Abstract: A Ni-based alloy powder for additive manufacturing contains, in terms of % by mass, 3.5% to 5.5% of Al, 0.8% to 4.0% of Cr, 0.02% to 0.06% of C, 1.0% to 1.8% of Si, 1.5% or less of Mn, and 0.001% to 0.050% of O, and a balance consisting of Ni and inevitable impurities, in which the content of Zr in the inevitable impurities is limited to 0.01% or less.

Abstract: A crack evaluation method of an additively manufactured object, which is a method evaluating a crack sensitivity of an additively manufactured object, includes the following. A crack evaluation device is additively manufactured using a raw material powder. The crack evaluation device includes: a body part, a base part opposed to the body part, a connecting part connecting one end side of the body part and the base part, a stress concentration part connecting another end side of the body part and the base part, and a comb tooth part connecting, by comb teeth, the body part and the base part between the connecting part and the stress concentration part. The crack sensitivity is evaluated based on cracked comb teeth at the crack evaluation device serving as the additively manufactured object.

Abstract: An austenitic stainless steel includes a mixed grain structure composed of a columnar crystal having an average crystal grain size of 20 ?m or less and an equiaxed crystal having an average crystal grain size of 5.0 ?m or less, in which an area proportion of the columnar crystal in the mixed grain structure is 20% or more, and an average crystal grain size of the whole mixed grain structure is 5.0 ?m or less. Accordingly, it is possible to provide a material having excellent irradiation resistance and mechanical properties.

Abstract: An object of the invention is to provide: an alloy article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the alloy article; and a product using the alloy article. There is provided an alloy article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities. And, ultrafine particles with an average diameter of 40 nm or less are dispersedly precipitated in matrix phase crystals of the alloy article.

Abstract: An austenitic stainless steel includes a mixed grain structure composed of a columnar crystal having an average crystal grain size of 20 ?m or less and an equiaxed crystal having an average crystal grain size of 5.0 ?m or less, in which an area proportion of the columnar crystal in the mixed grain structure is 20% or more, and an average crystal grain size of the whole mixed grain structure is 5.0 ?m or less. Accordingly, it is possible to provide a material having excellent irradiation resistance and mechanical properties.

Abstract: A manufacturing system of an additive manufacturing body is provided, by which the accuracy of evaluating a defect during additive manufacturing and the quality of the body can be improved. A manufacturing system of an additive manufacturing body of the present invention includes: an additive manufacturing device; an inspection device having a camera for photographing the powder layer or the solidified layer; and a control device that controls the additive manufacturing device and the inspection device, in which: the camera can photograph the powder layer for each powder layer forming step that is performed repeatedly, or can photograph the solidified layer for each solidified layer forming step that is performed repeatedly; and the control device selects a photographing condition of the camera according to the conditions of the additive manufacturing process.

Abstract: A nuclear reactor fuel rod is a fuel rod for a light-water reactor. The nuclear reactor fuel rod includes a fuel cladding tube and an end plug, both of which are formed of a silicon carbide material. A bonding portion between the fuel cladding tube and the end plug is formed by brazing with a predetermined metal bonding material interposed, and/or by diffusion bonding. The predetermined metal bonding material has a solidus temperature of 1200° C. or higher. An outer surface of the bonding portion, and a portion of an outer surface of the fuel cladding tube and the end plug, which is adjacent to the outer surface of the bonding portion are covered by bonding-portion coating formed of a predetermined coating metal. The predetermined metal bonding material and the predetermined coating metal have an average linear expansion coefficient which is less than 10 ppm/K.

Abstract: An object of the invention is to provide: an HEA article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the HEA article; and a product using the HEA article. There is provided an HEA article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities.

Abstract: There is provided an additive manufacturing apparatus that can effectively removing fume even in a vacuum state. An additive manufacturing apparatus 1 includes a fume capturing mechanism 8 that is provided to be movable in a space R defined between a beam source 9 and a stage 51, and that captures fume F generated due to melting of a powder P.

Abstract: An alloy structure has an arbitrary shape dimension which has high uniformity in the distribution of the element composition. The alloy structure contains Fe and at least four elements, which are selected from the group consisting of elements from atomic number 13 to atomic number 79 included in Group 3 to Group 16 of the periodic table of the elements and have a ratio of the atomic radius to an Fe atom of 0.83 or more but 1.17 or less, each of Fe and the four elements is contained in an atomic concentration range of 5 at % or more but 30 at % or less, a difference in atomic concentration between at least four elements among the at least four elements and Fe is in a range of less than 3 at %, and the alloy structure has, a column crystal in which the at least four elements and Fe are solid-dissolved.

Abstract: An alloy structure which has high uniformity in the distribution of the element composition and the mechanical strength and excellent high-temperature strength and corrosion resistance, contains Fe and at least four elements, which are selected from the group consisting of elements from atomic number 13 to atomic number 79, included in Group 3 to Group 16 of the periodic table of the elements, and have a ratio of the atomic radius to an Fe atom of 0.83 or more but 1.17 or less, each of the elements in an atomic concentration range of 5 at % or more but 30 at % or less, a difference in atomic concentration among the at least four elements and Fe is in a range of less than 3 at %, and the alloy structure has, as a main crystal, a column crystal in which the at least four elements and Fe are solid-dissolved.

