Experimental Study Of Phase Interfaces In Ni/sn And Ti/sn Solid/liquid Diffusion Couple

The study on binary alloy is a basic issue in material science. This thesis studies the interface diffusion between Ni and Sn, Ti and Sn. Ni/Sn and Ti/Sn solid/liquid diffusion couples with curving interfaces were prepared by crucible-type mechanical method, in which Ni and Ti are matrixes and Sn is filler. The former was annealed at the temperature from 600℃to 900℃for 10min-180min, The latter was annealed at the temperature from 600℃to 800℃for 10min -180min. With optical microscope and scanning electron microscopy, the interface migration were investigated. The results show that the number and the thickness of the diffusion layers increase with the growth of heat-treat temperature and time. The thickness and the temperature satisfy Arrhenius relationship, and the thickness and the time satisfy parabolic relationship. It has been showed that, the diffusion zone has apparent interface with Ni and Ti matrix and has vague one with Sn filler. There are compounds Ni3 Sn, Ni3 Sn2 and Ni3 Sn4 in Ni/Sn diffusion couples. There are TiSn, Ti2 Sn3 and TiSn4 in Ti/Sn diffusion couples. The formation heat calculated by Miedema Model and the experimental results showed the order of appearation of the compound. For Ni/Sn system, Ni3 Sn4 appears first, and then Ni3 Sn4 appears between Ni and Ni3 Sn, and Ni3 Sn2 appears last. For Ti/Sn system, TiSn, Ti2 Sn3 and TiSn4 are first, second and last respectively.