(Session 9B )Growth behaviour of intermetallic compound in weld interface of dissimilar metal weld by friction stirring

摘要

Friction stir welding is effective method to fabricate dissimilar metal weld between aluminum and steel with higher weld strength due to suppression of intermetallic compound layer growth in the weld interface by low heat input during welding. Growth behaviour of intermetallic compound in the weld interface by post weld heat treatment was studied. The weld strength decreased with the thickness of intermetallic compound layer in the weldinterface above 1 ?m in the thickness. From transmission electron microscope observation, the intermetallic compound layer in the weld interface was composed of Fe2Al5 and FeAl phases. From in-situ synchrotron X-ray diffraction during the heat treatment, significant growth of Fe2Al5 phase with heating time was observed.