Abstract: A method of imparting high strength, high ductility, and high fracture toughness to a refractory metal alloy workpiece includes: (i) subjecting the workpiece to at least one pass that reduces the initial cross-sectional area of said workpiece, (ii) annealing the workpiece subsequent to the at least one pass, and (iii) subjecting the workpiece to a final working step comprising at least one pass conducted at a temperature between ambient and 300.degree. C., the final working step further reducing the cross-sectional area of the workpiece such that the total reduction in the initial cross-sectional area of the workpiece is approximately 40%-75% and the final cold working is 0.30 to 0.75 of the total reduction in cross-sectional area. The resulting article has a tensile yield strength of approximately 170-200 Ksi, a tensile elongation of approximately 12%-17%, and a Charpy 10 mm Smooth Bar impact toughness of approximately 100 ft.-lb. to 240 ft.-lb.

Abstract: A method for controlling oxygen in valve metal materials. The method includes deoxidizing a valve metal material, typically tantalum, niobium, or alloys thereof, and leaching the material in an acid leach solution at a temperature lower than room temperature. In one embodiment of the present invention, the acid leach solution is prepared and cooled to a temperature lower than room temperature prior to leaching the deoxidized valve metal material. The method of the present invention has been found to lower both the oxygen and fluoride concentrations in valve metal materials, as the use of reduced acid leach temperatures provide lower oxygen for a given quantity of a leach acid, such as hydrofluoric acid.

Abstract: Silicon-containing residues, as they accumulate especially during the synthesis of organosilanes out of metallic silicon, and especially methyl chloride, are processed according to the invention to briquettes, being additives for the quality adjustment of cast iron being produced in a cupola furnace in order to avoid either costly regeneration for the recovering of the valuable components or the total dumping of said silicon-containing residues. Besides the silicon-containing residue the briquettes contain 1-10 percent by weight of cardboard fiber, 5-40 percent by weight of hydraulic cement and 0-20 percent by weight of additional additives having influence on the quality of the cast iron. The cement- and cardboard fiber-containing briquettes are mechanically and thermally sufficiently stable with respect to the operation of the melting furnace. The yielding rate of the inserted small-sized silicon in the cast iron is about 85% and reaches thereby the same range of lumpy ferrosilicon.

Abstract: Inner or outer cylindrical worked surfaces of powder metal components are bearingized by orbiting tapered rollers against them using a tapered mandrel having points for impacting the rollers against the worked surface.

Abstract: A treatment process for a composite comprising a matrix of a precipitation hardenable aluminum alloy and a particulate or short fiber ceramic reinforcement. The process includes hot and/or cold working the composite, subjecting the composite to a controlled heating step in which the composite is raised from ambient temperature to a temperature of from 250 to 450.degree. C. at a rate of temperature increase less than 1000.degree. C. per hour, and subjecting the resulting heat treated composite to a solution treating step.

Abstract: Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains.

Abstract: A method of tempering powdered metallurgical constructs, that includes first deoxygenating and dehydrating powdered metal compacts before tempering. During the process, the sintered compacts are first preheated to a temperature that desorbs water vapor and oxygen from interstitial spaces of the compact, while not accelerating the rate of oxidation of any metal component. Once deoxygenation and dehydration has been achieved, the compact is heated to a tempering temperature in a substantially oxygen and water vapor-free environment and is maintained at that temperature until tempering is complete. Substantially oxygen and water-vapor free environmental conditions are maintained while the tempered compacts are cooled, to avoid post-oxidation. The resultant tempered powdered metal devices have increased strength, ductility and better machinability than conventionally tempered constructs.

Abstract: A sputtering target, for forming a recording layer of an optical recording medium in which information is written and erased through a transition between two phases by utilizing electromagnetic wave energy, consists of a heat-treated and sintered composition represented by the formula:Ag.sub..alpha. In.sub..beta. Te.sub..gamma. Sb.sub..delta.wherein2.ltoreq..alpha..ltoreq.303.ltoreq..beta..ltoreq.3010.ltoreq..gamma..ltoreq.5015.ltoreq..delta..ltoreq.83.alpha.+.beta.+.gamma.+.delta.=100A method of producing the sputtering target, an optical recording medium having a recording layer formed through sputtering by use of the sputtering target, and a method of forming the recording layer are also disclosed.

