CN115556359A - Stripe scanning method, 3D printing method and apparatus, and storage medium - Google Patents

Abstract

The invention relates to the field of laser 3D printing, and aims to solve the problems that in the prior art, in the planning and scanning of a strip-type scanning path, warping, bending deformation of a forming melt channel and/or color change sometimes occur in narrow areas. A stripe scan method, a 3D printing method and apparatus, and a storage medium are provided. The strip scanning method comprises the following steps: carrying out strip type partition on the scanning surface; the scanning path of the strip area comprises a scanning line group, and the scanning line group comprises a plurality of scanning lines which are sequentially arranged at intervals along the length direction of the corresponding strip area; for the length not less than the preset standard length L ₀ The scanning line of (2) adopts a first scanning strategy; the power adopted by the first scanning strategy is the set standard power P ₀ (ii) a For length less than preset standard length L ₀ The scanning line of (2) adopts a second scanning strategy; the power adopted by the second scanning strategy is power P _n In which P is _n <P ₀ . The invention has the advantages ofThe problem of warping or color change of a narrow area in the scanning process can be well solved.

Description

Stripe scanning method, 3D printing method and apparatus, and storage medium

Technical Field

The invention relates to the field of 3D printing, in particular to a strip type scanning method, a 3D printing method and equipment and a storage medium.

Background

Additive Manufacturing (AM) is different from material reduction manufacturing such as turning and material equivalent manufacturing such as injection forging, and has certain advantages for manufacturing complex components or non-standardized components. Common additive manufacturing techniques include Selective Laser Melting (SLM), selective Laser Sintering (SLS), electron Beam Melting (EBM), etc., which scan each sliced scan plane along a planned path by an energy beam such as a laser beam, an electron beam, etc.

Due to factors such as the shape of the slice scan plane of the manufactured target part, warping, bending deformation of the forming tunnel line and/or color change sometimes occur at locations such as corners or other narrow areas during, for example, strip scan path planning and scanning.

Disclosure of Invention

The present application is directed to providing a stripe scan method, a 3D printing method and apparatus, and a storage medium to solve the above-mentioned problems.

The embodiment of the application is realized as follows:

a method of stripe scanning for 3D printing, comprising:

carrying out strip type partition on the scanning surface of each layer, and dividing the scanning surface into a plurality of strip areas which are sequentially arranged along a first direction;

setting a scanning path of each strip area, wherein the scanning path of each strip area comprises a scanning line group, and the scanning line group comprises a plurality of scanning lines which are sequentially arranged at intervals along the length direction of the corresponding strip area;

for length not less than preset standard length L ₀ The scanning line of (2) adopts a first scanning strategy; the power adopted by the first scanning strategy is set standard power P ₀ ；

For length less than preset standard length L ₀ The scanning line of (2) adopts a second scanning strategy; the power adopted by the second scanning strategy is power P _n In which P is _n <P ₀ 。

The scheme is generated by exploring and solving the problems of partial area warping, melting channel bending deformation or color change in scanning forming, which occur in practice by the inventor. The inventor researches and discovers that the strip scanning method proposed by the scheme is adopted, and the scanning surface is partitioned in a strip mode, and a smaller power P different from the standard power is adopted for the shorter length of the scanning line in each strip area _n The above problems can be solved well.

In one embodiment:

power P _n ＝m×P ₀ Wherein m is between 0.90 and 0.95.

In one embodiment:

the value of m decreases as the thermal conductivity of the printing material decreases.

In one embodiment:

the standard length L ₀ Is set in such a manner that the set standard length L is set ₀ And power P _n Is positively correlated with the magnitude of (a).

In one embodiment:

standard length L ₀ The value is 3-4mm.

In one embodiment:

the scanning path adopts a reciprocating zigzag scanning path or a straight-line scanning path.

In one embodiment:

the extending direction of the scanning lines is perpendicular to the long direction of the strip region or obliquely intersects with the long direction of the strip region.

In one embodiment:

the width of each swathe is equal.

The embodiment of the present application further provides a 3D printing method, which includes:

slicing and layering the target piece;

scanning is performed for each layer by the above-described stripe scanning method.

