A powder intended for the manufacture of a sintered dental article, The powder has a chemical analysis such that, as weight percentages based on the oxides: Al.sub.2O.sub.3: 0.2%, oxides other than ZrO.sub.2, HfO.sub.2, Yb.sub.2O.sub.3, Y.sub.2O.sub.3 and Al.sub.2O.sub.3: <0.5%, and ZrO.sub.2+HfO.sub.2+Yb.sub.2O.sub.3+Y.sub.2O.sub.3: balance to 100%, with HfO.sub.2<2%. The contents of Yb.sub.2O.sub.3 and Y.sub.2O.sub.3, as molar percentages based on the sum of ZrO.sub.2, HfO.sub.2, Yb.sub.2O.sub.3 and Y.sub.2O.sub.3, being such that Yb.sub.2O.sub.3≥1%, 0.5%≤Y.sub.2O.sub.3<2%, and Yb.sub.2O.sub.3+Y.sub.2O.sub.3≤5.5%. The powder has a specific surface area of greater than or equal to 5 m.sup.2/g and less than or equal to 16 m.sup.2/g. The powder has a median size of greater than or equal to 0.1 μm and less than or equal to 0.7 μm.

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 T1 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.

In a silicon nitride substrate including a silicon nitride sintered body including silicon nitride crystal grains and a grain boundary phase, a plate thickness of the silicon nitride substrate is 0.4 mm or les, and a percentage of a number of the silicon nitride crystal grains including dislocation defect portions inside the silicon nitride crystal grains in a 50 μm×50 μm observation region of any cross section or surface of the silicon nitride sintered body is not less than 0% and not more than 20%. Etching resistance can be increased when forming the circuit board.

Provided is halloysite powder having a small b value. The halloysite powder is powder including a granule in which halloysite including halloysite nanotubes is aggregated, the granule has a first pore deriving from a tube hole of the halloysite nanotubes and a second pore different from the first pore, and the Fe.sub.2O.sub.3 content is not more than 2.00 mass %.

A solid electrolyte which contains a garnet-type composite metal oxide phase (L) and shows an excellent lithium ion conductivity is provided. The solid electrolyte contains a garnet-type composite metal oxide phase (L) and a phase (D) different from the phase (L). The phase (L) contains Li, La, Zr, O, and Ga, and an Li site in the phase (L) is substituted with the Ga. A lattice constant of the solid electrolyte is not smaller than 12.96 Å. The phase (D) contains at least one of LiF, BaZrO.sub.3, YF.sub.3, SrF.sub.2, and ScF.sub.3.

The present invention discloses a guide pin, which comprises a base support layer (1) and a protective layer (2). The base support layer (1) is a rod-shaped structure. The protective layer (2) tightly wraps the surface of the base support layer (1). A manufacturing method for the guide pin made of various materials is also disclosed. The guide pin manufactured by the method of the present invention is not prone to bending or deformation and has good corrosion resistance and acid/alkaline resistance properties; it is wear resistant and has of extended service life; it is easy to be processed and is low in cost.

An aluminum nitride sintered body contains 1 to 5% by weight of yttrium oxide (Y.sub.2O.sub.3), 10 to 100 ppm by weight of titanium (Ti), and the balance being aluminum nitride (AlN). Accordingly, a volume resistance value and thermal conductivity at a high temperature are improved, and the generation of impurities during a semiconductor manufacturing process can be suppressed.

Composite structures are provided whose composite matrix is a fully-dense (greater than 95%) magnesium oxide-containing phase and whose entrained phase, by virtue of its' decomposition temperature or chemical reactivity, would otherwise not be fabricable. Notably, a methodology is provided whereby a range of composite structures are formed by applying an advanced manufacturing technique and a blend of ceramic powder whose sintering is enhanced by small amounts of a metal halide sintering aid. This methodology and process significantly lowers the processing temperature of refractory ceramics such as magnesium oxide allowing formation of ceramic bodies incorporating phases such as metal hydrides, fragile ceramic phases, and highly reactive species such as beryllides. In all cases, the final product is substantially-free, or even devoid, of the metal halide sintering aid, resulting in a phase-pure ceramic matrix composed of the host phase and the entrained phase.

A method includes molding a raw material powder containing a ceramic powder and a thermoplastic resin having a glass transition temperature higher than room temperature into a shape by isostatic pressing and in which a raw material powder slurry is prepared by adding the ceramic powder and the thermoplastic resin to a solvent so that the thermoplastic resin is 2% by weight or more and 40% by weight or less with respect to a total weight of the ceramic powder and the thermoplastic resin, a cast-molded body is to formed by wet-casting the raw material powder slurry into a shape, dried, and subjected to first-stage isostatic press molding at a temperature lower than the glass transition temperature of the thermoplastic resin, then this first-stage press-molded body is heated to the glass transition temperature of the thermoplastic resin or above, and warm isostatic press (WIP) molding is performed.

A method for producing a honeycomb structure, the method comprising the steps of: kneading a forming raw material containing a cordierite forming material and then forming it to produce a honeycomb formed body; and firing the honeycomb formed body to provide a honeycomb structure. In the producing method, from 0.1 to 6.0 parts by mass of a magnesium silicate mineral having a 2:1 ribbon type structure per 100 parts by mass of the cordierite forming material is added to the forming raw material.