Abstract: A journal bearing assembly includes a steel bearing body and a Babbitt metal liner which defines an internal bearing surface and provides a sliding bearing for a rotating journal. A porous metal bonding layer of NiAl 80/20 or AlSi 12 is applied between the bearing body and the liner. The bonding layer is spray deposited onto the bearing body and the liner is spray deposited onto the bonding layer. The liner is most porous at the bonding layer interface with decreasing porosity toward the bearing surface. The bonding layer may be flame sprayed or applied in powder form and fused. Similarly, the liner may be flame sprayed or applied in powder form and fused.

Abstract: There is disclosed a composite slide member which suppresses the exposure of a porous metal layer even when the amount of cutting from a surface of the slide member increases, thereby enhancing an anti-seizing property without adversely affecting a rear resistance. The composite slide member includes a back plate, and a slide layer including a porous metal layer with a porosity of 50% to 80% and a composite synthetic resin composition impregnated and coated in pores of the porous metal layer. The porous metal layer is joined to a surface of the back plate. The porous metal layer is formed by sintering metal powder without applying pressure thereto, and an apparent density of the metal powder is 20% to 40% of its theoretical density. The porous metal and the composite synthetic resin are dispersed on a sliding surface of the slide layer in a substantially mixed condition.

Abstract: The invention relates to a plate which is intended to produce either an anode or a cathode of an electrolytic condenser. The plate is in the form of an electricity conducting substrate coated with an aluminium based deposit constituted of grain agglomerates where more than 50% by weight of the total deposited aluminium is in oxide state and forms a porous matrix of aluminium oxide containing metallic aluminium crystallites. The invention enables plates to be obtained which have an increased output, and the invention thus enables the condensers which will be associated with them to be of reduced size.

Abstract: A metallic coating on a part made from a ceramic composite is obtained from a powder obtained by mixing two powders: namely,a base powder A comprising 2 to 5% of a reactive element Ti or Zr, at least one melting element B or Si in proportions ensuring a liquidus temperature between 1000.degree. C. and 1300.degree. C. and additional metallic elements including at least 50% Ni or Ni+Co;a powder B in a weight ratio of 5 to 30%, the elements of which are chosen to impart to the part particularly desired surface properties such as anti-wear, anti-oxidation and/or anti-corrosion, and to ensure a liquidus temperature of powder B greater than that of powder A.

Abstract: An impregnated cathode comprising three layers: a very thin emitting surface layer of metal such as an alloy of tungsten with a high fraction of an activating metal of the platinum group to provide low workfunction; an underlying, thin buffer layer of porous tungsten alloyed with a fraction of activating metal, to retard diffusion loss of activating metal from the emitting layer; and a substrate of porous tungsten impregnated with barium aluminate.

Abstract: Disclosed are a hard sintered alloy having fine pores which comprises a sintered alloy comprising 2 to 30% by volume of a dispersed phase of at least one of oxide, carbide and sulfide of Ca, Sr or Ba and mutual solid solutions of these, and the balance of a binder phase comprising at least one metal of Co, Ni and Fe or an alloy containing said metal as a main component and a hard phase of at least one of carbide, nitride and boride of the 4a (Ti, Zr, Hf), 5a (V, Nb, Ta) or 6a (Cr, Mo, W) group metal of the periodic table and mutual solid solutions of these, with a volume ratio of said binder phase to said hard phase being 2:98 to 95:5, wherein fine pores are formed by removing said dispersed phase from a surface portion of said sintered alloy, and a process for preparing the same.

Abstract: An article coated with a thermal barrier coating system for high temperature use, has its thermal cyclic spallation life improved by the application of an aluminide to the outer portion of a bonding coating disposed on a substrate. The bond coating has a surface roughness in the range of about 200-600 microinches Ra prior to application of covering thermal barrier coating.

