Abstract: Stiction failure of a magnetic recording medium is reduced by forming a lubricant topcoat having a first thickness over the landing zone greater than a second thickness over the data zone, with a sharp transition step having an angle of at least about 70° with respect to a line perpendicular to the surface. Embodiments include depositing a lubricant topcoat at a substantially uniform thickness and reducing the thickness of the lubricant topcoat over the data zone by about 20% to about 80% employing a laser light beam to volatilize the lubricant.

Abstract: A structure having layers of controllable electrical properties is prepared by furnishing a sheet of a substrate material, patterning a pattern of recesses into a surface of the sheet of the substrate material, filling the pattern of recesses with a mixture of an active phase and a matrix, and laminating the sheet to a base structure. The filled recesses may be of any desired shape, depth, and orientation. The active phase is particles of a material such as an electrical conductor or semiconductor, or magnetic particles.

Abstract: A method has been provided to counteract the inherent tension in a deposited film. A wafer substrate is fixed to a wafer chuck having a curved surface. When the chuck surface is convex, a tensile stress is implanted in a deposited film. Upon release from the chuck, the deposited film develops a compressive stress. When the chuck surface is concave, a compressive stress is implanted in the deposited film. Upon release from the chuck, the deposited film develops a tensile stress. Loading a film with a compressive stress is helpful in making films having an inherently tensile stress become thermal stable. Stress loading is also used to improve adhesion between films, and to prevent warping of a film during annealing. A product-by-process using the above-described method is also provided.

Abstract: A plated product and apparatus for forming recesses or grooves on material to be plated to produce such a product. The product includes material having a surface having many recesses, each having an opening of size d, where d is in the range 5-100 microns, a depth in the range from 0.2 d to d, or many grooves. In preferred embodiments, each groove or recess has an anchor portion. In some embodiments, each groove has a ridge portion at each of both edges of its opening. The angle of each groove to the surface of the material and each groove's depth and opening width are preferably in specified ranges. When the material is plated, part of the thin metal film enters the anchor portions of its grooves or recesses, so that the plated metal has superior capacity to resist peeling off of the plated metal.

Abstract: A magnetic disc substrate is provided, which includes a magnetic disc substrate body made of glass and is characterized in that a metal element capable of absorbing light in at least a surface portion of the magnetic disc substrate body, and a texture is formed on a surface of the magnetic disc substrate body. Ions of the metal element are dispersed in the surface portion of the magnetic disc substrate, or the metal element is contained in a composition of the glass constituting the magnetic disc substrate in the form of an oxide. The glass is preferably a crystallized glass a Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2 based crystallized glass, which particularly preferably contains 65 to 85 wt % of SiO.sub.2, 8 to 15 wt % of Li.sub.2 O, 2 to 8 wt % of Al.sub.2 O.sub.3, 1 to 5 wt % of P.sub.2 O.sub.5 and 1 to 10 wt % of ZrO.sub.2 and has lithium disilicate (Li.sub.2 O.2SiO.sub.2) as a main crystalline phase.

Abstract: The leading edge of a lower pole is constituted by a protruded central parallel portion, opposite end parallel portions, and slanted portions coupling the central parallel portion and the opposite end parallel portions. The width T.sub.wc of the central parallel portion is set to 10 to 25% of the total width T.sub.wa of the lower pole. The thickness P1' of the opposite end portion is set in the range from 1/3 or thicker to 2/3 or thinner than the thickness P19 of the central parallel portion.

Abstract: A method of making an optical fiber device, which comprises the steps of providing an optical fiber element comprising an optical fiber having at least one thermally removable coating thereon, and thermally removing all or a predetermined portion of the thermally removable coating(s) to sufficiently expose said optical fiber for a subsequent processing step. Following removal of the thermally removable coating, the optical fiber has a predetermined median fracture stress, as measured according to FOTP-28. The optical fiber may then be processed into an optical fiber device and optionally recoated.

Abstract: A film that exhibits increased scratch resistant characteristics. The film is formed from a layer of crosslinkable oligomeric resin composition on a base. The film is made by: forming the layer of crosslinkable oligomeric resin composition on the base, and curing the resin composition to an extent that the film exhibits a haze decrease of less than or equal to 60 percent after abrading according to the ASTM D-968-81 procedure using 200 milliliters of sand. Preferably, the layer has a microstructure of alternating tips and grooves. Such films are useful in backlit displays which are useful in computers and the like.

