Abstract: A target for magneto-optical recording media having a microstructure having a matrix phase of a eutectic structure of a rare earth metal and an iron-group metal, particles I made of a pure iron-group metal or an alloy thereof and having an average diameter of 200 .mu.m or less and particles II made of a corrosion resistance-improving metal and an iron-group metal and having an average diameter of 200 .mu.m or less is produced by mixing rapidly-quenched powder A made of the rare earth metal and the iron-group metal and having a eutectic structure with powder B made of a pure iron-group metal or an alloy thereof and having an average diameter of 200 .mu.m or less, and powder C made of the corrosion resistance-improving metal and the iron-group metal and having an average diameter of 200 .mu.m or less, and pressure-sintering the resulting mixed powder at a temperature lower than a liquid phase-appearing temperature.

Abstract: A powder-metallaurgically produced material or extruded semi-finished product for electric contacts of silver or a silver-based metal material with 0.5 to 10 wt. % carbon and 0 to 2 wt. % of an additional metal. The material contains powdered carbon in combination with carbon fibers in the mass ratio of 10:1 to 1:10, whereby the diameter of the powder particles is on average smaller than half the length of the fibers.

Abstract: A solder preform (250) has solder particles of one alloy (210) arranged within a matrix of a second solder alloy (200). This arrangement forms a structure having the desired predetermined shape of the solder preform. The solder particles comprise one or more of the following elements: tin, lead, bismuth, indium, copper, antimony, cadmium, arsenic, aluminum, gallium, gold, silver. The particles have a predetermined melting temperature. The second solder alloy is compositionally distinct from the solder particles, and has a melting temperature that is lower than the melting temperature of the solder particles. The solder particles may comprise about 88% by weight of the solder preform, and the second solder alloy comprises about 12% by weight of the preform.

Abstract: Fiber-reinforced titanium alloy and intermetallic matrix composites having improved stability and tensile strength properties at elevated temperatures. The base reinforced fibers are pre-coated with a tailorable tri-layer coating, such as Ti--TiN--Ti. Preferably the TiN layer is graded so as to have metal-rich outer surfaces, such as titanium-rich TiN, providing excellent bonding affinity for the base titanium layer, bonded to the surface of the fibers, such as silicon carbide, and for the outer titanium layer, bonded to the titanium aluminum matrix, and a compound core, such as stoichiometric TiN, providing a stable interfacial barrier against chemical reactions, whereby the tensile strength and resistance to cracking of the composite is preserved even at elevated temperatures of 900.degree. C. or higher.

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: A solder-clad printed circuit board (100) has solder particles of one alloy (120) arranged within a matrix of a second solder alloy (115). This arrangement forms a flat structure that is alloyed to the solder pads (105) on the substrate. The solder particles (120) have a predetermined melting temperature and are made from one or more of the following elements: tin, lead, bismuth, indium, copper, antimony, cadmium, arsenic, aluminum, gallium, gold, silver. The second solder alloy (115) is compositionally distinct from the solder particles, and has a melting temperature that is lower than the melting temperature of the solder particles. The solder particles may comprise about 88% by weight, and the second solder alloy may comprise about 12% by weight of the solder cladding.

Abstract: A turbine blade including a blade and blade foot. The blade foot is formed by a ductile material and the blade comprises a material which is brittle compared to the ductile material but resistant to high temperature. The two materials are alloys of the same base compositions but differ as to presence and/or quantity of at least one doping element. The alloys can be hot-compacted with the formation of a transition zone joining the blade and blade root wherein fine crystallites of the blade root interpenetrate coarse crystallites of the blade. The two materials can comprise a gamma-titanium aluminide containing 0.5 to 8 atomic percent of a dopant. The turbine blade exhibits outstanding mechanical properties at high temperatures, good ductility at room temperature and a long service life.