Abstract: A pressure sensitive adhesive sheet or label comprising an adhesive coated substrate of paper or synthetic resin film, the adhesive coating containing an acrylic copolymer prepared by copolymerization of 0.1 to 20 weight % of (A) at least one unsaturated monomer of the formula: ##STR1## wherein R is hydrogen or methyl group, R.sup.1 and R.sup.2 are hydrogen or a C.sub.1 -C.sub.4 alkyl, n is 1 to 4; 0.01 to 10 weight % or (B) at least one unsaturated monomer of the formula: ##STR2## wherein Y is an organic group having a radical polymerizable unsaturated bond and R.sup.3, R.sup.4 and R.sup.5 are an aryl, or an unsubstituted or substituted alkyl; 0 to 10 weight % of (C) at least one unsaturated monomer of the formula: ##STR3## wherein R.sup.6 R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are hydrogen or --CH.sub.2 OH; 60 to 99.89 weight % of (D) at least one unsaturated monomer of the formula: ##STR4## wherein R.sup.11 is hydrogen or methyl group and R.sup.12 is a C.sub.1 -C.sub.14 alkyl.

Abstract: An improved welding auxiliary material for producing welded joints between refractory metal parts of high-wattage electric light sources is described. The characteristic feature of the invention is that the welding auxiliary material has a porous structure surface layer sintered from a refractory metal powder having a melting point of above 2000.degree. C.

Abstract: A composite sliding member includes a metal wire mesh or expanded metal impregnated and covered with a composition of 0.1-50% by volume of one or more of PFA, FEP and EPE, and 0.1-50% by volume of at least one of oxybenzoyl polyester, polyphenylene sulfide, thermosetting resin, metal lubricant, metal oxide, composite metal oxide, metal sulfide, metal fluoride, carbon-based self lubricant, fiber material, and ceramics, with the remainder being substantially PTFE.

Abstract: It is the object of the invention to reduce the propagation of noises, in particular shifting noises, in mechanical transmissions. The invention consists in the use of a sintered shaped part formed in an individualized configuration as a noise-damped component, and in particular a gearwheel for a transmission. In the novel configuration, an axially symmetrical sintered shaped part has individual, approximately annular zones of material, for example, an inner rim zone close to the axis and an outer rim zone remote from the axis, the inner and outer rim zones having a high strength and being largely free from voids and a central region being highly porous and comparatively ductile.

Abstract: Disclosed herein is a multilayered sliding member comprising a lubricating composition comprising polytetrafluoroethylene and, as filler, 1-25 wt % of fibrous magnesium oxysulfate, fan-shaped magnesium oxysulfate or a mixture thereof, and a porous sintered metal layer formed on a steel backing,the lubrication composition being impregnated in and coated on a porous sintered metal layer formed on the steel backing.

Abstract: A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

Abstract: A porous electrode for pacemakers is comprised of a plurality of platinum globules sintered together to form a porous mass of semi-hemispherical shape at the end of a platinum electrode stem. The globules, which are themselves made by sintering together spherically-shaped particles of approximately one micron diameter, provide the globules with an irregular outer surface of high total surface area. The globules have diameters within a critical range of 40-200 microns. The large total surface area of the globules improves the sensing function of an electrode configuration of given size and surface area, while the globule diameters of 40-200 microns have been found to beneficially accommodate tissue ingrowth within the electrode. In a preferred method of making the electrode, the platinum globules, which are formed by sintering together platinum particles of much smaller size, are mixed with organic solvent and organic binder to form a paste.

Abstract: Disclosed herein are a fluororesin composition for a sliding member comprising a fluororesin, at least one of fillers selected from the group consisting of glass fiber, glass powder, carbon fiber and carbon powder, and a phosphate, and a sliding member thereof.

Abstract: A heat-resistant metallic monolith, manufactured by forming metal powders into a honeycomb structure and by sintering the structure, has a heat-resistant metal oxide coated on the surface of the cell walls and that of the pores thereof. Such a heat-resistant metallic monolith is manufactured by mixing metal powders, an organic binder and water to prepare a mixture, by forming the mixture into a shape of a desired honeycomb configuration, by sintering the shape in a non-oxidizing atmosphere at a temperature between 1000.degree. and 1450.degree. C. and then by coating a heat-resistant metal oxide on a surface of the cell walls and that of the pores of the obtained sintered body.