Embodiments of the present application further provide a storage medium having at least one instruction stored thereon, where the instruction, when loaded by a processor, performs the stripe scan method as described above.

The embodiment of the present application further provides a 3D printing apparatus, which includes:

an energy beam source for providing scanning laser light;

a control device comprising a memory in which a plurality of program modules are stored and a processor for loading the plurality of program modules, the processor performing the method as described above when loading the plurality of program modules and transmitting a signal having a power for scanning the energy beam;

and the power adjusting device is electrically connected with the energy beam source and the control device and is used for adjusting the power of the scanning energy beam in real time according to the signal.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic view of a use state of a 3D printing apparatus in an embodiment of the present invention;

fig. 2 is a schematic diagram of a scan surface of a 3D printing apparatus after stripe division according to an embodiment of the present invention;

FIG. 3 shows a schematic diagram of a 3D printing device after planning a scanline group in one of the bands in an embodiment of the present invention;

figure 4 shows a schematic diagram of a reciprocating zig-zag scanning path of a 3D printing apparatus in an embodiment of the invention;

FIG. 5 shows a schematic diagram of a line-shaped scan path of a 3D printing device in an embodiment of the invention;

fig. 6 shows a flowchart of a 3D printing method in an embodiment of the present invention.

Description of the main element symbols:

100-3D printing device; 200-target part; 210-a scan plane; 110-an energy beam source; 120-a power conditioning unit; 131-a storage medium; 130-a control device; 211-swathe zone; y1-a first direction; 211 a-both end portions; 211 b-middle part; 221-scan line group; 2211-scan line; 220 a-reciprocating zig-zag scan path; 220 b-a line-shaped scan path; 132-a comparison unit; 133-control unit.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Some embodiments of the present application are described in detail. In the following embodiments, features of the embodiments may be combined with each other without conflict.

Layered additive 3D printing belongs to additive manufacturing technology, and is characterized in that layered slicing processing is carried out on a target part, each layer of scanning surface is sequentially scanned through an energy beam source according to a scanning path, a scanned part substance is formed, each layer of structure is sequentially overlapped and accumulated, and finally a required target part is formed.

In this technique, it is known that parameters such as the scanning power and the scanning speed of the energy beam source are generally set in advance, and then the whole scanning is performed according to the parameters.

The method for planning the scanning path includes dividing a scanning surface into a plurality of strip regions, and planning the scanning path for each strip region. However, the inventors have found in practice that when scanning of the scanning surface is performed by the stripe scanning, a partial region may be warped or a color may be changed.

Since there are many factors affecting the product quality, such as the forming environment, the physical properties of the powder material, the layering thickness, the scanning speed, the scanning path planning, etc., which may cause the above problems, the search for a solution to the problem is difficult, and the art does not disclose the above problems and the information for analyzing the corresponding reasons.

In view of the great influence of the problem on the production of products, the inventors have conducted various studies and proposed an improved strip scan method, which includes:

carrying out strip type partition on the scanning surface of each layer, and dividing the scanning surface into a plurality of strip areas which are sequentially arranged along a first direction;

the scanning path of the strip area comprises a scanning line group, and the scanning line group comprises a plurality of scanning lines which are sequentially arranged at intervals along the length direction of the corresponding strip area;

for length not less than preset standard length L ₀ The scanning line of (2) adopts a first scanning strategy; the power adopted by the first scanning strategy is set standard power P ₀ ；

For length less than preset standard length L ₀ The scanning line of (2) adopts a second scanning strategy; the power adopted by the second scanning strategy is power P _n In which P is _n <P ₀ 。

The following examples are given for illustrative purposes.

Examples

In fig. 1a 3D printing device 100 is shown for manufacturing a target part 200 by means of 3D printing. A scan plane 210 of the target part 200 is shown. The 3D printing apparatus 100 in this embodiment may be represented as a 3D printer. The 3D printing device 100 may be based on SLM (Selective laser melting) technology.

The 3D printing device 110 comprises an energy beam source 110, a control means 130 and a power adjusting unit 120.

In this embodiment, the energy beam source 110 adopts a laser device for providing the scanning laser 111.

The power adjusting unit 120 is cooperatively connected to the energy beam source 110 for adjusting the power of the energy beam source 110.

