Abstract: A method for purifying a powder including grains and contaminants, includes preparing a suspension including the metal powder and a solvent; then while applying mechanical energy to the suspension; dispersing the grains and the contaminants in the solvent; removing the contaminants and the solvent, and drying the grains under a controlled atmosphere.

Abstract: A method of manufacturing powder from a first and a second materials for use in additive manufacturing, the manufacturing process including melting the first and second materials by an electric arc; spraying the melted materials so as to form droplets; cooling the droplets by a carrier gas so as to form solid particles; separating the solid particles from the carrier gas and collecting the solid particles so as to form the powder; and enriching the droplets and/or the particles by means of an active substance.

Abstract: A method of manufacturing powder from a first and a second materials for use in additive manufacturing, the manufacturing process including melting the first and second materials by an electric arc; spraying the melted materials so as to form droplets; cooling the droplets by a carrier gas so as to form solid particles; separating the solid particles from the carrier gas and collecting the solid particles so as to form the powder; and enriching the droplets and/or the particles by an active substance.

Abstract: The invention relates to method for cutting a part using a laser beam, involving the use of laser beam generation means comprising at least one ytterbium-based fibre having a wavelength of between 1 and 4 ?m in order to generate the laser beam. The laser beam is selected to have a power of less than 100 kW, a power density of at least 1 MW/cm2, a focused beam diameter of at least 0.1 mm and a quality factor (BPP) of less than 10 mm·mrad.

Abstract: The invention relates to a particular optical configuration employed in a solid-state laser, in particular a fiber laser, cutting head for controlling the problems of focal drift and laser damage of the optics of the focusing head and to a laser unit equipped with such a focusing head, in particular an ytterbium-doped fiber laser unit.

Abstract: The invention relates to a method for welding at least one, preferably two metal parts to each other, by a laser beam consisting in using a laser beam (10), a first gas flow and a welding nozzle provided with an output orifice which is passed through by the laser beam and the first gas flow and in welding the part(s) by melting the metal thereof at a point of the laser beam impact with said weldable part(s) in such a way that a capillary (11) or a key hole (12) filled with metal vapour is formed. During welding, the first gas flow is directed only to the aperture of the metal vapour capillary in a direction perpendicular to the weldable part(s) in such a way that a dynamic gas pressure is produced.

Abstract: Binary gas mixture for welding using a laser beam of up to 12 kW, consisting of 30% to 60% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

Abstract: Binary gas mixture for welding using a laser beam of up to 12 kW, consisting of 30% to 60% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

Abstract: Process for welding together the two longitudinal edges of a sheet of austenitic, ferritic or martensitic stainless steel so as to obtain a welded pipe, employing at least one laser beam having a power ranging up to 12 kW, and in which a gas mixture is used that consists of 30% to 80% nitrogen by volume and of helium for the remainder (up to 100%). The stainless steel sheet has a thickness of 0.5 to 4 mm and the pipe obtained has a diameter of 5 mm to 50 cm. The welding is full-penetration welding.

Abstract: Method of welding tailored blanks consisting of a material mostly containing steel and a proportion greater than 0.015% aluminium by weight, using at least one laser beam, in which at least one weld joint of the full-penetration type is made using a gas mixture consisting of 30% to 80% nitrogen by volume, the rest being helium (up to 100%) in order to assist the said laser beam. The method of the invention is particularly recommended for welding motor vehicle elements, especially bodywork, doors, bonnets or the like.

Abstract: Binary gas mixture for welding using a laser beam of up to 8 kW, consisting of 60% to 80% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

Abstract: Binary gas mixture for welding using a laser beam of up to 12 kW, consisting of 30% to 60% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

Abstract: Binary gas mixture for welding using a laser beam of up to 8 kW, consisting of 60% to 80% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

Abstract: Process for welding together the two longitudinal edges of a sheet of austenitic, ferritic or martensitic stainless steel so as to obtain a welded pipe, employing at least one laser beam having a power ranging up to 12 kW, and in which a gas mixture is used that consists of 30% to 80% nitrogen by volume and of helium for the remainder (up to 100%). The stainless steel sheet has a thickness of 0.5 to 4 mm and the pipe obtained has a diameter of 5 mm to 50 cm. The welding is full-penetration welding.

Abstract: Method of welding tailored blanks consisting of a material mostly containing steel and a proportion greater than 0.015% aluminium by weight, using at least one laser beam, in which at least one weld joint of the full-penetration type is made using a gas mixture consisting of 30% to 80% nitrogen by volume, the rest being helium (up to 100%) in order to assist the said laser beam. The method of the invention is particularly recommended for welding motor vehicle elements, especially bodywork, doors, bonnets or the like.

Abstract: The invention relates to a plasma arc welding process and a plasma arc welding device for aluminum and its alloys, which process comprises at least one step of initiation of a pilot arc by means of an auxiliary current which is delivered by an auxiliary current source and flows in a pilot-arc circuit, one step of feeding with plasma gas, one step of initiation of a main arc by means of a main current which is delivered by a main current source and flows in a main circuit, one step of cyclic variation of the polarity of the main current so as to obtain at least one phase of descaling the material to be welded with a first current polarity and at least one phase of welding the material with a second current polarity, and in which process the supply of auxiliary current to the pilot-arc circuit is stopped during the descaling phase and the main circuit and to the pilot-arc circuit are supplied with main current.

Abstract: To terminate welding, the mean energy of the arc is first reduced to obtain plugging of the hole, then this energy is briefly increased before again being decreased. Application to plasma arc welding of carbon steels.

Abstract: The invention relates to a process for striking an arc and to a torch employing said process. An electronic ignitor located at a maximum distance of 8 meters from the torch has a high-voltage conductor which leads to a spark gap adjacent the part to be welded. The high-voltage circuit is closed in the region of the zone to be ionized between the welding electrode and the part.