Abstract: There is provided a method for the manufacture of a multilevel metal part, the method comprising the steps of: a) compacting agglomerated spherical metal powder to a green multilevel preform such that an open porosity exists, wherein the green multilevel preform fulfills the relation zg=zHVC·a, b) debinding the green preform, c) sintering the green preform in an atmosphere comprising hydrogen d) compacting the green preform with high velocity compaction to a density of at least 95% TD, e) subjecting the part to densification to a density of at least 99 % TD. There is further provided a multilevel metal part. Advantages of the method include that it is possible to manufacture a multilevel part which is essentially uniform throughout the entire part and which has excellent tolerance, which at the same time has virtually full density and thereby having excellent mechanical properties as well as excellent corrosion properties.

Abstract: A process for making full dense components of a carbon-containing steel, comprises the steps of: a) making a powder of the carbon-containing steel by gas atomization wherein the carbon content is low, less than 0.15 wt %, b) agglomerating the powder from step a) with at least one hydrocolloid and elemental carbon, c) compacting the agglomerated powder from step b) to a density of at least 80% of theoretical density, with the proviso that the compacted agglomerated powder still is porous allowing transport of gas to and from its interior, and d) sintering the compacted powder to a density of more than 98% of theoretical density, preferably more than 99% of theoretical density, wherein a gas comprising carbon is added during sintering and finally subjecting the component to HVC. Advantages include that it is possible to manufacture a dense component of powders which otherwise are difficult to compact.

Abstract: There is provided a method for the manufacture of a metal part from powder comprising the steps: a) providing a spherical metal powder, b) mixing the powder with a hydrocolloid in water to obtain an agglomerated metal powder, c) compacting the agglomerated metal powder to obtain a part of compacted agglomerated metal powder, wherein the structure of the part is open, d) debinding the part to remove the hydrocolloid, e) compacting the part using high velocity compaction (HVC) preferably to a density of more than 95% of the full theoretical density, f) further compacting the part using hot isostatic pressing (HIP) preferably to more than 99% of the full theoretical density to obtain a finished metal part, wherein at least one oxide is added to the metal powder before step c), which oxide has a melting point higher than the melting point of the metal powder.

Abstract: There is provided a method for the manufacture of a multilevel metal part, the method comprising the steps of: a) compacting agglomerated spherical metal powder to a green multilevel preform such that an open porosity exists, wherein the green multilevel preform fulfils the relation zg=zHVC·a, b) debinding the green preform, c) sintering the green preform in an atmosphere comprising hydrogen d) compacting the green preform with high velocity compaction to a density of at least 95% TD, e) subjecting the part to densification to a density of at least 99 % TD. There is further provided a multilevel metal part. Advantages of the method include that it is possible to manufacture a multilevel part which is essentially uniform throughout the entire part and which has excellent tolerance, which at the same time has virtually full density and thereby having excellent mechanical properties as well as excellent corrosion properties.

Abstract: A method for the manufacture of a multilevel metal part, the method including the steps of: a) compacting agglomerated spherical metal powder to a green multilevel preform such that an open porosity exists, wherein the green multilevel preform fulfils the relation zg=zHVC·a, b) debinding the green preform, c) sintering the green preform in an atmosphere including hydrogen, d) compacting the green preform with high velocity compaction to a density of at least 95% TD, e) subjecting the part to densification to a density of at least 99% TD. There is further provided a multilevel metal part. Advantages of the method include that it is possible to manufacture a multilevel part which is essentially uniform throughout the entire part and which has excellent tolerance, which at the same time has virtually full density and thereby having excellent mechanical properties as well as excellent corrosion properties.

Abstract: The invention refers to a new method for preparing sintered structural parts of carbon or tool steels or high speed steel having a carbon content of up to 2% by weight, wherein an agglomerated spherical powder comprising at least 0.5% of a thermo-reversible hydrocolloid is pressed to a green body of high density which is then heated at 450–650° C. to remove the non-carbon content of the hydrocolloid and subsequently sintered at about 1100–1400° C. to structural parts having high strength properties.

Abstract: The invention refers to a new method for preparing sintered structural parts of carbon or tool steels or high speed steel having a carbon content of up to 2% by weight, wherein an agglomerated spherical powder comprising at least 0.5% of a thermo-reversible hydrocolloid is pressed to a green body of high density which is then heated at 450-650° C. to remove the non-carbon content of the hydrocolloid and subsequently sintered at about 1100-1400° C. to structural parts having high strength properties.

