Showing papers on "Electroplating published in 1978"

Bright electroless plating process and plated articles produced thereby

Abstract: An adherent bright metallic coating which may be any metal or alloy capable of being deposited electrolessly, is applied to the surface of a plastic or other dielectric part (or to a metal part) by an electroless process comprising suitable pretreatment of said surface, deposition of a primary electroless copper to produce an underlayer, then depositing a bright secondary electroless coating of the desired metal (the overlayer) with complete elimination of any subsequent electroplating process [usually required to achieve this brightness]. The required overlayer may also be limited to selected surface areas of a coated part by mechanically removing portions of the primary electroless copper prior to immersion of the part in the secondary electroless bath to produce the desired overlayer metal.

Non-cyanide bright silver electroplating bath therefor, silver compounds and method of making silver compounds

Abstract: A silver and silver alloy electroplating bath; electrolytic solution; water-soluble silver complex for incorporation therein; and the process for electrodeposition of silver and silver alloys; wherein the electrolytic solution and bath have a pH of at least 6, is free of cyanide, and comprises a water-soluble complex formed from the reaction of a silver salt or compound and an organic complexing agent selected from a pyrrolidine-2,5-dione or a 3-pyrroline-2.5-dione.

Process of mechanically shaping metal articles

Abstract: Articles made of ferrous, non-ferrous and light metals and alloys thereof, e.g., aluminum, beryllium, magnesium, molybdenum, steel, tantalum, titanium, tungsten, vanadium and zinc and their alloys, are pretreated before coating and surface finishing in an anhydrous, inert, aprotic liquid, and subsequently electroplated with aluminum, cadmium, indium or zinc in an aprotic organo-metal electrolyte essentially free of molecular oxygen and water and, optionally, additionally finished by anodizing, chemical oxidation or diffusion. The pretreatment may be by erosion with finely-divided abrasive particles suspended in such liquid and impinged upon the surface of the article by hydraulic jetting, or with an aprotic liquid by the liquid-drop erosion method. Alternatively, the pretreatment may be by electrolytic action in a circuit where the article serves as the anode and is immersed in an anhydrous, aprotic electrolyte. Articles so pretreated and electroplated are thereafter more readily surface-finished or mechanically shaped.

Finned heat transfer tube with porous boiling surface and method for producing same

Abstract: The invention relates to finned heat transfer tubes and to a method for impoving the heat transfer properties in boiling liquids of such tubes by plating the tubes in an electroplating bath containing conductive particles such as graphite powder to produce a porous plated surface. The tips of the fins are covered before plating with a non-conductive coating to prevent plating of the tips. The non-conductive coating can be dissolved away or mechanically removed after plating.

Selective electroplated chromium blacks.

Abstract: The electrodeposition of chrome black selective surfaces on polished metal substrates has been studied by measuring the properties of samples as a function of plating time. Optical measurements show that in the first 50 sec a lossy dielectric film (apparently Cr2O3) of 0.6-μm thickness is deposited. The weights of deposits and their emittances, as well as the surface profiles of the samples, show that most (0.4–0.5 μm) of this dielectric film falls off between 50-sec and 60-sec plating time. An absorbing layer of chromium metal particles is then deposited on the remaining dielectric film to produce the high solar absorptance characteristic of these films. Calculations based on a particulate chromium deposit linearly graded with air using a recent theory of McKenzie and McPhedran are able to reproduce the film properties with deposit weights similar to those actually measured. It is shown that the thickness of the dielectric layer left under the particulate chromium deposit is important in obtaining the optimum performance in the trade-off between solar absorptance and thermal emittance.

