Abstract: A ceramic-metal composite joint body wherein a projection of a ceramic member is connected to a metal member, having a construction such that a ratio D between a circularity c of an outer portion of the projection and an outer diameter d of the projection: i.e., D=(c/d).times.100(%), is set to less than 0.03%. In this invention, since the ratio D=(c/d).times.100(%) is set to less than 0.03%, a stress concentration generated at a connection edge of the projection of the ceramic member can be reduced, and thus a ceramic-metal composite joint body having good reliability and durability can be obtained.

Abstract: A ceramic turbo charger rotor having a bearing structure in which an inner race of an angular ball bearing and a spacer are assembled to a journal shaft as one unit in such a manner that one end of the spacer is assembled to a turbine-side connecting portion of the journal shaft by a pressure inserting manner and the other end of the spacer is assembled to a compressor-side connecting portion of the journal shaft by a clearance fitting manner. Therefore, the deviation between a center axis and a rotational axis of the rotor caused by the pressure insertion of the spacer is released at the compressor side and the amount of the unbalance before correcting of the rotor is remarkably reduced.

Abstract: In a method of manufacturing a ceramic turbo charger rotor, wherein an inner race of an angular ball bearing and a spacer are integrally secured to a journal portion of a metal shaft for connecting a ceramic turbine rotor and a metal compressor rotor, the inner race and the spacer are inserted to the journal portion of the metal shaft under a condition such that a tensile load is applied to the metal shaft.

Abstract: In a shaft composite structure wherein a ceramic shaft integrally formed with a ceramic turbine rotor is fixed to a metal sleeve integrally formed with a metal rotary shaft of a compressor impeller, a connection edge is located at a position corresponding to a recess for seal ring, and a thickness of tip portion of the metal sleeve is made thin to reduce a stiffness.Therefore, a stress concentration at the connection edge can be eliminated effectively and thus a reliable shaft composite structure can be obtained.

Abstract: A ceramic-metal composite body is produced by fitting a protruding portion of a ceramic member into a concave portion of a metallic member. In this case, the protruding portion has a quantity of undulation in a plane including the axial line of the protruding portion of not more than 5 .mu.m.

Abstract: Ceramic parts of complicated configurations with different thicknesses at different portions can be mass produced economically with high production yield and excellent quality using an injection molding process.

Abstract: A metal-ceramic composite body comprises a metallic member and a ceramic member fitted thereinto. The metallic member has an effective strain A represented by the equation: A=(T.sub.a -T.sub.r).times..DELTA..sub.a +.DELTA..sub.d.

Abstract: Disclosed herein is a method of manufacturing ceramics, which comprises the steps of: applying a film of an elastic material on a ceramic shaped body and hydrostatically pressing the resulting shaped body, heating the pressed body while being buried into an inorganic powder having an average particle size of 10 to 300 .mu.m to remove the elastic film, and firing the resulting body.

Abstract: A method of producing a radial type ceramic turbine rotor having a shaft, a hub connected thereto, a blade portion radially extending from the hub whose end on an air exit side extends from an end of the blade portion on the air exit side, comprises steps of injection molding a ceramic material into a ceramic rotor body and machining extra thicker portions of the molded rotor to a predetermined shaped turbine rotor.According to the invention, the molded rotor is formed by the injection molding so as to be at least 0.5 mm thicker than a predetermined thickness at a fillet between the hub and the blade portion on the air exit side and the molded rotor is then machined by a diamond wheel to remove the extra thicker portions until the thicker fillet becomes to the predetermined thickness to from a predetermined shaped turbine rotor which is free from cracks to have a high strength.