Abstract
In the past, lead and tin was used as the primary material in soldering due to its low melting point. However, as medical research revealed the hazards of lead to humans a search began for a replacement. One such material is an alloy of bismuth and tin. The objective of this study is to obtain familiarity with using both DSC and XRD, as well as generate data to analyze and learn more about Bismuth and Tin mixtures. DSC and XRD are essential to the future of materials engineering in the field of materials characterization and identification. As an aid for teaching phase equilibria to undergraduate students, we have designed a laboratory exercise that allows them to create a phase diagram from data produced by DSC and hands-on insight by an exposure to modern analytical instrumentation and practice quantitative skills such as calculation (e.g., peak temperatures with % of Bi-Ti alloys, phases, graphing etc.). The samples is also analyzed through the use of a DSC in order to learn at what temperature different compositions of this material undergo phase changes and to create an experimental phase diagram and 57wt% Bi would be the best fit for soldering as an replacement for lead-tin.
Key words: primary soldering material, Sn-Bi alloys, Bismuth and Tin mixtures DSC, powder XRD, replacement for lead