JP7241325B2 - Method for manufacturing three-dimensional shaped article, three-dimensional shaped article, and oxide powder used for manufacturing three-dimensional shaped article - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a three-dimensional shaped article, a three-dimensional shaped article, and an oxidized powder used for manufacturing a three-dimensional shaped article.

A method of manufacturing a three-dimensional shaped article by irradiating a powder material with a light beam (commonly referred to as a “powder bed fusion method”) has been known for some time. In this method, powder layer formation and solid layer formation are alternately and repeatedly performed based on the following steps (i) and (ii) to manufacture a three-dimensional shaped article.
(i) A step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt and solidify the powder at the predetermined portion to form a solidified layer.
(ii) a step of forming a new powder layer on the obtained solidified layer and similarly irradiating with a light beam to form a further solidified layer;

According to such a manufacturing technique, it becomes possible to manufacture a complicated three-dimensional shaped article in a short time. When inorganic metal powder is used as the powder material, the resulting three-dimensional shaped article can be used as a mold. On the other hand, when organic resin powder is used as the powder material, the obtained three-dimensional shaped object can be used as various models.

A case where metal powder is used as the powder material and the resulting three-dimensional shaped object is used as a mold will be taken as an example. As shown in FIG. 9, first, the squeegee blade 23 is moved to form a powder layer 22 having a predetermined thickness on the modeling plate 21 (see FIG. 9(a)). Next, a predetermined portion of the powder layer 22 is irradiated with a light beam L to form a solidified layer 24 from the powder layer 22 (see FIG. 9B). Subsequently, a new powder layer 22 is formed on the solidified layer 24 thus obtained, and the light beam is irradiated again to form a new solidified layer 24 . When the powder layer formation and the solidified layer formation are alternately repeated in this way, the solidified layers 24 are laminated (see FIG. 9(c)), and finally a three-dimensional structure composed of the laminated solidified layers 24 is obtained. A shaped article can be obtained. Since the solidified layer 24 formed as the bottom layer is in a state of being combined with the modeling plate 21, the three-dimensional shaped object and the modeling plate 21 form an integrated object, and the integrated object can be used as a mold. can be done.

Japanese Patent Publication No. 1-502890 JP 2019-108570 A

Here, when a three-dimensional shaped article is manufactured by irradiating a powder material with a light beam, anisotropy may occur in the mechanical strength of the obtained three-dimensional shaped article. In this case, the mechanical strength in a predetermined direction of the three-dimensional shaped article can satisfy any strength criteria that can be individually required depending on the use of the shaped article. On the other hand, there is a possibility that the mechanical strength in a direction different from the predetermined direction of the three-dimensional shaped article does not satisfy the arbitrary strength standard. Therefore, as a whole, there is a possibility that the obtained three-dimensional shaped article cannot be suitably used for any purpose.

The present invention has been made in view of such circumstances. That is, the object of the present invention is to provide a method for producing a three-dimensional shaped article that can suitably improve the mechanical strength of the obtained three-dimensional shaped article, a three-dimensional shaped article obtained by the manufacturing method, and An object of the present invention is to provide an oxidized powder used for manufacturing a three-dimensional shaped object.

In order to achieve the above object, in one embodiment of the present invention,
A method for manufacturing a three-dimensional object by sequentially forming a plurality of solidified layers by irradiating a powder with a light beam,
Using at least an oxidized powder whose surface has been oxidized as the powder,
A manufacturing method is provided, wherein the oxidized powder comprises a main component and a sub-component that is relatively more likely to form an oxide than the main component.

In order to achieve the above object, in one embodiment of the present invention,
A three-dimensional shaped object,
comprising a base composed of a main component and a sub-component oxide that is relatively easier to oxidize than the main component,
A three-dimensional shaped article is provided, wherein said oxide of said sub-component is interspersed in an interior region of said base and formed on a portion of a surface region of said base.

In order to achieve the above object, in one embodiment of the present invention,
An oxidized powder used for manufacturing a three-dimensional shaped object,
Provided is an oxidized powder having an oxidized surface and comprising a main component and a sub-component that is more likely to form an oxide than the main component.

According to one embodiment of the present invention, it is possible to preferably improve the mechanical strength of the obtained three-dimensional shaped product.

1 is a cross-sectional view schematically showing oxidized powder used for manufacturing a three-dimensional shaped object according to one embodiment of the present invention; FIG. Schematic diagram for explaining common technical knowledge of a person skilled in the art. Sectional drawing which shows typically the manufacturing method of the three-dimensional-shaped molded article which concerns on one Embodiment of this invention. Cross-sectional views schematically showing a method for manufacturing a three-dimensional shaped object according to one embodiment of the present invention (Fig. 4(a) at the time of light beam irradiation, Fig. 4(b) at the time of melt part formation, Fig. 4(c) (during the formation of the three-dimensional modeled object in FIG. 4(d)). FIG. 5 is a cross-sectional view schematically showing an aspect of manufacturing a three-dimensional shaped article by the powder bed fusion method (FIG. 5(a) at the time of light beam irradiation, FIG. 5(b) at the time of formation of the three-dimensional shaped article). FIG. 6 is a cross-sectional view schematically showing a mode of manufacturing a three-dimensional shaped article by a directed energy deposition method (FIG. 6(a) at the time of light beam irradiation, FIG. 6(b) at the time of formation of a three-dimensional shaped article). BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows typically the three-dimensional-shaped molded article which concerns on one Embodiment of this invention. 8A and 8B are cross-sectional views schematically showing a method for manufacturing a three-dimensional shaped article according to another embodiment of the present invention (FIG. 8A at the time of light beam irradiation, FIG. 8B at the time of formation of a three-dimensional shaped article); Cross-sectional views schematically showing the process mode of stereolithography composite processing in which the powder bed fusion method is performed (Fig. 9(a): when powder layer is formed, Fig. 9(b): when solidified layer is formed, Fig. 9 ( c): during lamination) Perspective view schematically showing the configuration of the stereolithography combined processing machine Flowchart showing the general operation of the stereolithography multitasking machine

An embodiment of the invention is described in more detail below with reference to the drawings. The form and size of various elements in the drawings are for illustration only and do not reflect the actual form and size.

