| abstract |
[PROBLEMS] To overcome a drawback of a conventional ceramic sinter that, due to a fact that, in a floating quantity of not more than 10 nm, an importance has become placed to surface smoothness of a floating face, in order to provide this floating face, polishing should be carried out using small diamond abrasive grains having an average particle diameter of not more than 0.1 μm, and, hence, the machinability of the conventional ceramic sinter is so poor that a magnetic head manufactured from this ceramic sinter has not satisfied a requirement for a floating quantity of not more than 10 nm. [MEANS FOR SOLVING PROBLEMS] A ceramic sintercomprises an Al2O3 crystal grain, an internal TiC crystal grain present within the Al2O3 crystal grain, and an external TiC grain other than the internal TiC crystal grain. After sintering, stress attributable to the difference in coefficient of thermal expansion remains in the Al2O3 crystal grain and the external TiC crystal grain. At the interface of the Al2O3 crystal grain and the external TiC crystal grain, mutually pulled state occurs. In this case, upon machining, in addition to shear force caused by this machining, the residual stress causes easy progress of microcracks at the interface contributing to improved machinability. |