Abstract: A casting member comprising hot-die steel or high-speed steel as base material and having coating layers at least on its working plane, wherein the outermost layer among the coating layers consists essentially of at least one nitride, oxinitride or carnonitride composed mainly of V, and another coating layer comprising at least one nitride, oxinitride or carnonitride composed mainly of Cr is formed as a layer just above the base material. If necessary, an intermediate layer comprising at least one nitride, oxinitride or carnonitride composed mainly of V and Cr may be formed as a coating layer on the boundary surface between the outermost layer and the layer just above the base material. The thickness of the outermost layer is preferably 0.5 to 5.0 ?m, the thickness of the layer just above the base material is preferably 0.5 to 3.0 ?m, and the thickness of the intermediate layer is preferably 1.0 ?m or less.

Abstract: The present invention provides coating systems that minimize thermal and residual stresses to create a fatigue- and soldering-resistant coating for aluminum die casting dies. The coating systems include at least three layers. The outer layer is an alumina- or boro-carbide-based outer layer that has superior non-wettability characteristics with molten aluminum coupled with oxidation and wear resistance. A functionally-graded intermediate layer or “interlayer” enhances the erosive wear, toughness, and corrosion resistance of the die. A thin adhesion layer of reactive metal is used between the die substrate and the interlayer to increase adhesion of the coating system to the die surface.

Abstract: This invention relates to foundry binder systems, which cure in the presence of sulfur dioxide and an oxidizing agent, comprising (a) an epoxy resin; (b) an ester of a fatty acid; (c) an effective amount of a oxidizing agent, and (d) no ethylenically unsaturated monomer or polymer. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings, particularly ferrous castings.

Abstract: A simple, cost-effective stamping or molding in the nanometer range is enabled using a stamping surface or molding face with a surface layer having hollow chambers that have been formed by anodic oxidation.

Abstract: The present application relates to a method of producing a metal article having an internal passage coated with a ceramic coating. The method comprises: preparing a core for defining the internal passage; applying the ceramic coating on the core; assembling the core with the ceramic coating applied thereon into a mold; casting metal into the mold at a pour temperature lower than the melting temperature of the ceramic coating; and removing the core. The ceramic coating may be applied by plasma spraying or slurry deposition.

Abstract: A plasticizing barrel for a plastics processing machine includes a body having a hollow cylindrical configuration and defining an axis; and a coating formed on an inner wall surface of the body and including at least one groove extending in axial direction of the body. The coating, e.g., a wear-resisting protective layer, may be produced through centrifugal casting, whereby the grooves are formed by projections of a negative mold inserted in the hollow-cylindrical body.

Abstract: The aim of the invention is to produce a light-alloy bearing bush with a rough external surface. To achieve this, particles, which are subsequently surrounded in part by the molten metal, are applied to the surface of the casting mould. When the bearing bush is released from the mould, the particles remain in said bush and are subsequently removed from the bearing bush preform either mechanically or by being dissolved in liquid.

Abstract: There is provided a method for manufacturing a cylinder for an internal combustion engine by making use of an insert core, which makes it possible to manufacture the cylinder by a die casting method such as a high-pressure die casting method at low cost and in high accuracy.

Abstract: A mould (1) for the manufacture of a casting (2) using moulding material (3). In order to achieve simple and cheap manufacture, the mould (1) is provided with an outer first mould carrier (4), an outer second mould carrier (5), a mould body (6) arranged between said mould carriers (4, 5) and an inner layer (12) of moulding material (3) applied to said mould carrier (6) at least in areas, to form the mould cavity.

Abstract: A liquid-cooled mold for a continuous casting of metals, including mold plates made of copper or a copper alloy, which are connected respectively to an adapter plate or a cooling-water tank by clamping bolts. The mold is characterized in that the clamping bolts are fastened to plateau pedestals which project in an island-like manner from the cooling arrangement side of the mold plate, which jut at least partially into a cooling arrangement gap formed between the mold plate and the adapter plate or the cooling-water tank, respectively, and have a streamlined shape adjusted to the flow direction of the cooling arrangement.