Abstract: A method of treating metal working dies by the steps of: forming a metal working die part to be constituted of consolidated particulate material with a porosity in the range of 0.01-0.5%; immersing the part in a lubricant that is flowable under the working conditions of use for the die part, the lubricant being contained within a pressure chamber; raising the pressure within the chamber to 3,500 psi and the temperature of the lubricant to about 100.degree. C. for a period of time sufficient to allow the lubricant to migrate and be trapped within the micro pores of the part with a positive internal pressure; and placing into use the treated cold working die part so that such die part is subjected to shear, such use being without the need for burn in and redressing.

Abstract: A method of producing copper powder having little variation in its particle size and an excellent monodispersion properties. A copper complex ion solution is prepared from a copper-containing solution and a complexing agent, then a reducing agent is added to the copper complex ion solution to precipitate metallic copper. The copper-containing solution herein contains copper sulfate, copper formate, copper pyrophosphate, copper chloride or copper carbonate and the complexing agent is at least one carboxylate or phosphate.

Abstract: In a process for making superplastic steel powder or flakes, molten steel rapidly solidified to form a solidified material comprising substantially single-phase austenitic steel powder or flakes having a grain size of no greater than about 2 .mu.m. The powder or flakes are heated at a temperature of 300.degree. C. to 600.degree. C. to produce superplastic steel comprising a mixture of ferrite steel and at least one metal carbide, the ferrite steel having a randomly oriented structure and having a grain size of no greater than about 2 .mu.m, the at least one metal carbide having a grain size no greater than about 0.5 .mu.m. The steel powder or flake is then recovered for further processing. A consolidated superplastic steel can be formed from the powder or flake by hot pressing the powder or flake at a temperature of between about 650.degree. C. and about 950.degree. C. and at a pressure of about 10 MPa to about 100 MPa for a time sufficient to form a fully dense consolidate.

Abstract: A method of stabilizing a fluidized bed in a fluidized bed roasting process for metal sulphide concentrate comprises the step of controlling the particle size distribution of the particulate material in the bed so that a minimum amount of no less than about 30% of the concentrate falls in a size range of from about 100 to about 420 microns. The minimum amount preferably falls in the range of from about 35% to about 40%. In one embodiment of the invention the particle size distribution is controlled by maintaining the amount of lead in the concentrate in a range from about 3% to about 4%, preferably 3.7% to about 3.8%. In another embodiment the particle size distribution is controlled by using a pelletized feed or by the combination of the steps of using a pelletized feed and regulating the lead content of the concentrate.

Abstract: A method for forming nickel base superalloy articles of manufacture by a combination of hot die forging, isothermal forging and heat treatment below and above the solvus.

Abstract: A method for fabricating articles of high-temperature aluminum alloys having a compressional strength of at least 20 kg/mm.sup.2 at temperatures of 300.degree. C. or greater, is disclosed. The method comprises the steps of: (a) forming a porous preform from particles of a first aluminum alloy via cold-pressing, the preform having the shape and dimension of the aluminum alloy article to be fabricated; (b) squeeze-casting a molten second aluminum alloy into void spaces of the porous preform to form an aluminum composite containing the first aluminum alloy, which serves as a reinforcement phase, dispersed in the second aluminum alloy, which serves as a matrix phase; (c) wherein the molten second aluminum alloy is cast at such temperatures so as to cause a surface of the first aluminum alloy particles to melt and thereby form a strong bonding with the second aluminum alloy.

Abstract: In a process for making superplastic steel powder or flakes, molten steel is rapidly solidified to form a solidified material comprising substantially single-phase austenitic steel powder or flakes having a grain size of no greater than about 2 .mu.m. The powder or flakes are heated at a temperature of 300.degree. C. to 600.degree. C. to produce superplastic steel comprising a mixture of ferrite steel and at least one metal carbide, the ferrite steel having a randomly oriented structure and having a grain size of no greater than about 2 .mu.m, the at least one metal carbide having a grain size no greater than about 0.5 .mu.m. The steel powder or flake is then recovered for further processing. A consolidated superplastic steel can be formed from the powder or flake by hot pressing the powder or flake at a temperature of between about 650.degree. C. and about 950.degree. C. and at a pressure of about 10 MPa to about 100 MPa for a time sufficient to form a fully dense consolidate.

