Powder, method for producing article, mechanical component, mechanical device, and production device

Abstract

This powder for shaping includes boron, carbon and silicon, a structure including a first solid phase composed of silicon carbide and a second solid phase composed of boron carbide is formed by melting and solidifying the powder, and a difference between a molar fraction of silicon carbide and a molar fraction of boron carbide in the structure portion 20 is 60 mol% pt or less.

Description

Powder, manufacturing method of article, machine part, machine device, manufacturing device

[0001] The present invention relates to ceramic materials.

[0002] It is desirable to realize ceramic articles with excellent mechanical properties using additive manufacturing techniques. Patent Document 1 discloses additive manufacturing using powder containing silicon carbide and a metal boride having a melting point lower than the sublimation temperature of silicon carbide.

[0003] Japanese Patent Application Laid-Open No. 2019-064226

[0004] The powder and shaped object disclosed in Patent Document 1 have room for improvement in ease of shaping and mechanical properties of the shaped object. An object of the present invention is to provide a technology that is advantageous for realizing an article or a machine part with excellent mechanical properties.

[0005] A first aspect of the means for solving the above problem is a powder for shaping, the powder containing boron, carbon, and silicon, and a structure including a first solid phase consisting of silicon carbide and a second solid phase consisting of boron carbide is formed by melting and solidifying the powder, and the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide in the structure portion 20 is 60 mol % pt or less.

[0006] A second aspect of the means for solving the above problem is a powder for shaping, which contains silicon carbide and boron carbide, and is characterized in that the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide in the powder is 60 mol % pt or less.

[0007] A third aspect of the means for solving the above problems is a mechanical component comprising a structural structure including a first solid phase made of silicon carbide and a second solid phase made of boron carbide, wherein in a portion having the structural structure, the difference between the molar fraction of boron carbide and the molar fraction of silicon carbide is 60 mol % pt or less.

[0008] According to the present invention, it is possible to provide a technique that is advantageous in realizing an article having excellent mechanical properties or a machine part having excellent mechanical properties.

[0009] Schematic diagram for explaining powder and texture. Schematic diagram for explaining powder and texture. Schematic diagram for explaining powder and texture. Schematic diagram for explaining powder and texture. Schematic diagram for explaining powder. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining infrared laser melting method. Schematic diagram for explaining a mechanical part. Table showing results of Examples and Comparative Examples. SEM observation image and element mapping image in Example 1. SEM observation image and element mapping image in Example 1. SEM observation image and element mapping image in Example 6. SEM observation image and element mapping image in Example 6. SEM observation image and element mapping image in Example 9. SEM observation image and element mapping image in Example 9. SEM observation image and element mapping image in Example 11. SEM observation image and element mapping image in Example 11. SEM observation image and element mapping image in Example 16. SEM observation image and element mapping image in Example 16. SEM observation image and element mapping image in Example 17. SEM observation image and element mapping image in Example 17.

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description and drawings, common reference numerals are used to designate components common to multiple drawings. Therefore, common components will be described with mutual reference to multiple drawings, and descriptions of components with common reference numerals will be omitted as appropriate.

[0011] In this specification, silicon carbide is referred to as SiC, and boron carbide is referred to as B. ４ C, titanium diboride TiB ２Each substance may have multiple crystal structures or may have an amorphous structure. In addition, each substance may contain other impurities such as hydrogen, oxygen, and nitrogen. In addition, the stoichiometric ratio is not limited to the numerical values ​​described, and for example, B ４ The "4" part of C may be 3 to 5, or 3.5 to 4.5. ４ Not only C but also B １０ C is fine, or B １２ C ３ and B １２ C ２ In the case where the stoichiometric ratio is not specified, the combination of B ｘ C ｙ It can also be written as: Boron carbide B ｘ C ｙ In the formula, x / y may be 3 to 11. Silicon carbide is also Si ｘ C ｙ and metal borides can also be expressed as Me ｘ B ｙ It should be noted that x and y may be replaced with other alphabets.

[0012] The molding powder of this embodiment is suitable for a direct molding method known as a powder bed fusion method or an infrared laser melting method.

[0013] An embodiment of a powder for forming an article will be described. FIGS. 1A and 1B schematically illustrate a powder 10. The powder 10 includes a large number of particles. The large number of particles included in the powder 10 can be classified into multiple types based on their shape (including size) and material, but can also be composed of a large number of particles with uniform shape and material. FIG. 1A illustrates an example of a configuration in which the particles can be classified into three particle groups, a first particle group 11, a second particle group 12, and a third particle group 13, based on the material of the particles. The elements included in the powder 10 include boron (B), carbon (C), and silicon (Si). In a more preferred embodiment, the powder 10 further includes a metal element (with a fictitious element symbol Me). Any one of the particles included in the powder 10 may include boron (B), carbon (C), silicon (Si), and the metal element (Me). For example, the second particle group 12 and the third particle group 13 may contain boron (B). For example, the first particle group 11 and the second particle group 12 may contain carbon (C). For example, the first particle group 11 may contain silicon (Si). For example, the third particle group 13 may contain a metal element (Me). These elements contained in the powder 10 may be simple substances, but are preferably compounds. For example, the second compound 2 and the third compound 3 may contain boron (B). For example, the first compound 1 and the second compound 2 may contain carbon (C). For example, the first compound 1 may contain silicon (Si). For example, the third compound 3 may contain a metal element (Me). Typical compounds that the powder 10 may contain are borides, carbides, and silicides, but may also be oxides, nitrides, etc. Typical compounds that the powder 10 may contain are metal compounds, silicon compounds, and carbon compounds. More typical compounds that the powder 10 may contain include silicon carbide (SiC), boron carbide (B ４ C), metal carbide (MeC), metal boride (MeB) ２ ), silicon boride (SiB ６ ), metal silicides (MeSi or MeSi ２ The powder 10 preferably contains carbon (C) and silicon (Si) as at least silicon carbide (SiC). The powder 10 preferably contains carbon (C) and boron (B) as at least boron carbide (B ４The powder 10 preferably contains boron (B) and a metal element (Me) as at least a metal boride (MeB ２ The powder 10 preferably contains silicon carbide (SiC) and boron carbide (B ４ C), and further preferably contains a metal boride (MeB ２ ) is also preferred.

[0014] The metal element (Me) is preferably a transition element rather than a typical element. Specifically, the metal element (Me) is preferably an element of Groups 4 to 6, such as titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), or tungsten (W). Metal borides (MeB), which are borides of the metal element (Me), are also suitable. ２ ) is, for example, titanium boride (TiB ２ ), zirconium boride (ZrB ２ ), hafnium boride (HfB ２ ), vanadium boride (VB ２ ), niobium boride (NbB ２ ), tantalum boride (TaB ２ ), chromium boride (CrB ２ ), tungsten boride (WB ２ )

[0015] In this embodiment, the mole fraction (mol%) is the percentage of the amount of substance (mol) of each material relative to the amount of substance (mol) of all materials in a unit mass (e.g., 10 g) of powder 10. Each material may be a compound, a simple substance, a mixture of compounds, a mixture of simple substances, or a mixture of a compound and a simple substance. In particular, attention is paid to the mole fraction a (mol%) of silicon carbide, the mole fraction b (mol%) of boron carbide, and the mole fraction c (mol%) of metal boride in powder 10. Note that a>0, b>0, and c≧0.

[0016] The sum of the molar fraction a (mol%) of silicon carbide, the molar fraction b (mol%) of boron carbide, and the molar fraction c (mol%) of the metal boride is preferably 75 mol% or more, also preferably 86 mol% or more, more preferably 90 mol% or more, and may be 100 mol%. The molar fraction d (mol%) of the compound which is not silicon carbide, boron carbide, or a metal boride is preferably smaller than both the molar fraction a (mol%) of silicon carbide and the molar fraction b (mol%) of boron carbide (a>d, b>d). The molar fraction d (mol%) of the compound that is not silicon carbide, boron carbide, or a metal boride is preferably smaller than the molar fraction a (mol%) of silicon carbide, the molar fraction b (mol%) of boron carbide, or the molar fraction c (mol%) of a metal boride (a>d, b>d, c>d). The molar fraction of the compound that does not contain either boron (B) or carbon (C) is preferably 14 mol% or less. It is also preferable that the molar fraction of the compound that does not contain either boron (B) or carbon (C) is less than 10 mol%.

[0017] In this embodiment, the difference (|a-b|) between the molar fraction a of silicon carbide and the molar fraction b of boron carbide is 60 mol% Pt or less. The difference (|a-b|) between the molar fraction a of silicon carbide and the molar fraction b of boron carbide is preferably 50 mol% Pt or less, also preferably 40 mol% Pt or less, and more preferably 30 mol% Pt or less. The difference (|a-b|) between the molar fraction a of silicon carbide and the molar fraction b of boron carbide may be 20 mol% Pt or less, or may be 5 mol% Pt or more.

[0018] In this way, by reducing the difference (|a-b|) between the molar fraction a of silicon carbide and the molar fraction b of boron carbide in powder 10, the melting point of powder 10 can be made lower than the melting points of silicon carbide and boron carbide.

