Reactions in Sn corner of Cu–Sn

Abstract

In the expectation of a possible connection between Sn–Cu₆Sn₅ and Sn–Zn binary eutectics, several alloy compositions were selected along a possible joining path. Samples of each were solidified unidirectionally at a very slow rate, approximating freezing with complete mixing in the liquid (the ‘solidification path’ technique). This procedure allows the detection of reactions by the change in the phases frozen out with the change in composition of the liquid due to segregation. Three quasi-peritectic reactions (U1–U3) and a ternary eutectic reaction were found: U1, L+Cu₆Sn₅ CuZn+Sn; U2, L+CuZn Cu₅Zn₈+Sn; U3, L+Cu₅Zn₈ CuZn₄+Sn; and E, L (Sn)+(Zn)+CuZn₄.