Abstract: The subject of the invention is a method of making a clad metal, neutron absorbing element, and the neutron absorbing element produced by preparing compactable metal products comprising (weight %) HF at least 25%, Zr and/or Zr alloys=0 to 75%; Ti and/or Ti alloys=0 to 75%; Hf-ZR alloys containing <55% Zr=0 to 75%; Hf-Ti alloys containing <55% Ti=0 to 75%; neutron absorbing metal elements melting at over 400.degree. C.: <0.2% and other metal elements melting at over 400.degree. C.: 0 to the balance, the balance being less than 5%; introducing at least some of these products into a metal container with an open end; compressing the products in the container, or compressing them before putting them into the container; if necessary repeating the introduction and compression of the products until the container is at least 95% full; and closing the open end of the container by welding on a metal lid or plug and providing an internal vacuum. The element is used, e.g.

Abstract: A method of, and an apparatus for, introducing at least one halide into the bath of cell for dry electrolysis. The method confines a portion of the bath in an annular space and upward motion is imparted to the confined portion of the bath by introduction of a gas and halide into the annular space. The apparatus for carrying out the method consists of two concentric tubes: an inner tube through which the halide and the gas are introduced and which tube is open at its bottom end and which tube has orifices on its lateral wall; and an outer tube which is open at its bottom end, closed at the top end and provided on its lateral wall with apertures situated at a level higher than that of the orifices. The method and apparatus can be applied to the operation and construction of electrolysis baths in which the concentration by weight of the halide and its mean valency must be maintained within a narrow range and be able to be adjusted progressively and precisely.

Abstract: A process for obtaining a plate of zirconium alloy comprising at least one portion of excess thickness of at least 0.5 mm relative to a large adjacent face, the portion having edges with angles equal to 90.degree. to 105.degree. and flanks which are connected without depressions to the large adjacent faces. According to the process, a surface portion of a blank plate located straight above a desired portion of excess thickness is coated with a continuous coating which is resistant to a pickling composition to be used, the coated portion widened beyond the desired portion of excess thickness by 0.5-1.5 times the amount of the excess thickness. The coated blank plate is immersed a plurality of times, without passage of electric current, in a pickling bath comprising HF, an oxidizing agent and water, and having a dissolved Zr content less than 12 g/l and a temperature below 35.degree. C. Each immersion removes less than 0.3 mm of thickness over the portions of the blank plate which are not coated.

Abstract: A diaphragm is disclosed for molten salt bath electrolysis of metal halides, the diaphragm comprising carbon fibers disposed in one plane an in at least one direction, embedded at least partially in a rigid and inert material which can be graphite, carbides, oxides or nitrides. The diaphragm has a porosity between 10% and 60% in the form of apertures of an area between 1 and 50 mm.sup.2.

Abstract: The present invention relates to a cold crucible adapted to be discharged through the bottom. The crucible consists of a conductive wall consisting of a plurality of longitudinal hollow segments which are electrically insulated at least partially from one another and which are by virtue of the longitudinal hollows adapted to be traversed internally by a cooling fluid and which crucible is adapted to be placed inside an inductor and in which the wall is provided in its bottom part with an aperture inside which there is a removable occluding member, formed of segments which member is cooled like the wall of the crucible. The crucible is used in the processing of materials of high purity which can be recovered in the liquid state in a convenient complete and rapid manner.

Abstract: The invention relates to an apparatus for the continuous production of a polyvalent metal by electrolysis of a halide of the metal in a bath of at least one melted salt. The apparatus comprises an electrodismutation cell and a prereduction cell in a contiguous configuration sharing a common wall in the form of a grid which is electrically insulated from the cell walls. The electrodismutation cell includes at least one deposition cathode and at least two anodes which are connected to an at least partly direct current. The prereduction cell includes at least one anode and a cathode constituted by the grid, the anode and cathode being separated by a diaphragm and connected to an at least partly direct current power supply. Means are provided to cause bath flow by forced convection through the grid to produce a top-to-bottom movement in the electrodismutation cell and a bottom-to-top movement in the prereduction cell.

Abstract: The invention relates to a process and apparatus for the supply of a Kroll reactor with zirconium tetrachloride vapor, in which zirconium chloride powder is vaporized in a sublimator by heating power and the vapor obtained is passed into the reactor. Part of the heating power applied in the sublimator is supplied to the powder by an internal heating means, and the remainder of the heating power is supplied to the wall of the sublimator by an external heating means. The heating power of the internal heating means is used for the sublimation of the zirconium tetrachloride powder and the heating power of the external means is applied in order to compensate the heat losses of the wall of the sublimator.

