Abstract: Methods and apparatus for forming a conformal conductive layer on a substrate for an electroplating process are provided. In one aspect, a method is provided for processing a substrate including depositing a conductive barrier layer on the substrate, and then depositing a nucleation layer on the conductive barrier layer. The nucleation layer is deposited by depositing a first conductive material on the substrate and then depositing a second conductive material on the first conductive material by an electroless deposition process. The second conductive material may comprise nickel, tin, or combinations thereof. The substrate may then be further processed by electroplating a third conductive material on the second conductive material and/or annealing the substrate.

Abstract: A process for anodizing an Si-based aluminum alloy comprises the steps of subjecting the Si-based aluminum alloy to electrolysis in an electrolyte containing phosphate and fluoride to form an anodized film on the aluminum alloy, infiltrating a photosetting or thermosetting resin in liquid form into microholes in the anodized film, and radiating light or heat at the infiltrated resin to make the resin become hardened. Phosphate makes diameters of the microholes large while fluoride dissolves Si moderately and facilitates growth of the film. As a result, a large amount of the photosetting or thermosetting resin can be infiltrated into the microholes of the film, thereby making a surface of the film flat.

Abstract: Disclosed is a forming electrolyte for forming metal oxide coating films which comprises one or more kinds of solutes selected from the group consisting a salt of inorganic acid and salt of organic carboxylic acid dissolved in a solvent having analcoholic hydroxyl group or aprotic organic solvent, provided that, when the solvent having an alcoholic hydroxyl group is selected, the salt of organic carboxylic acid is selected from salts of aromatic carboxylic acids, salts of aliphatic polycarboxylic acid having 3-5 carbon atoms with no hydroxyl groups, salts of monohydroxy carboxylic acid having 2-5 carbon atoms, and salts of amino acid. By anodically oxidizing metal using the forming electrolyte, there can be formed an oxide coating film of high insulation property with a high throughput, in which hillocks are effectively suppressed.

Abstract: A process for controlling grain growth in the microstructure of thin metal films (e.g., copper or gold) deposited onto a substrate. In one embodiment, the metal film is deposited onto the substrate to form a film having a fine-grained microstructure. The film is heated in a temperature range of 70-100°C. for at least five minutes, wherein the fine-grained microstructure is converted into a stable large-grained microstructure. In another embodiment, the plated film is stored, after the step of depositing, at a temperature not greater than −20° C., wherein the fine-grained microstructure is stabilized without grain growth for the entire storage period.

Abstract: Disclosed herein is a method of fabricating a catalyzed porous electrode for fuel cell, which electrode can be fabricated in a simple and easy manner without forming a catalyst support layer of carbon particles, and has an excellent, stable catalytic efficiency. The method comprises treating an electrically conductive, porous carbon substrate with an oxidizing agent; making one face of the porous carbon substrate in contact with an electrodeposition solution As containing ions of a catalytic metal; applying a pulsed potential to the electrodeposition solution to deposit the catalytic metal on the porous substrate, thereby catalyzing the porous substrate; and heat-treating the catalyzed porous substrate.

Abstract: The invention is directed to the use of electrochemical deposition to fabricate thin films of a material (e.g., bismuth) exhibiting a superior magnetoresistive effect. The process in accordance with a preferred embodiment produces a thin film of bismuth with reduced polycrystallinization and allows for the production of single crystalline thin films. Fabrication of a bismuth thin film in accordance with a preferred embodiment of the invention includes deposition of a bismuth layer onto a substrate using electrochemical deposition under relatively constant current density. Preferably, the resulting product is subsequently exposed to an annealing stage for the formation of a single crystal bismuth thin film. The inclusion of these two stages in the process produces a thin film exhibiting superior MR with a simple field dependence in the process suitable for a variety of field sensing applications.

Abstract: The object of the invention is to provide a method for producing a photocatalytic material which consists of a titanium oxide, exhibits a higher photocatalytic activity and has excellent appearances. The above object is attained by the provision of a method for preparing a photo catalytic material by oxidizing the surface of a substrate consisting of titanium or a titanium alloy, the method comprising a step of anodizing the substrate in an electrolyte containing an organic acid and/or a salt of the organic acid and a step of further oxidizing the anodized substrate in an atmosphere.

