Method for manufacturing metal additively manufactured article

Abstract

To provide a method for manufacturing a metal additively manufactured article, capable of: suppressing the deformation and cracking of the metal additively manufactured article; and suppressing the deformation of a base plate.SOLUTION: A method for manufacturing a metal additively manufactured article includes: a step of attaching a base foundation onto a building table (1); a step of attaching a base plate onto the base foundation (2); a step of forming a metal powder layer on the base plate installed on the base foundation, and irradiating a light beam onto a predetermined portion of the metal powder layer to melt and solidify the metal powder at the predetermined portion, thereby forming a solidified layer (3); and a step of repeatedly forming a new metal powder layer on the obtained solidified layer and irradiating a light beam onto a predetermined portion of the new metal powder layer to form a further solidified layer (4). The base plate is a divided base plate divided into a plurality of sections, and has a higher thermal conductivity than the base foundation, while the base foundation has higher strength than the divided base plate.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing metal additive products. [Background technology]

[0002] In recent years, additive manufacturing (also known as lamination manufacturing) has come into use as a method for producing metal parts. Among additive manufacturing methods, powder bed fusion is a technique in which metal powder is spread on a base plate placed on a vertically movable base, and this metal powder is melted and solidified or sintered using an energy source such as a laser or electron beam to obtain a solidified layer, and then more metal powder is spread on top of that to obtain a further solidified layer, repeating this process to obtain a three-dimensional metal additive product.

[0003] In such additive manufacturing processes in which a solidified layer is obtained from a metal powder using an energy source, it is known that after the solidified layer is obtained by melting and solidifying the metal powder, the solidified layer gradually shrinks over time. As a result, there is a problem in that the shrinkage of the solidified layer formed later in the additive manufacturing process causes deformation of the lower solidified layer formed earlier in the additive manufacturing process, as if it were pulled upward.

[0004] In response to these problems, Patent Document 1 discloses an additive manufacturing device that includes a substrate including a plurality of divided plates that support powder, a powder solidification unit that solidifies the powder on the divided plates, and a guide that includes a direction regulating unit that regulates the direction of movement and / or deformation of the divided plates. With this configuration, the direction of movement and / or deformation of the substrate is regulated by the direction regulating unit, and as a result, the substrate can flexibly follow the thermal deformation of the object. This prevents unintended thermal stress from being generated in the thermally deformed object, and suppresses a decrease in the molding accuracy or quality of the object. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-168787 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the divided plates described in Patent Document 1, the rigidity of the divided plates may become insufficient toward the latter half of the additive manufacturing process, resulting in deformation of the underlying solidified layer and the divided plates. Furthermore, deformation or surface irregularities on the divided plate surface can disrupt the distribution of the metal powder layer. As a result, defects such as incomplete melting can occur in the solidified layer in contact with the divided plates. As the solidified layer formed later in the additive manufacturing process shrinks, these defects can lead to deformation and cracks.

[0007] The present invention has been made in consideration of these circumstances, and provides a method for manufacturing a metal additive product that can suppress deformation and cracking of the metal additive product and also suppress deformation of the base plate. [Means for solving the problem]

[0008] The method for manufacturing a metal additive manufacturing product of the present invention includes the steps of (1) attaching a base substrate onto a building table, (2) attaching a base plate onto the base substrate, (3) forming a metal powder layer on the base plate placed on the base substrate, and irradiating a light beam onto a predetermined location of the metal powder layer to melt and solidify the metal powder at the predetermined location to form a solidified layer, and (4) forming a new metal powder layer on the obtained solidified layer, and irradiating a light beam onto a predetermined location of the new metal powder layer to form a further solidified layer, and repeating this process; the base plate is a divided base plate divided into multiple pieces, and has a higher thermal conductivity than the base substrate, and the base substrate has a higher strength than the divided base plate.

[0009] Furthermore, after step (4), the method includes a step of removing the metal additive product integrated with the divided base plate from the base support, and a step of separating the metal additive product from the divided base plate, and the multiple divided base plates after separation are regenerated through a grinding step in which grinding marks are formed in the same direction on the surface on which the metal powder layer is formed and processed to the same thickness, and the multiple regenerated divided base plates are used as base plates in step (2).

[0010] It is preferable that the thermal conductivity of the divided base plates is 40 W / (m·K) or more at room temperature, and the strength of the base is 40 HRC or more at room temperature.

