摘要:
A method of production of a reduction resistant dielectric ceramic composition having a superior low frequency dielectric characteristic and further improved in accelerated lifetime of insulation resistance, specifically a method of production of a dielectric ceramic composition containing a main component including a dielectric oxide of a specific composition, a first subcomponent including a V oxide, a second subcomponent containing an Al oxide, a third subcomponent containing an Mn oxide, and a fourth subcomponent containing a specific sintering aid in a specific ratio, including a step of mixing at least part of the materials of the subcomponents excluding one or both of at least the material of the third subcomponent and material of the fourth subcomponent with the starting materials prepared for obtaining the material of the main component to prepare the pre-reaction material, a step of causing the prepared pre-reaction material to react to obtain a reacted material, and a step of mixing the materials of the subcomponents excluded when preparing the pre-reaction material with the obtained reacted material to obtain a dielectric ceramic composition.
摘要:
A multilayer ceramic capacitor having internal electrode layers and dielectric layers, wherein a thickness of said dielectric layer is 2.0 μm or less, and an average particle number per one dielectric layer obtained by dividing the thickness of said dielectric layer by an average particle diameter of dielectric particles composing said dielectric layer is 3 or more and 6 or less.
摘要:
A method of production of a multilayer ceramic capacitor or other multilayer ceramic electronic device with few structural defects and improved highly accelerated life, that is, a method of production of a multilayer ceramic electronic device having a firing step of firing a stack comprised of a dielectric layer paste and an internal electrode layer paste including a base metal alternately arranged in a plurality of layers, a first annealing step of annealing, at a temperature T1 of 600 to 900° C., the stack after firing and a second annealing step of annealing, at a temperature T2 of 900 to 1200° C. (however, excluding 900° C.), the stack after said first annealing.
摘要:
In a multilayer ceramic capacitor of the present invention, a first rare earth element (R1) and a second rare earth element (R2) respectively diffuse in each of crystal grains forming dielectric layers and, assuming that, in the crystal grains each having an average grain diameter D, a ratio of a depth d1 of a diffusion layer of the first rare earth element (R1) from the surface of the crystal grain relative to the diameter D of the crystal grain is given as X1(%) and a ratio of a depth d2 of a diffusion layer of the second rare earth element (R2) from the surface of the crystal grain relative to the diameter D of the crystal grain is given as X2(%), the depth d2 of the diffusion layer of the second rare earth element (R2) reaches deeper than the depth d1 of the diffusion layer of the first rare earth element (R1) and a relationship of X1=10 to 35% and X2>X1 (synonymous with d2>d1) is established. Therefore, the multilayer ceramic capacitor is excellent in reliability wherein the capacitance-temperature characteristic, i.e. a time-dependent change in capacitance, satisfies the EIA standard X8R characteristic (ΔC/C=±15% at −55 to +150° C.) and the resistance change ratio in an acceleration test is small (average life is long).
摘要:
There are provided steps of polarizing a ceramic composition including a perovskite compound containing Pb, Zr, Ti and Mn as main components and a heat treatment step for keeping the polarized ceramic composition within a temperature range lower than Tc (Tc denoting the Curie temperature of the ceramic composition) for 1 to 100 minutes.
摘要:
The present invention is a composite material, a process and a product formed by the process. The composite is formed by a process that includes forming a fibrous structure comprising fibers into a preform, coating the fibers of the fibrous structure preform with elemental carbon to impregnate that preform, infiltrating the preform with boron carbide to form an impregnated green body. The impregnated green body is infiltrated with liquid naphthalene or other carbon precursor, which is thereafter pyrolyzed to form a carbon char. Then, the char infiltrated green body is infiltrated with molten silicon to form a continuous matrix throughout the composite. The silicon in the continuous matrix is reacted with the carbon char to form silicon carbide.
摘要:
A piezoelectric ceramic composition contains a compound containing Na, Li, Nb and O, and having a perovskite structure, as a main component. The main component has a crystal phase in a semi-stable state at room temperature, such crystal phase originally not being stable at room temperature but being stable at a higher temperature.
摘要:
Systems and methods are described for loss dielectrics. A method of manufacturing a lossy dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer and then densifying together. The systems and methods provide advantages because the lossy dielectrics are less costly and more environmentally friendly than the available alternatives.
摘要:
The invention concerns a process for manufacturing a part made of high temperature-resistant, ceramic material based on aluminum nitride and reaction sintering. The process comprises the steps of preparing a homogeneous mixture of boron nitride powder, aluminum powder and a paste-like binder, capable of solidifying by chemical reaction and by solvent loss through drying. The mixture is formed by mold casting and then pressed and heated, to a temperature not exceeding approximately 70° C., to harden the binder and to obtain a solid and manipulable unfired part. The binder is eliminated by heating to a temperature of approximately 300° C. Pores of the unfired part are impregnated by immersing the part in a bath of molten aluminum or aluminum alloy to form an impregnated preform. Thereafter, the impregnated preform is removed from the bath, cooled, and machined to the final dimensions of the part. A ceramic is obtained by reaction sintering the machined part at a temperature of 900 to 1000° C. Residual aluminum is removed from the pores of the ceramic part by heat treating it, at a temperature of 1100 to 1250° C., cooling it, and mechanically eliminating the aluminum that has collected on the surface of the part.
摘要:
High-Tc superconducting ceramic oxide products and macroscopic and microscopic methods for making such high-Tc superconducting products. Completely sealed high-Tc superconducting ceramic oxide products are made by a macroscopic process including the steps of pressing a superconducting ceramic oxide powder into a hollow body of a material inert to oxygen; heat treating the superconducting ceramic oxide powder packed body under conditions sufficient to sinter the ceramic oxide powder; and then sealing any openings of the body. Optionally, a waveform or multiple pulses of alternate magnetic field can be applied during the heat treatment. The microscopic method of producing a high-Tc superconducting ceramic oxide product includes the steps of making a high-Tc superconducting ceramic oxide thin film; optionally sintering the deposited thin film in a magnetic field; and removing partial oxygen content of the thin film by a scanning tunneling electron treatment machine to form a microscopic insulation layer between two high-Tc superconducting domains of the thin film.