Abstract: In a continuous vertical casting operation carried out in a mould 3, a coil 7 applies a periodic magnetic field of variable strength whose direction is substantially parallel to the axis of the mould 3 to the liquid 5 as it solidifies, in order to regulate the level of the line of contact of the free surface of the metal 5 with the mould 3. The height of the contact of the metal with the mould can be reduced from h.sub.1 to h.sub.2 by applying the magnetic field, and the strength of the field is adjusted in dependence on the desired level. The procedure is used in casting semifinished metallurgical products, in particular in aluminium and its alloys, in which there is a wish to obtain a cortical region of zero thickness, a fine grain without the preliminary addition of refining agents, and an absence of pitting.

Abstract: The invention concerns Al-base alloys with substantial proportions of Li and Si, containing, by weight:from 3.6 to 8% Lifrom 5 to 14% Sifrom 0 to 1% of each of the following optional elements: Fe, Co, Ni, Cr, Mn, Zr, V, Ti, Nb, Mo, O.sub.2, Sc, andfrom 0 to 2% of each of the optional elements Cu, Mg and/or Zn, the total amount of the optional elements being less than 5%, and the balance being Al and impurities, each impurity.ltoreq.0.05%, with total impurities.ltoreq.0.15%. The products are obtained by rapid solidification processes and contain from 15 to 60% by volume of phase T (Al, Si, Li), in the form of particles of from 0.01 to 10 .mu.m.

Abstract: The invention relates to a process for improving the surface condition of Li-containing Al alloy products. According to the process, heating at a temperature exceeding 300.degree. C. takes place in an atmosphere containing, in volume percent, 5 to 98% CO.sub.2, 2.ltoreq.dry air.ltoreq.95% and the remainder water. The process prevents the appearance of surface pitting and reduces the depth of the Li-depleted surface zone.

Abstract: The invention relates to a process and an apparatus for casting in a pit, without risk of explosion, of aluminum and its alloys, particularly with lithium.It comprises placing an elastic shield (3) around the cast product in order to stop the cooling water and any liquid metal outpouring, the water and metal being collected by flowing over the shield, into inclined channels (5 to 14), where the water forms a film and the metal is stopped in portionwise manner by strips (19) located at appropriate distances within the channels.

Abstract: The present invention relates to Al-base alloys essentially containing additions of Li, Mg and Cu and possibly minor additions of Cr, Zr, Ti and Mn, which have high specific mechanical characteristics, a low density and good resistance to corrosion.The alloys according to the invention contain (in % by weight): Li 1.8 to 3.5; Mg 1.4 to 6.0; Cu 0.2 to 1.6 with Mg/Cu.gtoreq.1.5; Cr up to 0.3; Mn up to 1; Zr up to 0.2; Ti up to 0.1 and/or Be up to 0.02, Fe up to 0.20; Si up to 0.12; Zn up to 0.35%.The homogenization and solution treatments must be taken to a sufficiently advanced stage to dissolve the quaternary intermetallic phases (Al, Li, Mg, Cu) which are larger than 5 .mu.m in size. Such alloys present a compromise between their mechanical characteristics and their density, which is higher than that of the knwn Al Cu Mg alloys, and alloys containing Li.

Abstract: A non-contacting, eddy current, measuring method for determining the thickness and temperature of a moving metal sheet as in a metal rolling operation. Two separate magnetic fields are generated by applying two voltages of differing frequencies to a primary winding on one side of the sheet to induce two voltages in an opposed secondary winding on the other side of the sheet. The generated voltages are used to determine the calibration constants required to calculate the thickness and temperature of the moving sheet.

Abstract: The present invention relates to Al-base alloys essentially containing Li, Cu and Mg, and having high specific characteristics and a high degree of ductility. Their composition is as follows (% by weight):______________________________________ Li 1.7 to 2.9 Cu 1.5 to 3.4 ##STR1## Mg 1.2 to 2.7 Fe .ltoreq. 0.20 Si .ltoreq. 0.06 Cr 0 to 0.3 Mn 0 to 1.0 Zr 0 to 0.2 Ti 0 to 0.1 Be 0 to 0.01 Other elements (impurities) each .ltoreq. 0.05 total .ltoreq. 0.15 balance: Al ______________________________________The heat treatment comprises a homogenization step at about .theta.(.degree.C.)=535-5 (% Mg) which practically dissolves the compounds Al-Cu (Li-Mg); a solution treatment at between .theta.+10.degree. C.; a quenching step; and a tempering step at from 170.degree. to 220.degree. C. for a period ranging from 8 to 48 hours. The mechanical strength and ductility characteristics obtained are equivalent to those of conventional alloys 2000 or 7000.

Abstract: Castings made from aluminum and its alloys have at least one face including at least one region of wear-resistant zones. These castings are formed by a controlled distribution of zones hardened by local melting effect. The zones, no matter what their length and shape, have a width and depth between 3 and 150 .mu.m and the surface fraction or percentage of the zones for the wear-resistant region is between 5 and 60%.

Abstract: The invention relates to a mould for vertical casting of molten metal and including a means for regulating the level at which the inner surface of the mould contacts the free surface of the metal being cast. The mould is formed at least in its lower part of metal, and the means for regulating the level comprises an electrically insulating material intentionally coated onto the inner surface of the mould, an insert of electrically insulating material disposed along at least one generatrix of the mould, over the entire height and thickness of the mould, and two terminals for connection to a source of alternating current provided on the outer surface of the mould at its lower part, with one terminal provided on each side of the insert. The mould finds application in the casting of metallurgical semi-finished products, in particular of aluminum and aluminum alloys.