Abstract: Disclosed is a practical aluminum based alloy containing 1 to 99 weight percent beryllium, and improved methods of semi-solid processing of aluminum alloys containing beryllium. The present methods avoid molten beryllium, agitation of molten aluminum-beryllium alloys and the need for introducing shear forces by utilizing atomized or ground particles of beryllium mixed with solid, particulate or liquidus aluminum.

Abstract: A metallic composite solid, containing alloys and/or intermetallics, is formed by compacting at moderate pressure a mixture of powder particles, foils or sheets at a temperature close to room temperature, well below the melting temperature of the constituent components and without the addition of low melting metals such as mercury, indium or gallium acting as a sintering agent. This low temperature consolidation of the powder mixture is enhanced by having the surface oxide of the powder particles removed, prior to consolidation, and/or by coating the particles with an oxide-replacing metal such as silver or gold. The coating process may be replacement reactions, autocatalytic reduction or electrolytic reduction. The composite formation is assisted by the addition of a liquid acid such as fluoroboric acid, sulfuric acid, fluoric acid, adipic acid, ascorbic acid, or nitric acid.

Abstract: An aluminum alloy structural member is crystalline. In producing this aluminum alloy structural member, a procedure is employed which includes forming a green compact by use of aluminum alloy having an amorphous phase, and subjecting the green compact to a powder forging technique. An aluminum alloy powder exhibiting an exotherm E smaller than 20 J/g at the time of the crystallization of the amorphous phases is used. By setting the exotherm E in such a range, cracking of the green compact due to a degassing can be avoided, even if the green compact is rapidly heated in a temperature-rising or heating course.

Abstract: A tantalum-containing nickel base superalloy having a .gamma.' phase has greatly improved maximum tensile strength which is substantially independent of the frequency of the stress is processed by forging above the .gamma.' solvus temperature and annealing above the recrystallization temperature of the alloy.

Abstract: A cutting tool is decarburized by placing the tool in a protective environment, heating in this environment to a temperature of 600.degree.-1100.degree. C., and maintaining this temperature for a period of 15-120 minutes. The cutting tool may be a cemented carbide microdrill which contains primary cutting edges which form an angular surface on the forward end of a rake surface at the cutting tip, and a radius surface which extends from the angular surface to a flank surface which extends from an outer diameter of the cutting tip to an axis of symmetry of the tool.

Abstract: A method for inhibiting the oxidation of powder of a hard metal, characterized by heat-treating the milled powder of a hard metal at a temperature between about 300.degree. C. and 500.degree. C. for at least 1 hr in vacuum is disclosed.

Abstract: A method of supersolvus forging is described for Ni-base superalloys, particularly those which comprise a mixture of .gamma. and .gamma.' phases, and most particularly those which contain at least about 40 percent by volume of .gamma.'. The method permits the manufacture of large grain size forged articles having a grain size in the range of 50-150 .mu.m. The method comprises the selection of a fine-grained forging preform of a Ni-base superalloy. Supersolvus forging in the range of 0.degree.-100.degree. F. above the alloy solvus temperature then performed at slow strain rates in the range of 0.01-0.001 s.sup.-1. Subsequent supersolvus annealing followed by controlled cooling may be employed to control the distribution of the .gamma.', and hence influence the alloy mechanical and physical properties. The method may also be used to produce location specific grain sizes and phase distributions within the forged article.

Abstract: A method is provided for reducing the tendency for thermally induced porosity within a .gamma.' precipitation strengthened nickel-base superalloy which has been processed to obtain a uniform and coarse grain microstructure. This method is particularly useful for forming components such as gas turbine compressor and turbine disk assemblies in which optimal mechanical properties, such as low cycle fatigue and creep resistance, are necessary for operating at elevated temperatures within a gas turbine engine. The method generally entails alloying a .gamma.' precipitation strengthened nickel-base superalloy to have a boron content of not more than about 0.02 weight percent, and then forming a billet by melting an ingot of the superalloy in an argon gas atmosphere and atomizing the molten superalloy using argon gas. The above atomizing technique encompasses both powder metallurgy and spray forming processes.

