Abstract: A method for manufacturing a core (S1) includes: a coating step (S20) of adding an organic binder to a large particle group composed of silica-containing large particles, and coating surfaces of the large particles with the organic binder; a mixing step (S30) of mixing, after the coating step (S20), the large particle group and a small particle group composed of silica-containing small particles having a smaller particle size than the large particles; a laminate shaping step (S40) of forming, after the mixing step (S30), a molding in which a mixture of the large and small particle groups is used; and a sintering step (S60) of sintering the molding after the laminate shaping step (S40).

Abstract: A coating layer including solely silicon alkoxide or mixed alkoxide of silicon alkoxide and aluminum alkoxide is formed on a surface of a sintered precision-casting core body mainly including silica particles so as to seal holes formed in the surface. As a result, it is possible to prevent the breakage of the core during casting.

Abstract: Provided is a Ni-based single crystal superalloy containing 6% by mass or more and 12% by mass or less of Cr, 0.4% by mass or more and 3.0% by mass or less of Mo, 6% by mass or more and 10% by mass or less of W, 4.0% by mass or more and 6.5% by mass or less of Al, 0% by mass or more and 1% by mass or less of Nb, 8% by mass or more and 12% by mass or less of Ta, 0% by mass or more and 0.15% by mass or less of Hf, 0.01% by mass or more and 0.2% by mass or less of Si, and 0% by mass or more and 0.04% by mass or less of Zr, and optionally containing at least one element selected from B, C, Y, La, Ce, and V, with a balance being Ni and inevitable impurities.

Abstract: A method for manufacturing a core (S1) includes: a coating step (S20) of adding an organic binder to a large particle group composed of silica-containing large particles, and coating surfaces of the large particles with the organic binder; a mixing step (S30) of mixing, after the coating step (S20), the large particle group and a small particle group composed of silica-containing small particles having a smaller particle size than the large particles; a laminate shaping step (S40) of forming, after the mixing step (S30), a molding using to a laminate shaping method in which a mixture of the large and small particle groups is used; and a sintering step (S60) of sintering the molding after the laminate shaping step (S40).

Abstract: A coating layer including solely silicon alkoxide or mixed alkoxide of silicon alkoxide and aluminum alkoxide is formed on a surface of a sintered precision-casting core body mainly including silica particles so as to seal holes formed in the surface. As a result, it is possible to prevent the breakage of the core during casting.

Abstract: A precision-casting core body is formed by mixing and sintering silica particles and silica fume. The resistance of the mixture of silica fume decreases during heating injection molding, and hence the fluidity is improved by the addition of silica fume. As a result, since the fluidity is improved, it is possible to decrease an injection molding pressure when a core is manufactured. Further, the mixture can be applied to a thin compact and a complex compact with improved fluidity.

Abstract: A coating layer including solely silicon alkoxide or mixed alkoxide of silicon alkoxide and aluminum alkoxide is formed on a surface of a sintered precision-casting core body mainly including silica particles so as to seal holes formed in the surface. As a result, it is possible to prevent the breakage of the core during casting.

Abstract: Provided is a precision casting mold to be used to produce a cast product. The precision casting mold includes a core having a shape corresponding to an internal hollow portion of the cast product and an outer mold corresponding to a shape of an outer peripheral surface of the cast product, and the outer mold is made up of: a prime layer which is formed on an inner peripheral surface and is formed from a slurry film obtained by drying slurry for the precision casting mold including mono-dispersed alumina (Al2O3) ultrafine particles having a particle size of 1.0 ?m or smaller; and a multi-layered backup layer which is formed on the outside of the prime layer by repeatedly forming a first backup layer obtained by forming and drying a slurry layer formed from the slurry for the precision casting mold and a stucco layer in which a stucco material is adhered to the slurry layer.

Abstract: Provided is a precision casting mold to be used to produce a cast product. The precision casting mold includes a core having a shape corresponding to an internal hollow portion of the cast product and an outer mold corresponding to a shape of an outer peripheral surface of the cast product, and the outer mold is made up of: a prime layer which is formed on an inner peripheral surface and is formed from a slurry film obtained by drying slurry for the precision casting mold including mono-dispersed ultrafine alumina particles having a particle size of 1.0 ?m or smaller; and a multi-layered backup layer which is formed on the outside of the prime layer by repeatedly forming a first backup layer obtained by forming and drying a slurry layer formed from the slurry for the precision casting mold and a stucco layer in which silicon carbide (SiC) as a stucco material is adhered to the slurry layer.

