THREE-DIMENSIONAL OBJECT MANUFACTURING METHOD

A three-dimensional object manufacturing method includes a molding step of molding a first three-dimensional object, a second three-dimensional object and a first support part for coupling the first and second three-dimensional objects at mutually different positions on a base plate by an additive manufacturing, and a separation step of separating the first three-dimensional object, the second three-dimensional object, the first support part and the base plate from each other. In the separation step, the first and second three-dimensional objects are separated from each other by dividing the first support part after at least one of the first and second three-dimensional objects is separated from the base plate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2021-082277, filed May 14, 2021, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

Field

The present disclosure relates to a three-dimensional object manufacturing method.

Related Art

JP2020-164890A discloses a method for molding an object on a base plate by an additive manufacturing.

Many objects may be efficiently manufactured by forming a plurality of objects on a base plate at once. However, in the case of molding the plurality of objects on the base plate at once, there is a possibility that the objects contact each other to be damaged in separating the objects from the base plate.

SUMMARY

According to one aspect of the present disclosure, a three-dimensional object manufacturing method is provided. This three-dimensional object manufacturing method includes a molding step of molding a first three-dimensional object, a second three-dimensional object and a first support part for coupling the first and second three-dimensional objects at mutually different positions on a base plate by an additive manufacturing, and a separation step of separating the first three-dimensional object, the second three-dimensional object, the first support part and the base plate from each other. In the separation step, the first and second three-dimensional objects are separated from each other by dividing the first support part after at least one of the first and second three-dimensional objects is separated from the base plate.

DETAILED DESCRIPTION

A. First Embodiment

FIG. 1is a sectional view schematically showing a schematic configuration of a additive manufacturing apparatus10used in a method for manufacturing three-dimensional objects100in a first embodiment. In the present embodiment, the additive manufacturing apparatus10includes a molding unit20, a powder layer forming unit30, a laser emitting unit40and a control unit50. In the present embodiment, the additive manufacturing apparatus10molds the three-dimensional objects100by an additive manufacturing of the powder bed fusion type, more specifically by an additive manufacturing of the SLM (Selective Laser Melting) type. In the following description, the three-dimensional object100may be simply called an object100.

The molding unit20includes a molding container21, a molding table23and a molding table elevator25. The molding container21has an opening in an upper surface. The molding table23is arranged in the molding container21. The molding table elevator25vertically moves the molding table23. In the present embodiment, the molding table elevator25is constituted by an electric actuator which is driven under the control of the control unit50.

A base plate27is mounted on the upper surface of the molding table23. A plurality of the objects100, first support parts for coupling the objects100to each other and second support parts for coupling each object100and the base plate27are molded on the base plate27. To be molded on the base plate27also means to be molded above the base plate27away from the upper surface of the base plate28besides being molded in contact with the upper surface of the base plate27. The base plate27is, for example, formed of a steel material such as alloy steels including carbon steel and stainless steel. The base plate27may be, for example, formed of a metal material other than the steel material such as a titanium alloy instead of the steel material or may be formed of a ceramic material instead of the metal material.

The powder layer forming unit30includes a powder storage container31, a powder extrusion table33, a powder extrusion table elevator35and a recoater37. The powder storage container31is arranged adjacent to the molding container21. The powder storage container31has an opening in an upper surface. The powder extrusion table33is arranged in the powder storage container31. The powder extrusion table elevator35vertically moves the powder extrusion table33. In the present embodiment, the powder extrusion table elevator35is constituted by an electric actuator which is driven under the control of the control unit50.

A metal powder PD used as a raw material of the objects100is stored in a space surrounded by the powder storage container31and the powder extrusion table33. The kind of metal of the metal powder PD is, for example, an aluminum alloy. The kind of the metal of the metal powder PD may be, for example, a titanium alloy, a nickel alloy, a stainless steel, a maraging steel or the like instead of the aluminum alloy. The metal powder PD stored in the powder storage container31is extruded to an upper part of the powder storage container31by the ascent of the powder extrusion table33.

