=αX+β, α and β are coefficients, and X is the value of the molten pool monitoring heat exceeding the threshold value of the current layer.

[0024] As a further preferred embodiment of the present invention, the second preset value is a variable value, and in the scanning process from the starting point to the end point of the filling vector, the second preset energy value changes gradually or stepwise.

[0025] As a further preferred embodiment of the present invention, when the area of ​​the virtual area is less than half of the area of ​​the corresponding polygon, the second preset value changes in steps; when the virtual area is greater than or equal to half of the area of ​​the corresponding polygon, the second preset value changes gradually.

[0026] The present invention also provides an additive manufacturing device, comprising:

[0027] A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes any of the above-mentioned laser scanning methods based on molten pool monitoring by executing the computer instructions.

[0028] The present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute any of the above-mentioned laser scanning methods based on molten pool monitoring.

[0029] The laser scanning method, additive manufacturing equipment and computer storage medium based on molten pool monitoring of the present invention, wherein the laser scanning method comprises: slicing the model of the workpiece to be printed to obtain the contour section of each layer; scanning the contour section of each layer in a preset direction using a plurality of preset filling vectors, wherein the energy of the preset filling vectors is a first preset energy value; based on the molten pool monitoring, analyzing the heat of each layer of the formed contour section, when the contour section of a certain layer has an overheated area whose heat exceeds a threshold, the contour section of the next layer is re-determined in the following manner. The scanning path and scanning energy are re-determined: the overheated area of ​​the current layer is projected onto the next layer The contour section of the area to be processed is obtained, all the filling vectors passing through the area to be processed are extracted and interrupted, and the interruption points are within the area to be processed and its boundary; the energy of the filling vectors in the area to be processed is controlled to be a second preset energy value, and the second preset energy value is less than the first preset energy value, so that the laser scanning method of the present invention can uniformize the heat in the overheating area by changing the scanning path and scanning energy of the filling vectors, thereby avoiding further concentration of heat in the overheating area, preventing warping during the printing process, helping to reduce crack initiation, and effectively improving the success rate, printing surface quality and performance of the parts to be printed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a method flow chart of an embodiment of the laser scanning method based on molten pool monitoring provided by the present invention;

[0032] Figure 2 The laser scanning method based on molten pool monitoring of the present invention provides the working example of the first embodiment. Figure 1 ;

[0033] Figure 3 The laser scanning method based on molten pool monitoring of the present invention provides the working example of the first embodiment. Figure 2 ;

[0034] Figure 4 The laser scanning method based on molten pool monitoring of the present invention provides the working example of the first embodiment. Figure 3 ;

[0035] Figure 5 The laser scanning method based on molten pool monitoring of the present invention provides the working example of the first embodiment. Figure 4 ;

[0036] Figure 6 The laser scanning method based on molten pool monitoring of the present invention provides the working example of the first embodiment. Figure 5 ;

[0037] Figure 7 The laser scanning method based on molten pool monitoring of the present invention provides the working example of the first embodiment. Figure 6 ;

[0038] Figure 8 The laser scanning method based on molten pool monitoring of the present invention provides the working example 2 Figure 1 ;

[0039] Fig. 9 The laser scanning method based on molten pool monitoring of the present invention provides the working example 2 Figure 2 . DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0041] like Figure 1 As shown, the present invention provides a laser scanning method based on molten pool monitoring, comprising the following steps:

[0042] Step S1, slicing the model of the part to be printed to obtain the contour section of each layer;

[0043] Step S2, the contour section of each layer is scanned in a preset direction using a plurality of preset filling vectors, and the energy of the preset filling vector is a first preset energy value; specifically, the contour section of each layer is scanned using a plurality of mutually parallel preset filling vectors. The energy of the filling vector in the present application is composed of parameters such as power, speed, spacing, jump delay, etc. The preset direction of this step can be predetermined by the designer, for example, the scanning can be performed in the order from left to right and then from right to left.

[0044] Step S3, based on the melt pool monitoring, the heat of each layer of the formed contour section is analyzed. When there is an overheating area in the contour section of a certain layer where the heat exceeds the threshold, the contour section of the next layer redefines the scanning path and scanning energy in the following manner: It should be noted here that the heat analysis of each layer of the formed contour section based on the melt pool monitoring in this step belongs to the prior art in this field. For example, the heat value of each layer of the formed contour section can be obtained in real time through the melt pool monitoring, and it can be determined by analysis whether it exceeds the threshold. This threshold can be comprehensively determined by the designer based on the material type, equipment parameters, printing parameters, etc. of the part to be printed.

