A lead-free solder which can reduce the occurrence of voids and a connecting member which uses the solder and has excellent adhesion, bonding strength, and workability are provided. The lead-free solder alloy contains Sn: 0.1-3% and/or Bi: 0.1-2%, and a remainder of In and unavoidable impurities and has the effect of suppressing the occurrence of voids at the time of soldering. The connecting member is prepared by melting the lead-free solder alloy, immersing a metal substrate in the melt, and applying ultrasonic vibrations to the molten lead-free solder alloy and the metal substrate to form a lead-free solder alloy layer on the surface of the metal substrate. A heat sink and a package are soldered to each other through this connecting member by reflow heating in the presence of flux.

An assembly includes a first steel component that is joined to a second steel component by a weld joint formed in a hybrid welding process. At least one of the first and second steel components is a through-hardened bearing steel. In the hybrid welding process, base material of the first and second steel components is melted, and a molten filler material including at least 90% nickel is added. The weld joint is formed after solidification of the molten base material and of the molten filler material. The weld joint has a central solidified portion and a peripheral solidified portion, and the central solidified portion includes at least 80% filler material and the peripheral solidified portion includes no more than 20% filler material.

Provided is a heat exchanger, in particular for motor vehicles, with at least one exchanger tube of an aluminium alloy and with at least one component connected fluidically to the exchanger tube, wherein the exchanger tube and the component (14, 16) are connected to one another by way of a common soldered connection and wherein the component connected to the exchanger tube has a core layer of an aluminium alloy with the following composition: Si: max. 0.7% by weight, Fe: max. 0.70% by weight, Cu: max. 0.10% by weight, Mn: 0.9-1.5% by weight, Mg: max. 0.3% by weight, Cr: max. 0.25% by weight, Zn: max. 0.50% by weight, Ti: max. 0.25% by weight, Zr: max. 0.25% by weight, unavoidable impurities individually max. 0.05% by weight, altogether max. 0.15% by weight, the remainder aluminium.

A method for joining heat transfer plates, comprising: applying a melting depressant composition on individual application areas of a first metal sheet, each application area comprising a mid-section and two end-sections; pressing ridges and grooves in the metal sheet, the ridges extending in a direction that extends between the end-sections of the application areas, such that the application areas are located on top of the ridges; bringing the metal sheet into contact with a second, pressed metal sheet, such that contact points are formed where the mid-sections of the application areas re located; heating the sheets until melted metal is formed at the application areas where the melting depressant composition is applied; and allowing the melted metal to solidify such that a joint is obtained at the contact points.

A method for joining heat transfer plates, comprising: applying a melting depressant composition on individual application areas of a first metal sheet, each application area comprising a mid-section and two end-sections; pressing ridges and grooves in the metal sheet, the ridges extending in a direction that extends between the end-sections of the application areas, such that the application areas are located on top of the ridges; bringing the metal sheet into contact with a second, pressed metal sheet, such that contact points are formed where the mid-sections of the application areas re located; heating the sheets until melted metal is formed at the application areas where the melting depressant composition is applied; and allowing the melted metal to solidify such that a joint is obtained at the contact points.

The present disclosure relates generally to an improved design of a metal-cored welding wire electrode for use on a high deposition rate welding process that resistively preheats the wire prior to being subjected to the welding current. The preheat circuit reduces the welding current drawn by the electrode so that higher wire feed speeds, and thus higher deposition rates, may be obtained. The metal-cored welding wire includes both a higher fill rate (a greater percentage of the welding wire is the granular core) along with added sulfur and an added bead wetting agent. The bead wetting agent may be one or more of selenium, tellurium, arsenic, gallium, bismuth, and tin. The improved metal-cored welding wire leads to an enhanced weld deposit appearance that means the weld deposits are less likely to be rejected as unusable.

Electrical insulating properties between adjacent copper plates are improved while a defect of a bonded substrate which is caused by concentration of stress to end portions of the copper plates is prevented. A bonded substrate includes a silicon nitride ceramic substrate, a copper plate, and a bonding layer. The copper plate and the bonding layer are disposed on the silicon nitride ceramic substrate. The bonding layer bonds the copper plate to the silicon nitride ceramic substrate. The bonding layer includes: an interplate portion between the silicon nitride ceramic substrate and the copper plate; and a protruding portion protruding from between the silicon nitride ceramic substrate and the copper plate. Exposure of the silicon nitride ceramic substrate is prevented at a position where the protruding portion is disposed.

A micro-region semi-solid additive manufacturing method is provided, where rod-shaped materials are used as consumables, and front ends of the consumables are heated by means of high-energy beam, an electric arc, a resistance heat, or the like, to enable the front ends to be in a semi-solid state in which the solid-liquid two phases coexist; at the same time, the rotational torsion and the axial thrust are applied to the consumables to perform shearing, agitation and extrusion on the semi-solid front ends, that is, the mold-free semi-solid rheoforming is performed. The consumable is transmitted to the bottom layer metal continuously in this manner to form metallurgical bonding, the stacking process is repeated according to a planned route obtained after discretization slicing treatment, and then an object or a stack layer in a special shape can be formed.

A micro-region semi-solid additive manufacturing method is provided, where rod-shaped materials are used as consumables, and front ends of the consumables are heated by means of high-energy beam, an electric arc, a resistance heat, or the like, to enable the front ends to be in a semi-solid state in which the solid-liquid two phases coexist; at the same time, the rotational torsion and the axial thrust are applied to the consumables to perform shearing, agitation and extrusion on the semi-solid front ends, that is, the mold-free semi-solid rheoforming is performed. The consumable is transmitted to the bottom layer metal continuously in this manner to form metallurgical bonding, the stacking process is repeated according to a planned route obtained after discretization slicing treatment, and then an object or a stack layer in a special shape can be formed.

A method is disclosed for electrically bonding a first semiconductor component to a second semiconductor component, both components including arrays of contact areas. In one aspect, prior to bonding, layers of an intermetallic compound are formed on the contact areas of the second component. The roughness of the intermetallic layers is such that the intermetallic layers include cavities suitable for insertion of a solder material in the cavities, under the application of a bonding pressure, when the solder is at a temperature below its melting temperature. The components are aligned and bonded, while the solder material is applied between the two. Bonding takes place at a temperature below the melting temperature of the solder. The bond can be established only by the insertion of the solder into the cavities of the intermetallic layers, and without the formation of a second intermetallic layer.