Abstract: A turbine blade including a blade foot and a blade. The blade foot is formed by a ductile material and the blade comprises a material which is brittle compared to the ductile material but resistant to high temperature. The two materials are alloys of different chemical compositions and are hot-compacted with the formation of a boundary layer joining the blade foot and blade to produce a bimetallic composite material. The blade foot predominantly comprises a titanium-base alloy and the blade comprises a gamma-titanium aluminide containing 0.5 to 8 atomic percent of a dopant. The turbine blade exhibits outstanding mechanical properties at high temperatures, good ductility at room temperature and a long service life.

Abstract: A semifinished product for electric contact made from a composite material based on silver-tin oxide is described as well as a powder-metallurgical process of making said product. The structure of the semifinished products contains regions which contain no metal oxide or very little metal oxide in alternation with regions which contain the entire metal oxide component or a greatly predominating/share thereof in a fine division.

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 metal matrix composite is produced by forming a rapidly solidified aluminum base alloy into powder. The powder is plasma sprayed onto at least one substrate having thereon a fiber reinforcing material to form a plurality of preforms. Each of the preforms has a layer of the alloy deposited thereon, and the fiber reinforcing material is present in an amount ranging from about 0.1 to 75 percent by volume thereof. The preforms are bonded together to form an engineering shape.

Abstract: A high strength structural member formed in a forming process using a starting powder of a light alloy. The starting powder is a mixture of a crystalline phase main powder component and at least 5% by volume of an additional powder component which includes between 5% and 100% by volume of an amorphous phase of the light alloy powder and the balance of a crystalline phase.

Abstract: Composite structures having a higher density, stronger reinforcing niobium based alloy embedded within a lower density, lower strength niobium based alloy are provided. The matrix is preferably an alloy having a niobium and titanium base according to the expression:Nb--Ti.sub.27-40.5 --Al.sub.4.5-10.5 --Hf.sub.1.5-5.5 Cr.sub.4.5-8.5 V.sub.0-6,where each metal of the metal/metal composite has a body centered cubic crystal structure, andwherein the ratio of concentrations of Ti to Nb (Ti/Nb) is greater than or equal (.gtoreq.) to 0.5, andwherein the maximum concentration of the Hf+V+Al+Cr additives is less than or equal (.ltoreq.) to the expression:16.5+(5.times.Ti/Nb),and the reinforcement may be in the form of strands of the higher strength, higher temperature niobium based alloy. The same crystal form is present in both the matrix and the reinforcement and is specifically body centered cubic crystal form.

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 titanium-tungsten target material used to form, by sputtering, a barrier metal or the like for use in semiconductor devices. The titanium-tungsten target material is substantially composed of tungsten particles and a titanium-tungsten alloy phase surrounding the tungsten particles. The area ratio at which tungsten grains occupy in a cross section of the titanium-tungsten target material is, preferably, not more than 15%, more preferably, not more than 10%. If the average crystal grain size of the target material is not more greater 15 .mu.m, a uniform thin film can be obtained by sputtering. The target material can be obtained by sintering a titanium powder and a tungsten powder.

Abstract: Composite structures having a higher density, stronger reinforcing niobium based alloy embedded within a lower density, lower strength niobium based alloy are provided. The matrix is preferably an alloy having a niobium and titanium base according to the expression:Nb--Ti.sub.32-45 --Al.sub.3-18 --Hf.sub.8-15and the reinforcement may be in the form of strands of the higher strength, higher temperature niobium based alloy. The same crystal form is present in both the matrix and the reinforcement and is specifically body centered cubic crystal form.

Abstract: Composite structures having a higher density, stronger reinforcing niobium based alloy embedded within a lower density, lower strength niobium based alloy are provided. The matrix is preferably an alloy having a niobium and titanium base according to the expression:Nb-Ti.sub.35-45- Hf.sub.10-15,and the reinforcement may be in the form of strands of the higher strength, higher temperature niobium based alloy. The same crystal form is present in both the matrix and the reinforcement and is specifically body centered cubic crystal form.

Abstract: A porous intermediate compact is first prepared from metal particles, carbon and a temporary binder. The compact is then heated to remove the binder and then infiltrated with the vapor of a metal having a melting point lower than the compact.

