Laser scanning method, device and storage medium for three-dimensional object manufacturing

Abstract

A laser scanning method, device and storage medium for manufacturing three-dimensional objects, wherein the laser scanning method includes: slicing the workpiece to be printed to obtain the cross-sectional profile of each layer, wherein the cross-sectional profile is one or more closed polygons; setting a number of fill vectors inside each polygon; extracting all fill vectors connected to or close to the profile in a preset area, and controlling the direction of the fill vectors connected to or close to the profile so that the endpoints of all fill vectors connected to or close to the profile are the end points of the fill vectors, and the starting points of all fill vectors are far away from the profile; and performing laser scanning according to the direction of all the fill vectors finally obtained. The present invention can effectively avoid the fluctuation of the molten pool at the starting point of the scanned fill vector, that is, it can suppress local (especially the contour) warping during the printing process, thereby improving the printing success rate, that is, it can effectively improve the surface quality of the workpiece to be printed.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to a laser scanning method, device, computer equipment and storage medium for manufacturing three-dimensional objects. Background Art

[0002] Additive manufacturing technology is a rapid manufacturing technology that forms three-dimensional objects by controlling laser scanning layer by layer and stacking layer by layer. The process flow is as follows: first, the three-dimensional model of the workpiece is sliced ​​to obtain the contour information of each layer of the workpiece; the powdered material is evenly spread on the surface of the work platform, and the laser selectively melts the powder according to the system instructions; after a section is completed, a new layer of material is spread, and the scanning continues to be selective according to the section information corresponding to the three-dimensional object; according to this method, the next section is scanned for powder spreading, and finally a three-dimensional object is obtained.

[0003] The scanning methods of the prior art mainly include parallel line scanning, contour equidistant line scanning, and a combination of the two. In parallel line scanning, the directions of two adjacent scanning vectors can be the same or opposite. In the above scanning methods of the prior art, the heat distribution in the area scanned by the laser is concentrated, which is easy to form a large temperature gradient with the surrounding powder that is not scanned by the laser, thereby causing problems such as warping, cracking, etc. For technicians in this field, the scanning path, scanning power, scanning speed, scanning spacing, etc. of the laser during the scanning process can affect the distribution of heat and residual stress, thereby causing warping of the workpiece. Therefore, the optimization and improvement of the laser scanning method has always been a research topic in this technology. Summary of the invention

[0004] In order to solve the technical problem that the laser scanning method in the prior art causes warping and deformation of the workpiece to be printed, the present invention provides a laser scanning method, device, computer equipment and storage medium for three-dimensional object manufacturing. The laser scanning method can suppress local (especially contour) warping during the printing process and improve the printing success rate, that is, it can effectively improve the surface quality of the workpiece to be printed.

[0005] In order to achieve the above object, the present invention provides a laser scanning method for manufacturing a three-dimensional object, comprising:

[0006] Slicing the workpiece to be printed to obtain a cross-sectional profile of each layer, wherein the cross-sectional profile is one or more closed polygons;

[0007] Set several filling vectors inside each polygon;

[0008] Extract all the filling vectors connected to or close to the contour in the preset area, and control the directions of the filling vectors connected to or close to the contour so that the endpoints of all the filling vectors connected to or close to the contour are the end points of the filling vectors, and the starting points of all the filling vectors are far away from the contour;

[0009] Laser scanning is performed in the direction of all the finally obtained filling vectors.

[0010] As a further preferred embodiment of the present invention, all the filling vectors connected to or close to the outline of the preset area are extracted, and by controlling the direction of the filling vectors connected to or close to the outline, the endpoints of all the filling vectors connected to or close to the outline are the end points of the filling vectors, and the starting points of all the filling vectors are far away from the outline. Specifically include:

[0011] Step 1: extract all the filling vectors connected to or close to the outline of the preset area to form a vector set A;

[0012] Step 2: Perform the following judgment on each filling vector Ai in the vector set A: when the starting point and the end point of a filling vector Ai are both connected to or close to the contour, the filling vector Ai is divided into two filling vectors Bi and Ci; otherwise, the filling vector Ai is recorded as Di; all the filling vectors Bi, Ci and Di form a new vector set E, where i is 1, 2, 3, ... N, and N is the total number of filling vectors;

[0013] Step 3. Make the following judgments on each filling vector Ei in the vector set E: when the end point of a filling vector Ei is connected to or close to the contour, the filling vector Ei remains unchanged and is recorded as Fi; otherwise, the filling vector Ei is reversed to obtain a new filling vector Hi, and all the filling vectors Fi and Hi form the final vector set J.

[0014] As a further preferred embodiment of the present invention, the preset area is an upper surface area or a lower surface suspended area of ​​the workpiece to be printed.

