KR20190043220A - Method of manufacturing three dimensional shapes using laser and metal powder - Google Patents

Abstract

The present invention relates to a method to manufacture a three-dimensional shape using laser and metal powder, comprising: a step of dividing; a step of first pre-heating; a step of first deposition; a step of second pre-heating; and a step of second deposition. The step of dividing is to divide a pattern area divided on a powder layer corresponding to a shape to make by deposition into a plurality of pre-heating areas. The step of first pre-heating is to pre-heat by respectively irradiating a first laser beam having a first power towards each pre-heating area, but not to irradiate the first laser beam to those pre-heating areas near the pre-heating area to which the first laser beam is irradiated. The step of first deposition is to respectively irradiate a second laser beam having a second power, which is higher than the first power, to each of the pre-heating areas pre-heated in the step of first pre-heating and to deposit powder included in the powder layer. The step of second pre-heating is to pre-heat by respectively irradiating the first laser beam to the pre-heating areas, to which the first laser beam is not irradiated in the step of first pre-heating, but not to irradiate the first laser beam to those pre-heating areas near the pre-heating areas, to which the first laser beam is irradiated. The step of second deposition is to respectively irradiate the second laser beam to the pre-heating areas pre-heated by the step of second pre-heating and to melt the powder included in the powder layer. According to the present invention, the method is able to remove residual stress in the manufactured product, minimize deformation of the product, and improve durability of the product.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a three-dimensional shape manufacturing method using laser and metal powder,

The present invention relates to a method of manufacturing a three-dimensional shape using a laser and a metal powder, in which a laser beam is irradiated onto a coated powder layer to melt a metal powder into a desired shape, And a method of manufacturing a three-dimensional shape using the same.

Generally, a three-dimensional printer means a device for producing a three-dimensional shape by slicing CAD data of a product to be manufactured in one direction on a computer and sequentially printing and stacking sliced two-dimensional cross-sectional shapes.

3D printers have been mainly used for detecting and correcting problems in actual products by producing prototypes before putting new products on the market. Recently, however, three-dimensional printers and materials have been developed, As the durability and dimensional accuracy of products are improved, the field of application is increasing.

A three-dimensional printer is a method in which a material is selectively extruded through a nozzle or an orifice to be laminated, a method in which a material ink is dropped by using an inkjet head, a method in which ultraviolet light or a laser beam is irradiated onto a liquid resin or a powder- A method in which a liquid adhesive is selectively sprayed onto a powder material by using an inkjet head to laminate the material, and a method in which a powder material is blown into a fine molten pool made by focusing a laser beam or an electron beam on the surface of the material And then laminating them.

Among these methods, in the case of a method of manufacturing a product by depositing and laminating the coated metal powder by irradiating a laser beam, the temperature of the powder layer rises rapidly in a state before the laser beam is irradiated and while the laser beam is irradiated The powder layer is melted. When the irradiation of the laser beam is finished, the temperature rapidly drops and coagulates and residual stress is generated inside the product. Due to such residual stress, dimensional accuracy due to deformation of a product made of a three-dimensional printer is lowered, and defects are generated therein, resulting in a problem that the durability of the product is deteriorated.

Korean Patent Laid-Open Publication No. 2012-0128171 (Nov. 27, 2012, entitled: Three-dimensional printing of metal powder laminated laser welding method)

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a preheating apparatus and a method for manufacturing the same, By performing the welding step for each of the preheated preheating regions after skipping and preheating, it is possible to minimize the deformation of the product by removing the residual stress in the manufactured product and to improve the durability of the product by using laser and metal powder And a method for manufacturing a three-dimensional shape.

