Modulus map of a tin / lead solder alloy

Elastic modulus overlaid on topography of a tin/lead alloy solder. Tin-rich (lighter) and lead-rich (darker) regions can be identified in the modulus map. Modulus values differ from the bulk values of the pure metals because the phases do not consist of the pure metals but instead mixes rich in one or the other. Imaged using AM-FM Viscoelastic Mapping Mode on a Cypher S with blueDrive photothermal excitation, scan size 8 ?m.