Toshiba Ceramics Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Toshiba Monofrax Co., Ltd.

Hiroaki Kotaka

Hidenori Yamaoka

Shuitsu Matsuo

Nobuhisa Kurono

Tetsuya Suganuma

Hajime Saito

Yasuo Misu

Yoshitomo Shintani

Mikiya Fujii

Yoshirou Aiba

Shuuitsu Matsuo

Hiroyuki Terada

Masahiro Ando

Disclosed is a method of manufacturing aluminum nitride, which comprises the steps of preparing a mixed gas consisting essentially of an ammonia gas and at least 0.5% by volume of a hydrocarbon gas, calcining .gamma.-Al.sub.2 O.sub.3 or a precursor thereof at 300.degree. to 1,100.degree. C. so as to prepare the .gamma.-Al.sub.2 O.sub.3 having a moisture content of 1 weight % or less; heating the calcined .gamma.-Al.sub.2 O.sub.3 in the mixed gas at a temperature of 1,200.degree. to 1,700.degree. C., thereby preparing porous aluminum nitride having a specific surface area of 10 m.sup.2 /g or more; and heat-treating the porous aluminum nitride in an atmosphere of an ammonia gas, or a mixed gas of an ammonia gas and an inert gas, at 1600.degree. to 2000.degree. C., so as to make contents of both carbon and oxygen contained in the aluminum nitride 1 weight % or less.

Method of manufacturing aluminum nitride

Quartz material is subjected to a heat contact treatment with ammonia gas at 1200.degree. C. less under the presence of a carbon generating source to form a silicon oxynitride layer on the surface of the quartz material easily and rapidly. The obtained surface-treated quartz material has excellent heat resistance, and no exfoliation of the silicon oxynitride layer from the quartz material occurs even when it is subjected to a repetitive heat cycle. Further, if a second surface treatment step of coating a silicon nitride film on the silicon oxynitride layer using a CVD method or the like is performed after the surface treatment step of forming the silicon oxynitride layer on the surface of the quartz material, the heat resistance is more improved.

Surface treatment method for quartz material

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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Nagoya, Japan

Hiroaki Kotaka