Ngk Insulators, Inc.

Takashi Ando

Nobuo Tsuno

Yoshizumi Nakasuji

Takao Soma

Isao Oda

A metal-ceramic joined, composite body comprises a metallic member and a ceramic member. The metallic member and the ceramic member are provided with a recess and a projection, respectively, and are integrally joined by inserting the projection into the recess. The recess of the metallic member is provided with a stepped portion to increase an inner diameter of the recess at an opening portion thereof, and a brazing metal is interposed at least in a gap between the stepped portion and the projection of the ceramic member. Alternatively, a groove is provided over substantially the entire periphery of the projection of the ceramic member in vicinity of an end of a joined portion between the metallic member and the ceramic member, and a brazing metal is interposed at least between an edge of the groove and the recess of the metallic member. Besides the above, the axial length L.sub.2 of the joined portion and the diameter D of the projection may be set to satisfy the following relationship: ##EQU1##

Metal-ceramic joined composite bodies

Composite bodies comprise a metallic member and a ceramic member integrally joined together by joining a projection of the ceramic member to a recess of the metallic member. Their joining strength is improved by substantially limiting brazing metal to an interface between the outer peripheral surface of the projection of the ceramic member and the innner peripheral surface of the recess of the metallic member. The joining strength is also improved by forming a groove around the outer periphery of the metallic member at the joined end. The joining strength is also improved by providing a space or an intermediate member between a tip end surface of the projection and a bottom surface of the recess and attaining the relation: ##EQU1## in which G, L.sub.1, .alpha., .alpha.', T.sub.S and T.sub.R are the thickness of the space or the intermediate member, a distance from the bottom surface of the recess of the metallic member to the joining end, a coefficient of thermal expansion of the metallic member, a coefficient of thermal expansion of the ceramic member, a solidifying temperature of the brazing metal, and room temperature, respectively. The joining strength is also improved by radially enlarging the recess near the opening and thinning the brazing metal toward the opening of the recess.

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Nagoya, Japan

Takashi Ando