Patent classifications
C04B2235/3248
Surface Modified Particulate In Sintered Products
Disclosed are coated inorganic particulate and polymer composite material for use in molding/sintering processes. The composite material is uniquely adapted for forming powdered materials into solid objects and associated processes. Improved products are provided under process conditions through surface interfacially modified powders.
Ceramic slurry compositions and methods of use thereof
A slurry composition includes, by volume, a ceramic composition in an amount of from about 60 to about 75 percent and a binder in an amount of from about 25 to about 40 percent, plus a platinum group metal catalyst and a dopant. The ceramic composition includes, by volume of the ceramic composition, fine fused silica particles having a particle size d.sub.50 of from about 4 m to about 7 m, in an amount of from about 7 to about 40 percent; coarse fused silica particles having a d.sub.50 of from about 25 m to about 33 m, in an amount of from about 29 to about 60 percent; inert filler particles having a d.sub.50 of from about 5 m to about 25 m, in an amount of from about 8 to about 40 percent; and fumed silica particles, in an amount of up to about 15 percent.
METHODS OF IDENTIFYING AND PREPARING A CERAMIC MATERIAL EXHIBITING AN ELECTRIC FIELD INDUCED STRAIN
The present invention relates to a method for identifying a solid solution ceramic material of a plurality of perovskite compounds which exhibits an electric field induced strain derived from a reversible phase transition, as well as a method for making such ceramic materials and ceramic materials obtainable therefrom. In particular, the present invention is directed to a method of identifying a solid solution ceramic material of at least three perovskite compounds which exhibits an electric field induced strain derived from a reversible phase transition; said method comprising the steps of: i) determining a molar ratio of at least one tetragonal perovskite compound to at least one non-tetragonal perovskite compound which, when combined to form a solid solution, provides a ceramic material comprising a major portion of a tetragonal phase having an axial ratio c/a of greater than 1.005 to 1.04; and ii) determining a molar ratio of at least one additional non-tetragonal perovskite compound to the combination of perovskite compounds from step i) at the determined molar ratio which, when combined to form a solid solution, provides a ceramic material comprising a major portion of a pseudo-cubic phase having an axial ratio c/a of from 0.995 to 1.005 and/or a rhombohedral angle of 900.5 degrees.
Dielectric composition and multilayer ceramic capacitor containing the same
A multilayer ceramic capacitor includes: a ceramic body including dielectric layers and first and second internal electrodes disposed to face each other with respective dielectric layers interposed therebetween; and first and second external electrodes disposed on an external surface of the ceramic body, wherein the dielectric layer contains a barium titanate-based powder particle having a core-shell structure including a core and a shell around the core, the shell having a structure in which titanium is partially substituted with an element having the same oxidation number as that of the titanium in the barium titanate-based powder particle and having an ionic radius different from that of the titanium in the barium titanate-based powder particle, and the shell covers at least 30% of a surface of the core.
Piezoelectric element oscillatory wave motor and optical apparatus
A piezoelectric element that can decrease the output voltage for detection relative to the input voltage for driving without requiring a step-down circuit between a detection phase electrode and a phase comparator and an oscillatory wave motor including the piezoelectric element are provided. A piezoelectric element includes a piezoelectric material having a first surface and a second surface, a common electrode disposed on the first surface, and a drive phase electrode and a detection phase electrode disposed on the second surface. An absolute value d(1) of a piezoelectric constant of the piezoelectric material in a portion (1) sandwiched between the drive phase electrode and the common electrode and an absolute value d(2) of a piezoelectric constant of the piezoelectric material in a portion (2) sandwiched between the detection phase electrode and the common electrode satisfy d(2)<d(1). An oscillatory wave motor includes this piezoelectric element.
Piezoelectric material, piezoelectric element, and electronic apparatus
The present invention provides a lead-free piezoelectric material having a high piezoelectric constant over a wide operating temperature region. Therefore, the present invention relates to a piezoelectric material including a perovskite-type metal oxide represented by general formula (1) below as a main component, wherein the average valence, of Sn contained in the general formula (1) lies between 2 and 4.
(Ba.sub.vCa.sub.wSn.sub.xTi.sub.yZr.sub.z)O.sub.3 (where 0.620v0.970,0.010w0.200,0.030x0.230,0.865y0.990,0z0.085, and 1.986v+w+x+y+z2.100)General Formula (1)
Engineered matrix self-healing composites
An engineered matrix is provided to blunt and self-heal matrix cracks to reduce oxygen ingress into a fiber reinforced composite.
High intensity focused ultrasonic piezoelectric actuator and method of manufacturing the same
Disclosed is a focused ultrasonic piezoelectric actuator having a novel type of piezoelectric device for focusing ultrasonic waves. The focused ultrasonic piezoelectric actuator includes a dome-shaped piezoelectric body for focusing ultrasonic waves and a rim configured to facilitate focusing of ultrasonic waves of the body and injection of the dome-shaped piezoelectric body during a powder injection molding process, remove warpage of the dome-shaped body during a sintering process, and reinforce focusing intensity of the ultrasonic waves. The rim is integrally formed with the body. Accordingly, in the focused ultrasonic piezoelectric actuator, a dome-shaped focused ultrasonic piezoelectric actuator for focusing ultrasonic waves using a thickness vibration mode at a MHz frequency band is easily manufactured by a powder injection molding method, and thus an ultrasonic focusing effect is maximized.
Dielectric composition and multilayer ceramic capacitor containing the same
A multilayer ceramic capacitor includes: a ceramic body including dielectric layers and first and second internal electrodes disposed to face each other with respective dielectric layers interposed therebetween; and first and second external electrodes disposed on an external surface of the ceramic body, wherein the dielectric layer contains a barium titanate-based powder particle having a core-shell structure including a core and a shell around the core, the shell having a structure in which titanium is partially substituted with an element having the same oxidation number as that of the titanium in the barium titanate-based powder particle and having an ionic radius different from that of the titanium in the barium titanate-based powder particle, and the shell covers at least 30% of a surface of the core.
ABRADABLE COATING FOR COMPONENTS IN HIGH-TEMPERATURE MECHANICAL SYSTEMS
An article may include a substrate including a metal or alloy; a bond coat directly on the substrate; an intermediate ceramic layer on the bond coat; and an abradable ceramic layer directly on the intermediate ceramic layer. The intermediate ceramic layer includes a stabilized tetragonal prime phase constitution and defines a first porosity. The abradable ceramic layer includes zirconia or hafnia stabilized in the tetragonal prime phase by a second mixture including between about 5 wt. % and about 10 wt. % ytterbia, between about 0.5 wt. % and about 2.5 wt. % samaria, and between about 1 wt. % and about 4 wt. % of at least one of lutetia, scandia, ceria, neodymia, europia, or gadolinia, and a balance zirconia or hafnia. The abradable ceramic layer defines a second porosity, and the second porosity is higher than the first porosity.