Abstract: Provided is a piezoelectric element according to the invention including a stacked body in which a piezoelectric layer and an internal electrode layer are stacked. In addition, the internal electrode layer contains at least one kind of element selected from palladium, nickel, platinum, gold, and silver, and copper, and the content of copper contained in the internal electrode layer is 1 to 50 at % in terms of a copper element.

Abstract: The present invention provides a thermal barrier coated component, monitoring or evaluation of the soundness of which is able to be adequately carried out on the basis of the thermal boundary conditions that are detected by a sensor. A thermal barrier coated component according to the present invention comprises: a base material; a first bond coat layer that is a metal bonding layer formed on the base material; a sensor unit that comprises a sensor and a conductive wire, which are formed on the first bond coat layer; a second bond coat layer that is formed on the first bond coat layer so as to cover at least the sensor unit, while having a surface roughness higher than that of the first bond coat layer; and a top coat layer that is formed on the second bond coat layer.

Abstract: A breaker includes a fixed piece having a fixed contact, a movable piece having an elastically deformable elastic portion and a movable contact formed at a tip portion of the elastic portion and pushed to contact with the fixed contact, a thermally actuated element deformable according to a temperature change to shift the state of the movable piece from a conductive state to a cut-off state, and a case accommodating the fixed piece, the movable piece, and the thermally actuated element. The movable piece is cantilevered by the case on a base end portion side of the elastic portion, the elastic portion includes a first narrow portion having a smaller width dimension in a short direction perpendicular to a longitudinal direction of the elastic portion than the base end portion, and the first narrow portion has an arc-shaped contour in plan view from a thickness direction of the elastic portion.

Abstract: The present disclosure relates, according to some embodiments, to a method of determining a quantitatively measured photoprotection of a photoprotective composition, the method comprising: (a) distributing the photoprotective composition in a position in between a drawdown bar and at least one substrate to produce a distributed photoprotective composition; (b) drawing down the distributed photoprotective composition to a thickness on at least one substrate to produce a drawn down sample film; (c) drying the drawn down sample film to produce a dried sample film; (d) measuring a UV absorption of the dried sample film to produce a UV absorption spectrum; (e) determining the quantitatively measured photoprotection of the photoprotective composition from the UV absorption spectrum.

Abstract: A semiconductor device has a substrate with first and second opposing surfaces. A plurality of conductive vias is formed partially through the first surface of the substrate. A first conductive layer is formed over the first surface of the substrate electrically connected to the conductive vias. A first semiconductor die is mounted over the first surface of the substrate. The first semiconductor die and substrate are mounted to a carrier. An encapsulant is deposited over the first semiconductor die, substrate, and carrier. A portion of the second surface of the substrate is removed to expose the conductive vias. An interconnect structure is formed over a surface of the substrate opposite the first semiconductor die. A second semiconductor die can be stacked over the first semiconductor die. A second semiconductor die can be mounted over the first surface of the substrate adjacent to the first semiconductor die.

Abstract: The present invention provides templating methods for replicating patterned metal films from a template substrate such as for use in plasmonic devices and metamaterials. Advantageously, the template substrate is reusable and can provide plural copies of the structure of the template substrate. Because high-quality substrates that are inherently smooth and flat are available, patterned metal films in accordance with the present invention can advantageously provide surfaces that replicate the surface characteristics of the template substrate both in the patterned regions and in the unpatterned regions.

Abstract: One exemplary embodiment includes a thermo-reversible polymer adhesive including a dry adhesive layer and shape memory polymer layer, the shape memory polymer material capable of transitioning from a first shape to a second shape upon heating and imposition of a load to conform to the surface topography of a substrate to which the adhesive is applied.

Abstract: One embodiment includes a multilayer thermo-reversible dry adhesive system comprising of at least one layer of soft dry adhesive and one layer of shape memory polymer.

Abstract: The invention provides an electronic device including an anode and a cathode, between which there are at least two organic phototransducing units where the units are separated by an intermediate connecting region which comprises in sequence: an organic p-type layer, an intermediate layer in direct contact with the organic p-type layer and including a compound that has a LUMO more negative than ?3.0 eV and is different from the organic compound in the organic p-type layer, and an n-type doped organic layer in direct contact with the intermediate layer and including an electron transport material as a host and an organic n-dopant with a HOMO less negative than ?4.5 eV. In one embodiment, the electronic device is a tandem OLED.

