High-temperature oxidation of nickel-plated copper vs pure copper

Thin layers of nickel were plated onto copper to improve oxidation resistance at high temperatures. Pure copper and nickel-plated copper were oxidized at 600-800 degrees C in air for various lengths of time. The degree of oxidation was determined by the mass gain. It was found that the nickel-plated copper oxidizes at a rate of about 1/20 of that of pure copper. The oxidation rate of both the pure copper as well as the nickel-plated copper was approximately parabolic in the temperature range studied. The thicknesses of the oxidized layers for copper and nickel-plated copper are given by the following two equations, respectively Cu: t(mm) = 50,000 x root exp(-1.97-18,000/T(K)) x root Years Ni plated Cu: t(mm) = 23,000 x root exp(-7.3-17,300/T(K)) x root Years (C) 2000 Canadian Institute of Mining and Metallurgy. Published by Elsevier Science Ltd. All rights reserved.