Abstract: The present invention provides a process for the manufacture of printed orthopedic casting tapes. A knit, open mesh fibrous tape having elastic filaments extending in the length direction is stretched in a predetermined amount and a pattern is printed onto the stretched fibrous tape using a low temperature drying ink. The printed tape is thereafter passed through a drying zone maintained at a temperature of less than about 100.degree. C. while the tape is maintained in the stretched condition. The printed tape is thereafter allowed to relax and is subsequently coated with a hardenable liquid resin.

Abstract: A rug or mat having a pattern in relief is formed by printing a pattern on a rug having face yarns of a thermoplastic fiber, and subsequently heating the printed rug. The ink is applied by silk-screen, stencil or the like to apply enough ink to raise the melting point of the thermoplastic yarns, so the printed portions do not shrink as much as the untreated, or unprinted, portion of the rug. A plastisol ink has been found to protect the printed yarns. Because an ink is used to protect the yarns, the pattern can be defined by yarn height and color.

Abstract: An improvement is proposed in the preparation of, for example, a ceramic heater consisting of a substrate plate of boron nitride, a patterned layer of pyrolytic graphite (PG) on the substrate to serve as an electric resistance element and an overcoating layer of pyrolytic boron nitride (PBN) in a process comprising the steps of depositing PG on the substrate surface, pattern-wise removing the PG layer by mechanical working to form grooves and depositing PBN all over. According to the inventive improvement, which can be obtained by forming the grooves in such a fashion that the angle between the direction of a normal line to the facet surface formed by the mechanical working and the growing direction of the substrate of boron nitride is in the range from 0.degree. to 45.degree. so that the internal stress caused in the overcoating layer, which is due to the anisotropy in the thermal expansion of boron nitride, is decreased to prevent the overcoating layer from occurrence of cracks and falling during service.

Abstract: A method of making a cast concrete stepping stone whose exposed upper surface has the appearance of two or more grouted attractive natural stepping stones. A liquid release agent is applied to the mold which is then placed on a vibrator table and filled with wet concrete. The mold is vibrated for about 30 seconds and the surface of the concrete troweled smooth. Dry body color is sprinkled over the concrete surface and troweled to completely cover the concrete. A dry release agent containing powdered color having a darker shade than the body color is sprinkled over the dry body color covering the concrete. The desired pattern is then pressed into the surface of the concrete and after a six hour drying time, the cast stepping stone is removed from the mold. Excess body color and release agent are washed away and the washed surfaces totally dried. Finally a clear concrete sealer is applied to the exposed upper surface of the concrete stepping stone.

Abstract: A decorative glass sheet including a glass panel having an upper surface and a lower surface. An applique overlies a portion of the upper surface of the glass panel and has a periphery, an upper surface and a lower surface. An adhesive coupler is interposed between the upper surface of the glass panel and the lower surface of the applique. The applique is secured to the glass panel by the adhesive coupler. The decorative glass sheet may also include one or more grooves formed in the glass panel. Further, one or more coatings may be disposed on the surface of the glass panel. Preferably, the applique covers the entirety of the portion of the glass panel underlying the applique.

Abstract: The substrate of a magnetic recording medium is laser textured employing a dual fiber-optic laser delivery system which enables separate control of nucleation and crystallization. An embodiment of the invention includes laser texturing glass, ceramic and glass-ceramic substrates without microcracking to form a texture comprising uniform protrusions.

Abstract: A method for producing components such as knobs, switches, and other controls having multiple color display graphics is disclosed. The invention is particularly applicable to the production of graphics that are backlit for night time viewing. In one embodiment, a substrate is initially formed from a light-colored translucent polymeric material. A relatively dark-colored coating is provided on a surface of the translucent substrate, followed by removal of a portion of the coating from the substrate by laser etching to produce on a surface of the component a graphic comprising the material of the substrate. A translucent dye is transferred to the surface of the component by a sublimation dying process. The dye is visible on the graphic, but is either not present or not visible on the remaining surface portion of the component.

Abstract: An apparatus and method for the safe and controlled production of glue chipped glass. This custom glue chipped glass processor and method facilitate the production of glue chipped glass for either artisans creating highly specialized works of art, or beginners in the field.

