Abstract: A tungsten heavy alloy system is modified by replacing from 2% to 10% of the tungsten by weight with tantalum to increase the strength and hardness characteristics for the alloy. This renders the alloy particularly useful for kinetic energy penetrators.

Abstract: A descending stream of molten metal is directed from a ladle into a bath of molten metal in a tundish. Molten alloying ingredient is added to the molten metal, either directly to the descending stream within a shroud, or it is injected into the bath, through a sidewall of the tundish, at a region of turbulence. The molten alloying ingredient is protected from the atmosphere outside the tundish.

Abstract: The invention provides a method of producing an alloy containing titanium carbide particles, the method comprising thoroughly dispersing carbon powder particles into a metal melt, and causing the dispersed carbon particles to react with titanium within the metal melt so as to produce a dispersion of fine particles comprising titanium carbide within the melt. A preferred use for alloys produced by the invention is as a grain refiner for aluminium-based metals, especially those containing zirconium, chromium and/or manganese, which tend to poison current titanium-boron-aluminium grain refiners.

Abstract: This invention relates to a process for making in-situ precipitated second phase in a metal matrix which mixture is rapidly solidified to form a product. The invention also relates to a rapidly solidified product.

Abstract: Aluminium is alloyed by adding alloying ingredients to the molten metal in an intermediate treatment vessel or ladle rather than as at present in a casting furnace. If several ladles are used to supply the casting furnace, the alloying ingredients may be added to some but not all of them. A preferred order of addition of alloying ingredients is: (i) AlF.sub.3 to reduce unwanted Na, Ca and Li; (ii) one or more of Mn, Fe, Cr, Ni, Cu, Zn and Si in powder form; (iii) one or more of Zn, Cu and Si in massive form; (iv) Mg. A ladle/impeller design is described.

Abstract: A new material for use in the manufacture of semiconductor devices, a method of manufacturing the new material, and a heat radiator structure for a semiconductor device. The material is an aluminum alloy containing 30-60% by weight of Si and the remaining weight % is Al. The method of manufacture includes solidifying molten material into a powder and forming the powder by hot plastic working. The heat radiator structure includes a substrate of envelope material and an Al-Si alloy layer glued to the substrate through a function layer.

Abstract: The present invention relates to a process for the production of chromium-aluminum balls for adding chromium into molten aluminum baths.In order to obtain balls containing x% of chromium and y% of aluminum, where x and y are gravimetric contents corresponding to the following relationships:70.ltoreq.x.ltoreq.8020.ltoreq.y.ltoreq.30x+y=100an alloy of chromium and aluminum containing gravimetric chromium and aluminum contents approximating to x by an excess and to y by a deficit respectively is prepared by melting and this alloy is then finely ground into a crude powder; the chromium and aluminum contents of the alloy or of the crude powder are determined and, if required, an additional amount of finely divided aluminum is added so as to obtain a powder containing x% of chromium and y% of aluminum, the additional amount of finely divided aluminum corresponding to less than 10% by weight of the crude powder; a compacting is then carried out.

Abstract: A process for producing a dispersion hardened copper alloy includes admixing to a copper melt from 0.3 to 15 weight % of molybdenum to provide a mixture which is a melt; superheating the mixture to a temperature ranging from about 200.degree. C. to about 1000.degree. C. above the melting point of coper to provide a superheated melt; and subjecting the superheated melt to very rapid solidification at a cooling rate ranging from 104.degree. to 106.degree. C./sec. The above process produces dipsersion hardened copper alloy comprising copper and from 1 to 15 weight % of molybdenum which is present in the dispersion hardened copper alloy as particles having a diameter of less than 0.1 .mu.m embedded in the copper matrix. Such dispersion hardened copper alloys are useful for providing electrical conductors which are subjected to elevated temperatures, such as for providing spot welding electrodes, particularly for welding of zinc-galvanized sheet metal.

Abstract: A process for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR).

Abstract: Novel materials having the ability to reversibly store hydrogen are amorphous metal alloys of the formulaA.sub.a M.sub.b M'.sub.cwhereinA is at least one metal selected from the group consisting of Ag, Au, Hg, Pd and Pt;M is at least one metal selected from the group consisting of Pb, Ru, Cu, Cr, Mo, Si, W, Ni, Al, Sn, Co, Fe, Zn, Cd, Ga and Mn; and M' is at least one metal selected from the group consisting of Ca, Mg, Ti, Y, Zr, Hf, Nb, V, Ta and the rare earths; andwhereina ranges from greater than zero to about 0.80;b ranges from zero to about 0.70; andc ranges from about 0.08 to about 0.95;characterized in that (1) a substantial portion of A is disposed on the surface of said material and/or (2) that said material functions as an active surface layer for adsorbing/desorbing hydrogen in conjunction with a bulk storage material comprising a reversible hydrogen storage material.