[0019] The molar fraction a of silicon carbide may be greater than the molar fraction b of boron carbide (a>b), but it is preferable that the molar fraction a of silicon carbide is smaller than the molar fraction b of boron carbide (a<b), which is advantageous in lowering the melting point of powder 10.

[0020] When powder 10 contains a metal boride (c>0), it is preferable that the molar fraction a of silicon carbide is greater than the molar fraction c of the metal boride (a>c), and it is also preferable that the molar fraction b of boron carbide is greater than the molar fraction c of the metal boride (b>c). This is advantageous in terms of reducing the weight of powder 10 and a shaped object formed from powder 10.

[0021] The molar fraction a of silicon carbide is preferably 35 to 60 mol%. The molar fraction a of silicon carbide is preferably 35 to 45 mol%. The molar fraction b of boron carbide is preferably 36 to 65 mol%. The molar fraction b of boron carbide is preferably 36 to 59 mol%. The molar fraction c of metal boride is preferably 4 to 40 mol%.

[0022] FIG. 2A shows silicon carbide (SiC) and boron carbide (B ４ C) and metal borides (MeB ２ ) and the composition that can be assumed to be a eutectic composition is shown in a triangular graph of mole fractions. The unit of each axis is mol%, and the scale intervals are 20 mol%. Note that the term "eutectic composition" in this specification is not a narrow term that refers to a composition in which all of the substances that make up the eutectic simultaneously change from a liquid phase to a solid phase at a specific temperature (eutectic temperature). The term "eutectic composition" in this specification is used in a broader sense to refer to a composition in which a liquid phase, which is a mixture of multiple substances, separates into multiple solid phases upon cooling. Therefore, the concept of a eutectic includes the concepts of a hypoeutectic and a hypereutectic. The metal elements attached to each point in Figure 2A are specific examples of a hypothetical metal element Me. For example, if the metal element is titanium (Ti), 37 mol% of silicon carbide (SiC) and 37 mol% of boron carbide (B ４ C) 45 mol%, titanium boride (TiB ２ ) is 18 mol % is a composition that can be assumed to be a eutectic composition. ２ When the metal boride (MeB ２It is believed that a composition close to the eutectic composition can be obtained if the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide is 60 mol % Pt or less, regardless of the presence or absence and type of metal boride (MeB ２ ) and the presence or absence of metal borides (MeB ２ Regardless of the type of silicon carbide, it is believed that a composition closer to the eutectic composition can be obtained if the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide is 20 mol % Pt or less. Based on this, the difference (|a-b|) between the molar fraction a of silicon carbide and the molar fraction b of boron carbide in powder 10 is set so as to resemble a composition closer to the eutectic composition.

[0023] In the powder 10 of this embodiment, the positions and areas of contact between particles are random. Therefore, even if a strict eutectic composition is blended, the positions and areas where the eutectic reaction occurs are random. However, if the compounds constituting the powder 10 are blended within a range that allows the eutectic reaction to occur, the eutectic reaction will occur randomly when the powder 10 is heated, and the liquid phase generated by the melting will flow, causing a chain reaction of eutectic reactions, thereby melting the powder 10.

[0024] In the compositions that can be assumed to be the eutectic compositions shown in FIG. 2A, the melting points can fall within the range of 1800 to 2200°C. This is because silicon carbide (SiC) and boron carbide (B ４ C) and metal borides (MeB ２ ), which means that it can be melted at a lower temperature. ４ C) and metal borides (MeB ２ ) is shown as an example.

[0025] As shown in FIG. 1A , a typical powder 10 of this embodiment may include a first particle group 11 made of a first compound 1 and a second particle group 12 made of a second compound 2. The powder 10 may further include a third particle group 13 made of a third compound 3. In this manner, the powder may be composed of a plurality of particle groups each made of a different material. A method for producing such a powder may involve mixing particles obtained by pulverizing or the like a base material of each material. As another example of the composition of the powder 10, each particle may be made of a plurality of materials. A method for producing such a powder may involve pulverizing or the like a base material containing a mixture of a plurality of materials.

[0026] The powder 10 preferably contains particles having a particle diameter of 10 μm or more, and more preferably contains particles having a particle diameter of 20 μm or more. By containing such particles having a particle diameter of 10 μm or more, it is possible to impart suitable fluidity to the powder 10. In order to impart suitable fluidity to the powder 10, the particle diameter of the particles having a particle diameter of 10 μm or more or 20 μm or more may be 100 μm or less, or may be 50 μm or less. The presence of particles having a particle diameter of 100 μm or more may reduce the molding accuracy.

[0027] The powder 10 preferably has a particle diameter of 1 μm or more and contains particles containing silicon carbide. The powder 10 preferably has a particle diameter of 5 μm or more and contains particles containing silicon carbide. The powder 10 preferably has a particle diameter of 10 μm or more and contains particles containing silicon carbide. The powder 10 preferably has a particle diameter of 20 μm or more and contains particles containing silicon carbide. The powder 10 preferably has a particle diameter of 100 μm or less and contains particles containing silicon carbide. The powder 10 preferably has a particle diameter of 50 μm or less and contains particles containing silicon carbide. The group of particles containing silicon carbide may contain particles having a particle diameter of less than 1 μm or less than 5 μm.

[0028] Here, the particle size can be defined for at least one particle, but it is preferable to evaluate it as a representative particle size of the particle size distribution in a particle group consisting of particles of the same type. Here, the representative particle size is the particle size (median diameter D５０ ) is preferable. In this embodiment, the representative particle size may be a catalog value of a compound supplier, or a value measured by the manufacturer. As the representative particle size, an average particle size, which is a particle size that is the average value in a particle size distribution, or a mode diameter, which is a particle size that is the most frequent value in a particle size distribution, may be used.

[0029] The median particle size of the silicon carbide-containing particle group is preferably 1 μm or more, more preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. The median particle size of the silicon carbide-containing particle group is preferably 100 μm or less, and more preferably 50 μm or less.

[0030] The powder 10 preferably has a particle diameter of 1 μm or more and contains particles containing boron carbide. The powder 10 preferably has a particle diameter of 5 μm or more and contains particles containing boron carbide. The powder 10 preferably has a particle diameter of 50 μm or less and contains particles containing boron carbide. The powder 10 preferably has a particle diameter of 20 μm or less and contains particles containing boron carbide.

[0031] The boron carbide-containing particle group may contain particles with a particle diameter of less than 1 μm or particles with a particle diameter of less than 5 μm. The median particle diameter of the boron carbide-containing particle group is preferably 1 μm or more, and also preferably 5 μm or more. The median particle diameter of the boron carbide-containing particle group is preferably 50 μm or less, and more preferably 15 μm or less. The median particle diameter of the boron-containing particle group is preferably 100 μm or less, and more preferably 50 μm or less.

[0032] When the thermal conductivity of the first compound 1 is higher than the thermal conductivity of the second compound 2, it is preferable that the median particle diameter Da of the first particle group 11 is larger than the median particle diameter Db of the second particle group 12 (Da>Db).

[0033] When the density of the third compound 3 is higher than the density of the second compound 2, it is preferable that the median particle diameter Dc of the third particle group 13 is smaller than the median particle diameter Db of the second particle group 12 (Db>Dc).

[0034] For reference, Figure 2B shows the physical properties of some relevant materials. Silicon carbide (SiC) is a ４ Therefore, the first compound 1 is silicon carbide (SiC) and the second compound 2 is boron carbide (B ４ The metal boride can be boron carbide (B ４ The density is higher than that of C). Therefore, the third compound 3 can be a metal boride.

[0035] When the first compound 1 is silicon carbide, the second compound 2 is boron carbide, and the third compound 3 is a metal boride, it is preferable that the median particle diameter Da of the first particle group 11 is larger than the median particle diameter Db of the second particle group 12 (Da>Db). It is also preferable that the median particle diameter Dc of the third particle group 13 is smaller than the median particle diameter Db of the second particle group 12 (Db>Dc).

[0036] It is also preferable that the median particle diameter Da of the first particle group 12, the median particle diameter Db of the second particle group 12, and the median particle diameter Dc of the third particle group 13 satisfy Db / Da<0.4 and Dc / Da<0.33. In this case, Db>Dc or Db<Dc may be satisfied.

[0037] A characteristic texture is formed by melting and solidifying the powder 10 of this embodiment. FIG. 1B schematically shows a texture structure portion 20, which is a portion having a texture structure. The powder of this embodiment is formed by melting and solidifying the powder, and is composed of a first solid phase 21 made of silicon carbide (SiC) and a second solid phase 22 made of boron carbide (B ４ The powder 10 contains boron (B), carbon (C), and silicon (Si) so as to form a structure including a second solid phase 22 made of a metal boride (MeB), which is a boride of the metal element (Me). ２) The texture structure 20 may include a third solid phase 23 consisting of a void 24. The void ratio in the texture structure 20 is preferably less than 50%, more preferably less than 25%, and even more preferably less than 10%. The value obtained by subtracting the void ratio from 100% can be referred to as the relative density (%).