Abstract: A method and apparatus for electrochemically depositing a metal into a high aspect ratio structure on a substrate are provided. In one aspect, a method is provided for processing a substrate including positioning a substrate having a first conductive material disposed thereon in a processing chamber containing an electrochemical bath, depositing a second conductive material on the first conductive material as the conductive material is contacted with the electrochemical bath by applying a plating bias to the substrate while immersing the substrate into the electrochemical bath, and depositing a third conductive material in situ on the second conductive material by an electrochemical deposition technique to fill the feature. The bias may include a charge density between about 20 mA*sec/cm2 and about 160 mA*sec/cm2. The electrochemical deposition technique may include a pulse modulation technique.

Abstract: A method of improving the oxidation and corrosion resistance of a superalloy article comprises providing a superalloy substrate having a sulphur content which is less than 0.8 ppm by weight, and depositing on the substrate a protective antioxidation coating having a sulphur content also less than 0.8 ppm by weight. A heat barrier layer may also be provided by depositing on the protective anti-oxidation coating a ceramic coating of columnar structure.

Abstract: A method for filling recessed microstructures at a surface of a microelectronic workpiece, such as a semiconductor wafer, with metallization is set forth. In accordance with the method, a metal layer is deposited into the microstructures with a process, such as an electroplating process, that generates metal grains that are sufficiently small so as to substantially fill the recessed microstructures. The deposited metal is subsequently subjected to an annealing process at a temperature below about 100 degrees Celsius, and may even take place at ambient room temperature to allow grain growth which provides optimal electrical properties. Various novel apparatus for executing unique annealing processes are also set forth.

Abstract: The invention generally provides a method for preparing a surface for electrochemical deposition comprising forming a high conductance barrier layer on the surface and depositing a seed layer over the high conductance barrier layer. Another aspect of the invention provides a method for filling a structure on a substrate, comprising depositing a high conductance barrier layer on one or more surfaces of the structure, depositing a seed layer over the barrier layer, and electrochemically depositing a metal to fill the structure.

Abstract: The invention is directed to corrosion and wear resistant metallic coatings containing nickel, boron, particles. The coatings are preferably deposited on catalytically active substrates from an electroless coating bath containing nickel ions, a stabilizer, a metal ion complexing agent, particles and a borohydride reducing agent, at a pH of about 10 to about 14.

Abstract: A process for the production of copper or a copper base alloy that provides a surface having improved characteristics suitable for the production of a connector or a charging-socket of an electric automobile by having a decreased coefficient of friction on the surface and improved resistance to abrasion. The process comprises coating copper or a copper alloy with Sn, followed by heat treating the resulting Sn-plated copper or copper base in an atmosphere having an oxygen content of no more than 5%, thereby forming on an outermost surface thereof an oxide film and beneath the surface a layer of an intermetallic compound mainly comprising Cu—Sn.

Abstract: A process for fabricating a silica-based optical device on a silicon substrate is disclosed. The device has a cladding formed in a silicon substrate. The device also has an active region, and that active region is formed on the cladding. The cladding is fabricated by forming a region of porous silicon in the silicon substrate. The porous silicon is then oxidized and densified. After densification, the active region of the device is formed on the cladding.

Abstract: A method of applying a conductive carbon coating to a nonconductive surface, conductive carbon compositions for that purpose, and a printed wiring board having through holes or other nonconductive surfaces treated with such carbon compositions are disclosed. A conditioning agent, made (for example) by condensing a polyamide and epichlorohydrin, is applied to the nonconductive surface to form a conditioned surface. A liquid dispersion of electrically conductive carbon (for example, graphite) having a mean particle size no greater than about 50 microns is coated on the conditioned surface to form an electrically conductive carbon coating. The conductive carbon coating is then optionally fixed on the (formerly) nonconductive surface. Fixing may be accomplished, for example, by applying a fixing liquid such as a dilute aqueous acid to the carbon-coated surface. The coating is then dried.

Abstract: An object of the invention is to provide a surface-treated copper foil capable of consistently attaining a percent loss in peel strength in resistance against hydrochloric acid degradation of 10% or less as measured on a copper pattern prepared from the copper foil and having a line width of 0.2 mm, by bringing out the maximum effect of the silane coupling agent employed in copper foil coated with an anti-corrosive layer formed of a zinc-copper-tin ternary alloy. Another object is to impart excellent moisture resistance and heat resistance to the surface-treated copper foil.

