Abstract: The invention relates to enhanced heat transfer surfaces and methods and tools for making enhanced heat transfer surface. Certain embodiments include a boiling surface that include a plurality of primary grooves, protrusions and secondary grooves to form boiling cavities. The boiling surface may be formed by using a tool for cutting the inner surface of a tube. The tool has a tool axis and at least one tip with a cutting edge and a lifting edge. Methods for making a boiling surface are also disclosed, including cutting through the inner surface of a tube to form primary grooves, then cutting and lifting the inner surface to form protrusions and secondary grooves.

Abstract: A metallic heat exchanger tube (1) with a tube wall (2) and with integrally formed ribs (3) which run around on the tube outside (21) and which have a rib foot (31), rib flanks (32) and a rib tip (33), the rib foot (31) projecting essentially radially from the tube wall (2), and the rib flanks (32) being provided with additional structural elements which are formed as material projections (4) arranged laterally on the rib flank (32), the material projections (4) having a plurality of boundary faces (41, 42), at least one of the boundary faces (42) of at least one material projection (4) being curved convexly.

Abstract: The invention relates to an extrusion billet having two end sides, characterized in that the surface of at least one end side face has a three-dimensional topography which is composed of a substantially planar end side face from which local elevations protrude.

Abstract: A metallic heat exchanger tube has fins which run helically around the outside of the tube, are molded integrally therefrom and are of continuous design and the fin base of which protrudes substantially radially from the tube wall, and with primary grooves located between respectively adjacent fins. At least one undercut secondary groove is arranged in the region of the groove base of the primary grooves. The secondary groove is delimited toward the primary groove by a pair of mutually opposite material projections formed from the material of respectively adjacent fin bases and the cross-section thereof is varied at regular intervals without having an influence on the shape of the fins. There is a spacing between the opposite material projections, the spacing being varied at regular intervals, as a result of which local cavities are formed.

Abstract: A copper alloy having an improved combination of yield strength and electrical conductivity consists essentially of, by weight, from 1% to 2.5% of nickel, from 0.5% to 2.0% of cobalt, with a total nickel plus cobalt content of from 1.7% to 4.3%, from 0.5% to 1.5% of silicon with a ratio of (Ni+Co)/Si of between 3.5 and 6, and the balance copper and inevitable impurities wherein the wrought copper alloy has an electrical conductivity in excess of 40% IACS. A further increase in the combination of yield strength and electrical conductivity as well as enhanced resistance to stress relaxation is obtained by a further inclusion of up 1% of silver. A process to manufacture the alloys of the invention as well as other copper-nickel-silicon alloys includes the sequential steps of (a). casting the copper alloy; (b). hot working the cast copper-base alloy to effect a first reduction in cross-sectional area; (c).

Abstract: The invention relates to a method for the manufacture of tubes bent in a U-shape (hairpin tubes) from a nonferrous metal, immediately following a tube production line. For that purpose, according to the invention, the method for the manufacture of tubes bent in a U-shape from a nonferrous metal, immediately following a tube production line, has the consecutive steps of: a) uncoiling the drawn tube material from a basket winder, b) straightening the drawn tube material, c) annealing and subsequently cooling the drawn tube material before or after cutting, for separation into tube portions, to the starting length for a tube bent in a U-shape, and d) bending the tube portions into a U-shape.

Abstract: The invention relates to a material composite in strip form, process for producing said composite and use of the material composite as a sliding element. The material composite comprising a layer consisting of a copper multicomponent alloy which is permanently joined to a steel supporting layer, where the copper multicomponent alloy is composed of [in % by weight]: Ni 1.0 to 15.0%, Sn 2.0 to 12.0%, remainder Cu and inevitable impurities, optionally up to 5% manganese, optionally up to 3% silicon, optionally individually or in combination up to 1.5% Ti, Co, Cr, Al, Fe, Zn, Sb, optionally individually or in combination up to 0.5% B, Zr, P, S, optionally up to 25% Pb.

Abstract: The invention relates to a method of producing a plain bearing bush or bearing shell of varying width from a flat strip material, which comprises the following steps: incorporating grooves in the flat strip material along the bush or bearing-shell contour, rolling or bending the flat strip material into a bush or bearing-shell shape, mechanical severing of the excess marginal regions along the grooves, obtaining a finished plain bearing bush or bearing shell which has the final shape. In this case, the invention is based on the idea of producing trapezoidal or stepped bushes as “shaped bushes” from strip material. The starting point in this case may be a strip of rectangular cross section, which is normally used for cylindrical bushes. The grooves can be incorporated in the flat strip material.

Abstract: The invention relates to a process for producing a sliding bearing with a sliding surface, which is made of a copper multicomponent alloy with at least two phase constituents, in which process at least one phase constituent at the sliding surface is dissolved by means of an acid, and at least one further phase constituent is retained in a raised form. The sliding bearing preferably is made of a copper/aluminum multicomponent bronze.

Abstract: The invention relates to a process for producing a sliding body made up of a base body and a slide plate with a running surface arranged on the base body, wherein the slide plate and the base body are joined to one another by capacitor discharge welding. It is preferable for sliding bodies of this type to be used as a sliding shoe for hydrostatic piston engines. The running surface of the slide plate is made of a nonferrous-metal sliding bearing material produced by spray-compacting and, in particular, is made of a copper-tin-titanium alloy produced by spray-compacting and contains 13.5 to 20% by weight of tin, 0.05 to 0.5% by weight of titanium, remainder copper and optionally one or more of the elements selected from silicon, chromium and zirconium up to a total amount of 1.0% by weight, plus inevitable impurities.

