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After a comprehensive review of the thermochemical and phase diagram data in the Cu–Li system, new experiments were performed to clarify existing contradictions. Several Cu–Li samples were prepared and powder X-ray diffraction (XRD) was performed on quenched Cu–Li alloys. Our experimental work could not confirm the presence of the intermetallic phase Cu 2 Li 3 which has been recently proposed. Additionally, the results of our high temperature enthalpy of mixing measurements of the liquid phase indicate that the Li-rich liquidus line is more Cu-rich than presented in previous works. Based on our experimental data, a Calphad approach was used to obtain a self-consistent thermodynamic description of the Cu–Li binary system. Furthermore, a preliminary description of the ternary Cu–Li–Sn liquid phase was developed by combining the new description of the liquid phase in the Cu–Li system with the description of the liquid phase from our previous Cu–Sn and Li–Sn assessments. The enthalpies of mixing of the liquid phase calculated using extrapolations according to the associate, Muggianu, and Toop models are compared to the enthalpies of mixing reported in the literature. Our work shows that the enthalpies of mixing calculated using the associate model are in excellent agreement with the literature data, and no additional ternary interaction parameters are necessary. The contribution of the formation of Li 4 Sn associates to the enthalpy of mixing of the ternary liquid was discussed. [ABSTRACT FROM AUTHOR]

The Li–Sn phase diagram was re-investigated using differential thermal analysis (DTA). A special thermal analysis technique was used to clarify the characters of the invariant reactions between the liquid, Li 17 Sn 4 and Li 7 Sn 2 phases and between the liquid, Li 7 Sn 2 and Li 13 Sn 5 phases. Using this technique, the eutectic reaction: L ↔ Li 17 Sn 4 + Li 7 Sn 2 and the peritectic reaction: L + Li 7 Sn 2 ↔ Li 13 Sn 5 were confirmed. The enthalpy of formation of the Li 17 Sn 4 phase was measured using high temperature solution calorimetry. A self-consistent thermodynamic description of the Li–Sn system was developed using the CALPHAD method. The liquid phase was described using the associate model, the Li 17 Sn 4 , Li 13 Sn 5 , Li 5 Sn 2 , Li 7 Sn 3 , LiSn and Li 2 Sn 5 phases were modeled as stoichiometric compounds, and the Li 7 Sn 2 phase was modeled to exhibit a homogeneity range at higher temperatures. Phase diagrams and property diagrams calculated using the new thermodynamic description for the Li–Sn system are in good agreement with the experimental data performed in this work and with literature data. [ABSTRACT FROM AUTHOR]

Thermodynamic data of seven Cu-Li-Sn alloys were determined by the Knudsen Effusion Mass Spectrometry (KEMS) for the solid, solid-liquid or liquid region. Thermodynamic activities of components, enthalpies and entropies of mixing were calculated in the temperature range of 623–933 K. The intermetallic phases Cu 6 Li 3 Sn 4 (s), CuLi 2 Sn 2 (s), and CuLi 3 Sn(s) have been described in literature quite recently. These phases were observed by powder X-ray diffraction (XRD) measurements after sample preparation. The thermodynamic data obtained by KEMS and the crystallographic data will enhance the available information for calculating the phase diagram for the ternary Cu-Li-Sn system by CALPHAD approach. [ABSTRACT FROM AUTHOR]