Inorganic structure and method for producing inorganic structure

Abstract

Provided are: an inorganic structure having different mechanical properties depending on parts; and a method for producing the inorganic structure. An inorganic structure (1) according to an embodiment of the present invention is provided with a plurality of solidified parts (SA) comprising an inorganic material. The plurality of solidified sections (SA) include a first solidified section (SA1) and a second solidified section (SA2), the first solidified section (SA1) being preferentially oriented in a first crystal orientation (CO1), and the second solidified section (SA2) being preferentially oriented in a second crystal orientation (CO2) that is a different orientation from the first crystal orientation (CO1).

Description

Technical Field

[0001] The present disclosure relates to an inorganic structure composed of an inorganic material and a method for manufacturing the same, and more specifically, to an inorganic structure formed by a layered modeling method using an additive manufacturing technology AM (Additive Manufacturing) and a method for manufacturing the same. Background Art

[0002] Inorganic structures made of ceramics or metals are sometimes used in medical implants such as artificial joints and bone plates, mobile objects such as automobiles, airplanes, and ships, or industrial equipment such as factory equipment and manufacturing equipment. For such inorganic structures, mechanical properties such as Young's modulus, strength, and impact absorption are required depending on the application.

[0003] For example, when inorganic structure is applied to medical implant, sometimes the inorganic structure is required to have a Young's modulus equal to that of biological bone. However, the Young's modulus of solid inorganic structure is higher than that of biological bone. Therefore, when solid inorganic structure is embedded in organism as implant, due to the difference of Young's modulus, biological bone at the interface of biological bone and implant will be destroyed, or normal stress will not be loaded on biological bone. Such phenomenon is called stress blocking. In order to suppress stress blocking, it is necessary to adjust the Young's modulus of inorganic structure to be equal to that of biological bone.

[0004] In addition, when an inorganic structure is applied to a mobile body, the mechanical properties required by the inorganic structure are different depending on the position in the mobile body. For example, for an inorganic structure, a high Young's modulus is sometimes required at a certain position, and a low Young's modulus is required at other positions. In the past, inorganic structures were made of solid metals, etc., and the metals as raw materials were hot-worked or cold-worked to form inorganic structures of a specified shape. However, for inorganic structures formed by previous manufacturing processes, it is difficult to have different mechanical properties depending on the position.

[0005] Therefore, the present inventors proposed inorganic structures capable of adjusting mechanical properties in Japanese Patent Application Laid-Open No. 2011-136083 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2013-94390 (Patent Document 2).

[0006] The structures disclosed in Patent Documents 1 and 2 have a solidified portion formed by melting inorganic powder particles, and a sintered portion formed by sintering inorganic powder particles and combined with the solidified portion. The sintered portion has a gap inside, so the density is lower than that of a solid material. Therefore, the inorganic structure disclosed in Patent Document 1 can reduce the elastic modulus compared to a solid inorganic structure. Such an inorganic structure can be formed, for example, by a stacking modeling method of AM (Additive Manufacturing), an additive manufacturing technology.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2011-136083

[0010] Patent Document 2: Japanese Patent Application Publication No. 2013-94390 Summary of the invention

[0011] Problem that the invention aims to solve

[0012] In Patent Documents 1 and 2, the density of each part of the inorganic structure is adjusted to provide different mechanical properties for each part. However, it is also possible to provide different mechanical properties for each part by other means.

[0013] An object of the present disclosure is to provide an inorganic structure having different mechanical properties depending on the location, and a method for producing the same.

[0014] Solutions for solving problems

[0015] The inorganic structure disclosed in the present invention has a plurality of solidified parts composed of inorganic materials. The plurality of solidified parts include a first solidified part and a second solidified part. The crystal direction in a predetermined direction of the first solidified part is preferentially oriented along the first crystal direction. The crystal direction in the predetermined direction of the second solidified part is preferentially oriented along a second crystal direction that is different from the first crystal direction.

[0016] In the inorganic structure of the present invention, the first solidification portion and the second solidification portion are preferentially oriented along mutually different crystal directions. Therefore, the first solidification portion and the second solidification portion have mutually different mechanical properties. Therefore, the inorganic structure of this embodiment has different mechanical properties depending on the location.

[0017] Preferably, the solidified portion includes a plurality of sub-solidified regions each surrounded by a plurality of molten pool interfaces. The sub-solidified region includes a plurality of unit cells and a plurality of unit cell interfaces that are interfaces between unit cells adjacent to each other.

[0018] In this case, mechanical properties such as strength and Young's modulus are improved through the unit cells and unit cell interfaces.

[0019] It is preferred that the first solidified portion has a shape different from that of the second solidified portion.

[0020] In this case, the inorganic structure has different mechanical properties depending on the location due to the difference in crystal orientation and shape.

[0021] Preferably, the sub-solidified region includes a plurality of unit cell regions each composed of a plurality of unit cells and a layered interface as an interface between adjacent unit cell regions. In the layered interface, the crystal direction of one of the adjacent unit cell regions is preferentially oriented in an orientation different from the crystal direction of the other unit cell region.

[0022] In this case, solute segregation at the atomic level occurs in the lamellar interface, and mechanical properties such as strength and Young's modulus are improved by the solute segregation.

[0023] Preferably, the sub-solidified region includes a plurality of unit cell regions each consisting of a plurality of unit cells and an association interface as an interface between adjacent unit cell regions. In the association interface, the crystal direction of one of the adjacent unit cell regions is preferentially oriented along the same direction as the crystal direction of the other unit cell region.

[0024] In this case, solute segregation occurs at the bond interface at the atomic level, and mechanical properties such as strength and Young's modulus are improved by the solute segregation.

[0025] Preferably, the inorganic structure further includes a sintered portion which is a sintered body of an inorganic material.

[0026] In this case, the inorganic structure has different mechanical properties depending on the location due to the difference in crystal orientation and the difference in morphology (solidified portion or sintered portion).

[0027] Preferably, a gap is formed between adjacent solidified portions.

[0028] In this case, the inorganic structure has different mechanical properties depending on the location due to the difference in crystal orientation and shape.

[0029] Preferably, in the first solidified portion, the crystal direction in the stacking direction is along <001> , <011> and <111> In the second solidification part, the crystal direction in the stacking direction is along <001> , <011> and <111> The material is preferably oriented in any one of the crystal directions and in a crystal direction different from the crystal direction of the first solidified part.

[0030] In this case, the first solidified portion and the second solidified portion are preferentially oriented along mutually different crystal directions. Therefore, the inorganic structure has different mechanical properties depending on the location.

[0031] The solidified portion is preferably composed of a single crystal, a quasi-single crystal, or a polycrystal.

[0032] The manufacturing method of the inorganic structure disclosed in the present invention comprises a design process and a forming process. In the design process, a scanning method of a beam used to form the inorganic structure to be manufactured is determined. In the forming process, the beam is scanned based on the scanning method of the beam determined in the design process, and the inorganic powder particles that will become the raw material of the inorganic structure are melted to form the inorganic structure. The design process includes: a process of dividing the inorganic structure to be manufactured into a plurality of solidified layers in the stacking direction; a process of dividing each solidified layer into a plurality of solidified regions when viewed from the stacking direction; an orientation determination process; and a scanning method determination process. In the orientation determination process, the orientation of the crystal direction of each solidified region is determined based on the mechanical properties required by each solidified region. In the scanning method determination process, the scanning method of the beam in each solidified region is determined based on the determined crystal direction orientation. In the forming process, the layer forming process and the melting process are alternately repeated, and a plurality of solidified layers are stacked to form an inorganic structure having the above-mentioned structure. In the layer forming process, inorganic powder particles are supplied to a base to form an inorganic powder layer. In the melting step, the beam is scanned based on the beam scanning method determined in the scanning method determining step to melt the inorganic powder layer, thereby forming a solidified layer composed of a plurality of solidified regions having the crystal orientation determined in the orientation determining step.

[0033] In the production method of the present invention, the inorganic structure of the present disclosure having the above-mentioned configuration can be produced.

[0034] Preferably, in the orientation determination step, the crystal orientation of the stacking direction of each solidification region is determined to be <001> , <011> and <111> In the scanning method determination step, when determining <001> In the solidification region of the crystal direction, the scanning direction of the beam when forming the j-th (j is a natural number) solidification layer is adjusted to be orthogonal to the scanning direction of the beam when forming the j-1th solidification layer as the lower layer of the j-th layer. <011> In the solidification region of the crystal direction, the scanning direction of the beam when forming the j-th solidification layer is adjusted to be parallel to the scanning direction of the beam when forming the j-1-th solidification layer. <111> In the solidification region of the crystal direction, the scanning direction of the beam when forming the j-th solidified layer is adjusted to intersect the scanning direction of the beam when forming the j-1-th solidified layer at 120 degrees.

[0035] In this case, the crystal orientation of the stacking direction of the solidified portion can be along <001> , <011> and <111> Any one of them is preferred.

[0036] Preferably, in the scanning method determination step, the scanning method of the beam includes information on a scanning path of the beam in the solidification region of the reference size. In the melting step, when the solidification region to be melted is smaller than the solidification region of the reference size, the beam is irradiated at a portion of the scanning path of the beam that overlaps with the solidification region to be melted, and the beam irradiation is stopped at a portion of the scanning path of the beam that does not overlap with the solidification region to be melted.

