Abstract
Sn-In-Ag-Zn alloys are promising Pb-free solders. Various Sn-rich Sn-In-Ag-Zn alloys are prepared, and their heating and cooling curves are determined by using differential thermal analysis at a scanning rate of 5oC/min. These alloys' solidification behaviors are illustrated based on their cooling curves and the liquidus projection of the quaternary Sn-In-Ag-Zn system. The liquidus projection of the Sn-In-Ag-Zn quaternary system is constructed in this study. Sn-In-Ag-Zn alloys of various compositions are prepared, and their primary solidification phases are determined. The liquidus projection of the quaternary Sn-In-Ag-Zn system is constructed according to the data of primary solidification phases, and the liquidus projections of its four constituent ternary systems, Sn-In-Ag, Sn-In-Zn, Sn-Ag-Zn and Ag-In-Zn. At the Sn-rich corner, the primary solidification phases are Sn, -Ag3Sn and phases. No ternary and quaternary phases are observed as the primary solidification phases.