As used herein, the term "powder layer" means, for example, a "metal powder layer made of metal powder" or a "resin powder layer made of resin powder". Also, the “predetermined portion of the powder layer” substantially refers to the region of the three-dimensional modeled object to be manufactured. Therefore, by irradiating a light beam to the powder present at such a predetermined location, the powder is sintered or melted and solidified to form a three-dimensional shaped object. Furthermore, the "solidified layer" means a "sintered layer" when the powder layer is a metal powder layer, and a "hardened layer" when the powder layer is a resin powder layer.

In addition, the “up and down” direction described directly or indirectly in this specification is, for example, a direction based on the positional relationship between the modeling plate and the three-dimensional shaped object, and is a three-dimensional direction based on the modeling plate. The side on which the shaped article is manufactured is referred to as "upward" and the opposite side is referred to as "downward."

[Powder Bed Fusion Method]
First, the powder bed fusion bonding method, which is one of the methods used in the manufacturing method according to one embodiment of the present invention, will be described. In particular, composite stereolithography processing, in which cutting processing of a three-dimensional shaped object is additionally performed in the powder bed fusion method, will be taken as an example. FIG. 9 schematically shows the process mode of the stereolithography combined processing, and FIGS. 10 and 11 are flow charts of the main configuration and operation of the stereolithography combined processing machine capable of performing the powder bed fusion method and the cutting process. are shown respectively.

As shown in FIG. 10, the stereolithography composite processing machine 1 includes powder layer forming means 2, light beam irradiation means 3 and cutting means 4. As shown in FIG.

The powder layer forming means 2 is a means for forming a powder layer by spreading powder such as metal powder or resin powder with a predetermined thickness. The light beam irradiation means 3 is a means for irradiating the light beam L onto a predetermined portion of the powder layer. The cutting means 4 is a means for cutting the side surface of the laminated solidified layer, that is, the surface of the three-dimensional shaped object.

The powder layer forming means 2 mainly comprises a powder table 25, a squeegee blade 23, a shaping table 20 and a shaping plate 21, as shown in FIG. The powder table 25 is a table that can move up and down within a powder material tank 28 whose outer periphery is surrounded by a wall 26 . The squeegee blade 23 is a blade that can be moved horizontally to present the powder 19 on the powder table 25 onto the build table 20 to obtain the powder layer 22 . The modeling table 20 is a table that can move up and down in a modeling tank 29 whose outer periphery is surrounded by a wall 27 . The modeling plate 21 is arranged on the modeling table 20 and serves as a base for a three-dimensional shaped object.

The light beam irradiation means 3 mainly includes a light beam oscillator 30 and a galvanomirror 31, as shown in FIG. The light beam oscillator 30 is a device that emits a light beam L. FIG. The galvanomirror 31 is means for scanning the emitted light beam L onto the powder layer 22, that is, scanning means for the light beam L. As shown in FIG.

The cutting means 4 mainly includes a cutting tool 40 (end mill) and a drive mechanism 41, as shown in FIG. An end mill is a cutting tool for cutting the side surfaces of laminated solidified layers, that is, the surface of a three-dimensional modeled object. The drive mechanism 41 is means for moving the cutting tool 40 to a desired location to be cut.

The operation of the optical molding combined processing machine 1 will be described in detail. As shown in the flowchart of FIG. 11, the operation of the stereolithography composite processing machine 1 consists of a powder layer forming step (S1), a solidified layer forming step (S2) and a cutting step (S3). The powder layer forming step ( S<b>1 ) is a step for forming the powder layer 22 . In the powder layer forming step (S1), first, the modeling table 20 is lowered by Δt (S11) so that the level difference between the upper surface of the modeling plate 21 and the upper end surface of the modeling tank 29 becomes Δt. Next, after raising the powder table 25 by Δt, the squeegee blade 23 is horizontally moved from the powder material tank 28 toward the modeling tank 29 as shown in FIG. 9(a). As a result, the powder 19 placed on the powder table 25 can be transferred onto the modeling plate 21 (S12), and the powder layer 22 is formed (S13). Examples of the powder material for forming the powder layer 22 include "metal powder with an average particle size of about 5 μm to 100 μm" and "resin powder such as nylon, polypropylene or ABS with an average particle size of about 30 μm to 100 μm". can. After the powder layer 22 is formed, the process proceeds to the solidified layer forming step (S2). The solidified layer forming step (S2) is a step of forming the solidified layer 24 by light beam irradiation. In the solidified layer forming step (S2), the light beam L is emitted from the light beam oscillator 30 (S21), and the light beam L is scanned to a predetermined position on the powder layer 22 by the galvanomirror 31 (S22). As a result, the powder at predetermined portions of the powder layer 22 is sintered or melted and solidified to form a solidified layer 24 as shown in FIG. 9B (S23). As the light beam L, a carbon dioxide laser, Nd:YAG laser, fiber laser, direct diode laser (DDL), ultraviolet rays, or the like may be used.

