Abstract:
A monolithic piezoelectric actuator is made of stoichiometric PZT ceramics (2) with low A-site doping and silver- and palladium-containing electrode layers (1). The piezoelectric actuator has improved mechanical resistance and good piezoelectric properties. The disclosed production process leads to optimum grain sizes and optimum piezoelectric properties, independently from B-site doping, and makes it possible to produce multilayer piezoelectric actuators which can be used at high temperatures of up to 150 DEG C.
Abstract:
Novel processes are provided for the production of porous ceramic preforms, metal activated porous ceramic preforms and intermetallic/ceramic/metal composites. These products are all manufactured using processes which are based on tape casting techniques.
Abstract:
A one step ceramic brazing material preferably for use in joining ceramics to each other or in joining a ceramic to a metal. The brazing material includes a strip of a metal of alloy and greater than 3 % titanium or titanium hydride in powder form, in a polymer coating thereon, to enhance the wettability of the braze metal onto ceramics and metals. The brazing material is made in the form of a coated strip so that it can be stamped to washers rings or discs for particular applications.
Abstract:
Method to create a good bonding between a free standing thermal barrier coating and a green CMC. By providing a (partially) sintered free standing TBC (7) which is pressed onto a green CMC substrate (4) and sintering this composite structure the resulting sintered composite reveals a good bonding between the TBC and sintered CMC. Preferably an oxide matrix and oxide fibers are used for the CMC, and a zirconia based TBC.
Abstract:
The present invention provides a low cost preparation of ultra-low CTE and low dielectric loss high temperature co-fired ceramic (HTCC) substrates for highly integrated monolithic millimeter-wave integrated circuits (MMICs) utilized in high temperature environment. This HTCC zircon substrate is advantageous over currently available HTCC substrates in terms of cost effectiveness, excellent dielectric properties, close to zero thermal expansively, high thermal conductivity and good mechanical properties.
Abstract:
The invention relates to a method for the preparation of a blank of a ceramic material, wherein a first ceramic material and then a second ceramic material of different compositions are filled into a die and wherein the materials are pressed and after pressing are sintered. A layer of the first ceramic material is thereby filled into the die and a first cavity formed in the layer, the second ceramic material is then filled into the first open cavity and the materials pressed together and then heat-treated.
Abstract:
Multilayer ceramic chip capacitors which satisfy COG requirements and which are compatible with reducing atmosphere sintering conditions so that non-noble metals such as nickel and nickel alloys thereof may be used for internal and external electrodes are made in accordance with the invention. The capacitors exhibit desirable dielectric properties (high capacitance, low dissipation factor, high insulation resistance), excellent performance on highly accelerated life testing, and very good resistance to dielectric breakdown. The dielectric layers comprise a barium strontium zirconate matrix doped with other metal oxides such as TiO 2 , CaO, B 2 O 3 , and MgO in various combinations.
Abstract translation:根据本发明制备满足COG要求并且与还原气氛烧结条件相兼容的多层陶瓷片式电容器,使得非贵金属如镍和镍合金可用于内部和外部电极。 电容器表现出所需的介电特性(高电容,低损耗因数,高绝缘电阻),在高度加速寿命测试中具有出色的性能,以及非常好的耐电介质击穿能力。 电介质层包括以各种组合掺杂其它金属氧化物如TiO 2,CaO,B 2 O 3和MgO的锆酸锶锆基体。
Abstract:
Thus, one aspect of the invention relates to a green ceramic layer comprising a ceramic material, a binder, and a dual-role dispersant and plasticizer, wherein said dual-role dispersant and plasticizer is an organic di- or tri-ester selected from compounds of formula (I), (II), (III) and (IV). Another aspect of the present invention relates to a slurry for use in the manufacturing of a green ceramic layer comprising a ceramic material, a solvent, a binder, and a dual-role dispersant and plasticizer, wherein said dual role dispersant and plasticizer is an organic di- or tri- ester. Further aspects include uses of and methods of manufacturing said green ceramic layers.
Abstract:
The present invention provides a process for the preparation of a prepreg for a ceramic matrix composite material, said process comprising the steps of: a) impregnating an arrangement of ceramic fibers with a slurry of a ceramic powder, which slurry contains: 10 to 40 vol%, based on the total volume of the slurry, of the ceramic powder, 10 to 20 wt%, based on the total weight of the ceramic powder in the slurry, of glycerol, 0 to 2 wt%, based on the total weight of the ceramic powder in the slurry, of an organic binder, and water; b) reducing the water content in the slurry which is retained by the arrangement of ceramic fibers after impregnation so as to increase the volume ratio of the ceramic powder in the slurry and to provide a prepreg containing a slurry of a ceramic powder with a volume ratio of the ceramic powder of 45 vol% or more in the slurry. It further provides a prepreg obtainable from the process. In further aspects of the invention, laminates containing the above prepregs and a process for their production are provided. In yet a further aspect, the invention provides a ceramic matrix composite green body and a process for its preparation, and a process for the preparation of a ceramic matrix composite body, using the prepregs or the laminated prepregs in accordance with the invention.