Abstract: A weather resistant sign and a method of printing a sign including the steps of providing a sign component and an image definition, applying dry toner powder to surface portions corresponding to the image definition, and fusing the applied toner. Preferably, the fused toner is protected from weather by a transparent protective layer. A toner composition and a computer program for printing are also disclosed.

Abstract: This invention teaches a method for forming a tempered, coated, grooved and/or beveled decorative glass sheet. The decorative glass sheet includes a coating on a surface thereof and a groove or bevel formed in the surface. The coating is substantially registered with at least on peripheral edge of the groove or bevel such that the coating is not disposed within the groove or bevel. The decorative glass sheet is formed by applying a coating, preferably by screen printing, to a surface of the glass panel. The coating is fired so as to set the coating into the glass panel. A groove and/or bevel is formed in the coated surface. The glass panel is then tempered. Preferably, the step of firing the coating is followed by the step of cooling the glass panel at a rate sufficient to temper the glass panel and, more preferably, at a rate sufficient to induce heat strengthening.

Abstract: The present invention pertains, in a preferred embodiment, to a method for selectively aperturing a nonwoven web exhibiting a plurality of surface energy gradients.

Abstract: A texture treatment for a carbon substrate of a magnetic disk or for a carbon overcoat layer of a magnetic disk is effective to prevent the generation of a stiction phenomenon between a magnetic head and the surface of a magnetic disk. The texture treatment for a carbon substrate or carbon overcoat of a magnetic disk involves the steps of: preparing the carbon disk surface; forming a catalytic material layer on the surface; and performing a heat treatment of the disks in an oxidizing atmosphere. Preferably, islands of catalytic material are formed on the surface by sputtering, and a laser heat treatment is used in an oxidizing atmosphere.

Abstract: A positive metallization process for metallizing a plastic composite piece containing a polymer and grains of one or more oxides, includes three successive steps. The first step consists of irradiating the plastic piece surface to be metallized with a light beam emitted by an excimer laser. The second step consists of immersing the irradiated piece into at least one autocatalytic bath containing metal ions and without palladium. This immersion induces the deposit of the metal ions onto the irradiated surface to form a metal film onto the surface. The third step consists of thermally processing the metallized plastic piece to induce the diffusion of the deposited metal into the plastic piece.

Abstract: A process for creating an array of bumps to texture a brittle nonmetallic surface, such as a glass substrate for data recording disks. The texturing process uses a laser to provide pulses of proper energy fluence to the brittle glass surface to produce a plurality of raised bumps in the surface. The bump creation is accomplished without unwanted micro-cracking or ejection of surface material by limiting the laser pulse fluence to a value in a narrow operating region discovered below the abrupt thermal shock fluence threshold for the brittle nonmetallic surface material. The process is also applicable to other brittle surface textures, such as those intended for use as "stamping surfaces" for the contact reproduction of the negative of a surface pattern, such as an optical disk.

Abstract: A process for making an absorbent structure having a capillary substrate and regions of osmotic absorbent on the capillary substrate. The osmotic absorbent is cured from a liquid precursor applied to the capillary substrate. The capillary substrate has regions of topographically different elevations, taken normal to the plane of the capillary substrate. The capillary substrate is passed through a gap between a transfer roll and an anvil roll in a printing apparatus. The transfer roll has at liquid precursor on its periphery. The liquid precursor is applied to only the topographically elevated regions of the capillary substrate which contact the periphery of the transfer roll. By changing the topography of the capillary substrate, the liquid precursor can be applied to the capillary substrate in different pattern, without changing the transfer roll.

Abstract: Process for coating flexible belt seams including providing a flexible belt having an outwardly facing surface and a welded seam, forming a smooth liquid coating comprising a hardenable film forming polymer on the welded seam, the coating being substantially free of fugitive solvent, and hardening the coating to form a smooth solid coating on the seam.

Abstract: A process for increasing the corrosion resistance of honeycomb core panel construction by using an ion beam enhanced deposition. In one aspect of the invention, molybdenum ions are embedded a predetermined depth into the front and back surfaces of a honeycomb-shaped core. The ions interact with the core metal to form an aluminum-molybdenum alloy which is impervious to corrosion. A thin film coating of metal simultaneously is produced on the surface of the metal-ion embedded core metal. The process also may be used to embed ions into the outer skin layers to achieve enhanced corrosion resistance.