Abstract: This invention discloses a method, using pure niobium as a transient liquid reactive braze material, for fabrication of cellular or honeycomb structures, wire space-frames or other sparse builtup structures or discrete articles using Nitinol (near-equiatomic titanium-nickel alloy) and related shape-memory and superelastic alloys. Nitinol shape memory alloys (SMAs), acquired in a form such as corrugated sheet, discrete tubes or wires, may be joined together using the newly discovered joining technique. Pure niobium when brought into contact with nitinol at elevated temperature, liquefies at temperatures below the melting point and flows readily into capillary spaces between the elements to be joined, thus forming a strong joint.

Abstract: A composition and process for forming an electrodeposited coating comprising a co-deposit of a metal and MCrAlY particles. The composition includes a metal and a MCrAlY particles, and the electrodeposited coating comprises a metal matrix and MCrAlY particles dispersed in the matrix. In one aspect, a coating is provided that exhibits excellent oxidation resistance and tribological characteristics at high temperatures, including up to at least about 1350° F. A high temperature coating may comprise a nickel/cobalt alloy matrix comprising MCrAlY particles and chromium carbide particles dispersed in the nickel/cobalt matrix.

Abstract: A metallic laminate composite having a first alloy layer having a low coefficient of thermal expansion, and a second alloy layer having a higher coefficient of thermal expansion. Additional and optional layers may be included in the laminate composite.

Abstract: A method for producing a single-clad or multiple-clad product includes providing a welded assembly comprising a cladding material disposed on a substrate material. Both the substrate material and the cladding material are individually selected alloys. At least a first edge of the cladding material of the welded assembly does not extend to a first edge of the substrate material and thereby provides a margin between the first edges. A material that is an alloy having hot strength greater than the cladding material is within the margin and adjacent the first edge of the cladding material. The welded assembly is hot rolled to provide a hot rolled band, and the material within the margin inhibits the cladding material from spreading beyond the edge of the substrate material during the hot rolling. In certain embodiments of the methods, the substrate material is stainless steel and the cladding material is nickel or a nickel alloy.

Abstract: The invention concerns a nanoprinted device comprising point shaped metallic patterns, in which each metallic pattern has a bilayer structure controlled in hardness and in chemical properties comprising a lower layer (30) constituting the base of the point and an upper layer (31) constituting the point itself.

Abstract: The present invention provides a plated article that has a thin seed layer having a uniform thickness, formed by electroless plating and allowing formation of ultrafine wiring, and that avoids the complicated formation of a bilayer of a barrier layer and a catalytic metal layer prior to forming the seed layer. The present invention also provides a method for manufacturing the plated article. The plated article has an alloy thin film formed on a substrate and containing a catalytically active metal (A) for electroless plating and a metal (B) capable of undergoing displacement plating with a metal ion contained in an electroless plating solution, and a metal thin film formed on the alloy thin film by electroless displacement and reduction plating. The alloy thin film of the catalytically active metal (A) and the metal (B) capable of displacement plating has a composition comprising 5at% to 40at% of the metal (A).

Abstract: A method for coating a substrate of a turbine engine component, the method comprising cold spray depositing a metal-based material onto a surface of the substrate, and heating the deposited metal-based material to increase the porosity of the deposited metal-based material.

Abstract: A printed wiring board having a conductor circuit comprising a copper layer adjacent to an insulating layer and an electroless gold plating, wherein the insulating layer has ten-point mean surface roughness (Rz) of 2.0 ?m or less is provided. According to the present invention, there is no such a defect that gold plating is deposited on a resin, and fine wiring formation with accuracy is realized.

Abstract: A method of bonding a wire between a first bonding location and a second bonding location is provided. The method includes bonding a first end of a wire to a first bonding location using a wire bonding tool to form a first wire bond. The method also includes forming a looped portion in the wire adjacent the first wire bond. The method also includes lowering the wire bonding tool in a direction towards the first wire bond after the forming step. The lowering step is interrupted prior to the wire bonding tool contacting the first wire bond. The method also includes bonding a second end of the wire to a second bonding location.

