Activity Measurement of the Constituents in Molten Sn-Mg-Zn Ternary Lead Free Solder Alloys by Mass Spectrometry

摘要

Activities of the constituents in an alloy proposed for the Pb-free solder, Sn-Mg-Zn, were studied experimentally using a mass spectrometer. The ion current ratios of Mg to Zn were measured in the temperature range 700-800 K. From the experimental results and the assessed thermodynamic properties of molten Sn-Mg, Sn-Zn, and Mg-Zn binary alloys, the excess Gibbs free energy of liquid Sn-Mg-Zn ternary alloy was determined. Also, phase diagram of Sn-Mg-Zn ternary system was determined.