Abstract: A liquid-cooled heat sink includes a top plate having an array of circuitous liquid channels, each channel having a separate channel inlet and a common central outlet channel. The heat sink further includes a bottom plate having an inlet port and an outlet port. The heat sink further includes an intermediate plate having inlet guide channels providing fluid communication between the inlet port of the bottom plate and channel inlets of the top plate, said intermediate plate further including an outlet guide channel providing fluid communication between the common central outlet channel of the top plate and the outlet port of the bottom plate.

Abstract: A device for generating electrical energy in a rotating system for the purpose of supplying electric current to electronic components in the system, comprising external forces, acting on the system, that act on piezoelectrically active energy converters in the system, as a result of which electrical energy is generated, and comprising an electronic system for processing the generated electrical energy and transferring it to the components.

Abstract: Components having ceramic bases provided with a metalized structure on at least two opposite and/or juxtaposed faces at the same time, wherein metal in the form of pastes, films or sheets is provided for metallization and is applied to the surfaces of the ceramic base to be provided with a metalized structure.

Abstract: A material based on SiAlON contain 70-97 vol. % of alpha and beta-SiAlON and an amorphous or partially crystalline grain boundary phase and 3 to 30 vol.% of a hard material. The material has an alpha-SiAlON gradient which decreases from the outside to the inside.

Abstract: Both ceramic and intermetallic materials as a rule have a very small elongation at break of distinctly less than 0.3% and therefore a break behaviour with low damage tolerance. In order to increase the damage tolerance, it is important to increase the elongation at break to at least 0.3% or more. This can be achieved by introducing, for example, fibres consisting of carbon or ceramic or metal fibres into the matrix. It is important in this respect for the distribution of the fibres in the matrix to be homogeneous and/or defined. It is of advantage and therefore as a rule desirable for the fibres for reinforcing a material or component to be oriented in a defined direction which is adapted to the main stress.

Abstract: A composite of a metal matrix with one or more incorporated secondary phases is referred to as a metal matrix composite (MMC). Secondary phase refers to all the particles or fibers which have a different composition than the metal matrix, and which are incorporated therein. As incorporation phases, elements and compounds are possible which, as a result of their material characteristics, are suited for improving individual properties of the metal matrix. Besides an improvement in individual properties of the pure metal matrix as a result of the incorporated secondary phase, certain properties of the metal are also degraded, in particular by particles having a size of 1 to 50 ?m. For example, the elongation at break decreases, the strength may decrease, or the tribology may become less favorable.

Abstract: The production of moulded bodies from hard-metal powders by pressing and simultaneous or subsequent heat treatment is known. The mixture of hard material powders and aluminium powders for producing dry-pressed moulded bodies is an example thereof. As a result of the risk of demixing and the loss of homogeneity, the upper limit, for example according to prior art, for the proportion of hard material particles added to the aluminium powder is approximately 20 vol. %. The aim of the invention is to increase the proportion of hard material particles it the mixture. To this end, the inventive method for producing metal ceramic composite materials is characterised by dry-pressing powders with base compositions of between 25 and 79 vol. % of at least one metallic phase, preferably aluminium and the alloys thereof, and between 75 and 21 vol. % of at least one non-metallic inorganic constitnent, as ceramic materials, preferably silicon carbides, aluminium oxides, titanium oxides, carbon and silicates.

Abstract: A hip prosthesis has a shaft which is implantable in the femur, a ball head anchored on the shaft, a socket in which the ball head is movably supported, and a bipolar shell placed between the ball head and the socket, whereby the ball head rotates in the bipolar shell and the bipolar shell rotates in the socket.

Abstract: The invention relates to piezoelectric ceramic materials based on the system Pb(Zr,Ti)O3, i.e. solid solutions of lead zirconate PbTO3, characterized by having very good dielectric and electromechanical properties that can be adopted for different uses by modifying the composition. The piezoelectric ceramic materials based on the system Pb(Zr,Ti)O3 are modified in order to obtain a high level of piezoelectric activity. The invention provides piezoelectric ceramic materials based on lead zirconate titanate (PZT) having the crystal structure of perovskite with formula A2+B4+O32?, which are characterized by a substitution of heterovalent acceptor and donator ions at Zr/Ti sites.

Abstract: Structural components that are subject to high stresses, especially caused by wear, can be protected by coating them with a hard material. For metal-cutting tools it is for example known that their wear resistance can be improved by coating them with a hard material. Different thermal expansion coefficients of the substrate material and the coating material and different layer materials in a multilayer coating may produce great stresses. The stress increases as the thickness of the coating increases, thereby increasing the danger of the coating chipping off. In order to solve this problem, the invention proposes an intermediate layer (5) to be interposed between at least two layers (4, 9) of the coating (3), said intermediate layer mainly or exclusively consisting of a material component (6, 8) of an element of the fourth to eighth subgroup of the fourth and fifth period of the periodic system.

Abstract: A cutting matrix has a top surface, a first cavity for tightening the cutting matrix in a cutting tool, and a cutting edge for cutting by stock removal. A second tightening cavity is arranged coaxially with respect to the first cavity. The first cavity is deeper than the second, and both are below the upper surface of the cutting matrix.

Abstract: A block of stacked green films provided with internal electrodes is laminated, at least one actuator is separated from the block, the actuator obtains its shape by means of a machining operation, is then sintered, and the sinter skin produced by the sintering is used as an insulating layer. The sinter skin is abraded at the points where the internal electrodes are connected to the external electrodes.