Abstract: An injection mold for casting a semi-solidified Fe alloy includes a scalping gate for eliminating surface oxide film of a semi-solidified Fe alloy injected into the mold cavity from a pressure chamber. The scalping gate is arranged between the pressure chamber and a runner that is in communication with the mold cavity. The mold halves and the scalping gate are each formed of a copper alloy having a thermal conductivity of not less than 120 W/(m·K) and a hardness of not less than 180 HB. The mold halves and the scalping gate each have a cermet layer consisting essentially of at least one member selected from a group consisting of Co, Cu, Cr and Ni. The cermet layer is formed by electro-spark deposition, via an intermediate layer of Ni alloy, which is also formed by electro-spark deposition.

Abstract: Disclosed is a method for manufacturing a disintegrative core for use in high pressure casting. The disintegrative core can be applied where a light metal such as an aluminum alloy or magnesium alloy is subjected to high pressure casting, such as die casting or squeeze casting and is manufactured from a water-soluble salt which is high in latent heat and ranges, in melting point, from 280 to 520° C. and, in heat transfer coefficient (&kgr;), from 9.8×10−2 to 1.2×10 W/m·° C. The water-soluble salt, alone or in combination with a fine hard powder, is melted and solidified in a core mold. Alternatively, the melt is processed into a fine powder which is then molded in a core mold. The method can be applied for the manufacture of complex shapes of cores. Also, disclosed is a method for extracting such a core from a high pressure molded product.

Abstract: A method for producing a non-carbon inert anode for metal oxide electrolytic reduction by coating a metal, cermet, or ceramic substrate with a molten metal oxide compound of a ferrite and at least one divalent metal selected from iron, nickel, manganese, magnesium, and cobalt. The coated anode is protected from attack by the liberated oxygen and the solute in the electrolysis of metals, such as aluminum, magnesium, lithium, or calcium. Apparatus for carrying out the method, and the resulting product are also disclosed.

Abstract: Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with titanium carbide. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with titanium carbide via either chemical deposition or plasma assisted chemical vapor deposition, magnetron sputtering or sputtering. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

Abstract: The invention relates to a mould (1) for the manufacture of a casting (2) using moulding material (3). In order to achieve simple and cheap manufacture, the mould (1) is provided with an outer first mould carrier (4), an outer second mould carrier (5), a mould body (6) arranged between said mould carriers (4, 5) and an inner layer (12) of moulding material (3) applied to said mould carrier (6) at least in areas, to form the mould cavity.

Abstract: A copper casting mold for the continuous casting of steel melts is provided, in the presence of zinc and or sulfur in the thermally most greatly stressed contact region with the steel melt, with an at least single-layer diffusion barrier layer made of at least one metallic/metalloid material.

Abstract: A metal object is formed by die-casting with the use of a specially treated mold. The mold has cavity-defining surfaces covered by a heat-insulating layer made of a material that includes ceramic powder and heat-resistant resin. Molten metal is injected into the cavity coated with the heat-insulating layer.

Abstract: This invention relates to foundry binder systems, which will cure in the presence of sulfur dioxide and a free radical initiator, comprising (a) an aliphatic epoxy resin; (b) a multifunctional acrylate; and (c) an effective amount of a free radical initiator. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings, particularly aluminum castings.

Abstract: This invention relates to foundry binder systems, which will cure in the presence of sulfur dioxide and a free radical initiator, comprising (a) an aliphatic epoxy resin; (b) a multifunctional acrylate; and (c) an effective amount of a free radical initiator. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings, particularly aluminum castings.

Abstract: A manufacturing process for casting amorphous metallic parts separates the filling and quenching steps of the casting process in time. The mold is heated to an elevated casting temperature at which the metallic alloy has high fluidity. The alloy fills the mold at the casting temperature, thereby enabling the alloy to effectively fill the spaces of the mold. The mold and the alloy are then quenched together, the quenching occurring before the onset of crystallization in the alloy. With this process, compared to conventional techniques, amorphous metallic parts with higher aspect ratios can be prepared.