[0011] It is preferable that the base is divided into a plurality of parts, and that each divided base plate is attached to one base, and another divided base plate is attached to another base. [Effects of the Invention]

[0012] According to the manufacturing method of the metal additive product of the present disclosure, the divided base plates have a higher thermal conductivity than the base foundation, which improves the heat dissipation of the divided base plates and prevents deformation and cracking of the metal additive product. In addition, since the divided base plates are fixed to the base foundation, which has high strength and rigidity, deformation of the metal additive product and the divided base plates can be suppressed. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing an example of an additive manufacturing apparatus for carrying out the method for manufacturing a metal additive product of the present invention. [Figure 2] FIG. 1 is a schematic diagram showing an example of a method for manufacturing a metal additive product of the present invention. [Figure 3] FIG. 1 is a schematic diagram showing a method for carrying out a grinding step in the method for manufacturing a metal additive product of the present invention. [Figure 4]FIG. 10 is a schematic diagram showing another example of the grinding step in the method for manufacturing a metal additive product of the present invention. [Figure 5] 1 is a schematic diagram showing an example of a divided base plate and a base foundation of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment for carrying out the present invention will be described in detail with reference to the accompanying drawings. First, the configuration of an additive manufacturing apparatus for carrying out the present invention will be described, and then a method for manufacturing a metal additive product of the present invention will be described.

[0015] [Additive manufacturing equipment] FIG. 1 shows a schematic diagram of an additive manufacturing apparatus 1 for carrying out the method for manufacturing metal additive products of the present invention. The additive manufacturing apparatus 1 has a chamber (not shown) that surrounds the entire apparatus, and the chamber is equipped with a modeling table 2, a divided base plate 3, a base platform 4, a powder stage 5, a powder spreading means 6, a powder collector 7, a heat source 8, and metal powder 9. When manufacturing metal additive products using the additive manufacturing apparatus 1, the chamber can be placed in a vacuum, low-pressure state, or filled with an inert gas. This prevents deterioration of the metal additive products due to oxidation or other causes during the additive manufacturing process.

[0016] A base support 4 is installed on the upper surface of the modeling table 2, and a divided base plate 3 is installed on the upper surface of the base support 4. The modeling table 2 can be moved up and down, and by lowering the modeling table 2 by the amount of the solidified layer formed on the upper surface of the divided base plate 3 during the additive manufacturing process, the height of the metal powder layer during the additive manufacturing process can be kept constant. In this way, it is no longer necessary to change the output of the heat source 8 during the additive manufacturing process depending on the height of the metal powder layer.

[0017] The powder stage 5 is filled with metal powder 9 before being spread. The powder stage 5 can be moved up and down, and can be raised by the amount of metal powder to be spread on the divided base plate 3 or the top surface of the solidified layer.

[0018] The metal powder 9 filled in the powder stage 5 is spread on the upper surface of the divided base plate 3 or the solidified layer using a powder spreading means 6. There are no particular limitations on the powder spreading means 6, but specifically, a recoater is used to scrape the metal powder 9 on the powder stage 5 onto the uppermost surface of the divided base plate 3 or the solidified layer formed on the divided base plate 3, thereby forming a metal powder layer.

[0019] The powder collector 7 is provided to collect the excess metal powder 9 spread from the powder stage 5 by the powder spreading means 6. The powder collector 7 may be directly connected to a collection container inside or outside the apparatus, for example, or may be a mechanism that is movable up and down as shown in Figure 1 and moves up and down depending on the amount of excess metal powder 9. This prevents the metal powder 9 from flying up when the excess metal powder 9 is collected by the powder collector 7.

[0020] The heat source 8 is required to form a solidified layer on the metal powder layer. A light beam is most preferably used as the heat source 8 because it provides high resolution during modeling, but other melting heat sources such as an electron beam or arc heat source can also be used. This method can also be applied to the binder jet method, which also forms a metal powder layer for modeling. The following embodiment will show an example using the most preferred light beam.

[0021] In the additive manufacturing apparatus 1 described above, the divided base plates 3 and the base base 4 have the following configuration.

[0022] (Split base plate) As shown in Figure 5, the divided base plate 3 is placed on the top surface of the base foundation 4, which will be described later. By dividing the base plate into multiple pieces rather than one piece, it is possible to disperse the thermal stress that occurs as the solidified layer shrinks. Furthermore, the size of each divided base plate 3 can be reduced compared to a one-piece base plate, making it easier to improve flatness during manufacturing. There is no particular limit to the number of divided base plates 3. This number can be set appropriately depending on the size of the molded product, i.e., the size of the area where thermal stress occurs.