[0037] In this case, even a solidification region with a smaller size than the solidification region with the size that becomes the benchmark will melt with the same thermal history as the solidification region with the size that becomes the benchmark. As a result, even a solidification region with a smaller size can obtain the same solidification structure as the solidification region with the size that becomes the benchmark. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a perspective view showing an example of the inorganic structure according to the present embodiment.

[0039] Figure 2 It is a perspective view of the inorganic structure according to the first embodiment.

[0040] Figure 3 It is to illustrate Figure 2 A three-dimensional diagram showing the separation of the solidified parts in the image.

[0041] Figure 4 This is a diagram showing the relationship between the crystal orientation and Young's modulus when the inorganic material is a titanium alloy and the solidified portion is a single crystal.

[0042] Figure 5 Yes means Figure 2 Schematic diagram of the microstructure of the solidified part of the inorganic structure.

[0043] Figure 6 This is a graph showing the relationship between the presence or absence of a cell interface in a solidified portion and the hardness (GPa) measured by a nanoindentation method.

[0044] Figure 7 It is a perspective view of the inorganic structure of the second embodiment.

[0045] Fig. 8A It means Figure 5 Photographic images of the microstructure of different sub-solidification zones.

[0046] Figure 8B yes Fig. 8A Schematic diagram of a photographic image.

[0047] Fig. 9A It means Figure 5 , Fig. 8A and Figure 8BPhotographic images of the microstructure of different sub-solidification zones.

[0048] Fig. 9B yes Fig. 9A Schematic diagram of a photographic image.

[0049] Fig. 9C yes Fig. 9A A stereogram of the sub-solidification region is shown.

[0050] Fig. 10A The crystal orientation of the stacking direction Z is <001> Schematic diagram of the microstructure of the sub-solidification zone at .

[0051] Fig. 10B yes Fig. 10A A stereogram of the sub-solidification region is shown.

[0052] Fig.11A The crystal orientation of the stacking direction Z is <111> Stereoscopic image of the sub-solidification area at the time of .

[0053] Fig. 11B The crystal orientation from the stacking direction Z to the stacking direction Z is <111> Schematic diagram obtained by observing the inorganic structure 1.

[0054] Fig.12 is with Figure 2 Perspective views of inorganic structures according to various embodiments.

[0055] Fig.13 is with Fig.12 Perspective views of inorganic structures according to various embodiments.

[0056] Fig.14 It is a perspective view of an inorganic structure according to a sixth embodiment.

[0057] Fig.15 This is a diagram showing the relationship between various inorganic structures having different shapes and crystal orientations and Young's modulus in the X direction, Y direction, and Z direction.

[0058] Fig.16 It is a schematic diagram of a stacking molding apparatus for manufacturing the inorganic structure of this embodiment.

[0059] Fig.17 This is a flowchart of the method for producing the inorganic structure according to the present embodiment.

[0060] Fig.18 yes Fig.17 Flowchart of the design process in .

[0061] Fig.19 This is a schematic diagram for explaining solidified layers formed by dividing the inorganic structure in the stacking direction.

[0062] Fig. 20 It is to use multiple solidification areas DA Fig.19 Schematic diagram of the solidification layer partitioning in .

[0063] Fig.21 It indicates that the crystal orientation adopted by the solidification region is <001> A diagram showing the scanning method (scanning path) of the beam when .

[0064] Fig. 22 It indicates that the crystal orientation adopted by the solidification region is <011> A diagram showing the scanning method (scanning path) of the beam when .

[0065] Fig.23 It indicates that the crystal orientation adopted by the solidification region is <111> A diagram showing the scanning method (scanning path) of the beam when .

[0066] Fig.24 yes Fig.17 Flow chart of the formation process in .

[0067] Fig.25 Yes means Fig.24 A schematic diagram of one process step in the formation process.

[0068] Fig.26 It means to continue Fig.25 Schematic diagram of the subsequent process.

[0069] Fig. 27 It means to continue Fig.26 Schematic diagram of the subsequent process.

[0070] Fig.28 It means succession Fig. 27 Schematic diagram of the subsequent process.

[0071] Fig.29 It means succession Fig.28 Schematic diagram of the subsequent process.

[0072] Fig.30 It means succession Fig.29 Schematic diagram of the subsequent process.

[0073] Fig.31A The scanning path of the beam in the coagulation region of a reference size is shown.

[0074] Fig.31B This is a schematic diagram for explaining a scanning path of a beam in a coagulation region having a smaller size than a coagulation region having a reference size.

[0075] Fig.32 This is a pole diagram showing the effect of setting a stop time period.

[0076] Fig.33 is used to get Fig.32 Top view of the inorganic structure used in the experiment. DETAILED DESCRIPTION

[0077] [Overview of Inorganic Structure of the Present Embodiment]

[0078] Figure 1 1 is a perspective view showing an example of an inorganic structure 1 according to the present embodiment. The inorganic structure 1 is, for example, a medical implant. The inorganic structure 1 can also be used for purposes other than medical implants. In the following description, as an example of the inorganic structure 1, the case where the inorganic structure 1 is applied to a medical implant is described as an example.

[0079] In biological bones, bone density varies depending on the site. Specifically, biological bones include cortical bones covering the outer surface and cancellous bones formed inside. In the parts of biological bones where high stress is applied, the density of cancellous bones increases. On the other hand, in the parts of biological bones where only low stress is applied, the density of cancellous bones decreases. Therefore, biological bones have different mechanical properties depending on the site.

[0080] When the inorganic structure 1 is used as a substitute for biological bone, the mechanical properties of the inorganic structure 1 are preferably equivalent to those of the biological bone to be substituted. That is, the inorganic structure 1 is required to have different mechanical properties depending on the site.

[0081] In Patent Documents 1 and 2, as elements constituting the structure, a solid solidified portion formed by melting and solidifying metal powder particles and a sintered portion formed by sintering metal powder particles are prepared. The strength of the solidified portion is higher than that of the sintered portion. Therefore, in the structure, the solidified portion is arranged in the area where high stress is applied, and the sintered portion is arranged in the part where low stress is applied. In this way, in Patent Documents 1 and 2, parts (solidified portion and sintered portion) with different physical structures (density) are arranged in the structure. As a result, the structure has different mechanical properties depending on the part.

[0082] On the other hand, inorganic materials have a crystal structure and have crystal orientations. For example, in the case of an inorganic material having a cubic crystal structure, <001> Crystal direction, <011> Crystal orientation and <111> Therefore, when the inorganic structure 1 is composed of a plurality of solidified parts having different crystal directions preferentially oriented in a predetermined direction, the inorganic structure 1 can have different mechanical properties depending on the part.

[0083] The inorganic structure of this embodiment is completed based on the above-mentioned technical concept. Hereinafter, the structure of this embodiment will be described.

[0084] [First embodiment]

[0085] Figure 2 It is a stereoscopic view of the inorganic structure of the first embodiment. The inorganic structure 1 has a plurality of solidification portions SA (SA1 to SA3). It should be noted that an interface BO is formed between adjacent solidification portions SA. The solidification portion SA is composed of an inorganic material. Specifically, the solidification portion SA is formed by melting and solidifying a plurality of inorganic powder particles. Inorganic powder particles are powder particles composed of inorganic substances. The inorganic powder particles are composed of, for example, metals, intermetallic compounds, ceramics, etc. The metal is a pure metal or an alloy. Preferably, the inorganic powder particles are metal powder particles.

[0086] exist Figure 2 In the figure, the inorganic structure 1 has three solidification parts SA (SA1 to SA3). However, the inorganic structure 1 may have two solidification parts SA or may have four or more solidification parts SA. The plurality of solidification parts SA of the inorganic structure 1 are integrally formed by a stacking molding method of an additive manufacturing technology AM (Additive Manufacturing) described later.

[0087] In the following description, Figure 2 The inorganic structure 1 is configured in the orthogonal coordinate system (X-axis, Y-axis, Z-axis) shown in the figure, and the description is continued. Here, the Z direction refers to the stacking direction in the stacking modeling method described later. In the subsequent description, the Z direction as the stacking direction will also be referred to as the stacking direction Z. The stacking direction Z can be specified based on the appearance of the inorganic structure 1. The stacking direction Z can also be specified by etching the cross section of the inorganic structure 1.

[0088] Figure 3 For the purpose of explanation Figure 2 A three-dimensional diagram showing the separation of each solidified portion SA. Figure 2 and Figure 3 , the solidification portion SA1 and the solidification portion SA2 are preferentially oriented along different crystal directions. For example, in the solidification portion SA1, the crystal direction of the stacking direction Z is preferentially oriented along the crystal direction CO1. In the solidification portion SA2, the crystal direction of the stacking direction Z is preferentially oriented along the crystal direction CO2, which is different from the crystal direction CO1. Here, preferential orientation refers to a state in which the orientation rate of a specific crystal direction of the inorganic structure 1 toward a specific direction is higher than the orientation rate measured when the orientation is disordered.

[0089] It should be noted that in Figure 3 In the solidified portion SA3 , the crystal direction in the stacking direction Z is preferentially oriented along the same crystal direction CO1 as that of the solidified portion SA1 .

[0090] Reference Figure 2 , an interface BO is formed between adjacent solidified portions SA. That is, the adjacent solidified portions SA are formed integrally, and an interface BO exists between adjacent solidified portions SA.