[0038] FIG. 2B shows silicon carbide (SiC) and boron carbide (B ４ The graph shows the density and Young's modulus of boron carbide (B ４ C) and silicon carbide (SiC) are denser than silicon (Si), but boron carbide (B ４ C) has a lower density than silicon carbide (SiC). ４ C) has a higher Young's modulus than silicon carbide (SiC), but boron carbide (B ４ Silicon carbide (SiC) and silicon carbide (SiC) have a higher Young's modulus than silicon (Si). ４ A shaped object having a texture structure 20 including a second solid phase 22 made of (C) can achieve light weight (low density) and high rigidity (high Young's modulus). Young's modulus [GPa] / density [g / cm ３ ] can be evaluated as specific rigidity. If it is light, the inertia force is small, allowing for agile movement. The higher the specific rigidity, the more suitable it is for mechanical parts that require precise movement.

[0039] In the texture structure 20, the percentage of the amount of substance (mol) of each compound with respect to the amount of substance (mol) of all compounds in the texture structure 20 is defined as the molar fraction (mol%). Particular attention is paid to the molar fraction A (mol%) of silicon carbide, the molar fraction B (mol%) of boron carbide, and the molar fraction C (mol%) of metal borides in the texture structure 20. Note that A > 0 mol%, B > 0 mol%, and C ≥ 0 mol%.

[0040] The sum of the molar fraction A (mol%) of silicon carbide, the molar fraction B (mol%) of boron carbide, and the molar fraction C (mol%) of the metal boride is preferably 75 mol% or more, preferably 86 mol% or more, more preferably 90 mol% or more, and may be 100 mol%. The molar fraction D (mol%) of the compound that is not silicon carbide, boron carbide, or a metal boride is preferably smaller than both the molar fraction A (mol%) of silicon carbide and the molar fraction B (mol%) of boron carbide (A>D, B>D). The molar fraction D (mol%) is preferably smaller than the molar fraction C (mol%) of the metal boride (C>D). The molar fraction D (mol%) of the compound that is not silicon carbide, boron carbide, or a metal boride is preferably smaller than the molar fraction A (mol%) of silicon carbide, the molar fraction B (mol%) of boron carbide, or the molar fraction C (mol%) of a metal boride (A>D, B>D, C>D). The molar fraction D (mol%) is preferably less than 10 mol%. The molar fraction of the compound that does not contain either boron (B) or carbon (C) is preferably 14 mol% or less. The molar fraction of the compound that does not contain either boron (B) or carbon (C) is also preferably less than 10 mol%.

[0041] The mole fraction of the textured structure portion 20 may be measured, for example, for a compound within a planar area of ​​a square of M (μm) × N (μm) or within a three-dimensional area of ​​a square prism of L (μm) × M (μm) × N (μm). Here, L, M, and N are, for example, 1 μm or more, 5 μm or more, 10 μm or more, 50 μm or more, 100 μm or more, 1000 μm or less, or 500 μm or less. Figure 2B also shows a textured structure of a square prism (cube) of similar dimensions.

[0042] In this embodiment, the difference (|A-B|) between the molar fraction A of silicon carbide and the molar fraction B of boron carbide is 60 mol% pt or less. The difference (|A-B|) between the molar fraction A of silicon carbide and the molar fraction B of boron carbide is preferably 50 mol% pt or less, also preferably 40 mol% pt or less, and more preferably 30 mol% pt or less. The difference (|A-B|) between the molar fraction A of silicon carbide and the molar fraction B of boron carbide may be 20 mol% pt or less, or may be 5 mol% pt or more.

[0043] In this way, the difference (|A-B|) between the molar fraction A of silicon carbide and the molar fraction B of boron carbide in the textured structure portion 20 is set to be similar to a composition that is closer to a eutectic composition, thereby making it possible to make the melting point of the textured structure portion 20 lower than the melting points of silicon carbide and boron carbide.

[0044] The molar fraction A of silicon carbide may be greater than the molar fraction B of boron carbide (A>B), but it is preferable that the molar fraction A of silicon carbide is smaller than the molar fraction B of boron carbide (A<B). As can be seen from Figure 2A, when the molar fraction A of silicon carbide is smaller than the molar fraction B of boron carbide, silicon carbide and boron carbide tend to form a eutectic composition.

[0045] When the structure includes a third solid phase consisting of a metal boride (C>0), it is preferable that the molar fraction A of silicon carbide is greater than the molar fraction C of the metal boride (A>C), and it is also preferable that the molar fraction B of boron carbide is greater than the molar fraction C of the metal boride (B>C). As can be seen from FIG. 2B, the metal boride (MeB ２ ) has a higher density than silicon carbide, so a large molar fraction C of the metal boride is disadvantageous in terms of weight reduction. Therefore, when weight reduction is the goal, it is preferable that the molar fraction C of the metal boride be as small as possible. For weight reduction and a low melting point, it is preferable to use a metal element (e.g., Ta, Nb, Ti, Hf, Zr) such that the molar fraction C of the metal boride in the eutectic composition in FIG. 2A is 40 mol % or less. It is more preferable to use a metal element (e.g., Ti, Hf, Zr) such that the molar fraction C of the metal boride in the eutectic composition in FIG. 2A is 20 mol % or less.

[0046] The molar fraction A of silicon carbide is preferably 35 to 60 mol%, and more preferably 35 to 45 mol%, the molar fraction B of boron carbide is preferably 36 to 65 mol%, and more preferably 36 to 59 mol%, and the molar fraction C of metal boride is preferably 4 to 40 mol%.

[0047] In the structure portion 20, a first solid phase made of silicon carbide (SiC) and a second solid phase made of boron carbide (B ４ It is preferable that at least one (preferably two) of the first solid phase made of silicon carbide (SiC) and the second solid phase made of boron carbide (B ４ C), and a second solid phase consisting of metal boride (MeB ２ It is preferable that at least one (preferably two, more preferably three) of the third solid phases consisting of the above-mentioned crystalline and amorphous solid phases be crystalline. A crystalline solid phase constituting the texture structure portion 20 is more advantageous in terms of increasing strength than an amorphous solid phase.

[0048] The melting point of the texture structure 20 is preferably 1500° C. or higher and 2500° C. or lower. The density of the texture structure 20 is preferably 2.6 to 4.4 [g / cm ３ ]. This density is between the density of simple boron carbide and the density of simple titanium boride. The Young's modulus of the texture structure portion 20 is preferably 300 [GPa] or more. It is also preferable that the Young's modulus of the texture structure portion 20 is 390 [GPa] or more. The Young's modulus of the texture structure portion 20 may be 1000 [GPa] or less, or may be 500 [GPa] or less. Young's modulus [GPa] of the texture structure portion 20 / density [g / cm ３ ], that is, the specific rigidity is preferably 100 or more, and more preferably 135 or more. If the specific rigidity of the texture structure portion 20 is 100 or more, it exceeds the specific rigidity of SiC.

[0049] A shaped object can be manufactured by an additive manufacturing method using a powder-based material that satisfies the above-mentioned conditions. A shaped object can be manufactured by irradiating the powder-based material with infrared rays. The infrared rays are preferably a laser beam, but a lamp can also be used. A shaped object can be manufactured by irradiating the powder-based material with a laser beam. A shaped object can be manufactured by heating the powder-based material. Light heating using infrared rays or the like is preferred as a heating method, but heating using an electron beam or heating in a heating furnace using resistance heating or induction heating methods is also acceptable. For any type of shaped object, the desired article can be manufactured by appropriately processing the object. In particular, powder bed fusion using an infrared laser (infrared laser melting) is preferred. In infrared laser powder bed fusion, an infrared laser beam is irradiated onto a powder layer to heat and melt it, and this process is repeated to perform additive manufacturing. In addition to the additive manufacturing method, a molded object conforming to the shape of the cavity can be produced by placing powder 10 in a mold in which a cavity having a shape corresponding to the shape of the target object is formed, and heating the powder 10. Also, a powder injection molding method can be used in which the powder 10 is placed in the mold by injection.

[0050] The basic flow of shaping in a manufacturing method using an infrared laser melting method that can use the shaping powder of this embodiment will be described with reference to the schematic diagrams of FIGS. 4A to 4H.

[0051] First, raw material powder 101 is placed on a base 130 mounted on a stage 151, and is then spread evenly with a roller 152 to a predetermined thickness to form a powder layer 102 (FIGS. 4A and 4B). A laser beam emitted from a laser light source 180 is irradiated onto the powder layer 102 while being scanned by a scanner unit 181 based on slice data generated from shape data of a desired three-dimensional model. The beam diameter Φ of the laser beam is, for example, 10 to 1000 μm, e.g., 30 to 300 μm, or e.g., 50 to 150 μm. The wavelength λ of the laser beam is, for example, a wavelength in the infrared range, e.g., 0.75 to 15 μm. In the laser beam irradiation area 182, the raw material powder melts and then solidifies, forming a solidified portion 100 corresponding to the slice data for one layer (FIG. 4C). Next, the stage 151 is lowered, forming a new powder layer 102 on the solidified portion 100 (FIG. 4D), and the laser beam is irradiated based on the slice data. This series of steps is repeated a number of times according to the slice data to obtain a molded object 110 ( FIGS. 4E and 4F ). Finally, the unsolidified raw material powder 103 is removed, and if necessary, unnecessary portions of the molded object are removed or the molded object is separated from the base ( FIGS. 4G and 4H ). Furthermore, a heat treatment may be performed thereafter, if necessary.