The powder layer forming step (S1) and the solidified layer forming step (S2) are alternately repeated. As a result, a plurality of solidified layers 24 are stacked as shown in FIG. 9(c).

When the laminated solidified layer 24 reaches a predetermined thickness (S24), the process proceeds to the cutting step (S3). The cutting step (S3) is a step for cutting the side surface of the laminated solidified layer 24, that is, the surface of the three-dimensional shaped object. A cutting step is started by driving the cutting tool 40 (see FIGS. 9(c) and 10) (S31). Specifically, while moving the cutting tool 40 by the drive mechanism 41, the side surface of the laminated solidified layer 24 is cut (S32). At the end of such a cutting step (S3), it is determined whether or not a desired three-dimensional shaped object has been obtained (S33). If the desired three-dimensional shaped object has not yet been obtained, the process returns to the powder layer forming step (S1). After that, the powder layer forming step (S1) to the cutting step (S3) are repeatedly performed to further laminate the solidified layers and perform the cutting process, thereby finally obtaining the desired three-dimensional shaped object.

[Directed energy deposition method]
A manufacturing method according to an embodiment of the present invention is not limited to powder bed fusion bonding, but directed energy deposition may be used. The directed energy deposition method is a method of forming a solidified layer by performing material supply and light beam irradiation substantially simultaneously. In contrast to the powder bed fusion method, the directed energy deposition method has the feature of not forming a powder layer when obtaining a solidified layer. Powders or filler metals may be used as raw materials in directed energy deposition methods. In other words, in the directed energy deposition method, a light beam is applied to a raw material supply point, and powder or a filler material is directly supplied to the raw material supply point. A solidified layer is formed from the additive.

For example, when powder is used, the supplied powder is sintered or melted and solidified by light beam irradiation to directly form a solidified layer from the powder. Preferably, the powder is sprayed and supplied to the condensed portion of the light beam L of the light beam irradiation (that is, the irradiated portion of the light beam that is the raw material supply portion), thereby solidifying the powder by sintering or melting and solidifying it. form a layer. A powder feed nozzle may be used for atomized feeding of the powder. The powder type used in directed energy deposition may be the same as the powder type used in powder bed fusion bonding. That is, the powder in the directed energy deposition method may be the powder that constitutes the powder layer in the powder bed fusion method.

[Characteristic part of the present invention]
An embodiment of the present invention will be described below.

1. Powders used for manufacturing three-dimensional shaped articles The inventors of the present application have earnestly studied solutions for suitably improving the mechanical strength of the obtained three-dimensional shaped articles. As a result, the inventors of the present application have newly discovered that the finally obtained three-dimensional shaped product can have a unique configuration when using powder having the following characteristics (see FIG. 1).

Specifically, in one embodiment of the present invention, the powder used for manufacturing the three-dimensional shaped article may be the oxide powder 19A. In particular, in one embodiment of the present invention, the oxidized powder 19A comprises a main component _19A1 and a sub-component _19A2 , wherein the sub-component _19A2 is relatively more prone to oxide formation than the main component _19A1 . It's becoming

The term “oxidized powder” as used herein broadly refers to oxidized powder or oxidized powder, and narrowly refers to surface-oxidized powder or surface-oxidized powder. Furthermore, the "oxidized powder" as used herein may be in the form of a single substance containing both the main component and the sub-component, or an aggregate of the main powder containing the main component and the sub-powder containing the sub-component. Or it may be in the form of a mixture. The term "main component" as used herein broadly refers to a main component that constitutes the oxide powder and has a relatively higher content ratio than sub-components. The term “main component” as used herein narrowly means a main component that constitutes the oxide powder, and the proportion of the content in the entirety is 90% to 99.9% on a mass basis.

Further, the term "sub-component" as used in this specification broadly refers to a sub-component that constitutes the oxide powder and has a relatively lower content ratio than the main component. The term "sub-component" as used herein narrowly means a sub-component that constitutes the oxide powder and has a content ratio of 0.1% to 10% based on the total mass.

In one embodiment of the present invention, the main component _19A1 of the oxide powder 19A may contain at least 50% by mass or more of Fe-based component. Without being limited to this, the main component _19A1 of the oxide powder 19A may further contain, for example, a Cr-based component and a Ni-based component in addition to the Fe-based component. Although not particularly limited, the main component _19A1 of the oxide powder 19A may contain 0% by mass or more and less than 50% by mass of a Cr-based component and/or a Ni-based component.

As described above, the sub-component 19A- ₂ of the oxidized powder 19A is relatively more likely to form an oxide than the main component 19A- ₁ . Examples of the sub-component 19A- ₂ include Al, Y, It may contain at least one element selected from the group consisting of Zr, Mn, Hf, Ti, Ta and Si. It should be noted that the feature of the sub-component _19A2 , ``it is relatively easier to form an oxide than the main component _19A1 ,'' means that when the sub-component _19A2 contains a metal element, the free energy for oxide formation is is smaller than the constituent elements of the main component _19A1 .

