| 摘要 |
627,964. Electrodeposition of metals. POOR & CO. July 24, 1945, No. 18972. Convention date, April 14. [Class 41] A method of electro - depositing metals comprises passing a plating current of abnormal wave - form having peaks and valleys through an alkaline plating bath of a metal to be deposited, the valley value of the voltage being within the range of a maximum of 1.9 volts to a minimum of minus two-thirds of the positive peak value. As shown, an anode 2 comprising one or more electrodes, and a cathode 3 are in a circuit containing a rheostat 9, a lowvoltage direct current generator 8 and the secondary 4 of a transformer 5. The primary 6 is connected through a regulating autotransformer 7 to a source of alternating current. In one example of a method of electroplating, a plating bath containing cadmium oxide and sodium cyanide is subjected to a current in sine wave-form with four volts alternating current and six volts direct current. The valley voltage is just below 1.9 volts. In another example a plating bath containing copper cyanide, sodium cyanide, sodium hydroxide and potassium gluconate is subjected to current from an A.C. voltage of 7 volts superimposed on a D.C. voltage of 6 volts. Other examples are given in connection with electro-deposition of zinc and tin. Reference has been directed by the Comptroller to Specification 599,707.
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