[0052] When a shaped object is created by heating a powder-based material, cracks can occur in the shaped object due to thermal expansion and contraction. Cracks in the shaped object can be repaired using a material containing at least one of boron, carbon, silicon, and a metal element. There are several methods for crack repair, including sintering alone and using a repair source. When using a repair source, methods can be classified by process. For example, there are methods that add a material that contributes to repair to the raw powder, and methods that add a material that contributes to repair to the cracked portion of the shaped object. Both methods facilitate the repair effect by sintering. When the latter repair source is used, the material used to repair the cracks can be a liquid containing at least one of boron, carbon, silicon, and a metal element. By immersing the shaped object in the liquid, the liquid can penetrate into the cracks in the shaped object and repair the cracks. Examples of liquids that can be used to repair cracks include particle dispersions such as Si nanoparticle dispersions, polycarbosilane, a precursor polymer that becomes SiC when fired, and diluted solutions thereof. Cracks can be repaired effectively if the material used to repair cracks contains the same elements as those contained in the object. It is also preferable to heat the object at a temperature between 1000°C and 2000°C after the liquid has been infused into the object. On the other hand, when the former repair source is used, the material used to repair cracks can be a powder containing silicon. After a molded object is molded using a mixed powder obtained by mixing a powder serving as the repair source with a powder of the main raw material, the molded object can be heated at a temperature between 1400°C and 2200°C, thereby effectively repairing cracks. For example, silicon-containing powders include Si, TiSi, and the like. ２ The heating temperature for repair is preferably equal to or higher than the melting point of the powder that serves as the repair source, and for example, when Si, which has a melting point of 1400°C, is used as the repair source, the heating temperature may be 1400°C or higher.

[0053] As a material using powder, powder itself can be used, but a mixed powder made by adding other powders to the powder can also be used. Alternatively, a material made by mixing powder and liquid can also be used. Furthermore, a liquid can be applied to desired areas of the powder to form a shape. These liquids act as a binder to bind the powder particles together and may contain a resin.

[0054] When forming a shaped object by irradiating a powder-based material with a laser beam, it is preferable that the laser beam and the powder satisfy the following relationship. Assume that the median particle diameter Da of the first particle group 11 is larger than the median particle diameter Db of the second particle group 12, and the median particle diameter Dc of the third particle group 13 is smaller than the median particle diameter of the second particle group 12 and smaller than Db. It is preferable that the beam diameter Φ of the laser beam is larger than the median particle diameter Da of the first particle group 11. In this way, the particles of the first particle group 11 can be efficiently irradiated with the laser beam. It is preferable that the wavelength λ of the laser beam is smaller than the median particle diameter Dc of the third particle group 13. In this way, the particles of the third particle group 13 can be efficiently irradiated with the laser beam. It is preferable that the light irradiation of the particles be a form that can be approximated by geometric optics rather than Rayleigh scattering or Mie scattering.

[0055] The article thus obtained can be used, for example, as a mechanical part. The mechanical part is composed of a structure including a first solid phase made of silicon carbide and a second solid phase made of boron carbide. The characteristics of this structure can be similar to those of the structure described above. In the mechanical part, the first solid phase made of silicon carbide provides strength, and the second solid phase made of boron carbide provides lightness. This allows for the realization of a lightweight and high-strength mechanical part.

[0056] Various devices can be configured by combining the mechanical component 7 with at least one of electrical components, optical components, and resin components. The devices can be printing devices or office equipment, such as inkjet printers, laser printers, scanners, copiers, and multifunction devices. The devices can be imaging devices, such as cameras, displays, and projectors. The devices can be optical devices, such as interchangeable lenses and binoculars. The devices can be medical devices, such as X-ray devices, CT scanners, MRI scanners, and endoscopes. The devices can be industrial devices, such as exposure devices, film deposition devices, generators, and robots. The devices can be various types of mobile or transportation equipment, such as automobiles, aircraft, and ships. The devices can also be scientific instruments, such as nuclear reactors (nuclear fusion reactors and nuclear fission reactors) and accelerators, or space equipment, such as rockets and artificial satellites.

[0057] FIG. 5 shows an example of how the mechanical component 7 is used. In a mechanical unit 4 including the mechanical component 7 and a moving mechanism 9 for moving the mechanical component 7, the lightweight and strong mechanical component 7 allows the mechanical component 7 to be moved at high speed and with high precision. The mechanical component 7 is, for example, a link component used as a hand or arm. However, it may also be a transmission component such as a gear, cam, or shaft, or a connecting component such as a screw. The mechanical component of this embodiment may have a melting point of 1000°C or higher, preferably 1500°C or higher, and therefore may also be used as a heat-resistant or fire-resistant component. The moving mechanism 9 may include, for example, a motor. An example of a device including the mechanical component 7 is a manufacturing apparatus 30. The manufacturing apparatus 30 includes a mechanical unit 4 for holding and / or transporting a workpiece 5 and a processing unit 6 for processing the workpiece 5, improving manufacturing accuracy and throughput. The manufacturing target of the manufacturing apparatus 30 is not particularly limited, and may be an electrical equipment manufacturing device, a transportation equipment manufacturing device, or an electronic device manufacturing device such as an exposure apparatus, an etching apparatus, or a film formation apparatus.

[0058] Hereinafter, the powder 10 of the present embodiment described above will be described based on a more specific example suitable for powder for layered manufacturing.

[0059] To meet the need for a lightweight mechanical component 7, it is preferable that the density of the material used be low. However, in the infrared laser melting method, it is necessary to be careful about how to handle SiC, which can decompose at around 2545°C when heated. SiC has a density of 3.21 g / cm ３ Although the density is low, in order to further reduce the weight, the inventors have intensively investigated the possibility of modifying the density by adding different materials.

[0060] In order to make the apparent density lower than that of SiC, B, a carbide with a lower density than SiC, is used. ４ Addition of C is effective. In addition, in order to add a material with a higher density than SiC and further make the apparent density comparable to that of SiC, it is necessary to add B, which is a carbide with a lower density than SiC. ４ Addition of C is effective. When heat treating the material to develop desired physical properties after it has been separated from the substrate after additive manufacturing, temperatures of 2100°C or higher, even exceeding 2200°C, are often required. However, from the viewpoint of productivity, the heat treatment temperature is preferably 2200°C or lower, and more preferably 2000°C or lower. For example, SiC-B ４ In the C (43:57 molar ratio) eutectic system, the eutectic temperature is 2150°C, and B ４ C-TiB ２ In the (76:24 molar ratio) eutectic system, the eutectic temperature is 2200°C. Therefore, heat treatment can be performed at 2200°C or less while suppressing the decomposition of SiC. ４ In contrast to C, as a crack repair source, for example, Si or TiSi ２ The decomposition of SiC can be suppressed even when SiC-B is added to the raw material. ４ For C, TiB ２ It is preferable to use a ternary eutectic system with the addition of SiC-B. ４ C-TiB ２ The ternary eutectic has a eutectic temperature of 1945°C, which is below 2000°C, and is sufficiently far from the decomposition temperature of SiC, so the decomposition of SiC can be suppressed. ４ C-TiB ２ On the other hand, as a crack repair source, for example, Si or TiSi ２When added to the raw material, the decomposition of SiC can be suppressed.

[0061] SiC-B ４ C-TiB ２ The composition ratio of the ternary eutectic is SiC:B in molar ratio. ４ C: TiB ２ It is considered that the ratio is included in the range including 38.0:44.0:18.0 and 40.8:51.1:8.1.

[0062] Therefore, SiC, B ４ C, TiB ２ In the powder for additive manufacturing consisting of the above three compounds, it is preferable to configure the composition that can approximate a ternary eutectic within the following range: The mole fraction of SiC is 30 to 50 mol%, preferably 36 to 43 mol%, for example 38.0 to 40.8 mol%. ４ The molar fraction of C is 30 to 60 mol%, preferably 40 to 55 mol%, for example 44.0 to 51.1 mol%. ２ The molar fraction of is 1 to 30 mol%, preferably 3 to 23 mol%, for example 8.1 to 18.0 mol%. In this case, the apparent density is 2.97 to 3.03 g / cm ３ and the density of SiC is 3.21 g / cm ３ is lower than

[0063] The volume ratio can be, for example, in the following range: SiC 27.7 to 29.1 vol%, B ４ C is 56.2 to 63.8 vol%, TiB ２ is 7.1 to 16.1 vol%.

[0064] The molecular weight of SiC is 40.11 and the density is 3.21 g / cm ３ And B ４ C molecular weight 55.255, density 2.52 g / cm ３ and TiB ２ Molecular weight 69.489, density 4.52 g / cm ３ The apparent density was calculated using these composition ratios.