[0023] It is preferable that the multiple divided base plates 3 are all aligned to the same thickness. Furthermore, the upper surface is a ground surface 12 with grinding marks 13. When each divided base plate 3 is installed on the base support 4, it is preferable that the ground surfaces 12 are aligned so that the grinding marks 13 of each divided base plate 3 are oriented in the same direction. This arrangement uniforms the resistance between the metal powder 9 and the divided base plates 3 on the divided base plates 3, and by aligning the thicknesses of all the multiple divided base plates 3, the thickness of the layer of metal powder 9 formed on the divided base plates 3 is uniform. This improves the ability to spread the metal powder 9 across the entire base plate. The accuracy of the uniform thickness of the multiple divided base plates 3 here means that the absolute value of the deviation from the target thickness is less than half the thickness of a single metal powder layer. This is because if the divided base plates 3 have a deviation from the target thickness greater than half the thickness of a single metal powder layer, the individual divided base plates 3 may have thickness differences that exceed the thickness of a single metal powder layer, making it impossible to spread the metal powder layer uniformly. The absolute value of the deviation of each divided base plate 3 from the target thickness is preferably 0.02 mm or less, and more preferably 0.01 mm or less.

[0024] Furthermore, when placing the separate base plates 3 on the base support 4, it is preferable to provide a width between adjacent individual base plates 3 in order to distribute thermal stress. Taking into consideration deformation due to thermal expansion of the separate base plates, the width between adjacent individual separate base plates 3 is preferably 0.1 mm or more, so that the metal powder layer formed on the upper surface of the separate base plates 3 can maintain a constant layer thickness. On the other hand, if the width is too wide, it will be necessary to form a metal powder layer between the separate base plates that is not required for molding, so the width is preferably 10 mm or less. It is more preferably 5 mm or less.

[0025] The material of the divided base plates 3 is selected to have a higher thermal conductivity than the base support 4 (described later). This allows for efficient dissipation of heat energy from the light beam irradiated by the heat source 8, improving the cooling rate of the metal additive manufacturing product. Improving the cooling rate of the metal additive manufacturing product prevents deformation and cracking during cooling. As described below, pre-hardened steel may be used as the material for the base support 4. Therefore, the thermal conductivity of the divided base plates 3 is preferably 40 W / m·K or higher at room temperature, so that it is higher than that of pre-hardened steel. The specific material of the divided base plates 3 is preferably selected from alloys similar to or compatible with the metal powder 9, such as iron, aluminum alloy, or copper alloy, depending on the material of the metal powder 9. In this case, using a magnetic material for the divided base plates 3 allows them to be fixed using a magnetic chuck, which is preferable because it facilitates processing in the grinding process of the divided base plates 3 (described later). In consideration of productivity, multiple sets of split base plates 3 may be ground together and stored before being used for molding. In this case, if rust develops during storage, the split base plates 3 will need to be re-ground, so it is preferable that the split base plates 3 have corrosion resistance that can withstand storage. Therefore, by using stainless steel as the material for the split base plates 3, rust can be prevented. For this reason, if the split base plates 3 are made of a non-magnetic material, it is more preferable to use an austenitic stainless steel material, and if they are made of a magnetic material, it is more preferable to use a ferritic or martensitic stainless steel material.

[0026] The method for fixing the divided base plates 3 is not particularly limited, but examples include fixing with screws or, as described above, using a magnetic chuck by making the divided base plates 3 magnetic material. When fixing with screws, each divided base plate 3 is provided with a screw hole that penetrates from the top to the bottom. It is also preferable to provide a counterbore on the top side of the screw hole in each divided base plate 3. This prevents the screw head from protruding from the top surface of the divided base plate 3 and prevents a decrease in the spreading ability of the metal powder 9. When using a magnetic chuck, the divided base plates 3 can be fixed by providing an electromagnet or permanent magnet chuck on the top surface of the grinding machine surface plate or the building table 2.

[0027] (Base foundation) The base support 4 is provided to secure the split base plate 3 to the modeling table 2. By sandwiching the base support 4 between the split base plate 3 and the modeling table 2, the split base plate 3 can be secured to the modeling table 2 even if the method for securing the split base plate 3 differs from the method for securing the base plate to the modeling table 2. The base support 4 may also be a split base support divided into multiple pieces. In this case, the split base plate 3 can be secured to the modeling table 2 by attaching each of the split base supports to the top surface of each split base support.

