《Bi-Sn-Zn (Bismuth-Tin-Zinc)》.pdf

202 Bi–Sn–Zn Bismuth – Tin – Zinc Joachim Gröbner Introduction Experimental investigations of the Bi-Sn-Zn phase diagram date from the end of the nineteen century when composition of two coexisting liquids was determined by chemical analysis of separated layers [1891Wri, 1892Wri]. However these results should be considered as semi-quantitative, because later is was shown by [2000Mal1] that immiscibility can not take place above 600°C. A first part of the ternary miscibility gap for this solder system was given by [1949Jae1] at 650 and 750°C. [1949Jae2] showed a liquidus surface which was based on the earlier experimental work of [1923Muz]. [1923Muz] measured thermal arrests of 104 liquid alloys using cooling curves. The first and second recorded arrests could be identified as two- and three-phase equilibria, while the third one corresponded to eutectic equilibrium. Microscopic analysis was also applied by [1923Muz]. [1987Mal] reviewed the experimental data of the Bi-Sn-Zn based on activity determination from emf measurements of [1959Ole], [1966Pta] and calculations of [1977Pel]. A complete thermodynamic calculation of the ternary system is given by [2000Mal1]. This work included a detailed summary of the experimental work. The experimental works of the Bi-Sn-Zn system are summarized in Table 1. Binary Systems The phase diagrams for binary systems are taken from [1994Oht] for Bi-Sn, from [2000Mal2] for Bi-Zn and from [1999Oht] for Sn-Zn according to recommendation of [2000Mal1]. Phase diagram of the Sn-Zn is of simple eutectic type. The phase diagram of this binary system calculated in [1999Oht] is similar to the latest recommendation of [2002Per]. However, the temperature of eutectic reaction l (Zn) + (Sn) according to calculation of [1999Oht] is 6 degrees lower than in [2002Per]. The differences between phase diagram of [1999Oht] and [2002Per] are within uncertain