Formation Mechanism of Phase Interface for Diffusion Couple of Pb/Sn Layered Composite

Abstract

This paper prepares the diffusion couple of Pb/Sn layered composite by hot pressing, treat it at different holding times, and investigates the appearance characteristics and forming mechanism of the couple by means of SEM-EDS. The results show that Sn atoms preferentially diffuse into the Pb side under the heating temperature of 503K and the pressure of 0.5MPa. With the increase of the welding time, a eutectic liquid layer is formed on the interface of Pb/Sn and the diffusion-dissolution of Pb and Sn atoms are completed by simulta-neous extension and homogenization. The research also demonstrates the star studded distribution of α-Pb and β-Sn solid solutions.