[0091] The inorganic structure 1 having the above structure can have different mechanical properties depending on the location by configuring a plurality of solidified parts that are preferentially oriented along different crystal directions. Figure 2 and Figure 3 In the example, it is assumed that the crystal orientation CO1 is <111> , the crystal orientation of CO2 is <001> . Figure 4 This is a diagram showing the relationship between the crystal orientation and Young's modulus when the inorganic material is a titanium alloy and the solidified portion SA is a single crystal. Figure 4 , in titanium alloys with a cubic crystal structure, <111> The Young's modulus is the highest when <001> The Young's modulus is the lowest.

[0092] like Figure 2 and Figure 3 As shown, the crystal orientation of the solidified portion SA2 disposed in the central portion of the stacking direction Z in the inorganic structure 1 is <001> In addition, the crystal orientation of the solidified parts SA1 and SA3 is <111> Therefore, in the stacking direction Z, the Young's modulus of the solidified portions SA1 and SA3 is higher than the Young's modulus of the solidified portion SA2. Therefore, the inorganic structure 1 has different mechanical properties depending on the location.

[0093] For example, when the inorganic structure 1 is a medical implant and the solidification parts SA1 and SA3 of the inorganic structure 1 are fixed to the biological bone by bolts, a high Young's modulus is required for the solidification parts SA1 and SA3 in the stacking direction Z, and a low Young's modulus close to the Young's modulus of the biological bone is required for the solidification part SA2. In this case, as described above, the Young's modulus of the solidification parts SA1 and SA3 in the stacking direction Z of the inorganic structure 1 can be made higher than the Young's modulus of the solidification part SA2 in the stacking direction Z. In this way, the inorganic structure 1 can obtain different mechanical properties according to the position by having a plurality of solidification parts preferentially oriented along different crystal directions.

[0094] Solidification portion SA can be pure metal or alloy. Solidification portion SA can also be inorganic materials other than metals such as ceramics. When solidification portion SA is composed of pure metal, no segregation occurs. In addition, even if it is an alloy, depending on the composition and the cooling conditions in the stacking modeling method, there is sometimes a situation where segregation does not occur substantially. It should be noted that the cooling rate depends on the energy density, scanning speed, scanning pattern and other conditions of the beam in the stacking modeling method. In this way, when segregation does not occur substantially, the unit cell and unit cell interface described later will not be formed in the solidification portion SA. However, such solidification portion SA can also be oriented along different crystal directions relative to a specified direction. Thus, different mechanical properties are obtained according to the position.

[0095] In addition, Figure 2 and Figure 3As an example, solidification portions SA1 and SA3 and solidification portion SA2 are preferentially oriented along different crystal directions in the stacking direction Z, but there is no particular limitation on the direction in which they are preferentially oriented along different crystal directions. Multiple solidification portions SA can be preferentially oriented along different crystal directions in the X direction, or preferentially oriented along different crystal directions in the Y direction. Multiple solidification portions SA can also be preferentially oriented along different crystal directions in other directions different from the X direction, the Y direction, and the Z direction. That is, the inorganic structure 1 only needs to include a first solidification portion whose crystal direction in a specified direction is preferentially oriented along a first crystal direction, and a second solidification portion whose crystal direction in the above-mentioned specified direction is preferentially oriented along a second crystal direction in an orientation different from the first crystal direction.

[0096] [About the Microstructure of the Solidified Portion SA of the Inorganic Structure 1]

[0097] It is preferable that the solidified portion SA includes a plurality of sub-solidification regions each surrounded by a plurality of molten pool interfaces, and the sub-solidification region includes a plurality of unit cells and a plurality of unit cell interfaces that are interfaces between unit cells adjacent to each other. Figure 5 Yes means Figure 2 sectional view of the microstructure of the solidified portion SA of the inorganic structure 1 in FIG. Figure 5 The cross-sectional view is a cross-sectional view perpendicular to the beam scanning direction when the inorganic structure 1 is manufactured by a layered molding method described later.

[0098] Reference Figure 5 , the solidification portion SA includes a plurality of sub-solidification areas SSA. The molten pool interface MI is formed between adjacent sub-solidification areas SSA. In other words, the sub-solidification area SSA is surrounded by a plurality of molten pool interfaces MI. Each sub-solidification area SSA includes a plurality of unit cells CE and a unit cell interface CI which is an interface between adjacent unit cells. Unit cell CE is one of the solidification forms when the molten inorganic material solidifies, and includes dendrites that do not have secondary dendrite arms. It should be noted that the solidification form changes in the order of smoothness, unit cell, columnar dendrite, and equiaxed dendrite.

[0099] As described above, the inorganic structure 1 is integrally formed by the stacking molding method of the additive manufacturing technology AM. In the stacking molding method, the solidification portion SA is formed by melting and solidifying the inorganic powder particles. The cooling rate during solidification in the stacking molding method is extremely fast. Therefore, in the solidification structure of the sub-solidification area SSA in the solidification portion SA, a plurality of unit cells CE extending in the growth direction and unit cell interfaces CI formed between adjacent unit cells CE are formed.

[0100] The solidified portion SA including the sub-solidified region SSA including a plurality of unit cells CE and unit cell interfaces CI exhibits extremely high plastic deformation resistance. Figure 6 This is a graph showing the relationship between the presence or absence of a cell interface CI in a solidified portion and the hardness (GPa) measured by a nanoindentation method. Figure 6In the embodiment, as the inorganic structure 1, Inconel (trademark) 718, which is a Ni-based alloy having a cubic crystal structure, is used.

[0101] Reference Figure 6 , the crystal orientation in the stacking direction Z of the solidification portion SA is <011> In the case of , the hardness of the solidified portion SA with the cell interface CI is 13% higher than the hardness of the solidified portion SA without the cell interface CI. In addition, the crystal orientation in the stacking direction Z of the solidified portion SA is <001> In the case of , the hardness of the solidified portion SA having the cell interface CI is also 16% higher than the hardness of the solidified portion SA having no cell interface CI.

[0102] The sub-solidified region SSA of the inorganic structure 1 includes a plurality of unit cells CE and unit cell interfaces CI, so that high mechanical properties can be obtained.

[0103] As described above, the inorganic structure 1 includes a plurality of solidified portions SA, and the plurality of solidified portions SA include solidified portions SA preferentially oriented along mutually different crystal directions. Therefore, the inorganic structure 1 can have locally different mechanical properties.

[0104] [Second Embodiment]

[0105] The plurality of solidified portions SA of the inorganic structure 1 of the first embodiment have the same shape. However, the plurality of solidified portions SA of the inorganic structure 1 may have shapes different from each other.

[0106] Figure 7 2 is a perspective view of an inorganic structure 1 according to the second embodiment. Figure 7 The inorganic structure 1 includes a plurality of solidified portions SA1 to SA3 and interfaces BO formed between adjacent solidified portions SA. In the inorganic structure 1, the solidified portions SA1 and SA2 among the plurality of solidified portions SA are preferentially oriented in mutually different crystal directions as in the first embodiment.

[0107] exist Figure 7 In the inorganic structure 1 of the second embodiment, the solidification parts SA1 and SA2 also have different shapes from each other. Therefore, the solidification parts SA1 and SA2 of the inorganic structure 1 of the second embodiment are preferentially oriented along different crystal directions and have different shapes from each other. Therefore, different mechanical properties are obtained in the solidification parts SA1 and SA2 by the difference in shape and crystal direction.

[0108] For example, suppose Figure 7 The crystal direction of the stacking direction Z of the solidified parts SA1 and SA3 is along <111> Preferred orientation, the crystal direction of the stacking direction Z of the solidified portion SA2 is along <001> Select the best orientation. Figure 7In the embodiment, the cross sections of the solidified portions SA1 and SA3 perpendicular to the stacking direction Z are larger than the cross section of the solidified portion SA2 perpendicular to the stacking direction Z. Therefore, the rigidity of the solidified portions SA1 and SA3 is significantly larger than the rigidity of the solidified portion SA2.

[0109] [Third Embodiment]

[0110] In the first embodiment, the sub-solidified area SSA of the inorganic structure 1 includes a plurality of unit cells CE and a plurality of unit cell interfaces CI. However, the microstructure of the sub-solidified area SSA of the inorganic structure 1 may be in other forms.

[0111] Fig. 8A It means Figure 5 Photo images of the microstructure of different sub-solidification areas SSA, Figure 8B yes Fig. 8A Schematic diagram of the photo image. Fig. 8A and Figure 8B The sub-solidification region SSA includes a plurality of unit cell regions CA (CA1 to CA3). Each unit cell region CA includes a plurality of unit cells CE and a plurality of unit cell interfaces CI formed between adjacent unit cells CE. The plurality of unit cells CE in the unit cell region CA grow in the same direction. In other words, the plurality of unit cells CE in the unit cell region CA extend in the same direction.

[0112] In the adjacent unit cell regions CA1 and CA2, the extension direction of the unit cell CE of one unit cell region CA1 intersects with the extension direction of the unit cell CE of the other unit cell region CA2. Moreover, a layered interface LI is formed between the adjacent unit cell regions CA1 and CA2. In the layered interface LI, the crystal direction of one unit cell region CA1 among the adjacent unit cell regions CA1 and CA2 is preferentially oriented along an orientation different from the crystal direction of the other unit cell region CA2. The same is true for the adjacent unit cell regions CA2 and CA3.

