This disclosure relates to a high cBN content polycrystalline cubic boron nitride, PCBN, material. The binder matrix material comprises 19 to 50 wt. % chromium, or a compound thereof.

An object of the present invention is to provide ferrite particles for a filtering medium excellent in filtration ability having a small apparent density, capable of various properties maintained in the controllable state and filling a specified volume with a small amount, and a filtering medium made from the ferrite particles. In order to achieve the object, ferrite particles provided an outer shell structure containing Ti oxide for a filtering medium, and a filtering medium made from the ferrite particles are employed.

A sintered body includes a crystal grain containing silicon nitride, and a grain boundary phase. If dielectric losses of the sintered body are measured while applying an alternating voltage to the sintered body and continuously changing a frequency of the alternating voltage from 50 Hz to 1 MHz, an average value ε.sub.A of dielectric losses of the sintered body in a frequency band from 800 kHz to 1 MHz and an average value ε.sub.B of dielectric losses of the sintered body in a frequency band from 100 Hz to 200 Hz satisfy an expression |ε.sub.A−ε.sub.B|≤0.1.

Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120° C. and positive 300° C.; ECMCs that need to be able to contain a flame of 1900° C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid “ceramic microdomains” (CMDs); the CMDs are connected to one another by a dense network of “elastic microelements” (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.

A method for forming a refractory material is described comprising the steps of placing a core material 12 into a granulator device 16, operating the granulator device 16 to form the core material into granules 16, adding a coating material 18 to the granulator device 16, operating the granulator device 16 to result in the formation of a layer 20 of the coating material 18 encapsulating the granules 16, and then heating the coated granules 22. Materials manufactured using the method are also described.

Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120° C. and positive 300° C.; ECMCs that need to be able to contain a flame of 1900° C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid “ceramic microdomains” (CMDs); the CMDs are connected to one another by a dense network of “elastic microelements” (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.

A coated particle having excellent thermal expansion control and electrical insulation properties includes a core of a first inorganic compound containing a metal or semimetal element P; and a shell of a second inorganic compound containing a metal or semimetal element Q. The first inorganic compound satisfies 1, and the coated particles satisfy 2 and 3. 1: |dA(T)/dT| is ≥10 ppm/°C at T1 of -200° C. to 1,200° C. A is (an a-axis lattice constant of a crystal in the first inorganic compound)/(a c-axis lattice constant of a crystal in the first inorganic compound). 2: in XPS of a surface of each of the coated particles, a ratio of a number of atoms of Q contained in the shell to a number of atoms of P contained in the core t is 45 to 300. 3: an average particle diameter of each coated particle is 0.1 to 100 .Math.m.

This disclosure relates to a high cBN content polycrystalline cubic boron nitride, PCBN, material. The binder matrix material comprises 2 to 15 wt. % titanium diboride (TiB2).

A sintered body includes a crystal grain containing silicon nitride, and a grain boundary phase. If dielectric losses of the sintered body are measured while applying an alternating voltage to the sintered body and continuously changing a frequency of the alternating voltage from 50 Hz to 1 MHz, an average value ε.sub.A of dielectric losses of the sintered body in a frequency band from 800 kHz to 1 MHz and an average value ε.sub.B of dielectric losses of the sintered body in a frequency band from 100 Hz to 200 Hz satisfy an expression |ε.sub.A−ε.sub.B|≤0.1.

The present invention relates to non-metallic interference pigments, in particular laminar interference pigments, which comprise a thin high-refractive layer and an outermost layer that contains crystalline carbon in the form of graphite and/or graphene. The invention also relates to a method for producing such pigments and the use of the thus produced pigments.