Abstract: A thin film-forming method according to the present invention is characterized by comprising the steps of introducing TiCl.sub.4, hydrogen, nitrogen and NF.sub.3 into a film-forming chamber containing a semiconductor substrate (1) having a groove made in its surface, after the chamber has been evacuated to 10.sup.-4 Torr or less; and converting these gases into plasma, thereby forming a thin TiN film on only that portion of the groove which is other than the wall surfaces of the groove.

Abstract: A process for producing a nitrogen-alloyed stainless steel layer on steel by applying nitride containing mixed metal powder or stainless powder to the steel surface, and thereafter treating the steel with laser beams.

Abstract: A silicon/silicon carbide material which eliminates contamination by outgassing and direct contact is described as well as wafer processing pans made of this material and wafer processing methods using the silicon/silicon carbide material. An ultraclean silicon/silicon carbide material may be formed by first forming a Si/SiC part by prior art methods. The Si/SiC part then is subjected to a temperature sufficient to cause the impurities within the silicon carbide to either react and/or diffuse into the silicon fill. The contaminated silicon fill is then removed, either by high temperature evaporation or by a chemical etch. Clean silicon is then impregnated within the pore space of the silicon carbide pan. The part which results has ultraclean silicon and silicon carbide grains which have most, if not all, of the impurities removed from the surface of the grains. Thus, an ultraclean material results which will not outgas or directly contaminate silicon wafers.

Abstract: The invention is a method for assembling heat transfer plates, introducing a plastic protective material into the plate interspaces as a vapor, and condensing the material on the surfaces of the heat transfer plates.

Abstract: A process for repairing surface defects in plastic articles, especially plastic articles formed from fiber reinforced thermosetting resins, includes the steps of applying a powder coating composition to a defective area on the surface of a plastic article, curing the applied powder coating composition through the application of heat, and removing excess cured powder coating composition from the area of the defect to conform the area of the defect to the proper contours of the plastic article. The process can be utilized for repairing surface defects such as porosity, scratches, gouges and sand-through areas of cured thermoset substrates such as automotive body panels formed from sheet or bulk molding compounds.

Abstract: There is now provided a method of manufacturing a coated ceramic body with improved performance when used as a tool insert for metal cutting purposes. By subjecting the body after the coating to a hot isostatic pressing operation at a pressure of 10-300 MPa and a temperature of >1200.degree. C., an improved adherence of the coating has been achieved. The method is particularly applicable to whisker-reinforced ceramic composites.

Abstract: A silicon/silicon carbide material which eliminates contamination by outgassing and direct contact is described as well as wafer processing parts made of this material and wafer processing methods using the silicon/silicon carbide material. An ultraclean silicon/silicon carbide material may be formed by first forming a Si/SiC part by prior art methods. The Si/SiC part then is subjected to a temperature sufficient to cause the impurities within the silicon carbide to either react and/or diffuse into the silicon fill. The contaminated silicon fill is then removed, either by high temperature evaporation or by a chemical etch. Clean silicon is then impregnated within the pore space of the silicon carbide part. The part which results has ultraclean silicon and silicon carbide grains which have most, if not all, of the impurities removed from the surface of the grains. Thus, an ultraclean material results which will not outgas or directly contaminate silicon wafers.

Abstract: The method for metallizing the surface of dielectric materials according to the invention comprises a first step wherein a metal powder, the size of the grains of which is comprised between 10 and 5000 nm, is deposited and then incorporated into the surface of the dielectric material. In a second step of the method, the dielectric material which is so impregnated with metal, is immersed into an autocatalytic bath to coat the impregnated zones of the material with a layer of the metal contained in the bath in a thickness which is proportional to the immersion time. This method enables to metallize materials such as oxides, polymers and composites containing these oxides and/or these polymers. The characteristics of the metal deposits are controlled, on the one hand, by the type of metal, and the size and the geometry of the metal powder grains and, on the other hand, by the type and the structure of the dielectric materials coated with these deposits.

Abstract: A highly reliable electrical component, a plurality of such electrical components, and a method for manufacturing the electrical component and the plurality thereof with high productivity are provided. The plurality involves a dielectric substrate including multiple separable chips. Each of the chips is provided with two parallel winding grooves, into which pasted copper is filled under a reduced pressure, dried and solidified to form electrical conductors. By connecting pins to ends of the electrical conductors, capacitors or noise filters are obtained. The plurality is manufactured, tested, packaged and transported, before being divided into separate chips for use.

