Toyota Jidosha Kabushiki Kaisha

Toshiba Ceramics Co., Ltd.

Yoshitomo Shintani

Tetsuya Suganuma

Hajime Saito

Shuitsu Matsuo

Katsuichi Kitagawa

Yukio Okochi

Hidenori Yamaoka

Hiroaki Kotaka

Nobuhisa Kurono

A method of measuring the density of a plurality of defects that occur in a single crystal for each type of defect, includes: etching an observation surface, which is a surface of the single crystal, to form an etch pits at each defect; calculating the maximum depth, mean depth and depth curvature of each of etch pits formed at a plurality of defects present within a predetermined area on the observation surface; and comparing the measured maximum depth, mean depth and depth curvature with respective reference values to determine the type of each defect within the predetermined area.

Method of measuring defect density of single crystal

The present invention provides a process for producing aluminum oxide fibers and, particularly, a process for producing aluminum fibers that have a high aspect ratio and can be accurately aligned, said process for producing aluminum oxide fibers comprising the steps of: uniformly mixing an aluminum or aluminum alloy powder with a boron oxide powder or a powder which, upon heating, can be converted to a boron oxide powder; and heating the mixed powder, or comprising the steps of: mixing not more than 50% by weight, in terms of titanium, of a titanium or titanium alloy powder to the starting mixture; and heating the mixed powder.

Process for producing aluminum oxide fibers

Aluminium borate whiskers by which a composite material having a higher strength than ever is available by definitely suppressing a generation of spinel along the surface of the whiskers are prepared by heating aluminium borate whiskers bearing a r-alumina surface layer in an atmosphere of ammonia gas or ammonia gas and a hydrocarbon gas such that a layer of a nitro-oxide and oxide of aluminium is generated along the surface of the whiskers.

Method of manufacturing aluminum borate whiskers having a reformed

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Susono, Japan

Yoshitomo Shintani