[0045] Step S4, projecting the overheated area of ​​the current layer to the contour section of the next layer to obtain the area to be processed, extracting all the filling vectors passing through the area to be processed and interrupting them, and the interruption points are within the area to be processed and at its boundary;

[0046] Step S5: Control the energy of the filling vector in the area to be processed to be a second preset energy value, where the second preset energy value is smaller than the first preset energy value.

[0047] It can be understood that when there is no overheating area with heat exceeding the threshold in the contour section of a certain layer in step S3, the contour section of the next layer can continue to be scanned with reference to the preset direction and the first preset energy value of step S2, that is, the technical solution of the present invention is not activated.

[0048] In a specific implementation, the contour section includes a plurality of closed polygons, and at least one polygon of the next layer redefines the scanning path and scanning energy in the following manner:

[0049] The overheated area of ​​the current layer is projected onto at least one polygon of the next layer to obtain the area to be processed, which includes at least one closed virtual area. When the virtual area coincides with the corresponding polygon, the break point in the virtual area is the starting point of all fill vectors in the virtual area; when the virtual area is a local area of ​​the corresponding polygon, the break point in the virtual area is the end point of all fill vectors in the virtual area. The corresponding polygon in this application refers to the polygon that contains the virtual area. The above-mentioned area to be processed is divided into at least one closed virtual area according to whether the virtual area is continuous, that is, the area to be processed is divided into one or more discontinuous closed virtual areas, each polygon can contain at least one virtual area, and a virtual area can only be contained by one polygon.

[0050] It is understandable that the above only describes how to redefine the scanning path and scanning energy by taking one polygon as an example. Preferably, the scanning strategies of other polygons can be executed with reference to this polygon, but of course they can also be executed without reference to this polygon, and no repetitive explanation is given here.

[0051] Specifically, depending on whether the virtual area partially or completely occupies its corresponding polygon, the corresponding scanning strategy is also different, which is specifically described as follows:

[0052] When the virtual area is a local area of ​​the corresponding polygon, the polygon of the next layer redefines the scanning path and scanning energy in the following manner:

[0053] Extracting all filling vectors passing through the virtual area and interrupting them, wherein the interruption points of each filling vector include at least one intersection point with the virtual area and a midpoint of the filling vector located in the virtual area;

[0054] Control at least one interrupted fill vector outside the virtual area of ​​the polygon to scan according to a preset direction and a first preset energy value; control the direction of at least one interrupted fill vector within the virtual area to remain unchanged or rotate 180 degrees, so that the end points of all interrupted fill vectors within the virtual area are the midpoints of the fill vectors within the virtual area, and control the energy of all interrupted fill vectors within the virtual area to be a second preset energy value.

[0055] When the virtual area coincides with the corresponding polygon, the polygon of the next layer redefines the scanning path and scanning energy in the following manner:

[0056] Obtain two quarter points close to the contour boundary of each filling vector in the polygon, and record them as the first quarter point and the second quarter point respectively;

[0057] Connect the first equally divided points of all the filling vectors on one side in sequence to form a first line, connect the second equally divided points of all the filling vectors on the other side in sequence to form a second line, and then extend the first line and the second line to both ends to intersect to obtain a closed random area;

[0058] All filling vectors are interrupted, and the interruption point of each filling vector is randomly located on the filling vector in the random area;

[0059] The directions of the interrupted filling vectors are controlled to remain unchanged or rotated 180 degrees, so that the starting points of all the interrupted filling vectors are interruption points, and the energies of all the interrupted filling vectors are controlled to be a second preset energy value.

[0060] Similarly, the above only describes how to redefine the scanning path and scanning energy by taking one virtual area as an example. Similarly, the scanning strategies of other virtual areas are executed with reference to this virtual area, and no repeated description is given here.

[0061] Preferably, in order to further improve the printing quality, the second preset energy value is a constant value Y, and it satisfies the following formula:

[0062] Y=αX+β, α and β are coefficients, and X is the value of the melt pool monitoring heat exceeding the threshold value of the current layer. In specific implementation, α can be determined by the designer according to the printing material, and β can be determined according to the actual printing parameters.

[0063] In order to make the heat in the overheated area more uniform, thereby reducing the risk of warping in the risk area, the first preferred method is: the second preset value is a variable value, and in the scanning process from the starting point to the end point of the filling vector, the second preset energy value changes gradually or in steps; the second preferred method is: when the overheated area is located inside the workpiece to be printed, low power can be used at the starting point and high power can be used at the end point to improve the heat distribution in the overheated area; when the overheated area is located at the edge of the workpiece to be printed, low power can be used at the starting point and low power can also be used at the end point to make the heat in the overheated area more uniform and reduce the risk of warping in the risk area.

[0064] Further preferably, when the area of ​​the virtual area is less than half of the area of ​​the corresponding polygon, the second preset value changes in steps; when the virtual area is greater than or equal to half of the area of ​​the corresponding polygon, the second preset value changes gradually, which can also make the heat distribution more uniform.

