Re-investigation the phase equilibria and thermodynamic assessment of the Nd-Sn binary system.

The Nd-Sn phase diagram has been investigated within the range of 20–80 at.% Sn using X-ray diffraction (XRD), scanning electron microscope equipped with energy dispersive spectrometer (SEM-EDS), and differential scanning calorimetric (DSC). In addition to the nine known compounds, Nd 5 Sn 3 , Nd 5 Sn 4 , Nd 11 Sn 10 , NdSn, Nd 3 Sn 5 , NdSn 2 , Nd 3 Sn 7 , Nd 2 Sn 5 and NdSn 3 , two reported compounds, Nd 3 Sn and Nd 2 Sn 3, as well as two new compounds Nd 2 Sn and Nd 4 Sn 5 , have been detected. The formation of Nd 2 Sn, Nd 4 Sn 5 and Nd 2 Sn 3 has been determined as follows: Nd 2 Sn forms by peritectoid reaction Nd 3 Sn + Nd 5 Sn 3 → Nd 2 Sn at 1134 °C; Nd 4 Sn 5 and Nd 2 Sn 3 form by peritectic reaction at 1168 °C and 1146 °C, respectively. Nd 3 Sn and Nd 3 Sn 5 are only stable at high temperatures, Nd 3 Sn forms by a peritectic reaction at 1163 °C and decomposes at 1114 °C, and Nd 3 Sn 5 is formed via a peritectic reaction at 1153 °C and decomposes at 1136 °C. Additionally, five invariant reaction temperature have been updated. The Nd-Sn system was modeled using the Calphad approach, incorporating new experimental data along with all other available experimental information. A comprehensive thermodynamic description of the Nd-Sn system has been obtained, and extensive comparisons between calculated and experimental data indicating that almost all adopted experimental and theoretical data are satisfactorily matched. • Nd and Sn are important elements for magnesium alloys. An accurate Nd-Sn binary phase diagram and reasonable thermodynamic data are crucial for the design of a novel Mg alloy. • The phase equilibria of the Nd-Sn system was re-investigated byXRD, SEM-EDS and DSC. In addition to eleven known compounds, two new compounds: Nd 4 Sn 5 and Nd 2 Sn, have been identified in this range. • The Nd-Sn system was modeled using the Calphad method, which provides a complete thermodynamic description of the Nd-Sn system based on the new experimental data and all other available experimental information. [ABSTRACT FROM AUTHOR]