The recoater37conveys the metal powder PD extruded to the upper part of the powder storage container31to the molding container21and flatly lays the metal powder PD on the base plate27, thereby forming a powder layer PL made of the metal powder PD on the base plate27. In the present embodiment, the recoater37is constituted by a squeegee and an electric actuator for moving the squeegee under the control of the control unit50. It should be noted that the recoater27may be constituted by a roller and an electric actuator for moving the roller in another embodiment.

The laser emitting unit40includes a laser oscillator41, an optical fiber43and a laser head45. The laser oscillator41generates a laser beam IS. In the present embodiment, the laser beam LS is a fiber laser beam. It should be noted that the laser beam LS may be, for example, a solid-state laser beam other than the fiber laser beam such as a disk laser beam, a semiconductor laser beam or a YAG laser beam or may be, for example, a gas laser beam such as a carbon dioxide laser beam instead of the solid-state laser beam.

The laser head45is arranged above the molding container21. The laser head45is connected to the laser oscillator41by the optical fiber43. The laser head45emits the laser beam LS supplied from the laser oscillator41via the optical fiber43toward the powder layers PL. In the present embodiment, the laser head45includes a built-in Galvano scanner, and the laser head45moves an irradiation position of the laser beam LS along two axial directions parallel to a horizontal plane.

The control unit50is configured as a computer including a CPU, a memory and an input/output interface. In the present embodiment, the control unit50molds the objects100by controlling the molding table elevator25, the powder extrusion table elevator35, the recoater37, the laser oscillator41and the laser head45as described later. It should be noted that the control unit50may be constituted by a combination of a plurality of circuits instead of the computer.

FIG. 2is a flow chart showing contents of the method for manufacturing the objects100in the present embodiment. First, in Step S110, the base plate27is mounted on the upper surface of the molding table23. Subsequently, in Step S120, the plurality of objects100having a desired shape and the first and second support parts are molded on the base plate27by the control unit50controlling each component of the additive manufacturing apparatus10. In the following description, a processing of Step S120is called a molding step. The molding step is described in detail later.

Thereafter, in Step S130, the base plate27is removed from the molding table23. In Step S140, each object100is separated from the base plate27. In Step S150, the objects100are separated from each other to complete each object100. A processing from Step S140to Step S150is called a separation step. The separation step is described in detail later.

FIG. 3is a diagram showing a state of the molding step in the present embodiment. In the present embodiment, the molding step includes a powder layer forming step, a melting/solidifying step and a lowering step. The molding step is performed under the control of the control unit50.

First, in the powder layer forming step, the control unit50moves the powder extrusion table33upward and extrudes a predetermined amount of the metal powder PD from the powder storage container31by controlling the powder extrusion table elevator35. The control unit50flatly lays the metal powder PD extruded from the powder storage container31on the base plate27to form the powder layer PL on the base plate27by moving the recoater37.

Subsequently, in the melting/solidifying step, the control unit50irradiates a laser beam LS to a predetermined region on the powder layer PL to melt the powder layer PL in this region by controlling the laser oscillator41and the laser head45. The melted powder layer PL is, for example, cooled and solidified for several seconds to become a molding layer ZL.

Thereafter, in the lowering step, the control unit50lowers the molding table23and the base plate27by a distance corresponding to a thickness of the molding layer ZL by controlling the molding table elevator25. The control unit50stacks the molding layer ZL on the molding layer(s) ZL by repeating the powder layer forming step, the melting/solidifying step and the lowering step until the formation of all the molding layers ZL is finished, thereby molding the plurality of objects100and the first and second support parts.

FIG. 4is a perspective view showing an example of the plurality of objects100molded on the base plate27. In an example shown inFIG. 4, three objects100A to100C are formed at mutually different positions on the base plate27. The objects100A to100C have the same shape. In the following description, the object100A may be called a first three-dimensional object100A or first object100A, the object100B may be called a second three-dimensional object100B or second object100B and the object100C may be called a third three-dimensional object100C or third object100C. When being described without being particularly distinguished, the objects100A to100C may be called the three-dimensional objects100or objects100. It should be noted that the number of the objects100molded on the base plate27is not limited to three, but may be two, four or more. The objects100A to100C may have mutually different shapes.

In the example shown inFIG. 4, a first support part110A for coupling the first and second objects100A,100B, a first support part110B for coupling the second and third objects100B,100C, a second support part120A for coupling the first object100A and the base plate27, a second support part120B for coupling the second objects100B and the base plate27and a second support part1200for coupling the third object100C and the base plate27are molded on the base plate27besides the first, second and third objects100A,100B and100C.