[0065] In addition, it is sufficient that the apparent density of the molded object is low, so SiC-B ４ C-TiB ２The raw material powder composition of the ternary eutectic object is SiC, B ４ C, TiB ２ The composition is not limited to those consisting of only these three compounds. As long as the overall composition is maintained, ４ C-SiB ６ It may be composed of five types of compounds, such as TiC-C, and carbon.

[0066] As described above, the powder for additive manufacturing of this embodiment is composed of elements such as boron, carbon, silicon, and a metal element (titanium in this example), and may contain three or more types of compounds. Therefore, when titanium is used as the metal element, the compounds may contain SiC, B ４ C, SiB ３ , SiB ６ , TiB, TiB ２ , TiC, TiSi, TiSi ２ It is preferable to select from the group consisting of:

[0067] It is important for powders for additive manufacturing that are suitable for infrared laser melting to be manufactured at a temperature at which SiC does not decompose in order to obtain dense objects. ４ C, TiB ２ The necessary conditions were examined for the case where the compound is composed of the above three compounds.

[0068] The time it takes for these three types of compound particles to reach a certain temperature when heated was calculated. ４ Assuming a situation in which C melts, the surface temperature of each compound particle was kept constant at 2400°C, and the time until the central temperature reached 2350°C due to thermal diffusion to the inside was calculated. For the calculation, the thermal conductivity of SiC was 186 W / m K, the specific heat was 670 J / kg K, and the density was used, and the thermal diffusion coefficient was 8.65 × 10 －５ m ２ / sec, B ４ Using the thermal conductivity of C of 37 W / m K, specific heat of 950 J / kg K, and density, the thermal diffusion coefficient is 1.55 x 10 －５ m ２ / sec, TiB ２ Using the thermal conductivity of 25 W / m K, specific heat of 578 J / kg K, and density, the thermal diffusion coefficient is 9.61 x 10－６ m ２ / sec was used.

[0069] When heated under these conditions, SiC does not reach the decomposition temperature, and TiB ２ Although it does not melt, B, which has the highest volume ratio, ４ C (56.2 to 63.8 vol%) melts and SiC and TiB ２ The melting proceeds in a manner that involves the melting of the alloy, and finally a eutectic composition is formed, which accelerates the melting.

[0070] Figure 3 shows the correlation between the particle size of each compound (assuming the particle size is uniform) under these conditions and the time it takes to reach a certain temperature. ４ C is dashed line, TiB ２ The dashed line indicates the time required to reach the same temperature. From FIG. 3, it can be seen that the particle size increases in the order of the thermal diffusion coefficient. For example, when the particle size of SiC is about 30 μm, it takes about 0.005 msec for the surface temperature to reach 2400°C and the central temperature to reach 2350°C. ４ When the particle size of C is about 12 μm, the center temperature becomes 2350 °C, and TiB ２ It can be seen that when the particle diameter is about 10 μm, the central temperature is 2350°C.

[0071] From the above, in the powder for additive manufacturing of this embodiment, in order for the top three types of compounds with the highest molar fractions to heat up to the same central temperature in approximately the same amount of time, it is preferable that the compound with the highest thermal diffusion coefficient (thermal conductivity / specific heat / density) has a larger particle size. Therefore, it is preferable that the compound with the highest thermal conductivity has a larger particle size, and it is preferable that the compound with the lowest specific heat or density has a larger particle size. In other words, it is preferable that the representative particle size of the compound with the highest thermal diffusion coefficient is larger than the representative particle size of the compound with the lowest thermal diffusion coefficient (the other two types of compounds). Similarly, it is preferable that the representative particle size of the compound with the highest thermal conductivity is larger than the representative particle size of the compound with the lowest thermal conductivity (the other two types of compounds). It is preferable that the representative particle size of the compound with the lowest specific heat is larger than the representative particle size of the compound with the highest specific heat (the other two types of compounds). It is preferable that the representative particle size of the compound with the lowest density is larger than the representative particle size of the compound with the highest density (the other two types of compounds). Here, the representative particle size is preferably the median D ５０ The representative particle size is the median particle size in the particle size distribution of a certain compound. In this embodiment, the representative particle size may be a catalog value of a compound supplier, or a value measured in-house. Note that the representative particle size may be an average particle size, which is the particle size that is the average value in the particle size distribution, or a mode diameter, which is the particle size that is the most frequent value in the particle size distribution.

[0072] Furthermore, the powder for additive manufacturing in this embodiment is SiC, B ４ C, TiB ２ particle diameter (e.g., median D ５０ ) are Da, Db, and Dc, it is preferable that Db / Da<0.4 is satisfied, and it is also preferable that Dc / Db<0.33 is satisfied.

[0073] On the other hand, the infrared laser melting method includes a step of forming the powder layer 102 by spreading the powder to a predetermined thickness with a roller 152. However, if the particles that account for 70 vol % of the entire powder for additive manufacturing have a diameter of less than 8 μm, the fluidity of the powder will be significantly reduced, and poor spreading will be likely to occur. Therefore, in order to avoid this, it is necessary to consider the particle diameter of SiC (for example, the median diameter D) from FIGS. 2A and 2B.５０ ) is preferably 20 μm or more.

[0074] Furthermore, the ternary eutectic SiC-B ４ C-TiB ２ The powder for additive manufacturing to constitute the ４ C, TiB ２ In the case of a mixed powder of compound particles consisting of the above, it is preferable that the three types can be considered to have a uniform composition within the infrared laser spot size. For example, the laser used in the infrared laser melting method is preferably a Nd:YAG laser, Yb fiber laser, or the like, with a wavelength of around 1060 to 1070 nm and a focal size of approximately 60 to 100 μm. Therefore, consider the case where the laser spot diameter is 100 μm and the powder space filling rate is 50%. When a hemispherical portion of powder with a laser spot diameter of 100 μm is melted, taking into account a filling rate of 50% in its volume, the melting point is approximately 131,000 μm. ２ is the volume occupied by the powder. An example of a range similar to the ternary eutectic composition is SiC:B ４ C: TiB ２ = 29.1:63.8:7.1 vol%, the volume occupied by each compound is SiC 38121 μm ２ , B ４ C is 83578 μm ２ , TiB ２ is 9301 μm ２ Here, the particle diameter of SiC is about 30 μm, and B ４ When the particle diameter of C is about 20 μm, about 3 SiC particles are included, and B ４ Here, the condition for the surface temperature of the SiC particle to be unlikely to exceed the decomposition temperature is that the number of B ４ It is preferable that the number of SiC particles is 6 or more. If the number is 5 or less, the probability that half of the SiC particles are individually exposed to the infrared laser increases. Furthermore, TiB, which occupies the smallest volume ratio, ２ In order for SiC and B to be uniformly distributed, ４It is preferable that at least one of the SiC particles contacts the total of about 23 C particles, so it is preferable that the number is 23 or more. Therefore, the derived particle diameter is about 4.6 μm. Furthermore, when the SiC particle diameter is 30 μm and the B ４ When the particle diameter of C is 11 μm, about 3 SiC particles are included, and B ４ It contains approximately 120 C atoms. ２ The preferred particle size of the compound with the smallest volume among the top three compounds is calculated as above, and is found to be approximately 2.6 μm. In this way, by determining the particle size of the compound with the smallest volume among the top three compounds and maintaining the particle size relationship, it is possible to achieve good melting. As a result, it is possible to obtain a dense shaped object.

[0075] Figure 6 shows a list of examples and comparative examples of the present invention. The table includes the composition of the raw material powder, moldability, firing temperature, density, relative density, three-point bending strength (measured in a test conforming to JIS R1601), Young's modulus (measured in a test conforming to JIS R1602), specific rigidity (Young's modulus [GPa] / density [g / cm ３ ]) should be written.

[0076] 7A to 12B show SEM observation images (labeled SEM) of the structures according to Examples 1, 6, 9, 11, 16, and 17, and element mapping images (labeled EDX_E: E is the element) of B, C, Si, Ti, etc., obtained by SEM-EDX evaluation. The fields of view of each SEM observation image and the element mapping image match. In the element mapping images, areas that are close to black indicate low concentrations of the corresponding element, and areas that are close to white indicate high concentrations of the corresponding element. The observation magnification of Figs. 7A, 8A, 9A, 10A, 11A, and 12A was 500 times, and the fields of view were 150 μm vertical × 200 μm horizontal (30,000 μm ２ ) and is smaller than 100 μm long x 150 μm wide (15,000 μm ２ 7A, 8A, 9A, 10A, 11A and 12A show a wide range of structures (150 μm long x 200 μm wide (30,000 μm)). ２ ) and is smaller than 100 μm long x 150 μm wide (15,000 μm ２7B, 8B, 9B, 10B, 11B, and 12B were observed at a magnification of 30,000 times, and the field of view was 3 μm vertically × 4 μm horizontally (12 μm ２ ) and is 2 μm long x 3 μm wide (6 μm ２ 7B, 8B, 9B, 10B, 11B and 12B are larger than the narrow range of the structure (3 μm long × 4 μm wide (12 μm ２ ) and is 2 μm long x 3 μm wide (6 μm ２ 7A, 7B, and 9A to 12B, the narrow-area observation portion is located within the white frame shown in the wide-area SEM observation image. In FIGS. 8A and 8B, the narrow-area observation portion is located outside the wide-area SEM observation image.