Abstract: Normally reject sponge metal fines, especially those produced by the crushing and screening of a regulus of zirconium and/or hafnium metal sponge, are added to the initial reduction charge of the metal tetrachloride and magnesium metal, and the so-modified charge is then passed through the conventional reduction and vacuum distillation steps to produce a regulus of the metal that has the reject fines incorporated therein by sintering.

Abstract: A method of altering the crystal form of an alloy is disclosed. To accomplish this change in crystal form, the concentrations of the more volatile constituents of the alloy are reduced and the concentration of the less volatile constituents is increased on a relative basis. The process may be carried out in forming a reinforced structure. For this purpose, an improved reinforced matrix and a method of forming it are taught. The reinforcement may be silicon carbide filaments or other reinforcing filaments. The matrix is a titanium 1421 alloy nominally containing 14 weight percent of aluminum and 21 weight percent of niobium. The matrix is formed by plasma-spray forming a powder of the alloy to impart to the alloy particles a superheat during the plasma-spraying as the particles traverse the plasma plume. As a result of the superheat, the alloy is changed in its composition to reduce the aluminum concentration and to increase the niobium and titanium concentrations on a relative basis.

Abstract: Composite materials having improved fracture toughness are formed by dispersing ductile inclusions in a less ductile matrix. The matrices may be formed from metals, such as high-strength aluminum alloys or ceramics. Bonding should be present between the inclusions and the matrix so that cracks in the composite material must pass through the inclusions.

Abstract: A method of forming a composite of fibers having high strength at high temperatures in a high temperature metal matrix is taught. The high strength fibers may be silicon carbide fibers. The fibers are aligned and disposed on a substrate surface. A metal to serve as a matrix is provided in powder form with relatively larger particles of the order of more than 100 .mu.m. The powder is plasma spray deposited on the fiber coated substrate surface to cause the metal to at least partially envelop the fibers. The composite is then separated from the substrate.

Abstract: A printed circuit board is provided wherein a composite metal layer is affixed to at least one surface of a flexible dielectric substrate, the composite metal layer comprising an inner aluminum layer and an outer copper layer. Owing to the relatively high elongation of the aluminum layer, when the printed circuit board is flexed the circuit thereon does not crack.

Abstract: A composite material is made from silicon carbide and/or silicon nitride short fibers embedded in a matrix of metal. The metal is an alloy consisting essentially of between approximately 2% to approximately 6% of copper, between approximately 0.5% to approximately 3% of silicon, and remainder substantially aluminum. The short fibers may be all silicon carbide short fibers, or may be all silicon nitride short fibers, or may be a mixture of silicon carbide and silicon nitride short fibers. The fiber volume proportion of the silicon carbide and/or silicon nitride short fibers may desirably be between approximately 5% and approximately 50%, and may more desirably be between approximately 5% and approximately 40%.

Abstract: Disclosed is a gas turbine disk made from powder metal, wherein the bore has improved fatigue life compared to conventional articles because the bore is formed from a fine fraction of powder separated from a lot of conventional powder metal suitable for hot isostatic compaction. The outer and rim portions of the disk, which are less prone to fatigue failure, are made from the remainder of the lot but nonetheless have no more limited performance from that resulting when a unitary unseparated powder lot is used. Improved bore fatigue properties result because the coarse fatigue failure-causing nonmetallic inclusions are biased into the outer portions of the disk where they do not have adverse effect.

Abstract: A precision molded article, such as a die cavity, is made by combining granules of a first metal or alloy and a second metal or alloy, the second metal or alloy having a homogeneous appearance at some temperature below its melting point, and a higher Rockwell Hardness than the first metal or alloy, mixing the granules with a heat fugitive organic binder, molding the granule-binder mixture into a green molded preform, thermally degrading and removing essentially all the binder to form a skeletal preform, and infiltrating the preform with a third metal or alloy which will wet the second metal or alloy and has a lower Rockwell Hardness than the second metal or alloy, thereby forming a molded article having granules of first metal or alloy the majority of which are fully enveloped within a single skeleton of the second metal or alloy, the skeleton of second metal or alloy being surrounded by layers or matrices of softer metals.