Abstract: The purpose of the present invention is to obtain an additive manufacturing device capable of manufacturing while reducing the flow rate of Ar gas. This additive manufacturing device is characterized in that a reduced-pressure atmosphere is maintained in a manufacturing area, an inert gas is supplied to the manufacturing area, the proportion of gaseous impurities in the manufacturing area is detected, and in case where the proportion of gaseous impurities exceeds a threshold value, the supply of inert gas is reduced.

Abstract: An object of the invention is to provide: an alloy article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the alloy article; and a product using the alloy article. There is provided an alloy article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities. And, ultrafine particles with an average diameter of 40 nm or less are dispersedly precipitated in matrix phase crystals of the alloy article.

Abstract: An object of the invention is to provide: an HEA article that has excellent homogeneity in the alloy composition and microstructure as well as significant shape controllability, using an HEA with significant mechanical strength and high corrosion resistance; a method for manufacturing the HEA article; and a product using the HEA article. There is provided an HEA article comprising: Co, Cr, Fe, Ni, and Ti elements, each element in content of 5 to 35 atomic %; more than 0 atomic % to 8 atomic % of Mo %; and remainder substances of unavoidable impurities.

Abstract: A nuclear reactor fuel rod is a fuel rod for a light-water reactor. The nuclear reactor fuel rod includes a fuel cladding tube and an end plug, both of which are formed of a silicon carbide material. A bonding portion between the fuel cladding tube and the end plug is formed by brazing with a predetermined metal bonding material interposed, and/or by diffusion bonding. The predetermined metal bonding material has a solidus temperature of 1200° C. or higher. An outer surface of the bonding portion, and a portion of an outer surface of the fuel cladding tube and the end plug, which is adjacent to the outer surface of the bonding portion are covered by bonding-portion coating formed of a predetermined coating metal. The predetermined metal bonding material and the predetermined coating metal have an average linear expansion coefficient which is less than 10 ppm/K.

Abstract: An electric storage device includes a container which houses an electric generating element, and a sealing plug which seals a liquid injecting hole into which an electrolyte is injected. The liquid injecting hole is provided in a bottom surface of a recessed portion provided to be recessed on one side surface of the container. The sealing plug includes an inserting portion to be inserted into the liquid injecting hole and a fitting portion to be fitted into the recessed portion. At least either a rim portion of the fitting portion or an opening rim portion of the recessed portion is provided with a plurality of plastic deformation portions.

Abstract: An alloy structure which has high uniformity in the distribution of the element composition and the mechanical strength and excellent high-temperature strength and corrosion resistance, contains Fe and at least four elements, which are selected from the group consisting of elements from atomic number 13 to atomic number 79, included in Group 3 to Group 16 of the periodic table of the elements, and have a ratio of the atomic radius to an Fe atom of 0.83 or more but 1.17 or less, each of the elements in an atomic concentration range of 5 at % or more but 30 at % or less, a difference in atomic concentration among the at least four elements and Fe is in a range of less than 3 at %, and the alloy structure has, as a main crystal, a column crystal in which the at least four elements and Fe are solid-dissolved.

Abstract: An alloy structure has an arbitrary shape dimension which has high uniformity in the distribution of the element composition. The alloy structure contains Fe and at least four elements, which are selected from the group consisting of elements from atomic number 13 to atomic number 79 included in Group 3 to Group 16 of the periodic table of the elements and have a ratio of the atomic radius to an Fe atom of 0.83 or more but 1.17 or less, each of Fe and the four elements is contained in an atomic concentration range of 5 at % or more but 30 at % or less, a difference in atomic concentration between at least four elements among the at least four elements and Fe is in a range of less than 3 at %, and the alloy structure has, a column crystal in which the at least four elements and Fe are solid-dissolved.

Abstract: An object of the present invention is to reduce spatter generation by stabilizing a keyhole in a laser welding method. A welded joint in which a plurality of workpieces are welded by irradiation with a laser beam, wherein the following formulae 1 to 3 are satisfied, b/a?0.6—(formula 1), h/d?1.0—(formula 2), and h/a<3.0—(formula 3), where a is a surface width of a weld bead formed across the plurality of workpieces, h is a maximum penetration depth of the weld bead, b is a penetration width of the weld bead at a position where a penetration depth of the weld bead is h/2, and d is the penetration depth at a center position of the weld bead.

Abstract: An electric storage device includes a container which houses an electric generating element, and a sealing plug which seals a liquid injecting hole into which an electrolyte is injected. The liquid injecting hole is provided in a bottom surface of a recessed portion provided to be recessed on one side surface of the container. The sealing plug includes an inserting portion to be inserted into the liquid injecting hole and a fitting portion to be fitted into the recessed portion. At least either a rim portion of the fitting portion or an opening rim portion of the recessed portion is provided with a plurality of plastic deformation portions.