SOME POSSIBLE ROLES OF CATHODIC FILMS IN ELECTRODEPOSITION OF ALLOYS .1.

A series of experiments was run on electrodeposition of alloys from aq ueous pastes of insoluble compounds in a sandwich cell, to test the hy pothesis that the 1:1 atomic ratio of the nickel-tin alloy could be fo rmed by electrodeposition from a film of an insoluble compound contain ing the metals in a 1:1 ratio precipitate on the cathode. It was shown that the reduction of pastes of several insoluble compounds containin g two reducible metal ions produced binary alloys in which the atomic ratios of the two metals were the ratios of simple whole numbers, in a greement with the prediction. The ratio of the metals varied with the substrate, however, and the ratios in the deposit were not the same as the ratios in the insoluble compounds. From this, it was concluded th at the insoluble compounds used were converted to another insoluble co mpound before they were reduced to the metal.