The objects100A to100C are arranged at a distance from each other. The first support part110A is arranged between the first and second objects100A,100B, and the first support part110B is arranged between the second and third objects100B,100C. In the present embodiment, each first support part110A,110B includes two first plate-like parts111provided to cross each other. Each first plate-like part111is in the form of a flat plate. The first support parts110A,110B are configured into an X shape when viewed in a direction parallel to the upper surface of the base plate27. To suppress a reduction of material yield, the first support parts110A,110B are preferably arranged at positions where intervals between the objects100A to100C are narrow. It should be noted that the first support parts110A,110B may be configured into an X shape when viewed in a direction perpendicular to the upper surface of the base plate27.

Each object100A to100C is arranged at a distance from the base plate27. The second support part120A is arranged between the first object100A and the base plate27, the second support part120B is arranged between the second object100B and the base plate27and the second support part120C is arranged between the third object100C and the base plate27. Each second support part120A to120C supports the corresponding object100A to100C. In the present embodiment, each second support part120A to120C includes five second plate-like parts121provided in parallel to each other. Each second plate-like part121is in the form of a flat plate. It should be noted that the number of the second plate-like parts121is not limited to five and may be an arbitrary number. However, the number of the second plate-like parts121is preferably more than that of the first plate-like parts11M.

Each first support part110A,110B has strength and rigidity to withstand the weight of each object100A to100C when the base plate27is inclined with respect to the horizontal plane. In the present embodiment, the strength and rigidity of each second support part120A to120C are higher than those of each first support part110A,110B. In the present embodiment, the control unit50makes an energy density of the laser beam LS for molding each object100A to100C and each second support part120A to120C higher than that of the laser beam LS for molding the first support parts110A,110B by controlling the laser emitting unit40in the molding step. For example, the control unit50sets the energy density of the laser beam LS for molding each first support part110A,110B to 80% of the energy density of the laser beam LS for molding each object100A to100C and each second support part120A to120C. As the energy density of the laser beam LS irradiated to the powder layers PL increases, a melting degree of the powder layers PL increases. As the melting degree of the powder layers PL increases, a clearance by unmelted parts is less likely to be formed. Thus, a density of the molding layers ZL increases.

FIG. 5is a first diagram showing a state of the separation step in the present embodiment.FIG. 6is a second diagram showing a state of the separation step in the present embodiment.FIGS. 5 and 6show a state where the three objects100A to100C shown inFIG. 4are separated from each other.

In the present embodiment, each second support part120A to120C coupling each object100A to100C and the base plate27is first divided as shown inFIG. 5. By dividing each second support part120A to120C, each object100A to100C is separated from the base plate27. In the present embodiment, each second support part120A to120C is divided by being cut by a contour machine (band saw). If each object100A to100C is separated from the base plate27with the base plate27facing upward, in other words, with a stacking direction of the objects100A to100C and a gravitational direction G set in parallel, there is a possibility that the objects100A to100C having lost support by the second support parts120A to1200fall down and contact a blade of the contour machine. Accordingly, in the present embodiment, each object100A to100C is separated from the base plate27with the base plate27facing laterally, in other words, with the stacking direction of the objects100A to100C and the gravitational direction G set perpendicular to each other to prevent the contact of each object100A to100C with the blade of the contour machine.

Subsequently, as shown inFIG. 6, the first support parts110A to110B coupling the objects100A to100C to each other are divided with the stacking direction of the objects100A to1000and the gravitational direction G set parallel to each other. For example, the first support parts110A to110B are divided, for example, by being cut by a nipper. The objects100A to100C are separated from each other by dividing the first support parts110A,110B.

