Disclosed are a composite sintered body for a cutting tool and a cutting tool using the same. The composite sintered body for a cutting tool has enhanced heat conductivity and electrical conductivity to be strong against abrasion by heat and impact and to be capable of minimizing an influence on an edge during an Electrical Discharge Machine (EDM) operation.

A W.sub.18O.sub.49 peak is confirmed by X-ray diffraction analysis of a sputtering surface and a cross section orthogonal to the sputtering surface, a ratio I.sub.S(103)/I.sub.S(010) of a diffraction intensity I.sub.S(103) of a (103) plane to a diffraction intensity I.sub.S(010) of a (010) plane of W.sub.18O.sub.49 of the sputtering surface is 0.38 or less, a ratio I.sub.C(103)/I.sub.C(010) of a diffraction intensity I.sub.C(103) of the (103) plane to a diffraction intensity I.sub.C(010) of the (010) plane of W.sub.18O.sub.49 of the cross section is 0.55 or more, and an area ratio of W.sub.18O.sub.49 phase of a surface parallel to the sputtering surface is 37% or more.

One aspect relates to a process for producing a sintered workpiece, which includes sintering of a ceramic material at a temperature of at least 1000° C. and in an atmosphere, in the case of which the partial pressure of atmospheric air is reduced to less than 10.sup.−6-times, based on the ambient air at the same temperature under equilibrium conditions.

A method for producing a ceramic complex includes: preparing a raw material mixture that contains 5% by mass or more and 40% by mass or less of first rare earth aluminate fluorescent material particles containing an activating element and a first rare earth element different from the activating element, 0.1% by mass or more and 32% by mass or less of oxide particles containing a second rare earth element, and the balance of aluminum oxide particles, relative to 100% by mass of the total amount of the first rare earth aluminate fluorescent material particles, the oxide particles, and the aluminum oxide particles; preparing a molded body of the raw material mixture; and obtaining a sintered body by calcining the molded body in a temperature range of 1,550° C. or higher and 1,800° C. or lower.

A transparent complex oxide sintered body is manufactured by sintering a compact in an inert atmosphere or vacuum, and HIP treating the sintered compact, provided that the compact is molded from a source powder based on a rare earth oxide: (Tb.sub.xY.sub.1-x).sub.2O.sub.3 wherein 0.4≤x≤0.6, and the compact, when heated in air from room temperature at a heating rate of 15° C./min, exhibits a weight gain of at least y % due to oxidative reaction, y being determined by the formula: y=2x+0.3. The sintered body has a long luminescent lifetime as a result of controlling the valence of Tb ion.

A cordierite-based sintered body according to the present invention contains cordierite as a main component and silicon nitride or silicon carbide. The cordierite-based sintered body preferably has a thermal expansion coefficient less than 2.4 ppm/° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1 μm or less.

A ceramic complex including a first crystal phase containing a first rare earth aluminate fluorescent material containing an activating element and a first rare earth element that is different from the activating element, and a second crystal phase containing aluminum oxide, having a content of the first crystal phase in a range of 5% by volume or more and 40% by volume or less and a content of the second crystal phase in a range of 57% by volume or more and 95% by volume or less based on a total amount of the ceramic complex, having an average value of a second crystal diameter of the second crystal phase measured under the particular measurement condition of 12 μm or less, and having a QD value of 0.5 or less expressed by QD=(D.sub.75−D.sub.25)/(D.sub.75+D.sub.25), wherein D.sub.25 and D.sub.75 are defined in the disclosure.

Provided is at least one of a zirconia sintered body and a method for producing the same. The zirconia sintered body can be used in a wide range of applications compared with ceramic joined bodies of the related art that include transparent zirconia. A zirconia sintered body includes a transparent zirconia portion and an opaque zirconia portion, wherein the zirconia sintered body has a biaxial flexural strength of greater than or equal to 300 MPa.

A sputtering target includes at least one single piece with a length of at least 600 mm. The sputtering target has a backing structure provided with target material for sputtering. At least 40% of the mass of the target material includes a so-called target volatile material which shows, at pressures between 700 hPa and 1300 hPa, either a sublimation temperature, or decomposition temperature below its melting point or a melting temperature and an absolute boiling temperature being close to each other. The sputtering target has a target material density of at least 95% of the theoretical density of the target material. The sputtering target includes a bonding layer with a thickness of 0 to 500 μm between the backing structure and the target material.

A method of manufacturing a sputtering target includes the steps of providing a backing structure, providing target material comprising ceramic target material for spraying, subsequently thermal spraying the target material over the backing structure thus providing a target product where at least 40% in mass, for example at least 50% in mass, of the target material including a ceramic target material, and subsequently performing hot isostatic pressing on the target product thus increasing the density of the target material.