Also, as described above, the oxidized powder 19A has an oxidized surface on the powder. One example of an oxidation treatment method is to heat-treat metal powders commonly used in powder bed fusion and/or directed energy deposition methods in a high-temperature furnace to force the powder to oxidize. The metal powder before the oxidation treatment is not particularly limited. For example, SUS316L (average particle diameter : 30 μm) can be used. As for the heat treatment conditions, it is desirable to treat the metal powder in a furnace (furnace atmosphere: air) at 500° C. for 2 hours. Oxidized powder 19A is obtained by forced oxidation of the metal powder accompanying this heat treatment. It should be noted here that the surface of the oxidized powder 19A has an oxide-rich layer due to the oxidation treatment, that is, a layer _19A3 having a relatively large amount of oxide. Specifically, on the surface of the oxidized powder 19A, a layer rich in the oxide derived from the main component _19A1 and the oxide derived from the sub-component _19A2 , that is, the layer _19A3 containing a relatively large amount of these oxides is formed. ing. As a result, the surface of the oxidized powder 19A may contain an oxygen component due to the oxidation treatment.

From the above, in one embodiment of the present invention, the powder (specifically, the oxidized powder 19A) used for manufacturing the three-dimensional shaped article includes (1) the main component 19A In addition to ₁ , the main The point of using a subcomponent _19A2 that is relatively more likely to form an oxide than the component _19A1 , and (2) an oxygen component that is intentionally included due to the oxidation treatment of the surface. It is characterized by

(Common technical knowledge of a person skilled in the art)
In addition, according to the common technical knowledge of a person skilled in the art in the field of additive manufacturing, it can be interpreted as follows (see FIG. 2).

Specifically, the conventional powder 19' is generally composed of components or materials that form the base (main body) of the finally obtained three-dimensional shaped article 100'. Under this circumstance, it is not easy for those skilled in the art to intentionally and positively oxidize the surface of this conventional powder 19'.

The reason is as follows. The conventional powder 19' may mainly contain an Fe-based component as a constituent material or component of the base of the three-dimensional shaped article 100'. When the surface of the conventional powder 19' mainly containing Fe-based components is oxidized, the powder 19' will contain an oxygen component. Therefore, during the production of the three-dimensional shaped article 100', the Fe-based component and the oxygen component, which are the main component 19α' contained in the conventional powder 19', are combined, and the strength is relatively higher than that of the main component 19α' itself. Low iron oxide may be produced.

Based on the above, those skilled in the art believe that the finally obtained three-dimensional shaped article 100' may contain unintended oxides, and the strength of the three-dimensional shaped article 100' may rather decrease. is normal. Therefore, as described above, it is not easy for a person skilled in the art to intentionally and positively oxidize the surface of the conventional powder 19'.

Further, as a conventional aspect, a mixed powder comprising a first powder having components corresponding to the main component and the sub-components of the present invention, and a second powder supported on the surface of the first powder. (see Patent Document 2). This second powder contains an oxide of a component (Fe) corresponding to the main component referred to in the present invention. In such a conventional embodiment, when the mixed powder is melted using a laser or the like, the oxygen contained in the unstable oxide of the second powder forms a solid phase within the crystal grains of the mother phase composed of the component corresponding to the main component. Oxygen that has diffused and solid-phase diffused reacts with the component corresponding to the sub-component to form the oxide of the sub-component.

On the other hand, the oxidized powder of the present invention corresponds to the first powder having the components corresponding to the main component and the sub-component, and the surface of the first powder is oxidized. It differs in that it does not contain powder.

As will be described later, the sub-component oxide contributes to the improvement of the strength of the finally obtained shaped article. In this regard, in the conventional embodiment, the oxygen, which is the raw material for forming the sub-component oxide that contributes to the improvement of the strength of the shaped article, is contained in the oxide of the component (Fe) corresponding to the main component in the present invention. be. On the other hand, in the present invention, oxygen, which is a raw material for forming the sub-component oxide that contributes to the strength improvement of the modeled object, is oxidized from the main component _19A1 contained in the surface of the oxidized powder 19A along with the surface oxidation treatment. and subcomponent _19A2 -derived oxides.

From the above, in the conventional embodiment, oxygen, which is a raw material for forming the oxide of the sub-component that contributes to the strength improvement of the shaped article, is mixed with the first powder "having the components corresponding to the main component and the sub-component." The second powder "containing an oxide of a component (Fe) corresponding to the main component" is procured by separately preparing it. On the other hand, in the oxidized powder of the present invention, oxygen, which is a raw material for forming the oxide of the sub-component that contributes to the improvement of the strength of the model, is added to the "main component and By surface-oxidizing the surface of the powder having subcomponents (corresponding to the conventional first powder) itself, the oxide derived from the main component _19A1 and the oxide derived from the subcomponent _19A2 are procured. In this respect, the present invention differs from the conventional embodiment in terms of an approach to procuring oxygen, which is a raw material for forming the sub-component oxide that contributes to the improvement of the strength of the shaped article.

2. Method for Manufacturing a Three-Dimensional Shaped Object of the Present Invention Next, a method for manufacturing a three-dimensional shaped object according to one embodiment of the present invention will be described. A manufacturing method according to an embodiment of the present invention assumes that at least one of a powder bed fusion method and a directed energy deposition method is used. That is, the manufacturing method according to one embodiment of the present invention described below is premised on manufacturing a three-dimensional shaped object by sequentially forming a plurality of solidified layers by irradiating powder with a light beam (Fig. 3).

A manufacturing method according to an embodiment of the present invention is characterized in that at least the oxidized powder 19A described above is used as the powder to which the light beam L is irradiated. As described above, the oxidized powder 19A has an oxidized surface and comprises a main component _19A1 and _a subcomponent _19A2 that is relatively more likely to form an oxide than the main component 19A1. .