Abstract: An object of the invention is to provide a surface-treated copper foil capable of consistently attaining a percent loss in resistance against hydrochloric acid degradation of 10% or less as measured on a copper pattern prepared from the copper foil and having a line width of 0.2 mm, by bringing out the maximum effect of the silane coupling agent employed in copper foil coated with an anti-corrosive layer formed of a zinc-copper-nickel ternary alloy. Another object is to impart excellent moisture resistance to the surface-treated copper foil.

Abstract: A method employed to dry a copper foil having been subjected to various surface treatments, which method comprises irradiating at least one surface-treated side of the copper foil with near infrared rays to dry the copper foil, and an apparatus suitable to the method. The drying of the copper foil having undergone surface treatments can be accomplished by a simple apparatus with low electric power while controlling the heating of the surface of the copper foil so that the drying temperature can be held at 100° C. or higher at which a eutectic alloying of rust preventive metal and copper foil, for example, alloying (brass formation) of zinc and copper on the surface of the copper foil is effected.

Abstract: Deposition of metal in a preferred shape, including coatings on parts, or stand-alone materials, and subsequent heat treatment to provide improved mechanical properties. In particular, the method gives products with relatively high yield strength. The products often have relatively high elastic modulus, and are thermally stable, maintaining the high yield strength at temperatures considerably above 25° C. This technique involves depositing a material in the presence of a selected additive, and then subjecting the deposited material to a moderate heat treatment. This moderate heat treatment differs from other commonly employed “stress relief” heat treatments in using lower temperatures and/or shorter times, preferably just enough to reorganize the material to the new, desired form. Coating and heat treating a spring-shaped substrate provides a resilient, conductive contact useful for electronic applications.

Abstract: The invention relates to a process for the deposition of light-absorbing polyaniline, particularly on a titanium substrate, the process comprising: a fluoronitric etching, a chemical conversion treatment, a hydrolysis and a deposition of polyaniline by electropolymerization.

Abstract: A method of forming a conductor pattern on a wiring board, in which a conductor pattern forming process on the wiring board can be simplified; and an interval between the conductor patterns can be further reduced by suppressing the etching conducted on the side portions of the electrolytic copper plated layer.

Abstract: Before the application of an external coating having a base of polyester or epoxy resin, or of a mixture of the two by spraying with an electrostatic spray gun, the parts to be coated are subjected to an initial zinc coating treatment by electrolytic process and a layer of an acrylic paint is applied to the zinc coating and polymerized to define a bonding sublayer between the metal and the external coating.

Abstract: An apparatus and a method for electroplating for forming a metal film by an electroplating method. The apparatus comprises a plating bath provided in a non-oxidative atmosphere, and in the method, an article to be plated is immersed in a plating bath through a non-oxidative atmosphere.

Abstract: A method for depositing a multi-layered protective and decorative coating on an article comprising first depositing at least one coating layer on the article by electroplating, removing the electroplated article from the electroplating bath and subjecting it to pulse blow drying to produce a spot-free surface on the electroplated article, and then depositing, by physical vapor deposition, at least one vapor deposited coating layer on the electroplated article.

Abstract: A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

Abstract: A process for producing a coating for protecting superalloy articles against high temperature oxidation and hot corrosion comprises forming, on the surface of the article, a first deposit of an agglomerated powdered alloy containing at least chromium, aluminum and an active element, and filling the open pores of the powder deposit by a second, electrolytically applied, deposit of a precious platinum group metal. An appropriate thermal treatment is then carried out to effect interdiffusion between the powder based deposit and the electrolytic deposit and produce a coating including chromium, an active element such as yttrium, and a precious platinum group metal throughout its thickness.

Abstract: The invention provides a process for producing a coated Cu alloy having a surface which has a low coefficient of friction and a high resistance to abrasion and is suitable for fabricating connectors, charging-sockets of electric automobiles etc. The coated Cu alloy is produced by coating the surface of a copper alloy with Sn and heat treating the coated Cu alloy at a temperature in the range of 100-450° C. for 0.5-24 hours. The Cu alloy which is coated with Sn consists of 1-41 wt % Zn with the balance being Cu and incidental impurities. By using the coated Cu alloy, the force of insertion, resistance to abrasion and resistance to corrosion of connectors can be significantly improved.

