Phase equilibria in Fe–Sn–Ti ternary system at 1073 K and 1273 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.