Abstract: A ferro-sintered alloy having wear resistance at elevated temperatures comprising a matrix in which, on a weight basis, 25-75% of an alloying base A of the following composition is irregularly dispersed with 75-25% of an alloying base B of the following composition, the matrix having dispersed therein 3-15% of at least one of the following hard phases C and D, and optionally being impregnated in its pores with lead:______________________________________ Base A Base B ______________________________________ Cr 2-4% Co 5.5-7.5% Mo 0.2-0.4% Ni 0.5-3% V 0.2-0.4% Mo 0.5-3% C 0.6-1.2% C 0.6%-1.2% Fe the remainder Fe the remainder Hard phase C: 45-60% Co - 33-36% Mo. - and remainder Si Hard phase D: 45-60% Fe - 33-36% Mo - and remainder Si.

Abstract: A vacuum circuit breaker comprising a vacuum vessel and a pair of electrodes disposed in the vessel, which is superior in chopping current characteristic, at least a contact of at least one of the electrodes being made of a member having a skeleton of an iron group element, pores in which skeleton are impregnated with at least one kind selected from a group consisting of silver; an alloy of Ag and at least one of Te, Se, Bi, Pb, Tl, In, Cd, Sn and Sb; and the intermetallic compound of Ag, the breaker having rated voltage of 3.6 to 36 KV and rated breaking currents of 8 to 60 KA.

Abstract: A sintered alloy for a valve seat comprising, in weight percent, 0.5 to 1.7% C, 0.5 to 2.5% Ni, 3.0 to 8.0% Cr, 0.1 to 0.9% Mo, 1.0 to 3.8% W and 4.5 to 8.5% Co, the balance being substantially Fe provided by a base atomized powder; said alloy containing 8 to 14% by volume of 250 mesh or less C-Cr-W-Co-Fe and Fe-Mo hard grains and 6 to 13% by volume of cells, with the continuous cells being infiltrated by a copper alloy.

Abstract: Improved recovery of platinum lost from the catalyst gauze in a nitric acid plant is obtained by using palladium containing recovery gauzes configured to enhance the mass transfer characteristics of the system.

Abstract: A precision molded article, such as a die cavity, is made by combining iron powder granules and optional manganese granules with a heat fugutive organic binder, molding the granule-binder mixture into a green molded preform, thermally degrading and removing essentially all the binder to form a skeletal preform, and infiltrating the preform with an infiltrant which has a lower melting point than the iron powder granules and which optionally contains manganese, with the proviso that either the above decribed manganese granules are employed or manganese-containing infiltrant is employed, thereby forming a molded article having a skeleton of ferroalloy granules having a martensitic or perlitic core and an outer layer of austenitic manganese steel, the skeleton being surrounded by infiltrant.

Abstract: A process for producing a Cu-infiltrated sintered Fe-base material without requiring a separate Cu infiltration step is disclosed. The process comprises the steps of preparing two powder mixes, one having a predetermined composition with a powder of infiltrating material containing Cu powder or Cu alloy powder as the primary component, and the other having a predetermined composition without said powder of infiltrating material; pressing the two powder mixes into a compact having said powder of infiltrating material present locally; and sintering the compact under ordinary conditions so as to cause the infiltrant to penetrate into the infiltrant-free area simultaneously with the sintering.Also disclosed is a two-layer valve seat produced by this process.

Abstract: The shrinkage normally encountered when molding a mixture of spherical cobalt-containing particles and thermoplastic binder, heating the resulting molded article to degrade the binder and form a porous preform, and infiltrating the same is counteracted by adding finely divided elemental iron or elemental nickel to the spherical cobalt-containing particles. In addition to improving dimensional control, the elemental powder addition increases impact strength while maintaining hardness.

Abstract: Article produced in a mould for a plastics moulding tool having a mould surface defining the contours of the article, with the article comprising a body formed from a composition comprising a sinterable material having a sintering temperature which material, before sintering, is shapable into a desired shape and which during sintering forms a porous body having pores, the sinterable material being at least partially sintered in the mould, and also comprising a matrix having a lower melting point than the sintering temperature of the sinterable material, with the matrix comprising a matrix metal which is infiltrated in the porous body to substantially fill the pores.