Abstract: An in situ process is provided for producing a composite comprising a refractory material dispersed in a solid matrix. A molten composition comprising a matrix liquid, and at least one refractory carbide-forming component are provided, and a gas is introduced into the molten composition. A reactive component is also provided for reaction with the refractory material-forming component. The refractory material-forming component and reactive component react to form a refractory material dispersed in the matrix liquid, and the liquid composite is cooled to form a solid composite material. In one embodiment, the reactive component is a carbonaceous component in the form of a component of the gas, a solid in the gas or the molten composition, or both. The carbonaceous component is provided for reaction with a refractory carbide-forming component to yield a refractory carbide. In a preferred embodiment, the matrix liquid is molten aluminum and the refractory carbide-forming component is tantalum.

Abstract: A process for producing an alloy product of improved ductility from metal powder. It includes the steps of: providing metal powder having at least 5 wt. % of one or more reactive elements from the group consisting of titanium, aluminum, hafnium, niobium, tantalum, vanadium and zirconium; consolidating the powder to an essentially fully dense shape; and progressively melting and solidifying localized areas of the consolidated shape so as to produce a product of improved ductility.

Abstract: A method of alloying powdered aluminum into lead to form lead-calcium-aluminum alloys with relatively high recoveries and low standard deviations of recoveries. The method comprises melting lead, heating the lead, injecting simultaneously calcium-containing granules and aluminum powder into the lead under the surface. The alloying material preferably has a total calcuim content of between about 65% and 80% by weight and a total aluminum content of between about 35% and 20%. The material is preferably injected into an injection bell to hold the alloying material under the surface of the lead.

Abstract: This invention relates to ceramic-ceramic composites comprising a dispersion of ceramic particles in a ceramic matrix. The production of these composites involves the in-situ precipitation of ceramic particles in a solvent metal matrix and the conversion of the matrix to a ceramic by reacting it with a matrix reactive species. Exemplary ceramic dispersoids include TiB.sub.2, ZrB.sub.2, TiC and TiN. Exemplary ceramic matrices include AlN, Al.sub.2 O.sub.3 and SiO.sub.2.

Abstract: A crucible for melting metals therein to form an active brazing alloy is made of slip cast silica with an yttria lining on the inside surface thereof.

Abstract: A method for introducing grain refiners into molten media, such as molten aluminum, utilizes a chamber having a discharge immersed in the molten media and having a plasma therein extending from the molten media at the chamber discharge to a site above the discharge. Grain refiner is provided to said site and converted into a superheated spray for introduction into the media. An alternate embodiment includes supplying one or more constituents of a grain refiner compound to the plasma for reaction to form the grain refiner. A gas exits the chamber and enhances introduction into the media.

Abstract: A method of producing intermetallic particles such as TiAl.sub.3, NiAl.sub.3 and others utilizes a chamber having a discharge immersed in molten media such as molten metal and having a plasma therein extending from the molten media at the chamber discharge to a site above the discharge. One or more constituents of the desired compound are provided to said site and converted into a superheated spray. The constituents react with each other or with one or more constituents in the aforesaid media to produce the desired compound. A gas exits the chamber and enhances contact and reaction and also transfer to the media.

Abstract: A method and apparatus for preparing cast composite materials of nonmetallic particles in a metallic matrix, wherein particles are mixed into a molten metallic alloy to wet the molten metal to the particles, and the particles and metal are sheared past each other to promote wetting of the particles by the metal. The mixing occurs while minimizing the introduction of gas into the mixture, and while minimizing the retention of gas at the particle-liquid interface. Mixing is done at a maximum temperature whereat the particles do not substantially chemically degrade in the molten metal during the time required for processing, and casting is done at a temperature sufficiently high that there is no solid metal present in the melt. Mixing is preferably accomplished with a dispersing impeller, or a dispersing impeller used with a sweeping impeller.