Abstract: An assembly between a metal piece and a ceramic material piece made of SiC and/or C based ceramic material. The assembly includes a stack structure including the following elements assembled together in pairs in this order, by brazing: the metal piece; a first intermediate piece; a second intermediate piece; and the ceramic material piece. The second intermediate piece is made of another ceramic material, that is chemically less reactive relative to metals than are SiC or C, and that presents a coefficient of expansion smaller than that of the material constituting the metal piece. The first intermediate piece is made of metal and can deform to compensate for expansion difference between the metal piece and the second intermediate piece. The assembly can be used in a turbomachine.

Abstract: A material and method for adhering at least two materials that includes the step of interposing at least one intermediate layer between the two materials and associated adhesion material. The materials to be adhered exhibit at least one characteristic dissimilarity and the intermediate material interposed contains at least one shape memory alloy, the shape memory alloy capable of exhibiting superelasticity.

Abstract: A component for use in manufacturing circuit boards, such as printed circuit boards, or flex substrates is adapted for use with pick-and-place equipment to provide a first material overlay disposed over a second material base layer. Such a component may include a first electrically conductive material disposed over a second electrically conductive material, and a soluble tape backing disposed over and attached to the second electrically conductive material. The component may be attached to a circuit board by solder relow, after which the soluble tape backing is removed. Although typical embodiments involve electrically conductive materials, it is noted that an electrically insulating material can also be disposed over and attached to an underlying material which itself is disposed on a circuit board.

Abstract: A soldering method achieving a high-strength joint between a solder and an nickel/gold electroless plated surface is disclosed. The nickel/gold electroless plated layer is soldered using a solder including tin (Sn), silver (Ag), and copper (Cu). At a solder joint, a layer sturcture of nickel layer/intermetallic compound layer/solder layer is formed. The intermetallic compound layer is composed mainly of tin (Sn) and copper (Cu), and further including nickel (Ni). The intermetallic compound layer has cauliflower-shaped surfaces formed in a solder-layer's side thereof.

Abstract: An uncoated cutting tool that comprises a body containing a pocket. A polycrystalline cubic boron nitride blank has a cutting tip. The blank is brazed into the pocket using a braze alloy whereby there is a braze joint between the body and the polycrystalline cubic boron nitride blank. The braze alloy has a liquidus temperature of at least about 900 degrees Centigrade wherein the braze alloy is selected from the group comprising a nickel-gold braze alloy containing nickel and gold, a copper-gold braze alloy containing copper and gold, a silver-titanium braze alloy containing silver and titanium, and a silver-palladium braze alloy containing silver and palladium.

Abstract: The conductive fabric is fabricated by preparing a base fibrous fabric substrate having the form of a woven, non-woven, or mesh sheet, forming a first layer formed on the fibrous fabric substrate in accordance with an electroless plating process, the first layer being made of copper, and forming a second layer as an externally exposed layer, on the first layer continuously, the second layer being made of gold or platinum.

Abstract: A method for using a novel ternary nickel-gold-phosphorus brazing alloy for joining nickel-based components together and the assembly so formed.

Abstract: In one embodiment, the present invention relates to a composite article, comprising a metal foil having a first side and a second side; a protective film of at least one inert silane, titanate or zirconate overlying the first side of the metal foil; and a metal sheet having a first side and a second side, the first side overlying the protective film. In another embodiment, the present invention relates to a method of increasing tarnish resistance of metal foil comprising contacting the metal foil with an inert silane, titanate or zirconate compound to form a protective film having a thickness from about 0.001 microns to about 1 micron on a surface of the metal foil; and attaching the foil to a metal sheet.

Abstract: A separable bonding system including two opposed rigid adherends and a deformed shape memory alloy element disposed between and adhesively bonded to facing surfaces of the two rigid adherends. A method of adhesively bonding and selectively debonding and separating at least two rigid adherends including mechanically straining a shape memory alloy element to form a deformed shape memory alloy element; disposing the deformed shape memory alloy element between and adhesively bonding the deformed shape memory alloy element to facing surfaces of at least two rigid adherends; elevating the temperature of the deformed shape memory alloy element sufficient to transform the deformed shape memory alloy element from the mechanically strained state to a recovered shape, thereby weakening adhesive bonds formed between the shape memory alloy element and separating the facing surfaces of the at least two rigid adherends.

Abstract: A metal layer is bonded to the ferrite core of an inductive component. A defined electric potential is thereby set for the ferrite core of an inductive component and/or the damping of the inductive component is reduced which is caused by losses induced from its magnetic field.