[0028] The material of the base substrate 4 is selected to be stronger than the divided base plates 3. This prevents the divided base plates 3 from deforming due to thermal contraction of the metal additive manufacturing product. Furthermore, if the base substrate 4 is made of a material with high hardness, it will be less susceptible to damage during use and storage, allowing it to be used repeatedly over a long period of time as the reference surface of the divided base plates 3. An example of such a material is pre-hardened steel, and its strength is preferably 40 HRC or higher at room temperature. Furthermore, using a magnetic material for the base substrate 4 is preferable because it allows fixation by a magnetic chuck in the grinding process described below. Furthermore, dividing the base substrate 4 is preferable because it allows stress to be distributed.

[0029] The method for fixing the base foundation 4 is not particularly limited, but examples include fixing with screws or using a magnetic chuck by making the base foundation 4 a magnetic material, as with the divided base plates 3. When fixing with screws, the base foundation 4 is provided with a screw hole that penetrates from the top surface to the bottom surface.

[0030] The combination of the material of the split base plates 3 and the material of the base support 4 is not particularly limited. The split base plates 3 and the base support 4 may both be made of magnetic materials and fixed with a magnetic chuck, or the split base plates 3 and the base support 4 may both be made of non-magnetic materials and fixed with screws. Of course, the split base plates 3 may be made of a magnetic material and the base support 4 may be made of a non-magnetic material, and only the split base plates 3 may be fixed with a magnetic chuck, or the split base plates 3 may be made of a non-magnetic material and the base support 4 may be made of a magnetic material, and only the base support 4 may be fixed with a magnetic chuck. Even when the split base plates 3 or the base support 4 are made of a magnetic material, screw fixing may be used instead of magnetic chuck fixing. In cases such as when the metal powder 9 is made of a magnetic material, screw fixing may be preferable to magnetic chuck fixing. Therefore, the fixing method can be selected appropriately regardless of the material of the split base plates 3 or the base support 4.

[0031] Furthermore, it is preferable to provide pins or spacers between the divided base plates 3 and the base support 4 to set the positions of the divided base plates.

[0032] [Metal Additive Manufacturing Methods] The method for manufacturing a metal additive manufacturing product of the present invention includes the steps of: (1) attaching a base substrate onto a building table; (2) attaching a base plate onto the base substrate; (3) forming a metal powder layer on the base plate placed on the building table, irradiating a predetermined location of the metal powder layer with a light beam to melt and solidify the metal powder at the predetermined location to form a solidified layer; and (4) forming a new metal powder layer on the obtained solidified layer, and repeating the process of irradiating a predetermined location of the new metal powder layer with a light beam to form a further solidified layer, wherein the base plate is a divided base plate divided into multiple pieces and has a higher thermal conductivity than the base substrate, while the base substrate has a higher strength than the divided base plate. That is, a method for manufacturing a metal additive product, in which a metal additive product is formed by powder bed fusion on a base plate placed on a building table, wherein the base plate is made up of multiple components, and the divided base plate has a higher thermal conductivity than the base base, and the base base has a higher strength than the divided base plate.

[0033] Figure 2 shows a flow diagram of an example of a manufacturing method for a metal additive product of the present invention. Below, each step will be explained in the order of (a) to (h) in the flow of Figure 2. In this example, the grinding steps (a) to (b) are performed as separate steps (operations at a different location or time), and this is an example of a manufacturing method in which these are connected to the additive manufacturing steps (c) to (g).

[0034] (Grinding process: (a) to (b)) The manufacturing method of the metal additive product of this embodiment preferably includes a grinding step of grinding the divided base plates 3. This is because grinding the divided base plates 3 to the same height improves the packing of the metal powder and makes it less likely for cracks to occur in the metal additive product. As mentioned above, the precision of uniform thickness here refers to the absolute value of the deviation from the target thickness being less than half the thickness of one metal powder layer. First, in the grinding step (a), multiple divided base plates 3 are fixed to a surface grinding machine 10 and ground with a grinding wheel 11 to form ground surfaces 12 with grinding marks 13 aligned in the same direction on the surface on which the metal powder layer is formed, resulting in multiple divided base plates 3 of the same thickness. Figure 3 shows a schematic diagram of an example of the grinding step performed while the divided base plates 3 are fixed to a base support 4. While the grinding step may involve grinding a single divided base plate 3 individually, it is preferable to use an intensive grinding step in which multiple divided base plates 3 are ground together. Grinding multiple divided base plates 3 in an intensive manner makes it easier to align the grinding surfaces 12 of each divided base plate 3 with the grinding marks 13 aligned in a uniform direction, and also makes it easier to uniform the thickness of each divided base plate 3. Hereinafter, the ground surface 12 of each divided base plate 3 is referred to as the upper surface. Although FIGS. 2(a) and 2(b) show an example in which a magnetic chuck is used to fix the divided base plate 3 to the surface grinder 10, fixing with a fixing screw 14 may also be used.

