The Co-Ni-Sn (Cobalt-Nickel-Tin) System

Abstract

The Co-Ni system [1991Nas] (Fig. 1) is a simple isomorphous system. In the fcc a solid solution, there are indications of formation of short range order near the CoNi3 composition. The Co-Sn system [1983Nis, Massalski2] (Fig. 2) has three intermediate phases, Co3Sn2 in two allotropic forms, Co3Sn2(HT) and Co3Sn2(LT); CoSn; and CoSn2. The Co3Sn2 phase melts congruently at 1170 C and the other two phases form through peritectic reactions L + Co3Sn2(HT)MCoSn at 936 C and L + CoSn M CoSn2 at 525 C. Co3Sn2(HT) fi Co3Sn2(LT) transformation occurs at 500 C. Two eutectic reactions L M (aCo) + Co3Sn2(HT) and L M CoSn2 + (bSn) occur at 1112 and 229 C, respectively. The fcc (aCo) fi hcp (eCo) reaction, possibly a eutectoid type reaction, occurs at 420 C. The Ni-Sn system [1991Nas, Massalski2] (Fig. 3) has three intermediate phases, Ni3Sn and Ni3Sn2, both of which exist in two allotropic forms, and Ni3Sn4. Both Ni3Sn2 and Ni3Sn phases melt congruently at 1264 and 1174 C, respectively, and the Ni3Sn4 phase forms through a peritectic reaction L + Ni3Sn2 M Ni3Sn4 at 795 C. Three eutectic reactions L M (Ni) + Ni3Sn(HT), L M Ni3Sn(HT) + Ni3Sn2(HT), and L M Ni3Sn4 + (bSn) occur respectively at 1130, 1160, and 231 C. The Ni3Sn(LT) phase forms through a congruent transformation at 977 C. The Ni3Sn2(HT) fi Ni3Sn2(LT) transformation occurs at 600 C.