Abstract: Arrangement (1) for decreasing galvanic corrosion between metal components that includes at least a first component (2) in which a first metal is a part, and at least a second component (3) in which a second metal is a part, whereby the first metal has a higher normal-electrode potential (e0) than the second metal. The first component (2) is intended, after mounting, to be in electrical contact with the second component (3). The first component (2) is coated with a substantially continuous surface layer (4) that is adjusted to give the second component (3) an insignificant galvanic corrosion velocity after mounting. The invention is preferably applied in association with attachment elements such as bolt or screw joint reinforcements, which include a more noble metal than the component or the components with which the attachment element should be in contact with after mounting, and is particularly, preferred for vehicle components.

Abstract: For a two-layer printed wiring board including a polyimide substrate produced with varnish containing polyamic acid as the raw material for the polyimide and a copper alloy foil laminated with the polyimide substrate, there is provided, for the copper alloy foil, a copper alloy containing, in addition to copper and unavoidable impurities, either (1) 0.02 to 1.0 weight percent Ag and/or 0.01 to 0.5 weight percent In or (2) alloy composition (1) plus a total of 0.005 to 2.5 weight percent of at least one of the additional elements Al, Be, Co, Fe, Mg, Mn, Ni, P, Pb, Si, Ti and Zn, or (3) 0.001 to 0.5 weight percent Sn or (4) alloy composition (3) plus a total of 0.005 to 2.5 weight percent of at least one of the additional elements of alloy composition (2) and each of (1), (2), (3) and (4) preferably having a heat resistance of at least 300° C.

Abstract: In one embodiment, the present invention relates to a composite article, comprising a metal foil having a first side and a second side; a protective film of at least one inert silane, titanate or zirconate overlying the first side of the metal foil; and a metal sheet having a first side and a second side, the first side overlying the protective film. In another embodiment, the present invention relates to a method of increasing tarnish resistance of metal foil comprising contacting the metal foil with an inert silane, titanate or zirconate compound to form a protective film having a thickness from about 0.001 microns to about 1 micron on a surface of the metal foil; and attaching the foil to a metal sheet.

Abstract: A surface-mount device attach method for attaching solder ball-grid array or solder column-grid array surface-mount devices to a printed circuit board where the conventional solder mask structure is replaced with a layer of plated nickel to prevent printed circuit board warping caused by the mismatch in the coefficients of thermal expansion between the conventional solder mask and the printed circuit board. A native nickel-oxide layer that forms on the surface of the exposed portions of the plated nickel layer functions as a solder dam.

Abstract: A stabilized GMR device includes a GMR stack having a first and a second edge. Stabilization means are positioned adjacent to the first and the second edge of the GMR stack for stabilizing the GMR stack. The GMR stack includes a first layer of ferromagnetic material and a second layer of ferromagnetic material. A spacer layer is positioned between the first and the second ferromagnetic layers. A buffer layer is positioned adjacent to the first magnetic layer and a cap layer is positioned adjacent to the second ferromagnetic layer. The stabilization means include a first coupler layer positioned adjacent to the first edge of the GMR stack and a second coupler layer positioned adjacent to the second edge of the GMR stack. The stabilization means also include a first ferromagnetic layer positioned adjacent to the first coupler layer and a second ferromagnetic layer positioned adjacent to the second coupler layer.

Abstract: The present invention relates to a piezoelectrical device whose electrode layers contain copper. The usage of copper in electrode layers is enabled by a debindering process, which is carried out by steam.

Abstract: A first level packaging wafer is made of a semiconductor or insulating material. The bumps on the wafer are made using vertical integration technology, without solder or electroplating. More particularly, vias are etched part way into a first surface of the substrate. Metal is deposited into the vias. Then the substrate is blanket-etched from the back side until the metal is exposed and protrudes from the vias to form suitable bumps. Dicing methods and vertical integration methods are also provided. Solder or electroplating are used in some embodiments.

Abstract: A magnetic recording medium comprising a non-magnetic substrate having thereon a non-magnetic undercoat, a magnetic film and optionally a protective film. The magnetic film comprises a material containing Co as a main component. The non-magnetic undercoat comprises at least two layers including a first undercoat film and a second undercoat film provided on the first undercoat film. The first undercoat film comprises a material containing Cr as a main component, and the second undercoat film comprises a material selected from the group consisting of a Cr/Nb-base alloy, a Cr/W-base alloy, a Cr/V-base alloy and a Cr/Mo-base alloy as a main component.

