Interface characteristics and recrystallization mechanism of dissimilar titanium bonds

Characteristics of Ti–6Al–4V (TC4)/Ti–5Al–2Sn–2Zr–4Mo–4Cr (TC17) bonding interface were investigated via electron backscatter diffraction, transmission electron microscopy and high-resolution transmission electron microscopy techniques. Special attention was paid to clarify the recrystallization mechanism at the bonding interface. The original bond line mainly transformed into the α(TC4)/β(TC17) phase boundary, which was characterized by highly disordered lattice. The plastic flow in the vicinity of α(TC4)/β(TC17) PB occurred in the β phase of TC17 via the dislocation motion, resulting in a curved morphology of the α(TC4)/β(TC17) phase boundary. The enhancement of plastic flow in the β phase of TC17 near the α(TC4)/β(TC17) phase boundary contributed to the occurrence of recrystallized β grains.