FIG. 7is diagram showing a state of the separation step in a comparative example. In the comparative example, the first support parts110A,110B are not provided. When the first support parts110A,110B are not provided, there is a possibility that the objects100A to100C having lost support by the second support parts120A to120C fall down and contact each other to be broken as shown inFIG. 7if the second support parts120A to120C are cut with the base plate27facing laterally. Even if the second support parts120A to120C are cut with the base plate27facing upward, there is a possibility that the objects100A to100C having lost support by the second support parts120A to120C fall over and contact each other to be broken. The mutual contact of the objects100A to100C can be avoided by inserting cushioning materials between the objects100A to100C. However, in the case of inserting the cushioning materials between the objects100A to100C, production efficiency is reduced since it takes effort and time to insert the cushioning materials. Further, it is difficult to insert the cushioning materials between the objects100A to100C if intervals between the objects100A to100C are narrow.

In contrast, according to the method for manufacturing the three-dimensional objects100in the present embodiment described above, the first support part110A for coupling the first and second objects100A,100B and the first support part110B for coupling the second and third objects100B,100C are molded in the molding step. Thereafter, in the separation step, the objects100A to100C are separated from each other by cutting each first support part110A,110B after each object100A to100C is separated from the base plate27. Thus, the intervals between the objects100A to100C can be ensured by the first support parts110A,110B in separating each object100A to100C from the base plate27. Therefore, it can be suppressed that each object100A to100C is damaged due to the mutual contact of the objects100A to100C in separating each object100A to100C from the base plate27. Particularly, in the present embodiment, the mutual contact of the objects100A to100C can be suppressed in separating each object100A to100C molded by the additive manufacturing of the SLM type for irradiating the laser beam LS to the powder layers PL formed of the metal powder PD from the base plate27.

Further, since the second support parts120A to120C for coupling each object100A to100C and the base plate27are molded in the molding step in the present embodiment, each object100A to100C can be supported by each second support part120A to120C. Thus, each object100A to100C can be molded with good dimensional accuracy by suppressing the collapse of the shape of each object100A to100C during the molding of each object100A to100C.

Further, since the rigidity of each second support part120A to120C is higher than that of each first support part110A,110B in the present embodiment, it is possible to suppress the deformation of each second support part120A to120C during the molding of each object100A to100C. Particularly, in the present embodiment, it is possible to suppress the deformation of each second support part120A to120C caused by the objects100A to100C pulling each other via each first support part110A,110B due to shrinkage when the melted powder layers PL are solidified.

Further, since the energy density of the laser beam IS for molding each second support part120A to1200is higher than that of the laser beam LS for molding each first support part110A,110B in the present embodiment, the density of each second support part120A to1200can made higher than that of each first support part110A,110B. Thus, each second support part120A to120C can made less deformable.

Further, since each first support part110A,110B includes two first plate-like parts111provided to cross each other in the present embodiment, the rigidity of each first support part110A,110B can be easily ensured. Thus, the mutual contact of the objects100A to100C due to the deformation of each first support part110A,10B can effectively suppressed in separating each object100A to100C from the base plate27.

Further, in the present embodiment, each second support part120A to120C is constituted by a plurality of the second plate-like parts121and the number of the second plate-like parts121is more than that of the first plate-like part111of each first support part110A,110B. Thus, each second support part120A to120C can be made less deformable as compared to the case where the number of the second plate-like parts121of each second support part120A to1200is equal to or less than that of the first plate-like part111of each first support part110A,110B.

B. Second Embodiment

FIG. 8is a perspective view showing an example of a plurality of objects100molded on a base plate27by a method for manufacturing three-dimensional objects100in a second embodiment. The second embodiment differs from the first embodiment in that each first support part110A,110B includes first rod-like parts112instead of the first plate-like parts111and each second support part120A to120C includes second rod-like parts122instead of the second plate-like parts121. The other configuration is the same as in the first embodiment unless particularly described.

In the present embodiment, each first support part110A,110B includes three first rod-like parts112provided along mutually different directions. Each first rod-like part112is in the form of a straight rod. The first rod-like parts112are preferably arranged at mutually twisted positions. It should be noted that the number of the first rod-like parts112may be not three, but four or more. The first rod-like parts112may be arranged to cross each other or may be arranged in parallel to each other.

In the present embodiment, each second support part120A to120C includes twenty second rod-like parts122arranged perpendicular to the upper surface of the base plate27. The second rod-like parts122are arranged in five columns and four rows on the base plate27. Each second rod-like part122is in the form of a straight rod. The number of the second rod-like parts122may be an arbitrary number without being limited to twenty. However, the number of the second rod-like parts122is preferably more than that of the first rod-like parts112.

