Abstract: A method of bonding a particle material to near theoretical density, includes placing a particle material in a die. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps, is applied. The method can be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material. The method may also be applied to perform combustion synthesis of a reactive material, followed by consolidation or joining to near-net shaped articles or parts.

Abstract: A method and apparatus for fabricating high density monolithic metal and oy billets. The process requires preheating precursor materials of metal or alloy billets by means of a combustion synthesis called Self-Propagating High-Temperature Synthesis (SHS). The reaction takes place in an insulated reaction vessel where the precursors, in a powder form, are heated to high temperatures. The precursors are then compacted to high density by means of pressure waves generated by detonation of an explosive. The method is capable of producing high purity tungsten and tungsten-based alloys of greater than 90% theoretical density.

Abstract: An apparatus for bonding a particle material to near theoretical density, includes a chamber, a punch and die assembly for supporting a particle material, plungers for applying shear and/or axial pressures, and a power supply for applying a current. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps. is applied. The apparatus may be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material.

Abstract: A method for making dies or molds from powdered metals is disclosed. The method includes the steps of: providing a pattern of a desired shape to define the mold or die cavity configuration; providing a canister; placing the pattern in the canister and filling the canister with a selected powdered metal; hot isostatic pressing the canister and powdered metal to produce a consolidated and densified compact; and sectioning the compact along a plane to enable removal of the pattern and thus providing the desired die or mold cavity in the fully densified powdered metal die or mold set so formed.

Abstract: A method and apparatus for filling a cavity with powder wherein a pipe having holes for discharging gas is disposed in a powder box and gas is discharged into the powder in the powder box as the powder enters the cavity so that particles of the powder are movable relative to each other. Due to the gas discharge, the powder can enter the cavity smoothly without whirling up in the cavity and settling unevenly, so that a filling time period is shortened and a particle size distribution in the cavity is uniform.

Abstract: A plurality of blanks divided at a division end face 5 or a blank-bonded product comprising a plurality of blanks sintered and bonded together are or is compressed in the same mold, so that they are plastically deformed until the division end faces 5 are cohered. Thereafter, a load is applied to the plastically worked product in a direction of breaking of the division end faces 5 to break the division end faces 5 and divide the plastically worked product into a plurality of members. In this manner, a split type mechanical part having irregularities meshed with each other on mating faces and easily positionable relative to each other can be produced with a good dimentional accuracy.

Abstract: Ferrous powder particles are coated with vaporized phosphorus in a fluid-bed reactor to obtain homogeneous coatings of phosphorus. The coated powders are useful feed for pressed structural parts, exhibiting improved green density, compressibility and sintered density thus improving magnetic and tensile properties.

Abstract: A firearm bolt prepared from an alloy of tungsten, nickel and iron having a density of about from 14.1 g/cc to 18.0 g/cc. The alloy preferably also contains at least one of molybdenum, cobalt, rhenium, tantalum and gold. The alloy is preferably manufactured by standard powder metallurgical techniques followed by a liquid phase sinter and vacuum anneal. The bolt can also be manufactured using solid state sintering. The bolt can also be manufactured by mechanically working the material after sintering, after annealing, or after both sintering and annealing.

Abstract: Disclosed is a manufacturing process of a sintered connecting rod assembly comprising a first member with a projection and a second member with a concavity in which the first member and the second member are mated with each other by engaging the projection with the concavity. A powdered raw material is compacted into a first compact and a second compact for the first and second members, wherein the projection of the first compact has a width slightly larger than the width of the concavity of the second compact. Then the projection of the first compact is engaged with the concavity of the second compact to mate the first compact with the second compact, thereby the projection and the concavity are tightly pressed against each other. After sintering the mated first and second compacts, they are forced to release the projection from the concavity. The die for compacting the raw material has a whole cavity and a removable core for dividing the whole cavity into two cavities.

