US564748A - Harry l - Google Patents

Description

{No Model.) I H L HAAS PROCESS OF NICKEL PLATING.

N 564,748. Patented July 28, 1896.

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ATTORNEYS free at the anode.

UNITED STATES PATENT ()FFIQE.

HARRY L. HAAS, OF NEW YORK, N. Y., ASSIGN OR TO THE ZUCKER & LEVETT & LOEB COMPANY, OF SAME PLACE.

PROCESS OF NICKEL-PLATING.

SPECIFICATION forming part of Letters Patent No. 564,748, dated July 28, 1896.

Application filed November 27, 1895.

To all whom it may concern:

Be it known that I, HARRY L. HAAS, of the city, county, and State of New York, have invented certain new and useful Improvements in Processes of Nickel-Plating, of which the following is a specification, reference being had to the accompanying drawing.

My invention relates to improvements in the art of nickel-plating, the objects being, first, to more quickly accomplish the plating than heretofore; second, to use an electric current of small voltage; third, to more uniformly, as regards thickness, adhesion, and color, accomplish the depositing of nickel upon the cathode, and, fourth, to render unnecessary the addition, during the plating operation, of nickel-salts to strengthen'the plating-bath, as heretofore.

In the accompanying drawing there is shown a partly-sectional view of a nickel-plating bath, the source of electrical energy, which may be of any useful form, being omitted.

In the accompanying drawing I have shown one form of apparatus which may be employed in carrying out my new process of nickelplating.

A represents the box for containing the electrolyte or solution B. A suspended anode O, of nickel, is partly immersed in the solution. This anode differs from those used prior to my invention, in that it presents to the electrolyte a much greater surface than is presented by a plane fiat anode of the same length and breadth, and although other forms of nickel anodes constructed so as to have an increased surface may be employed with advantage, yet I prefer to use a corrugated anode made substantially as shown in the accompanying drawing. This anode is suspended from a metallic rod D by means of hooks F F, and is connected by conductor E to the positive pole of the generator. The metallic rod G, from which the cathode is suspended, is connected to the negative pole of such generator.

During electrolysis both the sulfate of nickel and the sulfate of ammonia are decomposed, and sulfuric acid and ammonia are'set The sulfuric acid forms anequivalent quantity of sulfate of nickelb y its action on the anode, which it dissolves.-

If the amount of ammonia freed at the Serial No. 570,291. (No specimens.)

anode becomes too great, in proportion to the amount of sulfuric acid set free, the solution will, in a short time, become Weak in metal and decidedly alkaline, and it has been found 'that the more intensethe current of electricity employed the more rapid will be the ungreater surface than would be the case if a plane anode were .used, I find that an electric current of very loW intensity may be employed, even as low as two volts, and that such current may be more uniformly maintained and that less ammonia is liberated than when the plane anode is used, and I find also that a much greater amount of nickel is dissolved from the corrugated anode because of the increased surface presented, and that the strength. of the bath is more uniformly maintained,with the direct result that the nickel deposited upon the cathode is more regular and uniform in color and thickness, adheres more tenaciously, and does not scale therefrom, as was the case heretofore, due to excess of hydrogen at the cathode by the deposited nickel. Furthermore, I have found that with the use of-a corrugated anode the action'of the gases formed at the anode is quite different from that which occurs when a plane or flat anode is used. lVith a plane or fiat anode the gases developed at the anode are apt to proceed in considerable quantities directly across to the cathode, and their presence at the cathode acts deleteriously upon the deposit of nickel, as the nickel is apt to be flaky and non-adherent. hand,with a corrugated anode, the gases are developed on surfaces which are inclined to each other, and the gas developed on one surface meets that developed on the surface inclined to. it, and instead of proceeding in any marked quantity across to the cathode it On the other' increased surface to the solution.

forms into bubbles,which rise to the surface of the solution. As a result of this action the deposit of nickel is whiter and more malleable when a corrugated anode is used than when a plane or flat anode is used, the other conditions being the same.

