A ceramic composite sintered body, including: a metal oxide as a main phase, and silicon carbide as a sub-phase, in which crystal grains of the silicon carbide are dispersed in crystal grains of the metal oxide and at crystal grain boundaries of the metal oxide, and an average crystal grain size of the silicon carbide dispersed at the crystal grain boundaries of the metal oxide is 0.30 μm or less.

In a silicon nitride sintered body including silicon nitride crystal grains and a grain boundary phase, dislocation defect portions exists inside at least some of the silicon nitride crystal grains. A percentage of a number of the at least some of the silicon nitride crystal grains among any 50 of the silicon nitride crystal grains having completely visible contours in any cross section or surface of the silicon nitride sintered body is not less than 50% and not more than 100%. It is favorable that a plate thickness of the silicon nitride substrate, in which the silicon nitride sintered body is used, is within the range not less than 0.1 mm and not more than 0.4 mm. The TCT characteristics can be improved by using the silicon nitride substrate in the silicon nitride circuit board.

A piezoelectric ceramic containing a perovskite-type compound containing at least Pb, Zr, Ti, Mn, and Nb, in which in an X-ray crystal structure analysis chart of the perovskite-type compound, there is no X-ray diffraction peak branching between a (101) plane of a main peak of a PZT tetra phase in a range of 2θ=30.5° to 31.5° and a (110) plane on which an X-ray diffraction peak is in a range of 2θ=30.8° to 31.8°, and a number of X-ray diffraction peaks based on the (101) plane and the (110) plane is one.

The localized formation of graphene and diamond like structures on the surface of boron carbide is obtained due to exposure to high intensity laser illumination. The graphitization involves water vapor interacting with the laser illuminated surface of boron carbide and leaving behind excess carbon. The process can be done on the micrometer scale, allowing for a wide range of electronic applications. Raman is a powerful and convenient technique to routinely characterize and distinguish the composition of Boron Carbide (B.sub.4C), particularly since a wide variation in C content is possible in B.sub.4C. Graphitization of 1-3 μm icosahedral B.sub.4C powder is observed at ambient conditions under illumination by a 473 nm (2.62 eV) laser during micro-Raman measurements. The graphitization, with ˜12 nm grain size, is dependent on the illumination intensity. The process is attributed to the oxidation of B.sub.4C to B.sub.2O.sub.3 by water vapor in air, and subsequent evaporation, leaving behind excess carbon. The effectiveness of this process sheds light on amorphization pathways of B.sub.4C, a critical component of resilient mechanical composites, and also enables a means to thermally produce graphitic contacts on single crystal B.sub.4C for nanoelectronics.

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.

A corrosion resistant member has a portion to be exposed to a corrosive gas. The portion to be exposed to the corrosive gas is formed of a ceramic sintered body. The mean width (Rsm) of profile elements of a surface of the ceramic sintered body is 25 μm or less, and the ratio (Rsm/Ra) of the mean width (Rsm) of the profile elements to the arithmetic mean roughness (Ra) of the surface of the ceramic sintered body is 4,000 or less.

A multilayer ceramic capacitor includes: a multilayer structure in which each of a plurality of dielectric layers and each of a plurality of internal electrode layers are alternately stacked. A ceramic protection section includes a cover layer and a side margin. A main component ceramic of the ceramic protection section is a ceramic material having a perovskite structure expressed as a general formula ABO.sub.3. An A site of the perovskite structure includes at least Ba. A B site of the perovskite structure includes at least Ti and Zr. A Zr/Ti ratio which is a molar ratio of Zr and Ti is 0.010 or more and 0.25 or less. An A/B ratio which is a molar ratio of the A site and the B site is 0.990 or less.

Polycrystalline diamond cutters and methods of making thereof are described. The cutters include a substrate and a diamond body. The diamond body includes diamond particles spatially arranged according to a gradient of particle sizes. The methods include steps of suspending diamond particles in a liquid and allowing their sedimentation according to a gradient of particle sizes resulting in regions spatially arranged axially and/or radially in which a majority of diamond particles in one region have lower average sizes or average diameters comparative to a majority of diamond particles in a second region.

Disclosed is a method for fabricating a solid article from a boron carbide powder comprising boron carbide particles that are coated with a titanium compound. Further disclosed herein are the unique advantages of the combined use of titanium and graphite additives in the form of water soluble species to improve intimacy of mixing in the green state. The carbon facilitates sintering, whose concentration is then attenuated in the process of forming very hard, finely dispersed TiB.sub.2 phases. The further recognition of the merits of a narrow particle size distribution B.sub.4C powder and the use of sintering soak temperatures at the threshold of close porosity which achieve post-HIPed microstructures with average grain sizes approaching the original median particle size. The combination of interdependent factors has led to B.sub.4C-based articles of higher hardness than previously reported.

The present disclosure relates to a device for melting a material without a crucible and for atomizing the melted material in order to produce powder, comprising: an atomizing nozzle; an induction coil having windings, which become narrower in the direction of the atomizing nozzle at least in some sections; and a material bar at least partially inserted into the induction coil. The induction coil is designed to melt the material of the material bar in order to produce a melt flow. The induction coil and the atomizing nozzle are arranged in such a way that the melt flow is or can be introduced into the atomizing nozzle through a first opening of the atomizing nozzle in order to atomize the melt flow by means of an atomizing gas, which can be introduced into the atomizing nozzle.