High-resolution transmission electron microscopy study of discontinuously precipitated Ni3Sn

Under appropriate aging treatments Ni-Sn supersaturated solutions (alpha') decompose at an advancing reaction front into alternating lamellae of Sn-de pleted face-centered cubic (fcc) alpha and DO19 Ni3Sn. This precipitation a nd the typical defect structures generated within the DO19 compound were in vestigated by using conventional and high-resolution transmission electron microscopy (CTEM and HRTEM). Complete characterization of defects lying on the basal planes of Ni3Sn lamellae was achieved by HRTEM imaging and iterat ive digital image matching. The spatial arrangement of stacking faults, rot ation interfaces and antiphase boundaries revealed important aspects of the defect formation mechanisms. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.