In one aspect, sintered ceramic bodies are described herein which, in some embodiments, demonstrate improved resistance to wear and enhanced cutting lifetimes. For example, a sintered ceramic body comprises tungsten carbide (WC) in an amount of 40-95 weight percent, alumina in an amount of 5-30 weight percent and ditungsten carbide (W.sub.2C) in an amount of at least 1 weight percent.

An aluminum nitride-based sintered compact includes: aluminum nitride crystal particles containing Mg; composite oxide containing a rare earth element and Al, the composite oxide having a garnet crystal structure; and composite oxynitride containing Mg and Al. Particles of the composite oxide and particles of the composite oxynitride are interspersed between the aluminum nitride crystal particles. The composite oxide may include Y. A content of Mg in the aluminum nitride crystal particles may fall in a range of 0.1 mol % or more and 1.0 mol % or less, based on a total of all metal elements contained in the aluminum nitride crystal particles taken as 100 mol %. A semiconductor holding device includes the aluminum nitride-based sintered compact; and an electrostatic adsorptive electrode.

A window pane for an interceptor missile includes a light transmissive base material and light transmissive additive particles dispersed within a thickness of the light transmissive base material so as to define stress nodes, the stress nodes localizing, upon applied thermal shock or thermal heating, crack propagation around each stress node and/or between two or more adjacent stress nodes and preventing a continuous crack propagation through any one of a length, a width and a thickness of the window pane.

A sintered material includes a first phase and a second phase, wherein the first phase is composed of cubic boron nitride particles, and the following relational expressions are satisfied when more than or equal to two cubic boron nitride particles adjacent to and in direct contact with each other among the cubic boron nitride particles are defined as a contact body, Di represents a length of an entire perimeter of the contact body, n represents the number of contact locations at which the cubic boron nitride particles are in direct contact with each other, d.sub.k represents a length of each of the contact locations, and d.sub.k (where k=1 to n) represents a total length of the contact locations: Dii=Di+(2d.sub.k (where k=1 to n)); and [(DiiDi)/Dii]10050.

Embodiments of transparent ceramic particles are described. A particle includes an outer shell having an outer surface and an inner surface forming a hollow core; and a response unit housed inside the hollow core.

A sintered material includes a first material and a second material, the first material being partially stabilized ZrO.sub.2 having a crystal grain boundary or crystal grain in which 5 to 90 volume % of Al.sub.2O.sub.3 is dispersed with respect to a whole of the first material, the second material including at least one of SiAlON, silicon nitride and titanium nitride, the sintered material including 1 to 50 volume % of the first material.

The present invention relates to a light-transmitting ceramic sintered body which contains air voids having pore diameters of 1 m or more but less than 5 m at a density within the range of from 10 voids/mm.sup.3 to 4,000 voids/mm.sup.3 (inclusive), while having a closed porosity of from 0.01% by volume to 1.05% by volume (inclusive). With respect to this light-transmitting ceramic sintered body, a test piece having a thickness of 1.90 mm has an average transmittance of 70% or more in the visible spectrum wavelength range of 500-900 nm, and the test piece having a thickness of 1.90 mm has a sharpness of 60% or more at a comb width of 0.5 mm.

Provided is a method for producing a -sialon fluorescent material, comprising preparing a composition containing a silicon nitride that contains aluminium, oxygen, and europium; heat-treating the composition at a temperature in a range of 1300 C. or more and 1600 C. or less to obtain a heat-treated product; subjecting the heat-treated product to a temperature-decrease of from the heat treatment temperature to 1000 C. as a first temperature-decrease step; and subjecting the heat-treated product to a temperature-decrease of from 1000 C. to 400 C. as a second temperature-decrease step. The first temperature-decrease step has a temperature-decrease rate in a range of 1.5 C./min or more and 200 C./min or less, and the second temperature-decrease step has a temperature-decrease rate in a range of 1 C./min or more and 200 C./min or less

To provide a sintered material having excellent oxidation resistance, as well as excellent abrasion resistance and chipping resistance. A sintered material containing a first compound formed of Ti, Al, Si, O, and N is provided.

A SiAlON sintered body according to the present invention is represented by Si.sub.6-zAl.sub.zO.sub.zN.sub.8-z (0<z4.2) and has an open porosity of 0.1% or less and a relative density of 99.9% or more. A ratio of a total of intensities of maximum peaks of components other than SiAlON to an intensity of a maximum peak of the SiAlON in an X-ray diffraction diagram is 0.005 or less.