Local Cell Action during the Scaling of Metals, I

ll nickel is covered by a borate melt under an oxygen atmosphere, practically no oxidation takes place. li, however, the nickel sample is in electrical contact with an electronic conductor, e.g., a noble metal gauze, which extends up to the melt--oxygen irterface, nickel is attacked rapidly by virtue of local cell action. In this case, electron transfer is accomplished by the metal gauze and ions migrate through the borate melt. Electrochemical measurements show that the reaction is controlled mainly by polarization of the cathcde where oxygen molecules are reduced to ions. (auth)