According to an aspect of the present invention, there is provided a method of manufacturing a three-dimensional shape using laser and metal powder, the method including: a dividing step of dividing a pattern area partitioned into a powder layer corresponding to a shape to be welded into a plurality of preheating areas; A first preheating step of irradiating the preheating region with a first laser beam having a first power to each of the preheating regions and not irradiating the preheating region adjacent to the preheating region irradiated with the first laser beam with the first laser beam; A first welding step of irradiating a second laser beam having a second power higher than the first power to the preheating region preheated in the first preheating step to deposit powder contained in the powder layer; Wherein the first laser beam is irradiated to the preheating region not irradiated with the first laser beam and is preheated, and the preheating region adjacent to the preheating region irradiated with the first laser beam is irradiated with the first laser beam, A second preheating step of not irradiating the beam; And a second welding step of irradiating the second laser beam to the preheating region preheated in the second preheating step to deposit powder contained in the powder layer.

In the method for manufacturing a three-dimensional shape using a laser and a metal powder according to the present invention, the preheating region may overlap the neighboring preheating regions.

In the method for manufacturing a three-dimensional shape using laser and metal powder according to the present invention, in the first welding step and the second welding step, a welding region irradiated with the second laser beam is disposed in the preheating region, The area of the welding region may be less than or equal to the area of the preheating region.

In the method of manufacturing a three-dimensional shape using a laser and a metal powder according to the present invention, the machining direction of the first preheating step and the machining advancing direction of the first welding step may be opposite to each other, Direction and the machining direction of the second welding step may be opposite to each other.

In the method of manufacturing a three-dimensional shape using a laser and a metal powder according to the present invention, the method includes the steps of: dividing, A first layer on which a deposition step is performed, and a powder layer having a predetermined thickness on the first layer, wherein the partitioning step, the first preheating step, the first welding step, the second preheating step, There is a second layer on which the step is performed and the boundary line of the deposition region partitioned by the first layer and the boundary line of the deposition region partitioned by the second layer may not coincide with each other.

In the method of manufacturing a three-dimensional shape using a laser and a metal powder according to the present invention, the first laser beam and the second laser beam may be irradiated by a polygon scanner.

In the method of manufacturing a three-dimensional shape using laser and metal powder according to the present invention, the first laser beam may be irradiated by a polygon scanner, and the second laser beam may be irradiated by a galvanometer scanner.

In the method of manufacturing a three-dimensional shape using laser and metal powder according to the present invention, the preheating region may be formed in a polygonal shape.

In the method for manufacturing a three-dimensional shape using a laser and a metal powder according to the present invention, the preheating region may be formed in the same shape or different shape in one powder layer.

In the method of manufacturing a three-dimensional shape using laser and metal powder according to the present invention, the preheating region may be formed to have the same size or different sizes in one powder layer.

In the method of manufacturing a three-dimensional shape using a laser and a metal powder according to the present invention, in the first welding step and the second welding step, the traveling directions of the second laser beams irradiated to different preheating areas are at an angle .

According to the method of manufacturing a three-dimensional shape using the laser and the metal powder of the present invention, residual stress inside the manufactured product can be removed to minimize deformation of the product and enhance durability of the product.

In addition, according to the three-dimensional shape manufacturing method using the laser and the metal powder of the present invention, the heat treatment process for removing the internal stress of the product after the completion of stacking of the product can be omitted.

According to the method of manufacturing a three-dimensional shape using the laser and the metal powder according to the present invention, since the powder in the preheating region is sintered according to the preheating condition to serve as a support, the number of supports required for preventing overheating during lamination can be minimized have.

In addition, according to the method of manufacturing a three-dimensional shape using the laser and the metal powder of the present invention, the physical properties of the product manufactured by the lamination can be designed by adjusting the shape of the preheating region and the preheating condition.

