Nkk Corporation

Fuji Electric Co., Ltd.

Canon Kabushiki Kaisha

Hitoshi Nagashima

Kenji Morita

Daiji Okamura

Hisao Kamo

Takatoshi Tanaka

Isamu Oguri

Hiroyoshi Suenaga

Kenichi Yamaguchi

Makoto Takada

Masanori Ohmura

Keigo Gouda

Hiroshi Asakawa

Noboru Kurata

Kouichirou Okumura

Masahito Miyabe

Takakazu Mizutani

Iwao Ida

Toshio Sakiyama

Yoko Okano

Naoto Kohshiro

Saki Suzuki

Shin-Ichi Hakamada

The object of the present invention is to provide titanium discs to be used as high-density read-while-write magnetic discs. Further object of the present invention is to provide said titanium discs coated with a non-magnetic plated layer. Titanium discs to be used as magnetic discs which satisfy the above object have the following structures: A titanium disc to be used as magnetic disc having the mean height of the peaks from the center line, R.sub.a, of 0.0002 .mu.m to 0.0060 .mu.m and pits on its surface of 25 .mu.m or less in diameter or 5 .mu.m or less in depth. Further, said titanium disc to be used as a magnetic disc is coated with a non-magnetic plated layer with a thickness of 0.09 .mu.m to 5 .mu.m. Moreover, a titanium disc that is most suitable to be used as a magnetic disc is the titanium disc provided with a plated layer of 30/100 or less in a knife-cut peeling test.

Titanium discs useful for magnetic discs

A method of manufacturing a magnetic disk substrate made of titanium, in which chemical etching is performed on a titanium disk for magnetic disk substrate, thereby removing a surface portion thereof having a thickness of at least 2 nm, and the new surface of the titanium disk, formed by the chemical etching, is anodized, thereby forming anodized film on the titanium disk.

Method of manufacturing a magnetic disk substrate of titanium

Growing community of inventors

Tokyo, Japan

Hitoshi Nagashima