Axial and radial interface instabilities of copper/tantalum cylindrical conductors

The shape evolution of conductors is investigated when axial and radial sin usoidal fluctuations appear simultaneously on the cylindrical surface of a stressed surface. An energy variation calculation is performed to determine the theoretical wavelengths of these oscillations, while the profile of th e surface is predicted. A study of the rod surface kinetics is also perform ed to characterize the evolution of the rough ness vs time. The results are compared with the experimental observations of the interface of copper/tan talum conductors. The good agreement between the theory and the experiment confirms the interpretation of the phenomenon in terms of Grinfeld instabil ities. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. A ll rights reserved.