Abstract: A method for adding alloying material to a molten metal media, such as molten aluminum, is disclosed. The method includes converting the alloying material into a spray of superheated alloy material and directing the spray into the molten metal media at a depth below the media's surface to enhance dissolution and dispersion of the alloying material in the molten media.

Abstract: This invention relates to a composite material comprising an in-situ precipitated second phase in an intermetallic matrix, and to the process for making such a composite.

Abstract: This invention relates to a process for making composite materials involving the in-situ precipitation of second phase particles in a metal matrix, and the products thereof. The process involves the use of initial compound materials as a source of second phase-forming reactants in the production of metal-second phase composites. The composites produced may comprise distributions of either single or multiple second phase materials. Exemplary initial compound precursors include boron nitride, boron carbide, boron oxide, aluminum nitride, aluminum carbide, aluminum boride, iron oxide and copper oxide.

Abstract: A rare earth-iron-boron alloy powder which consists essentially of:12.5 to 20 at % R wherein R.sub.1 is 0.05 to 5 at %, 4 to 20 at % B, and 60 to 83.5 at % Fe,wherein R.sub.1 is at least one heavy rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm and Yb, 80 to 100 at % of R.sub.2 consists of Nd and/or Pr, the balance in the R.sub.2 being at least one element selected from the group consisting of rare earth elements including Y and except for R.sub.1, and R=R.sub.1 =R.sub.2 by atomic %, wherein a major phase of at least 80 vol % of the entire alloy coinsists of a tetragonal structure, and wherein oxygen does not exceed 10,000 ppm, carbon does not exceed 1000 ppm and calcium does not exceed 2000 ppm. The alloy powder is produced by directly reducing a mixture comprising rare earth oxide, iron and other ingredients or oxide thereof with a reducing agent Ca and CaCl.sub.2, putting the reduced product into water, then treating with water. Up to 35 at % Co may be substituted for Fe.

Abstract: An injection apparatus for introducing fluid material, such as a reactive element to a molten metal bath while resisting undesired oxidation. The injection apparatus consists of a body assembly having a chamber defined therein, and inlet and outlet passageways communicating with the chamber which cooperate to define a passageway therethrough. The lower end of the outlet extends below the surface of the molten metal bath. Purging gas is introduced through a gas inlet and provide a substantially purged atmosphere throughout the molten metal passageway. The atmosphere in the passageway is purged in order that the fluid material can be safely introduced into the molten bath. The injection apparatus is readily assembled and disassembled by means of a unique clamping device employed with the body assembly.

Abstract: This invention relates to a method of manufacturing thermoelectric material which has the steps of quenching a thermoelectric alloy in a molten state at a quenching rate higher than 10.sup.3 .degree. C./sec into a membrane or powdery form and subjecting the membrane or powder to cold-forming or sintering. The thermoelectric alloy is a Bi--Sb series alloy having a composition represented by{(Bi.sub.100-x .multidot.Sb.sub.x).sub.100-y .multidot.E.sup.II.sub.y }.sub.100-z .multidot.E.sup.I.sub.zwhere E.sup.I represents a group III or group IV element, E.sup.II represents a group IV or group VI element, x represents a number of 5-20, y represents an integer of 0-20 and z represents a number of 0.05-10, respectively.

Abstract: Lithium feed to an aluminum-lithium alloy production system is achieved at a highly controlled rate by advancing a plunger at a predetermined volumetric rate into a body of molten lithium retained in a holding vessel to displace the lithium toward an overflow port through which it is fed into a mixing vessel where it is combined with molten aluminum. Control of the aluminum feed rate is achieved by maintaining a constant head height upstream of an orifice. The thus metered streams of molten lithium and aluminum are then combined in a vortex bowl, whose outlet is then fed to a casting station.

Abstract: Silicon carbide particulate reinforced aluminum alloy matrix composites are formed using techniques which include agitation of a melt of aluminum alloy, containing magnesium, and silicon carbide particulates in a manner whereby the silicon carbide particles are maintained, during agitation, within the body of the melt; the agitation, which involves shearing or wiping of the particles in the liquid, is carried out under vacuum; and may involve incorporation into the melt of an additional amount of magnesium such that that amount compensates for the amount of magnesium which segregates to the carbide surfaces, and is sufficient to effect strengthening of the resulting composite. Aluminum alloy matrix composites, containing copper, are produced using similar agitation and mixing procedures, with the copper being incorporated in such a way as to discourage reaction between the copper and SiC particles.