[0077] (Example 1) SiC particles with a median particle size of about 30 μm, B particles with a median particle size of about 20 μm ４ C particles, TiB with a median particle size of 3.7 μm ２ Particles were prepared. SiC:B ４ C: TiB ２ About 5.8 g of SiC was mixed with B to give a molar ratio of 40.8:51.1:8.1. ４ 10g of C, TiB ２ The powder was weighed out at a ratio of 2 g, poured into a 1 L plastic container up to 70% of the capacity, and zirconia beads of φ5 mm were added. The mixture was mixed in a roller mixer for 30 minutes to prepare powder for additive manufacturing. The powder composition was similar to the composition of a ternary eutectic, consisting of SiC and B. ４ The difference in the mole fraction of C is 60 mol% pt or less, which satisfies the preferred composition range, and B is ４ The number of C particles is six times or more, and TiB ２ The number of particles is SiC and B ４ The total number of C particles is more than the ratio of SiC:B ４ C: TiB ２ is approximately 3:20:351, which is an example of a preferred situation of the present invention.

[0078] For the infrared laser melting method, a ProXDMP100 manufactured by 3D Systems was used. This device has a roller recoater and is characterized by its ability to form a uniform powder layer 102. The infrared laser has specifications that allow it to output up to 50 W.

[0079] A 50 x 50 mm aluminum substrate was placed on the modeling stage 151 of this device, and modeling was performed on it. The thickness of the powder layer 102 during additive manufacturing was set to 20 μm per layer. However, since the maximum particle diameter of the powder used was 30 μm, the initial thickness was set to at least 40 μm. Seven 5 x 38 mm shapes were arranged in parallel, and a modeling up to 5 mm in height was performed. The modeling conditions were an infrared laser power of 40 W, a scan speed of 140 mm / sec, and a scan pitch of 60 μm. The seven pieces were separated from the substrate, and the average density of the seven pieces was calculated from the weight and volume of the 5 x 38 x 4.5 mm size. The relative density was 92.5%. In this way, a dense model exceeding 90% was obtained, avoiding the situation where the decomposition temperature of SiC was reached and densification would not progress.

[0080] Here, the theoretical true density calculated from the feed composition of the ternary eutectic is 2.97 g / cm ３ The obtained molded product was subjected to a heat treatment at 1950°C. Within the wide area shown in Figure 7A, remnants of SiC particles that were not completely melted and remained unmelted were observed, but around this area, SiC regions formed through the melting of the SiC particles were observed. Within the obtained structure, within the narrow area shown in Figure 7B, there was a region made of SiC, B ４ C, TiB ２ A region consisting of Si, C, B, and Ti was observed. As shown in Figure 7A, cracks were observed, but some of them were repaired. The three-point bending strength of the structure of Example 1 was 174 MPa, and the specific rigidity was 126.

[0081] (Example 2) Examples 1 to B ４ Only the particle size of C was changed, and SiC particles with a median particle size of about 30 μm and B particles with a median particle size of about 11 μm were used. ４ C particles, TiB with a median particle size of 3.7 μm２ Particles were prepared. SiC:B ４ C: TiB ２ About 5.8 g of SiC was mixed with B to give a molar ratio of 40.8:51.1:8.1. ４ 10g of C, TiB ２ The powder was weighed out at a ratio of 2 g, poured into a 1 L plastic container up to 70% of the capacity, and zirconia beads of φ5 mm were added. The mixture was mixed in a roller mixer for 30 minutes to prepare powder for additive manufacturing. The powder composition was SiC and B, which are similar to the composition of a ternary eutectic. ４ The difference in the mole fraction of C is 60 mol% pt or less, which satisfies the preferred composition range, and B is ４ The number of C particles is six times or more, and the number of TiB2 particles is greater than that of SiC and B. ４ The total number of C particles is more than the ratio of SiC:B ４ C: TiB ２ is approximately 3:120:351, which is an example of a preferred situation of the present invention.

[0082] The same shape was produced using the same molding device and molding conditions as in Example 1, and the relative density was calculated in the same way, and was found to be 95.2%. ４ By reducing the particle size of C, SiC, B ４ C, TiB ２ The median particle size (D ５０ ) are Da, Db, and Dc, Db / Da=0.366<0.4, and Dc / Da<=0.123<0.33. Furthermore, the median particle diameter satisfies the preferable particle diameter relationship, which can be said to improve the density.

[0083] (Examples 3, 4, and 5) Only the mixing ratio of particles was changed from Example 1, and powders mixed in the amounts shown in Figure 6 were prepared. These powder compositions were SiC and B ４ The preferable composition range is satisfied when the difference in the molar fraction of C is 60 mol% pt or less. The same shapes were manufactured using the same molding apparatus and molding conditions as in Example 1, and the relative densities were calculated in the same way. The results were 96.9% for Example 3, 94.5% for Example 4, and 88.8% for Example 5.

[0084] (Examples 6 and 7) For the purpose of repairing cracked areas, Si particles in the amount shown in Figure 6 were mixed with the powder of Example 1 in the same manner as for the other particles. This mixed powder was used to produce a shaped object in the same manner as in Example 1. The shaped object was subjected to heat treatment under the same conditions as in Example 1. Remnants of SiC particles that were not completely melted were observed within the wide area shown in Figure 8A, but around this, SiC regions formed through the melting of the SiC particles could be observed. Within the obtained structure, within the narrow area shown in Figure 8B, there were regions made of SiC, B ４ C, TiB ２ A region consisting of Si, C, B, and Ti was observed. The SEM image shown in Figure 8A confirmed that the cracked regions had been sufficiently repaired. The three-point bending strength of the structures of Examples 6 and 7 was a high value of 200 MPa or more. In addition, the specific rigidity of the structure of Example 6 was a high value of 135 or more. It can be said that the mechanical properties were improved by sufficiently repairing the cracked regions.

[0085] (Examples 8 and 9) For the purpose of repairing cracked areas, the powder of Example 1 was added with TiSi in the amount shown in FIG. ２ The particles were mixed in the same manner as the other particles. Using this mixed powder, a shaped object was produced in the same manner as in Example 1. The shaped object was subjected to heat treatment under the same conditions as in Example 1. Within the wide area shown in Figure 9A, remnants of SiC particles that were not completely melted and remained unmelted were observed, but around them, SiC regions formed through the melting of the SiC particles could be observed. Within the obtained structure, within the narrow area shown in Figure 9B, there were regions made of SiC, B ４ C, TiB ２ A region consisting of Si, C, B, and Ti was observed. The SEM image shown in Figure 9A confirmed that the cracked region had been sufficiently repaired. The three-point bending strength of the structures of Examples 8 and 9 was a high value of 200 MPa or more. It can be said that the mechanical properties were improved by sufficiently repairing the cracked region.

[0086] (Example 10) A shaped article similar to that of Example 1 was subjected to heat treatment at 2050°C. The obtained structure contained a region made of SiC, a region made of B ４ C, TiB ２A region consisting of Si, C, B, and Ti was observed. It was also confirmed that the cracked region had been sufficiently repaired. The three-point bending strength was a high value of 300 MPa or more. It can be said that the mechanical properties were improved by sufficiently repairing the cracked region.

[0087] (Example 11) SiC particles with a median particle size of about 30 μm, B particles with a median particle size of about 30 μm ４ C particles were prepared, and SiC:B ４ The powder was mixed in the same manner as in Example 1 so that the molar ratio of SiC to B was 50.0:50.0. ４ The preferable composition range is satisfied when the difference in the C molar fraction is 60 mol% pt or less. The same shape was produced using the same molding device and molding conditions as in Example 1, and the relative density was calculated in the same way, resulting in 97.6%. The molded object was subjected to heat treatment under the same conditions as in Example 1. Remnants of SiC particles that were not completely melted were observed within the wide area shown in Figure 10A, but around this, SiC regions formed through the melting of the SiC particles can be seen. In the obtained structure, within the narrow area shown in Figure 10B, there are regions made of SiC, B ４ A region consisting of C and a region consisting of Si, C, and B were observed. The SEM image shown in Figure 10A confirmed that the cracked region was partially repaired. The three-point bending strength of the structure of Example 11 was 160 MPa.

[0088] (Examples 12, 13, and 14) Only the particle mixing ratio was changed from Example 11, and powders mixed in the amounts shown in Figure 6 were prepared. These powder compositions were SiC and B ４ The preferable composition range is satisfied when the difference in the molar fraction of C is 60 mol% pt or less. The same shapes were produced using the same molding apparatus and molding conditions as in Example 1, and the relative densities were calculated in the same way. The results were 94.6% for Example 12, 85.3% for Example 13, and 96.9% for Example 14.

