A method for preparing a carbon/boron carbide composite material includes the following steps (A) providing a carbon compound, a carbon fiber, a boron compound and a binder to perform a pretreatment mixing procedure to form a precursor; (B) putting the precursor into a spray granulator for performing a granulation process and mixing the precursor to form an injection material with a uniform composition; (C) feeding the injection material into an injection molding machine for performing a compression molding process, thereby forming a carbon compound/boron compound green body; and (D) subjecting the carbon compound/boron compound green body to a two-stage heat treatment process to obtain the carbon/boron carbide composite material.

A tungsten carbide powder 1 includes bonded bodies 10 each including a plurality of tungsten carbide crystal grains 11, in which the bonded bodies 10 include, at a grain boundary 11a between the plurality of tungsten carbide crystal grains 11, a chromium-concentrated region 12 which has a chromium concentration higher than that in the tungsten carbide crystal grains 11.

An optical converter is provided that has both a stable colour even at highest luminous powers and a high luminous efficiency. The optical converter includes a ceramic element that is fluorescent so that light of a first wavelength is absorbed in the ceramic element and fluorescent having longer wavelength light is emitted. The ceramic element includes pores spatially irregularly distributed within the ceramic element. The distribution of the pores within the ceramic element is inhomogeneous so that the radial distribution function of the pore locations deviates from unity and has a maximum at a characteristic distance, the maximum having a value of at least 1.2.

A multicolor light-storing ceramic for fire-protection indication and a preparation method thereof are provided. The preparation method includes: adding a glass based raw material, a light-storing powder, a dispersant and an alumina powder into a granulator, adding water mixed with a pore-forming agent and then mechanically stirring for granulation; adding a plasticizer after the stirring of 4˜8 h, and continuing the stirring for 1˜3 h to thereby obtain a mixture; packing the mixture into a mold and performing tableting; demolding and obtaining a light-storing self-luminous quartz ceramic by drying and firing using a kiln; printing a pattern onto a surface of the ceramic and then curing to obtain a light-storing ceramic for indication sign. Using an industrial waste glass has advantages of low sintering temperature and green environmental protection; dispersed pores and alumina introduced as scattering sources improves light absorption efficiency, fluorescence output phase ratio and light transmission of the ceramic.

An alumina sintered body comprising 0.01 to 1.0 mass % of one or more types selected from Ta, Nb, and V in terms of oxide thereof. The alumina sintered body may further comprise 0.01 to 1.0 mass % of Mg in terms of Mg oxide. It is particularly preferable that the alumina sintered body has an alumina purity of 99% or more. An alumina sintered body having low dielectric loss as compared with that in related art can therefore be produced at low cost.

A tungsten carbide powder contains tungsten carbide as a main component and chromium, in which, when mass concentrations of tungsten and chromium are measured at 100 or more analysis points randomly selected from a field of view of SEM observation of the tungsten carbide powder, a standard deviation σ of distribution of the ratio by percentage of the concentration of chromium to the total concentration of tungsten and chromium is 0.5 or less.

The present application relates to a barium strontium titanate-based dielectric ceramic material, a preparation method, and application thereof. The composition of the barium strontium titanate-based dielectric ceramic material comprises: aBaTiO3+bSrTiO3+cTiO2+dBi.sub.2O.sub.3+eMgO+fAl2O3+gCaO+hSiO2, wherein a, b, c, d, e, f, g, and h are the molar percentage of each component, 20≤a≤50 mol %, 15≤b≤30 mol %, 10≤c≤20 mol %, 0≤d≤10 mol %, 0≤e≤35 mol %, 0≤f≤6 mol %, 0≤g≤6 mol %, 0≤h≤1 mol %, and a+b+c+d+e+f+g+h=100 mol %.

A ferrite sintered body contains from 45.0% by mole to 49.7% by mole Fe in terms of from Fe.sub.2O.sub.3, 2.0% by mole to 8.0% by mole Cu in terms of CuO, from 25.0% by mole to 45.0% by mole Ni in terms of NiO, and from 1.0% by mole to 20.0% by mole Zn in terms of ZnO, in which when Fe, Cu, Ni, and Zn are converted to Fe.sub.2O.sub.3, CuO, NiO, and ZnO, respectively, and when the total amount of the Fe.sub.2O.sub.3, the CuO, the NiO, and the ZnO is 100 parts by weight, the ferrite sintered body contains from 5 ppm to 25 ppm B in terms of elemental B and from 6 ppm to 25 ppm Nb in terms of elemental Nb.

A piezoelectric material includes: an oxide containing Na, Ba, Nb, Ti, and Mn, in which the oxide has a perovskite-type structure, a total amount of metal elements other than Na, Ba, Nb, Ti, and Mn contained in the piezoelectric material is 0.5 mol % or less with respect to a total amount of Na, Ba, Nb, Ti, and Mn, a molar ratio x of Ti to a total molar amount of Nb and Ti is 0.05≤x≤0.12, a molar ratio y of Na to Nb is 0.93≤y≤0.98, a molar ratio z of Ba to Ti is 1.09≤z≤1.60, a molar ratio m of Mn to the total molar amount of Nb and Ti is 0.0006≤m≤0.0030, and 1.07≤y×z≤1.50 is satisfied.

The invention relates to a method for producing a scandium aluminum nitride (ScAlN) target body for pulsed laser deposition (PLD), which includes the steps of: providing a scandium aluminum alloy body; pulverizing the scandium aluminum alloy body into scandium aluminum particles; nitridizing the scandium aluminum particles into scandium aluminium nitride particles; and hot pressing the scandium aluminum nitride particles into a scandium aluminum nitride target body.