[0113] If a layered interface LI is formed in the sub-solidification region SSA, a crystal orientation difference at the atomic level is formed in the layered interface LI, and solute segregation occurs at the atomic level. Such a small crystal orientation difference and a small amount of solute displacement at the atomic level will improve the mechanical properties such as the strength of the sub-solidification region SSA. As a result, the mechanical properties of the inorganic structure 1 are improved.

[0114] [Fourth Embodiment]

[0115] In the first embodiment, the sub-solidified region SSA of the inorganic structure 1 includes a plurality of unit cells CE and a plurality of unit cell interfaces CI. However, the sub-solidified region SSA of the inorganic structure 1 may have other forms.

[0116] Fig. 9A It means Figure 5, Fig. 8A and Figure 8B Photographic images of the microstructure of different sub-solidification areas SSA. Fig. 9B yes Fig. 9A Schematic diagram of the photo image. Fig. 9A and Fig. 9B The sub-solidification region SSA includes a plurality of unit cell regions CA (CA1 and CA2). Each unit cell region CA1 and CA2 includes a plurality of unit cells CE and a plurality of unit cell interfaces CI formed between adjacent unit cells CE. The plurality of unit cells CE in each unit cell region CA1 and CA2 grow (elongate) in the same direction. Fig. 9B In the unit cell region CA1, multiple unit cells CE are arranged along <010> The plurality of unit cells CE in the unit cell region CA2 are <001> elongation.

[0117] An association interface AI is formed between the adjacent unit cell regions CA1 and CA2. As described above, in the adjacent unit cell regions CA1 and CA2, the extending direction of the unit cell CE of one unit cell region CA1 is <010> The extension direction of the unit cell CE of another unit cell region CA2 <001> Therefore, in the bonding interface AI, the crystal direction of one of the adjacent unit cell regions CA1 and CA2 is along the same direction as the crystal direction of the other unit cell region CA2. <011> Preferred orientation. Here, the same orientation means that the orientation difference between the preferred orientation of the crystal direction in one unit cell region CA1 and the preferred orientation of the crystal direction in another unit cell region CA2 is within 10°.

[0118] As described above, in the association interface AI, the crystal direction of one of the adjacent unit cell regions CA1 and CA2 is preferentially oriented along the same orientation as the crystal direction of the other unit cell region CA2. If the association interface AI is formed in the sub-solidification region SSA, solute segregation occurs at the atomic level in the association interface AI. Such a small amount of solute displacement at the atomic level will improve the mechanical properties such as the strength of the sub-solidification region SSA. As a result, the mechanical properties of the inorganic structure 1 are improved.

[0119] For example, when the inorganic structure 1 is manufactured by the stacking modeling method described later, self-adjustment is performed during the manufacturing process in a manner that the difference in the crystal orientation in the solidified layers and the bonding interface AI described later becomes smaller as they are stacked in sequence. As a result, in the bonding interface AI of the manufactured inorganic structure 1, the crystal orientations of the adjacent unit cell regions CA1 and CA2 are consistent. That is, the adjacent unit cell regions CA1 and CA2 become single crystals or quasi-single crystals. The crystal orientation continues in the stacking direction Z by epitaxial growth. As a result, the orientation rate of the crystal orientation in the stacking direction Z of the solidified portion SA can be further improved.

[0120] [The crystal orientation with respect to the stacking direction Z is <011> Sub-solidification area SSA in the case of

[0121] exist Fig. 9A and Fig. 9B In the unit cell region CA1, the unit cell CE is <010> elongation, the unit cell CE in the unit cell area CA2 is <001> Therefore, the bonding interface AI where the unit cell region CA1 contacts the unit cell region CA2 extends in the stacking direction Z, and the extension direction of the bonding interface AI is equivalent to <011> So, in Fig. 9A and Fig. 9B In the sub-solidification region SSA, a single crystal or a quasi-single crystal is formed, and the crystal direction of the stacking direction Z becomes <011> . Reference Fig. 9A and Fig. 9B , the association interface AI extends in the stacking direction Z. Furthermore, Fig. 9C As shown in FIG. 1 , the bonding interface AI extends in the X direction, which is the extension direction of the sub-solidification region SSA. The sub-solidification region SSA extends along the scanning line along which the beam moves in the stacking molding method described later. Therefore, the crystal orientation of the stacking direction Z of the solidification portion SA composed of a plurality of sub-solidification regions SSA is along <011> Select the best orientation.

[0122] [The crystal orientation with respect to the stacking direction Z is <001> Sub-solidification area SSA in the case of

[0123] Fig. 10A and Fig. 10B The crystal orientation of the stacking direction Z is <001> Schematic diagram of the microstructure of the sub-solidification area SSA in the case of Fig. 10A The sub-solidification region SSA includes three unit cell regions CA1, CA2 and CA3. In the unit cell region CA1, the unit cell CE is <010> In the unit cell region CA3, the unit cell CE is elongated in the <0-10> direction. The unit cell region CA2 is arranged between the unit cell region CA1 and the unit cell region CA3. In the unit cell region CA2, the unit cell CE is elongated in the <0-10> direction. <001> Therefore, in the unit cell regions CA1, CA2 and CA3, the crystal orientations match. Therefore, the sub-solidified region SSA constitutes a single crystal or a quasi-single crystal. As a result, a plurality of bonding interfaces AI between adjacent unit cell regions CA (CA1 to CA3) extend in the stacking direction Z. <001> Furthermore, if Fig. 10B As shown, the two bonding interfaces AI extend in the X direction, which is the extension direction of the sub-solidification region SSA. Therefore, the crystal direction of the stacking direction Z of the solidification portion SA composed of a plurality of sub-solidification regions SSA is along <001> Select the best orientation.

[0124] [The crystal orientation with respect to the stacking direction Z is <111> Sub-solidification area SSA in the case of

[0125] Fig.11A The crystal orientation of the stacking direction Z is <111> A perspective view of the sub-solidification area SSA1 in the case of Fig.11A The sub-solidification region SSA1 includes two unit cell regions CA1 and CA2. In the first surface SF1 inclined 35.3° from the stacking direction Z to the direction X, the unit cell CE of the unit cell region CA1 is along the direction relative to <011> Tilt 45° <001> Stretch, the <011> The unit cell CE of the unit cell region CA2 is inclined 35.3° from the stacking direction Z. <011> Tilt 45° <010> Therefore, in the sub-solidification area SSA1, the crystal directions of the unit cell areas CA1 and CA2 match, and the bonding interface AI extends in the X direction, which is the extension direction of the sub-solidification area SSA1. Furthermore, in the first surface SF1, the bonding interface AI extends along <011> extend.

[0126] Fig. 11B The crystal orientation from the stacking direction Z to the stacking direction Z is <111> Schematic diagram obtained by observing the inorganic structure 1. Fig. 11B , the sub-solidification area SSA2 as the upper layer of the sub-solidification area SSA1 is at X 120 The X 120 The direction is a direction rotated 120° from the X direction around the stacking direction Z with respect to the sub-solidification region SSA1. Similar to the sub-solidification region SSA1, the sub-solidification region SSA2 includes two unit cell regions CA not shown. 120 In the second plane SF2 which is inclined by 35.3° and is orthogonal to the first plane SF1, the unit cell CE of a unit cell region CA is along the direction relative to <110> Tilt 45° <100> Stretch, the <100> The unit cell CE of another unit cell region CA is inclined 35.3° from the stacking direction Z. <110> Tilt 45° <010> Therefore, in the sub-solidification region SSA2, the crystal orientations of the two unit cell regions CA match, and the bonding interface AI is at X 120 Furthermore, in the second surface SF2, the bonding interface AI is <110> extend.

[0127] In addition, the sub-solidification area SSA3 which is the upper layer of the sub-solidification area SSA2 is 240 The X 240 The direction is a direction rotated 240° from the X direction around the stacking direction Z with respect to the sub-solidification region SSA1. Similar to the sub-solidification region SSA1, the sub-solidification region SSA3 includes two unit cell regions CA not shown. 240In the third plane SF3 which is inclined by 35.3° and is orthogonal to the first plane SF1 and the second plane SF2, the unit cell CE of one unit cell region CA is along the direction relative to <101> Tilt 45° <100> Stretch, the <101> The unit cell CE of another unit cell region CA is tilted 35.3° from the stacking direction Z along the direction relative to <101> Tilt 45° <001> Therefore, in the sub-solidification region SSA3, the crystal orientations of the two unit cell regions CA match, and the bonding interface AI is in the direction X. 240 Furthermore, in the third surface SF3, the bonding interface AI is <101> extend.

[0128] As a result of the above, each sub-solidification region SSA1 to SSA3 constitutes a single crystal or a quasi-single crystal, and the crystal orientation in the stacking direction Z is <111> As a result, in the YZ plane in the sub-solidification area SSA, the bonding interface AI extends in the stacking direction Z. <111> Therefore, the crystal orientation of the stacking direction Z of the solidified portion SA composed of a plurality of sub-solidified regions is along <111> Select the best orientation.