Electroplating aluminum articles

Abstract: In a process for electroplating aluminum articles, the article is first electrolytically treated, as anode, in a bath consisting essentially of a solution of caustic alkali, and thereafter electroplated. The electrolytic caustic cleaning step, preferably involving agitation, is found specially suitable in composition and indeed is effective in a relatively short time to afford an essentially bare aluminum surface, i.e., free of anodic oxide film and also free of pitting or smut, for advantage in plating, as with tin or other metal. Intermediate steps can be employed such as immersion tinning or zincating and brief electroplating such as a bronze strike; the electrolytic cleaning co-acts well with the intermediate stages, indeed requiring fewer steps over all. Although applicable batchwise, the process is particularly appropriate for continuous electroplating wherein the aluminum wire or strip may pass rapidly through the electrolytic cleaning, intermediate and plating baths in succession.

Bright tin electroplating bath

Abstract: Improved electrolytic tin deposition from aqueous, acid electroplating baths is achieved by addition of a new formula of brighteners. These results are achieved by further addition of unsaturated aliphatic acids or their derivates and still better results are achieved by further addition of certain heterocyclic quarternary compounds.

Corrosion resistant plating and method utilizing alloys having micro-throwing power

Abstract: A multi-layer plating and method for improving the corrosion resistance of ferrous metal articles, such as steel fasteners, are provided in accordance with the invention. The multi-layer plating comprises, in sequence over a ferrous metal substrate, a layer of an alloy which has micro-throwing power, such as nickel-cadmium, nickel-zinc, iron-cadmium, iron-zinc, cobalt-cadmium, or cobalt-zinc, a layer of cadmium, cadmium-tin alloy, a dual layer of cadmium and tin, zinc or zinc alloy, a layer of copper, a layer of nickel, and a layer of chromium or a metallic chromium substitute. The method comprises plating, and preferably electroplating, the aforementioned layers of alloy and metals over an article having a ferrous metal substrate to obtain improved corrosion resistance.

Anticorrosive overlap-coated steel material

Abstract: An anticorrosive overlapped coating so far practiced as applied to such iron and steel materials as plates, pipes, bars or wires is formed by electroplating an iron or steel material on the surface with an Sn base - Zn alloy layer and applying a chromate-treatment on it. However, this requires such long time in forming a plated layer thickness that a reduction of the plating time together with a further improvement of the anticorrosion is hoped for today. The present invention has succeeded in making it possible to reduce the plating time while improving the anticorrosion and in improving the productivity by forming an electroplated layer of an Sn base - Zn alloy directly or through an electroplated layer of Zn on the surface of a steel material, then forming an electroplated layer of Zn on the electroplated layer of said alloy and further applying a chromate-treatment on said Zn layer.

Electrodeposition process for forming amorphous silicon

Abstract: A method for electroplating amorphous silicon from a non-aqueous solution containing a silicon solute wherein a heat treatment is requisite to producing stable coatings of photoconductive amorphous silicon.

Gold alloy plating bath and method

Abstract: An aqueous bath for electroplating a gold/silver alloy includes a water soluble electrolyte such as potassium pyrophosphate, gold and silver present as their respective alkali metal cyanides, and a water soluble brightener system. The water soluble brightener system comprises a selenium compound containing selenium in the -2 valance state and a polyethyleneimine compound. The bath has a pH of about 8 to 10 and may include tetraethanolamine borate ester to decrease the tensile stress of the electrodeposit.

Electro-optical device based on electroplating action

Abstract: Electrically activated optical switches, couplers, and modulators are disclosed which can be incorporated in waveguide networks in optical communications systems. Disclosed devices comprise an electroplating medium in combination with a suitable source of an electric field whose strength can be varied to cause transition of the electroplating medium between plated and unplated states. Changes of reflectivity and refractive index are the bases of switching and coupling applications, respectively.

Method for manufacturing substantially flat dies

Abstract: There is described a method for manufacturing by electroplating substantially flat dies or similar, which comprises adjusting the electric current strength by varying the sparing between the cathode and the anode inside the electrolyte proper.