Abstract: Optical interference structures incorporating porous films are disclosed. These structures are capable of exhibiting a color by interference effects caused by the interference of light reflected from various layers within the structure. Basically, the structures comprise a reflective substrate, a porous transparent dielectric film on the substrate and at least one semi-transparent layer supported by the porous dielectric film. The structure is such that there are at least two reflective surfaces separated by an optically thin porous layer of the dielectric film. These structures can be formed by several methods, but the most convenient involves the porous anodization of a substrate metal (e.g. aluminum) to form the dielectric film and the deposition of a semi-transparent metal layer within the pores or on the film surface. The structures can be made inexpensively and are capable of generating strong and, if desired, dichroic colors. The porous nature of the film can also be exploited to create color shifts.

Abstract: An essentially flat "arc-grained" surface of a sheet of aluminum alloy is produced with a coarse and non-uniform microstructure which, after it is coated with a durable phosphate-free coating, provides excellent lithoplate. Though such arc-grained microstructure is much coarser than an electrochemically etched surface typically used on lithoplate, the very coarse surface is peculiarly well-adapted to provide durable lithoplate after it is coated with a phosphate-free protective surface. After the coated surface is coated with a photoresist the excellent resolution of prints is maintained over a large number of repeated uses in an off-set printing press.

Abstract: Disclosed are a sliding material comprising a backing metal having a porous metal layer formed on the surface thereof in which pores are defined and a composition for impregnation coating impregnated and coated to the pores and the surface thereof, wherein the composition for impregnation coating is a composition composed of (a) 5-30 vol % of metal lead having a relative surface area of 1,000-8,500 cm.sup.2 /g in an average particle size, and the remaining portion substantially composed of PTFE, a sliding material comprising a backing metal having porous metal layer formed on the surface thereof in which pores are defined and a composition for impregnation coating impregnated and coated to the pores and the surface thereof, wherein the composition for impregnation coating is a composition composed of (b) 5-30 vol % of metal lead having a relative surface area of 1,000-8,500 cm.sup.2 /g in an average particle size, 0.

Abstract: The present invention relates to a method of producing a mold material used for obtaining a mold for casting metals such as Zn, Al and the like or molding resins. In the method, the short fibers having an aspect ratio of 30 to 300 and obtained by cutting ferritic stainless steel long fibers having a width of 100 .mu.m or less, ferritic stainless steel powder and at least one of Cu powder and Cu alloy powder are used as raw materials. The raw materials are blended to obtain a material mixture which is then compressed under pressure in a Cold Isostatic Press process. The thus obtained compressed product is sintered in a vacuum atmosphere. The sintered material is held in an atmosphere of nitrogen gas or decomposed ammonia gas so that 0.3 to 1.2 wt % of nitrogen is added to the stainless steel in the sintered material. The thus obtained mold material has a hardness of HMV 250 to 500.

Abstract: The present invention is directed to a method of preparing a composite material excellent in joint strength and heat conductivity, and more specifically to a method of preparing a composite material composed of a high-melting material W and low-melting material Cu. The method comprising a first step of forming pores in the high-melting material W, to obtain a substrate material having a porosity distribution, with a high porosity at at least one region of the surface of the substrate material and the porosity gradually decreasing outward from the region; and a second step of impregnating the low melting material Cu to the substrate material obtained in the first step from the region of the highest porosity gradually downward. The substrate material being formed to have a gradient distribution of a composite ratio of the high-melting material and the low-melting material.

Abstract: A substrate for a magnetic disk, having fine roughness formed on its surface by subjecting aluminum or an aluminum alloy to anodic oxidation, packing pores in the anodized layer thereby formed, with a material different in the physicochemical properties from the anodized layer, and letting a plating material grow selectively by an epitaxial method.

Abstract: A fully alloyed porous metallic coating is applied to the surface of a metallic prosthetic component by producing a slurry comprising a suspension of the alloy in particulate form in a solution of water containing a film-forming binder material, applying to one or more surfaces of the component a coating of the slurry, forming concave and re-entrant depressions by pressing heat degradable spheres into the coating to promote fixation of the component when in use, heating the slurry to dry the same, and sintering the coated component to bond the particulate alloy onto the component, the spheres burning off during the subsequent heating or sintering step.

Abstract: A sintered metallic light-weight structural material consists of spherical voids and lattice-type webs of intermetallic compounds. Owing to its weight-specific strength, which is superior to that of conventional super-alloys, this material is suited especially for application in aircraft and turbine engine construction.