Abstract: A method is taught for the introduction of in-situ precipitated second phase materials, such as ceramic or intermetallic particles in a metal matrix, to a host metal. When an initial solvent-assisted reaction is utilized, metal-second phase composites having highly superior properties may be obtained. The invention may utilize the reaction of the second phase-forming constituents in a solvent metal medium to provide an intermediate material of finely-dispersed second phase particles in an intermediate metal matrix, in the form of a porous mass or sponge. Any desired loading of second phase in the final composite may be achieved by the admixture of this preformed intermediate material having a relatively high content of particulate material, with a molten host metal. Exemplary materials include titanium diboride in an aluminum matrix and titanium carbide in an aluminum matrix.

Abstract: The surface of a base metal is alloyed with the aid of a laser or electron beam which locally melts the surface. During the alloying, defects are prevented from occurring due to the use of an deoxidizing agent and a low-melting-point metal having a lower melting point than than of the base metal.

Abstract: The invention provides a method of producing an alloy containing titanium carbide particles, the method comprising thoroughly dispersing carbon powder particles into a metal melt, and causing the dispersed carbon particles to react with titanium within the metal melt so as to produce a dispersion of fine particles comprising titanium carbide within the melt. A preferred use for alloys produced by the invention is as a grain refiner for aluminium-based metals, especially those containing zirconium, chromium and/or manganese, which tend to poison current titanium-boron-aluminium grain refiners.

Abstract: According to a method of dispersion hardening copper, silver or gold, melts on the basis of the matrix metals with stoichiometric additions of boron and boride-forming metals are superheated by 300.degree. to 750.degree. C. and subsequently subjected to extremely rapid solidification at a rate of at least 10.sup.3 to 10.sup.4 .degree.C. per second. The boride-forming metals used are preferably titanium and/or zirconium. An excess of preferably about 5 to 20% of boride-forming metal over the stoichiometric amount yields particularly favorable products.

Abstract: In this method for making an alloy of a first metal and a second metal which has a stronger tendency to form an oxide than the first metal, a powdered solid is prepared comprising at least one of a compound of the first metal with oxygen and the second metal, the compound is mixed with the second metal, and an alloying process is carried out of alloying a melt with the powdered solid, in which the second metal is oxidized by the oxygen of the compound of the first metal with oxygen which is reduced. The compound of the first metal with oxygen may be an oxide, and may be a simple oxide or a compound oxide. As one variation, the powdered solid may contain the compound of the first metal with oxygen, in which case the melt will contain the second metal; or alternatively the powdered solid may contain the second metal, in which case the melt will contain the compound of the first metal with oxygen.

Abstract: Method and apparatus for the agitation of base metal on alloy melts, and for the agitation and alloying of base metal melts with at least one alloying metal. A rotatable device is suspended in a melt of base metal and the device is rotated to draw at least a partial vortex in the melt. The device comprises a hollow cylinder having an open top and a closed bottom. An array of openings in the cylinder side wall is adapted to allow melt of the base metal to pass through. In the agitation of a base metal or alloy melt, the amount of dross formed on the melt is reduced. In alloying, the at least one alloying metal may be added directly to the melt or may be added in particulate form into the vortex in the device, the latter being particularly useful when the melting point of the alloying metal is higher than that of the base metal or alloy.

Abstract: In this method for manufacturing an aluminum alloy, a porous preform is manufactured from a mixture of a finely divided oxide of a metallic element which has a weaker tendency to form oxide than does aluminum, and an additional substance substantially more finely divided than that metallic oxide. Then an aluminum alloy containing a substantial quantity of silicon is permeated in the molten state through the porous preform. This causes the metallic oxide to be reduced by a thermite reaction, to leave the metal which it included as alloyed with the aluminum alloy. At this time, the silicon in the aluminum alloy does not tend to crystallize out upon the particles of the metallic oxide, which would interfere with such a reduction reaction by forming crystalline silicon shells around such metallic oxide particles and would lead to a poor final product, because instead the silicon tends to crystallize out upon the particles of the additional substance.

Abstract: A powder filled tube has a steel outer wall which consists of two layers formed as two complete turns of a spiral made from a single strip and welded together at their interface to form a unitary wall. The method for the continuous manufacture of this tube involves(i) forming a steel strip into a channel,(ii) introducing the powder filling into the channel,(iii) closing the channel by rolling it into a tube in which, as seen in cross section, the steel strip overlaps itself by at least 360.degree. so that the tube wall has two layers around its whole circumference and the powder filling is compacted,(iv) heating the tube and while hot subjecting it to stretch/reduction rolling in which simultaneous size reduction and extension of length take place and in which the two wall layers are welded together by the effect of the elevated temperature and the pressure applied in rolling.