Abstract: A method of extruding a boron carbide-aluminum alloy metal matrix composite includes heating the ingots of the composite to temperatures of about 570.degree. C., holding the ingots at about 570.degree. C. to soften the ingots, placing the ingots in a heated extrusion chamber, and extruding the softened ingots at pressures about 15% to 20% higher than typical pressures used to extrude aluminum alloys. A method of casting a boron carbide-aluminum alloy metal matrix composite includes heating ingots of the composite to about 700.degree. C. to melt the ingots, gently stirring the melt, removing dross from the melt, vigorously stirring the melt with an impeller without creating a vortex, degassing the melt with an argon diffuser wand, and continuously removing froth formed during degassing until the rate of froth formation is reduced and the melt gently bubbles.

Abstract: A two layer valve seat insert and a method for its manufacture is described. The method comprises the steps of preparing two powder mixtures; a first powder mixture for forming the valve seat face layer; a second powder mixture for forming the valve seat base layer; sequentially introducing a predetermined quantity of each of said first and said second powder mixtures into a powder compacting die and having an interface therebetween substantially perpendicular to the axis of said die; simultaneously compacting said first and said second powder mixtures to form a green compact having two layers and sintering said green compact, wherein at least one of the chemical composition or the physical characteristics of at least one of said first and said second powder mixtures is adjusted so as to result in said valve seat face layer and said valve seat base layer having substantially the same density after compaction.

Abstract: A method of manufacturing a connecting rod is disclosed, in which a formed body of a connecting rod integrated with a cap section of iron metal powder is heated, before or after being sintered, with a bearing metal ring set in the bearing section thereof. During or after sintering, the bearing metal is infiltrated in the bearing section, followed by the forging as required. Then the cap section is separated. In this way, the manufacturing steps are reduced, while at the same time preventing the bearing section from being overheated and seizured due to an improved heat conductivity between the connecting rod body and the bearing section.

Abstract: Process for producing multilayer ceramic substrates using greensheet technology and thin dielectric ceramic greensheets for miniaturization purposes. The process avoids the screening of the thin greensheets by forming self-supporting fusible particulate metal electrode layers, interposing them with the thin greensheets and sintering the assembly to form the multilayer substrates such as integrated capacitors.

Abstract: A connecting rod as a shaft clamping member includes a rod member and cap, each of which has mating faces at circumferentially opposite ends of a semi-circular recess and which are fastened to each other by bolts by matching the opposed mating faces to each other to define a crank pin hole by the two semi-circular recesses. The rod member and the cap are forgings formed from an aluminum alloy and simultaneously produced by forging powder preforms of the rod member and cap in a cavity having the desired shape of the connecting rod. After forging, the opposed mating faces have an infinite number of recesses and projections which are formed from the flow of the material during the forging and which are in a matched and fitted relation to each other. Thus, any misalignment between and in a direction parallel to the mating faces can be prevented to avoid the generation of a situation that only the rod member receives a stress. This achieves a prolongation in the life of the connecting rod of the aluminum alloy.

Abstract: A camshaft assembly comprising a shaft, a lobe, a gear, and a boss portion is disclosed. The lobe includes a first powdered metal and has a first density, while the gear includes a second powdered metal and has a second density. The boss portion is formed on one of the lobe or gear, and has an aperture sized to cooperate with the shaft and a periphery cooperating with the other of the lobe or gear to fix the lobe against rotation relative to the gear. The boss portion has a third density less than the density of the lobe or gear on which the boss portion is formed. A method of making a camshaft component is also disclosed.

Abstract: A rotor for a rotary screw machine has helical lobes (12) and grooves (14). A shell structure (18) forming the external surface of the rotor is made of pressed metal power. The rotor is manufactured by cold isostatic pressing of a powder in a vessel having a surface shaping rotor. The pressure is applied radially by means of a cast bag in which high pressure liquids acts. After the pressing process, the rotor blank is sintered and attached to a shaft (16).