Abstract: A structure comprising a mixture of metals and metal alloys which are sintered into a hard porous body is presented. The structure can be useful for many different chemical and physical purposes, such as for catalysis, desorption and absorption, and selective leaching of the structure components into solutions.

Abstract: A coating for a heat engine part, particularly a turbo-machine part made of superalloy, comprises an electrophoretically deposited metallic structure of cellular form with uniformly disposed cells of predetermined size, the structure preferably being composed of M, Cr, Al, and Y, where M denotes Ni, Co, Fe and mixtures thereof. The cellular metallic structure is consolidated by a sintering treatment, which may be reactive, or metallization, preferably in the vapor phase, and the coating is completed by a ceramic material applied by plasma spraying.

Abstract: A sintered diamond compact or high pressure form boron nitride compact with an improved brazability, suitable for use for wear resisting tools, cutting tools, drill bits, dressers and wire-drawing dies is provided. This compact comprises a compact part containing at least 20% by volume of diamond and/or high pressure form boron nitride and a cemented carbide substrate bonded directly or through an interlayer to the compact part, characterized in that the surface of the compact is coated, at least partly, with a thin film consisting essentially of at least one member selected from the group consisting of carbides, carbonitrides and nitrides and mixtures or solid solutions thereof of at least one element selected from the group consisting of silicon and Group IVa, Va and VIa of Periodic Table, and having a thickness of 1 to 20 .mu.m.

Abstract: A titanium or titanium alloy composite having a porous surface layer, which comprises a titanium or titanium alloy substrate and a porous titanium or titanium alloy layer that adheres strongly to said substrate, said porous layer being formed by first providing said substrate with a firmly adhering sinter of a mixture of a titanium or titanium alloy powder and a magnesium powder, and then removing magnesium from the sinter. A process for producing a titanium or titanium alloy composite having a porous surface layer, comprising: providing a coating composition comprising a binder added to a mixture of a titanium or titanium alloy powder and a magnesium powder; applying said composition to the surface of a titanium or titanium alloy substrate; heating the substrate at a temperature of from 650.degree. to 800.degree. C. in vacuo or an inert atmosphere so as to form a sinter of the powders of titanium or titanium alloy and magnesium which firmly adheres to said substrate; and removing magnesium from said sinter.

Abstract: A high temperature multi-layer thermal insulation is constructed especially for insulating spacecraft. For this purpose the insulation is formed of a plurality of porous material layers, such as ceramic fiber layers, separated from each other by highly reflective gas permeable foils. The insulation has an outer hot side and an inner cold side. The ceramic fibers are so arranged that the layer density increases from the outer side toward the inner side while the fiber diameter decreases from the outer side to the inner side. Compared to conventional heat shield type insulations of spacecraft, the present insulation is relatively lightweight and is able to better discharge again at lower flight altitudes any heat stored in the insulation at higher transient re-entry altitudes.

Abstract: The improved friction facing has a porous, resilient fused metallic matrix with a second metal having a lower boiling point being infused into and alloyed with the matrix.

Abstract: A dental material of a metal composition for reinforcing the metal framework of a dental restoration comprising an aggregate combination of metal particles including a first high fusing temperature precious metal component and a second low fusing temperature component which form a porous sponge-like structure upon heat treatment.

Abstract: The method and material of the present inventioin includes a combination of a high-fusing temperature metal component and a low-fusing temperature metal component which are adapted to be heat treated at a temperature above the melting temperature of the low-fusing temperature metal component, such that a porous, sponge-like structure is formed with a total void volume of 20-80%.

Abstract: A strip getter structure comprising getter powder pressed into and onto an open reticulated network carrier strip. The getter powder particles form an agglomeration with strength derived both from interlocking of said getter particles and from support of the getter agglomeration by the network. The getter strip structure is manufactured by continuous rolling of getter powder into and onto the network carrier strip by means of a gravity powder feed and a cylindrical rolling mill.