The control device 130 comprises a memory 131 storing a plurality of program modules and a processor 132 for loading the plurality of program modules, wherein the processor 132 executes the strip scanning method (described in detail below) proposed by the present embodiment when loading the plurality of program modules and sends a signal having a power for scanning the energy beam.

The stripe scanning method provided by the embodiment comprises the following steps:

step S21: referring to fig. 2, the scanning surface 210 of each layer is partitioned into stripe regions, and the scanning surface 210 is divided into a plurality of stripe regions 211 sequentially arranged along the first direction Y1. The illustration shows a rectangular scanning surface 210 as an example, and the first direction Y1 is a direction inclined to the length and width of the rectangle, respectively. The widths defined by the band regions 211 may be set to be equal to each other, or may be set to be different from each other as necessary. In this embodiment, the width defined by each stripe is a uniform width d, for example, the stripe is divided by a width d =5 mm. In this division, the maximum width of the middle stripe region 211 is generally 5mm, and stripe regions 211 with a width smaller than 5mm may exist on both sides.

As can be seen from fig. 2, a plurality of stripe-shaped partitions are obtained by this partitioning method, and both end portions 211a and middle portions 211b (if any) of each stripe region 211 are portions having a smaller width and a uniform width.

In fact, for other shapes of regular or irregular scan surfaces 210, depending on the selected stripe division direction, it may occur that the stripe includes a portion having a width equal to the stripe's defined width and a portion having a width less than the defined width.

Step S22: after the division is completed, a scanning path is planned for each divided band region 211 as a route of the laser scanning. The scan path of each swathe 211 should traverse each swathe 211 so that the powder at the corresponding location is able to receive laser energy to fuse shape. In the present embodiment, the scan path of the stripe region 211 includes a scan line group 221, and the scan line group 221 includes a plurality of scan lines 2211 arranged at intervals in sequence along the longitudinal direction of the stripe region 211. The spacing between the scan lines 2211 in the scan line group 221 can be set as desired. The extending direction of the scan line 2211 may be perpendicular to the longitudinal direction of the stripe region 211, or may obliquely intersect the longitudinal direction of the stripe region 211. In this embodiment, the extending direction of the scanning line 2211 is selected to be perpendicular to the longitudinal direction of the stripe region 211. In this embodiment, according to the above-described division manner, the longitudinal direction of the stripe region 211 is perpendicular to the first direction Y1. Fig. 3 is a schematic diagram of the arrangement of the scan line group 221 in each band region 211.

To traverse each scan line 2211 in scan line group 221, one approach is to use a reciprocating zig-zag scan path 220a, which is formed by first connecting or last connecting each scan line 2211 in sequence, with the opposite scan direction for adjacent scan lines 2211, as shown in fig. 4; another way is to use a linear scanning path 220b, which is formed by connecting the scanning lines 2211 end to end in sequence, and the scanning directions of the adjacent scanning lines 2211 are the same, as shown in fig. 5, wherein the laser does not work in the return path.

In this embodiment, the distance between the scan lines 2211 is set small enough, for example, the distance is 0.08-0.12mm. The scanning path is not clearly shown in the figure, but rather the spacing is shown to be larger, and no limitation on the spacing is implied.

Step S23: the scanning strategy is set according to the length of each scanning line 2211 of the scanning path, and scanning is performed. Specifically, the length is not less than the preset standard length L ₀ The scan line 2211 (e.g., the scan line 2211 located in the middle portion 211b of the swathe 211 in fig. 3), using a first scan strategy; the power adopted by the first scanning strategy is set standard power P ₀ (ii) a For length less than preset standard length L ₀ The scanning line 2211 (e.g., the scanning line 2211 located at both end portions 211a of the stripe region in fig. 3) employs the second scanning strategy; the power adopted by the second scanning strategy is power P _n In which P is _n <P ₀ . In this embodiment, the standard length L ₀ The width d of the swathe 211 may be selected to be equal, e.g., to a standard length L ₀ = d =5mm; the standard length L can also be set ₀ ＝3-4mm<d =5mm, which can be set according to actual conditions. In one embodiment, the standard length L ₀ Is set in such a manner that the set standard length L is set ₀ And power P _n Is positively correlated with the magnitude of (A), in combination with the power P _n ＝m×P ₀ It can be known that when the standard power P is used ₀ And/or the larger the value of m, the longer the standard length L ₀ The value of (a) is also large.

