Abstract: The invention relates to a method for the vertical semi-continuous direct chill casting of composite billets or plates comprising at least two layers of aluminum alloys, using a separator which is in contact with the solidification front and which provides a seal between the two alloys during casting, said separator being vibrated while it is in contact with the solidification front, so that the separator is not frozen in and entrained by the solid metal. The invention also relates to a device that can be used to carry out said method.

Abstract: The invention relates to a method for the vertical semi-continuous direct chill casting of composite billets or plates comprising at least two layers of aluminium alloys, using a separator which is in contact with the solidification front and which provides a seal between the two alloys during casting, said separator being vibrated while it is in contact with the solidification front, so that the separator is not frozen in and entrained by the solid metal. The invention also relates to a device that can be used to carry out said method.

Abstract: The invention relates to a manufacturing method for making an unwrought semi-finished product having at mid thickness a density of micropores of size greater than 90 ?m less than 50% and preferably less than 20% of the density of micropores of size greater than 90 ?m obtained by a method according to prior art. The method according to the invention comprises in particular an ultrasound treatment step for the molten metal bath in a furnace and/or a vessel using an immersed device comprising at least one ultrasound transmitter. The semi-finished products obtained according to the method of the invention are particularly advantageous for manufacturing by rolling sheets designed for the aircraft industry to produce spars, ribs, upper and lower wing skins and for manufacturing by extrusion sections designed for the aircraft industry to produce stiffeners.

Abstract: An aluminum-based welding filler wire is made with an aluminum alloy that contains between 0.1 and 6 wt. % titanium, including one portion in the form of TiB2 particles, TiC particles, or a combination thereof, and another portion in the form of free titanium. The filler wire can be used in welding aluminum-based materials.

Abstract: Process for manufacturing aluminium alloy products, with high toughness and fatigue resistance comprising: (a) preparing an aluminium alloy bath, (b) adding a refining agent containing particles of AlTiC type phases into the bath, (c) casting an as-cast form such as an extrusion ingot, a forging ingot or a rolling ingot, (d) hot transforming the as-cast form, possibly after scalping, to form a blank or a product with final thickness, (e) optionally cold transforming the blank to a final thickness, (f) applying a solution heat treatment and quenching the product output from (d) or (e), followed by relaxation by controlled stretching with permanent elongation between 0.5 and 5%, and optionally annealing, wherein the quantity of refining agent is chosen such that the average casting grain size of the as-cast form is more than 500 ?m. The present invention may be used, for example, to manufacture fuselage sheet or light-gauge plates made with 6056 alloy.

Abstract: Process for manufacturing aluminum alloy products, with high toughness and fatigue resistance comprising: (a) preparing an aluminum alloy bath, (b) adding a refining agent containing particles of AlTiC type phases into the bath, (c) casting an as-cast form such as an extrusion ingot, a forging ingot or a rolling ingot, (d) hot transforming the as-cast form, possibly after scalping, to form a blank or a product with final thickness, (e) optionally cold transforming the blank to a final thickness, (f) applying a solution heat treatment and quenching the product output from (d) or (e), followed by relaxation by controlled stretching with permanent elongation between 0.5 and 5%, and optionally annealing, wherein the quantity of refining agent is chosen such that the average casting grain size of the as-cast form is more than 500 ?m. The present invention may be used, for example, to manufacture fuselage sheet or light-gauge plates made with 6056 alloy.

Abstract: Process for manufacturing aluminium alloy products, with high toughness and fatigue resistance comprising: (a) preparing an aluminium alloy bath, (b) adding a refining agent containing particles of AlTiC type phases into the bath, (c) casting an as-cast form such as an extrusion ingot, a forging ingot or a rolling ingot, (d) hot transforming the as-cast form, possibly after scalping, to form a blank or a product with final thickness, (e) optionally cold transforming the blank to a final thickness, (f) applying a solution heat treatment and quenching the product output from (d) or (e), followed by relaxation by controlled stretching with permanent elongation between 0.5 and 5%, and optionally annealing, wherein the quantity of refining agent is chosen such that the average casting grain size of the as-cast form is more than 500 ?m. The present invention may be used, for example, to manufacture fuselage sheet or light-gauge plates made with 6056 alloy.

Abstract: Process for forming an aluminum alloy strip, including the steps of a) obtaining an aluminum alloy consisting essentially of, by weight, 0.5 to 13% Si, 0 to 2% Mg, 0 to 2% Cu, 0 to 1% Mn, 0 to 2% Fe, other elements less than 0.5% each and less than 2% total, and remainder Al; and b) continuously casting the aluminum alloy between twin cooled rolls having a force applied thereto, to obtain a cast strip of thickness between 1.5 and 5 mm, and optionally cold rolling the cast strip. The force applied to the rolls is maintained below an amount represented by a straight line between a point A and a point B on a graph of specific applied force (y-axis) vs. cast width (x-axis), where point A is (1.5 mm, 750 tons/meter at cast width) and point B is (5 mm, 500 tons/meter of cast width).