Abstract: This invention relates to foundry binder systems, which will cure in the presence of sulfur dioxide and a free radical initiator, comprising (a) an epoxy resin; (b) an acrylate; (c) an alkyl silicate; and (d) an effective amount of a free radical initiator. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings, particularly ferrous castings.

Abstract: The invention relates to a method for the uphill casting of cast pieces in sand dies with resinous, or, in particular, binder-containing cast cores and controlled solidification of metallic cast pieces, comprising at least one cavity. Said pieces are, in particular, prototypes of engine blocks, or cylinder heads, for example, for internal combustion engines, with a cavity for the throughflow of cooling water. In order to guarantee a low-turbulence flow of fluid metal melt on ventilating the cast mould, the cast mould (1), with at least one feed (24), is connected to a sprue cup (24) by means of a casting system (22) and the metal melt contained therein forced into the cast mould (1) through the casting system (22) by gravity. After filling the cavity (11′) a vacuum is created in the metal melt, greater than the pressure of core gases generated in the core.

Abstract: Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with pyrolytic graphite. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with pyrolytic graphite via a chemical deposition process. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

Abstract: A method of forming a turbine engine component, includes providing a mold having a textured region, pouring a molten alloy into the mold, and cooling the molten alloy to form a turbine engine component, wherein the turbine engine component has an enhanced surface area region corresponding to the textured region of the mold, the enhanced surface area region comprising randomly arranged bumps.

Abstract: A method of making or reconstituting tooling to be used in the processing of high temperature molten material comprises machining an undercut in the tooling surface which terminates at a shoulder and provides an inset barrier receiving surface; a chemical barrier providing interface coating system to which a ceramic-based material will fuse, is fused over the undercut receiving surface. Then a thermally-insulative ceramic-based coating is fused to the interface system to fill the undercut and merge with the tooling surface.

Abstract: The present invention provides a cast iron component for enveloped casting which is characterized by that the cast iron component has a surface to which enveloped casting is applied and which has a surface roughness such that a maximum height Ry is from 65 to 260 &mgr;m and a mean spacing of profile irregularities Sm is from 0.6 to 1.5 mm; an enveloped casting product using it; and a method for its production.

Abstract: A metallic mold-casting method excellent in the resistance to penetration is herein disclosed and the method comprises the steps of forming a coating layer by applying a mixture comprising at least one member selected from the group consisting of high melting metals, ceramic materials and graphite, and an aqueous surfactant solution or low boiling liquid oils and fats to at least part of the surface of a metallic mold on its cavity side, then applying heat to the coated portion to thus adhere the mixture to the inner surface of the mold, and thereafter repeatedly casting a magnesium alloy in the metallic mold provided with the coating layer. The metallic mold-casting method permits the metallic mold casting of magnesium alloys with good resistance to penetration and this accordingly leads to the production of a cheap and high quality cast magnesium alloy product.

Abstract: Method for producing pressure die-cast or injection moulded articles having a unit for producing salt grains, a press for forming salt filler cores by compressing the said salt grains, a pressure die-casting machine for making the said articles by injecting a material in the liquid state into a mould having at least one salt filler core, and a salt removal and washing unit designed to remove the salt filler cores that have been trapped within the said articles; the said unit for producing salt grains being designed to atomize a saline solution which is supersaturated with salt into a plurality of drops so as subsequently to cause the salt present in solution/suspension in each drop of solution to solidify into a corresponding salt grain.

Abstract: A metal mold for manufacturing amorphous alloy. A metal mold is composed of a lower mold having a portion for fusing metal material and a cavity portion, and an upper mold working with the lower mold which presses molten metal in the portion for fusing metal material and pours the molten metal into the cavity portion to mold. And, surface roughness of a part of or all of an inner surface of the metal mold is arranged to be more than 12S in JIS indication.