For the areas with more short scanning lines 2211, such as the corners or narrow areas of the swathe 211, as shown in fig. 2 for the two end portions 211a, the value of m is preferably between 0.90 and 0.95. When m is less than 0.90, power P _n A smaller value of (a) may receive insufficient energy, resulting in poor fusion of the powder; and m is greater than 0.95 and is set to approximately 1, the corner warpage and/or color change described above is likely to occur in the corner or narrow area of the stripAnd (5) problems are solved. Further, for powder materials with a large thermal conductivity, m may take a large value; for powder materials with smaller heat conductivity coefficient, m can be smaller, namely the value of m can be reduced along with the reduction of the heat conductivity coefficient of the printing material.

With reference to fig. 6, the present embodiment further provides a 3D printing method, which includes the following steps:

step S10: the target part 200 is subjected to slice layering processing. In general, a three-dimensional model may be created for the target part 200 by three-dimensional modeling software, and then the three-dimensional model is sliced and layered according to a set thickness, so as to obtain the shape of the scanning surface 210 of each layer.

Step S20: scanning is performed for each layer by the above-described stripe scanning method. The stripe scanning method includes the aforementioned steps S21, S22, and S23.

Practice shows that by adopting the strip scanning method, the 3D printing method and equipment and the storage medium provided by the embodiment of the application, the problem that the corners or other narrow areas sometimes warp and/or change colors in the scanning process can be well solved, and the method and the equipment have industrial applicability.

Although the present application has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the present application.

Claims (10)

1. A method of stripe scanning for 3D printing, comprising:

carrying out strip type partition on the scanning surface of each layer, and dividing the scanning surface into a plurality of strip areas which are sequentially arranged along a first direction;

setting a scanning path of each strip area, wherein the scanning path comprises a scanning line group which comprises a plurality of scanning lines which are sequentially arranged at intervals along the length direction of the corresponding strip area;

for the length not less than the preset standard length L ₀ The scanning line of (2) adopts a first scanning strategy; the power adopted by the first scanning strategy is set standard power P ₀ ；

For length less than preset standard length L ₀ The scanning line of (2) adopts a second scanning strategy; the power adopted by the second scanning strategy is power P _n In which P is _n <P ₀ 。

2. The strip scanning method according to claim 1, characterized in that:

power P _n ＝m×P ₀ Wherein m is between 0.90 and 0.95.

3. The strip scanning method according to claim 2, characterized in that:

the value of m decreases as the thermal conductivity of the printing material decreases.

4. The strip scanning method according to any one of claims 1 to 3, characterized in that:

the standard length L ₀ Is set in such a manner that the set standard length L is set ₀ And power P _n Is positively correlated with the magnitude of (a).

5. The strip scanning method according to claim 1, characterized in that:

standard length L ₀ The value is 3-4mm.

6. The strip scanning method according to claim 1, characterized in that:

the scanning path adopts a reciprocating zigzag scanning path or a straight-line scanning path.

7. The strip scanning method according to claim 1, characterized in that:

the extending direction of the scanning lines is perpendicular to the long direction of the strip region or obliquely intersects with the long direction of the strip region.

8. A3D printing method, comprising:

slicing and layering the target piece;

scanning is performed for each slice using the strip scan method according to any one of claims 1 to 7.

9. A storage medium having at least one instruction stored thereon, characterized in that:

the instructions, when loaded by a processor, perform the striped scanning method of any one of claims 1-7.

10. A3D printing apparatus, comprising:

an energy beam source for providing a scanning energy beam;

a control device comprising a memory storing a plurality of program modules and a processor for loading the plurality of program modules, the processor performing the method of any one of claims 1-8 when loading the plurality of program modules and transmitting a signal having a power of the scanning energy beam;

and the power adjusting device is electrically connected with the energy beam source and the control device and is used for adjusting the power of the scanning energy beam in real time according to the signal.

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