1 is a view showing a plurality of preheating regions divided in a pattern region of a powder layer,
FIG. 2 is a diagram sequentially illustrating a method of manufacturing a three-dimensional shape using a laser and a metal powder according to an embodiment of the present invention,
FIG. 3 is a view showing a state in which the edge portion of the preheating region is overlapped in the three-dimensional shape manufacturing method using the laser and the metal powder of FIG. 2,
FIG. 4 is a view showing a welding region divided in the preheating region in the method of manufacturing a three-dimensional shape using the laser and the metal powder of FIG. 2,
FIG. 5 is a view showing the processing direction of the first preheating step, the first welding step, the second preheating step, and the second welding step in the three-dimensional shape manufacturing method using the laser and the metal powder of FIG. 2,
FIG. 6 is a view showing a welded region divided in the first layer and a welded region divided in the second layer in the three-dimensional shape manufacturing method using the laser and the metal powder of FIG. 2,
FIG. 7 is a view showing a traveling direction of a second laser beam irradiated to different preheating regions in a first welding step or a second welding step of the three-dimensional shape manufacturing method using the laser and metal powder of FIG. 2,
Fig. 8 is a view showing a modification of the three-dimensional shape manufacturing method using the laser and the metal powder of Fig. 2;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a three-dimensional shape manufacturing method using laser and metal powder according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing a plurality of preheating regions divided in a pattern region of a powder layer, FIG. 2 is a view sequentially showing a three-dimensional shape manufacturing method using a laser and a metal powder according to an embodiment of the present invention FIG. 3 is a view showing a state in which edge portions of the preheating region are overlapped in the method of manufacturing a three-dimensional shape using the laser and the metal powder of FIG. 2. FIG. 4 is a cross- FIG. 5 is a view showing a welding region divided in a preheating region in the method of FIG. 2, and FIG. 5 is a cross-sectional view showing a first preheating step, a first welding step, a second preheating step, FIG. 6 is a view showing a process direction in the welding step. FIG. 6 is a view showing a welding region partitioned by the first layer and a welding region partitioned by the second layer in the three-dimensional shape manufacturing method using the laser and the metal powder of FIG. The drawings.

Referring to FIGS. 1 to 6, a method for manufacturing a three-dimensional shape using laser and metal powder according to this embodiment is for manufacturing a product by welding a metal powder by irradiating a laser beam in a desired pattern shape, S10, a first preheating step S20, a first welding step S30, a second preheating step S40, and a second welding step S50.

The dividing step S10 divides the pattern region 10 partitioned in the powder layer 1 into a plurality of preheating regions 20 corresponding to the shape to be fused.

Generally, in a three-dimensional printer apparatus, when a predetermined amount of powder is supplied into a chamber from a powder supply unit, a powder layer 1 having a predetermined thickness can be stacked on the bottom surface of the chamber using a coater or the like. By repeating the process of irradiating the powder layer 1 with a laser beam to melt the powder in a desired shape and irradiating the laser beam while stacking the plurality of powder layers 1, a three-dimensional product can be completed.

Referring to FIG. 1, a pattern region 10 corresponding to a shape to be welded, that is, a pattern region 10 to which a laser beam is applied and a powder is welded to form a product is defined in the powder layer 1. This pattern region 10 is divided into a plurality of preheating regions 20. Here, the preheating region 20 means a unit region in which a laser beam is continuously irradiated for the purpose of preheating the powder before the powder is deposited.

Although the preheating region 20 is shown in FIG. 1 as a rectangular shape, the preheating region 20 may be formed in various shapes such as a triangular shape, a pentagonal shape, and a hexagonal shape.

1, the preheating region 20 may be partially different in size. In FIG. 1, the preheating region 20 is formed to have the same rectangular shape. However, various shapes such as a triangular shape and a rectangular shape may be mixed.

In the first preheating step S20, the first laser beam L1 having the first power is irradiated to the preheating region 20 and preheated.

The first laser beam L1 irradiated in the first preheating step S20 has a first power enough to preheat the powder to a predetermined temperature lower than the power enough to deposit the powder.

The first preheating step S20 of the present embodiment is characterized in that the first laser beam L1 is not irradiated to the preheating region 22 adjacent to the preheating region 21 irradiated with the first laser beam L1 . Referring to FIG. 2, in the first preheating step S20 of the present embodiment, the first laser beam L1 is irradiated to one preheating region 21 to preheat, then the neighboring preheating region 22 is skipped, And the first laser beam L1 is irradiated to the next preheating region 21 to preheat. That is, the preheating region 20 is skipped and preheated such that neighboring preheating regions 20 are not continuously preheated.