[0015] As a further preferred embodiment of the present invention, the distance between the endpoint of the fill vector connected to or close to the contour and the contour is within 0.5 mm.

[0016] As a further preferred embodiment of the present invention, the step divides the filling vector Ai into two filling vectors Bi and Ci, and the dividing point is the midpoint position of the filling vector Ai.

[0017] As a further preferred embodiment of the present invention, the step sets a plurality of filling vectors inside each polygon, wherein the plurality of filling vectors are straight lines, and some or all of the filling vectors are parallel to each other.

[0018] The present invention also provides a laser scanning device for manufacturing three-dimensional objects, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of any of the above-mentioned laser scanning methods for manufacturing three-dimensional objects are implemented.

[0019] The present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the above-mentioned laser scanning methods for manufacturing three-dimensional objects.

[0020] The laser scanning method for manufacturing three-dimensional objects of the present invention extracts all the filling vectors connected to or close to the contour in a preset area, and controls the direction of the filling vectors connected to or close to the contour, so that the endpoints of all the filling vectors connected to or close to the contour are the end points of the filling vectors, and the starting points of all the filling vectors are far away from the contour. This can effectively avoid the fluctuation of the molten pool at the starting point of the scanning filling vector, that is, the local (especially the contour) warping can be suppressed during the printing process, thereby improving the printing success rate, that is, it can effectively improve the surface quality of the workpiece to be printed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A method flow chart of Embodiment 1 of the laser scanning method for manufacturing three-dimensional objects provided by the present invention;

[0022] Figure 2 Working example 1 of the laser scanning method for manufacturing three-dimensional objects provided by the present invention Figure 1 ;

[0023] Figure 3 Working example 1 of the laser scanning method for manufacturing three-dimensional objects provided by the present invention Figure 2 ;

[0024] Figure 4 Working example 1 of the laser scanning method for manufacturing three-dimensional objects provided by the present invention Figure 3 ;

[0025] Figure 5 Working example 1 of the laser scanning method for manufacturing three-dimensional objects provided by the present invention Figure 4 ;

[0026] Figure 6 Working example 1 of the laser scanning method for manufacturing three-dimensional objects provided by the present invention Figure 5 ;

[0027] Figure 7 Working method of embodiment 2 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 1 ;

[0028] Figure 8 Working method of embodiment 2 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 2 ;

[0029] Fig. 9 Working method of embodiment 2 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 3 ;

[0030] Fig.10 Working method of embodiment 2 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 4 ;

[0031] Fig.11 Working method of embodiment 3 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 1 ;

[0032] Fig.12 Working method of embodiment 3 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 2 ;

[0033] Fig.13 Working method of embodiment 3 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 3 ;

[0034] Fig.14 Working method of embodiment 3 provided for the laser scanning method for manufacturing three-dimensional objects of the present invention Figure 4 . DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0036] In order to solve the technical problem that the laser scanning method in the prior art causes the workpiece to be printed to be warped due to the distribution of heat and residual stress, the present invention provides a laser scanning method for manufacturing a three-dimensional object, comprising:

[0037] Slicing the workpiece to be printed to obtain a cross-sectional profile of each layer, wherein the cross-sectional profile is one or more closed polygons;

[0038] Set several filling vectors inside each polygon;

[0039] Extract all the filling vectors connected to or close to the contour in the preset area, and control the directions of the filling vectors connected to or close to the contour so that the endpoints of all the filling vectors connected to or close to the contour are the end points of the filling vectors, and the starting points of all the filling vectors are far away from the contour;

[0040] Laser scanning is performed in the direction of all the finally obtained filling vectors.

[0041] The laser scanning method for three-dimensional object manufacturing of the present invention can effectively avoid defects caused by the molten pool fluctuation at the starting point of the scanning filling vector away from the contour and the workpiece surface, that is, it can suppress local (especially the contour) warping during the printing process, thereby improving the printing success rate, that is, it can effectively improve the surface quality of the workpiece to be printed.

[0042] The above-mentioned preset area is an area close to the contour of the workpiece to be printed, wherein the upper surface area or the suspended area of ​​the lower surface of the workpiece to be printed has the best application effect. Of course, in the specific implementation, the technical solution of the present invention can also be executed for all areas of the polygon of the workpiece to be printed, or for part of the polygon of the workpiece to be printed (such as the combined area of ​​the upper / lower surface area of ​​the workpiece to be printed and part of the non-upper / lower surface area), which can be determined according to actual needs.

[0043] It should be noted here that the filling vector connected to or close to the contour is a filling vector whose endpoint is within 0.5 mm from the contour.

[0044] Preferably, in the above step of dividing the filling vector Ai into two filling vectors Bi and Ci, the dividing point is the midpoint of the filling vector Ai to avoid the division from generating too short a vector.