Zinc electroplating baths and process

Abstract: Aqueous plating baths for the electrodeposition of a zinc coating on a substrate are disclosed and comprise zinc ions to which has been added an amount, effective to provide a level and bright zinc electrodeposit, of a polymeric nitrogen-containing compound prepared by reacting a poly(alkyleneimine) with a cyclic carbonate consisting of carbon, hydrogen and oxygen atoms. More particularly, the poly(alkyleneimine) has a molecular weight within the range of from about 200 to about 100,000, and the cyclic carbonate is one wherein the ring oxygen atoms adjacent to the carbonyl grouping are each bonded to a ring carbon atom, and the ring containing the oxygen and carbon atoms has only three carbon atoms and no carbon-to-carbon unsaturation. The aqueous plating baths of the invention may be acid zinc plating baths or alkaline cyanide or non-cyanide containing plating baths. In addition to the zinc ions and the polymeric nitrogen-containing compound, the zinc plating baths of the invention also may contain other desirable additives such as ethoxylated naphthols and aromatic carbonyl-containing compounds. Methods for the electrodeposition of level zinc deposits from such baths are disclosed.

Method of electroplating tin and alkaline electroplating bath therefor

Abstract: An improved electrotinplating process and electroplating bath therefor is disclosed. The electroplating bath contains tin ions, an alkali metal hydroxide, and a bismuth compound selected from the group consisting of at least one alkali metal bismuth salt of a linear polyhydroxymonocarboxylic acid having at least six carbon atoms, at least one alkali metal bismuthyl compound of glucono-delta-lactone, and mixtures thereof. The alkali metal bismuth compounds of this invention exhibit increased solubility and long-term stability in hot alkaline alkali metal stannate electroplating baths when compared to conventional alkali metal bismuthates. A preferred alkali metal bismuth compound is an alkali metal bismuthyl gluconate. An improved electrotinplating process is therefore provided which produces a plated tin-bismuth alloy which is resistant to the effects of tin pest.

Process for forming electrode on semiconductor device

Abstract: Semiconductor substrates electroplated with nickel-palladium alloy consisting of above 50 to 80 atomic percent nickel and below 50 to 20 atomic percent palladium exhibit excellent thermal stability.

Manufacture of corrosion resistant zinc composite- electroplated steel products

Abstract: PURPOSE: To obtain the title products without using an alloying means by plating steel products in a zinc plating bath contg. a specified amt. of one or more kinds of sols of a specified diameter so treated that they are positively charged and by heating the plated products to above 100°C. CONSTITUTION: The particle surfaces of one or more kinds of sols of a diameter below 100 nm such as Sio 2 , TiO and Zr which are negatively charged in general are so treated that they are positively charged, and a steel sheet is plated as a cathode in a zinc sulfate plating bath contg. 1W200 g/l of the treated sols at pH≤4 and a current density of 5W50 A/dm 2 with stirring. The plating conditions are restricted by definite reason. The plated sheet is then heated to above 100°C to enhance the water resistance, thus obtaining a zinc composite-electroplated sheet with superior corrosion resistance and no pinhole without using a conventional alloying means with Ni, Cr or the like. COPYRIGHT: (C)1979,JPO&Japio

Electroplating bath for depositing tin or tin alloy with brightness

Abstract: An electroplating bath for depositing tin or a tin alloy with satisfactory brightness, which comprises a mother bath of a pH-value ranging from 4 to 8 and containing citric acid or its salt, an ammonium salt and a water-soluble polymer as a brightener. The bath may further comprise an aldehyde compound as a co-brightener.

Forming method for heat and abrasion resisting protective coating

Abstract: PURPOSE:To form the above mentioned coating having a good adhesive property by carrying out plasma spraying of WC base cermet on the alloy plating layer containing not less than one kind of Ni and Co and not less than one kind of P and B, applied on the surface of metal substrate. CONSTITUTION:About 5-200mu thickness of alloy plating layer containing not less than one kind of Ni and Co and not less than one kind of P and B, is formed on the metal substrate by nonelectrolytic plating method or electroplating method. WC base cermet, for example, W-Co, WC-Al, WC-Ni, WC-self-fluxing alloy etc., is sprayed on the alloy plating layer by plasma spraying method and about 10-700mu thickness of WC base cermet layer is formed. Moreover, on occasion demands, the film composed of the alloy plating layer and cermet layer, is treated by heat at about 300-600 deg.C.