Abstract: A process for the surface treatment of inorganic fibers for reinforcing titanium or nickel, comprising the steps of coating the surface of inorganic fibers with an aqueous or organic solvent solution containing a titanate, borate, tetralkylammonium hydroxide and, if desired, dextrin and then heat treating the coated fibers at a high temperature in an inert or non-oxidizing atmosphere. In one embodiment, the heat treated inorganic fibers is further subjected to ionic or chemical plating with nickel.

Abstract: A molded, non-refractory metal article is made by molding in a flexible mold a plastic mixture of non-refractory, spherical metal powders and a heat-fugitive binder comprising thermoplastic material to form a green article of predetermined shape and dimensions, heating the green article to remove said binder and consolidate the non-refractory spherical powders in the form of a porous, monolithic skeleton of necked particles of non-refractory metal, infiltrating the skeleton with a molten metal having a melting point that is at least 25.degree. C. less than the melting point of the lowest melting of said spherical, non-refractory metal particles, and cooling the infiltrated skeleton thereby forming a homogeneous, void-free, non-refractory metal article of two intermeshed metal matrices.

Abstract: This invention provides a vacuum type breaker contact material prepared by infiltrating copper into a sintered tungsten matrix, wherein elementary particle size and the growth of the particle size by heat processing are controlled in such a manner that the ratio of the largest value/the smallest value of tungsten particle size becomes not more than 10, and that the maximum value of tungsten particle size is not larger than 2 .mu.m and the minimum value of tungsten particle size is not smaller than 0.3 .mu.m.

Abstract: In the preferred embodiment, a method is presented for forming an iron-base article by powder metallurgy, which includes compacting a powder mixture comprising a major portion of iron particles and between about 2 to about 5 weight percent of a powder consisting of hypereutectic tricopper phosphide Cu.sub.3 P compound. The compact is sintered at a temperature between about 970.degree. C. to about 1100.degree. C., whereupon the copper phosphide forms a liquid that flows and wets the iron particle surfaces. During sintering, phosphorus from the copper phosphide diffuses into the iron particles and resulting copper-enriched liquid forms a film coating pore surfaces in the compact. The sintered article displays an improved combination of ductility and strength, particularly in view of the relatively low sintering temperature.

Abstract: A ferro-sintered alloy having wear-resistance at elevated temperatures, comprises a perlite matrix having a copper content of from 0.2 to 1.5% by weight. 10 to 50% by weight of a phase A rich in heat and corrosion resistance is dispersed in the matrix with phase A including 9 to 20% Cr, 6 to 15% Ni, 1.5 to 9.5% Mo, 1.5 to 9.5% W, 0.7 to 4.5 Cu and an Fe remainder. In addition, 2 to 15% by weight of an additional component is dispersed in the matrix which is selected from one of a group of components which are wear-resistant. The group of components comprises:50.about.70% Mo-Fe Alloy (by weight)50.about.70% Cr-Fe Alloy (by weight)45.about.60% Fe-33.about.36% Mo-Si Alloy (by weight)45.about.60% Co-33.about.36% Mo-Si Alloy (by weight).

Abstract: Improved recovery of platinum lost from the catalyst gauze in a nitric acid plant is obtained by using palladium containing recovery gauzes configured to enhance the mass transfer characteristics of the system.

Abstract: A vacuum type circuit interrupter contact comprises a principal phase material selected from the group consisting of copper and solid solutions of chromium copper, iron copper and cobalt copper, and a second phase material selected from the group consisting of chromium, iron and cobalt. The second phase material is dispersed into the principal phase material and has a particle diameter in the range of 74 .mu.m to 250 .mu.m. The contact can be formed by powder metallurgy, an infiltration process or a fusion process.