Abstract: Precision castings such as brake calipers and other cast metal parts requiring a fine finish and having complex internal geometries can be produced by casting a shot of a semi-solid thixotropic metal alloy in a die having one or more inserts that have a lower melting point than the solid-to-semi-solid transition temperature of the thixotropic alloy. A core of the same or similar material may also be placed in the die between the inserts. Then, after the shot solidifies to form a casting, the inserts and core (if present) are melted from the casting.

Abstract: Process for making metallic microcylinders from pretreated diacetylenic lipid tubules which includes placing the tubules into an electroless plating bath containing a metal plating reagent, depositing by electroless plating on the surfaces of the tubules enough of a metal to make the tubules electrically conducting, separating the tubules from the plating bath, treating the tubules to remove the lipid and form the metal microcylinders, washing and drying the microcylinders to produce the metal microcylinders having aspect radio of about 12, weight average length of about 20 &mgr;, weight average outside diameter of about 1.5 &mgr;, and weight average wall thickness of about a quarter of one micron.

Abstract: To provide a novel casting mold for use in continuous casting, which has long life and excellent heat resistance, yet capable of completely preventing corrosion, which frequently occurs on the lower portion of the casting mold. A continuous casting mold for steel made from copper or a copper alloy, wherein said casting mold comprises a plane in contact with molten steel partly or wholly covered with a tungsten alloy plating containing either or both of nickel and cobalt, and said plating containing tungsten carbide forming a solid solution therewith. To produce the casting mold above, there is used a plating solution containing either or both of a nickel salt and a cobalt salt and a tungstate, together with at least one selected from an oxycarboxylic acid and salts thereof, and at least one type of an organic compound and salts thereof having two or less of carbon atoms within the molecule, provided that its oxidation decomposition potential is lower than that of the oxycarboxylic acid or a salt thereof.

Abstract: A metallic mold-casting method excellent in the resistance to penetration is herein disclosed and the method comprises the steps of forming a coating layer by applying a mixture comprising at least one member selected from the group consisting of high melting metals, ceramic materials and graphite, and an aqueous surfactant solution or low boiling liquid oils and fats to at least part of the surface of a metallic mold on its cavity side, then applying heat to the coated portion to thus adhere the mixture to the inner surface of the mold, and thereafter repeatedly casting a magnesium alloy in the metallic mold provided with the coating layer. The metallic mold-casting method permits the metallic mold casting of magnesium alloys with good resistance to penetration and this accordingly leads to the production of a cheap and high quality cast magnesium alloy product.

Abstract: A method of applying a refractory coating to densified foundry sand cores having micropores between the sand grains having the steps of: (a) mixing a dry powder refractory material (anhydrous MmgOSiO2 talc) with a dry powder impacting media, the refractory material having a particle size in the range of 5-40 microns and the weight ratio between the refractory material and the impacting media; (b) fluidizing the mixture in a contained zone by introducing positive air pressure at one end of the zone and applying a negative pressure at the other end of the zone; and (c) quickly and entirely immersing the sand cores in the zone containing the fluidized mixture and substantially immediately thereafter withdrawing (without reciprocal movement) such sand cores without the need for added motion to be coated with essentially only the refractory material as impacted by the impacting media. The cores will be coated continuously with the refractory material, impacted with the micropores of the sand core.

Abstract: Coatings of doped chromium nitride protect forming members such as dies from the corrosive effects of molten aluminum and other reactive metals.

Abstract: A continuous casting mould wall (1, 2) has a non-metallic coating (5) thereon the thickness of which is different at first and third regions (6, 9) closer to the inlet and outlet ends respectively of the mould passage (3), from that at a second region (8), whereby the meniscus of molten metal can be in the first region (6) and solidification can commence in contact with the first or second regions (6, 8), whilst the solidifying casting passes through the third region (9) with reduced wear on the mould.

Abstract: This invention relates to exothermic and/or insulating sleeves, their method of preparation, and their use. The sleeves are prepared by shaping a sleeve mix comprising (1) a sleeve composition capable of providing a sleeve, and (2) a chemical binder. The sleeves are cured in the presence of a catalyst by the cold-box or no-bake curing process. The invention also relates to a process for casting metal parts using a casting assembly where the sleeves are a component of the casting assembly. Additionally, the invention relates to the metal parts produced by the casting process.