Abstract: A method is provided for obtaining a uniform grain size on the order of about ASTM 5 or coarser in at least a portion of an article formed from a .gamma.' precipitation strengthened nickel-base superalloy. The method comprises forming an article by: providing a billet, preheating the billet above 2000.degree. F. for at least 0.5 hours, working at least a portion to near-net shape at working conditions including a first strain rate of less than about 0.01 per second and at a subsolvus temperature at or near the recrystallization temperature, supersolvus heating to form a grain size in the portion of at least 5 ASTM, and cooling to reprecipitate .gamma.' within the article. The method can be utilized to form a .gamma.' precipitation strengthened nickel-base superalloy article whose grain size varies uniformly between portions thereof, so as to yield a desirable microstructure and property gradient in the article in accordance with the in-service temperature and stress-state gradient experienced by the article.

Abstract: Disclosed herein are granulated particles for magnetic particles for magnetic recording, comprising: acicular ferric hydroxide oxide particles or acicular iron oxide particles; and at least one selected from the group consisting of semisynthetic starch and semisynthetic cellulose and having a bulk density of not less than 0.3 g/cm.sup.3 and a powdering ratio of not more than 40%, and a process for producing the granulated particles, and magnetic particles obtained from such granulated particles.

Abstract: A method is provided for obtaining uniform grain growth within .gamma.' precipitation strengthened nickel-base superalloys. The method includes forming a billet having a very fine grain size in order to achieve optimum superplasticity of the superalloy during forging. The article is then heated to a pre-working hold temperature in a manner which prevents coarsening of the microstructure and a loss of superplasticity. The article is then worked, such as by forging, at a temperature below the .gamma.' solvus temperature of the alloy, so as to maintain local strain rates within the article below a critical strain rate for random grain growth, and so as to maintain the strain rate gradient throughout the article below a critical upper limit. After working, the article is subjected to annealing at a temperature which is less than the .gamma.' solvus temperature of the alloy, and for a duration which is sufficient to remove accumulated metallurgical strain in the article.

Abstract: A thermal barrier coating system for high temperature nickel-based and cobalt-based superalloys includes a hardenable metallic coating on the substrate and a ceramic topcoat. The metallic coating is preferably a gamma/gamma prime hardenable nickel-based superalloy, and the ceramic topcoat is preferably zirconium oxide having from about 6 to about 20 percent yttrium oxide or from about 15 to about 40 percent cerium oxide. Optionally, there may be provided between the hardenable metallic layer and the ceramic topcoat an intermetallic coating such as a nickel aluminide.

Abstract: Articles having improved strength at high temperature are made from near-eutectic nickel-base superalloys. In such alloys, the improved properties are achieved by preventing the formation of a dispersed second phase during the production of alloy powder. After the powder is consolidated, a dispersion of the second phase is developed through thermal treatment. Consolidation may be achieved by direct application of pressure, or by incremental solidification processes. Some of these alloys are formulated to achieve additional strengthening by precipitation hardening.

Abstract: A wear-resistant layer on a component which is exposed to a high wear loading has a material mixture comprising at least one metallic material in powder form and a non-metallic oxide-dissolving fluxing agent in powder form which by the addition of a resin-like non-corroding stable binding agent is converted into a form which is applied to the component by being spread or laid thereon, and fused.

Abstract: The fracture resistance of titanium alloy matrix composites is increased by one of two methods. One method comprises the steps of consolidating a titanium alloy-fiber preform under suitable conditions to provide a metal matrix composite and thermally treating the thus-prepared composite at a temperature above the beta-transus temperature of the alloy for a brief time. In the second method, a composite having increased fracture resistance is produced by consolidating an alloy-fiber preform at a temperature above the normal consolidation temperature for a time less than the normal consolidation time.

Abstract: A nickel based superalloy composition is disclosed that provides increased high temperature stress-rupture strength and improved resistance to fatigue crack propagation at elevated temperatures up to about 760.degree. C. The composition is comprised of, by weight percent, about 10% to 12% chromium, about 17% to 19% cobalt, about 1.5% to 3.5% molybdenum, about 4.5% to 6.5% tungsten, about 3.25% to 4.25% aluminum, about 3.25% to 4.25% titanium, about 2.5% to 3,5% tantalum, about 0.02% to 0.08% zirconium, about 0.005% to 0.03% boron, less than 0.1% carbon, and the balance essentially nickel. Thermomechanical processing including isothermal forging at controlled strain rates and temperature ranges, supersolvus annealing, and slow cooling are disclosed for producing an enlarged grain structure that provides the improved properties in the alloy of this invention.

