Isothermal sections at 1400, 1100 and 900 °C of the Ti–Dy–Sn system below 40 at.% Sn

•The ternary compound Ti4.2−4.3Dy0.8−0.7Sn⩽3Sn⩽3 (τ) exists at 1400, 1100 and 900 °C.•It takes part in equilibria with the phases (Ti3Sn), (Ti2Sn), (Ti5Sn3), (Dy5Sn3).•The character of the isothermal sections is defined by the phase (Dy5Sn3).•At 1400 °C the liquid phase is present in the system.•At 1100 and 900 °C the liquid phase is absent.

By the methods of X-ray diffraction, SEM and electron probe microanalysis, phase equilibria in the Ti–Dy–Sn system below 40 at.% Sn at temperatures 1400, 1100 and 900 °C were studied. The isothermal sections at 1400, 1100 and 900 °C were constructed. It was shown that the ternary compound Ti4.2−4.3Dy0.8−0.7Sn⩽⩽3 (τ) is stable at these temperatures. At 1400 °C the liquid phase is present in the system. The isothermal section at this temperature is characterized by the three-phase regions L + (βTi) + (Dy5Sn3), (βTi) + (Тi3Sn) + (Dy5Sn3), (Ti3Sn) + τ + (Dy5Sn3), (Ti3Sn) + τ + (Ti2Sn) and (Ti2Sn) + τ + (Ti5Sn3) and appropriate two-phase fields. At 1100 and 900 °C the liquid phase is absent, instead the three-phase field (βTi) + (αDy) + (Dy5Sn3) appears. Other three-phase fields exist at all the temperatures studied. The isothermal sections at 1100 and 900 °C by their character are similar to the solidus surface.