[0089] (Examples 15 and 16) For the purpose of repairing cracked areas, the powder of Example 11 was mixed with Si in the amount shown in Figure 6 in the same manner as for the other particles. This mixed powder was used to produce a shaped object in the same manner as in Example 1. The shaped object was subjected to heat treatment under the same conditions as in Example 1. Within the wide area shown in Figure 11A, remnants of SiC particles that were not completely melted and remained unmelted were observed, but around this, SiC regions formed through melting of the SiC particles could be observed. Within the obtained structure, within the narrow area shown in Figure 11B, there were regions made of SiC, B ４ A region consisting of C and a region consisting of Si, C, and B were observed. The SEM image shown in Figure 11A confirmed that the cracked region had been sufficiently repaired. The three-point bending strength was a high value of 200 MPa or more. In addition, the specific rigidity of the structure of Example 15 was a high value of 135 or more. It can be said that the mechanical properties were improved by sufficiently repairing the cracked region.

[0090] Example 17: For the purpose of repairing cracked areas, the powder of Example 11 was mixed with TiSi in the amounts shown in FIG. ２ These were mixed in the same manner as the other particles. Using this mixed powder, a shaped object was produced in the same manner as in Example 1. The shaped object was subjected to heat treatment under the same conditions as in Example 1. Within the wide area shown in Figure 12A, remnants of SiC particles that were not completely melted and remained unmelted were observed, but around this, SiC regions formed through the melting of the SiC particles could be observed. Within the obtained structure, within the narrow area shown in Figure 12B, there were regions made of SiC, B ４ C, TiB ２ A region consisting of Si, C, and B was observed. The SEM image shown in FIG. 12A confirmed that the cracked region was sufficiently repaired. The three-point bending strength of the structure of Example 17 was a high value of 200 MPa or more. It can be said that the mechanical properties were improved by sufficiently repairing the cracked region.

[0091] (Example 18) A shaped article similar to that of Example 11 was subjected to heat treatment at 2050°C. The obtained structure contained a region made of SiC, a region made of B ４A region consisting of C and a region consisting of Si, C, and B were observed. It was also confirmed that the cracked region had been sufficiently repaired. The three-point bending strength was a high value of 300 MPa or more. It can be said that the mechanical properties were improved by sufficiently repairing the cracked region.

[0092] (Comparative Example 1) SiC particles with a median particle size of about 30 μm, the same as in Example 2, and B particles with a median particle size of about 11 μm ４ C particles, TiB with a median particle size of 3.7 μm ２ Particles were prepared. SiC:B was used as the main component. ４ C: TiB ２ = 80.0:11.9:8.1 (molar ratio) ４ 2.05g of C, TiB ２ The powder was weighed out at a ratio of 1.76 g, poured into a 1 L plastic container up to 70% capacity, and zirconia beads of φ5 mm were added. The mixture was mixed in a roller mixer for 30 minutes to prepare powder for additive manufacturing. ４ In the situation where the difference in the mole fraction of C exceeds 60 mol% pt and the number of B4C particles is not six times or more the number of SiC particles in terms of the median, the ratio of the number of particles is SiC:B ４ C: TiB ２ This is an example of a situation that differs from the preferred state of this embodiment.

[0093] When the same shape was produced using the same molding device and molding conditions as in Example 1, of the seven 5 x 38 mm shapes, four were defective during molding and were unable to maintain their shape, and three maintained their final shape but were porous and broke when separated from the substrate. Thus, when the conditions of the present invention were not met, densification could not be achieved, resulting in molding defects.

[0094] (Comparative Example 2) SiC particles with a median particle size of about 30 μm, the same as in Example 11, and B particles with a median particle size of about 30 μm ４ C particles were prepared. SiC:B ４ The powder was mixed in the same manner as in Example 1 so that the molar ratio of SiC to B was 90.0:10.0, to prepare powder for additive manufacturing. ４This is an example of a situation where the difference in the molar fraction of C exceeds 60 mol % pt, which is different from the preferred state of this embodiment.

[0095] When the same shape was produced using the same molding device and molding conditions as in Example 1, seven of the seven 5 x 38 mm shapes were defective during molding and could not maintain their shape. As such, when the conditions of the present invention were not met, densification could not be achieved, resulting in molding defects.

[0096] The above-described embodiments can be modified as appropriate without departing from the technical concept. For example, multiple embodiments can be combined. Furthermore, some features of at least one embodiment can be deleted or replaced. Furthermore, new features can be added to at least one embodiment.

[0097] The present disclosure includes the following techniques 1 to 31.

[0098] [Technology 1] A powder for use in shaping, the powder containing boron, carbon, and silicon, wherein a structure including a first solid phase made of silicon carbide and a second solid phase made of boron carbide is formed by melting and solidifying the powder, and the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide in a portion having the structure is 60 mol% pt or less.

[0099] [Technology 2] The powder according to Technology 1, wherein the powder contains a metal element, and the structure includes a third solid phase made of a metal boride that is a boride of the metal element.

[0100] [Technology 3] A powder for shaping, comprising silicon carbide and boron carbide, wherein the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide in the powder is 60 mol% pt or less.

[0101] [Technology 4] The powder according to any one of Technologies 1 to 3, containing a metal boride.

[0102] [Technology 5] The powder according to any one of technologies 1 to 4, which has a particle diameter of 5 μm or more and contains particles containing silicon carbide.

[0103] [Technology 6] The powder according to any one of Technologies 1 to 5, which has a particle diameter of 5 μm or more and contains particles containing boron carbide.

[0104] [Technology 7] The powder according to any one of technologies 1 to 6, which contains particles having a particle diameter of 20 μm or more.

[0105] [Technology 8] The powder according to any one of technologies 1 to 7, wherein the difference is 30 mol% pt or less.

[0106] [Technology 9] The powder according to any one of Technologies 1 to 8, wherein the molar fraction of silicon carbide is smaller than the molar fraction of boron carbide.

[0107] [Technology 10] The powder according to any one of technologies 1 to 9, wherein the molar fraction of the silicon carbide and the molar fraction of the boron carbide are greater than the molar fraction of the metal boride.

[0108] [Technology 11] The powder according to any one of techniques 1 to 10, wherein the molar fraction of silicon carbide is 35 to 60 mol % and the molar fraction of boron carbide is 36 to 65 mol %.

[0109] [Technology 12] The powder according to any one of Techniques 1 to 11, wherein the powder includes a first particle group made of a first compound and a second particle group made of a second compound.

[0110] [Technology 13] The powder according to Technology 12, wherein the thermal conductivity of the first compound is higher than the thermal conductivity of the second compound, and the particle diameter of the first particle group is larger than the particle diameter of the second particle group.

[0111] [Technology 14] The powder according to any one of techniques 1 to 13, wherein the powder includes a first particle group consisting of a first compound, a second particle group consisting of a second compound, and a third particle group consisting of a third compound.

[0112] [Technology 15] The powder according to Technology 14, wherein the density of the third compound is higher than the density of the second compound, and the particle diameter of the third particle group is smaller than the particle diameter of the second particle group.

[0113] [Technology 16] The powder according to Technology 14 or 15, wherein the first compound is silicon carbide, the second compound is boron carbide, and the third compound is a metal boride, and the particle diameter of the first particle group is larger than the particle diameter of the second particle group, and the particle diameter of the third particle group is smaller than the particle diameter of the second particle group.

[0114] [Technology 17] The powder according to any one of techniques 14 to 16, wherein the first compound is silicon carbide, the second compound is boron carbide, and the third compound is a metal boride, and a particle diameter Da of the first particle group, a particle diameter Db of the second particle group, and a particle diameter Dc of the third particle group satisfy Db / Da<0.4 and Dc / Da<0.33.

[0115] [Technology 18] The powder according to any one of Techniques 1 to 17, wherein the metal boride is titanium boride.

[0116] [Technology 19] A method for manufacturing an article, comprising manufacturing a shaped object from a material using the powder according to any one of Technologies 1 to 18 by layered manufacturing.

[0117] [Technology 20] A method for manufacturing an article, comprising irradiating a material using the powder according to any one of Technologies 1 to 18 with infrared rays to form a shaped object.

[0118] [Technology 21] A method for manufacturing an article, in which a shaped object is formed by irradiating a material using the powder according to any one of Technologies 1 to 18 with a laser beam, wherein the particle diameter of the first particle group is larger than the particle diameter of the second particle group, the particle diameter of the third particle group is smaller than the particle diameter of the second particle group, the beam diameter of the laser beam is larger than the particle diameter of the first particle group, and the wavelength of the laser beam is smaller than the particle diameter of the third particle group.

[0119] [Technology 22] A method for manufacturing an article, comprising: forming a shaped object by heating a material using the powder according to any one of Techniques 1 to 18; and repairing cracks present in the shaped object using a material containing at least one of boron, carbon, silicon, and a metal element.

[0120] [Technology 23] A mechanical component having a structure including a first solid phase made of silicon carbide and a second solid phase made of boron carbide, wherein in a portion having the structure, the difference between the molar fraction of boron carbide and the molar fraction of silicon carbide is 60 mol% pt or less.

[0121] [Technology 24] The mechanical component according to Technology 23, wherein the structure includes a third solid phase made of a metal boride.

[0122] [Technology 25] The mechanical component according to Technology 23 or 24, wherein the molar fraction of the silicon carbide is smaller than the molar fraction of the boron carbide.