Abstract: According to the method of the invention concerning tubes, of which the plating to be checked is at least 0.4 mm thick and in which the acoustic impedance differs by at least 1% relative from that of the core of the tube, a properly dampened transducer is selected which has a frequency of 4 to 10 MHz. The position of the transducer in respect to the tube is adjusted experimentally, and its parameters of distance and orientation are differently adjusted in order to increase the "signal-to-noise" ratio. For determining the thickness of the plating, at least one double echo from the interface between the plating and the tube core is used, or alternatively, a triple echo from this interface. Also, there is a corresponding ultrasonic measuring apparatus as well as an application of the method to the ultrasonic measuring of the thickness of the plating of Zr alloy tubes. The tubes are plated with non-alloyed Zr or with some other Zr alloy.

Abstract: The process and the device according to the invention relate to the introduction, at a stable, known flow rate, of sublimable tetrachloride into a column for continuous extractive distillation under pressure of the chlorides. The sublimable tetrachloride is dissolved in a hot dissolver in a liquid solvent such as KAlCl.sub.4, and is then recirculated by pump at a stable, known flow rate into an evaporator connected to the column. The solution is then heated in an evaporator in order to sublime the majority of the product which it contains, the sublimed vapors thus passing into the column at a stable, known flow rate. The process according to the invention is adapted, in particular, to a plant for the production of ArCl.sub.4 of nulear purity and of HfCl.sub.4.

Abstract: The invention concerns a process for the production of metal Zr by means of molten Mg in a reactor 1 having a hearth plate 3, comprising separating the magnesium chloride formed in the reduction reaction from the metal Zr formed. The process is characterized by separating the magnesium chloride formed by tapping off towards the bottom of the reactor 1 by means of a chimney 6 whose bottom end portion 5 is fixed to an orifice 4 in the hearth plate 3 and whose transverse open top end 7 is above the portion of the metallic mass Zr, Mg which borders the chimney 6 at the end of the reduction reaction. The invention also concerns the corresponding apparatus for the production of metal zirconium. The invention provides a simplification in the operation of separating the MgCl.sub.2 formed and possibly, by virtue of a particular structure of the chimney according to the invention, gives an improvement in the operation of extracting the sponge cake produced.

Abstract: The invention concerns a process for the production of a strip of Zircaloy 2 or 4 with an oxygen content of between 900 and 1600 ppm and with mechanical characteristics corresponding to the following conditions:E.sub.0.2 at 315.degree. C..gtoreq.250 MPa"long" uniform A% at 20.degree. C..gtoreq.4 and"transverse" uniform A% at 20.degree. C..gtoreq.4,wherein, after hot working of an ingot to provide a billet, said billet is cold rolled to form a strip with intermediate annealing operations, characterized in that: (a) each of the last two intermediate annealing operations is a treatment for from 0.5 min to 10 min at between 750 ad 650.degree. C., (b) the final heat treatment following the last rolling operation is for from 1.5 to 7 min at between 630 ad 590.degree. C., and (c) the strip is rolled with particular degrees of deformation for each of the last three rolling operations.

Abstract: A wrought and heat treated titanium alloy part is disclosed having the composition, by w eight, Al 4.5 to 5.4%, Sn 1.8 to 2.5%, Zr 3.5 to 4.8%, Mo 2.0 to 4.5%, Cr 1.5 to 2.5%, Cr+V 1.5 to 4.5%, Fe 0.7 to 1.5%, O 0.07 to 0.13%, the remainder being Ti and impurities. The part is characterized by a fine and regular alpha-beta structure and essentially segregation free microstructures, and has the mechanical characteristics: Rm.gtoreq.1200 MPa, R.sub.p0.2 .gtoreq.1000 MPa, A%.gtoreq.5, K.sub.1c at 20.degree. C..gtoreq.45 MPa..sqroot.m, creep at 400.degree. C. under 600 MPa:0.5% in more than 200 hours.

Abstract: A process is disclosed for improving the ductility of shape-memory alloy products based on Ti-Ni involving martensitic transformation. The process comprises at least one thermal treatment cycle of alternating hot and cold treatment, wherein the first thermal treatment cycle comprises a cold treatment at a temperature both lower than -50.degree. C. and lower than M.sub.s -50.degree. C., where M.sub.s is the temperature at which martensitic transformation of the product begins, and a hot treatment of the product at a temperature of 700.degree. to 900.degree. C. Each optional subsequent thermal treatment cycle comprises a cold treatment of the product at a temperature both lower than -50.degree. C. and lower than M.sub.s -30.degree. C., and a hot treatment of the product at a temperature of 600.degree. to 900.degree. C.

