Brass World: A Monthly Publication Relating to the Arts of Refining, Alloying, Casting, Rolling, Plating, Polishing and Finishing of the Non-Ferrous Metals and Their Alloys (October, 1929)

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ESTABLASHED 1905 BRASS WORLD PLATING — POLISHING — FINISHING A Monthly Publication Relating to the Arts of Refining, Alloying, Casting, Rolling, Plating, Polishing and Finishing of the Non-Ferrous Metals and Their Alloys NEW YORK, OCTOBER, 1929 VOL. 25. No. 10 The Use of Non-Ferrous Metals in the | Electroplating Industry | The Present State of the Art Briefly and Interestingly Reviewed —Supervision Has Already Passed from Foreman to Chemist; the -Metallurgist Will Be the Next to Assume Direction of the Work By FLOYD T. TAYLOR Vice-president, Hanson-Van Winkle-Munning Company, Matawan, N. J. AN ADDRESS AT JOINT DINNER OF INSTITUTE OF METALS AND IRON AND STEEL DIVISIONS, CLEVELAND, OHIO, SEPTEMBER, 10, 1929. N 1833, less than one hundred years ago, Michael ] Faraday discovered and stated the laws of elec- trolysis. His discovery formed the foundation of a new use of metals which has now reached a variety of application not ordinarily appreciated. Furthermore, things can be done with electro-deposited coatings which have thus far defied other methods. Some of the uses of electro-deposited coating are interesting. The ton- nage of metals already finding an outlet through such a channel is considerable. In general electro-deposits have two characteristics : ornament plus utility; utility plus ornament. - Both these factors are usually found associated in electro-deposits. Ornament plus utility was probably the first use. For example, the silver-plating of tableware, having its real birth in Birmingham, England, about 1844. However, this same ornament plus utility retarded the development of electro-plating, because in the beginning, electro-plated articles were branded with the odium of imitation and shunned accordingly. The gold brick of the swindler may be an exception to this. statement. When nickel-plating appeared on the scene, while its adoption was primarily on account of its ornamental value, nevertheless its utility, due to its protection of the underlying metal from corrosion, focused attention on the utility value of electro-deposits. The develop- ment of electro-refining is too familiar a subject to be reviewed for this audience. However, it is well to point out that the rarer metals are now recovered, in quantities hitherto impractical, through the shift from smelting to electro-refining. Electro-deposition furnishes an excel- lent ever-ready and ever-growing outlet: for these re- claimed metals, and consequently the metallurgist has a real interest in electro-deposition. Unfortunately electro-forming, that is producing some- thing of solid metal by, let us say, electrolyzing a solu- tion of a salt of the metal, seems limited in scope, because electro-forming is always a slow process and one in which the capital and floor-space investment is high. Only when the nature of the article itself is such that other methods are difficult, or impossible, does electro-forming play its part. In such cases, however, it plays its part well, and such applications put to use an appreciable ton- nage of metals. Most familiar is the electrotype of cop- per, or the so-called, nickel type when formed of nickel. Cheap, easy to make, faithfully reproducing its wax “inspiration,” electrotypes are really wonderful metal slabs, and so common that their character is unappreciated. Thin metal foils are expensive to produce by rolling or other mechanical methods. The cost of such foils increases or pyramids when very thin gages are pro- duced. They can readily be produced, in most metals, by electro-forming and paradoxically, the thinner, the quicker and the cheaper. The nickel flakes of the Edison storage battery are an example of what can be done by electro-forming. But it is in the field of coatings that electro-deposi- tion plays its important part; a field in which, for ex- ample, within a few years, electro-plating has trans- formed a reclaimed metal, which was a drug on the market, into a position of shortage, and has doubled the selling price. Electro-deposited coatings will prob- ably afford the best and cheapest method of arresting corrosion, especially when an outer metallic surface is desired. Attention is called to the distinction between corrosion and tarnish. Corrosion has to do with the metal underneath the coating; tarnish is an atmospheric discoloration of the outer surface of the coating. — 235