[0065] The present invention also provides an additive manufacturing device, comprising:

[0066] A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the laser scanning method based on molten pool monitoring described in any of the above embodiments by executing the computer instructions.

[0067] The present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the laser scanning method based on molten pool monitoring described in any of the above embodiments.

[0068] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is described in detail below in the form of embodiments in conjunction with the accompanying drawings.

[0069] Embodiment 1

[0070] The laser scanning method based on molten pool monitoring of this embodiment includes the following steps:

[0071] Step 11: Slice the workpiece to be printed to obtain the contour section of each layer. The contour section may contain multiple polygons. In this embodiment, only a single closed polygon is included. Figure 2 shown.

[0072] Step 12: Scan the contour section of each layer using a plurality of mutually parallel preset filling vectors in a preset direction and at a first preset energy value, such as Figure 3 shown.

[0073] Step 13: Based on the molten pool monitoring data, determine in turn whether there is an overheating area with a heat value exceeding a threshold value in the contour section of the current layer. If there is, extract the area with a heat value exceeding the threshold value to generate an overheating area, and re-determine the scanning path and scanning energy of the next layer of contour section according to the following steps 14 to 17. Otherwise, the next layer of contour section follows the preset direction and the first preset energy value pre-determined in the above step 12, that is, the scanning strategy and scanning energy of the next layer do not need to be changed;

[0074] Step 14: Project the overheated area of ​​the current layer to the contour section of the next layer to obtain the area to be processed. The area to be processed is a closed virtual area, and the virtual contour is the local area of ​​the corresponding polygon, such as Figure 4 As shown, the rectangular area is a virtual area.

[0075] Step 15: Extract all the filling amounts passing through the virtual area, such as Figure 5 The dotted line portion is shown.

[0076] Step 16: extract all the filling vectors passing through the virtual area and interrupt them. The interruption points of each filling vector include two intersection points with the virtual area and the midpoint of the filling vector located in the virtual area, such as Figure 6 shown.

[0077] Step 17, controlling at least one interrupted filling vector outside the virtual area of ​​the polygon to scan according to a preset direction and a first preset energy value; controlling the direction of at least one interrupted filling vector in the virtual area to remain unchanged or rotate 180 degrees, so that the end points of all interrupted filling vectors in the virtual area are the midpoints of the filling vectors in the virtual area, and controlling the energy of all interrupted filling vectors in the virtual area to be a second preset energy value, wherein the second preset energy value is less than the first preset energy value, such as Figure 7 During the scanning process, for all the filling vectors in the virtual area, the second preset value is a changing value and changes in a step-by-step manner.

[0078] Step 18, laser scanning is performed according to the scanning path and scanning energy of the filling vector of the contour section of all layers finally obtained to form a product. It should be noted here that since the first layer of contour section is the first layer, it does not need to re-determine the scanning path and scanning energy, and it can be scanned according to the filling vector of the preset direction and the first preset energy value.

[0079] Embodiment 2

[0080] The laser scanning method based on molten pool monitoring of this embodiment includes the following steps:

[0081] Step 21: Slice the workpiece to be printed to obtain the contour section of each layer, which is a closed polygon.

[0082] Step 22, scanning the contour section of each layer using a plurality of mutually parallel preset filling vectors in a preset direction and at a first preset energy value;

[0083] Step 23, based on the molten pool monitoring data, determine in turn whether there is an overheating area with a heat value exceeding a threshold in the contour section of the current layer. If there is, extract the area with a heat value exceeding the threshold, generate the overheating area, and re-determine the scanning path and scanning energy of the next layer of contour section according to the following steps 24 to 27. The next layer of contour section follows the preset direction and the first preset energy value pre-determined in the above step 12, that is, the scanning strategy and scanning energy of the next layer do not need to be changed;

[0084] Step 24: Project the overheated area of ​​the current layer to the contour section of the next layer to obtain the area to be processed. The area to be processed includes a closed virtual area, and the virtual contour completely overlaps with the corresponding polygon, such as Figure 8As shown, the virtual area is a polygon.

[0085] Step 25, obtain two quarter points close to the contour boundary of each filling vector in the polygon, and record them as the first quarter point and the second quarter point in turn; connect the first quarter points of all filling vectors on one side in turn to form a first line, and connect the second quarter points of all filling vectors on the other side in turn to form a second line, and then extend the first line and the second line to both ends to intersect to obtain a closed random area, such as Figure 8 The rugby area shown is the random area;

[0086] Step 26: interrupt all filling vectors, and the interruption point of each filling vector is randomly located on the filling vector in the random area, such as Fig. 9 The dots shown are the break points;

[0087] Step 27: Control the direction of the interrupted fill vector to remain unchanged or rotate 180 degrees, so that the starting points of all interrupted fill vectors are interruption points, that is, the dot is the starting point of the fill vector, and the arrow is the end point of the fill vector, such as Fig. 9 As shown; and the energy of all interrupted filling vectors is controlled to be a second preset energy value, wherein the second preset energy value is less than the first preset energy value; and during the scanning process of all filling vectors in the virtual area, the second preset value is a changing value and changes gradually.