A manufacturing method according to an embodiment of the present invention will be specifically described below (see FIG. 4). In addition, in FIG. 4, it is premised that a three-dimensional modeled object composed of two solidified layers along the stacking direction is manufactured.

(a) Step of supplying oxidized powder 19A onto molding plate 21 and irradiating oxidized powder 19A with a light beam (see FIGS. 4(a), 5(a) and 6(a))
First, the oxidized powder 19A is supplied onto the modeling plate 21, and the light beam L is irradiated onto the oxidized powder 19A. As the irradiation mode of the light beam L, the powder bed fusion method may be used as described above, or the directional energy deposition method may be used.

(b) Step of forming melted portion 50 (see FIG. 4(b))
The irradiation of the light beam L melts the oxide powder b19A, thereby forming the melted portion 50. As shown in FIG.

As described above, the oxidized powder 19A includes (1) a main component 19A ₁ and a sub-component 19A ₂ that is relatively easier to form an oxide than the main component 19A ₁ (i.e., is relatively easy to oxidize). and (2) containing an oxygen component due to surface oxidation treatment.

Therefore, when the oxidized powder 19A having the characteristic is irradiated with the light beam L (see FIG. 4A), the temperature of the oxidized powder 19A rises due to the heat converted from the light energy by the light absorption of the oxidized powder 19A. Then, the oxide powder 19A melts. At the same time, the subcomponent _19A2 combines with the oxygen component contained in the oxide powder 19A to form the oxide of the subcomponent. The generation of such oxides is due to the fact that the sub-component 19A- ₂ is relatively more likely to generate oxides than the main component 19A- ₁ , as described above. In addition, most of the oxide of the subcomponent mainly moves to the upper surface region side of the melt portion 50 containing the main component. At this time, not all of the sub-component oxide moves to the upper surface region of the melt portion 50, but part of it remains in the inner region of the melt portion 50 (see FIG. 4(b)).

In this state, the remaining oxides of the subcomponents can exist stably against heat. An entity 201 may be produced. In addition, since the sub-component oxide that has migrated to the upper surface region side of the melt pool 50 can exist stably against heat, the upper surface region of the first solidified layer 24A obtained by solidifying the melt portion 50 , an oxide 202 (specifically, an oxide film) derived from the sub-component may be produced.

(c) Step of supplying oxidized powder 19A onto the first solidified layer 24A and irradiating the oxidized powder 19A with a light beam (see FIG. 4(c))
The oxidized powder 19A is supplied onto the formed first solidified layer 24A, and the oxidized powder 19A is irradiated with a light beam.

When the oxidized powder 19A is irradiated with a light beam, the temperature of the oxidized powder 19A rises due to the heat converted from the light energy by the light absorption of the oxidized powder 19A, and the oxidized powder 19A melts. At the same time, the subcomponent _19A2 combines with the oxygen component contained in the oxide powder 19A to form the oxide of the subcomponent. In addition, most of the oxide 202 derived from the sub-component located in the upper surface region of the first solidified layer 24 is not reduced (without releasing oxygen) after being melted once, and the melt portion mainly containing the main component is to the upper surface region side of the At this time, rather than all of the sub-component oxide migrating to the upper surface region of the melt portion 50, some of the sub-component oxide remains in the interior region of the melt portion.

In this state, the remaining oxides of the sub-components exist stably against heat, so that the oxides 201 derived from the sub-components scattered in the second solidified layer 24B obtained by solidifying the melted portion. can be generated. In addition, since the oxides of the sub-components that have migrated to the upper surface region of the melt pool 50 exist stably with respect to heat, the upper surface region of the second solidified layer 24B obtained by solidifying the melt portion 50 is , a subcomponent-derived oxide 202 (specifically, an oxide film) may be produced.

(d) Step of forming a three-dimensional shaped object (see FIGS. 4(d), 5(b) and 6(b))
As described above, a three-dimensional shaped article according to an embodiment of the present invention can be manufactured. 4(d), 5(b), and 6(b) differ in the cross-sectional shape of the illustrated three-dimensional shaped object, but have the following common features: A three-dimensional shaped article according to an embodiment of the present invention has technical significance.

As described above, in the conventional embodiment (see Patent Literature 2), oxygen, which is a raw material for forming the sub-component oxide that contributes to the strength improvement of the shaped article, is obtained from the second powder that does not contain the sub-component. . On the other hand, in the present invention, the oxygen, which is the raw material for forming the oxide of the sub-component that contributes to the improvement of the strength of the shaped article, is the oxide derived from the main component _19A1 and the sub-component _19A2 provided to the surface of the oxidized powder by the oxidation treatment. derived from oxides. Comparing the previous embodiment with the present invention, the conventional embodiment does not contain a component corresponding to a sub-component, whereas the present invention can contain a sub-component. are different. It is understood that due to such a difference, the manner of formation of the oxides of the sub-components to be obtained also differs.

Specifically, in the conventional embodiment, oxygen solid-phase diffuses into the matrix phase composed of the component corresponding to the main component, and the solid-phase-diffused oxygen reacts with the component corresponding to the sub-component, thereby forming the sub-component. Oxides are formed for the first time. Therefore, it is basic to disperse the sub-component oxides that contribute to the strength improvement of the modeled product to the "inside" of the finally obtained modeled product.

In contrast, as described above, in the present invention, the oxidized powder 19A irradiated with the light beam may contain subcomponents not only in the internal region but also in the surface region. Therefore, due to this, most of the oxide of the sub-component obtained by combining the sub-component and oxygen tends to be formed in the upper surface region of the modeled object obtained after irradiating the oxidized powder 19A with the light beam. , part of which remains in the internal region of the modeled object.