In FIG. 2, one preheating region 21 is preheated and then the other preheating region 22 is skipped and the next preheating region 21 is preheated. However, two or more preheating regions may be skipped The preheating area may then be preheated.

2, the preheating region 22 is skipped in one direction and then the preheating region 21 is preheated. However, another preheating region 21 may be preheated by skipping the preheating region 22 on a plane.

The first welding step S30 irradiates the second laser beam L2 having a second power higher than the first power to the preheated preheating region 21 in the first preheating step S20, 1).

The second laser beam L2 irradiated in the first welding step S30 has a second power enough to deposit powder higher than the first power for preheating the powder to a predetermined temperature. After the initial temperature of the powder is raised through the first preheating step S20, the powder is welded by irradiating the powder with the second laser beam L2 through the first welding step S30, The residual stress can be reduced.

The second laser beam L2 is not irradiated to the preheating region 22 adjacent to the preheating region 21 preheated in the first preheating step S20 in the first welding step S30 of this embodiment . Referring to FIG. 2, in the first welding step S30 of the present embodiment, only the preheating region 21 preheated in the first preheating step S20 is irradiated with the second laser beam L2 to be included in the powder layer 1 The powder is fused by irradiating the preheated preheating region 21 in the first preheating step S20 with the second laser beam L2 and then the powder is fused in the first preheating step S20 The second laser beam L2 is irradiated to the preheated region 21 preheated in the first preheating step S20 to deposit the powder.

Here, the first laser beam L1 irradiated in the first pre-heating step S20 and the second laser beam L2 irradiated in the first welding step S30 may be irradiated by the polygon scanner, The beam L1 may be irradiated by a polygon scanner and the second laser beam L2 may be irradiated by a galvanometer scanner.

When a galvanometer scanner having a speed of several m / s is used, the time required for the preheating step is increased or the preheating effect can not be obtained due to the slow speed of the product manufactured using the 3D printer May also occur. Accordingly, the first preheating step (S20) and the first welding step (S30) may be performed using a polygon scanner having a speed of several hundreds m / s, or a polygon scanner may be used to perform a first preheating step (S20) By performing the first welding step (S30) using the scanner, the residual stress generated inside the product can be minimized.

On the other hand, as shown in Fig. 5, the machining direction A11 of the first preheating step S20 and the machining direction A12 of the first welding step S30 are preferably opposite to each other.

For example, when the first preheating step S20 is completed along the processing advancing direction A11 of the first preheating step S20 shown in FIG. 5, the scanner or the like irradiating the first laser beam L1 is heated (20).

At this time, if the scanner or the like is returned to the initial position on the left side of the preheating area 20 and the first welding step S30 is performed along the same direction as the machining direction A11 of the first preheating step S20, The time for returning the scanner to the initial position is added to the time, so that the manufacturing time of the product is inevitably increased.

Accordingly, the first welding step S30 is performed along the machining direction A12 of the first welding step S30, which is the opposite direction to the machining direction A11 of the first preheating step S20, at the position where the first preheating step S20 is completed. If step S30 is performed, the product manufacturing time can be shortened.

The second preheating step S40 irradiates the preheating region 22 to which the first laser beam L1 is not irradiated in the first preheating step S20 to preheat the first laser beam L1.

In the second preheating step S40 of the present embodiment, the preheating region 21 adjacent to the preheating region 22 irradiated with the first laser beam L1 is irradiated with the first laser beam L1 L1 is not irradiated. Referring to FIG. 2, in the second preheating step S40 of the present embodiment, the first laser beam L1 is irradiated to one preheating region 22 to preheat, then the neighboring preheating region 21 is skipped, The first laser beam L1 is irradiated to the next preheating region 22 to preheat. That is, the preheating region 20 is skipped and preheated such that neighboring preheating regions 20 are not continuously preheated.

