Interface-correlated bonding properties for a roll-bonded Ti/Al 2-ply sheet

Abstract We investigated the influence of annealing conditions on the interface-correlated microstructural evolution and subsequent bonding properties of a warm roll-bonded Ti/Al clad sheet. A TiAl 3 intermetallic compound layer with a thickness of 160 nm was initially generated at the joint interface between the Ti and Al alloys by warm rolling. When the annealing time and temperature were increased to a maximum of 6 h and 650 °C, respectively, the thickness of the TiAl 3 layer increased to 320 nm. The feasible annealing conditions for the optimum bonding strength were within 550 °C-6 h and 600 °C-3 h. An improvement in the bonding strength between Ti and Al is strongly correlated with the generation of considerable metallurgical bonding. This is manifested in the zipper-like failure mode that occurs at the TiAl 3 joint interface for a layer thickness of less than 300 nm.