Abstract: Parts are diecast from a light metal alloy which in the molten state is fed under gravity into a casting chamber of a diecasting machine and whence forced by a plunger into a mould chamber which undergoes controlled evacuation in accordance with the position of a plunger. A parting compound is applied to at least one mold half and the application of a lubricant to the plunger. The light metal alloy consists of a primary alloy of invariable composition, with a limit placed on the proportions of Cu, Fe and Zn; the alloy undergoes smelting treatment, de-gassing and/or filtration before being introduced. The vacuum in the mould chamber is below 50 mbar when the molten alloy is introduced and the parting compound contains alkali halides and anti-corrosion additives.

Abstract: A zinc alloy melt-out core comprises from 0.75% to 3% Cu, from 0% to 0.3% Ni, from 0% to 0.5% Al, and balance Zn. The zinc alloy melt-out core is used in pressure casting processes for producing an aluminum article having a hollow. The zinc alloy core has a shape-imparting outer surface. In the pressure casting process, the zinc alloy core preserves a space corresponding to the hollow. The zinc alloy core has improved hot strength and thus maintains its integrity during the pressure casting process, inhibiting seepage of the core material into the aluminum cast article. Preferred zinc alloy melt-out cores further comprise an outer coating of insulating material selected from the group consisting of mica, graphite, ceramics and combinations thereof.

Abstract: A hot chamber die casting machine for casting aluminum and its alloys includes separated ceramic parts, namely a ceramic injection cylinder constituting a pump body, a ceramic outer sleeve, a ceramic injection pipe, and a metallic or thermet flange avoiding a large one piece ceramic body and stress concentrations at critical points. The outer sleeve holds the injection cylinder together with the injection pipe in the molten metal. The flange is fixed to a structure which is outside of and independent from a molten metal container and a heating furnace, thus temperature fluctuations do not affect this injection apparatus. The flange can also be fixed to the structure to which an injection hydraulic cylinder is secured in such a manner that the centers of the hydraulic cylinder, the plunger and the injection cylinder are aligned to perform a stable injection operation. A seal ring is disclosed between no-parallel conical cone shaped-fitting ends between the injection pipe and the injection cylinder.

Abstract: A method of producing a casting by using a plastic core. The plastic core is made of a thermoplastic resin and set in a casting mold so as to form a cavity in the casting mold. A molten metal such as aluminum is poured under pressure into the cavity to form the casting (product). The plastic core maintains its initial shape during casting. The remaining heat of the casting or the solidifying metal causes the plastic core to melt after the casting so that the molten plastic core is easily removed.

Abstract: A casting method and apparatus using a resin core wherein a portion of a wall of the resin core that receives a greater heat and/or load than other portions of the wall of the resin core, is increased in thickness. As a result, even if the resin core receives more heat and/or load in places, a local deformation or breakage of the resin core is effectively prevented.

Abstract: In the production of castings from a melt of a reactive metal selected from the group consisting of titanium, titanium alloys, and titanium-based alloys, a reusable casting mold (20) is used; the mold, at least in the area of the surface which comes in contact with the melt, consists of at least one metal selected from the group consisting of tantalum, niobium, zirconium, and/or their alloys. The casting mold (20) preferably consists, at least in the area of the surface which comes in contact with the melt, of a tantalum based alloy containing at least 50 wt. % of tantalum. The casting molds can be made of a homogeneous metal, but it is also possible to insert shells of the metals in question into a base body to form the boundaries of the mold cavities, whereas the base body itself consists of some other metal or alloy or of a nonmetal such as graphite or silicon nitride.