[0123] [Technology 26] The mechanical component according to any one of technologies 23 to 25, wherein in the portion having the texture, the molar fraction of the silicon carbide and the molar fraction of the boron carbide are greater than the molar fraction of the metal boride.

[0124] [Technology 27] The mechanical part according to any one of technologies 23 to 26, wherein the metal boride is titanium boride.

[0125] [Technology 28] The mechanical component according to any one of Techniques 23 to 27, which satisfies at least one of the following: at least one of the first solid phase, the second solid phase, and the third solid phase is crystalline; and the melting point of the portion having the texture structure is 1500°C or higher and 2500°C or lower.

[0126] [Technology 29] The density of the part having the structure is 2.6 to 4.4 [g / cm ３ ], the Young's modulus of the part having the texture structure is 390 [GPa] or more, and the Young's modulus [GPa] / density [g / cm ３ 28. The mechanical part according to any one of techniques 23 to 27, which satisfies at least one of the following conditions:

[0127] [Technology 30] A mechanical unit comprising the mechanical part according to any one of Technologies 23 to 27 and a movement mechanism that moves the mechanical part.

[0128] [Technology 31] A manufacturing apparatus comprising a machine unit that holds and / or transports a workpiece and a processing unit that processes the workpiece, wherein the machine unit includes a machine part according to any one of techniques 23 to 27.

[0129] The disclosure of this specification includes not only what is explicitly described herein, but also all matters that can be understood from this specification and the drawings attached hereto. Furthermore, the disclosure of this specification includes the complement of each individual concept described herein. In other words, if this specification contains a statement that "A is B," for example, it can be said that this specification discloses the case where "A is not B," even if it omits a statement about the case where "A is not B." This is because a statement that "A is B" presupposes that the case where "A is not B" is taken into consideration.

[0130] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention.

[0131] This application claims priority based on Japanese Patent Application No. 2023-056852, filed on March 31, 2023, the entire contents of which are incorporated herein by reference.

[0132] 10 Powder 1, 2, 3 Compound 11, 12, 13 Particle (group) 21, 22, 23 Solid phase 7 Machine part

Claims

1. A powder for shaping, the powder contains boron, carbon, and silicon as elements, the powder contains particles having a particle diameter of 50 μm or less and containing boron carbide; a structure including a first solid phase made of silicon carbide and a second solid phase made of boron carbide is formed by melting and solidifying the powder; A powder characterized in that in the portion having the textured structure, the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide is 60 mol % pt or less.

2. the powder contains a metal element, 2. The powder of claim 1, wherein the structure includes a third solid phase comprising a metal boride, which is a boride of the metallic element.

3. A powder for shaping, the powder contains silicon carbide and boron carbide; the powder includes particles having a particle diameter of 5 μm or more containing silicon carbide and particles having a particle diameter of 50 μm or less containing boron carbide, A powder characterized in that the difference between the molar fraction of silicon carbide and the molar fraction of boron carbide in the powder is 60 mol % pt or less.

4. The powder of claim 3 containing a metal boride.

5. the powder includes a particle group containing silicon carbide, 4. The powder according to claim 1, wherein the median particle diameter of the particle group is 5 μm or more and 100 μm or less.

6. the powder includes a particle group containing boron carbide, 4. The powder according to claim 1, wherein the median particle diameter of the particle group is 5 μm or more and 50 μm or less.

7. The powder according to claim 1 or 3, which contains elemental silicon.

8. The powder according to claim 1 or 3, wherein the difference is 30 mol% pt or less.

9. The powder according to claim 1 or 3, wherein the mole fraction of silicon carbide is smaller than the mole fraction of boron carbide.

10. The powder according to claim 2 , wherein in the portion having the textured structure, the molar fraction of the silicon carbide and the molar fraction of the boron carbide are greater than the molar fraction of the metal boride.

5. The powder of claim 4, wherein the mole fraction of silicon carbide and the mole fraction of boron carbide are greater than the mole fraction of metal boride in the powder.

11. 4. The powder according to claim 1, wherein the molar fraction of said silicon carbide is 35 to 60 mol % and the molar fraction of said boron carbide is 36 to 65 mol %.

12. The powder according to claim 1 or 3, comprising a first particle group made of a first compound and a second particle group made of a second compound.

13. the thermal conductivity of the first compound is higher than the thermal conductivity of the second compound; The powder according to claim 12 , wherein the median particle diameter of the first particle group is larger than the median particle diameter of the second particle group.

14. 4. The powder according to claim 1, wherein the powder comprises a first particle group consisting of a first compound, a second particle group consisting of a second compound, and a third particle group consisting of a third compound.

15. the density of the third compound is higher than the density of the second compound; The powder according to claim 14 , wherein the median particle diameter of the third particle group is smaller than the median particle diameter of the second particle group.

16. the first compound is silicon carbide, the second compound is boron carbide, and the third compound is a metal boride; 16. The powder according to claim 15, wherein the median particle diameter of the first particle group is larger than the median particle diameter of the second particle group, and the median particle diameter of the third particle group is smaller than the median particle diameter of the second particle group.

17. the first compound is silicon carbide, the second compound is boron carbide, and the third compound is a metal boride; a median particle diameter Da of the first particle group, a median particle diameter Db of the second particle group, and a median particle diameter Dc of the third particle group, Db / Da<0.4 and Dc / Da<0.33 The powder according to claim 15, which satisfies the above formula.

18. 5. The powder of claim 2 or 4, wherein the metal boride is titanium boride.

19. A method for manufacturing an article, comprising: forming a shaped object from a material using the powder according to claim 1 or 3 by layered manufacturing.

20. A method for manufacturing an article, comprising irradiating a material using the powder according to claim 1 or 3 with infrared rays to form a shaped object.

21. A method for manufacturing an article, comprising irradiating a material using the powder according to claim 16 with a laser beam to form a shaped object, the particle diameter of the first particle group is larger than the particle diameter of the second particle group, and the particle diameter of the third particle group is smaller than the particle diameter of the second particle group; a beam diameter of the laser beam is larger than a particle diameter of the first particle group, and a wavelength of the laser beam is smaller than a particle diameter of the third particle group.

22. A method for manufacturing an article, comprising heating a material using the powder according to claim 1 or 3 to form a shaped object, A method for manufacturing an article, comprising repairing cracks present in the shaped object using a material containing at least one of boron, carbon, silicon and a metal element.

23. The silicon carbide alloy has a structure including a first solid phase made of silicon carbide and a second solid phase made of boron carbide, A mechanical component characterized in that in the portion having the structure, the difference between the molar fraction of boron carbide and the molar fraction of silicon carbide is 30 mol % pt or less.

24. 24. The machine component of claim 23, wherein the structure includes a third solid phase consisting of a metal boride.

25. 24. The mechanical component of claim 23, wherein the mole fraction of silicon carbide is less than the mole fraction of boron carbide.

26. 25. The mechanical component of claim 24, wherein in the structured portion, the mole fraction of the silicon carbide and the mole fraction of the boron carbide are greater than the mole fraction of the metal boride.

27. 25. The machine component of claim 24, wherein the metal boride is titanium boride.

28. at least one of the first solid phase, the second solid phase, and the third solid phase is crystalline; and the melting point of the portion having the textured structure is 1500°C or higher and 2500°C or lower; The mechanical component according to claim 24, which satisfies at least one of the following conditions.

29. The density of the part having the texture structure is 2.6 to 4.4 [g / cm ３ ], The Young's modulus of the portion having the texture structure is 390 [GPa] or more; and Young's modulus [GPa] / density [g / cm ３ ] is 100 or more, The mechanical component according to claim 23, which satisfies at least one of the following conditions.

30. A mechanical unit comprising: the mechanical component according to claim 23; and a movement mechanism that moves the mechanical component.

31. A manufacturing apparatus comprising a machine unit that holds and / or transports a workpiece, and a processing unit that processes the workpiece, wherein the machine unit includes the machine part according to claim 23.

32. A method for manufacturing an article, comprising heating a powder containing boron, carbon, and silicon as elements to form a shaped object, the method comprising: the powder contains boron carbide; The method for producing the boron carbide is characterized in that the boron carbide is melted by the heating.

33. a structure including a first solid phase made of silicon carbide and a second solid phase made of boron carbide is formed by melting and solidifying the powder; 33. The method of claim 32, wherein the mole fraction of silicon carbide is less than the mole fraction of boron carbide in the textured portion.

34. The method of claim 32, wherein the powder comprises particles having a particle size of 50 μm or less and containing boron carbide.

35. the powder includes a particle group containing boron carbide, The method according to claim 32, wherein the median particle diameter of the particle group is 1 μm or more and 50 μm or less.

36. The method of claim 32 , wherein the powder comprises elemental silicon.

37. The method of claim 32 , wherein the powder contains silicon carbide.

38. The method of claim 32, wherein the powder comprises a metal boride.

39. The method of claim 32 , wherein the powder comprises a metal silicide.

40. 40. A method according to any one of claims 32 to 39, wherein the heating is carried out by irradiating the material with an infrared laser beam.