Abstract: In order to facilitate resuming molecular beam epitaxy after etching a substrate or an epitaxial layer, the etching method is implemented in an ultra-high vacuum, and it consists in producing at least two simultaneous chemical beams converging towards the substrate or the layer, the beams being formed of substances, each of which is capable of reacting with elements of different types in the substrate or the layer so as to form volatile compounds. Application in particular to manufacturing photonic and optoelectronic components.

Abstract: A process for obtaining bimaterial parts by casting an aluminum alloy onto an insert coated with a metal film. In this process, the oxide layer is removed from the insert by treatment under vacuum, and then the insert is coated with a titanium based film by physical vapor deposition, and the insert is placed in a mold which is filled with a casting alloy.

Abstract: The disclosure relates to a method of obtaining, by moulding, bimaterial parts formed by two aluminium alloys one of which constitutes the core and the other the matrix. The method consists in using a core, optionally containing a refractory skeleton, removing a natural coating of alumina present on the surface of the core and immediately afterwards coating the assembly thus obtained with a film impermeable to gas and consisting of a metal such as nickel, placing the coated assembly in a mould which is filled with the alloy of the matrix in the molten state at a temperature such that at least 30% of the core is superficially remelted. The method can be applied to the manufacture of motor vehicle parts such as engine cylinder heads and the insertion of ducts into aeronautical parts.

Abstract: A charge coupled device (CCD) sensitive to infrared radiation composed of a succession of three layers of Group III-V semiconductor material. The layers are a window layer, a sensitive layer and a storage layer. The layers are fixed to a supporting plate serving as input for the radiation and as a rear surface of the device. The front surface of the device supports a plurality of control electrodes and at least one output electrode.The window layer and the storage layer of the CCD are made of a binary compound AB. The sensitive layer is made of an n-ary compound (A,X,Y . . . ).sub.III (B,M,N . . . ).sub.V having a larger forbidden energy band and a smaller absorption limit wavelength than the window and storage layers.The three layers of the device are formed by epitaxial growth on a substrate. The substrate is a layer of the binary compound AB coated with an epitaxial layer of the n-ary compound. The epitaxial substrate layer is a chemical blocking layer.

Abstract: A vitreous semiconductor supporting structure obtained by connecting semiconductor layers to a vitreous support constituted by at least two glasses. The semiconductor layers are constituted by an electrically and optically active n-ary III-V compound layer (3) and optional complementary layers for passivation (4), index adaptation (6), and protection (7). To keep the active layer in a compression state and optimize its electrical properties, the structure includes at least two glasses, an intermediate glass (15) providing thermoelastic properties and a supporting glass (16) providing a high softening temperature.

Abstract: An electron emitting device including an active semiconductor layer having a surface from which electrons are emitted. The layer is doped with impurity atoms at a density which decreases with distance from the surface.

Abstract: In manufacturing a semiconductor device by epitaxial growth from the liquid phase on a substrate of layers of gallium arsenide or gallium aluminum arsenide doped with elements such as germanium, the last growth melt is wiped off and the structure is cooled to a temperature from room temperature to 200.degree. C. During cooling, the structure's upper surface is contacted with a liquid gallium melt in such a manner that the doping elements present in the few remaining drops of the last growth melt not removed by the wiping off are dissolved.

Abstract: Disclosed is an internal combustion engine having a reservoir in communication through a passage with the combustion chamber. A valve is provided in the passage to enable the reservoir, when the valve is open, to receive a fraction of the air during the compression stage of the engine cycle. The valve closes in response to a decrease in pressure in the combustion chamber. The valve is automatically controlled to open at the beginning of the next compression stage to inject heated air into the combustion chamber. The valve then remains open to enable the reservoir to receive a fraction of air from the cylinder during its high pressure cycle for restitution to the cylinder chamber at the beginning of the next compression stage.

Abstract: A valve control device for an overhead camshaft engine including a rotatable cam interconnected through a rocker to a valve mounted for reciprocal movement from an open to a closed position. The valve is normally biased toward the closed position and engages the rocker at one end, the other end of the rocker directly engaging the cam. A hydraulic brake is connected to the rocker at its other end and retards movement of the valve toward the closed position.

Abstract: A two-stroke engine including a combustion chamber formed in the cylinder head and having the fuel mixture introduced directly into the combustion chamber. A ventilation chamber surrounds the combustion chamber and opens directly into the combustion chamber and the cylinder, a flange on the head of the piston, progressively closing the opening into the combustion chamber as the piston approaches top dead center. The ventilation chamber may be formed as a plurality of individual chambers evenly distributed around the combustion chamber or as a recess opposite the outer periphery of the piston head. In the latter embodiment, an annular recess on the piston head, formed by the flange, adds to the volume of the ventilation chamber.