Abstract: A combustible carbonaceous composition and method of making a charcoal briquette wherein a finely divided carbonaceous material is combined with an activated carbon and/or an activated graphite (which may be formed in-situ during pyrolysis of the composition by reacting a humic-containing ore with a low VOC-containing carbon and/or graphite). The combustible carbonaceous composition is present in the briquette composition in an amount of about 65% to about 99.9% by weight; a binder is included in the composition in an amount of about 1% to about 15% by weight when forming a charcoal briquette or an igniter log; and the activated carbon and/or activated graphite is present in an amount of about 0.1% to about 20% by weight. The activated carbon and/or activated graphite absorbs most of the VOCs entitled from the combustible carbonaceous material, thereby preventing the VOCs from escaping to the atmosphere.

Abstract: Crushed and graded magnetite ore is mixed with clay to form foundry moulds and cores. These moulds or cores are useful when casting non-ferrous metals or alloys, especially light metals and light-metal alloys.

Abstract: A free-form metal casting that simulates a natural metal nugget, and method of casting the same. Molten metal is poured into a recess in an upper surface of a bed of rock salt. While still molten, portions of the metal variously penetrate downward through the rock salt, thereby forming, as the metal cools, a unique casting having a random pattern of stalagmite extensions. The surfaces of the casting have a pitted, grainy texture impressed by the rock salt, which simulates the appearance of naturally occurring precious metal nuggets. Surface metal oxides are removed from the casting by electrofinishing. Cast nuggets of copper, brass and bronze are preferably electroplated with gold or silver. After polishing, the cast nuggets are suitable for use in jewelry and decorative art objects.

Abstract: A method of maintaining foundry molding sand and/or a foundry core sand compositions relatively free of benzene and/or total quantity of volatile organic compounds (total VOCs) at 1800.degree. F. and 1 atmosphere pressure by periodically analyzing the sand mold and/or sand core compositions for one or more aromatic hydrocarbons, such as benzene and/or other single ring aromatic hydrocarbons, such as toluene, and/or extractable organic matter (EOMs). If the sand composition is determined by analysis, e.g., by volatilizing the hydrocarbons and passing the volatilized material through a gas chromatograph, or by thermogravimetric analysis, to contain more than a desired amount of aromatic hydrocarbons, e.g., more than about 0.1 mg/g; and/or more than a desired amount of total VOCs, or extractable organic matter (EOM), e.g., more than about 0.5 mg/g total VOCs at 1800.degree. F.

Abstract: An improved soluble core for die casting metals or metal matrix composites is formed of a mixture of salt and up to about 20 weight % of ceramic material blended together to produce a homogeneous mixture and compacted under pressure to produce a soluble core having little or no porosity. The ceramic material can be in the form of fibers, particulates, whiskers, and/or platelets, and has a melting temperature greater than that of the salt. The core can include a thermally insulating outer ceramic coating to enable the core to withstand higher die casting temperatures than conventional salt cores. The improved soluble core is removable with hot water and/or steam and the core material can be reclaimed for reuse. The process is used to form hollow articles.

Abstract: A mold for casting aluminum or aluminum alloy made of a copper alloy having a thermal conductivity of not less than 0.20 cal/s.cndot.cm.degree.C. The mold cavity surface is locally or entirely formed with a coated layer. The coated layer may be either (i) a cermet layer including of at least one element selected from the group consisting of Co, Cu, Cr and Ni, or (ii) a Co--, Ni--, Cr --or Mo-based hard alloy layer. The copper alloy mold exhibits distinguished thermal conductivity and resistance to melt damages.

Abstract: An activated carbon and/or activated graphite foundry sand additive, and method of casting molten metal against a foundry sand containing the additive composition. In another embodiment, the activated carbon and/or activated graphite additive (or portion thereof) is formed in-situ by adding to the foundry sand a humic acid-containing and/or a humic acid salt-containing ore (hereinafter referred to separately or in combination as "humic-containing ore") and low VOC-containing (<1 mg/g at 1800.degree. F.) carbon or graphite or admixtures of low VOC-containing carbon and graphite. The combination of low VOC-containing carbon and/or graphite and the humic-containing ore react in-situ when the foundry sand is heated by contact with molten metal, at temperatures of about 450.degree. F. to about 2300.degree. F., particularly in the range of about 600.degree. F. to about 2000.degree. F., to activate the carbon and/or graphite.