Microstructure and fracture mechanism of Ti/Al layered composite fabricated by explosive welding.

Ti/Al layered composite was fabricated by explosive welding (EXW). The aim of this work is to study the microstructure and phase composition of the Ti/Al interface region and its effect on the fracture behavior. The interface region is composed of a wavy bonding zone and some local melted zones (LMZs). Ti 3 Al intermetallic compound is formed in the LMZ, and highly refined Ti grains and Al grains are formed around the Ti 3 Al compound. The bonding zone is composed of a mixture of Al 3 Ti intermetallic compound and recrystallized Al grains. Furthermore, the Al 3 Ti compound forms a good semi-coherent interface with the Ti matrix. In-situ tensile test shows that under tensile force, microcracks could be easily induced by the hard Ti 3 Al compound in the LMZ. Nevertheless, the initial defects did not demonstrate a tendency for further propagation. As the deformation increases, cracks nucleated at the Al 3 Ti compound of the bonding zone, forming locally delamination. Finally, the fracture occurred at the place where the delamination first formed. • Ti/Al layered composite was fabricated by explosive welding. • The microstructure and phase composition of interface region was investigated systematically. • The fracture behavior of Ti/Al layered composite was observed by in-situ tensile test. • The effect of the interface region on the fracture mechanism was discussed in detail. [ABSTRACT FROM AUTHOR]