Abstract: A method for manufacturing a fine pattern includes steps of forming a master substrate having an electrode layer patterned to a predetermined shape, forming peel layers made of a conductive water-repellent thin film on the master substrate, forming the fine pattern made of the electrodeposit resin on the peel layers, impregnating the electrodeposit resin with water, and stripping the fine pattern off the master substrate and transferring the fine pattern on a bonding layer of the media substrate. A color filter and a shading pattern filter are manufactured by the method for manufacturing the fine pattern. The color LCD element includes plastic film substrates, a transparent pixel electrode, a liquid crystal material, and color filters. The color filters are pasted on the plastic film with a bonding film laid therebetween.

Abstract: A process is disclosed for reducing the crystallization temperature of amorphous or partially crystallized ceramic films by providing a higher pressure under which the crystallization of the amorphous or partially crystallized ceramic films can be significantly enhanced. The present invention not only improves quality, performance and reliability of the ceramic films, but also reduces the cost for production. By lowering the crystallization temperature, the cost for thermal energy consumed during the crystallization process is greatly reduced. In addition, the interaction or interdiffusion occurring between films and substrates is significantly suppressed or essentially prevented, avoiding the off-stoichiometry and malfunction of thin films, which usually occur in the conventional high-temperature crystallization processes. The process of present invention also decreases the grain size of formed films, thus reducing the roughness of films and producing relatively smooth, good quality films.

Abstract: A steel sheet for a battery container is covered with nickel-tin alloy layer on one side to be the inner side of the battery container which is formed by drawing the steel sheet. A battery using the steel sheet is manufactured by firstly filling positive electrode mix consisting of manganese oxide, graphite and potassium hydroxide and secondly filling negative electrode active material consisting of zinc and potassium hydroxide in the battery container.

Abstract: Capacitor elements made with a solid polymeric electrolyte show reduced leakage current when reformed at about 60-85% of formation voltage during the impregnation phase between successive layers of polymeric electrolyte.

Abstract: A process and structure for enhancing electromigration resistance within a copper film using impurity lamination and other additives to form intermetallic compounds to suppress metal grain boundary growth and metal surface mobility of a composite copper film. The present invention provides an alloy seed layer and laminated impurities to incorporate indium, tin, titanium, their compounds with oxygen, and their complexes with oxygen, carbon, and sulfur into other films. The intermetallics form and segregate to grain boundaries during an annealing process to reduce copper atom mobility. A further aspect of the present invention is the use of high-temperature, inter-diffusion of additives included in an alloy seed layer to form a barrier layer by combining with materials otherwise unsuitable for barrier material functions.

Abstract: An archival medium, such as a compact disc, is made of a metal such as aluminum which is mechanically gained with particulate material under conditions that embed particulate material into the surface of the medium and visibly imageable by selective exposure to infrared laser radiation. A mechanically grained aluminum medium can also be anodically oxidized under conditions that do not impair the ability of the substrate to be laser imaged. The archival medium can be coated with opaque and transparent polymer coatings before or after imaging for security and/or protection. The coating can be a laser ablatable coating to provide a tamper-proof medium.

Abstract: A process for controlling grain growth in the microstructure of thin metal films (e.g., copper or gold) deposited onto a substrate. In one embodiment, the metal film is deposited onto the substrate to form a film having a fine-grained microstructure. The film is heated in a temperature range of 70-100.degree. C. for at least five minutes, wherein the fine-grained microstructure is converted into a stable large-grained microstructure. In another embodiment, the plated film is stored, after the step of depositing, at a temperature not greater than -20.degree. C., wherein the fine-grained microstructure is stabilized without grain growth for the entire storage period.

Abstract: An electromigration-resistant copper film structure and the process for forming the structure. The film structure contains a high impurity content, is resistant to grain growth, and possesses superior metallurgical, thermo-mechanical, and electrical properties. The process comprises the steps of: (a) providing a seed layer at least indirectly on a substrate, the seed layer having an exposed surface; (b) immersing the substrate in a plating solution; (c) electrodepositing a copper-containing film on the exposed surface of the seed layer, the copper-containing film having a first surface; (d) maintaining the substrate in an immersed state within the plating solution; (e) electrodepositing a further copper-containing film from the plating solution onto the first surface; (f) removing the substrate from the plating solution; and (g) drying the substrate.