From the above, in the present invention, the surface of the oxidized powder to which the light beam is irradiated can also contain the sub-components, compared to the conventional embodiments. There is a difference in the form of oxide formation.

3. Three-dimensional shaped article of the present invention Next, a three-dimensional shaped article according to one embodiment of the present invention obtained by the above-described manufacturing method will be described (see FIG. 7).

As a result of confirming the structure of the obtained three-dimensional shaped article, the following facts were newly found. Specifically, the three-dimensional shaped article 100 according to one embodiment of the present invention includes a base portion 101 (corresponding to a main body portion) composed of a main component and a sub-part that is relatively more easily oxidized than the main component. 200 of the constituent oxides.

In particular, in one embodiment of the present invention, the subcomponent oxide 200 is scattered in the inner region 101a of the base 101 of the three-dimensional shaped article 100, and part of the surface region 101b of the base 101. generated. In particular, in one embodiment of the present invention, a layered oxide (corresponding to an oxide film) is formed not only in the internal region but also in part of the surface region. In one aspect, the oxide of the subcomponent is produced so as to be exposed on the surface region of the three-dimensional shaped article. That is, it is possible to detect oxides as subcomponents in the surface region 101b of the three-dimensional shaped article 100 by elemental analysis such as energy dispersive X-ray spectrometry (EDX).

In one embodiment of the present invention, the sub-component oxide 201 is scattered in the inner region of the base 101 of the three-dimensional shaped article 100 so as to form particles, and the sub-component oxide 201 forms particles. 201 has a nanometer size. Although not particularly limited, the sub-component oxide 201 in particulate form can have a size of 10 nm to 500 nm, for example about 100 nm. Although not particularly limited, the distance between adjacent sub-component oxides 201 among the scattered sub-component oxides 201 may be 50 nm to 500 nm, for example, 200 nm.

The main component that can be the constituent material of the base 101 of the three-dimensional shaped article 100 according to one embodiment of the present invention can contain at least 50% by mass or more of the Fe-based component. Without being limited to this, the main component may further include, for example, a Cr-based component and a Ni-based component in addition to the Fe-based component. Although not particularly limited, the main component may contain 0% by mass or more and less than 50% by mass of a Cr-based component and/or a Ni-based component.

Further, the above sub-components are relatively easier to oxidize than the main component, that is, they are more likely to generate oxides. Examples of the sub-components include Al, Y, Zr, Mn, Hf, Ti, Ta and It may contain at least one element selected from the group consisting of Si. It should be noted that the feature of the sub-component, ``relatively oxidizable compared to the main component,'' means that when the sub-component contains a metal element, the free energy of oxide formation is smaller than that of the constituent elements of the main component. can be understood as

Then, in one embodiment of the present invention, when the oxides of the sub-components are scattered, that is, dispersed, in the interior of the obtained three-dimensional shaped article 100, the oxides of the sub-components that are scattered are It becomes possible to contribute to the overall strength improvement of the three-dimensional shaped article 100 . As a result, the mechanical strength of the obtained three-dimensional shaped article 100 can be favorably improved. Specifically, it is possible to improve the overall tensile strength, elongation at break, creep strength, fatigue strength, etc. of the three-dimensional shaped article 100 obtained. In particular, as described above, when the sub-component oxide 201 in the form of particles has a nanometer size, the effect of improving the overall strength of the three-dimensional shaped article 100 can be significant.

In addition, in the three-dimensional shaped article according to one embodiment of the present invention, an oxide (corresponding to an oxide film) having a layered form is formed not only on the internal region but also on a part of the surface region. If the oxide film formed on the surface region is not cut, the oxide film can be used as a heat-resistant film, for example.

In the field of iron and steel, which is different from the field of additive manufacturing, the existence of a structure in which metal oxides (eg, yttrium oxide) are interspersed is already known. In this regard, the three-dimensional shaped article according to one embodiment of the present invention is not only the internal region but also The structure is different in that an oxide film is also formed on part of the surface region. In this respect, it can be said that the three-dimensional shaped article according to one embodiment of the present invention has a unique structure. That is, in one embodiment of the present invention, the resulting three-dimensional shaped article 100 is not the conventionally known "oxide dispersion strengthened alloy" but "oxide internal dispersion and oxide surface exposed strengthening". can function as an alloy.

Although one embodiment of the present invention has been described above, it is merely a typical example within the scope of application of the present invention. Therefore, those skilled in the art will easily understand that the present invention is not limited to this and that various modifications can be made.

For example, in the above description, the aspect of finally obtaining the three-dimensional shaped article 100 using the oxide powder 19A according to one embodiment of the present invention has been described (see FIGS. 3 to 7). Without being limited to this, in the stage of manufacturing a three-dimensional shaped article, the oxide powder 19A according to one embodiment of the present invention and the normal powder 19 are used to manufacture a predetermined three-dimensional shaped article. you can go The “ordinary powder 19” referred to here means that the surface is not oxidized and is composed of main components (at least one selected from the group consisting of Fe-based components, Cr-based components and Ni-based components). refers to a powder that

Specifically, when using the obtained three-dimensional shaped article, for a portion that requires a high degree of resistance to external pressure etc. (for example, the base 101 of the three-dimensional shaped article in FIG. 8), this It is preferable to use oxidized powder 19A according to an embodiment of the invention. On the other hand, for portions that do not particularly require or require a low degree of resistance to pressure from the outside (for example, the base 102 of the three-dimensional shaped article in FIG. 8), the above-described ordinary powder 19' may be used. This makes it possible to selectively change the configuration of the three-dimensional shaped article to be obtained.