The second welding step S50 irradiates the second laser beam L2 onto the preheated preheating region 22 in the second preheating step S40 to deposit the powder contained in the powder layer 1. [

It is preferable that the second laser beam L2 irradiated in the second welding step S50 has the same power as the second laser beam L2 irradiated in the first welding step S30.

The second laser beam L2 is not irradiated to the preheating region 21 adjacent to the preheating region 22 preheated in the second preheating step S40 in the second welding step S50 of this embodiment . 2, in the second welding step S50 of the present embodiment, only the preheating region 22 preheated in the second preheating step S40 is irradiated with the second laser beam L2 to be included in the powder layer 1 The powder is fused by irradiating the preheated preheating region 22 in the second preheating step S40 with the second laser beam L2 and then the powder is fused in the second preheating step S40 The second laser beam L2 is irradiated to the preheated region 22 preheated in the second preheating step S40 to deposit the powder.

Like the relationship between the machining direction A11 of the first preheating step S20 and the machining direction A12 of the first welding step S30, the machining direction A21 of the second preheating step S40, The processing direction A22 of the two welding steps S50 is preferably opposite to each other.

In the present invention, it is preferable that the preheating step (S20, S40) is performed for a predetermined number of preheating areas (20), and then the preheating preheating area (20) is immediately subjected to the welding steps (S30, S50).

When performing the preheating steps S20 and S40 for all of the preheating regions 20 distributed over the pattern region 10 and then performing the welding steps S30 and S50 thereafter, The preheating effect can hardly be expected since the powder is changed into the already cooled state.

Therefore, the cooling rate of the powder is calculated in consideration of the power of the first laser beam L1 irradiated in the preheating steps S20 and S40, the characteristics of the material of the powder, and the like. Based on the cooling rate of the powder, (S20 and S40) and the preheating step (S20, S40) and the welding step (S30, S50) are sequentially performed on the determined amount of preheating area (20). Whereby the preheating effect of the powder can be improved.

For example, the preheating steps S20 and S40 are performed on the five preheating regions 20, the deposition steps S30 and S50 are performed immediately, and then the same process is repeated for the five preheating regions 20 can do.

In the present invention, the preheating step (S20, S40) and the welding step (S30, S50) are performed while the preheating area (20) is skipped.

When the preheating step (S20, S40) and the welding step (S30, S50) are performed continuously without skipping the preheating area (20), the preheating area (20) Stress can be generated, and directionality can be generated in such residual stress. Because of the excess and directionality of the residual stress, the product manufactured by the three-dimensional printer may be warped in any one direction, and the warping of the products may degrade the accuracy of the product and also cause problems in durability.

In the present invention, by performing the preheating step (S20, S40) and the welding step (S30, S50) while skipping the preheating area (20), the residual stress inside the product can be removed, The accuracy and durability of the product can be improved.

2, in order to prevent unnecessary confusion in the process of describing the entire process, the preheating region 20 is shown in such a manner that the boundary lines of neighboring preheating regions 20 are in contact with each other. However, as shown in FIG. 3, It is preferable that the edge portions 26 are overlapped with each other.

By overlapping the edge portions 26 between the neighboring preheating regions 20, it is possible to prevent the risk that the powder present in the edge portion 26 of the preheating region is not preheated, The heat loss of the edge portion 26 may be compensated.

4, in the first welding step S30 and the second welding step S50, the welding region 30 to which the second laser beam L2 is irradiated is placed in the preheating region 20, It is preferable that the area of the welding region 30 is equal to or smaller than the area of the preheating region 20. [ Here, the fusion region 30 refers to a region where the second laser beam L2 is substantially irradiated to deposit the powder, and a plurality of such fusion regions 30 may be gathered to form the pattern region 10 .

It is preferable that the area of the region for substantially preheating the powder is equal to or larger than the area of the region for the powder to be welded in order to evenly preheat the powder in the region to be welded irrespective of the center portion and the edge portion. Therefore, in the first welding step S30 and the second welding step S50, the preheating area 20 to which the first laser beam L1 is irradiated in the first preheating step S20 and the second preheating step S40, By forming the second laser beam L2 larger than the welding region 30 to be irradiated, the powder actually welded can be uniformly preheated.