Abstract: The rapidly solidified aluminum alloy powder is preformed in a cold or warm environment to form a powder compact having a relative density of 75-93%. Then, the preformed compact is heated and degassed in the atmosphere of an inert gas at temperature of 300.degree. C. to 560.degree. C. for 0.25-3 hours. Immediately thereafter, the compact is subjected to hot coining at 300.degree.-560.degree. C. to obtain a solidified compact having pores at a rate of 2-5%. The solidified compact is then subjected to sizing. Since the inorganic gas prevents reaction between the evaporated water and aluminum while preheating the compact, the hot coining can be carried out in a state where solid state diffusion easily occurs. Thus, the powder particles can be bonded together strongly with a single forging. Also, at the end of hot coining, pores remain in the solidified compact at the rate of 2-5%. Utilizing these pores, the compact can be subjected to sizing to improve its dimensional accuracy.

Abstract: A silver-metal oxide composite material comprising a silver matrix or silver-copper alloy matrix containing 50% by weight or less of copper, (a) from 0.5 to 25% by weight, in terms of elemental metal, of an oxide of at least one element selected from the group consisting of Mg, Al, Zr, Ca, Ce, Be, Th, Sr, Ti, Cr, Hf and Si, and, optionally, (b) from 0.01 to 5% by weight, in terms of elemental metal, of an oxide of at least one element selected from the group consisting of Bi, Pb, Cd, Zn, Sn, Sb, Mn and iron family metals; the oxide of the (a) element and, where present, the oxide of the (b) element being dispersed in the form of fine particles with a particle size of not more than about 0.1 .mu.m uniformly throughout the matrix from the surface to the core thereof; and process of producing the composite material using oxidation under the conditions in which a liquid phase and a solid phase coexist.

Abstract: Rapidly solidified aluminum base alloy is flow formed into tubes and tubular components using conventional flow forming equipment. A preform of preselected configuration and wall thickness for either forward or back spinning is fabricated. Flow forming is then carried out. The beginning of the flow forming step is offset by leaving undeformed a small section of the preform.

Abstract: The object is to provide a method of degassing or solidifying an aluminum alloy powder by utilizing an induction heating as a degassing means in a step of forming and solidifying an aluminum powder or aluminum alloy powder, whereby the disadvantages of the prior art can be overcome. The feature of the present invention consists in preforming an aluminum powder, aluminum alloy powder or aluminum composite alloy powder or mixed powders thereof with non-metallic grains to give a specific electric resistance of at most 0.2.OMEGA.cm, subjecting the preform directly to induction heating in an atmosphere at normal pressure, temperature-raising to 400.degree. to 600.degree. C. at a temperature gradient of at least 0.4.degree. C./sec in a temperature range of at least 300.degree. C. and removing heat-decomposable volatile components to obtain a hydrogen content of at most 10 ppm.

Abstract: A method for preparing a treated nanocrystalline metallic material. The method of preparation includes providing a starting nanocrystalline metallic material with a grain size less than about 35 nm, compacting the starting nanocrystalline metallic material in an inert atmosphere and annealing the compacted metallic material at a temperature less than about one-half the melting point of the metallic material.

Abstract: A method for heat-treatment of tungsten based alloys, capable of improving impact toughness while keeping tensile strength and elongation. The method comprises maintaining a sintered tungsten based alloy consisting of 86 to 99 weight % tungsten and the balance at least one selected from a group consisting of nickel, iron, copper, cobalt and molybdenum, at a temperature ranged from 950.degree. to 1,350.degree. C. for a maintenance time of one minute to 24 hours, quenching the sintered alloy in water or in oil, and repeating the maintaining and quenching steps.

Abstract: A method for treating sintered alloy is disclosed by exposing a portion of the sintered alloy at a temperature ranging from about 800.degree. C. to about 1300.degree. C. under an atmosphere that contains an amount of water vapor corresponding to dew points ranging from about 30.degree. C. to about 60.degree. C. The method according to the present invention gives sintered alloy with a satisfactory protective layer that excels in smoothness and uniformity, and that prevents abnormal oxidation. Moreover, the method is especially useful to a sintered alloy having a complex structure and/or thin walls, such as a honeycomb structure.