According to the method for manufacturing the three-dimensional objects100in the present embodiment described above, the rigidity of each first support part110A,110B can be easily ensured since each first support part110A,110B includes the three first rod-like parts112provided along the mutually different directions.

Further, in the present embodiment, each second support part120A to120C is constituted by the plurality of second rod-like parts122and the number of the second rod-like parts122is more than the first rod-like parts112of each first support part110A,110B. Thus, each second support part120A to120C can be made less deformable as compared to the case where the number of the second rod-like parts122of each second support part120A to120C is equal to or less than that of the first rod-like parts112of each first support part110A,110B.

FIG. 9is a side view showing an example of a plurality of objects100molded on a base plate27by a method for manufacturing three-dimensional objects100in a third embodiment. The third embodiment differs from the first embodiment in that a first object100A and a second object100B have parts overlapping each other when viewed in a stacking direction of the first and second objects100A,100B and a first support part110C for coupling the first and second objects100A,100B is provided between the first and second objects100A and100B in the stacking direction. The other configuration is the same as in the first embodiment unless particularly described.

In the present embodiment, the first and second objects100A,110B are coupled to each other by a first support part110A and the first support part1100. The first support part110C includes two first plate-like parts111provided to cross each other similarly to the first support part110A. It should be noted that the first support part110C may include three or more first rod-like parts112provided along mutually different directions.

In the present embodiment, in a separation step, the objects100A to100C are separated from each other by cutting each first support part110A to110C after each object100A to100C is separated from the base plate27.

According to the method for manufacturing the three-dimensional objects100in the present embodiment described above, an interval between the first and second objects100A,100B in the stacking direction can be ensured by the first support part110C even if the first and second objects100A,110.8have the parts overlapping each other in the stacking direction.

D. Other Embodiments

(D1) In the method for manufacturing the three-dimensional objects100in each of the embodiments described above, each object100A to100C, each first support part110A to110C and each second support part120A to120C are molded by the additive manufacturing of the SIM type for melting the powder layers PL by irradiating the laser beam LS to the powder layers PL, out of additive manufacturing of the powder bed fusion type. In contrast, each object100A to100C, each first support part110A to110C and each second support part120A to120C may be molded by an additive manufacturing of the SLS (Selective Laser Sintering) type for sintering the powder layers PL by irradiating a laser beam LS to the powder layers PL or may be molded by an additive manufacturing of the EMB (Electron Beam Melting) type for melting the powder layers PL by irradiating an electron beam to the powder layers PL, out of the additive manufacturing of the powder bed fusion type. Each object100A to100C, each first support part110A to1100and each second support part120A to120C may be molded, for example, by an additive manufacturing of the FDM (Fused Deposition Modeling) type or of the optical molding type instead of the additive manufacturing of the powder bed fusion type. In the case of the additive manufacturing of the FDM type or optical molding type, not the metal material, but a resin material may be used as the raw material of each object100A to100C, each first support part110A to110C and each second support part120A to120C.

(D2) In the method for manufacturing the three-dimensional objects100in each of the embodiments described above, in the separation step, the objects100A to100C are separated from each other by cutting each first support part110A to100C after each object100A to100C is separated from the base plate27. In contrast, in the separation step, the second object100B may be separated from the base plate27after the first object100A is separated from the base plate27and the first and second objects100A100B are separated by cutting the first support part(s)110A,110C. Thereafter, the third object100C may be separated from the base plate27after the second object100B is separated from the base plate27and the second and third objects100B,100C are separated by cutting the first support part110B. Even in this case, the mutual contact of the objects100A to100C can be suppressed in separating each object100A to100C from the base plate27. Note that the order of separating each object100A to100C from the base plate27is not limited to the aforementioned order. For example, the objects100A to1000may be separated in the order of the third object100C, the second object100B and the first object100A or in the order of the first object100A, the third object100C and the second object100B.

(D3) In the method for manufacturing the three-dimensional objects100in each of the embodiments described above, the second support parts120A to120C are molded between each object100A to100C and the base plate27. In contrast, the second support parts120A to120C may not be molded between each object100A to100C and the base plate27, and each object100A to100C may be provided with a predetermined cutting margin and molded in contact with the base plate27.

