Formation of ductile ultrafine eutectic structure in Ti-Fe-Sn alloy

A Ti67.79Fe28.36Sn3.85 (at.%) alloy has been prepared through arc-melting and solidification at a cooling rate of 40-10 K/s. The as-prepared microstructure exhibits a two-phase ultrafine eutectic consisting of FeTi (B2) and β-Ti (A2) phases. The mechanical properties (maximum strength, σmax = 1939 MPa; strain to fracture, εf = 13.5%) are considerably improved if compared with the model Ti70.5Fe29.5 eutectic alloy (σmax = 1733 MPa, εf = 3.4%). The improvement of plastic deformability is assessed in terms of a detailed investigation of the microstructure and fractographic studies. The presence of Sn is believed to boost the ease of slip transfer across the interface between the A2/B2 phases due a higher lattice mismatch between the structures. © 2006 Elsevier B.V. All rights reserved.