Abstract: The process permits applying a fluorocarbonated resin base coating on a flat metallic support (4). According to the invention, this coating is applied in a continuous manner, directly on the support (4) by serigraphy. Use particularly to coat cooking utensils with a layer of fluorocarbonated resin. (See FIG. 2).

Abstract: A method for manufacturing a composite material comprises the steps of furnishing a layer of a matrix material, forming a groove in the matrix-material layer using a laser to remove material from the layer of matrix material in the form of a groove, and placing a reinforcement into the groove. Preferably, the surface of the layer of matrix material is smoothed with a laser beam prior to formation of the groove. In most instances, more than one layer is desired, and the steps of furnishing, forming, and placing are repeated, using the same or different materials, to build up a multilayer composite material. Cylindrical, flat, or curved panel composite materials can be readily prepared, using metal, intermetallic, or ceramic materials for the matrix.

Abstract: The invention provides an apparatus and methods of using the apparatus to transfer conductive patterns onto substrates under conditions of heat and pressure. The apparatus comprises a master mold with a printing surface on which is produced a permanent mirror image of the conductive pattern to be created. This pattern is then coated with a loosely adherent film of conductive metal, such as copper, which is transferred onto a substrate to be printed.

Abstract: A method for producing a decorative panel wall paper and the like out of a flat piece of creaseable material wherein the piece is first creased along a multitude of crease lines to form a relatively flat production blank configured with a topography having peak portions and valley portions formed by regions of the piece between various ones of the crease lines, comprising the step of either spraying a sprayable pigment onto at least one side of the piece in an oblique direction so that the sprayable pigment impinges and is retained on windward sides of the peak portions with valley portions and leeward sides of the peak portions being shielded from the sprayable pigment, or immersing the piece into a fluid dip to coat the surface portions with a film operative to alter the appearance thereof and thereafter forming a relatively flat production blank.

Abstract: A stamp pad and the method for producing the stamp pad are disclosed. The stamp pad has a piece of porous padding member padded in a case. The porous padding member has a plurality of regions provided respectively with stamping ink of different colors. The method for producing a stamp pad includes compressing a piece of porous padding member by means of a hot pressing plate; preparing high concentration stamping ink of different colors; diluting the high concentration stamping ink with a diluent; depressing a die with a plurality of partitions on the porous padding member in order to form different regions on the porous padding member; adding the diluted stamping ink of different colors into the regions of the porous padding member; vacuum drying the porous padding member to remove the diluent in the porous padding member; and removing the die.

Abstract: The invention relates to a process for producing a plurality of magnetoresistive sensors on the same substrate. The invention particularly has as its object to facilitate a polishing phase of this process. The process of the invention comprises depositing a layer of a magnetoresistive material on a substrate, and then forming in this layer a plurality of magnetoresistive elements. The process further comprises making, at the site of each sensor and before the depositing the magnetoresistive layer, an inclined surface, in such a way that each magnetoresistive element is formed on this inclined surface and exhibits an edge directed outward from the substrate.

Abstract: There is provided a substrate for an optical recording disk capable of preventing non-uniformity of thickness of the transfer layer due to a camber of the substrate, and having a transfer layer excellent in uniformity of the thickness thereof. The substrate for the optical recording disk is manufactured in such a manner that a portion ranging from a center portion to an outer circumferencial portion of the substrate is forcively deformed in advance prior to the formation of the transfer layer so as to provide substantially a conical-convex shape, and thereafter, the transfer layer is formed onto a surface side of the conical-convex shape of the substrate.

Abstract: Method to form a photosensitive ink film having an even thickness over the entire surface of a broad plate material capable of obtaining a multiplicity of printed wiring boards. An emulsion pattern 4 is provided on a screen 3 on which a squeegee travels. The pattern 4 is formed correspondingly to a cutting spaces of a plate material for the purpose of obtaining a multiplicity of printed wiring boards. When a photosensitive ink is forced onto the broad plate material through a screen 3 for a screen printing, the photosensitive ink is dispersed by the pattern 4, thereby forming a film of even thickness over the entire surface of the plate material not corresponding to the emulsion pattern.

Abstract: Process for preparing and film coating a dosage form. An intagliated dosage form core is produced by inscribing one or more areas on the surface of the dosage form core prior to coating. An aqueous dispersion of a polymeric coating is then applied to the intagliated dosage form core. When placed in an environment of use, the film coating within the circumscribed region of the dosage form surface is reproducibly expelled, leaving a coated core tablet with a predefined aperture in the coating which exposes a discrete portion of the core surface to the environment of use.