(D4) In the method for manufacturing the three-dimensional objects100in each of the embodiments described above, the rigidity of each second support part120A to120C is higher than that of each first support part110A to110C. In contrast, the rigidity of each second support part120A to1200may be equal to or less than that of each first support part110A to110C. In this case, the rigidity of each second support part120A to120C is preferably equal to that of each first support part110A to110C.

(D5) In the method for manufacturing the three-dimensional objects100in each of the embodiments described above, the energy density of the laser beam LS for molding each second support part120A to120C is higher than that of the laser beam LS for molding each first support part110A to110C. In contrast, the energy density of the laser beam LS for molding each second support part120A to120C may be equal to or lower than that of the laser beam LS for molding each first support part110A to110C. In this case, the energy density of the laser beam LS for molding each second support part120A to120C is preferably equal to that of the laser beam LS for molding each first support part110A to110C.

(D6) In the method for manufacturing the three-dimensional objects100in each of the embodiments described above, the control unit50sets the energy density of the laser beam LS for molding each second support part120A to120C higher than that of the laser beam LS for molding each first support part110A to110C in the melting/solidifying step of the molding step. In contrast, the control unit50may not change the energy density of the laser beam LS in the melting/solidifying step. In this case, the control unit50may, for example, irradiate the laser beam LS for two layers each time instead of irradiating the laser beam LS for each layer to mold the first support parts110A to110C. By this method, the density of each first support part110A to110C can be made lower than that of each second support part120A to120C.

(D7) In the method for manufacturing the three-dimensional objects100in each of the first and third embodiments described above, each first support part110A to110C is constituted by the plurality of first plate-like parts111and each second support part120A to120C is constituted by the plurality of second plate-like parts121. In contrast, each first support part110A to110C may be constituted by the plurality of first plate-like parts111and each second support part120A to120C may be constituted by the plurality of second rod-like parts122. Alternatively, each first support part110A to110C may be constituted by the plurality of first rod-like parts112and each second support part120A to120C may be constituted by the plurality of second plate-like parts121.

The disclosure is not limited to any of the embodiment and its modifications described above but may be implemented by a diversity of configurations without departing from the scope of the disclosure. For example, the technical features of any of the above embodiments and their modifications may be replaced or combined appropriately, in order to solve part or all of the problems described above or in order to achieve part or all of the advantageous effects described above. Any of the technical features may be omitted appropriately unless the technical feature is described as essential in the description hereof. The present disclosure may be implemented by aspects described below.

(1) According to one aspect of the present disclosure, a three-dimensional object manufacturing method is provided. This three-dimensional object manufacturing method includes a molding step of molding a first three-dimensional object, a second three-dimensional object and a first support part for coupling the first and second three-dimensional objects at mutually different positions on a base plate by an additive manufacturing, and a separation step of separating the first three-dimensional object, the second three-dimensional object, the first support part and the base plate from each other. In the separation step, the first and second three-dimensional objects are separated from each other by dividing the first support part after at least one of the first and second three-dimensional objects is separated from the base plate.

According to the three-dimensional object manufacturing method of this form, an interval between the first and second three-dimensional objects can be ensured by the first support part. Thus, it is possible to suppress the damage of the first and second three-dimensional objects due to the mutual contact of the first and second three-dimensional objects in separating the first and second three-dimensional objects from the base plate.

(2) In the three-dimensional object manufacturing method of the above form, in the separation step, the first and second three-dimensional objects may be separated from each other by dividing the first support part after the first and second three-dimensional objects are separated from the base plate.

According to the three-dimensional object manufacturing method of this form, the mutual contact of the first and second three-dimensional objects can be suppressed in separating the first and second three-dimensional objects from the base plate.

(3) In the three-dimensional object manufacturing method of the above form, in the separation step, the second three-dimensional object may be separated from the base plate after the first three-dimensional object is separated from the base plate and the first and second three-dimensional objects are separated by dividing the first support part.

According to the three-dimensional object manufacturing method of this form, the mutual contact of the first and second three-dimensional objects can be suppressed in separating the first and second three-dimensional objects from the base plate.