Abstract: This invention relates to a method and an apparatus for lubricated forward extrusion of metals and alloys with radial forward removal of an outer shell or sheath. The method according to the invention consists of forming a gap in the form of a plane or slightly truncated cone-shaped circular outer ring having a constant thickness (j) and span (h) and open to the atmosphere between the end of the container adjacent to its bore and the assembly of extrusion tools situated opposite thereto. To facilitate the formation and especially the extraction of the outer shell, the extrusion apparatus comprises several knives situated in the above described gap, having their cutting edge directed towards the axis of the container and dividing the outer shell into as many "petals" in the course of extrusion.

Abstract: The invention relates to an apparatus for regulating the level of the line of contact of the free surface of the metal with the mould in vertical casting. It comprises a mould formed by a material having a level of resistivity of higher than 5 .mu..omega..cm, surrounded by an annular coil in which at least one alternating electrical current flows. It finds application in the casting of metallurgical semi-manufactured products, in particular of aluminium and alloys thereof, such as for example lithium-bearing alloys, and in which there is a wish to have both a cortical zone of virtually zero thickness, a fine grain without the previous addition of refining agents, and an absence of pitting.

Abstract: A connector for scaffolding or similar structure permitting vertical poles to be connected to longitudinal transverse members or bars includes a star-shaped portion with a central bore having a plurality of arms which at their ends each carry a pyramid-conical opening into which engages a pyramid-conical or conical hook. A clip which is movable about a horizontal axis makes it possible to avoid accidental dismantling of the assembly.

Abstract: The invention is directed to a process for plating Al alloys containing lithium by hot co-rolling under the usual heating conditions, in the air. The process comprises effecting controlled oxidation of the core alloy by heating in the air at between 450.degree. C. and 550.degree. C. for a period of time such that the depth affected by the surface loss of Li is between 50 and 700 .mu.m. The core is then treated mechanically or chemically to remove the surface oxides with a loss of alloy less than 30 .mu.m. An assembly of the core and platings is then co-rolled with reheating to a temperature of less than 500.degree. C. for less than 24 hours. The result is perfect adhesion of the core to the surface platings.

Abstract: A process for the preparation of a vinyl chloride polymer latex having particles with a mean diameter between about 0.2 and 0.8 .mu.m and containing at least one organosoluble polymerization initiator comprising dispersing in an aqueous reaction medium also containing parabenzoquinone, at least one monomer, at least one anionic emulsifier and optionally at least one nonionic emulsifier, and from about 0.004 to 0.16% by weight, with respect to said at least one monomer, of said initiator expressed in terms of active oxygen, polymerizing said at least one monomer at a desired polymerization temperature, .theta..sub.1, and continuously adding parabenzoquinone to said aqueous reaction medium during the polymerization when the temperature .theta..sub.2 of the reaction medium is such that the difference .theta..sub.2 -.theta..sub.1 exceeds a value from 0.degree. to +5.degree. C.

Abstract: The invention relates to a process for casting a sacrificial anode having a tubular steel insert bonded over its length to a dissimilar metal by casting and solidifying molten dissimilar metal on the steel insert in a vertical ingot mold having a movable base. A cooling fluid is passed through a pipe means located internal to the insert, to the level of solidification of the molten dissimilar metal, and the cooling fluid is then applied to the internal surface of the insert at the level of solidification. The level of solidification is raised by the cooling fluid relative to the level without cooling by a height equal to between about 1/4 and 3/4 of the maximum height of molten metal in the mold. The bond strength between the steel insert and the dissimilar metal is improved by this method.

Abstract: The invention relates to members constituting the elements of a load-carrying spatial structure. These members, which can have any cross section, have a central circular channel (3) projecting at least at one end for fastening to the corresponding joint element. In a variant, the members can have several axial channels. An element made from these members can also be used as a part for an intermediate connection between a simple tubular member and the joint of the structure.

Abstract: A process for the production by power metallurgy of a material based on an aluminum alloy, a solid lubricant and at least one ceramic is disclosed. The process is characterized by using a ceramic in powder form with a granulometry of between 1 and 10 .mu.m.This invention finds application in the manufacture of components which are subjected to friction, in particular under hot condition, such as engine liners. These components provide an optimum compromise coefficient of friction and resistance to seizure and wear.

Abstract: The invention relates to a process for the thermal treatment of aluminum alloys containing zinc, magnesium and copper as main alloying elements, and the products manufactured by this process and having an average particle diameter of Al--Mg--Cr phase of between 800 .ANG. and 1000 .ANG.. This process involves carrying out a treatment at high temperature for a sufficiently short period to prevent coalescense into particles which are too large. This treatment is preferably carried out at the homogenization stage for thin products and at the final dissolution stage for thick products. The invention is applied, in particular, to the manufacture of thin or thick sheets for the aeronautical industry.

Abstract: Apparatus for continuously brushing and lubricating rolls of rolling mills for rolled flat products without pollution of said products by the lubricant used; it can be used in hot or cold rolling, in particular for Al or alloys thereof.An enclosure of general parallelepipedic shape which is open on one face and whose opposite sides which are adjacent to the opening are delimited by a circular arc, the radius of which is substantially equal to that of the roll, is applied thereto by way of a continuous resilient peripheral seal. The enclosure which contains the rotary brushes is lubricated by oil circulation and is under a slight depression.

Abstract: The invention concerns a process for producing products of Al-base alloys essentially containing Li, Mg and Cu as main alloy elements and having a high level of ductility and isotropy. The process comprises subjecting the homogenized product to a "tepid" transformation operation at from 100.degree. to 420.degree. C. The intermediate annealing operations, if required, are carried out in the range of from 200.degree. to 550.degree. C. The rate of cooling after the intermediate annealing operations is generally kept at from 1500.degree. C./second to 30.degree. C./hour. The isotropy and ductility of the resulting products are considerably improved in comparison with the prior art processes.