[0035] Alternatively, multiple split base plates 3 may be fixed to a base support 4, and this base support 4 may be fixed to the surface plate of a grinding machine. In this case, the flow of the parts corresponding to (a) and (b) of FIG. 2, (a') to (b'), is shown in FIG. 4. In this way, by performing grinding while the individual split base plates 3 are fixed to the base support 4, the grinding marks 13 of the split base plates 3 are aligned in the same direction, which is preferable as it eliminates the need to reposition the split base plates 3. Furthermore, it is not necessary to re-fix the split base plates 3 from the surface plate of the grinding machine to the base support 4 before the additive manufacturing process. Note that multiple split base plates 3 fixed to the base support 4 can be disassembled once after grinding, cleaned, and then reassembled.

[0036] Although there are no particular limitations on the grinding machine used in the grinding process, it is preferable to use a surface grinding machine, as this allows multiple divided base plates 3 to be ground simultaneously. In the flow (b) of Figure 2, a surface grinding machine 10 is shown as an example. Other equipment that can be used includes a wire saw, an electric discharge machine, a cutting machine, etc.

[0037] (Additive manufacturing process: (c) to (g)) After that, additive manufacturing steps (c) to (g) are performed. As mentioned above, grinding steps (a) and (b) may be performed separately, so additive manufacturing steps (c) to (g) can be considered the initial steps in the manufacturing process of the present invention. Therefore, first, the base support 4 is attached to the building table 2, and then the divided base plates 3 are attached to the base support 4. At this time, in flow (c) of Figure 2, the individual ground divided base plates 3 can also be fixed to the base support 4 with fixing screws 14 or the like. In both cases, it is preferable to align the ground surfaces 12 of the divided base plates 3 in the same direction. This arrangement improves the spreading of the metal powder layer formed on the upper surfaces of the divided base plates 3. If the individual divided base plates 3 are fixed to the base base 4 before the base base 4 is fixed to the molding table 2, the base base 4 to which the divided base plates 3 are fixed is fixed to the molding table 2. This procedure is effective, for example, when the grinding process is performed with multiple divided base plates 3 fixed to the base base 4, as shown in FIG.

[0038] First, as shown in (d), the base support 4 and the divided base plates 3 are mounted on the building table 2 using fixing screws 14 or the like. Then, in (e), a metal powder layer 15 is formed on the divided base plate 3. Next, in (f), an energy beam is irradiated to predetermined locations on the metal powder layer to melt and solidify the metal powder at the predetermined locations, forming a solidified layer 16. Steps (e) through (f) constitute the first step. A new metal powder layer 15 is then formed on the formed solidified layer 16, and a predetermined location on this new metal powder layer is irradiated with an energy beam to form another solidified layer 16. This process is repeated as the second step. Then, in (g), an additive product 17 is formed. Here, the thickness of the divided base plates 3 is uniform, and uniform grinding marks 13 are formed on the grinding surface 12, resulting in a uniform metal powder layer 15 on the divided base plate 3. Therefore, in the solidified layer 16 obtained by energy beam irradiation, cracks and deformation originating from partial unmelted areas due to uneven thickness of the metal powder layer 15 can be prevented. It is also possible to prevent peeling between the solidified layer 16 and the divided base plate 3. When aligning the grinding marks 13, if they are parallel to the formation direction of the metal powder layer 15 on the grinding surface 12, i.e., the movement direction of the powder spreading means 6 in Figure 1, the powder may slide in the direction of the grinding marks 13 on the divided base plate 3, making it difficult to form the metal powder layer 15. To prevent this phenomenon, it is preferable to set the angle between the grinding marks 13 and the powder spreading means 6 to be 30 degrees or more and 90 degrees or less (i.e., perpendicular).

[0039] Here, it is preferable to preheat the divided base plates 3 when forming the metal powder layer 15 on the upper surface of the divided base plates 3. In this way, when the metal powder layer 15 is irradiated with an energy beam, the temperature gradient between the divided base plates 3 becomes gentle, and residual compression in the solidified layer can be suppressed.