(4) In the three-dimensional object manufacturing method of the above form, the molding step may include a powder layer forming step of forming a powder layer by laying a metal powder on the base plate and a melting/solidifying step of melting the powder layer by irradiating a beam to a predetermined region of the powder layer and solidifying the melted powder layer, and the first three-dimensional object, the second three-dimensional object and the first support part may be molded at mutually different positions on the base plate by repeatedly performing the powder layer forming step and the melting/solidifying step.

According to the three-dimensional object manufacturing method of this form, the mutual contact of the first and second three-dimensional objects can be suppressed in separating the first and second three-dimensional objects molded by irradiating the beam to the powder layer formed by the metal powder from the base plate.

(5) In the three-dimensional object manufacturing method of the above form, a second support part for coupling the first three-dimensional object and the base plate may be molded in the molding step.

According to the three-dimensional object manufacturing method of this form, it is possible to suppress the collapse of the shape of the first three-dimensional object during the molding of the first three-dimensional object since the first three-dimensional object is supportable by the second support part.

(6) In the three-dimensional object manufacturing method of the above form, the rigidity of the second support part may be higher than that of the first support part.

According to the three-dimensional object manufacturing method of this form, it is possible to suppress the collapse of the shape of the first three-dimensional object due to the deformation of the second support part during the molding of the first three-dimensional object since the second support part can be made less deformable.

(7) In the three-dimensional object manufacturing method of the above form, the first support part may include a plurality of first plate-like parts provided to cross each other.

According to the three-dimensional object manufacturing method of this form, the mutual contact of the first and second three-dimensional objects can be effectively suppressed in separating the first and second three-dimensional objects from the base plate since the rigidity of the first support part can be easily ensured.

(8) In the three-dimensional object manufacturing method of the above form, a second support part for coupling the first three-dimensional object and the base plate may be molded in the molding step, the second support part may include a plurality of second plate-like parts, and the number of the second plate-like parts may be more than that of the first plate-like parts.

According to the three-dimensional object manufacturing method of this form, it is possible to suppress the collapse of the shape of the first three-dimensional object due to the deformation of the second support part during the molding of the first three-dimensional object since the second support part may be made less deformable as compared to the case where the number of the second plate-like parts is equal to or less than that of the first plate-like parts.

(9) In the three-dimensional object manufacturing method of the above form, the first support part may include three or more first rod-like parts provided along mutually different directions.

According to the three-dimensional object manufacturing method of this form, the mutual contact of the first and second three-dimensional objects can be effectively suppressed in separating the first and second three-dimensional objects from the base plate since the rigidity of the first support part can be easily ensured.

(10) In the three-dimensional object manufacturing method of the above form, a second support part for coupling the first three-dimensional object and the base plate may be molded in the molding step, the second support part may include a plurality of second rod-like parts, and the number of the second rod-like parts may be more than that of the first rod-like parts.

According to the three-dimensional object manufacturing method of this form, it is possible to suppress the collapse of the shape of the first three-dimensional object due to the deformation of the second support part during the molding of the first three-dimensional object since the second support part can be made less deformable as compared to the case where the number of the second rod-like parts is equal to or less than that of the first rod-like parts.

(11) In the three-dimensional object manufacturing method of the above form, a second support part for coupling the first three-dimensional object and the base plate may be molded in the molding step, and an energy density of the beam for molding the second support part may be higher than that of the beam for molding the first support part.

According to the three-dimensional object manufacturing method of this form, the second support part can be made less deformable since the density of the second support part can be higher than that of the first support part.

(12) In the three-dimensional object manufacturing method of the above form, the first and second three-dimensional objects may have parts overlapping each other when viewed in a stacking direction of the first and second three-dimensional objects, and the first support part may be provided between the first and second three-dimensional objects in the stacking direction.

According to the three-dimensional object manufacturing method of this form, the mutual contact of the first and second three-dimensional objects can be effectively suppressed in separating the first and second three-dimensional objects molded to have the parts overlapping each other when viewed in the stacking direction of the first and second three-dimensional objects from the base plate.

The present disclosure is realizable in various forms other than the three-dimensional object manufacturing method. For example, the present disclosure is realizable by an additive manufacturing, a additive manufacturing apparatus, a control method of the additive manufacturing apparatus and the like.