Further, as described above, in one embodiment of the present invention, the oxidized powder is not only in a single form containing both the main component and the sub-component, but also contains the main powder containing the main component and the sub-component. It may be in the form of an aggregate or mixture with sub-powder. When the main powder containing the main component and the sub-powder containing sub-components take the form of an aggregate or mixture, the oxidized powder corresponds to an aggregate or mixture whose surface has been oxidized.

Even in the case of such an aggregate or mixture form, the oxidized powder itself contains the main component and the subcomponents. Therefore, as described above, the three-dimensional shaped article obtained using the oxide powder may contain oxides of sub-components interspersed therein. Therefore, it is possible to preferably improve the mechanical strength of the obtained three-dimensional shaped product because the scattered oxides of the sub-components contribute to the improvement of the overall strength of the three-dimensional shaped product. Become.

One embodiment of the present invention as described above includes the following preferred aspects.
First aspect :
A method for manufacturing a three-dimensional object by sequentially forming a plurality of solidified layers by irradiating a powder with a light beam,
Using at least an oxidized powder whose surface has been oxidized as the powder,
A manufacturing method, wherein the oxidized powder comprises a main component and a sub-component that is more likely to form an oxide than the main component.
Second aspect :
The manufacturing method according to the first aspect, wherein the oxide powder containing the oxide of the main component and the oxide of the sub-component is used on the surface.
Third aspect :
The manufacturing method according to the second aspect, wherein the oxide powder having the oxide-rich layer on the surface is used.
Fourth aspect :
The manufacturing method according to any one of the first to third aspects, wherein the sub-component of the oxidized powder is relatively easier to oxidize than the main component upon irradiation with the light beam.
Fifth aspect :
The manufacturing method according to any one of the first to fourth aspects, wherein the oxidized powder contains oxygen due to the oxidation treatment of the surface.
Sixth aspect :
In the fifth aspect, the sub-component and the oxygen contained in the oxidized powder make it possible for the oxide of the sub-component to be scattered at least in an internal region of the three-dimensional shaped article to be manufactured, A manufacturing method, wherein the oxidized powder is irradiated with the light beam.
Seventh aspect :
The manufacturing method according to any one of the first to sixth aspects, wherein the main component of the oxide powder contains 50% by mass or more of an Fe-based component.
Eighth aspect :
A manufacturing method according to any one of the first to seventh aspects, wherein the sub-component of the oxide powder comprises an element having a lower free energy of oxide formation than the element contained in the main component.
Ninth aspect :
In the eighth aspect above, the subcomponent of the oxide powder comprises at least one element selected from the group consisting of Al, Y, Zr, Mn, Hf, Ti, Ta and Si. Method.
Tenth aspect :
The manufacturing method according to any one of the first to ninth aspects, wherein the solidified layer is formed by a powder bed fusion method.
Eleventh aspect :
The manufacturing method according to any one of the first to tenth aspects, wherein the solidified layer is formed by a directed energy deposition method.
Twelfth aspect :
A three-dimensional shaped object,
comprising a base composed of a main component and a sub-component oxide that is relatively easier to oxidize than the main component,
A three-dimensional shaped article, wherein said oxide of said sub-component is interspersed in an interior region of said base and formed on a part of a surface region of said base.
Thirteenth Aspect :
The three-dimensional shaped article according to the twelfth aspect, wherein the oxide of the subcomponent is formed in a layered form in the surface region.
Fourteenth Aspect :
The three-dimensional shaped article according to the twelfth or thirteenth aspect, wherein the oxide of the subcomponent is exposed in the surface region.
Fifteenth Aspect :
In any one of the twelfth to fourteenth aspects, the oxide of the sub-component is scattered in the inner region so as to form particles, and the oxidation of the sub-component in the form of particles A three-dimensional shaped article, wherein the article has a nanometer size.
Sixteenth Aspect :
In the fifteenth aspect, the three-dimensional shaped article, wherein the size of the oxide of the subcomponent in the form of particles is 10 nm to 500 nm.
Seventeenth Aspect :
An oxidized powder used for manufacturing a three-dimensional shaped object,
An oxidized powder having an oxidized surface and comprising a main component and a sub-component that is relatively more likely to form an oxide than the main component.
Eighteenth Aspect :
In the seventeenth mode, the oxide powder, wherein the oxide of the main component and the oxide of the sub-component are formed on the surface.
Nineteenth aspect :
The oxidized powder according to the eighteenth aspect, wherein the oxide-rich layer is present on the surface.
Twentieth aspect :
In any one of the 17th to 19th aspects, the oxidized powder contains oxygen due to the oxidation treatment of the surface.
Twenty-first aspect :
The oxidized powder according to the twentieth aspect, wherein the oxide of the sub-component can be interspersed in at least an internal region of the three-dimensional shaped article to be manufactured by the sub-component and the oxygen.
Twenty-Second Aspect :
The oxide powder according to any one of the 17th to 21st aspects, wherein the main component contains 50% by mass or more of an Fe-based component.
Twenty-third aspect :
The oxide powder according to any one of the 17th to 22nd aspects, wherein the sub-component contains an element having an oxide formation free energy lower than that of the element contained in the main component.
Twenty-fourth aspect :
The oxide powder according to the twenty-third aspect, wherein the subcomponent comprises at least one element selected from the group consisting of Al, Y, Zr, Mn, Hf, Ti, Ta and Si.

