THE GRAS SAF PROJECT: RADIO OCCULTATION PRODUCTS FROM METOP

1. Disclosed is a ceramic sintered body comprising, as main components, (a) 60 to 80% by weight of alumina and (b) 20 to 40% by weight of titanium carbide or a combination of titanium carbide and titanium oxide, wherein said ceramic sintered body further comprises (c) 1 to 10 parts by weight, per 100 parts by weight of the sum of the components (a) and (b), of zirconium oxide, at least a part of which is composed of a tetragonal crystal, and (d) 0.4 to 11% by weight, based on the total ceramic sintered body, of a crystal phase of a composite oxide consisting of magnesium oxide and aluminum. This ceramic sintered body is excellent in the chipping resistance, machinability and surface smoothness, and the ceramic sintered body is suitable as a material of a substrate for a thin film head.