[0129] As described above, the crystal orientation of the stacking direction Z of the solidified portion SA constituting the inorganic structure 1 can be made to be along <001> , <011> , <111> Therefore, in one solidification portion SA among the plurality of solidification portions SA of the inorganic structure 1, the crystal direction in the stacking direction Z can be along <001> , <011> , <111> In the other solidified portion SA, the crystal direction in the stacking direction Z is preferably oriented along <001> , <011> , <111> The inorganic structure 1 is preferably oriented in a crystal direction different from the crystal direction of one solidified portion SA. Therefore, the inorganic structure 1 can have different mechanical properties depending on the location.

[0130] Preferably, the inorganic structure 1 includes a first solidified portion and a second solidified portion, and the crystal direction of the stacking direction Z of the first solidified portion is along <111> Preferred orientation, the crystal direction of the stacking direction Z of the second solidified part is along <111> Different crystal orientations <001> or <011> In this case, different mechanical properties can be formed in the first solidified portion and the second solidified portion.

[0131] [Fifth Embodiment]

[0132] In the first embodiment, the inorganic structure 1 includes a plurality of solidified portions SA. However, the inorganic structure 1 may include a component having another form other than the plurality of solidified portions SA.

[0133] Fig.12 is with Figure 2 A perspective view of an inorganic structure 1 according to different embodiments. Fig.12As shown, the inorganic structure 1 may include a solidified portion SA and a sintered portion SS. In this case, by adjusting the arrangement of the solidified portion SA and the sintered portion SS in the inorganic structure 1, the mechanical properties of the inorganic structure 1 can be adjusted to be different for each portion or to have anisotropy.

[0134] The sintered portion SS is formed by adjusting the energy density of the beam (laser or electron beam) in the stacking molding method to sinter the inorganic powder particles. In addition, the sintered portion SS can also be formed by heat treating the inorganic structure 1 after the stacking molding. Specifically, during the stacking molding, the beam is irradiated to the area corresponding to the solidification portion SA, and the irradiation of the beam is stopped in the area corresponding to the sintered portion SS. Then, the inorganic structure 1 is heat treated to form the sintered portion SS.

[0135] The sintered portion SS is porous. Therefore, the strength of the sintered portion SS is lower than that of the solidified portion SA. For example, the solidified portion SA is arranged at a portion requiring high strength in the inorganic structure 1, and the sintered portion SS is arranged at a portion requiring low strength. In this case, the inorganic structure 1 can have different mechanical properties depending on the portion.

[0136] Fig.13 is with Fig.12 A perspective view of an inorganic structure 1 according to a different embodiment. Fig.13 The inorganic structure 1 includes a sintering portion SS and a solidifying portion SA. The solidifying portion SA and the sintering portion SS are stacked in the X direction. <111> Preferred crystal orientation.

[0137] Assume that the inorganic structure 1 having the above configuration is applied to the front part of a car body. In this case, the inorganic structure 1 is arranged in the car in such a manner that the sintered portion SS is arranged on the front side of the car and the solidified portion SA is arranged on the side of the cab. When the car is impacted from the front along the X direction, the sintered portion SS in the inorganic structure 1 is plastically deformed by the impact and absorbs the impact. On the other hand, in the area near the cab in the front part of the car, the solidified portion SA is arranged along the X direction. <111> Preferred orientation of the solidified portion SA. <111> Therefore, the solidified portion SA is not easily deformed by an impact from the X direction, and the front part of the automobile can be prevented from deforming and intruding into the cabin.

[0138] As described above, the inorganic structure 1 includes not only the solidified portion SA but also the sintered portion SS, and thus can have different mechanical properties depending on the portion of the inorganic structure 1 .

[0139] [Sixth Embodiment]

[0140] Fig.14 2 is a perspective view of an inorganic structure 1 according to a sixth embodiment. Fig.14 The inorganic structure 1 has a gap SP between adjacent solidified portions SA. Specifically, the inorganic structure 1 includes a plurality of solidified portions SA1 extending in the stacking direction Z and a solidified portion SA2 extending in the Y direction and contacting the plurality of solidified portions SA1 at the center of the stacking direction Z. The solidified portions SA1 and SA2 are formed integrally. Fig.14 In the inorganic structure 1, a gap SP is formed between adjacent solidified portions SA1. <111> On the other hand, in the solidified portion SA2, in the stacking direction Z <001> Select the best orientation.

[0141] The inorganic structure 1 including the gap SP is not limited to Fig.14 The shape of the inorganic structure 1 is not particularly limited as long as it includes a plurality of solidified portions SA and a plurality of gaps SP formed between adjacent solidified portions SA. Fig.14 As shown, the gap SP may be a gap in which a part of the gap SP is open, or may be a closed space surrounded by the solidified portion SA.

[0142] When the gap SP is formed between the adjacent solidified portions SA, the difference in mechanical properties of the inorganic structure 1 between the locations can be further increased. Fig.15 This is a diagram showing the relationship between various inorganic structures 1 having different shapes and crystal orientations and Young's modulus in the X direction, Y direction, and Z direction. Fig.15 The inorganic structure (A) is a cube, and a through hole is formed at the center of each face. Furthermore, the solidified portion SA of the inorganic structure (A) is composed of polycrystals. The inorganic structure (B) has Fig.14 The inorganic structure (C) has the same shape as the inorganic structure 1 shown. However, the solidified portion SA is composed of polycrystals. Fig.14 The inorganic structure 1 shown has the same shape and the same crystal orientation.

[0143] Reference Fig.15 , in the inorganic structure (A) whose shape is isotropic in the X direction and the Z direction, the Young's modulus in the X direction and the Young's modulus in the Z direction are roughly the same. On the other hand, in the inorganic structure (B), the shapes observed from the X direction, the Y direction, and the Z direction are different, and the shape has anisotropy. Therefore, the Young's modulus in the X direction, the Young's modulus in the Y direction, and the Young's modulus in the Z direction of the inorganic structure (B) are greatly different. Specifically, the Young's modulus in the X direction is the lowest, and the Young's modulus in the Z direction is the highest. And then, in the inorganic structure (C), not only the shape has anisotropy, but also the crystal direction has anisotropy. Therefore, the inorganic structure (C) is compared with the inorganic structure (B), and the Young's modulus in the Z direction is greatly improved.

[0144] As described above, the inorganic structure 1 of the present embodiment can have significantly different mechanical properties at different locations by having shape anisotropy and crystal orientation anisotropy.

[0145] [Other embodiments]

[0146] The solidification portion SA of the inorganic structure 1 described in the above embodiment can be polycrystalline, or can be a quasi-single crystal or a single crystal. Preferably, the solidification portion SA is a quasi-single crystal or a single crystal. In this case, the orientation rate of a specific crystal direction can be improved. Therefore, it is easy to adjust different mechanical properties according to the position. Here, the quasi-single crystal refers to a structure in which the {001} pole is gathered into 3 in the {001} pole figure, for example, when the crystal structure of the inorganic structure 1 is a cubic crystal.

[0147] As described above, the inorganic structure 1 of the present embodiment includes a first solidification portion and a second solidification portion, wherein the crystal direction on the prescribed direction of the first solidification portion is preferentially oriented along the first crystal direction, and the crystal direction on the above-mentioned prescribed direction of the second solidification portion is preferentially oriented along the second crystal direction, which is different from the first crystal direction. In the inorganic structure 1, by including a plurality of solidification portions with different orientations of the crystal directions, different mechanical properties are obtained according to the position. As long as such an inorganic structure 1 is a structure composed of inorganic materials, its composition is not particularly limited. The inorganic structure 1 can be, for example, a composition composed of pure metals, a composition composed of alloys, or a composition composed of non-metallic inorganic materials such as ceramics. It should be noted that the prescribed direction is not particularly limited. It can be a stacking direction Z or other directions.

[0148] [Method for producing inorganic structure 1]

[0149] Next, a method for producing the inorganic structure 1 is described. In the method for producing the inorganic structure 1, for example, Fig.16 The stacked modeling device shown.

[0150] [Configuration of the stacking molding device]

[0151] Reference Fig.16 The lamination molding device 100 is a laser lamination molding device and includes a control device 10 , a beam generating device 14 , a lens system 15 , a mirror (galvanometer mirror) 16 , and a chamber 20 .

[0152] The beam generator 14 is a high energy heat source that emits a beam. The beam referred to here is a laser or an electron beam. The beam generator 14 is, for example, a fiber laser, a solid laser such as a YAG laser, a CO2 laser, etc. The lens system 15 converges the beam emitted from the beam generator 14 to form a beam 30. The reflector 16 performs an irradiation operation of the beam 30. That is, the position of the irradiation beam 30 is adjusted by the reflector 16.

[0153] The chamber 20 includes a bed forming chamber 201 , a powder supply chamber 202 , a molding table 203 , and a coating machine 205 .

[0154] The bed forming chamber 201 is cylindrical and has an opening at the upper end. The modeling table 203 is accommodated in the bed forming chamber 201 and is supported so as to be able to rise and fall in the vertical direction. The modeling table 203 is raised and lowered by a motor not shown. A base 208 is arranged on the modeling table 203. The base 208 is made of metal such as titanium, for example. The base 208 may also be other metals besides titanium. The inorganic structure 1 is formed on the base 208.