Abstract: The invention relates to a heat-exchanger tube structured on both sides with excellent heat transfer characteristics utilizing both outer and also inner fins and secondary grooves intersecting the inner fins. Two spaced-apart rolling tools are provided in the utilized device in order to form the outer fins of two adjacent rolling tools; the inner structure is formed by two differently profiled mandrels. The first mandrel forms in a first forming area the inner fins. The second mandrel forms in a second forming area the inventive secondary grooves into the earlier created inner fins.

Abstract: A lead-free copper alloy based on Cu—Zn—Si and a method of manufacture thereof. The copper alloy is built on the basis of copper, zinc and silicon without toxic additives and consists of: 70 to 83% Cu, 1 to 5% Si and the further matrix-active elements: 0.01 to 2% Sn, 0.01 to 0.3% Fe and/or Co, 0.01 to 0.3% Ni, 0.01 to 0.3% Mn, the remainder Zn and unavoidable impurities.

Abstract: The invention relates to a conductive material consisting of an alloy that contains copper, for use as a plug-in or clip connection. Said material comprises a cover layer that is deposited on at least some sections of the contact surface, said layer consisting at least of a support layer and an adhesive layer. The anti-friction layer has a carbon content greater or less than 40 and less than or equal to 70 atomic percent.

Abstract: A band-shaped semi-finished product is made out of a ductile material and is configured to be separated into at least two sections. At least one pair of wedge-shaped, non-cuttingly formed longitudinal notches are formed, between the tips of which there remains a thin web of material, which can be torn easily with little force. The semi-finished product is distinguished by burr-free separated edges, defined geometry of the separating surfaces, and extremely reduced breaking-surface portions. It shows improved resistance during static and dynamic stress, in particular for alternating bending loads, in comparison to conventional, for example via the rolling-cutting technique, separated semi-finished products.

Abstract: The invention relates to a layer sequence on a substrate made from copper, a copper-based alloy, a copper-plated substrate or a nickel or a nickel-based alloy for production of a composite material, in which a covering layer, consisting of tin or a tin-based alloy, which is arranged at least over part of the substrate, a barrier layer, which is located between the substrate and the covering layer and is in direct contact with the substrate, the barrier layer consisting of at least one element selected from the group consisting of Fe, Co, Nb, Mo or Ta, and an intermediate layer and a reaction layer, which is located between the barrier layer and the covering layer, the intermediate layer consisting of at least one element selected from the group consisting of Cu and Ni. The reaction layer required between covering layer and intermediate layer consists of Ag, an Ag alloy or Pt and Pd and its alloys.

Abstract: A device for sorting bent elongated articles, in particular rods or tubes, having a measuring span with an inclined plane, down which the articles roll. A separating system provided at the outlet end of the measuring span sorts the bent articles from the straight articles, whereby a pressure gauge is arranged in the measuring span in order to determine the force of the rolling-off articles onto the inclined plane. The measured force of the rolling-off articles in the measuring span is evaluated regarding a curvature and the articles are sorted by the evaluated signal through the separating system.

Abstract: The invention relates to the objectification of surface test methods through image processing. Information z(x, y) is measured and recorded for each image point (x, y) of the measuring field of an examined specimen surface, and resultant magnitudes are calculated therefrom. An objective correlation of these resultant magnitudes occurs with a scale of so far subjectively measured quality characteristic numbers of a characteristic of the examined specimen. A method for an objective evaluation of a bending edge of metal bands and for a wear test on metal bands is described in detail.

Abstract: An electrically conductive composite material for use in the manufacture of electrical contact components, consisting of a metal strip and a contact layer made of a silver or tin contact material, which contact layer is applied at least to one side of the metal strip, whereby the contact material contains as a first additive 0.5 to 60 weight percentage of carbon powder in the form of fine particles having a diameter of ø1=5 to 200 nm and 0.5 to 60 weight percentage of a second powdery additive in the form of fine particles having a diameter of ø2=5 to 200 nm. Moreover a device for the gas atomization of a jet of a flowable or liquid material and a method for the manufacture of an electrically conductive composite material and its use are disclosed.

Abstract: Cracking of a crucible can cause heavy damage to the system in melting furnaces. A reliable monitoring of threatening breaking out of the melt is therefore needed. For this purpose a monitoring device for melting furnaces is provided to monitor the breaking out of melt and includes a closed circuit consisting of several conductor sections with at least a partially conducting surface and a measuring/displaying device. A first conductor section is series connected through an ohmic resistor R to a second conductor section. The first conductor section is arranged directly adjacent, however, electrically isolatingly spaced from and with respect to the second conductor section.

Abstract: An electric contact comprises a main body consisting of a copper-based alloy or of stainless steel and a contact layer consisting of a gold-based alloy. The contact layer has a thickness of at least 0.3 ?m and consists of gold with a content of 0.5 percent by weight to 15 percent by weight of one or more platinum group metals, and that an intermediate layer consisting of silver or of a silver-based alloy or of nickel is provided between the main body and the contact layer. The contact layer is preferably applied on the main body by a PVD process.