Abstract: High performance metallic alloys which possess desirable characteristics such as high electrical conductivity, high strength, lightness, high thermal stability, etc. may be prepared by admixing three metals or metalloids by mechanical means. The process will result in the formation of a matrix material consisting of one metal and an intermetallic compound comprising the other two metals or metalloids to provide a finished alloy with the desirable characteristics hereinbefore set forth. The intermetallic compound will be present in a uniform dispersion in the matrix material in the form of particles which possess a size in the range of from about 0.001 to about 0.5 microns.

Abstract: A system is disclosed for efficiently mixing streams of molten metal to form a molten metal alloy while inhibiting oxidation and introduction of impurities such as hydrogen gas into the molten metal which comprises passing a first molten metal stream at a minimum velocity of at least 18 cm/sec into a mixing zone and feeding a second molten metal stream at a lower velocity into the mixing zone through a concentric feed tube around which the first molten metal stream is flowing. The first molten metal stream is maintained in turbulent flow conditions with a Reynolds number of greater than 2100. In a preferred embodiment, the minimum velocity of the first stream is raised before reaching the mixing zone by introducing a non-oxidizing gas into the stream.

Abstract: A method of making a molten ferroalloy product in a melting furnace by charging a briquet consisting essentially of metallized iron, granulated alloy metal oxide, and a carbon source, such as coke breeze, to the melting furnace, burning solid carbonaceous material to reduce the alloy metal oxide to metallized form and to heat the charge to form a molten ferroalloy product. Fluxes and slag formers are also charged to the furnace as required.

Abstract: The present invention provides a rapidly dissolving additive for metal melts, wherein it contains or consists of 2 to 50% by weight of a powdered component A, consisting of magnesium and/or a magnesium-containing alloy, and 50 to 98% by weight of a powdered component B, consisting of one or more alloying metals, the components A and B being intimately mixed and being present in pressed or compacted form.

Abstract: The invention relates to a device for continuous injection under low pressure of a powdered additive into a stream of molten metal.It comprises, in succession from top to bottom:a top compartment 5 for the admission of the molten metal,a treatment chamber 7 connected to the top compartment by a calibrated inlet orifice 8 and in which there opens, on the one hand, a tube 9 connected to a device for injection of powdered additive under gas pressure and, on the other hand, at least one conduit 11 for evacuation of gases, fumes and possible sullage,at least one buffer compartment 6 cooperating with a means for adjusting the discharge rate of the treated metal,a means for collecting the treated metal, for example a mould or a ladle.

Abstract: Process for the continuous forming of a metal tube filled with powdered elements, such as ferroalloys and other materials, utilizable in the treatment of liquid metals in ladle at same time of its forming, consisting in making advance a metal sheet (2) unrolling from a roll (1), in sending it into a filling matrix or chamber (5), then in depositing on the same sheet a metered and weighted amount of processing powders fed from separate hoppers, in subsequently bending said loaded sheet so as to let it assume a substantially U-shaped channel shape, and in making it then assume the shape of a closed tube with compacted powder inside it, due to partial overlapping of the side flanges of U-shaped channel and, finally, in dipping the so-formed tube into a ladle (16).

Abstract: An amorphous metal body is produced from an intermediate product formed by compacting at least two usually crystalline components of the alloy in powder form. The alloying components in the intermediate product extend in at least one dimension at most 1 um. The intermediate product is converted into the amorphous metallic body by means of a diffusion reaction at a predetermined elevated temperature. In order to produce bodies of larger size on a large technical scale, a mixture powder comprising particles is produced from the alloying components in powder form by a milling process which is terminated at a predetermined time in such a manner that the particles produced by milling have at least a predominantly layer-like structure of the alloying components. This mixture powder is then compacted into the intermediate product with the desired shape and dimensions. The intermediate product is optionally deformed.

Abstract: A method is taught for the in-situ precipitation of ceramic materials in a metal matrix. By means of the solvent assisted reaction, metal-ceramic composites having highly superior properties may be obtained. The invention involves the reaction of the ceramic forming constituents in a metal solvent medium to provide very finely-dispersed ceramic particles in the metal matrix. Exemplary materials include titanium diboride in an aluminum matrix.