Although the shape of the preheating region 20 and the shape of the deposition region 30 are shown in FIG. 4, the shape of the preheating region 20 and the shape of the deposition region 30 may be different.

On the other hand, as described above, when a product is manufactured using a three-dimensional printer, a plurality of powder layers 1 are laminated to produce a product.

When the powder layer 1 laminated to a certain thickness is defined as a first layer LA1 and the powder layer 1 laminated to a certain thickness on the first layer LA1 is defined as a second layer LA2, The above-described dividing step S10, the first preheating step S20, the first welding step S30, the second preheating step S40 and the second welding step S40 are performed for each of the layer LA1 and the second layer LA2, (S50).

6, the boundary line 37a of the welded region 30a partitioned by the first layer LA1 and the boundary line 37b of the welded region 30b partitioned by the second layer LA2, Are preferably not coincident with each other.

That is, the welding region 30a partitioned by the first layer LA1 and the welding region 30b partitioned by the second layer LA2 may not coincide with each other, or may be disposed at a certain angle with respect to each other.

When the boundaries of the weld zones 30 in the first layer LA1 and the second layer LA2 as well as the plurality of powder layers 1 are aligned along the vertical direction, A boundary surface may be formed along the upward and downward directions. Such a boundary surface may act as a discontinuity in which the continuity of fusion of the powder is broken, resulting in a crack, and the durability of the product may be considerably deteriorated.

Therefore, the boundary 37a of the welding area 30a partitioned by the first layer LA1 and the boundary line 37b of the welding area 30b partitioned by the second layer LA2 do not coincide with each other, So that the durability of the product as a whole can be improved.

FIG. 7 is a view showing a traveling direction of a second laser beam irradiated to different preheating regions in a first welding step or a second welding step of the three-dimensional shape manufacturing method using the laser and metal powder of FIG. 2;

7, in the first welding step S30 and the second welding step S50, the proceeding directions of the second laser beams L irradiated to the different preheating regions 21 and 22 are at an angle of .

For example, in the first welding step S30, the advancing direction B1 of the second laser beam L irradiating the first preheating area 21a and the advancing direction B1 of the second preheating area 21b in the first welding step S30, The advancing direction B2 of the second laser beam L irradiating the laser beam L may form a certain angle (e.g., about 90 degrees) with respect to each other.

Similarly, in the second welding step S50, the traveling direction B3 of the second laser beam L irradiated to the first preheating region 22a and the traveling direction B3 of the second laser beam L irradiated to the second preheating region 22b in the second welding step S50 The traveling direction B4 of the second laser beam L may form a certain angle (e.g., about 90 degrees) with respect to each other.

As described above, the progressing directions of the second laser beam L irradiated to the different preheating regions 21 and 22 are formed at a certain angle with each other, thereby preventing the residual stress from being formed in a specific direction, thereby improving the durability of the product .

Fig. 8 is a view showing a modification of the three-dimensional shape manufacturing method using the laser and the metal powder of Fig. 2;

In FIG. 2, a three-dimensional shape manufacturing method using a laser and a metal powder in units of one line is implemented. However, as shown in FIG. 8, in the first preheating step S20 ' A three-dimensional shape manufacturing method using laser and metal powder may be implemented while performing the welding step S30 ', the second preheating step S40', and the second welding step S50 '.

At this time, at least one of the first laser beam L1 and the second laser beam L2 may be a multi-beam.

In the method of manufacturing a three-dimensional shape using the laser and the metal powder of the present invention, the pattern area as a part of the product is divided into a plurality of preheating areas, and the preheating area By performing the welding step for each of the preheated preheating regions after skipping and preheating, the residual stress inside the manufactured product is removed, thereby minimizing the deformation of the product and improving the durability of the product.

