Hitachi Metals, Ltd.

Jidosha Kiki Co., Ltd.

Koichiro Kurihara

Yasunobu Ogata

Mitusuke Masaka

Yoshitsugu Furui

Kouji Hatanaka

A soft magnetic metal strip laminate that has high adhesion strength between metal strips, free from delamination, an excellent magnetic property, a high space factor, and a process for production thereof. A process for production of a soft magnetic metal strip laminate that includes plural soft magnetic metal strips laminated by using a polyamide acid solution includes the steps of applying the polyamide acid solution on the soft magnetic metal strip, performing semicuring heat treatment to obtain the degree of imidization of the polyamide acid solution which is in the range of 15 to 70%, laminating plural soft magnetic metal strips to each other through the polyamide acid solution, and performing the heat treatment of the heating and the hot pressing to obtain the degree of imidization of the polyamide acid solution which is more than 90%.

Soft magnetic metal strip laminate and process for production thereof

A glow plug for diesel engines in which a ceramic heater is supported, with the one end thereof cantilevered toward the outside, by the tip of a hollow holder; the ceramic heater is composed of a U-shaped heating portion and a pair of leads extending backwards from both ends of the U-shaped heating portion, both being formed integrally by an electrically conductive sintered sialon, which is formed by adding a small amount of Al.sub.2 O.sub.3 to a raw meal containing Si.sub.3 N.sub.4 as a principal ingredient, a small amount of AlN polytype and no greater than 5 wt. % of Y.sub.2 O.sub.3, and mixing the addition product with 23-70 vol. % of at least one type of Ti carbide, nitride and carbide-nitride; an insulating layer is provided on the outer periphery of at least one of the leads and bonded to, and held by, the inside of the holder; and the rear end of the other of the leads is connected by means of a metallic lead wire to an external connection terminal held in an insulated state at the lead end of said holder.

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Kumagaya, Japan

Koichiro Kurihara