Abstract: The process according to the invention comprises the following stages:(a) an ingot of the following composition is produced (% by weight): Al 3.8 to 5.4, Sn 1.5 to 2.5, Zr 2.8 to 4.8, Mo 1.5 to 4.5, Cr<2.5 and Cr+V 1.5 to 4.5, Fe<2.0, Si<0.3, 0<0.15, the remainder being Ti and impurities;(b) the ingot undergoes hot working, comprising a rough-shaping and then a final working preceded by preheating in the beta range;(c) the blank of the part obtained is solid solution heat treated by maintaining it at a temperature 10.degree. to 40.degree. C. lower than its real "beta transus";(d) ageing for 4 to 12 h at between 550.degree. and 650.degree. C. is then carried out on the blank of the part or the part itself.The invention also relates to the process and the parts obtained under preferred conditions, said parts having in particular a good mechanical strength (Rm and R.sub.p0.2 respectively at least equal to 1200 and 1100 MPa), a good tenacity and a good creep resistance at 400.degree. C.

Abstract: Apparatus for melting and continuously casting metals, comprising a vertical, conductive cold crucible (1) with at least part of the height of its wall in the form of longitudinal sectors (2) which are electrically insulated from one another and have a cooling fluid running through them; an inductor (6) with coils helically surrounding the crucible (1) over part of its height and supplied with alternating current both for heating and confining the metal; a system for drawing down the ingot; and possibly a chamber with a controlled external atmosphere, separating at least the contents of the crucible (1) from the external atmosphere, characterized in that the crucible (1) has an upper zone (4) divided into sectors, with parallel vertical generating lines, and a lower zone (5) divided into sectors and joined to the upper zone (4), the generating lines of the lower zone spreading apart in a downward direction from the join (45) between the two zones (4 and (5), and that the lowest coil (60) of the inductor (6) i

Abstract: The invention concerns a process for the production of a strip of Zircaloy 2 or 4 with an oxygen content of between 900 and 1600 ppm and with mechanical characteristics corresponding to the following three conditions:E.sub.0.2 at 315.degree.C..gtoreq.250 MPa`long` uniform A % at 20.degree.C..gtoreq.4 and`transverse` uniform A % at 20.degree. C..gtoreq.4,wherein, after hot working of an ingot to provide a billet, said billet is cold rolled to form a strip with intermediate annealing operations, characterized in that:(a) each of the last two intermediate annealing operations is a treatment of from 0.5 min to 10 min at between 750.degree. and 650.degree. C.,(b) the final heat treatment following the last rolling operation is for from 1.5 to 7 min at between 630.degree. and 590.degree. C., and(c) the strip is rolled with particular degrees of deformation for each of the last three rolling operations.

Abstract: The invention concerns a process for the production of metal Zr by means of molten Mg in a reactor (1) having a hearth plate (3), comprising separating the magnesium chloride formed in the reduction reaction from the metal Zr formed and the magnesium, then cooling, then extracting the sponge cake of metal Zr formed. The process is characterized by separating the magnesium chloride formed by tapping off towards the bottom of the reactor (1) by means of a chimney (6) whose bottom end portion (5) is fixed to an orifice (4) in the hearth plate (3) and whose transverse open top end (7) is above the portion of the metallic mass (Zr, Mg) which borders the chimney (6) at the end of the reduction reaction.The invention also concerns the corresponding apparatus for the production of metal zirconium.The invention provides a simplification in the operation of separating the MgCl.sub.

Abstract: Production of a substantially constant wall thickness in every cross section on cylindrical tubular parts produced for example by extrusion and rolling. The process of the invention comprises determining, by means of a suitable apparatus, the position of the center of the internal contour of a cross section of the tubular part, then rotating one with respect to the other a machining tool and the part about the axis of said internal contour and moving the machining tool towards the part until, over the periphery of said cross section, a constant wall thickness which is equal at most to the minimum thickness is obtained, and then repeating those operations on the successive desired sections of the tube, which are parallel to the first section.

Abstract: Process and apparatus for expansion shaping of at least one localized region in a running portion of the wall of a tube of substantial length, wherein the distance between the expanded region and one of the ends of the tube is to be adjusted with precision; comprising disposing a die around the tube in the region to be shaped, the die comprising an expansion chamber between two cylindrical bearing surfaces, introducing a mandrel into the interior of the tube in the portion thereof which is within the die and delimiting an annular space between the mandrel and the tube, by two sealing regions disposed on respective sides of the expansion chamber at the location of the cylindrical bearing surfaces of the die, introducing a pressure fluid through the mandrel into the annular space, and increasing the pressure of the fluid until the tube becomes deformed against the walls of the expansion chamber.