A part made of composite material includes fiber reinforcement including silicon carbide fibers presenting an oxygen content less than or equal to 1 % in atomic percentage; and a matrix present in the pores of the fiber reinforcement and including at least one sintered silicate phase including at least one rare earth silicate, mullite, or a mixture of mullite and of at least one rare earth silicate, the matrix including at least a first phase including mullite and a second phase, different from the first phase, including at least one rare earth silicate.

Provided are gallium nitride particles that have a low oxygen content and a high moldability and allow a gallium nitride sputtering target having a high density and a high strength to be produced. By causing a mixed powder of gallium oxide and gallium nitride to react at a temperature of 1000-1100° C. such that an ammonia reaction amount per hour is 1 or more times (by mole) an amount of gallium charged, gallium nitride particles are obtained of which an oxygen content is 1 atm % or less, an average particle size of primary particles is 5 μm or more, and a particle size of a range of 10 area % from smallest particles of a particle size distribution (10% particle size) is 3 μm or less.

A method for producing an oriented AlN sintered body includes a first step of preparing a formed body by forming a mixture obtained by mixing a sintering aid with an AlN raw-material powder containing a plate-like AlN powder whose plate surface is a c-plane and which has an aspect ratio of 3 or more and an average thickness of 0.05 to 1.8 m, wherein the mixture is formed such that the plate surface of the plate-like AlN powder is disposed along a surface of the formed body; and a second step of obtaining an oriented AlN sintered body by subjecting the formed body to hot-press sintering in a non-oxidizing atmosphere while applying a pressure to the surface of the formed body.

The invention relates to a copper-ceramic substrate comprising: a ceramic carrier, and at least one copper layer bonded to a surface of the ceramic carrier, which has a free surface for forming a conductor structure and/or for securing bonding wires, wherein the copper layer has a microstructure with an average grain size diameter of 200 to 500 m, preferably 300 to 400 m.

A ceramic molded body including a ceramic powder and an organic binder includes an oxidizable ceramic powder as the ceramic powder, includes an oxidizable metal or metal compound, or is in contact with a solid body including an oxidizable metal or metal compound. In a hydrogen atmosphere, the ceramic molded body is heated to a maximum temperature set within a range of 1,100 C. to 1,400 C. at a heating rate of more than 25 C./h, is degreased at the maximum temperature, and is then cooled at a cooling rate of more than 25 C./h.

A SiC powder containing 70% by mass or more of a -SiC, wherein in a volume-based cumulative particle size distribution measured by a laser diffraction method, a D50 is 8 to 35 m and a D10 is 5 m or more.

A ceramic structure 10 includes a heater electrode 14 within a disk-shaped AlN ceramic substrate 12. The heater electrode 14 contains a metal filler in the main component WC. The metal filler (such as Ru or RuAl) has a lower resistivity and a higher thermal expansion coefficient than AlN. An absolute value of a difference |CTE| between a thermal expansion coefficient of the AlN ceramic substrate 12 and a thermal expansion coefficient of the heater electrode 14 at a temperature in the range of 40 C. to 1000 C. is 0.35 ppm/ C. or less.

A process for manufacturing a composite material part including a particulate reinforcement densified by a ceramic matrix, the process including: formation of a blank of the part to be manufactured by shaping a mixture including a binder, first ceramic or carbon particles intended to form the particulate reinforcement of the part and second ceramic or carbon particles distinct from the first particles, removal or pyrolysis of the binder present in the blank to obtain a porous preform of the part to be manufactured, and infiltration of the porosity of the preform by a molten composition including a metal in order to obtain the part.

In a diamond polycrystal, a value of a ratio (d/d) of d to d is less than or equal to 0.98 in a Vickers hardness test performed under a condition defined in JIS Z 2244:2009, where the d represents a length of a diagonal line of a first Vickers indentation formed in a surface of the diamond polycrystal when a Vickers indenter with a test load of 4.9 N is pressed onto the surface of the diamond polycrystal, and the d represents a length of a diagonal line of a second Vickers indentation remaining in the surface of the diamond polycrystal after releasing the test load.

In a diamond polycrystal, a value of a ratio (a/a) of a to a is less than or equal to 0.99 in a Knoop hardness test performed under a condition defined in JIS Z 2251:2009, where the a represents a length of a longer diagonal line of a first Knoop indentation formed in a surface of the diamond polycrystal when a Knoop indenter with a test load of 4.9 N is pressed onto the surface of the diamond polycrystal, and the a represents a length of a longer diagonal line of a second Knoop indentation remaining in the surface of the diamond polycrystal after releasing the test load.