Abstract: The aim of the invention is to produce a light-alloy bearing bush with a rough external surface. To achieve this, particles, which are subsequently surrounded in part by the molten metal, are applied to the surface of the casting mould. When the bearing bush is released from the mould, the particles remain in said bush and are subsequently removed from the bearing bush preform either mechanically or by being dissolved in liquid.

Abstract: To prevent, in a cooled ring carrier (1) for pistons, durinh Alfin bonding, the formation of oxides induced by air that escapes due to porous ring carrier material and, as a consequence, an impairment of the ring carrier bond. To this end, the cooled ring carrier, once the ring carrier part and the sheet metal part (3) have been linked, is subjected to negative pressure in a vacuum tank.

Abstract: The aim of the invention is to produce a light-alloy bearing bush with a rough external surface. To achieve this, particles, which are subsequently surrounded in part by the molten melt, are applied to the surface of the casting mould. When the bearing bush is released from the mould, the particles remain in said bush and are subsequently removed from the bearing bush preform either mechanically or by being dissolved in liquid.

Abstract: To prevent, in a cooled ring carrier (1) for pistons, durinh Alfin bonding, the formation of oxides induced by air that escapes due to porous ring carrier material and, as a consequence, an impairment of the ring carrier bond. To this end, the cooled ring carrier, once the ring carrier part and the sheet metal part (3) have been linked, is subjected to negative pressure in a vacuum tank.

Abstract: A cooled ring carrier assembly for the piston of an internal combustion engine, comprising a metal-sheet cooling duct welded to a ring carrier. The cooling duct is press-fit into the inwardly-pointing surfaces of the ring carrier prior to welding. The angle between the inwardly pointing surface of the ring carrier, to which surface metal-sheet cooling duct is welded, and the metal-sheet cooling duct is smaller than 45.degree.. This allows the cooling duct to be press fit into the ring carrier rather than being shrunk in by temperature differences between the ring carrier and cooling duct.

Abstract: A light-metal piston has a sheet-metal cooling channel integrally cast in the piston head. In order to improve the heat transfer between the piston material and the cooling channel and to reduce the manufacturing costs of the cooling channel, the channel has a narrow slit, which allows oil to pass, extending along at least part of the channel wall.

Abstract: A method for the production of a molded casting, including the steps of providing a mold with a porous insert part which can subsequently be dissolved out. Placing the porous insert part having pores into the mold. Subsequently surrounding the porous insert part by a melt and then putting the melt under pressure. In the pore areas to be kept clear of the melt, gas pressure is maintained on the insert part which is equal to or slightly less than the melt pressure.

Abstract: The invention provides a method of testing silicon distribution in aluminium-silicon alloys by drawing a conductor across the surface of the alloy and measuring the changes of electric resistance between the conductor and the alloy.

Abstract: An aluminium-silicon alloy casting in which zones formed so as to have a particularly fine-grained structure are cooled by way of individual thin-walled mould wall portions, which are prevented from dissolving completely by the melt and are intermetallically bonded to the casting and are detachable from the finished casting only in a destructive manner.