Abstract: The cathode-forming method involves incorporating cobalt into a nickel plaque so that the exposed surfaces and the pores of the nickel plaque are uniformly covered with cobalt. The plaque is then treated to form nickel hydroxide in the pores and on the surfaces thereof. The cobalt is thus diposed at the interfacial boundary of the nickel plaque and nickel hydroxide so as to reduce the impedance and enhance charge conduction of the cathode. The mode of incorporation can vary. Thus, the sintered nickel plaque can be soaked in an aqueous solution of a water-soluble salt of cobalt, such as cobalt nitrate, then dried and resintered. Another mode involves dispersing a water-soluble cobalt salt in an aqueous slurry of nickel particles and water-soluble binder for the particles. The nickel particles are thus uniformly covered with the dissolved cobalt salt and then are compacted into a plaque. The plaque is dried and finally sintered.

Abstract: A frameless and coreless porous endosseous implant comprising a porous sintered metal layer (2) having a range of relatively large pores and porous sintered metal layers having a range of relatively small pores and laminated into one body by sintering integrally with the layer on either side thereof, or a porous singered metal layer having a range of relatively small pores and porous sintered metal layers having a range of relatively large pores and laminated into one body by sintering integrally with the layer on either side thereof, whereby the three layers each permit the ingrowth and penetration out of two or more kinds out of fibrous tissue, osteoid tissue and bone tissue in the pores thereof.

Abstract: The invention is related to a bearing material having multiple layers therein and a method for manufacturing the same. The invention features that a bearing layer consisting mainly of an integrated resin powder is formed on a porous layer covering a back metal, such as a steel plate of like, that the integrated resin powder consists of P T F E resin precipitate and F E P resin precipitate and/or P F A resin precipitate and that each particle of the integrated resin powder is covered with Pb-Sn alloy powders.Accordingly, the integrated resin powder independently provides a predetermined lubricating property. In addition, since these resin precipitates are in unity, it is possible to maintain excellent cavitation resistance property and load resistance property, even under severe boundary conditions.Furthermore, since each of the integrated resin powder is covered with the Pb-Sn alloy powder, an uniform and deep penetration of the alloy powder into pores of the porous layer can be easily obtained.

Abstract: Porous coating for substrates especially metal substrates. The pores are created by the removal of a fugitive material. The coatings have useful numerous applications also for heat exchange, optical coating and non-slip. Products formed from the coating and a method of forming such products are also disclosed.

Abstract: Metals are made pyrophoric by diffusing aluminum or zinc into them and then leaching it out, or by reacting with aluminum and then leaching aluminum out. Powdered aluminum and powdered nickel, iron or cobalt, can thus be carried on an elongated support web and reacted by heating for a few seconds to a few minutes, after which leaching will provide elongated pyrophoric foil suitable for decoying heat-seeking missile.

Abstract: A method of producing self-supporting ceramic or ceramic composite bodies having a polymer component, which includes first providing a self-supporting ceramic or ceramic composite body comprising (i) a polycrystalline oxidation reaction product formed upon oxidation of a molten parent metal with an oxidant, and (ii) interconnected porosity at least partially accessible from one or more surfaces of said ceramic body. The polymer is disposed or formed within the interconnected porosity. The polymer is situated so as to alter, modify or contribute to the properties of the ceramic or ceramic composite body originally formed.

Abstract: A composite is produced by depositing a slurry of infiltration-promoting material and organic binding material on a layer of boron nitride coated fibrous material forming a tape therewith on drying, firing the tape to burn out organic binding material and infiltrating the resulting porous body with a solution of boron and silicon.

Abstract: A method for making seamless, porous metal articles comprising:(a) rotating a mold containing a stabilized suspension of a metal particulate at a rate and for a time such that the particulate is separated from the suspension and distributed on the interior wall of the mold, thereby forming a structure conforming to the interior wall of the mold, the rate of rotation being sufficiently high that, preferably, at least about 65 Gs up to 100 Gs of centrifugal acceleration is achieved at the interior wall of the structure,(b) drying the formed structure to provide a structure having green or unsintered strength, and(c) sintering the dried structure to remove volatile material and fuse the individual particles of the particulate to each other to form the seamless, porous metal article.Metal articles in accordance with the invention have substantially uniform diameters, thicknesses and pore structurs, have Bubble Point ratios of greater than 1.5 up to 2.5, and find particular use as filters.