[0040] (Cutting process:(h)) After the additive manufacturing process is completed, as shown in (h), the additive product 17 integrated with the divided base plate 3 is removed from the base base together with the divided base plate 3, and the additive product 17 is separated from the divided base plate 3. The separation method is not particularly limited, but FIG. 2(h) shows an example in which an electric discharge machine using a machining wire 18 is used.

[0041] After separation, the used divided base plates 3 are preferably subjected to a grinding process again to remove residues of the additive product 17 and any altered portions resulting from the separation, and to obtain a new, smooth surface on the surface of the divided base plates 3 for repeated use. The flow of the grinding process in this case is similar to that of the grinding process described above. A challenge with repeated use of conventional base plates is that the base plate warps due to stress generated during the additive manufacturing process, requiring a thicker layer to be ground to obtain a smooth surface in the grinding process. If the warpage of the base plate is too great, the required thickness as a base plate cannot be achieved after grinding, and it may not be possible to use it for additive manufacturing. As described above, the divided base plates 3 of the present invention suppress deformation due to thermal stress during the additive manufacturing process. Therefore, by returning them to the grinding processes (a) and (b), they can be reused in additive manufacturing processes with less grinding, which has the effect of shortening the grinding process and increasing the number of times the base plate can be used.

[0042] The material of the divided base plates 3 is selected to have a higher thermal conductivity than the base support 4, which will be described later. This allows for efficient dissipation of heat energy from the light beam irradiated by the heat source 8, improving the cooling rate of the metal additive manufacturing product. Improving the cooling rate of the metal additive manufacturing product prevents deformation and cracking that occur during cooling. As will be described later, pre-hardened steel may be used as the material of the base support 4. Therefore, the thermal conductivity of the divided base plates 3 is preferably 40 W / m·K or higher at room temperature, so that it is higher than that of pre-hardened steel. Furthermore, the material of the base support 4 is selected to have a higher strength than the divided base plates 3. This prevents deformation of the divided base plates 3 due to thermal contraction of the metal additive manufacturing product. Furthermore, using a hard material for the base support 4 makes it less susceptible to damage during use and storage, allowing for repeated use over long periods of time as the reference surface of the divided base plates 3. One such material is pre-hardened steel, and its strength is preferably 40 HRC or higher at room temperature.

[0043] Furthermore, as mentioned above, using stainless steel as the material for the divided base plate 3 can prevent rusting, so the divided base plate 3 that has been subjected to the grinding process again after the additive manufacturing process can be used as is even if stored in a room temperature environment without the need for grinding before reuse. [Explanation of symbols]

[0044] 1: Additive manufacturing equipment 2: Modeling table 3: Split base plate 4: Base 5: Powder stage 6: Powder packing means 7: Powder collector 8:Heat source 9: Metal powder 10: Surface grinder 11: Grinding wheel 12: Grinding surface 13: Grinding marks 14: Fixing screw 15: Metal powder layer 16: Solidified layer 17: Additive manufacturing

Claims

1. A step (1) of attaching a base to a modeling table; Step (2) of attaching a base plate onto the base foundation; a step (3) of forming a metal powder layer on the base plate placed on the base foundation, and irradiating a light beam onto a predetermined location of the metal powder layer to melt and solidify the metal powder at the predetermined location to form a solidified layer; and (4) forming a new powdered metal layer on the solidified layer obtained, and irradiating a predetermined portion of the new powdered metal layer with a light beam to form a further solidified layer, and repeating this process; A method for manufacturing a metal additive manufacturing product, characterized in that the base plate is a divided base plate divided into multiple parts, has a higher thermal conductivity than the base foundation, and the base foundation has a higher strength than the divided base plates.

2. After the step (4), a step of removing the metal additive manufactured product integrated with the divided base plate from the base foundation; and separating the metal additive product from the segmented base plate; The method for manufacturing a metal additive product according to claim 1, characterized in that the plurality of divided base plates after separation are regenerated through a grinding process in which grinding marks are formed in the same direction on the surface on which the metal powder layer is formed and processed to have the same thickness, and the plurality of regenerated divided base plates are used as base plates in step (2).

3. The method for manufacturing a metal additive manufacturing product according to claim 1 or 2, characterized in that the thermal conductivity of the divided base plates is 40 W / (m·K) or more at room temperature, and the strength of the base foundation is 40 HRC or more at room temperature.

4. The method for manufacturing a metal additive product according to claim 1 or 2, characterized in that the base foundation is divided into a plurality of parts, and each divided base plate is attached to one base foundation, and another individual divided base plate is attached to another base foundation.

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