In this work, the results of the influence of Rare Earth elements on the kinetics of crystallisation of Mg-xLi-2Al alloys (x=4, 8 and 12 by weight percentage) as well as dilatometric behaviour and microstructure was presented. The thermo-derivative analysis was implemented using the UMSA platform (Universal Metallurgical Simulator and Analyzer) with cooling rate approx.≈0.5°Cs-1 that correspond to natural cooling. The coefficient of thermal expansion (CTE) of investigated light-weight alloys was measured in the temperature range from 20 to 400°C. Microstructural evaluations were identified by light microscope, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Obtained results from the thermalderivative analysis allowed to determine characteristic temperatures of phase transitions of the investigated alloy during crystallisation. The data used in this work can be used in order to improve simulations of casting processes. The relationships between solidification events and alloy chemistries will aid in the design and optimization of casting alloys and components [1, 2]. a) b) Fig. 1. Representative thermal characterization of LAE442 alloy and its changes of fraction solid