Abstract: The invention relates to a clamping claw having a securing leg and a clamping leg for securing an object in a first recess of a support, with the clamping claw in the installed state being secured on the support by way of its securing leg by means of a bolt and clamping the object in the recess by means of its clamping leg. To split the application of axial force applied to an object by a clamping claw in part into an application of force that acts transversely thereto, the clamping claw includes two portions, namely a clamping base and a clamping finger, the clamping base sits on the support in the installed state of the clamping claw, the clamping finger has a securing leg and a clamping leg, and the installed state the securing leg sits on the clamping base over an oblique plane formed as a sliding surface and clamps the object with its clamping leg.

Abstract: The characteristics of piezoceramic multilayer actuators based on lead-zirconate-titanate are determined to a great extent by the compatibility of PZT ceramics having a low sintering temperature with the AgPd internal metallisation during cofiring. It is important to take into consideration that Ag ions in PZT modifications have a high diffusivity at high temperatures (>800° C.) and in addition act as acceptor doping when integrated into the PZT system. The reduction of the fraction of the precious metal palladium, which prevents diffusion, is limited, as silver increasingly diffuses into the piezoceramic as the silver fraction in the internal electrodes increases. According to the invention, Ag+ ions are used to form valence-compensated compositions of the PZT system. A higher level of deformation is maintained, i.e. the acceptor-donor effect in the system is very similar to that of the PZT system modified conventionally without internal electrodes.

Abstract: Porous coatings on high-performance ceramics attempt to combine the mechanical and thermal characteristics, which fulfil stringent demands, of the substrate material with the advantageous properties of coating materials. The subsequent application of layers of this type to the pre-sintered substrate produces unsatisfactory results in several areas of use with regard to possible layer thickness, porosity and adhesion. According to the invention, a shaped body consisting of a sintered, inorganic material, whose surface comprises a porous layer is produced in such a way that the base body is first formed as a green body. A layer in the form of a suspension, also containing an inorganic material, is then applied to the surface or to one section of the surface of the base body. A predetermined fraction of a pore-forming substance is mixed with at least the material of said layer and the green body with its applied layer is subjected to the thermal treatments required for producing a monolithic sintered body.

Abstract: The invention relates to a method for the manufacture of piezoelectric multilayer actuator in which thin layers of a piezoceramic material, called “green leaves” on which at least one internal electrode is applied, are stacked to form a block such that the internal electrodes are guided in alternation to oppositely lying surfaces of the actuator, where they become bound together by an external electrode, the actuator compact being sintered and subjected to abrasive shaping, and then the base metallization is applied for the external electrode.

Abstract: This invention is about SiALON ceramics comprising an alpha SiAlON, a beta SiAlON and an intergranular amorphous and/or crystalline phase. Said alpha SiALON phase was prepared from a multi-cationic mixture including the element of calcium, at least one of yttrium and/or a rare earth element with atomic number greater than 62 and at least one of a rare earth element with atomic number equal or smaller than 62. The second phase, beta SiALON contains elements of Si, Al, O, N. The third phase, amorphous and/or crystalline intergranular phase contains in addition to elements of Si, AL, O, N, element of calcium, at least one of yttrium and/or a rare earth element with atomic number greater than 62 and at least one of a rare earth element with atomic number equal or smaller than 62. This material with its toughness, high fracture resistance and high temperature resistance is useful for cutting tool applications and components in machinery and engines.

Abstract: In piezoceramic multilayer actuators, the head region and the foot region consist of inactive, that is to say electrode-free, piezoceramic layers. Due to the arrangement of the metallic electrodes and the layers of the piezoceramic materials, the shrinkage of the piezoceramic material, in particular in the passive head region and foot region, is influenced during the sintering process and can cause the formation of cracks. Different expansion behavior of the active and of the passive region during operation also lead to stresses which favor crack formation, in particular at the boundary between both regions. According to the invention, it is therefore proposed that a transition region (11), whose shrinkage and expansion behavior lies between the shrinkage and expansion behavior of the active region (10) and the shrinkage and expansion behavior of an inactive region (8, 9) which are electrode free, adjoins the active region (10) up to the inactive head region (8) and up to the inactive foot region (9).

Abstract: The invention relates to a monolithic multilayer actuator comprising a sintered stack of thin films, made from piezo-ceramic with inlaid metallic inner electrodes which extend from the stack on alternate sides and are electrically wired in parallel with external electrodes (3, 4) and are provided with connector wires (5). According to the invention, the actuator may be supplied with nominal voltage over a long period of time, without a change in the properties thereof, whereby the multilayer actuator (1) is sealed within a metallic or ceramic housing (8, 11, 16), the connector wires (5) are integral parts of the housing base (11) and the housing (8, 11, 16) is filled with a water-absorbing medium (14) and a water-transporting, electrically-insulating medium (15).

Abstract: With actuators according to prior art, it is known that, in the inactive region, which is required for contact purposes, irregularities in expansion occur. These produce cracks in the piezoelectrically inactive electrode region, which may occur at regular intervals. As a result of the irregularities in expansion, the stresses accumulate in the passively expanded regions, up to a level at which they are relieved by crack formation. It is therefore proposed according to the invention that the contact surfaces (17), and therefore the inactive regions (15) assigned to them, of one or a predetermined number of electrodes of the same polarity (11; 30 to 37; 39, 40), arranged above one another in the same direction, are arranged offset to one another by a predetermined angle (22) of the size ?, opposite the contact surfaces (17), and therefore the inactive regions (15) assigned to them, of the preceding internal electrode or a predetermined number of preceding electrodes of the same alignment and the same polarity.