Abstract: A method for manufacturing a cathode for a molten carbonate fuel cell includes oxidation of a porous precursor electrode and contact with molten carbonate. Following assembly of a layered arrangement containing the precursor electrode, a matrix layer made of molten carbonate, and a porous anode, the precursor electrode is anodically oxidized with a preset curve for the current density, and doped by contact with molten carbonate.

Abstract: Methods for forming pastes of powder particles coated with an electrically conductive coating are described. The powder particles, with or without an optional first conductive coating layer applied to their surface, are placed in contact with a cathode surface and immersed in an electroplating solution. An anode covered with a nonconducting but ion-permeable membrane is immersed in the solution in close proximity to the cathode. Agitation to move and gently tumble the powder over the cathode surface is provided. The powder particles are plated with a metal or metal alloy coating by biasing the anode with a positive voltage relative to the cathode. The coated powder is removed, rinsed and dried. The powder is added to a polymer material to form a paste which is heated to fuse the powder coating surfaces to form a network of interconnected particles and is further heated to cure the polymer.

Abstract: According to one aspect of the invention, a plating system is provided which includes a tank for containing a plating solution, a substrate holder, and a temperature control device. The substrate holder is configured to support a substrate in position so that at least a first face of the substrate is exposed to the plating solution in the tank. The temperature control device provides selective control of temperature in various regions of the substrate during plating so as to control plating over the first face of the substrate.

Abstract: A method for forming a plating layer of a lead frame having excellent anti-corrosion properties is provided. At least a portion of a lead frame is plated, then a first heating of the plated portion of the lead frame to a first temperature is performed, and finally a second heating of the first heated plated portion of the lead frame to a second temperature higher than the first temperature is performed. The lead frame manufactured by this method has excellent anti-corrosion properties, such that deterioration of the plating layer, by cracking and inferior solderability, is not observed.

Abstract: A method of reforming a tungsten probe tip includes forming a non-oxidizing metallic film on the surface of the tungsten probe tip, heating the film in a non-oxidizing atmosphere or vacuum, and diffusing the film into the tungsten probe tip. The non-oxidizing metallic film can be formed from a metal such as gold, platinum, rhodium, palladium, and iridium. The reformed tungsten probe tip can be used in low voltage and low current testing, and has excellent abrasion resistance, conductivity and oxidation resistance.

Abstract: The present invention relates to an alloy film resistor containing mainly nickel and phosphorus having an excellent fuse function and a method for producing the alloy film resistor. After the conductivity is given to the surface of an electrical insulating substrate such as ceramics by sequentially performing an etching treatment, an activating treatment and an electroless plating treatment to the electrical insulating substrate, an alloy film containing mainly nickel and phosphorus is formed by not an electroless plating process but an electrolytic plating process. By adopting the electrolytic plating process, a film thickness of the formed alloy film of the middle part on the surface of the insulating substrate is thinner than that of the alloy film of the corner or ridge parts on the surface of the insulating substrate, and the thin part of the film thickness serves as a suitable fusing start part when applying an overload.

Abstract: A method for manufacturing a fine pattern is provided which method makes it possible to well reproducibly and completely strip and transfer the fine pattern, repetitively use a master substrate, and simply form a high-definition and high-density fine pattern with good massproductivity. Further, a color filter and a shading pattern filter are implemented by the fine pattern. A color LCD element with the color filter is provided which enables to output a well color-reproducibly high-quality image with no color or brightness evenness. Moreover, a color LCD element is provided which enables to continuously output a coloring function for a certain length of time after light from a light source or ambient light disappears and form a brighter and more vivid image.

Abstract: A method for depositing a multi-layered protective and decorative coating on the article comprising first depositing at least one coating layer on the article by electroplating, removing the electroplated article from the electroplating bath and subjecting it to pulse blow drying to produce a spot-free surface on the electroplated article, and then depositing, by physical vapor deposition, at least one vapor deposited coating layer on the electroplated article. The electroplated layers are selected from copper, nickel and chrome. The physical vapor deposited layers are selected from non-precious refractory metals, non-precious refractory metal alloys, non-precious refractory metal compounds, and non-precious refractory metal alloy compounds.

