摘要:
A silicon nitride sintered body having improved wear resistance and a wear-resistant member using the silicon nitride sintered body are provided. A silicon nitride sintered body according to an embodiment includes silicon nitride crystal grains and a grain boundary phase. An average value of solid solution oxygen amounts of the silicon nitride crystal grains in a 20 μm×20 μm region at any cross section is not less than 0.2 wt %. In a 50 μm×50 μm region at any cross section, an average value of major diameters of the silicon nitride crystal grains is not less than 0.1 μm and not more than 10 μm, and an average value of aspect ratios of the silicon nitride crystal grains is not less than 1.5 and not more than 10.
摘要:
Preparation of a slip including more than 4% and less than 50% of ceramic particles and including more than 1% of orientable ceramic particles made of a material including an oriented function, as volume percentage on the basis of the set of ceramic particles, wherein the fraction of non-orientable ceramic particles has a median length less than ten times the median length of the orientable ceramic particles if the set of ceramic particles includes less than 80%, as volume percentage, of orientable ceramic particles, oriented freezing of the slip by movement of a solidification front at a speed less than the speed of encapsulation of the ceramic particles; elimination of the crystals of solidified liquid phase of said block, optionally, sintering.
摘要:
The present invention relates to a dielectric element such as a thin-film capacitor including a dielectric film. The dielectric film contains a main component represented by the general formula (Ba1-xCax)z(Ti1-yZry)O3 wherein 0
摘要:
A silicon nitride substrate including a phase encompassed of silicon nitride particles, and intergranular phase formed from a sintering aid, wherein a separation layer is formed on the surface of a molded body including silicon nitride powder, sintering aid powder, and organic binder, by using a boron nitride paste containing boron nitride powder, organic binder, and organic solvent; the separation layer and molded body are heated; the organic binder is removed from the separation layer and molded body; subsequently molded bodies stacked with a separation layer therebetween, are sintered. Boron nitride paste contains 0.01 to 0.50% by oxygen mass and 0.001 to 0.5% by carbon mass, and c/a is within range of 0.02 to 10.00, where c is oxygen content in the powder of the boron nitride paste, and a carbon content in the degreased separation layer, which includes 0.2 to 3.5 mg/cm2 of hexagonal boron nitride powder.
摘要:
The present invention provides a silicon nitride sintered body comprising a silicon nitride crystalline particle and a grain boundary phase, the silicon nitride sintered body having an area ratio of the grain boundary phase per 100 μm×100 μm unit area of 15 to 35% when an arbitrary cross section thereof is photographed. Further, it is preferable that the area ratio of the grain boundary phase per 100 μm×100 μm unit area is 15 to 25%. Furthermore, the silicon nitride sintered body is suitable for a wear resistant member. Due to above structure, there can be provided a silicon nitride sintered body and a wear resistant member having a high processability (workability) and an excellent sliding property.
摘要:
Disclosed are a silicon carbide sintered body and a sliding component using the same, and a protective body which, even when fine cracks are generated due to thermal shock or mechanical impact over prolonged use, are capable of inhibiting development of the cracks. The silicon carbide sintered body contains silicon carbide grains as a major component and has a relative density of 95% or more. On an observation surface of the silicon carbide sintered body, coarse silicon carbide grains 1b having a surface area of 170 μm2 or more occupy 6 area % or more and 15 area % or less. The silicon carbide sintered body has excellent mechanical properties such as strength and rigidity. Even when fine cracks are generated due to thermal shock or mechanical impact, coarse silicon carbide grains 1b are capable of inhibiting development of the cracks.
摘要:
A product obtained by solid-phase sintering of a silicon carbide powder and of a sintering additive, the product having a relative density of greater than 98.5% and including: more than 92% by weight of SiC present in the form of grains, less than 2% by weight of elemental oxygen, less than 6% by weight, in total, of other elements, wherein more than 10% by number of the SiC grains, on the basis of the total number of the grains, have an elongation factor F of greater than 3 (F>3), wherein more than 50% by number of the grains, the elongation factor F of which is greater than 3, have a width of greater than 3 micrometers, and wherein the other SiC grains in the product have a mean equivalent diameter of greater than 1 micrometer and less than 20 micrometers.
摘要:
A method of forming a ceramic body including forming a mixture made of at least a first powder material (PM1) including carbon having a first average particle size (PS1), a second powder material (PM2) including carbon and different than the first powder material, the second powder material having a second average particle size (PS2) less than the first average particle size (PS1), and an aluminum content (AC2) greater than the aluminum content (AC1) of the first powder material, and further including forming a green body from the mixture, and sintering the green body and forming a ceramic body having a first type of grain having an average grain size of not greater than about 8 times the first average particle size (PS1).
摘要:
A sintered ferrite magnet having a ferrite phase with a hexagonal structure as the main phase, wherein the composition of the metal elements composing the main phase is represented by the following general formula (1): RxCamA1−x−m(Fe12−yMy)z: (1), x, m, y and z in formula (1) satisfying all of the conditions represented by the following formulas (2)-(6): 0.2≦x≦0.5: (2) 0.13≦m≦0.41: (3) 0.7x−m≦0.15: (4) 0.18≦yz≦0.31: (5) 9.6≦12z≦11.8: (6), and wherein the density of the sintered ferrite magnet is at least 5.05 g/cm3, and the crystal grains of the sintered ferrite magnet satisfy all of the conditions represented by the following formulas (7) and (8), where L μm is the average for the maximum value and S μm is the average for the minimum value among the diameters passing through the center of gravity of each grains in the crystal cross-section parallel to the c-axis direction of hexagonal structures. L≦0.95: (7) 1.8≦L/S≦2.5: (8).
摘要:
Densified composites of a metal such as copper or aluminum with a titanium-silicon-carbide or titanium-aluminum-carbide ceramic material are prepared by forming the ceramic material into a body, and infiltrating the body with the molten metal. The metal is able to rapidly penetrate into void spaces, between grain boundaries and even into the crystal structure of the ceramic grains to form a composite. The starting ceramic material may be previously densified, in which case various types of gradient structures can be produced easily. The process can be operated at low pressures, and so the hot pressing methods that normally must be used to densify these ceramic materials can be avoided.