Abstract: A micromachined element mounted to a substrate, the element including a cantilever having a proximal portion attached to the substrate and a coilable distal portion terminating in a free distal end. The coilable distal portion, upon being heated, is capable of bending away from the substrate and at least partially coiling upon itself to form a coiled portion. At least part of the micromachined element may be electrically conductive. In various embodiments, the micromachined element may function as a mechanical microspring, an electrically conductive link, and/or a magnetic coil. A method of fabricating the microelement may include the steps of selectively depositing various layers upon the substrate.

Abstract: In a magnetic storage apparatus having a magnetic recording medium, a drive unit for driving this medium in a prespecified recording direction, a magnetic head assembly including a recorder section and reproduction section, means for causing the magnetic head to move relatively with respect to the magnetic record medium, and a record/playback signal processor means for performing signal inputting to the magnetic head and for effecting reproduction of an output signal from the magnetic head, the reproduction section of said magnetic head is composed of a magnetic head of the magneto-resistance effect type, while said magnetic record medium is structured including a substrate and a magnetic layer formed thereover with one or several underlayers being sandwiched therebetween, wherein at least one of the underlayers is a specific layer that is made of amorphous or microcrystalline materials containing therein Ni as the principal or main component thereof and further containing at least one kind of element as sele

Abstract: A magnetic device uses laminated ferromagnetic layers containing antiferromagnetically coupled ferromagnetic films coupled together with improved antiferromagnetically coupling (AFC) films. The AFC films are formed of the binary and ternary alloys comprising combinations of Ru, Os and Re. The ferromagnetic film thicknesses, the AFC film thicknesses and the compositions of the films in the laminated layer can be varied to engineer the magnetic properties of the device. The magnetic devices whose properties are improved with the improved laminated layers include spin valve magnetoresistive read heads and magnetic tunnel junction (MTJ) devices for use as magnetic memory cells and magnetoresistive read heads.

Abstract: A magnetic recording medium having sufficiently low noise and high coercive force suitable for use with a MR head. The magnetic recording medium comprises a non-magnetic substrate 1, a non-magnetic underlayer 2, a magnetic layer 3 and a protective layer 4. The magnetic layer comprises a Co alloy and the non-magnetic underlayer comprises a first underlayer 21 comprising an Al--Co--Ni alloy and a second underlayer 22 comprising Cr or a Cr alloy laminated on the first underlayer.

Abstract: A ceramic thermal barrier coating layer for a superalloy article is caused to adhere to the superalloy article by applying platinum to the superalloy article and heat treating at a temperature of 1100.degree. C. to 1200.degree. C. for one hour. This causes aluminum to diffuse from the superalloy article into the platinum to form a platinum enriched outer layer which generally includes a platinum enriched gamma phase and a platinum enriched gamma prime phase. An alumina layer is formed between the platinum enriched outer layer and a ceramic coating. The platinum enriched gamma phase and the platinum enriched gamma prime phase in the outer layer reduces the migration of transition metal elements to the ceramic coating to enable a very pure alumina layer to be formed.

Abstract: An interface material for use in forming a coating interposed along a heat dissipating path between a solid state electronic device and a heat sinking surface. The coating consists of a formulation of a thermally stable wax which is formed as a polyorganosiloxane graft polymer of octadecene and a methylsiloxane host blended with a thermally conductive viscosity stabilizer consisting of a thermally conductive particulate material such as alumina, boron nitride, among others. The graft polymer, with its molecular weight of between approximately 10,000 and 15,000 has a density of between about 0.8 and 0.9 with a melting point of between about 30 degrees C. and 90 degrees C.

Abstract: A composition of materials having ferromagnetic and piezoelectric properties is disclosed. In the preferred embodiment, the composition of materials comprises a first layer of Pb.sub.(1-x-y) Cd.sub.x Fe.sub.y and a second layer of Cr.sub.(1-z-w) Zn.sub.z Te.sub.w where x, y, z and w are values within the ranges of 0.38.ltoreq.x.ltoreq.0.042, 0.08.ltoreq.y.ltoreq.0.094, 0.38.ltoreq.z.ltoreq.0.41, 0.28.ltoreq.w.ltoreq.0.31, and 0.25.ltoreq.(1-z-w).ltoreq.0.32. Additionally, each of the layers contain the elements of Bi, O, and S. A random-accessible, non-volatile memory built using the This memory provides for storing two independent bits of binary information in a single storage cell. Each cell comprises two orthogonal address lines formed on the opposite surface of a Si substrate, a composition of materials of the present invention formed over each of the address lines, and an electrode formed over each composition of materials. The data is stored electromagnetically and retrieved as a piezoelectric voltage.