Abstract: The process for extruding tantalum or niobium includes sealing a cold isostatically pressed charge of tantalum or niobium powder in a first metal cylinder and then sealing the first cylinder in a second metal cylinder with a metal powder of spherical shape in a gap between the cylinders. Thereafter, the second cylinder is cold isostatically pressed to prevent the metal powder in the gap from segregating. This is followed by heating and extrusion of the second container to form, e.g. an extruded bar. The ends of the bar and the skin on the bar can be removed to obtain a rod of tantalum (or niobium) with a yield of from 95% to 96% of the original powder.

Abstract: The invention is concerned with the production of pieces by powder metallurgy, and, more particularly, the use of powders with spherical particles, such as those obtained by pulverisation, in a gas of a liquid metal or alloy.The metallic powder according to the invention is constituted by granules, each of these comprising an assembly of spherical particles which have been agglomerated by at least 0.5% of gelatin.This powder is prepared by mixing with the spherical particles an aqueous solution of gelatin; a paste is thus obtained which is broken in such a way that granules are obtained by calibration and drying.Application to the production of pieces made of non-oxidising, fire-proof, or other, steels or alloys.

Abstract: The process of forming an extruded product of tantalum or niobium requires a cold isostatic pressing of a charge of the powder to a density sufficient to form a green compact which is then placed in a capsule. The capsule is then sealed and heated to a temperature and for a time sufficient to anneal the green compact. Thereafter, the capsule and encapsulated compact are subjected to a cold isostatic pressing to achieve a density of from 70% to 85%. This is followed by subsequent heating and extrusion of the heated capsule and encapsulated compact to form the extruded product. The outer layer on the capsule which has been formed by the capsule material can be removed, as by pickling, in the case of the capsule being a carbon steel.

Abstract: Method of producing powder-metallurgical objects, specifically elongate objects such as rods, sections, tubes or the like, wherein a powder of metal and/or metal alloys of great hardness, particularly tool steel or high-speed steel powder, is charged into a thin-walled capsule, said capsule is then sealed so as to be airtight, is heated, and subjected to isostatic compression to produce a blank which will then undergo hot-working, specifically extrusion, for the production of the finished product. In a first alternative, the airtight and sealed capsule is initially heated to a temperature higher than 1,000.degree. C. Following through-heating of the capsule, the latter is maintained at an elevated temperature for a prolonged period. Then the capsule is slowly cooled and subjected to cold isostatic compression prior to final shaping. In a second alternative, the capsule is sealed so as to be airtight, and then subjected to an initial cold isostatic compression.

Abstract: A method and an apparatus for producing moulded blanks by hot-pressing metal powder, preferably spherical metal powder, inside a thin-walled capsule comprising an outer sleeve (2), an insertion sleeve (4) disposed approximately centerally inside the latter, a base (3) and a cover (5), inside which one separable mould (1) of solid material may be inserted. The mould (1) and the two sleeves (2, 4) are dimensioned in such a way that between the inner insertion sleeve (4) and the mould (1) there is formed a mould cavity into which the metal powder may be poured. After the metal powder is poured in, the still open capsule is subjected to a preliminary compression by means of vibration. The capsule is subsequently closed in a gas-tight manner by means of the cover (5). Then the metal powder inside the capsule is subjected to a heat-isostatic pressing at an elevated pressure and an elevated temperature of approximately 1000.degree. to 1200.degree. C.

Abstract: A method of making pipes by powder metallurgy, in which powder of metal and/or metal alloys (17) is filled into a thin-walled casing consisting of inner pipe wall (12), outer pipe wall (11) and a bottom (13), subsequently the casing is closed on its side remote from the bottom (13) by an annular cover (14) and is subjected to a cold-isostatic pressure whereby the powder (17) is compacted within the casing to produce a solid or dimensionally stable pipe blank or compact (10), which is then hot-worked, e.g. extruded. In order to prevent thermal cracks on the inner pipe or inner pipe wall (12), especially in the region of the ends thereof, the inner pipe or inner pipe wall (12) is provided prior to hot-working on at least one end region thereof with at least one circumferentially extending bulge (15 or 16, respectively).

Abstract: A method of making powder-metallurgical articles, in which powder of metal and/or metal alloys is filled into a thin-walled casing, whereupon the casing is closed and subjected to cold-isostatic pressure. Thereby the powder within the casing is compacted to form a strong or, respectively, dimensionally stable article. When the casing wall includes a joining weld seam, said casing wall is provided with an elastically expandable layer in the close vicinity of the weld seam in order to prevent formation of a fold, preferably in such a way that an approximately uniform prestress is applied to the wall surface.

