Abstract: A lead-free KNN-based piezoelectric material represented by the composition formula (KaNabLic)(NbdTaeSbf)Og, where 0.4?a?0.5, 0.5?b?0.6, 0.01?c?0.1, 0.5?d?1.0, 0.05?e?0.15, 0.01?f?0.09, 1?g?3. In one embodiment, the lead-free KNN-based piezoelectric material has a d33>300 pm/V and a Tcurie>250° C. In one embodiment, the d33 and Tcurie of the lead-free textured KNN-based piezoelectric material can be adjusted by creating phase boundaries of (i) orthorhombic to tetragonal (O-T), (ii) rhombohedral to orthorhombic (R-O), and (iii) orthorhombic to tetragonal (O-T). In one embodiment, the lead-free KNN-based piezoelectric material is textured with NaNbO3 or Ba2NaNb5O15 seeds which are platelet or acicular shaped. In one embodiment, the amount, orientation, or particle size distribution of the NaNbO3 or Ba2NaNb5O15 texturing seeds in the lead-free textured KNN-based piezoelectric material can be altered.

Abstract: A transducer comprising a transducer element including a plate with a through-hole and a collar projecting from the plate and defining an interior cavity in communication with the through-hole. A piezoelectric bender includes at least first and second wafer layers stacked together. The bender is coupled to a peripheral end face of the collar. The first and/or second piezoelectric wafer layers bend at a resonant frequency and generate ultrasonic waves that flow through the collar interior cavity and the plate through-hole and create an in-air pressure pattern and acoustic field at a location spaced from the transducer. A plurality of transducers may be made by providing a monolithic transducer element structure including a plurality of the transducer elements formed thereon, coupling either a plurality of benders or a monolithic bender to the plurality of transducer elements, and then cutting the monolithic transducer element structure to define a plurality of individual transducers.

Abstract: A transducer comprising a transducer element including a plate with a through-hole and a collar projecting from the plate and defining an interior cavity in communication with the through-hole. A piezoelectric bender includes at least first and second wafer layers stacked together. The bender is coupled to a peripheral end face of the collar. The first and/or second piezoelectric wafer layers bend at a resonant frequency and generate ultrasonic waves that flow through the collar interior cavity and the plate through-hole and create an in-air pressure pattern and acoustic field at a location spaced from the transducer. A plurality of transducers may be made by providing a monolithic transducer element structure including a plurality of the transducer elements formed thereon, coupling either a plurality of benders or a monolithic bender to the plurality of transducer elements, and then cutting the monolithic transducer element structure to define a plurality of individual transducers.

Abstract: An improved fiber reinforced glass composite includes a carbon-coated refractory fiber in a matrix of a black glass ceramic having the empirical formula SiCxOy where x ranges from about 0.5 to about 2.0, preferably 0.9 to 1.6 and y ranges from about 0.5 to 3.0, preferably 0.7 to 1.8. Preferably the black glass ceramic is derived from cyclosiloxane monomers containing a vinyl group attached to silicon and/or a hydride-silicon group.

Abstract: An improved fiber reinforced glass composite includes a carbon-coated refractory fiber in a matrix of a black glass ceramic having the empirical formula SiCxOy where x ranges from about 0.5 to about 2.0, preferably 0.9 to 1.6 and y ranges from about 0.5 to 3.0, preferably 0.7 to 1.8. Preferably the black glass ceramic is derived from cyclosiloxane monomers containing a vinyl group attached to silicon and/or a hydride-silicon group. Graceful failure can be obtained after exposure of the composites to temperatures up to 1300.degree. C.

Abstract: An improved fiber reinforced glass composite includes a boron nitride-coated refractory fiber in a matrix of a black glass ceramic having the empirical formula SiCxOy where x ranges from about 0.9 to 1.6 and y ranges from about 0.7 to 1.8. Preferably the black glass ceramic is derived from cyclosiloxane monomers containing a vinyl group attached to silicon and/or a hydride-silicon group. Graceful failure can be obtained after exposure of the composites to temperatures up to 600.degree.-700.degree. C. in air.

Abstract: An improved fiber reinforced glass composite includes a carbon-coated refractory fiber in a matrix of a black glass ceramic having the empirical formula SiCxOy where x ranges from about 0.5 to about 2.0, preferably 0.9 to 1.6 and y ranges from about 0.5 to 3.0, preferably 0.7 to 1.8. Preferably the black glass ceramic is derived from cyclosiloxane monomers containing a vinyl group attached to silicon and/or a hydride-silicon group.

Abstract: This invention relates to a ceramic article having a crystalline and continuous silicon nitride phase, iron and a rare earth oxide, the article having a surface area of at least 3.5 m.sup.2 /g, a thermal expansion coefficient smaller than 6.times.10.sup.-6 m/m/.degree.C. measured in the range 20.degree.-800.degree. C. and a porosity of at least 30%. The ceramic article may also contain a discrete porous oxide phase such as alumina, aluminates, silica, spinel, titania, zirconia, zeolites and mixtures thereof. Further, the porous oxide may also contain a metal oxide such as barium oxide, nickel oxide, iron oxide, rare earth oxides and mixtures thereof. The ceramic article may be used as a catalyst support. Methods of manufacturing the ceramic article are also disclosed.

Abstract: This invention relates to a catalyst support structure, methods of preparing the support structure and a process for using the support structure. The catalyst support structure is composed of a substantially polycrystalline cordierite phase having a chemical composition by weight of 6-15% MgO, 33-40% Al.sub.2 O.sub.3 and 45-56% SiO.sub.2 and characterized in that it has a surface area of at least 2.7 m.sup.2 /g and preferably 8 m.sup.2 /g, a compressive strength of at least 31 MPa, a thermal expansion coefficient smaller than 5.2.times.10.sup.-6 m/m/.degree.C. and a porosity of at least 20%.

Abstract: Silicon nitride powder may be prepared by subjecting a composite comprising at least a monolayer of a carbonaceous pyropolymer possessing recurring units containing at least carbon and hydrogen atoms on the surface of a silica support to the action of nitrogen-containing atmospheres at nitriding conditions to form silicon nitride.