I have also discovered that,when the anode presenting an increased surface is not used, the strength of the solution will not be uniform, for, if the anode-surface is not considerably larger than that of the article to be deposited upon, more nickel will be deposited on the work than is dissolved from the anode, and all the sulfuric acid which is evolved at the anode will not be dissolved to form sulfate of nickel, but will combine with some of the ammonia, and the bath will become, in time, composed of sulfate of ammonia and very little sulfate of nickel, thereby weakening the solution in nickel and causing the deposit to become dark in color. To overcome this objection, it was customary to add nickelsalts to the solution, as required, but, by the use of my process, the addition of such salts is rendered unnecessary, due to the evenness existing between the resolving of the anode into the solution and the deposition of nickel upon the cathode. I have also found that when an anode having the increased surface is employed the increased size of the anode and its more even solution into the bath contribute to make the electrolyte a much better conductor of the current than when the plane anode is employed, the objection heretofore being that as the solution becomes weaker in nickel the resistance to the passage of the current was increased, and this diflicnlty rendered necessary the employment of a current much higher in voltage than is required in connection with anynew process of plating, which has been objectionable and expensive.

One of the disadvantages due to the employment of currents of high voltage is the tendency of the nickel to precipitate in the form of basic salt, impairing the metallic strength of the bath. This precipitation I prevent by the employment of a current of low voltage and an anode presenting a greatly- The process of nickel-plating therefore diifers from most, if not all, other plating processes in that a substantially neutral solution must be employed, which renders the rate of solution of the anode comparatively slow and unequal to the rate of deposit at the cathode, and this results in the necessity of constantly replenishing the solution with salts of nickel to maintain the requisite strength of the solution. These difficulties are remedied by my invention and the process rendered substantially even and continuous as long as the anode lasts.

I am aware of the United States Letters Patent to W. H. Remington, dated October 6, 1868, No. 82,877, and to A. O. Wenzel, dated September 10, 1878, No. 208,003, both of which show and describe anodes composed of boxes having perforated sides and bottoms and containing nickel in the form of grains, and I especially disclaim the forms of anodes shown and described in the said patents as being entire] y unfitted for the purposes of my invention, because of the imperfect electrical and mechanical contact between the grains,which results in the formation of an anode oifering an enormous resistance to the passage of electricity. My invention, on the contrary, contemplates the employment of a continuous solid anode.

I am also aware of the United States Letters Patent to DHumy, No. 367,705, dated August 2, 1887, for galvanic battery, which shows a corrugated element of iron or steel, and I especially disclaim from my invention the use of elements of iron or steel, and in fact all metals excepting those which are wholly or largely composed of nickel or an alloy thereof. I desire also to call attention to the fact that the DHumy patent does not describe any process of plating, and the uses and construction of my invention are quite different.

I am also aware of United States Letters Patent No. 317 ,246, dated May 5,1885, to E. P. Thompson, for an apparatus for the electrodeposition of gold from its chlorids, and I disclaim the apparatus and process there described, which cannot be used for the same purposes as my invention and which are different in material and important respects therefrom.

I also desire to be understood as not attempting to cover the use of plane flat anodes of nickel, which cannot advantageously be employed, requiring an unnecessary and undesirable enlargement of the size of the bath or a reduction of the quantity of the electrolyte.

I am also aware of what is disclosed in British Patent No. 3,533, of February 27, 1889, for improvements in the extraction of copper, zinc, and precious metals by electrolysis, in which, among other things, it is proposed to use an anode which may consist of pieces or plates of retort-carbon, conveniently shaped and in electric connection with each other, or perforated lead plates covered with small pieces of retort-carbon, or of lead plates with rather deep corrugations, likewise perforated to allow the liquid to pass through the plates, and make no claim thereto, as these would not be practicable for the purposes of my inface, and then passing an electric current through the anode and the solution, and, by the use of such anode, balancing the solution of the anode and the deposit at the cathode, whereby the metallic strength of the solution is maintained substantially uniform, substantially as and for the purpose described.

In witness whereof I have hereunto subscribed my name this 25th day of November, 1895.

HARRY L. HAAS.

In presence of- WM. H. BERRIGAN, J r., W. S. J ONES.

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