Abstract: An electrical contact element is made of material which is resistant to metal migration and which contains a major proportion by weight, at least two metallic components which are soluble in each other and form a composite material. At least one of the components consists of a noble metal, and the metallic components are heterogeneously embedded in the composite material as pure metallic components. A process for making such a contact element comprises forming jacket wires, made of the metallic components, into clusters and metallurgically joining the wires by plastic shaping to form the composite material.

Abstract: A precision molded article, such as a die cavity, is made by combining granules of a refractory and granules of a first metal or alloy which has a homogeneous crystalline appearance at a temperature below its melting point and has a lower Rockwell Hardness than the refractory, mixing the granules with a heat fugitive organic binder, molding the granule-binder mixture into a green molded preform, thermally degrading and removing essentially all the binder to form a skeletal preform, and infiltrating the preform with a second metal or alloy which will wet the first metal or alloy and has a lower Rockwell Hardness than the first metal or alloy, thereby forming a molded article having refractory granules fully enveloped within a single skeleton of the first metal or alloy, the refractory granules and skeleton of first metal being surrounded by layers or matrices of softer metals.

Abstract: A metal hydride storage device with a hydrogenatable storage metal powder and with an encapsulation of non-hydrogenatable material receiving the storage metal powder; the storage metal powder with a substantially uniformly distributed addition of about 2 to 10% by weight of powder-shaped non-hydrogenatable material forming a matrix powder, is contained in the encapsulation as form-rigid compressed or sintered body.

Abstract: A contact for a vacuum interrupter has excellent characteristics of high withstand voltage, low melt bonding property, large current durability and low chopping current and is prepared by uniformly distributing, in a copper matrix, two kinds of high melting point metal powders having a melting point of higher than 1450.degree. C. which have different particle diameters of (1) 80-300 .mu.m and (2) less than 30 .mu.m. The low chopping current characteristic is imparted by incorporating more than 10 wt. % of the high melting point metal powder. The high melting point metal powder can be selected from the group consisting of Cr, W, Mo, Ir and Co.

Abstract: A contact for a vacuum interrupter has excellent characteristics of high withstand voltage, large current durability and low chopping current and is prepared by infiltrating copper into a skeleton obtained by sintering a specific tungsten powder having an average diameter of less than 1 .mu.m.The skeleton is preferably prepared by a vacuum sintering process and the copper is infiltrating into the skeleton in hydrogen atmosphere or in vacuum.

Abstract: A porous sintered material of good permeability and effective sound absorbability, being formed by combining between particles of aluminum or aluminum alloy powder into a body by means of sintering and having connecting pores among the particles of said aluminum or aluminum alloy powder. Said porous sintered material is obtained by mixing aluminum or an aluminum alloy with a low melting point aluminum alloy, forming the mixture into the predetermined shape and sintering it at a temperature which is at least 10.degree. C. lower than the melting point of the base material and higher than that of the low melting point material.

Abstract: The subject of the invention is a grid of precious metals for the recovery of platinum metals escaping from a catalyst during the reaction of oxidation of ammonia in the production process of nitric oxide.In the reactions conducted in the presence of the catalysts containing platinum metals at the incandesence temperature a loss in the mass of precious metals occurs, which disadvantageously effects the economy of the process.For the recovery of platinum escaping from a catalyst during the reaction of oxidation of ammonia the grids mainly used are those made of palladium-gold alloy, which, in order to increase their strength, are spot-welded into packs, or the separating grids of heat-resisting materials are used.The known methods of increasing the strength and the durability of the recovery grids are disadvantageous, as the flow of reactants through a pack of grids meets additional resistance, which causes a decrease of the process effectiveness.

Abstract: Process for the production of small tubing, e.g., hollow fibers comprising(a) preparing a solution of an organic fiber-forming polymer, containing, in a uniformly dispersed form, a sinterable inorganic material;(b) extruding the inorganic material-containing polymer solution through a hollow fiber spinneret;(c) forming a polymeric precursor hollow fiber, laden with the inorganic material;(d) treating the polymeric precursor hollow fiber to remove the organic polymer; and(e) sintering the resulting inorganic material in hollow fiber form.