Abstract: A production method of a forged component made of a composite material in accordance with the present invention comprises packing pellet or powdery plastic particles, plastic particles coated on the surface with a metallic material or molten plastic material into a cylinder member made of a metallic material, fixing the cylinder member having the plastic material packed thereinto under the closed state by a sheet member made of a metallic material and equipped with an air vent or air vents so as to form an assembly, setting the assembly into a first mold and pressuring a second mold to the assembly so as to forge and mold the assembly into a predetermined shape.The forged component made of a composite material and producedin accordance with the present invention is light in weight and can be used preferably for producing engage components having high heat-resistance such as a piston.

Abstract: A novel process is disclosed by which contorted or distorted sheet gauge steel and other metal scrap material, generated by stamping and other deforming metal-working operations, is flattened by rolls for the purpose of increasing its bulk density and to provide a scrap product that can more efficiently be transported and used for remelting in steel-making and foundry furnaces. The process involves the steps of feeding contorted sheet metal scrap between a pair of moving compressive surfaces, compressing the scrap to substantial flatness, and discharging the flattened steel scrap. The novel apparatus for performing the process is also disclosed.

Abstract: A valve-seat insert for internal combustion engines comprises a double-layered, sintered alloy composed of a valve-seat layer on which a valve is seated, and a base layer integrated with the valve-seat layer and adapted to be seated in a cylinder head of an engine. The valve-seat layer is composed of a sintered alloy of a high heat resistance and a high wear resistance having a composition comprising, by weight, 4 to 8% Co, 0.6 to 1.5% Cr, 4 to 8% Mo, 1 to 3% Ni, 0.3 to 1.5% C, 0.2 to 0.6% Ca, and the balance of Fe and inevitable impurities, the additives, Co, Cr and Mo being present mainly in a form of a Co-Cr-Mo hard alloy and a hard Fe-Mo alloy dispersed in the Fe matrix. The base layer is composed of a sintered alloy of a higher heat resistance and a higher creep resistance than those of the valve-seat layer and having a composition comprising, by weight, 11 to 15% Cr, 0.4 to 2.0% Mo, 0.05 to 0.3% C, and the balance of Fe and inevitable impurities.

Abstract: A sintered metal body with at least one toothing thereon and a method of forming the same. The toothing is formed in a sintered metal blank with or without pre-toothing by metal forming. The final toothing is cold rolled into the sintered metal blank. The thus formed sintered metal body with at least one toothing can be used for highly stressed toothed gears, such as involutes, cycloids, and epicycloids, as used, for example, on bevel gears, and particularly curved-toothed bevel gears.

Abstract: A composite is provided which is adaptable to be a substrate for an electronic application. The composite comprises first material particles having a coefficient of thermal expansion in the range of about -20.times.10.sup.-7 to about 50.times.10.sup.-7 in/in/.degree. C. Second material particles having a coefficient of thermal expansion in the range of about 100.times.10.sup.-7 to about 200.times.10.sup.-7 in/in/.degree. C. are mixed with the first material particles. A bonding agent adheres the first and second material particles into a coherent composite having a coefficient of thermal expansion in the range of about 1.times.10.sup.-7 to about 50.times.10.sup.-7 in/in/.degree. C.

Abstract: A piston ring is formed by annular upper and lower parts which contact one another at respective surfaces normal to the axis of the piston ring. The parts can be injection moulded from thermoplastics materials with the parts themselves having no re-entrant portions, so allowing quick and easy manufacture, but with the parts together defining re-entrant portions such as a spring-receiving recess at the inward side of the ring or a pair of spaced oil control rails at the outward side of the ring.

Abstract: A cylinder unit of a cylinder-piston-combustion engine comprises a cylinder housing and a lining unit inserted into the cylinder housing. The lining unit consists of a cylindrical liner sleeve and a terminal wall and encloses a combustion space. The terminal wall is integral with the liner sleeve. The lining unit is manufactured by a non-cutting manufacturing method like cold impact forming, hot impact forming, deep drawing, tube reshaping, press molding or injection molding.