[0155] The powder supply chamber 202 is arranged next to the bed forming chamber 201. The powder supply chamber 202 is cylindrical and has a piston 204 that can be raised and lowered in the vertical direction. Inorganic powder particles 40 that become the starting material of the inorganic structure 1 are stacked on the piston 204. As the piston 204 rises, the inorganic powder particles 40 are discharged from the upper opening of the powder supply chamber 202 and supplied to the bed forming chamber 201.

[0156] The coating machine 205 is arranged near the upper opening of the powder supply chamber 202. The coating machine 205 is moved in a specific direction (horizontal direction) by a motor (not shown) and reciprocates between the powder supply chamber 202 and the bed forming chamber 201. Fig.16 In the embodiment, the coating machine 205 reciprocates in the L direction.

[0157] The coating machine 205 moves in the L direction to move the inorganic powder particles 40 discharged from the powder supply chamber 202 in the horizontal direction and supply them to the bed forming chamber 201. The inorganic powder particles 40 deposited on the base 208 of the molding table 203 in the bed forming chamber 201 form the inorganic powder layer 206. The inorganic powder particles 40 move in the horizontal direction by the coating machine 205 moving in the L direction, and the surface of the inorganic powder layer 206 is adjusted to be flat.

[0158] It should be noted that a roller may be used instead of the coater 205. When a roller is used, the inorganic powder layer 206 can be formed while arbitrarily pressurizing the inorganic powder particles 40 with the roller.

[0159] The control device 10 includes a central processing unit (CPU) (not shown), a memory, and a storage device represented by a HDD or SSD. The memory stores well-known CAD (Computer Aided Design) application software and CAM (Computer Aided Manufacturing) application software.

[0160] The control device 10 uses the known CAD application software to set the three-dimensional shape of the inorganic structure 1 to be manufactured. The control device 10 further uses the CAM application software to set the processing conditions based on the set three-dimensional shape. In the stacking modeling method, a plurality of solidified layers formed by the beam 30 are stacked, and the inorganic structure 1 is manufactured. The processing conditions include the processing conditions when each solidified layer is formed. The control device 10 controls the beam generating device 14, the lens system 15 and the reflector 16 based on the processing condition data, thereby adjusting the energy density, scanning speed, scanning pattern and beam irradiation position of the beam 30.

[0161] [About the manufacturing process]

[0162] The method for producing the inorganic structure 1 according to the present embodiment produces the inorganic structure 1 using a layered molding method. Fig.17 2 is a flowchart of a method for producing the inorganic structure 1 according to the present embodiment. Fig.17 In the manufacturing method of this embodiment, a design process S1 and a forming process S2 are included. In the design process S1, the three-dimensional shape and the crystal orientation of the inorganic structure 1 are determined. Then, based on the crystal orientation, the beam scanning method is set. In the forming process, the beam is scanned based on the set beam scanning method to melt the inorganic powder particles 40, and an inorganic structure 1 having a plurality of solidified portions SA with different preferred orientations of the crystal orientation is manufactured. The design process S1 and the forming process S2 are described in detail below.

[0163] [About design process S1]

[0164] Fig.18 This is a flow chart of the design process S1. Fig.18 First, the desired three-dimensional shape of the inorganic structure 1 is determined using the control device 10. In this example, the inorganic structure 1 is assumed to be in a cubic shape, and the description will be continued.

[0165] After the three-dimensional shape of the inorganic structure 1 is determined, Fig.19As shown, the three-dimensional shape of the inorganic structure 1 is divided into a plurality of solidified layers SLk (S11) stacked in the stacking direction Z. Specifically, with a predetermined stacking number kmax (number) of solidified layers SLk (k is a natural number, and the maximum number is kmax), the inorganic structure 1 is sliced ​​along a direction j perpendicular to the stacking direction Z and divided into a plurality of solidified layers SLk (k=1 to kmax). The shapes of the plurality of solidified layers SLk of the inorganic structure 1 are sometimes different. Therefore, processing condition data is set for each solidified layer SLk.

[0166] Furthermore, refer to Fig. 20 Observe each solidified layer SLk from the stacking direction Z, and divide the solidified layer SLk into a plurality of solidified areas DA (S12). The solidified area DA is a unit area of ​​a reference size for a scanning path to which beam scanning is applied. Fig. 20 In the embodiment, the solidification area DA is rectangular. However, the shape of the solidification area DA may be other than a rectangle. For example, the solidification area DA may be a triangle or a polygon other than a rectangle.

[0167] Next, the control device 10 determines the crystal orientation in each solidification area DA based on the mechanical properties required for each solidification area DA of each solidification layer SLk (S13) and determines the scanning method (scanning path) of the beam according to the determined crystal orientation (S14).

[0168] For example, the crystal orientation of the stacking direction Z in each solidification area DA is determined as <001> , <011> and <111> Any one of (S13).

[0169] In the determined crystal orientation <001> In the case of Fig.21 As shown, in deciding <001> In the solidification area DA of the crystal direction, the scanning direction of the beam when forming the j-th (j is a natural number) solidification layer SLj is adjusted to be orthogonal to the scanning direction of the beam when forming the j-1-th solidification layer SLj-1 which is the lower layer of the j-th layer. Then, the beam scanning is reciprocated in the solidification area DA. As a result, the crystal structure on the orthogonal coordinate system is as follows: Fig.21 As shown, in the stacking direction Z <001> Preferred crystal orientation.

[0170] In the selected crystal orientation <011> In the case of Fig. 22 As shown, in deciding <011> In the solidification area DA of the crystal direction, the scanning direction of the beam when forming the j-th solidification layer SLj is adjusted to be parallel to the scanning direction of the beam when forming the j-1-th solidification layer SLj-1. Then, the beam scanning is reciprocated in the solidification area DA. As a result, the crystal structure on the orthogonal coordinate system is as follows: Fig. 22 As shown, in the stacking direction Z <011> Preferred crystal orientation.

[0171] In the selected crystal orientation <111> In the case of Fig.23 As shown, in deciding <111> In the solidification area DA of the crystal direction, the scanning direction of the beam when forming the j-th solidification layer SLj is adjusted to intersect at 120° with the scanning direction of the beam when forming the j-1-th solidification layer SLj-1. Furthermore, the scanning direction of the beam when forming the j+1-th solidification layer SLj+1 is adjusted to intersect at 120° with the scanning direction of the beam when forming the j-th solidification layer SLj, and to intersect at 240° with the scanning direction of the beam when forming the j-1-th solidification layer SLj-1. Furthermore, in each solidification area DA, the beam scanning is not reciprocated but scanned only in one direction. As a result, the crystal structure on the orthogonal coordinate system is as follows. Fig.23 As shown, in the stacking direction Z <111> Preferred crystal orientation. When the solidification layers are formed sequentially from the j-1th solidification layer SLj-1 to the j+1th layer SLj+1, the beam scanning direction in each solidification layer can be rotated 120° clockwise according to the stacking order of the solidification layers in a top view, or can be rotated 120° counterclockwise according to the stacking order of the solidification layers in a top view.

[0172] By the above method, the crystal orientation of the stacking direction Z in each solidification area DA is determined (S13), and the scanning method of the beam based on the determined crystal orientation is determined (S14). It should be noted that in the step of determining the scanning method of the beam, the energy density (J / mm2) required for melting and solidifying the solidification area DA is determined. 2 ) will also determine the beam conditions (output E of beam 30, scanning speed, etc.).

[0173] The beam scanning path based on the crystal orientation and the information related to the beam conditions are stored in advance in the memory in the control device 10, for example, corresponding to the composition of the inorganic powder particles 40. Through the above steps, the processing condition data in each solidification area DA of each solidification layer SLk is prepared. The prepared plurality of processing condition data are stored in the memory in the control device 10, for example.

[0174] [Regarding the Forming Step S2]

[0175] In the forming step S2, beam scanning is performed based on the processing condition data determined in the designing step S1 to form each solidified layer SLk, thereby manufacturing the inorganic structure 1. The forming step S2 is performed after the chamber 20 of the stacking molding apparatus 100 is evacuated to a vacuum.

[0176] Fig.24 This is a flow chart of forming step S2. Fig.24, the control device 10 first sets the counter k to "1" (S21), and starts forming the first solidified layer SL1 which is the lowermost layer.

[0177] An inert gas (argon, nitrogen, helium, etc.) is supplied into the chamber 20 to preheat the base 208 disposed on the molding table 203. It should be noted that during preheating, the base 208 may be preheated without supplying the inert gas after evacuating the chamber 20. Alternatively, the base 208 may be preheated after supplying the inert gas without forming a vacuum. The base 208 may not be preheated.

[0178] Next, the control device 10 forms the inorganic powder layer 206 (S22). The control device 10 instructs the piston 204 of the powder supply chamber 202 to rise and discharge the inorganic powder particles 40 that become the starting material of the inorganic structure 1. The powder supply chamber 202 discharges the inorganic powder particles 40 according to the instruction from the control device 10. At this time, Fig.25 As shown, the coating machine 205 moves in the direction L. Thus, the discharged inorganic powder particles 40 move in the direction L and are supplied to the bed forming chamber 201. The inorganic powder particles 40 are deposited on the base 208 and the modeling table 203, and the inorganic powder layer 206 is formed.

[0179] The coating machine 205 further moves horizontally (in the L direction) on the surface of the inorganic powder layer 206 on the base 208. At this time, the inorganic powder particles 40 move in the horizontal direction. The thickness of the lowermost inorganic powder layer 206 is, for example, about 5 to 1000 μm.

