There is provided a ferrite sintered magnet having a high residual magnetic flux density. A ferrite sintered magnet 2 includes a plurality of main phase particles 5 including ferrite having a hexagonal structure, the number of core-shell structured particles 5A having a core 7 and a shell 9 covering the core 7, among the main phase particles 5, is smaller than the number of the main phase particles 5 other than the core-shell structured particles 5A.

A ceramic substrate and a method for production thereof are provided, in which the ceramic substrate includes a composite of : a first ceramic layer including Sr anorthite and Al.sub.2O.sub.3 or an oxide dielectric with a dielectric constant higher than that of Al.sub.2O.sub.3; and a second ceramic layer including Sr anorthite and cordierite and having a dielectric constant lower than that of the first ceramic layer.

A sintered ferrite magnet comprising (a) a ferrite phase having a hexagonal M-type magnetoplumbite structure comprising Ca, an element R which is at least one of rare earth elements and indispensably includes La, an element A which is Ba and/or Sr, Fe, and Co as indispensable elements, the composition of metal elements of Ca, R, A, Fe and Co being represented by the general formula of Ca.sub.1-x-yR.sub.xA.sub.yFe.sub.2n-zCo.sub.z, wherein the atomic ratios (1-x-y), x, y and z of these elements and the molar ratio n meet the relations of 0.3≦(1-x-y)≦0.65, 0.2≦x≦0.65, 0≦y≦0.2, 0.03≦z≦0.65, and 4≦n≦7, and (b) a grain boundary phase indispensably containing Si, the amount of Si being more than 1% by mass and 1.8% or less by mass (calculated as SiO.sub.2) based on the entire sintered ferrite magnet, and its production method.

Isopipes (13) for making glass sheets using a fusion process are provided. The isopipes are made from alumina materials which have low levels of the elements of group IVB of the periodic chart, i.e., Ti, Zr, and Hf, as well as low levels of Sn. In this way, the alumina isopipes can be used with glasses that contain tin (e.g., as a fining agent or as the result of the use of tin electrodes for electrical heating of molten glass) without generating unacceptable levels of tin-containing defects in the glass sheets, specifically, at the sheets' fusion lines. The alumina isopipes disclosed herein are especially beneficial when used with tin-containing glasses that exhibit low tin solubility, e.g., glasses that have (RO+R.sub.2O)/Al.sub.2O.sub.3 ratios between 0.9 and 1.1, where, in mole percent on an oxide basis, (RO+R.sub.2O) is the sum of the concentrations of the glass' alkaline earth and alkali metal oxides and Al.sub.2O.sub.3 is the glass' alumina concentration.

The invention relates to a binder, which contains water glass and further a phosphate or a borate or both. The invention further relates to a method for constructing molds and cores layer by layer, the molds and cores comprising a construction material mixture, which at least comprises a refractory molding base material, and the binder. In order to produce the molds and cores layer by layer in 3-D printing, the refractory molding base material is applied layer by layer and is selectively printed with the binder layer by layer, and consequently a body corresponding to the molds or cores is constructed and the molds or cores are released after the unbonded construction material mixture has been removed.

Provided is a lead-free piezoelectric material having satisfactory piezoelectric constant and mechanical quality factor in a device driving temperature range (−30° C. to 50° C.) The piezoelectric material includes a main component containing a perovskite-type metal oxide represented by Formula 1, a first auxiliary component composed of Mn, and a second auxiliary component composed of Bi or Bi and Li. The content of Mn is 0.040 parts by weight or more and 0.500 parts by weight or less based on 100 parts by weight of the metal oxide on a metal basis. The content of Bi is 0.042 parts by weight or more and 0.850 parts by weight or less and the content of Li is 0.028 parts by weight or less (including 0 parts by weight) based on 100 parts by weight of the metal oxide on a metal basis. (Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-yZr.sub.y)O.sub.3 . . . (1), wherein, 0.030≦x<0.090, 0.030≦y≦0.080, and 0.9860≦a≦1.0200.

The present invention discloses a dielectric ceramic formula enabling one to obtain a multilayer ceramic capacitor by alternatively stacking the ceramic dielectric layers and base metal internal electrodes. The dielectric ceramic composition comprises a primary ingredient:

[(Na.sub.1-xK.sub.x).sub.sA.sub.1-s].sub.m[(Nb.sub.1-yTa.sub.y).sub.uB1.sub.vB2.sub.w)]O.sub.3

wherein:
A is at least one selected from the alkaline-earth element group of Mg, Ca, Sr, and Ba;
B1 is at least one selected from the group of Ti, Zr, Hf and Sn;
B2 is at least one selected from transition metal elements;
and wherein:
x, y, s, u, v, and w are molar fractions of respective elements, and m is the molar ratio of [(Na.sub.1-xK.sub.x).sub.sA.sub.1-s] and [(Nb.sub.1-yTa.sub.y).sub.uB1.sub.vB2.sub.w)]. They are in the following respective range:
0.93≤m≤1.07;
0.7≤s≤1.0;
0.00≤x≤0.05; 0.00≤y≤0.65;
0.7≤u≤1.0; 0.0≤v≤0.3; 0.001≤w≤0.100;
a first sub-component composes of at least one selected from the rare-earth compound,
wherein the rare-earth element is no more than 10 mol % parts with respect to the main component; and
a second sub-component composes a compound with low melting temperature to assist the ceramic sintering process, said frit, which is Li free and could be at least one selected from fluorides, silicates, borides, and oxides. The content of frit is within the range of 0.01 mol % to 15.00 mol % parts with respect to 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 μm, and less than 6% binder phase (e.g., Co—Ni—Fe). 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.

Provided is a dielectric composition exhibiting a high strength and a high specific dielectric constant. The dielectric composition contains composite oxide particles having a composition formula represented by (Sr.sub.xBa.sub.1-x).sub.yNb.sub.2O.sub.5+y and an Al-based segregation phase. The Al segregation phase has niobium, aluminum, and oxygen.

(i) a step of disposing a powder that includes an absorber absorbing light of a wavelength included in a laser beam to be irradiated and silicon dioxide as a main component; (ii) a step of sintering or melting and solidifying the powder by irradiating the powder with a laser beam; and (iii) a step of heat-treating a shaped object formed by repeating the steps (i) and (ii) at 1470° C. or more and less than 1730° C.