Abstract: A friction stir welding tool (1) has a shoulder portion (2) and a probe portion (6) provided on a bottom surface of the shoulder portion (2). The probe portion (6) has a length of 5.5 mm or more. In the friction stir welding tool (1), a ceramic material whose main phase is silicon nitride or sialon is used as a base material.

Abstract: In one aspect of the present disclosure, there is provided an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula X3Al5O12:Ce. In the optical wavelength conversion member 9, atoms of element X are present also in an Al2O3 crystal grain adjacent to the interface between the Al2O3 crystal grain and an X3Al5O12:Ce crystal grain.

Abstract: One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula (Y,A)3B5O12:Ce. In the optical wavelength conversion member, a (Y,A)3B5O12:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A)3B5O12:Ce crystal grain is higher than that of an interior portion of the (Y,A)3B5O12:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A)3B5O12:Ce crystal grain differs from that in an interior portion of the crystal grain.

Abstract: A wavelength conversion member for soldering includes a ceramic fluorescent body for converting a wavelength of light entering from an incident surface of the ceramic fluorescent body, a reflection layer disposed on a back surface of the ceramic fluorescent body on a side opposite the incident surface and partially or entirely covering the back surface, and a junction layer composed of one or more films and covering at least the reflection layer selected from the back surface of the ceramic fluorescent body and the reflection layer. The junction layer has a projecting portion which projects, in relation to an outer circumferential portion of the junction layer, in a center portion of a surface on a side opposite a surface on a side where the junction layer covers at least the reflection layer selected from the back surface and the reflection layer.

Abstract: An optical wavelength converter (1) is configured such that an optical wavelength conversion member (9) is bonded to a heat dissipation member (13) having superior heat dissipation property. Thus, heat generated by light incident on the optical wavelength conversion member (9) can be efficiently dissipated. Therefore, even when high-energy light is incident on the optical wavelength converter, temperature quenching is less likely to occur, and thus high fluorescence intensity can be maintained. An intermediate film (21) is disposed between a reflective film (19) and a bonding portion (15). The presence of the intermediate film (21) improves the adhesion between the reflective film (19) and the bonding portion (15), thereby enhancing the heat dissipation from the optical wavelength conversion member (9) to the heat dissipation member (13). Thus, the temperature quenching of the optical wavelength conversion member (9) can be prevented, thereby enhancing fluorescence intensity.

Abstract: Provided is a ceramic sintered body having high wear resistance and chipping resistance. Also provided are an insert, a cutting tool and a friction stir welding tool, each of which uses such a high-performance ceramic sintered body. The ceramic sintered body includes Al2O3 (alumina), WC (tungsten carbide) and ZrO2 (zirconia), wherein Zr (zirconium) element is present at either one or both of: (1) a grain boundary between crystal grains of the Al2O3; and (2) a grain boundary of crystal grains of the Al2O and crystal grains of the WC, wherein the ceramic sintered body contains 55.0 to 97.5 vol % of the WC, 0.1 to 18.0 vol % of the ZrO2, and the balance being the Al2O3, and wherein the ZrO2 is in a phase of tetragonal structure (T) or a mixed phase of tetragonal structure (T) and monoclinic structure (M).

Abstract: An optical wavelength conversion device includes an optical wavelength conversion member configured to convert the wavelength of incident light; a heat dissipation member which is more excellent in heat dissipation than the optical wavelength conversion member; and a joint portion which joins the optical wavelength conversion member and the heat dissipation member together. The optical wavelength conversion member includes a plate-shaped ceramic fluorescent body and a reflecting film disposed on a heat dissipation member-side surface of the ceramic fluorescent body. The joint portion has a thermal conductivity of 120 W/mK or more. The joint portion has a melting point of 240° C. or higher.

Abstract: A kitchen knife (1) includes a blade (3). The blade (3) is formed of a material having a density of 12.9 g/cc or more and a Young's modulus of 345 GPa or more.

Abstract: A friction stir welding tool (1) has a shoulder portion (2) and a probe portion (6) provided on a bottom surface of the shoulder portion (2). The probe portion (6) has a length of 5.5 mm or more. In the friction stir welding tool (1), a ceramic material whose main phase is silicon nitride or sialon is used as a base material.

Abstract: An optical wavelength conversion member (9) provided with a ceramic plate (11) which is configured from a polycrystalline body that is mainly composed of Al2O3 and a component represented by A3B5O12:Ce; and each of A and B in A3B5O12 represents at least one element selected from the element groups described below. In addition, a dielectric multilayer film (13) which transmits a specific wavelength and reflects another specific wavelength is formed on a light incident surface (11a) of the ceramic plate (11). The ceramic plate (11) has a porosity of 2% by volume or less, while having an average surface roughness (an arithmetic mean roughness Sa) of 0.5 ?m or less. A: Sc, Y and lanthanoids (excluding Ce) B: Al and Ga. Also disclosed is a light-emitting device including the optical wavelength conversion member.

Abstract: In one aspect of the present disclosure, there is provided an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula X3Al5O12:Ce. In the optical wavelength conversion member 9, atoms of element X are present also in an Al2O3 crystal grain adjacent to the interface between the Al2O3 crystal grain and an X3Al5O12:Ce crystal grain.

Abstract: One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula (Y,A)3B5O12:Ce. In the optical wavelength conversion member, a (Y,A)3B5O12:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A)3B5O12:Ce crystal grain is higher than that of an interior portion of the (Y,A)3B5O12:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A)3B5O12:Ce crystal grain differs from that in an interior portion of the crystal grain.