Abstract: There is described a sheathing web consisting essentially of a waterproof-coated spunbonded of filaments of organic fiber-forming material. The sheathing web has on at least one surface a structure in the form of a weave pattern for increasing the slip resistance, this pattern having been embossed into the spunbonded in the course of its production.

Abstract: The method of forming a pattern on a substrate is described which includes first applying a film of thermo plastic material under pressure to a substrate. Energy is then supplied to dissipate heat at the surface of the film facing the substrate thereby to bond the film to the substrate. Next, areas of the film are selectively dry etched to form a predetermined pattern on the substrate and this is followed by depositing on the substrate in the areas where the film has been dry etched, a layer of patterning material. Finally, dry removal from the substrate is effected of the film remaining thereon. There is also described the application of this method to the manufacture of an array, drop-on-demand ink jet printer.

Abstract: In the silicon substrate having porous oxidized silicon layers of this invention, which consists of a silicon substrate the one surface of which is dotted with porous oxidized silicon dots, the residual internal stress (compression stress) is dispersedly distributed in the porous oxidized silicon dots. Therefore, the entire silicon substrate having porous oxidized silicon dots of this invention is only minimally warped.Adopting a method for producing the silicon substrate of this invention which consists of covering with a mask the surface of a silicon substrate except its dotting areas to be treated, subjecting the silicon substrate to anodic formation in an aqueous hydrofluoric acid solution to form porous silicon layers in the areas to be treated and not covered with the mask and then oxidizing the formed porous silicon layers enables secured production of a silicon substrate provided with a plurality of polygonal shaped dots of porous oxidized silicon.

Abstract: A process and machine are provided to manufacture furniture parts and the like with a unique, durable, low gloss finish which has a soft, satin feel, and imparts a monolithic appearance to the part. A blank cut from a suitable substrate material is grooved about its marginal edge to a depth near the opposite surface of the blank. A liquid edge protection material is poured into the groove and fully cured. The blank is then cut through at the filled groove to create a decorative protection strip about the marginal edge of the blank. The formed blank is next coated with a preselected paint or base material. After the base coat is cured, a layer of UV curable, protective material is applied to the painted surfaces of the blank. The UV coated blank is then translated through a multi-stage, continuous feed, ultraviolet processor to selectively and sequentially cure the protective coat. Powered rollers arranged in spaced apart groups convey the parts through the processor.

Abstract: A method of highly accurate printing using a web offset press, particularly suited for stereographic printing. Consistent reproductions of a composite image are produced on a paper web, and registry between the image and an embossed screen is maintained, by preshrinking (e.g., reducing the moisture content of) the paper prior to printing the composite image on the paper web. Preshrinking the paper prevents the subsequent ink drying operation from causing shrinkage of the paper and concomitant variations in the image, permitting inline formation of a screen in accurate registry with the image.

Abstract: A method and apparatus for masking a part during a multi-step process including a blasting process using abrasive media for etching or cleaning a part. In each step of the multi-step process, the workpiece and mask are aligned together by pins extending from a supporting surface of the apparatus. The pins have a lower surface configured to hold the workpiece and an upper part or portion of a triangular cross section to provide line contact with the walls of apertures in the mask and part. The triangular configuration keeps the mask aligned with the workpiece while at the same time allowing air to pass through the apertures. After the abrasive blasting process, a stream of compressed air is applied to the bottom of the part and mask to cause the mask to move or flutter up and down relative to the surface of the part.

Abstract: A process for obtaining a plate of zirconium alloy comprising at least one portion of excess thickness of at least 0.5 mm relative to a large adjacent face, the portion having edges with angles equal to 90.degree. to 105.degree. and flanks which are connected without depressions to the large adjacent faces. According to the process, a surface portion of a blank plate located straight above a desired portion of excess thickness is coated with a continuous coating which is resistant to a pickling composition to be used, the coated portion widened beyond the desired portion of excess thickness by 0.5-1.5 times the amount of the excess thickness. The coated blank plate is immersed a plurality of times, without passage of electric current, in a pickling bath comprising HF, an oxidizing agent and water, and having a dissolved Zr content less than 12 g/l and a temperature below 35.degree. C. Each immersion removes less than 0.3 mm of thickness over the portions of the blank plate which are not coated.