Niterra Co., Ltd.

Osaka University

Ntk Cutting Tools Co., Ltd.

Hiroki Takeuchi

Hidetoshi Fujii

Yoshiaki Morisada

Hiroki Yamauchi

Shohei Takaku

Yusuke Katsu

Shinji Ban

Hiroshi Watanabe

Tomoo Tanaka

Jun Moteki

Yosuke Yatsuya

Yuki Takeuchi

Katsuya Takaoka

Toshiyuki Sakurai

Satoshi Mori

Manami Fujii

Yasushi Hara

Hisashi Kozuka

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

The iron loss of a dust core is reduced. A dust core () includes soft magnetic metal particles () having an average particle size of 5 μm or more and 30 μm or less, and a particle boundary phase (). The particle boundary phase () includes a polycrystalline compound containing Al (aluminum). When a sectional structure of the dust core () is observed, an area percentage of α-AlOin the particle boundary phase () is 75% or less. An average thickness Ta of the particle boundary phase () is 10 nm or more and 300 nm or less. According to the present invention, the iron loss is reduced.

Dust core

There is provided a wavelength conversion member including: a fluorescent body and a reflective film. The fluorescent body is configured to emit fluorescence by an excitation light and has an incident surface into which the excitation light comes and a rear surface which faces the incident surface. The reflective film is arranged on a side of the rear surface of the fluorescent body and includes a metal layer and ceramic particles dispersed in the metal layer. The ceramic particles are crystalline, and a melting point of the ceramic particles is higher than a melting point of a metal constructing the metal layer.

Wavelength conversion member and light source device provided therewith

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

A fluorescent plate includes a fluorescent phase which emits fluorescence by excitation light, a light-transmitting phase which allows passage of the excitation light, and a plurality of voids surrounded by the fluorescent phase and the light-transmitting phase, wherein, in a cross section of the fluorescent plate including cross sections of the voids, an average ratio of a portion of the circumference of a void, which portion is in contact with the fluorescent phase to the entire circumference of the void, is higher than an area ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate.

Fluorescent plate, wavelength conversion member, and light source device

Growing community of inventors

Nagoya, Japan

Hiroki Takeuchi