Phase relations of the SmFeTi system around the compound SmFe₁₁Ti

Phase relations of the SmFeTi system were studied, especially surrounding the compound SmFe₁₁Ti. Isothermal sections of the iron-rich corner of the SmFeTi system were constructed, based tentatively on microstructural studies. The as cast SmFe₁₁Ti alloy was nearly single phase with a ThMn₁₂-type structure. It was found that the phases α-Fe(Ti), Fe₂Ti, Fe₁₇Sm₂, Fe₃Sm and Fe₂Sm exist around the composition of the SmFe₁₁Ti compound after annealing at 800 °C. After annealing at 1000 °C, a liquid and a high temperature phase exist instead of the Fe₃Sm and Fe₂Sm phases. The high temperature phase, which is believed to be non-magnetic or weakly magnetic, was observed in samarium-rich alloys with high titanium content. The composition of this high temperature phase was identified as SmFe₃Ti₂ by scanning electron microscopy and energy-dispersive X-rays. In the meltspun samples, the SmFe₁₁Ti showed the highest coercivity of the alloys studied. The course of coercivity of melt-spun samples revealed that coercivity is most sensitive to samarium content among the components of the SmFeTi system.