Active learning of eutectic phase diagram in engineering courses

The present article shows a new strategy used to cover phase diagrams for undergraduate mechanical engineering students. It is based on active learning in which students are required to investigate experimentally three different eutectic alloys by using X-ray diffraction and metallography. The first technique allows students to use Rietveld analysis to obtain the mass fraction of the present phases and they must compare their results with those obtained theoretically whilst the second one is used to characterize those phases and measured their area fractions. From these results, they can also compare them with those obtained theoretically, but considering the density of different phases. The results have shown that students understood more clearly concepts such as the lever rule, and the very interpretation of phase diagram: the liquidus and solidus curve and finally the eutectic point.

X-ray scattering study on the crystalline and semi-crystalline structure of water/PEG mixtures in their eutectic phase diagram

Water/PEG mixtures start to phase separate below the liquidus line. Above the eutectic temperature the solid phase is either pure water ice or semi-crystalline PEG. Below the eutectic line both crystals coexist, no mixed-crystalline phase is found.

Quantification of the liquid window of deep eutectic solvents

The non-ideality of the eutectic phase diagram is quantified using a single interaction parameter that could be determined directly from the experimental eutectic temperature of the mixture.

The Formation of Epitaxial Eutectic Modulated Structures

ABSTRACTThe thermodynamics of the formation of a coherent epitaxial two-phase modulated structures from a liquid solution is considered. It is shown that elastic interactions in the epitaxial system change the topologic features of the eutectic phase diagram. As a consequence an eutectic point splits into two eutectic points or it is transformed into a consolute point.