[0045] Further preferably, in the above step of dividing the filling vector Ai into two filling vectors Bi and Ci, an overlapping area is set at the dividing point of the two divided vectors, and the size range of the overlapping area is 0~0.5mm, and the overlapping area is remelted to avoid possible defects at the overlap, thereby further ensuring the scanning quality.

[0046] In a specific implementation, in the above step of setting a number of fill vectors inside each polygon, the several fill vectors are straight lines, and some or all of the fill vectors are parallel to each other. However, in a specific implementation, the present application is not limited to straight lines for the fill vectors, and they can also be curves, etc. Similarly, the present application does not limit the spacing between the fill vectors and the relationship between adjacent fill vectors. For example, adjacent fill vectors can also be in a vertical relationship, etc.

[0047] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the technical solution of the present invention is described in detail below in the form of embodiments and in conjunction with the accompanying drawings.

[0048] Embodiment 1

[0049] like Figure 1 As shown, the laser scanning method for manufacturing a three-dimensional object in this embodiment includes the following steps:

[0050] Step 11: Slice the workpiece to be printed to obtain the cross-sectional profile of each layer, where the cross-sectional profile is a closed polygon, such as Figure 2 As shown; it should be noted here that the specific number of closed polygons composed of the cross-sectional profile shown mainly depends on the shape of the workpiece to be printed.

[0051] Step 12: Set several parallel straight line filling vectors inside each polygon, such as Figure 3 As shown;

[0052] Step 13: extract all the filling vectors connected to or close to the outline of a polygon of the workpiece to be printed to form a vector set A, such as Figure 4 The dashed line shown;

[0053] Step 14: Perform the following judgment on each filling vector Ai in the vector set A: when the starting point and the end point of a filling vector Ai are both connected to or close to the contour, the filling vector Ai is divided into two filling vectors Bi and Ci; otherwise, the filling vector Ai is recorded as Di; all the filling vectors Bi, Ci and Di form a new vector set E, such as Figure 5 As shown. Where i is 1, 2, 3, ... N, and N is the total number of filling vectors;

[0054] Step 15: Perform the following judgment on each filling vector Ei in the vector set E: When the end point of a filling vector Ei is connected to or close to the contour, the filling vector Ei remains unchanged and is recorded as Fi; otherwise, the filling vector Ei is reversed to obtain a new filling vector Hi, and all the filling vectors Fi and Hi form the final vector set J, as shown in Figure 6 shown.

[0055] Step 16: Perform laser scanning in the direction of all the filling vectors finally obtained.

[0056] Embodiment 2

[0057] The laser scanning method for manufacturing a three-dimensional object of this embodiment includes the following steps:

[0058] Step 21, slicing the workpiece to be printed to obtain a cross-sectional profile of each layer, wherein the cross-sectional profile is a closed polygon;

[0059] Step 22: Set several fill vectors inside each polygon, such as Figure 7 As shown; a plurality of mutually parallel filling vectors are set in the surrounding area of ​​the closed polygon, and several sub-areas are set in the middle area. Each sub-area is composed of several mutually parallel filling vectors, and the filling vectors of adjacent sub-areas in each sub-area are perpendicular to each other.

[0060] Step 23: extract all the filling vectors connected to or close to the outline of the workpiece to be printed (also refers to the entire area of ​​a polygon) to form a vector set A, such as Figure 8 The dashed line shown;

[0061] Step 24, perform the following judgment on each filling vector Ai in the vector set A: when the starting point and the end point of a filling vector Ai are both connected to or close to the contour, the filling vector Ai is divided into two filling vectors Bi and Ci; otherwise, the filling vector Ai is recorded as Di; all the filling vectors Bi, Ci and Di form a new vector set E, such as Fig. 9 As shown. Where i is 1, 2, 3, ... N, and N is the total number of filling vectors;

[0062] Step 25, make the following judgments for each filling vector Ei in the vector set E: when the end point of a filling vector Ei is connected to or close to the contour, the filling vector Ei remains unchanged and is recorded as Fi; otherwise, the filling vector Ei is reversed to obtain a new filling vector Hi, and all the filling vectors Fi and Hi form the final vector set J, as shown in Fig.10 shown.

[0063] Step 26: Perform laser scanning in the direction of all the filling vectors finally obtained.