Abstract: A valve cladding method and associated system for implementation including the steps of preforming solid insert-members (22,24) of a vitreous material (having a rheological state that varys with temperature), to generally conform in shape to the cavity walls (12, 14) that are to be clad. The insert-member is fixtured (32) within the cavity to provide a generally concentric, annular space (28) of predetermined thickness and length between the insert-member and the adjacent walls to be clad, thereby defining an activation volume. This volume (28) is filled with loose metal powder (48) and vibrated to achieve tap density for a given powder blend. The activation volume is degassed, evacuated and sealed. The valve body (10') a thus loaded, is heated to a temperature at which the insert members becomes pliable, in the range from one-half to full melting temperature of the powder.

Abstract: A camshaft is prepared from separately formed cams and a shaft. The cams may for example be formed by sintering. The cams are provided with holes which are under-sized and are provided with serrations. They are located on a correspondingly shaped dummy shaft in their required relative orientations and angular positions. Next, the cams are clamped in these positions and the dummy shaft removed. The cams are then heated to red heat and the serrated holes in them broached to bring them to their final size and to concentricity. Finally, a shaft having an exterior profile corresponding to the shape and size of the broached profile of the holes, at ambient temperature, is introduced into the holes and the cams are then cooled so that they shrink fit on to the shaft so ensuring that they are accurately positioned on the shaft. The cams are then released from the jig to give a finished camshaft.

Abstract: This invention relates to methods of making metal fibers and devices for effecting such methods.A method of making metal fibers from spherical particles (6) of a metal powder to be practiced by an apparatus for making such metal fibers is proposed, the method residing in that the spherical particles (6) of metal powder are deformed by rolling each such spherical particle (6) along the path of the process and stretching this particle (6) along its axis of rotation between a main roll (2) and an additional roll (3) of a deforming tool (1). The stretching is executed at a rate exceeding the rate of plastic flow of metal in elongation during reducing the diameter of the deformable spherical particle (6), the additional roll (3) being used as a stretching device. The ready metal fibers (7) are then discharged.

Abstract: The present invention provides a method for constructing from fiber-composite material complex structures having two or more transversely disposed members. By way of example, a composite turbine blade 10 having an aerofoil 12 and an integrally formed footing 14 can be constructed using this new method, which method comprises the steps of forming from fiber-composite monotape a blank 40 in the general shape of aerofoil 12 with the fibers 18' of the monotape being oriented in a generally spanwise direction, exposing the fibers 18' at the root 42 of the aerofoil blank 40, inserting transversely between the exposed fibers 18' a plurality of foot-forming monotapes 17 to form a transversely meshed, tape and fiber structure 68, filling the voids in the transversely meshed structure with powdered matrix material and hot-pressing the filled-in structure 70 substantially according to the desired final shape of the fiber-composite turbine blade.

Abstract: Manufacture of a workpiece from a creep-resistant nickel superalloy which is hardened by means of an oxide dispersion, by a powder-metallurgical process in which the mechanically alloyed powder is subjected to an isothermal or quasi-isothermal hot-rolling operation, in the course of which the powder particles are converted into a flake-shaped form with a pronounced longitudinal axes, and the rolled powder is introduced into a steel container and is compressed by isostatic hot-pressing. The workpiece is afterwards subjected to an annealing treatment which is designed to develop a coarse grain size. A preferred embodiment comprises the introduction of the powder into the mold or container in an oriented manner, in order to obtain a stratified packing of the powder, and an annealing treatment which is designed to develop a coarse grain size and is performed as a zone-annealing treatment.

Abstract: A dual alloy cooled turbine is manufactured by casting a hollow cylinder of first nickel-base alloy material with high creep resistance to produce directionally oriented grain boundaries. A preform of a second nickel-base alloy material with high tensile strength and high low-cycle-fatigue strength is diffusion bonded into the bore of the hollow cylinder by subjecting the cylinder and preform to hot isostatic pressing. The resulting cylindrical block is cut into thin precisely flat wafers. A plurality of alignable holes for forming fluid cooling passages are photochemically etched into the individual wafers. The wafers then are laminated by vacuum diffusion bonding techniques, with the holes aligned to form fluid cooling passages. The resulting laminated block is machined to produce the turbine wheel with turbine blades through which the cooling passages extend.