Abstract: Provided is a precision casting mold to be used to produce a cast product. The precision casting mold includes a core having a shape corresponding to an internal hollow portion of the cast product and an outer mold corresponding to a shape of an outer peripheral surface of the cast product, and the outer mold is made up of: a prime layer (first dried film) (101A) which is formed on an inner peripheral surface and is formed from a slurry film obtained by drying slurry for the precision casting mold including mono-dispersed ultrafine zirconia particles having a particle size of 1.0 ?m or smaller (preferably, 0.3 to 0.5 ?m, disclosed in Examples); and a multi-layered backup layer (105A) which is formed on the outside of the prime layer (first dried film) (101A) by repeatedly forming a backup layer (second dried film) (104-1) obtained by forming and drying a slurry layer (102) formed from the slurry for the precision casting mold and a stucco layer (103) in which a stucco material is adhered to the slurry layer.

Abstract: Provided is a precision casting mold including a core having a shape corresponding to an internal hollow portion of a cast product and an outer mold corresponding to a shape of an outer peripheral surface of the cast product, and the outer mold is made up of: a prime layer which is formed on an inner peripheral surface and is a slurry film obtained by drying slurry for the precision casting mold which includes mono-dispersed ultrafine alumina particles and silica sol having a particle size of 1.0 ?m or smaller and functions as mullite during firing; and a multi-layered backup layer which is formed on the outside of the prime layer by repeatedly forming a first backup layer obtained by forming and drying a slurry layer formed from the slurry for the precision casting mold and a stucco layer in which a stucco material is adhered to the slurry layer.

Abstract: Provided is a precision casting mold including a core and an outer mold, and the outer mold is made up of: a prime layer which is formed from a slurry film obtained by drying slurry for the precision casting mold including a silica sol having a particle size of 20 nm; and a multi-layered backup layer which is formed on the outside of the prime layer by repeatedly forming a first backup layer obtained by forming and drying a slurry layer formed from the slurry for the precision casting mold and a stucco layer in which stucco particles as a stucco material having particle size distribution, in which a mixing ratio of the fine particles having a particle size of 50 to 500 ?m is 1; the mixing ratio of the medium particles having a particle size of 0.5 to 2 mm is 1 to 16; and the mixing ratio of the coarse particles having a particle size of 2 to 4 mm is 1 to 40, is adhered to the slurry layer.

Abstract: Provided is a Ni-based single crystal superalloy containing 6% by mass or more and 12% by mass or less of Cr, 0.4% by mass or more and 3.0% by mass or less of Mo, 6% by mass or more and 10% by mass or less of W, 4.0% by mass or more and 6.5% by mass or less of Al, 0% by mass or more and 1% by mass or less of Nb, 8% by mass or more and 12% by mass or less of Ta, 0% by mass or more and 0.15% by mass or less of Hf, 0.01% by mass or more and 0.2% by mass or less of Si, and 0% by mass or more and 0.04% by mass or less of Zr, and optionally containing at least one element selected from B, C, Y, La, Ce, and V, with a balance being Ni and inevitable impurities.

Abstract: A welding method forms a molten build-up portion on a base material that is any one of a single crystal material and a unidirectionally solidified crystal material. The method includes forming a plurality of build-up portions on the base material while maintaining a predetermined gap between adjacent build-up portions; and forming a build-up portion in each of the predetermined gaps.

Abstract: A welding method forms a molten build-up portion on a base material that is any one of a single crystal material and a unidirectionally solidified crystal material. The method includes forming a plurality of build-up portions on the base material while maintaining a predetermined gap between adjacent build-up portions; and forming a build-up portion in each of the predetermined gaps.

Abstract: Provided is a directional solidification casting apparatus capable of heightening a cooling effect when molten material poured in a mold is directionally solidified. A mold (20) disposed around a predetermined area is drawn out from a heating chamber (10) heated above a melting temperature of metals for producing a casting (31), and molten metals (32) held in a cavity (21) of the mold (20) are directionally solidified. The directional solidification casting apparatus (100) comprises a driving rod (42) by which the mold (20) is drawn out from the heating chamber (10), a gas nozzle (52b) through which a cooling gas is jetted from inside a predetermined area where the mold (20) is disposed so as to rapidly cool the mold (20), and a gas nozzle (52a) through which a cooling gas is jetted from outside the predetermined area where the mold (20) is disposed so as to rapidly cool the mold (20). A baffle (15) that does not move even when the driving rod (42) moves up and down is additionally provided.

Abstract: Provided is a directional solidification casting apparatus capable of heightening a cooling effect when molten material poured in a mold is directionally solidified. A mold (20) disposed around a predetermined area is drawn out from a heating chamber (10) heated above a melting temperature of metals for producing a casting (31), and molten metals (32) held in a cavity (21) of the mold (20) are directionally solidified. The directional solidification casting apparatus (100) comprises a driving rod (42) by which the mold (20) is drawn out from the heating chamber (10), a gas nozzle (52b) through which a cooling gas is jetted from inside a predetermined area where the mold (20) is disposed so as to rapidly cool the mold (20), and a gas nozzle (52a) through which a cooling gas is jetted from outside the predetermined area where the mold (20) is disposed so as to rapidly cool the mold (20). A baffle (15) that does not move even when the driving rod (42) moves up and down is additionally provided.