Phase diagram of the eutectic type LiCl-PrCl3-KCl system with wedging liquidus of binary compound

Abstract

Based on the published experimental data (phase diagrams of three binary systems, four isothermal sections and DTA curves of 33 alloys), a spatial (three-dimensional – 3D) computer model of the LiCl-PrCl3-KCl phase diagram has been constructed. It is shown that, in the general case, the diagram is formed by 66 surfaces and 27 phase regions; however, due to the negligible solubility of the initial chlorides and the stoichiometry of the two binary compounds in reality, it consists of 31 surfaces and 14 phase regions. The evaluation of the quality of the obtained 3D model is a comparison of model and initial isothermal sections and calculation of response functions for 33 alloys with temperature values at the boundaries of the primary crystallization regions shown on DTA traces. The geometric structure of the LiCl-PrCl3-KCl phase diagram is also considered as an illustration of the features of ternary systems of the eutectic type, depending on the nature of the formed in them binary compounds.