Abstract: A method to increase the fracture resistance of titanium alloy matrix composites which comprises thermally treating a composite at a temperature about 5 to 10% above the beta-transus temperature of the alloy for about 4 to 60 minutes.

Abstract: A rapidly solidified zirconium containing aluminum lithium alloy powder consisting essentially of the formula Al.sub.bal Li.sub.a Cu.sub.b Mg.sub.c Zr.sub.d where "a" ranges from 2.1 to 3.4 wt %, "b" ranges from about 0.5 to 2.0 wt %, "c" ranges from 0.2 to 2.0 wt % and "d" ranges from greater than about 0.6 to 1.8 wt %, the balance being aluminum. The powder is degassed in a vacuum at a temperature of at least about 450.degree. C. Components consolidated from the powder exhibit high tensile strength and elongation together with excellent notched impact toughness.

Abstract: A cylindrical, iron-based sintered slug comprising an iron-based sintered alloy having a surface hardness represented by an HRB of 40-90 is formed such that its interior porosity is 5% or less but greater than 0%, the porosities of both its surface layer regions lying at most 1 mm below its outer and inner surfaces are fixed at at least 3% or less but greater than 0% and the distribution of pores in each of the surface layers is decreased gradually toward the surface.

Abstract: A process for producing a copper alloy composite containing dispersed graphite. The process comprises locating compacted uncoated graphite in a preheated die, pouring molten copper alloy over the compacted graphite and infiltrating the compacted graphite with the molten copper alloy.

Abstract: Process for the preparation of a substantially homogeneous alpha phase copper-nickel-tin alloy comprising copper and 4-18% by weight of nickel and 3-13% by weight of tin, comprising atomizing a molten alloy having the before-indicated composition and collecting atomized particles on a collecting surface in such a way that solid collected material is obtained having a temperature, of at least 700.degree. C., followed by quick cooling of the collected material to a temperature below 300.degree. C.The alloy thus obtained may be hardened, preferably after shaping, by spinodal decomposition.

Abstract: A method is disclosed for manufacturing a finished product which consists at least partially of a copper nickel and tin based alloy which has undergone spinodal decomposition. A liquid bath of the Cu Ni Sn based alloy is prepared containing also titanium and possibly lead. A semi-finished product is formed by spray-deposition of this alloy onto a backing then transformed with an annealing stage followed by rapid tempering. The product obtained after transformation of the semi-finished product is subjected to a heat annealing treatment in order to carry out spinodal decomposition of the part of the said product which is constituted by Cu Ni Sn based alloy, to obtain a finished product. A semi-finished product or product is obtained by this method. Connectors and machinable products based on Cu Ni Sn and of high and homogeneous hardness are manufactured.

Abstract: The present invention relates to a method of making metal ceramic composites and the metal ceramic compositions and articles made therefrom, especially net-shaped articles having a wide variety of applications.The present invention involves preparing a combustion synthesis mixture comprising at least one substance containing a combustible mixture of powders and at least one low-melting metal, forming this mixture into a desired final shape in a die, and carrying out a combustion synthesis therewith. Ceramic or metallic reinforcements may be incorporated in the combustion synthesis.The present invention allows the control of porosity in the resultant composite compositions and can result in composites having high toughness characteristics.

Abstract: The process of the invention relates to forming MA iron-base ODS alloys. A billet of iron-base ODS alloy is provided. The billet is consolidated at a temperature within a predetermined range of sufficient temperature for formation of coarse and/or fine grain sizes during a final heat treatment. The consolidated billet is worked into final form. The object is annealed to recrystallize grains to a size determined by the temperature of the consolidation and the working of the extruded billet.

Abstract: This invention is characterized by working which improves metal formability. This is contrary to the usual result of working metals, where formability decreases during working.

Abstract: A cylindrical, iron-based sintered slug comprising an iron-based sintered alloy having a surface hardness represented by an HRB of 40-90 is formed such that its interior porosity is 5% or less but greater than 0%, the porosities of both its surface layer regions lying at most 1 mm below its outer and inner surfaces are fixed at at least 3% or less but greater than 0% and the distribution of pores in each of the surface layers is decreased gradually toward the surface.