It is shown that protective films of pure beryllium oxide can be formed on a copper base copper-beryllium alloy, by heating it to temperatures higher than 600° C on condition that the partial pressure of oxygen in the atmosphere be maintained lower than 0,02mm Hg.

This result is in agreement with Mott's theory on the oxidation of metals.

Protected samples of the alloy are unaltered by contact with normal atmosphere at 400 or 500° C. Unprotected samples are rapidly oxidized at these temperatures and the films formed contain a little beryllium oxide and large quantities of copper oxides.