Abstract: A method for making seamless, porous metal articles comprising:(a) rotating a mold containing a stabilized suspension of a metal particulate at a rate and for a time such that the particulate is separated from the suspension and distributed on the interior wall of the mold, thereby forming a structure conforming to the interior wall of the mold, the rate of rotation being sufficiently high that at least about 100 Gs of centrifugal acceleration is achieved at the interior wall of the structure,(b) drying the formed structure to provide a structure having green or unsintered strength, and(c) sintering the dried structure to remove volatile material and fuse the individual particles of the particulate to each other to form the seamless, porous metal article.Metal articles in accordance with the invention have substantially uniform diameters, thicknesses and pore structures, have Bubble Point ratios of 1.5 or less, and find particular use as filters.

Abstract: Pyrophoric preparations made of crushable open-celled metal skeleton such as honeycomb, metal foam or expanded twisted foil, filled with pyrophoric powder, so that when crushed to make a compact disc the metal skeleton is deformed and helps lock the powder particles in place.

Abstract: A sintered metal part which has a pressed and sintered core; the part is coated with a sintered metal surface layer; the layer has a property different from that of the metal part; the interior regions of the core are free of the metal constituting the coating; and process for making the parts.

Abstract: A process is described in which hollow spheres or hollow-sphere composites (moldings) having high-strength walls are produced. Additional layers are applied to metallized spherical lightweight particles having a core of foamed polymer. In order to increase the strength of the wall of the spherical particle and the strength of the molding, metallized lightweight spherical particles having a metal wall thickness of 5 to 20 microns are treated (coated) with a dispersion of particulate metal or metal oxide or particulate ceramic or refractory material, the lightweight spherical particles coated in a thickness from 15 to 500 microns are dried, the dried particles are heated to a temperature of about 400.degree. C. to effect a pyrolysis of the polymer core, and the particles are subsequently sintered at a temperature from 900.degree. to 1400.degree. C.

Abstract: The present invention relates to a composite bearing material comprising three layers: (1) a metal backing, (2) a porous metal interlayer bonded to the metal backing which includes bronze or other copper alloy particles from two distinct particle size ranges and (3) a PTFE based composition intermixed with and overlying the porous metal interlayer. In accordance with the method of the present invention, the porous metal interlayer substantially comprises a relatively non-homogeneous mixture of particles from the two distinct particle size ranges, wherein a substantial portion of the relatively fine powder is segregated adjacent the metal backing. The present invention includes a significant thickness of the PTFE based composition applied to and remaining above the surface of the porous metal backing.

Abstract: A process for preparing a porous metal plate is disclosed which is adapted to use short metal fiber to prepare the plate. The process is capable of providing a porous metal plate which has increased bending strength and porosity, of which the porosity and thickness are controlled as desired and which has a wide and lengthy shape. The so-formed porous metal plate is capable of being extensively utilized, for example, not only as a filter and a sound absorption material but for a fuel cell, a catalyst and the like. It is formed by applying adhesive onto a surface of a substrate, and embedding short metal fibers in the adhesive. The composite thus formed is then pressed, to push over the short metal fibers, and the composite is then sintered. The substrate is a material which is capable of being burned out, or is a metal net, or is a release paper, so that the final plate will be porous throughout.

Abstract: A porous, sintered powdered metal article having excellent corrosion resistance is provided. A porous metal such as prepared from a sintered iron powder and suitable for further treatment is phosphatized with a solvent phosphatizing composition. The phosphatized metal is then coated with a chromium-containing coating composition. The thus treated powdered metal part may be further topcoated and, in either case, exhibits outstanding corrosion resistance.

Abstract: A material which is intended for use in sliding surface bearings comprises a metallic backing, a porous metallic substrate layer applied to said backing, and a PTFE-filler mixture, which completely fills the pores of the substrate layer and constitutes an antifriction layer. The bond strength between the antifriction layer and the substrate layer is improved by coating that surface of the substrate layer which faces the antifriction layer with a primer.

Abstract: Preselected surface areas of a prosthesis are covered by a blend of matching primary metallic particles and expendable particles. The particles are compressed and heated to assure that deformation and metallurgical bonding occurs between them and between the primary particles and the surface boundaries of the prosthesis. Porosity is achieved by removal of the expendable material. The result is a coating including discrete bonded particles separated by a network of interconnected voids presenting a homogeneous porous coating about the substrate. It has strength suitable for bone implant usage without intermediate adhesives, and adequate porosity to promote subsequent bone ingrowth.