Abstract: A method for producing an optical wavelength conversion member (9) composed of a sintered body containing, as main components, Al2O3 and a component represented by formula A3B5O12:Ce; an optical wavelength conversion member; an optical wavelength conversion component including the optical wavelength conversion member; and a light-emitting device including the optical wavelength conversion member or the optical wavelength conversion component. The production method of the sintered body includes firing in a firing atmosphere having a pressure of 104 Pa or more and an oxygen concentration of 0.8 vol. % or more and less than 25 vol. %.

Abstract: An optical wavelength conversion member according to one aspect of the present disclosure includes a ceramic sintered body, wherein the ceramic sintered body has a fluorescent phase containing, as a main. component, fluorescent crystal grains that generate fluorescence in response to incident light, and a translucent phase containing translucent crystal grains as a main component. The optical wavelength conversion member includes a metal layer having light reflectivity and provided on a side of the ceramic sintered body opposite the side on which the light is incident, and a dielectric multilayer film including dielectric layers having different optical refractive indices and provided between the ceramic sintered body and the metal layer.

Abstract: An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The light-emitting device (1) includes a container (3), a light-emitting element (5), and an optical wavelength conversion member (9). The optical wavelength conversion member (9) is composed of a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains of a component represented by formula A3B5O12:Ce. Specifically, A and B of the A3B5O12 individually represent at least one element selected from the following element groups: A: Sc, Y, and lanthanoids (except for Ce), and B: Al and Ga; the at least one element selected from the element groups is present in each crystal grain and the crystal grain boundary of the ceramic sintered body; and the element concentration of the crystal grain boundary is higher than the element concentration of the crystal grain.

Abstract: Provided is an optical wavelength conversion device in which heat of an optical wavelength conversion member can be dissipated efficiently while the joint strength between the optical wavelength conversion member and a heat dissipation member is maintained. In the present disclosure, the optical wavelength conversion device includes an optical wavelength conversion member configured to convert the wavelength of incident light; a heat dissipation member which is more excellent in heat dissipation than the optical wavelength conversion member; and a joint portion which joins the optical wavelength conversion member and the heat dissipation member together. The optical wavelength conversion member includes a plate-shaped ceramic fluorescent body and a reflecting film disposed on a heat dissipation member-side surface of the ceramic fluorescent body. The joint portion has a thermal conductivity of 120 W/mK or more. The joint portion has a melting point of 240° C. or higher.

Abstract: An optical wavelength conversion member (9) provided with a ceramic plate (11) which is configured from a polycrystalline body that is mainly composed of Al2O3 and a component represented by A3B5O12:Ce; and each of A and B in A3B5O12 represents at least one element selected from the element groups described below. In addition, a dielectric multilayer film (13) which transmits a specific wavelength and reflects another specific wavelength is formed on a light incident surface (11a) of the ceramic plate (11). The ceramic plate (11) has a porosity of 2% by volume or less, while having an average surface roughness (an arithmetic mean roughness Sa) of 0.5 ?m or less. A: Sc, Y and lanthanoids (excluding Ce) B: Al and Ga. Also disclosed is a light-emitting device including the optical wavelength conversion member.

Abstract: An optical wavelength converter (1) is configured such that an optical wavelength conversion member (9) is bonded to a heat dissipation member (13) having superior heat dissipation property. Thus, heat generated by light incident on the optical wavelength conversion member (9) can be efficiently dissipated. Therefore, even when high-energy light is incident on the optical wavelength converter, temperature quenching is less likely to occur, and thus high fluorescence intensity can be maintained. An intermediate film (21) is disposed between a reflective film (19) and a bonding portion (15). The presence of the intermediate film (21) improves the adhesion between the reflective film (19) and the bonding portion (15), thereby enhancing the heat dissipation from the optical wavelength conversion member (9) to the heat dissipation member (13). Thus, the temperature quenching of the optical wavelength conversion member (9) can be prevented, thereby enhancing fluorescence intensity.

Abstract: The durability of a ceramic sintered body is improved, and a reduction in its light emission intensity and the occurrence of a chromaticity variation are suppressed. The ceramic sintered body contains alumina and a compound represented by M13-XM2XM35O12. The volume percent of the compound in the ceramic sintered body is from 3% to 70% inclusive. The ratio of the intensity of XRD from a complex oxide of aluminum and M2 to the intensity of XRD from the compound in the ceramic sintered body is less than 0.05. The average grain diameter of the alumina contained in the ceramic sintered body is from 0.30 (?m) to 3.00 (?m) inclusive. M1 is at least one selected from Sc, Y, and lanthanoid elements, and M2 is at least one selected from lanthanoid elements except any lanthanoid element selected for M1. M3 is at least one of Al and Ga, and X is from 0.003 to 0.500 inclusive.

Abstract: An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The optical wavelength conversion member (9) is formed of a ceramic sintered body having a fluorescent phase containing fluorescent crystal grains as a main component and a translucent phase containing translucent crystal grains as a main component. Crystal grains of the fluorescent phase have a composition represented by formula A3B5O12:Ce, where the element A is selected from Sc, Y, and lanthanoids (except for Ce), and the element B is selected from Al and Ga. In the optical wavelength conversion member (9), 0.3<a<34 and 300 ?m<y<1,050 ?m are satisfied, wherein a represents the area ratio of the translucent phase to the fluorescent phase in a cross section of the optical wavelength conversion member (9), and y represents the interfacial length of the fluorescent phase.