Phase equilibria in Fe-Sn-Ti ternary system at 1073Â K and 1273Â K

Phase equilibria in the Fe-Sn-Ti ternary system at 1073 and 1273 K were experimentally investigated through alloy sampling approach facilitated with electron probe micro-analyzer and X-ray diffraction. Two ternary compounds TiFe2Sn and Ti2FeSn were detected. Ten 3-phase equilibria at 1073 K, including β(Ti)+Ti3Sn+FeTi, Ti3Sn+FeTi+Ti5Sn3, FeTi+Ti5Sn3+Ti2FeSn, Ti2FeSn+Fe2Ti+TiFe2Sn, Ti2FeSn+Ti5Sn3+Ti6Sn5, FeTi+Fe2Ti+Ti2FeSn, Ti2FeSn+Ti6Sn5+TiFe2Sn, TiFe2Sn+Ti6Sn5+Liquid, TiFe2Sn+Fe5Sn3+Liquid and α(Fe)+Fe2Ti+TiFe2Sn, and seven 3-phase equilibria including β(Ti)+Ti3Sn+FeTi, Ti3Sn+FeTi+Ti5Sn3, Ti3Sn+Ti2Sn+Ti5Sn3, FeTi+Fe2Ti+Ti5Sn3, Fe2Ti+Ti2FeSn+Ti5Sn3, Ti2FeSn+Fe2Ti+TiFe2Sn and Ti2FeSn+Ti6Sn5+TiFe2Sn at 1273 K were experimentally confirmed. At 1073 K, the homogeneity ranges of Ti2FeSn were 45.5-51.4 at% Ti and 24-27.7 at.% Sn while TiFe2Sn exhibited a large homogeneity range of 46.9-66.4 at% Fe and 22.7-26.4 at% Sn, the solubility of Sn in Fe2Ti,Fe in Ti5Sn3, Ti in Fe5Sn3 and Fe in Ti6Sn5 can be up to 4.6 at.%, 10.2 at%, 3.7 at% and 21 at%, respectively, while at 1273 K, Solubility of Sn in Fe2Ti considerably increased to 10.8 at%, Fe in Ti5Sn3 changes little. According to the measured phase relations, an invariant reaction was further deduced, which was Fe2Ti+Ti5Sn3↔FeTi+Ti2FeSn occurring between 1073 K and 1123 K.