Abstract: An alloy is made of a first material and a second material which has a substantially lower melting point than the first material, by (a) forming from the first material a body which has multiple fine interstices; (b) pouring the second material in the molten state around the body formed from the first material; and (c) allowing the resultant mass to cool. Thus, in the parts of the resultant mass in which the body formed from the first material was originally present, an alloy mass comprising the first metal and the second material alloyed together is made. Optionally, the body made from the first material may be preheated, desirably to a temperature higher than the melting point of the second material; and optionally the molten second material may be pressurized so as to enter into the interstices of the body.

Abstract: In the production of alloy by evaporation from an evaporation bath and condensation under vacuum, charge replenishment is achieved by a procedure involving bleeding charge from the bath and admixing the bled charge with replenishment material and introducing replenishment from the admixture. An apparatus for use in the process comprises a mixing passageway encompassing an evaporation bath and distributed sub-surface bleed ports and feed ports linking the evaporation bath and the mixing chamber. Flow of metal through the ports is induced by pumped circulation in the mixing chamber. The circulation is turbulent for good mixing of the metals.

Abstract: A process for manufacturing structural parts of complicated shape from intermetallic phases capable of sintering by means of special additives which serve at the same time as sintering assist and increase the ductility of the finished structural part. The process includes the steps of making by melting a pre-alloy of the intermetallic phase, comminuting the pre-alloy into fine powder and mixing the fine powder with one or more additives into a mass which can then be shaped and subsequently sintered at a temperature of 70 to 95% of the absolute melting point of the intermetallic phases into a structural part of increased ductility and a density greater than 95% of the theoretical density which might possibly be subjected to subsequent pressing operations.

Abstract: Selenium-containing amalgam alloys for dental restoration comprises 0.1-50% by weight of any one of the following alloy powders (A), (B) and (C) mixed with 50-99.9% by weight of the following amalgam alloy powders (D).(A): Silver alloy powders containing no less than 50% by weight of silver and 0.01-10% by weight of selenium,(B): Copper alloy powders containing no less than 50% by weight of copper and 0.01-5% by weight of selenium,(C): Alloy powders mix of (A) with (B) wherein the total amount of silver and copper is adjusted to no less than 50% by weight, and the amount of selenium to 0.01-10% by weight, and(D): Silver-tin-copper amalgam alloy powders.At least one of the any one of (A), (B) and (C) and (D) may be pre-amalgamated with mercury in an amount of no higher than 3% by weight based on the total weight thereof.

Abstract: A process for producing an internal-oxidized alloy, which comprises allowing a plasma generated in the presence of oxygen, a gas of an oxygen atom-containing compound or a mixture of oxygen and a gas of an oxygen atom-containing compound to act on an alloy consisting of at least two metal elements, thereby selectively oxidizing at least one metal element other than the matrix metal in said alloy. Particles of the internal-oxidized alloy thus obtained can, if necessary, be molded into a desired shape and sintered. Said process enables one to produce an internal-oxidized alloy at a high speed at a temperature of not more than 0.9 Tm (Tm: the melting point of the starting alloy) and does not require the step of separating an internal-oxidizing agent which step is required in the conventional process.

Abstract: The present invention relates to a process for the heat treatment of uranium alloy members.This process comprises at least one .gamma.-phase homogenization stage, followed by an induction heating stage and a hardening stage. The use of induction heating makes it possible to only heat the member and therefore modify the structure thereof at the surface. Thus, the hardness in the core and on the surface can optionally be adjusted by supplementary hardening and/or tempering stages.Application to the production of protective materials.

Abstract: A system for alloying lead with minor amounts of alloyants which have a higher melting point than, and a lower solid solubility in, lead. The system includes a melting furnace retaining Pb melt at a first temperature, a sealed vessel containing chunks of alloyant-rich material, a heated conduit between the furnace and the vessel for conducting melt to the vessel while heating it to the melting temperature of the material in the vessel, a conduit for returning superheated melt from the vessel to the furnace and a pump for circulating a small portion of the melt from the furnace through the vessel for dissolution of the alloyant into that portion.

Abstract: This invention relates to a sintering process. More particularly, this invention relates to a process for preparing a sintered form having a tungsten content which comprises the steps of:(a) sintering a porous form of pressed tungsten alloy powders having a high tungsten content in solid phase, and(b) heat treating the sintered part from step (a) in a liquid phase.