A. A. El-Daly, H. A. Hashem, N. Radwan, F. El-Tantawy, T. R. Dalloul, N. A. Mansour, H. M. Abd-Elmoniem, E. H. Lotfy
الملخص العربي
Sn–9Zn lead-free solders possess remarkable
potential as candidates for low temperature electronic
applications. In this study, it is proposed to utilize the
advantages of Bi alloying and reducing the amount of Zn to
improve oxidation resistance and reliability of eutectic Sn–
9Zn solder. The results indicate that hypoeutectic Sn–
6.5Zn alloy composed of b-Sn-rich phase and a-Zn fiber.
1.0 wt Bi addition caused a strong inhibition of a-Zn fiber
inside the alloy matrix. Moreover, the fiber spacing of a-Zn
phase increased and its diameter decreased. With increasing
Bi content to 3.0 wt, small bright of Bi particles are
observed. The addition of Bi could effectively reduce the
onset and eutectic temperatures, while the amount of
undercooling\1.0 C was recorded. The tensile strength of
Bi-containing solders was enhanced to about 180 %,
although the ductility was slightly decreased. The higher
strength was contributed by solid solution effect and
precipitations hardening of Bi atoms or particles, which can
remarkably modify the microstructure, blocks the dislocation
motion and increases the tensile strength of Bi-containing
solders.
اسلام حمادة لطفي محمد | islam hamada lotfy mohamed | 4187