[0180] Next, the control device 10 preheats the inorganic powder layer 206 (S23). The preheating can be performed by various methods. For example, the inorganic powder layer 206 can be preheated by irradiating the beam 30, or the inorganic powder layer 206 can be preheated by heating the molding table 203. The inorganic powder layer 206 can also be preheated by heating the inorganic powder particles 40 in the bed forming chamber 201 with a heater.

[0181] Next, based on the beam scanning method determined in the design step S1, the inorganic powder layer 206 is scanned by the beam 30 to melt the inorganic powder layer 206 and form the first solidified layer SL1 (S24). The control device 10 reads the processing condition data of the first solidified layer SL1 from the memory among the plurality of processing condition data prepared in the design step S1. Based on the read processing condition data, the control device 10 controls the beam 30.

[0182] Specifically, the control device 10 uses the beam scanning path (beam scanning method) corresponding to the determined crystal orientation to scan each solidified area DA in the solidified layer SL1 with the beam 30. Thus, the solidified layer SL1 composed of a plurality of solidified areas DA oriented in the crystal orientation determined in the design step S1 is formed.

[0183] In the melting step (S24), not only the inorganic powder layer 206 but also the surface layer of the base 208 may be melted. The inorganic powder layer 206 is melted by scanning the beam 30 under the above-mentioned beam conditions. Fig.26 At this time, the inorganic powder particles 40 arranged in the inorganic powder layer 206 in the region other than the solidified layer SL1 are not melted and are not sintered.

[0184] After forming the first solidified layer SL1, the control device 10 determines whether the count k is kmax (S25). Here, since the count k=1 (No in S25), the control device 10 sets the count k to k+1=2 (S26). Then, the control device 10 prepares to form the second solidified layer SL2.

[0185] The control device 10 lowers the molding table 203 by the stacking pitch Δh (S27). Fig. 27 As shown, the surface of the inorganic powder layer 206 is Fig.26 Compared with the previous example, only Δh is reduced.

[0186] After step S27 is completed, the process returns to step S22. At this time, the control device 10 forms a new inorganic powder layer 206 on the inorganic powder layer 206 on which the solidified layer SL1 is formed (S22). Specifically, according to the instruction of the control device 10, the piston 204 in the powder supply chamber 202 rises, and the inorganic powder particles 40 are discharged again. At this time, Fig.28 As shown, the coating machine 205 moves in the direction L. Therefore, the inorganic powder particles 40 move in the direction L to form a new inorganic powder layer 206 having a thickness Δh. The surface of the new inorganic powder layer 206 is adjusted by the coating machine 205 to be flat.

[0187] Next, the control device 10 preheats the inorganic powder layer 206 (S23) to form a second solidified layer SL2 (S24). At this time, the control device 10 irradiates the inorganic powder layer 206 with the beam 30 based on the processing condition data of the kth layer (here k=2). As a result, Fig.29 As shown, the inorganic powder layer 206 in the region irradiated with the beam 30 melts and solidifies to form a solidified layer SL2. Through the above steps, the solidified layer SL2 is stacked on the solidified layer SL1.

[0188] Next, the process proceeds to step S25, and the control device 10 repeats the operations of steps S22 to S27 until k=kmax, that is, until the uppermost solidified layer SLkmax is formed. That is, the control device 10 repeats the layer forming process (S22) and the melting process (S24) until k=kmax, that is, until the uppermost solidified layer SLkmax is formed. Fig.30 As shown, the inorganic structure 1 having a desired three-dimensional shape is completed.

[0189] It should be noted that the shape of the solidified layer SLk is not limited by the shape of the underlying solidified layer SLk-1, and can be set to a shape larger than the solidified layer SLk-1, or a shape smaller than the solidified layer SLk-1. Furthermore, one or more gaps can be formed in the shape of the solidified layer SLk. In this case, the structure can have a closed space, or have a shape that cannot be obtained in a conventional cutting process, such as a complex hole shape. The above manufacturing method can manufacture the inorganic structure 1 of this embodiment.

[0190] [About the case where the target solidification area DA is smaller than the reference solidification area DA]

[0191] As described above, in the manufacturing method of this embodiment, as a basis for determining the scanning method including the scanning path of the beam, Fig. 20 That is, the scanning path of the beam is determined based on the coagulation area DA which is a reference size.

[0192] Fig.31A The scanning path of the beam in the coagulation region of the reference size is shown. Fig.31B This is a schematic diagram for explaining a scanning path of a beam in a coagulation region having a smaller size than a coagulation region having a reference size.

[0193] like Fig.31A As shown, it is assumed that in the solidification area DA as the reference size, the crystal direction of the stacking direction Z is <001> The scanning path of the beam at that time is PAT1. Here, the scanning path PAT1 refers to a path in which the beam irradiation position moves at a predetermined scanning speed in the solidification area DA serving as a reference. The scanning path PAT1 includes a plurality of scanning lines SCL. The scanning lines SCL are parallel to each other. The plurality of scanning lines SCL are arranged in a direction perpendicular to the extension direction of the scanning lines SCL. While the beam irradiation position moves on the scanning path at a predetermined scanning speed, the stacking molding device 100 irradiates the beam 30 to the beam irradiation position. As a result, the beam 30 is irradiated to the inorganic powder layer 206 along the scanning path, so that the inorganic powder layer 206 is melted.

[0194] Specifically, when the scanning path PAT1 is applied to the solidification area DA of the reference size, the beam irradiation position moves on the scanning line SCL1 at a predetermined scanning speed. While the beam irradiation position moves on the scanning line SCL1, the stacking modeling device 100 irradiates the beam 30 to the beam irradiation position. After the beam irradiation position moves the entire length of the scanning line SCL1, the stacking modeling device 100 moves the beam irradiation position to the end point of the scanning line SCL2 adjacent to the scanning line SCL1. Thereafter, the beam irradiation position moves on the scanning line SCL2 at a predetermined scanning speed. While the beam irradiation position moves on the scanning line SCL2, the stacking modeling device 100 irradiates the beam 30 to the beam irradiation position. Similarly, for other scanning lines SCL other than the scanning lines SCL1 and SCL2 in the scanning path PAT1, the beam 30 is irradiated to the entire length of the scanning path PAT1 to melt the solidification area DA.

[0195] On the other hand, Fig. 20 As shown in FIG. 1 , when the solidified layer SLk is divided into a plurality of solidified regions DA of a reference size, the end of the solidified layer SLk may be divided into the following regions: Fig.31B The solidified areas DAs shown are smaller in size than the solidified areas DA of the standard size. When the melting step is performed on the solidified areas DAs of such small size, the heat amount of the beam is adjusted by the following method.

[0196] Specifically, the beam is irradiated at the portion of the scanning path PAT1 that overlaps with the solidification area DAs to be melted (the solid line portion in PAT1), and the beam irradiation is stopped at the portion of the scanning path PAT1 that does not overlap with the solidification area DAs (the dotted line portion in PAT1). That is, within the scanning path PAT1, the beam irradiation position is irradiated with the beam while the beam irradiation position moves at a predetermined scanning speed at the portion that overlaps with the solidification area DAs, and the beam irradiation is stopped during the stop time period while the beam irradiation position moves at a predetermined scanning speed at the portion that does not overlap with the solidification area DAs.

[0197] refer to Fig.31B When the scanning path PAT1 in the solidification area DA of the reference size is applied to the solidification area DAs which is smaller than the solidification area DA of the reference size, the scanning line SCL1 does not overlap with the solidification area DAs in the range from the end point P0 to the point P1 on the scanning line SCL1. Therefore, the stacking molding device 100 stops irradiating the beam 30 while the beam irradiation position moves from the end point P0 to the point P1 at a predetermined scanning speed. That is, in the scanning line SCL1, the moving time from the end point P0 to the point P1 is set as the stop time period.

[0198] After the beam irradiation position reaches point P1, the scanning line SCL1 overlaps with the solidification area DAs in the range from point P1 to point P2. Therefore, while the beam irradiation position moves from point P1 to point P2 at a predetermined scanning speed, the stacking molding apparatus 100 irradiates the beam 30 to the beam irradiation position.

[0199] After the beam irradiation position reaches point P2, the scanning line SCL1 does not overlap the solidification area DAs in the range from point P2 to end point P3. Therefore, the stacking molding apparatus 100 sets the movement time of the beam irradiation position from point P2 to end point P3 as the stop time period.

[0200] Similarly, for the scanning line SCL2, the stacking molding device 100 sets the movement time of the beam irradiation position from the end point P4 to the point P5 and the movement time of the beam irradiation position from the point P6 to the end point P7 as the stop time period. In addition, while the beam irradiation position moves from the point P5 to the point P6 at a predetermined scanning speed, the stacking molding device 100 irradiates the beam 30 to the beam irradiation position.

[0201] By the above method, in other scanning lines SCL other than scanning lines SCL1 and SCL2 of scanning path PAT1, the beam 30 is irradiated to the beam irradiation position during the movement time of the range overlapping with coagulation area DAs, and the movement time of the range not overlapping with coagulation area DAs is set as the stop time period.