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 method for producing an alloy article, such as a valve or valve component, and an assembly for use therewith. The article is produced by hot isostatic compacting wherein a lining of prealloyed powdered metal of an alloy composition different than that of the remainder of the article is confined on a surface of an internal passage or cavity in the article. A solid lining element is provided contiguous with at least a portion of the powdered metal lining the surface of said internal passage, the lining element is of an alloy also different from that of the remainder of the article. The powdered metal and solid lining element are heated and then hot isostatically pressed to densify and bond the powdered metal and the lining element to the surface of the internal passage of the article to provide a clad lining of dissimilar metal.

Abstract: A component, such as a turbine disk, made from a metal or metal alloy which has been processed to display superplastic properties at elevated temperatures, is diffusion bonded to a component or components, such as turbine blades, made from another metal or metal alloy, by disposing the components in a press with the surfaces to be bonded in mating contact. Moisture and oxygen are removed from between the surfaces. Heat and pressure are then applied, such as by forging at an elevated temperature or by hot isostatic pressing, to cause superplastic deformation of at least one of the components at the bonding surfaces. The heat and pressure are held sufficiently long to diffusion bond the surfaces. The new integral assembly is then heat treated to obtain desired properties. Consistently good diffusion bonds are achieved by this method.

Abstract: A vane compressor is provided which has a rotor formed therein with a plurality of axial slits opening in its outer peripheral surface in a circumferentially spaced arrangement, and in each of which a vane is received, and a plurality of cavities located between adjacent ones of the axial slits. The rotor is formed of at least two rotor elements integrally joined in an axial alignment, each rotor element being formed of a sintered alloy compact. The rotor elements are brazed along their end faces abutting against each other.

Abstract: The method of forming a lining in the cavities of a body by application of powdered metal consolidated and bonded thereon by a hot isostatic pressing process. A space lining the cavities in the body is provided by tubular members, one intersecting with the other or in close spaced relation thereto, powdered metal fills the space, a vacuum is drawn on the space, the body is subjected to forming conditions and then the body cavities are machined to their final shape with such machining generally removing the tubular members.

Abstract: A method of mounting a hard, wear-resistant insert for use as a core tube, wire drawing die, and the like in which a cylindrical metal casing is provided with opposite front and back sides, the casing having a cylindrical cavity formed in the front side with a flat bottom spaced from the back side. A cylindrical plug is provided having top and bottom ends, the plug being proportioned to have a close fit in the casing cavity. The casing-plug assembly has a reference position with the casing cavity bottom facing upwardly and the plug bottom end facing downwardly. Prior to insertion of the plug in the cavity, either the plug or the casing is inverted from its reference position. A hard insert element is centered with respect to either the inverted end of the plug bottom or the casing cavity bottom and is adhered thereto. Either the plug or the casing is again inverted to the reference position, and the plug is inserted in the casing cavity with the bottom end and insert element facing the cavity bottom.

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: There is disclosed a process for producing elongated metal articles by atomizing molten metal in an inert atmosphere and cooling the particles to remove at least some heat of fusion, but not below 40% of the solidus temperature on the centrigrade scale, while they fall onto a bed of particles on a moving support. The particles are then consolidated by means such as passing the bed through rolls to form an elongated metal article.

Abstract: A watch case is made from an electrically conductive hard material compoud from aluminum oxide and titanium carbide by forming a blank by sintering the material, subjecting the blank to a heat treatment, spark machining the blank to its final form, and fine grinding and polishing the blank to a desired finish.

Abstract: Metal powders are hot isostatically pressed in a can or container produced from superplastic metal sheet.

