Composite ceramic materials are disclosed herein which comprise two or more crystalline phases, wherein a first crystalline phase comprises a first refractory material having a first melting point, and a second crystalline phase comprises a second refractory material having a second melting point which is lower than the first melting point, and the second crystalline phase comprises large domain sizes of the second refractory material. Articles comprising such a composite ceramic material, such as honeycomb bodies, catalytic substrates, and particulate filters, are also disclosed herein, in addition to methods of manufacture thereof.

A dielectric composition with high voltage resistance and favorable reliability, and an electronic component using the dielectric composition. The dielectric composition contains, as a main component, a tungsten bronze type composite oxide represented by a chemical formula (Sr.sub.1.00-(s+t)Ba.sub.sCa.sub.t).sub.6.00-xR.sub.x(Ti.sub.1.00-aZr.sub.a).sub.x+2.00(Nb.sub.1.00-bTa.sub.b).sub.8.00-xO.sub.30.00, in which the R is at least one element selected from Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and s, t, x, a, and b satisfy 0.50s1.00, 0t0.30, 0.50s+t1.00, 1.50<x3.00, 0.20a1.00, and 0b1.00. At least one selected from Mn, Mg, Co, V, W, Mo, Si, Li, B, and Al is contained as a sub component in 0.10 mol or more and 20.00 mol or less with respect to 100 mol of the main component.

Provided is a wear resistant, sintered body made of a binderless carbide, cermet or cemented carbide, e.g., WC, W2C and/or eta-phase, with a grain size less than 6.0 ?m, and less than 6% binder phase (e.g., CoNiFe). At least some working surfaces of the sintered body are surface treated with a boron yielding method including applying a low viscosity liquid medium having boron or aluminum content and heating at 1200? C. to 1450? C. under a pressure less than atmospheric pressure or a hydrogen containing atmosphere to from a hardness gradient with an increased hardness of the treated working surfaces of at least 50 to 200 HV5 and favorable compressive stresses in a surface zone that gives a tougher working surfaces of the boronized sintered bodies.

A dielectric ceramic composition includes a main component of a perovskite type compound represented by a general formula of ABO.sub.3, in which A is an element in an A-site, B is an element in a B-site, and O is an oxygen element. A includes Ba. A further includes at least one of Ca and Sr. B includes Ti. A sintered-body lattice volume obtained by X-ray diffraction method is 64.33 .sup.3 or below.

A dielectric ceramic composition includes a main component of a perovskite type compound represented by a general formula of ABO.sub.3, in which A is an element in an A-site, B is an element in a B-site, and O is an oxygen element. A includes Ba. B includes Ti and Zr. A sintered-body lattice volume obtained by X-ray diffraction method is 64.50 .sup.3 or above.

A superconducting composition of matter including overlapping first and second regions. The regions comprise unit cells of a solid, the first region comprises an electrical insulator or semiconductor, and the second region comprises a metallic electrical conductor. The second region extends through the solid and a subset of said second region comprise surface metal unit cells that are adjacent to at least one unit cell from the first region. The ratio of the number of said surface metal unit cells to the total number of unit cells in the second region being at least 20 percent.

The invention relates to multi-layer oxide ceramic bodies and in particular to presintered multi-layer oxide ceramic blanks and oxide ceramic green bodies suitable for dental applications. These bodies can be thermally densified by further sintering without distortion and are thus particularly suitable for the manufacture of dental restorations. The invention also relates to a process for the manufacture of such multi-layer oxide ceramic bodies as well as to a process for the manufacture of dental restorations using the multi-layer oxide ceramic bodies.

A sintered friction material, in which a content of a copper component is 0.5 mass % or less, is provided. The sintered friction material includes a titanate and a metal material other than copper, as a matrix. A content of the metal material other than copper is 10.0 volume % to 34.0 volume %. A method for manufacturing a sintered friction material is provided. The method includes a mixing step of mixing raw materials containing a titanate and a metal material other than copper, a molding step of molding the raw materials mixed in the mixing step, and a sintering step of sintering, at 900? C. to 1300? C., a molded product molded in the molding step. In the sintered friction material, the titanate and the metal material other than copper form a matrix, and a content of the metal material other than copper is 10.0 volume % to 34.0 volume %.

Methods of manufacturing a ceramic honeycomb body having a honeycomb structure with a matrix of intersecting walls, and a skin disposed on an outer peripheral portion of the matrix where the skin has a first average porosity and the interior portion of the matrix has a second average porosity that is greater than the first average porosity. The methods include coating at least the skin with a fluid formulation containing a sintering aid and subsequently firing the honeycomb structure. In certain embodiments, a glass layer is formed in the skin or in regions of the walls directly adjacent to the skin. In certain embodiments, the coating is applied to a green honeycomb structure, and in other embodiments the coating is applied to a ceramic honeycomb structure. Other honeycomb bodies and methods are described.

The present invention relates to a zirconia mullite refractory composite comprising 55 wt.-% to 65 wt.-% Al.sub.2O.sub.3, 15 wt.-% to 25 wt.-% SiO.sub.2, 15 wt.-% to 25 wt.-% ZrO.sub.2 and less than 3 wt.-% raw material based impurities, whereby the mineralogical composition of the composite comprises 65 wt.-% to 85 wt.-% mullite and 15 wt.-% to 35 wt.-% zirconia.