Interface characteristics and mechanical properties of a Ti–TiAl laminated composite.

In this study, a laminated composite (Ti–6Al–4V (wt%)/Ti–44Al–8Nb–0.2 W–0.2B–0.03Y (at.%) (Ti–44Al–8Nb)) was successfully fabricated via a hot-pack rolling process. The microstructure and mechanical properties of the composite were investigated. No defects were observed at the interfacial region, thereby indicating a high bonding strength between Ti–44Al–8Nb and Ti–6Al–4V alloys. Electron back-scattered diffraction analysis exhibited a few dislocations, sub-structures, and residual stress in the interfacial region. The flexural strength of the composite in the arrester orientation (AO) was 2001.7 MPa, which was 53% higher than that of the Ti–44Al–8Nb alloy. The fracture toughness of the composite in AO (44.5 MPa·m1/2) was 3.4 times to that of Ti–44Al–8Nb alloy. Tensile test at 25 °C indicated higher ultimate tensile strength (802 MPa), yield strength (688 MPa), and tensile plastic strain of the composite (0.94%) than those of the monolithic Ti–44Al–8Nb alloy. The toughening, strengthening, and fracture mechanisms of the composite were discussed in detail. • Ti6Al4V (wt.%)/Ti-44Al-8Nb-0.2 W-0.2B-0.03Y (at.%) laminated composite is successfully fabricated by hot-pack rolling. • The interfacial region of composite can be divided into three parts and few dislocations, sub-structures and residual stress are stored. • Compared with TiAl alloy, the flexure strength and toughness of composite in arrester orientation are much improved. • Due to the defect free interfacial region, the room temperature tensile plastic strain of composite is enhanced. [ABSTRACT FROM AUTHOR]