Various articles can be manufactured by carrying out the method for manufacturing a three-dimensional shaped article according to one embodiment of the present invention. For example, in the case where the powder layer is an inorganic metal powder layer and the solidified layer is a sintered layer, the resulting three-dimensional shaped object is molded using a plastic injection mold, a press mold, a die-cast mold, It can be used as a mold for casting and forging.

Cross-reference to related applications

This application is Japanese Patent Application No. 2019-164418 (filing date: September 10, 2019, title of the invention: "Method for manufacturing three-dimensional shaped article, three-dimensional shaped article, and three-dimensional shaped article claiming priority under the Paris Convention based on oxidized powder used for the manufacture of The entire disclosure of that application is hereby incorporated by reference.

100, 100' Three-dimensional shaped article 101 Base portion (main body portion) of three-dimensional shaped article
19A oxidized powder 19A ₁ main component of oxidized powder 19A ₂ sub-components of oxidized powder 19A ₃ oxide-rich layers 24A, 24B solidified layers 200 oxide 201 oxide scattered in the inner region of the base of the three-dimensional shaped object 202 Oxides formed on the surface region of the base of the three-dimensional shaped object

Claims (23)

A method for manufacturing a three-dimensional object by sequentially forming a plurality of solidified layers by irradiating a powder with a light beam,
Using at least an oxidized powder whose surface has been oxidized as the powder,
The oxidized powder comprises a main component and a sub-component that is more likely to form an oxide than the main component,
the main component and the sub-component each contain a metal element,
The production method , wherein the content of the sub-component in the entire oxide powder is 0.1% by mass to 10% by mass . 2. The manufacturing method according to claim 1, wherein the oxide powder containing the oxide of the main component and the oxide of the sub-component is used on the surface. 3. The manufacturing method according to claim 2, wherein the oxidized powder having the oxide-rich layer on the surface is used. 4. The manufacturing method according to any one of claims 1 to 3, wherein the sub-component of the oxidized powder is relatively easier to oxidize than the main component when irradiated with the light beam. The manufacturing method according to any one of claims 1 to 4, wherein the oxidized powder contains oxygen due to the oxidation treatment of the surface. The sub-component and the oxygen contained in the oxidized powder allow the oxide of the sub-component to be scattered in at least an internal region of the three-dimensional shaped article to be manufactured. 6. The manufacturing method according to claim 5, wherein irradiation with a light beam is performed. The production method according to any one of claims 1 to 6, wherein the main component of the oxide powder contains 50% by mass or more of Fe-based component. 8. The manufacturing method according to any one of claims 1 to 7, wherein said sub-component of said oxide powder comprises an element having a lower free energy of oxide formation than an element contained in said main component. 9. Manufacture according to claim 8, wherein said subcomponents of said oxidized powder comprise at least one element selected from the group consisting of Al, Y, Zr, Mn, Hf, Ti, Ta and Si. Method. The manufacturing method according to any one of claims 1 to 9, wherein the solidified layer is formed by a powder bed fusion method. The manufacturing method according to any one of claims 1 to 10, wherein the solidified layer is formed by directed energy deposition. A three-dimensional shaped object,
comprising a base composed of a main component and a sub-component oxide that is relatively easier to oxidize than the main component,
the main component and the sub-component each contain a metal element,
The content ratio of the sub-component in the three-dimensional shaped article is 0.1% by mass to 10% by mass,
A three-dimensional shaped article, wherein said oxide of said sub-component is interspersed in an interior region of said base and formed on a part of a surface region of said base. 13. The three-dimensional shaped article of claim 12, wherein said oxides of said subcomponents are formed in layered form at said surface regions. 14. The three-dimensional shaped article according to claim 12 or 13, wherein said oxide of said subcomponent is produced so as to be exposed at said surface region. 15. The method of claims 12 to 14, wherein said oxide of said sub-component is interspersed in said inner region in a form of particles, said oxide of said sub-component in said form of particles having a nanometer size. The three-dimensional modeled article according to any one of the above. 16. The three-dimensional shaped article according to claim 15, wherein the size of the oxide of the subcomponent in the form of particles is from 10 nm to 500 nm. An oxidized powder used for manufacturing a three-dimensional shaped object,
The surface is oxidized and comprises a main component and a sub-component that is relatively more likely to generate oxides than the main component,
the main component and the sub-component each contain a metal element,
The content of the subcomponent in the entire oxide powder is 0.1% by mass to 10% by mass,
an oxide of the main component and an oxide of the sub-component are formed on the surface;
oxidized powder. 18. The oxidized powder of claim 17, wherein the oxide-rich layer is present on the surface. 19. Oxidized powder according to claim 17 or 18 , containing oxygen due to said oxidation treatment of the surface. 20. The oxidized powder according to claim 19 , wherein the sub-component and the oxygen allow the oxide of the sub-component to be interspersed in at least an internal region of the three-dimensional shaped article to be manufactured. The oxidized powder according to any one of claims 17 to 20 , wherein said main component contains 50% by mass or more of an Fe-based component. 22. The oxidized powder according to any one of claims 17 to 21, wherein said sub-component comprises an element having an oxide free energy of formation lower than that of the element contained in said main component. 23. The oxidized powder of claim 22 , wherein said subcomponent comprises at least one element selected from the group consisting of Al, Y, Zr, Mn, Hf, Ti, Ta and Si.

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