Also, in the method of manufacturing a three-dimensional shape using the laser and the metal powder of the present invention constructed as described above, since the edge portions are overlapped with each other between neighboring preheating regions, the risk that the powder present at the edge portion of the preheating region is not preheated And it is possible to obtain an effect that the heat loss of the edge portion having a large heat loss can be compensated for as compared with the central portion.

In addition, in the method of manufacturing a three-dimensional shape using the laser and the metal powder of the present invention configured as described above, the preheating region is formed to be equal to or larger than the welding region, .

In addition, in the method of manufacturing a three-dimensional shape using the laser and the metal powder of the present invention configured as described above, the boundary lines of the welding regions partitioned in the respective layers are arranged at mutually different positions, The effect can be obtained.

In addition, the method of manufacturing a three-dimensional shape using the laser and the metal powder of the present invention configured as described above has an effect of minimizing an increase in product manufacturing time by performing the preheating step and the deposition step using a polygon scanner .

Further, the three-dimensional shape manufacturing method using the laser and the metal powder according to the present invention constructed as described above can reduce the manufacturing time of the product by reversing the machining direction of the preheating step and the machining advancing direction of the welding step Effect can be obtained.

The scope of the present invention is not limited to the above-described embodiments and modifications, but can be implemented in various forms of embodiments within the scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

10: pattern area
20: Preheating area
30: welding area
L1: the first laser beam
L2: the second laser beam
S10: Split step
S20: First preheating step
S30: First welding step
S40: second preheating step
S50: second welding step

Claims (11)

A dividing step of dividing the pattern area partitioned into the powder layer corresponding to the shape to be welded into a plurality of preheating areas;
A first preheating step of irradiating the preheating region with a first laser beam having a first power to each of the preheating regions and not irradiating the preheating region adjacent to the preheating region irradiated with the first laser beam with the first laser beam;
A first welding step of irradiating a second laser beam having a second power higher than the first power to the preheating region preheated in the first preheating step to deposit powder contained in the powder layer;
Wherein the first laser beam is irradiated to the preheating region not irradiated with the first laser beam and is preheated, and the preheating region adjacent to the preheating region irradiated with the first laser beam is irradiated with the first laser beam, A second preheating step of not irradiating the beam; And
And a second welding step of irradiating the second laser beam to the preheating region preheated in the second preheating step to deposit the powder contained in the powder layer. Dimensional shape manufacturing method. The method according to claim 1,
Wherein the preheating region is formed by overlapping edge portions between neighboring preheating regions. The method according to claim 1,
In the first welding step and the second welding step,
Wherein a welding region to which the second laser beam is irradiated is disposed in the preheating region,
Wherein the area of the welding region is equal to or smaller than the area of the preheating region. The method according to claim 1,
The processing advancing direction in the first preheating step and the processing advancing direction in the first welding step are opposite to each other,
Wherein the machining direction of the second preheating step and the machining direction of the second welding step are opposite to each other. The method of claim 3,
A first layer on which the partitioning step, the first preheating step, the first welding step, the second preheating step and the second welding step are performed, the layer being made of a powder layer having a predetermined thickness, A second layer in which the dividing step, the first preheating step, the first welding step, the second preheating step, and the second welding step are performed,
Wherein the boundary line of the weld zone divided by the first layer and the boundary line of the weld zone defined by the second layer do not coincide with each other. The method according to claim 1,
Wherein the first laser beam and the second laser beam are irradiated by a polygon scanner. The method according to claim 1,
Wherein the first laser beam is irradiated by a polygon scanner and the second laser beam is irradiated by a galvanometer scanner. The method according to claim 1,
Wherein the preheating region is formed in a polygonal shape. The method according to claim 1,
Wherein the preheating region is formed in the same or different shape in one powder layer. The method according to claim 1,
Wherein the preheating region is formed to have the same size or different sizes in one powder layer. The method according to claim 1,
Wherein the progressing directions of the second laser beams irradiated to different preheating regions in the first welding step and the second welding step form a certain angle with respect to each other.

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