Abstract: A production, automated method of hot forging finished articles from powder metal preforms, and an apparatus for carrying out the method, wherein the preforms are passed through an induction heating device, whereby they are heated to at least forging temperature. Thereafter, the heated preforms are passed to a pair of dies whereby they are forged into finished articles, after which they are cooled. The entire process may, if required, be conducted in a non-oxidizing atmosphere. The apparatus includes an induction heating means, a forging means, a cooling station, feeding or conveying means to introduce the preforms into the induction heating means, and conveying means to move the preforms from the heating means to the forging means and from the forging means to the cooling station. The entire operation is automatic, including the feeding of the preforms through the apparatus, the control of temperature, and the lubrication and preheating of the dies.

Abstract: A method and a capsule and a blank for producing tubes, bars or similar profiled elongated dense metal objects, preferably in stainless steel qualities, by single or multi-stage extrusion of capsules which are filled with powder of metals or metal alloys or mixtures thereof or with mixtures of powder of metals and/or metal alloys with ceramic powder and sealed and which are adapted in their form to the desired object or intermediate product, as starting material a powder being used which consists at least predominantly of substantially spherical grains and the capsule filled with said powder and sealed being compressed by means of cold-isostatic pressure acting all round until the density of the powder reaches at least 80% of the theoretical density.

Abstract: An aluminum sheet having a prescribed thickness is obtained by compacting aluminum powder into a green sheet of packed aluminum powder, sintering the green sheet at temperatures of 300.degree. C to 600.degree. C and subsequently rolling and annealing the sintered sheet of aluminum powder at least once. A high-density sintered aluminum laminate is produced by piling a plurality of green sheets of packed aluminum powder one on top of another, sintering the pile of green sheets and then rolling and heating the sintered pile of sheets at least once.

Abstract: A multi-material earthworking ripper tip having a leading nose portion comprised of a material having greater wear resistance and strength at elevated temperatures than the material which comprises the rearward shank supporting portion of the tip. In one embodiment, a bi-metallic nose portion is inertial welded to the shank support portion of the tip. In another embodiment powdered tungsten carbide is sintered in situ within a hollow bore of a steel nose portion. Alternately, a solid core of tungsten carbide could be soldered, brazed or press fitted within said hollow bore.

Abstract: A machine element consisting of a shaft having thereon an enlargement such as a gear or cam is made in composite form at a much lower cost in labor and materials than in one-piece form by providing a solid metal supporting shaft of the desired dimensions with a roughened zone, as by coarse-knurling it. A sintered powdered metal preform of suitable metal for the enlargement is prepared in a conventional manner of slightly smaller diameter and of slightly greater length than the finally-desired configuration, and with a central longitudinal bore of slightly larger diameter than the shaft, to allow for expansion of both preform and shaft when both are heated to a forging temperature of 1800.degree. F. to 2000.degree. F.

Abstract: Disks are cut from copper or a copper alloy which can be precipitation-hardened. A copper alloy powder is prepared and dispersion-hardened. The disks are assembled in a stack and alternate with powder layers and extruded. Subsequent heat treatment of the extruded product strengthens it throughout. The method is used specifically to make a hardened copper alloy to be used for making electrodes for resistance welding.

Abstract: This invention provides a magnetic head constituted by a magnetic core having a winding wound thereon, the magnetic core being a ferrite body composed of crystallites which have (111)-crystallographic planes thereof oriented substantially parallel with each other. The ferrite body is a dense polycrystalline and has much improved wear characteristics. The method of manufacturing the polycrystalline ferrite body includes the steps of mixing starting materials which include an .alpha.-Fe.sub.2 O.sub.3 powder with particles having a thin disc shape and other compounds in the weight ratio of given ferrite composition, cold-pressing the mixture into a cold-pressed body by a uniaxial pressure and sintering the cold-pressed body into a solid body so that the crystallites of the sintered body have the (111) 111)-planes substantially oriented.

Abstract: The method of forming a lining in the cavities of a body by application of powdered metal consolidated and bonded thereon by a hot isostatic pressing process. A space lining the cavities in the body is provided by tubular members, one intersecting with the other or in close spaced relation thereto, powdered metal fills the space, a vacuum is drawn on the space, the body is subjected to forming conditions and then the body cavities are machined to their final shape with such machining generally removing the tubular members.