Silver-electroplating process

Abstract: A process for silver-plating, which comprises steps of preplating a substrate material in an aqueous preplating solution comprising 10 -5 to 0.02 mole/l of silver and more than 0.01 mole/l of a silver complexing agent such as thiocyanic ions under non-current density, to preplate a sufficient thickness of silver to restrain or substantially prevent substitution plating, and then electroplating the preplated substrate material until a sufficient thickness by supplying an electric current to said material in an aqueous silver plating solution comprising silver ions, thiocyanic ions and a film improving agent.

Low free cyanide high purity silver electroplating bath and method

Abstract: A bath for electroplating substantially pure silver deposits includes 2-240 grams per liter of alkali metal silver cyanide, a water-soluble electrolyte and a water-soluble selenium compound containing selenium in the -2 oxidation state. The bath has a pH of 8-10 and a free cyanide content of less than 1.5 grams per liter. The bath is maintained at a temperature of 18°-24° Centigrade and may be operated to provide current densities of 0.1-75 amperes per square decimeter.

Method of electroplating and treating electroplated ferrous based wire

Abstract: Method of treating ferrous based wire comprised of (A) electroplating a negatively charged ferrous based wire in a prescribed aqueous electrolyte solution containing a positively charged stationary anode and, in combination, simultaneously, in the same electrolyte solution, (B) deplating a similarly electroplated ferrous based wire by passing said plated wire as a supplemental, additional, positively charged, moving anode through said solution to effect a removal of its electroplated outer metal coating.

Selective absorber on glass and method for its production

Abstract: An improved selective absorber on a glass substrate having high solar absorption and low infrared emission. The Selective Absorber on a glass substrate includes an electrically conducting layer of silver metal having a thickness on the order of 0.1 microns, and an absorbing layer of either black nickel or, alternatively, a layer of oxidized iron over a layer of nickel or bright nickel. The method of this invention defines the process of producing the Selective Absorber on a glass substrate by thoroughly cleaning the glass, chemically depositing a thin layer of silver metal over the clean glass surface, then electroplating an absorbing layer over the silver layer. The absorbing layer may be electroplated black nickel or, alternatively, an electroplated layer of nickel or bright nickel, such as cobalt-nickel, and an electroplated cover layer of iron. The glass substate and composite layers are heat treated to thermally cured to improve its optical and properties.

Cyanide-free alkaline zinc baths

Abstract: Cyanide-free alkaline zinc electroplating baths for depositing highly lustrous zinc coatings on steel or iron. The results are attained with alkaline zinc baths containing a reaction product obtained by conversion of substantially equal molar quantities of (a) a reaction product of a nitrogen compound containing at least two nitrogen atoms with an epihalohydrin, or a mixture of such reaction products, with either (b1) a reaction product of an alcohol or a carboxylic acid with an epihalohydrin, or a mixture of such reaction products, and/or (b2) a pyridine compound having from 1 to 3 methyl or ethyl groups and/or 1 to 3 carboxylic groups, or salts of (b1) and (b2). Zinc coated objects produced with the baths can be tempered without adversely affecting the zinc coating.

Electrodeposition of black deposit and electrolytes therefor

Abstract: Aqueous alkaline bath composition for electroplating a black metallic co-deposit on ferrous and non-ferrous substrates comprised of an antimony-containing compound; a copper, nickel or zinc compound, and a strong base.

Periodic Reverse Current Process in Electroplating Using Acid Copper Electrolytes

Abstract: SummaryThe effect of periodic reverse current on deposit properties is investigated by varying current parameters and electrolyte composition. Using high reversal frequencies, plating speed, throwing power and surface quality can be increased in comparison with d c plating. By choosing convenient current parameters, the benefit of periodic reverse plating can be considerable.

Method and electrolyte for electrodeposition of bright gold and gold alloys

Abstract: Bright gold or gold alloy electroplating employing a preformed fully neutralized salt of a cobalt or nickel metal organophosphorus chelate as the brightening agent.