[0064] Embodiment 3

[0065] The laser scanning method for manufacturing a three-dimensional object of this embodiment includes the following steps:

[0066] Step 31, slicing the workpiece to be printed to obtain a cross-sectional profile of each layer, wherein the cross-sectional profile is a closed polygon;

[0067] Step 32: Set a number of parallel straight line filling vectors inside each polygon, such as Fig.11 As shown;

[0068] Step 33: extract the filling vectors of the part of the workpiece to be printed that are connected to or close to the contour to form a vector set A, such as Fig.12 The dashed line shown;

[0069] Step 34, perform the following judgment on each filling vector Ai in the vector set A: when the starting point and the end point of a filling vector Ai are both connected to or close to the contour, the filling vector Ai is divided into two filling vectors Bi and Ci; otherwise, the filling vector Ai is recorded as Di; all the filling vectors Bi, Ci and Di form a new vector set E, such as Fig.13 As shown. Where i is 1, 2, 3, ... N, and N is the total number of filling vectors;

[0070] Step 35, make the following judgments for each filling vector Ei in the vector set E: when the end point of a filling vector Ei is connected to or close to the contour, the filling vector Ei remains unchanged and is recorded as Fi; otherwise, the filling vector Ei is reversed to obtain a new filling vector Hi, and all the filling vectors Fi and Hi form the final vector set J, as shown in Fig.14 shown.

[0071] Step 36: Perform laser scanning in the direction of all the filling vectors finally obtained.

[0072] The steps performed in the second embodiment are similar to those in the first embodiment, except that the filling vectors set in the second embodiment and the first embodiment are different.

[0073] The steps performed in Example 3 and Example 1 are similar, except that Example 3 performs the above technical solution of the present invention only on a partial area of ​​interest (lower surface) of the workpiece to be printed; while Example 1 performs the above technical solution of the present invention on the entire area of ​​a certain polygon of the workpiece to be printed.

[0074] The present invention also provides a laser scanning device for manufacturing three-dimensional objects, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the laser scanning method for manufacturing three-dimensional objects described in any of the above embodiments are implemented.

[0075] The present invention further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the laser scanning method for manufacturing three-dimensional objects described in any of the above embodiments are implemented.

[0076] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-mentioned embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several deformations and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of this application shall be based on the attached claims.

Claims

1. A laser scanning method for manufacturing three-dimensional objects, characterized in that: include: Slicing the workpiece to be printed to obtain a cross-sectional profile of each layer, wherein the cross-sectional profile is one or more closed polygons; Set several filling vectors inside each polygon; Extract all the filling vectors connected to or close to the contour in the preset area, and control the directions of the filling vectors connected to or close to the contour so that the endpoints of all the filling vectors connected to or close to the contour are the end points of the filling vectors, and the starting points of all the filling vectors are far away from the contour; Laser scanning is performed in the direction of all the finally obtained filling vectors.

2. The laser scanning method for manufacturing three-dimensional objects according to claim 1, characterized in that: Extract all the filling vectors connected to or close to the contour in the preset area, and control the directions of the filling vectors connected to or close to the contour so that the endpoints of all the filling vectors connected to or close to the contour are the end points of the filling vectors, and the starting points of all the filling vectors are far away from the contour. Specifically include: Step 1: extract all the filling vectors connected to or close to the outline of the preset area to form a vector set A; Step 2: Perform the following judgment on each filling vector Ai in the vector set A: when the starting point and the end point of a filling vector Ai are both connected to or close to the contour, the filling vector Ai is divided into two filling vectors Bi and Ci; otherwise, the filling vector Ai is recorded as Di; all the filling vectors Bi, Ci and Di form a new vector set E, where i is 1, 2, 3, ... N, and N is the total number of filling vectors; Step 3. Make the following judgments on each filling vector Ei in the vector set E: when the end point of a filling vector Ei is connected to or close to the contour, the filling vector Ei remains unchanged and is recorded as Fi; otherwise, the filling vector Ei is reversed to obtain a new filling vector Hi, and all the filling vectors Fi and Hi form the final vector set J.

3. The laser scanning method for manufacturing three-dimensional objects according to claim 1 or 2, characterized in that: The preset area is an upper surface area or a lower surface suspended area of ​​the workpiece to be printed.

4. The laser scanning method for manufacturing three-dimensional objects according to claim 1 or 2, characterized in that: The filling vector connected to or close to the contour is a filling vector whose end point is within 0.5 mm from the contour.

5. The laser scanning method for manufacturing three-dimensional objects according to claim 1 or 2, characterized in that: The step divides the filling vector Ai into two filling vectors Bi and Ci, and the dividing point is the midpoint position of the filling vector Ai.

6. The laser scanning method for manufacturing three-dimensional objects according to claim 1 or 2, characterized in that: In the step, a plurality of filling vectors are set inside each polygon, wherein the plurality of filling vectors are straight lines, and some or all of the filling vectors are parallel to each other.

7. A laser scanning device for manufacturing three-dimensional objects, characterized in that: It comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the laser scanning method for manufacturing three-dimensional objects described in any one of claims 1 to 6 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the laser scanning method for manufacturing a three-dimensional object according to any one of claims 1 to 6 are implemented.

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