Abstract: This self-supported, anisotropic conductive film has a partly annealed polymer layer (46) containing through holes, nail-shaped conductive elements (51) filling the through holes, having a central portion and ends, and the central portion of the nails is made from a hard material (52) and each end respectively of a first and a second meltable materials (44, 54).

Abstract: In a manufacturing method of a MIM nonlinear device (50) having a Ta electrode layer (16), an anodic oxidation film (18) and a Cr electrode layer (20), tantalum oxidation film (14) is first formed on the transparent substrate (12). The Ta electrode layer (16) is formed on the tantalum oxidation film (14) and the anodic oxidation film (18) is formed on the Ta electrode layer (16). Then, heat treatment is performed to the substrate. The final temperature drop in the heat treatment process is carried out in the atmosphere that contains water vapor. After that, the Cr electrode layer (20) is formed to complete the MIM nonlinear device (50). By conducting the heat treatment in the atmosphere that contains water vapor, the nonlinear characteristics of the MIM device can be improved as well as the improvement of the resistance characteristic in the OFF state.

Abstract: The present invention provides electronically conducting polymer films formed from photosensitive formulations of pyrrole and an electron acceptor that have been selectively exposed to UV light, laser light, or electron beams. The formulations may include photoinitiators, flexibilizers, solvents and the like. These formulations can be used to manufacture multichip modules on typical multichip module substrates, such as alumina, fiberglass epoxy, silicon and polyimide. The formulations and methods of the invention enable the formation of passive electronic circuit elements such as resistors, capacitors and inductors in multichip modules or printed wiring boards.

Abstract: The invention relates to a process for the preparation of a superconductor material of the mixed oxide type, such as oxides of the YBaCuO and Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8 type. This process consists of the deposition by electrolysis on a conductive substrate of successive layers of metallic elements entering in the constitution of the superconductor material, using a single element in each layer and carrying out, following the deposition of at least one of the layers, an intermediate oxidation-reaction heat treatment for fixing the element of said layer before depositing the following layer, optionally repeating one or more times at least part of the aforementioned operations, and subjecting all the layers to a final, oxidation heat treatment to form the mixed superconductor oxide.

Abstract: A process for the preparation by electrodeposition of metal oxide film and powder compounds for ferroelectric memory materials and ferrites wherein the metal oxide includes a plurality of metals. The process comprises providing an electrodeposition bath, providing soluble salts of the metals to this bath, electrically energizing the bath to thereby cause formation of a recoverable film of metal on the electrode, recovering the resultant film as a film or a powder, and recovering powder formed on the floor of the bath. The films and powders so produced are subsequently annealed to thereby produce metal oxide for use in electronic applications. The process can be employed to produce metal-doped metal oxide film and powder compounds for transparent conductors. The process for preparation of these metal-doped metal oxides follows that described above.

Abstract: An apparatus for simultaneously anodizing the heads of several aluminum pistons includes a plating tank with an array of apertures extending through one side wall, one aperture for each piston; a fixture on the wall providing a cylindrical bore aligned with each aperture adapted to receive a piston; and a plurality of actuators which, when pivoted and locked into alignment with the fixture bores, operate to secure individual pistons in their respective apertures. A masking/sealing assembly within each fixture bore ensures that each aperture is sealed upon the securing of a piston therein, with only the piston's head and peripheral land being placed in fluid communication with the interior of the plating tank. A remote storage tank provides a supply of an electrolyte which is circulated by a fluid supply network between the storage tank and the thus-sealed plating tank during electrolysis. After the desired coating is achieved, the electrolyte is drained from the tank.

Abstract: A process, particularly a continuous process, for industrially producing a high-quality inexpensive porous iron metal while preventing the conventional rusting problem which process comprises coating the surface of a conductive porous base material by iron electroplating, removing the base material, and then reducing the coating. The iron electroplating was conducted in an acid iron plating bath which contains at least one from acid aluminum compound and/or at least one acid titanium compound, using an anode which contains at least either of aluminum and titanium and has a surface area not smaller than 1/3 of and not larger than that of the base material. The reduction is conducted by a two-step heat treatment for improving the iron structure and for softening.