Abstract: Co-precipitated CoCuMn and CoCuMg catalysts are used in Fischer-Tropsch synthesis.

Abstract: Co-precipitated CoCuMn and CoCuMg catalysts are used in Fischer-Tropsch synthesis.

Abstract: A method of bonding a sheet of metal such as copper on a substrate of aluminum nitride, the method comprising the following steps known per se: i) growing a layer of alumina on the aluminum nitride substrate by means of heat treatment; and ii) placing the sheet of metal on the alumina layer and then bonding them together; the method being wherein alumina-growing step i) is performed under a controlled oxidizing atmosphere which is free from moisture.

Abstract: Disclosed is a method for the direct bonding of a copper sheet to a substrate made of an electrically insulating material, with the heating of the copper/substrate set in order to obtain a eutectic mixture. The method according to the invention consists in cleaning the copper to eliminate traces of oxidation on its surface before placing said copper on the substrate, in heating the copper/substrate set under a neutral atmosphere until a temperature greater than the temperature for the formation of the eutectic mixture is reached, and in applying the oxidating reactive gas only after the temperature greater than the temperature for the formation of the eutectic mixture is reached, in such a way that this temperature is reached before any oxidation of the surface of the copper.

Abstract: A metallic alloy is cast in a mold to produce a solid body by unidirectional solidification. The alloy, initially in a molten state, is cast into a mold and is completely and progressively cooled in the mold while a unidirectional thermal gradient superimposed thereon parallel to a direction determined by the configuration of the mold (predetermined direction) until a metastable equilibrium is reached in which the entire body of the melt is in a super-cooled state as a homogeneous liquid. The equilibrium is then broken to cause solidification of the alloy and the formation of dendritic crystals with their principal axes parallel to the thermal gradient substantially instantly and without noticeable advance of a solidification front across the melt.