A polycrystalline ceramic solid and a method for producing a polycrystalline ceramic solid are disclosed. In an embodiment a polycrystalline ceramic solid includes a main phase with a composition of the general formula: (1-y)Pb.sub.a(Mg.sub.bNb.sub.c)O.sub.3-e+yPb.sub.aTi.sub.dO.sub.3 with 0.055≤y≤0.065, 0.95≤a≤1.02, 0.29≤b≤0.36, 0.63≤c≤0.69, 0.9≤d≤1.1, and 0≤e≤0.1, and optionally one or more secondary phases, wherein, in each section through the solid, a proportion of the secondary phases relative to any given cross-sectional area through the solid is less than or equal to 0.5 percent, or wherein the solid is free of the secondary phases.

A composite sintered material includes a plurality of diamond grains, a plurality of cubic boron nitride grains, and a remainder of a binder phase, wherein the binder phase includes cobalt, a content of the cubic boron nitride grains in the composite sintered material is more than or equal to 3 volume % and less than or equal to 40 volume %, and an average length of line segments extending across continuous cubic boron nitride grains in appropriately specified straight lines extending through the composite sintered material is less than or equal to a length three times as large as an average grain size of the cubic boron nitride grains.

A filter for the filtration of a fluid, such as a liquid, includes or composed of a support element made of a porous ceramic material, the element having a tubular or parallelepipedal shape delimited by an external surface and including, in its internal portion, a set of adjacent channels with axes parallel to one another and separated from one another by walls of the porous inorganic material, wherein at least a portion of the channels and/or at least a portion of the external surface are covered with a porous separating membrane layer, wherein the layer is made of a material essentially composed of sintered grains of silicon carbide (SiC), and the weight content of elemental oxygen of the layer is less than 0.5%.

Provided is a zirconia sintered body having both high translucency and high strength. The zirconia sintered body includes crystal grains that include a cubic domain and a tetragonal domain, wherein a stabilizer and lanthanum is dissolved as a solid solution therein. The sintered body can be obtained by a manufacturing method including: a mixing step of obtaining a mixed powder by mixing a zirconia source, a stabilizer source, and a lanthanum source; a molding step of obtaining a green body by molding the obtained mixed powder; a sintering step of obtaining a sintered body by sintering the obtained green body at a sintering temperature of 1650° C. or higher; and a temperature lowering step of lowering the temperature from the sintering temperature to 1000° C. at a temperature lowering rate exceeding 1° C./min.

A particle mixture having: ZrO.sub.2+HfO.sub.2+Y.sub.2O.sub.3+CeO.sub.2; 0%≤Al.sub.2O.sub.3≤1.5%; other oxides than ZrO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, CeO.sub.2 and Al.sub.2O.sub.3: between 0.5% and 12%. The contents of Y.sub.2O.sub.3 and CeO.sub.2, on the basis of the sum of ZrO.sub.2, HfO.sub.2, Y.sub.2O.sub.3 and CeO.sub.2, being such that 1.8%≤Y.sub.2O.sub.3≤3% and 0.1%≤CeO.sub.2≤0.9%. The mixture includes between 0.5% and 10% of particles of an oxide pigment. The content of other oxides and which are not included in the oxide pigment being less than 2%. The particles of the oxide pigment including, for more than 95%, of a material chosen from: oxide(s) of perovskite structure or equivalent of precursor(s) of these oxides, oxides of spinal structure or an equivalent amount of precursor(s) of these oxides, and oxides of hematite structure E.sub.2O.sub.3, oxides of rutile structure FO.sub.2, with “E” and “F” being chosen.

[Object] Provided are a Zn—Sn—O-based oxide sintered body which is used as a sputtering target or a tablet for vapor deposition and which is resistant to crack formation and the like during film formation, and a method for producing the same. [Solving means] The oxide sintered body is characterized in that tin is contained with an atomic ratio of Sn/(Zn+Sn) being 0.01 to 0.6, an average crystal particle diameter of the sintered body is 4.5 μm or less, and a degree of orientation represented by I.sub.(222)/[I.sub.(222)+I.sub.(400)] is 0.52 or more, where I.sub.(222) and I.sub.(400) represent integrated intensities of the (222) plane and the (400) plane of a Zn.sub.2SnO.sub.4 phase measured by X-ray diffraction using the CuKα radiation. The oxide sintered body has an improved mechanical strength, so that the oxide sintered body is resistant to breakage during processing of the sintered body and also is resistant to breakage and crack formation during film formation of transparent conductive films when used as a sputtering target or a tablet for vapor deposition.

An alumina/titanium silicon carbide composite material is prepared by making titanium aluminum carbide (Ti.sub.3AlC.sub.2) in uniform contact with silicon monoxide (SiO), and carrying out vacuum sintering. The composite material is obtained through mutual diffusion of aluminum and silicon and has high compactness and stable performance. In the composite material, the alumina is generated by means of a reaction between the titanium aluminum carbide and the silicon monoxide, and can be uniformly wrapped around surfaces of titanium silicon carbide crystals to form a relatively compact oxide film, such that substance exchange between a matrix and the outside is hindered, and overall antioxidation of the composite material is improved. Toughness of the composite material is enhanced by means of the titanium silicon carbide. The prepared composite material has relatively high purity, relatively low sintering temperature, and relatively high bending strength. The process is simple and convenient for industrial production.

A cBN sinter comprising cubic boron nitride grains and a binder phase, the binder phase comprising Ti.sub.2CN and TiAl.sub.3, wherein the ratio I.sub.Ti2CN/I.sub.TiAl3 of the peak intensity I.sub.Ti2CN of Ti.sub.2CN appearing at 2θ=41.9° to 42.2° to the peak intensity I.sub.TiAl3 of TiAl.sub.3 appearing at 2θ=39.0° to 39.3° is in a range of 2.0 to 30.0 in an XRD measurement.

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.

A precursor of an alumina sintered compact including aluminum, yttrium, and at least one metal selected from iron, zinc, cobalt, manganese, copper, niobium, antimony, tungsten, silver, and gallium. The aluminum content is 98.0% by mass or more as an oxide (Al.sub.2O.sub.3) in 100% by mass of the precursor of an alumina sintered compact; the yttrium content is 0.01 to 1.35 parts by mass as an oxide (Y.sub.2O.sub.3) based on 100 parts by mass of the content of the aluminum as an oxide; the total content of the metals selected from the foregoing group is 0.02 to 1.55 parts by mass as an oxide based on 100 parts by mass of the content of aluminum as an oxide; and the aluminum is contained as α-alumina. Also disclosed is an alumina sintered compact, and a method for producing an alumina sintered compact and for producing abrasive grains.