Ngk Spark Plug Company, Limited

Osaka University

Ntk Cutting Tools Co., Ltd.

Jun Moteki

Takeshi Mitsuoka

Yusuke Katsu

Tsuneyuki Ito

Shohei Takaku

Kuniharu Tanaka

Hidetoshi Fujii

Yoshiaki Morisada

Hiroki Takeuchi

Yuki Takeuchi

Yuki Shimura

Yoshihiro Kuroki

Hironobu Kusanagi

Yasushi Hara

A friction stir welding tool and a friction stir welding method that can increase the amount of heat generation, while reducing the amount of escaping heat are provided. The friction stir welding tool () has a shoulder portion () and a probe portion () provided on a bottom surface of the shoulder portion (). The base material of the friction stir welding tool () is a ceramic material whose main phase is silicon nitride or sialon. The shoulder portion () has a diameter of 35 mm or greater.

Friction stir welding tool and friction stir welding method

A method for producing an optical wavelength conversion member () composed of a sintered body containing, as main components, AlOand a component represented by formula ABO: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 10Pa or more and an oxygen concentration of 0.8 vol. % or more and less than 25 vol. %.

Method for producing light wavelength conversion member, light wavelength conversion member, light wavelength conversion component and light emitting device

An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The light-emitting device () includes a container (), a light-emitting element (), and an optical wavelength conversion member (). The optical wavelength conversion member () is composed of a polycrystalline ceramic sintered body containing, as main components, AlOcrystal grains and crystal grains of a component represented by formula ABO:Ce. Specifically, A and B of the ABOindividually 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.

Light wavelength conversion member and light emitting device

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 M1M2M3O. 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 (&#x3bc;m) to 3.00 (&#x3bc;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.

Ceramic sintered body

An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The optical wavelength conversion member () 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 ABO: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 (), 0.3&#x3c;a&#x3c;34 and 300 &#x3bc;m&#x3c;y&#x3c;1,050 &#x3bc;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 (), and y represents the interfacial length of the fluorescent phase.

Optical wavelength conversion member and light-emitting device

An optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, AlOcrystal grains and crystal grains of a component represented by formula ABO:Ce, wherein A is at least one element selected from Sc, Y and lanthanoids (except for Ce), and B is at least one element selected from Al and Ga. Further, the following relations are satisfied: 0%&#x2264;X&#x2264;25%, 9%&#x2264;Y&#x2264;45%, and 48%&#x2264;Z&#x2264;90%, wherein X represents a proportion corresponding to the ratio a/N, Y represents a proportion corresponding to the ratio b/N, and Z represents a proportion corresponding to the ratio c/N and a, b, c and N are as defined herein. Also disclosed is a light-emitting device including the optical wavelength conversion member.

Light wavelength conversion member and light emission device

In a ceramic composition mainly composed of alumina (AlO), tungsten carbide (WC) and zirconia (ZrO), zirconium (Zr) is distributed in a first grain boundary as an interface where an alumina (AlO) crystal grain is adjacent to a tungsten carbide (WC) crystal grain and in a second grain boundary as an interface where two alumina (AlO) crystal grains are adjacent to each other.

Ceramic composition and cutting tool

A ceramic sintered body includes tungsten carbide, zirconia, and alumina. The content of the tungsten carbide is 20 to 50 vol %, and the content of the zirconia is 5 to 25 vol %. The crystal phase of the zirconia is a tetragonal crystal or a mixture of tetragonal and monoclinic crystals. The ceramic sintered body does not substantially include Ti compounds. The average particle diameter of the tungsten carbide, the average particle diameter of the zirconia, and the average particle diameter of the alumina are all 1 &#x3bc;m or less.

A sintered body containing alumina crystal particles and zirconia crystal particles as main components includes the tetragonal crystal particles as the zirconia crystal particles. The zirconia crystal particles satisfy relations 0%&#x2266;A&#x2266;3%, 3%&#x2266;B&#x2266;22% and 77%&#x2266;C&#x2266;96%,where A, B and C are as defined herein.

Growing community of inventors

Seto, Japan

Jun Moteki