Provided is a piezoelectric ceramics having a gradual change in piezoelectric constant depending on an ambient temperature. Specifically, provided is a single-piece piezoelectric ceramics including as a main component a perovskite-type metal oxide represented by a compositional formula of ABO.sub.3, wherein an A site element in the compositional formula contains Ba and M.sub.1, the M.sub.1 being formed of at least one kind selected from the group consisting of Ca and Bi, wherein a B site element in the compositional formula contains Ti and M.sub.2, the M.sub.2 being formed of at least one kind selected from the group consisting of Zr, Sn, and Hf, wherein concentrations of the M.sub.1 and the M.sub.2 change in at least one direction of the piezoelectric ceramics, and wherein increase and decrease directions of concentration changes of the M.sub.1 and the M.sub.2 are directions opposite to each other.

Antiballistic armour plate includes a ceramic body including a hard material, provided, on its inner face, with a back energy-dissipating coating. The ceramic body is monolithic. The constituent material of the ceramic body includes grains of ceramic material having a Vickers hardness that is higher than 15 GPa, and a matrix binding the grains, the matrix including a silicon nitride phase and/or a silicon oxynitride phase, the matrix representing between 5 and 40% by weight of the constituent material of the ceramic body. The maximum equivalent diameter of the grains of ceramic material is smaller than or equal to 800 micrometres. The constituent material of the ceramic body has an open porosity that is higher than 5% and lower than 14%. The metallic silicon content in the material, expressed per mm of thickness of the body, is lower than 0.5% by weight.

The object of the present invention is to provide a dielectric ceramic composition having good properties, particularly good IR property and high temperature accelerated lifetime.

The dielectric ceramic composition of the present invention has a main component made of a perovskite type compound expressed by a compositional formula of (Ba.sub.1-x-ySr.sub.xCa.sub.y).sub.m(Ti.sub.1-zZr.sub.z)O.sub.3 (note that, m, x, y, and z of the above compositional formula all represent molar ratios, and each satisfies 0.9m1.1, 0x0.5, 0y0.3, 0(x+y)0.6, and 0.03z0.3), and

a first sub component made of an oxide of a rare earth element R (note that, R is at least one selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), wherein

the dielectric ceramic composition includes a dielectric particle and a particle boundary, and the dielectric particle include a complete solid solution particle in which Zr is solid dissolved to the entire dielectric particle,

when Za represents a concentration of Zr in the dielectric ceramic composition in case a concentration of Ti atom in the dielectric ceramic composition is deemed to be 100 atom % and when Zb represents an average concentration of Zr in the complete solid solution particle in case a concentration of Ti atom in the complete solid solution particle is deemed to be 100 atom %,

0.7<(Zb/Za) is satisfied, and

a standard deviation and an average value of the Zb measured satisfies

(the standard deviation/the average value)0.15.

Methods for forming ceramic cores are disclosed. A ceramic core formed using the method of the present application includes a silica depletion zone encapsulating an inner zone. The inner zone includes mullite and the silica depletion zone includes alumina. The method includes heat-treating a ceramic body in a non-oxidizing atmospheric condition for an effective temperature and time combination at a pressure less than 10.sup.2 atmosphere to form the silica depletion zone at a surface of the ceramic core.

Molded devices are made by a molding method comprising use of magnetic fields to place magnetic particles into optimal configurations. The optimal configurations are set in place by the curing of a continuous solid-forming mixture that surrounds the particles. An example system uses urethane monomers to set iron powder mixtures into an inner and outer core of an electromagnetic coil. In addition to attractive forces to concentrate ferromagnetic particles, repulsive forces may be used to concentrate diamagnetic particles of aluminum or copper.

A multilayer ceramic capacitor include: a ceramic body including first and second surfaces opposing each other and third and fourth surfaces connecting the first and second surfaces; a plurality of internal electrodes disposed inside the ceramic body and exposed to the first and second surfaces, the plurality internal electrodes each having one end exposed to the third or fourth surface; and first and second side margin portions disposed on sides of the internal electrodes exposed to the first and second surfaces. A dielectric composition of the first and second side margin portions is different from a dielectric composition of the ceramic body, and a dielectric constant of the first and second side margin portions is lower than a dielectric constant of the ceramic body.

The present invention discloses a slurry feedstock for extrusion-based three-dimensional, 3D, printing of a functionally graded article, and/or for casting an article under a low pressure at a room temperature, a method of preparing the same, a method of extrusion-based 3D printing and/or casting, and a system therefor. The slurry feedstock comprises a build material comprising a metal, a ceramic or any combinations thereof, an organic polymer binder, an additive and a volatile organic solvent. The build material mixed with the additive and the organic polymer binder dissolved with the volatile organic solvent form a first pre-mix and a second pre-mix, respectively, that are mixed to form a substantially homogeneous and flowable slurry mixture that is used for producing articles.

A method for masking the appearance of a support structure underlying a highly translucent ceramic dental restoration is provided. The porous form of a zirconia ceramic dental restoration is treated with a liquid masking composition comprising 0.4 wt % to 50 wt % of one or more masking agents. The masking composition is applied to the internal surface of a restoration and a region of the facial surface of the restoration that is opposite the internal surface. After application of the masking compositions, treated zirconia restoration is sintered to greater than 98% theoretical density.

An alumina sintered body having a low dielectric loss tangent and a method for manufacturing the alumina sintered body are provided. An alumina sintered body contains Al.sub.2O.sub.3 99.50 mass % or more, and 99.95 mass % or less and sodium and silicon, wherein at a surface layer A in any given cross-section and a central portion B of the cross-section in a depth direction from the surface layer A, a concentration ratio of sodium to silicon in the surface layer A is smaller than the concentration ratio of sodium to silicon at the central portion B.

Techniques of additive deposition for producing articles of manufacture are disclosed herein. In one embodiment, an article of manufacture can include a substrate having a surface and composed of a metal or metal alloy and multiple layers of composite materials deposited on the surface of the substrate. The composite materials is composed of the metal or metal alloy and a ceramic material. The individual composite materials at each of the multiple layers has a composition with a corresponding ratio between the metal or metal alloy material and the ceramic material. The ratios between the metal or metal alloy material and the ceramic material change along at least one dimension of the article of manufacture.