Abstract: A tubular composite element of metal, particularly steel, whereby at least the two opposite ends of the tubular composite element consist of different materials, for example carbon steel and stainless steel, and a process and a pressing for simultaneously producing two or more of such composite elements, at least two powders each consisting of one of the different materials, which have been produced by atomizing melts of the materials in question, are introduced alternately and separately from one another into three or more sections each extending over a predetermined axial length of a metallic hollow cylindrical casing and are condensed by vibration and/or ultrasound to around 60 to 70% of the theoretical density and by cold isostatic pressing of the closed casing under a pressure of at least about 3000 bars to at least 80% of the theoretical density and the pressing thus obtained is heated, subsequently hot-extruded to form a tube and the tube thus formed is divided up into the two or more composite element

Abstract: This invention relates to a capsule for pressings pressed by isostatic pressure and to these pressings used for extruding metallic objects, particularly tubes, of stainless steel, the outer and inner wall of the capsule consisting of thin-walled sheet metal, and at least the outer wall having substantially the same strength properties in the axial direction over its circumference and particularly consisting of a spiral-welded tube and being preferrably provided with a bulge which is directed outwardly against the shrinkage occurring during isostatic pressing, and at least on the front end of the capsule an insert being provided, which consists of one or more pieces of a ductile solid material or a ductile material pressed from powder. The invention further relates to a process for the production of such capsules and pressings and to a process for extruding tubes and to the tubes obtained according to this process.

Abstract: This invention relates to a capsule for pressings pressed by isostatic pressure and to these pressings used for extruding metallic objects, particularly tubes, of stainless steel, the outer and inner wall of the capsule consisting of thin-walled sheet metal, and at least the outer wall having substantially the same strength properties in the axial direction along its circumference and particularly consisting of a spiral-welded tube, and preferably at least on the front end of the capsule an insert being provided, which consists of one or more pieces of a ductile solid material or a ductile material pressed from powder. The invention further relates to a process for the production of such capsules and pressings and to a process for extruding tubes and to the tubes obtained according to this process.

Abstract: This invention relates to a process and an apparatus for converting lump-size material, particularly scrap, of titanium metal or its alloys, preferably of low oxygen content, into powder-form material, which is useable for forming in a powder-metallurgical way pressings and workpieces, wherein the lump-size material is highly embrittled by charging with hydrogen, the embrittled material is size-reduced by means of size-reducing machines, particularly impeller breakers, impact mills, hammer mills, impact hammer mills or hammer breakers, the size-reduced brittle material preferably having a particle size of less than about 10 mm and more particularly of less than about 6 mm is further size-reduced by means of at least one jet stream by impinging on a baffle plate or an anvil or on the particles of at least one other jet stream for the purpose of conversion into the powder-form material, and the powder-form material is converted into the ductile state by heating, preferably at temperatures above 450.degree. C.

Abstract: A process for the after-treatment of powder-metallurgically produced extruded tubes of stainless steel or highly alloyed nickel steels, pressings initially being produced by introducing into a capsule of thin sheet steel a powder consisting predominantly of spherical particles which have been produced from the required starting material by sputtering and, after the capsule has been closed, the density of the powder is increased to at least about 80% to about 93% of the theoretical density by cold isostatic pressing and the pressings obtained are then extruded into tubes at temperatures around 1200.degree. C.

Abstract: PCT No. PCT/EP78/00011 Sec. 371 Date Apr. 17, 1979 Sec. 102(e) Date Apr. 17, 1979 PCT Filed Aug. 16, 1978 PCT Pub. No. WO79/00100 PCT Pub. Date Mar. 8, 1979A process for the production of sheet an strip from ferritic, stabilized, stainless chromium-molybdenum-nickel steels by hot-rolling of cast blocks to form heavy plate or crude strip and subsequent cold-rolling to the required thickness, wherein the blocks are hot-rolled at temperatures above about 850.degree. C. to form heavy plate or crude strip and, immediately afterwards, the heavy plate or crude strip thus formed is suddenly (rapidly) quenched with water to a temperature just below 450.degree. C. and subsequently annealed, the annealing step being followed by sudden (rapid) cooling from temperatures above about 850.degree. C. to temperatures below 500.degree. C.