[0088] Step 28: Perform laser scanning according to the scanning path and scanning energy of the filling vectors of the contour sections of all layers finally obtained to form a product.

[0089] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A laser scanning method based on molten pool monitoring, characterized in that: The following steps are involved: Slice the model of the part to be printed to obtain the contour section of each layer; Scanning the contour section of each layer in a preset direction using a plurality of preset filling vectors, wherein the energy of the preset filling vectors is a first preset energy value; Based on the molten pool monitoring, the heat of each layer of the formed profile section is analyzed. When the profile section of a layer has an overheated area with a heat value exceeding the threshold, the profile section of the next layer re-determines the scanning path and scanning energy in the following way: The overheated area of ​​the current layer is projected onto the contour section of the next layer to obtain the area to be processed, and all the filling vectors passing through the area to be processed are extracted and interrupted, and the interruption points are within the area to be processed and at its boundary; The energy of the filling vector in the area to be processed is controlled to be a second preset energy value, where the second preset energy value is smaller than the first preset energy value.

2. The method according to claim 1, characterized in that: The contour section of each layer is scanned using several mutually parallel preset filling vectors.

3. The method according to claim 2, characterized in that The contour section includes a plurality of closed polygons, and at least one polygon of the next layer redefines the scanning path and scanning energy in the following manner: The overheated area of ​​the current layer is projected onto at least one polygon of the next layer to obtain the area to be processed, which includes at least one closed virtual area. When the virtual area coincides with the corresponding polygon, the break point in the virtual area is the starting point of all filling vectors in the virtual area; when the virtual area is a local area of ​​the corresponding polygon, the break point in the virtual area is the end point of all filling vectors in the virtual area.

4. The method according to claim 3, characterized in that: When the virtual area is a local area of ​​the corresponding polygon, the polygon of the next layer redefines the scanning path and scanning energy in the following manner: Extracting all filling vectors passing through the virtual area and interrupting them, wherein the interruption points of each filling vector include at least one intersection point with the virtual area and a midpoint of the filling vector located in the virtual area; Control at least one interrupted fill vector outside the virtual area of ​​the polygon to scan according to a preset direction and a first preset energy value; control the direction of at least one interrupted fill vector within the virtual area to remain unchanged or rotate 180 degrees, so that the end points of all interrupted fill vectors within the virtual area are the midpoints of the fill vectors within the virtual area, and control the energy of all interrupted fill vectors within the virtual area to be a second preset energy value.

5. The method according to claim 3, characterized in that: When the virtual area coincides with the corresponding polygon, the polygon of the next layer redefines the scanning path and scanning energy in the following manner: Obtain two quarter points close to the contour boundary of each filling vector in the polygon, and record them as the first quarter point and the second quarter point respectively; Connect the first equally divided points of all the filling vectors on one side in sequence to form a first line, connect the second equally divided points of all the filling vectors on the other side in sequence to form a second line, and then extend the first line and the second line to both ends to intersect to obtain a closed random area; All filling vectors are interrupted, and the interruption point of each filling vector is randomly located on the filling vector in the random area; The directions of the interrupted filling vectors are controlled to remain unchanged or rotated 180 degrees, so that the starting points of all the interrupted filling vectors are interruption points, and the energies of all the interrupted filling vectors are controlled to be a second preset energy value.

6. The method according to any one of claims 1 to 5, characterized in that: The second preset energy value is a constant value Y, and it satisfies the following formula: Y=αX+β, α and β are coefficients, and X is the value of the molten pool monitoring heat exceeding the threshold value of the current layer.

7. The method according to any one of claims 1 to 5, characterized in that: The second preset value is a variable value, and in the scanning process from the starting point to the end point of the filling vector, the second preset energy value changes gradually or stepwise.

8. The method according to claim 7, characterized in that When the area of ​​the virtual region is less than half of the area of ​​the corresponding polygon, the second preset value changes in steps; when the virtual region is greater than or equal to half of the area of ​​the corresponding polygon, the second preset value changes gradually.

9. An additive manufacturing device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the laser scanning method based on molten pool monitoring as described in any one of claims 1-8 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the laser scanning method based on molten pool monitoring according to any one of claims 1-8.

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