Abstract: A pulse generating element formed of a switchable magnetic wire is worked so as to have an arcuate shape such that the ratio R/d between the radius of curvature R and diameter d of the wire in a state free from external force ranges from 65 to 95. This is achieved by subjecting a wire of a ferromagnetic material, such as Fe--Co--V, to drawing-bending work. The pulse generating element, which is obtained by cutting the switchable magnetic wire to a predetermined length, is restricted to a substantially straight state by a retaining member, and undergoes a drastic flux reversal when it is subjected to an alternating field.

Abstract: It is an object of the present invention to provide a bimetal having a same or wider proportional temperature range than a bimetal using a 42 wt % Ni--Fe alloy as a low thermal expansion alloy, and a higher bending characteristic of a large bending coefficient than a bimetal using a 36 wt % Ni--Fe alloy. The bimetal is formed by bonding a Ni--Co--Fe group low thermal expansion alloy, wherein a total amount of Ni and Co restricted to a very narrow containing range is within a specific composition range, a thermal expansion coefficient at 30 to 100.degree.C. is made similar to that of a 31 wt % Ni--5 wt % Co--Fe alloy of a nominal composition, a thermal expansion is very small and 2.times.10.sup.-6 /.degree.C. or less in the temperature range of 30.degree.to 300.degree. C., and further, a transition point is 250.degree. C. or higher and a transformation temperature is 50.degree. C.

Abstract: In a ceramic multi-layer wiring board, a surface conductor layer is made of a copper-based material and an inner conductor in the ceramic multi-layer is a non-copper metal having a melting point higher than a temperature at which the ceramic multi-layer is fired, typically Ag. Cu and Ag form eutectic crystals when firing the surface conductor layer of Cu. This can be prevented by connecting the surface conductor layer and the inner conductor with Ag--Pd or a metal which is different from the materials of the surface wiring layer and the inner conductor and which does not form eutectic crystals with the material of the surface wiring layer at the temperature at which the surface wiring layer is fired.

Abstract: In a ceramic multi-layer wiring board, a surface conductor layer is made of a copper-based material and an inner conductor in the ceramic multilayer is a non-copper metal having a melting point higher than a temperature at which the ceramic multilayer is fired, typically Ag. Cu and Ag form eutectic crystals when firing the surface conductor layer of Cu. This can be prevented by connecting the surface conductor layer and the inner conductor with Ag-Pd or a metal which is different from the materials of the surface wiring layer and the inner conductor and which does not form eutectic crystals with the material of the surface wiring layer at the temperature at which the surface wiring layer is fired.

Abstract: Substantially improved resistance to sea water corrosion along with adequate hydrophilicity and retention or even improvement of hydrophilicity after exposure to high temperature can be provided on a metal substrate, particularly an aluminum alloy of the type used for heat exchanger fins, by an aqueous liquid hydrophilicizing treatment composition containing poly{alkylene imine} and alkali metal silicae, and, optionally, polyether polyols. The hydrophilicizing treatment is preferably applied over a conventional conversion coating, particularly a chromium phosphate or chromium oxide conversion coating.

Abstract: A high density, substantially oxide-free metal layer is deposited by spray deposition on a substrate in an atmosphere containing ambient air having an oxygen content above about 0.1% by weight. This is accomplished by directing a supersonic-velocity jet stream of hot gases carrying metal particles at the substrate through an inert gas shroud. The layer is useful as a corrosion barrier and for repairing metal substrates.

Abstract: A printed circuit comprising an electrically insulating substrate and an electrically conductive layer on the substrate, this layer being a pseudo-elastic or elastically deformable alloy that undergoes significant deformations in a reversible manner and is a copper alloy containing at least 50% by weight copper in the form of large-grained polycrystals that undergo martensitic transformation. Preferably, the layer contains 60-80% by weight of copper, the large-grained polycrystals having a grain size of at least about 3 mm. The martensitic transformation takes place within the temperature range -55.degree. C. to +125.degree. C., and the layer has a thickness between 30.mu. and 200.mu., preferably about 100.mu..