[0202] In this way, when the solidification area DAs is smaller than the solidification area DA of the reference size, within the scanning path PAT1, the beam 30 is irradiated only on the path of the portion where the solidification area DAs is repeated, and the irradiation of the beam 30 is stopped on the path of the portion where the solidification area DAs is not repeated (during the stop time). When such a stop time is set, the thermal history applied to the solidification area DAs by the beam 30 is close to the thermal history applied to the solidification area DA of the reference size by the beam 30. Therefore, even in the solidification area DAs of a smaller size than the solidification area DA of the reference size, a microstructure close to the solidification area DA can be formed, and it can be preferentially oriented along the same crystal direction as the solidification area DA.

[0203] Fig.32 This is a pole diagram showing the effect of setting a stop time period. Fig.32 It can be obtained by the following method. Fig.33As shown, inorganic structures (solidified layer SL1 layer portion) SAM1 and SAM2 having a right triangle bottom surface and a height of 3 mm in the Z direction are manufactured, wherein the bottom surface of the right triangle has a side of 5 mm in the X direction and a side of 10 mm in the Y direction. The material of the inorganic structures SAM1 and SAM2 is Ti-15Mo-5Zr-3Al alloy, specifically, the composition contains 15% Mo, 5% Zr and 3% Al by mass%, and the remainder is Ti and impurities.

[0204] In the inorganic structure SAM1 shown in "No Stop Time", a scanning path is set to include a scanning line that reciprocates in the X direction. In the melting process, the beam irradiation position is moved in the X direction on a scanning line to irradiate the beam. Then, after the irradiation of the entire length of a scanning line is completed, the beam irradiation position is transferred to the Y direction, and the beam is irradiated on the adjacent scanning line. In "No Stop Time", the stop time period is not set. That is, the scanning path is set in a way that the scanning line does not exceed the frame of the triangular area.

[0205] exist Fig.33 In the inorganic structure SAM2 shown in "with stop time", the stop time period is set. Specifically, until the Y-direction length in the triangular region is from 0 mm to the region A1 of 4 mm, the scanning line is set to the range within the frame of the triangular region. It should be noted that in the region A1, a single crystal-like structure is formed.

[0206] On the other hand, in the area A2 other than the area A1, the total length of each scanning line is set to 3 mm. Furthermore, both end points of the scanning line are arranged outside the frame of the triangular area. Furthermore, the arrangement of the scanning line is determined so that the length of the upper part of the triangular area outside the frame is the same as the length of the lower part of the triangular area outside the frame in the scanning line.

[0207] The beam irradiation position is irradiated with a beam while the beam irradiation position moves in the portion where each scanning line overlaps with the triangular area. Then, the beam irradiation is stopped while the beam irradiation position moves in the portion where each scanning line does not overlap with the triangular area, which is referred to as the stop time period. Fig.33 In the inorganic structures SAM1 and SAM2, the beam conditions other than the scanning path are the same. Through the above process, a layer in the stacking direction Z is manufactured. <110> Inorganic structures SAM1 and SAM2 with preferred crystal orientation.

[0208] In the manufactured inorganic structures SAM1 and SAM2, Fig.32 The {100} pole figure is obtained from the observation points B1 to B8 shown in the figure. Fig.32In the figure, the dotted line L1 is a line segment connecting the center position of the X-direction side of the triangular region and the vertex of the diagonal angle of the X-direction side. The spacing between adjacent observation points B1 to B8 in the Y direction is 1.0 mm. The obtained extreme figure is shown in Fig.32 .

[0209] Reference Fig.32 , the upper part is the pole figure of the inorganic structure SAM1, and the lower part is the pole figure of the inorganic structure SAM2. In the inorganic structure SAM1 without a stop time period, the scan line becomes shorter as it moves forward in the Y direction. Therefore, no clear pole can be confirmed at observation point B5 and later, and the crystal direction confirmed at observation points B1 to B4 is not continued at observation points B5 to B6. On the other hand, in the inorganic structure SAM2 with a set stop time period, clear poles are confirmed even at observation point B5 and later, and all observation points B1 to B8 of the inorganic structure SAM2 become quasi-single crystals.

[0210] As described above, by providing the stop time period, it is possible to ensure a preferred orientation of the crystal direction.

[0211] The embodiments of the present disclosure are described above. However, the above embodiments are merely examples for implementing the present disclosure. Therefore, the present disclosure is not limited to the above embodiments, and the above embodiments can be appropriately modified within the scope of the present disclosure.

[0212] Description of Reference Numerals

[0213] 1Inorganic structures

[0214] CA, CA1, CA2, CA3 cell regions

[0215] CO1, CO2 crystal orientation

[0216] SA, SA1, SA2, SA3 solidification part

[0217] SSA sub-solidification area

Claims

1. An inorganic structure comprising a plurality of solidified parts composed of an inorganic material, The plurality of solidification parts include a first solidification part and a second solidification part, The crystal direction in the prescribed direction of the first solidified portion is preferentially oriented along the first crystal direction, The crystal direction of the second solidified portion in the predetermined direction is preferentially oriented along a second crystal direction that is different from the first crystal direction.

2. The inorganic structure according to claim 1, wherein The solidification portion includes a plurality of sub-solidification regions, and the plurality of sub-solidification regions are respectively surrounded by a plurality of molten pool interfaces. The sub-solidification area comprises: multiple unit cells; and A plurality of unit cell interfaces which are interfaces of the unit cells adjacent to each other.

3. The inorganic structure according to claim 1, wherein The first solidified portion has a shape different from that of the second solidified portion.

4. The inorganic structure according to claim 2, wherein The sub-solidification area comprises: a plurality of unit cell regions, each of which is composed of a plurality of the unit cells; and a lamellar interface, which is the interface between adjacent said unit cell regions, In the layered interface, the crystal direction of one of the adjacent unit cell regions is preferentially oriented along a direction different from the crystal direction of the other unit cell region.

5. The inorganic structure according to claim 2, wherein The sub-solidification area comprises: a plurality of unit cell regions, each of which is composed of a plurality of the unit cells; and an association interface, which is the interface between adjacent said unit cell regions, In the bonding interface, the crystal direction of one of the adjacent unit cell regions is preferentially oriented along the same orientation as the crystal direction of the other unit cell region. The inorganic structure according to claim 1 , further comprising a sintered portion which is a sintered body of an inorganic material. The inorganic structure according to claim 1 , further comprising gaps formed between adjacent solidified portions.

8. The inorganic structure according to claim 1, wherein In the first solidified portion, the crystal orientation in the stacking direction is <001> , <011> and <111> Any one of the crystal orientations is preferred, In the second solidified portion, the crystal direction in the stacking direction is along <001> , <011> and <111> The first solidified portion is preferably oriented in any one of the crystal directions and in a crystal direction different from the crystal direction of the first solidified portion.

9. The inorganic structure according to claim 1, wherein The solidified portion is composed of a single crystal, a quasi-single crystal, or a polycrystal.

10. A method for producing an inorganic structure, which is the method for producing an inorganic structure according to claim 1, comprising: Designing a process for determining a scanning method of a beam for forming the inorganic structure to be manufactured; and a forming step of scanning the beam based on the scanning method of the beam determined in the designing step to melt inorganic powder particles that will be a raw material of the inorganic structure to form the inorganic structure, The design process includes: The step of dividing the inorganic structure to be manufactured into a plurality of solidified layers in a stacking direction; A step of dividing each solidified layer into a plurality of solidified regions when viewed from the stacking direction; an orientation determining step of determining the orientation of the crystal direction of each solidification region based on the mechanical properties required of each solidification region; and a scanning method determining step of determining a scanning method of the beam in each of the solidification regions based on the determined crystal orientation; In the forming step, the layer forming step and the melting step are repeated alternately to stack a plurality of solidified layers to form the inorganic structure according to claim 1. The layer forming step supplies the inorganic powder particles onto a base to form an inorganic powder layer. The melting step scans the beam based on the beam scanning method determined in the scanning method determining step to melt the inorganic powder layer, thereby forming the solidified layer composed of the plurality of solidified regions oriented along the crystal direction determined in the orientation determining step.

11. The method for producing an inorganic structure according to claim 10, wherein: In the orientation determination step, the crystal orientation of the stacking direction of each solidification region is determined as <001> , <011> and <111> Any one of In the scanning method determination step, In deciding <001> In the solidification region of the crystal direction, the scanning direction of the beam when forming the j-th solidification layer is adjusted to be orthogonal to the scanning direction of the beam when forming the j-1-th solidification layer as the lower layer of the j-th layer, wherein j is a natural number, In deciding <011> In the solidification region of the crystal direction, the scanning direction of the beam when forming the j-th solidification layer is adjusted to be parallel to the scanning direction of the beam when forming the j-1-th solidification layer, In deciding <111> In the solidification region of the crystal direction, the scanning direction of the beam when forming the j-th solidified layer is adjusted to intersect the scanning direction of the beam when forming the j-1-th solidified layer at 120°.

12. The method for producing an inorganic structure according to claim 10, wherein: In the scanning method determination step, the scanning method of the beam includes information on a scanning path of the beam in the coagulation region having a reference size. In the melting process, when the solidification region to be melted is smaller than the solidification region of the reference size, the beam is irradiated at a portion of the scanning path of the beam that overlaps with the solidification region to be melted, and the beam irradiation is stopped at a portion of the scanning path of the beam that does not overlap with the solidification region to be melted.

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