Scanning electron microscopy (SEM) was introduced into undergraduate physical chemistry laboratory curriculum to help students observe the phase composition and morphology characteristics of tin-lead alloys and thus further their understanding of binary alloy phase diagrams. The students were captivated by this visual analysis method, which allowed them to more fully consider the relationship between macroscopic behaviors and microscopic structures of materials. During this process, the abilities of critical thinking were inspired, and a spirit of team work came into being.